Generic Visual Perception Processor free essay sample

The generic visual perception processor (GVPP) has been developed after 10 long years of scientific effort . Generic Visual Perception Processor (GVPP) can automatically detect objects and track their movement in real-time  . The GVPP, which crunches 20 billion instructions per second (BIPS), models the human perceptual process at the hardware level by mimicking the separate temporal and spatial functions of the eye-to-brain system. The processor sees its environsment as a stream of histograms regarding the location and velocity of objects. GVPP has been demonstrated as capable of learning-in-place to solve a variety of pattern recognition problems. It boasts automatic normalization for varying object size, orientation and lighting conditions, and can function in daylight or darkness. This electronic eye on a chip can now handle most tasks that a normal human eye can. That includes driving safely, selecting ripe fruits, reading and recognizing things. Sadly, though modeled on the visual perception capabilities of the human brain, the chip is not really a medical marvel, poised to cure the blind Introduction of  GVPP The GVPP tracks an object, defined as a certain set of hue, luminance and saturation values in a specific shape, from frame to frame in a video stream by anticipating where its leading and trailing edges make differences with the background. We will write a custom essay sample on Generic Visual Perception Processor or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page That means it can track an object through varying light sources or changes in size, as when an object gets closer to the viewer or moves farther away. The GVPPS major performance strength over current-day vision systems is its adaptation to varying light conditions. Todays vision systems dictate uniform shadow less illumination ,and even next generation prototype systems, designed to work under â€Å"normal† lighting conditions, can be used only dawn to dusk. The GVPP on the other hand, adapt to real time changes in lighting without recalibration, day or light. For many decades the field of computing has been trapped by the limitations of the traditional processors. Many futuristic technologies have been bound by limitations of these processors . These limitations stemmed from the basic architecture of these processors. Traditional processors work by slicing each and every complex program into simple tasks that a processor could execute. This requires an existence of an algorithm for solution of the particular problem. But there are many situations where there is an inexistence of an algorithm or inability of a human to understand the algorithm. Even in these extreme cases GVPP performs well. It can solve a problem with its neural learning function. Neural networks are extremely fault tolerant. By their design even if a group of neurons get, the neural network only suffers a smooth degradation of the performance. It wont abruptly fail to work. This is a crucial difference, from traditional processors as they fail to work even if a few components are damaged. GVPP recognizes stores , matches and process patterns. Even if pattern is not recognizable to a human programmer in input the neural network, it will dig it out from the input. Thus GVPP becomes an efficient tool for applications like the pattern matching and recognition HOW IT WORKS: Basically the chip is made of neural network modeled resembling the structure of human brain. The basic element here is a neuron. There are large number of input lines and an output line to a neuron. Each neuron is capable of implementing a simple function. It takes the weighted sum of its inputs and produces an output that is fed into the next layer. The weights assigned to each input are a variable quantity. A large number of such neurons interconnected form a neural network. Every input that is given to the neural network gets transmitted over entire network via direct connections called synaptic connections and feed back paths. Thus the signal ripples in the neural network, every time changing the weighted values associated with each input of every neuron. These changes in the ripples will naturally direct the weights to modify into those values that will become stable . That is, those values does not change. At this point the information about the signal is stored as the weighted values of inputs in the neural network. A neural network geometrizes computation. When we draw the state diagram of a neural network, the network activity burrows a trajectory in this state space. The trajectory begins with a computation problem. The problem specifies initial conditions which define the beginning of trajectory in the state space.

Amazing Outstanding Persuasive Essay Samples For Children

Amazing Outstanding Persuasive Essay Samples For ChildrenIf you are planning to write a persuasive essay, you should know that there are many exceptional outstanding persuasive essay samples. There are some for example; Some examples of persuasive essay samples for children that can help you decide on the format and the correct subject matter to use.The first persuasive essay samples for children is based on the subject of bullying. This can be used in a number of ways; you could also use it as a guide for your own bullying problem in school or if you are going on an outing. You might also use it if you need to write a persuasive essay for any situation where someone has been bullied.Another good persuasive essay samples for children is one called The Difference Between Passion. This is a real life story from an actual person who was bullied by his classmates and then has worked to change things through his own life experiences. This can be used for more than just to create a persuas ive essay.One of the really good persuasive essay samples for children is one called, 'Teaching Children to Respond to Urgent Situations.' This is a very interesting topic, one that has been used by educators around the world for a long time. This is probably the best one for people to learn what they can do to help them deal with this topic.One of the best and most excellent, persuasive essay samples for children is one called One Beautiful Child. It is one that describes a young child who has endured many kinds of abuse, but yet now as a young adult is considered to be a model of what it means to be a happy, healthy and caring person.There are also two other examples of persuasive essay samples for children that are very easy to understand and which you might be able to put in your own children's hands. One is the 'Generation Heist' which is one about a group of teens who get together to steal some expensive gadgets for themselves. The other is 'The Different Race of the Nile', wh ich describes how children in ancient Egypt were forced to dress up as each other and acted out elaborate games, though they didn't know how to play the games and as a result were given punishments.There are of course hundreds of other persuasive essay samples for children and this does not even touch on them all. But they should give you a good start to looking for great examples to use. You will then have more ideas on what to write in your own persuasive essay.

