• 제목/요약/키워드: A level-set method

검색결과 1,385건 처리시간 0.031초

시각장애인 점자블록의 휘도대비 기준에 대한 연구 (A Study on Luminance Contrast Criteria for Tactile Walking Surface Indicators)

  • 신동홍;박광재;김상운
    • 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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    • 제22권1호
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    • pp.7-15
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    • 2016
  • Purpose: There are the number of color tactile walking surface indicators installed in Korea, because of indefinite regulation in blind and vision-impaired persons' tactile walking surface indicators. In case of yellow tactile walking surface indicators, it shows a deviation severe color. In this study, the researchers suggested color and brightness reference for helping blind and vision-impaired persons' walking through analyzing the color references of tactile walking surface indicators and the color luminance between tactile walking surface indicators and sidewalk currently used. Method: Reasonable luminance contrast criteria is suggested by examining ways of improving the recognition and recognition of objects according to color contrast visually impaired through literature review and analyzing standards of tactile walking surface indicators and the Europe, Japan and Australia of color and luminance contrast criteria. And by examining the color of the tactile walking surface indicators reported in Korea currently used to derive the problem presented by the luminance contrast in the reference and comparison. Finally, the visually impaired tactile walking surface indicators is set for color selection criteria for the recognition rate improves. Results: In order to improve the recognition rate to be tactile walking surface indicators of the contrast of the visually impaired and the environment than the color of the tactile walking surface indicators itself to secure always a certain level or more of brightness contrast values in the set of the color of the tactile walking surface indicators so important. Implication: In order to set the blind tactile walking surface indicators color recognition based on the verification of the real pedestrian based on the results presented in this paper it is required. It is to be understood as an element of the barrier free configuration for securing the walking pedestrian safety.

유연생산시스템의 효율적 운용을 위한 지능적 기법의 적용에 관한 연구 (Application of Intelligent Technique for the Efficient Operation of the Flexible Manufacturing System)

    • 한국경영과학회지
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    • 제24권2호
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    • pp.1-15
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    • 1999
  • This research involves the development and evaluation of a work flow control model for a type of flexible manufacturing system(FMS) called a flexible flow line(FFL). The control model can be considered as a kind of hybrid intelligent model in that it utilizes both computer simulation and neural network technique. Training data sets were obtained using computer simulation of typical FFL states. And these data sets were used to train the neural network model. The model can easily incorporate particular aspects of a specific FFL such as limited buffer capacity and dispatching rules used. It also dynamically adapts to system uncertainty caused by such factors as machine breakdowns. Performance of the control model is shown to be superior to the random releasing method and the Minimal Part Set(MPS) heuristic in terms of machine utilization and work-in-process inventory level.

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A COMPUTATIONAL MODEL FOR OSMOSIS PHENOMENA OF CELLS THROUGH SEMI-PERMEABLE MEMBRANES

  • Kim, Im-Bunm;Ha, Tae-Young;Sheen, Dong-Woo
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제13권2호
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    • pp.123-140
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    • 2009
  • The effect of a solute concentration difference on the osmotic transport of water through the semi-permeable membrane of a simple cell model is investigated. So far, most studies on osmotic phenomena are described by simple diffusion-type equations ignoring all fluid motion or described by Stokes flow. In our work, as the governing equations, we consider the coupled full Navier-Stokes equations which describe the fluid motion and the full transport equation that takes into account of convection and diffusion effects. A two dimensional finite difference model has been developed to simulate the velocity field, concentration field, and semi-permeable membrane movement. It is shown that the cell swells to regions of lower solute concentration due to the uneven water flux through the semi-permeable membrane. The simulation is applied on a red blood cell geometry and the relevant results are presented.

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인터넷 검색을 통한 암호화폐 수익률 및 변동성에 대한 인과검정: 적률인과 접근 (Tests for Causality from Internet Search to Return and Volatility of Cryptocurrency: Evidence from Causality in Moments)

  • 정기호;하성호
    • 한국정보시스템학회지:정보시스템연구
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    • 제29권1호
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    • pp.289-301
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    • 2020
  • Purpose This study analyzes whether Internet search of cryptocurrency has a causal relationship to return and volatility of cryptocurrency. Design/methodology/approach Google Trend was used as a measure of the level of Internet search, and the parametric tests of Granger causality in the 1st moment and the 2nd moment were adopted as the analysis method. We used Bitcoin's dollar-based price, which is the No. 1 market value among cryptocurrency. Findings The results showed that the Internet search measured by Google Trends has a causal relationship to cryptocurrency in both average and volatility, while there is a difference in causality and its degree according to the search area and category that Google Trend user should set. Because the Granger causality is based on the improvement of prediction, the analysis results of this study indicate that Internet search can be used as a leading indicator in predicting return and volatility of cryptocurrency.

