My father had told me that I should consider first my budget

I am so excited in buying my first car. Can’t wait to drive it! As I was browsing through catalogues and asking friends and family I’ve learned that there are factors that I have to consider in purchasing a car. I thought it was as easy as buying a chocolate bar at the store. My father had told me that I should consider first my budget. What’s the budget I’ve allotted for my car? It was only then that I had thought about it. It seems that my budget won’t match the car I’ve dreamed of buying.So my father told me to think of the other factors, such as, look for a car that would fit my budget. Next is the quality of the car, like the engine and the body; and lastly are the features of the car. What I did was look through the catalogues and brochures again. Write on a piece of paper the features I like and the kind of engine that fits my lifestyle. On the other side are the features of the cars I’m looking at. Cross out the things that I d on’t like, and left out what I like and the things that match them.It was only then that I was able to choose the car that I’ll be purchasing. But there are three choices left, which I really have to think about and consider. I again consulted my father about it to finalize my decision. He told me to go and check out the cars that are in my list, â€Å"Once you’re there and check them you’ll know which one is for you. † And I did went to check the cars out. I wasn’t able to see the third choice for when I saw the second car I knew it was for me.As if it was calling me, when I approached it to check out the seats, the interiors and engine, I didn’t waste any time at all and spoke to the car salesman. That afternoon I negotiated with the salesman and was able to purchase the car less than my budget. I felt so accomplished and victorious. The salesman told me to go back after a few days for the car. I called my father while I was walking out of the office, telling him what happened. He was just laughing while I was talking.I kept on talking as if I didn’t hear he was laughing on the other line. When I was finished he said, â€Å"That’s what I was telling you. Now you know what I was saying. And I can say that you’re too proud and happy that you were able to purchase your first car on your own. † When I heard that I just nodded and said, â€Å"Thank you very much, Dad. I love you. † It was such a fulfilling feeling that, I won’t forget that experience. I go with the same process every time I would purchase something. I’ve learned a lot from my father.

Sustainability and Green House Gases

B. You will hold to take a Sustainability/relevant study of a Vietnamese/Multinational company from any one of the undermentioned industries. 1. Electrical and Electronicss 2. Airlines 3. Plastic 4. Agricultural Merchandises REQUIRED: You are required to analyze the chosen study and to compose a study non more than 800 words. Your studies is expected to cover the undermentioned standards 1. Extent of revelation ( Quantitative and Qualitative inside informations ) 2. Format of revelation 3. Carbon coverage criterions adopted by the company 4. Evidence of societal audit in the study, if any Corporate Social Responsibility is a direction issue whereby companies integrate societal and environmental concerns in their concern operations and interactions with their stakeholders. Samsung extremely focuses on uninterrupted betterment and bring forthing enduring returns to stockholders by keeping best pattern in CSR as a seaport for capital and endeavor in the market place, a nurturer of the environment, a developer of communities and a supplier of chances at the workplace. Net Gross saless by Business of Samsung increases 31 % from 2012 around four state such as Americas, Asia, Africa, and China. Samsung Electronics maintains four major types of merchandise including consumer electronic, it and nomadic, semiconducting materials and show panels. Company invested KRW 24.1 trillion for the betterment of production line public presentation in 2013. Furthermore, Samsung invested KRW 536.3 billion to local communities. True and just fiscal coverage, care of sound internal control systems and appropriate hazard direction model, proper precaution of the Group ‘s assets and bar of fraud and other abnormalities are purely committed by the Board. Besides, the company seek their best in convey quality information to investors, regulators, clients, providers, employees and general populace as timely and transparently as possible. There is a web site where employees can give feedback and study fraud or abnormalities from unethical concern of Samsung Electronic s’ employees. The website operates in English, Nipponese, Chinese, and Spanish, and involves 69 locations around the universe with 14 linguistic communications. hypertext transfer protocol: //sec-audit.com is the nexus of website whereby employees can incorporate with company. In workplace country, they perceive that long-run success will be determined by human resource therefore they guarantee a healthy and safe working status, invest in professional growing by supplying preparation and development plans and earnestly see just wage and staff benefits. They prevent hurts and occupational wellness jeopardies by supplying preparation and awareness plan for employees. All employees at all ages, gender, race, faith, nationality and instruction have equal opportunity to boom at common environment. Depending on the place, all staffs can take part in developing plan to better abilities. Loyalty grasp, retirement and public presentation awards are organized to enter employees’ attempt and advance other to seek. In general, Samsung continues to keep their first-class revelation in coverage, in conformity to the Global Reporting Initiative ( GRI-G3 ) model for Sustainability Reporting. They show the uninterrupted betterment in societal and environment concern by supplying extra information where possible. Under CSR study, companies provide a positive image to communities by taking duties in chief countries such as environment market place ( green direction model such as C describing criterion ) , communities and workplace. Samsung Electronics’ GHG emanations reached 2.23 dozenss of CO2 ( Less 0.15 dozenss compare with mark 2.38 dozenss CO2 ) in 2013. However, the decreases in GHG emanations is larger with mark measure is 3.90 million dozenss ( 88.59 million dozenss ) . ( Appendix 1 ) Samsung Electronics receives enfranchisement for about exemplary merchandise ( amount 40 theoretical accounts ) including nomadic phones, proctors, Personal computers, and air conditioners, and parts like LED and semiconducting material memories from participates in KEITI’s C labeling. On the other manus, Samsung received the Low Carbon Product Certification for two air purifier theoretical accounts ( cut down C emanations by up to 32 per centum to heighten energy efficiency ) in February 2014. Samsung Electronics received a Carbon Footprint label for two merchandises ( Galaxy S2 and Galaxy Note 2 ) in 2012 with planetary certification. Up to now, there are seven merchandises has been received a enfranchisement from the Carbon Trust. In the side of merchandises and services quality, they comply with all legal demands and topographic point best quality in their merchandises and services by following ISO 14001 and OHSAS 18001. Besides, company besides received the ISO 50001 enfranchisement for energy direction systems at all operation site. To realize the societal part, Samsung set an attempt of quality instruction, occupation chances, and health care were identified as the highest precedences. At the beginning from 2013, company has operated societal part into five cardinal plans ( Samsung operates 383 Smart Schools and wasted KRW 32.8 billion, and wasted KRW 6.5 billion to run 23 Tech Institutes, vocational support plans for young person, puting 11.7 billion for Tomorrow plan and 6.7 billion for the Care Drive plan, 4.4 billion for The Nanum Village plan ) . Corporate societal duty plays a cardinal function in the hereafter development of the company and society. Making CSR, Samsung can convey positive image of the company to society and make stable hard currency flow and work force. On the other manus, it can be a portion of the sensed value in merchandises and services ensuing in higher client satisfaction. degree Celsiuss.Write a brief study on GHG emanations and its relevancy to concern in non more than 250 words. GHG emanations have been hold of import function in making concern. The planetary heating and the lateness in cut downing GHG emanation in the company ( Entire emanations that must be reduced to militate against clime alteration ) kept serious effects to the stable development. Furthermore, GHG can emission straight from the mill and indirectly influence to the procedure of bring forthing authorization. There are seven green house gas ( GHG ) emanations such as Carbon dioxide ( CO2 ) , Methane ( CH4 ) , Azotic oxide ( N2O ) , hydro fluorocarbons ( HFCs ) , per fluorocarbons ( PFCs ) , and hexafluoride ( SF6) and nitrogen tri fluoride ( NF3) . ( Appendix 2 ) All emanations are entered the ambiance or were born from the firing fossil fuels, or by the decay of organic waste in municipal solid waste landfills or during making in agricultural and industrial activities. There are some ways to cut down and command the GHG emanations are represented as followers:Provide C describing criterio n ( the gaining control and storage engineerings ) , ( Appendix 3 )Raise the efficient of authorization,Protect and heighten the reservoir emanations,Promote the agricultural and industrial activities to develop sustainability,Use the merchandise can be recycled, andReduce through methane by recycling every bit good as in bring forthing, bringing, and administering empower.If the GHG emanations have non been controlled by the company, it may be lead to destruct the environment. Hence, company should establish on the criterion for GHG emanations to command and pull off the emanation as possible. Mentions hypertext transfer protocol: //www.samsung.com/us/aboutsamsung/sustainability/sustainabilityreports/ hypertext transfer protocol: //www.samsung.com/us/aboutsamsung/sustainability/sustainabilityreports/sustainabilityreports2014.pdf hypertext transfer protocol: //www.samsung.com/us/aboutsamsung/sustainability/sustainabilityreports/download/2014/18_Environmental_Report.pdf hypertext transfer protocol: //www.epa.gov/climatechange/ghgemissions/ Appendix 1 GHG KPIs and AccomplishmentsKPIDescription200820092010201120122013Korea GHG emanations decreases relative to sales* ( ton CO2 /KRW 100 million )Goal–6.855.654.622.872.38Performance7.445.835.114.462.542.23Reduction ( % , compared to 2008 )–2231404753Global accumulated decreases during product-use stage.Goal––1,1692,6955,1088,469Performance––1,5293,2925,8348,959Appendix 2 The first interview expert can be an academic/researcher on Global warming/environmental scientific discipline. We carried out the first interview with Nguyen Thuy Trang who is pupil at IS-VNU. From the interviewer, we collected some information about the Global heating /environmental scientific discipline. She told that there are seven emanations for green gas: Carbon dioxide ( CO2 ) , Methane ( CH4 ) , Azotic oxide ( N2O ) , hydro fluorocarbons ( HFCs ) , per fluorocarbons ( PFCs ) , and hexafluoride ( SF6) and nitrogen tri fluoride ( NF3) . Furthermore, she assumed that company in heavy industry ( Infrastructure, empower ) , agricultural and forestry through more emanations enter the ambiance. On the other manus, she told us some stages to command and pull off GHG emanations. She commented that if the GHG emanations are non controlled cause by destructing environment. Appendix 3 The 2nd interview conducted with a professional from an audit/accounting house or caputs of Sustainability accounting subdivisions. We carried out the 2nd interview with a individual who is Le Minh Tu, work at State Audit of Vietnam. We had one meeting to interview her some inquiry about the function of GHG study in making concern. She told us the importance of C coverage to any concern and the international Carbon Reporting Standards and some duties in Vietnam to understand extent of C coverage. She convinced that a successful company that carry out the GHG Protocol Corporate Standard by strong and recognized method. Company uses the certification of Carbon Trust Standard to pass on with client. Based on C pes printing to cut down cost and put mark.Furthermore, the C study helped company recognizes the chance to cut down cost and hazard in making concern. hypertext transfer protocol: //www.carbontrust.com/resources/guides/carbon-footprinting-and-reporting/mandatory-carbon-reporting

