• 한국공간정보시스템학회:학술대회논문집
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• 2005.11a
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• pp.87-91
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• 2005

최근 언론매체나 인터넷을 통해 자주 접하게 되는 용어 중 하나가 '유비쿼터스'이다. 각종 서비스, 도시건설, 아파트 등 다양한 대상에 'Ubiquitous' 또는 'U-'라는 수식어를 붙이는 것을 흔히 접할 수 있으며, 마치 매우 편리한 환경을 상징하는 키워드처럼 인식되고 있다. 이와 관련하여 현재 우리나라에서는 정보화도시(U-City 또는 디지털시티라고도 함) 건설 추진 및 그에 대한 논의가 활기를 띠고 있다. 이를 통한다면 우리나라는 건설 및 IT강국이라는 핵심역량을 바탕으로 내수경기 부양뿐만 아니라 지역 간 불균형을 해소할 수 있고, 국내성공 사례로 글로벌 시장개척을 위할 수 있으며 넓게는 동북아 비즈니스 허브구축의 발판이 마련될 수 있겠다. 이밖에도 정보화도시(U-City)건설은 많은 산업화의 가치를 가지고 있기 때문에 정부와 지자체, 또한 기업체에서 기술 개발 및 시범사업에 박차를 가하고 있다. 그러나 새로운 도시유형으로서 정보화도시(U-City)의 개념은 아직까지 제도적으로 정립되어 있지 않을 뿐만 아니라 도시건설 시 어떤 특별한 유인책도 마련되어 있지 않다. 그리하여 지방자치단체, 공기업 등 추진주체마다 전개되는 양상이 다르며 이에 수반되는 다양한 문제가 발생한다. 따라서 정보화도시(U-City)의 성공을 위해서는 글로벌 인재들이 유인할 수 있는 매력을 갖추어야 하며 사회적 투자를 지속시킬 수 있는 효과적 방안이 필요하겠고 핵심기술과 이의 활용방안이 마련되어야겠다. 그러나 무엇보다도 정보화도시 건설관련 법, 제도, 사회시스템 정비가 선행되어야하겠다.

• Water for future
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• v.25 no.3
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• pp.65-77
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• 1992

The purpose of this study is to analyse existing hysteresis models and to propose a new type of model. The existing hysteresis models are classified by three types: interpolation model, scaling model and domain model, of which the domain model is based on the theoretical approach. Models which need one branch of hysteresis loop for calibration are developed based on the independent domain concept, however, they are not successful to accurately simulate the real data and Rubicon Sandy Loam and Dune Sand. There is a possibility that a new model is based on the dependent domain model considering the pore blockage effect against air entry for homogeneous porous media(modelIII-1, Mualem, 1984). Concludingly, a new type of hysteresis model is proposed by simplifying ModelIII-1 using a proper assumption.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1335-1340
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• 2007

The media transport systems, such as printers, copy machines, facsimiles, ATMs, cameras, etc. have been widely used and being developed rapidly. In the development of those sheet-handling machineries, it is important to predict the static and dynamic behavior of the sheet with a high degree of reliability because the sheets are fed and stacked at such a high speed. Flexible media are very thin, light and flexible, so they behave in geometric nonlinearity with large displacement and large rotation but small strain. In the flexible media analysis, aerodynamic effect from the surrounding air must be included because any small force can make large deformation. In this paper, surrounding air was modeled by incompressible Navier-Stokes flow and an arbitrary Lagranigan-Eulerian(ALE) finite element method with automatic mesh-updating technique was formulated for large domain changes. In the numerical simulations, the results with consideration of the air fast decayed and converged into static results while the results without considering air oscillated continuously.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10c
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• pp.216-221
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• 2007

