Search results for "computational complexity"

showing 10 items of 249 documents

Reducing complexity in H.264/AVC motion estimation by using a GPU

2011

H.264/AVC applies a complex mode decision technique that has high computational complexity in order to reduce the temporal redundancies of video sequences. Several algorithms have been proposed in the literature in recent years with the aim of accelerating this part of the encoding process. Recently, with the emergence of many-core processors or accelerators, a new approach can be adopted for reducing the complexity of the H.264/AVC encoding algorithm. This paper focuses on reducing the inter prediction complexity adopted in H.264/AVC and proposes a GPU-based implementation using CUDA. Experimental results show that the proposed approach reduces the complexity by as much as 99% (100x of spe…

SpeedupComputational complexity theoryComputer science020206 networking & telecommunicationsData_CODINGANDINFORMATIONTHEORY02 engineering and technologyParallel computingCUDAAlgorithmic efficiency0202 electrical engineering electronic engineering information engineeringWorst-case complexity020201 artificial intelligence & image processingContext-adaptive binary arithmetic codingData compressionContext-adaptive variable-length coding
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Simplified spiking neural network architecture and STDP learning algorithm applied to image classification

2015

Spiking neural networks (SNN) have gained popularity in embedded applications such as robotics and computer vision. The main advantages of SNN are the temporal plasticity, ease of use in neural interface circuits and reduced computation complexity. SNN have been successfully used for image classification. They provide a model for the mammalian visual cortex, image segmentation and pattern recognition. Different spiking neuron mathematical models exist, but their computational complexity makes them ill-suited for hardware implementation. In this paper, a novel, simplified and computationally efficient model of spike response model (SRM) neuron with spike-time dependent plasticity (STDP) lear…

Spiking neural networkQuantitative Biology::Neurons and CognitionComputational complexity theoryContextual image classificationComputer sciencebusiness.industryImage segmentationNetwork topologyExternal Data RepresentationSignal ProcessingArtificial neuronArtificial intelligenceElectrical and Electronic EngineeringbusinessInformation SystemsBrain–computer interfaceEURASIP Journal on Image and Video Processing
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Wavelet Frames Generated by Spline Based p-Filter Banks

2014

This chapter presents a design scheme to generate tight and so-called semi-tight frames in the space of discrete-time periodic signals. The frames originate from oversampled perfect reconstruction periodic filter banks. The filter banks are derived from discrete-time and discrete periodic splines. Each filter bank comprises one linear phase low-pass filter (in most cases interpolating) and one high-pass filter, whose magnitude response mirrors that of a low-pass filter. In addition, these filter banks comprise a number of band-pass filters. In this chapter, frames generated by four-channel filter banks are briefly outlined (see Chap. 17 in [2] for details) and tight frames generated by six-…

Spline (mathematics)Frequency responseWaveletComputational complexity theoryComputer scienceFilter bankAlgorithmLinear phaseImpulse responseWavelet packet decomposition
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Unary Probabilistic and Quantum Automata on Promise Problems

2015

We continue the systematic investigation of probabilistic and quantum finite automata (PFAs and QFAs) on promise problems by focusing on unary languages. We show that bounded-error QFAs are more powerful than PFAs. But, in contrary to the binary problems, the computational powers of Las-Vegas QFAs and bounded-error PFAs are equivalent to deterministic finite automata (DFAs). Lastly, we present a new family of unary promise problems with two parameters such that when fixing one parameter QFAs can be exponentially more succinct than PFAs and when fixing the other parameter PFAs can be exponentially more succinct than DFAs.

State-transition matrixDiscrete mathematicsDeterministic finite automatonUnary operationMarkov chainUnary languageProbabilistic logicQuantum finite automataBinary numberComputer Science::Computational ComplexityComputer Science::Formal Languages and Automata TheoryMathematics
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Steady-state and tracking analysis of a robust adaptive filter with low computational cost

2007

This paper analyses a new adaptive algorithm that is robust to impulse noise and has a low computational load [E. Soria, J.D. Martin, A.J. Serrano, J. Calpe, and J. Chambers, A new robust adaptive algorithm with low computacional cost, Electron. Lett. 42 (1) (2006) 60-62]. The algorithm is based on two premises: the use of the cost function often used in independent component analysis and a fuzzy modelling of the hyperbolic tangent function. The steady-state error and tracking capability of the algorithm are analysed using conservation methods [A. Sayed, Fundamentals of Adaptive Filtering, Wiley, New York, 2003], thus verifying the correspondence between theory and experimental results.

