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GEOMETRIC DESIGN OF DEPLOYABLE/RETRACTABLE MAST 被引量:1
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作者 杨玉龙 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2006年第4期250-256,共7页
To simplify the complicated design process of deployable/retractable structures, a new design process is developed. The process is divided into three phases: the concept design phase, the model phase and the optimiza... To simplify the complicated design process of deployable/retractable structures, a new design process is developed. The process is divided into three phases: the concept design phase, the model phase and the optimization phase. In each phase, different parameter targets have to be fulfilled. According to three phases, a deployable/retractable mast composed of four right triangle prism modules in the longitudinal direction is designed. It can be deployed and folded simultaneously by the linear movements of sleeve-joints. The deployable and retractable movement of the mast is analyzed and key joint forms are designed. Then bar diameters and joint forms are modified based on mast structural mechanics characteristics in the optimization phase. Finally a 1:1 scaled model mast is built to verify the design and the optimization. Analytical results show that the model mast has the advantages of simple locking mechanism, fewer types of joints and bars, so it can be easily manufactured. 展开更多
关键词 deployable/retractable mast geometric design design process OPTIMIZATION
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APPLICATION OF MECHANICAL RELIABILITY PREDICATION BASED ON FUZZY THEORY 被引量:2
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作者 赵德孜 温卫东 段成美 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2004年第1期76-80,共5页
Mechanical reliability prediction (MRP) is an important task of mechanical reliability design. In the initial design stage (IDS), the lack of reliability data and some fuzzy characteristics of MRP make this work hardn... Mechanical reliability prediction (MRP) is an important task of mechanical reliability design. In the initial design stage (IDS), the lack of reliability data and some fuzzy characteristics of MRP make this work hardness. Because fuzzy synthetical assessment (FSA) can well utilize expert′s experience and fuzzy data, it is used to assess the influence factors of reliability. On the basis of the assessed results, the predicted value of reliability is inferred by the fuzzy inference system (FIS). This approach particularly suits to predict the reliability of complex machinery (including other products) in IDS, so that it can remedy some defects of the existing methods. An example is discussed to interpret how to utilize it. 展开更多
关键词 mechanical reliability reliability prediction fuzzy synthetical assessment fuzzy inference
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METHOD FOR ESTIMATING GEOMETIC CHARACTERISTICS OF NUMERICAL CONCEPTUAL AIRCRAFT MODELS BASED ON SURFACE ELEMENTS 被引量:2
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作者 刘虎 白振东 武哲 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2003年第2期140-146,共7页
To estimate the geometric characteristics, especially wet areas and section areas, of three dimensional numerical conceptual aircraft models, a method based on surface elements is proposed. On the premise that numerou... To estimate the geometric characteristics, especially wet areas and section areas, of three dimensional numerical conceptual aircraft models, a method based on surface elements is proposed. On the premise that numerous surface elements are generated to represent each component surface, a component wet area of the surface is estimated by adding up the areas of such elements that are not covered by any other component surfaces. The elements are also used to get the section polygons of such composite surfaces as the whole aircraft at a given body station, then a section area is approximated with the sum of trapezoidal areas between such sides of polygons that are not covered by any other component and a reference axis. Practical application to a computer aided aircraft conceptual design system shows that the methed is applicable to different kinds of conceptual aircraft models and its precision is satisfying to the conceptual design. 展开更多
关键词 wet areas section areas surface elements aircraft design
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COOPERATIVE DESIGN UNDER CONCURRENT ENGINEERING ENVIRONMENT 被引量:1
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作者 应维云 周儒荣 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1997年第1期98-103,共6页
This paper outlines a concurrent engineering environment that supports interaction between members of a geographically dispersed multidisciplinary team who is engaged in engineering design activities. Some ideas of en... This paper outlines a concurrent engineering environment that supports interaction between members of a geographically dispersed multidisciplinary team who is engaged in engineering design activities. Some ideas of engineering design, especially conceptual design are reviewed. A deeper scientific analysis of intelligent design is discussed. A new problem solving strategy and methodologies to implement cooperative design are proposed. Finally, a conceptual model of a blackboard system for accomplishing conceptual design automation is presented. Its fundamental principles, system organization and key implementation techniques are investigated in detail. 展开更多
