2×2 Switch Simulation in Matlaab

2Ãâ€"2 Packet Switch Simulation Using Matlab Interim Report Contention, output-buffer, queuing process, analytical analysis, simulation Student Name: Deniz Ozdemir Email: [email  protected] qmul. ac. u Supervisor: Dr John Schormans Deniz Ozdemir ec09502 Interim report Contents Page 1. 1 Aim 1. 2 Methodology 1. 3 Objectives 2. Background 2. 1 Performance Evaluation 2. 1. 1 Measurement 2. 1. 2 Analysis/Simulation 2. 2 Packet Switched Networks 3. Introduction 4. Theory 4. 1 Queuing Theory 4. 1. 1 Queuing Model 4. 1. 1. 1 Concept of a queuing model 4. . 2 Queuing theory notation 4. 1. 3 The M/M/1 Queue 4. 1. 4 The M/D/1 Queue 4. 2 Switching 4. 2. 1 Switching Concept 4. 2. 1. 1 Internal Link Blocking 4. 2. 1. 2 Output Port Contention 4. 2. 1. 3 Head Of Line Blocking 4. 2. 2 Time Between Arrivals 4. 2. 3 Counting Arrivals 4. 2. 4 The Queuing Behaviour Of Packets In Output Buffers 4. 2. 4. 1 Calculating The State Probability Distribution 5. Analytical /Simulation Results 5. 1 2Ãâ€"2 Swi tch 5. 1. 1 Analytical Results 5. 1. 2 Simulation Results 5. 2 4Ãâ€"4 Switch 5. 2. 1 Analytical Results 5. 2. Simulation Results 5. 3 8Ãâ€"8 Switch 5. 3. 1 Analytical Results 5. 3. 2 Simulation Results 5. 4 16Ãâ€"16 Switch 5. 4. 1 Analytical Results 5. 4. 2 Simulation Results 6. Conclusion 7. Project Management 7. 1 Risk Analysis 7. 2 Gant Chart 8. References 9. Appendix 2 2 2 2 2 2 2 3 3 3 3 3 4 5 5 7 9 9 9 9 11 11 13 14 14 15 15 15 17 19 19 20 22 22 23 25 25 26 28 28 28 28 28 29 1 Deniz Ozdemir ec09502 Interim report 2Ãâ€"2 Packet Switch Simulation Using Matlab 1. Aim Build a simple 2Ãâ€"2 packet switch simulation using Matlab and study its performance 1. 2 Methodology ? Test out simulation on fundamental 2Ãâ€"2 switch element. ? Then expand it. 1. 3 Objectives ? Learn about Matlab. ? Learn about simulation. ? Build simple test model and try it. ? Build 2Ãâ€"2 element in Matlab. ? Simulate results. ? Process results. ? Simulate any new results required. ? Write report. 2. Background 2. 1 Performance Evaluation When networks are designed, the goal of the performance evaluation is that to determine the best effect of the equipment sed. Methods for performance evaluation are measurement techniques , analysis and simulation. [3] 2. 1. Measurement For measurement methods real networks are used for experimentation. The advantage of direct measurement of network performance is that no detail of network operation is excluded but experience hard to test performance limits. Customers won’t like it when you crash the system. [3] 2. 1. 2 Analysis/ Simulation In comparing analysis and simulation, the main factors to consider are the accuracy of results, the time to produce results, and the overall cost of using the method. Advantage of analytical solutions is that they are quite good fit to reality and produces results quickly. However assumptions required to define equations and parameters and they can be very complex. Simulation provides system representation to required precision. However simulation can be time and cost demanding. [3] 2 Deniz Ozdemir ec09502 Interim report 2. 2 Packet Switched Networks In a packet switched network all nodes interconnected by directed links. Packets are routed independently. Packets enter the network at a specific node where they may be queued in a buffer to wait for an outgoing channel to become free. This continued in a hop by hop manner until the packets finally arrive at their destination. Packets may arrive the same destination by taking different routes. That increases efficiency of transmission resources. Also queued packets in the buffer will cause a variable delay and throughput, depending on traffic load. Basic network is shown in figure 1. [1] Figure 1: Packet Switched Network 3. Introduction Contention in a switch affects the performance of a switch. To prevent this some switching techniques are developed. One of the most common switching techniques is the one with output-buffered switch. In this report, queuing process of performance evaluation, for such a switch is done analytically first than simulation analysis is done using Matlab. In the end of the report comparison of two results is done. 4. Theory 4. 1 Queuing Theory Analysis of the queuing process is basic and essential part of the performance evaluation. Because queues are form in a network when there is a high demand on limited resources. 4. 1. 1 Queuing Model Packets arrive at a queuing system to be served for a certain time. If service is not immediately available they wait for service in a storage area (buffer). After a certain length of time, they are served and leave the system. Basic queuing system is shown in figure 2. 3 Deniz Ozdemir ec09502 Interim report Figure 2: Schematic diagram for a single server queuing system [3] Also basic queuing relationship is shown in table below General q=?. W=?. = + Table 1: Basic queuing relationship Single Server ? =?. q=W+? 4. 1. 1. 1 Concept Of A Queuing Model Let N (t) be the number of packets waiting in the queue plus the one who is being served (1,2,3). A series of packets arrive at instants T1

