• Asia pacific journal of information systems
• /
• 제20권3호
• /
• pp.191-204
• /
• 2010

Recently, the CO2 emission and energy consumption have become critical global issues to decide the future of nations. Especially, the spread of IT products and the increased use of internet and web applications result in the energy consumption and CO2 emission of IT industry though information technologies drive global economic growth. EU, the United States, Japan and other developed countries are using IT related environmental regulations such as WEEE(Waste Electrical and Electronic Equipment), RoHS(Restriction of the use of Certain Hazardous Substance), REACH(Registration, Evaluation, Authorization and Restriction of CHemicals) and EuP(Energy using Product), and have established systematic green business/IT strategies to enhance the competitiveness of IT industry. For example, the Japan government proposed the "Green IT initiative" for being compatible with economic growth and environmental protection. Not only energy saving technologies but energy saving systems have been developed for accomplishing sustainable development. Korea's CO2 emission and energy consumption continuously have grown at comparatively high rates. They are related to its industrial structure depending on high energy-consuming industries such as iron and steel Industry, automotive industry, shipbuilding industry, semiconductor industry, and so on. In particular, export proportion of IT manufacturing is quite high in Korea. For example, the global market share of the semiconductor such as DRAM was about 80% in 2008. Accordingly, Korea needs to establish a systematic strategy to respond to the global environmental regulations and to maintain competitiveness in the IT industry. However, green competitiveness of Korea ranked 11th among 15 major countries and R&D budget for green technology is not large enough to develop energy-saving technologies for infrastructure and value chain of low-carbon society though that grows at high rates. Moreover, there are no concrete action plans in Korea. This research aims to deduce the priorities of the Korean green business/IT strategies to use multi attribute weighted average method. We selected a panel of 19 experts who work at the green business related firms such as HP, IBM, Fujitsu and so on, and selected six assessment indices such as the urgency of the technology development, the technology gap between Korea and the developed countries, the effect of import substitution, the spillover effect of technology, the market growth, and the export potential of the package or stand-alone products by existing literature review. We submitted questionnaires at approximately weekly intervals to them for priorities of the green business/IT strategies. The strategies broadly classify as follows. The first strategy which consists of the green business/IT policy and standardization, process and performance management and IT industry and legislative alignment relates to government's role in the green economy. The second strategy relates to IT to support environment sustainability such as the travel and ways of working management, printer output and recycling, intelligent building, printer rationalization and collaboration and connectivity. The last strategy relates to green IT systems, services and usage such as the data center consolidation and energy management, hardware recycle decommission, server and storage virtualization, device power management, and service supplier management. All the questionnaires were assessed via a five-point Likert scale ranging from "very little" to "very large." Our findings show that the IT to support environment sustainability is prior to the other strategies. In detail, the green business /IT policy and standardization is the most important in the government's role. The strategies of intelligent building and the travel and ways of working management are prior to the others for supporting environment sustainability. Finally, the strategies for the data center consolidation and energy management and server and storage virtualization have the huge influence for green IT systems, services and usage This research results the following implications. The amount of energy consumption and CO2 emissions of IT equipment including electrical business equipment will need to be clearly indicated in order to manage the effect of green business/IT strategy. And it is necessary to develop tools that measure the performance of green business/IT by each step. Additionally, intelligent building could grow up in energy-saving, growth of low carbon and related industries together. It is necessary to expand the affect of virtualization though adjusting and controlling the relationship between the management teams.

