Interpreting the negative mood-helping literature via "mega"-analysis: A contrary view.

"Mega"-analysis was developed by M. Carlson and N. Miller (see record 1987-31249-001) as an extension of traditional meta-analytic procedures for conducting integrative reviews of existing research literatures. One such mega-analysis was conducted by Carlson and Miller to synthesize the literature on the relation between negative mood states and helping. That analysis found no support for a theoretical account (negative state relief) that had been confirmed previously by using various experimental approaches. In an attempt to reconcile the discrepancy, the logic and methods used in Carlson and Miller's mega-analysis of the negative mood-helping literature were examined, and several serious problems were found. These problems are discussed, and data are presented to show that the results of that mega-analysis, and perhaps all mega-analyses, should not be viewed with confidence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exact probabilistic testability measures for multi-output circuits

The computation of probabilistic testability measures has become increasingly important and some methods have been proposed, although the exact solution of the problem is NP-hard. An exact analytical method for singleoutput combinational circuits is extended to deal with multi-output circuits. Such circuits are reduced to singleoutput ones by introducing a dummy gate, the X-gate, and applying to the resulting graph the analysis based on supergates.     

基于SoC的嵌入式DRAM存储器内建自测试设计

内建自测试(Built-in Self Test,BIST)是测试片上系统(System on- Chip,SoC)中嵌入式存储器的重要技术;但是,利用BIST技术采用多种算法对嵌入式存储器进行测试仍面临诸多挑战;对此,提出了一种基于SoC的可以带有多种测试算法的嵌入式DRAM存储器BIST设计,所设计的测试电路可以复用状态机的状态,利用循环移位寄存器(Cyclic Shift Register,CSR)产生操作命令,利用地址产生电路产生所需地址;通过对3种BIST电路支持的算法,全速测试,面积开销3个方面的比较,表明提出的嵌入式DRAM存储器BIST设计在测试时间,测试故障覆盖率和测试面积开销等各方面都取得了较好的性能.     

Influence of base resistance on extracting thermal resistance for SiGe HBTs

In this article, the influence of base resistance on extracting thermal resistance for SiGe heterojunction bipolar transistors is studied and an improved approach for determining the junction temperature and thermal resistance is presented. The proposed method for extracting thermal resistance is based on the temperature sensitivity of the base–emitter (B–E) voltage when the device is biased with a fixed emitter current density. This approach not only takes into account the self‐heating during the different ambient temperature measurement but also revises the empirical equation of B–E voltage due to the influence of base resistance during the power dissipation increment measurement. Results are obtained for devices with different emitter lengths and fingers. Compared with the conventional method, the thermal resistance is about up to 15% improvement for the device with 0.3 × 1.9 μm² emitter area and 13.8% for the device with 0.3 × 13.9 μm² emitter area. The accurate thermal resistance implemented in HICUM model has resulted in better fit for transistor output characteristics. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.     

Direct adaptive fuzzy control with membership function tuning

In this paper, a direct self‐structured adaptive fuzzy control is introduced for the class of nonlinear systems with unknown dynamic models. Control is accomplished by an adaptive fuzzy system with a fixed number of rules and adaptive membership functions. The reference signal and state errors are used to tune the membership functions and update them instantaneously. The Lyapunov synthesis method is also used to guarantee the stability of the closed loop system. The proposed control scheme is applied to an inverted pendulum and a magnetic levitation system, and its effectiveness is shown via simulation. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

基于多信号流模型的模型封装与解包技术

随着科技的快速发展,设备系统的复杂程度越来越高,多信号流模型是系统测试性分析的常用模型,为解决复杂系统建模分析时对其各分系统信息保密问题,提出了一种基于多信号流模型的模型封装与解包方法。该方法首先确定了封装模块数据信息并实现封装,然后构建封装模块测试信息描述表,描述了封装模块内部故障、内部测试与外部信息的关系以及封装模块本身对外部信息的影响,实现了模块的解包。实验表明,该描述方法可以有效地屏蔽了被封装的分系统模型的技术信息,有利于各分系统设计者之间的信息保密,同时利用该描述方法,还可以有效地减少测试性分析所需的时间。     

基于关联规则与PLC的同步电机高精度转角自适应控制方法

常规的转角自适应控制方法未能与同步电机的实际运行数据精准结合,导致实际控制中精度不足,因此提出基于关联规则与PLC设计的同步电机高精度转角自适应控制方法。计算同步电机的增益效率,将结果加权处理,得到同步电机转角理想传动比的计算方法。建立关联数据库,基于关联规则优化转角控制增益系数。以适应性系数判断算法终止条件,建立自适应模型结构,得到同步电机中的转角质心偏离距离,设计转角模糊自适应算法。在对比试验中,试验组中适应性系数均值为0.48/0.92 μm,3个对照组的均值分别为0.27/0.82、0.42/0.57、0.26/0.86 μm。通过试验数据可知,基于关联规则与PLC的同步电机高精度转角自适应控制方法比常规算法更适应同步电机的实际运行,具备更高的精度控制效果。     

石墨化率不同的自焙炭块的热膨胀

采用精密垂直拉杆膨胀仪在１４～１０００℃范围内测量了具有不同石墨化率的自焙炭块的相对热伸长量，并由此获得了热线膨胀系数α。结果表明：石墨化率一定时，α值在较低温度下随温度升高而增加，在较高温度下，α值随温度变化不明显；恒温时，石墨化率越高，α值越低。讨论了单位热应力下的弹性模量概念     

高水头船闸第二分流口自分流体型水力特性研究

高水头船闸输水水流能量巨大,水力指标高,对输水系统布置和型式提出了更高要求。大藤峡水利枢纽工程船闸最大设计水头40.25 m,输水系统第二分流口拟采用空腔自分流型式,在国内外尚无先例。通过采用三维数值模拟的技术手段对该分流口型式及输水系统整体分流性能进行系统研究,详细分析在各典型充、泄水时刻第二分流口部位的水动力特性,论证在工程实际应用中的可行性。研究结果表明,在合理布置各分支廊道的出水支孔尺寸后,该分流口型式在充、泄水过程中分流效果较好,但在分流口内部存在典型流速、压力分布区域,特别是在泄水工况下分流口大墩头附近存在较大范围三角低流速紊动区域,可能会对分流口结构造成不利影响。研究成果可为全面掌握该分流口型式的水力特性以及进一步改进优化提供技术参考。