Basant Should Not Be Banned

Basalt should be allowed to celebrate as it has now become a part of our peoples culture, heritage and lifestyle and nobody has a right to ban them. Basalt is deeply rooted in peoples psyche and lifestyle. Most the public are not only against the ban on Basalt but also are offended by this government decision. Main E]AZ, acting district coordination officer during the Decos absence said, Basalt should not be banned because It attracts people from all over the world and is a cultural event. He lamented about grave problems caused by Basalt but said that the public was unwilling to support a ban (All 7). Basalt has been in our tradition from a long time and has become a custom and very important part of our lives. But there are some people especially elisions ones who raise the point of Basalt being a Hindu festival and demand a ban on it. Actually this is not the case; this is Just wrong accusation made by these people to show their importance in the community. The Hindu festival which these people refer is Vacant Panoramic which is also called Basalt. Vacant Panoramic is the Hindu festival that highlights the advent of spring. It is a Hindu festival celebrating the glory of Shirtwaist, the goddess of knowledge, music and art. In India particularly Indian Bengal, during this festival children are taught to write their first words; Brahmins are fed; ancestors worship (Pit-tartan) Is performed; the god of love Kamikaze Is worshipped ( Manhood). The festival Hindu celebrates only Limits to worshipping, wearing same color clothes and meeting each other. There Is no sign of kite flying In their festival.So our tradition Is different from theirs. This means that to say this festival Is UN-locals Is a wrong statement. Basalt Is a huge and a big festival which Is recognized all over the world. It Is a sport which mainly exists In Pakistan but Is well known to all the rest of the world. It Is a colorful festival consisting not only of tie flying but also of music. People gather together to enjoy and celebrate the arrival of spring. Basalt is also a way of attracting tourists not only national but also international.According to the newspaper reporter, Hasty Sadder, It attracts tourists, not just locally but from all over the world (7). Because of the uniqueness of Basalt, Tourism Development Corporation of Punjab, the Basalt Kite Festival, held in Lahore, has become such a major tourist attraction that people flock from countries worldwide to participate in this unique occasion. The increase in tourism due to Basalt in turn boosts the economy of Pakistan. It provides different sources of income to the country; through hotels, restaurant and others ways.Another reason why Basalt should not be banned is the amount of revenue generated from it is enormous. There are several ways in which revenue is generated during the Basalt. Thousands of people travel and visit Pakistan to Join in the festival. The revenue from the hotels greatly increases during Basalt because of the increased tourists. Kite flying is not the only way of generating revenue. During the festival a lot of events sake place such as musical events and food streets are Jammed packed with people. The intense economic activity that went with Basalt (trade, travel, hotel, tourism, shopping, etc. ) was touching the $ 250 million mark ? not bad, for a week-long celebration. To top it off various other quality festivals started around the Basalt bonanza (notably the music conference and the international drama and puppet festival) (Mira 3). However, there is some opposition and criticism about the Basalt being not profitable, rather resulting in losses due to damages done on the electric wires and poles.According to All Prevail, a newspaper reporter, Basalt also faced opposition from Water and Power Development Authority (WPAD) and its distribution companies mainly the Lahore Electric Supply Company (LESSON) and Granular Electric Power Company (COP) as kite flying also resulted in frequent power tripping besides damaging the sensitive installations of WPAD and its companies. The main cause of this power failure is the use of metallic or chemical- coated string. These strings, when comes contact with electric wires causes the wire to tear and power tripping.But this is a problem which can be easily resolved. By introducing and properly implementing a law which impose a ban on the use of such types of strings can result in overcoming this power failure and claims made by these companies. Kite flying business is a very large one. The industry related to it is very large with a very large market. About a week or two before the Basalt, shopkeeper starts to make preparations of selling kites and strings. Huge numbers of shops are set up and people invest millions of rupees in the trade. Many people are employed in the factories in which kites and strings are made. String and kite makers are irking overtime on roadsides and in small factories in places like Shadier, Murdered, Buchannan, Chair and Shadbush. Kite making has become a sort of cottage industry involving even women and children the year round (Hanoi). So if Basalt is banned, thousands of workers will get unemployed. There would be no source of income for such families and they would be in a very bad condition. For example, during the Basalt the owners of the previously abandoned and dilapidated houses in Glissandos food street become rich overnight as many multi-national companies hustle to rent their rooftops for the occasion.The ban on Basalt would affect them along with other in the kite flying business very roughly. The main incidents that lead to the ban on Basalt were the use of the metallic and chemical- coated strings. Basalt was officially banned in 2005 when a great deal of people in various cities including Rawlins lost their lives due to metallic or chemical-coated issue regarding the ban was the damages that these razor-sharp strings caused. Many people lost lives by getting their neck cut by strings while driving motorcycles or walking. But banning is not the solution. Government should restrict the use of these types of strings.Also during these two days of kite flying, government should set a curfew on the people walking and driving motorcycles because most of the accidents happen to them. The government should alternatively provide free public bus transport during these days to accommodate people who want to travel. In conclusion, Basalt should not be banned as it creates revenue for a country and most importantly is a part of our culture. To ban Basalt is Just like erasing an integral part our culture which is unacceptable. Yes, there have been many unfortunate incidents in the recent past but banning Basalt because of them is not the solution.For example, no government has banned flying of aircraft because some planes have crashed in the long history. They rather focused on making flying a safer experience. Likewise, the government should focus on making this festival safer by reducing loss to life and property to minimum and nil if possible. Designated grounds should have been prepared for flying kites and citizens who wish to participate in the activity should have been facilitated to do so in safety in these designated areas. Banning a festival which was like the smile of a child in spirit is too harsh a step ?akin to rendering the city soulless (Sadder 7).

