• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.104-104
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• 2015

Due to the demand of the cold neutron flux in the neutron science and beam utilization technology, the cold neutron source (CNS) has been constructed and operating in the nuclear research reactor all over the world. The majority of the heat load removal scheme in the CNS is two-phase thermosiphon using the liquid hydrogen as a moderator. The CNS moderates thermal neutrons through a cryogenic moderator, liquid hydrogen, into cold neutrons with the generation of the nuclear heat load. The liquid hydrogen in a moderator cell is evaporated for the removal of the generated heat load from the neutron moderation and flows upward into a heat exchanger, where the hydrogen gas is liquefied by the cryogenic helium gas supplied from a helium refrigeration system. The liquefied hydrogen flows down to the moderator cell. To keep the required liquid hydrogen stable in the moderator cell, the CNS consists of an in-pool assembly (IPA) connected with the hydrogen system to handle the required hydrogen gas, the vacuum system to create the thermal insulation, and the helium refrigeration system to provide the cooling capacity. If one of systems is running out of order, the operating research reactor shall be tripped because the integrity of the CNS-IPA is not secured under the full power operation of the reactor. To prevent unscheduled reactor shutdown during a long time because the research reactor has been operating with the multi-purposes, the introduction of the standby cooling system (STS) can be a solution. In this presentation, the design considerations are considered how to design the STS satisfied with the following objectives: (a) to keep the moderator cell less than 350 K during the full power operation of the reactor under loss of the vacuum, loss of the cooling power, loss of common electrical power, or loss of instrument air cases; (b) to circulate smoothly helium gas in the STS circulation loop; (c) to re-start-up the reactor within 1 hour after its trip to avoid the Xenon build-up because more than certain concentration of Xenon makes that the reactor cannot start-up again; (d) to minimize the possibility of the hydrogen-oxygen reaction in the hydrogen boundary.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.61-66
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• 2004

In this paper an effort is made to develop an innovative spatial arrangement concept pertaining to ship building industry. The spatial scheduling is the problem that concentrates on effective planning of available space and arrangements of blocks and in a priority manner. In order to create an effective spatial scheduling. a database providing the priority has to be available to make the erection sequence. Such a system works hand in hand with erection sequence generator program The erection sequence program works on the conventional network analysis method which uses a typical parent-children idea for the calculation of the ENT(possible earliest network start time) and LNT(possible latest network start time). This program works in a cyclic manner taking turns by calculating the ENT in upward trace and LNT on the return trace thereby generating the entire erection sequence diagram for the requisite problem The generated database serves as an input data for spatial scheduling problem. When the system works it takes into consideration the entire system based on heuristic concepts as mentioned. There system uses the spatial aspects such as the available area of the P. E area and plan area of the corresponding blocks and its priority of erection from the erection sequence generator program develops the spatial scheduling arrangement. In this paper using all these concepts an innovative spatial schedule development system developed.

• 한국전자통신학회논문지
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• 제10권9호
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• pp.1027-1032
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• 2015

RFID(Radio Frequency Identification)는 라디오파를 이용하여 사물에 부착된 태그에 저장되어 있는 고유정보를 무선으로 전송하는 기술이다. 건축 분야에서 RFID를 사용하여 자재의 투입량과 재고 관리를 위한 자재관리 시스템의 구축사례가 증가 하고 있는 추세이다. 기존의 자재관리 시스템은 자재의 투입량과 재고 관리를 위해 자재에 RFID태그를 부착시키고 자재 투입 시 자재에 부착된 태그를 인식하는 기능만을 가진 시스템이 대부분이고, 자재의 재사용을 위해 자재의 위치정보를 RFID를 활용하여 자동으로 인식하고 관리할 수 있는 시스템 개발은 활발히 이루어지고 있지 않다. 본 논문에서는 건축자재의 효율적인 재사용을 위해 특정 서브와 리더기의 거리측정값을 기반으로 자재의 위치를 추정하여 메인 서버에 저장하는 기능을 가지는 RFID 시스템을 제안한다. 시스템의 구조는 RFID 리더부, 거리측정부, 통신부, 저장부로 구성된다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.873-878
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• 2008

