Uncertainty is inherent and unavoidable in almost all engineering systems. It is of essential significance to deal with uncertainties by means of reliability approach and to achieve a reasonable balance between reliab...Uncertainty is inherent and unavoidable in almost all engineering systems. It is of essential significance to deal with uncertainties by means of reliability approach and to achieve a reasonable balance between reliability against uncertainties and system performance in the control design of uncertain systems. Nevertheless, reliability methods which can be used directly for analysis and synthesis of active control of structures in the presence of uncertainties remain to be developed, especially in non-probabilistic uncertainty situations. In the present paper, the issue of vibration con- trol of uncertain structures using linear quadratic regulator （LQR） approach is studied from the viewpoint of reliabil- ity. An efficient non-probabilistic robust reliability method for LQR-based static output feedback robust control of un- certain structures is presented by treating bounded uncertain parameters as interval variables. The optimal vibration con- troller design for uncertain structures is carried out by solv- ing a robust reliability-based optimization problem with the objective to minimize the quadratic performance index. The controller obtained may possess optimum performance un- der the condition that the controlled structure is robustly re- liable with respect to admissible uncertainties. The proposed method provides an essential basis for achieving a balance between robustness and performance in controller design ot uncertain structures. The presented formulations are in the framework of linear matrix inequality and can be carried out conveniently. Two numerical examples are provided to illustrate the effectiveness and feasibility of the present method.展开更多
目的:评价中文版神经精神病学评定表2.1(Schedules for Clinical Assessment in Neuropsychiatry Version 2.1,SCAN2.1)在精神科应用的信度和效度。方法:选取门诊及住院的各类精神障碍患者100例,选取与精神障碍组在性别、年龄及教育程...目的:评价中文版神经精神病学评定表2.1(Schedules for Clinical Assessment in Neuropsychiatry Version 2.1,SCAN2.1)在精神科应用的信度和效度。方法:选取门诊及住院的各类精神障碍患者100例,选取与精神障碍组在性别、年龄及教育程度相匹配的正常对照100例作为对照。由6名研究人员对8例病例同时进行评定以检验研究者信度;选取另外10例病例由1名研究人员1周后进行重测,以检验重测信度。精神科医生对200例入组者根据国际疾病和相关健康问题统计分类第十版(ICD-10)做出的临床诊断作为"金标准",6名研究者对200例被试用SCAN2.1中的精神现状检查第十版(PSE-10)部分进行访谈,得出诊断结果与"金标准"进行比较,评估中文版SCAN2.1的效度;结果:SCAN2.1中文版研究人员之间信度和重测信度kappa值分别为0.76和0.74。校标效度中,灵敏度95.0%,特异度100%,阳性预测值100%,阴性预测值95.2%,kappa值0.95。对精神分裂症病诊断的灵敏度88.5%、特异度100%、阳性预测值100%、阴性预测值98.9%、kappa值0.89;对心境障碍病的灵敏度100%、特异度100%、阳性预测值100%、阴性预测值100%、Kappa值1.0,对神经症、应激相关及躯体形式障碍病种的灵敏度92.3%、特异度100%、阳性预测值100%、阴性预测值98.9%、kappa值0.95。结论:神经精神病学评定表2.1中文版有较高的信度和效度,可在国内临床中应用。展开更多
My purpose in this paper is to argue for two separate, but related theses. The first is that contemporary analytic philosophy is incoherent. This is so, I argue, because its methods contain as an essential constituent...My purpose in this paper is to argue for two separate, but related theses. The first is that contemporary analytic philosophy is incoherent. This is so, I argue, because its methods contain as an essential constituent a non-classical conception of intuition that cannot be rendered consistent with a key tenet of analytic philosophy unless we allow a Bayesian-subjectivist epistemology. I argue for this within a discussion of two theories of intuition： a classical account as proposed by Descartes and a modem reliabilist account as proposed by Komblith, maintaining that reliabilist accounts require a commitment to Bayesian subjectivism about probability. However, and this is the second thesis, Bayesian subjecfivism is itself logically incoherent given three simple assumptions： （1） some empirical propositions are known, （2） any proposition that is known is assigned a degree of subjective credence of 1, and （3） every empirical proposition is evidentially relevant to at least one other proposition. I establish this using a formal reductio proof. I argue for the t-u-st thesis in section 1 and for the second in section 2. The final section contains a summary and conclusion.展开更多
