• 제목/요약/키워드: unit elements

검색결과 802건 처리시간 0.025초

A Development of DCS Binding Delay Analysis System based on PC/Ethernet and Realtime Database

  • Gwak, Kwi-Yil;Lee, Sung-Woo;Lim, Yong-Hun;Lee, Beom-Seok;Hyun, Duck-Hwa
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1571-1576
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    • 2005
  • DCS has many processing components and various communication elements. And its communication delay characteristic is affected diverse operating situation and context. Especially, binding signal which traversed from one control-node to another control-node undergo all sort of delay conditions. So its delay value has large deviation with the lapse of time, and the measurement of delay statistics during long time is very difficult by using general oscilloscope or other normal instruments. This thesis introduces the design and implementation of PC-based BDAS(Binding Delay Analysis System) System developed to overcomes these hardships. The system has signal-generator, IO-card, data-acquisition module, delay-calculation and analyzer module, those are implemented on industrial standard PC/Ethernet hardware and Windows/Linux platforms. This system can detect accurate whole-system-wide delay time including io, control processing and network delay, in the resolution of msec unit, and can analyze each channel's delay-historic data which is maintained by realtime database. So, this system has strong points of open system architecture, for example, user-friendly environment, low cost, high compatibility, simplicity of maintenance and high extension ability. Of all things, the measuring capability of long-time delay-statistics obtained through historic-DB make the system more valuable and useful, which function is essential to analyze accurate delay performance of DCS system. Using this system, the verification of delay performance of DCS for nuclear power plants is succeeded in KNICS(Korea Nuclear Instrumentation & Control System) projects

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THINNED PIPE MANAGEMENT PROGRAM OF KOREAN NUCLEAR POWER PLANTS

  • Lee, S.H.;Lee, Y.S.;Park, S.K.;Lee, J.G.
    • Corrosion Science and Technology
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    • 제14권1호
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    • pp.1-11
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    • 2015
  • Local wall thinning and integrity degradation caused by several mechanisms, such as flow accelerated corrosion (FAC), cavitation, flashing and/or liquid drop impingements, are a main concern in carbon steel piping systems of nuclear power plant in terms of safety and operability. Thinned pipe management program (TPMP) had been developed and optimized to reduce the possibility of unplanned shutdown and/or power reduction due to pipe failure caused by wall thinning in the secondary side piping system. This program also consists of several technical elements such as prediction of wear rate for each component, prioritization of components for inspection, thickness measurement, calculation of actual wear and wear rate for each component. Decision making is associated with replacement or continuous service for thinned pipe components. Establishment of long-term strategy based on diagnosis of plant condition regarding overall wall thinning is also essential part of the program. Prediction models of wall thinning caused by FAC had been established for 24 operating nuclear plants. Long term strategies to manage the thinned pipe component were prepared and applied to each unit, which was reflecting plant specific design, operation, and inspection history, so that the structural integrity of piping system can be maintained. An alternative integrity assessment criterion and a computer program for thinned piping items were developed for the first time in the world, which was directly applicable to the secondary piping system of nuclear power plant. The thinned pipe management program is applied to all domestic nuclear power plants as a standard procedure form so that it contributes to preventing an accident caused by FAC.

MBL 활용 수업이 중학교 학생들의 과학탐구능력과 그래프 작성 및 해석능력에 미치는 효과 (The Effects of MBL-Used Instruction on Scientific Inquiry Skill and Graph Construction and Interpreting Abilities of Middle School Students)