• Journal of Biosystems Engineering
• /
• 제8권2호
• /
• pp.39-48
• /
• 1983

This study was performed to obtain the basic data which could be used for the modification of the manual center-burner-type rice-husk furnace into a small scale automatic type for the multi-purpose use in the farm. For this purpose, first, the utilization feasibility of the rice-husk furnace in the farm was analyzed briefly in aspects of available amount of rice-husk for the fuel, annual operation time and replaceble amount of residential heating energy with rice-husk in the farm. For the experiment a prototype furnace geared with an automatic feeding device was fabricated, and feed rate, mold size and chimney height were changed to investigate the combustion efficiency of rice-husk and thermal efficiency of the furnace. Also, optimum and limiting operational factors were observed in each treatments. The results obtained are summarized as follows. 1. If the rice-husk is intensively used for residential heating in the farm for winter season, on an average 51 percent of the total heating energy can be replaced with the rice-husk. Therefore, development of a small scale automatic rice-husk furnace was recognized to be feasible. 2. The operational condition depending on husk-feed rates was very important factor for successive steady burning operation of the given furnace. When the feed-rate was 1.5 kg/hr, the top of the burning zone should be kept at the position about 55 cm from the bottom of the combustion chamber with the periodic removal of ash (termed as steady state position), which was 18 cm above the mold waist. When the feed rates were 2.4 kg/hr and 3.0 kg/hr, the steady state position was at about 4 cm above the mold waist. 3. The mold size affected inflow rate of air into the furnace and consequently CO content in the exhaust gas. The relatively bigger mold gave positive effect on the air-inflow rate. 4. When the husk-feed rates were 1.5 kg/hr, 2.4 kg/hr, 3.0 kg/hr, the combustion efficiencies of the rice-husk were 98.5%, 97.4% and 95.0%, the thermal efficiencies of the furnace were 93.4%, 93.2% and 87.6%, and CO content in the exhaust gas were 1.21%, 1.03%, and 2.43%, respectively. The air-inflow rates were decreased with the increase of feed rates. When the amount of excess air was 30-40%, the CO content in the exhaust gas was at the minimum level. 5. When the chimney height was lowered from 260 cm to 96 cm, the air-inflow rate was slightly decreased, but the average temperature in the combustion chamber, CO content in the exhaust gas and combustion and thermal efficiencies were not changed significantly. 6. The incidental problems associated with the protytype furnace were accumulation of the ash inside the mold, accumulation of the cinder between the outer-drum of the furnace and the combustion chamber wall, and accumulation of the cinder in the chimney.

• 한국정보과학회논문지:시스템및이론
• /
• 제29권7호
• /
• pp.422-430
• /
• 2002

주어진 논리 회로를 시분할 FPGA 칩으로 효과적으로 합성하기 위해서는 전체 회로를 여러 개의 부분회로로 나눈 후, 각 부분 회로가 동일한 하드웨어 회로를 시간차를 두고 공유하도록 하여야 한다. 이를 위해 칩에 대한 시간별 재구성 정보를 미리 만들어, 칩 내부의 특정 메모리 영역에 저장하여 두었다가 정해진 시간대가 되면 칩 전체를 재구성하도록 하여야 한다. 그런데, 시분할 FPGA 합성에서 사용하는 세부적인 재구성 기법(일반적으로 스케쥴링이나 다중 회로 분할 기법을 사용)에 따라 동일 시간대에 필요한 LUT의 개수, 즉 FPGA의 용량이 달라질 수 있다. 본 논문에서는 입력되는 논리 회로를 직접 합성하지 않고서도 그 회로가 필요로 하는 전체 LUT 개수에 대한 하한을 추정함으로써 재구성 기법에 관계없이 필요한 최소한의 LUT 개수를 파악한다. 만일, 기존의 재구성 결과가 본 연구에서 추정된 하한과 일치할 경우, 그 결과는 최적의 결과를 의미한다. 반면에, 하한과의 차이가 있는 경우에는 기존의 연구 결과에 비해 더 좋은 재구성 결과가 존재하거나, 또는 본 연구에서 추정한 하한보다 더 좋은(큰, 정확한) 하한이 실제 존재함을 의미한다. 따라서 이러한 비교 분석을 통해, 기존 연구의 결과가 최적인지, 또는 개선의 여지가 있는지를 판단하는 좋은 지표를 제공할 수 있다. 실험 결과, 실험한 대부분의 예제에서, 기존의 연구 결과에서 출력한 결과와 본 논문에서 제안한 방법으로 추정한 하한이 정확히 일치하는 것을 발견할 수 있었는데, 이는 기존의 합성 시스템에서 생성한 결과의 최적성을 확인하게 하는 한편, 본 논문에서 제안한 하한 추정의 정확성을 반증하는 것으로 해석될 수 있다.

