Creative thinking of business Essay Example | Topics and Well Written Essays - 1500 words

Creative thinking of business - Essay Example 1). While noting that the social environment can influence the frequency and level of creative behaviour, Amabile points out that creativity involves the production of novel, practical, and helpful ideas in any domain (Amabile 1996, p. 1). She further notes that the idea or product may not be different from their counterparts for merely the sake of being different. Instead, it should be relevant to the goal so desired, of value, correct, or meaningfully expressive. In respect to innovation, Amabile notes that it relates to the successful implementation of creative ideas within a business (Amabile 1996, p. 1). An analysis of Amabile’s definition of innovation reveals that the innovation begins by the creativity of a group or individual. Worth noting at this point is the fact that the success of an innovation not only depends on the creative ideas that apply to it but also on other factors and influences external to the organization. The don is also quick to note that creativity goes beyond intelligence and can be applied in any domain (science or art). Creative ideas and innovations can be good or bad (Amabile 1996, p. 1) or may be applied toward negative ends in as much as they may be good. Many business experts appreciate the notion of entrepreneurship being the application of creative destruction. What this basically means is that the entrepreneur pursues an idea and pursues it to make a profit overcoming obstacles to the creative process and therefore destroying existing equilibrium in the market or industry in which they operate. For entrepreneurs, creativity and innovation go together (Ekvall 1987, p. 56). The entrepreneur may apply creativity (and innovation) in developing new product/services, obtaining production resource, delivering products, identifying new markets for business services or products, and coming up with new ways of

General Safety and Security Essay Example for Free

General Safety and Security Essay * Investment in surveillance camera systems by school districts ensures parents and guardians that the general safety and security of children are being addressed during schools hours and at all after-school extracurricular activities and programs. 2. Crime Deterrent * The presence of highly visible surveillance cameras at strategic locations in buildings and public areas/premises of a school property prevents theft, vandalism and acts as a deterrent to thieves and criminals from indulging in illegal activities. 3. Sexual Predators * One of the biggest threats that school children face is the threat of sexual predators and pedophiles hanging around unobtrusively on school campuses or in parking lots. Camera systems footage is very useful in tracking down predators or helping inform police about threatening situations in real time. 4. Prevent Bullying * New-generation surveillance camera systems have audio, voice and sound capturing capabilities. Teenagers bullying or harassing other students can be disciplined based on video and audio footage records. 5. Emergency Evacuation * School security personnel manning surveillance camera systems in real-time can take quick action about evacuating children, faculty and staff in case of emergencies related to fire or other potentially dangerous situations. Prevent Theft and Illegal Activities * The primary purpose of installing surveillance cameras is to act as deterrence to robbers, criminals, petty thieves and unscrupulous elements from indulging in theft, illicit and criminal activities. Security cameras are installed in bungalows, townhouses, apartment buildings, condominiums, schools, university campuses, offices, stores, malls and other public areas. These cameras monitor suspicious activities; stop theft, vandalism and shoplifting; and alert stationed security officers about real-time thefts. Staff monitoring cameras and centrally manned systems in large businesses can also inform county and state law enforcement officials about developing dangerous situations.