Apple Essay Example | Topics and Well Written Essays - 500 words - 2

Apple - Essay Example Verganti describes Job’s management style as â€Å"management by meaning† because of the scope of Job’s managerial decisions and objectives that focused on establishing value for both clients and employees (Verganti 2011, p. 1). The management approach identifies people’s psychological and social aspects and seeks to create meaning to people though incorporating their â€Å"rational, cultural, and emotional dimensions† (Verganti 2011, p. 1). This defines an abstract management approach that transcends a variety of management and leadership styles with the aim of meeting clients and employees’ needs. Jobs, especially after being asked to resign from Apple’s top management, incorporated democratic, visionary, and transformational management styles that he applied according to situations and desired meanings to be created (Dhima, Qorri, Arapi and Sinani 2011, p. 7). Christopher also offers an account of Job’s transformational leade rship style in the company and identifies him among top visionary leaders and managers of the period (Christopher 2012, p. 357). Job’s management style and its development from an experience in his career suffered a setback proved a success and led Apple to an innovative era. The diversified approach to Job’s management identifies effectiveness to meeting his ultimate objective of maximizing utility among employees and customers and the three incorporated management styles, democratic, transformational, and visionary management styles, succeeded in meeting employees needs towards output that generated products for customers’ utility. The transformational management style benefited Jobs’ approach because of its ability to empower and motivate employees towards achieving desired objectives. The developed potentials among employees and their desire to deliver culminated to the realized innovation and development of new products at Apple. Visionary managerial style, with its

Water Pollution Essay Example | Topics and Well Written Essays - 750 words

Water Pollution - Essay Example Limitation of fresh water is an ever growing danger, despite water being a renewable resource. Agriculture, according to environmentalists, affects lakes, rivers, and other important estuaries. On the other hand, most agricultural operations are counter-productive to the growth of most crops because of different varieties of water pollution (Maude 129). It is because of contamination of sediments, bacteria emanating from animal manure, and nitrogen from fertilizers. These comprise some of the agricultural factors interfering with most fresh water bodies. Availability of fresh water bodies in most parts of the globe also signify the renewability of the resource for consumption by the human population. For instance, 2.53 percent entails the entire fresh water spread across the globe. It demonstrates the limitation is growing gradually because of human waste and pollution (Maude 139). The wastage of 2 million tons daily, according to a U.N. report, projects danger as opposed to the accusations that agriculture is the central cause of water pollution. Potentiality of climate change and extreme pollution caused by depositing of industrial refuse into water bodies is another example of effects on fresh water bodies often ignored. The World Water Report has distributed figures in regards to nations that will suffer from water problems in the future. It places the figure at 2 billion per 48 nations or 7 billion for 60 countries without factoring the implications of agriculture in the overall problem.

Aristotle & Hume Term Paper Example | Topics and Well Written Essays - 1500 words

Aristotle & Hume - Term Paper Example Passion is a feeling which has no boundaries, if aroused naturally and authentically in an individual. Hume understands the concepts and elements of life as he is a deep thinker and has contemplated on life and human psychology in various ways. Here the intention is to comprehend the statement of Hume and interpret it with one of the greatest Greek philosophers the world has seen, Aristotle. The view of Aristotle is distinctive and unique and can be contradictory or resembling to that of Hume. The attempt here is to argumentatively interpret the statement by Hume and convey how Aristotle would converse regarding this issue. Passion being a natural feeling cannot be influenced or affected by other qualities or personality traits of human being. People can analyze the feeling and reciprocate on it in varied ways, but it really depends on the philosophical perspective and reasoning ability of a philosopher. Here the perspective and argumentative stand of Hume and Aristotle would bring a bout more of depth to the thinking ability and philosophical values of both. Arguments Passion is natural and contradictory to reasoning Aristotle, as an intellectual thinker and philosopher, connects virtue to feelings. Passion is an aggressive and intense feeling of human being. Aristotle was of the opinion that with intellectual thinking intellectual virtues like wisdom, reasoning and intellectual skills are connected; on the other hand, moralistic virtues are related to one of the component of soul where feelings reside. If a person holds a pure soul, then he would be morally ideal and realistically passionate. Passion is attached to soul; it is a feeling arising from the inner most depth of a human soul and heart. A person who possesses high intelligence needs not necessarily have a passionate soul or heart. According to Morgan, â€Å"[f]or when the beings are of different kinds, the parts of the soul naturally suited are of different kinds, since the parts possess knowledge b y being somehow similar appropriate† (Morgan 307). It is normally observed that a person with intelligence and a high reasoning ability focuses more on analytical facts and gives importance to brain faculty rather than desire. Here we can understand that Hume’s ideology and Aristotle’s perspective match in a positive manner. Aristotle would totally agree with Hume and would proclaim that passion in no way can be combatted by reasoning. Reasoning is a quality of physical body whereas passion is both spiritual and physical and can surpass reason in all manners. Aristotle would postulate the fact that passion, as a strong feeling, could change a man’s thinking and reasoning ability to a great extent. Aristotle would further suggest that a man who is passionately evoked cannot be tethered by reasoning or intelligence as he is completely surrendered to the soul. A soul is the ultimate powerhouse of a human being, and when enslaved to soul, no intelligence can r ule the mental status of a person. Reason is an egoistic value and passion a natural feeling Aristotle, being a soul lover, would comment to Hume that soul is the universal energy, and nothing in the world which is related to ego can fight with it. Passion is the essence of a soul, and a man, being a soul enriched being, can be overwhelmingly overtaken by passion. Reasoning is a component of soul, but it is not a moralistic virtue even though it is a virtue. Aristotle would continue that all virtues are not idealistic, and

Organisational Behaviour Literature Review Example | Topics and Well Written Essays - 1250 words

Organisational Behaviour - Literature review Example In this situation, it is the duty of company to motivate them and make them work in the previous pace. They might think of themselves as victims who would work on whatever the organizations assign them to do as they consider it as the company’s grace. If the employees work in this state of mind then it would be very difficult for organization to achieve the objective of downsizing (Wagner, 1991). However, a smaller proportion of people take it as exciting and career expanding because they become optimistic about themselves, optimistic in a way that there must be some extraordinary quality in them; this did not let them go out of the organization. Nevertheless, one cannot deny that larger proportion of people is always in fear and organizations must take some impactful steps to bring them on the right track. Alcoa Inc. an aluminum producing company faces the same situation during many mergers and other developmental efforts. It is one of the largest creators of air pollution in united states proving to be harmful for many human lives therefore it became urgent and serious for it to take a step. Alcoa therefore invested $330 million in a plant to help reduce the emissions such as nitrogen dioxide and sulfur dioxide. As one can see that $330 million is not small amount of money, therefore they must have thought of implementing downsizing in the company making many of their employees leave the jobs. Moreover, in 2006 installed a new plant in its branch of Swansea again requiring a huge amount of money generated by reduction in administrative costs. A joint venture of Alcoa and Alumina Limited might have caused the need for downsizing too. All these instances left Alcoa’s remaining employees with a low morale and spirit to work and managers with a great worry and apprehension of low productivity. However, one should not lose hope keep striving to achieve the best. Firstly, knowing the reasons that make employees not feel easy after downsizing would be a great help in understanding their emotions and treat them in view of that. One of the reasons is that they do not have interest in learning new skills because they assume that this will increase their workload. Naturally, no one likes to work more than he was doing earlier with a good salary. However, organizations need to change this behavior of employees buy assuring them that new skills will work in their favor, making them more profitable for the company and provide them with more chances of personal growth in the industry. Additionally, they would get more compensation with higher profits ultimately building their self-esteem and self-security. In any case, employees should feel that they contribute in the growth and development of the company this would stimulate them to work more passionately and ardently. Another reason of breaking of trust and emotions of employees is that they have lost some of very close colleagues and friends. Some might feel guilty that some of their friend lost their jobs because they were give preferences over them. All these problems occur because different people react differently towards change. Some have difficulty in accepting the change; others will find great opportunities behind them. Change, which is demolishing for ones, might prove to be exciting for others. Some express their anger and frustration, while others fight with it silently. Some get release after complaining whereas others talk a lot but actually are encouraging the

The math behind the Pendulum Research Paper Example | Topics and Well Written Essays - 2250 words

