• 제목/요약/키워드: work uniform design

검색결과 150건 처리시간 0.032초

PRRA로 제안된 ATM Switch 설계 (A Design of Proposed ATM Switch using PRRA)

  • Seo, In-Seok
    • 한국컴퓨터정보학회논문지
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    • 제7권2호
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    • pp.115-123
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    • 2002
  • 본 논문은 중재기가 제공되는 새로운 타입의 입출력 버퍼 ATM스위치를 제안하고 다양한 트래픽 상태하에서 그 성능을 연구하였다. 제안된 스위치는 PRI 신호를 제어할 수 있는 중재기의 구조와 특성을 최대한 활용하기 위한 목적으로 설계되었다. 제안된 스위치의 기본적인 목적은 간단한 입력 버퍼 스위치에 발생하는 HOL블록킹 현상을 제거 또는 적어도 최소화하는 것이다. 여러 가지 HOL 중재 알고리즘들이 이러한 목적으로 논문을 통해 제안되었다. 제안된 스위치에서는 중재기와 출력단에 버퍼를 이용하여 HOL 블록킹 현상의 억제를 효과적인 방식으로 시도하였다. 중재기는 다수의 잘 알려진 HOL 조정 알고리즘 중에서 Three Phase Algorithm을 사용하도록 설계되었다. 제안된 스위치는 REQ신호를 통하여 우선 전송의 제어를 요청, 이 신호를 중재기로 전송함으로써 중재기는 입력 버퍼로부터 전송된 신호를 제어한다. 컴퓨터 시뮬레이션 결과는 균일 트래픽 상태하에서 제안된 스위치의 효과를 설명하기 위해 제공하였다.

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고속 네트워크를 위한 ATM Switch 설계 (A Design of ATM Switch for High Speed Network)

  • Seok, Seo-In;Kuk, Cho-Sung
    • 한국컴퓨터정보학회논문지
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    • 제8권2호
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    • pp.97-105
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    • 2003
  • 본 논문은 중재기가 제공되는 새로운 타입의 입출력 버퍼 ATM스위치를 제안하고 다양한 트래픽 상태하에서 그 성능을 연구하였다. 제안된 스위치는 PRI 신호를 제어할 수 있는 중재기의 구조와 특성을 최대한 활용하기 위한 목적으로 설계되었다. 제안된 스위치의 기본적인 목적은 간단한 입력 버퍼 스위치에서 발생하는 HOL 블록킹 현상을 제거하거나, 적어도 줄일 수 있도록 하는 것이다. 여러 가지 HOL 중재 알고리즘들이 이러한 목적으로 논문을 통해 제안되었다. 제안된 스위치에서는 중재기와 출력단에 버퍼를 이용하여 HOL 블록킹 현상의 억제를 효과적인 방식으로 시도하였다. 중재기는 다수의 잘 알려진 HOL 조정 알고리즘 중에서 Three Phase Algorithm을 사용하도록 설계되었다 제안된 스위치는 REQ신호를 통하여 우선 전송의 제어를 요청, 이 신호를 중재기로 전송함으로써 중재기는 입력 버퍼로부터 전송된 신호를 제어한다. 컴퓨터 시뮬레이션 결과는 비균일 random 트래픽 상태 하에서 제안된 스위치의 효과를 설명하기 위해 제공하였다.

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단채널 현상을 줄이기 위한 수직형 나노와이어 MOSFET 소자설계 (Device Design of Vertical Nanowire MOSFET to Reduce Short Channel Effect)

