• 한국물환경학회지
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• 제22권6호
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• pp.1094-1100
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• 2006

In this study, the reservoir sediment reduction methods for long-term operation are proposed by the analysis of both sediment deposit characteristics and sediment reduction effect by each method. To that end, a flowchart for sediment analysis in reservoir is established and sediment deposit is simulated by SMS-SED2D model. The sediment reduction methods which are sediment passing (sluicing), flushing, trapping, bypassing and mechanical removal are used. From the simulation results, the effective method for sediment reduction is operation which is coupled by both sediment passing with sand gate and sediment trapping with debris dam. And If sediment flushing will be used once a year after 50 years, conservation storage can be secured until 100 years after dam construction.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.105-112
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• 2006

Freak waves in the ocean are recently drawing much attention as a natural disaster to ocean structures and navigating ships as well. Several observation data, among them the Draupner New Year Wave, show the very impressive feature of Freak waves whose wave height is up to three times as high as the significant wave height of surrounding waves, In addition, Freak wave appears as an isolated very high crest in somewhat stationary random waves of same order in their wavelengths. Bearing such characteristics in mind, one notices its extraordinary steepness. This strongly suggests that Freak wave is not long lived but transient nature on the whole. A great number of studies to explain these natures were published from both theoretical and numerical point of view. However it is not sure if they are applicable to actual ocean environment. In this paper, we deal with the results concerning abnormal and/or Freak waves from in-situ ocean wave data and point out several remarks to the problems lain behind the contributions in this context. A physical experiment is described to reinforce the subject discussed from the observation data.

• Geomechanics and Engineering
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• 제20권6호
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• pp.547-556
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• 2020

An understanding of the influence of MR (Magmatic Rock) thickness on the surrounding rock behaviors is essential for the prevention and management of dynamic disasters in coal mining. In this study, we used FLC3D to study the breaking and instability laws of surrounding rock with different MR thicknesses in terms of strata movement, stress and energy. The mechanism of dynamic disasters was revealed. The results show that the thicker the MR is, (1) the smaller the subsidence of the overlying strata is, but the subsidence span of the overlying strata become wider, and the corresponding displacement deformation value of the basin edge become smaller. (2) the slower the growth rate of abutment pressure in front of the working face is, but the peak value is smaller, and the influence range is larger. The peak value decreases rapidly after the breaking, and the stress concentration coefficient is maintained at about 1.31. (3) the slower the peak energy in front of coal wall, but the range of energy concentration increases (isoline "O" type energy circle). Finally, a case study was conducted to verify the disaster-causing mechanism. We anticipate that the research findings presented herein can assist in the control of dynamic hazards.

• 환경영향평가
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• 제20권5호
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• pp.717-727
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• 2011

Impervious surface affects urban climate, flood, and water pollution and has important role as basic data for urban planning and environmental and resources management uses. With a high paved rate, increased quantity of the outflown water and brings urban flooding during a heavy rain. Moreover, these non-point source pollution is getting increased the water pollution. In this regard, it is definitely important to research and keep monitoring the current situation of paved surface, which influences urban ecosystem, disaster and pollution. In this study, we suggest a method to utilize high resolution satellite image data for efficient survey on the current condition of paved surface. We analysed the paved surface condition of Dae-jeon metropolitan city area using KOMPSAT-2 image and validate its practicalness and limitation of this method.

• 대한원격탐사학회지
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• 제32권5호
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• pp.539-550
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• 2016

육상의 수체를 탐지하는 것은 홍수, 태풍, 지진해일과 같은 재해 모니터링에 있어 핵심적인 사항이며, 습지, 빙하 등 지표 수자원의 시 공간적 변화를 파악하는데 중요한 역할을 한다. 본 연구에서는 Kompsat-5 SAR 영상으로부터 육상의 수체를 탐지하기 위하여 임계값에 기반한 접근방법의 적용성을 분석하고, 다양한 임계값 설정 기법의 탐지 성능을 평가하였다. 또한 SAR 영상의 스펙클 필터링이 임계값 설정에 미치는 영향을 분석하였으며, 영상에서 수체가 차지하는 비율에 따른 탐지 성능의 변화에 대한 정량적인 평가를 수행하였다. 추가적으로 탐지 성능을 향상시키기 위해 히스토그램의 bimodality 검정과 majority filtering 처리를 활용하는 새로운 알고리즘을 제안하였다. 세종시 지역의 사례의 경우 제안된 알고리즘을 통해 최종적으로 약 96%의 탐지율과 0.3%의 오탐지율로 수체를 탐지할 수 있음을 보였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.216-219
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• 2008

