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1.
Overshadowing and associability change: Examining the contribution of differential stimulus exposure
In two appetitive conditioning experiments with rats, we investigated the mechanisms responsible for demonstrations of the superior associability of overshadowed conditioned stimuli (CSs) relative to control CSs. In Experiment 1, we investigated whether previous demonstrations were a consequence of differences in the relationship between the CSs and the unconditioned stimulus (US) or of differences in the conditions of exposure to the CSs. Rats received trials with X, Y, and an AB compound, but no delivery of the US (X–, Y–, AB–). A subsequent AY–, AX+, BY + test discrimination revealed that the AY/BY component of the discrimination was solved more readily than the AY/AX component—suggesting the contribution of an exposure effect. In Experiment 2, we better equated the conditions of exposure between A and Y by using AB+, XY+, X– training in Stage 1. In Stage 2, instrumental responses were rewarded during an AY compound. A final test revealed that Y took better control of instrumental responding than did A. The results of these experiments are discussed in terms of classical and contemporary theories of learning and attention. 相似文献
2.
在本中，我们证明了下面主要结果：如果U=（X，B）是一个t-(υ t,κ t,1）设计（t≥1),Y=(υ1，υ2，…，υt)∈X，用UY表示U在Y上的限制，如果D=UY是一个2-对称设计，并且D中的超椭圆的个数至多为tυ(υ-1)(υ-κ)/[κ(κ^2-1)]，则这些超椭圆可以分为t类，每一类构成一个2-设计，它们的块图都是强正则图，并且它们的并也是一个2-设计，作为一个推论，我们给出了一个2-设计可以扩张的判据，最后我们给出一个例子说明我们的方法有效。 相似文献
3.
徐庆生 《楚雄师范学院学报》2003,18(6):1-5
本文首先论述了软件性能工程(SPE)方法，包括SPE概念、SPE过程、SPE与其它软件开发模型的集成、SPE策略及SPE工具，然后讨论了如何在从基于数据流模型(包括分析模型和设计模型)再工程为UML模型过程使用SPE的方法。 相似文献
4.
Gautam Puhan Timothy P. Moses Mary C. Grant Frederick McHale 《Journal of Educational Measurement》2009,46(3):344-362
A single-group (SG) equating with nearly equivalent test forms (SiGNET) design was developed by Grant to equate small-volume tests. Under this design, the scored items for the operational form are divided into testlets or mini tests. An additional testlet is created but not scored for the first form. If the scored testlets are testlets 1–6 and the unscored testlet is testlet 7, then the first form is composed of testlets 1–6 and the second form is composed of testlets 2–7. The seven testlets are administered as a single administered form, and when a sufficient number of examinees have taken the administered form, the second form (testlets 2–7) is equated to the first form (testlets 1–6) using an SG equating design. As evident, this design facilitates the use of an SG equating and allows for the accumulation of data, both of which may reduce equating error. This study compared equatings under the SiGNET and common-item equating designs and found lower equating error for the SiGNET design in very small sample size conditions (e.g., N = 10). 相似文献
5.
陈明富 《四川师范学院学报》2011,(1):75-82
形比句是比较句的一个类别,指谓语是形容词及形容词性成分的比较句。从调查的语料来看,东汉至宋时,差比类形比句句式的肯定形式主要有八种类型：XA焉、XA於Y、XA于Y、XA乎Y、XA如Y、XA似Y、X比YA、X比似YA。否定形式主要有七种类型：X无以A于Y、X未必A于Y、X非A乎Y、X不比YA、X不如YA、X不似YA。否定形式的用量要远远小于肯定形式。肯定形式中,“X比YA”型句式最终成为汉语差比类形比句的主要表达形式。 相似文献
6.
从语义角度探讨“的”字短语“X+的+Y的特点,认为“的”字短语的实质就是以X的语义类别为分类角度对Y进行分类.“的”字短语的语义特点是:Y具有可分类性;X具有分类功能;X的语义类别是对Y分类的角度;“X+的”是分类结果中的一类.运用这些观点可对有关语言现象进行合理解释. 相似文献
7.
Equating of tests composed of both discrete and passage-based multiple choice items using the nonequivalent groups with anchor test design is popular in practice. In this study, we compared the effect of discrete and passage-based anchor items on observed score equating via simulation. Results suggested that an anchor with a larger proportion of passage-based items, more items in each passage, and/or a larger degree of local dependence among items within one passage produces larger equating errors, especially when the groups taking the new form and the reference form differ in ability. Our findings challenge the common belief that an anchor should be a miniature version of the tests to be equated. Suggestions to practitioners regarding anchor design are also given. 相似文献
8.
Rats received training in which two auditory target stimuli, X and Y, were signaled by two visual stimuli, A and B, and followed by food (i.e., A-->X+, B-->Y+). The test consisted of presentations of X and Y preceded either by the same signal as during training (same trials: A-->X, B-->Y) or by the alternative signal (different trials: A-->Y, B-->X). After 8 training sessions, the animals responded less on same trials than on different trials; this effect was significantly reduced after 24 training sessions. In two additional experiments, animals that had also experienced presentations of A and B alone, either before or during training, showed the opposite pattern of results, responding more on same trials than on different trials. These results are interpreted as being due to the interaction between the effects of occasion setting and negative priming (see Wagner, 1981). 相似文献
9.
