In this paper, we propose a novel genetic algorithm based on the quantum chromosome - QGA. We adopt quantum chromosome to represent a linear superposition of solutions, after the observation that simulates the quantum...
详细信息
In this paper, we propose a novel genetic algorithm based on the quantum chromosome - QGA. We adopt quantum chromosome to represent a linear superposition of solutions, after the observation that simulates the quantum collapse. The algorithm has better diversity than its counterpart. In addition, the quantum evolutionary operator - quantum mutation is constructed, which is used to speed up the convergence. Rapid convergence and global search capacity characterize the performance of QGA. The paper also gives some simulation experiments to prove its superiority over the classical genetic algorithm.
quantum entanglement, a special correlation that can exist between subsystems of quantum multipartite systems, is increasingly seen as one of the most specific physical resources of quantum world. It is a resource tha...
详细信息
quantum entanglement, a special correlation that can exist between subsystems of quantum multipartite systems, is increasingly seen as one of the most specific physical resources of quantum world. It is a resource that is not only behind the fact that quantuminformationprocessing can be more efficient than classical ones and that quantum communication can be both more efficient and more secure than classical one, but, and this is perhaps the main point, also behind an increasing confidence that quantum entanglement can lead to new quantuminformationprocessing technology and to a new, and deeper, understanding of important and complex (quantum) physics phenomena. In this paper we concentrate on this new physical resource and on its various, sometimes even mysterious, consequences and impacts on computations and communications. In addition, we briefly summarize main problems and outcomes of the research concentrating on the understanding of the structure, laws and limitations of entanglement itself.
In many real-life situations, we are interested in the value of a physical quantity y that is difficult or impossible to measure directly. To estimate y, we find some easier-to-measure quantities x(1),..., x(n) which ...
详细信息
In many real-life situations, we are interested in the value of a physical quantity y that is difficult or impossible to measure directly. To estimate y, we find some easier-to-measure quantities x(1),..., x(n) which are related to y by a known relation y = f (x(1),..., x(n)). Measurements are never 100% accurate;hence, the measured values (x) over tilde (i) are different from x(i), and the resulting estimate (y) over tilde = f((x) over tilde (i),..., (x) over tilde (n)) is different from the desired value y = f (x(1),..., x(n)). How different can it be ? Traditional engineering approach to error estimation in data processing assumes that we know the probabilities of different measurement errors Deltax(i) (=) def (x) over tilde (i) - x(i). In many practical situations, we only know the upper bound Delta(i) for this error;hence, after the measurement, the only information that we have about x(i) is that it belongs to the interval x(i) (=) def [(x) over tilde (i)- Delta(i), (x) over tilde (i) + Delta(i)]. In this case, it is important to find the range y of all possible values of y = f (x(i),..., x(n)) when x(i) epsilon x(i). We start the paper with a brief overview of the computational complexity of the corresponding interval computation problems: Most of the related problems turn out to be, in general, at least NP-hard. In this paper, we show how the use of quantum computing can speed up some computations related to interval and probabilistic uncertainty. We end the paper with speculations on whether (and how) "hypothetic" physical devices can compute NP-hard A problems faster than in exponential time. Most of the paper's results were first presented at NAFIPS'2003 [30]. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Summary form only given. We address the problem of efficient out-of-core code generation for a special class of imperfectly nested loops encoding tensor contractions. These loops operate on arrays too large to fit in ...
详细信息
Summary form only given. We address the problem of efficient out-of-core code generation for a special class of imperfectly nested loops encoding tensor contractions. These loops operate on arrays too large to fit in physical memory. The problem involves determining optimal tiling and placement of disk I/O statements. This entails a search in an explosively large parameter space. We formulate the problem as a nonlinear optimization problem and use a discrete constraint solver to generate optimized out-of-core code. Measurements on sequential and parallel versions of the generated code demonstrate the effectiveness of the proposed approach.
The particle swarm optimization algorithm is a new methodology in evolutionary computation. It has been found to be extremely effective is solving a wide range of engineering problems, however, it is of low efficiency...
