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1.
IntroductionAdvances in computer networks and informationtechnology have enabled product designers tomore effectively communicate,collaborate,ob-tain and exchange a wide range of design re-sources during product development.ComputerSupported Cooperative Work( CSCW) describesa research area concerned with people working ingroups and computer systems supporting them,and collaborative design is an important applica-tion of CSCW.Collaborative design has typicallydistributed multiple functional…  相似文献   

2.
IntroductionThe learning approaches of neural network canusually be distinguished into three classes:su-pervised learning,unsupervised learning and re-inforcement learning.The supervised learningscheme has the highest efficiency but requiresthe learning systems to provide with desired out-puts.Obviously,it is very difficultin many cas-es.Unsupervised learning methods constructin-ternal models at capture regularities in their in-puts without receiving any additional informa-tion.Therefore,its …  相似文献   

3.
IntroductionDynamics of almost all plants in reality variesaccording to the condition under which the plantis operated.An idea to describe the variation ofplant dynamics is interpolating a number of rep-resentative models defined at representative op-erating points.In Ref. [1 ] ,the plant was as-sumed to described as a linear interpolation ofproper stable coprime factorizations of transferfunctions of two representative models and thestabilization problems have been considered. InRef.[2 ] ,it…  相似文献   

4.
IntroductionBecause of the differences of crystal chemistryproperties,physical properties and surface con-ditions between ceramic and metal,the metallur-gical compatibility is very poor.It is essential tochoose suitable interlayer materials to achievethe high strengh ceramic/ metal joint.Interlayermaterials must be suitable to the propertieswhich( 1 ) would obviously reduce residual stress injoint,which may occur during cooling period be-cause of the differnet thermal expansion coeffi-cient be…  相似文献   

5.
IntroductionIt is very important to master the locomotionprinciple of a micro piezoelectric actuator for peo-ple to design a micro piezoelectric actuator or arobot. so far,experimental method has been theonly approach available to design a micro piezoelec-tric actuator or a robot[1~ 4 ] .As a result,itis diffi-cult to make a parameterized design or an optimaldesign for a micro piezoelectric robot. Therefore,it is in dire need to constitute the locomotion equa-tion of the robot. In the paper,t…  相似文献   

6.
IntroductionWall- climbing robots with magnetic tracks arewidely used in the fields such as oil tank surfaceinspection,paints spraying shown in Fig.1 .Therobot attaches to the steel wall surface due to anumber of magnetic suckers on both tracks andis driven by the rear chain wheels. In order todecrease the robot's weight and improve its at-tractive ability on steel wall surface,the mag-netic suckers should be small in size,light inweight and powerful in attractive force.Theseare some of the i…  相似文献   

7.
PREDICTION OF WELDING DEFORMATIONS BY FEM BASED ON INHERENT STRAINS   总被引:6,自引:0,他引:6  
IntroductionIt is of importance to predict and control theresidual deformations caused by welding pro-cesses to ensure the accuracy of a welded produc-tion.Nowadays there are three ways to deter-mine the welding deformations:( 1 ) empiricalformulas or curves based on the experiments;( 2 ) thermo- elasto- plastic analysis by FEM;( 3)inherent strain method.The empirical formulasare only suited to the cases of simple plates orbeams that undergo a welding cycle close to theexperiment conditions. …  相似文献   

8.
IntroductionCase- Based Reasoning ( CBR) ,as a relativelynew methodology,has attracted wide concern ofAI researchers since1 980 's.The number of suc-cessful applications of CBR is growing rapidly,especially in the fields of architecture and indus-try,e.g. ARCHI- II[1] for the architecture designof courthouse and MIDAS[2 ] for the conceptualdesign of aircraft.The currently prevailing CBD systems mostlytreat cases as instances of some predeterminedand static case template.Such an appro…  相似文献   

9.
IntroductionMany investigators have investigated rigid lineinclusion and elastic inclusion problem.Early inthe 60 s,there were investigations aboutthe ex-perimental respects[1,2 ] and theoretical re-spects[3,4] of the inclusion problem . Wang etal[5 ]discussed the elastic stress field near the rigidline tips carefully.They put forward three frac-ture models of rigid lines corresponding to thethree fracture models of cracks and they pro-posed to use stress singularity coefficient( SSC)to desc…  相似文献   

10.
MERGING AND SPLITTING SECOND-ORDER SELF-SIMILAR PROCESSES (TRAFFICS)   总被引:2,自引:0,他引:2  
Recent traffic measurements in corporate LANs, Variable-Bit-Rate (VBR) video sources, ISDN control channels, and other communication systems, have indicated traffic behavior of self-similar nature, which has implications for design, control and analysis of high-speed networks. Merging and splitting are two basic networking operations. This paper gave the necessary and sufficient conditions for that merging of second-order self-similar traffic streams also results in a second-order self-similar stream. It shows that splitting traffic streams of the second-order self-similar stream are still self-similar streams by the independent splitting operation.  相似文献   

