共查询到19条相似文献,搜索用时 234 毫秒
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模仿熟练操作者通过记忆多步连续调控系统的方式,将记忆用上下文无关文法表示.根据控制经验和滚动预测优化建立特征状态转换表和构造不确定有穷自动机,给出了转换确定有穷自动机的算法.在任意特征状态下,通过一系列的DFA状态转换函数的复合运算,得到使系统稳定下来的控制模态序列. 相似文献
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有穷自动机,一种计算能力极其有限的计算模型,具有解决素性测试的能力通过构造法得到了证明。既而提出了一种基于有穷自动机的测试一个整数是否为素数的DNA算法,并且详细描述了该有穷自动机的构造方法,将有穷自动机的状态用DNA单链分子来编码,而输入则用DNA双链分子编码,用带环的双链DNA分子来编码状态转移规则,通过限制性内切酶的切割实现状态的转移。该算法的创新之处在于它是基于有穷自动机这种计算能力极其有限的计算模型的,并且该算法不仅能判断一个整数是否是素数,还能用于素因子分解。该算法的优点是实验实现容易,所需的时间是输入的多项式函数而不是指数函数。 相似文献
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识别关键类可以帮助人们尽快理解不熟悉的软件系统.尽管目前已有一些关键类识别方面的工作,但是大部分方法构建的依赖图是无权的,未考虑类之间交互的种类及次数.有鉴于此,提出了一种基于软件网络加权k-核分析的关键类识别方法.首先,用加权类耦合网络抽象类(接口)、类(接口)间的交互及其次数;然后,引入加权k-核分解方法计算类的加权核数;最后,以加权核数作为类重要性的量度指标,降序排列所有类,并通过过滤得到候选关键类.真实软件上的数据实验验证了本文方法的有效性. 相似文献
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基于自动机理论模型检测的一个关键算法是判断有穷状态系统是否满足属性的判空检测.对标准Büchi自动机作判空检测,容易引起状态爆炸.本文以TGBA为研究对象,提出基于启发式SCCs的广义Büchi自动机判空检测算法.该算法在on-the-fly算法的基础上结合启发式深度优先搜索和SCCs检测算法,能较快地判断TGBA的非空性.通过正确性证明、复杂性分析和实验验证了该算法的正确可行性.在TGBA非空的情况下,该算法的时空性能比已有算法更优. 相似文献
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提出了一种基于LCS的特征树最大相似性匹配网页去噪算法.通过将目标网页和相似网页转化为特征树,并将特征树映射为一个特征节点序列,利用LCS算法能获得最长子序列全局最优解的特点,找出两棵特征树之间的不同节点作为候选集,并对候选集进行聚集评分找出网页重要内容块.给出了算法的原型系统,并对每一个模块的实现做了详尽的描述. 相似文献
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UIO序列是对有限状态机进行功能测试的有效手段,在VLSI、通信协议等时序系统中有很强的实际应用背景.本文基于可区分状态组这一概念设计了一个搜索算法,进一步利用搜索信息建立了一个基于"小于"关系的启发策略,有效的剪枝策略的设计将尽可能消除没有意义的搜索分枝,新设计出的多路OPEN/CLOSED表存储机制也加快了相关的判别、处理过程.根据实验结果,分析了优化措施对于改进了搜索过程、减少搜索信息的产生、提高搜索速度有显著的贡献.该算法与以往的算法相比,在时间复杂度和空间复杂度两方面都得到了很大改进. 相似文献
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该文提出一种在JPEG2000算法中兼容5/3小波变换和9/7小波变换高效硬件定点实现技术。所提出的技术使用9/7提升小波变换的有界输入有界输出(Bounded Input Bounded Output, BIBO)增益来确定小波变换中间值的存储位深,使用5/3提升小波变换的BIBO增益来确定9/7提升小波变换中量化参数的选择方式和量化的实现方式,最终使用同一存储空间来存放定点5/3提升小波变换和定点9/7提升小波变换系数。该文提出的技术不仅大大节省了JPEG2000算法中小波实现模块中的硬件存储资源和算法计算量,而且也节省了后续基于上下文的位平面算术编码模块和率失真优化截取模块的存储资源和算法计算量。 相似文献
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Clemens Buchacher Joachim Wehinger Mario Huemer 《Journal of Signal Processing Systems》2011,64(1):31-40
The coefficients of a Linear Minimum Mean Square Error (LMMSE) equalizer for a stationary random signal are defined by a Toeplitz
system. The Toeplitz structure can be exploited to reduce computational complexity. In this paper we investigate the Levinson
and Schur algorithm, as well as circulant embedding and circulant approximation methods applied to the Preconditioned Conjugate
Gradient (PCG) method and Frequency Domain Equalization (FDE). We develop a novel circulant approximation method which improves
the performance/complexity tradeoff. We show that the optimal choice of algorithms largely depends on the antenna configuration.
