|
Common Cause And Special Cause (statistics)
Common and special causes are the two distinct origins of variation in a process, as defined in the statistical thinking and methods of Walter A. Shewhart and W. Edwards Deming. Briefly, "common causes", also called natural patterns, are the usual, historical, quantifiable variation in a system, while "special causes" are unusual, not previously observed, non-quantifiable variation. The distinction is fundamental in philosophy of statistics and philosophy of probability, with different treatment of these issues being a classic issue of probability interpretations, being recognised and discussed as early as 1703 by Gottfried Leibniz; various alternative names have been used over the years. The distinction has been particularly important in the thinking of economists Frank Knight, John Maynard Keynes and G. L. S. Shackle. Origins and concepts In 1703, Jacob Bernoulli wrote to Gottfried Leibniz to discuss their shared interest in applying mathematics and probability to game ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Statistical Thinking
Statistical thinking is one of the tools for process analysis. Statistical thinking relates processes and statistics, and is based on the following principles: * All work occurs in a system of interconnected processes. * Variation exists in all processes * Understanding and reducing variation are keys to success. W. Edwards Deming promoted the concepts of statistical thinking, using two powerful experiments: 1. The Red Bead experiment, in which workers are tasked with running a more or less random procedure, yet the lowest "performing" workers are fired. The experiment demonstrates how the natural variability in a process can dwarf the contribution of individual workers' talent. 2. The Funnel experiment, again demonstrating that natural variability in a process can loom larger than it ought to. The takehome message from the experiments is that before management adjusts a process -- such as by firing seemingly underperforming employees, or by making physical changes to an appa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Statistical Control
Statistical process control (SPC) or statistical quality control (SQC) is the application of statistical methods to monitor and control the quality of a production process. This helps to ensure that the process operates efficiently, producing more specification-conforming products with less waste (rework or scrap). SPC can be applied to any process where the "conforming product" (product meeting specifications) output can be measured. Key tools used in SPC include run charts, control charts, a focus on continuous improvement, and the design of experiments. An example of a process where SPC is applied is manufacturing lines. SPC must be practiced in two phases: The first phase is the initial establishment of the process, and the second phase is the regular production use of the process. In the second phase, a decision of the period to be examined must be made, depending upon the change in 5M&E conditions (Man, Machine, Material, Method, Movement, Environment) and wear rate of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Full Employment
Full employment is a situation in which there is no cyclical or deficient-demand unemployment. Full employment does not entail the disappearance of all unemployment, as other kinds of unemployment, namely structural and frictional, may remain. For instance, workers who are "between jobs" for short periods of time as they search for better employment are not counted against full employment, as such unemployment is frictional rather than cyclical. An economy with full employment might also have unemployment or underemployment where part-time workers cannot find jobs appropriate to their skill level, as such unemployment is considered structural rather than cyclical. Full employment marks the point past which expansionary fiscal and/or monetary policy cannot reduce unemployment any further without causing inflation. Some economists define full employment somewhat differently, as the unemployment rate at which inflation does not continuously increase. Advocacy of avoiding acceleratin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ludwig Von Mises
Ludwig Heinrich Edler von Mises (; 29 September 1881 – 10 October 1973) was an Austrian School economist, historian, logician, and Sociology, sociologist. Mises wrote and lectured extensively on the societal contributions of classical liberalism. He is best known for his work on praxeology studies Bureaucracy (book), comparing communism and capitalism. He is considered one of the most influential economic and political thinkers of the 20th century. Mises emigrated from Austria to the United States in 1940. Since the mid-20th century, libertarian movements have been strongly influenced by Mises's writings. Mises' student Friedrich Hayek viewed Mises as one of the major figures in the revival of classical liberalism in the post-war era. Hayek's work "The Transmission of the Ideals of Freedom" (1951) pays high tribute to the influence of Mises in the 20th century libertarian movement. Mises's Private Seminar was a leading group of economists. Many of its alumni, including Friedri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Expected Utility
The expected utility hypothesis is a popular concept in economics that serves as a reference guide for decisions when the payoff is uncertain. The theory recommends which option rational individuals should choose in a complex situation, based on their risk appetite and preferences. The expected utility hypothesis states an agent chooses between risky prospects by comparing expected utility values (i.e. the weighted sum of adding the respective utility values of payoffs multiplied by their probabilities). The summarised formula for expected utility is U(p)=\sum u(x_k)p_k where p_k is the probability that outcome indexed by k with payoff x_k is realized, and function ''u'' expresses the utility of each respective payoff. On a graph, the curvature of u will explain the agent's risk attitude. For example, if an agent derives 0 utils from 0 apples, 2 utils from one apple, and 3 utils from two apples, their expected utility for a 50–50 gamble between zero apples and two is 0.5''u''(0 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knightian Uncertainty