  • 김희진;최은지;신강현;박종태
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2015년도 추계학술대회
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    • pp.879-882
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    • 2015
  • 본 연구에서는 시뮬레이션을 통해 채널 폭과 채널 도핑 형태에 따른 수직형 나노와이어 GAA MOSFET의 특성을 비교, 분석하였다. 첫 번째로, 드레인의 끝부분을 20nm로 고정시키고 소스의 끝부분이 30nm, 50nm, 80nm, 110nm로 식각된 모양으로 설계한 구조의 특성을 비교, 분석하였다. 두 번째로는 드레인, 채널, 소스의 폭이 50nm로 일정한 직사각형 모양의 구조를 설계하였다. 이 구조를 기준으로 삼아 드레인의 끝부분이 20nm가 되도록 식각된 사다리꼴 모양과 반대로 소스의 끝부분이 20nm가 되도록 식각된 역 사다리꼴 모양의 구조를 설계하여 위 세 구조의 특성을 비교, 분석하였다. 마지막으로는 폭 50nm의 직사각형 구조의 채널을 다섯 구간으로 나누어 도핑 형태를 다양하게 변화시킨 것의 특성을 비교, 분석하였다. 첫 번째 시뮬레이션에서는 채널 폭이 가장 작을 때, 두 번째 시뮬레이션에서는 사다리꼴 모양의 구조일 때, 세 번째 시뮬레이션에서는 채널의 중앙 부분이 높게 도핑 되었을 때 가장 좋은 특성을 보였다.

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자연대류를 고려한 스프레이 코팅 룸에서의 온도분포 해석 (Numerical Analysis of Natural Convection inside Spray Coating Room on Temperature Distributions)

  • 김남웅;김보선;김국원
    • 한국산학기술학회논문지
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    • 제20권8호
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    • pp.425-430
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    • 2019
  • 아연말 코팅은 친환경성 및 고성능으로 인하여 널리 사용되고 있다. 일반적으로 코팅온도가 코팅층 두께 및 코팅 품질을 결정하는 주요한 요소이며 아연말 코팅의 경우에도 코팅 룸 내 균일하며 적절한 코팅온도가 요구된다. 본 연구에서는 일반적으로 사용하는 자연대류 상태에서의 아연말 스프레이 코팅 룸의 온도 분포를 해석하기 위해 룸 내부의 공기 유동을 포함하는 열 유동 전산 시뮬레이션을 수행하였다. 3차원 CAD 프로그램인 SolidWorks를 이용하여 스프레이 코팅 룸 전체와 예열실과 건조실을 모두 고려한 모델링을 수행하였으며 ANSYS의 FLUENT 프로그램을 이용하여 열 유동연성 해석을 수행하였다. 해석 결과 스프레이 코팅 룸에서의 온도 분포 특성을 파악할 수 있었으며, 현재의 상태로는 목표 온도 값인 $25^{\circ}C$에 미달하고 있었음을 알 수 있었다. 이에 두 가지 다른 경계조건 (히터를 추가하는 방법과 현재 상태에서 Open 부분을 닫는 방법) 에 대해 열 유동 시뮬레이션을 수행하였으며, 시뮬레이션 결과 히터를 추가하기보다는 Open된 부분을 닫는 방법이 더 좋은 결과를 나타내었다.

DED 방식을 적용한 플래너 밀러의 손상된 스핀들 키 보수 작업에 관한 연구 (A Study on the Repair Work for Spindle Key with Damaged Part in Planner Miller by Directed Energy Deposition)

  • 이재호;송진영;진철규;김채환
    • 한국산업융합학회 논문집
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    • 제25권4_2호
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    • pp.699-706
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    • 2022
  • In this study, Directed energy deposition (DED) among additive manufacturing is applied to repair damaged spindle key parts of planner miller. The material of the spindle key is SCM415, and the P21 Powder is used. In order to find the optimal deposition conditions for DED equipment, a single-line deposition experiment is conducted to analysis five parameters. The laser power affects the width, and the height is a parameter affected by coaxial gas and powder gas. In addition, laser power, powder feed rate, coaxial gas, and powder gas are parameters that affect dilution. Otimal deposition is that 400 W of laser power, 4.0 g/min of powder feed rate, 6.5 L/min of coaxial gas, 3.0 L/min of powder gas and 4.5 L/min of shield gas. By setting the optimum conditions, a uniform deposition cross section in the form of an ellipse can be obtained. Damage recovery process of spindle key consists of 3D shape design of the base and deposition parts, deposition path creation and deposition process, and post-processing. The hardness of deposited area with P21 powder on the SCM415 spindle key is 336 HV for the surface of the deposition, 260 HV for the boundary area, and 165 HV for the base material.