Commercial Law Practitioner Essays - Insolvency, Bankruptcy

Commercial Law Practitioner Essays - Insolvency, Bankruptcy Commercial Law Practitioner Commercial Law Practitioner 2014 *47 Time Limits and the Appointment of ReceiversAn Analysis of Recent Authorities Mark Heslin* Time limits arise in many contexts in legal practice. A statute may allow a specific period for something to be done. A contract may require a particular act by a given time. Practitioners unilaterally set deadlines for a response, in default of which there will be specific consequences. For instance, a demand may seek payment immediately or by close of business, but what do those phrases mean? Can one validly demand immediate payment outside normal banking hours, and when do these start and end? This article proposes to examine the attitude of the courts to compliance with certain important time limits, and how disputes and ambiguities in relation to such phrases have been dealt with, particularly in the context of the appointment of a The Belohn Ltd (Belohn) owned and operated bars and a restaurant on the corner of Merrion Street and Merrion Row, Dublin, under the name Foley's. The company ran into financial difficulties and on October 10, 2012, its bank appointed a receiver and manager over Belohn's assets. On December 18, 2012, a challenge to the receiver's appointment was brought by Belohn's holding company, The Merrow Ltd (Merrow). Judgment was given in the High Court on the morning of March 22, 20131 appointment was void, a finding based primarily on a requirement in one of the relevant debentures that the bank appoint by writing under its seal a Receiver of the mortgaged property. The receiver's appointment had not been made under seal. by Mr Justice Gilligan. The court held that the receiver's Following the delivery of Gilligan J.'s judgment, the bank's solicitors made a demand on Belohn, later the same day, for the repayment of in excess of 4 million. At the same time, a demand was made on Merrow for in excess of 1 million then due. The demands, which were handed to the relevant director at 16.15 on March 22, required payment by 17.00. In the absence of payment being made, the bank, at 17.10, appointed the same receiver over all of Merrow's property and assets. The only assets of Merrow were its subsidiary, Belohn. The appointment at 17.10 on March 22 was not communicated to Merrow until approximately 16.30 on Sunday, March 24. Petition to Appoint Examiner Upon learning of the receiver's appointment, Merrow presented a petition in its name and that of Belohn seeking to appoint examiners to each company. The application was heard, ex parte, at about 21.00 at the home of Mr Justice Hogan on the evening of Sunday, March 24, 2013.2 petitioner impressed upon Hogan J. the importance of the petition being presented before midnight. Under s.2 of the Companies (Amendment) Act 1990 (the 1990 Act), the court may appoint an examiner upon a petition being presented. Section 3(6) of the 1990 Act specifies an important time limit, providing that the court shall not hear any petition if a receiver stands appointed to the company and has been so for a continuous period of at least 3 days prior to the Of particular interest is the analysis by Hogan J. of the three-day time limit by which a petition must be presented for the appointment of an examiner, following the appointment of a receiver, and the court's comments on any effort to frustrate the bringing of such petitions. The court heard that financial institutions often appoint receivers late on a Friday, because an application for the appointment of an examiner will depend, first, on the company learning that a receiver has been appointed, and, secondly, locating a duty judge over the weekend. The court found that if a receiver is appointed on a Friday, an application on the following Monday would be too late, having regard to s.18(h) of the Interpretation Act 2005. This provides: Where a period of time is expressed to begin on or be reckoned from a particular date, that day shall be deemed to be included in the period and, where a period of time is expressed to end on or be reckoned to a particular date, that day shall be deemed to be included in the Therefore, even if a receiver is not appointed until late on a Friday evening, that day will be included in the computation of the relevant three-day period, which will expire at midnight on Sunday. Financial institutions hoping that a petitioner seeking to appoint an examiner will not become aware of such an appointment in

Major General Oliver O. Howard in the Civil War

Major General Oliver O. Howard in the Civil War Oliver O. Howard - Early Life Career: The son of Rowland and Eliza Howard, Oliver Otis Howard was born at Leeds, ME on November 3, 1830. Losing his father at age nine, Howard received a strong education at series of academies in Maine before electing to attend Bowdoin College. Graduating in 1850, he decided to pursue a military career and sought an appointment to the US Military Academy. Entering West Point that year, he proved a superior student and graduated fourth in a class of forty-six in 1854. Among his classmates were J.E.B. Stuart and Dorsey Pender. Commissioned as a second lieutenant, Howard moved through a series of ordnance assignments including time at Watervliet and Kennebec Arsenals. Marrying Elizabeth Waite in 1855, he received orders to take part in a campaign against the Seminoles in Florida two years later. Oliver O. Howard – The Civil War Begins: Though a religious man, while in