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111.
对于一类目标函数中有无限个分式的广义分式规划,给出了一个混合型对偶,并在(F,α,ρ,d)-凸性的条件下,证明了相应的弱对偶定理、强对偶定理及严格逆对偶定理.  相似文献   
112.
采用鸡体药效试验法测定了柔嫩艾美尔球虫对球佳、球安、加福三种药物的抗药性。试验结果表明:球佳、球安、加福的最适抗球虫活性百分率(poAA)分别为58.po%、78.23%、叨.27%;病变记分减少率(RLS)为100%、72。73%、74.03%;相对盲肠卵鲢产量(ROP)为限26%、577.6%。288.6%。POAA‘PLS显示柔嫩艾美尔球虫对三种药物均无抗药性,而ROP显示对球安、加福有抗药性。综合POAA、RLS、ROP三项参数指标判定柔嫩艾美尔球虫对球佳敏感,对球安、加福有轻度抗药性。  相似文献   
113.
研究了生长于广东沿海地区,即香港米埔、湛江高桥、大亚湾澳头、稔山、三门岛和恩平洪窑等地的白骨壤(Avicennia marina)、秋茄(Kandelia candel)、木榄(Bruguiera conjugata)、红海榄(Rhizophor stylosa)及苦槛蓝(Hyoporum bontioides)等5种红树植物叶片多酚氧化物酶(Polyphenol oxidase,PPO)、过氧化物酶(Peroxidase,POD)活性,除发现同一地区不同种的红树植物叶片酶活性存在种间差异外,生长于不同地区的同一种红树植物其叶片酶活性亦存在较大的差异。本文对其可能原因进行了探讨。  相似文献   
114.
We propose an efficient group sequential monitoring rule for clinical trials. At each interim analysis both efficacy and futility are evaluated through a specified loss structure together with the predicted power. The proposed design is robust to a wide range of priors, and achieves the specified power with a saving of sample size compared to existing adaptive designs. A method is also proposed to obtain a reduced-bias estimator of treatment difference for the proposed design. The new approaches hold great potential for efficiently selecting a more effective treatment in comparative trials. Operating characteristics are evaluated and compared with other group sequential designs in empirical studies. An example is provided to illustrate the application of the method.  相似文献   
115.
116.
This paper addresses a batch delivery single-machine scheduling problem in which jobs have an assignable common due window. Each job will incur an early (tardy) penalty if it is early (tardy) with respect to the common due window under a given schedule. There is no capacity limit on each delivery batch, and the cost per batch delivery is fixed and independent of the number of jobs in the batch. The objective is to find the optimal size and location of the window, the optimal dispatch date for each job, as well as an optimal job sequence to minimize a cost function based on earliness, tardiness, holding time, window location, window size, and batch delivery. We show that the problem can be optimally solved in O(n8)O(n8) time by a dynamic programming algorithm under a reasonable assumption on the relationships among the cost parameters. A computational experiment is also conducted to evaluate the performance of the proposed algorithm. We also show that some special cases of the problem can be optimally solved by lower order algorithms.  相似文献   
117.
Little is known about the perceived health risks of electromagnetic fields (EMFs) and factors associated with risk perception in non‐Western countries. Psychological conditions and risk perception have been postulated as factors that facilitate the attribution of health complaints to environmental factors. This study investigated people's perceived risks of EMFs and other environmental sources, as well as the relationships between risk perception, psychopathology, and the degree of self‐reported sensitivity to EMFs. A total of 1,251 adults selected from a nationwide telephone interviewing system database responded to a telephone survey about the relationships between environmental sources and human health. The interview included questions assessing participants’ psychiatric conditions and the presence and degree of sensitivity to EMFs. One hundred and seventy participants were self‐identified as having sensitivity to EMFs, and 141 met the criteria for psychiatric conditions without EMF sensitivity. More than half of the survey respondents considered power lines and mobile phone base stations to affect people's health to a big extent. Higher sensitivity to EMFs, psychopathology, being female, being married, more years of education, and having a catastrophic illness had positive associations with perceived risks of EMF‐related environmental sources as well as for all environmental sources combined. We observed no moderating effect of psychopathology on the association between degree of sensitivity to EMF and risk perception. Thus, psychopathology had influence on general people's risk perception without having influence on the relationship between people's degree of sensitivity to EMF and risk perception. The plausible explanations are discussed in the text.  相似文献   
118.
中国企业战略管理行为的情景嵌入式研究   总被引:4,自引:2,他引:4  
伴随着中国经济的迅速崛起和中国企业的巨大需要,国内战略学者急需增加自信和采取更加符合中国实际的研究视角.根据中国经济转型所表现出的渐进性、分权式和试验性的特点及其对中国企业经营环境和战略行为的影响,强调应该对转型期中国企业战略管理行为进行情景嵌入式的研究,重点分析制度影响、共同演化和例外企业,从而使我国战略学者在知识创新和指导实践2个方面实现根本性的提升.  相似文献   
119.
There are some shortages to ascertain attribute weight based on rough set in current studies. In this paper, attrib- ute importance represented by rough set is studied deeply. Aiming at the existing problems, algebra presentation of rough sets is proved to be more comprehensive than its information presentation, then a new method of ascertaining attribute weigh is put forward based on rough set conditional entropy. Finally, it is shown that the new method is more reasonable than the old one by an example.  相似文献   
120.
针对传统AHP中专家权重确定方法的局限性,本文提出一种基于利益相关者视角的专家权重确定方法对AHP进行改进。首先计算专家之间的利益相关系数,然后依据评价值矩阵得到所有专家的综合评价值,进而确定每一位专家在专家群体中的评价权重,最后将传统AHP所得指标权重与专家评价权重进行加权平均即得各指标的综合权重。再以改进AHP得到的评价值作为先验样本进行BP神经网络的训练与测试,得到可供推广的分类器。以建筑企业循环经济评价进行实证研究,结果表明构建的改进AHP-BP神经网络模型所得评价结果较已有方法更为准确可靠。  相似文献   
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