Racism: Communication and Robert B. Moore

Racism in the English Language Robert B. Moore 1) Explain why language is an integral part of any culture. Why is it important to study language? Language is necessary to culture because it shows an understanding that differentiates between other cultures. Language is vital for communication; we are able to express our thoughts, ideas and especially because it is one of the main ways we can communicate. 2) According to Moore, how do the symbolic meanings attached to whiteness and blackness affect beauty ideals in our society?Moore was emphasizing on the complete opposite meaning of black and white; white symbolizes such as purity and positivity, while black symbolizes negativity and wickedness. The racism between the within the language affects the beauty ideals in society by stressing on which is more â€Å"admirable†, blondes with blue eyes or â€Å"dusky. † 3) Explain how the statement â€Å"slaves were brought to America† is misleading and inaccurate?The stat ement is inaccurate because the European immigrants did not just bring them to America; they destroyed the culture of many African tribes, separated families, sold them across vast areas in the Americas as if they were merchandise. 4) In your own words, describe what a â€Å"loaded† word is. What are some examples? When a simple term is said and it is blown out of proportion to evoke emotion. For example, if one is Filipino and called chink. Chink is a loaded word because its negatively used. 5) Explain how the casual use of the words â€Å"gay† and â€Å"fag† can influence our perceptions of the LGBT (Lesbian, Gay, Bisexual, Transgender) community.The casual use of the words stated may influence our perception of the sexually varying community by instigating hate with in us for someone being different. Violent words can force someone to feel fear, which in turn can cause a sexually different person to be scared of admitting their difference. Using such words wi ll also influence our thoughts of such groups negatively as the usage of the words in today's culture is frowned upon due to it being offensive, even if one is not applicable to the term.

Mise-En-Scene Essay

Forrest Gump For over a century now, individuals have been flocking to witness the magic of motion pictures. It is a world made possible by a director and a dream. Unbeknownst to many, the making of a motion picture is a tedious event, involving scripts, takes, re-takes, and an abundance of post-production editing. Many people sit and enjoy a movie without realizing the complexities and the amount of individuals involved in creating the film. These individuals create the landscapes and backboards for us, the ultimate image also known as the mise-en-scene. My favorite film of all time is Forrest Gump. Forrest Gump will go down in history as one of the greatest films ever made. This film was nominated for thirteen Academy Awards, and took home six of them. This is in part because of the phenomenal cast and crew members involved in the production of this film; individuals such as the director, cinematographer, and art director, to the actors, sound people, and most importantly the editor, who pulled everything together and created the final cut. All of these plus additional elements such as sound, style, societal impact, genre, and film criticism make the film such a masterpiece. In this paper I will go into detail about these elements and as to why they add character and zest to the overall success of the film. Forrest Gump is a film that draws out every emotion that is available to the viewer; at times it draws empathy, as well as sympathy and sadness because of the real-life elements that are a part of the plot. The film is also loaded with irony and many opportunities to laugh at the naivety of the main character, Forrest Gump. Forrest Gump is a story about an â€Å"Unusual man doing unusual things† (Groom, 1996, pg. v). As a result of how fantastic the film was, and how great the crew and cast were, Forrest Gump was nominated for thirteen Oscars at the Academy; which is a highly prestigious honor. Almost all elements of this film were up to be recognized. The list of elements that won an Oscar: best actor, best director, best effects (visual effects), best film editing, best picture, and best writing. However, the list goes on even further when me ntioning the additional ones that were nominated but did not win. This would include: best supporting actor, best art direction-set decoration, best cinematography, best effects (sound effects), best make-up, best music, and best sound (Dirks, 2010). Every one of these elements is crucial to the popularity and overall success of this film. What I plan to take notice of first is the director, Robert Zemeckis. Robert has led a successful career of directing many blockbuster hit movies. Movies such as the Back to the Future trilogy, Cast Away, Contact, and Who Framed Roger Rabbit, just to name a few. It is no wonder why Robert is such a successful and well-known name in Hollywood. Robert is a director that continually makes great films that have recurring actors, Tom Hanks being one of these actors. The style of storyline that Robert chose to use in this film is mostly in chronological order; however, the story is narrated by Forrest in the future, so the story also has moments of incongruous editing. The text states that incongruous editing is when a film jumps around in time (Goodykontz & Jacobs, 2011). You see ’future’ Forrest is telling the story of his life to numerous people who are sitting next to him at the bus stop. The story that he tells is in chronological order, basically catching up to where he is at that moment, at the bus stop. I highly enjoyed this approach that the director used; the story would continually flip back to ‘future’ Forrest as the movie went on. I believe that the movie would have been dull, had it not been from the perspective of Forrest in the future. Excitement is added by the way that he remembers the events in his life, and how even today he is still excited about them. This movie was adapted from the book of the same name, written by Warren Groom and the screenplay was written by Eric Roth. Although much of the story was changed, between the book and the film, it still remains based on the book. This is a story of a man who is highly naive, some would say slightly mentally challenged, who travels the world and is involved with many political events that occurred from the 1960’s to 1990’s. He faces hardships and overcomes adversity. In the final scenes devastating news is given to Forrest; the conclusion in this movie really pulls the whole movie together and makes it very satisfying. The exposition of this movie is right out the box with this film. It starts with a feather floating high in the shy aimlessly, drifting down towards the ground. At first the audience thinks nothing of it, however, as we later on see, this feather floating and landing on the ground in front of a dingy, worn pair of running shoes, is a symbol of the story. It is a symbol of the life of Forrest Gump, a man who drifts everywhere and becomes a part of many cultural events. We then come to realize that Forrest is a little slow and does not perceive the world as the majority of people do; with this we find a lot of verbal irony on Forrest’s behalf. The set-up is that Forrest is pushed away by his peers except a little girl named Jenny. Forrest is the protagonist in this film and his friend Jenny is the antagonist. Goodykoontz and Jacobs describe a protagonist as the main character in a movie; they also describe the antagonist as the character in conflict with the main character (Goodykontz & Jacobs, 2011). Forrest is highly conservative, and Jenny is an outright liberal. As the story goes on, Jenny becomes more and more rebellious towards society’s standards. The confrontation is that Forrest is forever seeking to save Jenny, and to get her to conform to the way of life that he lives. However, Jenny is highly rebellious and wants to live the unhealthy lifestyle that she lives. Jenny was abused as a child and she lives very domineering to the men in her life, and since Forrest is good, she pushes him away, because all she knows is destruction. The conclusion brings everything to a head. This is where Forrest goes to Jenny’s house where she lays on him that she has a son and it is his. This is where it gets all fuzzy, emotionally, because we find out that finally Jenny is settling down and accepting Forrest and his conservative ways. However, in the final moments of the film the story turns sad and Jenny dies of an unknown illness; which leaves Forrest to care for his son that he previously knew nothing about. The main character in this movie, Forrest, is played by Tom Hanks, who is a career veteran of great movies; he is a wild card actor because he is able to play various types of roles (Goodykontz & Jacobs, 2011). There are a couple of secondary actors, Jenny, played by Robin White; Lieutenant Dan Taylor, played by Gary Sinise; and Benjamin Buford â€Å"Bubba† Blue, played by Mykelti Williamson; all of these actors would be classified as character actors, because they have been in other various films, but were always secondary characters (Goodykoontz & Jacobs, 2011). Sally Field is also in this film as Forrest’s mother, but the audience does not see too much of her. Tom Hanks won an Oscar for his grand performance in Forrest Gump. He also won many other prestigious awards such as a Screen Actors Guild award, a Golden Globe, a Kansas City Film Critics award, and an American Comedy award. Robin White and Gary Sinise were nominated for a Golden Globe and a Screen Actors Guild award, but neither won. The cinematographer in this film is a man by the name of Don Burgess. Don was also the cinematographer in other Robert Zemeckis films, such as Contact, Cast Away, and The Polar Express (the latter two films had Tom Hanks in them). The cinematographer in a film is the one who directs the camera and chooses what kind of shot will take place, whether it be a long shot, a close-up, or somewhere in between. They also control the lighting and determine what will be best for each particular scene. The cinematographer designs the mise-en-scene. In the beginning we see a medium shot of a feather floating in the wind; the feather then lands on the ground which the cinematographer uses an extreme close-up of the feather and Forrest’s sneakers. Following this the camera zooms out and moves up to display Forrest sitting on a bus stop bench, next to a woman, as he is commenting about her shoes. This series of events and different shots really adds to the zest of the film. Right off we can hear Forrest’s manner of speaking, in addition to the way that he perceives the world. Another scene that I would like to point out is when Forrest is in Vietnam, and he finds Bubba shot. In this scene the cinematographer uses a lot of close-up shots of Forrest and Bubba. I believe this is to hype up the dramatics of the situation. However, a few moments later Forrest picks up Bubba and runs with him out of the jungle. In this scene the cinematographer uses an extreme long shot; the scene lasts a full 25 seconds, which is a long time for a shot in a movie (Goodykontz & Jacobs, 2011). In this scene, Forrest and Bubba start from far away as they exit the jungle, it continues to progress until finally they run past the camera. This is a very important scene in the film where Bubba eventually dies. The cinematographer did an excellent job of capturing the planes overhead bombing, while Forrest is trying to save his friend. This scene is very meaningful. The editor of this film is Arthur Schmidt. An editor is the person who pieces all the appropriate shots into the final cut, basically rearranging the story into a plot (Goodykontz & Jacob, 2011). Arthur Schmidt won an Academy Award for his stupendous work in this film. There was a ton of post-production done on this film. There was a scene where Forrest meets, President John F. Kennedy, the visual effects team along with the editor made this scene possible; since John F. Kennedy is currently diceased. Another scene takes place where Forrest is running rom some boys because they are chasing him down. In this scene Forrest is wearing leg braces, but there is a moment when Forrest begins breaking out of the braces, while he is running. The editor slows this scene down and closes in on Forrest’s legs, in order to emphasize him breaking out of the bondage that the braces caused. This is a pivotal scene, it is the prelude to the rest of the movie where Forrest is constantly on the move; his legs are a way for him to escape. In addition, this scene is full of direct cuts and jump cuts. A jump cut is when there is an obvious jump in the action during a transition, and a direct cut is when one shot instantly takes over for another shot (Goodykontz & Jacobs, 2011). The various elements that the editor used were simply fantastic; it is no wonder why he won an Oscar for this film. There are many moments in this film where all types of sound are utilized, specifically sound effects and music. Each of these effects boosts the emotional value of scenes. There is a scene where Forrest is getting on the school bus for the first time. He is having trouble finding a seat because all of the students are denying him there seat. All of a sudden he hears the voice of a little girl saying, â€Å"you can sit hear†. During this scene, sentimental music plays in the background, simply adding emotional value to what Tom Hanks is saying. Forrest says to the woman on the bench next to him, as he is narrating the scene, that he finds it, â€Å"amazing what a young man recollects,† how he doesn’t, remember many of his ‘firsts’, but he cannot forget the first time he heard Jenny’s voice, he says that, â€Å"she was like an angel† (Finerman, Tisch, & Newirth, 1994). In addition to the music, every sound other than dialogue was a sound effect that was added post-production. This film was also recognized for its phenomenal soundtrack. In some movies songs are intentionally written for that particular movie, but in Forrest Gump these are previously existing songs that the director thought would fit the tone or mood of the particular scene(s) (Goodykontz & Jacobs, 2011). It is the soundtrack of the 60’s, filled with political songs such as â€Å"For What it’s Worth,† by Buffalo Springfield, and â€Å"Fortunate Son,† by Creedance Clearwater Revival. It also contained songs suitable for the action that was taking place, like â€Å"Sloop John B,† by The Beach Boys, while Forrest is in Vietnam. The song mentions the lyrics, â€Å"This is the worst trip I’ve ever been on,† and, â€Å"I feel so broke up, I wanna go home, let me go home,† these lyrics seem highly fitting for the scenario that the troops were in. The soundtrack won both an Academy Award and a Golden Globe. In our text it quotes that, â€Å"even though we go to films to be entertained†¦movies are something more than that†¦they are also historical documents that help us see—and perhaps more fully understand—the world in which they are made† (Goodykontz & Jacobs, 2011). Forrest Gump touched on a lot cultural events and stigmas. First off is that Forrest is disabled and still was able to do more than most people who are not disabled do in their life. In addition, Forrest saw all people as equal, no matter what skin color they had. He also gave money to Bubba’s family, even though Bubba had died before Forrest created the Bubba Gump Shrimp Co. Forrest gave Bubba’s half of the profits to Bubba’s remaining family. Bubba gave Forrest the idea and Forrest was paying due to his lost friend, through his family. This is something that he definitely did not have to do. He stands for anyone who has ever felt inadequate. Forrest Gump will go down in the history books as one of the greatest films ever made. This is because a huge number of cast and crew made this possible, from the director, cinematographer, and art director, to the actors, sound people, and most importantly the editor, who pulled everything together and created the final cut. Additional elements should be recognized as well for the overall success of the film, such as sound, style, societal impact, genre, and film criticism. A lot of hard work, time and effort go into making a movie, and unfortunately not a lot of the public are aware of this. However, once they learn a few things and realize the distinct meaning behind a slow-motion shot or the color of a characters costume, they take a more appreciative look as to what they are viewing. The mise-en-scene makes all the difference; it is what makes or breaks any movie.