Coastal management

THE LOBBY and several bedrooms parted company with the Holbeck Hall Hotel yesterday, leaving half of the four-star establishment behind. Engineers said heavy rain this spring after several dry summers was the probable cause of the landslip, which has sent sections of the hotel toppling into the North Sea. The north-east wing of the 30-bedroom hotel collapsed into Scarborough's South Bay on Saturday night. Guests had been evacuated early on Friday after huge cracks appeared overnight. The rest of the east wing gave way yesterday, leaving the hotel barely half intact, but what remains is likely to be demolished. Geologists say the east Yorkshire coast, with it's steep clay cliffs, has always been vulnerable. South of Scarborough, the 40-mile stretch of cliffs of Holderness is the fastest-eroding coastline in Europe and is experiencing the worst land-slips for 40 years. But Mr Michael Clements, director of technical services for Scarborough council, said sea erosion was not a factor in the Holbeck landslip. The cliffs below the hotel are protected at their base by a sea wall. The main problem, he said, was probably heavy rain which penetrated layers of sand and gravel in the cliffs, lubricating the clay which had cracked in hot weather. â€Å"There is a long history of cliff movements in the area,† Mr Clements said. â€Å"According to local records, the first Scarborough spa was carried away by a landslide in 1770, while the Holbeck cliffs suffered a major slip in 1912. Cliff stabilisation schemes were carried out further north at Whitby in the 1980's and at Robin Hood's Bay in the 1970's. In the fishing village of Staives, the breakwaters were recently raised. Pressure for further protection has run up against the obstacle of expense. â€Å"The cost of protecting these cliffs is phenomenal.† Mr Clements said. â€Å"The work at Whitby cost à ¯Ã‚ ¿Ã‚ ½3.4 million.† Most developed areas around Scarborough have seawalls but this is not the case further south, where Mr Eddie Knapp, principal engineer of Holderness council, said there had been â€Å"unusually large and particularly worrying† land losses over the past six months. â€Å"The average rate of erosion is 6ft a year but this year it has been up to 65ft in places,† Mr Knapp said. At Skirlington, 65ft of land has recently fallen into the sea, carrying away 23 bases at a caravan park, while 70ft of land has gone at Aldbrough caravan park, leaving 15ft of unfenced land before a 60ft drop into the sea. A family living in a chalet at Atwick, near Hornsea, was rehoused when the cliff edge came perilously close. Mrs Sue Earle, chairman of the Holderness Coast Protection Committee, is to outline local concerns in talks at the Agriculture Ministry today. Mrs Earle, whose farm-house is 30ft from the cliff edge at Cowden, said: â€Å"Now that this has happened in a nationally-known resort, I hope it will help to bring the issue out into the open. Daily Telegraph, 7.6.93 South Coast subsiding as the sea level rises By Christine McGourty, Technology Correspondent PART of the south coast of England is sinking at a rate of almost an inch every five years, according to new research. The find comes from an analysis of tidal measurement data from 1962 until about 1985 by Portsmouth University researchers. The higher tide measurements were thought to be a combination of subsidence and rising sea levels. Discovery of the subsidence à ¯Ã‚ ¿Ã‚ ½ from Portsmouth to Newhaven à ¯Ã‚ ¿Ã‚ ½ follows evidence from around the world that global sea levels have risen by four to six inches over the past 100 years. The subsidence will add to the problems expected from the sea level rise associated with global warming. Sea levels on the south coast are expected to rise by at least eight inches by 2050. Dr Janet Hooke, director of the university's river and coastal environment research group, said: â€Å"Most previous studies showed the subsidence was confined to East Anglia. This is the first analysis to show that parts of the south coast may be subsiding too. The movement may have origins back in the last ice age.† Malcolm Bray, one of the researchers, said at the Institute of British Geographers' annual conference in Nottingham: â€Å"It seems frightening. â€Å"What we're doing now is to work out what it means for the local authorities affected. â€Å"We can't stop flooding à ¯Ã‚ ¿Ã‚ ½ that's an act of God à ¯Ã‚ ¿Ã‚ ½ but we may be able to minimise the impact through coherent local and regional strategies. â€Å"We need to study the coast over longer distances and look slightly further into the future to stop authorities doing something that could have detrimental effects on their neighbours. â€Å"Our research shows that some parts of the coast are independent but many parts are interconnected.† They found the stretch from Lyme Regis to Newhaven could be divided naturally into nine â€Å"coastal cells†. Dr Hooke said: â€Å"Some preventative measures need to be taken now while the opportunity is there. â€Å"We don't want to see building on very vulnerable zones, which could just create problems for the future with flooding and erosion. â€Å"Plans may be needed to manage conservation of wetlands which are particularly vulnerable.† The researchers welcomed the Government's strategy for coastline management, announced last October, and said that more coherent analysis of longer stretches of coastline were needed all around the country. * Navy beans, from which baked beans are produced, could be grown in England if the global temperature rises as predicted in the next century, according to a study. Researchers at Coventry University and Horticultural Research International have found that navy beans could be grown in Hampshire, East and West Sussex and Kent if the temperature rose by just 0.5C in the next century. The climate is too cold at present for navy bean crops and most are imported from America and Canada. Daily Telegraph 8.1.94 Erosion-hit resorts pin hopes on reef of tyres By Richard Spencer and Lynda Murdin RESIDENTS along the fastest eroding coastline in Europe are hoping a plan to dump millions of tyres in the sea as a protective reef will be given the go-ahead by the Government. Villages and the resorts of Withernsea and Hornsea on the Holderness coast in Humberside are in danger of slowly falling into the sea. If the Ministry of Agriculture grants a licence for the trial tyre-reef scheme, it could lead to one of the most ambitious coastal engineering projects in Europe since the Dutch reclaimed its polders from the other side of the North Sea. The area from Hull to the low, muddy cliffs of the Humberside coast has always suffered erosion. Spurn Head, the spit of land which juts out into the Humber estuary, has been washed away and re-formed six times in recorded history, while many villages already lie underwater. But, in the past five years, the pace of change has rapidly increased. Some homes have been abandoned and farmers are seeking compensation for loss of land and buildings. The Humberside trial would submerge a bank