关键词 CAD artificial intelligence cooperative design concurrent engineering conceptual design
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Shape Optimal System for Linear Elastic Structures
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作者 邢杰 蔡坪 《Journal of Beijing Institute of Technology》 EI CAS 1992年第2期103-110,共8页
An integrated system FSOP2D,including modules for the shape optimal modeling,structural analysis,sensitivity analysis,optimal method library and post- processing,is developed.By selecting fictitious loads as the desig... An integrated system FSOP2D,including modules for the shape optimal modeling,structural analysis,sensitivity analysis,optimal method library and post- processing,is developed.By selecting fictitious loads as the design variables that has a linear relationship with the grid point locations and using design sensitivity analysis of the domain method,it is easier to solve the velocity field.In the course of optimal iterations,mesh distortion is kept to a minimum,sensitivity derivatives of object function,stress constraints and displacement constraints are derived.Computation of sensitivity analysis is achieved in the system.Two engineering examples are used to prove the system's effectiveness,the optimal results can successfully be obtained by lesser number of iterations. 展开更多
关键词 optimum design finite element analysis sensitivity/shape optimum design design variable
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INTEGRATED DESIGN OF AN ELECTRIC POWERED UNMANNED AIR VEHICLE USING CONCURRENT SUBSPACE DESIGN 被引量:1
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作者 余雄庆 MarcA.Stelmack StephenM.Batill 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2000年第2期140-149,共10页
The concurrent subspace design (CSD) framework has been used to conduct a preliminary design optimization of an electric powered, unmanned air vehicle (EPUAV) operating at a low Reynolds number. A multidisciplinary sy... The concurrent subspace design (CSD) framework has been used to conduct a preliminary design optimization of an electric powered, unmanned air vehicle (EPUAV) operating at a low Reynolds number. A multidisciplinary system analysis that includes aerodynamics, weights, propulsion, performance and stability and control has been developed for this class of vehicles. The CSD framework employs artificial neural network based response surfaces to provide approximations to the design space. The EPUAV system includes 25 continuous and 4 discrete design variables. The CSD framework was able to identify feasible designs with significant weight reductions relative to any previously considered (i.e. initial database) designs. This was accomplished with a limited number of system analyses. The results also demonstrate the nature of this design framework adaptive to changes in design requirements. 展开更多
关键词 aircraft design multidisciplinary design optimization unmanned air vehicle OPTIMIZATION
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Research and Design of Sleeve Detach and Reunion Drive Mechanism of Screw Melt Extruder Equipment
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作者 张秀德 《Agricultural Science & Technology》 CAS 2012年第9期2034-2036,共3页
The design of sleeve detach and reunion drive device of screw melt ex- truder equipment was optimized, based on the present installation of hygraulic drive device to achieve the mechanical opening and closing of the s... The design of sleeve detach and reunion drive device of screw melt ex- truder equipment was optimized, based on the present installation of hygraulic drive device to achieve the mechanical opening and closing of the sleeve, the dynamic model of the sleeve detach and reunion drive was theoretically measured, and it was verified that the device is simple to operate and convenient to maintain, thus it has great social values. 展开更多
关键词 Clutch device Hydraulic cylinder LINKAGE Bearing connection SLEEVE
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TOOTH CROWN DEFORMABLE DESIGN BASED ON DIRECT MANIPULATION OF FFD
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作者 程筱胜 俞青 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第4期285-290,共6页
A flexible and adaptable design method for the tooth crown is presented based on the direct manipulation of free-form deformation (FFD). The correct shape of the tooth crown can be obtained by adding, modifying, and... A flexible and adaptable design method for the tooth crown is presented based on the direct manipulation of free-form deformation (FFD). The correct shape of the tooth crown can be obtained by adding, modifying, and deleting constraint points or load points based on stretching and compressing operation. Finally, an example is given to illustrate the method to be efficient. 展开更多
关键词 free-form deformation deformable design design for tooth crowns prosthodontics CAD/CAM
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AN APPROACH TO FEATURE-BASED PARAMETRIC DESIGN FOR DIE AND MOULD
