The Outsiders By SE Hinton Essays - Films, The Outsiders, Greaser

The Outsiders by SE Hinton In this book analysis, about the book ?The Outsiders? by S. E. Hinton I will discuss character and plot development, as well as the setting, the author's style and my opinions about the book. In this part of the analysis I will give some information about the subjects of the book, and about the author. The author wrote the story when she was just 16 years old, in the 1950s. The book was successful, and it was sold, and still being sold, in many copies as a young adults novel. There was a movie made about it, and today there are still many schools that use this book in junior high and high schools for English classes. There were plays made about the book too. The Outsiders is about a gang. They live in a city in Oklahoma. Ponyboy Curtis, a 14 year old greaser, tells the story. Other characters include Sodapop and Darry, Ponyboy's brothers, Johnny, Dallas, and Two- Bit, that were also gang members and Ponyboy's friends. This story deals with two forms of social classes: the socs, the r ich kids, and the greasers, the poor kids. The socs go around looking for trouble and greasers to beat up, and then the greasers are blamed for it, because they are poor and cannot affect the authorities. I hope you would enjoy and learn something about the book from reading this analysis. Plot Development The plot development in the book, ?The Outsiders? by S.E. Hinton, was easy to follow. In this part of the book analysis I will give some more details about the plot development. There were no hooks or hurdles in the beginning of the book, the first sentence starts right away with the plot?without any forewords. This is the beginning of the first sentence: ?When I stepped out into the bright sunlight from the darkness of the movie house...? (page 9). As you can see, it goes straight to the point without any prologues or any kind of introduction. The plot development in the middle of the story was sensible and easy to understand. It was clear and simple, and the events have occurred in a reasonable order. The ending of the story was a bit expected. I anticipated the death of Johnny because a broken neck usually means death. The death of Dally was not as predictable as Johnny's death because it was said that: ?He was tougher than the rest of us?tougher, colder, meaner.? (page 19). I did not think that such a tough person would get himself killed because of a death of a friend, although it was said a short time before the death of Dally that: ?Johnny was the only thing Dally loved.? (page 160). The climaxes at the end of the story were the deaths of Johnny and Dally. Here are quotations about the deaths: Johnny's death: ?The pillow seemed to sink a little, and Johnny died.? (page 157). Dally's death: ?He was jerked half around by the impact of the bullets, then slowly crumpled with a look of grim triumph on his face. He was dead before he hit the ground.? (page 162). To conclude I can say that the plot development was simple and easy to understand and to follow. The author organized it in a way that fits the actual content of the plot. Character Development The characters in the book, ?The Outsiders? by S.E. Hinton, were not very heroic?they were just humans?it was easy to believe that this is the way they should be. The characters in the plot give the reader a feeling this can be a true story. The author has created the personality of the characters through the descriptions of Ponyboy?the narrator?and through their actions. Following are some examples of these methods of getting familiar with a character. Here is an example for a description of Ponyboy: ?Steve Randle was seventeen, tall and lean, with thick greasy hair he kept combed in complicated swirls. He was cocky, smart, and Soda's best buddy since grade school. Steve's specialty was cars...? (page 17). The reader can find this kind of descriptions almost everywhere in the story, but especially in the beginning. I

The Detrimental Character Iago in essays

The Detrimental Character Iago in essays In the drama Othello, there is no character in all of Shakespeare's plays so full of deceitful power and poison as Iago. He is envious of Michael Cassio and suspects that Othello has wronged his honor; but his malignancy is all out of proportion even to his alleged motives, through which he shows his ambivalence of nature. Allowing this green-eyed monster, envy, and jealousy, to get the best of him, will ultimately lead to his downfall. During most of the Play, the audience finds itself constantly trying to find a motive for Iagos actions but finds none that can justify him deceiving Othello. Despite Iagos recognizing that, indeed, the Moor is of a free and open nature (1.3.381), he still does despise him. Iago has to be examined closer to discover his motives: of course, he is jealous of Cassios appointment as Othellos lieutenant, and this jealousy is an ultimate irony in itself as he later mocks Othello for his own jealousy, having given in to the green-eyed monster. There are a lso Iagos blatant racial slurs and his obvious hatred towards Othello, as well as his paranoia regarding the supposed infidelity of his wife, And it is thought abroad that twixt my sheets hes [Othellos] done my office (1.3.369). However, the latter excuse may seem less reasonable, considering that Iago also utters later that he believes that Cassio has also slept with his wife. "O, Beware, my lord, of jealousy! It is the green-eyed monster (3.3.195-96)..."If a monster with green eyes were coming at an individual, what would one do? The answer of course, depends on the circumstances of that particular person. Would one permit the green-eyed monster to conquer his or her own mind, and control his or her every move? In this case the green-eyed monster would indeed be jealousy. Iago, for example, was prejudice towards the African American, Ot...