of 1.5 million compressed tyres bound with nylon and concrete into a tangle of ropes six or seven metres high, 110 metres long and 60 metres wide. Placed up to 1,000 metres offshore, it would be tested for its stability, effects on local currents and pollution. If it worked, the full scheme could place more than a billion tyres in seven, two-kilometre long strips all the way up the coast. Humberside County Council accepts that such an ambitious project is unlikely to go ahead quickly – possibly not even this decade. In the meantime, the coast depends on smaller schemes under the supervision of Holderness Borough Council. The most recent, at the village of Mappleton, was opened with fanfares four years ago but, while it has saved the village, it has also caused resentment. Other villages say that it has accelerated the rate of erosion elsewhere by preventing the protective sand that drifts down the coast from reaching the beaches. It raised expectations that other schemes could be put in place, hopes the Government dashed in 1993 with a review of policy imposing new environmental and financial demands. The Department of the Environment is expected shortly to approve a controversial à ¯Ã‚ ¿Ã‚ ½4.5 million, 1,000-metre sea wall around the North Sea gas terminal run by BP and British Gas near Easington. A full plan, which would also have protected the village, was turned down by the department. Mr Robin Taylor, Holderness's director of development, said this appeared to be because under the new guidelines schemes had to prove not just â€Å"cost-beneficial† but to be in the national interest. Saving gas supplies probably was, saving villages not. Mr Ambrose Larkham, who owns the Easington Beach Caravan and Leisure Park, is demanding a public inquiry. â€Å"The ludicrous thing is it is almost as cheap to build 1,600 metres while the equipment's there as it is 1,000,† he said. Mr Taylor said: â€Å"The question of why we are protecting the terminals and not the people of the village is likely to become very controversial. The issue is whether we should be protecting multinational companies and not our own residents.† But Mr Geoffrey Twizell, terminal manager for British Gas and himself a resident, said: â€Å"We are happy to contribute to any scheme that meets everyone's aspirations. Nobody would be talking about any protection at all for Easington if it weren't for the gas terminals here.† Daily Telegraph 1.4.95 Essex drops its guard to let nature take its course By A J McIlroy A TACTICAL retreat could be the answer to coastal erosion on the Essex coast, Government engineers have decided. Contractors from the Ministry of Agriculture and English Nature yesterday lowered the sea wall to flood 21 hectares at Tollesbury Fleet on the Blackwater Estuary. The area is being restored to salt marshes intended to absorb the power of waves that have been pounding artificial sea defences. If the experiment succeeds it will be extended along the Blackwater and to other saltwater estuaries. Roy Hathaway, of the Ministry of Agriculture's flood and coastal defence division, said tracts of coastal marshes were lost when drainage engineers in the 17th and 18th Centuries built sea walls to reclaim land for farming. Now, as a result of the gradual rise in sea level, many of the hundreds of miles of sea wall are crumbling. These are costing millions of pounds to repair, a financial burden that is â€Å"becoming increasingly hard to justify†. He said that to encourage private landowners to accept coastal flooding, the Government had written a â€Å"saltmarsh option† into its set-aside programme, the European Union measure to take farmland out of production. In exchange for allowing their land to become inter-tidal again, farmers would receive à ¯Ã‚ ¿Ã‚ ½190 per hectare per year for grassland and à ¯Ã‚ ¿Ã‚ ½500 for arable land. The payments are guaranteed for 20 years. Mr Hathaway said the ministry was working with conservation groups to maximise the gain to wildlife by restoring the salt marshes. Daily Telegraph 5.8.95 SHORING UP THE COASTLINE By John Hodder THE PRETTY little Suffolk town of Woodbridge was snoozing under a cloudless sky, with a soft breeze taking the sting out of the sun. I gazed out over the placid surface of the River Deben. It was midday in midsummer and this was quiet, gentle England at its most benign – the sort of place, the sort of time that makes it hard to feel threatened by anything, let alone the forces of nature. Twenty-four hours later I was on the beach at Dunwich, 20 miles to the north. The conditions were not very different – the same blue sky and hot sun, cooled now by a rather more blustery wind coming off the sea. But here the threat felt very real – probably because here it is very real. Dunwich is at the mercy of the elements, as it has been down the centuries, and the cliffs just carry on crumbling. If the sea is left to its own devices over the next 70-odd years, the shoreline will retreat by about 200 metres. That, at least, is the experts'projection. Projections, of course, are not the same as firm predictions. But they underline what the problem is – in this case, chronic erosion. The first and obvious question is: â€Å"What can be done to stop it?† The second and much more taxing one is: â€Å"Should anything be done to stop it?† Neither question has an easy answer. If Dunwich is not simply to be abandoned to its fate, a difficult balance will have to be struck between its interest and those of its neighbours. Coastal protection is a tricky science. Nobody knows that better than Roy Stoddard. His title is senior engineer (coast protection) with the Suffolk Coastal District Council and it was to pick his brains that I had gone to Woodbridge. His job is to oversee the 30-mile stretch of coastline from Felixstowe to Southwold, an area whose sand and shingle beach is notoriously unstable when pounded by the waves of the North Sea. It has suffered grievously in a series of violent storms this century. The task of looking after it is now shared between the local authority and the National Rivers Authority (NRA), overseen by the Ministry of Agriculture, Fisheries and Food (MAFF). They work closely together and their common enemy is the sea. The approach to coastal protection has shifted significantly over the past 20 years. â€Å"‘Fight against the sea' was the message until the 1970s,† says Stoddard. â€Å"Now we are not trying to fight against it so much as to work with it, using its peculiar ways to destroy its own energy.