循环图的转发指数

本文研究了循环网络的转发指数.利用循环图是Cayley图的性质,获得循环图的点转发指数和边转发指数紧的上界和下界.并确定了一些网络的转发指数.     

一种基于规则的情境感知系统设计与实现

情境感知系统能够感知用户所处的情境,以及情境的变化,并根据情境信息去提供用户需要的服务.针对情境信息复杂性和实效性双重特点,本文基于面向对象的情境建模方法,在情境信息分类的基础上,提出了一个LUTERS情境对象模型.在情景信息模型化的基础上,本文阐述了情境推理规则的定义,提出了基于规则引擎的情境推理框架,有效的提升了情景感知系统的灵活性.     

多少有点问题

题目 飞机正常飞行的概率是p,至少有50％的引擎正常工作,飞机能正常飞行,且各引擎是独立的.现使用4引擎飞机比使用2引擎飞机更安全,求p的取值范围.     

机动目标的跟踪与反跟踪建模研究

针对机动目标跟踪建模及目标机动规律分析问题,首先建立了基于Kalman滤波的Singer模型和修正的当前模型并利用MATLAB对其进行了求解,然后给出了两种模型下的目标的机动规律.针对飞行目标的航迹关联问题,首先建立了基于直观法的航迹起始模型,然后分别建立基于特征判决的最近邻域航迹关联模型和基于Kalman滤波的航迹关联模型并求解,结果显示,两种航迹关联模型都能较好实现航迹的分离.最后,针对高速机动目标跟踪与航迹预测问题,提出了一种基于初值的Singer模型并分析了高速机动目标的机动规律,然后分别建立了基于空间曲线拟合和基于Kalman滤波的航迹预测模型,并对两种模型进行求解与分析.     

Panel Data模型基于Within估计的最优设计

本文研究二元Panel Data模型基于Within估计在恒等设计类中的D-,A-,I-和E-最优设计.文章首先证明了二元Panel Data模型基于Within估计在恒等设计类中的几类最优设计可在设计域的顶点处获得;研究发现模型的D-,A-和E-最优设计均为设计域顶点上的等权重设计,I-最优设计为对称设计;结果还表明等权重设计具有较高的I-效.     

融合两阶段过程模型和改进Bass模型的网络社交平台上产品信息扩散研究

提出并验证了融合两阶段过程模型和改进Bass模型的网络社交平台上产品信息扩散模型。考虑用户转发动机构建产品信息扩散两阶段过程模型;考虑用户兴趣衰减效应改进Bass模型;融合这两个模型,考虑产品信息发布者明星效应、产品信息质量对产品信息扩散的影响,提出了产品信息扩散模型。以2019年11~12月新浪电影发布的电影预告片转发数据验证了所提模型,并与Bass模型进行了比较。结果表明,用户转发动机和用户兴趣衰减效应对产品信息扩散均有显著影响,所提模型的预测精度和拟合效果均优于Bass模型。所提模型可用于存在不同转发动机及具有衰减效应的其他信息转发量预测,尤其适合于在产品信息投放前期和早期对转发量的预测,是对信息扩散模型的补充。     

智能动画创作系统 PNAI 的研究进展

计算机动画制作是一件十分耗费时间的工作,提高计算机动画的效率是一项重要的研究课题.近几年我们研制的计算机动画生成系统中的3个底层子系统以及其中涉及的方法,为计算机动画生成提供了有效的支持.在场景设计方面,我们提出了基于场景实例和场景设计知识的场景设计方法;在自动摄影中,我们提出了一种基于摄影脚本的摄影方法;在脸部动画方面,我们采用了RBF方法以及利用了一些预先编成的MEL脚本     

基于智能控制的高速线材轧机水冷控制系统优化

针对武汉钢铁集团公司大型轧钢厂当前在高速线材生产线中存在的水冷控制系统可靠性差,轧线温度波动范围大等问题,应用智能计算理论及方法对上述工业控制系统进行系统辨识、建模以及优化.分析比较了基于梯度下降搜索BP算法、径向基函数网络、Levenberg Marquardt BP算法的前馈神经网络对SMS水冷系统的逼近精度、训练速度.研究了采用Levenberg-Marquardt BP算法的前馈神经网络在样本集和测试集上的表现,建立了基于Levenberg-Marquardt BP算法的前馈神经网络水冷控制系统模型.解决了高速线材水冷控制系统可靠性,温度控制精度问题.     