详细信息
ISBN:
(纸本)0780385152
The particle swarm optimization algorithm is a new methodology in evolutionary computation. It has been found to be extremely effective is solving a wide range of engineering problems, however, it is of low efficiency in dealing with the discrete problems. In this paper, a new discrete particle swarm optimization algorithm based on quantum individual is proposed. It is simpler and more powerful than the algorithms available. The simulation experiments and its application in the CDMA also prove its high efficiency.
One of the more difficult problems in image processing is segmentation. The human brain has an ability that is unmatched by any current technology for breaking down the world into distributed features and reconstructi...
详细信息
One of the more difficult problems in image processing is segmentation. The human brain has an ability that is unmatched by any current technology for breaking down the world into distributed features and reconstructing them into distinct objects. Neurons encode information both in the number of spikes fired in a given time period, which indicates the strength with which a given local feature is present, and in the temporal code or relative timing of the spike, indicating whether the individual features are part of the same or different objects. Neurons that respond to contiguous stimuli produce synchronous oscillations, while those that are not fire independently. Thus, neural synchrony could be used as a tag for each pixel in an image indicating to which object it belongs. We have developed a simulation based on the primary visual cortex. We found that neurons that respond to the same object oscillate synchronously while those that respond to different objects fire independently.
We exhibit two black-box problems, both of which have an efficient quantum algorithm with zero-error, yet whose composition does not have an efficient quantum algorithm with zero-error. This shows that quantum zero-er...
详细信息
We exhibit two black-box problems, both of which have an efficient quantum algorithm with zero-error, yet whose composition does not have an efficient quantum algorithm with zero-error. This shows that quantum zero-error algorithms cannot be composed. In oracle terms, we give a relativized world where ZQP(ZQP) not equal ZQP, while classically we always have ZPP(ZPP) = ZPP. (C) 2003 Elsevier Science B.V. All rights reserved.
The enormous theoretical potential of quantuminformationprocessing (QIP) is driving the pursuit for its practical realization by various physical techniques. Currently, nuclear magnetic resonance (NMR) has been the ...
详细信息
The enormous theoretical potential of quantuminformationprocessing (QIP) is driving the pursuit for its practical realization by various physical techniques. Currently, nuclear magnetic resonance (NMR) has been the forerunner by demonstrating a majority of quantumalgorithms. In NMR, spin-systems consisting of coupled nuclear spins are utilized as qubits. In order to carry out QIP, a spin-system has to meet two major requirements: (i) qubit addressability and (ii) mutual coupling among the. qubits. It has been demonstrated that the magnitude of the mutual coupling among qubits can be increased by orienting the spin-systems in a liquid crystal matrix and utilizing the residual dipolar couplings. While utilizing residual dipolar couplings may be useful to increase the number of qubits, nuclei of the same species (homonuclei) might become strongly coupled. In strongly coupled spin-systems, spins lose their individual identity of being qubits. We propose that even such strongly coupled spin-systems can be used for QIP and the qubit-manipulation can be achieved by transition-selective pulses. We demonstrate experimental preparation of pseudopure states, creation of maximally entangled states, implementation of logic gates and implementation of Deutsch-Jozsa (DJ) algorithm in strongly coupled 2, 3 and 4 spin-systems. The energy levels of the strongly coupled 3 and 4 spin-systems were obtained using a Z-COSY experiment.
The quantum Fourier transform (QFT) is a key subroutine of quantumalgorithms for factoring and simulation and is the heart of the hidden-subgroup problem, the solution of which is expected to lead to the development ...
详细信息
The quantum Fourier transform (QFT) is a key subroutine of quantumalgorithms for factoring and simulation and is the heart of the hidden-subgroup problem, the solution of which is expected to lead to the development of new quantumalgorithms. The QFT acts on the Hilbert space and alters the quantum mechanical phases and probability amplitudes. Unlike its classical counterpart its schematic representation and visualization are very difficult. The aim of this work is to develop a schematic representation and visualization of the QFT by running it on a quantum computer simulator which has been constructed in the framework of this research. Base states, superpositions of base states and entangled states are transformed and the corresponding schematic representations are presented. The visualization of the QFT presented here and the quantum computer simulator developed for this purpose may become a useful tool for introducing the QFT to students and researches without a strong background in quantum mechanics or Fourier analysis.
暂无评论