On progressively truncated maximum likelihood estimators

Summary The basic regularity conditions pertaining to the asymptotic theory of progressively truncated likelihood functions and maximum likelihood estimators are considered, and the uniform strong consistency and weak convergence of progressively truncated maximum likelihood estimators are studied systematically. Work done during the first author's visit (as a visiting scholar) to the University of North Carolina at Chapel Hill, supported by the Ministry of Education of the Japanese Government. Work supported by the (U.S.) National Heart, Lung and Blood Institute, Contact NIH-NHLBI-F1-2243-L.     

Universality two-dimensional Kauffman model for parallel and sequential updating

Kauffman's random Boolean nets are studied on the square lattice by computer simulation comparing parallel and sequential updating of the automata. At the phase transition the fractal dimensions of time and actual damage are found to be independent of the updating method.     

Progressive hedging and tabu search applied to mixed integer (0,1) multistage stochastic programming

Many problems faced by decision makers are characterized by a multistage decision process with uncertainty about the future and some decisions constrained to take on values of either zero or one (for example, either open a facility at a location or do not open it). Although some mathematical theory exists concerning such problems, no general-purpose algorithms have been available to address them. In this article, we introduce the first implementation of general purpose methods for finding good solutions to multistage, stochastic mixed-integer (0, 1) programming problems. The solution method makes use of Rockafellar and Wets' progressive hedging algorithm that averages solutions rather than data. Solutions to the induced quadratic (0,1) mixed-integer subproblems are obtained using a tabu search algorithm. We introduce the notion of integer convergence for progressive hedging. Computational experiments verify that the method is effective. The software that we have developed reads standard (SMPS) data files.     

Extremal graphs for the k‐flower

The Turán number of a graph H, , is the maximum number of edges in any graph of order n that does not contain an H as a subgraph. A graph on vertices consisting of k triangles that intersect in exactly one common vertex is called a k‐fan, and a graph consisting of k cycles that intersect in exactly one common vertex is called a k‐flower. In this article, we determine the Turán number of any k‐flower containing at least one odd cycle and characterize all extremal graphs provided n is sufficiently large. Erdős, Füredi, Gould, and Gunderson determined the Turán number for the k‐fan. Our result is a generalization of their result. The addition aim of this article is to draw attention to a powerful tool, the so‐called progressive induction lemma of Simonovits.     

关联规则快速聚焦算法研究与实现

提出了一种实用的快速聚焦关联规则更新算法。在需要反复调整最小支持度的情况下,如何充分利用以往挖掘过程中的信息,避免多次扫描数据集;在如何有针对性的产生候选项集,从而减少候选集的规模;在如何提高候选项集的支持事务计数的效率等方面进行了研究,给出了算法的具体实现。通过分析,本算法是可行的。     

以学生为中心的递进式“精细化工”实验教学

针对学生实验课积极性不高、实验教学效果不理想的问题，对一门选修课"精细化工"的实验进行了重新思考和设计，让学生参与从实验具体内容制定、操作到结果讨论的整个过程，并首次以"递进式"实验的方式由学生参与第2次实验（基于前一个实验的改进和完善），使学生了解理论知识转化为可行实验方案的具体做法，切身体会在实验原理相同的情况下，实验方案的细微调整对实验结果的巨大影响。结果表明，这种"以学生为中心"的改进能让学生注重实验细节，同时关注实验失败的原因，并在第2次实验中及时修正。这为学生实验综合素质的培养提供了一种教学思路。     

一种基于地图爬虫的场景边界识别与质量监控方法

本文提出了一种基于地图爬虫的场景边界识别与质量监控方法，参考互联网爬虫技术实现场景边界自动识别，依靠“MR+OTT”和“帕累托法则”实现场景资源信息自动更新，在此基础上，关联网优大数据实现重点场景网络质量的智能预警监控。在某市进行试点，方案上线后自动识别场景4361处，实现场景小区自动更新，初次评估覆盖率92.85%，经过两个月的整治，覆盖率提升至94.22%，弱覆盖小区占比下降4.72PP。     

TF‐CPABE: An efficient and secure data communication with policy updating in wireless body area networks

The major challenge in wireless body area networks (WBAN) is setting up a protected communication between data consumers and a body area network controller while meeting the security and privacy requirements. This paper proposes efficient and secure data communication in WBANs using a Twofish symmetric algorithm and ciphertext‐policy attribute‐based encryption with constant size ciphertext; in addition, the proposed scheme incorporates policy updating to update access policies. To the best of the author's knowledge, policy updating in WBAN has not been studied in earlier works. The proposed scheme is evaluated in terms of message size, energy consumption, and computation cost, and the results are compared with those of existing schemes. The result shows that the proposed method can achieve higher efficiency than conventional methods.     

一种适用于概率LDPC译码器的双路更新边缘存储器

针对采用传统边缘存储器结构的概率低密度奇偶校验(Low Density Parity Check,LDPC)译码器中仍存在锁存问题的现象,借鉴全并行Turbo译码器中的多路更新策略,提出了一种增强的变量节点和校验节点双路更新边缘存储器结构。利用双路更新结构引入的增强随机选择特性,可以显著降低概率迭代译码过程中的锁存现象。仿真分析表明,相比于单路更新结构,采用双路更新边缘存储器结构的概率LDPC译码器能够在误比特率接近10-4量级处获得0.4 dB左右的译码性能增益,同时也能够显著降低迭代译码周期数量,提升译码速率。     

Multi-authority attribute-based encryption scheme with policy dynamic updating

Attribute-based encryption (ABE) is a new cryptographic technique which guarantees fine-grained access control of outsourced encrypted data in the cloud environment.However,a key limitation remains,namely policy updating.Thus,a multi-authority attribute-based encryption scheme with policy dynamic updating was proposed.In the scheme,an anonymous key issuing protocol was introduced to protect users’ privacy and resist collusion attack of attribute authority.The scheme with dynamic policy updating technique was secure against chosen plaintext attack under the standard model and can support any types of policy updating.Compared to the existing related schemes,the size of ciphertext and users’ secret key is reduced and can significantly reduce the computation and communication costs of updating ciphertext.It is more effective in the practical application.