• 한국지리정보학회지
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• 제6권3호
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• pp.1-10
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• 2003

최근 수정범용토양유실공식을 활용한 토양침식 연구가 활발히 진행중에 있으나, 실측자료와의 비교가 어렵기 때문에 계산된 결과를 정량적으로 검증하지는 못하였다. 본 연구에서는 RUSLE 모형을 구성하고 있는 인자들을 GIS 격자분석기법으로 분석하였으며, 특히 1:250,000 개략토양도를 주로 활용하였던 기존의 연구와 달리 1:25,000 정밀토양도를 활용한 토양침식인자를 제시하였다. 그리고 RUSLE 모형으로 계산한 토양침식량의 검증을 위해 보성강 유역의 비퇴사량 실측자료를 이용하였으며, 토양도의 축척을 고려한 결과 1:25,000 개략토양도의 경우는 120m의 해상도가 적합한 것으로 평가되었고 1:25,000 정밀토양도를 고려한 경우는 150m 해상도가 적합한 것으로 평가되었다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제5권3호
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• pp.159-167
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• 2005

Quantization effects (QEs), which manifests when the device dimensions are comparable to the de Brogile wavelength, are becoming common physical phenomena in the present micro-/nanometer technology era. While most novel devices take advantage of QEs to achieve fast switching speed, miniature size and extremely small power consumption, the mainstream CMOS devices (with the exception of EEPROMs) are generally suffering in performance from these effects. In this paper, an analytical model accounting for the QEs and poly-depletion effects (PDEs) at the silicon (Si)/dielectric interface describing the capacitance-voltage (C-V) and current-voltage (I-V) characteristics of MOS devices with thin oxides is developed. It is also applicable to multi-layer gate-stack structures, since a general procedure is used for calculating the quantum inversion charge density. Using this inversion charge density, device characteristics are obtained. Also solutions for C-V can be quickly obtained without computational burden of solving over a physical grid. We conclude with comparison of the results obtained with our model and those obtained by self-consistent solution of the $Schr{\ddot{o}}dinger$ and Poisson equations and simulations reported previously in the literature. A good agreement was observed between them.

• 한국해양공학회지
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• 제21권1호
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• pp.7-17
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• 2007

Based on the Boussinesq wave model, the wave distribution in the Chagui-Do sea area in Jeju was simulated by applying the directional irregular waves at an incident boundary. The time and spatial variations of monthly mean wave height and period were investigated, which aims to provide basic information on optimal sites for wave power generation. The grid size and time interval of the Boussinesq wave model were validated by examining wave distributions around a surface piercing wall, fixed at sea bottom with a constant slope. Except for the summer season, the significant wave height is dominated by wind waves and appears to be relatively high at the north sea of Chagui-Do, which is open to the ocean, while it is remarkably reduced at the rear sea of Chagui-Do because of its blocking effect on incident waves. In the summer, the significant wave height is higher at the south sea, and it is dominated by the swell waves, which is contributed by the strong south-west wind. The magnitude of significant wave height is the largest in the winter and the lowest in the spring. Annual average of the significant wave height is distinctively high at the west sea close to the Chagui-Do coast, due to a steep variation of water depth and corresponding wave focusing effect. The seasonal and spatial distribution of the wave period around Chagui-Do sea reveals very similar characteristics to the significant wave height. It is suggested that the west sea close to the Chagui-Do coast is the mast promising site for wave power generation.

• 건축역사연구
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• 제18권3호
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• pp.7-25
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• 2009

Hakbongjongtaek(The head house of Uisong Kim family, 鶴峯宗宅), firstly built in the early 17th century, was moved to its neighboring place in the late 18th century. The man who led the relocation(移建) of the house was the eldest grandson of the family, Jong-soo, Kim. He made and overall plan and also participated in building the house. There remain four Gados(family paintings, 가도(家圖)) related to the relocation plan. This paper aims to make an analysis of these Gados, and through analysis, to find what was the essential poing of the relocation plan and how the point was represented in the paintings. The result of analysis is as follows: 1. The main focus of relocation plan was the form of Anchae(the inner house). Anchae was designed as asymmetrical form, and restricted to four kan. Only Andaechung needed to be 6 kan size for religious ceremonies. 2. For the design of Sarangchae, the displacement of large Sarangbang and small Sarangbang was an important issue. There were two ways of layout: parallel type and facing type. The latter was chosen. 3. The representation and techniques of Gado is quite concrete, in spite of differences among them. The expression of doors, windows, attic and kitchen was based on the understanding of space. Also the spatial division, which was expressed line on the grid, was based on the scaled ruler. As we've seen before, painting the relocation plan was a kind of endeavors to make the housing type as a realization of Garye. Also, we can find out that role of the eldest grandson of the family was quite important to carry out the plan. As well as, it was meaningful to examine Sadaebu (the aristocrat of Chosun)'s perception of housing.

• 한국산업정보학회논문지
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• 제9권1호
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• pp.7-16
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• 2004

효율적인 최종 NC코드를 만들어내기 위해서 공구경로는 효과적인 방법으로 결정되어 져야한다. 이는 3축 CNC 공작기계상에서 자유형상의 벽을 가진 자유곡면을 가공할 때 특히 중요하다. 많은 CAD/CAM 시스템들은 자유곡면가공을 위한 NC코드 생성 시 직선 보간을 이용한다. 그러나 이 방법은 가공된 바닥 표면의 매끄러움과 가공시간, 그리고 CL파일 사이즈를 줄이기 위해서 보정되어야 한다. 곡선 가공이 이러한 문제들을 줄이기 위한 해결책이 될 수 있다. 단일화된 황삭과 정삭 알고리즘과 공구경로가 그래픽으로 시뮬레이션 되었다. 본 연구에서는 자유곡면 바닥을 가진 파켓을 3축 CNC 공작기계를 이용하여 일반적인 파켓 밀링을 위한 직선 보간과 직선+아크를 혼합한 보간을 위한 NC 공구경로 데이터를 만들기 위한 3D 격자 항행 알고리즘을 개발하였다.