In economics, Knightian uncertainty is a lack of any quantifiable knowledge about some possible occurrence, as opposed to the presence of quantifiable risk (e.g., that in statistical noise or a parameter's confidence interval). The concept acknowledges some fundamental degree of ignorance, a limit to knowledge, and an essential unpredictability of future events. Knightian uncertainty is named after University of Chicago economist Frank Knight (1885–1972), who distinguished risk and uncertainty in his 1921 work ''Risk, Uncertainty, and Profit:''Knight, F. H. (1921Risk, Uncertainty, and Profit Boston, MA: Hart, Schaffner & Marx; Houghton Mifflin Company :"Uncertainty must be taken in a sense radically distinct from the familiar notion of Risk, from which it has never been properly separated.... The essential fact is that 'risk' means in some cases a quantity susceptible of measurement, while at other times it is something distinctly not of this character; and there are far-re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Click Fraud
Click, Klick and Klik may refer to: Airlines * Click Airways, a UAE airline * Clickair, a Spanish airline * MexicanaClick, a Mexican airline Art, entertainment, and media Fictional characters * Klick (fictional species), an alien race in the game ''Alternity'' * Click, a minor character in The Rock-afire Explosion Music Stage Show Film * ''Click'' (2006 film), an American comedy starring Adam Sandler * ''Click'' (2010 film), a Hindi horror film Music * ''The Click'' (album), a 2017 album by pop band AJR * Click track Artists * The Click, an American hip hop group Songs * "Click" (ClariS song) * "Click" (Charli XCX song) * "The Click" (song), a song by Good Charlotte * "Click", a song by Anahí, Ale Sergi and Jay de la Cueva * "Click", a song by Little Boots from ''Hands'' Print * ''Click'' (comics) * Click (novel) * ''Click!'', a newspaper * ''Click'', a science magazine for children by the publishers of ''Spider'' * "Click", a short story by R. L. Stine in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltage Spike
In electrical engineering, spikes are fast, short duration electrical transients in voltage (voltage spikes), current (current spikes), or transferred energy (energy spikes) in an electrical circuit. Fast, short duration electrical transients (overvoltages) in the electric potential of a circuit are typically caused by * Lightning strikes * Power outages * Tripped circuit breakers * Short circuits * Power transitions in other large equipment on the same power line * Malfunctions caused by the power company * Electromagnetic pulses (EMP) with electromagnetic energy distributed typically up to the 100 kHz and 1 MHz frequency range. * Inductive spikes In the design of critical infrastructure and military hardware, one concern is of pulses produced by nuclear explosions, whose nuclear electromagnetic pulses distribute large energies in frequencies from 1 kHz into the gigahertz range through the atmosphere. The effect of a voltage spike is to produce a correspond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crash (computing)
In computing, a crash, or system crash, occurs when a computer program such as a software application or an operating system stops functioning properly and exits. On some operating systems or individual applications, a crash reporting service will report the crash and any details relating to it (or give the user the option to do so), usually to the developer(s) of the application. If the program is a critical part of the operating system, the entire system may crash or hang, often resulting in a kernel panic or fatal system error. Most crashes are the result of a software bug. Typical causes include accessing invalid memory addresses, incorrect address values in the program counter, buffer overflow, overwriting a portion of the affected program code due to an earlier bug, executing invalid machine instructions (an illegal opcode), or triggering an unhandled exception. The original software bug that started this chain of events is typically considered to be the cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sleeping While On Duty
Sleeping while on duty or sleeping on the job – falling asleep while one is not supposed to – is considered gross misconduct and grounds for disciplinary action, including termination of employment, in some occupations. Recently however, there has been a movement in support of sleeping, or napping at work, with scientific studies highlighting health and productivity benefits, and over 6% of employers in some countries providing facilities to do so. In some types of work, such as firefighting or live-in caregiving, sleeping at least part of the shift may be an expected part of paid work time. While some employees who sleep while on duty in violation do so intentionally and hope not to get caught, others intend in good faith to stay awake, and accidentally doze. Sleeping while on duty is such an important issue that it is addressed in the employee handbook in some workplaces. Concerns that employers have may include the lack of productivity, the unprofessional appearance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Response Time (technology)
In technology, response time is the time a system or functional unit takes to react to a given input. Computing Response time is the total amount of time it takes to respond to a request for service. That service can be anything from a memory fetch, to a disk IO, to a complex database query, or loading a full web page. Ignoring transmission time for a moment, the response time is the sum of the service time and wait time. The service time is the time it takes to do the work you requested. For a given request the service time varies little as the workload increases – to do X amount of work it always takes X amount of time. The wait time is how long the request had to wait in a queue before being serviced and it varies from zero, when no waiting is required, to a large multiple of the service time, as many requests are already in the queue and have to be serviced first. With basic queueing theory math you can calculate how the average wait time increases as the device providi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wear And Tear
Wear and tear is damage that naturally and inevitably occurs as a result of normal wear or aging. It is used in a legal context for such areas as warranty contracts from manufacturers, which usually stipulate that damage from ''wear and tear'' will not be covered. Wear and tear is a form of depreciation which is assumed to occur even when an item is used competently and with care and proper maintenance. For example, repeated impacts may cause stress to a hammer's head. This stress is impossible to prevent in the normal use of the tool for its designed task, and any attempt to avert it impedes its functionality. At the same time, it is expected that the normal use of a hammer will not break it beyond repair during a reasonable life cycle. The phenomenon of wear and tear reflects the second law of thermodynamics, in which objects stray from their original form and function over time unless energy from an external force is used to maintain them. If restoration is impossible, an ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
