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.     

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.

CEO and Chairperson characteristics and firm performance

This paper focuses on the relationship between Chief Executive Officer (CEO) and Chairperson characteristics and firm performance. Specifically, the study examines the association between the characteristics of the CEO and the Chairperson of the board and firm performance. Using a sample of S&P 500 firms, the evidence found suggests that demographic and experience-related characteristics may be associated with the market valuation and financial performance of the firm. In particular, the reported results indicate a positive relationship between the presence of female CEOs or Chairs and firm performance, thus suggesting that gender-based differences may affect the CEO’s/Chairperson’s success. Moreover, the findings concerning the age of the CEO or Chair are mixed, while their experience and quality appear positively related to firm performance. Interestingly, a CEO or Chairperson holding multiple board seats is negatively associated with firm performance, whereas CEO duality has a positive relationship with Tobin’s Q and the return on assets (ROA) of the firm.     

Career orientations and career success among research,and development and engineering professionals

Managing the careers of research, development and engineering (RD&E) professionals is important to the strategic use of RD&E in the economy. Appropriate mechanisms for motivating RD&E professionals will probably emerge as a critical success factor for organizations that want to compete in world markets. This study examines dimensions and levels of career orientation and their correlations with individual and work-related outcome variables among 78 RD&E professionals. The findings reveal a rich diversity of career orientation in RD&E professionals. The data strongly suggest that RD&E professionals are service, lifestyle and security oriented. However, they scored low on technical orientation and entrepreneurship. This paper suggests that the dual career ladder is not an effective device for managing RD&E professionals. Organizations must be careful to provide career paths that retain and motivate workers and, more importantly, find matches between organizational needs and individuals' needs, and restructure jobs accordingly. The authors offer suggestions for future research and identify implications for management.     

David and Goliath: causes and effects of coopetition between start-ups and corporates

Coopetition (collaboration between competitors) among young firms (i.e. start-ups) and larger, more established firms (i.e. corporates) may be beneficial for both partners as each party typically has something to offer that is missing in the other. Start-ups often develop innovative ideas, are flexible and agile, willing to take risks, and aspire to achieve high growth, but they tend to lack the required resources, capabilities, and knowledge due to their newness and smallness. Corporates have resources, routines, and experience that enable them to work efficiently but lack a certain innovation capability. Research has suggested that coopetition represents an opportunity for start-ups facing restrictions in resources, while corporates benefit from start-ups’ innovative ideas. However, it is yet unknown whether start-ups and corporates engage in coopetition with each other and, if so, how and why they do this. This study seeks to fill this void by exploring the motives of coopeting start-ups and corporates, how they manage their coopetitive relationship, and what implications occur including potential benefits and risks. We present a multiple case study based on qualitative data collected through 70 interviews with Austrian-based start-ups and corporates representing 35 coopetitive partnerships. Discussing the findings based on our data, we propose relationships concerning coopetition and its role to enlarge resource- and technology-bases as well as its role in the development of dynamic capabilities.     

Chronic stress and chronic disease in life and work: Conceptual and methodological issues

This paper argues that the lack of strong prospective evidence linking occupational and social stress to chronic disease stems from the failure of research designs to attend sufficiently to the aetiological chronicity of such diseases. Studies of both supposedly acute stress (life events) and chronic stress in life or work must increasingly be designed to distinguish between stress which is sustained or chronic over a period of yean or even decades, and hence capable of causing a serious chronic disease, and brief or transient stress, which may produce transient or brief psychological or physiological disturbances but cannot generate major chronic disease. Prospective studies are needed which collect measures of both stress and health or disease at multiple points over an extended period of time. Measures of stress should focus more on affect (for example, feelings of pressure and tension) than on cognition (for example feelings of satisfaction). Limited existing evidence is consistent with these ideals.     

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.     

管理者与领导者的区别与联系

(一)由于领导和管理的区别,因而产生了领导者和管理者的区别;由于领导和管理的联系,因而也决定了领导者和管理者的相通之处。领导者要履行好自己的职责,在很大程度上要依靠开发动力、启迪觉悟,要依靠思考符号和形象。尼克松说:“伟大的领导是一种特有的艺术形式,既需要超群的力量,又需要非凡的想像力。”伟大的领导者必须具备伟大的想像力、伟大的思想。这种想像力和思想激励着领导者本人勇往直前,使他怀着一种令自己激动并奋斗不息的使命感,从而不畏艰难险阻和挫折失败。领导者的伟大的想像力和思想,也像一团不熄的火焰,在公众的眼前和心中…     

Beliefs and the Perception of Risks and Accidents

Identifying the causes of accidents is a necessary prerequisite for preventive action. Some research suggests however that the analysis of accidents does not only differ between experts and laymen but that it is also linked to certain characteristics inherent in the analyst and in the social group to which he belongs: beliefs, value systems, norms, experiences in common, attitudes, roles, social and technical practices, etc. Culturally determined bias seems to affect the perception of risk and the causes of accidents. This article presents a certain number of thoughts and results based upon research carried out on causal attributions of traffic accidents in The Ivory Coast (West Africa) and discusses the importance of culture in risk-taking and accident prevention. It shows in particular that fatalistic beliefs and mystical practices influence the perception of accidents and consequently incite one to take more risks and neglect safety measures.     

National Culture and Industrial Relations and Pay Structures

The paper develops an explanatory model of comparative industrial relations and labour market structures based on national culture. The four cultural variables derived by Hofstede (Culture’s Consequences, Beverly Hills: Sage, 1984) are used to investigate the relationship between national culture and various dimensions of industrial relations and pay structures. The paper finds national culture to be associated with the centralization of bargaining, the extent of corporatism, the degree of co‐ordination in bargaining, the coverage of collective bargaining, trade union density, the extent of worker participation in decision making, and most dimensions of the pay structure. Hofstede’s MAS variable, measuring cultural values representing gender social structuring, is associated with both industrial relations institutions and the pay structure. The results provide support for our cultural model.     

争不争争什么怎么争

人们在工作、学习和生活中,常常离不开争取,离不开努力。但是,争不争、争什么、怎么争,不是小问题。争取的方法、努力的方向,对人们的理想、信念、行为方式、工作取向和生活情趣都有着很大的影响。对于“争”,态度要科学,取向要正确,境界要高尚。一般来说,人人都有“争”的欲望和潜意识,总希望通过努力争取,保证自己在各方面都能不掉队、不落伍,走在前列。但在现实生活中,在争与不争的问题上,人们的态度是有差别的。有的人总是保持着一股不松懈、不怠慢的劲头,一种欲与天公试比高的精神和不服输、不认低的心志,为真理、为群众,孜孜以求,越争…     

Surviving and succeeding during mergers and consolidations.

Mergers and acquisitions are occurring at a feverish pace throughout U.S. business. Even firms that are not seeking to grow through acquisition are making defensive moves--internal reorganizations that involve cutting out entire layers of management or divesting whole divisions--to raise stock prices in hopes of fending off unwanted takeover bids. Mergers and reorganizations are especially prominent in the health care industry. The push for cost containment enhances the attractiveness of perceived synergies to be gained through combination. Moreover, the specter of an industry shake out prompts executives to adopt an "eat or be eaten" mentality.     

股票回购与公司价值--理论与实证分析

股票回购是西方发达国家上市公司一种常见的股利分配政策和资本运作方式,在回顾与总结国内外相关理论的基础上,从实证角度分析了股票回购对于我国上市公司价值的影响.研究结果表明,股票回购对于我国上市公司具有特殊的积极意义,有利于公司价值的提升.     

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 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.     

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.