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Research on Multiple Access Algorithms for Wireless network

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Journal of Electronic Research and Application 2024年第4期8卷 55-63页

作者： kaifeng Yao Space Engineering university Beijing 101400China

Nodes in the communication network mainly depend on the Media Access Control(MAC)layer protocol *** ensure the MAC protocol achieves high throughput,low latency,and high service quality,this paper designed a“centralized-distribution”system MAC protocol combined with a slot allocation *** allows it to quickly adapt to the topology changes in the network and the overall network frame *** the centralized time slot allocation,since the system’s frame structure changes across the entire network,the root node must gather information from other *** ensures that the root node can collect the latest topology information when the network topology changes and subsequently adjust the frame structure of the whole network for the distributed time slot *** simulation results show that the adaptive time-division multiple access mechanism can quickly adapt to changes in topology and the network’s frame *** enables adaptive changes in node transmission times,ensures the rapid transmission and circulation of large-capacity data between nodes,and improves transmission efficiency.

关键词： TDMA Wireless network MAC protocol Time gap allocation

A Graph-based Clustering for Web Content Mining

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A Graph-based Clustering for Web Content Mining

A new heuristic algorithm for the circular packing problem with equilibrium constraints

2010 Third Pacific-Asia Conference on Web Mining and Web-based Application (WMWA 2010)

作者： Ming Tingtang network information center{3. kaifeng china Li Jun network information center{3. kaifeng china

In this paper we will introduce a new method of clustering where the data to be clustered will be represented by graphs instead of vectors or other ***,we will extend the classical k-means clustering algorithm to work with graphs that represent web *** modeled web documents Content as graphs because they can allow us to retain information which is often discarded in simpler *** experiments comparing the performance of clustering when using the traditional vector representation and our novel graph-based representations showed improvements in clustering quality and executing time over vector-based model.

关键词： Web Mining Web Content Mining Graph Similarity Graph Matching.

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Science china(information Sciences) 2011年第8期54卷 1572-1584页

作者： LIU JingFa 1,2,LI Gang 3.& GENG HuanTong 1 1 School of Computer and Software,Nanjing university of information Science & Technology,Nanjing 210044,china 2 {3. information center,Nanjing university of information Science & Technology, Nanjing 210044,china 3.School of Mathematics and Physics,Nanjing university of information Science & Technology,Nanjing 210044,china School of Computer and Software Nanjing University of Information Science & Technology Nanjing China network information center Nanjing University of Information Science & Technology Nanjing China School of Mathematics and Physics Nanjing University of Information Science & Technology Nanjing China

The circular packing problem with equilibrium constraints is an optimization problem about simplified satellite module layout design.A heuristic algorithm based on tabu search is put forward for solving this *** algorithm begins from a random initial configuration and applies the gradient method with an adaptive step length to search for the minimum energy *** jump out of the local minima and avoid the search doing repeated work,the algorithm adopts the strategy of tabu *** the process of tabu search,we improve the traditional neighboring solutions,tabu objects and the acceptance criteria of the current solution *** test two sets of benchmarks consisting of 11 representative instances from the current *** numerical results show that the proposed algorithm breaks the records in seven out of 11 instances,and obtains the optimal solutions for the other four instances.

关键词： equilibrium constraints packing problem heuristic algorithm tabu search layout optimization

Seamlessly Secure Communication Based on the Commutative Encryption

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计算机工程 2002年第S1期28卷 97-100页

作者： ZHAO Xianfeng , WANG Weinong (network and information center, Shanghai Jiaotong {3., Shanghai 20003.,china) network and information center Shanghai Jiaotong University Shanghai 200030China

To cross the security gap between 2 or more autonomous domains, an approach based on commutative encryption is proposed. In the new scheme, the proxy connecting the domains does not have to decrypt the input ciphertext by the algorithms used in the departure domain before it can encrypt it by the algorithms used in the destination domain. On the contrary, it can encrypt the input first. Therefore, no plaintext emerges on the way linking the domains. Although most existing cryptosystems do not support the commutative operation, this paper gives an algorithmic implementation based on symmetric stream cipher and Blum-Goldwasser probabilistic public key encryption.

