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91.
Sergio Martin Gabriel Diaz Inmaculada Plaza Elena Ruiz Manuel Castro Juan PeireAuthor vitae 《Journal of Systems and Software》2011,84(11):1883-1891
The emergence of mobile and ubiquitous technologies as important tools to complement formal learning has been accompanied by a growing interest in their educational benefits and applications. Mobile devices can be used to promote learning anywhere and anytime, to foster social learning and knowledge sharing, or to visualize augmented reality applications for learning purposes. However, the development of these applications is difficult for many researchers because it requires understanding many different protocols; dealing with distributed schemas, processes, platforms, and services; learning new programming languages; and interacting with different hardware sensors and drivers. For that reason, the use of frameworks and middleware that encapsulate part of this complexity appears to be fundamental to the further development of mobile learning projects. This study analyzes the state of the art of frameworks and middleware devoted to simplifying the development of mobile and ubiquitous learning applications. The results can be useful to many researchers involved in the development of projects using these technologies by providing an overview of the features implemented in each of these frameworks. 相似文献
92.
Olivier Kerbrat Pascal Mognol Jean-Yves HascoëtAuthor vitae 《Computers in Industry》2011,62(7):684-692
Design for manufacturing (DFM) approaches aim to integrate manufacturability aspects during the design stage. Most of DFM approaches usually consider only one manufacturing process, but product competitiveness may be improved by designing hybrid modular products, in which products are seen as 3-D puzzles with modules realized individually by the best manufacturing process and further gathered. A new DFM system is created in order to give quantitative information during the product design stage of which modules will benefit in being machined and which ones will advantageously be realized by an additive process (such as Selective Laser Sintering or laser deposition). A methodology for a manufacturability evaluation in case of a subtractive or an additive manufacturing process is developed and implemented in a CAD software. Tests are carried out on industrial products from automotive industry. 相似文献
93.
Pierre Aubert Nicolas Di Césaré Olivier Pironneau 《Computing and Visualization in Science》2001,3(4):197-208
This work deals with an implementation of automatic differentiation of C++ computer programs in forward mode using operator overloading and expression templates. We report on the efficiency of such implementation and its obvious advantage : the ability to perform sensitivity analysis
without touching the source of the computer program by simply adding a library to it. We apply this tool to a flow control
problem : minimize the drag of a cylinder, in subsonic unsteady turbulent flow, by controlling the boundary condition of the
cylinder.
Received: 1 June 1999 / Accepted: 29 May 2000 相似文献
94.
95.
This paper introduces the use of sets of multiple networks (bundled networks) to manage the variability due to different initialization parameters. This method makes it statistically impossible for the networks to be trapped in the same local minimum, and therefore allows better control of the confidence of the prediction eventually given. The spread of the forecasts given by these different networks can be used for prediction reliability purposes. An illustration of this usage is given with the El Niño phenomenon. 相似文献
96.
In this study, the effect of the centrifugal forces on the eigenvalue solution obtained using two different nonlinear finite
element formulations is examined. Both formulations can correctly describe arbitrary rigid body displacements and can be used
in the large deformation analysis. The first formulation is based on the geometrically exact beam theory, which assumes that the cross section does not deform in its own plane and remains plane after deformation. The second formulation,
the absolute nodal coordinate formulation (ANCF), relaxes this assumption and introduces modes that couple the deformation of the cross section and the axial and bending
deformations. In the absolute nodal coordinate formulation, four different models are developed; a beam model based on a general
continuum mechanics approach, a beam model based on an elastic line approach, a beam model based on an elastic line approach
combined with the Hellinger–Reissner principle, and a plate model based on a general continuum mechanics approach. The use
of the general continuum mechanics approach leads to a model that includes the ANCF coupled deformation modes. Because of these modes, the continuum mechanics model differs from the models based on the elastic line approach. In both
the geometrically exact beam and the absolute nodal coordinate formulations, the centrifugal forces are formulated in terms
of the element nodal coordinates. The effect of the centrifugal forces on the flap and lag modes of the rotating beam is examined, and the results obtained using the two formulations are compared for different values of
the beam angular velocity. The numerical comparative study presented in this investigation shows that when the effect of some
ANCF coupled deformation modes is neglected, the eigenvalue solutions obtained using the geometrically exact beam and the
absolute nodal coordinate formulations are in a good agreement. The results also show that as the effect of the centrifugal
forces, which tend to increase the beam stiffness, increases, the effect of the ANCF coupled deformation modes on the computed
eigenvalues becomes less significant. It is shown in this paper that when the effect of the Poisson ration is neglected, the
eigenvalue solution obtained using the absolute nodal coordinate formulation based on a general continuum mechanics approach
is in a good agreement with the solution obtained using the geometrically exact beam model. 相似文献
97.
Nawal Guermouche Olivier Perrin Christophe Ringeissen 《Electronic Notes in Theoretical Computer Science》2008,200(3):155
Web services are becoming one of the main technologies for designing and building complex inter-enterprise business applications. Usually, a business application cannot be fulfilled by one Web service but by coordinating a set of them. In particular, to perform a coordination, one of the important investigations is the compatibility analysis. Two Web services are said compatible if they can interact correctly. In the literature, the proposed frameworks for the services compatibility checking rely on the supported sequences of messages. The interaction of services depends also on other properties, such that the exchanged data flow. Thus, considering only supported sequences of messages seems to be insufficient. Other properties on which the services interaction can rely on, are the temporal constraints. In this paper, we focus our interest on the compatibility analysis of Web services regarding their (1) supported sequences of messages, (2) the exchanged data flow, (3) constraints related to the exchanged data flow and (4) the temporal requirements. Based on these properties, we study three compatibility classes: (i) absolute compatibility, (ii) likely compatibility and (iii) absolute incompatibility. 相似文献
98.
International Journal of Computer Vision - 相似文献
99.
Training a support vector machine in the primal 总被引:3,自引:0,他引:3
Chapelle O 《Neural computation》2007,19(5):1155-1178
Most literature on support vector machines (SVMs) concentrates on the dual optimization problem. In this letter, we point out that the primal problem can also be solved efficiently for both linear and nonlinear SVMs and that there is no reason for ignoring this possibility. On the contrary, from the primal point of view, new families of algorithms for large-scale SVM training can be investigated. 相似文献
100.
On the hardness of offline multi-objective optimization 总被引:1,自引:0,他引:1
Teytaud O 《Evolutionary computation》2007,15(4):475-491
It has been empirically established that multiobjective evolutionary algorithms do not scale well with the number of conflicting objectives. This paper shows that the convergence rate of all comparison-based multi-objective algorithms, for the Hausdorff distance, is not much better than the convergence rate of the random search under certain conditions. The number of objectives must be very moderate and the framework should hold the following assumptions: the objectives are conflicting and the computational cost is lower bounded by the number of comparisons is a good model. Our conclusions are: (i) the number of conflicting objectives is relevant (ii) the criteria based on comparisons with random-search for multi-objective optimization is also relevant (iii) having more than 3-objectives optimization is very hard. Furthermore, we provide some insight into cross-over operators. 相似文献