Florida Howard experienced a deep conversion to evangelical Christianity. Promoted to first lieutenant that July, he returned to West Point as a mathematics instructor that fall. While there, he frequently considered leaving the service to enter the ministry. This decision continued to weigh on him, however as sectional tensions built and the Civil War neared, he resolved to defend the Union. With the attack on Fort Sumter in April 1861, Howard prepared to go to war. The following month, he took command of the 3rd Maine Infantry Regiment with the rank of colonel of volunteers. As the spring progressed, he rose to command the Third Brigade in Colonel Samuel P. Heintzelman’s Third Division in the Army of Northeastern Virginia. Taking part in the First Battle of Bull Run on July 21, Howard’s brigade occupied Chinn Ridge but was driven off in confusion after being attacked by Confederate troops led by Colonels Jubal A. Early and Arnold Elzey . Oliver O. Howard – An Arm Lost: Promoted to brigadier general on September 3, Howard and his men joined Major General George B. McClellan’s newly-formed Army of the Potomac. Recognized for his devout religious beliefs, he soon earned the sobriquet â€Å"the Christian General† though this title was often used with a degree of sarcasm by his comrades. In the spring of 1862, his brigade moved south for the Peninsula Campaign. Serving in Brigadier General John Sedgwick’s division of Brigadier General Edwin Sumner’s II Corps, Howard joined McClellan’s slow advance towards Richmond. On June 1, he returned to combat when his men met the Confederates at the Battle of Seven Pines. As the fighting raged, Howard was hit twice in the right arm. Taken from the field, the injuries proved serious enough that the arm was amputated. Oliver O. Howard - A Rapid Rise: Recovering from his wounds, Howard missed the remainder of the fighting on the Peninsula as well as the defeat at Second Manassas. Returning to his brigade, he led it during the fighting at Antietam on September 17. Serving under Sedgwick, Howard took command of the division after his superior was badly wounded during an attack near the West Woods. In the fighting, the division sustained heavy losses as Sumner had ordered it into action without conducting proper reconnaissance. Promoted to major general in November, Howard retained command of the division. With Major General Ambrose Burnside’s ascent to command, the Army of the Potomac moved south to Fredericksburg. On December 13, Howard’s division took part in the Battle of Fredericksburg. A bloody disaster, the fighting saw the division make a failed assault on the Confederate defenses atop Marye’s Heights. Oliver O. Howard - XI Corps: In April 1863, Howard received an appointment to replace Major General Franz Sigel as commander of XI Corps. Largely comprised of German immigrants, the men of XI Corps immediately began lobbying for Sigel’s return as he too was an immigrant and had been a popular revolutionary in Germany. Imposing a high level of military and moral discipline, Howard quickly earned his new command’s resentment. In early May, Major General Joseph Hooker, who had replaced Burnside, attempted to swing around to the west of Confederate General Robert E. Lee’s position at Fredericksburg. In the resulting Battle of Chancellorsville, Howard’s corps occupied the right flank of the Union line. Though advised that his right flank was in the air by Hooker, he took no action to anchor it on a natural obstacle or construct substantial defenses. On the evening of May 2, Major General Thomas â€Å"Stonewall† Jackson mounted a devastating flank attack which routed XI Corps and des tabilized the Union position. Though shattered, XI Corps mounted a fighting retreat that saw it lose around a quarter of its strength and Howard was conspicuous in his attempts to rally his men. Effectively spent as a fighting force, XI Corps did not play a meaningful role in the rest of the battle. Recovering from Chancellorsville, the corps marched north the following month in pursuit of Lee who intended to invade Pennsylvania. On July 1, XI Corps moved to the aid of Brigadier General John Buford’s Union cavalry and Major General John Reynolds I Corps which had become engaged in the opening phases of the Battle of Gettysburg. Approaching on the Baltimore Pike and Taneytown Road, Howard detached a division to guard the key heights of Cemetery Hill to the south of Gettysburg before deploying the rest of his men on I Corps’ right north of town. Attacked by Lieutenant General Richard S. Ewell’s Second Corps, Howard’s men were overwhelmed and forced to fall back after one of his division commanders, Brigadier General Francis C. Barlow, blundered by moving his men out of position. As the Union line collapsed, XI Corps retreated back through town and assumed a defensive position on Cemetery Hill. As Reynolds had been killed early in the fighting, Howard served as the senior Union leader on the field until Major General Winfield S. Hancock arrived with orders from army commander Major General George G. Meade to take over. Despite Hancock’s written orders, Howard resisted ceding control of the battle. Remaining on the defensive for the remainder of the battle, XI Corps turned back Confederate attacks the next day. Though criticized for his corps’ performance, Howard later received the thanks of Congress for selected the ground on which the battle would be fought. Oliver O. Howard – Going West: On September 23, XI Corps and Major General Henry Slocum’s XII Corps were detached from