Philiosophy journal Essay Example | Topics and Well Written Essays - 1000 words

Philiosophy journal - Essay Example God might have attached an immaterial thinking substance to certain material bodies, he is allowing that, as a result of divine intervention, material structures might think after all. That is, he has abandoned any claim to know at first hand that material structures simply could not be conscious. If some material structures could be conscious, how can we know a priori that material structures cannot of themselves give rise to consciousness. If, instead of supposing that material structures themselves sometimes think, we assumed that there are immaterial substances, minds, or souls, associated with our bodies, we should have to say that matter somehow acts upon these immaterial things (in perception) (Moreland and Nielssen 72). For most of believers, God is a unity, the main source that allows the construction and experience of religion. The concept of God can be explained as a static one evolving during centuries. It is important to note that God is the common feature of human's per sonality, so many philosophers identify the causes and events that push people to be ethical, especially if their actions will affect another person. In this case, the inner nature and morals of people is closely connected with their believes which prove the exultance of God (Moreland and Nielssen 82). . ... And this perfect cause of the universe is God. What is more, without God morality would be impossible (Moreland and Nielssen 32). There must be a Lawgiver (God) who originates and stands by moral law. A universal moral law cannot exist accidentally. There must be a basis behind it, which is God. According to this view, every person is born with an inherent understanding of right and wrong. Everyone, for example, understands that murdering an innocent person is wrong. Everyone realizes that helping a drowning person is right. Where did this internal understanding of right and wrong come from I'm convinced that this understanding comes from God. He was the one to put it into the hearts of every person (Moreland and Nielssen 87). There is no reason why a non-personal principle of creative value should be encumbered with omniscience. Nevertheless, Leslie is right to confront this problem. For if goodness, ethical equality is the sole creative principle and the only explanation why there is any world at all, we can indeed ask, Whence, then, is evil It would obviously be less satisfactory, because less simple, to admit that value is, even in principle, only a partial explanation of what there is, that there is also an element of the sheer unexplained brute fact, of things just happening to be there; for the recognition of such unexplained brute facts was the rejected alternative to the hypothesis that ethical norms are creative (Leslie 43). Leslie's answer to the problem of evil is, in effect, to argue that there may well be no unabsorbed evils, when we take account of the value of lives that involve real choices against a background of discoverable causal regularities--whether those choices are causally

Financial Statement Analysis & Security Valuation Essay

Financial Statement Analysis & Security Valuation - Essay Example The Morrison plc relies on the viable, competitive benefits and the corporate picture or image regards for improvement the strategic requirements. The financial analysis will make use of Reformulation, ratio, valuation using AOP and FCF model (including sensitivity and WACC calculation) to help in creating a meaningful summary of information based on financial statement of the company. The exhibited big difference between cost of goods sold (CGS) to sales and selling, general and administrative expense to sales indicates that Morrison Plc classify their costs based on the major expense category differently. The unexpected dividend changes normally results to the signaling effects and wealth-transfer. The transfer of the wealth between the debt holders and the equity holders in the market depends on the unexpected changes in the market; hence, the wealth transfers in the market (Fabozzi & Grant 2000, 87). The signaling effect is the change in the stock prices in the market with the unexpected change in the dividend. The unexpected increase in dividend will normally signal the decrease in the price of the stock in the market. The dividend is a significant determinant of the operation in the market because it determines the future earnings of the managers in the market. The higher dividend implies that the managers are reducing the agency problems between them and th eir shareholders; hence, they will be able to involve the shareholders in the increase of stock price (MacMinn, 2005, p. 20). The dividend policy determines the payment of which the business will pay to its shareholders. It determines whether the business will be paying the fraction of the profit to the shareholders, or they will be keeping the whole profit in the business (Baker & Kolb 2009). The dividend policy determines the image the firm will be able to uphold in the market especially to the investors. The market

As janie goes throuth life her search for self identity takes many Essay - 1

As janie goes throuth life her search for self identity takes many terns for the worse and a few for betters, but in the end she finds her true identity. Discus. five paragraphs - Essay Example ined to be filled with unfortunate circumstances of abuse or injustice and while Leafy’s character according to the novel serves as a reflection of weakness that ran away from her obligation of potential hope, in the person of her daughter, Janie proves otherwise. With an arranged marriage to Logan Killicks Janie, in her innocence, anticipates a loving kind of relationship only to be disillusioned by Logan’s objective of acquiring a wife to be a hard-working partner in tending his farm. At this stage, readers may already sense the likelihood of a dramatic turning point bound at allowing Janie to perceive how unbearable it could get to live a life with a man she is forced into. To this extent, a picture and sentiment of a helpless girl at the verge of losing esteem and recognition of her purpose is quite poignant and the author seemingly meant to indicate an aspect of injustice toward women in the form of slavery and of violating their will or being entitled to personal decision. This is all the more aggravated by an overall view of gender inequality in male domination over Janie’s situation as a wife. The quest for comfort and self-worth proceeds as Janie gathers sufficient strength to leave L. Killicks and find solace and affection with Joe Starks, a lover who makes acquisition of a significant parcel of land in Eatonville on which he puts up merchandising establishment by employing the service of town inhabitants who highly approves of him and in return, entrusts him to become their mayor. Once again, Janie is about to discover herself in a position unfavorably governed and configured by her husband who restricts her image to the level that only enhances his desired reputation though at the expense of his wife’s right to social freedom. Upon his loss, Janie sets out in appeasing settlement of confusing distress as she makes a third encounter that would essentially be the key to refining her foundation of real character. Her relationship with Tea Cake

Poverty in Sierra Leo Essay Example | Topics and Well Written Essays - 1500 words

Poverty in Sierra Leo - Essay Example The destruction of the infrastructure and the decline of the economy led to impoverishing of various communities. Such poverty was evidenced by poor health and nutrition indicators. The economy of Sierra Leone has for a considerably long time been distinguished by high unemployment and inflation rates (Christiaensen et al, 2002). Majority of the unemployed youths are former combatants that have no stable source of income. Such unemployed youthful population remains a principal threat to national security and economic stability. In simpler terms; unemployed youths enhance insecurity and other social evils such as prostitution. This paper seeks to explain poverty in the context of Sierra Leone, a country that has been defined as the poorest country in the world for a considerably long time. Sierra Leone is a third world nation or banana republic in West Africa. It has a total population of just about six million people from different communities and a diversity of cultures. Considered one of the most financially weakest countries in the entire world, Sierra Leone is not expected to be self-sufficient anytime soon, thanks to the ten-year-old internal armed conflict (Fosu, 2009). The civil war that lasted from late nineteen ninety to mid two thousand and two was brought to a standstill by the joint effort of such African countries as Kenya and Nigeria. The African Union made a unanimous decision to intervene after the war proved to be endless and detrimental to the interests of the economy as a whole. Today, Sierra Leone is one of the countries gaining economic stability having indicated a 7% per annum growth rate. Sierra Leone has placed reliance on international donors and well-wishers for the reconstruction of the entire economy. Democratization and stabilization of the political climate are among the major concerns of the civilized members of the society. According to UN agencies, Sierra Leone is fast moving towards macroeconomic stability. This is to say that the third world country has invested a lot of time and resources in dealing with such macroeconomic variables such as unemployment, inflation, and population growth rate (Manson & Knight, 2009). Among the poorest people in Sierra Leone are the people rendered landless by the internal armed conflicts. Small-scale farmers and single mothers heading families constitute a great percentage of the poor rural population. People that were internally displaced by the civil war are destitute and own or access no resources. As such, they resort to such desperate measures as begging or working for little pay so as to support their survival. It is estimated that 75% of the people of Sierra Leone live below the poverty line, with 27% living in extreme abject poverty. This was according to a 2005 research, which established that fifty percent of the entire populace lives on slightly less than one US dollar per day. According to the records of the year 2005, 80% of the people living in the rural ar eas lived in extreme poverty. Similarly, the people of the eastern districts were hard hit by the civil strife and lived in extreme poverty (Manson & Knight, 2009). Internal displacement was a common phenomenon that was brought about by fear and lack of foresight.

Law for Business Assignment Brief Case (The Water Cooler Disaster) Essay

Law for Business Assignment Brief Case (The Water Cooler Disaster) - Essay Example In this scenario, there is clearly an agreement, whereby the trader promises to deliver 100 water coolers and 1000 50 litre replacement bottles of water in return for a consideration of ? 6000. There is the intention to create legally binding agreement, which is evidenced in writing through the terms of the contract. Consequently, a contract exists between the trader and the company. Contractual terms define the obligation of both parties to a contract. A failure to comply in full with a performance of an obligation, devoid of any lawful excuse, is a breach of the contract. In a contract for the sale of goods, there are both the express and implied conditions. Express conditions are usually spelt out in the contract, while most implied terms are statutorily derived. This scenario involves a contract of sale of goods. A contract for sale of goods is defined at section 1 of the Sale of Goods Act 1979 to mean â€Å"a contract by which the seller transfers or agrees to transfer the prop erty in goods to the buyer for a money consideration called price.† Therefore, beside the express terms in the contract, the terms implied by the Sale of Goods and Services Act 1982, shall apply. The Company can recover damages from the trader for breach of the contract. ... With regards to the express terms, the contract stipulates that the trader was to provide water coolers that take standard sized replacement bottles which are widely available. However, the water coolers actually supplied were not of universal size and design and it will not be possible to buy replacement bottles. This is breach of a condition. A condition is a term that goes to the root of the contract, the breach of which entitles the innocent party to terminate the contract and to have compensation of the damages awarded. In Behn V. Burness1 a ship was stated in the contract of charter party to be ‘now in Amsterdam.’ The fact that the ship was not in the port at the date of the contract discharged the charter from performance. Section 13(1) of sale of goods Act 1979 provides that â€Å"where there is a contract for the sale of goods by description, there is an implied condition that the goods will correspond with description.† In this scenario, the water cooler s to be delivered were described to be able to take standard sized replacement bottles. Therefore, this was a condition implied on the contract by the Sale of Goods Act 1979. To add, Sale of Goods Act implies the condition that the goods sold ought to be of merchantable quality. Section 14(2) stipulates that â€Å"where seller sells goods in the course of business, there is an implied condition that the goods supplied under the contract are of merchantable quality, except that there is no such condition-†¦ (b) If the buyer examines the goods before the contract is made, as regards defects which that examination ought to reveal.† Consequently, there is evidently breach of conditions both express and implied. A breach of a condition entitles the injured party to damages. In this scenario, the

What do you think should be Project Procurements added contribution in Essay

What do you think should be Project Procurements added contribution in the likely difficult economic climate for business in 2012 - Essay Example The Project Management Institute (2004, 269) defines this as the process of acquiring or purchasing the results, products or services required from outside the team members of the project to perform the work. The essay will discuss the added value that project procurement may bring in the volatile and diffi9cult 2012 business environment. In order to understanding the added value that comes with project procurement, one needs to properly understanding the project procurement process. The first steps involved in the process include planning, acquisitions and purchases (Walker and Rowlinson, 2008). In this stage, the needs of the project that require outsourcing are identified after which the sources for obtaining the required results, goods or services are differentiated by conducting a market analysis.The next step is planning the procurement as noted by Walker and Rowlinson (2008). Here, the objectives of the project are reviewed to ensure that the acquisition activities do not differ from the objectives of the project. Wysocki et al. (2000) explain that the completion of this step includes pointing out the resources required for the acquisition to take place, the determination of the type of contract to be engaged in so as to secure the acquisition, and finally, procurement management plan preparation. The other three steps that need to be completed before project procurement is conducted are requesting seller responses, selecting sellers, and contract planning according to Wysocki et al (2000). In contract planning, the products or services required are described in detail. Vendors are then identified and the best is chosen based on their ability to provide the results, goods or services required (Cheung et al, 2001).After successful vendor selection, the contract is negotiated. This is the forth step, also known as contract administration. This is when the

Critically evaluate the role counseling and psychotherapy theory and Essay

Critically evaluate the role counseling and psychotherapy theory and practice in the application of adventure therapy - Essay Example It is important to note the appropriate role and use of counseling in the context of society and in relation to abnormal psychology. For example, the counselor is primarily dealing with normal, functioning children and adults that may at some point during their life develop psychological or emotional problems with which they benefit from personal and professional assistance. Generally, between 5% to 10% of the population at any time can be expected to display the signs and symptoms of major mental illness as defined in abnormal psychology, such as schizophrenia, bipolar disorders, manias, psychosis, etc., though less than 1% will require clinical hospitalization. (NIMH, 2008, See: Appendix) This leaves counseling as a profession tasked with first separating cases of abnormal psychology from problems of normal development of individuals, and secondly, assisting in the provision of effective treatment to the individuals who are seeking counseling. It is in this context that Adventure T herapy should be understood, as well as its application, for there may be human development problems that are caused by the individual’s relation to modern society that can better be solved by treatments fostering social relationships and exercise activities as opposed to pharmaceuticals or institutionalization. Nevertheless, there may also be instances where a combination of medication and Adventure Therapy can also assist in the treatment of those afflicted with psychological problems and mental illness. Creating the ability to distinguish the causes and treatments for patients is an important aspect of training that the counselor must undertake, including research in a multiplicity of methods and a willingness to experiment in finding the treatment that best suits the unique nature of every individual and effectively promotes positive mental health recoveries. The life of an individual can be viewed on a continuum of functionality related to self-realization with normality at the center, functioning at the highest levels of individual mental and physical operations at one extreme, and the psychoses and neuroses of severe mental illness or insanity at the other extreme. The counselor can expect the range of behavior for most people to stay within the realm of normal operations on usual occasions, straying into psychological crisis through challenges, problems, and obstacles in life or relationship issues that occasionally need to be addressed by the individual. Viewing the counselor’s office as a mixture between a general practitioner’s office and an emergency room highlights the manner that the counselor must prepare for all of the contingencies of not only mental illness, but also for mental health, in the population he or she is tasked with serving. Counseling in this regard can be seen as a tool to help maintain or restore normalcy to individuals based upon their own self-definition of importance and accepted societal standards of fu nctioning. In being able to distinguish between the critical and clinical symptoms of severe mental illness and the factors that are required to build a stronger sense of well-being and mental health, the counselor can begin to serve the diversity of needs that he or she will encounter within a given population, as well as to understand some of the causes that lead people to psycho-spiritual crisis and life

Big Five Personality Traits Essay Example for Free

Big Five Personality Traits Essay The Big Five personality traits are extraversion, agreeableness, conscientiousness, emotional stability (or neuroticism), and openness to experience (Scholte, Van Lieshout, DeWit, Aken, 2005). The factors that are considered most important or least important would depend on who was making the evaluation and the priorities of the individual. For example, a person who valued learning or someone who needed an employee who could adapt to new circumstances quickly might say that openness to new experience was the most important factor. Another person who placed a greater emphasis on relationships, for example, might believe that emotional stability is more important. While everyone likes an agreeable person, people who are too agreeable can create problems if they simply go along with anything and do not at least occasionally think for themselves and challenge something. Trying to select the most important of these traits is like trying to choose the most important among equals. It is also interesting that Scholte, Van Lieshout, DeWit, and Aken (2005) found that the Big Five traits and their effects on adolescents are consistent across cultures. The trait that is the most applicable to me is openness to new experience. I enjoy trying new things and meeting new people. I do not enjoy doing the same thing all the time. I believe that the openness trait is closely related to the trait of extraversion. Extraverted people tend to be focused on external things, while introverts have a more internal focus. Since new things are almost always found in other people and places, then it seems that the extravert would be more likely to pursue and be open to new experiences, while the introverted person would be less likely to seek out new things in the outside world but more likely to look for new revelations within or about himself or herself. I consider myself an extraverted person who is open to new experiences. I am usually agreeable, relatively conscientiousness, and fairly stable emotionally. References Scholte, R. , Van Lieshout, C. DeWit, C. and Aken, M. (2005). Adolescent personality types and subtypes and their psychosocial adjustment. Merrill-Palmer Quarterly, 51 (3), p. .258-286. Retrieved April 4, 2008, from www. Questia. com database. http://www. questia. com/read/5011758638

Beauty of Nature as appreciated by Wordsworth

Beauty of Nature as appreciated by Wordsworth Beauty of Nature as appreciated by Wordsworth Poetry, which came much before prose in human history, has been a vehicle for the spiritual and social progress in man. The natural world with its great beauty and mystery has long been a source of inspiration to poets. The Romantic poets like Wordsworth and Keats, who were active in the nineteenth century, experienced the most inspiration through nature, which they captured in their poetry. William Wordsworth, especially, in his poetry, uses descriptions of nature to raise the mind to mystic heights. With the advent of the Industrial Revolution, the attitude of people changed from an awe of nature to a desire to harness everything natural for the benefit of man, which the Romantic poets viewed with concern. In his poems â€Å"The World is Too Much with Us† and â€Å"Nutting†, William Wordsworth makes use of the portrayal of the beauties of nature to deplore the greed of man who is mindlessly exploiting nature. Written in Germany, the poem â€Å"Nutting† evokes Wordsworths remembrance of turbulent feelings he had when he had gone nutting as a boy. William Wordsworth writes about a beautiful, pristine wood whose beauty and purity he had destroyed by his greed to gather the nuts .Continuing in the same vein, in â€Å"The World is too much with Us†, the poet laments the heartlessness of humankind, which has come under the sway of unfathomable avarice, and which no longer is moved by the beauty of nature. Wordsworth describes the secret, unexplored place he went to after clambering over rocks and stepping over tangled ferns in â€Å"Nutting†. It is a place of perfect peace where the poets heart experiences great joy. He describes the nook where he sits down among the flowers under the trees The poem conveys a deep sense of peace and meditation attained by man by connecting with nature. The final lines of the poem convey the spiritual feeling that the beauty of nature inspired in the poet. The symbolism of the plentiful hazelnut clusters which cover the trees alludes to the bounty of nature. The tattered old clothes the boy wears symbolizes the poverty of spirit of man. The poet describes how the unsullied nook is ravaged by the violent acts of the boy. Although he is now rich with the nuts he came to gather, he feels a twinge of guilt and pain when he gets a final glimpse of the virgin nook he has destroyed. The symbolism of the earth being exploited mercilessly and violently by man is evident in this poem. He tells us to cultivate a ‘gentleness of heart ‘and exhorts us to be gentle with nature so that we are in harmony with it. Wordsworth continues to regret the crass, materialistic attitude of man in his Petrarchan sonnet, â€Å"The World is too much with us.† He cries out that we waste our resources by consuming too much. He states that we are not in tune with nature any longer as we have become too insensitive. Using the powerful imagery of howling winds which are gathered up like flowers, the poet conveys a sense of urgency in his poem. By portraying the sea as laying bare its bosom to the moon, he alludes to the connectedness of every great and small thing in nature.. He feels angry that the beauty, mystery and force of nature have no effect on the insensitive soul of man, who is out of harmony with nature. The mercenary goals of man disgusts him so much that he wishes he were born as a pagan, who would have had a better communion with the sea and the land. For Wordsworth, nature is not something to be consumed and exploited, but nature is something that leads man to the universal soul. He makes use of his great descriptive talents to portray that humanity is losing its connected feeling with nature by following the materialistic ideals of getting and spending.