When an exam consists, in whole or in part, of constructed-response items, it is a common practice to allow the examinee to choose a subset of the questions to answer. This procedure is usually adopted so that the limited number of items that can be completed in the allotted time does not unfairly affect the examinee. This results in the de facto administration of several different test forms, where the exact structure of any particular form is determined by the examinee. However, when different forms are administered, a canon of good testing practice requires that those forms be equated to adjust for differences in their difficulty. When the items are chosen by the examinee, traditional equating procedures do not strictly apply due to the nonignorable nature of the missing responses. In this article, we examine the comparability of scores on such tests within an IRT framework. We illustrate the approach with data from the College Board's Advanced Placement Test in Chemistry 相似文献
10.
Two methods of local linear observed‐score equating for use with anchor‐test and single‐group designs are introduced. In an empirical study, the two methods were compared with the current traditional linear methods for observed‐score equating. As a criterion, the bias in the equated scores relative to true equating based on Lord's (1980) definition of equity was used. The local method for the anchor‐test design yielded minimum bias, even for considerable variation of the relative difficulties of the two test forms and the length of the anchor test. Among the traditional methods, the method of chain equating performed best. The local method for single‐group designs yielded equated scores with bias comparable to the traditional methods. This method, however, appears to be of theoretical interest because it forces us to rethink the relationship between score equating and regression. 相似文献
11.
张时阳 《郴州师范高等专科学校学报》2011,(4):58-61,70
从语义角度探讨“的”字短语“X＋的＋Y”的特点,认为“的”字短语的实质就是以X的语义类别为分类角度对Y进行分类。“的”字短语的语义特点是：Y具有可分类性;X具有分类功能;X的语义类别是对Y分类的角度;“X＋的”是分类结果中的一类。运用这些观点可对有关语言现象进行合理解释。 相似文献
12.
李永红 《昆明师范高等专科学校学报》1997,(Z1)
Stone提出了用最小二乘法和非参数方法结合使用估计回归函数m(x)=E(Y│x=x)的方法并建立了估计的弱相合性;此文在一定条件下,得到了m(x)的估计■_n(x)=■_n~′x sum from i=1 to n(W_(ni)(x)δ_i)的强相合性. 相似文献
13.
本文讨论南宁粤语短差比式"X+A+过"的来源和演化,主要结论是:短差比式"X+A+过"来源于差比式"X+A+过+Y"中基准Y的删略,这种短差比式的出现极有可能是壮语南部方言影响的产物。 相似文献
14.
汉语"非X不Y"结构已经从单纯的否定词"非"和"不"走向了凝固化的稳定结构,在语义层面上也体现了强调主观和客观的感情色彩.该结构满足了其语法化的要素.在进行语义解读的时候,X和Y值的变化起着关键的作用. 相似文献
15.
对二重积分的定义中的λ（｜｜T｜｜）→0分四种情况：分割的份数n→∞;△σi面积的最大值s→0;用平行于x轴、y轴的直线网对D进行分割;用平行于x轴、y轴的直线网对D在x轴、y轴上投影分别进行n等分（n→∞）作了分析,前两种分割是不可行的,后两种是可行的,并通过实例进行了验证。 相似文献
16.
The selection of bandwidth in kernel equating is important because it has a direct impact on the equated test scores. The aim of this article is to examine the use of double smoothing when selecting bandwidths in kernel equating and to compare double smoothing with the commonly used penalty method. This comparison was made using both an equivalent groups design and a nonequivalent group with anchor test design. The performance of the methods was evaluated through simulation studies using both symmetric and skewed score distributions. In addition, the bandwidth selection methods were applied to real data from a college admissions test. The results show that the traditional penalty method works well although double smoothing is a viable alternative because it performs reasonably well compared to the traditional method. 相似文献
17.
李凤吟 《泉州师范学院学报》2006,24(3):149-154
“从X到Y”是现代汉语中的一个固定格式,这种格式具有语表形式相同而内部结构、语义、及句法、语用功能不同的特征,文章通过对其进行综合的分析考察,揭示其更具价值的内在规律。 相似文献
18.
讨论获得Y上的拓扑使f连续的最大拓扑的充要条件是f为商映射.由此也就有Y上的拓扑使f连续的最大拓扑的充要条件是Y的子集U为开集当且仅当f-1(U)是X的开集.从而更加密切了商映射与最大拓扑的关系. 相似文献
19.
考虑变系数多维线性结构关系EV模型y=xτβ(t),Y=y+ε,X=x+u中的参数β(t)=(β1(t),β2(t),….,βP(t))τ的估计,利用线性模型中的M方法和权函数方法,构造出t=t0处的参数β(t0)的加权M估计量βn(t0),并证明了它具有相合性. 相似文献
20.