† That shift in approach is reflected in marked changes in the sort of barriers now being erected to stem the apparently relentless advance of the waves. As a result, the traditional beach scene is changing. For example, the solid sea walls built behind the beach – and the wide promenades that have accompanied them since Victorian times – are now out of favour. Walls merely repel the waves: they do nothing to reduce their speed or power, which is now recognised as the key to the successful preservation of the shor e. Instead, efforts are being concentrated on protecting and building up the beaches themselves. Similarly, a profusion of timber groynes jutting out at right angles into the sea – the time-honoured means of defence and a common sight along this coast – is seen as far less effective than a few large, rock-based structures shaped like fish-tails. The old wooden ones are fine for leaning against while you have your lunch or sheltering behind on a cold, blowy day. But they are not good at sheltering the shore. The main problem with them -apart from their propensity to rot – is that they cannot be made long enough or deep enough to significantly slow down the incoming rush of water. Hence the move towards the new fish-tail variety. A series of these has been built at Clacton, 20 miles to the south of Stoddard's patch. He is now proposing to develop the concept further by building two similar groynes at Cobbolds Point in Felixstowe, using rock and concrete. Despite their size, which might be considered ugly and intrusive, few people dislike them, he says, and the arguments in their favour are compelling. By confronting the sea farther out they do much more to take the steam out of the waves before they reach the shore. And the farther out you go, the more shore you protect by creating two calm areas in the lee of the two wings of the â€Å"tail†. Thus you help to build up a long stretch of sheltered beach. â€Å"Fish-tailed groynes are many times the length of wooden groynes but you only need one about every kilometre rather than one every 20-30 metres,† says Stoddard. â€Å"As well as being more environmentally-friendly because they enable people to walk along the whole beach – something they couldn't do before, at least not without stepping over groynes every few yards. â€Å"They have another advantage over sea walls. If you build them and find they don't work as well as you'd like, you can pick them up and move them. You can't do that with a massive sea wall.† Stoddard sees the introduction of fish-tail groynes as a â€Å"soft-engineering solution† in contrast to the old â€Å"hard† solution of building walls, which is now seen as causing more difficulties than it solves. â€Å"The problem is that whenever you build a hard wall it is almost invariably accompanied by the beach levels falling. The sea is thrown back off the wall and drags the sand and shingle out. Sometimes the wall itself is undermined – you can shore it up but in time the same thing will happen again.† Solid walls are the most concrete (literally) expression of the view that you must at all costs protect the land against the sea. That view is now being challenged. â€Å"You have four options,† says Stoddard. â€Å"Do nothing, hold the line, advance or retreat. Ten years ago the general view was that everything that could be saved should be saved. Now people are far more aware that harsh decisions have to be made.† Such decisions have worrying implications for places like Dunwich. There, to stop the erosion, you would have to start building some form of protective structure along the beach: merely reinforcing the shingle bank is not enough to stop continuing inroads being made into the coast. So why the hesitation over doing something more effective about it? Simply this: the erosion of the cliffs at Dunwich has positive benefits for the beach immediately to the south at Sizewell. Dunwich's loss is thus Sizewell's gain: that is nature's way. It is a conundrum repeated all along the coast. â€Å"If you have got to save the cliffs at Dunwich, you've got to find alternative means of feeding the beach at Sizewell,† says Stoddard. â€Å"In the end, you have to say that there are some places you won't protect – and people have got to come to terms with that.† Such a hard-nosed attitude can stir up fierce emotions, not least because of the way it could affect both the people who live there now and those who would like to join them. Consequently, it has serious implications for local planners. Do you, for example, go on allowing people to build houses near the sea, thus continually extending the number of years that you have to go on protecting that particular bit of coast – probably at someone else's expense? Another issue arousing controversy is the question of compensation for landowners whose land is gobbled up by the sea. At the moment there is no provision for compensation – indeed, it was specifically excluded from the 1949 Coast Protection Act. But as Stoddard says: â€Å"How do you tell a farmer that his 500 acres of productive arable land would be far better as salt marsh? The question of compensation is going to have to be addressed very shortly.† The difficult questions roll in almost as relentlessly as the sea. I pondered them late at night as I walked the beach at Aldeburgh, with the wind strengthening from the north-east and the waves crashing on to the shingle. They were still nagging away later still, as I lay in bed listening to the roar on the shore just below my hotel window. The sound that had been so soothing in the summer sunshine had taken on a darker edge. Suddenly the forces of nature seemed far less benign. Leisurely progress coastal protection has developed piecemeal over the past 150 years, driven not so much by pure science as by the demand to fulfil social expectations. It was essentially that pressure which led to the widespread introduction of sea walls. From the mid-19th century wealthy Victorians sought the development of coastal resorts. To realise their leisurely ambitions, engineers were drafted in to build the walls and the promenades which went with them. Over the years it has become increasingly obvious that such a haphazard approach is unsatisfactory and that activity on one bit of the coast could have damaging effects on another. The need for greater planning and co-ordination, recognised in the 1949 Coast Protection Act, is now universally acknowledged: it will be reflected in the six new shoreline management plans that are being prepared for the whole of the east coast, from the Humber to the Thames. 26.8.95 From Compton's Complete Reference Collection Landforms that result from erosion, or wearing away of the land, make up some of the most scenic coastal areas in the world. Sea cliffs that border many rocky coasts are an example. These cliffs were created when pounding waves weakened the lower portion of the rock to the extent that parts of the cliffs above tumbled into the water, leaving a rock wall with rubble at the bottom. Solid rock shores that lack beaches are easily destroyed by the sea. Beaches consequently protect the shore. Sometimes groins (short piers that extend out into the sea from 30 to 200 meters, depending on the nature of the beach) are constructed to protect the shores from erosion. This has been done along the coasts of the Black Sea. In recent years, some beaches have been artificially restored with sand taken from the sea bottom or from nearby dunes. This has been done on many beaches in the United States and on the island of Norderney in the North Sea.