一种支持Prolog数据库操作和数值计算的顺序推理机系统结构的设计

为了高效实现Prolog,人们研制了面向Prolog的专用处理机或处理器片子。然而,已有的这类机器大多或者不能支持Prolog数据库操作的实现,或者不能进行快速的数值计算。本文论述了我们设计的一种基于WAM-PLUS模型的顺序推理机GKD-PLM的系统结构。该结构不仅能高速执行Prolog代码,而且支持数据库操作和数值计算。文中在论述GKD-PLM的特点之后,介绍了Prolog处理机SPP的指令系统、数据表示、执行部件的硬件结构、微程序控制器的结构等。并对其性能进行了评估。     

基于多切换传输的复变量混沌系统的有限时组合同步控制

针对一类复变量混沌系统, 研究了基于多切换传输的有限时同步控制问题.首先,针对网络信号在传输过程中的同步模式,分析了多个混沌系统之间的多切换同步行为.其次,基于预设的切换传输规则,给出了有限时组合同步的定义.进而,依据有限时稳定性理论,设计了一类实现快速同步的控制器,并给出了有限时组合同步的充分条件.最后,通过数值仿真和分析验证了所设计控制方案的有效性.     

Sufficient conditions for protection routing in IP networks

Providing fully distributed, fault tolerant, hop-by-hop routing is one of the key challenges for intra-domain IP networks. This can be achieved by storing two next-hops for each destination node in the forwarding table of the routers, and the packets are forwarded to primary next-hop (PNH), unless PNH is unreachable and secondary next-hop (SNH) is used instead. We follow the architecture by Kwong et al. in On the feasibility and efficacy of protection routing in IP networks, University of Pennsylvania (2010), where the routing tables are configured in a centralized way, while the forwarding and failure recovery is in a fully distributed way without relying on any encapsulation and signaling mechanisms for failure notification, to meet the standard IP forwarding paradigm. A network is protected if no single link of node failure results in forwarding loops. Kwong et al. (On the feasibility and efficacy of protection routing in IP networks, University of Pennsylvania 2010) conjectured that network node connectivity is not sufficient for a network to be protectable. In this paper we show that this conjecture is in contradiction with a conjuncture by Hasunuma (Discrete Math 234(1–3):149–157, 2001; in Graph-Theoretic Concepts in Computer Science, Springer, Berlin, pp. 235–245, 2002), and show that every four connected maximal planar graph and every underlying graph of a 2-connected line digraph has feasible protection routing.     

一种基于多级查找表的高效Huffman编码算法

本文研究了适用于数字信号处理器的一种高效的Huffman编码算法的问题.利用多级查找表建立规则,并将Huffman树分割为若干子树且为分割后的所有子树建立一个统一的查找表的方法,获得了可用较小的查找表来存储Huffman树且能对比特流进行快速解码的结果.     

微博传播波的函数解析实证研究

为定量地揭示微博传播行为内在的时间演化规律,将微博转发量随时间的变化定义为微博传播波.根据微博传播网络的结构,将微博传播波分解为由若干"大V"所引发的微博传播子波.通过实证,发现了微博传播子波所遵从的统一的指数衰减函数形式.最终实现了将微博传播行为重构为一系列指数衰减函数的叠加,并对该函数中各参数的意义及影响因素进行了初步的探讨.     

Application of a primarily deductive framework describing time consumption for hauling of logs to road-side

Forest management planning decisions are often based on the forest owner’s goals, which typically focus on economic criteria. Logging operation work productivity functions are used when costing forest operations. These functions affect the conclusions drawn during forest management analyses because different logging environments give rise to different harvesting costs. When evaluating new combinations of machines and environments, there is generally a shortage of field data on productivity that can be examined in advance. We applied a previously published deductive framework describing time consumption in forwarding to known environments, in which field studies on forwarding have been conducted and for which extensive data are available. We then adapted the deductive framework to better reproduce the results obtained in the time studies. The deductive framework accurately reproduced the observed forwarding productivities; on average, the adaptation process improved the accuracy of this reproduction. However, it may also have reduced the accuracy of individual predictions. We conclude that the deductive framework can be used as a basis for constructing work productivity functions for forest management analyses, and can serve as a foundation when constructing new productivity functions based on time study results to use when pricing forwarding.     

A novel combined cryptographic and hash algorithm based on chaotic control character

A novel combined cryptographic and hash algorithm based on chaotic control character is proposed in this paper. The control character is generated by chaotic iteration. The plaintext is pre-processed in terms of control character, and then encrypted by the look-up index table. At the same time, the chaotic trajectory is changed continuously according to the control character, which can avoid the dynamical degradation of chaos. Besides, the look-up index table is updated by utilizing the control character continuously, and the index item of the final look-up index table can be considered as the hash value of the whole paragraph of plaintext. Therefore, the proposed algorithm can perform both encryption/decryption and hash in a combined manner. Compared with Wong’s and our former algorithms, the proposed one has decreased the ratio of ciphertext/plaintext to 1, and improved the efficiency greatly. Theoretical analysis and computer simulation verify the validity of the proposed algorithm.     