Steady stateComputational complexity theoryAdaptive algorithmFunction (mathematics)Tracking (particle physics)Impulse noiseIndependent component analysisAdaptive filterControl and Systems EngineeringControl theorySignal ProcessingComputer Vision and Pattern RecognitionElectrical and Electronic EngineeringSoftwareMathematicsSignal Processing
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Three-dimensional phase unwrapping using the Hungarian algorithm.

2009

We propose a three-dimensional phase unwrapping technique that uses the Hungarian algorithm to join together all the partial residual loops that may occur in a wrapped phase volume. Experimental results have shown that the proposed algorithm is more robust and reliable than other well-known three-dimensional phase unwrapping algorithms. Additionally, the proposed algorithm is fast in terms of computational complexity, which makes it suitable for practical applications.

Synthetic aperture radarComputational complexity theorybusiness.industryComputer scienceResidualPhase unwrappingAtomic and Molecular Physics and OpticsStructured-light 3D scannerOpticsHungarian algorithmbusinessPhase retrievalTelecommunicationsAlgorithmPhase volumeOptics letters
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Evaluation of GPU-based Seed Generation for Computational Genomics Using Burrows-Wheeler Transform

2012

Unprecedented production of short reads from the new high-throughput sequencers has posed challenges to align short reads to reference genomes with high sensitivity and high speed. Many CPU-based short read aligners have been developed to address this challenge. Among them, one popular approach is the seed-and-extend heuristic. For this heuristic, the first and foremost step is to generate seeds between the input reads and the reference genome, where hash tables are the most frequently used data structure. However, hash tables are memory-consuming, making it not well-suited to memory-stringent many-core architectures, like GPUs, even though they usually have a nearly constant query time com…

Theoretical computer scienceBurrows–Wheeler transformComputational complexity theoryComputer scienceComputational genomicsParallel computingData structureTime complexityHash table2012 IEEE 26th International Parallel and Distributed Processing Symposium Workshops & PhD Forum
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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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Work Partitioning on Parallel and Distributed Agent-Based Simulation

2017

Work partitioning is a key challenge with ap- plications in many scientific and technological fields. The problem is very well studied with a rich literature on both distributed and parallel computing architectures. In this paper we deal with the work partitioning problem for parallel and distributed agent-based simulations which aims at (i) balancing the overall load distribution, (ii) minimizing, at the same time, the communication overhead due to agents' inter-dependencies. We introduce a classification taxonomy of work partitioning strategies and present a space-based work partitioning ap- proach, based on a Quad-tree data structure, which enables to: identify a good space partitioning …

Theoretical computer scienceComputational complexity theoryComputer Networks and CommunicationsComputer scienceDistributed computingContext (language use)02 engineering and technologyParallel ComputingSynchronization (computer science)0202 electrical engineering electronic engineering information engineeringOverhead (computing)Space partitioningAgent-based simulation020203 distributed computingAgent-based simulations; D-MASON; Distributed Systems; Parallel Computing; Work partitioning; Hardware and Architecture; Computer Networks and Communications; Information SystemsFlocking (behavior)Agent-based simulations020206 networking & telecommunicationsWork partitioningData structureDistributed SystemComputer Networks and CommunicationD-MASONDistributed SystemsHardware and ArchitectureBoidsInformation Systems2017 IEEE International Parallel and Distributed Processing Symposium Workshops (IPDPSW)
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An improved quantum query algorithm for computing AND Boolean function

2010

We consider the quantum query model for computing Boolean functions. The definition of the function is known, but a black box contains the input X = (x 1 , x 2 , …, x n ). Black box can be accessed by querying x i values. The goal is to develop an algorithm, which would compute the function value for arbitrary input using as few queries to the black box as possible. We present two different quantum query algorithms for computing the basic Boolean function — logical AND of two bits. Both algorithms use only one query to determine the function value. Correct answer probability for the first algorithm is 80%, but for the second algorithm it is 90%. To compute this function with the same probab…

Theoretical computer scienceComputational complexity theoryLogical conjunctionBlack boxGrover's algorithmAlgorithm designFunction (mathematics)Boolean functionAlgorithmComputer Science::DatabasesQuantum computerMathematicsIEEE Congress on Evolutionary Computation
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