Search results
Results from the WOW.Com Content Network
In epidemiology, a rate ratio, sometimes called an incidence density ratio or incidence rate ratio, is a relative difference measure used to compare the incidence rates of events occurring at any given point in time. It is defined as:
In contrast, a disease that has a short duration may have a low prevalence and a high incidence. When the incidence is approximately constant for the duration of the disease, prevalence is approximately the product of disease incidence and average disease duration, so prevalence = incidence × duration. The importance of this equation is in the ...
The Hubbert curve is an approximation of the production rate of a resource over time. It is a symmetric logistic distribution curve, [ 1 ] often confused with the "normal" gaussian function . It first appeared in "Nuclear Energy and the Fossil Fuels," geologist M. King Hubbert 's 1956 presentation to the American Petroleum Institute , as an ...
Crude oil production has since risen sharply from 2009 through 2014, so the rate of US oil production in October 2014 was 81% higher than the average rate in 2008. [12] The actual U.S. production curve deviates from Hubbert's 1956 curve in significant ways:
Mathematically, it is the incidence rate of the outcome in the exposed group, , divided by the rate of the unexposed group, . [3] As such, it is used to compare the risk of an adverse outcome when receiving a medical treatment versus no treatment (or placebo), or for environmental risk factors.
The crude death rate is defined as "the mortality rate from all causes of death for a population," calculated as the "total number of deaths during a given time interval" divided by the "mid-interval population", per 1,000 or 100,000; for instance, the population of the United States was around 290,810,000 in 2003, and in that year, approximately 2,419,900 deaths occurred in total, giving a ...
The Zoeppritz equations consist of four equations with four unknowns [] = [ ] [ ]R P, R S, T P, and T S, are the reflected P, reflected S, transmitted P, and transmitted S-wave amplitude coefficients, respectively, =angle of incidence, =angle of the transmitted P-wave, =angle of reflected S-wave and =angle of the ...
The model is defined in discrete time. It is usually expressed as [1] [2] + = + = with H the population size of the host, P the population size of the parasitoid, k the reproductive rate of the host, a the searching efficiency of the parasitoid, and c the average number of viable eggs that a parasitoid lays on a single host.