Developments in the West End Musical Scene

Developments in the West End Musical Scene DISCUSS THE RECENT DEVELOPMENTS IN THE WEST END MUSICAL SCENE; THIS SHOULD INCLUDE AN ANALYSIS OF THE MEGA-MUSICAL MANIA, THE TREND TO CREATE NEW MUSICALS BASED ON EXISTING SONGS (SONG MIGRATION) AND STAGE TRANSFERS OF SUCCESSFUL FILMS. From Sophocles through William Shakespeare to Eminem, writers have sought to use the rhythms of language to accentuate the story they are seeking to share. The pre-Caxton[1] society relied on an oral tradition to deliver stories of fact and fiction. Cultures spanning the entire globe and all ages of civilization have instinctively adopted musical storytelling; it is prominent in various forms even now – be it around a camp fire, at a tribal ceremony, an inner city playground or on a West End stage. In todays world, language and music are at our fingertips. They are both instantaneous. And they can be married in a second. Technically, music is intricate. Most writers will say the same about language. But in an inspired moment they can conjoin and express something wonderful both sonically and linguistically. The act of constructing such a moment can be the end result of many less fruitful moments – but there is always the chance that it could just happen instantaneously. Our logistical minds tell us that it just is not possible; that we would never be able to express ourselves beautifully and eloquently in musical form. And yet the compulsion to try and do so has arrested most people, even if only for a quickly aborted solitary moment. So perhaps here lies the fascination with musicals. They show life as we know it happily residing in an alternate reality – where music and language are easy bed partners and everything goes to extremes. Or does it? The West End is one of Londons most popular tourist attractions. It has built its reputation, in tandem with New Yorks Broadway, as the commercial mecca of musical theatre. Las Vegas has the showgirls but Broadway and the West End share the showtunes. Indeed, while their identities are undeniably distinct, the relationship between them is close; same sex twins rather than identical ones. Each has their own nuances of behaviour – the younger twin Broadway hunts that bit more keenly for the next off-beat musical whirlwind; the older West End plays percentages but plays them with palpable success. The term West End was originally coined as a geographical short cut – a way of describing a part of London synonymous with theatre. Since its inception into London vernacular the phrase West End has mutated to describe something meta-geographical. While once upon a time it merely represented an actual place, now it also describes the gateway to an invented world of glitz, glamour and show. The West End may still be the home of theatre, but the kind of theatre that it houses has become very easily classifiable. The listings do not lie. And neither do they try to. The West End is a haven for small ideas done big; big names, big shows, big spectacles, big budgets, big risks. The social and artistic significance of theatre as an art form has not suffered in the time since the West End theatres were constructed. But the immediacy of rival entertainments, chiefly television and film, has undoubtedly provided so comfortable an alternative for the borderline theatregoing public that its popularity has. Ultimately, the publics relationship with theatre has somewhat inverted itself; once the entertainment of the people, theatre has become high-brow, elitist, exclusive even. Or so we are led to believe. Every year the people entrusted with running the countrys theatres are ensconced in attempts to make theatre more accessible. Nicholas Hytner at the National Theatre has incorporated a sponsorship deal with Travelex with the express purpose of enabling its shows to be available to people for as little as  £10 a ticket. Theatrical output is continuing to diversify in new directions. The National Theatre still produces the time-honoured classics that will appease their traditional supporters. But they also invited outside companies including Theatre de Complicite, Improbable, Shunt and Kneehigh to co-develop their new work. Arts Council funding dictates a certain amount of programming for in-house producing theatres throughout the country. It is impossible to equate the artistic worth of a proposed project while it exists solely as an outline on a piece of paper. But it is easier to quantify the greater social import of the same project. Therefore the involvement in various local outreach initiatives including young peoples theatre and new writing programmes serves duplicate purposes. But in doing so it runs the risk of wrestling a certain amount of control from the artistic directors, or at least diluting the intent of their work. But the West End is not really concerned with any of this. The theatres are privately owned and have little social obligation. West End theatre is a notoriously unpredictable money market. Make a big success of yourself and you can eventually buy it up – which is exactly what Andrew Lloyd Webber and Cameron Mackintosh have ended up doing. Lloyd Webbers Really Useful Group are the proprietors of twelve of the capitals larger theatres. By January 2006 Delfont Mackintosh will control another seven, and will have begun constructing the Sondheim Theatre – the first theatre to