Do memeories hinder or help people in their efforts to learn from the Essay

Do memeories hinder or help people in their efforts to learn from the past and succeedin the present - Essay Example The real power of memories and experiences is they can be used to help us succeed today. A favorite work of literature I often return to is the Outsiders by S.E. Hinton. The entire structure of the book is one long memory of the protagonist, Pony Boy. The tragedies, triumphs and tensions described in the telling of the story all lead to one important point in time. It is the moment that Pony Boy sits down to write the story of his young life. Without these experiences would Pony Boy have been the same person he was when he sat down to tell his tale? If he had not experienced the class conflict, the loss of a friend and the witnessed wasting of life, would he have been as powerful a narrator? Perhaps the real question is would he have had story to tell? Though Pony Boy is a character of fiction, he is real in the sense that all of us need to use our past experiences and memories to help us succeed today. Success for Pony Boy was the writing of his life story in a touching, dramatic wa y. We all have a past that we must use to reach our potential. Every human being has aspirations and dreams. I believe that we experience certain things in our lives that can be stumbling blocks or springboards for accomplishing our dreams. Pony Boy Curtis used tragedy to tell the story of his life. We all have a different story, but a story we all do have. In my life, I can already see that some experiences and failures I have experienced have provided opportunities for me to learn or for me to regress in my learning. When I was a boy, I had a fever that caused swelling in my hands and feet. I was very sick. The doctors warned that if the condition was not brought under control, I would continue to swell-up like a balloon. Although this sounds funny now, at the time it was in-fact a life threatening condition. Up until this time, I was a kid that only ever wanted to watch TV and play video games. My parents would constantly push me out of the house to go play, but I hated it. I was much more interested in movies. Once I got sick, I had to lie in bed for two weeks without moving. My feet did not touch the floor from my bed for this whole period of time. I remember lying there in bed just wishing that I could somehow get up and go run around outside. I was so tired of watching TV after the first week that I didn’t even turn it on after the first seven days. After I regained the use of my feet and hands, I remember spending almost all of my time outside. I remember how good it felt just to have the breeze on my face and the sun shining on my skin. To this day, I am still the sort of person that appreciated the outdoors. This experience taught me that being inside and craving electronic entertainment is not a happy way to live life. I would be a much different person if I had never gotten sick all of those years ago. Our experiences in the past shape who we are today. A final reason I feel the past is important is because a firm understanding and memory of the past is important for keeping us firmly rooted in the present. Another book that I enjoy is George Orwell’s 1984. This book describes a dystopian society that is controlled by conflict, despair and the ever-present Big Brother. The main character, Winston Smith, actually works for the government in 1984. His job is to destroy the evidence of past events that contradict the official party line as told by the government. By controlling the past and the reported happenings of history, the government is

Mexican-American War (i would prefer either domestic or personal level Essay

Mexican-American War (i would prefer either domestic or personal level of analysis ) - Essay Example As such, the move undermined the Mexican population. The master plan focused on the region occupied by the freehold and yeoman farmers. The eventual impact ignited a political hiccup associated to slavery and inhuman practices. Although other levels of analysis can be applied, I believe that the Mexican American war is best explained through a domestic level of analysis. In the year 1898, a conflict between Spain and the United States of America ignited an armed battle between the two countries. Americans managed to gain access into the Latin America, as well as the Western Pacific, by the end of the war. The events resulted in a great territorial expansion from the American authority. The military involvement in the war signified a historical event. As such, America’s image portrayed a self-centered institution operating on self-interest. Additionally, the events attracted the world’s attention as the media documented the details of the entire war. America advanced about 525,000 square miles into the Mexican territory. The incident led to the signing of a treaty agreement that marked the end of the war. The treaty signing redefined American from a national state to a transcontinental state. As such, both parties engaged in diplomatic settlement scheme to end the war. Other documentation of the treaty revealed the onset of colonialism. The colonialism feature paved way for a commercial assumption and resource expropriation (Lynn, 2013). The impact of colonialism in Mexico resulted in obdurate legal disputes over the vast land. These occasions prompted the advent of different theories to explain the superiority of the involved states. Significant changes defined other perceptions of the colonialism. The onset of communication advancement, development of the transport industry resulted in national pride. The Mexicans believed that the American move served a divine ordination in the vast Mexico territory. The Mexican-American war served as an indicator

Estonia Gender Problems Essay Example for Free

Estonia Gender Problems Essay Throughout history, women have constantly struggled for equal rights. However, even after women have gained increased equality in many countries, gender inequality still exists on an international scale. The European country Estonia, in particular, faces a noticeably greater gap between men’s and women’s rights in comparison with its European neighbors. Despite the Estonian Gender Equality Law passed in 2004, sexism and gender stereotypes are still largely prevalent in Estonia’s government and society. The problem of gender inequality has negatively impacted Estonian women in economic, social, and political aspects of life in Estonia. One major result of gender inequality is the limiting of economic opportunities for women. Because of traditional gender stereotypes, Estonian women are believed to be less valuable in the workplace than men. This form of sexism has heavily impacted the ability of women to obtain and maintain employment and salary: â€Å"in the 1990s women’s unemployment exceeded that of men (38.3% of women and 24.7% of men)† (Erickson 278). In addition to the high unemployment rate for women, Estonia’s pay gap (the difference between men and women’s wages for the same job) is currently the highest in Europe: â€Å"women are paid over 30% less than men for the same profession† (Domsch 73). Since Estonian women are economically disadvantaged by unfair employment and salary, many women are forced to become economically dependent on their husbands or fathers. Overall, Estonia’s large pay gap reflects its economic sexism and the detrimental effects of gender ineq uality on women. Gender inequality in Estonia has also led to social prejudice against women. Since Estonia’s incorporation into the Soviet Union, gender roles have been deeply established into Estonian society. These gender roles dictate what women are allowed to do and what small spheres of influence they have on economics, government, and politics. Gender roles have also inevitably led to sexism: â€Å"The relationship between men and women on a societal level represents relationship with unequal power distribution, where men dominate and women are subordinated or under-represented in most spheres of life.