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Bitstream decoding and SEU-induced failure analysis in SRAM-based FPGAs

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Science china(Information Sciences) 2012年第4期55卷 971-982页

作者： WANG ZhongMing 1,2,YAO ZhiBin 2,GUO HongXia 2 & LV Min 1 1 department of Engineering physics,tsinghua university,beijing 100084,china 2 Northwest Institute of Nuclear Technology,Xi'an 710024,china department of Engineering physics Tsinghua University Beijing China Northwest Institute of Nuclear Technology Xi’an China

Reconfigurable SRAM-based FPGAs are highly susceptible to radiation induced single-event upsets (SEUs) in space *** bit flip in FPGAs configuration memory may alter user circuit permanently without proper bitstream reparation,which is a completely different phenomenon from upsets in traditional memory *** is important to find the relationship between a programmable resource and corresponding control bit in order to understand the impact of this *** this paper,a method is proposed to decode the bitstream of FPGAs from Xilinx Corporation,and then an analysis program is developed to parse the netlist of a specific design to get the configuration state of occupied programmable logic and *** that,an SEU propagation rule is established according to the resource type to identify critical logic nodes and paths,which could destroy the circuit topological *** decoded relationship is stored in a *** database is queried to get the sensitive bits of a specific *** result can be used to represent the vulnerability of the system and predict the on orbit system failure *** analysis tool was validated through fault injection and accelerator irradiation experiment.

关键词： radiation effect single-event effect single-event upset SRAM-based FPGA fault injection

Synthesis,field emission and microwave absorption of carbon nanotubes filled with ferromagnetic nanowires

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Science china(Technological Sciences) 2010年第6期53卷 1453-1459页

作者： LV RuiTao1,KANG Feiyu1,GU Jialin1,WANG Kunlin2 & WU DeHai2 1 Laboratory of Advanced Materials,department of Materials Science and Engineering,tsinghua university,beijing 100084,china 2 department of Mechanical Engineering,tsinghua university,beijing 100084,china Laboratory of Advanced Materials Department of Materials Science and Engineering Tsinghua University Beijing China department of Mechanical Engineering Tsinghua University Beijing China

Carbon nanotubes filled with ferromagnetic metal nanowires (M-CNTs) were synthesized by using chlorine-contained benzene (***) as *** wall thicknesses of M-CNTs synthesized by trichlorobenzene are much thinner than those by precursor without Cl (***).As-synthesized thin-walled M-CNTs exhibit remarkably enhanced field electron emission performance with a low turn-on field of 0.3 V/μm and better field-emission ***-absorption coatings were made by dispersing as-synthesized M-CNTs into epoxy resin *** is found that the reflection losses in S-band (2-4 GHz),C-band (4-8 GHz) and X-band (8-12 GHz) are enhanced in the order of FeCoNi-CNTs 2.35 kg/m2 when the coating thickness is 2.0 *** demonstrates that M-CNTs are promising to be used as lightweight and wide-band microwave absorbers.

关键词： carbon nanotubes ferromagnetic nanowires field emission microwave absorption

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 China tsinghua National Laboratory 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

Aeroservoelastic model based active control for large civil aircraft

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Science china(Technological Sciences) 2010年第4期53卷 1126-1137页

作者： FAN Yong1,ZHU JiHong1,HU ChunHua2,MENG Xianyu1,WANG XiangYang2 & GE AiXue1 1 department of Computer Science and Technology,tsinghua university,beijing 100084,china 2 School of Astronautics and Aeronautics,tsinghua university,beijing 100084,china department of Computer Science and Technology Tsinghua University Beijing China School of Astronautics and Aeronautics Tsinghua University Beijing China

A modeling and control approach for an advanced configured large civil aircraft with aeroservoelasticity via the LQG method and control allocation is *** models and implementation issues for the multi-input/multi-output(MIMO) aeroservoelastic system simulation developed for a flexible wing with multi control surfaces are described.A fuzzy logic based optimization approach is employed to solve the constrained control allocation problem via intelligently adjusting the components of output vector and find a proper vector in the attainable moment set(AMS) *** basic idea is to minimize the L2 norm of error between the desired moment and achievable moment using the designing freedom provided by redundantly allocated actuators and control *** the constraints of control surfaces,in order to obtain acceptable performance of aircraft such as stability and maneuverability,the fuzzy weights are updated by the learning algorithm,which makes the closed-loop system ***,an application example of flight control designing for the advanced civil aircraft is discussed as a *** studies we have performed showed that the advanced configured large civil aircraft has good performance with the proper designed control law designed via the proposed *** gust alleviation and flutter suppression are applied with the synergetic effects of elevator,ailerons,equivalent rudders and *** results show good closed loop performance and meet the requirement of constraint of control surfaces.

