According to the tunnel test, distance constants of big, medium,small cup anemometers produced and used in our country, they are determined to be:Lbig c.a.=8.4m Lmedium c.a.=5.8m Lsmall c.a.=4.0m.
The estimation of gear selectivity is a critical issue in fishery stock assessment and management.Several methods have been developed for estimating gillnet selectivity,but they all have their limitations,such as inap...The estimation of gear selectivity is a critical issue in fishery stock assessment and management.Several methods have been developed for estimating gillnet selectivity,but they all have their limitations,such as inappropriate objective function in data fitting,lack of unique estimates due to the difficulty in finding global minima in minimization,biased estimates due to outliers,and estimations of selectivity being influenced by the predetermined selectivity functions.In this study,we develop a new algorithm that can overcome the above-mentioned problems in estimating the gillnet selectivity.The proposed algorithms include minimizing the sum of squared vertical distances between two adjacent points and minimizing the weighted sum of squared vertical distances between two adjacent points in the presence of outliers.According to the estimated gillnet selectivity curve,the selectivity function can also be determined.This study suggests that the proposed algorithm is not sensitive to outliers in selectivity data and improves on the previous methods in estimating gillnet selectivity and relative population density of fish when a gillnet is used as a sampling tool.We suggest the proposed approach be used in estimating gillnet selectivity.展开更多
We study the Stiickelberg holographic superconductors away from the probe limit. We find that the backreaction of the spacetime can bring richer physics in the phase transition. Moreover we observe that the ratio ω9 ...We study the Stiickelberg holographic superconductors away from the probe limit. We find that the backreaction of the spacetime can bring richer physics in the phase transition. Moreover we observe that the ratio ω9 /Tc changes with the strength of the backreaction and is not a universal constant.展开更多
文摘According to the tunnel test, distance constants of big, medium,small cup anemometers produced and used in our country, they are determined to be:Lbig c.a.=8.4m Lmedium c.a.=5.8m Lsmall c.a.=4.0m.
基金Supported by National Key Technology R&D Program of China(No.2006BAD09A05)
文摘The estimation of gear selectivity is a critical issue in fishery stock assessment and management.Several methods have been developed for estimating gillnet selectivity,but they all have their limitations,such as inappropriate objective function in data fitting,lack of unique estimates due to the difficulty in finding global minima in minimization,biased estimates due to outliers,and estimations of selectivity being influenced by the predetermined selectivity functions.In this study,we develop a new algorithm that can overcome the above-mentioned problems in estimating the gillnet selectivity.The proposed algorithms include minimizing the sum of squared vertical distances between two adjacent points and minimizing the weighted sum of squared vertical distances between two adjacent points in the presence of outliers.According to the estimated gillnet selectivity curve,the selectivity function can also be determined.This study suggests that the proposed algorithm is not sensitive to outliers in selectivity data and improves on the previous methods in estimating gillnet selectivity and relative population density of fish when a gillnet is used as a sampling tool.We suggest the proposed approach be used in estimating gillnet selectivity.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 11275066 and 10905020Program of Changjiang Scholars and Innovative Research Team in University under Grant No. IRT0964Hunan Provincial Natural Science Foundation of China under Grant Nos. 12JJ4007 and 11JJ7001
文摘We study the Stiickelberg holographic superconductors away from the probe limit. We find that the backreaction of the spacetime can bring richer physics in the phase transition. Moreover we observe that the ratio ω9 /Tc changes with the strength of the backreaction and is not a universal constant.