† (Morten para. 6). The social dominance of men stems from Estonia’s incorporation into the Soviet Union in 1940. During this period, Estonia’s once Western attitudes and views on gender equality shifted to Soviet-centered beliefs, which emphasized the importance of submissive women who served men. Although the Soviet Union often used feminist propaganda to encourage women to work, women were frequently treated unfairly at home and in society. The gender roles established during the Soviet Union era continue to play a major role in Estonia’s society today. Gender inequality is prevalent in both the household, where men are expected to exert dominance over their wives, and in social gatherings, where women’s opinions are held in lower esteem (Domsch 148). In summary, gender inequality in Estonia has led to social discrimination against women. Another major result of gender inequality is the political prejudice that Estonian women face. After World War II, a period in which Estonia was politically and economically run by women due to a lack of men, the Communist Party reestablished men in the ruling bodies of Estonia. During this period, Estonian women were removed from politics and their political power was undermined. Very recently, some attempts have been made to solve the political gender inequality problem. In 2004, the government passed the Gender Equality Act to ensure that women had equal political power and economic stability (Domsch 127). However, many of the rights guaranteed in the Gender Equality Act were pre-existent in the Constitution of Estonia. In practice, women have yet to see true equality in political or economic aspects. For example, a recent study showed that â€Å"roughly 8% of Estonian government positions are held by women, while only 20% of parliament members are women† (Morten para. 4). The small percentage of women in Estonia’s government directly reflects on the sexism in Estonian politics. Estonia’s male and female populations, though equal in size, are not equally politically represented, as shown by the clearly imbalanced gender ratio in their government. Overall, although small steps have been made toward gender equity, sexism and gender inequality are still widely extant, and have led to comparatively less political empowerment for Estonian women. Although women’s rights have been improved internationally, many countries still face challenges in establishing true gender equality. Estonia currently faces significant problems for women in many major aspects of society. Originating from Estonia’s incorporation into the Soviet Union after World War II, gender stereotypes have negatively affected Estonian women to this day. With one of the largest pay gaps between men and women in Europe, Estonia has a significantly imbalanced gender ratio for employment. Furthermore, sexism has also led to the diminished social and political power of women in Estonian society. Despite the recent improvements that have been made by the Estonian government in the past decade, the economic, social, and political opportunities of Estonian women are still severely limited by gender inequality.

Reflection on Engineering Work

Reflection on Engineering Work PROFESSIONAL ENGINEER Summary Statement These are the competency Units and Elements. These elements must be addressed in the Summary Statement (see Section C). If you are applying for assessment as a Professional Engineer, you will need to download this page, complete it and lodge it with your application. Competency Element A brief summary of how you have applied the element Paragraph number in the career episode(s) where the element is addressed PE1 KNOWLEDGE AND SKILL BASE PE1.1 Comprehensive, theory-based understanding of the underpinning natural and physical sciences and the engineering fundamentals applicable to the engineering discipline Theoretical knowledge gained from studying Renewable Energy Resources , Mechanics of Materials and Heating Ventilation and Air Conditioning was used in the projects. CE 1.2, 2.1, 2.2 PE1.2 Conceptual understanding of the mathematics, numerical analysis, statistics and computer and information sciences which underpin the engineering discipline I used different mathematical equations for the designing of Parabolic Trough. Heating and Cooling load for the Air Conditioning were calculated using load calculation equations. CAMEL software was used to optimize the load and analyze and compare it with manual calculations. CE 1.15, 1.16, 1.17, 1.18, 1.19, 3.8, 3.11, 3.12, 3.21 PE1.3 In-depth understanding of specialist bodies of knowledge within the engineering discipline Knowledge gained in Finite Element Methods and analysis software ANSYS helped to analyze the drop table. CE 2.1, 2.2, 2.10 PE1.4 Discernment of knowledge development and research directions within the engineering discipline Sequential switching of energy resources from traditional fossil fuels to renewable energy resources is seeming eminent. Parabolic Trough is the future of energy sector in energy deficient countries, like Pakistan. CE 1.1, 1.2,1.21 PE1.5 Knowledge of contextual factors impacting the engineering discipline Being aware of the side effects some of fossil fuels have on the environment, helped us to use the environmental friendly Solar power to generate electricity. It reduces the carbon foot print and hence, guarantees a greener and healthier future. CE 1.2, 1.21 PE1.6 Understanding of the scope, principles, norms, accountabilities and bounds of contemporary engineering practice in the specific discipline Being project leader the responsibility laid on my shoulders to ensure successful timely completion of the project. For this I employed Primavera and Microsoft Project software to finish the project within given timeline. CE 1.8, 2.7, 3.5, 3.7 PE2 ENGINEERING APPLICATION ABILITY PE2.1 Application of established engineering methods to complex engineering problem solving Working on renewable energy project incited students and industrialists to use this energy source to power their needs. And I visited them to help them design the projects. CE 1.21 PE2.2 Fluent application of engineering techniques, tools and resources I used the VRV system instead of the Central Air Conditioning as it is more energy efficient and gives more control. I used CAMEL to analyze the manual load calculations and suggest changings in the structure of