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991.
Esther Guerra Juan de Lara Paloma Díaz 《Journal of Visual Languages and Computing》2008,19(3):399-425
Ensuring model quality is a key success factor in many computer science areas, and becomes crucial in recent software engineering paradigms like the one proposed by model-driven software development. Tool support for measurements and redesigns becomes essential to help developers improve the quality of their models. However, developing such helper tools for the wide variety of (frequently domain specific) visual notations used by software engineers is a hard and repetitive task that does not take advantage from previous developments, thus being frequently forgotten.In this paper we present our approach for the visual specification of measurements and redesigns for Domain Specific Visual Languages (DSVLs). With this purpose, we introduce a novel DSVL called SLAMMER that contains generalisations of some of the more used types of internal product measurements and redesigns. The goal is to facilitate the task of defining measurements and redesigns for any DSVL, as well as the generation of tools from such specification reducing or eliminating the necessity of coding. We rely on the use of visual patterns for the specification of the relevant elements for each measurement and redesign type. In addition, SLAMMER allows the specification of redesigns either procedurally or by means of graph transformation rules. These redesigns can be triggered when the measurements reach a certain threshold.These concepts have been implemented in the meta-modelling tool AToM3. In this way, when a DSVL is designed, it is possible to specify measurements and redesigns that will become available in the final modelling environment generated for the language. As an example, we show a case study in the web modelling domain. 相似文献
992.
Agostinho de Medeiros Brito Junior Adri?o Duarte Dória Neto Jorge Dantas de Melo Luiz Marcos Garcia Goncalves 《Neural Networks, IEEE Transactions on》2008,19(6):1130-1140
In this paper, we propose a multiresolution approach for surface reconstruction from clouds of unorganized points representing an object surface in 3-D space. The proposed method uses a set of mesh operators and simple rules for selective mesh refinement, with a strategy based on Kohonen's self-organizing map (SOM). Basically, a self-adaptive scheme is used for iteratively moving vertices of an initial simple mesh in the direction of the set of points, ideally the object boundary. Successive refinement and motion of vertices are applied leading to a more detailed surface, in a multiresolution, iterative scheme. Reconstruction was experimented on with several point sets, including different shapes and sizes. Results show generated meshes very close to object final shapes. We include measures of performance and discuss robustness. 相似文献
993.
F. H. van Heesch M. A. Klompenhouwer G. de Haan 《Journal of the Society for Information Display》2008,16(10):1009-1019
Abstract— The spatio‐temporal aperture and sample rate of a video display determines both the static and dynamic resolution of the video signal that is rendered. The dynamic display characteristics like the visibility of large‐area flicker, motion judder, and motion blur can be derived from the frame rate and the temporal extent of the pixel aperture (i.e., the temporal aperture). For example, liquid‐crystal displays (LCDs) have an aperture that is relatively small in the spatial dimension and wide in the temporal domain. Consequently, moving objects displayed on an LCD suffer from motion blur. Especially in TV applications, the temporal dimension has a large impact on the overall picture quality. The temporal aperture, together with the frame rate, is shown to predict the amount of perceived large‐area flicker, motion judder, and motion blur and also the performance of motion‐blur reduction algorithms for LCDs. From this analysis it is further determined how to obtain the optimal temporal aperture of a television display, for which not only properties of the human visual system (HVS), but also the properties of the video signal have to be taken into account. 相似文献
994.
Marcel P. C. M. Krijn Siebe T. de Zwart Dick K. G. de Boer Oscar H. Willemsen Maarten Sluijter 《Journal of the Society for Information Display》2008,16(8):847-855
Abstract— An attractive concept for 3‐D displays is the one based on LCDs equipped with lenticular lenses. This enables autostereoscopic multiview 3‐D displays without a loss in brightness. A general issue in multiview 3‐D displays is their relatively low spatial resolution because the pixels are divided among the different views. To overcome this problem, we have developed switchable displays, using liquid‐crystal (LC) filled switchable lenticulars. In this way, it is possible to have a high‐brightness 3‐D display capable of fully exploiting the native 2‐D resolution of the underlying LCD. The feasibility of LC‐filled switchable lenticulars was shown in several applications. For applications in which it is advantageous to be able to display 3‐D and 2‐D content simultaneously, a 42‐in. locally switchable prototype having a matrix electrode structure was developed. These displays were realized using cylindrically shaped lenticular lenses in contact with LC. An alternative for these are lenticulars based on gradient‐index (GRIN) LC lenses. Preliminary results for such switchable GRIN lenses are presented as well. 相似文献
995.
The combined study of the literature about human resource management and the resource‐based view of the firm and organizational learning provides an analysis framework useful for understanding how strategic human resource management systems contribute to the creation and development of a sustained competitive advantage for the firm. This article has two major aims. First, it provides a conceptual framework linking simultaneously three theoretical blocks: (a) human resource management, (b) organizational learning and knowledge management, and (c) sustained competitive advantage. Second, the article builds a causal model and tests it with a sample of Spanish firms from the manufacturing industry using structural equation modeling (SEM). After the performance of a cluster analysis, a group of 72 learning firms is identified and used to test the model. Finally, major conclusions and implications for management are drawn and further avenues for research are suggested. © 2008 Wiley Periodicals, Inc. 相似文献
996.