The math behind the Pendulum - Research Paper Example As the period of a pendulum is constant, pendulums were used to regulate the movement of clocks. Until the 1930’s pendulums were the most accurate time keeping devices of the world. In 1583, the Italian scientist Galileo first noted the constancy of a pendulum’s period by comparing the movement of a swinging chandelier in a Pisa cathedral with his pulse rate. He found that the time was not a function of how wide the chandelier swung. As the wind was blowing the chandelier, it was swinging different distances side to side or amplitudes. Galileo found that the pendulum swung more slowly. Over a shorter swing, the chandelier took just as many of his heartbeats to complete a swing with greater amplitude. Galileo made an error in the calculation of the angle of the chandelier. In 1656, the Dutch mathematician and scientist Christian Huygens invented a clock controlled by the motion of a pendulum (Huygens and the Pendulum, Princeton). The accuracy of mechanical clocks improve d in the span of a couple of decades in the early 17th century from plus or minus half an hour per day to one second per day. This quantum increase in accuracy of timing enabled previously unimagined degrees of precision measurement in mechanics, astronomy and other fields of study. Time then for the first time was expressed as an independent variable in the investigation of nature. For example, each of the following could be reliably investigated for the first time: The effect of force on objects over time The distance of fall over time The change of speed over time The radial movements of planets over time The progress of chemical reactions over time All these investigations required that the time could be accurately and reliably measured. Thus the pendulum held a very important place as a time keeping device. Competent time measurement was a requirement for modern science and the pendulum enabled this to happen (Story behind the science, Web). The pendulum played more than a scie ntific and technical role in the formation of the modern world. It also indirectly changed cultures and societies through its impact on navigation. Position on the Earth’s surface is given by latitude and longitude. A traveler sailing across the sea must know the coordinates of his present position as well the coordinates of his destination. Hence the knowledge of position was essential for reliable traveling and trading. Accurate time measurement was long seen as the solution to the problem of longitude determination which had vexed European maritime nations in their efforts to sail beyond Europe’s shores. Treasure fleets from Latin America, trading ships from the Far East were all getting lost and running out of food and water. The pendulum thus played a pivotal role in resolving the longitude problem and thus holds an important place in Physics as well as History. This thesis will focus on the interesting aspects about the period of a pendulum and its mathematical d erivation. According to Hooke’s law, the restoring force of a spring is directly proportional to its displacement. Fig 1: Physical representation of Hooke’s law The above figure shows a spring elongated through a length x. F is the force that wants to drive the spring back to equilibrium. By Hooke’s law, |F| ? |x| F = -kx where k is the spring constant measured in Newton/metre (N/m) Here, the negative sign represents that the direction of F is opposite to that of x. Moving further on, consider the case

Lab#7 Beam Analysis Using Photoelastic Methods Lab Report

#7 Beam Analysis Using Photoelastic Methods - Lab Report Example Photoelasticity method is depended on the birefringence property that is shown by the transparent materials. Birefringence involves the property in which light rays are passed through a birefringent material of two refractive indices. This property has been seen in different optical crystals. When the stress is applied, the photoelastic material will show the birefringence property. The potential of the refractive index in each material section would be directly linked to the stresses in the given point. The term photoelasticity is a reflection of nature in this technique. Photo means the utility of light rays together with the optical techniques. Elasticity shows the elastic body deformation and stresses study in elastic bodies. In this respect, light rays are classified as electromagnetic vibrations that do travel in the form of waves. The vibrations are linked to the light that is perpendicular to the light travel direction or the propagation. The source of light gives out a wave train that contains the vibrations in planes that are perpendicular. Through the introduction of the polarized filter in the travel path, a single component of the vibrations would be transmitted using the filter considered being parallel to the axis. The organized light is referred to as polarized light. When anotherpolarised filter referred to as the analyzer is put on its way, there would be a total light beam extinction of the beam of light which can be obtained if the two filter axis is perpendicula r to one another. In many cases, light may travel in a vacuum or through air at a speed equivalent to 3 x 10 ^10 cm/sec. For the different transparent materials, the light speed v is minimum. In this case, the ration n=C/V is referred to as the refraction index. In bodies that are homogenous, the index would be constant despite the travel direction and the plane vibration. For the bodies that are homogenous the index is depended on the become optically heterogeneous