关键词： Commutative encryption Security domain Proxy Electronic commerce WAP security

RRM:An incentive reputation model for promoting good behaviors in distributed systems

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Science in china(Series F) 2008年第11期51卷 1871-1882页

作者： ZHANG Hong1,2,DUAN HaiXin1,3.& LIU Wu1,3.1 Tsinghua National Laboratory for information Science and Technology,Tsinghua university,Beijing 100084,china 2 Department of Computer Science and Technology,Tsinghua university,Beijing 100084,china 3.network Research center,Tsinghua university,Beijing 100084,china Tsinghua National Laboratory for information Science and Technology Tsinghua University Beijing China Department of Computer Science and Technology Tsinghua University Beijing China network Research center Tsinghua University Beijing China

Reputation systems represent soft security mechanisms that complement traditional information security mechanisms. They are now widely used in online e-commerce markets and communities in order to stimulate good behaviors as well as to restrain adverse behaviors. This paper analyzes the limitations of the conversational reputation models and proposes an incentive reputation model called the resilient reputation model （RRM） for the distributed reputation systems. The objective of this reputation model is not only to encourage the users to provide good services and, therefore, to maximize the probability of good transaction outcomes, but also to punish those adverse users who are trying to manipulate the application systems. The simulation results indicate that the proposed reputation model （RRM） could effectively resist against the common adverse behaviors, while protecting the profits of sincere users from being blemished by those adversaries.

关键词： reputation model distributed system trust soft security

A formal method to real-time protocol interoperability testing

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Science in china(Series F) 2008年第11期51卷 1723-1744页

作者： WANG ZhiLiang1,3.YIN Xia2,3.& JING ChuanMing2,3.1 network Research center,Tsinghua university,Beijing 100084,{3. 2 Department of Computer Science and Technology,Tsinghua university,Beijing 100084,{3. 3.Tsinghua National Laboratory for information Science and Technology(TNList) ,Beijing 100084,{3. network Research center Tsinghua University Beijing China Tsinghua National Laboratory for information Science and Technology (TNList) Beijing China Department of Computer Science and Technology Tsinghua University Beijing China

Interoperability testing is an important technique to ensure the quality of implementations of network communication protocol. In the next generation Internet protocol, real-time applications should be supported effectively. However, time constraints were not considered in the related studies of protocol interoperability testing, so existing interoperability testing methods are difficult to be applied in real-time protocol interoperability testing. In this paper, a formal method to real-time protocol interoperability testing is proposed. Firstly, a formal model CMpTIOA （communicating multi-port timed input output automata） is defined to specify the system under test （SUT） in real-time protocol interoperability testing; based on this model, timed interoperability relation is then defined. In order to check this relation, a test generation method is presented to generate a parameterized test behavior tree from SUT model; a mechanism of executability pre-determination is also integrated in the test generation method to alleviate state space explosion problem to some extent. The proposed theory and method are then applied in interoperability testing of IPv6 neighbor discovery protocol to show the feasibility of this method.

关键词： protocol testing interoperability testing real-time testing test generation timed input output automata(TIOA)

Theoretical research progress in new-generation Internet architecture

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Science in china(Series F) 2008年第11期51卷 1634-1660页

作者： WU JianPing1,2,3.LIU Ying2,3.& WU Qian2,3.1 Department of Computer Science,Tsinghua university,Beijing 100084,china 2 network Research {3.,Tsinghua university,Beijing 100084,china 3.Tsinghua National Laboratory for information Science and Technology(TNList) ,Beijing 100084,china Department of Computer Science Tsinghua University Beijing China network Research center Tsinghua University Beijing China Tsinghua National Laboratory for information Science and Technology (TNList) Beijing China

Internet has become the most important information infrastructure supporting modern socio-economic development, social progress and technological Innovation. Invented 3. years ago, today Internet is facing increasingly severe technical challenges. This paper introduces the progress of the major international newgeneration Internet research plans; analyzes its basic characteristics and the principal contradictions during the development; detsiledly introduces the research carried out by 973.Project ＂Research of Future Internet Architecture＂ on the key scientific issues of new-generation Internet architecture and its latest research results; and looks to the future of the research-focus faced with the new situations of the basic research of new-generation Internet architecture as well as the new demands of innovative applications on Internet architecture.