11.
IntroductionSafe,reliable and economical operation is thegoal of any industrial process control system,particularly in nuclear power industry,wherecatastrophic events can have severe economic andsafety consequences and where even small degra-dation in plant performance can result in largereplacement power costs.After the TMI acci-dent in1 979,a large number of computer- baseddiagnostic systems have been proposed to sup-port nuclear power plant ( NPP) operators.Theearly diagnostic approaches …  相似文献   

12.
IntroductionHMM method and neural networks as a feasiblemethod have been used in speech recognitionsystem for several years,many improved meth-ods are still being discussed and proposed to en-hance its performance.On the basis of tradition-al HMM method and selection mechanism ,anew CSL algorithm ( competitive and selectivelearning neural networks) is proposed in this pa-per,which enables the system to avoid localminimum and have high recognition rate usingwith HMM and PSHNN.Isodistortio…  相似文献   

13.
多抗甲素是我国首创的甲型链球菌抗癌制剂。动物实验及临床应用证明该药具有抑瘤作用,但对其作用机制不甚明了。本文用小鼠S180实体瘤对多抗甲素抑制肿瘤的机制进行了初步探讨实验结果表明多抗甲素确有抑瘤作用。多抗甲素可激活Mφ,使其呈现典型的活化特征,活化Mφ在体外粘附及杀伤瘤细胞能力增强:用药后瘤周浸润的Mφ数目增多,肿瘤出血坏死更为显著;提示在多抗甲素抑瘤效应中活化的Mφ起着重要作用。实验结果还提示多抗甲素的直接细胞毒性作用及宿主的特异性抗肿瘤免疫在本实验的抑瘤效应中并无实际意义。  相似文献   

14.
IntroductionIt is obvious that the gas flow in the exhaustmanifolds,especially at the conjunctions has amulti- dimensional characteristic[1] .The study onthis characteristic is very important for the uti-lization of exhaustenergy and the decrease of ex-haust pumping loss.In this paper,the measure-ment of cold flow has been carried out to studythe multi- dimensional phenomena of unsteadyflow in the exhaust manifolds.In order to em-phasis the important characteristics of the flowand reduce the a…  相似文献   

15.
IntroductionPhonetic and segmentvocoders are popular tech-niques used in speech coding at rates on the or-der of 1 0 0 bit/s.These coders are based onrecognition/synthesis technique.They use somekind of speech recognition technique to decom-pose speech signals to sequence of speech units,such as phonetic units or speech segment units,and then transmit indexes and durations of therecognized units.The decoders receive this in-formation,and synthesize speech by concatenat-ing typical instances of…  相似文献   

16.
IntroductionThe conventional passive constrained layerdamping (PCLD) treatments[1~ 3] are applied tomachines and structures widely over the lastcentu-ry because they are reliable and simple,however,they are not intelligent. Once the damping treat-ments are installed,they can not be adjusted andcan not adapt themselves to changeable environ-ment.Recently,active damping has received in-creasing attention in the aeronautic and astronauticindustries because of its significant and adjustabledamp…  相似文献   

17.
GLOBAL MEASURE ON IMAGE CONTENT   总被引:1,自引:0,他引:1  
IntroductionContent- based image retrieval has been proposedto allow retrieval to be performed on the basis ofa variety of aspects of image content[1] .A chal-lenging problem arises with many imagedatabases,within which queries are posed via vi-sual or pictorial examples.A common visualquery to an image database system would involvefinding all images in the database which containa subimage that is similar to the query image.Such retrievals must be based on embedded con-tent features,such as sh…  相似文献   

18.
建筑结构实验改革是土木工程专业学生素质化教育的主要途径.本文研究了实验课程的规范化管理、实验室开放、教学法改革和信息化体系的建设.  相似文献   

19.
以高等海事院校为背景,采用田纳西自我概念量表和临床症状自评量表(SCL-90),对355名大学生进行问卷调查与统计分析,了解在校航海类专业大学生自我概念与心理健康水平及其相关,为航海类专业大学生心理咨询、自我健康发展提供心理学依据.  相似文献   

20.
介绍了船舶避碰决策研究中的船舶碰撞危险度的确定方法,综合分析评价了船舶避碰决策系统的研究现状,指出基于AIS信息环境的船舶避碰决策系统研究是未来船舶自动避碰决策系统研究的新方向.  相似文献   

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