Remote Monitoring and Control System Essay Example for Free

Remote Monitoring and Control System Essay Remote Monitoring and Controlling System Based on ZigBee Networks Soyoung Hwang and Donghui Yu* Department of Multimedia Engineering, Catholic University of Pusan, South Korea {soyoung, dhyu}@cup.ac.kr Abstract Thanks to the rapid development of information technology and the growth of the Internet through high speed networks, network environments have even been changed from office oriented environments based on business industries and public institutions to the interconnection of digital electronics in home networks. Home network based applications are very diverse and the remote monitoring and control areas have been studied. Recently, ZigBee has become one of the most promising technologies for home networks. ZigBee is a specification for a suite of networking, security and application software layers using small, low-power, low data rate communication technology based on IEEE 802.15.4 standard for personal area networks. Moreover, owing to the rapid growth of mobile technology, highperformance smartphones are widespread and in increasing cases are utilized as a terminal device. In this paper, we propose the design and implementation of a remote monitoring and controlling system using ZigBee networks. This system targets a home network. Web services and a smartphone are used for the client system to monitor and control the home. Keywords: remote monitoring, ZigBee networks, remote control, smartphone, web service 1. Introduction Thanks to the rapid development of information technology and growth of the Internet through high speed networks, network environments have even been changed from office oriented environments based on business industries and public institutions to the interconnection of digital electronics in the home networks. Home network based applications are very diverse and the remote monitoring and control areas have been studied. Recently, ZigBee has become one of the most promising technologies for home networks. ZigBee is a specification for a suite of networking, security and application software layers using small, low-power, low data rate communication technology based on IEEE 802.15.4 standard for personal area networks. There have been various studies on ZigBee based home networks. To realize remote home automation based on ZigBee, implementation issues of home gateway and device nodes are proposed in [1]. It presents hardware platform consideration and software implementation for each of them. Similarly, hardware design issues are discussed for various home devices such as wireless communications transceiver modules base, USB expansion base and control switches for electrical appliances in a room [2]. Also, an effective architecture for dynamic integration of ad hoc ZigBee home network devices into OSGi (Open Service Gateway Initiative)-based home gateways is discussed. An ad hoc ZigBee home network device is represented by a device proxy service in the proposed architecture so that it can be dynamically registered, discovered, accessed and unregistered just like a common OSGi service [3]. [4] gives a way to construct ZigBee wireless sensor networks and implement remote monitoring and control by a GSM module. [5] describes the structure composition of the smar t home system based on ZigBee and gives a system design concept and implementation approach. Moreover, owing to the rapid growth of mobile technology, highperformance smartphones are widespread and in increasing cases they are utilized as a terminal device. In this paper, we propose design and implementation of a remote monitoring and controlling system using ZigBee networks. This system is targeting the home network. Web service and a smartphone are used for the client system to monitor and control the home. The remainder of this paper is organized as follows. In Section 2, IEEE 802.15.4 and ZigBee specifications are discussed as background technologies. Section 3 describes design issues of remote monitoring and controlling systems. Next, implementation results are included in Section 4. Finally, we conclude this paper in Section 5. 2. Background Technologies 2.1. IEEE 802.15.4 IEEE 802.15 is a working group for the standardization of WPAN (Wireless Personal Area Network). IEEE 802.15.4 is one of the seven task groups which are included in it. The first edition of the 802.15.4 standard was released in May 2003. IEEE 802.15.4 specifies the physical layer (PHY) and media access control (MAC) for low-rate WPAN. WPANs are used to convey information over relatively short distances. It focuses on low-cost, low-speed ubiquitous communication between devices. Unlike wireless local area networks (WLANs), connections effected via WPANs involve little or no infrastructure. This feature allows small, power-efficient, inexpensive solutions to be implemented for a wide range of devices. The basic framework conceives a 10-meter communication range with a transfer rate of 250 kbit/s. Important features include real-time suitability by reservation of guaranteed time slots, collision avoidance through CSMA/CA and integrated support for secure communications. Devices also include power management functions such as link quality and energy detection [6]. Several standardized and proprietary network layer protocols run over 802.15.4-based networks, including IEEE 802.15.5, ZigBee, 6LoWPAN, Wireless HART, and ISA100.11a. Potential application areas include the following: sensors, actuators, interactive toys, remote control, industry networks, home automation and so on. 2.2. ZigBee ZigBee is a standards-based technology that addresses the unique requirements of most remote monitoring and control and sensory network applications. ZigBee builds upon the physical layer and medium access control defined in IEEE 802.15.4 for low-rate WPANs. The specification goes on to complete the standard by adding four main components: network layer, application layer, ZigBee device objects (ZDOs) and manufacturer defined application objects which allow for customization and favor total integration. The initial markets for ZigBee included Consumer Electronics, Energy Management and Efficiency, Health Care, Home Automation, Telecommunication Services, Building Automation, and Industrial Automation. The core ZigBee specifications define smart, costeffective and energy-efficient mesh networks. It is a self-configuring, self-healing system of redundant, low-cost, very low-power nodes. ZigBee is available as two feature sets, ZigBee PRO and ZigBee. Both feature sets define how the ZigBee mesh networks operate [7]. 2.3. Home Network Technologies A home network is a residential local area network (LAN) for communication between digital devices typically deployed in the home, usually a small number of personal computers and accessories, mobile computing devices, mobile phones, digital TVs, PDAs and so on. An important function is the sharing of Internet access, often a broadband service provisioned by fiber-to-the-home or via Cable Internet access, Digital Subscriber Line (DSL) or mobile broadband by Internet service providers (ISPs). In a broader sense, it includes software and services for integration and operation of information appliances in addition to wired or wireless network devices. Home networking technologies can be classified into two kinds: wired and wireless. The telephone, power-line, Ethernet and IEEE 1394 exist as wired home network technologies. As wireless home network technologies, wireless LAN, HomeRF, HyperLAN, Bluetooth, UWB (Ultra Wide Band) and ZigBee are representative. Since wireless networking solutions based on the spread of mobile devices have emerged they can be applied to home networks also. 3. Design of Remote Monitoring and Controlling System This section deals with the design of remote monitoring and controlling systems. To design a system, we considered a home automation network. The system architecture is presented in Figure 1. Figure 1. System Architecture The system consists of a real-time home monitoring sub-system and a light control subsystem. A home server with a home camera caters for home status through video to client. It also works as a home gateway to provide interoperability between the heterogeneous ZigBee and Internet and local and remote control over the home’s light devices through the light control sub-system. A client can access the home server through a web service or smartphone. The client can monitor home status through a real-time monitoring sub-system and control the lights through the 3.1. Real-time Monitoring Sub-system The real-time monitoring sub-system captures images of the area of the home to be monitored and serves the client who accesses the server through the web or a smartphone. Figure 2. Operation Processes of Real-time Monitoring Sub-system Figure 2 shows the operation process of the real-time monitoring sub-system. The server finds a video device and captures images. Then, it generates captured data and transforms the data format for RTP communication. After that, it generates the session manager and streams media data to the client. A client using the web or a smartphone generates the session manager and connects to the server. Then, it receives media data and displays the video. In this way, the client can monitor the in-home status in real-time. 3.2. Light Control Sub-system Light control sub-system is composed of a server which works as a gateway, ZigBee coordinator, end-device, switch node and a light as shown in Figure 3. The operation of the sub-system is as follows. ï‚Ÿ A client program maintains a user interface which contains an on/off control panel. ï‚Ÿ A server which works as a gateway receives control commands from the client and relays the command to the ZigBee coordinator through the RS-232C serial communication. ï‚Ÿ The coordinator relays the control command which is received form the server to the end device through RF communication. ï‚Ÿ The end device receives the command from the coordinator and controls the port of the switch node. The switch node controls the switch of the light. ZigBee based remote controlling can be applied in several ways. In this paper, we considered a simple light control and adopted it for a remote control sub-system. 4. Implementation Results In this section we discuss implementation results of a real-time remote monitoring and controlling system. The server contains a web-cam and the monitoring and controlling programs are implemented using Java. Web-based remote monitoring with video capture, data encoding and RTP communication are implemented using JMF (Java Media Framework) which is a multimedia extension API of Java. A client using web service can access the server after user authentication. Of the ZigBee networks, we use two Chipcon CC2420DB evaluation boards with CC2420s (IEEE 802.15.4 radios) accompanying Z-Stack [8, 9, 10]. One is configured as a coordinator and the other is configured as an end-device. When the coordinator starts, it initializes all internal ports and waits for control commands from the home server. If the home server sends a control command to the coordinator through the serial communication, the coordinator receives the command and sends it directly to the end-device through RF communication. The end device receives the control command from the coordinator and controls the switch node. Figure 4. Implementation Result using Web Service Figure 4 shows the implementation results using web service. A client can access the server after user log-in. The client can monitor the rooms status and control the lights. In the figure, the client turns off the light. The implementation results using a smartphone are shown in figure 5. The client program is implemented on the android platform. Figure 5. Implementation Result using Smartphone As shown in the results, a client can monitor the in-home status in real-time and send light control commands using the control button on the smartphone. 5. Concluding Remarks Recently, the home environment has seen a rapid introduction of networked digital technology. This technology offers new and exciting opportunities to increase the connectivity of devices within the home for the purpose of home automation. Moreover, with the rapid expansion of the Internet, there is the added potential for the remote control and monitoring of such networked devices. ZigBee has become one of the most promising technologies for home networks. ZigBee is a specification for a suite of networking, security and application software layers using small, low-power, low data rate communication technology based on IEEE 802.15.4 standard for personal area networks. Moreover, owing to the rapid growth of mobile technology, highperformance smartphones are widespread and in increasing cases they are being utilized as a terminal device. This paper proposes design and implementation of a remote monitoring and controlling system based on ZigBee networks. Real-time remote monitoring is implemented with JMF which is a multimedia extension API of Java. The remote controlling is implemented using ZigBee networks. The client program in a smartphone is implemented on the android platform. Clients can monitor their homes and send light control commands using the web or a smartphone. This system can be applied in many areas such as elderly protecting systems, cultural heritage or forest fire monitoring systems, managing systems for agricultural cultivation and so on. As a future work, we consider expansion of the system using various sensors and actuators. References [1] Z. Shunyang X. Du, J. Yongping and W. Riming, â€Å"Realization of Home Remote Control Network Based on ZigBee†, Proceedings of the 8th International Conference on Electronic Measurement and Instruments, (2007), August 16-18, Xian, China. [2] A Fang, X. Xu, W. Yang and L. Zhang, â€Å"The Realization of Intelligent Home by ZigBee Wireless Network Technology†, Proceedings of the 2009 Pacific-Asia Conference on Circuit, Communications and System, (2009), May 16-17, Chengdu, China. [3] Y. Ha, â€Å"Dynamic Integration of Zigbee Home Networks into Home Gateways Using OSGi Service Registry†, IEEE Transactions on Consumer Electronics, vol. 55, no. 2, (2009). [4] J. W. H. Qin, â€Å"The Design of Wireless Intelligent Home System Base on ZigBee†, Proceedings of the 11th International Conference on Communication Technology, (2008), November 10-12, Hangzhou, China. [5] D. Yan and Z. Dan, â€Å"ZigBee-based Smart Home System Design†, Proceedings of the 3rd International Conference on Advanced Computer Theory and Engineering, (2010), August 20-22, Chengdu, China. [6] IEEE 802.15.4: Wireless medium access control (MAC) and physical layer (PHY)specification for low-rate wireless personal area networks (WPANs), (2006). [7] ZigBee Specification,(2008), Document 053474r17,ZigBee Alliance. [8] Figure 8 Wireless, ZigBee Implementer’s Guide, (2005). [9] Figure 8 Wireless, Z-Stack User’s Guide for the CC2420DB Board, (2005). [10] Figure 8 Wireless, Z-Stack/Z-Tool Serial Port Interface, (2005).