Cultural Change in International Markets Essay -- essays research pape

Competitive pressures caused by globalization, deregulation, and discontinuous technological changes seem to have forced many organizations into considering radical change as a way of surviving and growing. A big part of this radical change has to do with accepting and handling cultural differences among other nations. Organizations pursue change to enhance their competitive positions and to grow. Cultural Change Culture changes over time, despite the fact that one of the more important attributes of culture is that it is conservative and resistant to change. When marketing a new innovation to a foreign country, the marketer must possess a thorough knowledge of that country’s culture in order to be successful there, as new innovations can be fail or even cause offence if not marketed or designed in a manner appropriate to that particular culture.   Ã‚  Ã‚  Ã‚  Ã‚  There are six rules of thumb when doing business across cultures: 1.  Ã‚  Ã‚  Ã‚  Ã‚  Be prepared. Whether traveling or selling from home, you should never approach a foreign market with first researching the area. Some of the things to learn would include social and business etiquette, history, current affairs, the culture’s values, geography, religion, political structure, and practical matter such as currency and hours of business. 2.  Ã‚  Ã‚  Ã‚  Ã‚  Slow down. In America â€Å"Time is money.† Americans always seem to be in a rush and can seem unfriendly or arrogant. In other countries, patience is the key. 3.  Ã‚  Ã‚  Ã‚  Ã‚  Establish trust. Having crisp business relationships will get the salesperson nowhere. Product quality, pricing, and clear contracts are not as important as the personal relationship and trust that are developed over time. 4.  Ã‚  Ã‚  Ã‚  Ã‚  Understand the language. Languages differ in parts of the world one must have a vocabulary that is sensitive to nuance and connotation. An interpreter could also be helpful if needed. 5.  Ã‚  Ã‚  Ã‚  Ã‚  Respect the culture. Manner are important. The traveling person is a guest and must respect the hosts’ rules. 6.  Ã‚  Ã‚  Ã‚  Ã‚  Understand components of culture. There are two types: surface culture (fads, styles, foods, etc.) and deep culture (attitudes, beliefs, values). Importance of cultural unders... ...t be aware of this, as there can be serious repercussions for them and their company if there are adverse reactions to the new innovation regardless of the fact it may have been accidental.   Ã‚  Ã‚  Ã‚  Ã‚   Knowledge about other cultures and how they affect the way people do business may show business-people working in a culture different from their own that their solutions are not always the appropriate ones for a given task. Understanding this is the first step in learning how to use cultural differences to gain a strategic advantage. Mishandling or ignoring cultural differences can cause numerous problems, such as lost sales, the departure of competent employees, and low morale that contributes to low productivity. How can international businesspeople learn to live with other cultures? The first step is to realize that there are cultures different from their own. Then they must go and learn the characteristics of those cultures so that they can adapt to them. Traveling to this country and staying a while or undergoing an extensive, training program would be helpful to cover the main characteristics of the culture, including the language.

Epic of Gilgamesh Essay - The Ever-Changing Gilgamesh :: Epic Gilgamesh essays

The Ever-Changing Gilgamesh  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚      The main character in the book The Epic of Gilgamesh, is Gilgamesh himself. In the beginning of the book one realizes that Gilgamesh is an arrogant person. Gilgamesh is full of himself and abuses his rights as king. He has sexual intercourse with the virgins of his town and acts as though he is a god. Throughout the story, many things cause Gilgamesh to change. He gains a friend, he makes a name for himself by killing Humbaba, and he tries to become immortal because of the death of Enkidu. Through these main actions his personality changes and he becomes a better person. The quest for immortality after the death of Enkidu is the first sign that Gilgamesh has changed. Gilgamesh becomes frightened when he realizes that he isn’t immortal. After the death of Enkidu, Gilgamesh tries to find immortality by trying to cross the ocean to find it. He sounds pathetic as he rambles of his reason for trying to find everlasting life. His state of being at this part in the book, which is the end, is completely different from his arrogant beginning of this epic. Gilgamesh has gone from arrogant to scared. The death of Humbaba also changes Gilgamesh. Humbaba is evil. Many people who live in the city of Uruk fear Gilgamesh. Most would say that Gilgamesh himself is, in fact, evil. He has sex with the virgins, he does what he wants, and he tends to offend the gods. He has lots of problems with Ishtar. By going into the forest and facing Humbaba, Gilgamesh makes a name for himself and changes the views of the people in his city. This is a very arguable point. The great deed of killing Humbaba, makes him a better person because he protects his city.   Although it could be argued that Gilgamesh kills Humbaba only to make a name for himself, this not the case. Gilgamesh does this because of his love for Enkidu and his people, he has changed from the beginning of the epic. The main factor contributing to the changes in Gilgamesh the love that develops with Enkidu. Enkidu is made to make Gilgamesh more human. In the first paragraph of the book the gods are angry with Gilgamesh and send down an equal of himself, they send down Enkidu. After becoming friends, Gilgamesh changes because he has an equal to be with.