Doosan Mecatec has developed alignment system for Organic Light-Emitting Diode (OLED) display production using large size substrate. In the present article, The alignment system between the substrate and the mask, which is a core technology for producing the OLED product using the fourth-generation substrate with $730{\times}920mm^2$ or more, will be described by dividing into a substrate loader, a magnet unit, a CCD camera, etc. The substrate loader is optimized through the simulation where the central portion of the substrate droops by about 1.5mm by clamping each of a long side (920mm direction) and a short side (730mm direction) thereof by 6 point and 4 point. A magnet unit using a sheet type of rubber magnet is constituted and a CCD camera model with the specifications capable of minimizing the errors between a clear image and the same image is selected. The system to which an upward evaporation technique of small molecular organic materials will be applied has been developed so that repeatability and position accuracy becomes ${\pm}1{\mu}m$ or less using an UVW type of stage. Also, the vision accuracy of the CCD camera becomes ${\pm}1{\mu}m$ or less and the align process TACT becomes 30sec. or less so that the final alignment accuracy between the substrate and the mask becomes ${\pm}3{\mu}m$ or less. In order to meet an extra-large glass substrate, an evaporation system using an extra-large AMOLED substrate has been developing through a vertical type of an alignment system.

• 디지털콘텐츠학회 논문지
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• 제7권3호
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• pp.161-168
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• 2006

와이브로(Wibro - Wireless Broadband Internet)는 OFDMA/TDD (Orthogonal Frequency Division Multiple Access/Time Division Duplex)방식의 광대역 무선전송기술을 사용하여 상/하향 비대칭 전송 특성을 갖는 IP기반 무선데이터 트래픽을 효과적으로 수용할수 있는 시스템이다. 와이브로 서비스는 기존 셀률러망과 다르게 IP망을 기반으로 서비스되기 때문에 단말기의 이동과 관계없이 끊임없는 연결을 유지하기 위해서는 핸드오버가 지원되어야 한다. 기존의 Micro Mobility 방식과 일반적인 Mobile IP 방식은 핸드오프시 지연속도와 패킷손실의 문제점을 가지고 있다. 이러한 문제점을 최소화 하기위해서 IETF라는 프로토콜이 제안되었고, IETF의 Mip4, Mip6, Mipshop WG을 중심으로 표준화가 진행되었다. 본 논문에서는 와이브로 망에서의 문제점을 개선하여 단말기의 효율적인 핸드오버 지연을 최대한 줄이기 위한 기법들과 보안요구사항 및 지원방향 대해 연구 분석 함.

• KIEAE Journal
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• 제11권2호
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• pp.105-111
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• 2011

Aims of this study is to investigate the daylighting control strategy of venetian blind system was performed as a function of ratio of shading height to window and slat angles in the preliminary stage of the parametric study. Floor-to-ceiling window walls of living spaces are used widely in apartment buildings since the Korean government has legally allowed elimination of the balcony area. Enlarging living area by balcony elimination, the larger glass area of window is exposed to the direct sunlight. As a common sunlight controlling device, blind system can be used in all orientations and all latitudes and it may obstruct, absorb, reflect and transmit solar radiation to building by proper adjusting. However, blind system can produce discomfort in occupant and less energy efficiency, if it has not been controlled optimally. The simulation model was based on the unit module of typical living space with balcony elimination. The room dimension was $6.0m(w){\times}6.9m(d){\times}2.7m(h)$ with floor to ceiling height of 2.5m. The blind system was simulated at five slat angles (horizontal, $30^{\circ}$, $45^{\circ}$ upward and downward tilted) and the four ratio of shading height to window (fully closed, partly opened, no-blind) using the Desktop RADIANCE 2.0 program. The series of simulation results indicates that the advantages of available daylight and outside of view can be improved by proper adjusting blind system.

• 한국유기농업학회지
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• 제30권2호
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• pp.129-149
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• 2022

In March 2020, the National Assembly revised the Framework Act on Cooperatives, allowing a federation of heterogeneous cooperatives, and in October 2020, the Daegu Gyeongbuk Federation of Local Food Cooperatives was launched as the first federation of heterogeneous cooperatives in the country. The local food movement, which has been promoted upward in the local community as an alternative to the existing global food system, seems to be being activated by the government's food plan policy, but critics say that the government's policy goals are not fully achieved due to the top-down policy promotion and lack of communication. In response, this study first examines the role and significance of the local food federation of heterogeneous cooperatives in solving the problems raised in the process of establishing a food plan. In addition, the current status of the federation was investigated for the successful settlement and development of the Daegu Gyeongbuk Federation of Local Food Cooperatives. A survey of affiliated cooperatives, focus group interviews with managers and experts and related literature surveys were conducted. Based on this, the direction of activities was presented, such as the role of an intermediary in Daegu and Gyeongbuk and the role of an intermediary in the public and private sectors etc. In addition, six joint project tasks were specifically presented, including an integrated information sharing system & a logistics network, a planned production system & a joint processing center, an online sales system & a co-marketing promotion, a joint education system, a management of direct stores & restaurants, a sustainable public-private cooperation system etc.

