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Non-degeneracy of extremal points in multi-dimensional space

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Science China Mathematics 2015年第11期58卷 2255-2260页

作者： CHENG ChongQing ZHOU Min Department of Mathematics Nanjing University School of information management Nanjing University

For a family of smooth functions defined in multi-dimensional space,we show that,under certain generic conditions,all minimal and maximal points are non-degenerate.

关键词： non-degeneracy multi-dimensionM space smooth functions minimal and maximal points

A Robustness Model of Complex Networks with Tunable Attack information Parameter

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Chinese Physics Letters 2007年第7期24卷 2138-2141页

作者：吴俊谭跃进邓宏钟李勇 College of information Systems and management National University of Defense Technology Changsha 410073

We introduce a novel model for robustness of complex with a tunable attack information parameter. The random failure and intentional attack known are the two extreme cases of our model. Based on the model, we study the robustness of complex networks under random information and preferential information, respectively. Using the generating function method, we derive the exact value of the critical removal fraction of nodes for the disintegration of networks and the size of the giant component. We show that hiding just a small fraction of nodes randomly can prevent a scale-free network from collapsing and detecting just a small fraction of nodes preferentially can destroy a scale-free network.

关键词： INTENTIONAL ATTACK RANDOM GRAPHS RESILIENCE BREAKDOWN INTERNET

KEY FACTORS FOR EFFICIENTLY IMPLEMENTING CUSTOMIZED E-LEARNING SYSTEM IN THE SERVICE INDUSTRY

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Journal of Systems Science and Systems Engineering 2011年第3期20卷 346-364页

作者： Ta-Sheng LO Tien-Hsiang CHANG Lon-Fon SHIEH Ya-Chuan CHUNG Department of information management National Taiwan University of Science and Technology Department of information management National Kaohsiung University of Applied Sciences Department of Business management National United UniversityIndustrial Development BureauMinistry of Economic Affairs Advanced Semiconductor Engineering Inc.

In recent years, e-learning system has been adopted as a training tool in many firms, as it can help employees to complete training in a short time and at a low cost. Within this context, since 2003 the Industrial Development Bureau （IDB） of the Ministry of Economic Affairs （MOEA） in Taiwan sponsored more than 50 enterprises each year to help them implement customized e-learning systems. Past research on e-learning mostly focused on one criterion and adopted regression approach, such as examining the relationships between satisfaction or continued usage intentions and various antecedent factors. Although the regression method could uncover the significant factors of e-learning adoption, they can not show the can （weighting） of each factor, and thus firms cannot allocate the optimal levels of resources. To overcome this problem, this study collected factors related to finns implementing customized e-learning systems from a review of the literature and expert opinions, and then constructed a hierarchical factor table. Based on the appropriateness and independence of factors, and as assessed by experts in the project promotion office of the IDB, e-learning solution providers and project leaders of the IDB sponsored enterprises, this paper then designed an Analytical Hierarchy Process （AHP） format questionnaire and sent it to these same experts to gather their responses. The factor weightings were derived based on the Fuzzy Analytic Hierarchy Process （FAHP） method. Finally, analysis of key factors was performed and recommendations provided. Based on the results for this work, service industry firms with limited resources can achieve proper resource allocation and more quickly and successfully adopt customized e-Learning systems.

关键词： E-learning system platform fuzzy AHP

Non-differentiability of Alpha Function at the Boundary of Flat

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Acta Mathematica Sinica,English Series 2014年第8期30卷 1341-1352页

作者： Jian Lu ZHANG Min ZHOU Department of Mathematics Nanjing University School of information management Nanjing University

With the variational method introduced by Mather,we construct a mechanical Hamiltonian system whose α function has a flat F and is non-differentiable at the boundary *** the case of two degrees of freedom,we prove ... 详细信息

关键词： Mather theory α function mechanical systems

Controllability and Directionality in Complex Networks

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Chinese Physics Letters 2012年第10期29卷 257-260页

作者： HOU Lv-Lin LAO Song-Yang LIU Gang BAI Liang College of information Systems and management National University of Defense TechnologyChangsha 410073

We investigate how to assign link directions in a given complex network to enhance its *** on the node residual degree,a method of assigning link direction is *** simulation demonstrates that the method outperforms the random direction assignment method in enhancing the controllability of the ***,robustness of control is also improved.

