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31.
    
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32.
    
We study scheduling problems with controllable processing times on parallel machines. Our objectives are to maximize the weighted number of jobs that are completed exactly at their due date and to minimize the total resource allocation cost. We consider four different models for treating the two criteria. We prove that three of these problems are NPmathcal{NP} -hard even on a single machine, but somewhat surprisingly, the problem of maximizing an integrated objective function can be solved in polynomial time even for the general case of a fixed number of unrelated parallel machines. For the three NPmathcal{NP} -hard versions of the problem, with a fixed number of machines and a discrete resource type, we provide a pseudo-polynomial time optimization algorithm, which is converted to a fully polynomial time approximation scheme.  相似文献   
33.
    
In this paper, we consider data‐driven approaches to the problem of inventory control. We first consider the approach of operational statistics and review related results which enable us to maximize a priori expected profit uniformly over all parameter values, when the demand distribution is known up to the location and scale parameters. For the case of the unknown shape parameter, we first suggest a heuristic approach based on operational statistics to obtain improved ordering policies and illustrate the same for the case of a Pareto demand distribution. In more general cases where the heuristic is not applicable, we suggest linear correction and support vector regression approaches to better estimate ordering policies, and illustrate these using a Gamma demand distribution. In certain cases, our proposed approaches are found to yield significant improvements.  相似文献   
34.
    
Global games of regime change—coordination games of incomplete information in which a status quo is abandoned once a sufficiently large fraction of agents attack it—have been used to study crises phenomena such as currency attacks, bank runs, debt crises, and political change. We extend the static benchmark examined in the literature by allowing agents to take actions in many periods and to learn about the underlying fundamentals over time. We first provide a simple recursive algorithm for the characterization of monotone equilibria. We then show how the interaction of the knowledge that the regime survived past attacks with the arrival of information over time, or with changes in fundamentals, leads to interesting equilibrium properties. First, multiplicity may obtain under the same conditions on exogenous information that guarantee uniqueness in the static benchmark. Second, fundamentals may predict the eventual fate of the regime but not the timing or the number of attacks. Finally, equilibrium dynamics can alternate between phases of tranquility—where no attack is possible—and phases of distress—where a large attack can occur—even without changes in fundamentals.  相似文献   
35.
  总被引:4,自引:0,他引:4  
The extreme importance of critical infrastructures to modern society is widely recognized. These infrastructures are complex and interdependent. Protecting the critical infrastructures from terrorism presents an enormous challenge. Recognizing that society cannot afford the costs associated with absolute protection, it is necessary to identify and prioritize the vulnerabilities in these infrastructures. This article presents a methodology for the identification and prioritization of vulnerabilities in infrastructures. We model the infrastructures as interconnected digraphs and employ graph theory to identify the candidate vulnerable scenarios. These scenarios are screened for the susceptibility of their elements to a terrorist attack, and a prioritized list of vulnerabilities is produced. The prioritization methodology is based on multiattribute utility theory. The impact of losing infrastructure services is evaluated using a value tree that reflects the perceptions and values of the decisionmaker and the relevant stakeholders. These results, which are conditional on a specified threat, are provided to the decisionmaker for use in risk management. The methodology is illustrated through the presentation of a portion of the analysis conducted on the campus of the Massachusetts Institute of Technology.  相似文献   
36.
Auditors' assessment of management's dispositions presumably affects their subsequent judgments. However, little is known about the process by which auditors infer characteristics of management. This paper proposes the theory of correspondent inferences [25] as a framework for examining auditors' assessment of management's dispositions; the model is tested in a laboratory experiment using experienced audit managers. The results are consistent with the proposed theoretical framework. Implications for future research are discussed.  相似文献   
37.
In this paper we incorporate a linear demand function to model the price-volume causal relationship into stochastic cost-volume-profit (CVP) analysis. We assume that the objective function is to maximize expected profit; other objective functions are also discussed and compared. A linear stochastic model follows from which probabilistic statements can be easily obtained if the random variables are assumed to be multivariate normal. The basic framework is shown to be a special case of project value maximization where project value is the cash flow of the project discounted for time and risk according to the capital asset pricing model. Moreover, an intertemporal extension that considers inventory is developed. In summary, a new approach to stochastic CVP analysis that incorporates the management decision process in an uncertain environment is developed.  相似文献   
38.
The measurement of performance is critical to nearly all managerial disciplines. Yet little is known about the aggregation characteristics of the components of performance and how our notion of a ‘good performing firm’ relates to what we use as a dependent variable. In this paper we propose an approach to the measurement of performance that uses the logic of frontier analysis and the technique of data envelopment analysis. The approach is shown to be a reasonable representation of the multidimensional nature of performance and is shown to replicate, effectively, the components that strategic management scholars typically consider when discussing performance. It is also shown to be superior to the simpler alternatives based on traditional approaches to performance measurement.  相似文献   
39.
Much of the existing scholarly works portray institutional voids (IVs) in emerging economies as impeding forces against the development of new ventures. However, little attention has been paid to how such voids generate positive outcomes in emerging market new ventures. Drawing on the institutional theory, we propose IVs as crucial enablers of new venture internationalization. In addition, we investigate both how and when IVs enhance the degree to which new ventures internationalize by examining international learning effort (ILE) as a mediator and two domestic market environmental factors (i.e., environmental dynamism and competitive intensity) as important contingencies. We test our moderated mediation model using primary data gathered from 211 new ventures from Ghana. We found that ILE mediates the relationship between IVs and new venture internationalization and that both environmental dynamism and competitive intensity moderate the indirect relationship between home-country IVs and new venture internationalization. We discuss the theoretical and practical implications of this study.  相似文献   
40.
Much leadership literature neglects its historical-contextual antecedents and as a result over-emphasizes zeitgeist, or tenor of the time's social forces. This neglect impedes leadership research by encouraging academic amnesia and promoting a strong feeling of research déjà vu among many researchers and practitioners. In this article, we develop a leadership historical-contextual superstructure consisting of evolutionary antecedents, paradigmatic antecedents, purpose and definitional antecedents, stakeholder antecedents, levels of analysis and temporal antecedents, and research dissemination antecedents. We use this superstructure to analyze current work in the increasingly important relational leadership research stream to illustrate how the superstructure's use can aid leadership researchers and practitioners in avoiding leadership déjà vu and academic amnesia and help build a more cumulative field.  相似文献   
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