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Rheological Behavior for Polymer Melts and Concentrated Solutions——Part Ⅶ: A Quantitative Verification for the Molecular Theory of Non-linear Viscoelasticity with Entanglement Constraints in Polymer Melts 被引量:2
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作者 Mingshi SONG, Chen ZHANG and Guixian HU Research Institute of Polymeric Materials, Beijing University of Chemical Technology, Beijing 100029, China E-mail: wangzhchen@sina.com 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2001年第3期375-382,共8页
Based on the molecular theory of non-linear viscoelasticity with constrained entanglements in polymer melts, the material functions in simple shear flow were formulated, the theoretical relations between. eta((gamma) ... Based on the molecular theory of non-linear viscoelasticity with constrained entanglements in polymer melts, the material functions in simple shear flow were formulated, the theoretical relations between. eta((gamma) over dot), psi (10)((gamma) over dot) and shear rate ((gamma) over dot), and topologically constrained dimension number n ' and a were derived. Linear viscoelastic parameters (eta (0) and G(N)(0)) and topologically constrained dimension number (n ' a and <(<upsilon>)over bar>) as a function of the primary molecular weight (M-n), molecular weight between entanglements (M-C) and the entanglement sites sequence distribution in polymer chain were determined. A new method for determination of viscoelastic parameters (eta (0), psi (10), G(N)(0) and J(e)(0)), topologically constrained dimension number (n ', a and v) and molecular weight (M-n, M-c and M-e) from the shear flow measurements was proposed. It was used to determine those parameters and structures of HDPE, making a good agreement between these values and those obtained by other methods. The agreement affords a quantitative verification for the molecular theory of nonlinear viscoelasticity with constrained entanglement in polymer melts. 展开更多
关键词 Rheological Behavior for Polymer Melts and Concentrated Solutions A Quantitative Verification for the Molecular theory of Non-linear Viscoelasticity with Entanglement constraints in Polymer Melts PART
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Evolutionary Programming for IP/MIP Problems with Linear Constraints 被引量:2
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作者 Ren, Qingsheng Zeng, Jin Qi, Feihu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2000年第3期59-64,共6页
In this paper, we propose a modified evolutionary programming with dynamic domain for solving nonlinear IP/MIP problems with linear constraints, without involving penalty function or any transformation for the problem... In this paper, we propose a modified evolutionary programming with dynamic domain for solving nonlinear IP/MIP problems with linear constraints, without involving penalty function or any transformation for the problem to a linear model or others. The numerical results show that the new algorithm gives a satisfactory performance in which it works of high speed, and accuracy in IP/MIP problems. 展开更多
关键词 ALGORITHMS constraint theory Mathematical models Mathematical transformations Problem solving
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Discussion on Rural Finanical Problems From the Perspective of Theory of Constaint
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作者 QIAN Feng-lin CAO Can PU Xu-jin 《Asian Agricultural Research》 2011年第7期95-97,102,共4页
Inadequate rural financial services and low service efficiency lead to the situation that a large sum of money flows from rural areas to urban areas through commercial banks. The situation goes against the development... Inadequate rural financial services and low service efficiency lead to the situation that a large sum of money flows from rural areas to urban areas through commercial banks. The situation goes against the development of rural production and causes the extreme lack of rural capital, the difficuties in loaning and the prevalence of uaurious loan. In view of the problems exsited in rural financial system, the rural financial developmental trend, rural gross production, rural financial scale and rural financial efficiency from 1983 to 2008 are empirically analyzed by using the Pagano model in endogenous growth theory. The research assumes that, rural financial scale has positive relation with rural economic output, that is to say, the expansion of rural fiancial scale can facilitate the development of rural economy; the rural financial efficiency has negative relation with rural economic development. In Chinese rural areas, the economic development still relies on the expansion of rural fianance. However, at the same time of increasing the financial scale, the efficiency of rural finance is deceasing gradually. Thus, the support of rural finance on rural economic growth lies at the low level. Therefore, in view of the basic rerequisite of rural economic development, two solutions are adopted and Japanese and Kereaon experince are used. The measures are as follows. First, conducting organization innovation through promoting new village construction and gathering dispersed farmers to form rural cooperative organization to reduce trasaction cost. Second, transforming financial support from exogeneity to endogenity and marketizing rural finance so as to effectively solve the efficiency of rural finance. 展开更多
关键词 Rural finance Pagano modelm theory of constraint Organization innovation China
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On Detecting and Enforcing the Non-Relational Constraints Associated to Dyadic Relations in MatBase
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作者 Christian Mancas 《Journal of Electronic & Information Systems》 2020年第2期1-8,共8页
MatBase is a prototype data and knowledge base management expert intelligent system based on the Relational,Entity-Relationship,and(Elementary)Mathematical Data Models.Dyadic relationships are quite common in data mod... MatBase is a prototype data and knowledge base management expert intelligent system based on the Relational,Entity-Relationship,and(Elementary)Mathematical Data Models.Dyadic relationships are quite common in data modeling.Besides their relational-type constraints,they often exhibit mathematical properties that are not covered by the Relational Data Model.This paper presents and discusses the MatBase algorithm that assists database designers in discovering all non-relational constraints associated to them,as well as its algorithm for enforcing them,thus providing a significantly higher degree of data quality. 展开更多
关键词 Conceptual data modeling Database constraints theory Non-relational constraints Data structures and algorithms for data management Dyadic relation properties Data quality (Elementary)Mathematical Data Model MatBase
