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[转载]sign
haixia 2011-5-13 00:29
SIGN Signum function. For each element of X, SIGN(X) returns 1 if the element is greater than zero, 0 if it equals zero and -1 if it is less than zero.For the nonzero elements of complex X, SIGN(X) = X ./ ABS(X). 
1074 次阅读|0 个评论
[转载]开源复杂网络分析与可视化Cytoscape
yizhenzhong 2011-5-8 11:52
Cytoscape is an open source bioinformatics software platform for visualizing molecular interaction networks and biological pathways and integrating these networks with annotations, gene expression profiles and other state data. Although Cytoscape was originally designed for biological research, now it is a general platform for complex network analysis and visualization. Cytoscape core distribution provides a basic set of features for data integration and visualization. Additional features are available as plugins . Plugins are available for network and molecular profiling analyses, new layouts, additional file format support, scripting, and connection with databases. Plugins may be developed by anyone using the Cytoscape open API based on Java™ technology and plugin community development is encouraged. Most of the plugins are freely available . 信息来自:http://www.cytoscape.org/
个人分类: 研究微博|3812 次阅读|0 个评论
[转载]2011 International Symposium on Complex Networks and Systems
bhwangustc 2011-4-17 16:20
[转载]2011 International Symposium on Complex Networks and Systems
ISCNS 2011 nApril 23-24 Nanjing · Home · Organizing Committee · Invited Speakers · Program Schedule · Registration · Location and Sightseeing · Sponsors · Contact The 2011 International Symposium on Complex Networks and Systems (ISCNS'11) will be held on April 23-24 2011 in Nanjing, China, officially organized by the Department of Mathematics , Southeast University , China. The ISCNS'11 focuses on complex systems and networks, multi-agent systems, nonlinear dynamics and control, systems biology, sensor networks, communication networks, networked control systems, and their applications. The symposium will be sponsored by the Department of Mathematics , Southeast University , China. Latest News Due the limit budget, we cannot afford your travel fees in this workshop. What we can afford are the following: 1. your living cost (including 2 buffet lunch 自助餐 +1 banquet) 2. your accommodation fees in the reserved hotel 3. tour fee in Zhongshan Ling (中山陵) on 25 April after the workshop Please send me the filled accommodation form with some detailed information by 11 April so that we can reserve the accommodation for you. Program Schedule 23-24 April, 2011: Two-day Workshop Registration Apr. 22, 2011 ( Friday ) 9:00-21:00 Registration : Nanjing Shijiyuan Hotel (jinxianghe road 20) 南京世纪缘大酒店 ( 进香河路 20 号 ) 东南大学四牌楼校区 西门向南大约 800 米 Apr. 23, 2011 ( Saturday ) 9:00-17:40 Registration : Chunhui Hall ( 东南大学四牌楼校区春晖堂 ) 南京市四牌楼 2 号东南大学 Apr. 23, 2011(Saturday) Chunhui Hall(春晖堂) 09:00-09:30 OpenCeremony Session1 Chair:JindeCao 09:30- 10:20 Guanrong Chen LaplacianSpectra ofComplexNetworks andTheirEffects onSynchronization Performances 10:20- 10:40 TeaBreak 10:40- 11:30 Yusheng Xue TBD 12:00- 14:00 Lunch Session2 Chair:JinqingFang 14:00-14:50 Xiaofan Wang SocialLearningin ComplexNetworks 14:50-15:40 Binghong Wang TransportationDynamics onMobileNodeNetwork 15:40-16:00 TeaBreak 16:00-16:50 Jinqing Fang AFrameworkof Non-Equilibriumand EquilibriumStatistical EnsembleFormalism forComplexQuantumSystems 16:50-17:40 Fuchun Sun UniversalApproximationand ControlofMulti-Time-Scale DynamicalSystems 18:00 Banquet Apr.24,2011(Sunday) ChunhuiHall( 春晖堂 ) Session3 Chair:YuanqingXia 09:00-09:50 Jun-an Lu Synchronization-based ScalabilityofRingsand ChainsofDenseLumps 09:50-10:10 TeaBreak 10:10-11:00 Zhihong Guan ImpulsiveAlgorithms forConsensusof Multi-agentSystems 11:00-11:50 Yuanqing Xia AnalysisandSynthesisof NetworkedControlSystems 12:00- 14:00 Lunch Session4 Chair:WenwuYu 14:00-14:50 Zhisheng Duan Synchronizationof ComplexNetworksand ConsensusofMulti-AgentSystems: AUnifiedViewpoint 14:50-15:40 Daniel Ho APinningSchemeand AggregationApproach toComplexNetworks 15:40-16:00 TeaBreak 16:00-16:50 Guangming Xie ControlTheory forSmartSwarms 16:50-17:40 Wei Ren DistributedControl ofNetworkedMulti-agent Systems:Algorithms andApplications 17:40-18:00 ConclusionRemarks Apr. 25, 2011(Monday) Tourism in Zhongshan Ling(中山陵) All Rights Reserved 2011 - By ISCNS'2011
