多标准决策表中发现概率规则的变精度粗糙集方法

用优势关系代替不可分辨关系,本文提出了一种可以从多标准决策表中获取概率规则的扩展变精度粗糙集模型,该模型能够处理多标准决策表中可能的不一相容性,获取由偏好对象组成的概率决策规则集,并导出事例决策系统的偏好模型。研究结果表明:基于优势关系,从多标准决策表中获取的最小概率规则集,使用的条件数量较少,且导出规则的数量较少、较强。     

基于粗糙集理论的格序选择方法

在粗糙集理论中,为了识别由偏好属性导致的不相容性,已提出基于优势关系的粗糙集理论,然而这一理论在实际应用中往往导致多个决策规则的出现,如何辨别由偏好多属性决策表中获取的多个决策规则从而选取最优方案,尚未见到有关的研究文献。本文针对这一问题,利用格序理论,给出属性约简的贴近度,比较不同约简所得决策规则贴近于原知识库的程度,从而得到一种选择最优决策方案的方法。     

基于粗糙集理论的财务危机预警研究

本文针对财务危机预警中财务比率数量较多时计算量较大的问题,提出了基于粗糙集理论的财务危机预警模型,将财务比率分别作为条件属性,将企业所处的状态作为决策属性,从而构成一个财务预警决策系统.通过对决策表的属性约简和规则约简,得到决策系统的最小决策规则,从而实现财务危机预警.测试结果表明,该方法的预警结果正确、有效.     

基于粗糙集和神经网络的供应商决策选择研究

本文提出了一种基于粗集理论与神经网络相结合的供应商优化选择新方法.首先利用粗集理论对供应商原始指标决策表进行一致性属性约简,然后借助神经网络强大的学习能力对决策表进行自学习,完成属性的不一致约简,最后再由粗糙集对其进行值约简,得到最终的供应商优化选择决策规则,并给出了相应的算法.最后通过实例说明该方法的有效可行性.     

基于Rough Sets理论的证据获取与合成方法

证据理论是处理不确定性问题的有力工具,它处理的证据来源于专家.专家的知识经验是有限的,获取较困难,且可能存在一定的主观性.针对上述问题,提出了一种基于粗糙集理论的证据获取的新方法,并对证据合成和应用进行了研究.首先研究了大型决策表分解问题.利用粗糙集理论分析条件属性间的依赖关系,对条件属性集进行聚类,形成多个条件属性集相对独立的子决策表;其次对各子决策表进行分析,利用粗糙集的分类思想和隶属度概念,计算证据的基本可信度分配;最后文章对证据的合成及其在决策分析中的应用进行了研究,提出了相应的解决方法.     

一种基于VPRS的IT项目投标风险要素评价方法

变精度粗糙集模型允许有一定程度的错误分类率存在,利用这种特性可以有效消除投标风险信息系统中的数据噪声,提高风险要素评价的精度.结合层次分析法中判断矩阵方法提出一种基于变精度粗糙集的评价IT项目投标风险要素重要度的算法.首先,由专家对各要素风险程度打分,建立决策表;其次,利用变精度粗糙集属性依赖度求得属性间的相对重要性来构造判断矩阵;最后,确定各要素的综合重要度,并排序.     

基于模糊聚类和粗糙集提取我国经济增长的模糊规则

提出了一种基于模糊软分类和粗糙集理论来提取模糊规则的一种算法.该算法分为3个步骤①通过模糊软分类对样本进行模糊划分,得到隶属度矩阵;②运用粗糙集理论和得到的隶属度矩阵生成初始决策表;③简化决策表,提取规则.最后运用该算法提取我国经济增长的模糊规则.     

基于战略转换的企业战略风险预警模型研究

将粗糙集理论与神经网络相结合,构建了基于战略转换的企业战略风险预警模型。该模型首先运用基于信息熵与MDV函数的模糊聚类算法进行连续属性离散化,然后采用粗糙集理论约简出重要指标体系,最后采用BP神经网络进行学习和训练,进而对检验样本的风险等级进行判断。实证分析表明：基于MDV函数与信息熵的模糊聚类算法能够有效改善离散化效果;添加动量因子的改进BP算法提高了网络学习效率,且该预警模型对检验样本的总体预测精度较高,是一种有效和实用的战略风险预警工具。     

时间序列灰色定权聚类模型

本文首先指出了灰色定权聚类模型只能用于时间点而不能用于时间段的局限性,在此基础上提出了时间序列灰色定权聚类模型,并通过实例说明了新模型的应用.本文的结果拓广了灰色定权聚类模型的应用范围,使人们对事物的认识更趋深入.     

