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91.
根据新型军械装备损坏程度具有不确定性的特点,提出了基于D-S证据理论的新型军械装备损坏程度评估方法,并求出了新型军械装备损坏程度区分.通过对典型新型军械装备损坏程度的评估,验证了该方法的有效性和实用性. 相似文献
92.
评估指标的关联性是评估指标体系设计中常遇到且不易解决的问题。文章首先介绍了指标关联性研究的基本问题和相关概念;其次提出了评估指标之间关联关系的四类存在形式和若干组合类型;最后探讨了解决指标关联性问题的两个方向。为更有针对性地解决指标关联性问题提供了理论指导。 相似文献
93.
本文在阐述数据容灾概念与技术的基础上,简单分析了当前几种关键技术,并针对目前我国数字图书馆的可用性与安全性要求高的特点,提出了应用SAN技术实现数字图书馆容灾系统的设计方案,然后对此方案进行了分析,为其他容灾系统的建设起参考与借鉴作用。 相似文献
94.
大功率LED智能化照明控制系统设计 总被引:3,自引:0,他引:3
罗静华 《单片机与嵌入式系统应用》2010,(1):50-52,56
在绿色照明领域,既要体现节能,又要具备较高的光效,大功率LED驱动设计显得越来越重要。针对大功率LED的特性,研究设计了适用于不同参数指标的白光LED的驱动与控制系统。该系统以单片机C8051F040为核心,结合外围电路,用数字控制技术代替模拟电路控制,对大功率LED的恒流驱动电流进行高精度控制,以及对LED亮度进行自动调节控制,实现了多种大功率LED智能化照明。 相似文献
95.
Yongjun Shen Elke Hermans Da Ruan Geert Wets Tom Brijs Koen Vanhoof 《Expert systems with applications》2011,38(12):15262-15272
Data envelopment analysis (DEA) is a powerful analytical research tool for measuring the relative efficiency of a homogeneous set of decision making units (DMUs) by obtaining empirical estimates of relations between multiple inputs and multiple outputs related to the DMUs. To further embody multilayer hierarchical structures of these inputs and outputs in the DEA framework, which are prevalent in today’s performance evaluation activities, we propose a generalized multiple layer DEA (MLDEA) model. Starting from the input-oriented CCR model, we elaborate the mathematical deduction process of the MLDEA model, formulate the weights in each layer of the hierarchy, and indicate different types of possible weight restrictions. Meanwhile, its linear transformation is realized and further extended to the BCC form. To demonstrate the proposed MLDEA model, a case study in evaluating the road safety performance of a set of 19 European countries is carried out. By using 13 hierarchical safety performance indicators in terms of road user behavior (e.g., inappropriate or excessive speed) as the model’s input and 4 layered road safety final outcomes (e.g., road fatalities) as the output, we compute the most optimal road safety efficiency score for the set of European countries, and further analyze the weights assigned to each layer of the hierarchy. A comparison of the results with the ones from the one layer DEA model clearly indicates the usefulness and effectiveness of this improvement in dealing with a great number of performance evaluation activities with hierarchical structures. 相似文献
96.
Sven Groppe Jinghua Groppe Stefan Böttcher Thomas Wycisk Le Gruenwald 《Knowledge and Information Systems》2009,18(3):331-391
We have to deal with different data formats whenever data formats evolve or data must be integrated from heterogeneous systems.
These data when implemented in XML for data exchange cannot be shared freely among applications without data transformation.
A common approach to solve this problem is to convert the entire XML data from their source format to the applications’ target
formats using the transformations rules specified in XSLT stylesheets. However, in many cases, not all XML data are required
to be transformed except for a smaller part described by a user’s query (application). In this paper, we present an approach
that optimizes the execution time of an XSLT stylesheet for answering a given XPath query by modifying the XSLT stylesheet
in such a way that it would (a) capture only the parts in the XML data that are relevant to the query and (b) process only
those XSLT instructions that are relevant to the query. We prove the correctness of our optimization approach, analyze its
complexity and present experimental results. The experimental results show that our approach performs the best in terms of
execution time, especially when many cost-intensive XSLT instructions can be excluded in the XSLT stylesheet. 相似文献
97.
We developed a performance assessment model for e-commerce; it included indicators, indicator weights, and evaluation methods. The model has seven methods of assessing e-commerce performance and uses four criteria to compare and select the appropriate one for a particular situation. This model was tested in the retail sector of China. According to the data collected from 70 Chinese retailers, 16 indicators of e-commerce performance consisted of four constructs: marketing and sales, customer service, supply chain efficiency, and financial performance. The indicators for those constructs provide a comprehensive measurement of performance. Then weights were assigned for each indicator using a majority aggregation method. Comparison of the results from seven evaluation methods showed that discordance analysis and simple additive weighting were the best evaluation methods for the enterprises we had sampled. 相似文献
98.
99.
Feature extraction from images, which are typical of high dimensionality, is crucial to the recognition performance. To explore the discriminative information while depressing the intra-class variations due to variable illumination and view conditions, we propose a factor analysis framework for separate “content” from “style,” identifying a familiar face seen under unfamiliar viewing conditions, classifying familiar poses presented in an unfamiliar face, estimating age across unfamiliar faces. The framework applies efficient algorithms derived from objective factor separating functions and space mapping functions, which can produce sufficiently expressive representations of feature extraction and dimensionality reduction. We report promising results on three different tasks in the high-dimensional image perceptual domains: face identification with two benchmark face databases, facial pose classification with a benchmark facial pose database, extrapolation of age to unseen facial image. Experimental results show that our approach produced higher classification performance when compared to classical LDA, WLDA, LPP, MFA, and DLA algorithms. 相似文献
100.