be built on Shaftesbury Avenue since 1931. The long-term plan of Delfont Mackintosh is to refurbish and modernise theatreland. But one cannot help but think that their extreme makeover will be restricted to the facilities and layout – and that the entertainment will remain as traditional as ever. The musical-as-we-know-it grew out of the 19th Century tradition of music hall, which itself was the bastard son of drink and rowdiness. After removing the alcohol from drunken singalongs, and relocating from the pub to theatres, the 1860s saw the popularity of the newly-arrived music hall go from good idea to massively popular entertainment. The humbling beginnings of the musical cannot help but reveal the nucleus of the idea; it was born of accident – of people seeking to have pure, unadulterated entertainment. In that respect, it has no one form; no one philosophy; indeed no real sense of philosophy; no real sense of purpose other than fun, fun, fun! As the musical was developing it was the bastion of popular music of the time. Through Gilbert and Sullivan, Irving Berlin, Bertolt Brecht and Kurt Weill and Cole Porter, the men and women behind musical were the most revered song writers at work in the Western world. Ten years into the post-war era there was a marked shift. The musical standards that made dry, wry and witty observations about upper middle class were about to be trumped by rock and roll. And John Osbournes 1956 kitchen-sink-drama Look Back In Anger was going to have repercussions outside the world of the well-made play[2]. The birth of transmittable media was only going to swell the amount of music being produced. In the early days of the wireless radio, families gathered to listen to the songs of Ivor Novello or Noel Coward. By the mid-1960s many families had television sets in their front rooms; radio broadcasts were a competitive business; and air transport links had made the world traversable for all those who could afford it. Music was a commodity that could be sent from one side of the world to the other. And in the slipstream of the music were the musicians themselves. Through television and radio, songwriters and musicians had an identity. They became icons – the most celebrated people on the planet. And their music was nowhere near the West End stage. For the first time since their inception musicals were not using the popular music of the time. Rocknroll was being held in musical purgatory by traditionalists unhappy at its low-brow ideals. While cinema was running as fast and far as it could with the concept of the film musical, the stage was seeking to deliver variations on earlier themes. Elvis Presley made numerous musical films – as did The Beatles. In the 1960s the West End was awash with Broadway imports – the influence of Leonard Bernstein, Rodgers and Hammerstein, Lerner and Loewe and other transatlantic success stories was diluting the integrity of the West End as the older brother of the musical. But the psychedelic overtones of that time were to create musical anomalies; while some composers flirted with the conce pt of rock, others werent afraid to dive headlong into its bottomless pit. After its anti-Vietnam stance and inclusion of group nudity caused outrage on Broadway, Hair opened in the West End in 1968. From being the chosen playground of mild-mannered conservatives, the musical was being politicised – and modernised. Within five years, the Age of Aquarius[3] had been further capitalized upon by Godspell, Oh Calcutta and even Jesus Christ Superstar – which proved to be the foundation on which the new dawn of the musical would be built. Todays twin Godfathers of musical composition for Broadway and the West End carry the bright torch of yesteryear; Stephen Sondheim represents his forefathers fascination with the off-beat, with Andrew Lloyd Webber never straying from the musically conservative beat. There are various factors that dictate the recent successes and failures in West End theatre. But the starting point for every West End production is money – a fact beautifully demonstrated by the plot of one of the West Ends most popular current productions The Producers. Essentially, the capitalist dawn that swallowed up free love has made currency the new leading man in musical theatre. Producers need big ideas and big songs to legislate for big budgets. So instead of trying to predict what people may like and creating a musical story around it, the West End decided to reduce the risk and simply take the music that people already like and create a story around that. In some ways the origin of song migration is old revue style shows – popular hits belted out with no real desire to create an accompanying piece of drama or comedy. Coupled with the screen to stage success of musical films like The Lion King, a producer was now able to weigh up potential West End shows safe in the knowledge that a stable of worldwide smash hits could enable a musical to run for years, even with a bad review. Suddenly the sheer bankability of Lloyd Webber was looking like an outlandish risk alongside the music of Abba[4], Queen[5] or even (the critically lauded but never supergroup status) of Madness[6]. Negotiations are in process for the trend to continue, with Bob Marley, The Beatles and Elton John just some of the musical legends in line to have their songs shoe-horned into some money-spinning stage extravaganza that makes