The Experts below are selected from a list of 332910 Experts worldwide ranked by ideXlab platform
Rodrigo Oliveira Campos - One of the best experts on this subject based on the ideXlab platform.
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allometry coefficient variations of the length weight relationship of skipjack tuna katsuwonus pelamis caught in the southwest south atlantic
Fisheries Research, 2002Co-Authors: Humber Agrelli Andrade, Rodrigo Oliveira CamposAbstract:Abstract In most fishery analysis, a size-Frequency Sample of fish needs to be raised to estimate the size Frequency of all fish caught by the boat. This process is usually approached by building a raising factor which is the ratio between the total catch weight and the weight of the Sample measured to obtain the size Frequency. Estimates of the Sample’s weight can be obtained by using a length–weight relationship equation, and the Sampled size Frequency. Although, the parameters of the length–weight relationship could vary in time (e.g. by month), so the use of a single equation to build raising factors throughout the year could introduce a bias in the raised estimates of catch-at-length. To investigate the monthly variation of the length–weight relationship parameters of skipjack tuna (Katsuwonus pelamis), fish landed in Itajai-SC harbor from May 1995 to June 1996 were Sampled. Size frequencies Sampled in 1997 were used as a case study in the investigation of the effect of monthly variation of parameters on the raising factors and in consequence, on the estimate of annual catch-at-length. Considering all data, regardless the month of the Sample, the estimated length–weight relationship for the skipjack tuna was weight ( kg )=6.54 E −06× length ( cm ) 3.29 . There were monthly variations on the allometry coefficient (exponent of the power equation). However, the differences between the coefficient obtained for the grouped data and for each month were not significant in 50% of the cases. The differences between the estimated catch-at-length by using both a general length–weight relationship equation (all data) and several monthly equations, were low and not significant.
Humber Agrelli Andrade - One of the best experts on this subject based on the ideXlab platform.
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allometry coefficient variations of the length weight relationship of skipjack tuna katsuwonus pelamis caught in the southwest south atlantic
Fisheries Research, 2002Co-Authors: Humber Agrelli Andrade, Rodrigo Oliveira CamposAbstract:Abstract In most fishery analysis, a size-Frequency Sample of fish needs to be raised to estimate the size Frequency of all fish caught by the boat. This process is usually approached by building a raising factor which is the ratio between the total catch weight and the weight of the Sample measured to obtain the size Frequency. Estimates of the Sample’s weight can be obtained by using a length–weight relationship equation, and the Sampled size Frequency. Although, the parameters of the length–weight relationship could vary in time (e.g. by month), so the use of a single equation to build raising factors throughout the year could introduce a bias in the raised estimates of catch-at-length. To investigate the monthly variation of the length–weight relationship parameters of skipjack tuna (Katsuwonus pelamis), fish landed in Itajai-SC harbor from May 1995 to June 1996 were Sampled. Size frequencies Sampled in 1997 were used as a case study in the investigation of the effect of monthly variation of parameters on the raising factors and in consequence, on the estimate of annual catch-at-length. Considering all data, regardless the month of the Sample, the estimated length–weight relationship for the skipjack tuna was weight ( kg )=6.54 E −06× length ( cm ) 3.29 . There were monthly variations on the allometry coefficient (exponent of the power equation). However, the differences between the coefficient obtained for the grouped data and for each month were not significant in 50% of the cases. The differences between the estimated catch-at-length by using both a general length–weight relationship equation (all data) and several monthly equations, were low and not significant.
Zhiqin Zhao - One of the best experts on this subject based on the ideXlab platform.
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a wideband electromagnetic scattering analysis using mlfma with higher order hierarchical vector basis functions
IEEE Transactions on Antennas and Propagation, 2009Co-Authors: Zaiping Nie, Yi Ren, Yanwen Zhao, Zhiqin ZhaoAbstract:A method of the multilevel fast multipole algorithm (MLFMA) with the higher order hierarchical vector basis functions is introduced to solve the wideband electromagnetic scattering problems in Frequency domain. Instead of employing different meshing grids at different frequencies, this new method requires only one coarse mesh generated at the lowest Frequency of the given bandwidth. The scattering at other higher Frequency Sample points can be calculated simply by adjusting the order of the bases. This approach saves much work in geometrical modeling and leads to less unknowns than using the traditional bases for wideband scattering problem. Some important parameters in the numerical calculation (for example, the patch size, the order of the basis, and the cube size in the finest layer of MLFMA, etc.) and their coordination related to this new method are also discussed in detail. An improved interpolation method is introduced to get scattering results without the direct calculation at the points beyond the Frequency Samples. Some numerical examples are presented in this paper to show the advantages of the method in the wideband scattering analysis.
Zaiping Nie - One of the best experts on this subject based on the ideXlab platform.
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a wideband electromagnetic scattering analysis using mlfma with higher order hierarchical vector basis functions
IEEE Transactions on Antennas and Propagation, 2009Co-Authors: Zaiping Nie, Yi Ren, Yanwen Zhao, Zhiqin ZhaoAbstract:A method of the multilevel fast multipole algorithm (MLFMA) with the higher order hierarchical vector basis functions is introduced to solve the wideband electromagnetic scattering problems in Frequency domain. Instead of employing different meshing grids at different frequencies, this new method requires only one coarse mesh generated at the lowest Frequency of the given bandwidth. The scattering at other higher Frequency Sample points can be calculated simply by adjusting the order of the bases. This approach saves much work in geometrical modeling and leads to less unknowns than using the traditional bases for wideband scattering problem. Some important parameters in the numerical calculation (for example, the patch size, the order of the basis, and the cube size in the finest layer of MLFMA, etc.) and their coordination related to this new method are also discussed in detail. An improved interpolation method is introduced to get scattering results without the direct calculation at the points beyond the Frequency Samples. Some numerical examples are presented in this paper to show the advantages of the method in the wideband scattering analysis.
Mukti Zainuddin - One of the best experts on this subject based on the ideXlab platform.
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dinamika populasi ikan cakalang katsuwonus pelamis linnaeus di perairan laut flores sulawesi selatan population dynamics of skipjack tuna katsuwonus pelamis in flores waters south sulawesi
2013Co-Authors: Faisal Amir, Achmar Mallawa, Mukti ZainuddinAbstract:Total length Frequency Sample of Katsuwonus pelamis (Linnaeus) was collected from June to August 2013 in Flores waters, South Sulawesi, using fish aggregation devices and non-fish aggregation devices (FADs) purse seiner, and gill net. The von Bertalanffy growth formula was estimated as L∞ = 112.5 cm and K = 0.35 year -1 with response surface method at FISAT-II. Total mortality rate estimated using length-converted catch curve analysis was Z = 1.95 year –1 . Natural mortality estimated by Pauly’s empirical formula accounted was M = 0.632 year -1 . Fishing mortality (F) was 1.32 year –1 while Exploitation rate was reached at 0.68. A Beverton-Holt relative yield per recruit (Y/R’) and relative biomass per recruit (B/R’) model explored that exploitation rate is over-fishing that over 54.5% from the optimum exploitation with Lc, of 20.9 cm.
