• Nuclear Engineering and Technology
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• 제41권10호
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• pp.1255-1262
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• 2009

This paper introduces the status of and issues related to the PSHA (Probabilistic Seismic Hazard Analysis) of Korean Nuclear Power Plant sites. PSHA was first introduced to the nuclear industry in the mid-1980s. The Korean PSHA is based on Cornell and accommodates the modem approach for eliciting expertise and statistical treatment. Due to the low seismicity in Korea, large uncertainties exist in the PSHA database including seismic source maps, seismicity parameters of seismic sources, and attenuation formulae. Though research in seismology, geology, and earthquake engineering since the mid-1990s has significantly reduced uncertainties, a considerable amount still exists. Considering the low seismicity of the Korean Peninsula, especially the lack of strong motion data, further reduction will take several decades.

• International Journal of Computer Science & Network Security
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• 제23권6호
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• pp.49-58
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• 2023

Renewable energy is not a new terminology. One of the fastest growing renewable energies is solar energy. The implementation of solar energy provides several advantages including the reduction of some of the environmental risks of fossil fuel consumption. This research elaborated the importance of the adaption of solar energy by developing a spatial decision support system (SDSS), while the Residential Solar Energy Adoption (RSEA) is an instantiation artifact in the form of an SDSS. As a GIS web-based application, RSEA allows stakeholders (e.g., utility companies, policymakers, service providers homeowners, and researchers) to navigate through locations on a map interactively. The maps highlight locations with high and low solar energy adoption potential that enables decision-makers (e.g., policymakers, solar firms, utility companies, and nonprofit organizations) to make decisions. A combined qualitative and quantitative methodological approach was used to evaluate the application's usability and user experience, and results affirmed the ability of the factors of utility, usefulness, and a positive user experience of the residential solar energy adoption of spatial decision support system (RSEA-SDSS). RSEA-SDSS in improving the decision-making process for potential various stakeholders, in utility, solar installations, policy making, and non-profit renewable energy domains.

• 대한수학회보
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• 제32권2호
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• pp.211-214
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• 1995

Let M and N be compact Riemannian manifolds and $f : M \to N$ be a smooth map. Following J. Eells, f is exponentially harmonic if it represents a critical point of the exponential energy integral $$ E(f) = \int_{M} exp(\left\$\mid$ df \right\$\mid$^2) dM $$ where $(\left\ df $\mid$\right\$\mid$^2$ is the energy density defined as $\sum_{i=1}^{m} \left\$\mid$ df(e_i) \right\$\mid$^2$, m = dimM, for orthonormal frame $e_i$ of M. The Euler- Lagrange equation of the exponential energy functional E can be written $$ exp(\left\$\mid$ df \right\$\mid$^2)(\tau(f) + df(\nabla\left\$\mid$ df \right\$\mid$^2)) = 0 $$ where $\tau(f)$ is the tension field along f. Hence, if the energy density is constant, every harmonic map is exponentially harmonic and vice versa.

• 국제학술발표논문집
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• The 8th International Conference on Construction Engineering and Project Management
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• pp.485-492
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• 2020

Information on the energy consumption of buildings that can be obtained through conventional methods is limited. Therefore, this study aims to develop a model that can support decision making about building facility management through digital transformation technologies. Through the IoT sensor, the building's energy data and indoor air quality data are collected, and the monitored data is visualized through the ELK Stack and produced as a dashboard. In addition, the target building is photographed with a 360-degree camera and maps using a tool to create a 360-degree tour. Using such digital transformation technologies, users of buildings can obtain various information in real time without visiting buildings directly. This can lead to changes in actions or actions for building management, supporting facility management decisions, and consequently reducing building energy consumption.

• 한국지리정보학회지
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• 제17권3호
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• pp.195-206
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• 2014

본 연구에서는 휴대용 X-선 형광 분석기(X-Ray Fluorescence, XRF)와 지리정보시스템(Geographic Information Systems, GIS)을 이용하여 부산 폐광산 지역의 구리와 납에 관한 토양오염지도를 작성하였다. 연구지역의 수치표고모델(Digital Elevation Model, DEM)을 이용한 수문 분석을 통해 오염원으로부터 오염 물질이 확산될 수 있는 빗물의 흐름방향을 분석하였으며, 이를 고려하여 토양오염도 측정 지점을 24곳 선정하였다. 휴대용 X-선 형광 분석기를 이용하여 24곳 토양에서 구리와 납의 농도를 측정한 결과, 구리는 최대 8,255ppm, 납은 최대 2,146ppm가 검출되었다. 휴대용 X-선 형광 분석기로 측정한 구리와 납의 농도 자료를 ArcGIS 소프트웨어에 입력하였으며, 정규크리깅(ordinary kriging) 기법을 이용하여 공간보간(spatial interpolation)을 수행한 후 구리와 납에 관한 5m 해상도의 토양오염지도를 작성하였다. 그 결과 부산 폐광산 지역에서는 갱구들 주변에 적치되어 있는 폐석 및 광미를 중심으로 고농도의 구리와 납이 토양 내에 존재하는 것을 작성된 토양오염지도로부터 확인할 수 있었다. 본 연구를 통해 휴대용 X-선 형광 분석기와 GIS를 이용한 구리와 납의 토양오염지도 작성방법이 현장에서 효과적으로 사용될 수 있음을 알 수 있었다.

