检索结果-内蒙古大学图书馆

Effective usage of credit records promotes cooperation on weighted networks

Physical Review E 2010年第3期81卷 036112-036112页

作者： Chao Zhai Hai-Tao Zhang Yang Zhao Michael Z. Q. Chen Zhi-Hai Rong Bing-Hong Wang Key Laboratory of Image Processing and Intelligent Control Department of Control Science & Engineering Huazhong University of Science and Technology Wuhan 430074 People’s Republic of China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology Wuhan 430074 People’s Republic of China Department of Modern Physics University of Science and Technology of China Hefei 230026 People’s Republic of China School of Automation Nanjing University of Science and Technology Nanjing 210094 People’s Republic of China Department of Mechanical Engineering The University of Hong Kong Pok Fu Lam Road Hong Kong Department of Automation Donghua University Shanghai 200051 People’s Republic of China

The cooperative behaviors of players on weighted networks are investigated by incorporation of trust mechanisms into a well-accepted game model, i.e., the networked prisoner’s dilemma game, afterwards some weight-updating schemes are designed according to the credit records. Despite the differences in network topologies and strategy updating protocols, a simple yet significant principle surfaces that, to promote the emergence of cooperation over abundant weighted networks, only the latest credit record of partners is required to be taken into consideration, whereas incorporating more previous records may even deteriorate the cooperation performance. To support such an appealing principle, we have investigated more deeply into the role of credit records so as to give a detailed explanation underlying it. The virtue of this work lies in providing insights into the effective usage of the currently available credit records.

关键词： Network topology

来源：评论

学校读者我要写书评

暂无评论

Effects of BN and SiC nanoparticles on properties of conductive adhesive

Effects of BN and SiC nanoparticles on properties of conduct...

引用

2010 11th International Conference on Electronic Packaging technology and High Density Packaging, ICEPT-HDP 2010

作者： Lai, Huaxiang Lu, Xiuzhen Cui, Huiwang Liu, Xiaohua Chen, Si Chen, Tianan Liu, Johan Key State Laboratory of New Displays and System Applications and SMIT Center School of Automation and Mechanical Engineering Shanghai University 149 Yanchang Rd. Shanghai 200072 China SMIT Ltd. Co. No 101 of New Science and Technology Building No 149 Yan Chang Road Shanghai 200072 China SMIT Center and Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology SE-412 96 Gothenburg Sweden SHT Smart High-Tech AB Fysikgränd 3 Se 412 96 Göteborg Sweden

ISBN: (纸本)9781424481422

Isotropic conductive adhesives (ICAs) are a type of interconnect material used more and more widely in computer, robot, mobile phone, LED and so on. Compared with traditional solders, isotropic conductive adhesives have better working plasticity, creep resistance and heat resistance. In particular, isotropic conductive adhesives are more responsive in high density packaging than solder, which determines the dominance of ICAs in high density packaging in the future. In order to improve the thermal conductivity of ICA with acceptable electrical conductivity, Ag flakers, BN and SiC nanoparticles were added into the matrix. The content of silver flakes was 75wt%, and the content of nanoparticles (BN or SiC) in the isotropic conductive adhesives were 0wt%, 0.5wt%, 1.5wt%, 2.5wt%, 3wt%, 5wt% in weight. The conductive adhesives were coated on the PCBs with stencil printing and fifty SR1206 chip components were mounted on a PCB using conductive adhesive. All samples were cured at 150°for 1h. Further research into the reliability of the above isotropic conductive adhesives after temperature & humidity and thermal-cycling was carried out to analyze the effects of BN and SiC nanoparticals on the properties of ICA. The condition of the temperature & humidity test was 85 ° /85%RH, 500h. The thermal-cycling test was -40 °∼125°, 500 cycles and the soaking time and ramping rate were 19min and ±15°/min. Changes to electrical resistance were used to estimate the reliability of the isotropic conductive adhesives in this study. The microstructure of the failure samples was observed using a Scanning Electron Microscope (SEM). The water absorption of all ICAs is the same after 94h temperature and humidity aging and the rate of water absorption is also the same during the aging. The ICA with 3% boron nitride nanoparticles and 75% micron silver flakes shows the best temperature and humidity reliability, with the fewest cracks on the interface between ICA and component. After 500h thermal c

