Search results
Results From The WOW.Com Content Network
The Drake equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way Galaxy. [ 1][ 2][ 3] The equation was formulated in 1961 by Frank Drake, not for purposes of quantifying the number of civilizations, but as a way to stimulate scientific dialogue at the first ...
Merton's portfolio problem. Merton's portfolio problem is a problem in continuous-time finance and in particular intertemporal portfolio choice. An investor must choose how much to consume and must allocate their wealth between stocks and a risk-free asset so as to maximize expected utility.
(If N(t) is discrete, then this is the median life-time rather than the mean life-time.) This time is called the half-life, and often denoted by the symbol t 1/2. The half-life can be written in terms of the decay constant, or the mean lifetime, as: / = = ().
Customer lifetime value is an important concept in that it encourages firms to shift their focus from quarterly profits to the long-term health of their customer relationships. Customer lifetime value is an important metric because it represents an upper limit on spending to acquire new customers. [ 2 ]
Product lifetime or product lifespan is the time interval from when a product is sold to when it is discarded. [ 1] Product lifetime is slightly different from service life because the latter considers only the effective time the product is used. [ 1] It is also different from product economic life which refers to the point where maintaining a ...
Reliability engineering is a sub-discipline of systems engineering that emphasizes the ability of equipment to function without failure. Reliability is defined as the probability that a product, system, or service will perform its intended function adequately for a specified period of time, OR will operate in a defined environment without ...
The half-life of a radioactive isotope (usually denoted by t 1/2) is a more familiar concept than the mean-life, so although the equations above are expressed in terms of the mean-life, it is more usual to quote the value of 14 C 's half-life than its mean-life. The currently accepted value for the half-life of 14 C is 5,700 ± 30 years. [21]
Life expectancy, more technically called the curtate expected lifetime and denoted ,[ a] is the mean of —that is to say, the expected number of whole years of life remaining, assuming survival to age . [ 149] So, (2) Substituting ( 1) into the sum and simplifying gives the final result [ 150]