155,338 research outputs found

    Evaluation of analytical methodologies to derive vulnerability functions

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    The recognition of fragility functions as a fundamental tool in seismic risk assessment has led to the development of more and more complex and elaborate procedures for their computation. Although vulnerability functions have been traditionally produced using observed damage and loss data, more recent studies propose the employment of analytical methodologies as a way to overcome the frequent lack of post-earthquake data. The variation of the structural modelling approaches on the estimation of building capacity has been the target of many studies in the past, however, its influence in the resulting vulnerability model, impact in loss estimations or propagation of the uncertainty to the seismic risk calculations has so far been the object of restricted scrutiny. Hence, in this paper, an extensive study of static and dynamic procedures for estimating the nonlinear response of buildings has been carried out in order to evaluate the impact of the chosen methodology on the resulting vulnerability and risk outputs. Moreover, the computational effort and numerical stability provided by each approach were evaluated and conclusions were obtained regarding which one offers the optimal balance between accuracy and complexity

    Software-Engineering Process Simulation (SEPS) model

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    The Software Engineering Process Simulation (SEPS) model is described which was developed at JPL. SEPS is a dynamic simulation model of the software project development process. It uses the feedback principles of system dynamics to simulate the dynamic interactions among various software life cycle development activities and management decision making processes. The model is designed to be a planning tool to examine tradeoffs of cost, schedule, and functionality, and to test the implications of different managerial policies on a project's outcome. Furthermore, SEPS will enable software managers to gain a better understanding of the dynamics of software project development and perform postmodern assessments

    Does history matter for the relationship between R&D, Innovation and Productivity?

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    This paper analyzes the relationship between R&D expenditures, innovation and productivity growth, taking into account the possibility of persistence in firms’ behaviour. We study this relationship for a sample of Spanish manufacturing firms between 1990 and 2005, estimating a model with four equations: participation in technological activities, R&D intensity, the generation of innovations and the impact of these technological outputs on total factor productivity growth. Our results reflect the existence of true state dependence both in the decision of R&D investment and in the production of innovations. The omission of this persistence leads to an overestimation of the current impact of innovations on productivity growth. However, the presence of persistence in technological inputs and outputs entails current R&D activities having long–run effects on a firm’s productivity.CDM model, productivity growth, persistence in R&D and innovation.

    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

    Simulation Models for Analyzing the Dynamic Costs of Process-aware Information Systems

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    Introducing process-aware information systems (PAIS) in enterprises (e.g., workflow management systems, case handling systems) is associated with high costs. Though cost estimation has received considerable attention in software engineering for many years, it is difficult to apply existing approaches to PAIS. This difficulty particularly stems from the inability of existing estimation techniques to deal with the complex interplay of the many technological, organizational and project-driven factors which emerge in the context of PAIS. In response to this problem, this paper proposes an approach which utilizes simulation models for investigating the dynamic costs of PAIS engineering projects. We motivate the need for simulation, discuss the development and execution of simulation models, and give an illustrating example. The present work has been accomplished in the EcoPOST project, which deals with the development of a comprehensive evaluation framework for analyzing PAIS engineering projects from a value-based perspective
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