Gigabit 10 Gigabit Networking Applications

Gigabit 10 Gigabit Networking Applications Ethernet Ethernet technology refers to a packaged based network that is most suitable for LAN (local area network) Environments and includes LAN products of the IEEE 802.3ae. 10 Gigabit Ethernet standards which is an up gradation on all other earlier versions, works on an optical fibre and operates in full duplex mode (Held, 1996). The IEEE 802.3ae is an upgraded version of the IEEE 802.3 base version developed as early as 1980. Ethernet technology originated nearly 30 years ago as a least expensive high-speed LAN based option (Ferrero, 1996). Ethernet defines the CSMA/CD protocol and is currently used in major LAN-based settings. Ethernet has the advantages of low implementation cost, simplicity and ease of installation and maintenance, reliability and compatibility with LAN based networks. Almost all Internet traffic generates and terminates with an Ethernet connection, which has been adapted for higher speeds and the volume of traffic over the Internet. Ethernet technology is rapidly changing and the new 10 Gigabit technologies maintains certain older characteristics like package format and at the same time adapts itself to faster connections, higher speeds and more efficient handling of internet traffic. The newer versions of Ethernet like the Gigabit Ethernet and10 Gigabit technologies have wide-ranging applicability in LAN, WAN,MAN and SWAN (Axel son, 2003). We will discuss these points in greater detail in the dissertation beginning our discussion with a brief description of Ethernet technology, its history, modes of operations, Gigabit architecture and applications and the rise of the 10 Gigabit technology in Ethernet applications. In our final analysis we will analyse the uses of Gigabit technology and the advantages involved. We would also discuss the market demands as far as setting up the new technology in business and enterprises is concerned and conclude with a final short summary giving the prospects of Ethernet and Gigabit Ethernet in this information savvy New Age. Ethernet Technology: Ethernet tends to connect computers using hardware that could be used on different linking machines and workstations. It differs from the Internet because the Internet connects remotely located computers with telephone or cable line or a software system. Ethernet uses software but connects in LAN on the basis of hardware and the Ethernet patent is referred to as the Multipoint data communication system with collision detection. Ethernet was the first technology that could connect through LAN hundreds of computers located in the same region or building(Spurgeon, 2000). Ethernet technology can be used on optical fibre and twisted cables and it operates on a half-duplex and in recent versions, full duplex mode. There are three major varieties of Ethernet and these are Gigabit Ethernet, 10Base T Ethernet and Fast Ethernet that supports data transfer rate of 100mbps. Ethernet uses a star or bus topology and supports a data transfer rate of 10 mbps. The CSMA/CD protocols aroused to handle simultaneous demands and workloads. The newest Gigabit version supports a transfer rate of 1000 megabits per second and thus has a speed of a 1000mbps. Ethernet is the most widely used LA standards. Ethernet specifications are used in IEEE 802.3 standard software and specify physical software layers within the system. Ethernet is used in nearly 90% of LAN workstations and LAN-connected PCs in the world (Lee and Lee 2002). Although Ethernet is the most popular physical layer of LAN technology that is in use, the other common LAN types include the Token ring, Fibre Distributed Data Interface (FDDI), Local Talk, Asynchronous Transfer Mode or ATM, Fast Ethernet, a more advanced variety of Ethernet and Gigabit technology. Ethernet helps in giving a high-speed connection along with the ease and convenience of installation and maintenance. Ethernet applications and installation are comparatively inexpensive and it has wide applicability and compatibility with LAN and other widely used networks but LAN is the most popular compatible networking. Ethernet inacceptable in the computer market and supports all popular network protocols making Ethernet the ideal networking technology for all computers used at present. The Ethernet standard is set at IEEE 802.3,deriving its name from the Institute of Electrical and Electronic Engineers (IEEE), which defines this, standard. An adherence to the standards can ensure the efficient communication and links between the networking equipment’s and the networking protocols. The IEEE standard802.3 defines the rules for configuring an Ethernet network and also specifies how the elements in an Ethernet network can actually interact with each other. Brief History about Ethernet: Ethernet originated nearly 30 years ago when Xerox corporation used an experimental coaxial cable network with an original transfer rate of just 3 mbps using a CSMA/CD (carrier sense multiple access/collision detect protocol that could be used in then existing LAN and that could support some heavy traffic. This experimentation and development of the first Ethernet technology received some attention and around 1976-1980,DEC (Digital Equipment Corporation) and Intel joined Xerox Corporation to develop a LAN architecture that supported a data rate of 10 mbps. This was the Ethernet version 1.0 specification and the original version of IEEE 802.3 was also based on this initial Ethernet version specification. The draft of IEEE 802.3 version received its approval in1983 and was specified as an official standard by the IEEE in 1985.Ethernet and IEEE 802.3 and all versions of these are ultimately compatible, derived from and improved versions of this basic version of original Ethernet technology. A number of supplemental versions and technologically upgraded and advanced versions have been used to support higher data transfer rates. Thus Ethernet technology saw gradual development with a gradual LAN technology development in the1970s to the formation of IEEE subcommittee and approval of Ethernet version IEEE 802.3 later declared as standard in the 1980s. This was upgraded further with the development of Fast Ethernet and an associated speed of 100 mbps in 1995 with the final 1000 mbps Gigabit standards approved in the middle of June 1998. Ethernet Explained: A general description of what is Ethernet and how it works can be given as Ethernet seems to be based on the idea of a group of people within the same location and on the same network sending messages through a radio system and using a common wire or channel and this has been referred to as ether, a supposed medium that 19th century physicists believed helped in the propagation of light. Each member in the system seems to have a 48-bit key MAC address assigned to the network-interface card and this makes sure that all systems within the Ethernet network have their own distinct addresses. As Ethernet is found and available and compatible nearly everywhere with wide ranging applicability, manufacturers tend to build the functionality of an Ethernet card directly into PC motherboards, which are printed circuit boards used in personal computers, also known as main boards. In the initial stages of its development and discovery, Ethernet used shared coaxial cable, which was found in the building attached to every connected machine brought within the system. All computers in a building were connected to an attachment unit interface (AUI)transceiver and this in turn connected to another cable. A simple passive wire was used for small Ethernets and was considered not quite applicable to large extended networks as any damage to the wire could actually make the Ethernet segment dysfunctional. Within the Ethernet technology, the systems are run in such a way that all communications between PCs, happen along the same wire, and information transmitted bygone computer is received by all computers in the network even if the information was meant to go only to one computer or specific destination. The interface card of the network filters out all information that is not originally addressed to the entire network and the CPU is interrupted when applicable packets are received. This information sharing by all computers is considered one of the weaker points of the shared medium of Ethernet since any node within the entire network connected by the Ethernet can dig out information that seems to have been originally meant for a single location. Thus all traffic within the single wire used for the technology, can be intercepted and manipulated. A single cable thus has its ups and downs because not only is there an information security risk with such networking, the bandwidth is also shared so after a power failure or are start, traffic can crawl to a point that it can cause a slowing down of information transmission and data transfer due to too much crowding within a single wire. The computers with an Ethernet connection networking share the channel using the CSMA/CD technology that stands for Carrier Sense Multiple Access with Collision Detection. The CSMA was first developed and used for ALOHA net in Hawaii and is comparable to token Ring and master controlled networks we have discussed here. An algorithm is generally followed when the computers transmits data and there can be several commands from start, transmitting, end transmission, wire busy, to wire idle and transmission stopped or maximum transmission attempts exceeded. In this way, a medium, the Ethernet is chosen through computers try to transmit information. When there is too much traffic, there is an apparent cessation of these attempts, which renews again after a random period of time. This aid in avoiding collision and an exponential increase of back-off times are used when there is more than one failed attempt of transmission. Depending on the type of medium used Ethernet segments can have restricted size. A 10BASE5 coax cable can only have a maximum length of500 metres. An Ethernet repeater can be used to have a bigger length cable and this device uses the signal from one Ethernet cable and repeats it into another cable. This way Ethernet repeaters can be used to connect up to five different segments with a maximum three of these devices used as attached devices. Since many segments are connected, cable breakages can be handled more efficiently. Thus when any one of the Ethernet segments breaks off, most of the devices are unable to communicate as connections are broken, however Ethernet repeaters allow the workings of different segments