|
|
Schmid, J. (1991). Einiges über die Äsche (Vol. 1991).
Schlüsselwörter: Fisch, Biologie, Thymallus, Beschreibung
|
|
|
|
Sparre, P. (1991). Introduction to multispecies virtual population analysis (Vol. 193).
Schlüsselwörter: Fischerei, methode, vpa, statistik, Grundlage
|
|
|
|
Bax, N. J., Mehl, S., Godo, O. R., & Sunnana, K. (1991). Transparent multispecies analysis: an exploration of fisheries ans survey data off the Norwegian coast and Barents Sea (Vol. 193).
Schlüsselwörter: Fischerei, population, modell, Ökosystem, interaktion, statistik
|
|
|
|
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
|
|
|
|
Ganguly, S., & Chaudhuri, K. (1991). A note on an extension of Schaefer's model (Vol. 55).
Zusammenfassung: Schaefer's model on the exploitation of a single species fish community obeying the logistic law of growth has been modified by adopting an alternative functional form for the harvest rate. The stability of the nontrivial steady state is discussed. The existence of a bionomic equilibrium is proved. The problem for optimal exploitation of the fishery is studied by using variational calculus. Some results are numerically computed to make a comparative study of Schaefer's model and the present one.
Schlüsselwörter: Statistik, population, modell, algorithmus
|
|
|
|
Hofer, R., & Bucher, F. (1991). Zur Biologie und Gefährdung der Koppe (Vol. 44).
Schlüsselwörter: Groppe, Cottus gobio, Fisch, Biologie, Gefährdung
|
|
|
|
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
|
|
|
|
Schirmer, M. (1991). Verbreitung der Fische im Land Bremen (Vol. 41).
Schlüsselwörter: Fisch, Vorkommen, Bremen, Kartierung
|
|
|
|
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
|
|
|
|
Hsu, C. C. (1991). Parameters Estimation of Generalized von Bertalanffy Growth Equation (Vol. 26).
Schlüsselwörter: Fischerei, statistik, wachstum, methode, modell, theorie
|
|
