998 resultados para Comparative achievement


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In order to analyze the test anxiety of Beijing's high school students, relevant factors affecting test anxiety and how those factors have effect on the test anxiety of those high school students, a cross-sectional study had been conducted among 2,089 students randomly selected from 15 high schools in Beijing, using the Test Anxiety Scale(TAS), Parenting Style Scale (PSS) and Academic Aggregate Graphic (AAG). Five months later, 194 students from one of those high schools were retested with TAS with students remaining anonymous. In the retest, the classes and birth dates of those students were strictly matched. This paper is composed of three parts to examine the issue. The first part examines the test anxiety among high school students in Beijing and establishes the model; the second part conducts a comparative study of issues related to test anxiety and academic performance; the third part examines the factors affecting test anxiety and establishes the model. Results showed that: 1. The reliability and validity of TAS are satisfied and can meet survey requirement. The 25-item version of TAS turned out to have equal or even better performance compared with the original 37-item version. 2. Incidence of test anxiety in high schools of Beijing: 57.9 percent of samples have an overall score at or higher 15. 55 percent of male student samples have a score at or higher than 15 while that for female student samples is 61 percent. A score of 20 refers to fairly serious test anxiety and 31.9 percent of samples have a score over 20. 28.1 percent of the male student samples have a score of over 20 while that for female student samples is 35.9 percent. 3. The effect of grade and sex and the interaction between the two factors are statistically significant. Female students have higher test anxiety than male students and the level of test anxiety varies from grade to grade. 4. Samples are divided into two groups, one with test anxiety and the other without. The academic performance gap between the two groups is very significant. There is a significant negative correlation between academic score and test anxiety. 5. There is a negative correlation between test anxiety and mastery goal orientation and a positive correlation between test anxiety and performance goal orientation. Students with higher academic self-efficiency have lower test anxiety. The more one thinks study is valuable, the lower his/her test anxiety is. Those whose parents communicate smoothly with them have lower test anxiety. Those whose parents have an inconsistent communication style have higher test anxiety. 6. Achievement goal is mediate variable for the effect of lack of values on test anxiety. 7. The indirect effect of introduction of achievement goal and parenting style, including communication, monitoring and communication consistence, on test anxiety is significant. Key words: Test anxiety,reliability, validity, self-efficiency,parenting style,achievement goal orientation, academic values, academic score

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Comparative analysis is the problem of predicting how a system will react to perturbations in its parameters, and why. For example, comparative analysis could be asked to explain why the period of an oscillating spring/block system would increase if the mass of the block were larger. This thesis formalizes the task of comparative analysis and presents two solution techniques: differential qualitative (DQ) analysis and exaggeration. Both techniques solve many comparative analysis problems, providing explanations suitable for use by design systems, automated diagnosis, intelligent tutoring systems, and explanation based generalization. This thesis explains the theoretical basis for each technique, describes how they are implemented, and discusses the difference between the two. DQ analysis is sound; it never generates an incorrect answer to a comparative analysis question. Although exaggeration does occasionally produce misleading answers, it solves a larger class of problems than DQ analysis and frequently results in simpler explanations.

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The desulfurization of thiophene on Raney Ni and rapidly quenched skeletal Ni (RQ Ni) has been studied in ultrahigh vacuum (UHV) by X-ray photoelectron spectroscopy (XPS). The Raney Ni or RQ Ni can be approximated as a hydrogen-preadsorbed polycrystalline Ni-alumina composite. It is found that thiophene molecularly adsorbs on Raney Ni or RQ Ni at 103 K. At 173 K, thiophene on alumina is desorbed, while thiophene in direct contact with the metallic Ni in Raney Ni undergoes C-S bond scission, leading to carbonaceous species most probably in the metallocycle-like configuration and atomic sulfur. On RQ Ni, the temperature for thiophene dissociation is about 100 K higher than that on Raney Ni. The lower reactivity of RQ Ni toward thiophene is tentatively attributed to lattice expansion of Ni crystallites in RQ Ni due to rapid quenching. The existence of alumina and hydrogen may block the further cracking of the metallocycle-like species on Raney Ni and RQ Ni at higher temperatures, which has been the dominant reaction pathway on Ni single crystals. By 473 K, the C Is peak has disappeared, leaving nickel sulfide on the surface.