  • 최성봉
    • 한국지구과학회지
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    • 제29권6호
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    • pp.487-494
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    • 2008
  • 본 연구의 목적은 7학년 "해수의 성분과 운동" 단원에서 MBL 실험 수업이 학생들의 과학탐구능력과 그래프 작성 및 해석능력에 미치는 효과를 알아본 연구로 그 결과는 다음과 같다. 첫째, 6차시에 걸쳐 MBL 수업을 실시하고 사후 t-검정을 통해 학생들의 과학탐구능력에 미치는 영향에 대해 분석하였다. 그 결과 실험집단과 통제집단 간 과학탐구 능력 결과에서 유의미한 차이가 나타나 MBL 수업이 학생들의 과학탐구능력 향상에 더 효과적임을 알 수 있었다. 둘째, 사후 t-검정을 통해 학생들의 그래프 작성 및 해석능력에 미치는 영향에 대해 분석하였다. 그 결과 실험집단과 통제집단 간에 그래프 작성능력에서는 유의미한 차이를 보이지 않았으나, 그래프 해석능력에서는 두 집단 간 유의미한 차이를 나타내고 있어 MBL을 활용한 수업이 학생들의 그래프 해석능력의 향상에 더 효과적임을 알 수 있었다.

지능형 LED 실내조명을 위한 효율적인 제어 시스템 (An Efficient Control Sy7stem for Intelligent LED Indoor Lighting)

  • 홍성일;윤수정;인치호
    • 한국인터넷방송통신학회논문지
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    • 제14권6호
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    • pp.235-243
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    • 2014
  • 본 논문에서는 지능형 LED 실내조명을 위한 효율적인 제어 시스템을 제안한다. 제안된 지능형 LED 실내조명을 위한 효율적인 제어 시스템은 스케줄 정의에 의한 조명 스타일과 재실 감지에 의한 조명 스타일에 PIR 센서와 조도 센서에 의해 측정되는 주광강도와 같은 요소를 포함시켜 무선 센서 네트워크로 점등제어를 하고 에너지 절감을 할 수 있도록 설계하였다. 또한, 재실감지에 의한 실내조명 점등제어는 PIR 센서를 사용하여 미세 움직임을 감지하고, 창측과 내측의 불필요한 조명 밝기 제어는 조도센서를 이용하여 주광의 수준을 측정하여 제어하였으며, 주광 유입량이 많은 경우 창측 조명은 자동으로 어두워지고, 적으면 조명이 자동으로 밝아지도록 설계하였다. 제안하는 지능형 LED 실내조명을 위한 효율적인 제어 시스템의 효율성 검증 결과, 외부 조명이나 주광이 조금이라도 실내로 유입되면 실내조명의 밝기를 실시간으로 제어하여 에너지 절감 효과를 극대화할 수 있었다.

일부 한방병동간호사의 직무분석 (Analysis of the Job of Nurses Working on Oriental Medicine Wards)

  • 김명자;김미환;정희숙;김윤서
    • 간호행정학회지
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    • 제21권4호
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    • pp.341-353
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    • 2015
  • Purpose: The purpose of this study was to identify nurse's role through job analysis of nursing duties for nurses working on East Asia traditional medicine wards. Methods: Major steps in the study included a literature review, description of job activities of nurses on oriental medicine wards, comparative description of the literature, expert tests of validity of derived duties and tasks, and investigation of importance, difficulty and frequency of duties on job list. Results: The job of nurses on oriental medicine wards was classified into 12 duties, 59 tasks, and 295 task elements. The 12 duties were nursing assessment, nursing diagnosis, nursing planning, nursing implementation, nursing evaluation, supplies management, management of human resources, management of environment, management of documents, formation of cooperative relationships, self-development, and nursing activity in oriental medicine. 'Formation of cooperative relationships' was the duty ranked highest for importance (4.34), 'self-development' was ranked highest for difficulty (3.47), and 'Formation of cooperative relationships' was ranked highest for frequency (4.21). Conclusion: Basic education for nurses on an oriental medicine unit is necessary for the performance of oriental nursing to be considered as a specialized field. This study contributes to human resource management in the oriental medical hospital.