个人分类: 会议信息|2890 次阅读|0 个评论
[转载]Photos of KITPC 2011-March Program (Part B)
bhwangustc 2011-4-11 18:15
[转载]Photos of KITPC 2011-March Program (Part B)
March 25 KITPC Reception Dinner Photos taken by Prof.Jing Zhao (Department of Mathematics, Logistical Engineering University, Congqing) 03-25 KITPC reception-1 03-25 KITPC reception-2 03-25 KITPC reception-3 03-25 KITPC reception-4 03-25 KITPC reception-6
个人分类: 会议信息|2752 次阅读|0 个评论
The 5-th Week Schedule of KITPC 2011 March Program
bhwangustc 2011-3-25 17:26
The 5-th Week Schedule Program Schedule "Recent Progresses in Complex Networks Research" The Fifth Week (Mar 28-April 1) ====================================== Mar 28 Monday 10:00-11:30 Chairperson : Bing-Hong Wang B. Kahng ( Seoul National University ) : Explosive percolation transition of complex networks Lunch Break 15 : 00-16:00 Chairperson : Tao Zhou Wei Li (Max-Planck-Institute for Mathematics in the Sciences): Statistical Learning in an evolutionary game Mar 29 Tue 10:00-11:30 Chairperson : Bing-Hong Wang Hawoong Jeong (Korea Advanced Institute of Science and Technology) : S tructure and dynamics of the directed complex networks Mar 30 Wed 10:00-11:30 Chairperson : Bing-Hong Wang Zhou, Changsong ( Hong Kong Baptist University ) : Sustained activity in hierarchical modular neural networks: self-organized criticality and oscillations Mar 31 Thursday 10:00-11:30 Chairperson : Bing-Hong Wang David Saad ( The Non-linearity and ComplexityResearch Group, Aston University , UK ) Dynamics of Boolean networks - a Generating Functional Analysis Lunch Break 15 : 00-16:00 Chairperson : Tao Zhou You-Gui Wang ( Beijing Normal University): Self-Organized Criticality in Market Economies April 1 Friday 10:00-11:30 Chairperson : Bing-Hong Wang Tao Zhou (University of Electronic Science and Technology of China) : 1, Link prediction in complex networks; 2, Information extracting from networks: ranking and recommending; Lunch Break 15:00-17:00 Chairperson : Tao Zhou Discussion about recent progresses and future directions in complex networks research : All the participants: Chin-Kun Hu , B.Kahng , Beom Jun Kim, Bin Jiang , Renaud Lambiotte , Jing Zhao , Hyunggyu Park, Hawoong Jeong, Sumiyoshi Abe, Jae Dong Noh, David Saad , Changsong Zhou, Chenping Zhu, Wei Li, Zi-Ke Zhang, Lin-Yuan Lv , Mingsheng Shang, Tao Zhou , Bing-Hong Wang
个人分类: 会议信息|3462 次阅读|0 个评论
The Fourth Week Schedule of KITPC 2011 March Program
bhwangustc 2011-3-16 20:12
The Fourth Week Schedule Interdisciplinary Applications of Statistical Physics Complex Networks (KITPC/ITP-CAS, Feb 28 - Apr 1, 2011) Week 4, Mar 21 – Mar 25, 2011 Monday 21 / 3 /201 1 Room: 6620 Chairperson: Bing-Hong Wang 10:00-11:00 Chin-Kun Hu ( Institute of Physics, Academia Sinica , Taipei ) Some recent results for complex networks of nonlinear and biological systems' 11:00-11:30 Discussion Lunch Break Room: 6620 Chairperson: Tao Zhou 15:00-16:00 Bin Jiang (University of G?vle, Dept of Technology and Built Environment, Sweden) Scaling of geographic space with data-intensive geospatial computing. 16:00-16:20 Break 16:20-17:00 Jing Zhao (Department of Mathematics, Logistical Engineering University) Network based TCM pharmacology Tuesday 22 / 3 /201 1 Room: 6620 Chairperson: Bing-Hong Wang 10:00-11:00 Sumiyoshi Abe (Department of Physical Engineering, Mie University ) Aftershocks 11:00-11:30 Discussion Lunch Break Room: 6620 Chairperson: Tao Zhou 15:00-15:50 Renaud Lambiotte (Imperial College London; Institute for Mathematical Sciences ) Beyond Space For Spatial Networks 15:50-16:10 Break 16:10-17:00 Wen-Xu Wang (Arisona University, USA) TBA Wednesday 23 / 3 /201 1 Room: 6620 Chairperson: Bing-Hong Wang 10:00-11:00 Hyunggyu Park (School of Physics, Korea Institute for Advanced Study, Korea) Phase transitions on networks: Annealed verses quenched 11:00-11:30 Discussion Lunch Break Room: 6620 Chairperson: Tao Zhou 15:00-16:00 Renaud Lambiotte (Imperial College London; Institute for Mathematical Sciences) Multi-scale Modularity in Complex Networks 16:00-16:20 Break 16:20-17:00 Yueheng Lan (Department of