93 research outputs found

    On Modeling and Analyzing Cost Factors in Information Systems Engineering

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    Introducing enterprise information systems (EIS) is usually associated with high costs. It is therefore crucial to understand those factors that determine or influence these costs. Though software cost estimation has received considerable attention during the last decades, it is difficult to apply existing approaches to EIS. This difficulty particularly stems from the inability of these methods to deal with the dynamic interactions of the many technological, organizational and projectdriven cost factors which specifically arise in the context of EIS. Picking up this problem, we introduce the EcoPOST framework to investigate the complex cost structures of EIS engineering projects through qualitative cost evaluation models. This paper extends previously described concepts and introduces design rules and guidelines for cost evaluation models in order to enhance the development of meaningful and useful EcoPOST cost evaluation models. A case study illustrates the benefits of our approach. Most important, our EcoPOST framework is an important tool supporting EIS engineers in gaining a better understanding of the critical factors determining the costs of EIS engineering projects

    A Simple Model of the Economic Long Wave

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    Recent economic events have revived interest in the economic long wave or Kondratiev cycle, a cycle of economic expansion and depression lasting about fifty years. Since 1975 the System Dynamics National Model has provided an increasingly rich theory of the long wave. The theory revolves around "self-ordering" of capital, the dependence of the capital-producing sectors of the economy, in the aggregate, on their own output. The long-wave theory growing out of the National Model relates capital investment, employment and workforce participation, monetary and fiscal policy, inflation, productivity and innovation, and even political values. The advantage of the National Model is the rich detail in which economic behavior is represented. However, the complexity of the model makes it difficult to explain the dynamic hypothesis underlying the long wave in a concise manner. This paper presents a simple model of the economic long wave. The structure of the model is shown to be consistent with the principles of bounded rationality. The behavior of the model is analyzed, and the role of self-ordering in generating the long wave is determined. The model complements the National Model by providing a representation of the dynamic hypothesis that is amenable to formal analysis and is easily extended to include other important mechanisms that may influence the nature of the long wave

    Using a Dynamic Model to Simulate the Heuristic Evaluation of Usability

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    Among usability inspection methods, heuristic evaluation, or expert evaluation, is considered the most used and well-known usability evaluation method. The number of evaluators and their expertise are essential aspects that affect the quality of the evaluation, the cost that its application generates, and the time that it is necessary to spend. This paper presents a dynamic simulation model to analyze how different configurations of evaluator team have an effect upon the results of the heuristic evaluation method. One of the main advantages of using a dynamic simulation model is the possibility of trying out different decisions before carrying them out, and change them during the simulation of the evaluation process.Ministerio de Educación y Ciencia QSimTest TIN2007-67843-C06 03Ministerio de Educación y Ciencia TIN2007-67843-C06-0

    A Short Review on Jet Identification

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    Jets can be used to probe the physical properties of the high energy density matter created in collisions at the Relativistic Heavy Ion Collider (RHIC). Measurements of strong suppression of inclusive hadron distributions and di-hadron correlations at high pTp_{T} have already provided evidence for partonic energy loss. However, these measurements suffer from well-known geometric biases due to the competition of energy loss and fragmentation. These biases can be avoided if the jets are reconstructed independently of their fragmentation details - quenched or unquenched. In this paper, we discuss modern jet reconstruction algorithms (cone and sequential recombination) and their corresponding background subtraction techniques required by the high multiplicities of heavy ion collisions. We review recent results from the STAR experiment at RHIC on direct jet reconstruction in central Au+Au collisions at sNN=200\sqrt {s_{NN}}= 200 GeV.Comment: Proceedings for the invited talk of Hot Quarks 2008, Estes Park, CO 18-23 August 200

    Parton model versus color dipole formulation of the Drell-Yan process

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    In the kinematical region where the center of mass energy is much larger than all other scales, the Drell-Yan process can be formulated in the target rest frame in terms of the same color dipole cross section as low Bjorken-x deep inelastic scattering. Since the mechanisms for heavy dilepton production appear very different in the dipole approach and in the conventional parton model, one may wonder whether these two formulations really represent the same physics. We perform a comparison of numerical calculations in the color dipole approach with calculations in the next-to-leading order parton model. For proton-proton scattering, the results are very similar at low x_2 from fixed target to RHIC energies, confirming the close connection between these two very different approaches. We also compare the transverse momentum distributions of Drell-Yan dileptons predicted in both formulations. The range of applicability of the dipole formulation and the impact of future Drell-Yan data from RHIC for determining the color dipole cross section are discussed. A detailed derivation of the dipole formulation of the Drell-Yan process is also included.Comment: 20 pages, 5 figure

    Disequilibrium in development finance: the contested politics of institutional accountability and transparency at the World Bank inspection panel

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    This article examines the dynamic nature with which independent accountability mechanisms operate. Focusing on the World Bank, the authors argue that its Inspection Panel evolves according to internal and external pressures. In seeking to achieve equilibrium, and protect its authority and independence, the Panel has gone through several distinct phases: negotiation, emergence, protracted resistance, assertion of independence and authority, renewed tension, and contestation. The core novelty of the article is its application of concepts from outside the field of development studies — notably institutional accountability from the governance literature, and judicialization from the legal studies literature — to the topic of the Inspection Panel. Examining the Panel in this way demonstrates that accountability mechanisms represent a hybrid of transnational governance influenced by a range of actors including project-affected peoples, national governments, managers and development donors. Accountability in development finance is about competing interests as well as competing conceptions and expectations of accountability. In such a complex and multi-scalar system, the Panel is not only concerned with delivering well-researched investigation reports; it is also an entity seeking to ensure its own survival, as well as an arbiter of its own brand of legitimacy and accountability. © 2018 The Authors. Development and Change published by John Wiley & Sons Ltd on behalf of Institute of Social Studie
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