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本文提出了一种求解带约束非线性规划问题的一般方法。与现有的方法相比 ,它不受可导性 ,单峰性和是否病态等因素的限制 ,适用范围广。实例说明该算法对带约束非线规划问题的求解十分有效  相似文献   
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提出了一种求解带约束非线性规划问题的一般方法。与现有的方法相比,它不受可导性、单峰性和是否病态等因素的限制,适用范围广。实例说明该算法对带约束非线性规划问题的求解十分有效。  相似文献   
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本文主要阐述了XQuery对XML查询优化的相关内容,主要涉及的技术包括最小化、XML代数、索引技术、倒排列表、选择估计、重写机制等。本文阐述了其中基于多数据源的重写算法的具体思想和核心算法。  相似文献   
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Randomized controlled trials in educational research tend to be small. Small trials can have large, chance, imbalances in important covariates. For studies with sample sizes greater than 50, chance imbalances can be corrected using analysis of covariance; for small trials, however, statistical power is maximized if the trial is balanced and analysis of covariance is used in the analysis. The aim of the present study was to discuss methods of improving covariate balance in trial design and to demonstrate the method of minimization. Using an exemplar of a cluster or class‐randomized trial with 29 classes, we employed minimization to achieve covariate balance. Minimization achieved good balance on four prognostic variables. Many trialists in education use restricted forms of allocation, including pairing or stratified randomization. These approaches have disadvantages. Another approach rarely used in educational research is minimization. Minimization uses a simple arithmetic algorithm to produce balanced groups across a number of important covariates and should be more widely used in educational and psychological research.  相似文献   
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Ryanodine受体(骨骼肌RyR1)是目前为止克隆的最大的离子通道,其341位点突变会引起人恶性高热等疾病.应用分子动力学模拟给出RyR1的341位点附近肽段"GESLCFVQHV"的能量最小构象,说明能量最小化后其结构已经达到最稳定状态,即功能结构.  相似文献   
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Rough set axiomatization is one aspect of rough set study to characterize rough set theory using dependable and minimal axiom groups.Thus,rough set theory can be studied by logic and axiom system methods.The classic rough set theory is based on equivalent relation,but rough set theory based on reflexive and transitive relation(called quasi-ordering)has wide applications in the real world.To characterize topological rough set theory,an axiom group named RT,consisting of 4 axioms,is proposed.It is proved that the axiom group reliability in characterizing rough set theory based on similai relation is reasonable.Simultaneously,the minimization of the axiom group,which requires that each axiom is an equation and each is independent,is proved.The axiom group is helpful for researching rough set theory by logic and axiom system methods.  相似文献   
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针对有机化学实验过程中存在的环境问题,提出在有机化学实验中推行“减量化“”无害化“”资源化”的思路,以减少实验室环境污染和资源过度消耗,实现有机化学实验绿色化。  相似文献   
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Because of the ill-posedness of grasping, one feasible method must be selected from possible strategies. Among many factors, this paper focuses on the posture of an object: which object direction is best when it is grasped. Then, the object is assumed to be held with three points where the contact forces can be generated in any directions. To evaluate the object posture, the norm of contact force vector consisting of the normal and tangential forces is selected. Consequently, the contact force becomes minimal when the center of mass of the grasped object and the centroid of the triangle composed by three contact points are aligned in the gravitational direction.  相似文献   
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Abstract

Academics have a responsibility to ensure that their research findings are as truthful as possible. InIn every issue of a scientific journal, a large number of significance tests are reported (usually using P <0.05). Of course, most of these results will be true/correct. Unfortunately, due to the nature of sampling, researchers will occasionally make errors, often referred to as type I (probability = α) and type II (probability = β) errors. The power of a test (1-β) is the probability of correctly rejecting a false null hypothesis – that is, correctly detecting a real or true effect. Factors that are known to influence power include: (1) the level of significance (α), (2) the size of the difference or relationship in the population (the effect), (3) the sample size, and (4) unexplained error variance. As researchers, we have little control over most of these factors. The one factor that we have some influence over, however, is the ability to reduce the unexplained error variance. In the present article, we describe a range of methods that will increase the probability that a researcher has correctly identified a real effect by increasing the power of their statistical tests. Such methods will include ways of designing experiments to reduce error and uncertainty. The use of blocking and randomized block designs will reduce unexplained error, such as adopting matched or repeated-measures designs rather than using independent observations. The other method of reducing unexplained errors is to adopt more appropriate (e.g. biologically correct) models and checking the distribution assumptions associated with such models. In conclusion, researchers are responsible for maximizing the likelihood that their results are as accurate and truthful as possible. By carefully planning their experiments and adopting appropriate models, researchers are more likely to publish their findings with a greater degree of confidence, but not certainty.  相似文献   
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