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C. Shang and Q. Shen. Aiding classification of gene expression data with feature selection: a comparative study. Computational Intelligence Research, 1(1):68-76.

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Kibble, N., Campbell, A., Dishonoured Cheques: A Comparative Analysis (2001) 16/3 Journal of International Banking Law 77-83 RAE2008

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Russell M. Morphew, Hazel A. Wright, E. James LaCourse, Debra J. Woods and Peter M. Brophy (2007). Comparative proteomics of excretory-secretory proteins released by the liver fluke Fasciola hepatica in sheep host bile and during in vitro culture ex host. Molecular and Cellular Proteomics, 6 (6), 963-972. Sponsorship: BBSRC / EU RAE2008

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http://www.archive.org/details/childinthemidst028451mbp

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Intrinsic and extrinsic speaker normalization methods are systematically compared using a neural network (fuzzy ARTMAP) and L1 and L2 K-Nearest Neighbor (K-NN) categorizers trained and tested on disjoint sets of speakers of the Peterson-Barney vowel database. Intrinsic methods include one nonscaled, four psychophysical scales (bark, bark with endcorrection, mel, ERB), and three log scales, each tested on four combinations of F0 , F1, F2, F3. Extrinsic methods include four speaker adaptation schemes, each combined with the 32 intrinsic methods: centroid subtraction across all frequencies (CS), centroid subtraction for each frequency (CSi), linear scale (LS), and linear transformation (LT). ARTMAP and KNN show similar trends, with K-NN performing better, but requiring about ten times as much memory. The optimal intrinsic normalization method is bark scale, or bark with endcorrection, using the differences between all frequencies (Diff All). The order of performance for the extrinsic methods is LT, CSi, LS, and CS, with fuzzy ARTMAP performing best using bark scale with Diff All; and K-NN choosing psychophysical measures for all except CSi.

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This article compares the performance of Fuzzy ARTMAP with that of Learned Vector Quantization and Back Propagation on a handwritten character recognition task. Training with Fuzzy ARTMAP to a fixed criterion used many fewer epochs. Voting with Fuzzy ARTMAP yielded the highest recognition rates.

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The composition of equine milk differs considerably from that of the milk of the principal dairying species, i.e., the cow, buffalo, goat and sheep. Because equine milk resembles human milk in many respects and is claimed to have special therapeutic properties, it is becoming increasingly popular in Western Europe, where it is produced on large farms in several countries. Equine milk is considered to be highly digestible, rich in essential nutrients and to possess an optimum whey protein:casein ratio, making it very suitable as a substitute for bovine milk in paediatric dietetics. There is some scientific basis for the special nutritional and health-giving properties of equine milk but this study provides a comprehensive analysis of the composition and physico-chemical properties of equine milk which is required to fully exploit its potential in human nutrition. Quantification and distribution of the nitrogenous components and principal salts of equine milk are reported. The effects of the high concentration of ionic calcium, large casein micelles (~ 260 nm), low protein, lack of a sulphydryl group in equine β-lactoglobulin and a very low level of κ-casein on the physico-chemical properties of equine milk are reported. This thesis provides an insight into the stability of equine casein micelles to heat, ethanol, high pressure, rennet or acid. Differences in rennet- and acid-induced coagulation between equine and bovine milk are attributed not only to the low casein content of equine milk but also to differences in the mechanism by which the respective micelles are stabilized. It has been reported that β-casein plays a role in the stabilization of equine casein micelles and proteomic techniques support this view. In this study, equine κ-casein appeared to be resistant to hydrolysis by calf chymosin but equine β-casein was readily hydrolysed. Resolution of equine milk proteins by urea-PAGE showed the multi-phosphorylated isoforms of equine αs- and β-caseins and capillary zone electrophoresis showed 3 to 7 phosphorylated residues in equine β-casein. In vitro digestion of equine β-casein by pepsin and Corolase PP™ did not produce casomorphins BCM-5 or BCM-7, believed to be harmful to human health. Electron microscopy provided very clear, detailed images of equine casein micelles in their native state and when renneted or acidified. Equine milk formed flocs rather then a gel when renneted or acidified which is supported by dynamic oscillatory analysis. The results presented in this thesis will assist in the development of new products from equine milk for human consumption which will retain some of its unique compositional and health-giving properties.