As a future clean substitute energy, the Gas hydrate development projects are world widely carried out to prepare the shortage of petroleum and natural gas resources. The OIIP of gas hydrate is estimated approximately 10 Trillion LNG equivalent ton and it reaches almost the amount of 5 thousand years use for the world people. To develop the commercial production technology, several research projects like Malik and Alaska project have been carried by several advanced countries and teams, but nobody have succeeded it yet due to the technical problems and the high risks. The technologies developed up to now for the hydrate production are categorized to four methods, such as depressurization method, thermal recovery method, inhibitor injection method and replacement method. As these methods are highly related to the costs and the environmental problems, many other researches including the safety, environment and disaster prevention are actively fulfilled as well.

• 한국기록관리학회지
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• 제17권2호
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• pp.79-99
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• 2017

디지털 시대로 들어서면서 문화유산기관들의 정보자원 공유 및 통합서비스에 대한 필요성이 점차 높아지고 있으며 여러 나라들이 이러한 기관들의 자원공유를 목표로 통합과 협력을 시도하고 있다. 본 연구는 일본의 국립국회도서관과 국립공문서관의 공통점과 상이점을 비교한 후 향후 협력 방안을 도출하였다. 이를 위해 홈페이지와 관련 문헌 및 법령을 중심으로 역사, 체제, 법령, 정책, 그리고 서비스 등을 분석하였다. 양 기관의 협력 방안으로는 소장자료의 역사 관련 통합 DB와 재난 정보 아카이브의 구축, 공동전시회 개최, 학습 프로그램을 제시하였다.

• 전자공학회논문지
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• 제54권2호
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• pp.9-15
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• 2017

본 논문은 원활한 통신이 어려운 재난안전통신 환경에서 고출력 단말이 한정된 주파수 자원을 효율적으로 이용할 수 있는 자원할당 기법을 제안한다. 고출력 단말을 도입함에 따라 단말 당 전송률이 증가하고 서비스 영역이 커질 수 있지만 일반 단말과 동일한 주파수 자원을 재사용할 경우 간섭도 증가하여 재난지역 및 인접 지역 전체 시스템 성능 저하의 원인이 된다. 간섭에 의해 기존 셀룰러 시스템 성능에 영향을 미칠 수 있기 때문에 3GPP (3rd Generation Partnership Project)에서는 고출력 단말의 사용 가능 주파수 대역을 상향링크 788-798MHz, 하향링크 758-768MHz로 제한하고 있다. 이러한 제약조건 하에서 단말의 최저 성능 보장을 위한 자원할당 방식을 제안하고 제안한 자원할당 방식의 성능을 모의실험을 통해 검증한다.

• 한국해양공학회지
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• 제32권5호
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• pp.361-366
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• 2018

The present study analyzed the variation factors in inducing a salinity change using the existing observation network in the section between the Nakdong River Estuary Barrage and Changnyeong-Haman Weir, and also examined the seasonal changes in precipitation, salinity, and discharge. Furthermore, this study analyzed the causes of a salinity increase by collecting observational data during a period when abnormal salinity occurred, and further investigated the salinity transfer time in a section of approximately 5.3 km from the Nakdong River Estuary Barrage to Nakdong River Bridge to understand the behavioral characteristics of the salinity moving upstream. The study results would make it possible to control the increase in salinity and block salt water from moving upstream by understanding the salinity variation characteristics according to the discharge amount. This will provide stability in collecting water from various residential, agricultural, and industrial sources through water intake facilities scattered near the Nakdong River Estuary Barrage.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 추계종합학술대회
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• pp.274-277
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• 1999

대형 선박에는 각종 저장용 탱크가 산재해 있으며, 이들 각 탱크의 잔존량 및 이상 유무를 실시간으로 취합하여, 모니터링 할 수 있는 시스템은 선박에 있어서 필수적이다. 기존의 선박용 탱크 모니터링 시스템에서 입력되는 데이터의 종류가 많은 경우, 이를 구분하기 위한 처리와 전송 과정에서 발생되는 전송 에러에 대한 처리를 호스트 컴퓨터에서 수행하므로 많은 부하가 걸리게 된다. 따라서 된 논문에서는 에러 자동 검출 및 정정의 자동 수행 및 실시간 분산 제어 기능을 제공하는 CAN을 이용해 실시간 탱크 모니터링 시스템을 설계하고, 구현한다.