Genetically Modified Food and Gm Foods Essay

It’s been said that humans are what they eat. The relationship humans have with food is unappreciated. Food is the fuel that keeps humans going, gives them the energy needed to be creative and productive; it is the building block of society, after all, it wasn’t until the Neolithic Era, when humans figured out a way to domesticate plants and animals, that any form of organized society formed. Even during the previous hunter-gatherer foraging era, humans were very connected to the food they ate; understanding where it came and having an idea of how it came to be was crucial to knowing what was vital to survive. In this time, food sources like grains, fruits, and vegetables were naturally abundant, whole. Humans could choose between many different types of nutritious food because there were thousands of varieties of species. Unfortunately, as populations grew and more civilized societies formed, various farming techniques were created, and a vast majority of these species became extinct to make way for the harvesting of a select few (Pringle). In the industrial era, societies around the world, especially western ones, emphasized the importance of technological advancements. With this pursuit of technology, nature became something to control rather than live with; an attempt at making life simpler, better. Breaching the gap between nature and technology is optimization. It is this obsession with optimization that most accurately characterizes contemporary America. Undoubtedly, it comes with great costs. As it turns out, optimization is a business, and a profitable one. Thus, the costs and effects of optimization are often hidden from the public by industrial leaders in an effort to maintain profits. They control the businesses they run and protect themselves by dumping millions of dollars into politics. Today, it seems that the gap between nature and technology has been breached with the propagation of genetically modified organisms (GMOs). The aliens that now fill supermarkets nationwide represent the ultimate disconnect from natural, whole foods necessary for a healthy lifestyle. People are relatively uninformed about GM foods, issues include: their benefits, the testing and safety, the harmful effects they can have on the body and environment, the government’s role as overseer, the labeling controversy, and the â€Å"substantially equivalent† principle; all of these issues are conveniently hidden vitalities in understanding the danger, the deleterious effects, and the risks of GM foods. In tackling these issues, an additional understanding of the historic background of how GMOs came to be is equally important. Advocates for the rapid advance of technology will cite the numerous positive breakthroughs, the internet, healthcare, the numerous inventions; it’s hard to argue with, which is why when addressing GM foods, the emphasis should be placed on the relationship between technology and nature, specifically within the food industry, and how this relationship has become too intimate, to the point where it’s difficult to differentiate between technology and nature. The courtship leading to the marriage between technology and nature is exemplified in Peter Pringle’s book, Food, Inc. , in which he discusses the 1960’s Green Revolution, a turning point in agriculture during which producers moved from traditional to monoculture methods of farming. This vastly increased crop yields. But how? Farmers had high yields because they started to use fertilizers and pesticides containing chemicals like nitrogen, left over from World War II explosives. New irrigation systems were introduced and animals replaced some human labor in order to handle the large crop fields and monoculture agriculture provided food relief to starving nations post-war (Pringle). Farmers experienced a rude awakening when yields started to decline due to a number of unforeseen or unaddressed consequences. Although the Green Revolution saved or improved millions of lives during the 1960’s, little consideration was given to the future effects it could have on environmental sustainability. The lack of food plant diversity eventually led to multiple problems, like the mass destruction of crops that had contracted disease or succumbed to pesticide-resistant insects, chemically saturated and overly watered soils, and an inevitable decline in production yields (Pringle). Obviously, the United States needed to find a solution to this problem. By the late 1900s, many scientists and biotechnologists approved and advocated genetic engineering as the most viable solution. This process is best described by Lauren and Robin Ticciati in their book, Genetically Modified Foods: Are They Safe? You Decide. According to the Ticciati’s, scientists planned to take a gene from one completely different organism and insert it into the plant in order to make it yield a desired outcome (Ticciati). The goal was to create food plants that could grow and withstand harsh conditions like pesticides, infertile soil, unfavorable climates, and geographical locations. Despite wariness from skeptical environmentalists about the unknown future effects of genetic food engineering, the companies who profit from this new food technology proclaimed it to be the wave of the future. As the Ticciati’s evidenced, in 1996, when the FDA approved the use of genetically engineered foods with no special label requirements, the GM foods were introduced on grocery market shelves with relatively no consumer awareness. This is just another example of how society is not clueless by choice. If this seems a harsh diagnosis, take into context what Kathleen Hart exemplified in her book, Eating in the Dark; a survey which took place just a couple years after GM foods were released revealed about two-thirds of the American adult population had no idea that supermarkets were carrying such items (Hart). Since then, GMOs have become part of the staple food products in the diets of the everyday consumer. Part of the problem is that nobody is exactly sure how harmful GM foods are, but there is substantial evidence to show that they can have a devastating effect on the economy, the human body, and the environment. In Food, Inc. , Pringle discusses the farming method of artificial hybrid breeding which became a huge success in the mid-1900s and attracted a lot of commercial attention, spawning the term â€Å"agribusiness. † Scientists found that by crossing-breeding â€Å"two varieties [of a species of plant] that had been inbred, [and] fertilized by their own pollen for three or four generations showed a tremendous leap in hybrid vigor, with grain yields up to 50 percent higher [than the natural bred variety]† (Pringle). Unfortunately, when naturally crossed in the farmers’ fields, the hybrids’ strength did not withstand, so farmers had to rely on industry-produced super seeds. An economic boom occurred within the seed and fertilizer industries, with businesses rapidly sprouting up like the crops they helped produce. A few decades later â€Å"the early warnings of genetic uniformity suddenly became a reality,† (Pringle). One alarming discovery was the fact that since only one type of species was being harvested in a given area, if a crop contracted a disease, the entire field was wiped out, which meant no income that season for many farmers (Pringle). The companies who were invested in this new agricultural era and had seen the enormous profit potential in having a hand in controlling the food chain were not going to just quit. They pushed further into science, seeking ways to alter a species’ genetic make-up in order for it to conform to optimization, instead of considering natural solutions to these problems (Pringle). Today, there are GM super foods that are so genetically modified that they differ starkly from their ancestors. It is a teeter-totter industry; either profits are extremely high (like they have been for so long) or the industry fails and profits cease to exist. The latter doesn’t look like it’s going to occur any time soon because the government is firmly grasped by the biotech food companies that control the GM food industry. The most prominent of these companies, Monsanto, falsely advocates the necessity for GM foods, with the real motive the preservation of profits. Monsanto executive Hugh Grant claims â€Å"they [GM foods] can help feed the world and preserve the environment by reducing the need for pesticides,† (Harvest of Fear). Others advocate the hope that GM technology can save lives, like scientist Charles Arntzen, who is working on GM techniques to make edible vaccines to combat viruses in developing countries, (Harvest of Fear). More recently, companies like AquaBounty Technologies are working to develop genetically engineered animals. AquaBounty’s AquAdvantage salmon has been touted as â€Å"as safe as food from conventional Atlantic salmon,† by the FDA, but is still being met with numerous opposition (Pollack). The salmon â€Å"contain a growth hormone gene from the Chinook salmon and a genetic switch from the ocean pout that turns on an antifreeze gene,† which allows the salmon to make growth hormone in cold weather, whereas they usually produce it only in warm weather,† (Pollack). Genetic manipulation is causing drastic changes in the natural behavior of the organisms it’s implemented on, and it is believed that this could have multiple adverse effects on the environment and society. Those who have similar concerns, these cautious enemies to GM foods, can find strength in recent studies that are beginning to expose the numerous harmful effects of GM foods. In a study done by Gilles-Eric Seralini at the University of Caen in France, 200 rats were fed either genetically engineered corn or the herbicide Roundup and observed for two years, their entire life cycle and not just the normal ninety day period. It was found that they had an increased risk of developing tumors, suffering organ damage, and dying prematurely (Pollack, GMO Global Alert). Additional animal studies have shown other serious health risks associated with GM food consumption: infertility, immune dysregulation, accelerated aging, and changes in the liver, kidney, spleen, and gastrointestinal system (Genetic Roulette). To exemplify how this is portrayed in humans, statistical evidence shows that after 1996, when GMOs increased in the American diet, disorders like inflammatory bowel disease, ulcerative colitis, chronic constipation, gastrointestinal infections, Crohn’s disease, and gastroephageal reflux have all risen dramatically and consistently (Genetic Roulette). Further evidence indicates that GMOs cause food allergies, have increased toxicity, decreased nutritional value, and promote antibiotic resistance (UMN). Not only do GM foods have a great potential for negatively effecting humans, they are harmful to the environment. Companies like Monsanto claim that genetically modifying foods is environmentally friendly, but this has been proven wrong on a multitude of levels. There is lack of nutrients found in soil in which GM crops are planted (Ticciati). These crops hurt the soil and the food chain. The chemicals found in pesticides were not only killing pests but also small animals, especially birds, were also facing extinction (Robbins). Tampering with natural selection creates a domino effect and damages the entire ecosystem. Imposing an unnatural element in the form of GM foods changes the equation and disrupts natural balance, even if things balance out, they will be forever different, even this is dangerous. Although GM foods are responsible for massive crop yields and the increased food supply, the industry is precariously perched given the increasing amount of deleterious effects that are being exposed more and more each day. For this reason, the government needs to take action. This is another dilemma; it is easy to wonder how the government can do anything when it has such close relationships with the companies that all the fingers are being pointed at. The primary antagonist in this story is the company Monsanto, the inventor of saccharin, an artificial sweetener, and many additional products. Monsanto accounts for over two-thirds of genetically engineered soy, corn, and canola crops worldwide (Robbins). Hendrik Verfaillie, Monsanto’s Senior Vice President and Chief Financial Officer, described the company’s aggressive strategy with, â€Å"The biggest mistake that anyone can make is moving slowly, because the game is going to be over before you start,† (Robbins). It is understandable that a company this big has a profoundly large impact on government rulings regarding its industry. With Monsanto’s Roundup herbicide bringing in billions of dollars, the industry convinced the Supreme Court to allow the patenting of genetically engineered seeds so that the offspring would become the property of the seed manufacturer. In Genetic Engineering, Food and Our Environment, Luke Anderson exemplifies the impact of this ruling by stressing the profound repercussions it will have on the future of living organisms; â€Å"This extraordinary decision by the U. S. Supreme Court heralded a new era. Once a shared heritage, the gene pool of plants, animals, and humans was now a commodity waiting to be bought and sold† (Anderson). What appears to be mainly a business venture is an extremely important political issue, with companies pouring millions into politics to stay afloat. This is exemplified by the following quote, from the documentary The Future of Food. Here, director D. K. Garcia focuses on the 2000 Presidential Election and the biotechnology issue: â€Å"Agricultural biotechnology will find a support occupying the White House next year, regardless of which candidate wins the election in November† (Garcia). The Future of Food reveals top ranking officials from the Supreme Court, such as Justice Clarence Thomas who previously represented Monsanto as their Lawyer for Regulatory Affairs, to Donald Rumsfeld, The Secretary of Defense, who was previously the President of Searle, a Monsanto subsidiary. Given their backgrounds, it is difficult to ignore the likelihood that their political stances would not be swayed. Even worse is Linda Fisher, who has switched roles between the EPA (Environmental Protection Agency) and Monsanto a number of times; she was Monsanto’s Executive Vice President for nearly a decade and Deputy Administrator for the EPA as well as Commissioner for George Bush’s administration (Garcia). It’s frightening that the EPA, which acknowledges and regulates pesticides emitted into the environment, is likely to be biased in regards to the approval of genetically modified organisms into the environment. Needless to say, it’s shocking to see the connections that pose how much of an apparent influence Monsanto and the other leading biotech companies have on government regulations of GMOs. Evidence of this influence is presented in Seeds of Deception, in which Micah Sifry states, â€Å"the four leaders of the biotech industry Monsanto, Dow, DuPont, and Novartis gave more than $3. 5 million in PAC, soft-money, and large individual contributions between 1995 and 2000, three-quarters of it to Republicans† (Smith). Stricter guidelines and extensive testing are not required because the companies have such strong political ties that they can influence the policy that is implemented upon them. In 1992, former U. S. Vice President, Dan Quayle, exemplifies this in his speech on behalf of the Council of Competitiveness, â€Å"We will ensure that biotech products will receive the same oversight as other products, instead of being hampered by unnecessary regulation† (Garcia). The FDA approved genetically modified foods with a high sense of hesitant reluctance. Consumers are supposed to rely on the FDA to determine if food is safe for consumption; the agency is supposed to be a protective one. This was a landmark decision for the FDA, a decision which required strong political influence for the agency to decide against its own principles. This is evidenced in The Future of Food; Dan Quayle and the Bush administration appointed Michael Taylor as Deputy Commissioner for Policy, which Andrew Kimbrell divulges in an interview, noting that Taylor was formerly Monsanto’s Senior Counsel at the King and Spaulding law firm. Taylor instituted a no-regulation policy and left it to the biotech companies to determine whether or not genetically modified food was deemed safe for human consumption (Garcia). As the examples presented indicate, the successful clearance of GM foods has been engineered by companies like Monsanto and politicians, almost as much as the foods themselves. With the FDA swept out of the way, the companies that dominated the biotech industry were free to roam as they pleased, testing at their fingertips. How can the consumers trust Monsanto to act in their best interest, especially when the company’s Director of Corporate Communication, Phil Angell, says things like â€Å"Monsanto should not have to vouchsafe the safety of biotech food. Our interest is in selling as much of it as possible. Assuring its safety is the FDA’s job,† (Robbins). Without extensive testing, which would almost certainly yield new truths about the harmful effects of GM foods, Monsanto can achieve its goal of selling as much as possible while disregarding the consequences this has on society and the environment. Testing is probably the biggest grey area of them all. The FDA has a persona of an overseer and protector, meaning that people generally believe that all food undergoes tests by the FDA to ensure their safety. Unfortunately, this couldn’t be further from the truth. Testing genetically modified foods is dependent on the words of the companies that develop them. According to Consumer Union’s Jean Halloran, â€Å"When a company comes in with data, the FDA looks at it and writes a letter saying, â€Å"Dear Monsanto, you supplied information regarding the safety of corn variety X and we are confident about what you’ve shown,† â€Å"It is your responsibility,† (CBS). The FDA is in a difficult position. It is presented with its initial objective of protecting the American people but now, with biotechnology and GM foods, it is faced with a decision of whether or not to promote the biotech industry. The FDA regulates GM foods as part of the â€Å"coordinated framework† of federal agencies that also includes the EPA and the United States Department of Agriculture (Bashshur). The problem is that this framework has been the subject of critical analysis and calls for redesign; it is outdated, with the FDA policy unchanged since 1992. It is available online and contains a searchable database that covers â€Å"genetically engineered crop plants intended for food or feed that have completed all recommended or required reviews,† (Bashshur). The policy places responsibility on the producer or manufacturer to assure the safety of the food, explicitly relying on the producer or manufacturer to do so: â€Å"Ultimately, it is the responsibility of the producer of a new food to evaluate the safety of the food and assure that the safety requirement of section 402(a)(1) of the act is met,† (Bashshur). It is also this policy that establishes that the â€Å"substantially equivalent† concept, with which the FDA judges most GM crops as â€Å"substantially equivalent† to non-GM crops. In these cases, GM crops are â€Å"designated as â€Å"Generally Recognized as Safe† under the Federal Food, Drug, and Cosmetic Act (FFDCA) and do not require pre-market approval,† (Federation of American Scientists). Although these products are described as substantially equivalent, their manufacturers stress that they are different so that they can patent them and continue to profit. In this situation, the consumer must take the producer’s angle. Their products are dramatically different; their genetic composition is very different in comparison with that of their ancestral forms. In deciding whether or not to ingest these products, the consumer must realize that if the companies that produce them stress they are dramatically different, and there is minimal testing done on them, these GM food products could be extremely dangerous. Currently, there is no regulatory scheme requiring GM foods to be tested to see if it is safe for humans to eat or not. FDA guidance to the industry issued in 1997 covered voluntary â€Å"consultation procedures,† but â€Å"still relied on the developer of the product to provide safety data,† (Bashshur). There are numerous pieces of evidence that indicate that GM food testing is completely unregulated. The FDA’s policy is outdated and weak, â€Å"substantially equivalent† cannot be justified when such a small level of testing has been done. The fact that this policy has remained unchanged for two decades is staggering; there’s probably a lot of money keeping it that way. In tackling what Ramona Bashshur describes as the FDA’s â€Å"dual mission,† rational thought is vital. Although the FDA cannot ignore the opportunity to make scientific advances with the potential to better society, it must reflect on its original role, as a protector. While scientific advances with GMOs are rapidly continuing, there hasn’t been enough testing on them to determine how dangerous they are. If testing was done and the foods proved safe, which they probably wouldn’t, there would be nothing wrong with promoting it. In the meantime, as more and more harmful aspects of GM foods come to the surface, it would be smart for the FDA to revise its policy, improve the extent of testing done on these foods, so that America can move forward in science with the assurance that it won’t hurt its citizens. This is a difficult task; there is so much political influence on the industry that it may never occur. If the policy for testing cannot be amended, there is action that can be taken that could have a similar outcome. Specialized labeling for GM foods would set them apart from normal foods and make it easier for consumers to make healthy choices. In the United States, they aren’t labeled, while in Europe, Russia, China, and other countries, they are. This is an extremely popular movement in the United States. An example is California’s Proposition 37, which would’ve required â€Å"labeling on raw or processed food offered for sale to consumers if made from plants or animals with genetic material changed in specified ways. † And it would prohibit marketing â€Å"such food, or other processed food, as ‘natural,’† (Bittman). The numbers don’t lie; people supported Proposition 37; roughly 65% for to 20% against, with 15% undecided. From a national perspective on the labeling issue, 91% of voters believe that the FDA should require that â€Å"foods which have been genetically engineered or containing genetically engineered ingredients to be labeled to indicate that,† (Bittman). With these numbers as a reference for the support that Proposition 37 had, it’s hard to believe that it was struck down. Again, this is an instance of money having the loudest voice in the room. Money flew in from both sides, but the food companies that stood to lose in the situation, like Monsanto and The Hershey Co., contributed to what was â€Å"eventually a $44 million windfall for â€Å"No on Prop 37,† while proponents were only able to raise $7. 3 million,† (Almendrala). According to MapLight, an organization that tracks campaign contributions, biotech companies amassed $46 million to defeat the measure, with Monsanto contributing $8. 1 million and Kraft Foods, PepsiCo and Coca-Cola each contributing at least $1. 7 million (Pollack). In contrast, those who backed Proposition 37 were only able to contribute $9. 2 million; money made the difference. Proposition 37 was close, garnering 47% of the vote, with campaigns like the online based â€Å"Just Label It† collecting signatures and comments on a petition to the FDA, requesting rules â€Å"similar to those in the European Union, Japan, China, India and Australia, stating what transgenic food is in the package,† (Moskin). The biggest thing about Proposition 37 is that it had national implications; it wasn’t just California that the food conglomerates were worried about. If it passed, it could’ve been the beginning of a national labeling revolution, potentially the beginning of an even greater revolution. Throughout history, organisms have developed through a recurrence of genetic mutations that have naturally selected the organisms that are most fit for survival. The rise of GMOs can be viewed through the same lens. GMOs arose from the conditions following the monoculture agricultural shift in the 1960’s Green Revolution. The key here is that they are not natural. The â€Å"mutations† that have aided the rise of GMOs are manmade, manufactured, and abnormal. GMOs are a result of the American obsession with optimization, which manifests itself in technology. After World War II and throughout the Green Revolution, America sought numerous technological advancements as it relished its role as a world power. With GMOs, America breached the gap between technology and nature in an effort to optimize food. Companies like Monsanto, with their growing number of political connections, began using their funds to pave the way for GMOs to become and remain a staple contingent of the American diet. Today, GM foods are still privately and minimally tested and they remain unlabeled in the United States. While the FDA stands by its outdated 1992 policy, claiming that GM foods are â€Å"substantially equivalent,† the producers stress that they are different in an effort to obtain patents. America cannot trust the sources it looks to for accurate information because there has been little testing but there is hope on the horizon after California nearly passed a law forcing GM foods to be labeled. As concerned parties seek an answer, they must first look towards labeling these foods, sparking a chain reaction that causes uninformed consumers to ask questions like, â€Å"Why are these foods specially labeled?† and â€Å"What makes these foods different? † Labeling could prove to be the beginning of a further revolution to enhance regulation of GM foods. This revolution, though currently nonexistent, must occur before this problem mutates even further, before not just the American people, but the entire world, reaps the consequences for playing the role of Creator. Anderson, L. (1999). Genetic engineering, food, and our environment. Vermont: Chelsea Green Publishing. Clark, E. A. & Lehman, H. (2001). Assessment of GM crops in commercial agriculture. Journal of Agricultural and Environmental Ethics, 14 (1), 3-28. Retrieved October 26, 2006, from ProQuest Research Library. Guidance for industry: Voluntary labeling indicating whether foods have or have not Been developed using bioengineering. (2001) Retrieved November 8, 2006, from http://www. cfsan. fda. gov/~dms/biolabgu. html. Garcia, D. K. (Director, Producer, Writer). (2004). The future of food. [DVD]. Mill Valley: Lily Films. Hart, K. (2002). Eating in the dark. New York: Pantheon Books. Pascalev, A. (2003). You are what you eat: genetically modified foods, integrity, and society. Journal of Agricultural and Environmental Ethics, 16 (1), 583-594. Retrieved October 29, 2006, from ProQuest Research Library. Pringle, P. (2003). Food inc. New York: Simon & Schuster. Robbins, J. (2001). The food revolution: How your diet can help save your life and the world. Berkeley: Conari Press. Smith. J. (2003). Seeds of deception. Vermont: Chelsea Green Publishing. Ticciati, L. & Ticciati, R. (1998). Genetically engineered foods. Are they safe? You decide. New Canaan: Keats Publishing. http://documentarylovers. com/genetic-roulette-gamble-our-lives/ http://www. youtube. com/watch? v=Njd0RugGjAg&feature=related http://www. nytimes.com/2012/12/22/business/gene-altered-fish-moves-closer-to-federal-approval. html? pagewanted=all&_r=0 http://www. nytimes. com/2012/02/08/dining/a-suit-airs-debate-on-organic-vs-modified-crops. html http://opinionator. blogs. nytimes. com/2012/09/15/g-m-o-s-lets-label-em/? _r=0 http://www. nytimes. com/2010/09/21/business/energy-environment/21salmon. html http://www. nytimes. com/2010/09/04/health/policy/04salmon. html http://www. nytimes. com/2012/11/08/business/california-bid-to-label-genetically-modified-crops. Html http://www. nongmoproject. org/learn-more/ http://www. nytimes.com/2012/09/20/business/energy-environment/disputed-study-links-modified-corn-to-greater-health-risks. html? _r=0 http://enhs. umn. edu/current/5103/gm/harmful. html http://www. cbsnews. com/2300-204_162-10004920-2. html http://www. americanbar. org/content/newsletter/publications/aba_health_esource_home/aba_health_law_esource_1302_bashshur. Html http://www. huffingtonpost. com/2012/11/07/prop-37-defeated-californ_n_2088402. html http://www. fas. org/biosecurity/education/dualuse-agriculture/2. -agricultural-biotechnology/us-regulation-of-genetically-engineered-crops. html http://www. youtube. com/watch? v=Njd0RugGjAg&feature=related.

