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1.
量子算法与物理实现是量子计算机研究中的两个基本问题。本文首先总结了相关领域的主要进展,并讨论了有代表性的量子算法,特别介绍了用于求解线性方程组的量子算法,分析了影响新量子算法提出的因素。然后,探讨了物理实现的迪文森佐判据,并介绍了典型的实现方案及性能比较。同时,也关注了对量子计算机研究持有异议的观点。最后,对量子计算机的新研究方向作了探讨。 相似文献
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混合量子进化算法及其应用 总被引:1,自引:0,他引:1
文章将量子进化算法(QEA)和粒子群算法(PSO)互相结合,提出了两种混合量子进化算法。第一种算法叫做嵌入式粒子群量子进化算法,其主要思想是将简化的PSO进化方程嵌入QEA的进化操作中,简化了QEA算法的结构,增强了QEA跳出局部极值的能力。第二种算法叫做量子二进制粒子群算法,其主要思想是将QEA中的量子染色体的概念引入二进制粒子群算法(BPSO),提高了BPSO算法保持种群多样性的能力和运算速度。通过对0-1背包问题和多用户检测问题的求解表明,新的算法不仅操作更简单,而且全局搜索能力有了显著的提高。 相似文献
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改进实数编码量子进化算法及其在参数估计中的应用 总被引:1,自引:0,他引:1
借鉴量子计算的相关概念和原理,提出一种改进实数编码量子进化算法(IRCQEA).算法的核心是依据染色体的具体形式和目标函数的梯度信息设计互补变异进化染色体,以实现局部搜索和全局搜索的平衡;根据算法的进化过程动态缩小搜索空间,以加快收敛速度.对标准数值优化问题的求解结果表明,该算法具有寻优能力强、搜索精度高和稳定性好等优点.以非线性系统参数估计问题为例进行的仿真实验表明,所提出的算法能够有效提高估计参数的精度. 相似文献
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背包问题(Knapsack Problem, KP)是一类著名的组合优化问题,也是一类NP难问题,它包括0-1背包问题、有界背包问题、多维背包问题、多背包问题、多选择背包问题、二次背包问题、动态背包问题和折扣背包问题等多种形式,在众多领域有着广泛的应用.演化算法(EAs)是一类有效的快速近似求解KP的算法.本文对近十余年来利用EAs求解KP的研究情况进行一个较为详细的总结,它一方面讨论了利用EAs求解各种KP问题时个体的编码方法与处理不可行解的有效方法,另一方面为今后进一步利用最新提出的EAs求解KP问题提供一个可借鉴的思路. 相似文献
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Evolutionary design of Evolutionary Algorithms 总被引:1,自引:0,他引:1
Manual design of Evolutionary Algorithms (EAs) capable of performing very well on a wide range of problems is a difficult
task. This is why we have to find other manners to construct algorithms that perform very well on some problems. One possibility
(which is explored in this paper) is to let the evolution discover the optimal structure and parameters of the EA used for
solving a specific problem. To this end a new model for automatic generation of EAs by evolutionary means is proposed here.
The model is based on a simple Genetic Algorithm (GA). Every GA chromosome encodes an EA, which is used for solving a particular
problem. Several Evolutionary Algorithms for function optimization are generated by using the considered model. Numerical
experiments show that the EAs perform similarly and sometimes even better than standard approaches for several well-known
benchmarking problems. 相似文献
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《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2008,38(5):1347-1355
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Sebastian Dörn 《Theory of Computing Systems》2009,45(3):613-628
We present quantum algorithms for the following matching problems in unweighted and weighted graphs with n vertices and m edges:
Our quantum algorithms are faster than the best known classical deterministic algorithms for the corresponding problems.
In particular, the second result solves an open question stated in a paper by Ambainis and Špalek (Proceedings of STACS’06,
pp. 172–183, 2006). 相似文献
• | Finding a maximal matching in general graphs in time . |
• | Finding a maximum matching in general graphs in time . |
• | Finding a maximum weight matching in bipartite graphs in time , where N is the largest edge weight. |
8.