almost no sense at all. Not that the public really care. They want to go and sing-a-long like the pub dwellers of the 1840s that unknowi ngly helped begin the process of musical theatre. And who shall we choose to lead the sing-song? Well, preferably someone famous off the telly, of course. The West End is a remarkably lucrative place. For his unscheduled stint in the opening cast run of The Producers at the end of 2004, Nathan Lane was being paid  £42,000 a week for the lead role as Max Bialystock. It is a clear indication of the simple transaction between moneymen and talent; the star name guarantees the box office receipts. The West End has been flooded with stars – some of whom have no musical pedigree – because celebrity is deemed to have finally overridden talent. The good, bad and ugly (in no particular order) of recent years include David Hasselhoff[7], Martine McCutcheon[8] and Denise Van Outen[9]. And if you dont want to spend money on star names, then youd better be sure to have some seriously impressive stage gimmicks; Miss Saigon famously had a helicopter, Chitty Chitty Bang Bang got in to hot water when the eponymous flying car failed to take off in previews, and Phantom of the Opera has a plunging chandelier moment that will wake up anyone snoozing in the stalls. So with standard tickets averaging out at around  £40, the theatregoer demands a truly amazing experience. But amazing and original are poles apart – and thats why when the formula is right, all you need to do is repeat it. There are exceptions. The Bombitty of Errors was a rap interpretation of Shakespeares Comedy of Errors, and was a small but perfectly-formed global success. Stomp became a phenomenon through gradual word of mouth and because it is a different kind of spectacle. Jerry Springer: The Opera began life as an idea at a scratch night at the Battersea Arts Centre and grabbed the attention of every newspaper and fundamentalist Christian in the Western World. But such shows grow from humble beginnings and are swept away on public curiosity. As in any art form, there are people willing to take risks because they believe their work has a market. Bombay Dreams and The Far Pavilions identify a recently developed appreciation of Asian music and culture. The off-Broadway hit Batboy continues in the tradition of earlier pacesetters The Rocky Horror Picture Show and Hedwig and the Angry Inch for kitsch rock operas. But some of these are accidental intruders in the world of the West End. They werent sure if they were really invited but came anyway. One group that certainly were invited are blockbuster films; whether they have songs in them or not. Seemingly the films dont even have to have been that successful. The Witches of Eastwick had a successful run in the West End. But more than likely, the film will have a readymade audience. The Full Monty was relocated to middle America from Sheffield to make it a Broadway success. Billy Elliott is well into previews, but the advance word is that it will be a significant hit. Or better still, just take a film with songs already in them – you dont stand to make as much money, but the guarantee of an audience is that much stronger. Mary Poppins has been well-received by most, and Chitty Chitty Bang Bang is in its third year. There are currently 36 theatres in the West End of Londons theatreland[10]. As of Monday 2 May 2005, 27 are currently housing a production. 17 of those are musicals. This ratio is fairly consistent – and shows no signs of relenting. Essentially a hit West End musical needs a hook; star name, hit songs, hit movie, famous composer, popular revival. Something that can be reduced to a two-word phrase. If you havent got any of those, then heaven help you. Because the West End public certainly wont. BIBLIOGRAPHY In-yer-face Theatre: British Drama TodayAleks Sierz Faber Faber2001 Scene Unseen: Londons West End TheatresBarson, Kendall, Longman, SmithEnglish Heritage Publications 2003 Brewers Theatre: Phrase Fable DictionaryCassell Market House Books1994 MusicalsKurt Ganzl Carlton Books2004 Time Out (London) Issue No. 1810 April 27-May 4 2005 Musicals 101.com 1 Footnotes [1] William Caxton, inventor of the printing press (1474), which enabled literature to be mass-produced and readily available to the public. [2] A term coined by Terrence Rattigan for the four-act structure of a play that had been the norm for successful playwrights in the first half of the Twentieth Century. [3] A term synonymous with late 60s flower power and liberal ideologies – derived from a song from the musical Hair. [4] Mamma Mia. [5] We Will Rock You. [6] Our House. [7] Chicago, Adelphi Theatre, 2004 [8] My Fair Lady, Theatre Royal Drury Lane, 2001 [9] Chicago, Adelphi, 2001, Tell Me On A Sunday, Gielgud, 2003 [10] They are the Adelphi, Albery, Aldwych, Apollo, Arts, Cambridge, Comedy, Criterion, Dominion, Theatre Royal Drury Lane, Duchess, Duke of Yorks, Fortune, Garrick, Gielgud, Haymarket, Her Majestys, London Palladium, Lyceum, Lyric, New Ambassadors, New London, Palace, Phoenix, Piccadilly, Playhouse, Prince Edward, Prince of Wales, Queens, Savoy, Shaftesbury, St Martins, Strand, Trafalgar Studios, Vaudeville, Wyndhams. Other central theatres not classified as West End include the Donmar Warehouse, National Theatre, Old Vic, Victoria Palace, Apollo Victoria, Lilian Baylis Saddlers Wells, Peacock, Almeida and the Royal Court.

