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OBJECT ORIENTED DATA MODELLING WITH APPLICATIONS TO CAD
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作者 应维云 傅向阳 周儒荣 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1996年第2期69+63-68,共7页
An object oriented data modelling in computer aided design (CAD) databases is focused. Starting with the discussion of data modelling requirements for CAD applications, appropriate data modelling features are introdu... An object oriented data modelling in computer aided design (CAD) databases is focused. Starting with the discussion of data modelling requirements for CAD applications, appropriate data modelling features are introduced herewith. A feasible approach to select the “best” data model for an application is to analyze the data which has to be stored in the database. A data model is appropriate for modelling a given task if the information of the application environment can be easily mapped to the data model. Thus, the involved data are analyzed and then object oriented data model appropriate for CAD applications are derived. Based on the reviewed object oriented techniques applied in CAD, object oriented data modelling in CAD is addressed in details. At last 3D geometrical data models and implementation of their data model using the object oriented method are presented. 展开更多
关键词 computer aided design DATABASES data models object oriented data models complex objects geometrical models
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Polarization Projection for 3D Geometry-Based Stochastic Channel Model
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作者 PANG Lihua ZHANG Yang +5 位作者 GONG Fengkui WANG Anyi XIAO Liyuan LIANG Xiao WANG Qiaofeng LI Jiandong 《China Communications》 SCIE CSCD 2015年第10期52-63,共12页
Comprehensive radiation characteristics of polarized antenna are crucial in creating practical channel coefficients for next generation wireless communication system designs.Being currently supported within3 D geometr... Comprehensive radiation characteristics of polarized antenna are crucial in creating practical channel coefficients for next generation wireless communication system designs.Being currently supported within3 D geometry-based stochastic channel models(GSCM),field patterns are technically obtained by chamber measurement(or by its best fitting).However,in some channel related performance analysis scenarios,design insight can be crystallized better by starting the derivations with theoretical co-polarization and cross-polarization components.Specifically,these two components are mathematically linked with field patterns through the proposed polarization projection algorithm.In this manuscript,we focus on revealing the transformation criterion of polarization states between the antenna plane and the propagation plane.In practice,it makes retrieving the field patterns by electromagnetic computation possible.Meanwhile,the impact imposed by distinct antenna orientations is geometrically illustrated and consequently incorporated into the proposed algorithm.This will further facilitate flexible performance evaluation of related radio transmission technologies.Our conclusions are verified by the closed-form expression of the dipole field pattern(via an analytical approach) and by chamber measurement results.Moreover,we find that its 2D degenerative case is aligned with the definitions in 3^(rd) generation partnership project(3GPP)technical report 25.996.The most obvious benefit of the proposed algorithm is to significantly reduce the cost on generating channel coefficients in GSCM simulation. 展开更多
关键词 polarization 3D geometry-based stochastic channel model antenna orientation radiation characteristics dipole chamber measurement channel simulation
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The Feature-Based a New Object Coding Approach for Prismatic Parts at the Part Modeling
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作者 Ismet Celik Ali Unuvar 《Modeling and Numerical Simulation of Material Science》 2013年第4期129-138,共10页
Use of features in order to achieve the integration of design and manufacture has been considered to be a key factor recent years. Features such as manufacturing properties form the workpiece. Features are structured ... Use of features in order to achieve the integration of design and manufacture has been considered to be a key factor recent years. Features such as manufacturing properties form the workpiece. Features are structured systematically through object oriented modeling. This article explains an object coding method developed for prismatic workpieces and the use of that method in process planning. Features have been determined and modeled as objects. Features have been coded according to their types and locations on the workpiece in this given method. Feature codings have been seen to be very advantageous in process planning. 展开更多
关键词 FEATURE Feature Based modeling Object Oriented modeling Process Planning
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Research on Opportunity-Driven Redesign Process to Cooperate With Training Innovative Engineers in China 被引量:3
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作者 Run-Hua Tan Ya-Fan Dong +1 位作者 Bo-Jun Yang Peng Zhang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第4期148-159,共12页
Many design engineers in cross-domain industries have attended training classes of TRIZ to improve their innovative abilities in China. Most of them are successful, but others are not. So the latest target of the trai... Many design engineers in cross-domain industries have attended training classes of TRIZ to improve their innovative abilities in China. Most of them are successful, but others are not. So the latest target of the trainers is to improve the training process used now in industry in China and to make the engineers to understand the basic principles of TRIZ better. Based on the mass-engineer-oriented training model(MEOTM) and mechanical engineers’ design cases, a relationship between managing activities about the opportunities for innovation and the training process is set up. It is shown that the inventive problems come first from opportunity searching for engineers. A training and gate system for evaluation is developed to involve the managing activities of the companies in the training process. Then comparison between the general analogous process and the application of TRIZ is made, which shows the advantages and depth principles of TRIZ for the engineers to apply them confidently. Lastly a new process is formed in which opportunity searching, engineers training, inventive problems identifying and solving,and three redesign paths are connected seamlessly. The research proposes an opportunity-driven redesign path that cooperates the training and opportunity searching, which will be applied in future training classes to make more and more engineers to follow. 展开更多
关键词 TRIZ Mass-engineer oriented training model Redesign path Opportunity-driven Redesign process
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Fingerprint singular points extraction based on the properties of orientation model 被引量:1
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作者 SU Fei SUN Peng +1 位作者 WANG Bo-tao CAI An-ni 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2011年第1期98-104,共7页
A novel method for fingerprint singular points extraction including location and orientation is proposed based on some properties of the orientation field models. Singular points are located by clustering the results ... A novel method for fingerprint singular points extraction including location and orientation is proposed based on some properties of the orientation field models. Singular points are located by clustering the results of corner detection. Then, through examining the sub-block orientation fields at a number of selected positions on concentric circles centered about the located singular point, an iterative method based on the orientation differences is proposed to compute the orientation of the core point. Experimental results on NIST4 and FVC2002 four databases demonstrate the proposed method can consistently locate singular points with the high accuracy. The location and orientation of the detected singular points can be used for alignment (translation and rotation) parameters in fingerprint matching. 展开更多
关键词 FINGERPRINT orientation model singular points CORE DELTA
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Agent-oriented Aid-modeling for the Distributed Activity Network 被引量:4
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作者 DENG Gui\|shi\+1,\ LI Wen\|lei\+1,\ O. Moeschlin\+2 1.Institute of Systems Engineering, Dalian University of Technology Dalian 116024, China 2.Department of Mathematics, Fern University in Hagen, D 58084 Germany 《Systems Science and Systems Engineering》 CSCD 2000年第1期65-71,共7页
An agent in the decision support system (DSS) has to cope with quantitative analysis processing normally. However, from the view of agent working style, the agent oriented aid modeling operations need new procedure ... An agent in the decision support system (DSS) has to cope with quantitative analysis processing normally. However, from the view of agent working style, the agent oriented aid modeling operations need new procedure accepted by the agent. For example, in the distributed activity planning processes, the transforming problem description has to use a unified pattern first, then to compute the activity′s 6 time parameters, activity′s duration, entity plan scheme, optimal calculation and so on. In this paper, we propose a process manner of agent oriented modeling for the distributed activity network. The goal is to introduce an agent working procedure included model usage, multi agent cooperating, communicating among agents and interaction between system and human. Also, it included the problem representation, the initial process, agent design, transform and the computing with interaction in detail. 展开更多
关键词 AGENT agent oriented aid modeling multi agent cooperation
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