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Reduced analysis and confirmatory research on co-adaptability theoretical solution to conflicting events in construction engineering projects

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Science china(Technological Sciences) 2010年第2期53卷 480-485页

作者： HOU XueLiang1 , LU Mei2 & WANG Kai3 1 School of Business Administration, North china Electric Power university, beijing 102206, china 2 department of construction management, tsinghua university, beijing 100084, china 3 College of management, beijing Jiaotong university, beijing 100084, china School of Business Administration North China Electric Power University Beijing China department of construction management Tsinghua University Beijing China College of management Beijing Jiaotong University Beijing China

The co-adaptability theoretical solution to conflicting events in construction engineering projects has three problems. First, the transformation of constraint conditions of theoretical solution is very difficult in practical engineering applications; second, some coefficients are difficult to be determined; third, there are overfull circular arithmetic operations involved in it. To resolve these problems, a new method to reduce the theoretical solution complications is proposed. By analyzing the operating mechanism of theoretical solution model, redundancies in the theoretical solution can be eliminated, and the ISM mapping with the co-adaptability solution can be set up. Based on this approach, a procedure to solve practical conflicting events in construction projects is established by replacing characteristic variables with mathematic variables. The research results show that the procedure can replace the co-adaptability theoretical solution effectively and solve practical conflicting events in construction projects.

关键词： construction project conflict theoretical solution reduced analysis ISM confirmatory research

考虑专家权重的建设项目参与者协同群决策模型

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唐山学院学报 2011年第5期24卷 66-68页

作者：佟继英王金明关军唐山学院经济管理系河北唐山063000 清华大学建设管理系北京100084

建设项目协同群决策是建设项目管理集成化的内在要求,也是解决建设项目工作中效率低、超预算、质量安全事故多等问题的有效途径之一。以对建设项目协同群决策研究状况的评述入手,建立了以决策成员互评为方式的决策专家权重确定方法,以AH... 详细信息

建设项目协同群决策是建设项目管理集成化的内在要求,也是解决建设项目工作中效率低、超预算、质量安全事故多等问题的有效途径之一。以对建设项目协同群决策研究状况的评述入手,建立了以决策成员互评为方式的决策专家权重确定方法,以AHP法确定权重,提出了考虑专家决策权重的建设项目模糊综合协同群决策模型,并给出了算例。

关键词：建设项目协同群决策专家权重 AHP法模糊综合评价

Multi-dimensional project management models for mega-construction companies and their applications

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Science china(Technological Sciences) 2011年第S1期54卷 118-124页

作者： LIN ZhengHang 1,2,QIANG MaoShan 1,2,TANG WenZhe 1,2,FAN QiXiang 3 &LIU Qiang 4 1 Institute of Project management and construction Technology,tsinghua university,beijing 100084,china 2 State Key Laboratory of Hydraulic and Engineering,tsinghua university,beijing 100084,china 3 china Three Gorges Corporation,Yichang 443002,china 4 School of Software,tsinghua university,beijing 100084,china Institute of Project management and construction Technology Tsinghua University Beijing China State Key Laboratory of Hydraulic and Engineering Tsinghua University Beijing China china Three Gorges Corporation Yichang China School of Software Tsinghua University Beijing China

china is undertaking an increasing number of mega-infrastructure projects along with its rapid economic *** participants in these projects,understand how to adapt the proper and efficient management strategies is *** this paper,we propose three distinct models for companies under various background and management requirements,based on sophisticated data analysis and model ***,we successfully committed these models with hydropower development projects and achieved a great progress in enhancing management efficiency.