separately which can continue to work despite the cable breakage in one part of the network (Quinn,1997). Ethernet segments can usually be terminated with a resistor at both its ends within the network and as for the equipment’s used, each end of the coaxial cable must have 50 ohm resistor and head sink and this is called the terminator affixed to an N or BNC connector. When resistors are not used, it is usually perceived as a cable breakage and consequences will be such that the alternating current signal transmitted will be reflected and as a reflected signal is indistinguishable from a collision, similar results as in collision will take place with complete cut-off of all communication between the units. When Ethernet repeaters are used electrically different segments can continue to function even in isolation as separate units and this helps in regenerating and retiming the signals (Field, et al 2002). Most repeaters have an auto-partition function and this means they are capable of removing and isolating a segment from service when there are too many collisions, breakages, and traffic or when the collisions last too long. This is done to prevent the other segments from getting affected by such collisions or breakages and once there is a renewal of activities that are smooth and without collisions, the Ethernet repeaters reconnect the unattached segment to the original network. The advantages of using cables in the star Ethernet system has been used effectively by net workers who create Ethernet repeaters with multiple ports known as Ethernet hubs or fan outs that could be connected to other hubs or coax backbones. The earlier hubs were also known as multiport transceivers and DECs DELNI is one such example of an Ethernet fan out. Multiport transceivers allow the sharing of single transceiver by multiple hosts having AUI connections. This also allows the working of a standalone single Ethernet segment that does not essentially require a coax cable. Companies such as the DEC and Synoptic sold many multiport transceivers that could connect many10BASE-2 thin coaxial segments. However, coaxial Ethernet segments have been made obsolete by the development of unshielded twisted pair cables(UTP), which began with Starling and continued with 10BASE-T. The new developed of the unshielded twisted pair variety allowed Cat-3/ Cat-5cables and RJ45 telephone connectors to connect the fan outs to the ends. This further helped to replace the coaxial and AUI cables. Unshielded twisted pair Ethernet takes the termination problem into consideration and every segment is taken separately so that the termination could be built as a hardware component without requiring special and separate external resistor. However despite the development of the star topology, Ethernet networks use a half-duplex transmission access method and also use the CSMA/With minimal cooperation from the hub that deals with packet collisions. Every packet transmitted is sent to every port and node of the hub so what really remains are bandwidth and security problems due to this open information sharing, so to speak. Since the chance of collisions is proportional to the number of transmitters and the data that have to be transmitted, implying that the larger the amount of data sent, the higher are the chances of packet collisions. Modes of Operation: The Ethernet network elements have interconnecting media and network nodes which basically falls into two major classes known as the Data terminal equipment (DTE) which are the PCs, workstations, servers, and are usually the destination or source of data frames often referred toast end stations; the other category of network node is the Data communication equipment (DCE) that are the standalone intermediate devices such as the repeaters, interface cards, modems, switchers or routers (Hancock, 1988). The DCEs are intermediate network devices that receive and forward data frames across the entire network. The traditional Ethernet and IEEE 802.3 variety works in a half-duplex mode. For the other mode of operation as in Full-duplex CSMA/CD is not used. Auto-negotiation is another mode of operation for the Ethernet. Half-Duplex Mode of Transmission/ CSMA/CD Access Method: The Half-Duplex mode of transmission was developed in the original version of IEEE 802.3 Ethernet application and the CSMA/CD is considered as a means by which two or more stations could share common media in an environment that is switch less and does not require arbitration, or assigned time slots to indicate when workstations are ready to transmit information. This means that individual Ethernet Macias capable of determining when it can send a frame. The CSMA/CD access rules are given in the full form of the CSMA/Protocol as it involves Carrier sense multiple access and Collision Detect. Carrier sense implies that each station continuously keeps alert for traffic on the medium to determine when gaps between frame transmissions are seen. ‘Multiple access’ refers to stations that may begin transmission any time they detect that there is no traffic and the network is relatively quiet. Collision detect acronym implies that when there are two or more stations in the CSMA/CD network and if they begin transmitting data at the same instance the streams of bits from each of the workstations will collide with each other and both the transmissions which collide will then become unreadable (Halaby and McPherson, 2000). Each transmitting station should be able to determine and detect that a collision has taken place before the station has finished sending its frame. Each transmitting station then must stop transmitting any further data as soon as a collision is detected and then this workstation must show a state of abeyance in its activity for random length of time determined by a back-off algorithm before attempting to retransmit the frame all over again. In certain situations when two distant stations on the network need to send a frame and the second station does not even begin transmitting until just before frame of the first station arrives. In that case, the collision is detected immediately by the second station yet the first station does not detect it until the corrupted frame signal goes all the way to the station. The time required to detect a collision can reach a twice the time required for the signal propagation between two distant stations on the network situated at farthest points (Quinn,1997). This suggests that the maximum collision diameter and minimum frame length are directly related to the slot time and longer minimum frame lengths translate to longer slot times and larger collision diameters where the shorter the minimum frame lengths are they correspond to shorter slot times and smaller collision diameters. There was growing understanding and need to reduce the impact of collision recovery and the need for network diameters to be large enough to accommodate networks, which are large, sized. The general consensus was to choose the maximum network diameter of around 2500metres, and to set the minimum frame length to ensure that all potentially damaging collisions are reported quickly. This system worked for 10mbps speed of Ethernet but for higher transfer rate Ethernet connections and developers such as the Fast Ethernet, backward compatibility with earlier Ethernet networks were necessary and this involved the inclusion of the existing IEEE 802.3 frame format and error detection procedures as also all the networking software and applications which could run on the 10mbps networks (Quinn, 1997). For all transmission rates, the time required to transmit a frame is inversely related the transmission rate and at 100 mbps, a minimum length frame could be transmitted at one tenth of the defined and original slot time and so any collision that might occur at this time would go undetected. The maximum network diameters used and specified for 10 mbps could not be used for 1000mbps networks. Fast Ethernet networks and connections help in reducing the maximum network diameter by more than 200 meters. This problem is also seen in the Gigabit Ethernet, as there is a decrease in network diameters by a factor of 10to more than 20 meters for 1000 mbps operations. This is however potential hindrance although as a solution the same maximum collision domain diameters were used to increase the minimum frame size adding an extension field to frames shorter than the minimum lengths. Full-Duplex Mode: The full-duplex mode allows the simultaneous two way transmission of data along the same or one link. The full-Duplex mode is an MA capability that allows the two-way transmission of information over point-to-point links. This Full-duplex transmission is functionally much simpler than half duplex transmissions as no collisions, media contentions, schedule retransmissions and extension bits on short frames ends are involved. Since there is a reduction is the procedural complications, more time is available for transmission and there is also a doubling of link bandwidth and each width is capable of supporting full-rate, simultaneous two way transmission of data frames and each transmission begins as soon as frames are ready to send. The main restriction is inter-frame gap between two successive frames that has to be of a minimum specified length. Usually all frames conform tithe Ethernet standard frame formats. Ethernet Types: Apart from the broad varieties of Ethernet types that transmit data at10mbps (Ethernet), 100mbps (Fast Ethernet) and 1000 mbps (Gigabit Ethernet), 10 Gigabit Ethernet and the earlier varieties such as Starling, there can be variations in the Ethernet frame types as well. We give a brief description of Ethernet types below. The earliest and first varieties of Ethernet was the Xerox Ethernet which was the original 3m bit per second Ethernet implementation and had versions 1 and 2(Hall, 2003).The framing format version 2 is stilling use. The other earlier Ethernet application 10BROAD36 is now no longer used although it was one of the earlier standards supporting Ethernet overlong ranges. The broadband modulation techniques are similar as founding cable modems and systems operated on coaxial cables. Starling or 1BASE5 as the first Ethernet implementation on twisted paired wiring and operated at 1mbps speed. This was gradually replaced by the other versions. Among the more recent versions of the 10 mbps Ethernet is the 10BASE5that uses thick net coaxial cables also called thick wire or yellow cable is the original implementation of the 10mbps Ethernet. Transceivers could be connected using a vampire tap and connecting the core and the screen with N connectors. There is a cable that could be used to connect the transceiver to the AUI or Attachment unit Interface. This type of Ethernet can have 5 network segments with 4repeaters, with three of the segments that could be connected to the network. The bus topology is used here and the maximum segment lengths 500 meters with the overall length at 2500 metres. The minimum length between nodes is stipulated at 2.5 metres with the maximum number of nodes per segment at 100. This system is obsolete as of now. 10BASE2 uses the thin net coaxial cable, also called the Thin wire or Cheaper net, a BNC connector and bus topology with a terminator at the end of each cable. The cable specified for its purposes is RG-58 A/U orRG-58C/U with a 50 ohms resistance. the 5-4-3 rule is applicable here meaning like the 10BASE5 Ethernet there are 5 network segments, 4repeaters and 3 of these could be connected to computers. 