3상 22.9/3.3kV 유입변압기의 소손패턴 해석 및 발화원인 판정에 관한 연구 (Study on the Damage Pattern Analysis of a 3 Phase 22.9/3.3kV Oil Immersed Transformer and Judgment of the Cause of Its Ignition)

  • 최충석
    • 전기학회논문지
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    • 제60권6호
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    • pp.1274-1279
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    • 2011
  • The purpose of this paper is to present the manufacturing defect and damage pattern of a 3 phase 22.9/3.3kV oil immersed transformer, as well as to present an objective basis for the prevention of a similar accident and to secure data for the settlement of PL related disputes. It was found that in order to prevent the occurrence of accidents to transformers, insulating oil analysis, thermal image measurement, and corona discharge diagnosis, etc., were performed by establishing relevant regulation. The result of analysis performed on the external appearance of a transformer to which an accident occurred, the internal insulation resistance and protection system, etc., showed that most of the analysis items were judged to be acceptable. However, it was found that the insulation characteristics between the primary winding and the enclosure, those between the ground and the secondary winding, and those between the primary and secondary windings were inappropriate due to an insulating oil leak caused by damage to the pressure relief valve. From the analysis of the acidity values measured over the past 5 years, it is thought that an increase in carbon dioxide (CO2) caused an increase in the temperature inside the transformer and the increase in the ethylene gas increased the possibility of ignition. Even though 17 years have passed since the transformer was installed, it was found that the system's design, manufacture, maintenance and management have been performed well and the insulating paper was in good condition, and that there was no trace of public access or vandalism. However, in the case of transformers to which accidents have occurred, a melted area between the upper and the intermediate bobbins of the W-phase secondary winding as well as between its intermediate and lower bobbins. It can be seen that a V-pattern was formed at the carbonized area of the transformer and that the depth of the carbonization is deeper at the upper side than the lower side. In addition, it was found that physical bending and deformation occurred inside the secondary winding due to non-uniform pressure while performing transformer winding work. Therefore, since it is obvious that the accident occurred due to a manufacturing defect (winding work defect), it is thought that the manufacturer of the transformer is responsible for the accident and that it is lawful for the manufacture to investigate and prove the concrete cause of the accident according to the Product Liability Law (PLL).

지진대응 교육 및 훈련을 위한 Serious Game 시나리오 설계방법론 개발 -경상북도를 사례로- (Serious Game Scenario Design for Earthquake Response Education and Training in the Gyeongsangbuk-do Province)

  • 김성재;최지향;남광현
    • 한국재난정보학회 논문집
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    • 제17권4호
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    • pp.769-777
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    • 2021
  • 연구목적: 지진재난은 다양한 변수와 돌발상황들로 예측할 수 없는 상황이 빈번하게 발생하게 때문에 업무과정 자체가 일률적이지 못해 재난안전부서 공무원들은 지진 대응 행동 매뉴얼 숙지에 어려움을 겪고 있다. 이에 본 연구는 경상북도청 재난안전대책본부에 한하여 이루어지고 있는 현재의 업무 상황을 구체적이고 정확하게 파악하여 업무 진행 과정에 필요한 매뉴얼 학습의 시리어스 게임 시나리오 설계방안을 제시하고자 한다. 연구방법: 본 연구에서는 GBS(Goal Based Scenarios)모형을 기반으로 시나리오를 설계하고, 경상북도 재난 현장조치 행동 매뉴얼을 기반으로 미션과 역할을 부여하는 과정에서 경상북도청 지진관련 공무원들이 실제적인 과제를 해결하는 지식과 기능을 습득할 수 있도록 하였다. 연구결과: 제안된 기법의 시나리오 데이터는 지진관련 다양한 정보를 논리적 데이터로 가공하여 지진상황훈련을 위한 게임상 표현을 위하여 단순화, 추상화하여 체계적인 절차로 구현하였다. 결론: 시리어스 게임을 통한 학습으로 지진 상황 발생 시, 경상북도청 재난안전대책본부의 관련 공무원들은 다양한 지진재난에 신속한 대응이 가능할 것으로 기대된다.