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ON THE RELATIONSHIP BETWEEN THE VACCO MODEL AND CHETAEV MODEL
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作者 Liang, Lifu Liang, Zhongwei 《Acta Mechanica Solida Sinica》 SCIE EI 1994年第3期274-283,共10页
In this paper, the geometric property and the mechanical property of non-holonomic constraints are studied. Vacco equation is obtained by using the classical Hamilton principle. On the basis of Vacco equation, Chetaev... In this paper, the geometric property and the mechanical property of non-holonomic constraints are studied. Vacco equation is obtained by using the classical Hamilton principle. On the basis of Vacco equation, Chetaev condition is obtained by using mechanics principle of determining the ideal constraint. It is pointed out that the Vacco model is compatible with Chetaev model, so these two kinds of models are unified. 展开更多
关键词 constraint theory Geometry Mechanical properties MECHANICS VELOCITY
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Analyzing the time buffer in the Theory of Constraints based lean operations 被引量:2
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作者 Xiaofeng Zhao Jianrong Hou 《Journal of Management Analytics》 EI 2014年第3期185-199,共15页
This paper uses quantitative methods to estimate the size of the time buffer in lean operations controlled by the Theory of Constraints(TOC).The main focus of the operations system of TOC is the identification and man... This paper uses quantitative methods to estimate the size of the time buffer in lean operations controlled by the Theory of Constraints(TOC).The main focus of the operations system of TOC is the identification and management of constraints.To protect the constraints,they should be buffered with time buffers,which protecting the system’s output from disruptions and fluctuations.Despite the importance of time buffers,the approaches to identifying the size of the time buffer in literature are very empirical.In this paper,a queuing-theory based method is applied to calculate the time buffer sizes.It provides a mathematically exact expression for the coefficient of variation of waiting time for Markov queues.It then applies the concept of isomorphism to approximate the variance of customer waiting time in a general queue.Simulation experiments are conducted to verify the accuracy of approximation. 展开更多
关键词 theory of constraints lean operations queuing theory time buffer
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Development of a Theory of Constraints Based Scheduling System for Ship Piping Production
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作者 李瑞 濵田邦裕 下反贵裕 《Journal of Shanghai Jiaotong university(Science)》 EI 2010年第3期354-362,共9页
Manufacturing of ship piping system is one of the major production activities in shipbuilding.The schedule of pipe production has an important impact on master schedule of shipbuilding.In this research,the theory of c... Manufacturing of ship piping system is one of the major production activities in shipbuilding.The schedule of pipe production has an important impact on master schedule of shipbuilding.In this research,the theory of constraints(TOC) concept is introduced to solve the scheduling problems of piping factory,and an intelligent scheduling system is developed.The system integrates a product model,an operation model,a factory model and a knowledge database of piping production and can make the process planning and production scheduling automatically.In the paper,details of above points are discussed.Moreover,an application of the system in a piping factory,which achieves a higher level of performance as measured by tardiness,lead time and inventory,is demonstrated at the end of the paper. 展开更多
关键词 piping factory scheduling system theory of constraints(TOC)
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3D reconstruction based on spatial vanishing information 被引量:4
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作者 舒远 谈正 《Chinese Optics Letters》 SCIE EI CAS CSCD 2005年第3期146-148,共3页
An approach for the three-dimensional (3D) reconstruction of architectural scenes from two un-calibrated images is described in this paper. Prom two views of one architectural structure, three pairs of corresponding v... An approach for the three-dimensional (3D) reconstruction of architectural scenes from two un-calibrated images is described in this paper. Prom two views of one architectural structure, three pairs of corresponding vanishing points of three major mutual orthogonal directions can be extracted. The simple but powerful constraints of parallelism and orthogonal lines in architectural scenes can be used to calibrate the cameras and to recover the 3D information of the structure. This approach is applied to the real images of architectural scenes, and a 3D model of a building in virtual reality modelling language (VRML) format is presented which illustrates the method with successful performance. 展开更多
关键词 constraint theory Image processing Mathematical models Three dimensional Virtual reality
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Interactive Inconsistency Fixing in Feature Modeling
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作者 王波 熊英飞 +3 位作者 胡振江 赵海燕 张伟 梅宏 《Journal of Computer Science & Technology》 SCIE EI CSCD 2014年第4期724-736,共13页
Feature models have been widely adopted to reuse the requirements of a set of similar products in a domain. In feature models' construction, one basic task is to ensure the consistency of feature models, which often ... Feature models have been widely adopted to reuse the requirements of a set of similar products in a domain. In feature models' construction, one basic task is to ensure the consistency of feature models, which often involves detecting and fixing of inconsistencies in feature models. While many approaches have been proposed, most of them focus on detecting inconsistencies rather than fixing inconsistencies. In this paper, we propose a novel dynamic-priority based approach to interactively fixing inconsistencies in feature models, and report an implementation of a system that not only automatically recommends a solution to fixing inconsistencies but also supports domain analysts to gradually reach the desirable solution by dynamically adjusting priorities of constraints. The key technical contribution is, as far as we are aware, the first application of the constraint hierarchy theory to feature modeling, where the degree of domain analysts' confidence on constraints is expressed by using priority and inconsistencies are resolved by deleting one or more lower-priority constraints. Two case studies demonstrate the usability and scalability (efficiency) of our new approach. 展开更多
关键词 fixing software engineering requirement engineering feature modeling constraint hierarchy theory INCONSISTENCY
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