Physics, Tsinghua University) Novel computation of the growth rate of generalized random Fibonacci sequences Thursday 24 / 3 /201 1 Room: 6620 Chairperson: Bing-Hong Wang 10:00-11:00 Beom Jun Kim (Department of Physics, Sungkyunkwan University, Korea) Synchronization in two coupled networks 11:00-11:30 Discussion Lunch Break Room: 6620 Chairperson: Tao Zhou 15:00-16:00 Renaud Lambiotte (Imperial College London; Institute for Mathematical Sciences) Multirelational Organization of Large-scale Social Networks in an Online World 16:00-16:30 Lin-Yun Lv ( ) TBA Friday 25 / 3 /201 1 Room: 6620 Chairperson: Bing-Hong Wang 10:00-11:00 Jae Don Noh (Department of Physics, University of Seoul, Korea ) Scaling behavior of random walk centrality in general graphs 11:00-11:30 Discussion Lunch Break Room: 6620 Chairperson: Tao Zhou 15:00-16:00
个人分类: 会议信息|2353 次阅读|0 个评论
我的新书 "Modularity"
热度 2 jiankuihe 2011-3-11 15:31
我的新书 "Modularity"
应Lambert Academic Publishing之邀,我写的书 Modularity: The Principle of Evolution in Complex Systems今天出版了。 此书总结了我数年来在复杂网络,金融物理,和免疫系统进化方面的工作。主题围绕着“模块化” (modularity)展开。此书的核心是提出了生物进化中的模块化定律。 Modularity, understanding systems as the combination of separated components, is a prevalent concept in biology, social science and engineering design. This book offers a general theoretical model of emergence of modularity during evolution in changing environments. Evidences from protein interaction network and protein domain network support this theory as a general law of evolution in complex systems. Applying it to animal development, this theory appears to provide an explanation for the occurrence and timing of the Cambrian explosion. Applying it to trade networks, this theory predicts that globalized economy is more sensitive to recessions. This book also introduces a quantitative measure of hierarchy, a statistical method to predict the dominant flu strain and the first theoretical model to explain the bacterial acquired immunity (CRISPR). The information in the book should help shed some light in the study of complex systems, flu vaccine, and bacterial antibiotic resistance. 购买链接: http://www.amazon.com/Modularity-principle-evolution-complex-systems/dp/3844311416 前后封面
6689 次阅读|2 个评论
[转载]Program Schedule:Recent Progresses in Complex Networks
Fangjinqin 2011-3-8 18:36
Program Schedule "Recent Progresses in Complex Networks Research" (March 14-April 1) third week schedule.pdf
个人分类: 信息交流|1792 次阅读|0 个评论
[转载]International Symposium on Complex Networks 南京 东南大学
热度 3 bhwangustc 2011-2-27 01:15
The 2011 International Symposium on Complex Networks and Systems (ISCNS'11) http://www.ee.cityu.edu.hk/~wwyu/ISCNS11/index.html Welcome The 2011 International Symposium on Complex Networks and Systems (ISCNS'11) will be held on April 23-24 2011 in Nanjing, China, officially organized by the Department of Mathematics , Southeast University , China. The ISCNS'11 focuses on complex systems and networks, multi-agent systems, nonlinear dynamics and control, systems biology, sensor networks, communication networks, networked control systems, and their applications. The symposium will be sponsored by the Department of Mathematics , Southeast University , China. Latest News We will cover the travel (hard-seat tickets if by trains) and accommodation fees (in the reserved hotel) for some students and young teachers. Note that there are limited quota. Please send your registration form to us as soon as possible. All Rights Reserved 2011 - By ISCNS'2011 General Chairs Jinde Cao (SEU, China) Jijun Liu (SEU, China) Organizing Committees Jinling Liang (SEU, China) Qingshan Liu (SEU, China) Jianquan Lu (SEU, China) Xingmei Xue (SEU, China) Wenwu Yu (SEU, China) Invited Speakers (listed not in any particular order) Confirmed Guanrong Chen (CityU, HK) Zhisheng Duan (Peking University, China) Jinhu Lv (Chinese Academy of Sciences, China) Daniel W. C. Ho (CityU, HK) Yuanqing Xia (Beijing Institute of Technology, China) Unconfirmed Program Schedule 23-24 April, 2011: Two-day Workshop Related Download under construction Send Registration Form To Wenwu Yu Email: wenwuyu@gmail.com ; wwyu@seu.edu.cn Telephone: 0086-15051861330 Registration Form Download Sponsors Department of Mathematics , Southeast University , China Contact Dr. Wenwu Yu Department of Mathematics , Southeast University Nanjing 210096, P. R. China Tel: +86-25-52090596-8531 Fax: +86-25-83792316 Email: wenwuyu@gmail.com ; wwyu@seu.edu.cn