Flow blockage analysis for fuel assembly in a lead-based fast reactor

  • Wang, Chenglong;Wu, Di;Gui, Minyang;Cai, Rong;Zhu, Dahuan;Zhang, Dalin;Tian, Wenxi;Qiu, Suizheng;Su, G.H.
    • Nuclear Engineering and Technology
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    • 제53권10호
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    • pp.3217-3228
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    • 2021
  • Flow blockage of the fuel assembly in the lead-based fast reactor (LFR) may produce critical local spots, which will result in cladding failure and threaten reactor safety. In this study, the flow blockage characteristics were analyzed with the sub-channel analysis method, and the circumferentially-varied method was employed for considering the non-uniform distribution of circumferential temperature. The developed sub-channel analysis code SACOS-PB was validated by a heat transfer experiment in a blocked 19-rod bundle cooled by lead-bismuth eutectic. The deviations between the predicted coolant temperature and experimental values are within ±5%, including small and large flow blockage scenarios. And the temperature distributions of the fuel rod could be better simulated by the circumferentially-varied method for the small blockage scenario. Based on the validated code, the analysis of blockage characteristics was conducted. It could be seen from the temperature and flow distributions that a large blockage accident is more destructive compared with a small one. The sensitivity analysis shows that the closer the blockage location is to the exit, the more dangerous the accident is. Similarly, a larger blockage length will lead to a more serious case. And a higher exit temperature will be generated resulting from a higher peak coolant temperature of the blocked region. This work could provide a reference for the future design and development of the LFR.

Assessment of Legal Instruments and Applicability to the Use of Electronic Bills of Lading

  • Lee, Un-Ho
    • Journal of Korea Trade
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    • 제24권2호
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    • pp.31-52
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    • 2020
  • Purpose - This study mainly investigates two potential legal regimes expected to govern the use of electronic bills of lading: the Rotterdam Rules (2009) and the UNCITRAL Model Law on Electronic Transferable Records (2017). Widespread use of electronic bills of lading has been unsuccessful partly due to the absence of a uniform legal regime and protracted uncertainties. This paper aims to carry out an assessment of the possibilities where either of two potential legal regimes could provide certainty to the effect and validity of the use of electronic bills of lading, and contribute to the facilitation of electronically transferring the rights to goods carried by sea. Design/methodology - This paper first introduces two legal instruments and the relevance to electronic bills of lading. Since neither of these legal instruments has yet entered into force, the following section looks into the ratification or enactment possibilities based on a literature review and track records of the past legal regimes of the same kind. Assessment of the different adoption possibilities further requires comparative work of the two legal instruments, which will be based on an analysis of relevant provisions and a literature review. The literature review on the Rotterdam Rules delves into various studies and data produced since the UNCITRAL's adoption in 2009. The literature review on the UNCITRAL Model Law on Electronic Transferable Records heavily relies on UNCITRAL working group documents from 2011 to 2017 together with the final explanatory note. Findings - The main findings can be summarized as follows. Application of the Rotterdam Rules would negate the role of the UNCITRAL Model Law on Electronic Transferable Records assisting in the implementation of the Rotterdam Rules due to some conflicting issues. Enactment of the UNCITRAL Model Law alone can sufficiently provide a higher level of certainty in the use and effect of electronic bills of lading so long as lawmakers and parties are aware of some issues with the application. What concerns potential users most is the extension of the status quo, where neither of the legal instruments have any effect. It is necessary to take a number of alternatives into consideration, such as promotion of standard clauses and confirmation by a court ruling. Originality/value - Existing studies focus either on the Rotterdam Rules or on the UNCITRAL Model Law, but not both. Not many papers have yet dealt with the Model Law, which was adopted by UNCITRAL only 2 years ago, particularly in the context of a potential legal regime for electronic bills of lading. This paper attempts to introduce the differences between the two legal instruments in regulating the use of electronic bills of lading while providing an assessment of the various possibilities for which parties involved in international trade can be better prepared for the changing legal environment.

설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제27권7호
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    • pp.380-394
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    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.