Search results for "Linear"

showing 10 items of 7165 documents

Non-Linear Hysteretic Instability in Rotating Machinery

2013

The destabilizing influence of the shaft hysteresis on the supercritical whirl of rotating machines can be efficiently counterbalanced by proper external dissipative sources in the supports and/or anisotropic suspension systems. The hysteretic effect may be treated either by dry or viscous models obtaining different but somehow similar results in the hypothesis of small dissipation levels. Thus the linear viscous assumption is often accepted as a crude approximation for a straightforward analysis of the whirling instability. Nevertheless the internal friction should be regarded most likely as non-linear and could be approximated for example by Coulombian models taking thus into account also the releasing effect of some shrink-fit coupling present in the mechanical assembly.
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Parallel Calculation of CCSDT and Mk-MRCCSDT Energies.

2010

A scheme for the parallel calculation of energies at the coupled-cluster singles, doubles, and triples (CCSDT) level of theory, several approximate iterative CCSDT schemes (CCSDT-1a, CCSDT-1b, CCSDT-2, CCSDT-3, and CC3), and for the state-specific multireference coupled-cluster ansatz suggested by Mukherjee with a full treatment of triple excitations (Mk-MRCCSDT) is presented. The proposed scheme is based on the adaptation of a highly efficient serial coupled-cluster code leading to a communication-minimized implementation by parallelizing the time-determining steps. The parallel algorithm is tailored for affordable cluster architectures connected by standard communication networks such as …

Theoretical computer scienceBasis (linear algebra)Computer scienceComputationGigabit EthernetCode (cryptography)Parallel algorithmBenchmark (computing)Basis functionPhysical and Theoretical ChemistryComputer Science ApplicationsComputational scienceAnsatzJournal of chemical theory and computation
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"Master-Slave" Biological Network Alignment

2010

Performing global alignment between protein-protein interaction (PPI) networks of different organisms is important to infer knowledge about conservation across species. Known methods that perform this task operate symmetrically, that is to say, they do not assign a distinct role to the input PPI networks. However, in most cases, the input networks are indeed distinguishable on the basis of how well the corresponding organism is biologically well-characterized. For well-characterized organisms the associated PPI network supposedly encode in a sound manner all the information about their proteins and associated interactions, which is far from being the case for not well characterized ones. He…

Theoretical computer scienceBasis (linear algebra)business.industryComputer scienceFingerprint (computing)Process (computing)Master/slaveENCODETask (computing)Bioinformatics network analysisArtificial intelligencebusinessBiological networkOrganism
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Two-way quantum and classical machines with small memory for online minimization problems

2019

We consider online algorithms. Typically the model is investigated with respect to competitive ratio. In this paper, we explore algorithms with small memory. We investigate two-way automata as a model for online algorithms with restricted memory. We focus on quantum and classical online algorithms. We show that there are problems that can be better solved by two-way automata with quantum and classical states than classical two-way automata in the case of sublogarithmic memory (sublinear size).

Theoretical computer scienceComputational complexity theoryCompetitive analysisSublinear functionComputer scienceOnline algorithmFocus (optics)QuantumAutomatonQuantum computerInternational Conference on Micro- and Nano-Electronics 2018
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Modelling and simulation of several interacting cellular automata

2015

Cellular automata are used for modelling and simulation of many systems. In some applications, the system is formed by a set of subsystems that can be modelled separately, but, in such cases, the existence of interactions between these subsystems requires additional modelling and computer programming. In this paper we propose a modelling methodology for the simulation of a set of cellular automata models that interact with each other. The modelling methodology is described, together with an insight on implementation details. Also, it is applied to a particular cellular automata model, the Sanpile model, to illustrate its use and to obtain some example simulations.

Theoretical computer scienceComputer scienceAbelian sandpile modelbusiness.industryComputer programmingGeneral EngineeringVirtual realityDynamic modellingNonlinear Sciences::Cellular Automata and Lattice GasesCellular automatonComputer Science ApplicationsSet (abstract data type)Stochastic cellular automatonSimulació per ordinadorbusinessRobotsSoftware
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Canonical Retina-to-Cortex Vision Model Ready for Automatic Differentiation