• 한국의학물리학회지:의학물리
• /
• 제8권1호
• /
• pp.53-67
• /
• 1997

일반적인 전자파환경 중에서 의료기관은 특수한 전자파환경을 형성하고 있다. 첨단전자산업의 발전과 함께 다양한 주파수와 전자계를 출력하는 의료장비는 그 출력자체가 진단이나 치료에 중요한 요소인 동시에 정밀한 장비에 교란을 줄 수 있는 요인을 지니고 있다는 점이다. 또 일반적인 휴대통신장비의 확산도 이러한 환경요인에 인자가 될 수 있다. 특히 중앙수술실이나, 중환자실, 인공신장실등의 의료장비가 밀집된 시설에서는 주파수나 강도면에서 다양한 형태의 전자파환경을 보였으며, 국내외 규정에서 정의하는 안전지침보다 사용거리나 그 강도면에서 열악한 것으로 나타났다. 특히 전기소작기 (전기메스)는 넓은 대역에 걸쳐 50㏈$\mu$V/m 이상의 강도의 전자파를 복사함으로서 상대적 전자파감성 장비에 대하여 보다 감쇄된 환경적 고려가 요구되고, 흔히 사용하는 보호자들의 이동전화기도 중환자실 출입구에서 사용할 경우 거의 100$\mu$V/m 가까운 복사잡음을 방출함으로서 금지 영역을 제정하여 배제할 필요성이 있다는 결론을 얻었다. 본 연구에서 의료기관내 특정 전자파환경을 파악하고, 그 실태에 따른 개선점을 지속적으로 보고함으로서 효과적이고 양질의 진료환경을 제공할 수 있다.

• 한국통신학회논문지
• /
• 제39C권12호
• /
• pp.1298-1306
• /
• 2014

본 논문에서는 선박 내 IT 서비스에 대한 요구에 부응하기 위해 인지무선 최초 표준인 ECMA-392 네트워크를 사용한다. ECMA-392 기반 네트워크에서 멀티 홉을 지원하는 장치들의 충돌 문제에 대해 살펴보고, 이를 해결하기 위한 CRP 예약 충돌 해결 방안을 제안한다. 현재의 CRP 예약 기법은 3홉 거리에서 이동하는 ECMA-392 장치들 사이의 CRP 예약 충돌을 해결하지 못한다. 기존의 CRP 예약 충돌 해결 방안은 멀티미디어 스트리밍과 같은 실시간 서비스의 QoS를 보장할 수 없다. 그래서 우리는 새로운 2-hop CRP Availability IE의 제안과 CRP Control 필드의 변경을 통해 새로운 CRP 예약 충돌을 방지하는 방안을 제안한다. 시뮬레이션 결과는 제안된 3홉 CRP 예약 충돌 해결 방식이 디바이스의 데이터 수율을 향상시키고 있음을 나타낸다.

• 한국화재소방학회논문지
• /
• 제22권1호
• /
• pp.105-114
• /
• 2008

본 연구에서는 2006년 개정소방법의 시행에 따라 다중이용업소 및 고층건물에 피난설비 중 피난기구로 설치가 의무화 되고 있는 '완강기'의 현재 나타난 설치상의 문제점을 조사해보고, 제시된 문제점들을 각 항목별로 나누어 원인 분석 및 개선사항을 제시하였다. 설문조사를 통하여 총 367건의 문제점이 지적되었으며, 다음과 같이 설치실태의 문제점이 나타났다. 완강기를 이용한 탈출이 부적합한 창문(34%), 관련문구 미부착(23.7%), 부적합한 설치장소(20%) 및 완강기의 파손(20%) 등으로 조사되었다. 특히 완강기 설치상 문제점으로 완강기를 이용한 탈출에 부적합한 창문이라는 사항이 가장 많이 제시되었기에 탈출 시 필요한 유리의 파괴에 관한 응력해석을 수행한 결과 완강기가 설치된 곳의 유리두께는 3,6 mm로 규정되어야 할 것으로 나타났다. 또한 기존의 소방법에 따른 형식적인 설치가 아닌 화재발생 시 인명을 보호하는 피난도구로써의 완강기 설치 및 사용이 가능할 수 있는 실질적인 완강기 설치상의 개선대책을 제시했다.