基于粗集理论的一种归纳学习算法

归纳学习是粗集理论的主要应用领域.本文基于粗糙集理论,针对相容决策表,提出一种新的归纳学习算法.与以往的方法相比,这种算法比较简单,能够全面地获取规则且没有冗余.此外,还讨论了不相容决策表的学习,给出了具有较高可信度的规则挖掘过程.     

Educational Landscapes and Urban Development. Contextual and Spatial Interfaces and Linkages

In the broad sociopolitical discussion on education quality within the last decade, it has become apparent that education is gaining importance for urban development, as well as space and the urban context are important dimensions of education. This becomes particularly evident in concepts for local educational landscapes (Ger. Bildungslandschaften). The young field of research on educational landscapes is currently lacking empirical research from spatial and planning sciences. In the paper, the current state of scientific research on educational landscapes in Germany and Europe and first insights to contextual and spatial interfaces and linkages between education and urban development in general are presented.     

E-governance and Corruption-developments and Issues in Ethiopia

This paper reports the results of a survey of 400 respondents in Ethiopia about factors generating corruption and the potential of e-Governance to mitigate corruption. It is suggested that e-Governance can help not only in weeding out corruption but also in the establishment of sounder government citizen relationships in Ethiopia. While e-Governance cannot cure all the structural factors that breed corruption in the society, strategic implementation of e-Governance can help improve the critical variable in combating corruption-government citizen relationships. It is argued that while e-Governance initiatives can make important contributions to improving public services they can best do so by helping improve overall relationships between governments and citizens.

Inventory Models with Continuous and Poisson Demands and Discounted and Average Costs

We develop a new, unified approach to treating continuous‐time stochastic inventory problems with both the average and discounted cost criteria. The approach involves the development of an adjusted discounted cycle cost formula, which has an appealing intuitive interpretation. We show for the first time that an (s, S) policy is optimal in the case of demand having a compound Poisson component as well as a constant rate component. Our demand structure simultaneously generalizes the classical EOQ model and the inventory models with Poisson demand, and we indicate the reasons why this task has been a difficult one. We do not require the surplus cost function to be convex or quasi‐convex as has been assumed in the literature. Finally, we show that the optimal s is unique, but we do not know if optimal S is unique.     

The Challenge of Political and Economic Change in Poland and Central and Eastern Europe

This article discusses political and economic changes in Poland, Central and Eastern Europe emerging since the demise of the ‘closed system’ in 1989. The presentation explores the range of change, the method and the sequence of change. General lessons in economic transition as identified by Polish Finance Minister Lezak Balcerowicz are discussed. The challenges involved in macroeconomic stabilization, radical liberalization, currency convertibility, subsidy reduction and conversion of state-owned enterprises are reviewed. Despite their complexity, economic and political reforms proved necessary and inevitable. This revised version was published online in July 2006 with corrections to the Cover Date.     

Work and shopping overflow — Consequences and differentiation among selected psychological and demographic characteristics

Contemporary individuals are forced to deal with excessive stimulation, which causes an overload in the cognitive and emotional areas. The purpose of this paper is to investigate the possible factors differentiating the perceived level of work and shopping overflow experienced by individuals and consequences of these states. Two psychological variables: cognitive control and sensation seeking, are chosen as potential factors differentiating the perceived levels of overflow. We assume that individuals with high cognitive control and sensation seeking will report lower levels of both types of examined overflows. Experiencing low overflow levels may manifest in the search for additional stimuli, rather than in the desire to limit them. Two indexes of behavior connected to seeking extra stimulation are selected: one belonging to the area of consumer behavior (readiness to participate in the experience economy) and one belonging to vocational behavior (choosing a boundaryless career). The quantitative study is conducted on a sample of 297 management students who are currently employed. The research results support the relation between cognitive control and perceived level of work and shopping overflow. Individuals who can cognitively control the situation and the incoming stimuli report lower levels of overflow. No significant relationship between sensation seeking and the level of overflow is found. The demographic variables that influence the perceived overflow are age and salary for work overflow and age for shopping overflow. As far as consequences of overflow are concerned, a low level of shopping overflow is related to readiness to participate in the experience economy. However, there is no link between work overflow and preferred career pattern. The managerial implications for human resource management and marketing strategy design are discussed.     