个人分类: 会议信息|3799 次阅读|3 个评论
[转载][特别推荐]M. E. J.Newman: Complex Systems : A Survey
热度 3 Fangjinqin 2011-2-21 18:42
110221-Complex_systems_A_survey.pdf Complex Systems: A Survey M. E. J. Newman Department of Physics, University of Michigan, Ann Arbor, MI 48109 and Center for the Study of Complex Systems, University of Michigan, Ann Arbor, MI 48109 A complex system is a system composed of many interacting parts, often called agents, which displays collective behavior that does not follow trivially from the behaviors of the individual parts. Examples include condensed matter systems, ecosystems, stock markets and economies, biological evolution, and indeed the whole of human society. Substantial progress has been made in the quantitative understanding of complex systems, particularly since the 1980s, using a combination of basic theory, much of it derived from physics, and computer simulation. The subject is a broad one, drawing on techniques and ideas from a wide range of areas. Here I give a short survey and an annotated bibliography of resources for those interested in learning about complex systems. I. INTRODUCTION Complex systems is a relatively new and broadly interdisciplinary field that deals with systems composed of many interacting units, often called “agents.” The foundational elements of the field predate the current surge of interest in it, which started in the 1980s, but substantial recent advances in the area coupled with increasing interest both in academia and industry have created new momentum for the study and teaching of the science of complex systems. There is no precise technical definition of a “complex system,” but most researchers in the field would probably agree that it is a system composed of many interacting parts, such that the collective behavior of those parts together is more than the sum of their individual behaviors. The collective behaviors are sometimes also called “emergent” behaviors, and a complex system can thus be said to be a system of interacting parts that displays emergent behavior. Classic examples of complex systems include condensed matter systems, ecosystems, the economy and financial markets, the brain, the immune system, granular materials, road traffic, insect colonies, flocking or schooling behavior in birds or fish, the Internet, and even entire human societies. Unfortunately, complex systems are, as their name makes clear, complex, which makes them difficult to treat scientifically. Experimental observations are of course possible, though these fall largely within the realm of the traditional scientific disciplines and are usually not considered a part of the field of complex systems itself, which is primarily devoted to theoretical developments. Complex systems theory is divided between two contrasting approaches. The first involves the creation and study of simplified mathematical models that do not claim to mimic quantitatively the behavior of real systems but instead try to abstract their most important qualitative elements into a solvable framework from which we can gain scientific insight. The tools used in such studies include dynamical systems theory, information theory, cellular automata, networks, computational complexity theory, and numerical methods. The second approach is to create systematic computer simulations of the interacting parts of a complex system, often down to minute details, and then watch and measure the emergent behaviors that appear. The primary tool for this approach is agent-based simulation, around which a community of computer scientist scientists and software developers has grown up to create software tools for sophisticated computational research in complex systems. This resource letter focuses on the methods and theoretical tools of complex systems, including both the modeling and simulation approaches above, though I also include a short section of references to individual specific complex systems, such as economies or ecosystems, which can serve as a concrete foundation motivating the theoretical studies.