Why Art Programs are Essential in a Secondary School Cirriculum Essay

Why Art Programs are Essential in a Secondary School Cirriculum - Essay Example he fact that they apply logical models to their thinking basis and this facilitates in decision making and when they have to analyze things looking at it from a different perspective so to speak. Not only are the scientific subjects taken in the same esteem with the field of arts, but also the latter gains importance where the discussion is of understanding human values, emotions and sentiments. This means that there is a complete basis for understanding the individual’s very essence and how he interacts with people hailing from his own society, culture and traditions. The emotions are easily transmittable through the expression of art. This could be so very true in the wake of the different pictures which are sketched by artists and not to forget the photography done by film makers and directors alike. They also bring out a particular shade of life which has been kept non-apparent over a period of time from the people who own it. Art has no parallels when it comes to understanding human emotions, values and belief systems. (Meier, 1942) This suggests that the human basis gains more and more importance as arts attaches itself with them. One cannot fathom at any point in time that science and the related subjects gain an edge or two over the field of arts. The two remain in close connection with each other no matter what the critics and hardliners suggest every now and then. There should be efforts to mix the science classes with that of the art ones so that there is close coordination between the two and the end result is that the students gain fr om the usage of their minds in both the fields. Music is one of the most significant tenets that comes under the field of arts and which has been used with the passage of time in different cultures and societal backdrops. The people who listen to music can align their studies and work in close alliance with each other. Students can gain an advantage when it comes to comprehending mathematics and similar subjects.

The Origin of Modern American Capitalism and Society Assignment

The Origin of Modern American Capitalism and Society - Assignment Example The first section of the fourteenth amendment stated that all people born or resident in the United States are the citizens of the United States and of the state wherein they reside. There shouldn’t be discrimination among the people because of any law. The state is neither allowed to restrict people to have autonomy, liberty or property nor are they to be denied the protection of the law. The fifteenth amendment main emphasize was on human rights. It claimed that any citizen will not be denied to vote because of their race, color or religion. It also claimed that Congress has the authority to subject this article by adequate legislation. Furthermore, the right to abolish slavery and give the citizens the equal right to protection was put forward and passed in later years. Moreover, after opposing from people, this amendment banned franchise restriction or race color and religion too. Reaction to these amendments was not very pleasing. The fourteenth amendment was bitterly rejected by Southern states, which were required to sign it in order to return their delegation to Congress. The fifteenth amendments also faced strong rebuff initially. However, Republican, under the influence of Ulysses S. Grant was convinced that the involvement of blacks is good for the party’s future. Frederick’s ‘frontier thesis’ proved eligible between 1870 and 1900 when families and individual moved to trans-Mississippi because they got the way to increase the family farming procedure as they got more place.

Database assignment 2 Example | Topics and Well Written Essays - 2500 words

Database 2 - Assignment Example It is a car rental company based in the USA. As a car hire organization, Budget Car Hire Company requires various systems to manage its operations. The company has branches all over the world and booking can be made directly via branched or online through the company’s website and agent websites. Three Proposed Applications In this report, three proposed applications that fulfill the companies’ needs will be discussed. Specifically, the three applications are to facilitate transactions and operations. The applications are: Direct Renting from braches. Online booking system. Car purchasing system. The systems will have to be integrated into a single database and network for the purpose of data access and processing. This is the function of the data modeling process. Brief overview of the Applications Direct renting from braches This application describes the transaction where the client goes directly to the companies’ branches and asks for a car to rent. Depending on the availability of car, the customer has to provide staff with his licenses, bank card number and personal information such as name, age and address. A customer must also buy an insurance package only then, a member of staff will enter the information n the system and give back an invoice along with the car keys. Online booking system The online booking system is an application that will enable customers to do car reservation online through Budget website. The online booking should be able to process the booking and produce the corresponding confirmation message or travel vouchers to the applicant. The customer must fill a form on Budgets website that provides the company with his/her information like name, age, address and other personal and paying information. Most importantly, the type of car, pick up and return time and date, location. The website calculates the price for the selected vehicle for the specified period. After that, customers receive an email confirmation. Car purchasing system The third application is for car purchasing, where employees in the logistics department Budget gets to interact with different car vendors. The Budget employee has to select the car type, color, model, price and quantity. After that the application generates the name of the buyer (Budget), seller (vendor), purchasing date and time and the total price of the transaction including the cars specifications, quantity and date of manufacture. Key Data Required for Each Application The systems require various data items because they all manage different data and processes. Each database will have various datasets. Of course, some of the data sets will have common data fields shared between themselves (Heath and Bizer 36). The databases for each application will have local model with entity relationships specifically between the entities in them. Overall, the local models will be linked into a larger model, the global data model. The global data model will link the three databases in such a way that the three applications have relationships with each other through the relationships in their entities. Direct renting from braches Direct renting from braches application will have the following data entities: Entity Attribute RENTAL RENTAL_NO Primary Key (PK), CUST_ID foreign key (FK), RENTAL_TIME, RENTAL_DATE, PICKUP_DATE, RETURN_DATE, PICKUP_TIME, RETURN_TIME, CAR_ID (FK), PRICE_PAID,

SmartPhone Security Essay Example | Topics and Well Written Essays - 1000 words

SmartPhone Security - Essay Example Hackers, who know the default setting, can gain access to wireless network. In this way the network fails to require identification and verification of all users. This paper deals with the security issues in Smart phone. We will start our discussion with a brief introduction of Smart phone. Smart phones, as name implies that it is small device. It is small device but it has more functionality of mobile phone and computer. It use used for communication like mobile phone and computing functionality like computer. With the help of smart phone, a user can interact with different application at same time. It is so small you can put in your pocket. You can install more software in your smart phones (Kenneth, 1996). Smart phones combine the functions of pagers, cellular telephones, and personal digital assistants into a small single device. A smart phone is a wireless phone with text and Internet capabilities. It can handle wireless telephone calls, voice mail, email, and faxes, save addresses, and access information from Internet. Wireless networks can be more expensive, slower, and more error prone than wired networks. Bandwidth and energy supply in wireless devices require careful management from both hardware and software standpoints (Imielinski and Badrinath, 1994). Security and privacy will be more difficult to maintain because wireless transmission can be easily intercepted. Data cannot be transmitted seamlessly between different wireless networks if they use incompatible standards. The entire point of computer security is to eliminate or protect against threats. A threat is anything that can cause harm. A threat can be simple error, burglar or virus. A threat is not harm full unless it exploits an existing vulnerability. Vulnerability is a weakness, any thing that has not been protected against threats. Threats to your smart phone hardware involve incidents that have effect on the operation or maintenance of the smart phone. The smart phones are using

