异方差回归中的广义方差比检验

在同方差假设之下,线性模型在回归分析的理论与应用方面起着突出的作用,很受许多研究工作者的青睐.然而,回归模型中同方差性这一标准假设不一定总是成立的.因此我们考虑了用一类基于似残差的方法来检验异方差情形下线性模型拟合观测数据的情况.本文既给出了大量的模拟,又给出了实际数据作为应用的例子.效果都很好.     

自动检测系统原理应用和发展状况的研究

自动检测系统广泛应用于各类产品的设计、生产、使用、维护等各个阶段,对提高产品性能及生产率、降低生产成本及整个生产周期成本起着重要作用。首先介绍了检测、检验以及自动检测系统的概念,其次通过自动检测系统的各个组成部分,详述了系统的工作原理,介绍了自动检测系统组建的概念、结构以及在组建中所使用的关键技术。对早期的自动检测系统和新一代自动检测系统进行了介绍,并详述自动检测系统的3个发展阶段。     

离子束混合工艺对材料抗蚀性能的影响

本文介绍了离子束混合工艺方法。与直接注入相比较,离子束混合所使用的设备造价低1/4—1/2,而生产效率可提高1—2个数量级,因而使生产成本大幅度降低,这无疑对离子束工艺的实际应用将产生巨大的促进作用。 通过对轴承材料(GCr15和Cr4Mo4V)经Cr、N、Ta不同元素的混合处理后,在0.5M H_2SO_4和0.1M NaCl的缓冲溶液中的阳极极化曲线表明经混合处理后的两种材料试样,其抗蚀能力和抗点蚀能力均大大提高,这与直接注入的试样效果是一致的。 通过俄歇谱仪和透射电镜的分析结果表明混合是成功的,且在一定的条件下,形成非晶组织。 本文的结论是,无论是离子的直接注入还是离子束混合,对提高轴承材料的抗腐蚀性能都是有效的方法,特别是离子束混合技术具有更大的应用前景。     

Endoscopic Observation of Tissue by Narrowband Illumination

We propose a new illumination method for a medical endoscope: narrow band imaging (NBI), in which the spectral bandwidth of the filtered light is narrowed. To confirm how the spectral specifications of the filtered light influence a reproduced image, an experiment was conducted observing the endoscopic images of the back mucosa of a human tongue. In addition, the effect of NBI on endoscopic images was investigated through preliminary clinical tests in colonoscopy and upper gastrointestinal endoscopy. It has been shown that NBI can enhance the capillary pattern and the crypt pattern on the mucosa. These patterns are useful features for diagnosing an early cancer.     

Partial scan design and test sequence generation based on reduced scan shift method

This paper presents a partial scan algorithm, calledPARES (PartialscanAlgorithm based onREduced Scan shift), for designing partial scan circuits. PARES is based on the reduced scan shift that has been previously proposed for generating short test sequences for full scan circuits. In the reduced scan shift method, one determines proch FFs must be controlled and observed for each test vector. According to the results of similar analysis, PARES selects these FFs that must be controlled or observed for a large number of test vectors, as scanned FFs. Short test sequences are generated by reducing scan shift operations using a static test compaction method. To minimize the loss of fault coverage, the order of test vectors is so determined that the unscanned FFs are in the state required by the next test vector. If there are any faults undetected yet by a test sequence derived from the test vectors, then PARES uses a sequential circuit test generator to detect the faults. Experimental results for ISCAS'89 benchmark circuits are given to demonstrate the effectiveness of PARES.     

Test Generation for Crosstalk-Induced Faults: Framework and Computational Results

Due to technology scaling and increasing clock frequency, problems due to noise effects lead to an increase in design/debugging efforts and a decrease in circuit performance. This paper addresses the problem of efficiently and accurately generating two-vector tests for crosstalk induced effects, such as pulses, signal speedup and slowdown, in digital combinational circuits. These noise effects can propagate through a circuit and create a logic error in a latch or at a primary output. We have developed a mixed-signal test generator, called XGEN, that incorporates classical static values as well as dynamic signals such as transitions and pulses, and timing information such as signal arrival times, rise/fall times, and gate delay. In this paper we first discuss the general framework of the test generation algorithm followed by computational results. Comparison of results with SPICE simulations confirms the accuracy of this approach.     

物理实验课程考核、评估体系初探

对物理实验课程考核、评估方法进行了探讨，提出了物理实验课程考核、评估体系及实施细则．重点介绍了体系中的核心部分——正规的物理实验课程考试．     

Tests for Varying G

In this note we consider a variable G cosmology which is consistent with observation and which had successfully predicted an ever expanding accelerating universe with a small cosmological constant amongst other things. Three further tests are proposed in this note: First, the inexplicable anomalous accelerations of the Pioneer spacecrafts can be explained. It is then shown that the observed shortening of the orbital periods of binary pulsars is in good agreement with this model. Finally, more general changes in orbital parameters are deduced, which may be observed in the future.     

电火花铣削钛合金电极损耗在线补偿研究

根据电火花铣削等损耗理论，对用电火花铣削钛合金的加工中电极损耗补偿作了分析阐述。并根据正交试验的数据对理论分析结果进行对比，同时给出了一定的结论和建议。     

智能组卷系统试题库结构的研究

在分析了传统的组卷系统的组卷算法及相应的试题库结构的基础上，基于遗传算法提出了一种新的试题库结构，并给定具体结构的确定方法。实践表明，这种结构下的试题库很好地配合遗传算法实现了智能组卷，并且系统效率更高，冗余度更小。