운율 및 분절음의 독립적 발음 평가 연구: 영어 원어민과 한국인 영어 학습자의 영어 발음 평가 차이를 중심으로 (A Study of an Independent Evaluation of Prosody and Segmentals: With Reference to the Difference in the Evaluation of English Pronunciation between Native Speakers of English and Korean Learners of English)

  • 박한상
    • 말소리와 음성과학
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    • 제2권4호
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    • pp.101-107
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    • 2010
  • This study investigates the difference in the evaluation of English pronunciation quality between native speakers of English and Korean learners of English. This study employs a novel method of independently evaluating the prosody and segmentals of English sentences. A set of stimuli were made by swapping the prosody and the segmentals of English sentences read by a native speaker of American English and a Korean learner of English. Evaluations of the difference level of stimuli pairs and the goodness of the pronunciation quality showed that both native speakers of English and Korean learners of English give priority to the segmentals but native speakers of English were more sensitive to the difference in prosody in the evaluation of English pronunciation.

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Design of a Pseudo Gaussian Function Network Using Asymmetric Activation Functions

  • Kim, Byung-Man;Cho, Hyung-Suck
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.43.3-43
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    • 2001
  • In conventional RBF network, the activation functions of hidden layers generally are symmetric functions like gaussian function. This has been considered to be one of the limiting factors for the network to speed up learning of actuately describing a given function. To avoid this criticism, we propose a pseudo gaussian function (PGF) whose deviation is changed according to the direction of incoming pattern. This property helps to estimate the given function more effectively with a minimal number of centers because of its flexibility of functional representation. A level set method is used to describe the asymmetric shape of deviation of the pseudo gaussian function. To demonstrate the performance of the proposed network ...

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A GHz-Level RSFQ Clock Distribution Technique with Bias Current Control in JTLs

  • Cho W.;Lim J.H.;Moon G.
    • 한국초전도ㆍ저온공학회논문지
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    • 제8권2호
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    • pp.17-19
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    • 2006
  • A novel clock distribution technique for pipelined-RSFQ logics using variable Bias Currents of JTLs as delay-medium is newly proposed. RSFQ logics consist of several logic gates or blocks connected in a pipeline structure. And each block has variable delay difference. In the structure, this clock distribution method generates a set of clock signals for each logic blocks with suitable corresponding delays. These delays, in the order of few to tens of pS, can be adjusted through controlling bias current of JTL of delay medium. While delays with resistor value and JJ size are fixed at fabrication stage, delay through bias current can be controlled externally, and thus, is heavily investigated for its range as well as correct operation within current margin. Possible ways of a standard delay library with modular structure are sought for further modularizing Pipelined-RSFQ applications. Simulations and verifications are done through WRSpice with Hypres 3-um process parameters.

청계천 실시간 홍수예보를 위한 Flow Nomograph 개발 및 평가 (Development and Assessment of Flow Nomograph for the Real-time Flood Forecasting in Cheonggye Stream)