185-200metres is the maximum length for each segment and each machine uses at-adaptor to connect with a BNC connector. Although signal quality is considerably reduced with each barrel connector, barrel connectors could be added to link the smaller cable pieces in the network. Length between nodes is given at a minimum of 0.5 meters. This is one of the more widely used Ethernet applications. The Starling which was the first Ethernet twisted wire implementation later evolved into 10BASETwhich comprises of 4 wires and two twisted pairs with a Cat-3 or Cat-5 cable of up to 100 meters in length. At the middle of the connection is a hub or switch, which has a port for each node. The 10BASET uses star topology and as we mentioned 2 pairs of unshielded twisted wires. This category of the Ethernet is not subject to the 5-4-3 rule and can use 3, 4 or 5 cables with the best performance given by category 5 cable. The maximum segment length here is 100 meters. Maximum number of connected segments can be nearly thousand. The minimum length between nodes is 2.5 meters. Whereas only1 node can be present in every segment using the star topology, this system uses RJ-45 connectors. 10BASEF is the generic name for 10 Ambits/s Ethernet standards using fibre optic cable extending up to 2 mms in length. The number of network nodes can be 1024 with a maximum segment length of 200 meters. Specialized connectors for fibre optic cables are used here. This has three main varieties: the 10BASEFL is an updated and more advanced version of the FOIRL standard. FOIRL is the Fibre-optic inter-repeater link and the original standard for Ethernet on fibre optic. This Ethernet type is used to connect computers in a LAN setting a task not done mainly due to the incurring costs. This is the most widely used of the 10BASEF Ethernet type. The 10BASEFB that has never been used serves as a backbone between hubs. The 10BASEFP is a star network that does not require a repeater for its connections connect a number of computers with hubs and switches and gets cable distances up to 500metres. The 100BASET is also known as the Fast Ethernet and is a generic term for any of the three standard varieties if Ethernet that transfers data at 100mbits/s over twisted cables up to 100 meters long. These three varieties include 100-BASETX, 100BASE-T4 and 100-BASET2. Fast Ethernet uses RJ-45 connectors and star topology. The CSMA/CD media access issued here. The minimum length between nodes is specified at 2.5 meters. With 1024 maximum number of connected segments possible, the IEEE802.3specification is used. The 100BASETX is a star shaped configuration similar to 10BASE T and uses two pairs of wires and Cat-5 cable to achieve the 100mbit/s speed. 100BaseTX requires category 5 two pair cables and the maximum distance of these is given at 100 meters. The100BaseT4 requires a category 3 cable with 4 pair and maximum distance of these cables is 100 meters. This system uses a Cat-3 cabling and uses all four pairs in the cable limited to half-duplex access methods. As now the popular Ethernet cabling is the cat-5 cabling, his is now considered obsolete. The final variety 100BASEFX is a 100mbit/Ethernet type that uses a multimode fibre. The maximum length specified here is 400 metres for half-duplex connections and 2 mms for full duplex connections to ensure that all collisions are detected.100BASEFX can thus use fibre optic to transmit up to 2000 meters and for this purpose it requires two strands of fibre optic cable. 100VG LAN is also another Ethernet variety that uses star topology, a series of interlinked hubs and RJ-45 connectors. In addition to Ethernet packets this implementation also supports the Token ring packets and has an IEEE 802.12 specification. It requires 4 pairs of category 3 cable wires and the maximum distance covered is 100 metres(Held, 1996). However with a category 5 cable 150 metres could be reached. Additionally the fibre optic can be used to transmit data up to 2000 metres. We next turn to Gigabit Ethernet Technology, which being a new and improved version of Ethernet altogether requires a separate section. Gigabit Ethernet Technology: Also known in its abbreviated form Gibe, the Gigabit Ethernet technology describes the implementation of Ethernet networking and transmitting ate speed of one or more than one Gigabit per second. Gigabit Ethernet is supported with the use of optical fibre and twisted pair cables and the physical layer standards in this category includes 1000BASET. 1 Gaps issued over a category 5 cable with copper cabling and 1000BASE SX issued to attain for short to medium distances over fibre. The first Gigabit Ethernet standard was set at the IEEE 802.3 standard in 1998.Its relatively recent launch suggests that the Gigabit Ethernet is the latest version of the Ethernet, which is the most popular and widely used computing network worldwide (Katsambis, 1998). The Gigabit speed of1000 mbps of raw bandwidth is 100 times faster than the original Ethernet version of 10mbps and its greatest advantages lies in the fact that it is compatible with existing Ethernets and uses the existingCSMA/CD and MAC protocols. Gigabit Ethernet competes directly with ATMas far as market competition is concerned. It is deployed in high capacity backbone network links and for small installations Gigabitspeed is not yet necessary. Gigabit Ethernet has been used in desktop technology in apple computers, Power MacG5, Apples power notebook and is also being built into Pentium boards. One of its desktop features includes professional video editing. Gigabit Ethernet has been outsmarted by the 10gigabit Ethernet technology, which is the fastest Ethernet standard that became fully operational in 2002. Introduction to Gigabit Ethernet Our discussion on Gigabit Ethernet began by providing a brief description of the Gigabit technologies and the main characteristic of this upgraded Ethernet variety. The transceiver used for Gigabit Ethernet is the GBIC also known as the Gigabit Interface Converter. Thebe measures 8.5 mm by 13.4 mm and has a depth of about 50mm. A hot swap standard electrical interface of a one Gigabit Ethernet port can support any physical media including copper to 100 km of single mode fibre. The standard Gigabit Ethernet system operates at 1000 Mbps speed of transfer of information (Norris, 2002). The 802.3z is the standard that describes the specifications for fibre optics for the 1000BASE-XGigabit Ethernet system. The 802.3ab standard describes specifications for the category 1000BASE-T twisted pair Gigabit Ethernet system. This rate the major two varieties of Gigabit Ethernet technologies used. The10 Gigabit Ethernet is a further up gradation and has speeds reaching10000 Mbps. According to Frazier, the chair of the Gigabit Task Force developing the Gigabit Ethernet technology has been challenging and hard work mainly because this new technology aimed at developing a standard that scales the operation of Ethernet networks to 1000 Mbps while retaining the known characteristics that are compatible with Ethernet and that have made Ethernet the dominant-local area network (LAN) technology. The Draft D3.1 of the P802.3z was approved in a letter ballot of thieve 802.3 working group and this was only possible when an approval rate of 75% was obtained from the working group. The protocol layers in802.3 standards are the areas that have been developed and modified in802.3z version (Riley and Braver, 1998). The 100BASE SX and 1000BASE Fibre optic transceiver specifications have already been highlighted here. The 1000BASE-SX specifications for short wavelength laser transceivers uses 62.5 micron fibre and supports multimode fibre optic links of up to 260 meters. The 50 micron fibre can be used to support multimode fibre optic links of up to 550 metres. The 1000BASE Supports installations at longer distances and uses higher cost components with 62.5 micron fibre used for 440 meters and 50 micron fibre on 550 meters. On a single mode fibre, up to 3 mms of fibre optic links are possible. One of the latest technologies 1000BASE-CX that supports copper cabling links of 25 metres, is included in the 802.3zspecification for transceiver technology. Frasier goes on to describe that the Gigabit Ethernet encompasses the new full-duplex Media Access Control (MAC) and the Carrier Sense Multiple Access with Collision Detection (CSMA/CD) MAC. The full duplex operation takes advantage of the contention free access and flexible topologies and the 802.3z used the CSMA/CD MAC to work at an extended range of 1000Mbps. This was done with the aid of a technique known as ‘carrier extension which was added to the CSMA/CD to overcome certain limitations of the algorithm that was based on the rule that the roundtrip messaging time between two workstations could not be higher than that required to transmit the smallest frame. To improve the throughput of Gigabit CSMA/CD LANs, frame bursting was introduced as an optional feature. In the early stages of deployment of the Gigabit Ethernet it is mainly being used to interconnect high performance switches, routers and servers in LAN backbones. The full duplex operating mode is suited for this type for application environment and is favoured over the CSMA/Chalk duplex mode. This also ensures that high performance desktop computers can take advantage of high peak bandwidths of repeating hubs that are cost effective. Frasiers claim also points to the fact that gigabit technology may be more compatible with full duplex rather than half-duplex modes of Ethernet operation. The 10 Gigabit Ethernet is full-duplex technology and the half-duplex access mode cannot be used for its purposes. T