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| [[File:Risk_2.jpg]] | | [[File:Risk_2.jpg]] |
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− | One of the first major uses of this [[concept]] was at the planning of the [http://en.wikipedia.org/wiki/Delta_Works Delta Works] in 1953, a flood protection program in the Netherlands, with the aid of the mathematician [http://en.wikipedia.org/wiki/David_van_Dantzig David van Dantzig].[4] The kind of risk [[analysis]] pioneered here has become common today in fields like [http://en.wikipedia.org/wiki/Nuclear_power nuclear power], [http://en.wikipedia.org/wiki/Aerospace aerospace] and [http://en.wikipedia.org/wiki/Chemical_industry chemical industry]. | + | One of the first major uses of this [[concept]] was at the planning of the [https://en.wikipedia.org/wiki/Delta_Works Delta Works] in 1953, a flood protection program in the Netherlands, with the aid of the mathematician [https://en.wikipedia.org/wiki/David_van_Dantzig David van Dantzig].[4] The kind of risk [[analysis]] pioneered here has become common today in fields like [https://en.wikipedia.org/wiki/Nuclear_power nuclear power], [https://en.wikipedia.org/wiki/Aerospace aerospace] and [https://en.wikipedia.org/wiki/Chemical_industry chemical industry]. |
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| There are more sophisticated definitions, however. [[Measuring]] [[engineering]] risk is often difficult, especially in potentially dangerous industries such as nuclear energy. Often, the [[probability]] of a negative event is estimated by using the frequency of past similar events or by event-tree methods, but probabilities for rare failures may be difficult to estimate if an event tree cannot be formulated. [[Methods]] to calculate the cost of the loss of human life vary depending on the purpose of the calculation. Specific [[method]]s include what people are willing to pay to insure against death,[5] and radiological release (e.g., GBq of radio-iodine). There are many [[formal]] [[method]]s used to assess or to "measure" risk, considered as one of the critical indicators important for human [[decision]] making. | | There are more sophisticated definitions, however. [[Measuring]] [[engineering]] risk is often difficult, especially in potentially dangerous industries such as nuclear energy. Often, the [[probability]] of a negative event is estimated by using the frequency of past similar events or by event-tree methods, but probabilities for rare failures may be difficult to estimate if an event tree cannot be formulated. [[Methods]] to calculate the cost of the loss of human life vary depending on the purpose of the calculation. Specific [[method]]s include what people are willing to pay to insure against death,[5] and radiological release (e.g., GBq of radio-iodine). There are many [[formal]] [[method]]s used to assess or to "measure" risk, considered as one of the critical indicators important for human [[decision]] making. |
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| In [[statistics]], risk is often mapped to the [[probability]] of some [[event]] which is seen as undesirable. Usually, the probability of that event and some assessment of its expected harm must be combined into a believable scenario (an outcome), which combines the set of risk, regret and reward probabilities into an expected value for that outcome. (See also Expected utility.) | | In [[statistics]], risk is often mapped to the [[probability]] of some [[event]] which is seen as undesirable. Usually, the probability of that event and some assessment of its expected harm must be combined into a believable scenario (an outcome), which combines the set of risk, regret and reward probabilities into an expected value for that outcome. (See also Expected utility.) |
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− | Thus, in [http://en.wikipedia.org/wiki/Decision_theory statistical decision theory], the risk [[function]] of an estimator δ(x) for a parameter θ, calculated from some observables x, is defined as the expectation value of the loss function L, | + | Thus, in [https://en.wikipedia.org/wiki/Decision_theory statistical decision theory], the risk [[function]] of an estimator δ(x) for a parameter θ, calculated from some observables x, is defined as the expectation value of the loss function L, |
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| [[File:Loss_function.jpg]] | | [[File:Loss_function.jpg]] |
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− | In [http://en.wikipedia.org/wiki/Information_security information security], a risk is written as an asset, the threats to the asset and the vulnerability that can be exploited by the threats to impact the asset - an example being: Our desktop computers (asset) can be compromised by malware (threat) entering the environment as an email attachment (vulnerability). | + | In [https://en.wikipedia.org/wiki/Information_security information security], a risk is written as an asset, the threats to the asset and the vulnerability that can be exploited by the threats to impact the asset - an example being: Our desktop computers (asset) can be compromised by malware (threat) entering the environment as an email attachment (vulnerability). |
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| The risk is then assessed as a function of three variables: | | The risk is then assessed as a function of three variables: |
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| The two probabilities are sometimes combined and are also known as likelihood. If any of these variables approaches zero, the overall risk approaches zero. | | The two probabilities are sometimes combined and are also known as likelihood. If any of these variables approaches zero, the overall risk approaches zero. |
− | The management of actuarial risk is called [http://en.wikipedia.org/wiki/Risk_management risk management].[http://en.wikipedia.org/wiki/Risk] | + | The management of actuarial risk is called [https://en.wikipedia.org/wiki/Risk_management risk management].[https://en.wikipedia.org/wiki/Risk] |
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| [[Category: Statistics]] | | [[Category: Statistics]] |