A decentralized two-level transportation problem in a housing material manufacturer: Interactive fuzzy programming approach

In this paper, we deal with a transportation problem in a housing material manufacturer and derive a satisfactory solution to the problem by taking into account not only the degree of satisfaction with respect to objectives of the housing material manufacturer but also those of two forwarding agents to which the housing material manufacturer entrusts transportation of products. The two forwarding agents handle the regular transportation and the small lot transportation, and each of them assigns work force, the transformation tasks properly. There are two objectives in the housing material manufacturer: one is to minimize the transportation cost and the other is to minimize the opportunity loss with respect to transportation time. The objectives of the two forwarding agents are to maximize their profits. We formulate the transportation planning and work force assignment problem as a decentralized two-level integer programming problem, and derive a satisfactory solution by applying an interactive fuzzy programming method.     

Non-negatively constrained image deblurring with an inexact interior point method

Nonlinear image deblurring procedures based on probabilistic considerations have been widely investigated in the literature. This approach leads to model the deblurring problem as a large scale optimization problem, with a nonlinear, convex objective function and non-negativity constraints on the sign of the variables. The interior point methods have shown in the last years to be very reliable in nonlinear programs. In this paper we propose an inexact Newton interior point (IP) algorithm designed for the solution of the deblurring problem. The numerical experience compares the IP method with another state-of-the-art method, the Lucy Richardson algorithm, and shows a significant improvement of the processing time.     

Complete tree subset difference broadcast encryption scheme and its analysis

The subset difference (SD) method proposed by Naor, Naor and Lotspiech is the most popular broadcast encryption (BE) scheme. It is suitable for real-time applications like Pay-TV and has been suggested for use by the AACS standard for digital rights management in Blu-Ray and HD-DVD discs. The SD method assumes the number of users to be a power of two. We propose the complete tree subset difference (CTSD) method that allows the system to support an arbitrary number of users. In particular, it subsumes the SD method and all results proved for the CTSD method also hold for the SD method. Recurrences are obtained for the CTSD scheme to count the number, N(n, r, h), of possible ways r users in the system of n users can be revoked to result in a transmission overhead or header length of h. The recurrences lead to a polynomial time dynamic programming algorithm for computing N(n, r, h). Further, they provide bounds on the maximum possible header length. A probabilistic analysis is performed to obtain an O(r log n) time algorithm to compute the expected header length in the CTSD scheme. Further, for the SD scheme we obtain an explicit limiting upper bound on the expected header length.     

A Model for Studying Display Methods of Statistical Graphics

Abstract

A method of statistical graphics consists of two parts: a selection of statistical information to be displayed and a selection of a visual display method to encode the information. Some display methods lead to efficient, accurate visual decoding of encoded information, and others lead to inefficient, inaccurate decoding. It is only through rigorous studies of visual decoding that informed judgments can be made about how to choose display methods. A model has been developed to provide a framework for the study of visual decoding. The model consists of three parts: (1) a two-way classification of information on displays—quantitative-scale, quantitative-physical, categorical-scale, and categorical-physical; (2) a division of the visual processing of graphical displays into pattern perception and table look-up; (3) a specification of visual operations that are employed to carry out pattern perception and table look-up. Display methods are assessed by studying the visual operations to which they lead. Studies use the theory and experimental technique of various areas of vision research including psychophysics, cognitive psychology, and computational vision. This process is illustrated by studies of three display methods: visual reference grids for graphs with juxtaposed panels and common scales, encoding a categorical variable on a scatterplot by the type of plotting symbol, and choosing the aspect ratio of a factor-response graph.     

Upper bounds for the forwarding indices of communication networks

The decision version of the forwarding index problem is, given a connected graph G and an integer ξ, to find a way of connecting each ordered pair of vertices by a path so that every vertex is an internal point of at most such paths. The optimization version of the problem is to find the smallest ξ for which a routing of this kind exists. Such a problem arises in the design of communication networks and distributed architectures. A model of parallel computation is represented by a network of processors, or machines processing and forwarding (synchronous) messages to each other, subject to physical constraints bearing on either the number of messages that can be processed by a single machine or the number of messages that can be sent through a connection. It was in this context that the problem was first introduced by Chung et al. (IEEE Trans. Inform. Theory 33 (1987) 224). The aim of this paper is to establish upper bounds for the optimal ξ as a function of the connectivity of the graph.