building. ANSYS was used to analyze the drop table for the drop test. CE 2.2, 2.10, 3.4, 3.21, 3.22 PE2.3 Application of systematic engineering synthesis and design processes In each project I followed the engineering design process i.e. Defined the problem, searched for solution and picked a solution and developed it (Solar Power Plant). At the end, I prepared the report for each project including all experiments in systematic order. CE 1.21 PE2.4 Application of systematic approaches to the conduct and management of engineering projects I used my management skills and software i.e. Primavera and Microsoft Project to keep track of the progress and finish it within given time. CE 1.7, 1.8, 2.7, 3.5, 3.7 PE3 PROFESSIONAL AND PERSONAL ATTRIBUTES PE3.1 Ethical conduct and professional accountability Before the start of each project I made sure that my team follows the predefined guide lines to ensure professional and ethical conduct. Safety talks before every critical activity helped to achieve this goal. CE 1.8, 1.9, 1.20, 2.14 PE3.2 Effective oral and written communication in professional and lay domains I presented my Final Year Project (Solar Trough) in front of project supervisor, Chairman of Mechanical Engineering department and an external examiner. CE 1.21 PE3.3 Creative innovative and proactive demeanour Used economical techniques to select the Concentrated Solar Power technology, which need small absorbing surfaces and large reflective surfaces. Absorbing materials are more expensive than the reflective surfaces. CE 1.10 PE3.4 Professional use and management of information I kept record of all the meetings by writing minutes of meetings at the end of each meeting. Prepared the project reports using all the experimental and theoretical knowledge. CE 1.5,1.8,1.9,2.7,3.5,3.7 PE3.5 Orderly management of self, and professional conduct My leadership skills and professional attitude during my final year project helped me to be leader in next two projects as well. Leading project teams more than once groomed my leadership skills and helped to enhance my professional conduct. CE 1.7, 2.1, 3.5 PE3.6 Effective team membership and team leadership My leadership in the projects was effective enough to finish the projects well in time and in good team spirit. I inspired my team members to work through difficult situations and solve issues without being stressed out. CE 3.5, 2.11,

Analysis Network

CIRCUIT SWITCHING AND PACKET SWITCHING 1) INTRODUCTION Telecommunication networks carry information signals among entities, which are geographically for apart. The communication switching system enables universal connectivity. Switches can be valuable asset to networking[1]. Overall, they can increase the capacity and speed of our network. Every time in computer network we access the internet or another   computer network outside our immediate location, our messages are sent through a maze of transmission media and connection devices.The mechanism for moving information between different computer network and network segment is called switching in computer network[2]. Figure 1: Switched network Long distance transmission is typically done over a network of switched nodes. Nodes not concerned with content of data. A collection of nodes and connections is a communications network. Data routed by being switched from node to node. Nodes may connect to other nodes only, or to stations an d other nodes. Node to node links usually multiplexed. However, switching should not be seen as a cure-all for network issues.There are two different switching technologies which are: 1) Circuit switching and 2) Packet switching. 1. Circuit Switching Circuit switching was the first switching technique have been used in communication network. This is due to easy to carry analog signals. Circuit switching  network establishes a fixed bandwidth channel between nodes before the users may communicate, as if the nodes were physically connected with an electrical circuit. The bit delay is constant during the connection, as opposed to packet switching, where packet queues may cause varying delay.In circuit switching, the transmission medium is typically divided into channels using Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), or Code Division Multiplexing (CDM). A circuit is a string of concatenated channels from the source to the destination that carries an inf ormation flow. To establish the circuits, a signaling mechanism is used. This signaling only carriers control information, and it is considered an overhead. Since all decisions are taken by the signaling process, the signaling mechanism is the most complex part in circuit switching.Each circuit cannot be used by other callers until the circuit is released and a new connection is set up. Even if no communication is taking place in a dedicated circuit then, that channel still remains unavailable to other users. Channels that are available for new calls to be set up are said to be idle. Telephone network is example of circuit switching system. Virtual circuit switching is a packet switching technology that may emulate circuit switching, in the sense that the connection is established before any packets are transferred, and that packets are delivered in order.Unlike with packet switched networks, we cannot just send a ‘packet’ to the destination. We need to establish and la ter terminate the connection. We need to have some way of transmitting control information, we can either do this in band that the same channel we use for data or out of band which is on a seperate dedicated channel. Phone networks used in band signaling a while ago we could control switching and other functionality by playing tones into the telephone. Today in band signaling is considered unsecure and is not used except for compability with old systems[3]. 2. Packet SwitchingPacket switching  is a communications paradigm in which packets are routed between nodes over data links shared with other traffic. In packet-based networks, the message gets broken into small data packets. These packets are sent out from the computer and they travel around the network seeking out the most efficient route to travel as circuit become available. This does not necessarily mean that they seek out the shortest route. Each packet may go different route from the others. Each packet contains a  "header† with information necessary for routing the packet from source to destination.The header address also describes the sequences for reassembly at the destination computer so that the packets are put back into the correct order. Each packet in a data stream is independent. To be able to understand packet-switching, we need to know what a  packet  is. The  Internet Protocol (IP), just like many other  protocols, breaks data into chunks and wraps the chunks into structures called packets. Each packet contains, along with the data load, information about the IP address of the source and the destination nodes, sequence numbers and some other control information.A packet can also be called a segment or datagram. Once they reach their destination, the packets are reassembled to make up the original data again. It is therefore obvious that, to transmit data in packets, it has to be digital