铝合金双丝脉冲惰性气体保护(pulse metal inert gas,PMIG)焊焊接过程中两个电弧之间的相互作用对焊接稳定性的影响非常关键,并且焊接电弧等效电阻相较于焊接电流与弧压包含更全面的电弧信息,基于此提出了等效电阻互模糊熵方法来评价铝...铝合金双丝脉冲惰性气体保护(pulse metal inert gas,PMIG)焊焊接过程中两个电弧之间的相互作用对焊接稳定性的影响非常关键,并且焊接电弧等效电阻相较于焊接电流与弧压包含更全面的电弧信息,基于此提出了等效电阻互模糊熵方法来评价铝合金双丝PIMG焊接过程稳定性.对3A21铝合金进行了一系列双丝PMIG焊接试验研究,计算其等效电阻互模糊熵,证实焊接过程越稳定等效电阻互模糊熵值越大.设计了焊接稳定性状态存在突变的焊接试验,将焊接电弧等效电阻模糊熵与互模糊熵对稳定性突变的敏感性进行了对比.结果表明,等效电阻互模糊熵比模糊熵对焊接过程稳定性的变化更加敏感,能更准确地诊断出焊接过程稳定性的突变点.展开更多
Fuzzy entropy was designed for non convex fuzzy membership function using well known Hamming distance measure.The proposed fuzzy entropy had the same structure as that of convex fuzzy membership case.Design procedure ...Fuzzy entropy was designed for non convex fuzzy membership function using well known Hamming distance measure.The proposed fuzzy entropy had the same structure as that of convex fuzzy membership case.Design procedure of fuzzy entropy was proposed by considering fuzzy membership through distance measure,and the obtained results contained more flexibility than the general fuzzy membership function.Furthermore,characteristic analyses for non convex function were also illustrated.Analyses on the mutual information were carried out through the proposed fuzzy entropy and similarity measure,which was also dual structure of fuzzy entropy.By the illustrative example,mutual information was discussed.展开更多
In order to make a decision in the face of multiple objectives, it is necessary to know the relative importance of the different objectives. Yet, it is often very difficult to specify a set of precise weights before p...In order to make a decision in the face of multiple objectives, it is necessary to know the relative importance of the different objectives. Yet, it is often very difficult to specify a set of precise weights before possible alternatives solutions are known. In this paper, we present an improved weighted method, which is based on a modified definition by the membership function of fuzzy theory; an interactive, iterative method for arriving at an acceptable solution. The decision maker gradually discerns what is achievable and adjusts his aspirations and implicitly the specification of weights and trade-offs between his objectives, in the light of what he learns. To aid the decision maker＇s cognition and to allow him to express his wishes in a natural way, we present decision maker with grey relational degree to select the best solution from the finite solutions.展开更多
文摘铝合金双丝脉冲惰性气体保护(pulse metal inert gas,PMIG)焊焊接过程中两个电弧之间的相互作用对焊接稳定性的影响非常关键,并且焊接电弧等效电阻相较于焊接电流与弧压包含更全面的电弧信息,基于此提出了等效电阻互模糊熵方法来评价铝合金双丝PIMG焊接过程稳定性.对3A21铝合金进行了一系列双丝PMIG焊接试验研究,计算其等效电阻互模糊熵,证实焊接过程越稳定等效电阻互模糊熵值越大.设计了焊接稳定性状态存在突变的焊接试验,将焊接电弧等效电阻模糊熵与互模糊熵对稳定性突变的敏感性进行了对比.结果表明,等效电阻互模糊熵比模糊熵对焊接过程稳定性的变化更加敏感,能更准确地诊断出焊接过程稳定性的突变点.
基金Work supported by the Second Stage of Brain Korea 21 Projects Work(2010-0020163) supported by the Priority Research Centers Program through the National Research Foundation (NRF) funded by the Ministry of Education,Science and Technology of Korea
文摘Fuzzy entropy was designed for non convex fuzzy membership function using well known Hamming distance measure.The proposed fuzzy entropy had the same structure as that of convex fuzzy membership case.Design procedure of fuzzy entropy was proposed by considering fuzzy membership through distance measure,and the obtained results contained more flexibility than the general fuzzy membership function.Furthermore,characteristic analyses for non convex function were also illustrated.Analyses on the mutual information were carried out through the proposed fuzzy entropy and similarity measure,which was also dual structure of fuzzy entropy.By the illustrative example,mutual information was discussed.
基金This research is supported by National Natural Science Foundation of China（70471019）
文摘In order to make a decision in the face of multiple objectives, it is necessary to know the relative importance of the different objectives. Yet, it is often very difficult to specify a set of precise weights before possible alternatives solutions are known. In this paper, we present an improved weighted method, which is based on a modified definition by the membership function of fuzzy theory; an interactive, iterative method for arriving at an acceptable solution. The decision maker gradually discerns what is achievable and adjusts his aspirations and implicitly the specification of weights and trade-offs between his objectives, in the light of what he learns. To aid the decision maker＇s cognition and to allow him to express his wishes in a natural way, we present decision maker with grey relational degree to select the best solution from the finite solutions.