个人分类: 学术文章|4054 次阅读|3 个评论
可视化毫米级大脑功能链接组网络
zuoxinian 2010-12-28 12:46
最近,借助静息态磁共振数据,在4mm空间精度上,可视化出1003个被试的平均大脑功能网络。其包括2万2千多节点,20个功能模块。
个人分类: 科研笔记|6000 次阅读|1 个评论
[转载]复合事件处理(Complex Event Processing,CEP)
qhhuangscut 2010-11-2 09:39
文/ 蔡学镛 原文出处: http://www.programmer.com.cn/3276/ 这篇文章希望用浅显易懂的方式,介绍一个最近曝光率开始增加的技术领域:复合事件处理(ComplexEventProcessing,CEP)。有人将它翻译成复杂事件处理,但我认为复合或许比复杂更恰当一些。 人肉CEP 什么是复合事件处理?先看一些生活化的例子。其实你每天都在做人肉CEP,只是你不知道而已。所谓人肉CEP,就是通过各种感知器官,将感觉汇集到大脑,经过综合判断得到一个更具有意义的事件。在这个事件被判定出来之后,你可能会想要为此采取因应之道。 为加强说明,我推出了三个人肉CEP范例: 个人版、企业版、家庭版 。 先看个人版!皮肤感觉温度下降是一个基础事件(BaseEvent)或称简单事件(SimpleEvent)。耳朵听到远方传来的雷声、眼睛看到闪电,都是基础事件。集合以上基础事件,得到一个复合事件:快要下雨了。于是,你的因应之道是:收衣服或者出门要带伞。 接着看企业版!身为公司领导,你看到员工经常有一堆事没做完,居然还在上班时间上网偷菜。于是你得到一个复合事件,就是:这是一个不负责任的员工。你的处理方式就是将他辞退。 最后看家庭版!这个版本有点儿童不宜。老公老说要加班,身为老婆的你心里狐疑:哪有公司这么常加班的?回家后发现他在外面洗过澡,身上有肥皂味道,但他又否认。帮他整理衣服发现衣服上有一根长头发,而且不是你的。最糟糕的是,他对你性趣缺缺。帮老公接手机时,电话那头神秘不出声。因为这种种迹象,你得到一个复合事件:老公有外遇了。不过,CEP有误报警的可能。为了避免误报警导致夫妻间无谓的争端,你应该先找侦探跟踪老公,求证外遇是否属实,再决定作何反应。 看了这些例子,现在应该能了解CEP系统的大致作用了:先捕获各种细微的事件(基础事件),然后通过分析整理,找出更有意义的事件(复合事件),最后决定采取什么行动。其中事件的分析整理以找出更有意义的事件,正是CEP的核心,也是最困难的地方。 IT-CEP 下面我们来看看IT领域的CEP。 这是一个IT事件爆发的时代,各种IT系统之间或系统内部,每天产生大量事件。系统在关键点打日志、系统之间交流信息,都是事件。但我们对这些事件往往视而不见,当成垃圾一股脑儿全扔了。其实只要处理得当,垃圾也可以变成资源。 大致上,CEP可以帮助我们: 了解趋势 发现机会 避免威胁 业界普遍将CEP应用在: 商业活动监控(BAM) 发掘群众智能 避免网络攻击 预防金融犯罪 实施系统动态校验 其他 支付宝大量使用CEP用于防止犯罪(如网络诈欺、网络攻击、洗钱)和资金损失,并了解各种业务的现状、协助营销。支付宝使用外部厂商的CEP系统,也自行开发CEP系统。 目前知名的CEP产品来自Tibco、IBM、Oracle、StreamBase、Sybase等。微软也即将推出名为StreamInsight的CEP产品。 很有意思的是StreamBase与StreamInsight这两个CEP产品名称,刚好是CEP的三个关键字:Stream、Base、Insight。同时具备这三点才能算是CEP。这三个关键字的意义解释如下: Stream 连续不间断 实时处理 Base 资料量大 数据库 Insight 有用的信息 智能 CEP关键技术 CEP的关键过程包括: 格式化:将外部事件转成内部能处理的格式; 预处理:将事件依据字段内容进行处理; 模式侦测:将数个事件之间关联起来,找出复合事件; 事件发派:将复合事件发送到相应的处理模块; 报警:对严重的事件进行处置。 图1 CEP关键模块 如图1所示,CEP系统中比较关键的模块有八个,分别是: 1.EPL解析器:在CEP系统中,描述如何将基础事件合成复合事件的语言,称为EPL(事件处理语言)。EPL需要被解析成CEP引擎能理解的语言。 2.规则管理:管理EPL。 3.事件接入:通过SOA、ESB、MOM、读取日志等方式将消息接入。 4.预处理:将事件依据字段内容进行处理。 5.CEP引擎:找出事件关联。 6.数据模型:维护内部数据。 7.事件发派:将已经发现的复合事件发派到负责处理的行动模块中。 8.行动模块:对复合事件采取行动。 此外,CEP系统的辅助工具有: 规则制作工具 报表输出工具 实时仪表板 上述的八个CEP关键模块中,有四个值得详细说明:EPL解析器、预处理模块、CEP规则引擎、数据模型。 EPL是用来描述复合事件的语言,会被EPL解析器处理,成为内部可以使用的规则。EPL许多都扩展自SQL(微软的扩展自LINQ),底层的数据模型都是数据库,所以EPL解析器做的就是将EPL转成SQL,通常会使用到数据库的Trigger、StoredProcedure等机制。 预处理模块会将事件送进CEP引擎之前预先做处理,包括字段过滤、字段填入、事件过滤、事件分流、事件合流等。请注意:预处理过程一定需要读取事件内容,然后根据事件内容做处理(但不会将事件关联起来,因为这是CEP引擎的工作)。建议这个模块内部采用管线(pipeline)的架构方式,使用上会更灵活。 图2 复合事件规则引擎表示例 最后来看最重要的两个模块:规则引擎与数据模型。现在的CEP规则引擎几乎都采用数据库表当做底层数据模型。事件会先进入数据库,一定时间(或数量)之后进行检查,若符合规则,就找到了复合事件,将此复合事件放进另一个表中。以图2为例,外部事件根据类型的不同,分别被放进A、B、C三个表中。A与B表可以侦测出复合事件,放进D中。C与D表可以侦测出复合事件,放进E表中。 图3 规则分解示例 图3所示,要找到一个有用的复合事件,必须把规则写成许多片段的规则,像是河流的上下游,渐渐汇集成最终有用的复合事件。有些CEP系统允许事件逆流而上,更具有使用上的弹性。 何时扫描数据库表?一般支持定量扫描或定时扫描。扫描事件的方式分滑动或跳跃(也称为批处理)。滑动会连续进行,跳跃则是将事件分批处理。一般来说,滑动方式较耗费计算资源。 支付宝总督CEP 总督系统是支付宝全新打造的一套CEP,与一般CEP最大的差异是,底层不是数据库,而是状态机。 其他CEP系统往往有这些缺点:无法(或难以)描述相当复杂的复合事件;事件格式受到资料库表schema的限制,无法自由扩展;需要大量的存储。 总督CEP以状态机引擎为核心,搭配独特的算法,完全解决这三个问题。 各种CEP应用蓄势待发 目前的CEP市场相对小,只有少数企业采用相关技术。随着对信息的重视,CEP的应用势必越来越广。通过这篇文章,希望让大家重视事件和使用CEP。我相信,只要使用得宜,CEP一定可以帮助企业在复杂多变的商业环境中找到机会、躲避威胁。 作者简介: 蔡学镛,台湾台南人,毕业于台湾清华大学ComputerScience研究所,现任阿里巴巴支付宝架构师,负责新系统的开发。 (本文来自《程序员》 10年06期,更多精彩内容敬请关注06期杂志 )