关键词： III-V semiconductors

来源：评论

学校读者我要写书评

暂无评论

Grasping simulation of an underactuated finger mechanism for larm hand

引用

International Journal of Modelling and Simulation 2010年第1期30卷 87-97页

作者： Yao, S. Wu, L. Ceccarelli, M. Carbone, G. Lu, Z. School of Automation Science and Electrical Engineering Beihang University Beijing China College of Information Engineering Central University for Nationalities Beijing China State Key Laboratory of Intelligent Technology and Systems Department of Computer Science and Technology Tsinghua University Beijing China Beijing University of Aeronautics and Astronautics China and University of Cassino Italy LARM: Laboratory of Robotics and Mechatronics Cassino United States

In this paper, the grasp operation of an underactuated finger mechanism is simulated with the aim to characterize and analyze its performance. The design of the proposed mechanism is based on spring systems that give suitable underactuation characteristics. A CAD model is proposed and then it is used in a procedure for numerical simulation. Simulation results show suitable capability for grasping a wide range of objects in size and shape by operating the mechanism inside the finger body. The achieved grasp has been simulated as a human-like functionality with a grasp contact in each phalanx.

关键词： Computer aided design

来源：评论

学校读者我要写书评

暂无评论

Reliability study for high temperature stable conductive adhesives

Reliability study for high temperature stable conductive adh...

引用

2010 International Symposium on Advanced Packaging Materials: Microtech, APM '10

作者： Tao, Wenkai Chen, Si Berggren, Pär Liu, Johan Key State Laboratory of New Displays and System Applications and SMIT Center School of Automation and Mechanical Engineering Shanghai University 149 Yanchang Rd. Shanghai 200072 China SMIT Ltd. Co. No 101 of New Science and Technology Building Science Park No 149 Yan Chang Road Shanghai 200072 China SHT Smart High Tech AB Nordgårdsvägen 19 Se 428 34 Kållered Sweden SMIT Center and Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology SE-412 96 Gothenburg Sweden

ISBN: (纸本)9781424467563

With fast development of electronic packaging, the conductive adhesives were widely used in surface mount and chip interconnection. As an alternative to solder, it has many advantages, such as low processing temperature, less environment contamination and fine pitch capability. However, conductive adhesive joining technology also simultaneously faces a lot of challenges. The major problem of current conductive adhesives is easy to degrade during temperature and humidity aging. Therefore a high temperature stable matrix was developed for conductive adhesive fabrication. Based on this matrix, a kind of isotropic conductive adhesive (ICA) was fabricated in this work. The curing behavior of ICA was investigated by Differential Scanning Calorimeter (DSC). The properties such as glass transition temperature (Tg), storage modulus were detected by Dynamic Mechanical Analyzer (DMA). Thermogravimetric Analysis (TGA) was used to determine the decomposition behavior. The humidity test was subsequently carried out to evaluate moisture resistance of ICA. The electrical resistances of the ICA samples were measured by the multimeter. During humidity test, no obvious change of electrical resistance of ICA samples was observed. ©2010 IEEE.

关键词： Thermogravimetric analysis

来源：评论

学校读者我要写书评

暂无评论

Reliability study for high temperature stable conductive adhesives

Reliability study for high temperature stable conductive adh...

