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Level Set interface treatment and its application in Euler method

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science China(Physics,Mechanics & Astronomy) 2010年第2期53卷 227-236页

作者： WU KaiTeng1,2.HAO Li3,WANG Cheng4 & ZHANG Li1,2.1 Numerical Simulation Sichuan Higher School Key laboratory,Neijiang Normal University,Neijiang 641112.China 2.College of Mathematics and information {2.,Neijiang Normal University,Neijiang 641112.China 3 College of {2.,beijing University of Civil Engineering and Architecture,beijing 100044,China 4 State Key laboratory of Explosion {2. and technology,beijing Institute of technology,beijing 100081,China Numerical Simulation Sichuan Higher School Key laboratory Neijiang Normal University Neijiang China College of Mathematics and information science Neijiang Normal University Neijiang China College of science Beijing University of Civil Engineering and Architecture Beijing China State Key laboratory of Explosion science and {2. Beijing Institute of Technology Beijing China

Level Set interface treatment method is introduced into Euler method,which is employed for interface treatment method for multi-materials. Combined with the ghost fluid method,the moving interface is tracked. Fifth-order WENO spatial discretization and third-order TVD Runge-Kutta time discretization methods are used. Shock-wave action on bubble,implosion and velocity field Shock effect bubbles; implosion and velocity field are simulated by means of LS-MMIC3D programmed by C++. Nu-merical results show that the Level Set interface treatment method is effective and feasible for multi-material interface treatment in comparison with the WENO method.

关键词： Euler method Level Set method shock-wave action on bubble implosion numerical simulation

A three-dimensional variational ocean data assimilation system:Scheme and preliminary results

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science China Earth sciences 2006年第11期49卷 1212-1222页

作者： ZHU Jiang1,2. ZHOU Guangqing1, YAN Changxiang1, FU Weiwei1 & YOU Xiaobao1,3 1. International Center for Climate and Environment sciences, Institute of Atmospheric Physics, Chinese Academy of sciences, beijing 10002., China 2. Jiangsu Key laboratory of Meteorological Disaster, Nanjing University of information science and technology, Nanjing 2.0044, China 3. beijing Institute of Applied Meteorology, beijing 10002., China International Center for Climate and Environment sciences Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Jiangsu Key laboratory of Meteorological Disaster Nanjing University of Information Science and Technology Nanjing China beijing Institute of Applied Meteorology Beijing China

A new 3DVAR-based Ocean Variational Analysis System (OVALS) is developed. OVALS is capable of assimilating in situ sea water temperature and salinity observations and satellite altimetry data. As a component of OVALS, a new variational scheme is proposed to assimilate the sea surface height data. This scheme considers both the vertical correlation of background errors and the nonlinear temperature-salinity relationship which is derived from the generalization of the linear balance constraints to the nonlinear in the 3DVAR. By this scheme, the model temperature and salinity fields are directly adjusted from the altimetry data. Additionally, OVALS can assimilate the temperature and salinity profiles from the ARGO floats which have been implemented in recent years and some temperature and salinity data such as from expendable bathythermograph, moored ocean buoys, etc. A 2.-year assimilation experiment is carried out by using OVALS and the Tropical Pacific circulation model. The results show that the assimilation system may effectively improve the estimations of temperature and salinity by assimilating all kinds of observations. Moreover, the root mean square errors of temperature and salinity in the upper depth less than 42. m reach 0.63℃ and 0.34 psu.

关键词： data assimilation, 3DVAR, sea surface height, ARGO floats.

Timeliness evaluation of task-oriented networked space-based information system

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Journal of Systems Engineering and Electronics 2011年第4期22卷 621-627页

作者： Chen Chen 1,2.and Jie Chen 2.3 1.Department of Automation,tsinghua University,beijing {2.,P.R.China 2.School of Automation,beijing Institute of technology,beijing 100081,P.R.China 3.Complex System Intelligent Control and Decision,Ministry of Education,beijing 100081,P.R.China Department of Automation Tsinghua University Beijing 100084 P. R. China School of Automation Beijing Institute of Technology Beijing 100081 P. R. China School of Automation Beijing Institute of Technology Beijing 100081 P. R. China Complex System Intelligent Control and Decision Ministry of Education Beijing 100081 P. R. China

Task-oriented networked information system is an integrated information system which builds on multi-satellite networking to accomplish one or more tasks. In the background of emer- gency relief for applications, system working flow and response process are analyzed, and a timeliness effectiveness evaluation index system is constructed at multi-task level. The effectiveness is a measurement of promptness of information return. In evalua- tion process, system performance and tasks are associated, then an evaluation model based on efficacy function is established, and different evaluation criteria are selected for different tasks. A distributed simulation system is constructed, and the execution of task is decomposed. The simulation platform provides a comprehensive data source for evaluation. The results are easy to compare with each other, which reflects system time efficiency in different satellites networks and provides actual systems with basis and reference for design and application.