Mental Health Community in the 19th Century Essay -- Exploratory Essay

Mental Health Community in the 19th Century Mental health is a relevant issue in Joseph Conrad’s Heart of Darkness. Not only is Kurtz’ mental health questionable throughout the novel, but Marlow also has to be examined by a physician, to check both his physical and mental status, before he starts on the journey to Africa. The mental health community in the late 19th and early 20th centuries was not nearly as developed as it is today, but many developments during this time period had a profound impact on the way we analyze the human psyche and mental health today. Mental health patients were considered innately inferior and treated as the weaker portion of the human race due to the prevailing dominant theory of Social Darwinism in the 1800s. They were put in mental asylums, where conditions had deteriorated substantially from earlier in the century. (Floyd) The public’s interest about the unsatisfactory care of the mentally ill, championed by Dorothea Dix, led to some reforms, such as higher medical standards, more oversight into asylum practices, and more research into mental health. (Floyd) Nevertheless, the status of the mentally ill did not elevate much higher, and by the 1890s the repeated failure of asylum therapy convinced most that insanity and mental illness was incorrigible. Finding no alternatives, however, patients continued to be sent to asylums to attempt to cure them as much as to isolate them from the rest of society. (Roberts) Unfortunately, people also began to fear the proliferation of the mentally ill. When ste rilization became considered, unrealistic, more, cheaper asylums were built as a means of segregated them and preventing an increase in their numbers. (Roberts) ... ...h Care. 6 Oct. 2002 http://www.mind.org.uk/information/factsheets/N/notes/notes_on_the_history_of_menta l_health_care.asp> Floyd, Barbara. From Quackery to Bacteriology. University of Toledo. 6 Oct. 2002 Mills, Val. Cognitive Behavioural Therapy (CBT) 6 Oct. 2002 Mustard, Ronnie. Listings: the history of mental health. 6 Oct. 2002 . Roberts, Andrew. Mental Health History Timeline. 6 Oct. 2000 . Sabbatini, Renato M.E. â€Å"The History of Psychosurgery† June/August 1997. Brain & Mind Magazine. 14 Jun.1997. State University of Campinus, Brazil. 6 Oct. 2002 http://www.epub.org.br/cm/n02/historia/psicocirg_i.htm>

What is Bayesian Thinking?

It is common knowledge that human beings commit errors in judgment all the time. In areas of uncertainty, most of us go with our gut intuition, and in most cases this intuition turns out to be wrong. Much of this is derived from the fact that humans are poor statistical thinkers, and thus poor Bayesian thinkers. What is Bayesian thinking? Let us start with an illustrative example, called the Monty Hall problem — famously depicted in the Kevin Spacey movie â€Å"21.† There are three doors, and behind each door is either a goat or a car. There will always be two doors with goats and one door with a car. The player first chooses a door without opening, and the game show host whose interests are opposed to the player, proceeds to open a different door. Since the host knows what is behind each door, he always opens a door with a goat. Now that the player is left with the initially chosen door and another closed door, the host offers an opportunity to switch to the other unopened door. Should the player switch? The answer for an intuitive Bayesian, a purely statistical thinker, should be easy. Unfortunately, human beings are not intuitive Bayesians. In fact, most people answer that it doesn't matter if the player switches or not, since the probability of winning a car is 50% between the two doors anyways. They would be wrong. Now, before we examine the correct way to think about this problem, one might ask, so what? Why does it matter if humans are not intuitive Bayesians, or even more broadly, bad statistical thinkers? Simply, Bayesian reasoning corrects some of the issues with bad statistical thinking. Bad statistical thinking leads to bad judgments and decisions, which have a wide variety of consequences in everyday life as well as in arenas such as politics and science. Thus, everyone should become better Bayesian thinkers, because under uncertainty, accurate probabilistic judgments are useful and important.To give a accurate depiction of how Bayesian reasoning works, let us return to the Monty Hall problem, and examine why not only switching doors matters, but that it is beneficial to switch. When the host first opened the door with the goat, something happened: opening the door gave the player extra information, and thus changed the probability of outcomes. By utilizing this extra information, it is no longer a 50% chance for the player to win the car after switching doors, but a ~67% (2/3) chance. Let us suppose that the player picks the door which contains the car. The host opens either the first goat door or the second (it does not matter), and the player switches to the other goat door and loses. Now, suppose the player picks the first goat door instead, which means the host is forced to open the second goat door. Since the only other door contains the car, the player switches and wins. Lastly, suppose the player picks the second goat door. The host is forced to open the first goat door, which again, means the player will win the car after a switch. These are the only three possible scenarios, and so we see that the probability of winning is two out of three if the player switches. Conversely, what if the player doesn't switch? In the first scenario, the player wins the car, but in scenarios two and three, the player obviously loses. Thus, to not switch is to have only a 33% (1/3) chance to win the car.The Monty Hall problem is a rather simple illustration of how Bayesian reasoning works, so in order to gain a more complete understanding, we must explore its principles. In 1763, a paper by Reverend Thomas Bayes was published posthumously called â€Å"An Essay towards solving a Problem in the Doctrine of Chances,† and brought about a paradigmatic shift in statistics: by using ever-increasing information and experience, one can gradually approach the unknown or understand the unknown (of course, his main motive was to prove the existence