• 정보처리학회논문지B
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• 제15B권4호
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• pp.269-274
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• 2008

본 논문에서는 스테레오 영상(stereo image)을 이용하여 스네이크 기반 객체 추출 방법들이 강력한 외부 에너지(external energy)를 생성할 수 있도록 새로운 스테레오 일치화 방법을 제안한다. 제안하는 방법의 첫 번째 단계로 한 쌍의 스테레오 영상에서 다중 레벨 에지 지도를 만들고 상관관계를 파악하여 에지 기반의 변위 지도(disparity map)를 만든다. 이때 비슷한 세기를 가진 에지를 정합(matching)에 이용한다. 이 후 영상 내에서 추출하고자 하는 객체의 에지 지도를 얻기 위하여 다음의 과정을 거친다. 왼쪽 영상에서의 관심 영역의 에지 패턴을 얻고 다시 오른쪽에서도 똑같이 패턴을 얻어낸 후 두 패턴을 정합하여 객체의 변위(disparity)를 얻어낸다. 이렇게 얻어진 에지 지도를 이용하여 스네이크에서 사용될 외부 에너지를 만든다. 제안하는 방법을 이용하여 두 종류의 스네이크 모델에서 테스트를 한 결과 기존의 방법에 비해 더 나은 결과를 얻게 되었다.

• 한국측량학회지
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• 제36권6호
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• pp.483-497
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• 2018

여러 장의 영상을 조합하여 한 장의 영상으로 제작하는 영상 모자이크는 넓은 지역의 영상을 판독하고 분석하는데 효과적이며, 연속 영상지도 등 다양한 공간정보 분야의 활용에 중요하다. 영상 모자이크의 중요한 과정은 인접 영상의 중복지역에서 최적의 접합선 추출과 모자이크된 영상의 색조보정이다. 이를 위해 본 연구에서는 SURF(Speeded Up Robust Features)에 의한 영상정합을 수행하여 중복지역을 결정하였다. Canny 필터로 추출한 윤곽선의 특성에 따라 등급을 정하여 접합선이 될 가능성이 높은 윤곽선을 선별하고, Dijkstra 알고리즘을 사용하여 윤곽선들을 연결하여 접합선을 결정하였다. 특히 비등방성 필터와 영상 피라미드를 적용하여 신뢰성 있는 접합선을 추출할 수 있었다. 또한 수치지도의 건물과 도로 레이어를 이용하여 효과적이고 효율적인 접합선을 결정할 수 있었다. 최종적으로 인접 영상들의 색조를 조절하여 품질을 향상시키기 위하여 히스토그램 정합과 접합선 feathering을 수행하였다.

• 전기학회논문지
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• 제66권8호
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• pp.1207-1214
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• 2017

In the case of frequent braking, when driving downhill or long distance, conventional brakes using friction are problematic in braking safety due to brake rupture and fading phenomenon. Therefore auxiliary brakes is essential for heavy vehicles. And several research has been actively conducted to improve energy efficiency by regenerating mechanical energy into electric energy when the vehicles brake. In this paper, a voltage control method is utilized to recover the electric energy generated in the electromagnetic retarder instead of the eddy current. To regenerate the braking energy into the electrical energy, a resonant L-C circuit is configured in the retarder. The retarder can be modeled as self-excited induction generator due to its operating principle. The driving conditions according to the retarder's parameters are made into 3-D maps. Also, the voltage of the resonant circuit changing depending on the driving pulse applied to the FET was analyzed. For the control of this voltage, we proposed an algorithm using the PI controller. The controlled voltage is converted by a 3-phase AC/DC converter and then charged to a battery inside the heavy vehicles through a DC/DC converter. Electromagnetic retarder and its controller are validated using Matlab Simulink. We also demonstrate the voltage controller through the actual M-G set experiment.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.61-68
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• 2021

Experiments of vertically upward steam-water two-phase flow have been carried out in single-side heated narrow rectangular channel with a gap of 3 mm. Flow patterns were identified and classified through visualization directly. Slug flow was only observed at 0.2 MPa but replaced by block-bubble flow at 1.0 MPa. Flow pattern maps at the pressure of 0.2 MPa and 1.0 MPa were plotted and the difference was analyzed. The experimental data has been compared with other flow pattern maps and transition criteria. The results show reasonable agreement with Hosler's, while a wide discrepancy is observed when compared with air-water two-phase experimental data. Current criteria developed based on air-water experiments poorly predict bubble-slug flow transition due to the different formation and growth of bubbles. This work is significant for researches on heat transfer, bubble dynamics and flow instability.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.458-459
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• 2009

This global case study pursues diversification and intensification for an application system of the national wind map which has been developed to support national strategy building and promotion of wind energy dissemination. We chose nine counties' national wind maps and compared their map area, extraction height, temporal and spatial resolution, download services, etc. to derive a best practice for the Korea wind map application system. Therefore, the application system are designed to offer high resolution height information of which covers wind turbine rotor sweeping area and time-series dataset which can be downloaded for further analysis by users. It is anticipated that the system would contribute greatly to wind energy policy, business and research sectors once the derived ideas have been implemented to the application system