2020

Canonical vision models of the retina-to-V1 cortex pathway consist of cascades of several Linear+Nonlinear layers. In this setting, parameter tuning is the key to obtain a sensible behavior when putting all these multiple layers to work together. Conventional tuning of these neural models very much depends on the explicit computation of the derivatives of the response with regard to the parameters. And, in general, this is not an easy task. Automatic differentiation is a tool developed by the deep learning community to solve similar problems without the need of explicit computation of the analytic derivatives. Therefore, implementations of canonical visual neuroscience models that are ready…

Theoretical computer scienceComputer scienceAutomatic differentiationbusiness.industryComputationDeep learningPython (programming language)Task (project management)Nonlinear systemDistortionKey (cryptography)Artificial intelligencebusinesscomputercomputer.programming_language
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A study on graph representations for genetic programming

2020

Graph representations promise several desirable properties for Genetic Programming (GP); multiple-output programs, natural representations of code reuse and, in many cases, an innate mechanism for neutral drift. Each graph GP technique provides a program representation, genetic operators and overarching evolutionary algorithm. This makes it difficult to identify the individual causes of empirical differences, both between these methods and in comparison to traditional GP. In this work, we empirically study the behavior of Cartesian Genetic Programming (CGP), Linear Genetic Programming (LGP), Evolving Graphs by Graph Programming (EGGP) and traditional GP. By fixing some aspects of the config…

Theoretical computer scienceComputer scienceCode reuseEvolutionary algorithmGenetic programming0102 computer and information sciences02 engineering and technologyGenetic operator01 natural sciencesGraphOperator (computer programming)010201 computation theory & mathematicsProblem domainLinear genetic programming0202 electrical engineering electronic engineering information engineering020201 artificial intelligence & image processingProceedings of the 2020 Genetic and Evolutionary Computation Conference
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On the role of non-effective code in linear genetic programming

2019

In linear variants of Genetic Programming (GP) like linear genetic programming (LGP), structural introns can emerge, which are nodes that are not connected to the final output and do not contribute to the output of a program. There are claims that such non-effective code is beneficial for search, as it can store relevant and important evolved information that can be reactivated in later search phases. Furthermore, introns can increase diversity, which leads to higher GP performance. This paper studies the role of non-effective code by comparing the performance of LGP variants that deal differently with non-effective code for standard symbolic regression problems. As we find no decrease in p…

Theoretical computer scienceComputer scienceIntronContrast (statistics)Genetic programming0102 computer and information sciences02 engineering and technology01 natural sciences010201 computation theory & mathematicsLinear genetic programming0202 electrical engineering electronic engineering information engineeringCode (cryptography)020201 artificial intelligence & image processingSymbolic regressionProceedings of the Genetic and Evolutionary Computation Conference
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HOW SMART DOES AN AGENT NEED TO BE?

2005

The classic distributed computation is done by atoms, molecules or spins in vast numbers, each equipped with nothing more than the knowledge of their immediate neighborhood and the rules of statistical mechanics. These agents, 1023 or more, are able to form liquids and solids from gases, realize extremely complex ordered states, such as liquid crystals, and even decode encrypted messages. We will describe a study done for a sensor-array "challenge problem" in which we have based our approach on old-fashioned simulated annealing to accomplish target acquisition and tracking under the rules of statistical mechanics. We believe the many additional constraints that occur in the real problem ca…

Theoretical computer scienceComputer sciencebusiness.industryComputationDistributed computingMulti-agent systemGeneral Physics and AstronomyStatistical and Nonlinear PhysicsStatistical mechanicsEncryptionTarget acquisitionComputer Science ApplicationsNetwork managementComputational Theory and MathematicsSimulated annealingStochastic optimizationbusinessMathematical PhysicsInternational Journal of Modern Physics C
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A Tool for Implementing and Exploring SBM Models: Universal 1D Invertible Cellular Automata

2005

The easiest form of designing Cellular Automata rules with features such as invertibility or particle conserving is to rely on a partitioning scheme, the most important of which is the 2D Margolus neighborhood. In this paper we introduce a 1D Margolus-like neighborhood that gives support to a complete set of Cellular Automata models. We present a set of models called Sliding Ball Models based on this neighborhood and capable of universal computation. We show the way of designing logic gates with these models, propose a digital structure to implement them and finally we present SBMTool, a software development system capable of working with the new models.

Theoretical computer scienceComputer sciencebusiness.industryComputationSoftware developmentNonlinear Sciences::Cellular Automata and Lattice GasesCellular automatonMobile automatonlaw.inventionStochastic cellular automatonInvertible matrixlawLogic gateArtificial intelligencebusinessQuantum cellular automaton
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