스마트 학습활동 개발 프레임워크와 수업모형 개발 사례 (A Framework for Developing Learning Activities for Smart Education and an Instructional Model)

  • 김혜정;김현철
    • 컴퓨터교육학회논문지
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    • 제15권4호
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    • pp.25-39
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    • 2012
  • 스마트교육은 기존에 분리되어 있던 교육 요소들을 스마트인프라 기반으로 상호연결하여 교육적 가치를 만들어내는 것을 의미한다. 본 연구에서는 스마트교육의 정의와 성격, 스마트 학교들의 환경을 고려하여 스마트 학습활동 개발 프레임워크를 제안하고 관련하여 개발된 수업모형에 대해 살펴본다. 이 프레임워크는 스마트 학습활동을 중심으로 한 수업을 설계할 때 학습활동의 최소단위를 하나의 블록으로 표현하며, 스마트 학습활동 아이디어를 학습활동, 동기, 정보활동, 도구 및 환경 요소의 선택 과정을 통해 구성한다. 이 프레임워크를 적용하여 고안된 수업모형으로, 스마트교실 환경에서 공유와 검토 및 보완과정을 활성화시킨 생각나눔 수업모형을 소개하며, 교실에서 적용과 관련해서 논의한다.

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노인요양시설 거주노인의 활동공간 이용행동 및 점유행태 (A Study of the Residents' Use and Occupancy-Behavior in the Activity Areas of the Senior Nursing Facilities)

  • 이민아
    • 가정과삶의질연구
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    • 제27권5호
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    • pp.77-90
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    • 2009
  • The purpose of this study was to investigate the residents' use and occupancy-behavior in the activity areas of the senior nursing facilities, and to provide basic information to establish the appropriate physical elements for planning the activity areas. For the study, the observations in five facilities were conducted for one day, from 10 a.m. to 4 p.m by four researchers. The results of the study are summarized as follows: First, most of the using behaviors in the activity areas were the doing nothing or sleeping. The meals and program services were provided in only one activity area of the floor and it showed that the unit care system was perfunctorily conducted at those facilities. In the representative activity area, its openness was the main physical element influencing the spatial using frequency, while the accessibility and the openness in the sub-activity area were most important. The seating arrangements having comers were helpful for residents' interactions. Second, while facility programs and meals were provided in the specific activity area, there was no residents' occupancy in other activity areas at the same time. There were interactions including residents' conversations and watching/observations in non-designated activity areas such as the nursing stations and near corridors. But the residents' interactions and self-regulations were blocked by absence of territoriality, monotonous spatial compositions and furniture arrangements, insecurity of residents' privacy, wide or narrow areas, and isolated spatial type. Based on the results at the above, basic guidelines for planning the activity areas of senior nursing facilities can be proposed as follows: First, the isolated type and the sight interception should be avoided in representative activity areas. It should be partitioned with couple of areas through the appropriate furniture arrangements, and be prepared semi-private spaces in non-designated areas such as nursing station for the interactions among the residents and the staff. Second, in activity areas for small group, the isolated type is not also good for the residents' accessibility. The residents' privacy should be confirmed through the various spatial compositions, and enough areas need to be sure for the diverse furniture arrangements.

콘크리트의 전단마찰 내력에 대한 횡보강근 및 압축응력의 영향 (Effect of Shear Reinforcement and Compressive Stress on the Shear Friction Strength of Concrete)

  • 황용하;양근혁
    • 콘크리트학회논문집
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    • 제28권4호
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    • pp.419-426
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    • 2016
  • 이 연구에서는 다양한 콘크리트를 갖는 전단계면에서의 전단마찰거동에 대한 횡보강근 및 압축응력의 영향을 평가하였다. 12개 직접전단실험체로부터 균열진전, 전단하중-상대 미끄러짐 관계, 균열발생시 전단응력, 최대전단내력 및 횡보강근의 전단저항력 등이 측정되었다. 실험결과 동일 전단하중에서 상대 미끄러짐 제어에 대한 횡보강근 배근형상 및 콘크리트 압축강도의 영향은 미미하였다. 작용 압축응력의 증가와 함께 콘크리트의 전단전달력을 증가하는 반면, 횡보강근의 전단전달력은 감소하였는데, 횡보강근의 전단저항은 배근형태에 의해 영향을 받지 않았다. AASHTO-LRFD, Mattock 및 Hwang and Yang의 모델은 콘크리트의 전단마찰내력을 과소평가하였다. 반면, Hwang and Yang의 모델은 실험결과와의 비교에 대한 평균과 표준편차 값이 각각 1.02과 0.23으로서 기존 모델에 비해 다양한 변수의 영향을 적절히 고려하면서 콘크리트의 전단마찰내력을 잘 예측하였다.