关键词： new-generation Internet network architecture multi-dimension scalability

Ant Colony Optimization Algorithm for Continuous Domains

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Ant Colony Optimization Algorithm for Continuous Domains

The ERF transcription factor LTF1 activates DIR1 to control stereoselective synthesis of antiviral lignans and stress defense in Isatis indigotica roots

2010 International Conference on Computer and Communication Technologies in Agriculture Engineering (CCTAE 2010)

作者： Tingtang Ming Ruipeng Ding and Li jun network information center {3. of henan kaifeng henan Province china

Ant colony optimization is one of the popular metaheuristics used for tackling optimization *** this paper,we present a novel idea on how ACO may be extended to continuous domains with the pheromone modeled by probability density functions instead of a *** present a fully functional algorithm and evaluate the performance of our algorithm on a real-world problem of training neural networks for pattern *** results demonstrate that it is competitive,when compared to other algorithms.

关键词： Ant Colony Optimization (ACO) Continuous Optimization Problems (COPs) Neural networks(NNs) Classification Error Percentage (CEP)

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Acta Pharmaceutica Sinica B 2024年第1期14卷 405-420页

作者： Ruibing Chen Jian Yu Luyao Yu Liang Xiao Ying Xiao Junfeng Chen Shouhong Gao Xianghui Chen Qing Li henan Zhang Wansheng Chen Lei Zhang Department of Pharmaceutical Botany School of PharmacyNaval Medical UniversityShanghai 200433China Research and Development center of Chinese Medicine Resources and Biotechnology Shanghai University of Traditional Chinese MedicineShanghai 201203China Department of Pharmacy Shanghai Changzheng HospitalNaval Medical UniversityShanghai 200003China School of Medicine Shanghai UniversityShanghai 200433China Institute of Edible Fungi Shanghai Academy of Agricultural SciencesNational Engineering Research Center of Edible FungiKey Laboratory of Edible Fungi Resources and Utilization(South)Ministry of AgricultureShanghai 201403China College of Life Sciences and Medicine Key Laboratory of Plant Secondary Metabolism and Regulation of Zhejiang ProvinceZhejiang Sci-Tech UniversityHangzhou 310018China State Key Laboratory of Dao-di Herbs Beijing 100700China

Lignans are a powerful weapon for plants to resist stresses and have diverse bioactive functions to protect human *** the mechanisms of stereoselective biosynthesis and response to stresses of lignans is important for the guidance of plant ***,we identified the complete pathway to stereoselectively synthesize antiviral(-)-lariciresinol glucosides in Isatis indigotica roots,which consists of three-step sequential stereoselective enzymes DIR1/2,PLR,and ***1 was further identified as the key gene in respoJanuary 2024nse to stresses and was able to trigger stress defenses by mediating the elevation in lignan ***,the phytohormone-responsive ERF transcription factor LTF1 colocalized with DIR1 in the cell periphery of the vascular regions in mature roots and helped resist biotic and abiotic stresses by directly regulating the expression of *** systematic results suggest that DIR1 as the first common step of the lignan pathway cooperates with PLR and UGT71B2 to stereoselectively synthesize(-)-lariciresinol derived antiviral lignans in *** roots and is also a part of the LTF1-mediated regulatory network to resist *** conclusion,the LTF1-DIR1 module is an ideal engineering target to improve plant Defenses while increasing the content of valuable lignans in plants.

关键词： Lignans Stereoselective synthesis Stress resistance Dirigent protein ERF