检索结果-南通市图书馆

Corslet: A shared storage system keeping your data private

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science China(information sciences) 2011年第6期54卷 1119-1128页

作者： XUE Wei 1,2., SHU JiWu 1,2., LIU Yang 1 & XUE Mao 1 1 Department of Computer science and Technology, tsinghua university, Beijing 100084, China {2. national laboratory for information science and Technology, tsinghua university, Department of Computer science and Technology Tsinghua University Beijing China tsinghua national {2. for information science and Technology Tsinghua University Beijing China

With the exponential growth of digital data, it is becoming more and more popular to store data in shared distributed storage systems inside the same organization. In such shared distributed storage systems, an ordinary user usually does not have the control permission over the whole system, and thus cannot secure data storage or data sharing of his own files. To solve this issue, this paper proposes a new system architecture to secure file storing and sharing efficiently over untrusted shared storage and network environments. Based on this architecture, this paper designs and implements a stackable secure storage system called Corslet. Corslet can run directly on deployed underlying storage systems without modification, while bringing end-to-end confidentiality and integrity as well as efficient access control for user data. For individual users, Corslet is easy to use, and does not require users to maintain or manage any keys on their client machines locally. The Bonnie++ and IOzone benchmark results show that the throughput of Corslet over NFS can achieve more than 90% of native NFS throughput in most tests, proving that Corslet can provide enhanced security for user data while maintaining acceptable performance.

关键词： storage security access control key management shared file system

An introduction to tsinghua Cloud

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science China(information sciences) 2010年第7期53卷 1481-1486页

作者： ZHENG WeiMin1,2.1Department of Computer science and Technology, tsinghua university, Beijing 100084, China 2.2. national laboratory for information science and Technology, Beijing 100084, China Department of Computer science and Technology Tsinghua University Beijing China tsinghua national {2. for information science and Technology Beijing China

Cloud computing has become a trend that draws attention from both academia and industry all over the world. This paper unveils details of tsinghua Cloud, a comprehensive solution for cloud computing developed by Tsing... 详细信息

关键词： cloud computing distributed file system virtual computing environment data sharing

Buffer planning for application-specific networks-on-chip design

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science in China(Series F) 2009年第4期52卷 547-558页

作者： YIN ShouYi1,2.LIU LeiBo1,2.& WEI ShaoJun1,2.1 Institute of Microelectronics,tsinghua university,Beijing 100084,China 2.{2. laboratory for information science and Technology,tsinghua university,Beijing 100084,China Institute of Microelectronics Tsinghua University Beijing China national laboratory for {2. science and Technology Tsinghua University Beijing China

Networks-on-chip （NoC） is a promising communication architecture for next generation SoC. The size of buffer used in on-chip routers impacts the silicon area and power consumption of NoC dominantly. It is important to plan the total buffer-size and each router buffer-allocation carefully for an efficient NoC design. In this paper, we propose two buffer planning algorithms for application-specific NoC design. More precisely, given the traffic parameters and performance constraints of target application, the proposed algorithms automatically determine minimal buffer budget and assign the buffer depth for each input channel in different routers. The experimental results show that the proposed algorithms can significantly reduce total buffer usage and guarantee the performance requirements.

关键词： buffer planning networks-on-chip (NoC) design automation optimization

Real-time reliability prediction for dynamic systems with both deteriorating and unreliable components

在线全文

学校读者我要写书评

暂无评论

science in China(Series F) 2009年第11期52卷 2234-2246页

作者： XU ZhengGuo1,2. JI YinDong2.3 & ZHOU DongHua1,2. 1 Department of Automation, tsinghua university, Beijing 100084, China 2.tsinghua {2. laboratory for information science and Technology, tsinghua university, Beijing 100084, China 3 Research Institute of information Technology (RIIT), tsinghua university, Beijing 100084, China Department of Automation Tsinghua University Beijing China tsinghua national {2. for information science and Technology Tsinghua University Beijing China Research Institute of information Technology (RIIT) Tsinghua University Beijing China

As an important technology for predictive maintenance, failure prognosis has attracted more and more attentions in recent years. Real-time reliability prediction is one effective solution to failure prognosis. Considering a dynamic system that is composed of normal, deteriorating and unreliable components, this paper proposes an integrated approach to perform real-time reliability prediction for such a class of systems. For a deteriorating component, the degradation is modeled by a time-varying fault process which is a linear or approximately linear function of time. The behavior of an unreliable component is described by a random variable which has two possible values corresponding to the operating and malfunction conditions of this component. The whole proposed approach contains three algorithms. A modified interacting multiple model particle filter is adopted to estimate the dynamic system＇s state variables and the unmeasurable time-varying fault. An exponential smoothing algorithm named the Holt＇s method is used to predict the fault process. In the end, the system＇s reliability is predicted in real time by use of the Monte Carlo strategy. The proposed approach can effectively predict the impending failure of a dynamic system, which is verified by computer simulations based on a three-vessel water tank system.