The Handphone Influences People’s Behaviour

The handphone influences people’s behaviour Behaviour is not be formed by a thing constantly, but it is formed by many things continously. Because, everything what people saw, listened, and said forms his behaviour. One of them is one of media of communication, which is called handphone. Hand phone is one of the tool of communication between a person with others. Today, it is used by both adult or child, rich or poor, and because of necessery or style in our society. But, their behaviour is influenced unconsious by using it. The phone gives the big role to influence people’s behavior.First, it neglects the user. Usually it is happened in the users who can not control their self such as the students. For examples, when the teacher is teaching in the class they are busy by playing the game or texting a message to their friends. They are serious in their doing, sometimes they are laught and smile by theirself. Moreover, the the teacher does not give the rule or punishment for them. So, they will get nothing in the class. Besides, if the parents do not control, they also do not study or do homework. Second, disturbs the childen’s development or maturity.Because, there are many things in the phone. Such as camera, games, pictures, and others. Which changes the student’s attention and concentretion, both in the class or in the home. Moreover, it gives dishonest way. Exmple, in the examination they should cheat with others by sending message or searching the material about etc. In addition, by using handphone lets the students to send or receive everything is not good and educated. So, if we let them to use it free without controling, they will be the educated of technology, but not educated of knowledge or attitude.Third, it contibutes the people to be arrogant. Because, everyperson is different personality. Basicly, the phone is used for communication with others. But, some person are use it not only for communication but also for style. As we know, today are many merks and types of phone. Such as BlackBerry, Android, Nokia, Samsung etc. Some of us compete to buy the more expensive, exis and newer. Sometimes, they more emphasize to buy the new phone than other things. Example, the students able to buy the new phone, but do not able to buy the book.This is very bad to their maturity, which compete in the extravagance. Overall, the phone gives many good function for us. There are to communicate with others, save the things as a memorial, share information etc. But, we have to release that phone is same as another technology also has the negative effects should influence the people behaviour. Forthat, we have to be wise in using it, control and tell our family, student and society the positive and negative effects. Because the phone influence the people’s behaviour.

Behavorial Traps

Behavioral Traps There are five behavioral traps. Those five behavioral traps are: time delay, investment, deterioration, ignorance and collective. We fall into some of these traps easily and on a daily bases, while some of us find that they are also easily avoided. The trap that you fall into really only depends on you. I would like to define and give an example of each of the behavioral traps, before I discuss which I think is the easiest to fall for and the easiest to avoid. Time delay is momentary gratification that clashes with long term consequences (short term vs. ong term). An example is finding it hard to diet or exercise regularly (Plous, 1993). The ignorance trap is the negative behavior which are not understood or seen at the outset. An example would be: People, who smoked in the 19th Century, they didn’t realize that smoking led to lung cancer and if the information would have been available, many would never have begun to smoke in the first place (Plous, 1993). T he collective trap involves more than one party. The example for this one is rush hour traffic. Here everyone prefers to drive at the same time, taking their own self interest into play and letting everyone suffer (Plous, 1993). The investment trap occurs when prior expenditures of time, money or other resources lead people to make choices they normally wouldn’t make. An example would be investing money on something to help out the community only to find out at 90% done that another company is doing the same thing but theirs is better, debating on whether to finish the other 10% or not (Plous, 1993). Deterioration trap is similar to the investment trap but the cost and affect occur over time. An example for this trap is a heroin addict. You do it to get that great feeling but then your body becomes tolerant to the drug and you then up the dose to get that same great feeling, and then you’d rather take the drug to avoid withdrawal symptoms. So what started as a pleasurable feeling ends up in a nightmare of dependence (Plous, 1993). Those are the five behavioral traps, I studied and read because to a point they all are easy to fall into, but one that I know I have troubles with and that most people have fall easily to is the time delay trap. How many of us have tried diet after diet and exercise after exercise and end up not sticking to the plan. That’s what the time delay trap does to you. â€Å"Any situation in which short term consequences run counter to long term consequences can turn into a time delay trap† (Plous, 1993). Another example of the time delay trap could be the apples in the Garden of Eden, because the apple is regarded as bait and is the ultimate temptation with its entrapping consequences (Plous, 1993). As you look at the definitions in the earlier paragraph you might think that there really isn’t one that is easily avoided, but I believe that the deterioration is that one. I believe this because this trap takes time to occur/fall into, while with the other traps they seem more likely easier to fall for. The reason deterioration take more time than the others is because it produces behavior that may seem absurd or self-destructive to others whom haven’t seen the situation evolve. (Plous, 1993). Just like the heroin addiction, your body eventually gets use to all the things you are doing and you think you need more because you aren’t getting the same affect. So over time your body takes a beating and starts to be self destructive and so on. For the time delay trap the person wants to exercise and/or diet, but something keeps stopping you. The long term consequences for not exercising and/or dieting could result in health problems and obesity. I just happen to be one of those people. For months I have been planning to exercise more, but I always end up finding an excuse not to and then it only leads to me now being healthy or losing the weight that I have put on in the mean time. The thing that is striking about the time delay trap is that relative is that you end up with small pains and pleasures in the short run, will produce behavior that is devastating maybe even lethal in the long run. (Plous, 1993). Like for example smoking, it’s a short term pleasure but in the long run you can get cancer. We never really think that the things we do/ could be considered as a trap. We just go on day by day either eventually doing something about what we have been putting up with or just deal with the long term consequence. Which traps we find easy to fall for or to avoid really depend on you, we all have different weak points in our mind and bodies. We think about the things that we put into our bodies, but do we really think about the long term effects? References Plous, S. (1993). The Psychology of Judgment and Decision Making. McGraw-Hill: New York, NY.

Assessment as a Process of Making Judgements of Learners Knowledge

What is an assessment? Alan Rogers (1994, p172) defines assessment as collection of data on which we base our evaluation. According to Reece and Walker (2008, p5) assessment consists of tests and observations that we, as tutor, use to determine how well the students has achieved the objectives. Geoff Petty (2004, p449) writes that â€Å"Assessment measures the breadth and depth of learning†. Assessments are used in all areas and domain of everyday life, whether formal or informal, ranging from taking a written or practical driving test to claims for income support or acquiring life insurance on-line.Assessment is used to make a specific educational decision and is the process of evaluating the extent to which participants in education have developed their knowledge, understanding and skills. Assessment, both formative and summative, plays a significant part in the learning experience as it determines progression and enables learners to demonstrate that they have achieved their desired learning outcomes. There are generally two ways of assessment, formative and summative.According to Ashcroft and Forman-Peck (1994, p54) â€Å"Assessment is generally taken to mean a judgement about the progress (formative assessment) or achievement (summative assessment) of a particular student’s learning†. Reece and Walker’s (2008, p323) distinction between formative and summative is one to satisfy the needs of the society (‘summative’ assessment) and the other type of assessment is to help in both teaching and learning (‘formative’ assessment).Formative assessment is the assessment that takes place throughout the course or programme of study and is usually carried out by the assessor during mentoring and training. It provides feedback to both the learner and the assessor on how things are going and how learning can be improved. In contrast summative assessment is assessment of learning and is often used to determine what has been learnt or achieved in terms of acquired skills, knowledge and understanding at or towards the end of a course or programme of study.Further functions of assessment in learning and development are the measurement and recording of achievement, the identification of individual learners’ needs, that the assessment reflects the required standards and performance/assessment criteria and are fit for the purpose intended and that they contribute to quality assurance and the development of best practice. There are many reasons why we assess learners. Assessments enable tutors to measure learner’s progress towards their goal. And feedback can be given to help them such as outlining their strengths and weaknesses. Read also: Principles of Good Writing by L.A. HillFeedback is used to help learners learn and improve, and is the most important aspect of formative assessment. This can be given in various ways such as written, oral, in the form of graded/marked assignment etc. When giving feedback it is good practice to bear in mind the following points. It is important to give immediate feedback if possible; turn negative comment into constructive comments such as what to improve on before the next assessment; make assessment criteria clear, accurate and available; feedback to be clear, accurate and recorded; praise learner on achievement; encourage positive attitudes and make further suggestions.Learners can be encouraged through communication of how well they are doing and what skills and knowledge they are developing. I assess my students at regular intervals. Every time I ask a question to an individual or to a class I am assessing their knowledge and understanding. When I walk round the class watching students doing their tasks, checking their printouts, I am observing and noting against a checklist of expectations in my mind.When I receive or look at a printout from a mock exam I am comparing their performance with that which I would hope for from such a group or individual at such a stage in such a course at such a level. When giving verbal feedback to my learners, I use the following words of encouragement: very good, well done, brilliant, excellent, spot on. Throughout the delivery of a course I give my students formative, diagnostic and summative assessments and feedbacks.