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作者 翟建军 陈文亮 +1 位作者 黄翔 陈普仁 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1995年第2期168-171,共4页
An approach to feature-based parametric design for die and mould is proposed in this paper.The assembly relationship and parts of the die and mould are described by feature.The dependent relationship of features is de... An approach to feature-based parametric design for die and mould is proposed in this paper.The assembly relationship and parts of the die and mould are described by feature.The dependent relationship of features is described by parent-child operator structure.The feature shape and location can be modified by design parameters.An expert system is used for deriving a geometry of the features which satisfies the given constraints.This approach provides a more natural and convenient method of representing a parametric model of the die and mould. 展开更多
关键词 FEATURES expert systems computer aided design parametric design parent-child operator
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Landscape Design Method of Sustainable Development Based on the Modest Principle
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作者 许克福 龚杰 《Agricultural Science & Technology》 CAS 2016年第3期717-720,共4页
"Over" phenomenon exists in all fields of society, and over thoughts and behaviors not only waste resources, but also destroy the ecological environment.Landscape design is also facing the dilemma of over planning, ... "Over" phenomenon exists in all fields of society, and over thoughts and behaviors not only waste resources, but also destroy the ecological environment.Landscape design is also facing the dilemma of over planning, over design and over construction. Based on the paraphrase and explanation of "degree", the principle for modest landscape design with the concept of sustainable development was explored through the analysis on the concept of sustainable development, which emphasized the "degree" standard in landscape design, and the combination of regional features with native features to carry out ecological design, with the aim to facilitate the landscape designers to design the "modest" landscape with sustainable development. 展开更多
关键词 Over-design Sustainable development Landscape design MODEST Ecological design
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Village Renovation Advancement in Underdeveloped Areas based on Village Allocation Planning
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作者 李小云 易蓉 《Agricultural Science & Technology》 CAS 2015年第7期1531-1534,共4页
The research proposed the thoughts and countermeasures for advancing village renovation from the perspectives of formulating village renovation plans, pro- tecting building culture, reinforcing village administration,... The research proposed the thoughts and countermeasures for advancing village renovation from the perspectives of formulating village renovation plans, pro- tecting building culture, reinforcing village administration, improving supporting facili- ties and establishing multi-channel investment and financing mechanisms, on basis of status quo and problems of village constructions in underdeveloped areas. 展开更多
关键词 Village allocation Construction of new countryside Construction of beautiful countryside Village renovation
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Design of Aided Decision-Making Program for Prioritizing Construction Projects in Urban Road Network Planning
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作者 任刚 王炜 顾志康 《Journal of Southeast University(English Edition)》 EI CAS 2002年第3期249-253,共5页
The importance and complexity of prioritizing construction projects (PCP) in urban road network planning lead to the necessity to develop an aided decision making program (ADMP). Cost benefit ratio model and stage rol... The importance and complexity of prioritizing construction projects (PCP) in urban road network planning lead to the necessity to develop an aided decision making program (ADMP). Cost benefit ratio model and stage rolled method are chosen as the theoretical foundations of the program, and then benefit model is improved to accord with the actuality of urban traffic in China. Consequently, program flows, module functions and data structures are designed, and particularly an original data structure of road ... 展开更多
关键词 prioritizing construction projects program design urban road network planning aided decision making
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Device Robust-Design by Using Response Surface Methodology
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作者 谢晓锋 鲁勇 +1 位作者 张文俊 杨之廉 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2002年第8期817-824,共8页
Device robust-design is inherently a multiple-objective optimization problem.Using design of experiments (DoE) combined with response surface methodology (RSM) can satisfy the great incentive to reduce the number of t... Device robust-design is inherently a multiple-objective optimization problem.Using design of experiments (DoE) combined with response surface methodology (RSM) can satisfy the great incentive to reduce the number of technology CAD(TCAD) simulations that need to be performed.However,the errors of RSM models might be large enough to diminish the validity of the results for some nonlinear problems.To find the feasible design space,a new method with objectives-oriented design in generations that takes the errors of RSM model into account is presented.After the augment design of experiments in promising space according to the results of RSM model in current generation,the feasible space will be emerging as the model errors deceasing.The results on FIBMOS examples show that the methodology is efficient. 展开更多
