• 제목/요약/키워드: Restrictions

검색결과 1,919건 처리시간 0.029초

천계최적화에 의한 전극 및 절연체 형상설계 (Design of Electrode and Insulator Contour Using Field Optimization)

  • 조연옥;최병주;김광수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1989년도 하계종합학술대회 논문집
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    • pp.422-425
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    • 1989
  • This paper presents the algorithm of a new optimization method for axially symmetric electrode and insulator. The initial surface contour is divided into circular arc elements. The radii of the elements are determined so that the surface field distribution becomes uniform keeping the minimum gap distance and the direction of correction. By means of two examples, one for an electrode and the other for a spacer, the convergence behaviour and several restrictions of optimization are discussed.

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산업연관분석법을 통한 공공청사 신축공사단계의 에너지 소비량 및 CO2 발생량 평가 (An Assessment of the Energy Consumption & CO2 Emission during the Construction Stage of Government Building using the Input-Output Analysis)

  • 최영훈;이상범;송호산
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2011년도 추계 학술논문 발표대회
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    • pp.149-150
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    • 2011
  • Recently, Goverment's Energy-saving policy in Korea as 'Green Growth' is very remarkable effort. By intensive poliicies, the private is encouraged to participate in policy. Especially, it is very important in the field of architecture and we have to work for construction of law system. However, these efforts of the government buildings for energy efficiency in use stage is as mandatory system that may occur in the construction phase and the enviromental impact of greenhouse gas reductions is not affected. For this reason, Assess the amount of the energy consumption and CO2 emissioont of Government Buildings in 2010 ordered by PPS(Public Procurement Service) in the construction phase and suggest to recognize the need for legal restrictions.

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Key Distribution for Heterogeneous Public-Key Cryptosystems

  • Lv, Xixiang;Yi, Mu;Hui, Li
    • Journal of Communications and Networks
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    • 제15권5호
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    • pp.464-468
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    • 2013
  • The widespread use of cryptographic technologies is complicated by inconsistencies and duplication in the key management systems supporting their applications. The proliferation of key management systems or protocols also results in higher operational and infrastructure costs, and fails in interoperability. Thus, it is essential to realize key management interoperability between different and heterogeneous cryptosystems. This paper presents a practical and separable key management system for heterogeneous public-key cryptosystems. We achieve the interoperability between different cryptosystems via cryptography approaches rather than communication protocols. With our scheme, each client can freely use any kind of cryptosystemthat it likes. The proposed scheme has two advantages over the key management interoperability protocol introduced by the organization for the advancement of structured information standards. One is that all the related operations do not involve the communication protocol and thus no special restrictions are taken on the client devices. The other is that the proposed scheme does not suffer from single-point fault and bottleneck problems.

적응 슬라이딩 관측기를 이용한 매입형 영구자석 동기전동기의 센서리스 속도제어 (Sensorless Speed Control of IPMSM using an Adaptive Sliding mode Observer)

  • 강형석;김원석;김영석
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제55권5호
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    • pp.271-279
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    • 2006
  • In this paper, a new speed sensorless control based on an adaptive sliding mode observer is proposed lot the interior permanent magnet synchronous motor(IPMSM) drives. With using voltage equation only, the adaptive sliding mode observer was investigated. Since the parameter of the dynamic equation such as machine inertia or viscosity friction coefficient are not well known and these values can be easily changed during normal operation, there are many restrictions in the actual implementation. The proposed adaptive sliding mode observer applied to overcome the problem caused by using the dynamic equation. Furthermore, the Lyapunov function is used to prove the system stability included speed estimate and speed control. The effectiveness of the proposed algorithm is confirmed by the experiments.

Modeling of random effects covariance matrix in marginalized random effects models

  • Lee, Keunbaik;Kim, Seolhwa
    • Journal of the Korean Data and Information Science Society
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    • 제27권3호
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    • pp.815-825
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    • 2016
  • Marginalized random effects models (MREMs) are often used to analyze longitudinal categorical data. The models permit direct estimation of marginal mean parameters and specify the serial correlation of longitudinal categorical data via the random effects. However, it is not easy to estimate the random effects covariance matrix in the MREMs because the matrix is high-dimensional and must be positive-definite. To solve these restrictions, we introduce two modeling approaches of the random effects covariance matrix: partial autocorrelation and the modified Cholesky decomposition. These proposed methods are illustrated with the real data from Korean genomic epidemiology study.