the Army of the Potomac and set west to aid Major General Ulysses S. Grant’s efforts to relieve Major General William S. Rosecrans’ besieged Army of the Cumberland at Chattanooga. Collectively led by Hooker, the two corps aided Grant in opening a supply line to Rosecrans’ men. In late November, XI Corps took part in the fighting around the city which culminated with General Braxton Bragg’s Army of Tennessee being driven from Missionary Ridge and forced to retreat south. The following spring, Grant departed to take overall command of the Union war effort and leadership in the west passed to Major General William T. Sherman. Organizing his forces for a campaign against Atlanta, Sherman directed Howard to take over IV Corps in Major General George H. Thomas’ Army of the Cumberland. Moving south in May, Howard and his corps saw action at Picketts Mill on the 27th and Kennesaw Mountain a month later. As Shermans armies neared Atlanta, part of IV Corps took part in the Battle of Peachtree Creek on July 20. Two days later, Major General James B. McPherson, commander of the Army of the Tennessee, was killed at the Battle of Atlanta. With the loss of McPherson, Sherman directed Howard to take over the Army of the Tennessee. On July 28, he led his new command into battle at Ezra Church. In the fighting, his men turned back attacks by Lieutenant General John Bell Hood. In late August, Howard led the Army of the Tennessee at the Battle of Jonesboro which resulted in Hood being forced to abandon Atlanta. Reorganizing his forces that fall, Sherman retained Howard in his position and had the Army of the Tennessee serve as the right wing of his March to the Sea. Oliver O. Howard - Final Campaigns: Departing in mid-November, Shermans advance saw Howards men and Slocums Army of Georgia drive through the heart of Georgia, living off the land, and sweeping aside light enemy resistance. Reaching Savannah, Union forces captured the city on December 21. In the spring of 1865, Sherman pushed north into South Carolina with Slocum and Howards commands. After capturing Columbia, SC on February 17, the advance continued and Howard entered North Carolina in early March. On March 19, Slocum was attacked by General Joseph E. Johnston at the Battle of Bentonville. Turning, Howard brought his men to Slocums aid and the combined armies compelled Johnston to retreat. Pressing on, Howard and his men were present the following month when Sherman accepted Johnstons surrender at Bennett Place. Oliver O. Howard - Later Career: An ardent abolitionist before the war, Howard was appointed head of the Freedmens Bureau in May 1865. Charged with integrating freed slaves into society, he implemented a wide array of social programs including education, medical care, and food distribution. Backed by the Radical Republicans in Congress, he often clashed with President Andrew Johnson. During this time, he aided in the formation of Howard University in Washington, DC. In 1874, he assumed command of the Department of the Columbia with his headquarters in the Washington Territory. While out west, Howard took part in the Indian Wars and in 1877 mounted a campaign against the Nez Perce which resulted in the capture of Chief Joseph. Returning east in 1881, he briefly served as superintendent at West Point before taking command of the Department of the Platte in 1882. Belatedly presented with the Medal of Honor in 1893 for his actions at Seven Pines, Howard retired in 1894 after serving as commander of the Department of the East. Moving to Burlington, VT, he died on October 26, 1909 and was buried at Lake View Cemetery. Selected Sources Civil War Trust: Oliver O. HowardNNDB: Oliver O. Howard Civil War: Oliver O. Howard

As a policy matter, should the government be able to restrict the sale Essay

As a policy matter, should the government be able to restrict the sale of video games with violent content, and if so, what rest - Essay Example The students were reported to have played the video game â€Å"Doom,† and were inspired by it. This led to heated debates between two opposing sides. While advocates argued in favor of a restriction in sales of violent video games, groups of opponents led by the game developers argued against such move. They explained that correlation between the violent video games and the acts of the two students were incidental and could not be used as a justification (IDEA, 2012). While proponents argued about a link between violence and increased watching of violent games, the opponents denied any link between violent behaviors and watching of violent videos. Therefore despite the efforts the government has undertaken to restrict violent video games, the government is not able to regulate them as required due to legal implications and high demand of such games in the market. In 2011, the Supreme Court struck down a ban on selling violent games to minors. The Supreme Court found the Califo rnian law that sought to restrict the sale of violent games to minors to be in contradiction with the free speech rights and was overturned. The judgment was overwhelming in a 7 to 2 decision and declared that the Californian statute against the sale of violent games was in serious violation of the rights protection under the First Amendment (Richey, 2011). The Californian State as the judges agreed had the right to protect children against harm by such violent games. However, the judges noted that such powers cannot be free floating to restrict all ideas to which children have possibilities of being exposed to (Richey, 2011). This