data. The packet switching can broadly be divided into two main categories, first is the virtual circuit approach and other is the datagram approach. In the virtual circuit approach to packet switching, the relationship between all packets belonging to the message or a session is preserved. A single route is chosen between the sender and the receiver at beginning of the session.When the data are sent, all packets of transmission travel one after another along that route. The wide area networks use the virtual circuit approach to the packet switching. The virtual circuit approach needs a call setup for establishing a virtual circuit between the source and destination. A call teardown deletes virtual circuit. After the setup, routing takes place based on the identifier known as the virtual circuit identifier. This approach can be used in the WANs, frame relay and an ATM. In the other approach of packet switching that is the datagram approach, each packet is treated independently of all others.Even if one packet is just a piece of a multi-packet transmission, the ne twork treats it as though it is existed alone. Packets in this approach are known as the datagram. The internet has chosen datagram approach to switching in the network layer. It uses the universal addresses defined in network layer to route packets from the source to destination. In  packet-switching, the packets are sent towards the destination irrespective of each other. Each packet has to find its own route to the destination. There is no predetermined path; the decision as to which node to hop to in the next step is taken only when a node is reached.Each packet finds its way using the information it carries, such as the source and destination IP addresses[4]. 2) HISTORY OF CIRCUIT SWITCHING AND PACKET SWITCHING * Evolution of Circuit Switching Switches are used to build transmission path between telephone set on a flexible basis. Without switches, each telephone set would require a direct, dedicated circuit to every other telephone set in order to be able to communicate. This is a full-mesh physical topology network. Such a full mesh network clearly is resource-intensive, impractical and even impossible, as early experience proved.Circuit Switching were developed for voice communications. Contemporary circuit switches provide continuous access to logical channels over high-capacity physical circuits for the duration of the conversation. In January 1878, the first telephone switch went into operation in New Haven Connecticut. Switching technology had advanced drastically over the intervening decades, yet the basic function had remained the same: interconnect users of telephones by creating circuits between them. Every telephone has a line, or circuit, that connects physically to a telephone switch.In the simple case of both the person making the call and the person being called are connected to the same switch, the caller dials the number of the desired person, the switch checks to see if the line is available, and if it is, the two lines are interconnec ted by the switch. The connection is maintained until one person hangs up his or her telephone, at which time the switch terminates the connection, freeing both lines for other calls. Three characteristics of this type of switching, called â€Å"circuit switching,† are important.First, before the two parties can talk the circuit between them has to be created, and it takes time for a switch to check if a connection can be made and then to make the connection. Second, when a connection has been made, it creates a dedicated connection. No other party can reach either party of a dedicated connection until that connection has ended. Three, since switches are very expensive one accounting policy telephone companies implemented to recover their investment was to institute a minimum charge for every telephone call, generally three minutes.For voice calls that lasted many minutes, a minimum charge did not represent a problem. But communications between computers often last less than seconds, much less minutes. It was difficult to image how circuit switching could work efficiently for computer communications when such a system took minutes to make a connection, created dedicated connections so only one person, or party, could be in connection with another party, and had a prohibitive cost structure. Although these issues were generally understood before the experiments of Roberts and Marill in 1965, they were once again strongly confirmed.The experiments also made it abundantly clear that the problems confronting computer communications were not only with the circuit-switching architecture of the telephone system. Host operating system software of the day assumed there was only one Host and all connecting devices were as if â€Å"slaves. † Hosts were not designed to recognize or interact with peer-level computers; the concept of peer-level computing did not yet exist. Thus, in interconnecting two computers, one had to be master and one slave. The problem only became worse if more than two computers wanted to interconnect and communicate.Nevertheless, the problem of Host software was considered to be solvable if a suitable communication system could be designed and made to work. Fortunately, an inquisitive innovative scientist, Paul Baran, had already explored the problems of circuit switching beginning in 1959. By 1962, he had made his concept of a message-based communication system publicly known. Independently, in 1965, an English scientist, Donald Davies reached the same conclusions as had Baran and would coin its name: packet switching. * Evolution of Packet Switching The concept of packet switching had two independent beginnings, with Paul Baran and Donald Davies.Leonard Kleinrock conducted early research and authored a book in 1961 in the related field of digital message switching without explicitly using the concept of packets and also later played a leading role in building and management of the world’s first packet s witched network, namely the ARPANET. Baran developed the concept of packet switching during his research for the US Air Force into survivable communications networks, first published in 1962, and then including and expanding somewhat within a series of eleven papers titled â€Å"On distributed communications† in 1964.Baran’s earlier paper described a general architecture for a large-scale, distributed survivable communication network. His paper focused on three key ideas: 1) the use of a decentralized network with multiple paths between any two points, 2) dividing complete user messages into what he called message blocks (packets), and 3) delivery of this message by store and forward switching. Baran’s study paved the way for Robert Taylor and J. C. R.Licklider, both wide-area network evangelists working at the Information Processing Technology Office, and it also helped influence Lawrence Roberts to adopt the technology when Taylor put him in charge of developm ent of the ARPANET. Baran’s packet switching work similar to the research performed independently by Donald Davies at the National Physical Laboratory, UK. In 1965, Davies developed the concept of packet switched networks and proposed development of a U. K. wide network. He gave a talk on the proposal in 1966, after which a person from Ministry of Defense told him about Baran’s work.At the 1967 ACM Symposium on operating system principles, Davies and Robert bringing the two groups together. Interestingly, Davies had be chosen some of the same parameters for his original network design as Baran, such as a packet size of 1024 bits. Roberts and the ARPANET team took the name â€Å"packet switching† itself from Davies work. In 1970, Davies helped build a packet switched network called Mark I to serve the NPL in the UK. It was replaced with the Mark II in 1973, and remained in operation until 1986, influencing other packet communications research in UK and Europe[5]. 