个人分类: 科研天地|8283 次阅读|0 个评论
伴我同行——igraph
phoenix05056 2010-7-19 23:16
一开始做科研,为了高效、快速的开发出仿真环境或者相关算法,选择了OOP的楷模之一:C#。优势就不说了,劣势也明显,速度....当我在一个群落网络中模拟10W个点时,感觉那速度要命,即使机器的cpu和内存属于当前主流。 幸好才起步,所以一直想给自己科研道路找一门得心应手的开发包及相应语言,语言最好是大众化的,关键配有现成的复杂网络相关开发包或者开发库,这样能够在最短时间来构建自己所需要的网络拓扑等特殊需求。 在闫小勇老师的blog中提到过c语言的igraph库,这几天来学习使用,超牛逼! 由于以前做一个大工程,会boost或多或少有些掌握,igraph+boost+stl,太爽了,开发速度这快,效率之高! 强烈推荐给大家-igraph! http://igraph .sourceforge.net/
个人分类: 心得体会|6015 次阅读|1 个评论
[转载]SIAM REVIEW :Complex Singularities and the Lorenz Attractor
Fangjinqin 2010-6-2 16:24
Copyright by SIAM. Unauthorized reproduction of this article is prohibited. SIAM R EVIEW _ c 2010 Society for Industrial and Applied Mathematics Vol. 52, No. 2, pp. 294314 Complex Singularities and the Lorenz Attractor Divakar Viswanath Sonmez Sahuto?glu Abstract. The Lorenz attractor is one of the best-known examples of applied mathematics. However, much of what is known about it is a result of numerical calculations and not of mathematical analysis. As a step toward mathematical analysis, we allow the time variable in the three-dimensional Lorenz system to be complex, hoping that solutions that have resisted analysis on the real line will give up their secrets in the complex plane. Knowledge of singularities being fundamental to any investigation in the complex plane, we build upon earlier work and give a complete and consistent formal development of complex singularities of the Lorenz system using the psi series . The psi series contain two undetermined constants. In addition, the location of the singularity is undetermined as a consequence of the autonomous nature of the Lorenz system. We prove that the psi series converge, using a technique that is simpler and more powerful than that of Hille, thus implying a two-parameter family of singular solutions of the Lorenz system. We pose three questions, answers to which may bring us closer to understanding the connection of complex singularities to Lorenz dynamics. Key words. Lorenz attractor, psi series, complex singularities AMS subject classifications. 34M 35, 37D45 DOI. 10.1137/090753474 Complex Singularities and the Lorenz Attractor
个人分类: 学术交流|2391 次阅读|1 个评论
[转载]陈关荣等人新论文:Some recent advances in complex network synchronization
Fangjinqin 2010-3-27 11:25