关键词： timeliness efficacy function space-based informationsystem simulation system.

The optimization of DNA encodings based on GA/SA algorithms

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Progress in Natural science:Materials International 2007年第6期17卷 739-744页

作者： Wang Wei1, Zheng Xuedong2. Zhang Qiang1 and Xu Jin2.1. Liaoning Key laboratory of Intelligent information Processing, Dalian University, Dalian 11662., China 2. Department of Control {2. and Engineering, Huazhong University of {2. and technology, Wuhan 430074, China) Liaoning Key laboratory of Intelligent information Processing Dalian University Dalian 116622 China Department of Control science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

The design of DNA sequence plays an important role in improving the reliability of DNA computation. Proper constrained terms that DNA sequence should satisfy are selected, and then the evaluation formulas of each DNA individual corresponding to the selected constrained terms are proposed. The heuristic improved genetic algorithm (GA)/simulated annealing (SA) algorithm is presented to solve the multi-objective optimize problem, and the DNA sequence design system is developed. Furthermore, an example is illustrated to show the efficiency of our method given here.

关键词： DNA encoding multi-objective optimize GA/SA algorithms

Detection and formation mechanism of micro-defects in ultrafine pitch Cu-Cu direct bonding

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Chinese Physics B 2016年第1期25卷 802-808页

作者：刘子玉蔡坚王谦陈瑜 Institute of Microelectronics Tsinghua UniversityBeijing 100084China tsinghua national {2. for information science and technology Beijing 100084China

In this paper, Cu-Cu interconnects with ultrafine pad pitches of 6 p.m, 8 p.m, and 15 p.m are implemented on the 12.inch wafers by a direct bonding process. Defects are not found by traditional non-destructive （NDT） c-mode scanning acoustic microscopy （c-SAM）. However, cross sectional observation of bonding interfaces reveals that micro-defects such as micro seams are located at SiO2.bonding interfaces. In order to examine the micro-defects in the ultra-fine pitch direct bonding process by the NDT technology, a novel ＂defect-enlarged approach＂ is proposed. The bonded dies are first annealed in an N2.oven at 300 ℃ for a few hours and then cooled quickly in air. The c-SAM scanning images show large defects at the place where nothing can be detected by c-SAM before this treatment. Cross sectional observation of the bonding interfaces indicates that these defects consist of large size micro seams at the SiO2.bonding interface, especially near Cu pads with an ultrafine pitch of 6μm. However, these large defects disappear after several hours at room temperature, observed by c-SAM. It is inferred that the disappearance of these defects inspected by the ＂defect-enlarged approach＂ results from the combination of intrinsic micro seams and ＂weak＂ bonds in the silicon oxide layer. Then the underlying physical mechanism of these micro-defects is proposed, which is influenced by Cu pad surface topology and bonding models.

关键词： nondestructive testing of materials microscopy acoustical surface and interface

Study on NDVI-T_s space by combining LAI and evapotranspiration

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science China Earth sciences 2006年第7期49卷 747-754页

作者： HAN Lijuan1,2.3, WANG Pengxin4, YANG Hua1,2.3, LIU Shaomin1,2.3 & WANG Jindi1,2.3 1. Research Center for Remote Sensing and GIS, School of Geography, beijing Normal University, beijing 100875, China 2. State Key {2. of Remote Sensing science, beijing 100875, China 3. beijing Key {2. for Remote Sensing of Environment and Digital Cities, beijing 100875, China 4. Department of information Management, College of information and Electronic Engineering, China Agricultural University, beijing 100083, China Research Center for Remote Sensing and GIS School of Geography Beijing Normal University Beijing China State Key laboratory of Remote Sensing science Beijing China beijing Key laboratory for Remote Sensing of Environment and Digital Cities Beijing China Department of information Management College of Information and Electronic Engineering China Agricultural University Beijing China

This paper focuses on interpreting the different spatial relationships between NDVI and Ts, a triangular or a trapezoid, and on analyzing transformation conditions, the physical and ecological meanings of the vegetation index-surface temperature space as well. Further, we use the Tempera-ture-Vegetation Dryness Index (TVDI) to explain the existent meaning of a triangular space after NDVI reaches its saturated state by employing the relationships between NDVI, LAI and evapotranspiration. The specific relations between NDVI and Ts are useful for describing, validating and updating land surface models.