关键词： reliability failure prognostics dynamic systems fault prediction particle filtering interacting multiple model exponential smoothing,predictive maintenance

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

在线全文

学校读者我要写书评

暂无评论

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 {2. 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 {2. 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

Self-healing routing: failure,modeling and analysis

在线全文

学校读者我要写书评

暂无评论

science China(information sciences) 2011年第3期54卷 609-622页

作者： XU MingWei 1,2., LI Qi 1,2., YANG Yuan 1,2., HOU MeiJia 1,2.& PAN LingTao 1,2.1 Department of Computer science, tsinghua university, Beijing 100084, China {2. national laboratory for information science and Technology (TNList), Beijing 100084, China Department of Computer science Tsinghua University Beijing China tsinghua national {2. for information science and Technology (TNList) Beijing China

Network failures occur frequently, and self-healing ability of existing routing protocols cannot guarantee fast route convergence under these failures without impacting packet forwarding. During routing convergence, network routes may be incorrect and even routing black holes and loops occur, which will result in extensive packet loss and thus influence network performance. To solve this problem, several improved routing solutions have been proposed. In this paper, we propose the concept and model of self-healing routing and analyze the key problems in current intra-domain and inter-domain self-healing routing protocols after briefly reviewing the characteristics of network failures. We classify the different self-healing solutions into two categories based on their design principles: routing restoration and routing protection, and systematically analyze these different typical solutions. Finally, we discuss several key issues in self-healing routing and propose a hybrid protection and restoration based routing scheme.

关键词： failure intra-domain routing inter-domain routing self-healing routing

Theoretical research progress in new-generation Internet architecture

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

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 {2.,Beijing 100084,China 2.Network Research Center,tsinghua {2.,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 {2. 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 30 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

Arbitrarily long distance quantum communication using inspection and power insertion

在线全文

学校读者我要写书评

暂无评论

Chinese science Bulletin 2009年第1期54卷 158-162页

作者： WANG WanYing1,2.WANG Chuan1,2.ZHANG GuangYu1,3 & LONG GuiLu1,2.1 Department of Physics,tsinghua university,Beijing 100084,China {2. national laboratory for information science and Technology,tsinghua university,Beijing 100084,China 3 College of Applied science,Harbin university of science and Technology,Harbin 150080,China Department of Physics Tsinghua University Beijing China tsinghua national {2. for information science and Technology Tsinghua University Beijing China College of Applied science Harbin University of Science and Technology Beijing China

The biggest obstacle for long distance quantum communication is the channel loss and the channel noise on photons. In this paper,a method to solve this problem was analyzed using inspection and power insertion (IPI). It is proved that quantum communication may be established over arbitrarily long distance using this technology. The amount of resources required is a polynomial function of the dis-tance. IPI is proposed as a general technique to prolong quantum secure direct communication where secret messages are transmitted directly over a quantum channel.

关键词：长距离量子通信量子安全通信量子密匙分布噪声

Influence of magnetic current on the ground state entanglement in an isotropic transverse XY chain

在线全文

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2007年第10期17卷 1147-1151页

作者： Liu Dan1,2., Zhang Yong3 and Long Guilu1,2.1. Key laboratory for Atomic and Molecular Nanosciences, and Department of Physics,{2., Beijing 100084, China 2. Center of Quantum information science and Technology, tsinghua national laboratory for information science and Technology, Beijing 100084, China 3. Institute of Physics, School of sciences, Beijing university of Posts and Telecommunications, Beijing 100876, China) Key laboratory for Atomic and Molecular Nanosciences Department of Physics Tsinghua University Beijing 100084 China Center of Quantum information science and Technology Tsinghua National Laboratory for Information Science and Technology Beijing 100084 China Institute of Physics School of Sciences Beijing University of Posts and Telecommunications Beijing 100876 China

We study the ground state entanglement in a three-qubit XY chain under the influence of a magnetization current. It is found that the ground state changes from a W state to a disentangled state as the magnetic field varies. When the Lagrange multiplier λ>3, namely under a strong magnetic current, the ground state holds onto a W state for a large range of the magnetic field strength. A phase transition to the magnetization-current phase occurs under a certain condition.

关键词： Heisenberg-XY chain magnetic-current phase transition.