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Corslet: A shared storage system keeping your data private

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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 tsinghua national laboratory for information science and technology, tsinghua university, 1. Department of Computer science and technology Tsinghua University Beijing 100084 China2. Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing 100084 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

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

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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 national 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 100084 China tsinghua national laboratory for information science and technology Tsinghua University Beijing 100084 China Research Institute of information technology (RIIT) Tsinghua University Beijing 100084 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

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Suppression of Phase and Amplitude Damping Decoherence in a Three-Level Atom in A-Configuration Using Bang-Bang Controls

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Communications in Theoretical Physics 2007年第7期48卷 71-74页

作者： WANG Yan-Hui LIU Xiao-Shu LONG Gui-Lu1 Key laboratory for Atomic and Molecular Nanosciences and Department of Physics,tsinghua university,Beijing 100084,China2 tsinghua national laboratory for information science and technology,tsinghua university,Beijing 100084,China Key laboratory for Atomic and Molecular Nanosciences and Department of Physics Tsinghua University Beijing 100084 China tsinghua national laboratory for information science and technology Tsinghua University Beijing 100084 China

In this paper,we present decoupling bang-bang operations for the suppression of general decoherence,bothamplitude and phase damping,in a three-level system in *** give a program to design a sequence ofperiodic twinbor...

关键词： bang-bang operation general decoherence three-level system

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Arbitrarily long distance quantum communication using inspection and power insertion

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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 tsinghua 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 100084 China tsinghua national laboratory for information science and technology Tsinghua University Beijing 100084 China College of Applied science Harbin University of Science and Technology Beijing 100084 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

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A new DSmT combination rule in open frame of discernment and its application

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science China(information sciences) 2012年第3期55卷 551-557页

作者： WEN ChengLin1, XU XiaoBin1,2 , JIANG HaiNa1 & ZHOU Zhe1 1School of Automation, Hangzhou DianZi university, Hangzhou 310018, China 2Department of Automation and tsinghua national laboratory for information science and technology, tsinghua university, Beijing 100049, China 1. School of Automation Hangzhou DianZi University Hangzhou 310018 China2. Department of Automation and Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing 100049 China

A new combination rule based on Dezert-Smarandache theory (DSmT) is proposed to deal with the conflict evidence resulting from the non-exhaustivity of the discernment frame. A two-dimensional measure factor in Dempster-Shafer theory (DST) is extended to DSmT to judge the conflict degree between evidence. The original DSmT combination rule or new DSmT combination rule can be selected for fusion according to this degree. Finally, some examples in simultaneous fault diagnosis of motor rotor are given to illustrate the effectiveness of the proposed combination rule.

关键词： DSmT rule of combination open frame of discernment evidence conflict simultaneous faults diagnosis generalized basic probability assignment

Direct Regulation Estimation of Cellular Networks with Time Series and Steady State Data

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Direct Regulation Estimation of Cellular Networks with Time ...

An Integrated Algorithm for Hinging Hyperplanes and Its Application in Distillation Process

第三十届中国控制会议

作者： WANG Yali~1,ZHOU Tong~(1,2) 1.Department of Automation,tsinghua university,Beijing 100084,P.R.China 2.tsinghua national laboratory for information science and technology(TNList),tsinghua university,Beijing 100084,P.R.China

One of the main aims in systems biology is to gain knowledge about direct regulation effects among numerous cellular *** this paper,two algorithms are proposed to estimate direct causal regulations from noisy time series experimental *** incorporating a so-called power law which is an important network structural characteristic of most large scale cellular networks,a likelihood function is developed and minimized by three *** essential step is determining which chemical elements have direct regulation effects on a prescribed element,when the number of direct regulations is known. To avoid the inherent combinatorial computation problem,two procedures are proposed yo give analytical solutions about the positions of these *** addition,the possibility of integrating information of time series and steady state data into network inferences is also investigated in this paper,and finally two improved algorithms are developed based on these two kinds of data. These algorithms have been applied to many artificially constructed networks with 101 *** with total least squares(TLS) method,which is widely used in noisy measurement data case,numerical simulations show that,the false positive errors can be significantly reduced and estimation accuracy can be extremely ***,the performances of improved algorithms are greatly better than the time series data based algorithms.

关键词： Direct Regulation Cellular Network Power Law Maximum Likelihood Estimation

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An Integrated Algorithm for Hinging Hyperplanes and Its Appl...

Robust Output Tracking Controller Design for a Class of Uncertain MIMO Nonlinear Systems

第三十届中国控制会议

作者： GAO Xiaoyong~1,JIANG Yongheng~(1,2),HUANG Dexian~(1,2) 1.Department of Automation,tsinghua university,Beijing 100084,P.R.China 2.tsinghua national laboratory for information science and technology,tsinghua university,Beijing 100084,P.R.China

＜正＞Hinging hyperplanes（HH） is a kind of piecewise linear approximation methods which is proven to be effective for any continuous linear functions with arbitrary dimensions on compact sets in any given *** the open literatures,more attentions are concentrated on the representation capability and the convergence issue of parameter optimization is rarely concerned with,which is important for real world application,especially for real time online *** the application effect by the current parameter optimization method shows that the convergence rate becomes slower and slower along with iterations increase and hard to proceed when parameters are in a neighborhood of optimal *** cope with this drawback,a novel parameter optimization algorithm is introduced to accelerate the convergence rate,which integrates the Newton’s method with conjugate gradient *** effectiveness of proposed algorithm is verified by *** then a practical example is given to model the pour point of side-draw of atmospheric *** accuracy is satisfied for application and convergence rate by the integrated algorithm is accelerated compared with the original one.

关键词： Hinging Hyperplanes Convergence Rate Atmospheric Column

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Robust Output Tracking Controller Design for a Class of Unce...

An introduction to tsinghua Cloud

第二十九届中国控制会议

作者： YU Yao1,SHI Zongying1,ZHONG Yisheng1,2 1.Department of Automatic Control,tsinghua university,Beijing 100084,P.R.China 2.tsinghua national laboratory for information science and technology,tsinghua university,Beijing 100084,P.R.China

A new control design method based on signal compensation is proposed for a class of uncertain multi-input multi-output（MIMO）nonlinear systems in block-triangular form with nonlinear uncertainties,external disturbances,unknown virtual control coefficients and strongly coupled *** this method,the controller design is performed in a backstepping *** each step of backstepping procedure,a nominal virtual controller is first designed to get desired output tracking for the nominal disturbance-free subsystem,and then a robust virtual compensator is designed to restrain the effect of the uncertainty,disturbance involved in the subsystem and couplings among the *** is proved that global robust stability and global robust practical tracking property of the closed-loop system can be ensured and the tracking errors can be made as small as *** trait of our approach is that the designed controller is linear and time-invariant,so the explosion of terms in the control law is avoid.

关键词： MIMO Backstepping Robust Control Output Tracking Linear controller

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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 2tsinghua national laboratory for information science and technology, Beijing 100084, China 1. Department of Computer science and technology Tsinghua University Beijing 100084 China2. Tsinghua National Laboratory for Information Science and Technology Beijing 100084 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