Review and preview of productivity research and applications

During the last two decades, productivity research and applications have not been given adequate importance when trying to attain excellence in the management of manufacturing enterprises. Recent developments in managerial philosophies Total Quality Management and Business Process Re-engineering , manufacturing technologies Flexible Manufacturing Systems, Computer Integrated Manufacturing, etc. and Information Technology innovations have made the traditional productivity improvement techniques obsolete. This article presents a review consisting of analyses of literature on productivity and a survey of manufacturing enterprises. A five-step preview strategy on productivity is enumerated which provides a meaningful direction towards future productivity research and application. The article is concluded by briefly describing the current research that is being carried out based on the preview strategy evolved.     

Modeling Pathology Workload and Complexity to Manage Risks and Improve Patient Quality and Safety

Anatomic pathology (AP) laboratories provide critical diagnostic information that help determine patient treatments and outcomes, but the risks of AP operations and their impact on patient safety and quality of care remain poorly recognized and undermanaged. Hospital-based laboratories face an operational and risk management challenge because clinical work of unknown quantity and complexity arrives with little advance notice, which results in fluctuations in workload that can push operations beyond planned capacity, leading to diagnostic delays and potential errors. Modeling the dynamics of workload and complexity in AP offers the opportunity to better use available information to manage risks. We developed a stock-and-flow model of a typical AP laboratory operation and identified key exogenous inputs that drive AP work. To test the model, we generated training and validations data sets by combining data from the electronic medical records and laboratory information systems over multiple years. We demonstrate the implementation of 10-day AP work forecast generated on a daily basis, and show its performance in comparison with actual work. Although the model somewhat underpredicts work as currently implemented, it provides a framework for prospective management of resources to ensure quality during workload surges. Although full implementation requires additional model development, we show that AP workload largely depends on few and accessible clinical inputs. Recognizing that level loading of work in a hospital is not practical, predictive modeling of work can empower laboratories to triage, schedule, or mobilize resources more effectively and better manage risks that reduce the quality or timeliness of diagnostic information.     

Definitions and linkages between operational and strategic flexibilities

This paper aims at clarifying the concept of strategic flexibility, starting from that much more common of manufacturing flexibility (or operational one). After characterizing the dimensions of the latter, a classification of strategic flexibility is presented which distinguishes four categories. The measures of strategic flexibility are also investigated. Then two analogies are pointed out with the operational flexibility. The first, of the cause-effect type, is on two levels: at the business level, the operational flexibility estimates the variation of practices, while the strategic flexibility measures the effect obtained on performances; at the corporate level, the operational flexibility estimates the variation of competences, while the strategic flexibility evaluates the change in business. The second analogy, related to the classification variables, permits the main types of operational and strategic flexibilities to be placed in a single framework. So this study seeks to provide a framework—which has not been proposed in prior literature—for analyzing and evaluating the correlated concepts of operational and strategic flexibilities, to create a theoretical foundation for future research and empirical testing.     

Review and reappraisal of modelling and predicting mental workload in single- and multi-task environments

The concept of mental workload has long been recognized as an important factor in individual performance within complex systems. It is documented that either overload or underload may degrade performance, and further affect the efficiency of the whole system. Therefore, systems designers need some explicit models to predict the mental workload imposed on individuals by the system at an early design phase so that alternative system designs can be evaluated. In examining mental-workload literature, it is found that few predictive mental-workload models have considered factors specific to individuals. This research aims to develop a practical framework for predicting mental workload in both single- and multi-task environments considering such individual factors. In order to describe mental workload more precisely and more completely, a framework for mentalworkload definitions, which contains instantaneous workload, average workload, accumulated workload, peak workload and overall workload, is proposed. In order to model individual factors, two new variables, i.e. effective workload and ineffective workload, are introduced to model the taskgenerated workload and individual-generated workload. The extension of the model to multi-task environments is also discussed. The proposed conceptual models are domain-independent and could be used to guide the development of operational models for different specific tasks.     

Additive and Multiplicative Models and Multistage Carcinogenesis Theory

In light of the Armitage-Doll multistage carcinogenesis theory, this paper examines the assumption that an additive relative risk relationship is indicative of two carcinogens that affect the same stage in the cancer process. We present formulas to compute excess cancer risks for a variety of patterns for limited exposure durations to two carcinogens that affect the first and penultimate stages; and using an index of synergy proposed by Thomas (1982), we find a number of these patterns to produce additive, or nearly additive, relative risk relationships. The consistent feature of these patterns is that the two exposure periods are of short duration and occur close together.