Some Recent Advances in Complex Networks Synchronization _ Guanrong Chen, Xiaofan Wang, Xiang Li, and Jinhu Lv (陈关荣,汪小帆,李翔,吕金虎) 按语: 我把陈关荣等四位合作的文章推荐到这个专栏,完全是为了推动博文比赛. 因为 他们当中有三位是评委,自然将不参加评选. (方锦清2010、3、27) Abstract. The current study of complex dynamical networks is pervading almost all kinds of science, engineering and technology, ranging from mathematics to computers, physics to biology, even to sociology. Its impacts on the modern high-tech industries, financial markets and human life are prominent and will be far-reaching. Research on fundamental properties and dynamical features of such complex networks has indeed become overwhelming. This Chapter presents a brief overview of some past and current studies on the subject of complex dynamical network synchronization, particularly from an engineering and technological perspective. Some commonly concerned issues in the current research of network synchronization, mainly on Some recent advances in complex network synchroniz
个人分类: 信息交流|4498 次阅读|1 个评论
Hierarchical synchronization in complex networks with heterogeneous degrees
kingroupxz 2009-12-31 12:53
Chaos 16, 015104 (2006) Changsong Zhou and Jurgen Kurths 这是一篇我看到的极出色的文章,所研究的复杂网络上的分层同步(我就直译了)问题对识别网络的拓扑结构具有启发性。PRE80,016116(2009)也正是基于此,明确提出了用来网络探测。在没有看到更早的文献之前,我先当它是利用动力学来探测网络度分布的第一文了。如此说,EPL82,68001(2008)可能要觉得有点冤,因为那里宣称是首次。但在仔细阅读这三文章之后,我还是认为这里闪烁的原创性更明亮! 文章的摘要:We study synchronization behavior in networks of coupled chaotic oscillators with heterogeneous connection degrees. Our focus is on regimes away from the complete synchronization state, when the coupling is not strong enough, when the oscillators are under the influence of noise or when the oscillators are nonidentical. We have found a hierarchical organization of the synchronization behavior with respect to the collective dynamics of the network. Oscillators with more connections (hubs) are synchronized more closely by the collective dynamics and constitute the dynamical core of the network. The numerical observation of this hierarchical synchronization is supported with an analysis based on a mean field approximation and the master stability function. 1.在简介里隐约给出了复杂网络的研究对象主要就是指联接,或称为复杂的拓扑结构。而对于结点的研究则是动力学的范围。所以是否可以将我们研究的对象分为这么两层次:复杂系统是第一层、复杂网络与动力系统(微分动力系统)是第二层,这一层是拓扑结构与单一结点动力学。在第二层次上的单独研究都已经开展得很多了,而第一层的研究则包括常见的什么传播动力学、网络同步等。 2.MSF分析的是网络的完全同步(CS),但是网络的最自然状态往往是非完全同步的。在这种情况下,局部群体行为的分析也是十分令人感兴趣的。这对应以往斑图研究中的发达湍流与全局同步运动(规则斑图之一)之间的状态。当然以前斑图研究的也可以说成是简单连接的网络上的动力学研究。 3.Interestingly, the stability analysis of the CS state can be adopted to provide an understanding of the hierarchical synchronization.这是在简介结尾时说的一句话,可能是对应II(E)部分的,平均场分析。因为这一部分的分析方法与MSF相似。不同的是normalized耦合强度是结点度的显函数,且由之可知度大的结点耦合强度也大。所以可想而知的是有权连接对所讨论的对象也有很大的影响。 4.文章最后一句Our present interest is on self-organization of structures and dynamics due to the interplay between them令人浮想连翩。 5.总体还有个感觉就是工作量很大,做得很细,值得学习。
个人分类: 文献阅读|5350 次阅读|1 个评论
论文选读: 生态网络的复杂性影响稳定性吗?