was the first ruling on violent materials restriction, which was a huge setback to the California state in its bid to protect children against harm caused by such violent games. It implies that the government is not able to restrict or control such video games as required. The government has weak laws and statutes aimed at limiting such sale of violent ga mes to minors. In 1968 the Supreme Court upheld a New York statute that sought to restrict and ban any sale of nude and obscene materials to underage children. The court found that the government indeed had the right and the power to regulate and restrict sale of such sexual materials to children without violating the protection of free speech as stated under the First Amendment (Mcmahan 2013). However, the Supreme Court on the Californian case rejected any application of the same principles by arguing speech of violence is not obscene; thus the 1968 ruling could not be applied in the ban of violent materials. This revealed a serious anomaly under the First Amendment. As one of the 2 dissenting judges, Stephen Breyer noted, there was no sense of preventing a child from accessing a nude picture of a woman, while in the same violent games children are allowed to view such women and even go further to strangle them to death virtually (Mcmahan 2013) . The law in this case is contradicto ry and needs a more elaborate evaluation of the First Amendment to include violent materials under the same category with obscene materials to facilitate the government to use the, law in protecting children against such violent materials. Psychiatrists and research suggest that offering blanket blame to violent games would e missing the point behind violence in children, which would hugely impact on efforts by the government to restrict such games. Kathy Royer a clinical nurse specialist at 4Kid Help Center for Child Adolescent Psychiatry, Ohio

Inflation Essay Example | Topics and Well Written Essays - 1500 words - 3

Inflation - Essay Example As inflation is directly proportional with the aggregate demand in an economy and also the money supply, governments encourage a certain rate of inflation to prevail in an economy for gradual growth (Edwards, 1984). Prior to setting up of a business or preparing the annual financial budget for the economy, inflation is always taken into account. Measures are taken to control inflation so as to leave room for investment, global competitiveness and local demand in the economy. Therefore, attaining price stability through controlled inflation has always been one of the major concerns for all economies (Hart, 2010). Inflation is caused through various factors. It is however difficult to conclude as to what factor has precisely led to inflation and by how much. The forces of demand and supply and other factors concurrently result into inflation and the government has the tools of fiscal and monetary policy to control these factors simultaneously. The major causes of inflation can be because of a demand shocks, supply shocks, money supply and exchange rates, and future expectations (Mishkin, 1984): Inflation is directly proportional to the aggregate demand in an economy. This is because, when the economy is at its growth stage, there are more employment opportunities. As more people are able to work, households’ incomes rise giving them more purchasing power. This causes a rise in the aggregate demand. As the aggregate demand curve moves to the left, the producers also have to increase their supply to exploit this rise in demand. As they increase their production/extend their supply, their costs of production increase which results into an increase in the price level. This Demand-pull inflation can be so intense that it can also cause a Stagflation where an economy reaches at a stagnant growth with high unemployment and high inflation rates. (Martin, 1985). In contrast with Demand-Pull Inflation, Cost-Push Inflation is

The Arguments For And Against Wind Power

The Arguments For And Against Wind Power The idea of wind power as a sustainable energy source and a renewable replacement to the current method(s) of energy generation manages to divide opinion almost evenly. Due to the realisation of the damage being caused to our planet there has been a major emphasis on exploring new ways of acquiring energy or a source of energy. There will inevitably be pros and cons of wind energy to consider, more specifically wind turbine energy and with the aid of research and data analysis to illustrate arguments for both sides it will be become comprehensible that there are feasible reasons as to why I am somewhat sceptical. Wind power is an environmentally friendly and natural alternative form of energy that can be conserved and made useful by wind turbines. Wind turbines convert this energy into electricity, an energy by which the majority of human being as a race has become entirely dependent on. Whilst the reliance on electricity has increased, so too has the recognition of the possible affects current methods of energy generation has on the planet. Wind turbines are being looked at as a possible replacement for fossil energy for example. We know for sure that one day methods like burning fossil fuels will no longer be available. There is no doubt that alternatives are to be found for the sake of the future of the planet. These alternatives must be renewable and if possible inexhaustible. The question is, are wind turbines the answer? Personally I feel that without a dramatic progression wind power may not have enough to maintain