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How should a scientist argue when the data are insufficient to allow him to reason by classical or statistical models? After all, in most real world situations - in business or in war - that is the unhappy norm. In such cases the ordinary man instinctively argues by analogy, as Leibniz long ago showed; indeed if time presses, there is no alternative. The trouble, however, is that if we then include such arguments in our scientific reasoning, then, as we all know, this can lead to false conclusions. To escape from this dilemma, is there any alternative logical basis from which we can start our reasoning? What is proposed here is that instead of the well tried three valued logic of true, false or probable, we should adopt the three valued logic of true, false or possible. A rational system for analogue arguments can then be developed by these means, and with it the advantages brought by the use of symbols and so on. Such a method, however, includes many necessary changes as to how to structure our problems and how to apply new criteria; and it is some of these changes that are outlined in this note. For instance, it outlines the meaning of ‘causal relationships’ in analogue arguments, as well as how to define ‘rational choice’ in terms of analogue propositions. The advantage throughout is that this allows us to argue with less rather than more data.  相似文献   

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Uses and abuses of statistical simulation   总被引:1,自引:0,他引:1  
More and more problems are being tackled by simulation as large computing costs per hour approach those of mathematicians' time. Abuses of simulation arise from ignorance or careless use of little understood procedures, and some of the fundamental tools of the subject are much less well understood than commonly supposed. This is illustrated here by the saga of pseudorandom number generators, normal variate generators and the analysis of queueing system simulations. On the positive side, genuinely new uses of simulation are appearing, particularly in statistical inference. These are exemplified by recursive algorithms for simulating complex systems and simulation-based likelihood inference for point processes.  相似文献   

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本文提出了测定弹性等截面直杆自由扭转剪应力和抗扭刚度的一种新的比拟理论和方法——电涡流比拟。在理论部分建立了电涡流和自由扭转的比拟关系。在实验部分依照比拟理论设计了试验装置和测量线路;并通过对某些具有解析解的截面形状进行了实际测量,所得实验数据验证了本理论的正确性;还对集肤效应和影响精度的一些主要因素进行了讨论。本文所得结果可以推广到其它类似的流场或者具有一定边界条件的泊松方程(或拉普拉斯方程)求解。  相似文献   

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多元协方差分析用于艾滋病疗法的选择   总被引:1,自引:0,他引:1  
目的:优化HAART药物治疗方案,提高治疗效果,为广大患者和医生选择艾滋病的疗法提供科学的依据.方法:以CD4细胞数的增加值作为体现治疗效果的因变量,治疗时间和初始治疗CD4细胞数为协变量,通过四组疗法分组进行多元协方差分析。结果:患者治疗效果的差异主要是由于治疗方法和治疗时间以及初始治疗cd4值的差异所致;四种疗法的疗效总体上差异显著,满足完备性条件和显著性条件的疗法疗效优劣顺序是:M4>M2≈M3≈M1.结论:多元协方差分析用于艾滋病疗法的选择对实际工作有积极的指导意义.  相似文献   

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We propose an Analogy Principle in the context of Unary Inductive Logic and characterize the probability functions which satisfy it. In particular in the case of a language with just two predicates the probability functions satisfying this principle correspond to solutions of Skyrms? ‘Wheel of Fortune’.  相似文献   

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It is a prerequisite to a number of management orientated disciplines that a manager's needs for information are defined. An initial stage in being able to adequately define needs is to understand the ways in which information can affect management behaviour. Several ways are suggested in this paper and from these, implications are drawn which are of relevance to designers of information systems.  相似文献   

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We develop the concept of recessive compactness recently introduced by Luc and Penot. Then we employ this idea to extend some important results of functional analysis such as closed image criteria, a theorem on a family of unbounded sets having a finite intersection property, an existence condition for a variational inequality problem on a noncompact set, a fixed point theorem for nonexpansive maps on unbounded sets, and an existence result for periodic solutions of a nonlinear differential equation in a Hilbert space without a-priori estimates for the solutions of the equation to stay in a bounded region.  相似文献   

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On page 53, the value given for the coefficient c16, approximatelyhalf-way down the right-hand column, is incorrect as printed.The correct figure is as follows:  相似文献   

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本文介绍了MF11 12防毒面具计数调整整型抽检方案的制订过程及其使用情况.通过对该方案与我厂防毒面具一直采用的百分比抽检方案的对比分析──抽查特性及平均出厂质量对比、平均样本量对比和方案实施情况对比分析等,阐述了采用调整方案的优越性.  相似文献   

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This study compares the use of form and function analogy object boxes to more traditional lecture and worksheet instruction during a 10th‐grade unit on human body systems. The study was conducted with two classes (N= 32) of mixed ability students at a high‐needs rural high school in central New York State. The study used a pretest/posttest design, in which the two classes alternated between conditions for the four systems (skeletal, digestive, immune, nervous). Both conditions involved students in quality instruction addressing the same concepts for the same amount of time. Additionally, all students participated in hands‐on labs. The experimental condition presented students with a set of objects analogous in form and function to parts of a human body system. Students matched objects with cards describing body system parts, mapped the analogies on a chart, generated alternative objects that could be used for the analogy, and finally, created new analogies for other body system parts. Students made significantly higher posttest and gain scores on material learned in the experimental condition, with a mean gain score average of 12.4 points out of 25, compared to 6.2 points in the control condition. Cohen's Effect Size was large, 1.36.  相似文献   

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