Campaign Reform Essay Example | Topics and Well Written Essays - 500 words

Campaign Reform - Essay Example Non-profit organizations are considered corporations under this law and are therefore subject to the same rules and regulations as these other corporations. These are referred to as â€Å"Electioneering Communications,â€Å" or issue ads. This act amended the 1971 Federal Election Campaign Act. The BCFR was a big step towards campaign finance reform. As a direct effect, the organizations Swift Boat Veterans for the Truth, the League of Conservation Voters, MoveOn.org, and Progress for America Voter Fund were all fined for not following the new laws. In June of 2007, the US Supreme court found in Federal Election Commision Vs. Wisconsin Right to Life, Inc. that it was unconstitutional to apply the BCFR to ads that could be reasonably considered to be not specifically for or against a specific candidate. It will depend on the full extent of the 2008 election cycle to determine the extent to which this new ruling will affect campaign finance reform. While the BCFR has begun the process of finance reform, many people think that there is still a long way to go in the process. For instance, many people still feel that lobbyists and special interest groups still have too much influence on politicians, yet the BCFR does not specifically deal with lobbyists. Also, some groups have begun the process of challenging the BCFR, stating that it violates free speech. Bradley A. Smith, in the book Unfree Speech: the Folly of Campaign Finance Reform, states that not only was the system that was in place before the BCFR not as corrupt as many Americans seemed to believe, but the BCFR has made the situation worse, with incumbent and wealthy candidates being much more likely to elected than previously because the BCFR discourages grassroots organizations (Smith, 2001). Smith’s main opposition to current attempts at campaign finance reform, though,

How the Hip Hop Music Culture Spread Into Eastern Countries Essay

How the Hip Hop Music Culture Spread Into Eastern Countries - Essay Example Through the mandatory learning of the modern English language in Eastern countries during the 80s, to the technological revolution, including the accessibility of the internet and television, hip-hop music has been embraced, as well as evolved, within the East, as well as the rest of the world. Hip hop music originated in the United States of America in the 1970s, primarily in the â€Å"Bronx† in the state of New York in New York City (History, 2011). Though America, back then, was a for the most part considered to have a â€Å"white† majority, with many of its most successful business people being â€Å"white†, hip-hop music was actually created primarily by the African-American and Latino-American cultures (History, 2011) who chose to share their hard life and street experiences as a â€Å"minority† in a primarily â€Å"white† society through the use of â€Å"street poetry†, or â€Å"rap† music, if you will. The rhythm, rhyme and out rageous party themes of hip-hop/rap became so overwhelmingly popular that it drew crowds of all races and ages, especially the youth. However, in several of the Eastern countries, the lack of exposure to the genre caused a delay, especially in Europe, of its acceptance and evolution. Once introduced in America; however, it wasn’t long until the business people of America, regardless of the question of morality or immorality of its themes, realized that hip-hop music and the African-American and Latino-American cultures had the power to make music that could be marketed for a horrendous profit. Underground hip-hop artists and various rappers and â€Å"hip hopsters† began recording and distributing music across America. Though hip hop/rap music was not considered mainstream American music, the artists and their investors were making profits off marketing the â€Å"underground† releases.  

Martin Scorceses The Gangs of New York Movie Review

Martin Scorceses The Gangs of New York - Movie Review Example Ken Burns' genius was to bring those photographs together in almost a cinematic way to make the war, and the people involved, more real. Scorcese's movie, although it takes place during the Civil War, is really not about that War at all. It is more about the earlier- and later-arrived Irishmen, and how they inculcated themselves into a hierarchical society in New York City. The first great Irish immigration wave was during the building of the Erie Canal in the 1820's. Most of the Irishmen who were already there and under the leadership of Bill "The Butcher" Cutting were part of the 1840's Irish potato famine crowd-a rough time for Irishmen to enter the U.S. as there were few jobs after the depression of 1848, and an actively hostile reception both from established Irishmen and the WASP's who controlled the political machinery of New York. Since Scorcese's movie focuses on the tension between "old" Irish and newly-arrived Irishmen, led by Leonardo DiCaprio's Amsterdam Vallon, the Draft Riots of 1863 are an inconvenient truth whose underlying issues are ignored in the movie. Without a knowledge of the actual historical events of the time, and only viewing the movie, one might be led to believe that the riots were about old versus new immigrants, contained by a WASP police force under the leadership of Boss Tweed. The reality was quite different: General USS Grant and President Lincoln needed hundreds of thousands of troops in order to maintain a numerical superiority over the South, and they regarded the Irish immigrants of New York as a ready source of human capital for the war. Those in New York who had few roots in the American culture did not want to throw themselves in front of Gattling guns and cannons on battlefields like Gettysburg and Appomatox. So how was the "truth" injured by Scorcese's movie One might argue that he should have chosen a different era, perhaps before the Civil War and not related to the Draft Riots, to exploit the tension between old and new Irish immigrants. While the plot could have been truer to historical fact, the tension of the plot might not be there. Scorcese needed to have a dramatic tension, a build-up, in his movie, leading to an apocalyptic riot where all of New York was burning. The 1863 riots provided that dramatic backdrop, one which would not have been available in the past. As contrasted to other movies covering the same time period, "Gangs of New York" offers three original contributions: (1) it features a part of the population during the Civil War that was not at the front lines, (2) it gives a young person's perspective, as compared to the older, in-charge leaders such as Boss Tweed and Lincoln, and (3) it is a group pastiche, rather than a concentration on one leader, such as is found in "Glory." Perhaps the best comparison to "Gangs of New York" is the epic "Birth of a Nation" by D.W. Griffiths (1915). Like "Gangs," "Nation" was an ensemble piece, one which explored not just the leaders of movements, but the underlying motivations behind the resentments and conflicts-in this case, between blacks and whites at the time of the Civil War and just after. Of course,