sunon77 2009-9-16 00:25
Fig. 1 The more connection and species, the more unstable Recently my former group published one paper about the stability of complex food network in the journal 'Science'. This is not my direction. But I am near enough to understand their ideas of research. The basic question came from Robert May in the 70s. He found that there is a dilemma between the theory and the observation. People generally believe that the diversity in an ecological system makes it stable. But May showed it mathematically that with increasing connection links and interactive nodes, an ecological system will become more and more unstable. People with the experience of solving large nonlinear differential equations know that the system becomes more and more difficult to have steady states if the number of equations increase. So Which is correct: our intuition or our model? In this papery, they used a small trick before the simulation. If there is a steady state in a dynamic system, you can always re-scale the time for different variables to normalize one steady state to an unit vector = (1, 1, ..., 1). Then you can do usual stability analysis around this point. Based on Monte Carlo sampling of different parameters, you will know how they effect the stability of the system around this steady state locally. Using this half-analytical-half-numeric method, they generated 100 million food webs randomly and made a statistic how different factors effect the stability. They found that more connections and more species really de-stabilize the ecological system. That is, in a forest, if trees, birds, insects etc. form more connections and there are more species, the ecological system in this forest will be more inclined to collapse! (Really unintuitive?) The other conclusion is that the food web will be more stable if top predators like lions, tigers die fast, or they can eat more deer when deer population increases. This kind of idea is actually not new. In 1960s, when Kauffman tried to study the gene regulatory network of the living organism, he did the same thing by creating millions of random networks since the real genetic networks would come decades later (He simply can not wait). Based on his statistics on all these random gene networks, Kauffman concluded that if we need an evolution in Life, we have to have our gene network at the edge of Chaos. That is, it is not either in deterministic system with the fixed number of steady states, nor in totally chaos without any steady states at all. It is just at this delicate zone in between. Could this complexity analysis with large number of simulations will reveal more 'emergent properties' in Life? Let's just wait and see. Ref: Thilo Gross, Lars Rudolf, Simon A. Levin, Ulf Dieckmann, Generalized Models Reveal Stabilizing Factors in Food Webs, Science 7 August 2009, Vol. 325. no. 5941, pp. 747 - 750,DOI: 10.1126/science.1173536 END
个人分类: 生物物理-biophysics|5600 次阅读|0 个评论
Vespingnani a 的新书Dynamical Processes on Complex Networks 电子版
jnpengfei 2009-8-15 11:21
刚刚从网上 费了九牛二虎之力找到 这本书(夸张) 不知道 大家 有没有 做疾病传播的,想 通过 这本书 找到更多的 与此方向 有关的 牛仁。如果有需要的可以 索取 哈哈 小小伎俩,请勿见怪。 补充一句:附件大于5m,索取邮箱 jipeng_114@163.com, q q 360213506
个人分类: 生活琐事|1785 次阅读|6 个评论
Complex09 Call For Participation
Hsu 2009-2-20 16:51
Complex09 Call For Participation Welcome to Complex2009 The First International Conference on Complex Sciences: Theory and Applications 发件人Xiao Shi XiaoShi@ntu.edu.sg 回复Xiao Shi XiaoShi@ntu.edu.sg 发送至 COMPLEX_2009@mlist.ntu.edu.sg 日期2009年2月17日 下午7:03 主题Complex09 Call For Participation 邮送域mlist.ntu.edu.sg 隐藏详细信息 2月17日 (3天前) 回复 The interdisciplinary studies on complex systems have gained extensive research interests. Significant impacts have been made by such studies on a wide range of different areas including physics, biology, economics, social sciences, etc., and penetrating into various engineering applications. In the long-term future, the way we understand and cope with the world may all be revolutionized by such studies. Complex'2009, the First International Conference on Complex Sciences: Theory and Applications, aims to provide a unique and convenient platform for people working on theory and applications of complex systems to exchange their ideas and their latest research results. Topics of interests address, but not limited to, the following areas: - Structure and Dynamics of Complex Networks - Complex Biological Systems - Econophysics - Sociophysics - Complex Systems Methods - Complex Systems in Engineering We look forward to your participation in COMPLEX'2009 to make this conference a success. CONFERENCE DATE AND LOCATION February 23-25, 2009, Shanghai, China CONFERENCE PROGRAM The detailed conference program is available at http://www.complex-sys.org/ . The conference features: - Seventeen technical sessions consisting of more than 190 high-quality technical papers - Five collated workshops. - Four Distinguished Keynote Speakers and Fifteen Invited Speakers. COLLATED WORKSHOPS Causality in Complex Systems (ComplexCCS) http://www.complexsystems.net.au/wiki/Complex_%2709_Workshop_on_Causalit y_in_Complex_Systems Complex Engineering Networks (ComplexEN) http://complexen.icstweb.org/ Complexity Theory of Arts and Music (COART) http://coart.icstweb.org/ Modelling and Analysis of Human Dynamics (MANDYN) http://pil.phys.uniroma1.it/~gcalda/Complex2009Satellite/ Social Physics and its Applications (SPA) http://socialphysics.ac.cn/NewsView.Asp?id=46 For further information and registration: http://www.complex-sys.org/ 回复 全部回复 转发
个人分类: 学术科研|4792 次阅读|0 个评论
a PhD position in the field of complex network theory with applications to neuro
sunon77 2009-1-29 11:21
The Complexity Science Group in the Department of Physics Astronomy at the University of Calgary invites applications for a PhD position in the field of complex network theory with applications to neurosciences. The successful applicant is expected to work closely with other members of the Complexity Science Group and members of the Hotchkiss Brain Institute in an interdisciplinary environment. A background in statistical physics, computational physics, time series analysis, complex network theory and/or information theory is beneficial. Applicants should send an email to davidsen(at)phas.ucalgary.ca that includes a CV with a list of publications and a brief statement of research interests. Review of applications will begin on January 30, 2009 and continue until the position is filled. More information about the group is available at www.ucalgary.ca/complexity More detalis about the job in PDF fie: PhD Complex in neuroscience
个人分类: 招贤榜|4995 次阅读|0 个评论

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