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961.
Julio Vera Carlos González-Alcón Alberto Marín-Sanguino Néstor Torres 《Computers & Operations Research》2010,37(8):1427-1438
In this work we present a general (mono and multiobjective) optimization framework for the technological improvement of biochemical systems. The starting point of the method is a mathematical model in ordinary differential equations (ODEs) of the investigated system, based on qualitative biological knowledge and quantitative experimental data. In the method we take advantage of the special structural features of a family of ODEs called power-law models to reduce the computational complexity of the optimization program. In this way, the genetic manipulation of a biochemical system to meet a certain biotechnological goal can be expressed as an optimization program with some desired properties such as linearity or convexity.The general method of optimization is presented and discussed in its linear and geometric programming versions. We furthermore illustrate the use of the method by several real case studies. We conclude that the technological improvement of microorganisms can be afforded using the combination of mathematical modelling and optimization. The systematic nature of this approach facilitates the redesign of biochemical systems and makes this a predictive exercise rather than a trial-and-error procedure. 相似文献
962.
Arnaud Fréville Saïd Hanafi Frédéric Semet Nicolas Yanev 《Computers & Operations Research》2010,37(10):1688-1696
This article proposes a tabu search approach to solve a mathematical programming formulation of the linear classification problem, which consists of determining an hyperplane that separates two groups of points as well as possible in ?m. The tabu search approach proposed is based on a non-standard formulation using linear system infeasibility. The search space is the set of bases defined on the matrix that describes the linear system. The moves are performed by pivoting on a specified row and column. On real machine learning databases, our approach compares favorably with implementations based on parametric programming and irreducible infeasible constraint sets. Additional computational results for randomly generated instances confirm that our method provides a suitable alternative to the mixed integer programming formulation that is solved by a commercial code when the number of attributes m increases. 相似文献
963.
Zaid M. Odibat Cyrille Bertelle M.A. Aziz-Alaoui Gérard H.E. Duchamp 《Computers & Mathematics with Applications》2010,59(4):1462-1472
The differential transform method (DTM) is an analytical and numerical method for solving a wide variety of differential equations and usually gets the solution in a series form. In this paper, we propose a reliable new algorithm of DTM, namely multi-step DTM, which will increase the interval of convergence for the series solution. The multi-step DTM is treated as an algorithm in a sequence of intervals for finding accurate approximate solutions for systems of differential equations. This new algorithm is applied to Lotka–Volterra, Chen and Lorenz systems. Then, a comparative study between the new algorithm, multi-step DTM, classical DTM and the classical Runge–Kutta method is presented. The results demonstrate reliability and efficiency of the algorithm developed. 相似文献
964.
965.
Fatos Xhafa Leonard Barolli Santi Caballé Raul Fernández 《The Journal of supercomputing》2010,53(1):45-65
With the fast development of IT technologies, virtual organizations are more and more present in the current collaborative
work and learning activity. For instance, many subjects in virtual distance learning are organized as online groups of students,
who use groupware tools to complete their learning tasks. In this paper, we address the efficient management of peer groups
in JXTA-based P2P systems as a key issue in many P2P applications that use peer group as a unit such as for remote execution
of tasks in parallel and distributed applications. From this perspective, we consider peer grouping as the basis in the development
of groupware tools in P2P systems. 相似文献
966.
Termination is one of the most interesting problems when dealing with context-sensitive rewrite systems. Although a good number of techniques for proving termination of context-sensitive rewriting (CSR) have been proposed so far, the adaptation to CSR of the dependency pair approach, one of the most powerful techniques for proving termination of rewriting, took some time and was possible only after introducing some new notions like collapsing dependency pairs, which are specific for CSR. In this paper, we develop the notion of context-sensitive dependency pair (CSDP) and show how to use CSDPs in proofs of termination of CSR. The implementation and practical use of the developed techniques yield a novel and powerful framework which improves the current state-of-the-art of methods for automatically proving termination of CSR. 相似文献
967.
In Bayesian machine learning, conjugate priors are popular, mostly due to mathematical convenience. In this paper, we show
that there are deeper reasons for choosing a conjugate prior. Specifically, we formulate the conjugate prior in the form of
Bregman divergence and show that it is the inherent geometry of conjugate priors that makes them appropriate and intuitive.
This geometric interpretation allows one to view the hyperparameters of conjugate priors as the effective sample points, thus providing additional intuition. We use this geometric understanding of conjugate priors to derive the
hyperparameters and expression of the prior used to couple the generative and discriminative components of a hybrid model
for semi-supervised learning. 相似文献
968.
Designing and evaluating an energy efficient Cloud 总被引:1,自引:1,他引:0
Cloud infrastructures have recently become a center of attention. They can support dynamic operational infrastructures adapted
to the requirements of distributed applications. As large-scale distributed systems reach enormous sizes in terms of equipment,
the energy consumption issue becomes one of the main challenges for large-scale integration. Like any other large-scale distributed
system, Clouds face an increasing demand in energy. In this paper, we explore the energy issue by analyzing how much energy
virtualized environments cost. We provide an energy-efficient framework dedicated to Cloud architectures and we validate it
through different experimentations on a modern multicore platform. We show on a realistic example that our infrastructure
could save 25% of the Cloud nodes’ electrical consumption. 相似文献
969.
New techniques for simulating high performance MPI applications on large storage networks 总被引:1,自引:0,他引:1
Alberto Núñez Javier Fernández Jose D. Garcia Félix Garcia Jesús Carretero 《The Journal of supercomputing》2010,51(1):40-57
In this work, we propose new techniques to analyze the behavior, the performance, and specially the scalability of High Performance
Computing (in short, HPC) applications on different computing architectures. Our final objective is to test applications using
a wide range of architectures (real or merely designed) and scaling it to any number of nodes or components. This paper presents
a new simulation framework, called SIMCAN, for HPC architectures. The main characteristic of the proposed simulation framework
is the ability to be configured for simulating a wide range of possible architectures that involve any number of components.
SIMCAN is developed to simulate complete HPC architectures, but putting special emphasis on the storage and network subsystems.
The SIMCAN framework can handle complete components (nodes, racks, switches, routers, etc.), but also key elements of the
storage and network subsystems (disks, caches, sockets, file systems, schedulers, etc.). We also propose several methods to
implement the behavior of HPC applications. Each method has its own advantages and drawbacks. In order to evaluate the possibilities
and the accuracy of the SIMCAN framework, we have tested it by executing a HPC application called BIPS3D on a hardware-based
computing cluster and on a modeled environment that represent the real cluster. We also checked the scalability of the application
using this kind of architecture by simulating the same application with an increased number of computing nodes. 相似文献
970.
Luca Bertelli Shivkumar Chandrasekaran Frédéric Gibou B. S. Manjunath 《International Journal of Computer Vision》2010,90(3):267-282
In this paper we introduce novel regularization techniques for level set segmentation that target specifically the problem
of multiphase segmentation. When the multiphase model is used to obtain a partitioning of the image in more than two regions,
a new set of issues arise with respect to the single phase case in terms of regularization strategies. For example, if smoothing
or shrinking each contour individually could be a good model in the single phase case, this is not necessarily true in the
multiphase scenario. 相似文献