Ghosts and Supernatural with close reference to The Woman in Black and Violet Car Essay Example for Free

Ghosts and Supernatural with close reference to The Woman in Black and Violet Car Essay Ghost stories are all about death and dying. They help us to understand what happens after we die. They try to build up peoples fear of death and dying. They use peoples fear to build up suspense. Sometimes the author of the book will use the characters in the book to keep the reader wondering, grieving people sometime imagine things and the author can use this to keep the reader interested in the book. The reader would be wondering if it is the imagination of the character or a real ghost. Often ghost stories are based on someones premature or violent death. Some stories can use this to add more fear, because it could be an ordinary person that gets killed. Sometimes the author writes as if it had happened to them, this could help the reader to believe the story more. The Violet Car is about the violent death of a young girl. The man that had killed Mr. Eldridges daughter was driving though the village in his violet car. He pulled up to Mr. Eldridge, and asked him for directions to Hexham. It was a foggy day, and Mr. Eldridge didnt like the driver so he told him that it was straight on, and the driver drove straight of the edge of a cliff. Mr. Eldridge was haunted with the pictures of the car driving off the cliff and everyday he saw it. The only way that he could stop the visions was to stop the car from driving off the edge of the cliff. Mr. Eldridge stood on the corner of the road to stop the car as it came round the corner, it hit Mr. Eldridge and knocked him to the ground. The cause of death was heart failure, but he was really killed by the same car that had killed his daughter. The Woman in Black is about a ghost that haunts Eel Marsh House, an isolated house with a very dark secret. There is a ghost of a young woman that lost her son on the marshes near Eel Marsh House, which haunts the house. Mr. Drablow, the previous owner, died and Arthur Kipps is sent to sort out every thing in the house and make sure all the legal documents are correct. The ghost is of a woman called Jennet Humfrye, who had a son but was not allowed to keep him so she gave him up to Alice Drablow. Jennet came to see here son all the time and one day the child had been out in the town and come back on a horse and cart, but it had gone off the tracks and into the marsh. Arthur hears noises on the marsh of people dying, drowning in the mud of the marshes. Every time the ghost is seen a baby dies, but when no child died they thought that the curse of the old house had ended, but Arthurs child and wife die in an accident and the woman in black was left to haunt Crythin Gifford. The books are similar in many aspects, they are both written in the first person. Writing in first person is a common practice by Authors to make the reader believe the story more. The Woman in Black is written as if you are Arthur and the Violet Car is written from the point of view of the nurse. They are similar because they both try and achieve the same thing, just using different techniques. Susan Hill keeps the readers attention by using short sharp sentences, whereas Edith Nesbit uses lots of descriptions to keep the attention of the reader. The Woman in Black uses lots of very good descriptive words; they are very good for working up the suspense even more. The Woman in Black and Violet Car are both based on grief, The Woman in Black is the grief of Jennet, the Violet Car is about Mr. Eldridge and the grief he had because he sent the car off the edge of the cliff. In The Woman in Black Susan Hill make an eerie atmosphere by using short onomatopoeic sentences such as, Bump. Bump. Pause. Bump. Bump. Pause. Bump. Bump. Bump. Bump. Bump. Bump This kind of sentence helps to build up anticipation and anxiety. It is like you want to find out what is going to happen next but are too scared to find out. She does not use cliffhangers at the end of a chapter; however she does use them at the end of some paragraphs. The Violet Car is a very different book in that respect, Edith Nesbit writes in a different way to Susan Hill. E. Nesbit didnt write in short sentences; instead she told the story in a way that made you want to continue reading. Both the stories are traditional well told ghost stories that use different techniques to get the same result. They are both interesting and exciting and the kind of story that you dont want to put down because it is so full of suspense. I think that The Woman in Black is a better ghost story because a lot more happens in it and it has a more complex plot to the Violet Car, however The Woman in Black is a book whereas the Violet Car is a short story. The Woman in Black was described has Heartstoppingly chilling and I agree with this.