引用

International Symposium on Advanced Packaging Materials

作者： Wenkai Tao Si Chen Pär Berggren Johan Liu Key State Laboratory of New Displays and System Applications and SMIT Center School of Automation and Mechanical Engineering Shanghai University Shanghai China SHT Smart High Tech AB Kallered Sweden SMIT Center & Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Gothenburg Sweden

关键词： Temperature Conductive adhesives Independent component analysis Humidity Electric resistance Testing Electronics packaging Surface contamination Degradation Aging

来源：评论

学校读者我要写书评

暂无评论

Dynamic Niching Genetic Algorithm with Data Attraction for Automatic Clustering

引用

Tsinghua Science and technology 2009年第6期14卷 718-724页

作者：常冬霞张贤达 State Key Laboratory on Intelligent Technology and Systems Tsinghua National Laboratory for Information Science and TechnologyDepartment of AutomationTsinghua University

A genetic clustering algorithm was developed based on dynamic niching with data attraction. The algorithm uses the concept of Coulomb attraction to model the attraction between data points. Then, the niches with data attraction are dynamically identified in each generation to automatically evolve the optimal number of clusters as well as the cluster centers of the data set without using cluster validity functions or a variance-covariance matrix. Therefore, this clustering scheme does not need to pre-specify the number of clusters as in existing methods. Several data sets with widely varying characteristics are used to demonstrate the superiority of this algorithm. Experimental results show that the performance of this clustering algorithm is high, effective, and flexible.

关键词： clustering evolutionary computation genetic algorithms data attraction fitness sharing

来源：评论

学校读者我要写书评

暂无评论

A novel isotropic conductive adhesive with Ag flakes, BN and SiC nanoparticles

A novel isotropic conductive adhesive with Ag flakes, BN and...

引用

2010 International Symposium on Advanced Packaging Materials: Microtech, APM '10

作者： Lai, Huaxiang Lu, Xiuzhen Chen, Si Fu, Chune Liu, Johan Key State Laboratory of New Displays and System Applications School of Automation and Mechanical Engineering Shanghai University 149 Yanchang Rd. Shanghai 200072 China SMIT Ltd. Co. No. 101 of New Science and Technology Building Science Park No 149 Van Chang Road Shanghai 200072 China SHT Smart High Tech. AB Nordgårdsvägen 19 Se 428 34 Kållered Sweden SMIT Center Department of Microtechnology and Nanoscience Chalmers University of Technology SE-412 96 Gothenburg Sweden

ISBN: (纸本)9781424467563

Isotropic conductive adhesives (ICAs) with lower bonding temperature, higher resolution and environmental friendly have been used extensively in packaging process. In order to improve the electrical and thermal conductive properties of ICAs, two kinds of bimodal high temperature stable ICAs with matrix SHT6 and fillers with composition of macro silver flakes and boron nitride nanoparticles or macro silver flakes and silicon carbide nanoparticles were studied. In these two kinds of adhesives, the silver flakes were 75wt%, and the contents of nanoparticles were Owt%, 0.5wt%, 1.5wt%, 2.5wt%, 3wt%, 5wt% in weight. All the samples were cured at 150°C for 1 hour. SEM images and EDS results show the nanoparticles disperse randomly in the ICA. The electrical resistivity of these ICAs depends on the contents of silver flakes and is hardly affected by BN nanoparticles and SiC nanoparticles. The thermal conductivity of these ICAs increases firstly with the weight increase of the BN nanoparticles and SiC nanoparticles. And then it decreases when the content of the nanoparticles beyond a certain point. ©2010 IEEE.

关键词： Nanoparticles

来源：评论

学校读者我要写书评

暂无评论

Optimization of stiffness for isotropic conductive adhesives

Optimization of stiffness for isotropic conductive adhesives

引用

2010 International Symposium on Advanced Packaging Materials: Microtech, APM '10

作者： Fu, Chune Chen, Si Berggren, Pär Fan, Qiong Du, Wenhui Ganesh, Balan Liu, Johan Key State Laboratory of New Displays and System Applications School of Automation and Mechanical Engineering Shanghai University 149 Yanchang Rd. Shanghai 200072 China SMIT Ltd. Co. No 101 of New Science and Technology Building Science Park No 149 Yan Chang Road Shanghai 200072 China SHT Smart High Tech. AB Nordgårdsvägen 19 Se 428 34 Kållered Sweden SMIT Center Department of Microtechnology and Nanoscience Chalmers University of Technology SE-412 96 Gothenburg Sweden