关键词 response surface methodology design of experiments device robust-design
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On the mode of CRI English assisting college English teaching
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作者 纪鸿 《Sino-US English Teaching》 2007年第5期70-73,共4页
The English News of CRI possesses many advantages such as abundance of information and being easily accessible for English learners within the mainland of China. Unfortunately, it has been ignored by most teachers of ... The English News of CRI possesses many advantages such as abundance of information and being easily accessible for English learners within the mainland of China. Unfortunately, it has been ignored by most teachers of English and students. Based on the input hypothesis, affective filter hypothesis and schemata theory, this paper probes the mode of CRI English assisting English teaching in college. 展开更多
关键词 input hypothesis affective filter hypothesis schemata CRI listening teaching
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Integrated Assembly Structure Design Within Concurrent Engineering
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作者 常向青 宁汝新 +2 位作者 姚珺 张旭 唐承统 《Journal of Beijing Institute of Technology》 EI CAS 2001年第3期306-311,共6页
Taking a microwave product as an example, a system of integrated assembly structure design is presented. Getting design constraints from the upstream design section through product data management(PDM), the system gen... Taking a microwave product as an example, a system of integrated assembly structure design is presented. Getting design constraints from the upstream design section through product data management(PDM), the system generates the assembly scheme using the case? based method, then assigns the design requirements into each component of the assembly. The detail design for each component can be performed under these design constraints. In order to practise concurrent design, the system sends the final design result to the upstream section and downstream section through PDM to achieve information sharing and integration. 展开更多
关键词 concurrent engineering assembly structure design case-based reasoning design constraints
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A FORMAL REPRESENTATION FOR FEATURE-BASED DESIGN 被引量:1
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作者 孙正兴 丁秋林 张福炎 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1997年第1期37-46,共10页
Feature based design has been regarded as a promising approach for CAD/CAM integration.This paper aims to establish a domain independent representation formalism for feature based design in three aspects: formal re... Feature based design has been regarded as a promising approach for CAD/CAM integration.This paper aims to establish a domain independent representation formalism for feature based design in three aspects: formal representation,design process model and design algorithm.The implementing scheme and formal description of feature taxonomy,feature operator,feature model validation and feature transformation are given in the paper.The feature based design process model suited for either sequencial or concurrent engineering is proposed and its application to product structural design and process plan design is presented. Some general design algorithms for developing feature based design system are also addressed.The proposed scheme provides a formal methodology elementary for feature based design system development and operation in a structural way. 展开更多
关键词 CAD CAM product modelling design process feature based design representation formalism
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RELATION BETWEEN THE MRT BUILDING AND UNDERGROUND SPACE EXPLOITATION——A Case in Guangzhou City 被引量:5
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作者 LIWen-ling YANXiao-pei WANGFang 《Chinese Geographical Science》 SCIE CSCD 2003年第4期364-369,共6页
On the basis of analyzing the history and characteristics of the undergroundspace exploitation and the urban space development in Guangzhou, and making a thorough study on theunderground space exploitation based on th... On the basis of analyzing the history and characteristics of the undergroundspace exploitation and the urban space development in Guangzhou, and making a thorough study on theunderground space exploitation based on the subway building, this paper points out some mam problemsin the exploitation of underground space in Guangzhou, and emphasizes that Guangzhou must developthe underground space on a large scale with the aid of the subway building, and puts forward aproposal on the urban space coordinate development between on-ground and underground in GuangzhouCity. 展开更多
关键词 metro rail transit (MRT) underground space Guangzhou city
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Optimal design of pressure vessel using an improved genetic algorithm 被引量:5
