The growth and fecundity of Siniperca chuatsi and Siniperca kneri are investigated.The results show that Siniperca chuatsi grows faster than Siniperca kneri.There are curve regression relationships between the body we...The growth and fecundity of Siniperca chuatsi and Siniperca kneri are investigated.The results show that Siniperca chuatsi grows faster than Siniperca kneri.There are curve regression relationships between the body weight(m) and standard length(L) with relational expressions as follow: m=0 081 L 2.71 and m= 0 076 55 L 2.59. Siniperca chuatsi’s fecundity is bigger than that of Siniperca kneri. Siniperca chuatsi and Sniperca kneri attain maturity at two-winter-age and three-winter-age respectively.In addition,the growth equation,the growth speed and growth acceleration equation of body length and body weight are also studied.展开更多
A new method of combination forecast is proposed in this paper. Determining the weighting coefficient in a combination forecast model is translated into estimating significance of the attributes among rough set. Knowl...A new method of combination forecast is proposed in this paper. Determining the weighting coefficient in a combination forecast model is translated into estimating significance of the attributes among rough set. Knowledge entropy is computed and a computation approach of weighting coefficient in a combination forecast model is showed on the basis of establishing a relation data model about combination forecast. The proposed approach overcomes the subjectivity of traditional methods, avoids solving linear or nonlinear extremum problem, automatically collects predicting model, is simple in calculation and makes combination forecast more objective. The validity of the proposed approach is verified with a case.展开更多
文摘The growth and fecundity of Siniperca chuatsi and Siniperca kneri are investigated.The results show that Siniperca chuatsi grows faster than Siniperca kneri.There are curve regression relationships between the body weight(m) and standard length(L) with relational expressions as follow: m=0 081 L 2.71 and m= 0 076 55 L 2.59. Siniperca chuatsi’s fecundity is bigger than that of Siniperca kneri. Siniperca chuatsi and Sniperca kneri attain maturity at two-winter-age and three-winter-age respectively.In addition,the growth equation,the growth speed and growth acceleration equation of body length and body weight are also studied.
文摘A new method of combination forecast is proposed in this paper. Determining the weighting coefficient in a combination forecast model is translated into estimating significance of the attributes among rough set. Knowledge entropy is computed and a computation approach of weighting coefficient in a combination forecast model is showed on the basis of establishing a relation data model about combination forecast. The proposed approach overcomes the subjectivity of traditional methods, avoids solving linear or nonlinear extremum problem, automatically collects predicting model, is simple in calculation and makes combination forecast more objective. The validity of the proposed approach is verified with a case.
