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991.
信息系统安全风险的属性评估方法   总被引:5,自引:2,他引:3  
首次将属性理论和属性综合评估模型引入信息系统安全风险的评估领域 ,为信息系统安全风险程度的评估提出了一种新方法 ,对于信息系统安全性的动态管理有着积极的意义 .  相似文献   
992.
新产品设计前端的筛选与评价系统研究   总被引:2,自引:0,他引:2  
本着重于新产品设计前端的筛选与评价系统研究。设计了若干准则,有社会环境准则、经济成本准则、技术准则、时间准则、价值准则等,对新产品构思进行筛选。运用模糊理论,确定隶属度函数,得到评价矩阵,最终得到综合评价;运用加权评分法,确定评判的各影响因素及其各自所占的权重,给每种构思进行评分,根据最后总得分的多少来评定构思的优劣。最后,阐述了评价系统在设计过程中的重要作用,评价系统贯穿于整个设计过程中。  相似文献   
993.
Analyzing the Performance of Generalized Hill Climbing Algorithms   总被引:2,自引:0,他引:2  
Generalized hill climbing algorithms provide a framework to describe and analyze metaheuristics for addressing intractable discrete optimization problems. The performance of such algorithms can be assessed asymptotically, either through convergence results or by comparison to other algorithms. This paper presents necessary and sufficient convergence conditions for generalized hill climbing algorithms. These conditions are shown to be equivalent to necessary and sufficient convergence conditions for simulated annealing when the generalized hill climbing algorithm is restricted to simulated annealing. Performance measures are also introduced that permit generalized hill climbing algorithms to be compared using random restart local search. These results identify a solution landscape parameter based on the basins of attraction for local optima that determines whether simulated annealing or random restart local search is more effective in visiting a global optimum. The implications and limitations of these results are discussed.  相似文献   
994.
Wireline sampling tools withdraw a few litres of fluid from a permeable formation via a small sink probe pressed against the borehole wall. The aim is to recover, quickly and cheaply, a representative native fluid sample. Unfortunately, the formation in the near wellbore region is invaded by mud filtrate, and withdrawal of nonnative fluid initially is inevitable. It is therefore of interest to estimate the proportion of native fluid in the sample stream, as a function of time.Semi-analytical calculations of one- and two-phase sampling flows are presented, for the special case of constant total fluid mobility in the limits of very deep or very shallow invasion. Both the interaction of the initially cylindrically symmetric invasion profile with the spherically symmetric flow and the capillary shock-forming dynamics of two-phase flow are found to control the character of sample composition variation. The wide variety of sample stream composition histories is displayed.  相似文献   
995.
我国东西部城市经济实力比较的主成分分析   总被引:4,自引:0,他引:4  
蒋亮  罗汉 《经济数学》2003,20(3):48-53
本文运用主成分综合评价模型 ,对我国东、西部所辖 2 1个中心城市的 2 0 0 0年主要社会经济指标进行实证分析 ,给出这些城市经济发展水平的综合得分及其排序 ,进而对我国东、西部城市的经济实力进行定量比较 ,其结论得到系统聚类分析方法的印证  相似文献   
996.
This study focuses on speaking voice quality in male teachers (n = 35) and male actors (n = 36), who represent untrained and trained voice users, because we wanted to investigate normal and supranormal voices. In this study, both substantial and methodologic aspects were considered. It includes a method for perceptual voice evaluation, and a basic issue was rater reliability. A listening group of 10 listeners, 7 experienced speech-language therapists, and 3 speech-language therapist students evaluated the voices by 15 vocal characteristics using VA scales. Two sets of voice signals were investigated: text reading (2 loudness levels) and sustained vowel (3 levels). The results indicated a high interrater reliability for most perceptual characteristics. Connected speech was evaluated more reliably, especially at the normal level, but both types of voice signals were evaluated reliably, although the reliability for connected speech was somewhat higher than for vowels. Experienced listeners tended to be more consistent in their ratings than did the student raters. Some vocal characteristics achieved acceptable reliability even with a smaller panel of listeners. The perceptual characteristics grouped in 4 factors reflected perceptual dimensions.  相似文献   
997.
期权理论在风险投资项目评估中的应用   总被引:16,自引:0,他引:16  
本在对传统的现金流折现法DCF法分析基础上,引进Block-Scholes期权定价模型,对传统的DCF方法进行改进,克服了DCF方法局限性,增加了风险投资项目决策的科学性。  相似文献   
998.
最低价评标法若干问题探析   总被引:1,自引:0,他引:1  
从我国建设工程招投标评标方法入手,论述了最低价评标法的优缺点,分析了应用最低价评标法应把握几个问题,最后提出了实际最低价评标法的几项保障措施。  相似文献   
999.
We study the modelling of the subjective sensation of discomfort for subjects seated during a long time, in terms of local discomforts. The methodology uses fuzzy measures and integrals in a multicriteria decision making process, which enables the modelling of complex interaction between variables. Results of the experiment are detailed, giving models with respect to different kinds of discomfort, and to different macro-zones of the body.  相似文献   
1000.
The accurate transformation of device responses to tristimulus values is important at an early stage in color management and this transformation is usually called color correction. In this paper it is shown that the influence of noise on color correction can be suppressed if the square of the singular values by the singular value decomposition (SVD) of a sensor matrix represented by surface reflectance, SLVA1/2, is larger than the noise variance, where S is the M × N matrix of M channel spectral sensitivities, L is the N × N diagonal matrix for an recording illuminant, V is the N × N matrix which is composed of eigenvectors of an autocorrelation matrix for spectral reflectance of samples, A is the N × N diagonal matrix with eigenvalues of the autocorrelation matrix along the diagonal and N is the number of the dimension, respectively. A method to suppress the influence of noise on color correction by spectral sensitivities of sensors is presented for the first time.  相似文献   
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