Data and Computer Communications

DATA AND COMPUTER COMMUNICATIONS Eighth Edition William Stallings Upper Saddle River, New Jersey 07458 Library of Congress Cataloging-in-Publication Data on File Vice President and Editorial Director, ECS: Marcia J. Horton Executive Editor: Tracy Dunkelberger Assistant Editor: Carole Snyder Editorial Assistant: Christianna Lee Executive Managing Editor: Vince O’Brien Managing Editor: Camille Trentacoste Production Editor: Rose Kernan Director of Creative Services: Paul Belfanti Creative Director: Juan Lopez Cover Designer: Bruce Kenselaar Managing Editor,AV Management and Production: Patricia Burns  ©2007 Pearson Education, Inc.Pearson Prentice Hall Pearson Education, Inc. Upper Saddle River, NJ 07458 Art Editor: Gregory Dulles Director, Image Resource Center: Melinda Reo Manager, Rights and Permissions: Zina Arabia Manager,Visual Research: Beth Brenzel Manager, Cover Visual Research and Permissions: Karen Sanatar Manufacturing Manager, ESM: Alexis Heydt-Long Manufacturing B uyer: Lisa McDowell Executive Marketing Manager: Robin O’Brien Marketing Assistant: Mack Patterson All rights reserved. No part of this book may be reproduced in any form or by any means, without permission in writing from the publisher.Pearson Prentice Hallâ„ ¢ is a trademark of Pearson Education, Inc. All other tradmarks or product names are the property of their respective owners. The author and publisher of this book have used their best efforts in preparing this book. These efforts include the development, research, and testing of the theories and programs to determine their effectiveness. The author and publisher make no warranty of any kind, expressed or implied, with regard to these programs or the documentation contained in this book. The author and publisher shall not be liable in any event for incidental or consequential amages in connection with, or arising out of, the furnishing, performance, or use of these programs. Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 ISBN: 0-13-243310-9 Pearson Education Ltd. , London Pearson Education Australia Pty. Ltd. , Sydney Pearson Education Singapore, Pte. Ltd. Pearson Education North Asia Ltd. , Hong Kong Pearson Education Canada, Inc. , Toronto Pearson Educaci n de Mexico, S. A. de C. V. Pearson Education Japan, Tokyo Pearson Education Malaysia, Pte. Ltd. Pearson Education, Inc. , Upper Saddle River, New Jersey For my scintillating wife ATSWEB SITE FOR DATA AND COMPUTER COMMUNICATIONS, EIGHTH EDITION The Web site at WilliamStallings. com/DCC/DCC8e. html provides support for instructors and students using the book. It includes the following elements. Course Support Materials The course support materials include †¢ Copies of figures from the book in PDF format †¢ A detailed set of course notes in PDF format suitable for student handout or for use as viewgraphs †¢ A set of PowerPoint slides for use as lecture aids †¢ Computer Science Student Support Site: contains a number of links and documents that the student may find useful in his/her ongoing computer science education.The site includes a review of basic, relevant mathematics; advice on research, writing, and doing homework problems; links to computer science research resources, such as report repositories and bibliographies; and other useful links. †¢ An errata sheet for the book, updated at most monthly T DCC Courses The DCC8e Web site includes links to Web sites for courses taught using the book. These sites can provide useful ideas about scheduling and topic ordering, as well as a number of useful handouts and other materials. Useful Web Sites The DCC8e Web site includes links to relevant Web sites, organized by chapter.The links cover a broad spectrum of topics and will enable students to explore timely issues in greater depth. iv WEB SITE FOR DATA AND COMPUTER COMMUNICATIONS, EIGHTH EDITION v Supplemental Documents The DCC8e Web site includes a number of documents that expand on the treatment in the book. Topics include standards organizations, Sockets, TCP/IP checksum, ASCII, and the sampling theorem. Internet Mailing List An Internet mailing list is maintained so that instructors using this book can exchange information, suggestions, and questions with each other and the author.Subscription information is provided at the book’s Web site. Simulation and Modeling Tools The Web site includes links to the cnet Web site and the modeling tools Web site. These packages can be used to analyze and experiment with protocol and network design issues. Each site includes downloadable software and background information. The instructor’s manual includes more information on loading and using the software and suggested student projects. This page intentionally left blank CONTENTS Web Site for Data and Computer Communications Preface xv 1 iv Chapter 0 Reader’s and Instructor’s Guide 0. Outline of the Book 2 0. 2 Roadmap 3 0. 3 Internet and Web Resources 5 0. 4 Standards 6 PART ONE OVERVIEW 9 Chapter 1 Data Communications, Data Networking, and the Internet 10 1. 1 Data Communications and Networking for Today’s Enterprise 12 1. 2 A Communications Model 16 1. 3 Data Communications 19 1. 4 Networks 22 1. 5 The Internet 25 1. 6 An Example Configuration 29 Chapter 2 Protocol Architecture, TCP/IP, and Internet-Based Applications 2. 1 The Need for a Protocol Architecture 33 2. 2 The TCP/IP Protocol Architecture 34 2. 3 The OSI Model 42 2. 4 Standardization within a Protocol Architecture 44 2. Traditional Internet-Based Applications 48 2. 6 Multimedia 48 2. 7 Recommended Reading and Web Sites 53 2. 8 Key Terms, Review Questions, and Problems 54 Appendix 2A The Trivial File Transfer Protocol 57 PART TWO DATA COMMUNICATIONS 62 Chapter 3 Data Transmission 65 3. 1 Concepts and Terminology 67 3. 2 Analog and Digital Data Transmission 78 3. 3 Transmission Impairments 86 3. 4 Channel Capacity 91 3. 5 Recommended Reading and Web Si te 96 3. 6 Key Terms, Review Questions, and Problems Appendix 3A Decibels and Signal Strength 99 Chapter 4 Transmission Media 102 4. Guided Transmission Media 104 4. 2 Wireless Transmission 117 4. 3 Wireless Propagation 125 32 96 vii viii CONTENTS 4. 4 4. 5 4. 6 Line-of-Sight Transmission 129 Recommended Reading and Web Sites 133 Key Terms, Review Questions, and Problems 134 Chapter 5 Signal Encoding Techniques 138 5. 1 Digital Data, Digital Signals 141 5. 2 Digital Data, Analog Signals 151 5. 3 Analog Data, Digital Signals 162 5. 4 Analog Data, Analog Signals 168 5. 5 Recommended Reading 175 5. 6 Key Terms, Review Questions, and Problems 175 Chapter 6 Digital Data Communication Techniques 180 6. Asynchronous and Synchronous Transmission 182 6. 2 Types of Errors 186 6. 3 Error Detection 186 6. 4 Error Correction 196 6. 5 Line Configurations 201 6. 6 Recommended Reading 203 6. 7 Key Terms, Review Questions, and Problems 204 Chapter 7 Data Link Control Protocols 207 7. 1 Flow Control 209 7. 2 Error Control 216 7. 3 High-Level Data Link Control (HDLC) 222 7. 4 Recommended Reading 228 7. 5 Key Terms, Review Questions, and Problems 229 Appendix 7A Performance Issues 232 Chapter 8 Multiplexing 239 8. 1 Frequency-Division Multiplexing 242 8. 2 Synchronous Time-Division Multiplexing 248 8. Statistical Time-Division Multiplexing 258 8. 4 Asymmetric Digital Subscriber Line 265 8. 5 xDSL 268 8. 6 Recommended Reading and Web Sites 269 8. 7 Key Terms, Review Questions, and Problems 270 Chapter 9 Spread Spectrum 274 9. 1 The Concept of Spread Spectrum 276 9. 2 Frequency Hopping Spread Spectrum 277 9. 3 Direct Sequence Spread Spectrum 282 9. 4 Code-Division Multiple Access 287 9. 5 Recommended Reading and Web Site 290 9. 6 Key Terms, Review Questions, and Problems 291 CONTENTS ix PART THREE WIDE AREA NETWORKS 295 Chapter 10 Circuit Switching and Packet Switching 297 10. Switched Communications Networks 299 10. 2 Circuit Switching Networks 301 10. 3 Circuit Switching Concepts 304 10. 4 Softswitch Architecture 307 10. 5 Packet-Switching Principles 309 10. 6 X. 25 317 10. 7 Frame Relay 319 10. 8 Recommended Reading and Web Sites 324 10. 9 Key Terms, Review Questions, and Problems 325 Chapter 11 Asynchronous Transfer Mode 328 11. 1 Protocol Architecture 329 11. 2 ATM Logical Connections 331 11. 3 ATM Cells 335 11. 4 Transmission of ATM Cells 340 11. 5 ATM Service Categories 345 11. 6 Recommended Reading and Web Sites 348 11. Key Terms, Review Questions, and Problems 349 Chapter 12 Routing in Switched Networks 351 12. 1 Routing in Packet-Switching Networks 352 12. 2 Examples: Routing in ARPANET 362 12. 3 Least-Cost Algorithms 367 12. 4 Recommended Reading 372 12. 5 Key Terms, Review Questions, and Problems 373 Chapter 13 Congestion Control in Data Networks 377 13. 1 Effects of Congestion 379 13. 2 Congestion Control 383 13. 3 Traffic Management 386 13. 4 Congestion Control in Packet-Switching Networks 13. 5 Frame Relay Congestion Control 388 13. 6 ATM Traff ic Management 394 13. 7 ATM-GFR Traffic Management 406 13. Recommended Reading 409 13. 9 Key Terms, Review Questions, and Problems 410 Chapter 14 Cellular Wireless Networks 413 14. 1 Principles of Cellular Networks 415 14. 2 First Generation Analog 427 14. 3 Second Generation CDMA 429 14. 4 Third Generation Systems 437 14. 5 Recommended Reading and Web Sites 440 14. 6 Key Terms, Review Questions, and Problems 441 387 x CONTENTS PART FOUR LOCAL AREA NETWORKS 444 Chapter 15 Local Area Network Overview 446 15. 1 Background 448 15. 2 Topologies and Transmission Media 451 15. 3 LAN Protocol Architecture 457 15. 4 Bridges 465 15. 5 Layer 2 and Layer 3 Switches 473 15. Recommended Reading and Web Site 478 15. 7 Key Terms, Review Questions, and Problems 479 Chapter 16 High-Speed LANs 482 16. 1 The Emergence of High-Speed LANs 483 16. 2 Ethernet 485 16. 3 Fibre Channel 500 16. 4 Recommended Reading and Web Sites 504 16. 5 Key Terms, Review Questions, and Problems 506 Appendix 16A Digital Sig nal Encoding for LANs 508 Appendix 16B Performance Issues 514 Appendix 16C Scrambling 518 Chapter 17 Wireless LANs 522 17. 1 Overview 523 17. 2 Wireless LAN Technology 528 17. 3 IEEE 802. 11 Architecture and Services 531 17. 4 IEEE 802. 11 Medium Access Control 535 17. 5 IEEE 802. 1Physical Layer 543 17. 6 IEEE 802. 11 Security Considerations 549 Recommended Reading and Web Sites 550 17. 7 17. 8 Key Terms, Review Questions, and Problems 551 PART FIVE INTERNET AND TRANSPORT PROTOCOLS Chapter 18 Internetwork Protocols 556 18. 1 Basic Protocol Functions 558 18. 2 Principles of Internetworking 566 18. 3 Internet Protocol Operation 569 18. 4 Internet Protocol 576 18. 5 IPv6 586 18. 6 Virtual Private Networks and IP Security 596 18. 7 Recommended Reading and Web Sites 599 18. 8 Key Terms, Review Questions, and Problems 600 Chapter 19 Internetwork Operation 603 19. 1 Multicasting 605 19. Routing Protocols 614 19. 3 Integrated Services Architecture 625 19. 4 Differentiated Services 636 554 CONTENTS xi 19. 5 19. 6 19. 7 19. 8 Service Level Agreements 645 IP Performance Metrics 646 Recommended Reading and Web Sites 649 Key Terms, Review Questions, and Problems 651 657 Chapter 20 Transport Protocols 655 20. 1 Connection-Oriented Transport Protocol Mechanisms 20. 2 TCP 674 20. 3 TCP Congestion Control 683 20. 4 UDP 693 20. 5 Recommended Reading and Web Sites 695 Key Terms, Review Questions, and Problems 695 20. 6 PART SIX Chapter 21 21. 1 21. 2 21. 3 21. 4 21. 5 21. 6 21. 7 21. 8 21. INTERNET APPLICATIONS 699 Network Security 701 Security Requirements and Attacks 703 Confidentiality with Conventional Encryption 705 Message Authentication and Hash Functions 713 Public-Key Encryption and Digital Signatures 720 Secure Socket Layer and Transport Layer Security 727 IPv4 and IPv6 Security 732 Wi-Fi Protected Access 737 Recommended Reading and Web Sites 739 Key Terms, Review Questions, and Problems 740 Chapter 22 Internet Applications—Electronic Mail and Network Managemen t 22. 1 Electronic Mail: SMTP and MIME 745 22. 2 Network Management: SNMP 760 22. 3 Recommended Reading and Web Sites 770 22. Key Terms, Review Questions, and Problems 771 743 Chapter 23 Internet Applications—Internet Directory Service and World Wide Web 23. 1 Internet Directory Service: DNS 774 23. 2 Web Access: HTTP 784 23. 3 Recommended Reading and Web Sites 795 23. 4 Key Terms, Review Questions, and Problems 796 Chapter 24 Internet Applications—Multimedia 799 24. 1 Audio and Video Compression 800 24. 2 Real-Time Traffic 808 24. 3 Voice Over IP and Multimedia Support—SIP 811 24. 4 Real-Time Transport Protocol (RTP) 820 24. 5 Recommended Reading and Web Sites 831 24. 6 Key Terms, Review Questions, and Problems 832 773 ii CONTENTS APPENDICES 835 Appendix A Fourier Analysis 835 A. 1 Fourier Series Representation of Periodic Signals 836 A. 2 Fourier Transform Representation of Aperiodic Signals 837 A. 3 Recommended Reading 840 Appendix B Projects for Teaching Dat a and Computer Communications B. 1 Practical Exercises 842 B. 2 Sockets Projects 843 B. 3 Ethereal Projects 843 B. 4 Simulation and Modeling Projects 844 B. 5 Performance Modeling 844 B. 6 Research Projects 845 B. 7 Reading/Report Assignments 845 B. 8 Writing Assignments 845 B. 9 Discussion Topics 846 References Index 858 ONLINE APPENDICES WilliamStallings. om/DCC Appendix C Sockets: A Programmer’s Introduction C. 1 Versions of Sockets C. 2 Sockets, Socket Descriptors, Ports, and Connections The Client/Server Model of Communication C. 3 C. 4 Sockets Elements C. 5 Stream and Datagram Sockets C. 6 Run-Time Program Control C. 7 Remote Execution of a Windows Console Application Appendix D Standards Organizations D. 1 The Importance of Standards D. 2 Standards and Regulation D. 3 Standards-Setting Organizations Appendix E Appendix F The International Reference Alphabet Proof of the Sampling Theorem 847 841 Appendix G Physical-Layer Interfacing G. 1 V. 24/EIA-232-F G. ISDN Physical Interface Appendix H The OSI Model H. 1 The Model H. 2 The OSI Layers CONTENTS xiii Appendix I Queuing Effects I. 1 Queuing Models I. 2 Queuing Results Appendix J Orthogonality, Correlation, and Autocorrelation J. 1 Correlation and Autocorrelation J. 2 Orthogonal Codes Appendix K The TCP/IP Checksum K. 1 Ones-Complement Addition K. 2 Use in TCP and IP Appendix L TCP/IP Example Appendix M Uniform Resource Locators (URLs) and Uniform Resource Identifiers (URIs) M. 1 Uniform Resource Locator M. 2 Uniform Resource Identifier M. 3 To Learn More Appendix N Glossary Augmented Backus-Naur FormThis page intentionally left blank PREFACE Begin at the beginning and go on till you come to the end; then stop. —Alice in Wonderland, Lewis Carroll OBJECTIVES This book attempts to provide a unified overview of the broad field of data and computer communications. The organization of the book reflects an attempt to break this massive subject into comprehensible parts and to build, piece by piec e, a survey of the state of the art. The book emphasizes basic principles and topics of fundamental importance concerning the technology and architecture of this field and provides a detailed discussion of leading-edge topics.The following basic themes serve to unify the discussion: †¢ Principles: Although the scope of this book is broad, there are a number of basic principles that appear repeatedly as themes and that unify this field. Examples are multiplexing, flow control, and error control. The book highlights these principles and contrasts their application in specific areas of technology. †¢ Design approaches: The book examines alternative approaches to meeting specific communication requirements. †¢ Standards: Standards have come to assume an increasingly important, indeed dominant, role in this field.An understanding of the current status and future direction of technology requires a comprehensive discussion of the related standards. INTENDED AUDIENCE The book is intended for both an academic and a professional audience. For the professional interested in this field, the book serves as a basic reference volume and is suitable for self-study. As a textbook, it can be used for a one-semester or two-semester course. It covers the material in Networking (NET), a core area in the Information Technology body of knowledge, which is part of the Draft ACM/IEEE/AIS Computing Curricula 2005.The book also covers the material in Computer Networks (CE-NWK), a core area in Computer Engineering 2004 Curriculum Guidelines from the ACM/IEEE Joint Task Force on Computing Curricula. PLAN OF THE TEXT The book is divided into six parts (see Chapter 0): †¢ Overview †¢ Data Communications †¢ Wide Area Networks xv xvi PREFACE †¢ Local Area Networks †¢ Internet and Transport Protocols †¢ Internet Applications In addition, the book includes an extensive glossary, a list of frequently used acronyms, and a bibliography. Each chapter inc ludes problems and suggestions for further reading.The chapters and parts of the book are sufficiently modular to provide a great deal of flexibility in the design of courses. See Chapter 0 for a number of detailed suggestions for both top-down and bottom-up course strategies. INSTRUCTIONAL SUPPORT MATERIALS To support instructors, the following materials are provided: †¢ Solutions Manual: Solutions to all end-of-chapter Review Questions and Problems. †¢ PowerPoint Slides: A set of slides covering all chapters, suitable for use in lecturing. †¢ PDF files: Reproductions of all figures and tables from the book. Projects Manual: Suggested project assignments for all of the project categories listed below. Instructors may contact their Pearson Education or Prentice Hall representative for access to these materials. In addition, the book’s Web site supports instructors with: †¢ Links to Webs sites for other courses being taught using this book †¢ Sign up i nformation for an Internet mailing list for instructors INTERNET SERVICES FOR INSTRUCTORS AND STUDENTS There is a Web site for this book that provides support for students and instructors.The site includes links to other relevant sites, transparency masters of figures in the book, and sign-up information for the book’s Internet mailing list. The Web page is at WilliamStallings. com/DCC/DCC8e. html; see the section, Web Site for Data and Computer Communications, preceding the Table of Contents, for more information. An Internet mailing list has been set up so that instructors using this book can exchange information, suggestions, and questions with each other and with the author. As soon as typos or other errors are discovered, an errata list for this book will be available at WilliamStallings. om. PROJECTS AND OTHER STUDENT EXERCISES For many instructors, an important component of a data communications or networking course is a project or set of projects by which the student gets hands-on experience to reinforce concepts from the text. This book provides an unparalleled degree of support for including a projects component in the course. The instructor’s supplement not only includes guidance on how to assign and structure the projects but also includes a set of User’s PREFACE xvii Manuals for various project types plus specific assignments, all written especially for this book.Instructors can assign work in the following areas: †¢ Practical exercises: Using network commands, the student gains experience in network connectivity. †¢ Sockets programming projects: The book is supported by a detailed description of Sockets available at the book’s Web site. The Instructors supplement includes a set of programming projects. Sockets programming is an â€Å"easy† topic and one that can result in very satisfying hands-on projects for students. †¢ Ethereal projects: Ethereal is a protocol analyzer that enables students to study the behavior of protocols. Simulation projects: The student can use the simulation package cnet to analyze network behavior. †¢ Performance modeling projects: Two performance modeling techniques are provided a tools package and OPNET. †¢ Research projects: The instructor’s supplement includes a list of suggested research projects that would involve Web and literature searches. †¢ Reading/report assignments: The instructor’s supplement includes a list of papers that can be assigned for reading and writing a report, plus suggested assignment wording. Writing assignments: The instructor’s supplement includes a list of writing assignments to facilitate learning the material. †¢ Discussion topics: These topics can be used in a classroom, chat room, or message board environment to explore certain areas in greater depth and to foster student collaboration. This diverse set of projects and other student exercises enables the instructor to use t he book as one component in a rich and varied learning experience and to tailor a course plan to meet the specific needs of the instructor and students. See Appendix B for details.WHAT’S NEW IN THE EIGHTH EDITION This eighth edition is seeing the light of day less than four years after the publication of the seventh edition. During that time, the pace of change in this field continues unabated. In this new edition, I try to capture these changes while maintaining a broad and comprehensive coverage of the entire field. To begin the process of revision, the seventh edition of this book was extensively reviewed by a number of professors who teach the subject. The result is that, in many places, the narrative has been clarified and tightened, and illustrations have been improved.Also, a number of new â€Å"field-tested† problems have been added. Beyond these refinements to improve pedagogy and user friendliness, there have been major substantive changes throughout the book . Every chapter has been revised, new chapters have been added, and the overall organization of the book has changed. Highlights include: †¢ Updated coverage of Gigabit Ethernet and 10-Gbps Ethernet: New details of these standards are provided. †¢ Updated coverage of WiFi/IEEE 802. 