웹에는 방대한 양의 정보가 있지만 현재 그 활용은 제한적이다. 본 연구는 기존에 PC를 통해서만 접근 가능했던 웹 정보를 TV나 모바일 기기를 통해서 볼 수 있게 함으로써, 사용자로 하여금 시공간의 제약으로부터 자유로운 정보 환경을 제공하려는 취지에서 수행되었다. 현재의 웹 정보를 TV나 모바일 기기와 같은 일상적인 매체를 통해서도 활용할 수 있기 위해서는 각 디바이스의 화면에 적합하게 필터링과 요약을 통해 재구성하는 기술이 요구된다. 본 논문에서는 자연어처리 기술에 기반하여 온라인 뉴스 페이지를 개인 디바이스에 적합한 형태로 내용과 레이아웃을 재구성하는 시스템인 ONASys(Online News Adaptation System) 에 대해 소개한다. ONASys는 공간적, 내용적 속성을 이용하여 웹페이지 상의 중요 정보를 선별하는 #컨텐츠 필터링 모듈#, 패턴의 분석과 공기 정보를 통한 문법적 주 요소 인식을 통해 문장을 하는 #문장 요약 모듈#, 제목과 문장의 연관성을 통하여 문장의 중요도를 판단하는 #중요도 결정 모듈#로 구성된다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.610-612
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• 2003

본 논문은 무선 셀룰러 시스템 환경에서 일정구간을 이동하는 지하철, 기차와 같이 규칙적인 이동 패턴을 보이는 운송 매체에 탑승한 사용자들의 이동성을 지원하기 위해 PGLT(Profile­based Group Location Tracking) 기법을 제안한다. 최근 무선 통신 기술의 발전으로 인한 이동 사용자(Mobile Terminal, MT)의 급증은 시그널링 트래픽의 증가로 이어져 결국 위치 관리 비용까지 높아지게 되었다. MT들이 동시에 새로운 등록 영역으로 이동할 때 GLT(Group Location Tracking) 위치 관리 기법에서는 기존 IS­41의 각 사용자들의 개별적인 위치 갱신 요청 대신에 그룹을 이용한 위치 갱신 요청으로써 위치 관리 비용을 줄였다. 그러나 본 논문에서 제안하는 PGLT 기법은 GLT 기법을 향상시킨 기법으로서, 사용자들의 규칙적인 이동 패턴 특성을 살린 프로파일 정보를 이용하여 그룹에 대한 위치 갱신 비용까지도 줄일 수 있다. MSRP­VLR(Mobility Scheduler on Regular Path)과 RMB(Regular path Movement Buffer)를 이용하여 일정구간을 이동하는 TV(Transportation Vehicle)가 위치 갱신 요청을 하면, MSRP­VLR은 이동 경로에 대한 프로파일 정보를 보내어 TV의 RMB에 저장함으로써 그 경로를 이동 시 그룹에 대한 위치 갱신 요청을 할 필요가 없게 된다. 따라서 PGLT 기법은 GLT 기법의 그룹 위치 갱신 비용을 줄임으로써 일정구간을 이동하는 TV에 탑승한 많은 사용자들에 대한 위치 관리 비용을 현저히 줄일 수 있다.

• Solar Energy
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• v.18 no.3
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• pp.177-183
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• 1998

The thermal performance of a heating board with microencapsualted PCM was investigated and compared to conventional heating board. The employed PCM was the myristic acid $$ and was encapsulated by the multiple layers of PMMA and paraffin wax. The size of encapsulated PCM was $1{\sim}1.5mm$. Accoring to ANSI/ASHRAE test procedure, the close-loop test configuration was installed. Air was used as the heat transfer fluid and a calibrated orifice was employed for the measurement of air flow rates. The thermal performance test of two different heating boards(with 10 wt% PCM and without PCM) was conducted for different air flow rates and the heat transfer characteristics during cooling was compared. The test results showed that the surface temperature of heating board with 10 wt% PCM maintained higher during the cooling process than that of the heating board without PCM and experimentally determined heat transfer coefficient in heating board with PCM showed higher value compared to heating board without PCM.

