France, R., Holmes, J., & Lynch, A. (1991). Use of size-frequency data to estimate the age composition of crayfish populations (Vol. 48).
Zusammenfassung: Age-classes in crayfish populations can be determined from size-frequency data provided 4 tents are adhered to only crayfish collected from areas of rock substrate are used; trapping are excluded; species do not have longevities exceeding about 4 yr; and most importantly, sample sizes are greater than about 200. Studies that have failed to follow these guidelines have met with limited success in dissecting mixed frequency distributions. Further, 3 validation procedures must be undertaken: temporal replication within molting events to measure the precision of both data collection and size-frequency analysis; corroboration with known-age crayfish from either field recaptures or laboratory molt increments; and concordance with independent analysis of the mean size at onset of sexual maturity. When these checks support the size-frequency results, population age composition and analyses of rates of growth or mortality can be considered reliable.
Schlüsselwörter: Krebs, lÄngenfrequenz, methode, statistik, population
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(1991). ObjectWindows für C++.
Schlüsselwörter: Dokumentation, tips
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Murphy, B. R., Willis, D. W., & Springer, T. A. (1991). The Relative Weight Index in Fisheries Management: Status and Needs (Vol. 16).
Schlüsselwörter: Fischerei, statistik, wachstum, modell
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Stal, M. (1991). Systeminterna nach INI-Art.
Schlüsselwörter: Windows, tips
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Lepetit, M., Loranchet, S., Gillet, P., & Marion, J. M. (1991). Un Logiciel De Traitement Des Histogrammes De Structure De Population Par La M+Thode Des Differences Logarithmiques De Bhattachary (Vol. 41).
Zusammenfassung: The software “BHATTA”, achieved in Turbo Pascal on IBM PC makes possible histogram analysis for population structure. The base of the study is an analysis of population dynamics from histograms of size frequency. The program “BHATTA”, made from the method of logarithmic differences of Bhattacharya, cuts the histograms in order to display Gaussian components and to estimate the parameters: number (size of sample), mean and standard deviation for each generation or cohort to determine growth curves for each cohort.
Schlüsselwörter: Population, statistik, programm, pascal, lÄngenfrequenz, methode
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Sekine, M., Nakanishi, H., Ukita, M., & Murakami, S. (1991). A shallow-sea ecological model using an object-oriented programming language (Vol. 57).
Zusammenfassung: The purpose of this study is to construct a model that can predict the impact on fisheries caused by coastal development activities. To accomplish this, many species of fish must be incorporated in the model, because each type of fish has a different value as a fishery resource and a different behavior for the same impact. In addition the effect of fish swimming must be considered because even when the total resource amount of fish does not change, fish may still disappear from the object area. These factors make the model structure complicated. Meanwhile, a new concept called “object oriented programming” (OOP) is attracting the attention of modellers. In this paper, we have constructed a model called the “shallow-sea ecological model” (SSEM), by using Smalltalk, which is representative of the OOP language. This showed that the fishing ground environment are expressed very flexibly and plainly by Smalltalk.
Schlüsselwörter: Ökosystem, modell, oop, methode, theorie
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Hiramatsu, K. (1991). Possible Biases in the VPA Estimates of Population Sizes of the Plus Group (Vol. 39).
Zusammenfassung: Biases in estimating population sizes of the plus group are examined for bluefin tuna (Thunnus ) and swordfish (Xiphias gladius ). It is shown that the VPA estimates used in the 1990 ICCAT assessment are sensitive to the systematic ageing errors. The biases in the estimates of population sizes of the plus group might increase exponentially with tracing back to the earlier year.
Schlüsselwörter: Fischerei, statistik, vpa, population, methode, theorie, mathematik
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McKenna, J. E., & Saila, S. B. (1991). Application of an Objective Method for Detecting Changes in Fish Communities: Samar Sea, Philippines (Vol. 4).
Schlüsselwörter: Fischerei, statistik, Ökosystem, methode, programm, simulation
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Sparre, P. (1991). Introduction to multispecies virtual population analysis (Vol. 193).
Schlüsselwörter: Fischerei, methode, vpa, statistik, Grundlage
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Hsu, C. C. (1991). Parameters Estimation of Generalized von Bertalanffy Growth Equation (Vol. 26).
Schlüsselwörter: Fischerei, statistik, wachstum, methode, modell, theorie
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