3) COMPARISON BETWEEN CIRCUIT AND PACKET SWITCHINGCircuit Switching: In circuit switching a message path or data communication path or channel or circuit is dedicated to an entire message block during the process of message transmission. The entire bandwidth is dedicated to the said message as it were, and before any data transmission can take place circuit initialisation and setup has to be done to enable or determine the avalaibility of the link as in trying to make a call using the telephon line for voice messaging or even dial-up procedure where you need to establsih that the line is free for use in the first place; and then have the line engaged all through your time of use.All the message travel through the same path and keep the link engaged all the while when the block of message is been relayed or transmitted. In circuit switching, whole of the data travels along a single dedicated path between the two terminals whereas in datagram switching data is divided into packets an d each of these packets are treated indepently and travel along different paths, source and destination being the same. Circuit switching concept is used in Telephony networks where a dedicated line is assigned to particular connection, the connection in this case is permanent during the connection.Considerable amount of bandwidth is wasted in this process and at a time only one way communication is possible. Circuit switching is done at physical layer whereas datagram switching is generally done at network layer. Circuit switching requires the resources to be reserved before the transmission of data but datagram switching doesn’t require such reservation of resources. Advantages: 1. Fixed delays, because of the dedicated circuit – no interference and no sharing. 2. Guaranteed continous service, also because of the dedicated circuit. . Guaranted the full bandwidth for the duration of the call. Disadvantages: 1. Takes a relatively long time to set up the circuit. 2. Dif ficult to support variable data rates and is not efficient for burst traffic. The equipment may be unused for a lot of call, if no data is being sent the dedicated line still remains open. 3. During crisis or disaster, the network may become unstable or unavailable. 4. It was primarily developed for voice traffic rather than data traffic. Packet Switching:In packet switching the block of data is split into small units with each unit having a sequence number attached to it for orderly identification within a given message block and these different units are usaully sent across the available diffrent links or channels of data transmission from one end to the other end point where they arrvive at different times but have to be assembled together in the correct order at this location via the sequence numbers to get out the original message back without any data degredation occuring as a result of the different paths of transmissions from source to destination.Also no single data channel is dedicated to any given message block in the course of transmission as many units of different messages can be multiplexed and then get demultiplexed at their deffferent destinations correctly since there are codes to differentiate each unit of message, resulting to no conflict at all. Packet switching splits messages into small units and transmitting them to destination using different paths while at the same time keeping tracks or maintaining an orderliness of the units for proper and correct reassembling of the units to get the original message back.Packet switching is generally used in Internet data transmmission where we send data without minding if the link is free or not as far as we are connected and the pieces of information that we sent are then split into smaller units and then sent in packets, with each packets switched through different data channel most times and with no loss at the end. The main advantage of packet-switching is that it permits â€Å"statistical mu ltiplexing† on the communications lines. The packets from many different sources can share a line, allowing for very efficient use of the fixed capacity.With current technology, packets are generally accepted onto the network on a first-come, first-served basis. If the network becomes overloaded, packets are delayed or discarded (â€Å"dropped†)[6]. Advantages: 1. Since packet are typically short, the communication links between the nodes are only allocated to transferring a single message for a short period of time while transmitting each packet. Longer messages require a series of packets to be sent but do not require the link to be dedicated between the transmission of each packet.The implication is that packets belonging to other messages may be sent between the packets of the message being sent from one node to other node. This provides a much fairer sharing of the resources of each of the links. 2. The ability to do statistical multiplexing which can exploit the i nherent â€Å"burstiness† in many data applications and thereby enable sharing of the network resources more efficiently among multiple data streams is a major advantage. 3. Pipelining†- This simultaneous use of communications links represents a gain in effieciency, the total delay for transmission across a packet network may be considerebly less than for message switching, despite the inclusion of a header in each packet rather than in each message. Disadvantages: 1. Packets arriving in wrong order. 2. Under heavy use there can be delay. 3. Protocols are needed for a reliable transfer. 