关键词： modeling active control aeroelastic flutter suppression control allocation

LARGE DEFLECTION THEORY OF NANOBEAMS

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Acta Mechanica Solida Sinica 2010年第5期23卷 394-399页

作者： Dujuan Zeng Quanshui Zheng 1(department of Engineering Mechanics,tsinghua university,beijing 100084,china) department of Engineering Mechanics Tsinghua University Beijing China

One-dimensional nanostructured materials are often used as beams in many applications such as ultrahigh-frequency resonators and ultrasensitive sensors. Compared with usual macroscopic beams, nanobeams have much higher surface/volume ratios so that their surface energies may play a significant role. Besides, they often bear large deflections due to their typically large slenderness ratios and larger elastic ranges. There is, however, lack of a theory that takes into account of both the above two features owned by nanobeams. In this paper, we present such a theory and give applied examples to show that surface energy and large deflection may individually or jointly have notable effects.

关键词： nanobeam surface energy large deflection

Two mode photon bunching effect as witness of quantum criticality in circuit QED

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Science china(physics,Mechanics & Astronomy) 2009年第12期52卷 1898-1905页

作者： AI Qing1,WANG YingDan2,LONG GuiLu1,3 & SUN ChangPu4 1 department of physics,tsinghua university,beijing 100084,china 2 department of physics,university of Basel,Klingelbergstrasse 82,4056 Basel,Switzerland 3 tsinghua National Laboratory for Information Science and Technology,beijing 100084,china 4 Institute of Theoretical physics,Chinese Academy of Sciences,beijing 100080,china department of physics Tsinghua University Beijing China department of physics University of Basel Basel Switzerland tsinghua National Laboratory for Information Science and Technology Beijing China Institute of Theoretical physics Chinese Academy of Sciences Beijing China

We suggest a scheme to probe critical phenomena at a quantum phase transition (QPT) using the quantum correlation of two photonic modes simultaneously coupled to a critical system. As an experimentally accessible physical implementation,a circuit QED system is formed by a capacitively coupled Josephson junction qubit array interacting with one superconducting transmission line resonator (TLR). It realizes an Ising chain in the transverse field (ICTF) which interacts with the two magnetic modes propagating in the TLR. We demonstrate that in the vicinity of criticality the originally independent fields tend to display photon bunching effects due to their interaction with the ICTF. Thus,the occurrence of the QPT is reflected by the quantum characteristics of the photonic fields.

关键词： quantum phase transition photon bunching circuit QED

Research on dual-stator winding multi-phase high-speed induction generator with rectifier load

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Science china(Technological Sciences) 2008年第6期51卷 683-692页

作者： WANG XiangHeng1 & WU XinZhen2 1 department of Electrical Engineering, tsinghua university, beijing 100084, china 2 department of Electrical Engineering, Qingdao university, Qingdao 266071, china department of Electrical Engineering Tsinghua University Beijing China department of Electrical Engineering Qingdao University Qingdao China

Based on analysis and calculation of the relation between current harmonics and MMF harmonics in the dual-stator winding multi-phase high-speed induction gen-erator with a rectifier load, a new idea, which divides the generator system into two sub-systems to be analyzed individually, is presented. For the sub-system of the 12-phase power winding with a rectifier load, the loop current method is used to establish network equation set in terms of the network graph theory. The numerical stability problem is solved by alternating use of fixed time-step and varied time-step, and the voltage and current with their fundamental components of the power winding are obtained. For the other sub-system of the induction generator with dual-stator winding and solid cage rotor, the electromagnetic field analysis method and the multi-variable optimization approach are combined to get the con-trol winding current and stator frequency. Calculated results well match experiment results, indicating that the new proposed method is of effectiveness and high ac-curacy.

关键词： dual-stator winding induction generator rectifier load MMF analysis loop current method finite element method optimization approach

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

RECOVERY OF CADMIUM AND NICKEL FROM SCRAP Ni-Cd BATTERIES

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Acta Metallurgica Sinica(English Letters) 2001年第4期14卷 303-312页

作者： J.X. Zhu1), B. yu2), J.H. li1) and Y.F. Nie1) 1) department of Environmental Engineering, tsinghua university, beijing 100084, china 2) Institute of Nuclear Energy Technology, tsinghua university, beijing 100084, china Dept. of Environ. Eng. Tsinghua Univ. Beijing 100084 China

Several typical methods for the recovery of Ni-Cd batteries are described in detail. Based on the comparison between the hydrometallurgical process and the pyrometallurgical process, the latter is selected as the suit... 详细信息

关键词： Cadmium Nickel Recovery Scrap metal