of God). Fundamentally, Bayesian reasoning believes in the correction of probabilities over time, and that all probabilities are merely estimates of the likelihood of events to occur. Through the further efforts of mathematicians like Lagrange in perfecting the Bayesian framework, we now have a modern and complete theory of probability. First, there are what we call priors, which is the strength of our beliefs, or put it another way, the likelihood that we are to change our beliefs. Then, we have our posteriors, which is the empirical aspect, or the influx of new information. The Bayesian framework then takes these two components and mathematically analyzes how posteriors affect priors. If we know nothing about an event, then all we can do is estimate a probability. However, if there is new information, then the probability must be corrected based on this new information. Over time, as experiences grow through more information, these estimates of probabilities will eventually fit â€Å"reality.† In the Monty Hall case, the moment the the host opened the goat door, that influx of new information, or change in posteriors, immediately influences the player's priors. If the host doesn't open a door, the player merely has a 33% chance to win the car between the three doors, and switching makes no difference. However, since the host removes a door, and specifically the door that contains a goat, these two new posteriors directly influence the original prior from 33% to 66%. One might think that this method of thinking is mysteriously similar to the scientific method, which is certainly true. However, To put it another way, Bayesian thinking is how to use some known information or experience to judge or predict the unknown. For example, event A is â€Å"rainy tomorrow† and event B is â€Å"cloudy tonight†. If you see cloudy tonight, what is the probability of raining tomorrow? If you use the Bayes theorem directly, you only need to know the probability of raining every day, the probability of cloudy nightly, and if one day it rains, then the probability of the cloudy night of the previous night will be substituted into the formula and done. The question is, where do these probabilities come from, and how do we infer the possibility based on the information we have . In fact, most of the valuable problems are backward problems, for example: the stock market, through those few signs can be judged to be a more or less opportunity; the hospital, through which symptoms can determine what is the disease; science Research, through several experimental data, you can construct what theory to explain the model and so on. In general, mathematicians, physicists, etc. are all about backward problems, or they can not predict or judge the outcome with few signs or phenomena, and there is no value (by the way, do not know the reverse Problem-thinking people can not fight in the financial market or the stock market. At present, the most advanced research in the speculative market is almost a process of backward stochastic process and martingale theory. It is known that the incidence of a disease is 0.001, that is, 1 in 1,000 people is sick. There is a reagent that can test whether a patient is sick or not, and its accuracy is 0.99, which means that 99% of the patients may be positive when the patient really gets sick. Its false positive rate is 5%, which means that 5% of the patients may get positive if they do not get sick. There is a positive test result of a patient, what is the probability that he does get sick?We got a staggering result of about 0.019. In other words, even if the test is positive, the probability of getting sick is only increased from 0.1% to 2%. This is the so-called â€Å"false positive†, that is, the positive result is not enough to show that the patient is sick.Why is this? Why is the accuracy of this test up to 99%, but the credibility is less than 2%? The answer is related to its false positive rate. Here we see the power of the Bayesian theorem, that it allows us to deduce the unknown probability from the known probability and the information at hand.The human brain and quantification vs heuristic thinking. The advantage of Bayesian analysis is that it does not require any objective estimation, just guess a priori casually. This is the key, because most of the events that occur in the real world have no objective probability. This is actually very similar to the scientific method: we did not know anything from the beginning, but we are willing to experiment and gradually find out the laws of nature. Bayesian reasoning operates in the same way, through continually the posterior probability in accordance with existing experimental data. Biggest problem with Bayesian reasoning is that human brains cannot quantify information easily. The most commonly raised example is Malcolm Gladwell's â€Å"Outliers†, where many people who are trained enough in certain low-chaotic environments make correct decisions and judgments without using the Bayesian framework at all. Firefighters, for example, do not undergo a Bayesian calculus before deciding whether or not it's safe to pull a child out of a burning building. They just do it because they've done it many times before, and have a rough heuristic estimate on the safety of such an action. Similarly, chess players do not use Bayesian analysis to think many turns ahead; what research has found is that through thousands of hours of practice and becoming familiar and experienced with similar setpieces in the past, gives them an ability to predict moves assuming that the opposing player is also rational. Conversely, high chaotic environments, such as the political sphere, is where Bayesian reasoning thrives due to the high amount of uncertainty.The other criticism are from the frequentists. In general, the probability of teaching in school can be called frequencyism. An event, if performed repeatedly multiple times independently, dividing the number of occurrences by the number of executions yields a frequency. For example, throwing coins, throwing 10000 times, 4976 times positive, the frequency is 0.4976. Then if the implementation of many many, the frequency will tend to a fixed value, is the probability of this time. In fact, to prove it involves the central limit theorem, but it does not start.