4. Not so good for some types data streams. Real-time video streams can lose frames due to the way packets arrive out of sequence[7]. ) PERFORMANCE ANALYSIS Circuit Switching In circuit switching, a unique connection is used to move data between the two end user[8]. â€Å"Circuit-Switched type networks† are most commonly portions of the ubiquitous telephone networks to which we ar e all accustomed. In these networks, which generally transmit voice or data, a pribate transmission path is established between any pair or group of users attempting to communicate and is held as long as transmission is required.Telephone networks are typically circuit switched, because voice traffic requires the consistent timing of a single, dedicated physical path to keep a constant delay on the circuit. Figure 2: Example of circuit switching Figure 3: Public circuit switching network Subcribers: The device that attach to the network. Subscriber loop: The link between the subscriber and the network. Exchanges: The switching centers in the network. End office: The switching center that directly supports subscribers. Trunks: The branches between exchanges. They carry multiple voice-frequency circuit using either FDM or synchronous TDM.Figure 4: Circuit establishment Basic performance equation for a single link in a circuit-switched network: Let’s consider a system with N cir cuits on a single link, with customers arriving according to a Poisson process at rate ? customers per second, and with successful customers having a mean holding time of h seconds, distributed as a negative exponential distribution with parameter ? = 1/h. If a customer attempting a new call finds all the circuits busy, there are no waiting places, so we’ll assume that the customer just goes away and forgets about making the call.Define the state of our system by the random variable K, where K represents the number of customers currently in the system, then K can take on any integer value in the range from 0 to N. With these assumptions, our model is simply a state-dependent queue, with arrival rate (independent of the state), and service rate i when the system is in state K=i. This is known as an M/M/N/N queue: Markovian arrivals, Markovian service time, N servers, and a maximum of N customers in the system. We can draw the following Markov chain diagram to represent the sy stem.When there are I customers the service rate is i , which is due to the fact that there are i customers, each with a service rate ? , so the total service rate is i. Figure 5: Markov chain diagram Under conditions of statistical equilibrium, the solution is: pi=AiN! j=0NAjj! Observe that this is simply a truncated Poisson distribution and also the result depends on the traffic A, and not the specific values of ? and ?. To establish a path in circuit switching three consecutive phases are required: 1. Connection establishment. 2. Data transfer. 3.Connection teardown. Elements of a circuit-switch node (Figure 6): * Digital Switch: Provides a trasnparent signal path between any pair of attached devices. * Control Unit: Establishes, maintains and tears down connections. * Network Interface: Functions and hardware needed to connect digital and analog terminals and trunk lines. Figure 6: Circuit switch element Packet Switching In packet switching, data are broken into packets of fixed or variable size, depending on the protocol used. The performance of packet switching is called best effort performance.If you transmit from sender to receiver, all the network will do its best to get the packet to the other end as fast as possible, but there are no guarantees on how fast that packet will arrive. Figure 7: Example of packet switching Packet switching is used to optimize the use of the channel capacity available in digital telecommunication networks such as computer networks, to minimize the transmission latency, the time it takes for data to pass across the network. It is also used to increase robustness of communication. These layers are introduced to break down the complexity of communications.The top layer (layer 7) is the layer at user level. As the layers go down, they get increasingly primitive. Layer is most primitive from as it is just binary numbers prepared to be transmit to the end node. Seven layers of open systems interconnection models are shown in ta ble 1[7]: Layer Number| Name| Description| 1| Pysical Layer| Deals with physical connection between nodes in network. | 2| Data Link Layer| Maintaining and optimising actual connection. | 3| Network Layer| Deals with communication of data on a network. | 4| Transportation Layer| Sequencing, error detection and optimisation of communication. 5| Session Layer| Controls the communication between applications running on end nodes. | 6| Presentation Layer| Format data and provides syntaxes for application. | 7| Application Layer| Contains management functions. | Table 1: Layers of open systems interconnection model Every packet contain some control information in its header, which is required for routing and other purposes. Figure 8: Packet data format Initially, transmission time decreases as packet size is reduced. But, as packet size is reduced and the payload part of a packet becomes comparable to the control part, transmission time increases.Figure 9: Variation of transmission time with packet size. As packet size is decreased, the transmission time reduces until it is comparable to the size of control information. There is a close relationship between packet size and transmission time as shown in Figure 9. In this case it is assumed that there is a virtual circuit from station X to Y through nodes a and b. Times required for transmission decreases as each message is divided into 2 and 5 packets. However, the transmission time increases if each message is divided into 10 packets[9].The packet switched networks allow any host to send data to any other host without reserving the circuit. Multiple paths between a pair of sender and receiver may exist in a packet switched network. One path is selected between source and destination. Whenever the sender has data to send, it converts them into packets and forwards them to next computer or router. The router stores this packet till the output line is free. Then, this packet is transferred to next computer or router ( called as hop). This way, it moves to the destination hop by hop. All the packets belonging to a transmission may or may not take the same route.The route of a packet is decided by network layer protocols. As we know there are two approaches for packet switching which are: 1. Datagram switching, 2. Virtual circuit swtiching. 1. Datagram Switching: Each packet is routed independently through network which is also called connectionless packet-switching. Datagram packet switching sends each packet along the path that is optimal at the time the packet is sent. When a packet traverses the network each intermediate station will need to determine the next hop. Routers in the internet are packet switches that operate in datagraam mode.Each packet may travel by a different path. Each different path will have a different total transmission delay (the number of hops in the path may be different, and the delay across each hop may change for different routes). Therefore, it is possible for the p ackets to arrive at the destination in a different order from the order in which they were sent[10]. Figure 10: Datagram packet switching Figure 11: Delay in datagram packet switching There are three primary types of datagram packet switches: * Store and forward: Buffers data until the entire packet is received and checked for errors.This prevents corrupted packets from propagating throughout the network but increases switching delay. * Fragment free: Filters out most error packets but doesn't necessarily prevent the propagation of errors throughout the network. It offers faster switching speeds and lower delay than store-and-forward mode. * Cut through: Does not filter errors; it switches packets at the highest throughput, offering the least forwarding delay. 