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951.
艾新革 《广州大学学报(社会科学版)》2002,1(10):80-83
通过对新旧版《中图法》TP3 17及其下位类的比较 ,详细分析了新版该类类目采用“使用分离”时类目注释所存在的一些问题 ,并依考虑的侧重点不同 ,给出了两种可行性解决方法 相似文献
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953.
A generalization of step-up and step-down multiple test procedures is proposed. This step-up-down procedure is useful when the objective is to reject a specified minimum number, q, out of a family of k hypotheses. If this basic objective is met at the first step, then it proceeds in a step-down manner to see if more than q hypotheses can be rejected. Otherwise it proceeds in a step-up manner to see if some number less than q hypotheses can be rejected. The usual step-down procedure is the special case where q = 1, and the usual step-up procedure is the special case where q = k. Analytical and numerical comparisons between the powers of the step-up-down procedures with different choices of q are made to see how these powers depend on the actual number of false hypotheses. Examples of application include comparing the efficacy of a treatment to a control for multiple endpoints and testing the sensitivity of a clinical trial for comparing the efficacy of a new treatment with a set of standard treatments. 相似文献
954.
In several key functional areas of contemporary engineering and management science, neural networks have steadily been gaining recognition as robust and reliable tools for classification problems. This paper describes a new application of the learning vector quantization neural network: the classification of the degree of modularization appropriate for the construction of an industrial facility. This neural network uses variables related to plant location, labor issues, organizational issues, plant characteristics, project risks, and environmental issues as inputs to perform the classification. The neural network training and performance evaluation is also discussed. 相似文献
955.
Violet R. Syrotiuk Zhiqiang Zhang Charles J. Colbourn 《Journal of Combinatorial Optimization》2007,14(2-3):229-248
Transport protocols provide reliable, end-to-end communication between a source and a destination in a network. The Transmission
Control Protocol (TCP) uses backward error correction, where the destination explicitly returns feedback to the source. Forward
error correction (FEC) can also be used for transport; here the source includes enough redundancy in the encoding symbols
to allow the destination to decode the message. In this paper, we compare the performance of two transport schemes, TCP and
LT, a scheme based on rateless FEC codes, in a wireless ad hoc network when topology-transparent scheduling is used for channel access. These schedules are derived from cover-free families, a type of combinatorial design. They provide a mechanism to guarantee collision-free communication between any two nodes
provided that each of the N nodes of the network has at most a specified number D of active (transmitting) neighbours. We find that LT outperforms TCP in more strenuous network conditions.
To Frank Hwang on the occasion of his sixty-fifth birthday. 相似文献
956.
区间数多指标决策中确定指标权重的一种客观赋权法 总被引:7,自引:4,他引:7
研究了指标值以区间数形式给出的不确定性多指标决策中确定指标权重的问题。依据传统的客观赋权法—离差最大化方法,给出了一种确定区间数指标权重的误差分析方法。该方法具有概念清晰、实用的特点,得出的指标权重能够较好地反映各指标信息的差异程度。最后通过一个算例说明了该方法的实用性和有效性。 相似文献
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958.
This brief introduction sets the scene for the symposium. It identifies three factors which prompted its preparation, and then outlines the six contributions to it. 相似文献
959.
Donald W. K. Andrews Moshe Buchinsky 《Econometrica : journal of the Econometric Society》2000,68(1):23-51
This paper considers the problem of choosing the number of bootstrap repetitions B for bootstrap standard errors, confidence intervals, confidence regions, hypothesis tests, p‐values, and bias correction. For each of these problems, the paper provides a three‐step method for choosing B to achieve a desired level of accuracy. Accuracy is measured by the percentage deviation of the bootstrap standard error estimate, confidence interval length, test's critical value, test's p‐value, or bias‐corrected estimate based on B bootstrap simulations from the corresponding ideal bootstrap quantities for which B=∞. The results apply quite generally to parametric, semiparametric, and nonparametric models with independent and dependent data. The results apply to the standard nonparametric iid bootstrap, moving block bootstraps for time series data, parametric and semiparametric bootstraps, and bootstraps for regression models based on bootstrapping residuals. Monte Carlo simulations show that the proposed methods work very well. 相似文献
960.
语言迁移即母语迁移,是指语言学习者在学习新知识的过程中,对已有知识进行自动的潜意识的利用过程。任何人在第二语言习得过程中都或多或少地受到母语的影响。文章着重研究英语语法学习中的母语负迁移现象及应对策略,旨在帮助人们掌握一些应对母语负迁移的方法,减少母语负迁移,提高英语语法学习的成效。 相似文献