自上而下的注意控制定势在注意捕获中的作用

采用经典前线索范式的变式, 通过100%有效的提示考察了自上而下的注意控制定势在注意捕获中的作用。实验1要求被试在整个实验中只搜索一个固定颜色的目标, 但是通过在每个试次前对目标进行提示加强注意控制定势的强度。实验2通过在每个试次中变化要搜索的目标颜色使被试必须建立两个更强的注意控制定势。实验结果一致表明和目标颜色相匹配的线索捕获了注意, 而和目标颜色无关的线索被抑制; 实验2的捕获效应和抑制效应都显著大于实验1; 对无关冲突线索和无关中性线索的注意抑制效应没有差异, 抑制效应显著小于捕获效应。研究表明自上而下的注意控制定势通过把注意从和目标不匹配的特征位置转移发挥作用, 支持注意转移假说; 对匹配线索的捕获和对无关线索的抑制运用了同一加工系统, 抑制作为捕获的附加产品出现, 两者都可以作为注意捕获的指标。     

The Economic, Political, Strategic, and Rhetorical Uses of Simple Constructive Dilemma in Legal Argument

The author argues that simple constructive dilemma is a valuable argument form for reasoning under relative conditions of uncertainty. When applied to legal argument this value of simple constructive dilemma is shown in its political, strategic, rhetorical, and especially economic, uses by lawyers and judges. After considering some examples of the use of the form by trial lawyers, the author gives examples of the more interesting use of the form by appellate courts. Research into the use of simple constructive dilemma by appellate courts helps us to understand how those courts distribute judicial resources. It also helps us to understand the political role of the appellate courts with respect to the doctrine of the separation of powers. Given some of the specific examples of legal reasoning used by the appellate courts presented in this article, and given the discussion of the doctrine of precedent, the article’s focus is on common law legal systems of the Anglo-American-type.     

Exact Interval Estimation, Power Calculation, and Sample Size Determination in Normal Correlation Analysis

This paper considers the problem of analysis of correlation coefficients from a multivariate normal population. A unified theorem is derived for the regression model with normally distributed explanatory variables and the general results are employed to provide useful expressions for the distributions of simple, multiple, and partial-multiple correlation coefficients. The inversion principle and monotonicity property of the proposed formulations are used to describe alternative approaches to the exact interval estimation, power calculation, and sample size determination for correlation coefficients. The author thanks the referees for their constructive comments and helpful suggestions and especially the associate editor for drawing attention to several critical results which led to substantial improvements of the exposition. The work for this paper was initiated while the author was visiting the Department of Statistics, Stanford University. This research was partially supported by National Science Council Grant NSC-94-2118-M-009-004. Request for reprints should be sent to Gwowen Shieh, Department of Management Science, National Chiao Tung University, Hsinchu, Taiwan 30050, ROC.     

Tailoring the crack-tip microstructure: a novel approach

This investigation demonstrates a way to innovatively modify the ferritic microstructure at a local scale, particularly at the failure prone area such as Charpy V-notch (CVN) root. Tensile pre-strain (PS) up to 6% and 12% were employed before annealing (An) the samples at 650°C for 15?minutes. Ferrite grain size increased sharply and gradually (along the distance ahead of the notch root) within the microstructurally modified region in 6–12% pre-strained and annealed samples, respectively. The critical strain which promotes strain-induced boundary migration (SIBM), was found to be 0.1 which resulted in abnormally coarse ferrite grains.     

简单与复杂物理问题解决及状态元认知

本研究采用认知作业分析及问卷法,研究了中学生简单与复杂物理问题解决的表征机制及状态元认知结构。结果显示：(1)物理问题解决是对问题的表征状态不断转换的过程,其受认知主体信息的提取、转换、整合能力及状态元认知的影响;(2)中学生物理问题解决中的状态元认知主要由他的自我效能感、自我监测、策略系统三种成分构成;(3)复杂问题解决的关链是正确提取范畴性知识以形成对问题的深层表征。     

Within-session changes in the VI response function: separating food density from elapsed session time.

Previous studies examining the relationship between response rate and reinforcement rate on variable-interval schedules (the variable-interval response function) have confounded elapsed session time with within-session changes in food density. The present experiments attempted to manipulate these factors independently and thus isolate their effects on responding. In Experiment 1, 7 rats pressed a bar for food on a series of four variable-interval schedules (7.5 s, 15 s, 30 s, and 480 s). Elapsed session time was held constant while food density was manipulated via a presession feeding. Changes in food density altered the form of the variable-interval response function, independently of elapsed session time. In Experiment 2, 8 rats responded on the same series of variable-interval schedules as in Experiment 1, but food density was held constant and elapsed session time was manipulated via the use of timeout periods. The results revealed no evidence for an effect of elapsed session time independent of food density. The present results extend a recent analysis of the variable-interval response function by Dougan, Kuh, and Vink (1993) by identifying food density as an important factor determining the form of the function. The present results also help clarify the controversy over the correct empirical form of the variable-interval response function by further defining the variables responsible for differences in the form of that function.