• Title/Summary/Keyword: Function Representation

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An Expert System for Yarn Spinning Process Planning and Quality Characteristics Control in Textile Industry

  • Kwon, Young-il;Song, Suh-ill
    • Journal of Korean Society for Quality Management
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    • v.20 no.1
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    • pp.147-157
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    • 1992
  • This article describes a prototype expert system for yarn spinning process planning in textile industry. This expert system is intended as a consultant to give the technicians interactive assistance for the appropriate process planning in accordance with used materials, required count, and other factors affected yarn spinning by means of many types of machine. Also, this system has the other function that can be compared the standard values with the measured ones for quality characteristics control. VP-EXPERT-a rule-based microcomputer expert system development tool-provides the expert system components for this development. The details of knowledge organization, rule representation, inference reasoning process, and performance of this expert system are demonstrated with the practical yarn spinning operations.

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Network Reduction Method for Power System Transient Analysis ; Time-Domain Formulation Based On The Network Function (과도 상태 해석을 위한 계통 축약법 ; 계통 함수를 이용한 시간 영역 해석법)

  • Hong, J.H.;Kang, Y.C.;Cho, K.R.;Park, J.K.
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.417-421
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    • 1991
  • In electromagnetic transient analysis, complex transmission system should be modelled in detail. But in large system, this full representation of power transmission system has a big burden in many sides such as computation time, modelling efforts, etc. It is very required, therefore, in electromagnetic transients studies to represent parts of a complete system in a reduced or an equivalent form. This paper develops the method from which system equivalents may be derived. The suggested method is of an essentially transient form, and allows travelling wave interaction between the equivalent and explicit transmission network to be modelled.

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Expert-novice differences in visual information processing in air traffic control (항공관제 전문가와 훈련관제사의 시각정보처리 차이)

  • Kwon, Hyok-Jin;Ham, Seong-Soo;Kim, Hye-Jeong;Han, Jung-Won;Sohn, Young-Woo
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.18 no.1
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    • pp.72-82
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    • 2010
  • This study investigated how air traffic controllers (ATCs) perceive the visual information on radar screen and examined quantitative and qualitative differences as a function of expertise. Little research has shown that how much information is processed by ATC visually and perceptually, how ATCs represent the information, and what difference exists between experts and novices. Participants were asked to draw representing visual information on the blank sector map after a 5-second exposure. Data were analyzed by a superimposing method to identify correctly represented information. Results showed that the expert group had much larger size of chunking and their pattern was wider and more accurate than the novice group. The practical application and methodological implications are also discussed for further research.

A Genetic Algorithm for Improving the Workload Smoothness in Mixed Model Assembly Lines (혼합모델 조립라인에서 작업부하의 평활화를 위한 유전알고리듬)

  • Kim, Yeo-Keun;Lee, Soo-Yeon;Kim, Yong-Ju
    • Journal of Korean Institute of Industrial Engineers
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    • v.23 no.3
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    • pp.515-532
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    • 1997
  • When balancing mixed model assembly lines (MMALs), workload smoothness should be considered on the model-by-model basis as well as on the station-by-station basis. This is because although station-by-station assignments may provide the equality of workload to workers, it causes the utilization of assembly lines to be inefficient due to the model sequences. This paper presents a genetic algorithm to improve the workload smoothness on both the station-by-station and the model-by-model basis in balancing MMALs. Proposed is a function by which the two kinds of workloads smoothness can be evaluated according to the various preferences of line managers. To enhance the capability of searching good solutions, our genetic algorithm puts emphasis on the utilization of problem-specific information and heuristics in the design of representation scheme and genetic operators. Experimental results show that our algorithm can provide better solutions than existing heuristics. In particular, our algorithm is outstanding on the problems with a larger number of stations or a larger number of tasks.

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A Study on the Color Membership Computation Method using Fuzzy Color Model (패지 컬러 모델을 이용한 컬러의 소속 정도를 결정하는 방법에 관한 연구)

  • Kim, Dae-Won;Lee, Kwang. H.
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.04b
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    • pp.262-264
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    • 2002
  • In this paper we focused on the color representation prob1em based on fuzzy set theory. The main factor is the determination or computation of color membership function and color difference formula. The mathematical formula to calculate the color difference should generate a uniform color scaling, and due to this reason we adopted a CIELAB color- space as a fundamental feature space. With the help of the CIELAB color space we created a new color model, referred to fuzzy color model, which can represent the ambiguous characteristics underlying colors. Based on the proposed color difference formula between fuzzy colors, we could obtain the membership computation method of an arbitrary color for a given color family.