its challenge against the diminishing cheap natural gas and Middle Eastern Oil. However as we consume the final remaining years of the natural gas and oil the apparent affects on the Earth and therefore the necessity for a replacement is there for all to see. Wind power is certainly an issue that divides people. Globally the underlying support has begun to surface but there is still a lack of concern amongst those who dont feel there is much to worry about with regard to the current state of affairs or at least thats the way it seems The quality of wind turbine has progressed as the technology has been explored; one only has to look at the windmill which is an early example of todays wind turbine. With any debate like this though you must identify and evaluate the advantages and disadvantages. There are a number of issues that fall into both categories and I by assessing these issues in the context of importance I will portray my point of view http://upload.wikimedia.org/wikipedia/commons/thumb/5/56/Doesburgermolen.jpg/200px-Doesburgermolen.jpg(Figure 1) http://en.wikipedia.org/wiki/File:Doesburgermolen.jpg Above is the Does burger windmill. Windmills like these were used primarily to grind grain, although they were also used to pump water from low-lying land. Modern Wind turbines have evolved from this idea and usually consist of three blades. They are designed in such a way that the tip speed is high but torque ripple is low, thus giving it high reliability. An example is the turbine below in Denmark. http://upload.wikimedia.org/wikipedia/commons/thumb/7/72/Turbine_aalborg.jpg/200px-Turbine_aalborg.jpg(Figure 2) http://en.wikipedia.org/wiki/File:Turbine_aalborg.jpg History http://upload.wikimedia.org/wikipedia/commons/thumb/5/55/Wind_turbine_1888_Charles_Brush.jpg/200px-Wind_turbine_1888_Charles_Brush.jpg(Figure 3) The worlds first automatically operated wind turbine was built in Cleveland in 1888 by Charles F. Bush. It was as high as 60 feet, had a 12 kW turbine and weighed in excess of four tons. (Taken from: http://en.wikipedia.org/wiki/File:Wind_turbine_1888_Charles_Brush.jpg ) If you study the history of the wind turbine there are obvious trends of development. Initially the Persians light devices driven by drag proved to be pioneering and the majority of turbine ideas today are adapted in some way from this early interpretation. persian.bmp (27790 bytes)(Figure 4) It is clear that despite the lack of effectiveness due to the amount of the rotor that does not interact with the wind the idea however is a good on taking into consideration the times and resources. As you look further along in time you recognise the increased use of materials for drag devices. Go forward again and the modern era designs revert back to light efficient aerodynamic lift devices. Early windmills consisted of vertical sails which were an adaptation of the earliest use of wind power, sail boats. There were no drawings or documentation detailing the very first designs, but below is an example of a Persian design that was then copied by the Americans in the 19th Century. http://www.telosnet.com/wind/images/panemone.jpg(Figure 5) The earliest known use was for grain grinding and later for water pumping, and even as living quarters. The most modern have been the three blade design but the vertical designs have not been abandoned. The initial windmills found in Europe had the horizontal-axis configuration. Realising that structurally the efficiency would increase, they evolved to vertical-axis. This dealt with the problem of losing up to half of the rotor collection area. Over time there was an incremental improvement in efficiency of the windmill sail. The most advanced windmill sail shared the same characteristics of a wind turbine blade. The mills were almost like the electric motors of their time. Their applications ranged from irrigation, grain-grinding, the common water-mill, saw milling of timber, and even the processing of other commodities such as cocoa, paints and tobacco. In the 19th century the use of large tower mills in Europe declined as the popularity of steam engines increased. Further wind power development came from America where they introduced much smaller systems. An example of this is the steel-bladed water pumping windmill made in the Mid West of America in the late 1800s. http://www.telosnet.com/wind/images/fanmill.jpg(Figure 6) Most of these mills had tails to orient them into the wind, but some were weather-vaning mills that operated downwind of the tower. Speed control of some models was provided by hinging sections of blades, so that they would fold back like an umbrella in high winds, an action which reduced the rotor capture area to reduce thrust. The most important refinement of the American fan-type windmill was the development of steel blades in 1870. Steel blades could be made lighter and worked into more efficient shapes. They worked so well, in fact, that their high speed required a reduction (slow-down) gear to turn the standard reciprocal pumps at the required speed. (Darrell Dodge: http://www.telosnet.com/wind/early.html ) Figure 6 and quote above is an illustration of how the mills evolved and were getting ever closer to the turbine designs of today. It was from these types of designs and applications that in the late 19th sparked the idea of using these multi-blade windmill designs to generate electricity. Thus bringing about Charles F Bushs design shown in Figure 3. Despite its success for more than twenty years, there were limitations in its ability to produce