• 한국진공학회지
• /
• 제20권2호
• /
• pp.155-163
• /
• 2011

탄소나노튜브(CNT)와 합성기판 사이의 전도성 향상을 목적으로, 현재 리튬이온이차전지 등의 분야에서 전극으로 이용되고 있는 구리 호일을 합성기판으로 하여, 그 위에 수직배향 CNT 성장의 합성 최적화를 도모하였다. 합성은 수평식 CVD 합성장비를 이용하였으며, 최적의 합성조건은 구리호일 위에 10 nm의 Al2O3 버퍼층과 1 nm 두께의 Fe 촉매층을 증착한 후, 아세틸렌 가스를 이용하여 $800^{\circ}C$에서 20분간 합성한 조건으로 설정하였다. CNT는 base-growth의 성장형태를 따랐고, Fe 1 nm 두께인 경우, $7.2{\pm}1.5nm$의 촉매나노입자가 형성되었으며, 이를 이용하여 $800^{\circ}C$에서 20분 성장결과, 직경 8.2 nm, 길이 $325{\mu}m$의 수직배향 CNT를 얻을 수 있었다. 합성시간이 길어져도 CNT의 결정성, 직경 및 겹(wall) 수에는 큰 변화가 없었다. 끝으로, 구리호일 위에 수직 성장시킨 CNT의 전계방출 특성을 측정한 결과, 실리콘 산화막 위에 성장시킨 CNT와 비교하여, 월등히 낮은 전계방출 문턱전압과 10배 정도 높은 전계향상계수를 보였다. 이는 CNT와 금속기판 사이의 계면에서 전기전도도가 향상된 결과에 기인하는 것으로 사료된다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제48권5호
• /
• pp.285-295
• /
• 1999

Electroluminescent(EL) devices based on organic materials have been of great interest due to their possible applications for large-area flat-panel displays. They are attractive because of their capability of multi-color emission, and low operation voltage. An approach to realize such device characteristics is to use active layers of lanthanide complexes with their inherent extremely sharp emission bands in stead of commonly known organic dyes. In general, organic molecular compounds show emission due to their $\pi$-$\pi*$ transitions resulting in luminescence bandwidths of about 80 to 100nm. Spin statistic estimations lead to an internal quantum efficiency of dye-based EL devices limited to 25%. On the contrary, the fluorescence of lanthanide complexes is based on an intramolecular energy transfer from the triplet of the organic ligand to the 4f energy states of the ion. Therefore, theoretical internal quantum efficiency is principally not limited. In this study, Powders of TPD, $Eu(TTA)_3(phen) and AlQ_3$ in a boat were subsequently heated to their sublimation temperatures to obtain the growth rates of 0.2~0.3nm/s. Organic electrolumnescent devices(OELD) with a structure of $glass substrate/ITO/Eu(TTA)_3(phen)/AI, glass substrate/ITO/TPD/Eu(TTA)_3(phen)/AI and glass substrate/ITO/TPD/Eu(TTA)_3(phen)/AIQ_3AI$ structures were fabricated by vacuum evaporation method, where aromatic diamine(TPD) was used as a hole transporting material, $Eu(TTA)_3(phen)$ as an emitting material, and Tris(8-hydroxyquinoline)Aluminum$(AlQ_3)$ as an electron transporting layer. Electroluminescent(EL) and current density-voltage(J-V) characteristics of these OELDs with various thickness of $Eu(TTA)_3(phen)$ layer were investigated. The triple-layer structure devices show the red EL spectrum at the wavelength of 613nm, which is almost the same as the photoluminescent(PL) spectrum of $Eu(TTA)_3(phen)$.It was found from the J-V characteristics of these devices that the current density is not dependent on the applied field, but on the electric field.