11 wireless LANs: IEEE 802. 11 and the related WiFi specifications have continued to evolve. viii PREFACE †¢ New coverage of IP performance metrics and service level agreements (SLAs): These aspects of Quality of Service (QoS) and performance monitoring are increasingly important. †¢ Address Resolution Protocol (ARP): This important protocol is now covered. †¢ New coverage of TCP Tahoe, Reno, and NewReno: These congestion control algorithms are now common in most commercial implementations. †¢ Expanded coverage of security: Chapter 21 is more detailed; other chapters provide overview of security for the relevant topic.Among the new topics are Wi-Fi Protected Access (WPA) and the secure hash algorithm SHA-512. †¢ Domain Name System (DNS): This important scheme is now covered. †¢ New coverage of multimedia: Introductory section in Chapter 2; detailed coverage in Chapter 24. Topics covered include video compression, SIP, and RTP. †¢ Online appendices: Fourteen online appendices provide additional detail on important topics in the text, including Sockets programming, queuing models, the Internet checksum, a detailed example of TCP/IP operation, and the BNF grammar.In addition, throughout the book, virtually every topic has been updated to reflect the developments in standards and technology that have occurred since the publication of the seventh edition. ACKNOWLEDGMENTS This new edition has benefited from review by a number of people, who gave generously of their time and expertise. The following people reviewed all or a large part of the manuscript: Xin Liu- (UC, Davis), Jorge Cobb, Andras Farago, Dr. Prasant Mohapatra (UC Davis), Dr. Jingxi an Wu (Sonoma State University), G. R.Dattareya (UT Dallas), Guanling Chen (Umass, Lowell), Bob Roohaprvar (Cal State East Bay), Ahmed Banafa (Cal State East Bay), Ching-Chen Lee (CSU Hayward), and Daji Qaio (Iowa State). Thanks also to the many people who provided detailed technical reviews of a single chapter: Dave Tweed, Bruce Lane, Denis McMahon, Charles Freund, Paul Hoadley, Stephen Ma, Sandeep Subramaniam, Dragan Cvetkovic, Fernando Gont, Neil Giles, Rajesh Thundil, and Rick Jones. In addition, Larry Owens of California State University and Katia Obraczka of the University of Southern California provided some homework problems.Thanks also to the following contributors. Zornitza Prodanoff of the University of North Florida prepared the appendix on Sockets programming. Michael Harris of the University of South Florida is responsible for the Ethereal exercises and user’s guide. Lawrie Brown of the Australian Defence Force Academy of the University of New South Wales produc ed the PPT lecture slides. Finally, I would like to thank the many people responsible for the publication of the book, all of whom did their usual excellent job.This includes the staff at Prentice Hall, particularly my editor Tracy Dunkelberger, her assistants Christianna Lee and Carole Snyder, and production manager Rose Kernan. Also, Patricia M. Daly did the copy editing. CHAPTER READER’S AND INSTRUCTOR’S GUIDE 0. 1 0. 2 0. 3 0. 4 Outline of the Book Roadmap Internet and Web Resources Standards 0 1 2 CHAPTER 0 / READER’S AND INSTRUCTOR’S GUIDE â€Å"In the meanwhile, then,† demanded Li-loe, â€Å"relate to me the story to which reference has been made, thereby proving the truth of your assertion, and at the same time affording n entertainment of a somewhat exceptional kind. † â€Å"The shadows lengthen,† replied Kai Lung, â€Å"but as the narrative in question is of an inconspicuous span I will raise no barrier against your flatter ing request, especially as it indicates an awakening taste hitherto unexpected. † —Kai Lung’s Golden Hours, Earnest Bramah This book, with its accompanying Web site, covers a lot of material. Here we give the reader some basic background information. 0. 1 OUTLINE OF THE BOOK The book is organized into five parts: Part One. Overview: Provides an introduction to the range of topics covered in the book.This part includes a general overview of data communications and networking and a discussion of protocols, OSI, and the TCP/IP protocol suite. Part Two. Data Communications: Concerned primarily with the exchange of data between two directly connected devices. Within this restricted scope, the key aspects of transmission, interfacing, link control, and multiplexing are examined. Part Three. Wide Area Networks: Examines the internal mechanisms and user-network interfaces that have been developed to support voice, data, and multimedia communications over long-distance ne tworks.The traditional technologies of packet switching and circuit switching are examined, as well as the more recent ATM and wireless WANs. Separate chapters are devoted to routing and congestion control issues that are relevant both to switched data networks and to the Internet. Part Four. Local Area Networks: Explores the technologies and architectures that have been developed for networking over shorter distances. The transmission media, topologies, and medium access control protocols that are the key ingredients of a LAN design are explored and specific standardized LAN systems examined.Part Five. Networking Protocols: Explores both the architectural principles and the mechanisms required for the exchange of data among computers, workstations, servers, and other data processing devices. Much of the material in this part relates to the TCP/IP protocol suite. Part Six. Internet Applications: Looks at a range of applications that operate over the Internet. A more detailed, chapte r-by-chapter summary of each part appears at the beginning of that part. 0. 2 / ROADMAP 3 0. 2 ROADMAP Course EmphasisThe material in this book is organized into four broad categories: data transmission and communication; communications networks; network protocols; and applications and security. The chapters and parts of the book are sufficiently modular to provide a great deal of flexibility in the design of courses. The following are suggestions for three different course designs: †¢ Fundamentals of Data Communications: Parts One (overview) and Two (data communications) and Chapters 10 and 11 (circuit switching, packet switching, and ATM). Communications Networks: If the student has a basic background in data communications, then this course could cover Parts One (overview), Three (WAN), and Four (LAN). †¢ Computer Networks: If the student has a basic background in data communications, then this course could cover Part One (overview), Chapters 6 and 7 (data communication techniques and data link control), Part Five (protocols), and part or all of Part Six (applications). In addition, a more streamlined course that covers the entire book is possible by eliminating certain chapters that are not essential on a first reading.Chapters that could be optional are Chapters 3 (data transmission) and 4 (transmission media), if the student has a basic understanding of these topics; Chapter 8 (multiplexing); Chapter 9 (spread spectrum); Chapters 12 through 14 (routing, congestion control, cellular networks); Chapter 18 (internetworking); and Chapter 21 (network security). Bottom-Up versus Top-Down The book is organized in a modular fashion. After reading Part One, the other parts can be read in a number of possible sequences.Figure 0. 1a shows the bottom-up approach provided by reading the book from front to back. With this approach, each part builds on the material in the previous part, so that it is always clear how a given layer of functionality is supporte d from below. There is more material than can be comfortably covered in a single semester, but the book’s organization makes it easy to eliminate some chapters and maintain the bottom-up sequence. Figure 0. 1b suggests one approach to a survey course.Some readers, and some instructors, are more comfortable with a top-down approach. After the background material (Part One), the reader continues at the application level and works down through the protocol layers. This has the advantage of immediately focusing on the most visible part of the material, the applications, and then seeing, progressively, how each layer is supported by the next layer down. Figure 0. 1c is an example of a comprehensive treatment and Figure 0. 1d is an example of a survey treatment. 4 CHAPTER 0 / READER’S AND INSTRUCTOR’S GUIDEPart One Overview Part Two Data Communications Part Three Wide Area Networks Part Four Local Area Networks Part Five Internet and Transport Protocols Part Six Inter net Applications (a) A bottom-up approach Part One Overview Chapter 18 The Internet Protocol Part Six Internet Applications Part Five TCP/IP Part Three WANs Part Four LANs Part Two Data Communications (c) A top-down approach (d) Another top-down approach (b) Another bottom-up approach Part One Overview Chapter 18 The Internet Protocol Part Six Internet Applications Part Five TCP/IP Part Three WANs (10, 12) Part Four LANs (15) Part One Overview (1, 2) Part Two Data Communications (3, 6, 7, 8) Part Three WANs (10, 12) Part Four LANs (15) Part Five TCP/IP (18, 20) Figure 0. 1 Suggested Reading Orders Finally, it is possible to select chapters to reflect specific teaching objectives by not sticking to a strict chapter ordering. We give two examples used in courses taught with the seventh edition.One course used the sequence Part One (Overview); Chapter 3 (Data Transmission); Chapter 6 (Digital Data Communications Techniques); Chapter 7 (Data Link Control); Chapter 15 (LAN Overview); Cha pter 16 (High-Speed LANs); Chapter 10 (Circuit and Packet Switching); Chapter 12 (Routing); Chapter 18 (Internet Protocols); and Chapter 19 (Internet Operation). The other course used the sequence Part One (Overview); Chapter 3 (Data Transmission); Chapter 4 (Guided and Wireless Transmission); Chapter 5 (Signal Encoding Techniques); Chapter 8 (Multiplexing); Chapter 15 (LAN 0. 3 / INTERNET AND WEB RESOURCES 5 Overview); Chapter 16 (High-Speed LANs); Chapter 10 (Circuit and Packet Switching); Chapter 20 (Transport Protocols); Chapter 18 (Internet Protocols); and Chapter 19 (Internet Operation). 0. 3 INTERNET AND WEB RESOURCES There are a number of resources available on the Internet and the Web to support this book and to help one keep up with developments in this field.Web Sites for This Book A special Web page has been set up for this book at WilliamStallings. com/DCC/ DCC8e. html. See the two-page layout at the beginning of this book for a detailed description of that site. As soo n as any typos or other errors are discovered, an errata list for this book will be available at the Web site. Please report any errors that you spot. Errata sheets for my other books are at WilliamStallings. com. I also maintain the Computer Science Student Resource Site, at WilliamStallings. com/StudentSupport. html. The purpose of this site is to provide documents, information, and links for computer science students and professionals.Links and documents are organized into four categories: †¢ Math: Includes a basic math refresher, a queuing analysis primer, a number system primer, and links to numerous math sites †¢ How-to: Advice and guidance for solving homework problems, writing technical reports, and preparing technical presentations †¢ Research resources: Links to important collections of papers, technical reports, and bibliographies †¢ Miscellaneous: A variety of useful documents and links Other Web Sites There are numerous Web sites that provide informa tion related to the topics of this book. In subsequent chapters, pointers to specific Web sites can be found in the Recommended Reading and Web Sites section. Because the addresses for Web sites tend to change frequently, I have not included URLs in the book. For all of the Web sites listed in the book, the appropriate link can be found at this book’s Web site. Other links not mentioned in this book will be added to the Web site over time.The following are Web sites of general interest related to data and computer communications: †¢ Network World: Information and links to resources about data communications and networking. †¢ IETF: Maintains archives that relate to the Internet and IETF activities. Includes keyword-indexed library of RFCs and draft documents as well as many other documents related to the Internet and related protocols. 6 CHAPTER 0 / READER’S AND INSTRUCTOR’S GUIDE †¢ Vendors: Links to thousands of hardware and software vendors who currently have Web sites, as well as a list of thousands of computer and networking companies in a phone directory. †¢ IEEE Communications Society: Good way to keep up on conferences, publications, and so on. ACM Special Interest Group on Communications (SIGCOMM): Good way to keep up on conferences, publications, and so on. †¢ International Telecommunications Union: Contains a listing of ITU-T recommendations, plus information on obtaining ITU-T documents in hard copy or on DVD. †¢ International Organization for Standardization: Contains a listing of ISO standards, plus information on obtaining ISO documents in hard copy or on CD-ROM. †¢ CommWeb: Links to vendors, tutorials, and other useful information. †¢ CommsDesign: Lot of useful articles, tutorials, and product information. A bit hard to navigate, but worthwhile. USENET Newsgroups A number of USENET newsgroups are devoted to some aspect of data communications, networks, and protocols.As with virtually all USENET groups, there is a high noise-to-signal ratio, but it is worth experimenting to see if any meet your needs. The most relevant are as follows: †¢ comp. dcom. lans, comp. dcom. lans. misc: General discussions of LANs †¢ comp. dcom. lans. ethernet: Covers Ethernet, Ethernet-like systems, and the IEEE 802. 3 CSMA/CD standards †¢ comp. std. wireless: General discussion of wireless networks, including wireless LANs †¢ comp. security. misc: Computer security and encryption †¢ comp. dcom. cell-relay: Covers ATM and ATM LANs †¢ comp. dcom. frame-relay: Covers frame relay networks †¢ comp. dcom. net-management: Discussion of network management applications, protocols, and standards †¢ comp. rotocols. tcp-ip: The TCP/IP protocol suite 0. 4 STANDARDS It has long been accepted in the telecommunications industry that standards are required to govern the physical, electrical, and procedural characteristics of communication equipment. In the past, this view has not been embraced by the computer industry. Whereas communication equipment vendors recognize that their 0. 4 / STANDARDS 7 equipment will generally interface to and communicate with other vendors’ equipment, computer vendors have traditionally attempted to monopolize their customers. The proliferation of computers and distributed processing has made that an untenable position.Computers from different vendors must communicate with each other and, with the ongoing evolution of protocol standards, customers will no longer accept special-purpose protocol conversion software development. The result is that standards now permeate all of the areas of technology discussed in this book. There are a number of advantages and disadvantages to the standards-making process. We list here the most striking ones. The principal advantages of standards are as follows: †¢ A standard assures that there will be a large market for a particular piece of equipment or software. Thi s encourages mass production and, in some cases, the use of large-scale-integration (LSI) or very-large-scale-integration (VLSI) techniques, resulting in lower costs. A standard allows products from multiple vendors to communicate, giving the purchaser more flexibility in equipment selection and use. The principal disadvantages are as follows: †¢ A standard tends to freeze the technology. By the time a standard is developed, subjected to review and compromise, and promulgated, more efficient techniques are possible. †¢ There are multiple standards for the same thing. This is not a disadvantage of standards per se, but of the current way things are done. Fortunately, in recent years the various standards-making organizations have begun to cooperate more closely. Nevertheless, there are still areas where multiple conflicting standards exist.Throughout this book, we describe the most important standards in use or being developed for various aspects of data and computer commun ications. Various organizations have been involved in the development or promotion of these standards. The following are the most important (in the current context) of these organizations: †¢ Internet Society: The Internet SOCiety (ISOC) is a professional membership society with more than 150 organizational and 6000 individual members in over 100 countries. It provides leadership in addressing issues that confront the future of the Internet and is the organization home for the groups responsible for Internet infrastructure standards, including the Internet Engineering Task Force (IETF) and the Internet Architecture Board (IAB).All of the RFCs and Internet standards are developed through these organizations. †¢ IEEE 802: The IEEE (Institute of Electrical and Electronics Engineers) 802 LAN/MAN Standards Committee develops local area network standards and metropolitan area network standards. The most widely used standards are for the Ethernet family, wireless LAN, bridging, a nd virtual bridged LANs. An individual working group provides the focus for each area. 8 CHAPTER 0 / READER’S AND INSTRUCTOR’S GUIDE †¢ ITU-T: The International Telecommunication Union (ITU) is an international organization within the United Nations System where governments and the private sector coordinate global telecom networks and services.The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors of the ITU. ITU-T’s mission is the production of standards covering all fields of telecommunications. †¢ ATM Forum: The ATM Forum is an international nonprofit organization formed with the objective of accelerating the use of ATM (asynchronous transfer mode) products and services through a rapid convergence of interoperability specifications. In addition, the Forum promotes industry cooperation and awareness. †¢ ISO: The International Organization for Standardization (ISO)1 is a worldwide federation of national standards bod ies from more than 140 countries, one from each country.ISO is a nongovernmental organization that promotes the development of standardization and related activities with a view to facilitating the international exchange of goods and services, and to developing cooperation in the spheres of intellectual, scientific, technological, and economic activity. ISO’s work results in international agreements that are published as International Standards. A more detailed discussion of these organizations is contained in Appendix D. 1 ISO is not an acronym (in which case it would be IOS), but a word, derived from the Greek, meaning equal. PART ONE Overview The purpose of Part One is to provide a background and context for the remainder of this book. The broad range of topics that are encompassed in the field of data and computer communications is introduced, and the fundamental concepts of protocols and protocol architectures are examined.ROAD MAP FOR PART ONE Chapter 1 Data Communicati ons, Data Networks, and The Internet Chapter 1 provides an overview of Parts Two through Four of the book, giving the â€Å"big picture. † In essence, the book deals with four topics: data communications over a transmission link; wide area networks; local area networks; and protocols and the TCP/IP protocol architecture. Chapter 1 provides a preview of the first three of these topics. Chapter 2 Protocol Architecture, TCP/IP, and Internet-Based Applications Chapter 2 discusses the concept protocol architectures. This chapter can be read immediately following Chapter 1 or deferred until the beginning of Part Three, Four, or Five.After a general introduction, the chapter deals with the two most important protocol architectures: the Open Systems Interconnection (OSI) model and TCP/IP. Although the OSI model is often used as the framework for discourse in this area, it is the TCP/IP protocol suite that is the basis for most commercially available interoperable products and that is the focus of Parts Five and Six of this book. 9 CHAPTER DATA COMMUNICATIONS, DATA NETWORKS, AND THE INTERNET 1. 