2. Virtual Circuit Switching: Virtual circuit packet switching (VC-switching) is a packet switching technique which merges datagram packet switching and circuit switching to extract both of their advantages.VC switching is a v ariation of datagram packet switching where packets flow on so-called logical circuits for which no physical resources like frequencies or time slots are allocated shown in Figure 12. Each packet carries a circuit identifier, which is local to a link and updated by each switch on the path of the packet from its source to its destination[10]. A virtual circuit is defined by the sequence of the mappings between a link taken by packets and the circuit identifier packets carry on this link. In VC-switching, routing is performed at circuit establishment time to keep packet forwarding fast.Other advantages of VC-switching include the traffic engineering capability of circuit switching, and the resources usage efficiency of datagram packet switching. Nevertheless, a main issue of VC-Switched networks is the behavior on a topology change. As opposed to Datagram Packet Switched networks which automatically recompute routing tables on a topology change like a link failure, in VC-switching all virtual circuits that pass through a failed link are interrupted. Hence, rerouting in VC-switching relies on traffic engineering techniques[6].Figure 12: Virtual circuit packet switching Figure 13: Delay on packets in virtual-packet switching 5) APPLICATION OF CIRCUIT AND PACKET SWITCHING Circuit Switching 1. Plain Old Telephone Service (POTS) The plain old telephone system (POTS) is the largest circuit switched network. The original  GSM  network is also circuit switched. Prior to the existence of new types of networks, all communication systems had to be built based on the existing telecommunications facilities, which were largely oriented to what the common carriers refer to as plain old telephone service, known as POTS.Consequently, even today, in order to use POTS for data communications, it is necessary to use a modem to convert the data to a form suitable for voice-transmission media. The data transmission rate that can be obtained over a POTS connection is typically les s than 64 Kbps. These rates are adequate for text and audio transmission. However, they are not suf? cient for good quality video transmission in real-time. 2. Switched 56 Service Switched 56 service is a dial-up digital service provided by local and long distance telephone companies. For a connection, a data service unit/data channel unit (DSU/CSU) is used instead of a modem.Switched 56 service uses a 64 Kbps channel, but one bit per byte is used for band signaling, leaving 56 Kbps for data. This service allows the transmission of information over one or two twisted cable pairs to multiple points at a data rate of 56 Kpbs. 3. Integrated Services Digital Network (ISDN) The ISDN was designed in the 1980s to offer end-to-end digital connectivity, while providing the required QoS with data rates in the range of Kbps to Mbps over switched connections. In order to provide even higher data rates, the original ISDN was extended to broadband ISDN (BISDN) (Martin, 1985).The ISDN services are provided to users as ISDN interfaces, each comprising a number of ISDN channels. Using 64-Kbps channels, called bearer or B channels, ISDN provides access to the digital network. ISDN provides lower error rate compared to typical voiceband modems and a relatively high bandwidth data channel[11]. Packet Switching 1. VOIP It is becoming increasingly accepted to transmit delay sensitive data through a packet switched network (rather than circuit switched). There are protocols that can create a virtually real-time environment – which, for voice conversations, is sufficient.Voice over IP is essentially a voice signal encoded into a digital format, being sent through a packet switched network (or possibly any other network) using the Internet Protocol (IP). Over recent years there have been standards developed and supported by major companies including ITU-T H. 323. VOIP has a long way to evolve before it is used as widespread as circuit switched networks, but it is well on its wa y. 2. IPv6 The current protocol that is employed almost everywhere IP (IPv4) has come to the end of its useful life. This is mainly because it has run out of addresses to uniquely identify every non-private computer in the world.IPv6 has been deigned to be more efficient than IPv4 and solve the addressing problems that we face at present. Ipv6 will use 128 bits to address nodes, which provides 2128possibilities (roughly3. 4? 1038). It will incorporate a special ‘option mechanism’ to store optional headers in the transport layer (to maximize efficiency by reducing required space). Finally, Ipv6 will have support for resource allocation, allowing packets to be part of a ‘traffic flow’ which will provide better communication of data such as video/voice streams [VOIP]. 6) CONCLUSION In large networks there might be multiple paths  linking sender and receiver.Information may be switched as it travels through various communication channels. Data networks can be classified as using circuit-switching or packet-switching. Packet switching, which forms the basis of the Internet, is a form of statistical multiplexing in which senders divide messages into small packets. The switching centers receive the control signals, messages or conversations and forwards to the required destination, after necessary modification link amplification if necessary. In computer communication, the switching technique used is known as packet switching or message switch (store and forward switching).In telephone network the switching method used is called circuit switching. Circuit switching  is a technique that directly connects the sender and the receiver in an  unbroken path. In the modern and fast paced world, what we are looking for is efficiency, low costs and reliability and packet-switched networks seems to fulfill most of the criteria that the society is looking for. It would only be a matter of time before circuit switching becomes a thing of the past. 7) REFERENCES [1] Stallings, W. , Data and Computer Communications, 7th ed. 1999, Upper Saddle River, NJ: Prentice Hall. [2] Notes. com, C.What is Switching. Available from: http://ecomputernotes. com/computernetworkingnotes/computer-network/what-is-switching. [3] ABC, T. , Circuit Switching. 2005. [4] Jia, S. and G. Wang. Network performance analysis of packet-switching C;sup;3;/sup; system. in TENCON '89. Fourth IEEE Region 10 International Conference. 1989. [5] Wikipedia, Packet Switching, 2012, Wikipedia. [6] Torlak, P. M. , Telecommunication Switching and Transmission. Packet Switching and Computer Networks: UTD. [7] Heng Zheng Hann, C. Y. Y. , Fareezul Asyraf, Farhana Binti Mohamad, Fong Poh Yeee, Circuit Switching vs Packet Switching, C.Y. Y. Heng Zheng Hann, Fareezul Asyraf, Farhana Binti Mohamad, Fong Poh Yeee, Editor, Wikibooks. [8] Gebali, F. , Analysisof Computer and Communication. Switches and Routers2008, New York, USA: Springer. [9] Kharagpur, I. , Switching Techniqu es: Circuit Switching, CSE. [10] Notes. com, C. Datagram Packet vs. Virtual Packet. Available from: http://ecomputernotes. com/computernetworkingnotes/switching/distinguish-between-datagram-packet-switching-and-virtual-circuit-switching. [11] Dr. Farid Farahmand, D. Q. Z. , Circuit Switching. 2007.