Rudder 엑츄에이터 포화특성을 고려한 Anti-Windup 제어계의 설계 (Anti-Windup Controller Design for the Ship with the Rudder Saturation)

  • 김영복;최명수
    • 한국해양공학회지
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    • 제16권4호
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    • pp.61-69
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    • 2002
  • In the actual control systems, there exist many kinds of restrictions or nonlinearities. However, due to the nonlinearities in actuators and sensors, the designed controller may not be applicable in some practical situations. One such nonlinearity is amplitude saturation in actuators. Although sometimes it may be ignored, in other cases failure to consider actuator saturation may severely degrade closed-loop system performance and even lead to instability. On the other hand, limiting the controller gain to avoid saturation sacrifices control effort and may lead to loss of performance. Consequently, in some cases, the actuator saturation must be explicitly taken into account to ensure desired performance. However, in this paper, an anti-windup control system design method is introduced to suppress the windup due to the amplitude saturation of the actuator. The proposed control system has very simple design process and guarantees the good control performance. The validity of the proposed control system will be shown by comparing with the results of a reported paper.

L4 마이크로커널 기반 모바일 미들웨어의 설계 (Design of Lightweight Mobile Middleware Based on L4 Microkernel)

  • 이상민;신동렬
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.635-636
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    • 2008
  • Due to the rapid development of the hardware divisions, varied and low-price mobile devices were provided to not only end-users but also widespread industry. However, in the software divisions, the characteristics of the software such as closed and differentiation causing restrictions of development. Therefore, it requires high costs and long times in the development process. In this paper, we introduce the Mobile Platform Middleware based on L4 Microkernel which provides linux-like environment and services for other mobile application platforms such as BREW and WIPI to facilitate easily development and migration of applications for mobile devices.

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Study on Virtual Reality and E-commerce

  • Lee, Soowook;Oh, Younghwan
    • International Journal of Advanced Culture Technology
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    • 제4권4호
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    • pp.70-74
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    • 2016
  • Electronic commerce (E-commerce) using virtual reality (VR) has the advantage of being able to purchase products without restrictions of time and location by overcoming the limitations of existing offline transactions. It is still a rudimentary but fast growing technology, and the use of E-commerce in VR is expanding. The barriers that consumers might face in utilizing E-commerce in VR is the relevance to Information and Communications Technologies (ICT) technology. Fundamentally, it requires Internet access and use through PCs or mobile devices such as smart phones. Because unlike off-line markets, it is difficult to determine the purchase patterns of customers, customer purchasing behavior analysis must be done using computer access records. In order to expand and develop E-commerce in VR in the future, learning ability should be improved through combining with artificial neural network by deep learning that is recently in the spotlight, and the ability to overcome errors need to be improved to enable use in various fields.

Robot Off-line Programming Based on a 2D CAD Drawing of Shoe Outsoles

  • Kim, Jin-Young;Sung, Ho-Hyun;Kang, Dong-Joon;Cho, Hyung-Suck
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.179.4-179
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    • 2001
  • Most of shoes manufacturing processes are not yet automated, it puts restrictions on increasing of productivity. Among them, adhesive application processes particularly are holding the most workers and working hours. In addition, its working conditions are very poor due to the toxicity of adhesive agents. In case of automating adhesive application processes by using robots, the robot teaching by playback is difficult to produce high productivity because the kinds of shoes to be taught mount up to several thousands. Therefore, it is essential to generate the robot working paths automatically according to the kind, the size, and the right and left of shoes, and also to teach them to the robot automatically ...

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레이저 스페클간섭법에 있어서 스페클크기와 측정 한계에 관한 연구 (A study on speckle size and measurable limitations in laser speckle interferometry method)

  • 윤성운
    • 한국생산제조학회지
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    • 제5권1호
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    • pp.33-42
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    • 1996
  • The high coherence of laser beam has made it possible to observe interference effects even in the light scattered from rough surfaces. That's why, when object with a scattering surface is illuminated with laser light, we do see a speckled appearance due to random interference. This sort of unique property of laser speckle has bruht into existence the new noncontaciting techniques such as speckle metrology method of measuring deformation, displacement, and vibration etc of objects with high optical sensitivity. The measurable range of speckle metrology especially used to measure in -plane information, however, is limited by some factors, the so-called strain, rotation tilt of surface and out of displacement perpendicular to the plane of analysis This restrictions severly limits the measurable range of speckle metrology by causing the decorrelation of speckle patterns. It is the purpose of this paper to give a survey on the measurable limitation of speckle photography method that is one of speckle metrology. Namely we will discuss the mutual relationships and problems of each limitations adding the restriction on the largest and smallest displacement measurable with speckle methods.

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