136,618 research outputs found
Psychometrics in Practice at RCEC
A broad range of topics is dealt with in this volume: from combining the psychometric generalizability and item response theories to the ideas for an integrated formative use of data-driven decision making, assessment for learning and diagnostic testing. A number of chapters pay attention to computerized (adaptive) and classification testing. Other chapters treat the quality of testing in a general sense, but for topics like maintaining standards or the testing of writing ability, the quality of testing is dealt with more specifically.\ud
All authors are connected to RCEC as researchers. They present one of their current research topics and provide some insight into the focus of RCEC. The selection of the topics and the editing intends that the book should be of special interest to educational researchers, psychometricians and practitioners in educational assessment
Quality-aware model-driven service engineering
Service engineering and service-oriented architecture as an integration and platform technology is a recent approach to software systems integration. Quality aspects
ranging from interoperability to maintainability to performance are of central importance for the integration of heterogeneous, distributed service-based systems. Architecture models can substantially influence quality attributes of the implemented software systems. Besides the benefits of explicit architectures on maintainability and reuse, architectural constraints such as styles, reference architectures and architectural patterns can influence observable software properties such as performance. Empirical performance evaluation is a process of measuring and evaluating the performance of implemented software. We present an approach for addressing the quality of services and service-based systems at the model-level in the context of model-driven service engineering. The focus on architecture-level models is a consequence of the black-box
character of services
emgr - The Empirical Gramian Framework
System Gramian matrices are a well-known encoding for properties of
input-output systems such as controllability, observability or minimality.
These so-called system Gramians were developed in linear system theory for
applications such as model order reduction of control systems. Empirical
Gramian are an extension to the system Gramians for parametric and nonlinear
systems as well as a data-driven method of computation. The empirical Gramian
framework - emgr - implements the empirical Gramians in a uniform and
configurable manner, with applications such as Gramian-based (nonlinear) model
reduction, decentralized control, sensitivity analysis, parameter
identification and combined state and parameter reduction
The Diversity and Dynamics of Industrial Organisation: Transformation of Local Assemblers in the Vietnamese Motorcycle Industry
This paper focuses on an emerging arm's-length form of industrial organisation in the motorcycle industry, which had traditionally been characterised by tightly integrated form of organisation. By engaging in how this new form of organisation that emerged in China was transferred to Vietnam and evolved in the Vietnamese context, this paper seeks to illustrate how the rise of local firms in developing countries is driving the increased diversity and dynamics of industrial organisation in an industry that had previously been dominated by TNCs from developed countries.Motorcycles, industrial organisation, motorcycle industry, Asia, China, Vietnam
Cost-Effectiveness of Stronger Woodframe Buildings
We examine the cost-effectiveness of improvements in woodframe buildings. These include retrofits, redesign measures, and improved quality in 19 hypothetical woodframe dwellings. We estimated cost-effectiveness for each improvement and each zip code in California. The dwellings were designed under the CUREE-Caltech Woodframe Project. Costs and seismic vulnerability were determined on a component-by-component basis using the Assembly Based Vulnerability method, within a nonlinear time-history structural-analysis framework and using full-size test specimen data. Probabilistic site hazard was calculated by zip code, considering site soil classification, and integrated with vulnerability to determine expected annualized repair cost. The approach provides insight into uncertainty of loss at varying shaking levels. We calculated present value of benefit to determine cost-effectiveness in terms of benefit-cost ratio (BCR). We find that one retrofit exhibits BCRs as high as 8, and is in excess of 1 in half of California zip codes. Four retrofit or redesign measures are cost-effective in at least some locations. Higher quality is estimated to save thousands of dollars per house. Results are illustrated by maps for the Los Angeles and San Francisco regions and are available for every zip code in California
Improving Loss Estimation for Woodframe Buildings. Volume 2: Appendices
This report documents Tasks 4.1 and 4.5 of the CUREE-Caltech Woodframe Project. It presents a theoretical and empirical methodology for creating probabilistic relationships between seismic shaking severity and physical damage and loss for buildings in general, and for woodframe buildings in particular. The methodology, called assembly-based vulnerability (ABV), is illustrated for 19 specific woodframe buildings of varying ages, sizes, configuration, quality of construction, and retrofit and redesign conditions. The study employs variations on four basic floorplans, called index buildings. These include a small house and a large house, a townhouse and an apartment building. The resulting seismic vulnerability functions give the probability distribution of repair cost as a function of instrumental ground-motion severity. These vulnerability functions are useful by themselves, and are also transformed to seismic fragility functions compatible with the HAZUS software.
The methods and data employed here use well-accepted structural engineering techniques, laboratory test data and computer programs produced by Element 1 of the CUREE-Caltech Woodframe Project, other recently published research, and standard construction cost-estimating methods. While based on such well established principles, this report represents a substantially new contribution to the field of earthquake loss estimation. Its methodology is notable in that it calculates detailed structural response using nonlinear time-history structural analysis as opposed to the simplifying assumptions required by nonlinear pushover methods. It models physical damage at the level of individual building assemblies such as individual windows, segments of wall, etc., for which detailed laboratory testing is available, as opposed to two or three broad component categories that cannot be directly tested. And it explicitly models uncertainty in ground motion, structural response, component damageability, and contractor costs. Consequently, a very detailed, verifiable, probabilistic picture of physical performance and repair cost is produced, capable of informing a variety of decisions regarding seismic retrofit, code development, code enforcement, performance-based design for above-code applications, and insurance practices
Quality practices, priorities and performance: an international study
This paper presents the results of a survey administered across seventeen countries that seeks to examine quality practices, priorities and performance. The participating countries were Argentina, Australia, Belgium, Brazil, China, Croatia, Denmark, Germany, Hungary, Ireland, Italy, Netherlands, Norway, Spain,Sweden, UK and USA. The methodology involved the use of a self-administered questionnaire to director/head of operations/manufacturing in best practice firms within the sector of firms classified by ISIC(rev.2) Division 38. There is evidence of both similarities and differences across the countries studied. Further analysis is required to explore the convergence versus âculture specificâ argument.International, Practices, Priorities, Performance
Recent Achievements in Numerical Simulation in Sheet Metal Forming Processes
Purpose of this paper: During the recent 10-15 years, Computer Aided Process Planning and Die Design evolved as one of the most
important engineering tools in sheet metal forming, particularly in the automotive industry. This emerging role is strongly emphasized by
the rapid development of Finite Element Modelling, as well. The purpose of this paper is to give a general overview about the recent
achievements in this very important field of sheet metal forming and to introduce some special results in this development activity.
Design/methodology/approach: Concerning the CAE activities in sheet metal forming, there are two main approaches: one of them may
be regarded as knowledge based process planning, whilst the other as simulation based process planning. The author attempts to integrate
these two separate developments in knowledge and simulation based approach by linking commercial CAD and FEM systems.
Findings: Applying the above approach a more powerful and efficient process planning and die design solution can be achieved radically
reducing the time and cost of product development cycle and improving product quality.
Research limitations: Due to the different modelling approaches in CAD and FEM systems, the biggest challenge is to enhance the
robustness of data exchange capabilities between various systems to provide an even more streamlined information flow.
Practical implications: The proposed integrated solutions have great practical importance to improve the global competitiveness of sheet
metal forming in the very important segment of industry.
Originality/value: The concept described in this paper may have specific value both for process planning and die design engineers
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