关于万有引力定律的教学

分别计圆环、圆盘和球体与质点之间的引力,这有助于学生思维能力的培养。     

Discussion on National Standard GB 6167"Methods for Testing the Performance of Airborne Particle Counter

Classificationofaircleanlinessinanykindofclean roomsandcleanzoneswillbeaccomplishedintermsofconcentrationofairborneparticles .Alightdiscreteair borneparticlecounter (hereafterreferringtoasAPC)isusedtodeterminetheconcentrationofairborneparticlesequaltoandlargerthanthespecifiedsizesatdesignatedsamplinglocation[1,2 ] .Inthepracticalmeasurementofparticleconcentrationincleanrooms,itisfoundthetest ingresultsofparticlenumberinthesameareacountedbydifferentparticlecountersarequitedifferentanduptoanord…     

太阳能空间斯特林热机性能的优化分析

建立太阳能驱动的空间斯特林热机的循环模型，应用有限时间热力学理论和太阳能集热器的辐射损失模型，研究受热阻和回热损失影响的太阳能斯特林热机循环性能，导出空间热机效率的基本优化关系，确定太阳能集热器的最佳工作温度和效率界限，讨论各种不可逆性对空间热机性能的影响，所得结论可为太阳能空间斯特林热机的优化设计提供新的理论指导。     

论实施混合教学模式的必要性和现实性

教学过程信息化改革是教育信息化的核心构成,高校扩招引发的新问题新挑战使这一改革更形迫切。整合了传统教学模式和网络教学模式的整体优势的″双轨″式教学模式,成为稳步推进教学信息化进程中一个具有现实性和必要性的选择与过程。     

最优购书量的讨论

运用概率论和微分学的知识,讨论在一定的广告费用和书本贮存费用的情况下,根据图书的购进价和售出价确定书店的最优购书量．     

A novel method for mobile robot simultaneous localization and mapping

INTRODUCTION A key prerequisite for a truly autonomous robot is that it can simultaneously localize itself and accu-rately map its surroundings (Kortenkamp et al., 1998), which is known as Simultaneous Localization and Mapping (SLAM), which, when phrased as a state estimation problem, involves a variable number of dimensions. Murphy and Russell (2001) adopted Rao-Blackwellized particle filters (RBPFs) as an effective way for representing alternative hypotheses on robot paths and ass…     

论关联性在隐喻中的表现

隐喻的相似性构成了隐喻的基础,为理解隐喻提供了方便.但Sperber ＆ Wilson在专著Relevance：Communication and Cognition一书中提出了最佳关联原则,能更有力的解释隐喻,为隐喻的理解提供了新思路,然而究其实质,隐喻的相似性正是最佳关联性在隐喻中的表现,隐喻的理解实际上是寻求隐喻的的相似性,而寻求隐喻相似性的过程就是寻求本体和喻体的最佳关联.     

统计/判决电路在通信电子实验教学中的应用

鉴于通信电子技术课程的教学现状,提出了依据统计/判决电路来设计通信电子实验,在8分频的前提下,该电路可以在改进系统通信质量方面起到一定的作用,如改善信噪比,降低误码率,提高系统抗干扰性。通过对该电路的设计、制作和调试,学生能掌握诸如香农公式、数字信号最佳接收等理论知识。能较好实现培养理论和实际动手能力相结合的教学要求。     

Optimal Design for Two-Level Random Assignment and Regression Discontinuity Studies

An important concern when planning research studies is to obtain maximum precision of an estimate of a treatment effect given a budget constraint. When research designs have a multilevel or hierarchical structure changes in sample size at different levels of the design will impact precision differently. Furthermore, there will typically be differential costs of enrolling additional units at different levels of the hierarchy. The optimal design problem in multilevel research studies involves determining the optimal sample size at each level of the design given specified design parameters and a specified marginal cost of recruitment at each level. The current work extends existing results by considering optimal design for (a) unbalanced random assignment designs and (b) regression discontinuity designs.     

用平直光锥分析宇宙的视界

引入保形时间，利用平直光锥分析了宇宙模型的粒子视界和事件视界是否存在的问题，所得结果与文献[2]的相同。