The Hardship Of Vietnamese Students Education Essay

The Hardship Of Vietnamese Students Education Essay In a developing Asian country like Vietnam, studying is the most important activity in ones life. Unlike in the United States where going to school brings children happiness, Vietnamese schools are often considered a kind of mental and intellectual training. Except for some special students who are intelligent by birth, most ordinary students have to struggle in order to keep up with very strict requirements of the education system in Vietnam. This reality, however, is not commonly recognized by responsible adults. Because I used to be in that kind of environment, in my point of view, Vietnamese students are constantly suffering from enormous stress. First, parents expectations put students under a lot of pressure. As a matter of fact, most of Vietnamese families struggle to earn enough income to support their lives, and this has not changed at all for several centuries, even when the economic situation has improved a lot. As a result, most parents want their kids to live more comfortable life than the previous generation. This kind of wish is not wrong, because it comes from the hearts of parents who do not want their children to suffer like they did. However, parents use that reason to push the poor children beyond their threshold, for they think that the kids are a tool for them to fulfill the wishes they could not complete when they were young. Most people make their children go to cram school every day, and do not bring them home until eight in the evening. Some other parents make their children learn various subjects, like violin, piano, ballet, or martial arts after school time. They think that those actions help them expr ess their love for the kids. However, the adults do not understand that children need rest after school as much as they need rest after work. Personally, I have seen children in the age below twelve dozing off behind their parents on the motorbike when going home from a martial arts course. Regarding Vietnams transportation situation, it is very dangerous because the kids can fall off the bike any moments. Their own parents do not care, though. Moreover, parents in Vietnam lack sympathy for their children. They do not feel the need to understand their childrens problems because they are parents. When the kids get bad grades, instead of getting encouragement or at least consolation from their beloved parents, they only get some nasty words and even violence. Another mistake that most parents do is that they keep comparing their kids to some other kids on newspaper. The adults think that comparing will make their kids reflect on themselves and behave, but it only brings out negative e ffects on the children. Additionally, parents do not encourage their children to pursue their own dreams, but force the kids to become what the parents want. Most students do not have the chance to choose their paths, and it will lead to many bad consequences in the future if the students are not suitable for that major. To me and most of my friends when we were still in school, going home does not bring any kind of happiness, but only stress and pain. Second, the whole societys idea of success places even more stress on the students. In Vietnam, it is very hard to get a job without having powerful parents. In order to get a good position, a person from ordinary background must have excellent intellectual abilities, which is proved through their degrees and certificates. Therefore, students must study hard ever since elementary school in order to get in famous schools, and eventually graduate from the most well-known universities so as to get a job. Ever since they are young, students are taught that school performance is the only way to determine a persons value. Consequently, if a student cannot excel in class, he or she will be regarded as a useless person who will never get a good life and will probably spend the rest of his or her life collecting trash on the sidewalk for a living. Teachers also cause stress on their students. This traces back to the fact that teachers in Vietnam do not earn much income compared to other professions. As a result, teachers tend to do whatever they can to earn more money for their families. Most teachers have to open extra classes at home as an alternate source of income, which becomes another session of school for children. Unfortunate students are given extremely difficult tests so that they get bad results; then, they are threatened that they can never get good grades unless they become students at their teachers extra classes after school. Unfortunately, most parents do not detect this kind of evil actions of the teachers; they think the children are neglecting their studying, and blame them for the bad grades. This unjust action makes children very disappointed and even under more stress. In addition, many teachers teach their students very wrong ideas about the relation between success in school and in life. In their opinio n, if a student can do math and write good essays, that child will be rich in the future. On the other hand, if a student cannot do math or cannot write a decent essay, the child will most likely lead a pathetic life regardless of other talents that the kid may have. Some teachers, especially homeschool teachers, create a gap between good students and bad students, causing the bad ones many negative feelings toward their better classmates. Moreover, a small number of teachers have a tendency to treat one or two students better than the rest of the class due to their excellence in studying, or just because their parents are rich. In other words, students are taught that the value of one person do not depend on their personalities but on their social background and intellectual abilities. As if there is not enough pressure from their superiors, students create pressure on themselves and on their peers. Most children strive for their parents satisfaction, so they push themselves as hard as they can. They think that only through good grades can they be loved by their parents. Although they do realize that all the adults are wrong about the importance of school grades, they have no way to escape from it, nor do they have enough courage to break out of those invisible chains. As a result, they become the same as the adults who used to mentally abuse them, thus maintaining the vicious circle. Besides, students subconsciously become their classmates source of pressure. Because young children learn a lot from their peers, they are usually confused by their friends hard work and doubt whether they are already doing their best or not, which intensifies the competitiveness between classmates. Another factor that contributes to academic pressure on students is the excessive amount of schoolwork, especially in high school. At my high school, an average student has to attend class lectures for four hours every day from Monday to Friday in the morning. Three afternoons per week, the student have to go to school for another four hours; also, the student has another two more hours on Saturdays for extracurricular activities. After getting out of school at five in the afternoon, the student will most likely engage in another session of cram school, which usually last two hours or even more. Because most teachers offer extra classes which usually last four or three hours per week ,or even six hours for major subjects like mathematics, and a student often has to take at least two different extra classes, the total time for cram school can easily exceed eight to ten hours every week. In total, an average student at my high school spends at least 40 hours per week on going to school s and extra classes, as much time as a normal full-time worker does. However, it does not end there. At home, an ordinary student has to do homework and study for upcoming exams. The time for self-studying varies from one student to another, but as far as I know, half of my class stayed up late to do homework, and the other half did not go to sleep until past midnight. For students in middle and elementary schools, this amount of time is slightly reduced, but it does not mean that the amount of work is. From middle school, a student has to learn 13 subjects a week, all year long, and all of them are compulsory. If the student gets a final score of less than eight in any of those 13 subjects, he or she will probably lose the chance of getting a title of good student, which is very important for scholarships or other benefits in Vietnam. To make things even worse, none of those subjects can be considered easy. One friend of mine said ironically, At school, we have to be as knowledgeab le as Einstein, run as fast as Usain Bolt, draw as beautifully as Picasso, sing as well as Elvis Presley, have communist ideals like Karl Marx, and be as good a person as Mother Theresa. She was not entirely exaggerating, since her words practically described much of the education system in Vietnam, no matter how unbelievable it may sound. Even for pre-school children, the situation is not better, for they are expected to read and write smoothly before actually entering their first school year. Except for my elementary teachers who were all very nice to me, many other teachers will not hesitate to hit a young kid for making a mistake on their exams. Indeed, violence adds to academic pressure as well. Those kinds of pressure has become a part of everyday life, so no students can recognize how stressful their school years are until they get to university and look back on the previous time. Working hard in a long time is not all wasteful, however, because, in one way or another, it strengthens students mind and provides them with more than enough knowledge so as to prevail in foreign countries universities. Still, I hope that one day all those unfair stresses will be lifted away, so that the children can actually enjoy their childhood and no longer see their schools as a kind of prison, just like what I used to do throughout twelve years of my life.