electricity. The low speed and high solidity of the rotor failed to reach the output potential of a modern design. Cost One of the main arguments a cynic such as myself will bring to the table is the initial outlay required to erect a wind turbine. Although costs such as maintenance, subsequently may not be excessive the cost to build and put up just one can be. Professor Tony Day of London South Bank University provided an enlightening Costs Chart that highlights just some of the initial costs one faces when you think about installing a residential wind turbine. This chart was taken from a presentation given by Tony Day. It demonstrates the costs that were endured in an example project he undertook. This chart was also from the same presentation. These are typical costs that are to be expected for the installation of some wind turbines. These are ball park figures and an example of only some of the costs. It is likely that there are many more to consider which will only increase the outlay. The more productive in terms of power output turbines will cost a lot more. A large Megawatt wind turbine can cost up to 1 million US dollars and gets much more expensive when to consider a wind farm. Other Considerations One of the most important elements to consider is how much power we can create and make useful from a wind turbine or wind turbine farm. At present the reward maybe isnt as satisfying as the initial cost would demand. Aside from cost though to ensure optimum opportunity to produce high levels of energy the following must be regarded: High wind sites it is important to situate a wind farm in an area where it is very windy. An average minimum wind speed of 12-13 miles per hour (6 meters per second) is mandatory. Proximity of existing infrastructure High voltage lines can be extremely expensive to establish so it is important to consider their proximity to the turbines. Access Whether onshore or offshore you need to be able to access your site, initially to set it up but also subsequently to maintain it. Advantages Wind power is renewable, plentiful and much less affects the planet than power generated by fossil fuels. It is currently the UKs leading renewable energy source overtaking hydropower and currently accounts for around 2% of the UKs electricity supply. There are no waste products and wind is naturally, readily available. If a small home wind turbine was installed in an ideal location, you could be less dependent on fossil fuel energy and wind power could be a replacement, even if it is just boiling your kettle! Electricity that is generated by wind bares no CO2 emissions and cannot be exhausted and due to the simplicity of their mechanical processes, a wind turbines running cost can be next to nothing. Depending on where you seek your information it is suggested that in a prime location, position and if installed accurately a turbine designed to power a house can potentially provide about 30% of a households electricity. It will probably take up to ten years though for them to pay from themselves. Widen the scope to a large scale wind turbine farm and the potential is there for it to be a big player within energy generation game, unfortunately it isnt there yet. Disadvantages The unpredictability of the wind is a major issue. Many think that the worlds weather is changing and becoming more unpredictable. If the areas that are high in wind become less so once wind farms are erect what would happen? A backup energy source would require a traditional polluting method of energy generation and would rather defeat the object! Apart from the initial costs already discussed you have to consider the planning permissions also. It isnt always straight forward for a wind farm to spring up. Even home wind turbines will require permission from the council. How much electricity generated is dependent on the speed and direction of the wind which isnt something that we can control. Location is vitally important but not always available and depending on the location you need to consider, obstructions and the height of the turbine. There are many groups who feel that wind turbines cause damage to habitats and can be dangerous to birds. There are also those who despise their appearance and what they do to the environment aesthetically. Noise pollution is also an issue although there are wind turbines that seem to have minimised if not eradicated this problem. There arent as many sites available as initially thought and those people who wish to have a personal wind turbine are required to test the wind speed for 3 months with an anemometer. Power Output To calculate the amount of power a turbine can actually generate from the wind, you need to know the wind speed at the turbine site and the turbine power rating. Most large turbines produce their maximum power at wind speeds around 15 meters per second (33 mph). Considering steady wind speeds, its the diameter of the rotor that determines how much energy a turbine can generate. Keep in mind that as a rotor diameter increases the height of the tower increases as well, which means more access to faster winds. Rotor Size and Maximum Power Output Rotor Diameter (meters) 10 17 27 33 40 44 48 54 64 72 80 Sources: Danish Wind Industry Association, American Wind Energy Association At 33 mph, most large turbines generate their rated power capacity, and at 45 mph (20 meters per second), most large turbines shut down. There are a number of safety systems that can turn off a turbine if wind speeds threaten the structure, including a remarkably simple