ISBN: (纸本)9781424467563

With the rapid developments of electronic packaging, there is an increasing demand on high performance isotropic conductive adhesives (ICAs). However, the traditional ICAs are brittle, sensitive for crack formation and delamination, which is one of the major drawbacks that limits their use in a wide range of applications. Therefore great efforts have been made to make conductive adhesives more flexible. The present work aims at studying of several chemicals in terms of flexibilizing materials to modify the stiffuess modulus of the conductive adhesives. The effect of the flexibilizers has been characterized by different methods, such as Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), Thermogravimetric Analysis (TGA), etc. Moreover, the electrical resistance, thermal conductivity and viscosity are also measured in various conditions. Experimental results indicate that one of the flexibilizing materials using flexible ester-linkage is particular of interest as it offers low electrical resistance, high thermal performance and low modulus without decreasing glass transition temperature (Tg) and influencing curing and decomposition conditions. ©2010 IEEE.

关键词： Stiffness

来源：评论

学校读者我要写书评

暂无评论

Blind Carrier Frequency Offset Estimation via Power Spectrum Analysis in MIMO OFDM systems

引用

Tsinghua Science and technology 2009年第1期14卷 146-150页

作者：武露张贤达 State Key Laboratory on Intelligent Technology and Systems Tsinghua National Laboratory for Information Science and Technology (TNList) Department of Automation Tsinghua University

As a generalization of orthogonal frequency-division multiplexing （OFDM） systems, multi-input multi-output （MIMO） OFDM systems are very sensitive to carrier frequency offset （CFO）. This paper proposes a blind CFO estimation method based on power spectrum analysis, which has high bandwidth efficiency and is much less complex. This method can be used to estimate the residual CFO, which is less than half of the subcarrier spacing. The method uses a cosine cost function to get a closed-form CFO estimate. Simulation results illustrate that the method is effective for MIMO OFDM systems.

关键词： carrier frequency offset （CFO） multi-input multi-output orthogonal frequency-division multiplexing （MIMO OFDM） power spectrum analysis （PSA）

来源：评论

学校读者我要写书评

暂无评论

Optimization of stiffness for isotropic conductive adhesives

Optimization of stiffness for isotropic conductive adhesives

引用

International Symposium on Advanced Packaging Materials

作者： Chune Fu Si Chen Pär Berggren Qiong Fan Wenhui Du Balan Ganesh Johan Liu Key State Laboratory of New Displays and System Applications and SMIT Center School of Automation and Mechanical Engineering Shanghai University Shanghai China SMIT Limited Company Shanghai China SHT Smart High Tech AB Kallered Sweden SMIT Center & Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Gothenburg Sweden

With the rapid developments of electronic packaging, there is an increasing demand on high performance isotropic conductive adhesives (ICAs). However, the traditional ICAs are brittle, sensitive for crack formation and delamination, which is one of the major drawbacks that limits their use in a wide range of applications. Therefore great efforts have been made to make conductive adhesives more flexible. The present work aims at studying of several chemicals in terms of flexibilizing materials to modify the stiffness modulus of the conductive adhesives. The effect of the flexibilizers has been characterized by different methods, such as Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), Thermogravimetric Analysis (TGA), etc. Moreover, the electrical resistance, thermal conductivity and viscosity are also measured in various conditions. Experimental results indicate that one of the flexibilizing materials using flexible ester-linkage is particular of interest as it offers low electrical resistance, high thermal performance and low modulus without decreasing glass transition temperature (Tg) and influencing curing and decomposition conditions.

关键词： Conductive adhesives Independent component analysis Conducting materials Electric resistance Thermal conductivity Thermal resistance Electronics packaging Delamination Chemicals Calorimetry

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：