关键词： network assign Directional

Learning real-time search on c-space GVDs

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Frontiers of Computer Science 2017年第6期11卷 1036-1049页

作者： Quanjun YIN Long QIN Yong PENG Wei DUAN College of information System and management National University of Defense Technology Changsha 410073 China

In the context of robotics, configuration space （c- space） is widely used for non-circular robots to engage tasks such as path planning, collision check, and motion planning. In many real-time applications, it is important for a robot to give a quick response to the user＇s command. Therefore, a constant bound on planning time per action is severely im- posed. However, existing search algorithms used in c-space gain first move lags which vary with the size of the under- lying problem. Furthermore, applying real-time search algo- rithms on c-space maps often causes the robots being trapped within local minima. In order to solve the above mentioned problems, we extend the learning real-time search （LRTS） algorithm to search on a set of c-space generalized Voronoi diagrams （c-space GVDs）, helping the robots to incremen- tally plan a path, to efficiently avoid local minima, and to ex- ecute fast movement. In our work, an incremental algorithm is firstly proposed to build and represent the c-space maps in Boolean vectors. Then, the method of detecting grid-based GVDs from the c-space maps is further discussed. Based on the c-space GVDs, details of the LRTS and its implemen- tation considerations are studied. The resulting experiments and analysis show that, using LRTS to search on the c-space GVDs can 1） gain smaller and constant first move lags which is independent of the problem size; 2） gain maximal clear- ance from obstacles so that collision checks are much re- duced; 3） avoid local minima and thus prevent the robot from visually unrealistic scratching.

关键词： generalized Voronoi diagrams real-time search,robotics configuration space incremental algorithms

A consensus model for group decision making under interval type-2 fuzzy environment

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Frontiers of information Technology & Electronic Engineering 2016年第3期17卷 237-249页

作者： Xiao-xiong ZHANG Bing-feng GE Yue-jin TAN College of information System and management National University of Defense Technology Changsha 410073 China

We propose a new consensus model for group decision making(GDM) problems, using an interval type-2 fuzzy environment. In our model, experts are asked to express their preferences using linguistic terms characterized by interval type-2 fuzzy sets(IT2 FSs), because these can provide decision makers with greater freedom to express the vagueness in real-life situations. Consensus and proximity measures based on the arithmetic operations of IT2 FSs are used simultaneously to guide the decision-making process. The majority of previous studies have taken into account only the importance of the experts in the aggregation process, which may give unreasonable results. Thus, we propose a new feedback mechanism that generates different advice strategies for experts according to their levels of importance. In general, experts with a lower level of importance require a larger number of suggestions to change their initial preferences. Finally, we investigate a numerical example and execute comparable models and ours, to demonstrate the performance of our proposed model. The results indicate that the proposed model provides greater insight into the GDM process.

关键词： Group decision making (GDM) Interval type-2 fuzzy sets (IT2 FSs) Feedback mechanism

VKSE-MO: verifiable keyword search over encrypted data in multi-owner settings

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Science China(information Sciences) 2017年第12期60卷 192-206页

作者： Yinbin MIAO Jianfeng MA Ximeng LIU Junwei ZHANG Zhiquan LIU School of Cyber Engineering Xidian University School of information Systems Singapore Management University

Searchable encryption(SE) techniques allow cloud clients to easily store data and search encrypted data in a privacy-preserving manner, where most of SE schemes treat the cloud server as ***, in practice, the cloud server is a semi-honest-but-curious third-party, which only executes a fraction of search operations and returns a fraction of false search results to save its computational and bandwidth resources. Thus, it is important to provide a results verification method to guarantee the correctness of the search results. Existing SE schemes allow multiple data owners to upload different records to the cloud server,but these schemes have very high computational and storage overheads when applied in a different but more practical setting where each record is co-owned by multiple data owners. To address this problem, we develop a verifiable keyword search over encrypted data in multi-owner settings(VKSE-MO) scheme by exploiting the multisignatures technique. Thus, our scheme only requires a single index for each record and data users are assured of the correctness of the search results in challenging settings. Our formal security analysis proved that the VKSE-MO scheme is secure against a chosen-keyword attack under a random oracle model. In addition, our empirical study using a real-world dataset demonstrated the efficiency and feasibility of the proposed scheme in practice.

关键词： chosen-keywork attack efficiency and feasibility multi-owner settings result verification searchable encryption

Study on semantic-oriented hybrid indexing strategy of resource metadata in peer-to-peer network

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第1期8卷 88-94页

作者： LIU Zhen ZHOU Mao-wei HUANG Hong-bin LUO Xue-shan College of information System and management National University of Defense Technology Changsha 410073 China

Applying ontology to describe resource metadata richly in the peer-to-peer environment has become current research trend. In this semantic peer-to-peer environment, indexing semantic element of resource description to support efficient resource location is a difficult and challenging problem. This paper provided a hybrid indexing architecture, which combines local indexing and global indexing. It uses community strategy and semantic routing strategy to organize key layer metadata element and uses DHT (distributed hash table) to index extensional layer metadata element. Compared with related system, this approach is more efficient in resource location and more scalable.

关键词： Peer-to-peer (P2P) Ontology Metadata Resource indexing