vibration sensor used in some turbines that basically consists of a metal ball attached to a chain, poised on a tiny pedestal. If the turbine starts vibrating above a certain threshold, the ball falls off the pedestal, pulling on the chain and triggering a shut down. This information from howstuffworks.com shows how the rotor dimensions and its proportionality to power out. It portrays that an ideal wind speed is 33 mph. This is before it becomes dangerous. As already discussed a wind speed of about half of this is mandatory before you even think about building a wind turbine. When monitoring or calculating power output you must consider the correlation between it, the wind speed and the frequency of the wind speed. Below is a chart taken from Professor Tony Days presentation on wind turbines: The blue graph illustrates how the frequency and value of wind speed and what it means for power output. It confirms that at an average wind speed of about 6-8 metres per second, you can produce about 300 300kW of power. At this specific location you only get this about 8-9% of the time. And in that lies a problem. For wind power to be considered a major alternative you need a more frequent and reliable wind speed to ensure high levels of power is generated all the time. More to the point, the power that would be generated by wind farm for example given turbines of this specification; it would be a struggle to power a city let alone a nation. Whats next? There is clearly some way to go if the future of wind turbines is to overcome some peoples turbulent views. There are ideas in the pipeline and future design which will go some way to harnessing the energy more effectively to produce more power. Whilst residential wind turbines take the best part of a decade for you to see pay back on an investment the American Wind Energy Association suggest that payback can been seen a lot earlier with regard to wind farms. Overall, wind farms cost in the area of $1,000 per kW of capacity, so a wind farm consisting of seven 1.8-MW turbines runs about $12.6 million. The payback time for a large wind turbine is about three to eight months, according to the American Wind Energy Association. If this information is to be believed this payback time is reasonable but this does not take into consideration the initial cost of land, transmission lines and other infrastructure that are crucial to wind power systems. As time has gone on there have been some quite dramatic falls in the costs of wind energy. As technology improves the trend will continue it is just a question of how quickly. New ideas and designs are coming to light now also, for example the vertical axis turbine which seems to bare some advantages over its older brother is being reinvented all the time despite being a fairly new idea. Its design allows you to place the gear box and generators closer to the ground and there is no need to orient them in the direction of the wind. Also they can be kept closer together as they do not have a slowing affect on the air that a horizontal turbine would which means more can be build within a given space. Every Government wants to increase the amount of power generated by wind but the major stumbling block is always economic. Especially right now, cost of steel and turbines has increased immensely following the economic downturn so initial costs of a wind turbine are even higher. Even though wind will never run out, this makes it very difficult to budget for big plans to be implemented. Conclusion Whilst wind turbines present a great argument for clean reusable energy, there are issues that are positioned on the odds against category. It is widely believed that despite signs showing a change in the planets eco system the promotion of wind turbines has come about because of lobbying by industrialists as opposed to straightforward economics or science. Have we really caused as much damage as the green amongst us have suggested? Or has there been an overreaction? One issue you cannot ignore is that fossil fuel is exhaustible, maybe not in our life time but we certainly owe it to those who will inherit our planet to ensure they enjoy energy in the same way that we have. Costs of these machines are initially very high and many are only designed to last 25 years which adds a sting to an otherwise acceptable running cost. At the moment when running wind turbines coal generated power still has to be available as a backup which begs the question, are we really reducing our carbon emissions? Also the power generation from traditional methods is high and whilst it lasts is constant. There are no off days that can come about where the weather is concerned. Many also despise the look wind turbines and are against the damage visually that a wind farm can cause. There is also a very real danger to birds and the migration of birds as many have been injured by this new phenomenon. In an ideal world if wind power was to take over all wind farms will need to operate at 100% capacity 100% of the time which just cannot happen. The realistic operating maximum is about 50% and many wind farms fall below that now based on data from Ofgem, the energy regulator. Wind power is certainly one option we can turn to on a small scale its attributes will come in handy to an extent. But unless there are vast improvements in the technology and power output turbines will remain an entity that is perceived as useless by many because it produces derisory amounts of electricity at monumental cost. One could say, Too much wind and not enough puff!.