• 한국지능시스템학회논문지
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• 제18권5호
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• pp.692-699
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• 2008

본 논문은 보행보조기 사용자의 사용자 의지 파악을 통해 보행보조기의 최적 구동 방법을 제시하고자 한다. 최근에 노인인구의 증가로 인해 노인 및 장애인을 위한 보행 보조기에 대한 관심이 증가되고 있다. 그러나 대부분의 경우 동력이 없는 시스템으로써 경사 등의 공간에서 취약성을 가지고 있다. 이에 동력형 보행보조기에 대한 관심이 증가되고 있으나, 대부분의 경우 보행보조기 조종이 여의치 않다. 이에 본 논문에서는 사용자의 보행 의지를 파악할 수 있는 시스템을 도입하고 이를 기초로 보행자의 안정적인 구동을 수행할 수 있도록 퍼지 기반의 알고리즘을 적용한다. 먼저 사용자의 의지력은 FSR 센서를 이용하여 파악하고, 이를 기초로 사용자가 이동하고자 하는 이동 방향과 이동속도에 대해 퍼지 알고리즘을 적용하였다. 퍼지알고리즘으로부터 나온 데이터를 기초로 보행보조기의 차량 속도와 방향에 대해 구동 바퀴의 차동 구동을 통해 사용자의 의지에 맞춰 구동할 수 있도록 하였다. 이를 통해 사용자의 이동하려는 의지에 대해 안정적으로 차량을 이동시킬 수 있도록 최적의 보행 시스템을 구축하였다. 이 모든 과정을 실험을 통해 검증하였다.

• 한국산업보건학회지
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• 제18권2호
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• pp.149-160
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• 2008

Bag-filter system has been widely used in industrial field to remove the particulate matters from the exhaust gas. The cylindrical type of bag-filter has been generally used. But it has many shortcomings. The reattachment of separated particles on the surface of bags could result in high pressure drop of bag-filter system and subsequent decrease of air flow rate since the cylindrical type bag-filter system should have the upward flow pattern. In addition, the supply of very high pressure pulse air jet to remove particulate matters on the surface of filter could result in a frequent rupture of bags. To overcome these shortcomings of the cylindrical type, the rectangular type was developed in the developed countries and imported to Korea. But, there was not many design data available to understand the mechanisms. Thus, the fundamental experiments were conducted in this study to get some ideas about the pulse jet cleaning of rectangular type bag filter system. The experimental factors are as follows; pulse distance, pulse duration, pulse interval, pulse pressure and pulse nozzle type. Experiments followed the factorial design method. With the shorter pulse distance, the distribution of pressure drops was relatively not uniform while the particulate removal efficiency was higher. With the longer duration of pulsing and the more number of pulse nozzle, the removal efficiency was higher and the pressure drop distribution was more uniform.

• 한국항해항만학회지
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• 제28권10호
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• pp.955-960
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• 2004

선박에서 발생되는 밸러스트수를 전처리하기 위하여 수중에 포함되어 있는 미생물을 복극전해처리시스템을 이용하여 살균처하였다. 전해처리시스템에 유입되는 시료는 정량펌프를 사용하여 상향류로 전극판 사이를 통과하도록 하였으며, 반응시간별로 유량을 조절하여 체류시간을 다르게 하였다. 양극판은 티타늄에 이산화이리듐을 전착한 Ti/Ir02 극판으로 하였으며, 음극판은 스테인리스 스틸판을 사용하였다. 전원공급은 최대 전압이 250V, 전류가 100Amper의 맥류가 전혀 없는 트랜지스트 평활회로를 사용한 D.C. Power Supply를 사용하여 전류밀도를 조절하여 운전하였다. 반응시간에 따라 전류밀도를 0.1$\~$1.0A사이로 변화를 주어 실험한 결과 5초 이내에 E. coli, Bacteria, Bacillus sp.의 미생물이 사멸됨을 확인할 수 있었고, 전극간격은 75mm, 전류밀도 2.0A/dm2, 체류시간을 5초로 하였을 때 제거율이 $90\%$이상이였다. 연구결과를 통하여 밸러스트수 처리에 적용 가능한 기술임을 알 수 있었다.