关键词： NDVI, land surface temperature, evapotranspiration, leave area index.

Large-scale P2.VOD system:Focusing on clients

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science China(information sciences) 2011年第8期54卷 1677-1690页

作者： HUANG Yan 1,XU Ke 2.LI HaiTao 2., CAO Yang 1 & YAO Xin 1 1 Shanghai SynaCast Media Tech Co.,Ltd,Shanghai 2.12.4,China 2.Department of Computer science & technology,{2. University,beijing 100084,China Shanghai SynaCast Media Tech Co. Ltd Shanghai China Department of Computer science & technology Tsinghua University Beijing China

Using P2. network to provide video on demand (VOD) service can support large-scale users so as to save the bandwidth cost of *** VOD must support VCR characters (drag,pause,randomly choosing watching position,etc.),building a large-scale expansion of high-performance VOD system still faces huge *** paper first presents a P2. based reference model,defines the design object,and analyzes the *** then taking PPLive demand system as an example,it gives client-based solutions,including disk cache-out strategy,memory cache prefetch strategy,maintaining relations between neighbors,task scheduling,data upload strategies and so ***-demand systems are putting into practice at present with satisfactory fluency and drag *** largest number of simultaneous online users is over 2.0000,and online video data is over 700. Compared with traditional client-server model,the average bandwidth saving rate of servers is 88% or more,and the bandwidth saving rate of user-number's the peak value can be up to 93%.

关键词： P2. VOD server bandwidth saving rate fluency drag delay

Response synchronization: New progress in brain-visual information processing

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Chinese science Bulletin 1999年第16期44卷 1447-1458页

作者： ZHAO Songnian, XIONG Xiaoyun, YAO Guozheng and GUO Aike1. State Key laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry , Institute of Atmospheric Physics , Chinese Academy of sciences , {2. 10002., China 2. Commission of the national Natural science Foundation of China , {2. 100083, China 3. The Center of information science , Peking University, {2. 100871, China 4. Open laboratory of Visual information Processing , Institute of Biophysics , Chinese Academy of sciences , {2. 100101, China State Key laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Commission of the national Natural science Foundation of China Beijing China The Center of information science Peking University Beijing China Open laboratory of Visual information Processing Institute of Biophysics Chinese Academy of Sciences Beijing China

Studies on brain-vision have entered a new stage, after the stimulus-induced y synchronized oscillation of neuron group activities have been discovered in cat primary visual cortex. Naturally, how to understand the visual system became a very important methodological problem. From aspects such as information processing, nonlinear dynamics and neuronal network, some primary problems in vision studies have been deeply discussed, which are

关键词： neuron group (neural population) synchro-oscillation computational theory of vision response synchroniza-tion.

Quantum threshold group signature

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science China(Physics,Mechanics & Astronomy) 2008年第10期51卷 1505-1514页

作者： YANG YuGuang1,2.3 & WEN QiaoYan4 1 College of Computer science and technology, {2. University of technology, {2. 10012., China 2.State Key laboratory of Integrated Services Network, Xidian University, Xi’an 710071, China 3 State Key laboratory of information Security (Graduate University of Chinese Academy of sciences), {2. 100049, China 4 State Key laboratory of Networking and Switching technology, {2. University of Posts and Tele-communications, {2. 100876, China College of Computer science and technology Beijing University of Technology Beijing China State Key laboratory of Integrated Services Network Xidian University Xi’an China State Key laboratory of information Security Graduate University of Chinese Academy of Sciences Beijing China State Key laboratory of Networking and Switching technology Beijing University of Posts and Telecommunications Beijing China

In most situations, the signer is generally a single person. However, when the message is written on behalf of an organization, a valid message may require the approval or consent of several persons. Threshold signature is a solution to this problem. Generally speaking, as an authority which can be trusted by all members does not exist, a threshold signature scheme without a trusted party appears more attractive. Following some ideas of the classical Shamir’s threshold signature scheme, a quantum threshold group signature one is proposed. In the proposed scheme, only t or more of n persons in the group can generate the group signature and any t-1 or fewer ones cannot do that. In the verification phase, any t or more of n signature receivers can verify the message and any t-1 or fewer receivers cannot verify the validity of the signature.

关键词： threshold quantum signature trusted party quantum cryptography