关键词： project management models mega-construction companies applications hydropower development companies

The quantum general linear supergroup, canonical bases and Kazhdan-Lusztig polynomials

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Science china Mathematics 2009年第3期52卷 401-416页

作者： ZHANG HeChun department of Mathematical Sciences, tsinghua university, beijing 100084, china department of Mathematical Sciences Tsinghua University Beijing China

Canonical bases of the tensor powers of the natural $ U_q (\mathfrak{g}\mathfrak{l}_{m|n} ) $ -module V are constructed by adapting the work of Frenkel, Khovanov and Kirrilov to the quantum supergroup setting. This result is generalized in several directions. We first construct the canonical bases of the ?2-graded symmetric algebra of V and tensor powers of this superalgebra; then construct canonical bases for the superalgebra O q (M m|n ) of a quantum (m,n) × (m,n)-supermatrix; and finally deduce from the latter result the canonical basis of every irreducible tensor module for $ U_q (\mathfrak{g}\mathfrak{l}_{m|n} ) $ by applying a quantum analogue of the Borel-Weil construction.

关键词： canonical basis crystal basis Kazhdan-Lusztig polynomial 17B37 81R50

An atlas-based fuzzy connectedness method for automatic tissue classification in brain MRI

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Progress in Natural Science:Materials International 2006年第10期16卷 1106-1110页

作者： ZHOU Yongxin and BAI Jing (department of Biomedical Engineering, tsinghua university, beijing 100084, china) department of Biomedical Engineering Tsinghua University Beijing 100084 China

A framework incorporating a subject-registered atlas into the fuzzy connectedness (FC) method is proposed for the automatic tissue classification of 3D images of brain MRI. The pre-labeled atlas is first registered onto the subject to provide an initial approximate segmentation. The initial segmentation is used to estimate the intensity histograms of gray matter and white matter. Based on the estimated intensity histograms, multiple seed voxels are assigned to each tissue automatically. The normalized intensity histograms are utilized in the FC method as the intensity probability density function (PDF) directly. Relative fuzzy connectedness technique is adopted in the final classification of gray matter and white matter. Experimental results based on the 20 data sets from IBSR are included, as well as comparisons of the performance of our method with that of other published methods. This method is fully automatic and operator-independent. Therefore, it is expected to find wide applications, such as 3D visualization, radiation therapy planning, and medical database construction.

关键词： fuzzy connectedness atlas-based segmentation brain tissue classification MR1.

Truncation error calculation based on Richardson extrapolation for variable-step collaborative simulation

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Science china(Information Sciences) 2011年第6期54卷 1238-1250页

作者： ZHANG HeMing 1 , LIANG SiLu 2 , SONG ShiJi 1 & WANG HongWei 3 1 department of Automation, TNList, tsinghua university, beijing 100084, china 2 Computer and Information management Center, tsinghua university beijing 100084, china 3 Engineering Design Centre, Engineering department, Cambridge university, Cambridge CB2 1PZ, UK department of Automation TNList Tsinghua University Beijing China Computer and Information management Center Tsinghua University Beijing China Engineering Design Centre Engineering Department Cambridge University Cambridge UK

Collaborative simulation is an effective approach to performing simulation analysis for complex systems by integrating models developed for different engineering disciplines. Collaborative simulation issues include the modeling of coupled multidisciplinary systems, and the simulation running time integration of these models that are solved parallelly. Estimation of the local truncation error of coupling models is the key to solve multidisciplinary collaborative simulation problem, which is actually used to restrict the simulation step. This paper presents a variable-step method based on Richardson extrapolation for calculating the local truncation error to solve collaborative simulation problem of multidisciplinary coupling models. Formulas for estimating the local truncation error are derived through theoretical analysis by using integration methods and interpolation technologies, respectively. The simulation experiments are illustrated to validate the accuracy and efficiency of proposed collaborative simulation algorithm in comparison with the usual combinative algorithm.