1 1. 2 1. 3 1. 4 1. 5 1. 6 Data Communications and Networking for Today’s Enterprise A Communications Model Data Communications Networks The Internet An Example Configuration 1 10 The fundamental problem of communication is that of reproducing at one point either exactly or approximately a message selected at another point. The Mathematical Theory of Communication, Claude Shannon KEY POINTS †¢ The scope of this book is broad, covering three general areas: data communications, networking, and protocols; the first two are introduced in this chapter. Data communications deals with the transmission of signals in a reliable and efficient manner. Topics covered include signal transmission, transmission media, signal encoding, interfacing, data link control, and multiplexing. Networking deals with the technology and architecture of the communications networks used to interconnect communicating devices. This field is generally divided into the topics of local area networks (LANs) and wide area networks (WANs). †¢ †¢The 1970s and 1980s saw a merger of the fields of computer science and data communications that profoundly changed the technology, products, and companies of the now combined computer-communications industry. The computercommunications revolution has produced several remarkable facts: †¢ There is no fundamental difference between data processing (computers) and data communications (transmission and switching equipment). †¢ There are no fundamental differences among data, voice, and video communications. †¢ The distinction among single-processor computer, multiprocessor computer, local network, metropolitan network, and long-haul network has blurred.One effect of these trends has been a growing overlap of the computer and communications industries, from component fabrication to system integration. Another resul t is the development of integrated systems that transmit and process all types of data and information. Both the technology and the technical standards organizations are driving toward integrated public systems that make virtually all data and information sources around the world easily and uniformly accessible. This book aims to provide a unified view of the broad field of data and computer communications. The organization of the book reflects an attempt to break this massive subject into comprehensible parts and to build, piece by piece, a survey of the state of the art.This introductory chapter begins with a general model of communications. Then a brief discussion introduces each of the Parts Two through Four of this book. Chapter 2 provides an overview to Parts Five and Six 11 12 CHAPTER 1 / DATA COMMUNICATIONS, DATA NETWORKS, AND THE INTERNET 1. 1 DATA COMMUNICATIONS AND NETWORKING FOR TODAY’S ENTERPRISE Effective and efficient data communication and networking facilitie s are vital to any enterprise. In this section, we first look at trends that are increasing the challenge for the business manager in planning and managing such facilities. Then we look specifically at the requirement for ever-greater transmission speeds and network capacity. TrendsThree different forces have consistently driven the architecture and evolution of data communications and networking facilities: traffic growth, development of new services, and advances in technology. Communication traffic, both local (within a building or building complex) and long distance, both voice and data, has been growing at a high and steady rate for decades. The increasing emphasis on office automation, remote access, online transactions, and other productivity measures means that this trend is likely to continue. Thus, managers are constantly struggling to maximize capacity and minimize transmission costs. As businesses rely more and more on information technology, the range of services expand s. This increases the demand for high-capacity networking and transmission facilities.In turn, the continuing growth in high-speed network offerings with the continuing drop in prices encourages the expansion of services. Thus, growth in services and growth in traffic capacity go hand in hand. Figure 1. 1 gives some examples of information-based services and the data rates needed to support them [ELSA02]. Finally, trends in technology enable the provision of increasing traffic capacity and the support of a wide range of services. Four technology trends are particularly notable: 1. The trend toward faster and cheaper, both in computing and communications, continues. In terms of computing, this means more powerful computers and clusters of computers capable of supporting more demanding applications, such as multimedia applications.In terms of communications, the increasing use of optical fiber has brought transmission prices down and greatly increased capacity. For example, for long-d istance telecommunication and data network links, recent offerings of dense wavelength division multiplexing (DWDM) enable capacities of many terabits per second. For local area networks (LANs) many enterprises now have Gigabit Ethernet backbone networks and some are beginning to deploy 10-Gbps Ethernet. 2. Both voice-oriented telecommunications networks, such as the public switched telephone network (PSTN), and data networks, including the Internet, are more â€Å"intelligent† than ever. Two areas of intelligence are noteworthy.First, today’s networks can offer differing levels of quality of service (QoS), which include specifications for maximum delay, minimum throughput, and so on. Second, today’s networks provide a variety of customizable services in the areas of network management and security. 1. 1 / DATA COMMUNICATIONS AND NETWORKING FOR TODAY’S ENTERPRISE Speed (kbps) Transaction processing Messaging/text apps Voice Location services Still image t ransfers Internet/VPN access Database access Enhanced Web surfing Low-quality video Hifi audio Large file transfer Moderate video Interactive entertainment High-quality video Performance: Poor Adequate Good 9. 6 14. 4 28 64 144 384 2000 13 VPN: virtual private network Figure 1. 1 Services versus Throughput Rates 3.The Internet, the Web, and associated applications have emerged as dominant features of both the business and personal world, opening up many opportunities and challenges for managers. In addition to exploiting the Internet and the Web to reach customers, suppliers, and partners, enterprises have formed intranets and extranets1 to isolate their proprietary information free from unwanted access. 4. There has been a trend toward ever-increasing mobility for decades, liberating workers from the confines of the physical enterprise. Innovations include voice mail, remote data access, pagers, fax, e-mail, cordless phones, cell phones and cellular networks, and Internet portals.T he result is the ability of employees to take their business context with them as they move about. We are now seeing the growth of high-speed wireless access, which further enhances the ability to use enterprise information resources and services anywhere. 1 Briefly, an intranet uses Internet and Web technology in an isolated facility internal to an enterprise; an extranet extends a company’s intranet out onto the Internet to allow selected customers, suppliers, and mobile workers to access the company’s private data and applications. 14 CHAPTER 1 / DATA COMMUNICATIONS, DATA NETWORKS, AND THE INTERNET Data Transmission and Network Capacity RequirementsMomentous changes in the way organizations do business and process information have been driven by changes in networking technology and at the same time have driven those changes. It is hard to separate chicken and egg in this field. Similarly, the use of the Internet by both businesses and individuals reflects this cycli c dependency: the availability of new image-based services on the Internet (i. e. , the Web) has resulted in an increase in the total number of users and the traffic volume generated by each user. This, in turn, has resulted in a need to increase the speed and efficiency of the Internet. On the other hand, it is only such increased speed that makes the use of Web-based applications palatable to the end user.In this section, we survey some of the end-user factors that fit into this equation. We begin with the need for high-speed LANs in the business environment, because this need has appeared first and has forced the pace of networking development. Then we look at business WAN requirements. Finally we offer a few words about the effect of changes in commercial electronics on network requirements. The Emergence of High-Speed LANs Personal computers and microcomputer workstations began to achieve widespread acceptance in business computing in the early 1980s and have now achieved virtu ally the status of the telephone: an essential tool for office workers.Until relatively recently, office LANs provided basic connectivity services—connecting personal computers and terminals to mainframes and midrange systems that ran corporate applications, and providing workgroup connectivity at the departmental or divisional level. In both cases, traffic patterns were relatively light, with an emphasis on file transfer and electronic mail. The LANs that were available for this type of workload, primarily Ethernet and token ring, are well suited to this environment. In the 1990s, two significant trends altered the role of the personal computer and therefore the requirements on the LAN: 1. The speed and computing power of personal computers continued to enjoy explosive growth. These more powerful platforms support graphics-intensive applications and ever more elaborate graphical user interfaces to the operating system. . MIS (management information systems) organizations hav e recognized the LAN as a viable and essential computing platform, resulting in the focus on network computing. This trend began with client/server computing, which has become a dominant architecture in the business environment and the more recent Webfocused intranet trend. Both of these approaches involve the frequent transfer of potentially large volumes of data in a transaction-oriented environment. The effect of these trends has been to increase the volume of data to be handled over LANs and, because applications are more interactive, to reduce the acceptable delay on data transfers.The earlier generation of 10-Mbps Ethernets and 16-Mbps token rings was simply not up to the job of supporting these requirements. The following are examples of requirements that call for higher-speed LANs: †¢ Centralized server farms: In many applications, there is a need for user, or client, systems to be able to draw huge amounts of data from multiple centralized servers, called server farms. An example is a color publishing operation, in 1. 1 / DATA COMMUNICATIONS AND NETWORKING FOR TODAY’S ENTERPRISE 15 which servers typically contain tens of gigabytes of image data that must be downloaded to imaging workstations. As the performance of the servers themselves has increased, the bottleneck has shifted to the network. Power workgroups: These groups typically consist of a small number of cooperating users who need to draw massive data files across the network. Examples are a software development group that runs tests on a new software version, or a computer-aided design (CAD) company that regularly runs simulations of new designs. In such cases, large amounts of data are distributed to several workstations, processed, and updated at very high speed for multiple iterations. †¢ High-speed local backbone: As processing demand grows, LANs proliferate at a site, and high-speed interconnection is necessary. Corporate Wide Area Networking Needs As recently as the ear ly 1990s, there was an emphasis in many organizations on a centralized data processing model.In a typical environment, there might be significant computing facilities at a few regional offices, consisting of mainframes or well-equipped midrange systems. These centralized facilities could handle most corporate applications, including basic finance, accounting, and personnel programs, as well as many of the business-specific applications. Smaller, outlying offices (e. g. , a bank branch) could be equipped with terminals or basic personal computers linked to one of the regional centers in a transaction-oriented environment. This model began to change in the early 1990s, and the change accelerated through the mid-1990s. Many organizations have dispersed their employees into multiple smaller offices.There is a growing use of telecommuting. Most significant, the nature of the application structure has changed. First client/server computing and, more recently, intranet computing have funda mentally restructured the organizational data processing environment. There is now much more reliance on personal computers, workstations, and servers and much less use of centralized mainframe and midrange systems. Furthermore, the virtually universal deployment of graphical user interfaces to the desktop enables the end user to exploit graphic applications, multimedia, and other data-intensive applications. In addition, most organizations require access to the Internet.When a few clicks of the mouse can trigger huge volumes of data, traffic patterns have become more unpredictable while the average load has risen. All of these trends means that more data must be transported off premises and into the wide area. It has long been accepted that in the typical business environment, about 80% of the traffic remains local and about 20% traverses wide area links. But this rule no longer applies to most companies, with a greater percentage of the traffic going into the WAN environment [COHE 96]. This traffic flow shift places a greater burden on LAN backbones and, of course, on the WAN facilities used by a corporation.Thus, just as in the local area, changes in corporate data traffic patterns are driving the creation of high-speed WANs. Digital Electronics The rapid conversion of consumer electronics to digital technology is having an impact on both the Internet and corporate intranets. As these new gadgets come into view and proliferate, they dramatically increase the amount of image and video traffic carried by networks. Two noteworthy examples of this trend are digital versatile disks (DVDs) and digital still cameras. With the capacious DVD, the electronics industry has at last 16 CHAPTER 1 / DATA COMMUNICATIONS, DATA NETWORKS, AND THE INTERNET found an acceptable replacement for the analog VHS videotape.The DVD has replaced the videotape used in videocassette recorders (VCRs) and replaced the CD-ROM in personal computers and servers. The DVD takes video into the di gital age. It delivers movies with picture quality that outshines laser disks, and it can be randomly accessed like audio CDs, which DVD machines can also play. Vast volumes of data can be crammed onto the disk, currently seven times as much as a CDROM. With DVD’s huge storage capacity and vivid quality, PC games have become more realistic and educational software incorporates more video. Following in the wake of these developments is a new crest of traffic over the Internet and corporate intranets, as this material is incorporated into Web sites. A related product development is the digital camcorder.This product has made it easier for individuals and companies to make digital video files to be placed on corporate and Internet Web sites, again adding to the traffic burden. 1. 2 A COMMUNICATIONS MODEL This section introduces a simple model of communications, illustrated by the block diagram in Figure 1. 2a. The fundamental purpose of a communications system is the exchange of data between two parties. Figure 1. 2b presents one particular example, which is communication between a workstation and a server over a public telephone network. Another example is the exchange of voice signals between two telephones over the same network. The key elements of the model are as follows: †¢ Source.This device generates the data to be transmitted; examples are telephones and personal computers. Source system Destination system Source Transmitter Transmission System (a) General block diagram Receiver Destination Workstation Modem Public telephone network (b) Example Modem Server Figure 1. 2 Simplified Communications Model 1. 2 / A COMMUNICATIONS MODEL 17 †¢ Transmitter: Usually, the data generated by a source system are not transmitted directly in the form in which they were generated. Rather, a transmitter transforms and encodes the information in such a way as to produce electromagnetic signals that can be transmitted across some sort of transmission system .For example, a modem takes a digital bit stream from an attached device such as a personal computer and transforms that bit stream into an analog signal that can be handled by the telephone network. †¢ Transmission system: This can be a single transmission line or a complex network connecting source and destination. †¢ Receiver: The receiver accepts the signal from the transmission system and converts it into a form that can be handled by the destination device. For example, a modem will accept an analog signal coming from a network or transmission line and convert it into a digital bit stream. †¢ Destination: Takes the incoming data from the receiver.This simple narrative conceals a wealth of technical complexity. To get some idea of the scope of this complexity, Table 1. 1 lists some of the key tasks that must be performed in a data communications system. The list is somewhat arbitrary: Elements could be added; items on the list could be merged; and some items repr esent several tasks that are performed at different â€Å"levels† of the system. However, the list as it stands is suggestive of the scope of this book. The first item, transmission system utilization, refers to the need to make efficient use of transmission facilities that are typically shared among a number of communicating devices.Various techniques (referred to as multiplexing) are used to allocate the total capacity of a transmission medium among a number of users. Congestion control techniques may be required to assure that the system is not overwhelmed by excessive demand for transmission services. To communicate, a device must interface with the transmission system. All the forms of communication discussed in this book depend on the use of electromagnetic signals propagated over a transmission medium. Thus, once an interface is established, signal generation is required for communication. The properties of the signal, such as form and intensity, must be such that the signal is (1) capable of being propagated through the transmission system, and (2) interpretable as data at the receiver.Not only must the signals be generated to conform to the requirements of the transmission system and receiver, but also there must be some form of synchronization Table 1. 1 Communications Tasks Transmission system utilization Interfacing Signal generation Synchronization Exchange management Error detection and correction Flow control Addressing Routing Recovery Message formatting Security Network management 18 CHAPTER 1 / DATA COMMUNICATIONS, DATA NETWORKS, AND THE INTERNET between transmitter and receiver. The receiver must be able to determine when a signal begins to arrive and when it ends. It must also know the duration of each signal element.Beyond the basic matter of deciding on the nature and timing of signals, there is a variety of requirements for communication between two parties that might be collected under the term exchange management. If data are to be exchanged in both directions over a period of time, the two parties must cooperate. For example, for two parties to engage in a telephone conversation, one party must dial the number of the other, causing signals to be generated that result in the ringing of the called phone. The called party completes a connection by lifting the receiver. For data processing devices, more will be needed than simply establishing a connection; certain conventions must be decided on.These conventions may include whether both devices may transmit simultaneously or must take turns, the amount of data to be sent at one time, the format of the data, and what to do if certain contingencies such as an error arise. The next two items might have been included under exchange managem