  • 배덕효;심재범;윤성심
    • 한국수자원학회논문집
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    • 제45권11호
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    • pp.1107-1119
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    • 2012
  • 본 연구의 목적은 도시하천으로 복원된 청계천유역의 실시간 홍수예보를 위한 flow nomograph를 개발하고, 실측자료를 통해 flow nomograph의 적용성을 검토하는데 있다. 본 연구의 적용대상 지역인 청계천 유역은 높은 불투수율, 짧은 도달시간 및 복잡한 수문학적 특성을 갖고 있어 기존 강우-유출 모형에 의한 홍수예측 방법의 선행시간 확보 측면에서 실효성을 거두지 못하고 있는 실정이다. 이에 본 연구에서는 홍수예보 선행시간을 확보하기 위해 강우정보만으로도 홍수예보가 가능한 flow nomograph를 개발하였다. Flow nomograph는 강우강도, 강우지속시간 등의 강우변수와 유량, 수위간의 상관관계를 구한 것이다. 본 연구에서는 Flow nomograph 개발과정에서 예보 기준 설정을 위해 홍수예보 지점을 선정하여 지점별 기준 홍수위를 산정하였으며, 다양한 홍수사상을 반영하기 위해 가상 강우시나리오를 설정하여 강우조건별 강우강도와 강우지속시간을 산정하였다. 또한 수위-유량관계 곡선식을 이용하여 기준 홍수위에 따라 홍수량 범위를 결정하고, SWMM모형을 이용하여 강우조건에 따른 지점별 홍수량을 산정하여 예보지점별로 기준홍수 위에 따른 홍수량을 산정하였다. 산정된 강우 시나리오에 따른 강우정보와 기준 홍수위에 따른 홍수량을 이용하여 flow nomograph를 개발하였으며, 이를 실제 홍수사상에 적용하여 평가하였다. 평가 결과 청계천 유역에 대해 flow nomograph의 적용성이 높은 것으로 나타났다. 향후 청계천과 같은 도시하천유역의 홍수예측 방법으로 활용도가 높을 것으로 판단된다.

커피전문점 선택 속성과 점포유형의 결합 관계가 만족도에 미치는 영향 : 퍼지셋 질적비교분석(fsQCA)을 중심으로 (Effects of Coffee Shop Choice Attributes and Type of Coffee Shop on Customer Satisfaction : Using Fuzzy Set Qualitative Comparative Analysis(fsQCA))

  • 한영위;이용기;안성만
    • 한국프랜차이즈경영연구
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    • 제8권1호
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    • pp.31-41
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    • 2017
  • Purpose - As the domestic coffee market is rapidly growing and competition is intensifying, coffee shops need to establish a marketing strategy that grasps the needs and desires of consumers in order to secure a competitive advantage in terms of survival. From this point of view, this study suggests what choice attributes consumers consider when visiting coffee shops, and analyzes the effect of customer choice attributes on franchise and private coffee shops using fsQCA. Research design, data, and methodology - In the present study, we tried to understand the effect of the combination of choice attribute on satisfaction by the type of coffee shop based on the complex system theory, while studying the existing coffee shop choice attribute focuses on the causal relationship. FsQCA is a complementary analytical method between quantitative and qualitative research, and is a method for effectively analyzing the complex combination of causal variables. Result - The results of the study are as follows. First, cleanliness was found to be the most important factor in determining coffee quality, which is the most important factor affecting customer satisfaction. Second, customers who prefer franchise coffee shops seem to be most concerned about atmosphere, menu, cleanliness and price. On the other hand, customers who prefer private coffee shops consider image the most important. Conclusions - The implications of this study are as follows. Overall, coffee shops should manage cleanliness basically regardless of the type of store, but they should manage the choice attributes differently depending on the type of coffee shop. Franchise coffee shops will be able to increase the level of store satisfaction by systematically managing the store atmosphere, menu, cleanliness, and price according to the manual using the advantages of the franchise system. On the other hand, unlike the franchise coffee shops, private coffee shops can operate autonomous stores, so customers can use various marketing mixes to enhance their store image.

LP기법에 의한 생산계획 모형수립의 실증적 연구 (An Empirical Study of Production Scheduling Model Establishment by LP Technique)

  • 최원용
    • 산업경영시스템학회지
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    • 제19권40호
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    • pp.203-217
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    • 1996
  • This thesis describes a quantitative decision-making of production planning system. A mathmatical model of Linear Programming is used set up a production scheuling under the assumption. As the emphasis is laid on the applicability of the developed model, the linrar programming is applied to establish the production schedule for "F" furniture company which produces kitchin cabinet and OA furniture, The optimal solution is obtained by using the LP package, QBS. By the solution reduced to 14% of work force compared with the real data during all of the planning horizon. And it is also possible to reduce the work-force of the lowest level of employee by 10% for the reasonable management. There are some limitations in computerized data processing, which is only considering the economic costs without considering any external environment of case enterprise. As a result, it is shown that the LP model is very useful method of make aggregate production schedule. schedule.

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