关键词： multidisciplinary systems collaborative simulation variable-step algorithm error estimation

A multiphase mesostructure mechanics approach to the study of the fracture-damage behavior of concrete

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Science china(Technological Sciences) 2008年第S2期51卷 8-24页

作者： TANG XinWei1,ZHANG ChuHan1 & SHI JianJun2 1 State Key Laboratory of Hydroscience and Engineering,tsinghua university,beijing 100084,china 2 department of Urban construction,Nanhua university,Hengyang 421001,china State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing China department of Urban construction Nanhua University Hengyang China

A multiphase mesostructure mechanical model is proposed to study the deformation and failure process of concrete considering its heterogeneity at the meso scopic ***,concrete is taken as a type of three-component composite material composed of mortar matrix,aggregates and interfaces on the ***,an efficient approach to the disposition of aggregates of concrete and a state matrix method to generate mesh coordinates for aggregates are ***,based on the nonlinear continuum damage mechanics,a meso-scale finite element model is presented with damage softening stress-strain relationship for describing the mechanical behavior of different components of *** this method,heterogeneities of each component in the concrete are considered by assuming the material properties of three components conform to the Weibull distribution ***,based on this multiphase meso-mechanics model,a simulation analysis of fracture behavior of a rock-fill concrete(RFC) beam is *** study includes experimental tests for determining basic mechanical parameters of three components of RFC and four-point flexural beam tests for verification of the *** is preliminarily shown that the numerical model is applicable to studying failure mechanisms and process of concrete type material.

关键词： concrete multiphase mesostructure mechanics numerical simulation experimental research

Building a next generation Internet with source address validation architecture

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Science in china(Series F) 2008年第11期51卷 1681-1691页

作者： WU JianPing1,3,REN Gang1,3 & LI Xing2,3 1 department of Computer Science,tsinghua university,beijing 100084,china 2 department of Electronic Engineering,tsinghua university,beijing 100084,china 3 tsinghua National Laboratory for Information Science and Technology(TNList) ,beijing 100084,china department of Computer Science Tsinghua University Beijing China tsinghua National Laboratory for Information Science and Technology (TNList) Beijing China department of Electronic Engineering Tsinghua University Beijing China

The IP packet forwarding of current Internet is mainly destination based. In the forwarding process, the source IP address is not checked in most *** causes serious security, management and accounting problems. Based on the drastically increased IPv6 address space, a ＂source address validation architecture＂（SAVA） is proposed in this paper, which can guarantee that every packet received and forwarded holds an authenticated source IP address. The design goals of the architecture are lightweight, loose coupling, ＂multi-fence support＂ and incremental deployment. This paper discusses the design and implementation for the architecture, including inter-AS, intra-AS and local subnet. The performance and scalability of SAVA are described. This architecture is deployed into the CNGI-CERNET2 infrastructure a large-scale native IPv6 backbone network of the china Next Generation Internet project. We believe that the SAVA will help the transition to a new, more secure and dependable Internet.

关键词： IP source address validation network architecture network security

ELASTO-PLASTICITY ANALYSIS BASED ON COLLOCATION WITH THE MOVING LEAST SQUARE METHOD

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Acta Mechanica Solida Sinica 2003年第2期16卷 162-170页

作者： Song Kangzu Zhang Xiong Lu Mingwan (department of Engineering Mechanics,tsinghua university,beijing 100084,china) department of Engineering Mechanics Tsinghua University Beijing 100084 China

A meshless approach based on the moving least square method is developed for elasto-plasticity analysis,in which the incremental formulation is *** this approach,the dis- placement shape functions are constructed by using the moving least square approximation,and the discrete governing equations for elasto-plastic material are constructed with the direct collo- cation *** boundary conditions are also imposed by *** method established is a truly meshless one,as it does not need any mesh,either for the purpose of interpolation of the solution variables,or for the purpose of construction of the discrete *** is simply formu- lated and very efficient,and no post-processing procedure is required to compute the derivatives of the unknown variables,since the solution from this method based on the moving least square approximation is already smooth *** examples are given to verify the accuracy of the meshless method proposed for elasto-plasticity analysis.

关键词： meshless method elasto-plasticity collocation method moving least square incremental formulation