J. P. Dowling J. D. Franson H. Lee G. J. Milburn 《Quantum Information Processing》2004,3(1-5):205-213
Scalable quantum computation with linear optics was considered to be impossible due to the lack of efficient two-qubit logic gates, despite the ease of implementation of one-qubit gates. Two-qubit gates necessarily need a non-linear interaction between the two photons, and the efficiency of this non-linear interaction is typically very small in bulk materials. However, it has recently been shown that this barrier can be circumvented with effective non-linearities produced by projective measurements, and with this work linear-optical quantum computing becomes a new avenue towards scalable quantum computation. We review several issues concerning the principles and requirements of this scheme.
PACS: 03.67.Lx, 03.67.Pp, 42.50.Dv, 42.65.Lm 相似文献
9.
量子计算机进入实验阶段 总被引:2,自引:1,他引:1
首先简要介绍分层计算的制约;其次介绍最近量子信息的开发,在理论和实践两方面的通信和计算,诸如量子逻辑门、量子密码学、量子交缠性、超距传输的实验性实现、量子算法的首次实验性实现、量子因子分解、量子纪错码以及基于硅片的原子自旋量子计算机;最后讨论克服非相干性困难的方法。 相似文献
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随机时变背包问题(RTVKP)是一种新的动态背包问题,也是一种新的动态组合优化问题,目前它的求解算法主要是动态规划的精确算法、近似算法和遗传算法.本文首先利用动态规划提出了一个求解RTVKP问题的新精确算法,对算法时间复杂度的比较结果表明:它比已有的精确算法更适于求解背包载重较大的一类RTVKP实例.然后,分别基于差分演化和粒子群优化与贪心修正策略相结合,提出了求解RTVKP问题的两个进化算法.对5个RTVKP实例的数值计算结果比较表明: 精确算法一般不宜求解大规模的RTVKP实例,而基于差分演化、粒子群优化和遗传算法与贪心修正策略相结合的进化算法却不受实例规模与数据大小的影响,对于振荡频率大且具有较大数据的大规模RTVKP实例均能求得的一个极好的近似解. 相似文献
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Grover提出的量子搜索算法,可以用O(N1/2)的时间复杂度完成对规模为N的非结构化数据集的搜索,这在经典计算机上需要O(N)的复杂度。其中量子黑盒(又称为Oracle)依赖于具体问题,根据数据库搜索的要求,设计了量子黑盒的内部结构和相应的量子线路,给出了适合于数据库搜索的量子算法。 相似文献
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高维多目标进化算法研究综述 总被引:5,自引:0,他引:5
传统的多目标进化算法能够有效地解决2个或3个目标的优化问题,但当优化目标超过4维即具有高维目标时,其优化效果将大大下降,因此高维多目标进化算法的研究得到了较多的关注.鉴于此,对高维多目标进化算法的研究进展进行系统地分类综述,分析了高维目标对优化算法造成的困难以及改进的可视化技术;总结了各类算法的特点与缺陷,并给出进一步可能的研究方向. 相似文献
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Mathematical Theory of Duality Quantum Computers 总被引:1,自引:0,他引:1
Stan Gudder 《Quantum Information Processing》2007,6(1):37-48
We present a mathematical theory for a new type of quantum computer called a duality quantum computer that has recently been
proposed. We discuss the nonunitarity of certain circuits of a duality quantum computer and point out a paradoxical situation
that occurs when mixed states are considered. It is shown that a duality quantum computer can measure itself without needing
a separate measurement apparatus to determine its final state.
相似文献
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This correspondence presents several parallel algorithms for image template matching on an SIMD array processor with a hypercube interconnection network. For an N by N image and an M by M window, the time complexity is reduced from O(N2M2) for the serial algorithm to O(M2/K2 + M * log2 N/K + log2 N * log2 K) for the N2K2-PE system (1 ? K ? M), or to O(N2M2/L2) for the L2-PE system (L ? N). With efficient use of the inter-PE communication network, each PE requires only a small local memory, many unnecessary data transmissions are eliminated, and the time complexity is greatly reduced. 相似文献