基金supported by the National Natural Science Foundation of China(51175510)
文摘Uncertainty is inherent and unavoidable in almost all engineering systems. It is of essential significance to deal with uncertainties by means of reliability approach and to achieve a reasonable balance between reliability against uncertainties and system performance in the control design of uncertain systems. Nevertheless, reliability methods which can be used directly for analysis and synthesis of active control of structures in the presence of uncertainties remain to be developed, especially in non-probabilistic uncertainty situations. In the present paper, the issue of vibration con- trol of uncertain structures using linear quadratic regulator （LQR） approach is studied from the viewpoint of reliabil- ity. An efficient non-probabilistic robust reliability method for LQR-based static output feedback robust control of un- certain structures is presented by treating bounded uncertain parameters as interval variables. The optimal vibration con- troller design for uncertain structures is carried out by solv- ing a robust reliability-based optimization problem with the objective to minimize the quadratic performance index. The controller obtained may possess optimum performance un- der the condition that the controlled structure is robustly re- liable with respect to admissible uncertainties. The proposed method provides an essential basis for achieving a balance between robustness and performance in controller design ot uncertain structures. The presented formulations are in the framework of linear matrix inequality and can be carried out conveniently. Two numerical examples are provided to illustrate the effectiveness and feasibility of the present method.
文摘目的:评价中文版神经精神病学评定表2.1(Schedules for Clinical Assessment in Neuropsychiatry Version 2.1,SCAN2.1)在精神科应用的信度和效度。方法:选取门诊及住院的各类精神障碍患者100例,选取与精神障碍组在性别、年龄及教育程度相匹配的正常对照100例作为对照。由6名研究人员对8例病例同时进行评定以检验研究者信度;选取另外10例病例由1名研究人员1周后进行重测,以检验重测信度。精神科医生对200例入组者根据国际疾病和相关健康问题统计分类第十版(ICD-10)做出的临床诊断作为"金标准",6名研究者对200例被试用SCAN2.1中的精神现状检查第十版(PSE-10)部分进行访谈,得出诊断结果与"金标准"进行比较,评估中文版SCAN2.1的效度;结果:SCAN2.1中文版研究人员之间信度和重测信度kappa值分别为0.76和0.74。校标效度中,灵敏度95.0%,特异度100%,阳性预测值100%,阴性预测值95.2%,kappa值0.95。对精神分裂症病诊断的灵敏度88.5%、特异度100%、阳性预测值100%、阴性预测值98.9%、kappa值0.89;对心境障碍病的灵敏度100%、特异度100%、阳性预测值100%、阴性预测值100%、Kappa值1.0,对神经症、应激相关及躯体形式障碍病种的灵敏度92.3%、特异度100%、阳性预测值100%、阴性预测值98.9%、kappa值0.95。结论:神经精神病学评定表2.1中文版有较高的信度和效度,可在国内临床中应用。
文摘My purpose in this paper is to argue for two separate, but related theses. The first is that contemporary analytic philosophy is incoherent. This is so, I argue, because its methods contain as an essential constituent a non-classical conception of intuition that cannot be rendered consistent with a key tenet of analytic philosophy unless we allow a Bayesian-subjectivist epistemology. I argue for this within a discussion of two theories of intuition： a classical account as proposed by Descartes and a modem reliabilist account as proposed by Komblith, maintaining that reliabilist accounts require a commitment to Bayesian subjectivism about probability. However, and this is the second thesis, Bayesian subjecfivism is itself logically incoherent given three simple assumptions： （1） some empirical propositions are known, （2） any proposition that is known is assigned a degree of subjective credence of 1, and （3） every empirical proposition is evidentially relevant to at least one other proposition. I establish this using a formal reductio proof. I argue for the t-u-st thesis in section 1 and for the second in section 2. The final section contains a summary and conclusion.
