Evaluating dynamic performance: The influence of salient Gestalt characteristics on performance ratings.

It is well recognized that performance changes over time. However, the effect of these changes on overall assessments of performance is largely unknown. In a laboratory experiment, we examined the influence of salient Gestalt characteristics of a dynamic performance profile on supervisory ratings. We manipulated performance trend (flat, linear-improving, linear-deteriorating, U-shaped, and ∩-shaped), performance variation (small, large), and performance mean (negative, zero, positive) within subjects and display format (graphic, tabular) between subjects. Participants received and evaluated information about the weekly performance of different employees over a simulated 26-week period. Results showed strong main effects on performance ratings of both performance mean and performance trend, as well as interactions with display format. Theoretical and practical implications of the results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is evidence-based practice diverse enough? Philosophy of science considerations.

In its policy rationale for evidence-based practice in psychology (EBPP), the APA Presidential Task Force on Evidence-Based Practice (see record 2006-05893-001) claims to have constituted itself with "scientists and practitioners from a wide range of perspectives and traditions, reflecting the diverse perspectives within the field" (p. 273). We applaud this attention to diversity but contend that an entire perspective of the debate was omitted in the Task Force's newly approved policy and its underlying report. The failure to consider a philosophy of science perspective led the Task Force to make a number of epistemological assumptions that are not based on evidence or rationale and that thus violate the very spirit of evidence-based decision making. In this comment, we reveal a few of these assumptions and discuss their detrimental consequences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

History of depression and smoking cessation outcome: A meta-analysis.

The authors conducted a meta-analysis of published studies to (a) evaluate the premise that a history of major depression is associated with failure to quit smoking and (b) identify factors that moderate the relationship between history of depression and cessation outcome. Fifteen studies met the selection requirements and were coded for various study methodology and treatment characteristics. DSTAT was used to calculate individual study effect sizes, determine the mean effect size across studies. and test for moderator effects. No differences in either short-term (≤ 3 months) or long-term abstinence rates (≥ 6 months) were observed between smokers positive versus negative for history of depression. Lifetime history of major depression does not appear to be an independent risk factor for cessation failure in smoking cessation treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

用单透镜变换由多模光纤出射的大功率Nd：YAG激光束的特性

根据理论假设，通过选取单透镜的参数和位置，计算说明了单透镜使经由多模光纤出射的大功率Ｎｄ：ＹＡＧ激光束的发射角压缩，光束聚焦效率提高，光束截面场为高斯分布；文中的计算结果符合已知规律，从而说明了理论假设的正确性。     

ETR Ⅱ-30调速器液压控制系统

ETRⅠ-30调速器是瑞士爱舍维斯工厂生产的具有PID调节规律的电液调速器。本文对其液压控制系统作了较详细的介绍,供有关人员参考。     

Room temperature characterization of Hg1-xCdxTe P-on-n heterostructure photodiodes

Measurements of 77K R_oA and 300K reverse bias dynamic impedance (R_dA) products at one volt reverse bias has been carried out to assess the degree of correlation of this figure of merit. Planar P-on-n heterostructures were grown on near lattice-matched CdZnTe substrates with Hg_1-xCd_xTe (0.20< x <0.30) by molecular beam epitaxy. These devices were passivated with CdTe and doped with indium and arsenic as n- and p-type dopants, respectively. Current-voltage characteristic of these devices exhibit thermally generated dark currents at small and modest reverse bias. We have observed that R_oA values of these long wavelength infrared P-on-n heterostructure photodiodes at 77K correlate with room temperature R_dA values. Diode arrays with high room temperature R_dA values at one volt reverse bias also have high R_oA values at 77K. Similarly, low R_dA values at room temperature indicate poor performance at 77K where deviation from diffusion current occurs at reverse bias of 0.2 to 1 volt at room temperature. The results presented here, for a small samples of devices, demonstrate that room temperature measurements of current-voltage characteristics to evaluate Hg_1-xCd_xTe (0.22< x <0.28) diode performance and array uniformity at lower temperatures can be used. This provides an acceptable criteria for further study at lower temperatures.     

单层球面网壳地震反应特征分析

考虑不同矢跨比、荷载、跨度和支座刚度等多种因素的影响,对单层球面网壳在地震作用下的反应进行了较全面的研究,给出了其随各参数变化的规律,得出了在单层球面网壳抗震设计中起控制作用的是水平地震作用而不是竖向地震作用等有益的结论.此外本文还给出了由于阻尼比不同而需对引用现行抗震规范反应谱分析的网壳地震作用进行修正的建议.     

光接入网中DWMT调制技术的研究

研究了光纤－电缆调制解调器接入技术的上行信道调制方式，分析了离散小波多音（DWMT）调制与其它调制方式相比所具有的特点和优势，提出了DWMT调制解调器的实现模型，设计了使用DWMT调制解调器的光纤－电缆调制解调器双向传输的系统方案；并对DWMT调制的系统特性进行了计算机仿真分析。仿真结果表明，DWMT调制是一项能有效实用于光纤－电缆调制解调器系统上行信道的技术。     

爆破条件对爆破震动信号分析中小波包时频特征的影响

非平稳信号的小波包分析是在小波变换基础上发展起来的 ,它对小波分析中没有细分的高频部分进一步分解 ,从而能够对信号局部信息进行更为精细的掌握。爆破条件是影响爆破震动时频特征分布的主要因素之一。本研究中 ,针对在不同段药量、不同微差间隔时间及近似相同的其它条件下产生的爆破震动信号 ,运用小波包分析方法对其进行了时频分析 ,主要探讨了段药量、段微差间隔时间对爆破震动时频分布的影响规律。段药量对爆破震动波形时频特征的影响主要体现在各层小波包主振频带内的细节信号峰值质点振速方面 ,各细节信号的峰值质点振速随段药量增加而增大 ,但主振频带分布保持基本的一致性 ,同一主振频带下小波包细节信号的阻尼比也趋于一致 ;段微差时间间隔对爆破震动时频特征的影响主要表现在 :延长各主振频带小波包细节信号的振动持时 ,不同微差单段波形的叠加增加了主振频带个数 (优势频率个数 )并使各频带内的优势频率值有微弱增大的趋势     

Nonlinear adaptive algorithms for equalisation in mobile satellite communications

This paper considers the equalisation problem in Quadrature Phase-Shift Keying (QPSK) modulated signals which have been distorted by the passage through a transmission channel. The channel is modelled as a Rician fading channel to simulate the behaviour of the transmission channel in the mobile satellite context. The equalisation is treated as the generalisation of the channel behaviour, and some algorithms with the structure of an artificial neural network using the Multilayer Perceptron, Volterra Series and Radial Basis Function are described. Results for the BER performance of typical transversal equalisers, with Square-Root Kalman adaptation algorithm, and algorithms with artificial neural network structure are also reported and evaluated. Improved performance is exhibited by the artificial neural network approaches.