무전해 니켈도금 소재의 초정밀 가공에서 V-형상 미세 패턴 가공한계에 대한 실험적 평가 (Experimental evaluation of machining limit in machining V-shaped microgrooves on electroless nickel plated die materials)

  • 김현철
    • 한국생산제조학회지
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    • 제22권2호
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    • pp.263-267
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    • 2013
  • The continuing demand for increasingly slimmer and brighter liquid crystal display (LCD) panels has led to an increased focus on the role of light guide panels (LGPs) or optical films that are used to obtain diffuse, uniform light from the backlight unit (BLU). The most basic process in the production of such BLU components is the micromachining of V-shaped grooves. Thus, given the current trend, micromachining of V-shaped grooves is expected to play increasingly important roles in today's manufacturing technology. LCD BLUs comprise various optical elements such as a LGP, diffuser sheet, prism sheet, and protector sheet with V-shaped grooves. High-aspect-ratio patterns are required to reduce the number of sheets and enhance light efficiency, but there is a limit to the aspect ratio achievable for a given material and cutting tool. Therefore, this study comprised a series of experimental evaluations conducted to determine the machining limit in microcutting V-shaped grooves on electroless nickel plated die materials when using single-crystal diamond tools with point angles of $20^{\circ}-80^{\circ}$. Cutting performance was evaluated at various cutting speeds and depths of cut using different machining methods and machine tools. The experimental results are that V-shaped patterns with angles of $80^{\circ}$ or up can be realized regardless of the machining conditions and equipment. Moreover, the feed rate has little effect on machinability, and it is thought that the fly-cut method is more efficient for shallow patterns.

열음향 냉동기의 설계 및 개발 : I. 내부공간의 음향해석 및 에너지 변환 예측 (Design and Development of Thermoacoustic Rdfrierator : I. Acoustic Analysis of Resonator and Prediction of Energy Conversion)

  • 박철민;이정권
    • 한국음향학회지
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    • 제15권5호
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    • pp.44-52
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    • 1996
  • 열음향 냉동기의 설계시 요구되는 냉동기의 내부음장 특성을 예측하기 위해, 냉동기를 이루는 공명기 구조 및 선형화된 스피커의 모델에 대행 전달행렬기법을 이용하여 해석을 수행하였다. 여러 가지 기본 음향요소들의 전달행렬을 이용하여 공명기를 음향학적 요소들로 분해하고, 스피커의 선형화된 동특성 방정식과 함께 해석함으로써 음향요소들이 직렬로 배열되어 있는 공명기에 대한 음향특성을 얻어 내었다. 또한, 열음향 냉동기의 개발에 있어서 중요한 목표중 하나인 모세관 스택에서의 온도차이를 에너지 방정식을 이용하여 수치적으로 예측하였다. 한 개의 모세관 기공내에서의 음향일의 흐름, 열음향 흐름, 단위 길이당 에너지 손실 등을 단면변화함수를 이용해 표시한 후, 전체 스택에서의 에너지 흐름과 열평형을 고려하였다. 전체 스택에서의 에너지 흐름에 관한 식에 대하여, 내부음장 예측에 의해 구한 물리량을 이용하여, 수치적인 반복계산을 수행함으로써 온도비 및 성적계수를 예측할 수 있었다. 실제 설계된 공명기의 음향 특성의 해석결과가 실험과 잘 일치함을 관찰한 후, Hofler의 열음향냉동기에 대한 열음향 해석을 수행하여 실험결과와 잘 부합됨을 확인할 수 있었다.

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