• Journal of Environmental Impact Assessment
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• v.31 no.5
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• pp.321-333
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• 2022

In this study, the concentration and distribution characteristics of BTEX (benzene toluene, ethylbenzene, and xylene) emitted from Daesan Petrochemical Industrial Complex were examined to determine their potential hazards to local residents. Residents living nearby the complex areas may be exposed to the chemicals through various media (air, water, and soil), especially by air. This study evaluated human health risks by inhalation using both deterministic and probabilistic risk assessment approaches. As a result of the deterministic risk assessment, the non-cancer risk was much lower than the regulation limit of hazard index (HI 1.0) for all the points. However, in case of cancer risk evaluation, it was found that the risk of excess cancer for benzene at point A located in the industrial complex was 2.28×10^-6, which slightly exceeded the standard regulatory limit of 1.0×10^-6. In addition, the probabilistic risk assessment revealed that the percentile exceeding the standard of 1.0×10^-6was found to be 45.3%. The sensitivity analysis showed that exposure time (ET) had the greatest impact on the results. Based on the risk assessment study, it implied that ethylbenzene, toluene, and xylene had little adverse effects on potential human exposure, but benzene often exceeded the cancer risk standard (1.0×10^-6). Further studies on extensive VOCs monitoring are needed to evaluate the potential risks of industrial complex areas.

• Clean Technology
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• v.17 no.1
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• pp.69-77
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• 2011

The intrinsic $CO_2$ separation and hydrogen production system is a novel concept using oxidation and reduction reactions of oxygen carrier for both $CO_2$ capture and high purity hydrogen production. The process consists of a fuel reactor (FR), a steam reactor (SR) and an air reactor (AR). The natural gas ($CH_4$) is oxidized to $CO_2$ and steam by the oxygen carrier in FR, whereas the steam is reduced to hydrogen by oxidation of the reduced oxygen carrier in SR. The oxygen carrier is fully oxidized by air in AR. In the present study, the chemical looping moving bed reactor having 200 L/h hydrogen production capacity is designed and the hydrodynamic properties were determined. Compared with other reactors, two moving bed reactors (FR, SR) were used to obtain high conversion and selectivity of the oxygen carrier. The desirable solid circulation rates are calculated to be in the range of $20{\sim}100kg/m^2s$ from the conceptual design. The solid circulation rate can be controlled by aeration in a loop-seal. To maintain the gas velocity in the moving beds (FR, SR) at the minimum fluidization velocity is found to be suitable for the stable operation. The solid holdup in moving beds decrease with increasing gas velocity and solid circulation rate.

• Korean Journal of Ecology and Environment
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• v.54 no.3
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• pp.151-155
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• 2021

The application of environmental DNA in the domestic ecosystem is also accelerating, but the processing and analysis of the produced data is limited, and doubts are raised about the reliability of the analyzed and produced biological taxa identification data, and the sample medium (target sample, water, air, sediment, Gastric contents, feces, etc.) and quantification and improvement of analysis methods are also needed. Therefore, in order to secure the reliability and accuracy of biodiversity research using the environmental DNA of the domestic ecosystem, it is a process of actively using the database accumulated through ecological taxonomy and undergoing verification procedures, and experts verifying the resolution of the data increased by gene sequence analysis. This is absolutely necessary. Environmental DNA research cannot be solved only by applying molecular biology technology, and interdisciplinary research cooperation such as ecology-taxa identification-genetics-informatics is important to secure the reliability of the produced data, and researchers dealing with various media can approach it together. It is an area in desperate need of an information sharing platform that can do this, and the speed of development will proceed rapidly, and the accumulated data is expected to grow as big data within a few years.

• Journal of the Korea Concrete Institute
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• v.20 no.2
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• pp.157-164
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• 2008

In order to raise efficiency in construction, construction period, construction costs etc. that have been problematic in the methods of hydration heat reduction thus far, this study has developed a new method. The principle of the developed construction method involves the laying of a heat conducting medium such as the heat pipe in the concrete, and through the fast conduction of heat by the heat pipe, the hydration heat occurring within the mass concrete is transferred to the exterior by which the internal hydration heat is reduced. If the study results of the onsite test are summarized, on application of existing hydration heat reduction methods, the highest temperature was reached in about 2$\sim$4 days, but when the heat pipe of this study was used, the period was reduced to within 24 hours. Moreover, when the thermal crack index was calculated with the method using the heat pipe as developed in this study, a value of 1.2 or higher was revealed, which is a level that can restrict the occurrence of cracks. Therefore, when the hydration heat control method using the heat pipe as developed in this study is applied, not only the effects of construction efficiency and reduction in construction period, but also outstanding economical effects can be expected.