Investigated configurations are Single Input Single Output (SISO), Single Input Multiple Output (SIMO) and Multiple Input
Multiple Output (MIMO). All considered algorithms are benchmarked in terms of implementation complexity and capacity achieved
by a High Speed Downlink Packet Access (HSDPA) receiver in a multipath fading scenario. 相似文献
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We investigate a wireless network architecture that utilizes Tomlinson Harashima Precoded Multiple Input Multiple Output (THP MIMO) technique for improved system capacity. We consider THP MIMO in a multi user scenario, together with a proposed smart scheduling technique and we explore the capacity performance through extensive capacity analysis considering varying SNR levels, varying number of users and number of transmit/receive antennas, under fading and shadowing, also considering errors in channel state information (CSI). We also evaluate the complexity of THP MIMO and present a low-complexity scheduling algorithm that employs Gram-Schmidt algorithm for incremental implementation of THP’s QR factorization. In the end, we identify the network and channel conditions under which THP MIMO can be preferred over classical conventional MIMO, and we conclude that for practical transceivers with up to four antennas, THP MIMO can provide significant capacity enhancement over conventional MIMO at lower complexity, performing slightly below the sum rate capacity bound. Another important advantage that is observed in this study is better immunity of THP MIMO to CSI errors, as compared to conventional MIMO. 相似文献
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J. Ahmadi-Shokouh H. Keshavarz 《AEUE-International Journal of Electronics and Communications》2013,67(12):1079-1085
Using Multiple Input Multiple Output (MIMO) architecture in cognitive radio (CR) secondary users improves the system performance in terms of interference cancellation and data rate enhancement but at the expense of adding complexity and cost. A solution to reduce this complexity is employing radio frequency (RF) beamforming networks at the transmitter/receiver front-ends. In this paper, we consider a MIMO secondary user equipped with such RF beamforming network. Moreover, we find the transmit/receive optimum RF beamforming network for a MIMO spatial multiplexing system. We evaluate the performance of the optimally designed RF beamforming technique over a Rician channel via computer simulations. The simulation results are assessed for different RF beamforming structures and the number of primary transmitters which cause interference on the secondary receiver. 相似文献
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Principles and methods of testing finite state machines-a survey 总被引:23,自引:0,他引:23
Lee D. Yannakakis M. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1996,84(8):1090-1123
With advanced computer technology, systems are getting larger to fulfill more complicated tasks: however, they are also becoming less reliable. Consequently, testing is an indispensable part of system design and implementation; yet it has proved to be a formidable task for complex systems. This motivates the study of testing finite stare machines to ensure the correct functioning of systems and to discover aspects of their behavior. A finite state machine contains a finite number of states and produces outputs on state transitions after receiving inputs. Finite state machines are widely used to model systems in diverse areas, including sequential circuits, certain types of programs, and, more recently, communication protocols. In a testing problem we have a machine about which we lack some information; we would like to deduce this information by providing a sequence of inputs to the machine and observing the outputs produced. Because of its practical importance and theoretical interest, the problem of testing finite state machines has been studied in different areas and at various times. The earliest published literature on this topic dates back to the 1950's. Activities in the 1960's mid early 1970's were motivated mainly by automata theory and sequential circuit testing. The area seemed to have mostly died down until a few years ago when the testing problem was resurrected and is now being studied anew due to its applications to conformance testing of communication protocols. While some old problems which had been open for decades were resolved recently, new concepts and more intriguing problems from new applications emerge. We review the fundamental problems in testing finite state machines and techniques for solving these problems, tracing progress in the area from its inception to the present and the stare of the art. In addition, we discuss extensions of finite state machines and some other topics related to testing 相似文献