Relational Calculus Essay

Introduction Procedural Query language query specification involves giving a step by step process of obtaining the query result e.g., relational algebra usage calls for detailed knowledge of the operators involved difficult for the use of non-experts Declarative Query language query specification involves giving the logical conditions the results are required to satisfy easy for the use of non-experts Prof P Sreenivasa Kumar, Department of CS&E, IITM. 1 TRC – a declarative query language Tuple variable – associated with a relation ( called the range relation ) †¢ takes tuples from the range relation as its values †¢ t: tuple variable over relation r with scheme R(A,B,C ) t.A stands for value of column A etc TRC Query – basic form: { t1.Ai1, t2.Ai2,†¦tm.Aim | ÃŽ ¸ } predicate calculus expression involving tuple variables t1, t2,†¦, tm, tm+1,†¦,ts – specifies the condition to be satisfied Prof P Sreenivasa Kumar, Department of CS&E, IITM. 2 An example TRC query student (rollNo, name, degree, year, sex, deptNo, advisor ) department (deptId, name, hod, phone ) Obtain the rollNo, name of all girl students in the Maths Dept (deptId = 2) {s.rollNo,s.name| student(s)^ s.sex=‘F’^ s.deptNo=2} attributes required in the result This predicate is true whenever value of s is a tuple from the student relation, false otherwise In general, if t is a tuple variable with range relation r, r( t ) is taken as a predicate which is true if and only if the value of t is a tuple in r Prof P Sreenivasa Kumar, Department of CS&E, IITM. 3 General form of the condition in TRC queries Atomic expressions are the following: 1. r ( t ) -true if t is a tuple in the relation instance r 2. t1. Ai t2 .Aj compOp is one of {, ≠¥, =, ≠  } 3. t.Ai c c is a constant of appropriate type Composite expressions: 1. Any atomic expression 2. F1 ∠§ F2 ,, F1 ∠¨ F2 ,  ¬ F1 where F1 and F2 are expressions 3. (∀t) (F), (âˆÆ't) (F) where F is an expression and t is a tuple variable Free Variables Bound Variables – quantified variables Prof P Sreenivasa Kumar, Department of CS&E, IITM. 4 Interpretation of the query in TRC All possible tuple assignments to the free variables in the query are considered. For any specific assignment, if the expression to the right of the vertical bar evaluates to true, that combination of tuple values would be used to produce a tuple in the result relation. While producing the result tuple, the values of the attributes for the corresponding tuple variables as specified on the left side of the vertical bar would be used. Note: The only free variables are the ones that appear to the left of the vertical bar Prof P Sreenivasa Kumar, Department of CS&E, IITM. 5 Example TRC queries Obtain the rollNo, name of all girl students in the Maths Dept {s.rollNo,s.name | student(s) ^ s.sex=‘F’ ^ (âˆÆ' d)(department(d) ^ d.name=‘Maths’ ^ d.deptId = s.deptNo)} s: free tuple variable d: existentially bound tuple variable Existentially or universally quantified tuple variables can be used on the RHS of the vertical bar to specify query conditions Attributes of free (or unbound ) tuple variables can be used on LHS of vertical bar to specify attributes required in the results Prof P Sreenivasa Kumar, Department of CS&E, IITM. 6 Example Relational Scheme student (rollNo, name, degree, year, sex, deptNo, advisor) department (deptId, name, hod, phone) professor (empId, name, sex, startYear, deptNo, phone) course (courseId, cname, credits, deptNo) enrollment (rollNo, courseId, sem, year, grade) teaching (empId, courseId, sem, year, classRoom) preRequisite (preReqCourse, courseID) Prof P Sreenivasa Kumar, Department of CS&E, IITM. 7 Q2 Q3 Q4 Q5 Example queries in TRC (1/5) 1)Determine the departments that do not have any girl students student (rollNo, name, degree, year, sex, deptNo, advisor) department (deptId, name, hod, phone) {d.name|department(d) ^  ¬(âˆÆ' s)(student(s) ^ s.sex =‘F’ ^ s.deptNo = d.deptId) Prof P Sreenivasa Kumar, Department of CS&E, IITM. 8 Examples queries in TRC (2/5) Schema 2)Obtain the names of courses enrolled by student named Mahesh {c.name | course(c) ^ (âˆÆ's) (âˆÆ'e) ( student(s) ^ enrollment(e) ^ s.name = â€Å"Mahesh† ^ s.rollNo = e.rollNo ^ c.courseId = e.courseId } Prof P Sreenivasa Kumar, Department of CS&E, IITM. 9 Examples queries in TRC (3/5) Schema 3)Get the names of students who have scored ‘S’ in all subjects they have enrolled. Assume that every student is enrolled in at least one course. {s.name | student(s) ^ (∀e)(( enrollment(e) ^ e.rollNo = s.rollNo) → e.grade =‘S’)} person P with all S grades: for enrollment tuples not having her roll number, LHS is false for enrollment tuples having her roll number, LHS is true, RHS also true so the implication is true for all e tuples person Q with some non-S grades: for enrollment tuples not having her roll number, LHS is false for enrollment tuples having her roll number, LHS is true, but RHS is false for at least one tuple. So the implication is not true for at least one tuple. Prof P Sreenivasa Kumar, Department of CS&E, IITM. 10 Examples queries in TRC (4/5) Schema 4) Get the names of students who have taken at least one course taught by their advisor {s.name | student(s) ^ (âˆÆ'e)(âˆÆ't)(enrollment(e) ^ teaching(t) ^ e.courseId = t.courseId ^ e.rollNo = s.rollNo ^ t.empId = s.advisor} 5) Display the departments whose HODs are teaching at least one course in the current semester {d.name | department(d) ^(âˆÆ't)(teaching(t) ^ t.empid = d.hod ^ t.sem = ‘odd’ ^ t.year = ‘2008’)} Prof P Sreenivasa Kumar, Department of CS&E, IITM. 11 Examples queries in TRC (5/5) Schema 6)Determine the students who are enrolled for every course taught by Prof Ramanujam. Assume that Prof Ramanujam teaches at least one course. 1. {s.rollNo | student (s) ^ 2. (∀c)(course (c) ^ 3. ((âˆÆ't),(âˆÆ'p)( teaching(t) ^ professor(p) ^ 4. t.courseId = c.courseId ^ 5. p.name = â€Å"Ramanujam† ^ 6. p.empId = t.empId )) → 7. (âˆÆ'e) (enrollment(e) ^ 8. e.courseId = c.courseId ^ 9. e.rollNo = s.rollNo) 10. ) 11. } Prof P Sreenivasa Kumar, Department of CS&E, IITM. 12 Problem with unrestricted use of Negation What is the result of the query: {s.rollNo |  ¬ student(s)} ? Infinite answers !! Unsafe TRC expression : Any expression whose result uses â€Å"constants / values† that do not appear in the instances of any of the database relations. Unsafe expressions are to be avoided while specifying TRC queries. Prof P Sreenivasa Kumar, Department of CS&E, IITM. 13 Expressive power of TRC and Relational Algebra It can be shown that both Tuple Relational Calculus and Relational Algebra have the same expressive power A query can be formulated in (safe) TRC if and only if it can be formulated in RA Both can not be used to formulate queries involving transitive closure — find all direct or indirect pre-requisites of a course — find all subordinates of a specific employee etc. Prof P Sreenivasa Kumar, Department of CS&E, IITM.