Herbert Van de Sompel Ryan Chute Patrick Hochstenbach 《International Journal on Digital Libraries》2008,9(2):83-100
The need to federate repositories emerges in two distinctive scenarios. In one scenario, scalability-related problems in the
operation of a repository reach a point beyond which continued service requires parallelization and hence federation of the
repository infrastructure. In the other scenario, multiple distributed repositories manage collections of interest to certain
communities or applications, and federation is an approach to present a unified perspective across these repositories. The
high-level, 3-Tier aDORe federation architecture can be used as a guideline to federate repositories in both cases. This paper
describes the architecture, consisting of core interfaces for federated repositories in Tier-1, two shared infrastructure
components in Tier-2, and a single-point of access to the federation in Tier-3. The paper also illustrates two large-scale
deployments of the aDORe federation architecture: the aDORe Archive repository (over 100,000,000 digital objects) at the Los
Alamos National Laboratory and the Ghent University Image Repository federation (multiple terabytes of image files). 相似文献
997.
Erick Corrêa da Silva Aristófanes Corrêa Silva Anselmo Cardoso de Paiva Rodolfo Acatauassu Nunes 《Pattern Analysis & Applications》2008,11(1):89-99
This paper analyzes the application of Moran’s index and Geary’s coefficient to the characterization of lung nodules as malignant
or benign in computerized tomography images. The characterization method is based on a process that verifies which combination
of measures, from the proposed measures, has been best able to discriminate between the benign and malignant nodules using
stepwise discriminant analysis. Then, a linear discriminant analysis procedure was performed using the selected features to
evaluate the ability of these in predicting the classification for each nodule. In order to verify this application we also
describe tests that were carried out using a sample of 36 nodules: 29 benign and 7 malignant. A leave-one-out procedure was
used to provide a less biased estimate of the linear discriminator’s performance. The two analyzed functions and its combinations
have provided above 90% of accuracy and a value area under receiver operation characteristic (ROC) curve above 0.85, that
indicates a promising potential to be used as nodules signature measures. The preliminary results of this approach are very
encouraging in characterizing nodules using the two functions presented.
相似文献
Rodolfo Acatauassu NunesEmail: |
998.
Implementing an enterprise system involves capturing all information necessary to make business processes work in an integrated fashion, and reflecting this integration in source code. Enterprise resource planning implementations should also exploit reuse of existing system elements. ERP tools typically work on top of a framework, using prefabricated modules to create customized variants of the system. Among the free and open source ERP systems, only ERP5 offers a comprehensive set of tools tailored to its framework that, together with other off-the-shelf tools, provide support for creating new modules and entire new systems. 相似文献
999.
Yukawa M. de Lamare R.C. Sampaio-Neto R. 《IEEE transactions on audio, speech, and language processing》2008,16(4):696-710
This paper presents a new approach to efficient acoustic echo cancellation (AEC) based on reduced-rank adaptive filtering equipped with selective-decimation and adaptive interpolation. We propose a novel structure of an AEC scheme that jointly optimizes an interpolation filter, a decimation unit, and a reduced-rank filter. With a practical choice of parameters in AEC, the total computational complexity of the proposed reduced-rank scheme with the normalized least mean square (NLMS) algorithm is approximately half of that of the full-rank NLMS algorithm. We discuss the convergence properties of the proposed scheme and present a convergence condition. First, we examine the performance of the proposed scheme in a single-talk situation with an error-minimization criterion adopted in the decimation selection. Second, we investigate the potential of the proposed scheme in a double-talk situation by employing an ideal decimation selection. In addition to mean squared error (MSE) and power spectrum analysis of the echo estimation error, subjective assessments based on absolute category rating are performed, and the results demonstrate that the proposed structure provides significant improvements compared to the full-rank NLMS algorithm. 相似文献
1000.
Johan Montagnat Ákos Frohner Daniel Jouvenot Christophe Pera Peter Kunszt Birger Koblitz Nuno Santos Charles Loomis Romain Texier Diane Lingrand Patrick Guio Ricardo Brito Da Rocha Antonio Sobreira de Almeida Zoltán Farkas 《Journal of Grid Computing》2008,6(1):45-59
The medical community is producing and manipulating a tremendous volume of digital data for which computerized archiving,
processing and analysis is needed. Grid infrastructures are promising for dealing with challenges arising in computerized
medicine but the manipulation of medical data on such infrastructures faces both the problem of interconnecting medical information
systems to Grid middlewares and of preserving patients’ privacy in a wide and distributed multi-user system. These constraints
are often limiting the use of Grids for manipulating sensitive medical data. This paper describes our design of a medical
data management system taking advantage of the advanced gLite data management services, developed in the context of the EGEE
project, to fulfill the stringent needs of the medical community. It ensures medical data protection through strict data access
control, anonymization and encryption. The multi-level access control provides the flexibility needed for implementing complex
medical use-cases. Data anonymization prevents the exposure of most sensitive data to unauthorized users, and data encryption
guarantees data protection even when it is stored at remote sites. Moreover, the developed prototype provides a Grid storage
resource manager (SRM) interface to standard medical DICOM servers thereby enabling transparent access to medical data without
interfering with medical practice. 相似文献