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MULTIDIMENSIONAL SYMMETRIC STABLE PROCESSES

  • Chen, Zhen-Qing
    • Journal of applied mathematics & informatics
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    • v.6 no.2
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    • pp.329-368
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    • 1999
  • This paper surveys recent remarkable progress in the study of potential theory for symmetric stable processes. It also contains new results on the two-sided estimates for Green functions Poisson kernels and Martin kernels of discontinuous symmetric $alpha$ -stable process in bounded $C^{1,1}$ open sets. The new results give ex-plicit information on how the comparing constants depend on pa-rametrer $alpha$ and consequently recover the green function and Poisson kernel estimates for Brownian motion by passing $alpha{\uparrow}2$. In addition to these new estimates this paper surveys recent progress in the study of notions of harmonicity integral representation of harmonic func-tions boundary harnack inequality conditional gauge and intrinsic ultracontractivity for symmetric stable processes. Here is a table of contents.

A Study on the Roles of Shape Properties in Evaluation of Aesthetics values on Shapes (형태속성이 미학 특성 인지 과정에 미치는 영향에 관한 연구)

  • Cha Myung-Yeol
    • Korean Institute of Interior Design Journal
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    • v.14 no.2 s.49
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    • pp.197-205
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    • 2005
  • In estimating designed architectural buildings, many factors in various design domains such as function, structure, form, environment may be considered and then a building design might be selected or modified as final design from many possible design results. This paper proposed a method to obtain complexity values from two dimensional drawings which are floor plans or elevations. The Complexity values could be turned into esthetic values. The method has been developed based on information theory, shape pattern representation and cognitive theory. Results of measuring complexity value can make the computer evaluate and select final results produced from automatic design processes by the computer That is to say, aesthetic values based on order and chaos can be measured using complexity values and then some results having superior values can be selected as final result. Also some cognitive processes as perception of two dimensional drawings are discussed using shape representations. Aesthetic values could be varied in terms of shape properties such as size, individualities and knowledge as well as order and chaos.

Development of Evolution Program for Dynamic Channel Assignment in Wireless Telecommunication Network (무선통신 네트워크에서 동적채널할당을 위한 진화프로그램의 개발)

  • Kim, Sung-Soo;Han, Kwang-Jin;Lee, Jong-Hyun
    • IE interfaces
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    • v.14 no.3
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    • pp.227-235
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    • 2001
  • There is a rapidly growing demand for wireless telecommunication. However, the number of usable channel is very limited. Therefore, the problem of channel assignment becomes more and more important to use channels as efficiently as possible. The objective of this paper is to develop an evolution program (EP) to find an efficient dynamic channel assignment method for minimum interference among the channels within reasonable time. The series of specific channel number is used as a representation of chromosome. The only changed chromosomes by crossover and mutation are evaluated in each generation to save computation time and memory for the progress of improved EP. We can easily differentiate the fitness value of each chromosome using proposed evaluation function. We also control the weighting factor of the mutation rate and the used number of elitist chromosomes for the speed of convergence to the optimal solution.

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Field Weakening Control of a PM Electric Variable Transmission for HEV

  • Cheng, Yuan;Bouscayrol, Alain;Trigui, Rochdi;Espanet, Christophe;Cui, Shumei
    • Journal of Electrical Engineering and Technology
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    • v.8 no.5
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    • pp.1096-1106
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    • 2013
  • This paper presents the control of a Permanent Magnet Electric Variable Transmission (PM-EVT) for Hybrid Electric Vehicles (HEVs). Consisting of two electric machines, the EVT realizes the power split function in an electromagnetic way rather than in a mechanical way. A specific PM-EVT has been designed for Toyota Prius II. The control scheme of the entire vehicle is deduced using the Energetic Macroscopic Representation methodology. The energy management strategy yields local control references. A specific attention is paid for the field weakening for wide speed range. Simulation results are provided to illustrate the EVT modeling and control.

Computer-aided Design and Fabrication of Bio-mimetic Scaffold for Tissue Engineering Using the Triply Periodic Minimal Surface (삼중 주기적 최소곡면을 이용한 조직공학을 위한 생체모사 스캐폴드의 컴퓨터응용 설계 및 제작)

  • Yoo, Dong-Jin
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.7
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    • pp.834-850
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    • 2011
  • In this paper, a novel tissue engineering scaffold design method based on triply periodic minimal surface (TPMS) is proposed. After generating the hexahedral elements for a 3D anatomical shape using the distance field algorithm, the unit cell libraries composed of triply periodic minimal surfaces are mapped into the subdivided hexahedral elements using the shape function widely used in the finite element method. In addition, a heterogeneous implicit solid representation method is introduced to design a 3D (Three-dimensional) bio-mimetic scaffold for tissue engineering from a sequence of computed tomography (CT) medical image data. CT image of a human spine bone is used as the case study for designing a 3D bio-mimetic scaffold model from CT image data.