• 한국광학회지
• /
• 제29권1호
• /
• pp.19-27
• /
• 2018

일반적으로 광학계의 물체거리가 변하면 배율이 변하게 된다. 본 논문에서는 일반적인 이중 가우스(double-Gauss) 형태의 광학계에서 조리개를 기준으로 조리개 앞쪽에 위치한 렌즈군과 조리개 뒷쪽 렌즈군을 광축 방향으로 독립적으로 평행하게 이동하여 물체거리에 따라 배율과 상면이 고정되는 광학계를 제안하고 설계하였다. 이러한 광학계는 전방시현장치(head-up display, HUD), 두부장착디스플레이(head-mounted display, HMD) 등의 투사 광학계에 물체거리의 변화에 따라 상 크기가 변화하지 않도록 하여 전방시현장치 또는 두부장착디스플레이에서 초점 조절(focusing) 시에 화각이 변하지 않도록 하였다. 또한 반도체 칩과 IC 회로기판을 연결하는 와이어(wire)의 상태를 검사하는 과정에서 검사장비가 위 아래로 움직여서 물체거리가 변해도 광학계의 배율이 변하지 않도록 하여 고속검사가 가능할 수 있도록 별도 영상 처리를 시스템적으로 생략할 수 있었다. 본 논문에서 가우스 괄호법(Gaussian bracket method)을 이용하여 원하는 사양을 만족하도록 각 군의 이동량을 구해서 배율과 상면이 고정되도록 하였다. 초기 설계를 진행한 후, 최적화는 광학 설계 프로그램인 시놉시스(Synopsys)를 사용하였다.

• 한국연극학
• /
• 제53호
• /
• pp.167-202
• /
• 2014

When video composes mise-en-scene during the performance, it reflects the aspect of contemporary image culture, where the individual as creator joins in the image culture through the device of cell phone and computer remediating the former video technology. It also closely related with the contemporary theatre culture in which 1960's and 1970's video art was weaved into the contemporary performance theatre. With these cultural background, theatre practitioners regarded media-friendly mise-en-scene as an alternative facing the cultural landscape the linear representational narrative did not correspond to the present culture. Nonetheless, it can not be ignored that video in the performance theatre is remediating its historical function: to criticize the social reality. to enrich the aesthetic or emotional reality. I focused video in the performance theatre could feature the object with the image by realizing the realtime relay, emphasizing the situation within the frame, and strengthening the reality by alluding the object as a gesutre. So I explored its two historical manuel. First, video recorded the spot, communicated the information, and arose the audience's recognition of the object to its critical function. Second, video in performance theatre could redistribute perceptual way according to the editing method like as close up, slow motion, multiple perspective, montage and collage, and transformation of the image to the aesthetic function. Reminding the historical function of video in contemporary performance theatre, I analyzed two shows, Schaubuhne's Hamlet and Lenea de Sombra's Amarillo which were introduced to Korean audiences during the 2010 Seoul Theatre Olympics. It is known to us that Ostermeir found real social reality as a text and made the play the context. In this, he used video as a vehicle to penetrate the social reality through the hero's perspective. It is also noteworthy that Ostermeir understood Hamlet's dilemma as these days' young generation's propensity. They delayed action while being involved in image culture. Besides his use of video in the piece revitalized the aesthetic function of video by hypermedial perceptual method. Amarillo combined documentary theatre method with installation, physical theatre, and video relay on the spot, and activated aesthetic function with the intermediality, its interacting co-relationship between the media. In this performance theatre, video has recorded and pursued the absent presence of the real people who died or lost in the desert. At the same time it fantasized the emotional aspect of the people at the moment of their death, which would be opaque or non prominent otherwise. As a conclusion, I found the video in contemporary performance theatre visualized the rupture between the media and perform their intermediality. It attempted to disturb the transparent immediacy to invoke the spectator's perception to the theatrical situation, to open its emotional and spiritual aspect, and to remind the realities as with Schaubuhne's Hamlet and Lenea de Sombra's Amarillo.