No Free Lunch theorems for optimisation state that there does not exist any algorithm better than any other one when averaged performances over the whole set of possible problems are considered. However, it has been r...
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Executable Biology, also called Algorithmic Systems Biology, uses rigorous concepts from computer science and mathematics to build computational models of biological entities. P systems are emerging as one of the key ...
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ISBN:
(纸本)9781450300728
Executable Biology, also called Algorithmic Systems Biology, uses rigorous concepts from computer science and mathematics to build computational models of biological entities. P systems are emerging as one of the key modelling frameworks within Executable Biology. In this paper, we address the continuous backward problem: given a P system model structure and a target phenotype (i.e. an intended biological behaviour), one is tasked with finding the (near) optimal parameters for the model that would make the P system model produce the target behaviour as closely as possible. We test several real-valued parameter optimisation algorithms on this problem. More specifically, using four different test cases of increasing complexity, we perform experiments with four evolutionary algorithms, and one variable neighbourhood search method combining three other evolutionary algorithms. The results show that, when there are few parameters to optimise, a genetic and two differential evolution based algorithms are robust optimisera attaining the best results. However, when the number of parameters increases, the variable neighbourhood search approach performs better. Copyright 2010 ACM.
Variable Neighbourhood Search is a metaheuristic combining three components: generation, improvement, and shaking components. In this paper, we design a continuous Variable Neighbourhood Search algorithm based on thre...
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This paper presents a new method for constructing ensembles of classifiers based on Immune Network Theory, one of the most interesting paradigms within the field of Artificial Immune Systems. Ensembles of classifiers ...
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In this paper, we present an Open Grid Services Architecture (OGSA)-based decentralized allocation enforcement system, developed with an emphasis on a consistent data model and easy integration into existing schedulin...
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ISBN:
(纸本)1581138717
In this paper, we present an Open Grid Services Architecture (OGSA)-based decentralized allocation enforcement system, developed with an emphasis on a consistent data model and easy integration into existing scheduling, and workload management software at six independent high-performance computing centers forming a Grid known as SweGrid. The Swedish National Allocations Committee (SNAC) allocates resource quotas at these centers to research projects requiring substantial computer time. Our system, the SweGrid Accounting System (SGAS), addresses the need for soft real-time allocation enforcement on SweGrid for cross-domain job submission. The SGAS framework is based on state-of-the-art Web and Grid services technologies. The openness and ubiquity of Web services combined with the fine-grained resource control and cross-organizational security models of Grid services proved to be a perfect match for the SweGrid needs. Extensibility and customizability of policy implementations for the three different parties the system serves (the user, the resource manager, and the allocation authority) are key design goals. Another goal is end-to-end security and single sign-on, to allow resources - selected based on client policies - to act on behalf of the user when negotiating contracts with the bank in an environment where the six centers would continue to use their existing accounting policies and tools. We conclude this paper by showing the feasibility of SGAS, which is currently being deployed at the production sites, using simulations of reservation streams. The reservation streams are shaped using soft computing and policy-based algorithms. Copyright 2004 ACM.
This paper presents MONet (Multi-Objective coevolutive NET work), a cooperative revolutionary model for evolving artificial neural networks that introduces concepts taken from multi-objective optimization. This model ...
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Hebbian learning rules are generally formulated as static rules. Under changing condition (e.g. neoromodulation, input statistics) most rules are sensitive to parameters. In particular, recent work has focused on two ...
Hebbian learning rules are generally formulated as static rules. Under changing condition (e.g. neoromodulation, input statistics) most rules are sensitive to parameters. In particular, recent work has focused on two different formulations of spike-timing-dependent plasticity rules. Additive STDP [1] is remarkably versatile but also very fragile, whereas multiplicative STDP [2, 3] is more robust but lacks attractive features such as synaptic competition and rate stabilization. Here we address the problem of robustness in the additive STDP rule. We derive an adaptive control scheme, where the learning function is under fast dynamic control by postsynaptic activity to stabilize learning under a variety of conditions. Such a control scheme can be implemented using known biophysical mechanisms of synapses. We show that this adaptive rule makes the additive STDP more robust. Finally, wo give an example how meta plasticity of the adaptive rule can be used to guide STDP into different type of learning regimes.
Evidence indicates that members of many gene families in the genome of an organism tend to have homologues both within their own genome and in the genomes of other organisms. Amongst these homologues, typically only o...
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The European Computerized Human Brain Database (ECHBD) is an innovative approach to neuroscience, where state-of-the-art database technology has been utilised for building a system for meta-research. Meta-research her...
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The European Computerized Human Brain Database (ECHBD) is an innovative approach to neuroscience, where state-of-the-art database technology has been utilised for building a system for meta-research. Meta-research here refers to research on 3D brain images, obtained from various neuroimaging techniques. The system is built on top of the RASDAMAN rasterdata manager and the object-oriented DBMS O/sub 2/. A client/server interface allows access to the database over the Internet. The system will be open for use by the ECHBD project partners in July 1999. The ECHBD system focuses on ease of use, featuring visual navigation and query specification. We discuss basic data management problems in experimental neuroscience and describe how the ECHBD system is designed to address these problems.
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