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作者 Peng-fei LIU Ping XU +1 位作者 Shu-xin HAN Jin-yang ZHENG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第9期1264-1269,共6页
As the idea of simulated annealing (SA) is introduced into the fitness function, an improved genetic algorithm (GA) is proposed to perform the optimal design of a pressure vessel which aims to attain the minimum weigh... As the idea of simulated annealing (SA) is introduced into the fitness function, an improved genetic algorithm (GA) is proposed to perform the optimal design of a pressure vessel which aims to attain the minimum weight under burst pressure con- straint. The actual burst pressure is calculated using the arc-length and restart analysis in finite element analysis (FEA). A penalty function in the fitness function is proposed to deal with the constrained problem. The effects of the population size and the number of generations in the GA on the weight and burst pressure of the vessel are explored. The optimization results using the proposed GA are also compared with those using the simple GA and the conventional Monte Carlo method. 展开更多
关键词 Pressure vessel Optimal design Genetic algorithm (GA) Simulated annealing (SA) Finite element analysis (FEA)
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Research of CRP-based irregular 2D seismic acquisition 被引量:1
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作者 赵虎 尹成 +2 位作者 何光明 陈爱萍 敬龙江 《Applied Geophysics》 SCIE CSCD 2015年第1期73-78,122,共7页
Seismic exploration in the mountainous areas of western Chinese is extremely difficult because of the complexity of the surface and subsurface, which results in shooting difficulties, seismic data with low signal-to-n... Seismic exploration in the mountainous areas of western Chinese is extremely difficult because of the complexity of the surface and subsurface, which results in shooting difficulties, seismic data with low signal-to-noise ratio, and strong interference. The complexity of the subsurface structure leads to strong scattering of the refl ection points; thus, the curved-line acquisition method has been used. However, the actual subsurface structural characteristics have been rarely considered. We propose a design method for irregular acquisition based on common refl ection points(CRP) to avoid difficult-to-shoot areas, while considering the structural characteristics and CRP positions and optimizing the surfacereceiving line position. We arrange the positions of the receiving points to ensure as little dispersion of subsurface CRP as possible to improve the signal-to-noise ratio of the seismic data. We verify the applicability of the method using actual data from a site in Sichuan Basin. The proposed method apparently solves the problem of seismic data acquisition and facilitates seismic exploration in structurally complex areas. 展开更多
关键词 Geometry design irregular geometry acquisition design seismic data acquisition CRP analysis
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Spatial Distribution Pattern and Han Subgroup Characteristics of Traditional Villages in Guangdong 被引量:2
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作者 YUAN Shaoxiong YIN Xiaoling +2 位作者 XIONG Haixian SUN Zhongyu HUANG Guangqing 《Journal of Landscape Research》 2018年第1期25-32,共8页
A total of 126 traditional villages in Guangdong were selected for research to analyze their spatial distribution pattern, spatial autocorrelation, and Han subgroup characteristics through the spatial analysis with GI... A total of 126 traditional villages in Guangdong were selected for research to analyze their spatial distribution pattern, spatial autocorrelation, and Han subgroup characteristics through the spatial analysis with GIS. The results showed that the traditional villages in Guangdong were distributed compactly, which was similar to that in other provinces; on the prefecture-level city scale, they were mainly distributed in Meizhou, Qingyuan, Zhanjiang, and Zhaoqing, showing a central distribution; on the regional scale, they were mainly distributed in northern Guangdong and the Pearl River Delta, indicating an unbalanced distribution; their density of spatial distribution showed a significant difference with a provincial distribution density of 0.59 per thousand km^2 and the highest distribution density of 2.14 per thousand km^2; there were four gathering areas accommodating many traditional villages, namely Meizhou-Chaoshan area, Guangfo-Dongguan area, Leizhou in Zhanjiang, and Lianzhou in Qingyuan; the spatial distribution of traditional villages, which presented a pattern of hot spot—sub-hot spot—sub-cold spot—cold spot, had a significant global spatial autocorrelation, and areas in similar sizes were tending towards gathering; traditional villages in Guangdong belonged to the Cantonese-speaking group and Hakka-speaking group with a density of 0.59 per thousand km^2 and 0.48 per thousand km^2 respectively, and Han subgroup with the highest distribution density was the minority areas of 1.31 per thousand km^2, followed by Shaozhou dialect area with a density of 1.00 per thousand km^2. 展开更多
关键词 Traditional villages Spatial distribution pattern Spatial autocorrelation Han subgroup distribution GUANGDONG
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