155,338 research outputs found
Evaluation of analytical methodologies to derive vulnerability functions
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
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?
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
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
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An evaluation framework for stereo-based driver assistance
This is the post-print version of the Article - Copyright @ 2012 Springer VerlagThe accuracy of stereo algorithms or optical flow methods is commonly assessed by comparing the results against the Middlebury
database. However, equivalent data for automotive or robotics applications
rarely exist as they are difficult to obtain. As our main contribution, we introduce an evaluation framework tailored for stereo-based driver assistance able to deliver excellent performance measures while
circumventing manual label effort. Within this framework one can combine several ways of ground-truthing, different comparison metrics, and use large image databases.
Using our framework we show examples on several types of ground truthing techniques: implicit ground truthing (e.g. sequence recorded without a crash occurred), robotic vehicles with high precision sensors, and to a small extent, manual labeling. To show the effectiveness of our evaluation framework we compare three different stereo algorithms on
pixel and object level. In more detail we evaluate an intermediate representation
called the Stixel World. Besides evaluating the accuracy of the Stixels, we investigate the completeness (equivalent to the detection rate) of the StixelWorld vs. the number of phantom Stixels. Among many findings, using this framework enables us to reduce the number of phantom Stixels by a factor of three compared to the base parametrization. This base parametrization has already been optimized by test driving vehicles for distances exceeding 10000 km
Simulation Models for Analyzing the Dynamic Costs of Process-aware Information Systems
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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