• 한국해안·해양공학회논문집
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• 제27권6호
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• pp.391-405
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• 2015

본 연구에서는 원거리 지진해일에 대응하기 위한 기초 연구로써 유한 단층 모델과 순환 경계조건을 이용한 전지구 지진해일 예측 시스템을 제안하였다. 제안한 전지구 지진해일 예측 시스템을 2014년 칠레 지진해일에 적용하여 원거리 지진해일에 대한 대응 시스템으로써의 가능성을 검토하였다. 전지구 지진해일 예측 시스템의 경계조건, 지배방정식, 격자 크기, 단층 모델에 따른 지진해일 파고와 도달시각을 DART 부이, 조위관측소 관측 자료와 비교함으로써 유한 단층 모델과 순환 경계조건의 중요성을 확인하였다.

• 한국조경학회지
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• 제13권1호
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• pp.43-66
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• 1985

Korea needs proper and rational public policies on conservation and use of forest land and other natural resources because of the accelerating expansion of national land developments in recent years. Unfortunately, there is no systematic planning system to support the needs. Generally, forest land use planning needs suitability analysis based on efficient land classification system. The goal of this study was to classify a forest land using multivariate satistical methods. A case study was carried out in winter of 1983 on a mountainous area higher than 100m above sea level located at Mt. Kwanak in Anyang -city, Kyung-gi-do (province). The study area was 19.80 km$^2$wide and was divided into 1, 383 Operational Taxonomic Units (OTU's) by a 120m$\times$120m grid. Fourteen descriptors were identified and quantified for each OTU from existing national land data : elevation, slope, aspect, terrain form, geologic material, surface soil permeability, topsoil type, depth of the solum, soil acidity, forest cover type, stand size class, stand age class, stand density class, and simple forest soil capability class. For this study, a FORTRAN IV program was written for input and output map data, and the computer statistics packages, SPSS and BMD, were used to perform the multivariate statistical analysis. Fourteen variables were analyzed to investigate the characteristics of their fire quench distribution and to estimate the correlation coefficients among them. Principal component analysis was executed to find the dimensions of forest land characteristics, and factor scores were used for proper samples of OTU throughout the study area. In order to develop the classes of forest land classification based on 102 surrogates, cluster and discriminant analyses of principal descriptor variable matrix were undertaken. Results obtained through a series of multivariate statistical analyses were as follows ; 1) Principal component analysis was proved to be a useful tool for data selection and identification of principal descriptor variables which represented the characteristics of forest land and facilitated the selection of samples.

• 한국산학기술학회논문지
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• 제17권5호
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• pp.339-345
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• 2016

웹 사이트나 블로그 등에 사진을 업로드 할 때 특정인의 초상권을 보호하기 위해 사람의 얼굴을 블러링하거나 타인에게 혐오감을 주지 않기 위해 혐오스러운 물건들을 모자이크 처리하는 경우가 많이 있다. 본 논문에서는 다양하게 입력되는 영상에서 일정한 영역들을 가리기 위해 사용한 격자형 모자이크 영역들을 에지 프로젝션을 기반으로 정확하게 검출하는 새로운 알고리즘을 제안한다. 제안된 알고리즘에서는 먼저 입력 영상으로부터 캐니 에지를 검출하고, 수평과 수직 에지 프로젝션을 이용해 모자이크의 후보 영역들을 검출한다. 그런 다음, 크기나 밀집도 등의 기하학적인 특징들을 사용해 모자이크의 후보 영역들을 효과적으로 필터링함으로써 최종적으로 실제 모자이크 영역들을 검출한다. 실험 결과에서는 제안된 알고리즘이 입력되는 다양한 영상으로부터 모자이크 블록에 해당하는 영역들을 기존의 다른 검출 방법에 비해 보다 정확하게 검출한다는 것을 보여준다. 본 논문에서 제안된 모자이크 검출 방법은 개인 정보 블로킹, 영상 복원 및 후처리 등과 같은 멀티미디어 콘텐츠와 관련된 여러 가지 실제 응용분야에서 매우 유용하게 활용될 것으로 기대한다.

• 한국산업융합학회 논문집
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• 제23권4_2호
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• pp.617-626
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• 2020

The drilling mud is essentially used in oil and gas development. There are several roles of using the drilling mud, such as cleaning the bottomhole, cooling and lubricating the drill bit and string, transporting the cuttings to the surface, keeping and adjusting the wellbore pressure, and preventing the collapse of the wellbore. The fragments from rocks and micro-sized bubbles generated by the high pressure are mixed in the drilling mud. The systems to separate those mixtures and to keep the uniformly maintained quality of drilling mud are required. In this study, the simulation is conducted to verify the performance of the mud tank's agitation capacity. The primary role of the mud tank is the mixing of mud at the surface with controlling the mud condition. The container type is chosen as a mud tank pursuing efficient transport and better management of equipment. The single- and two-phase simulations about the agitation in the mud tank are performed to analyze and identify the inner flow behavior. The convergence of results is obtained for the vertical- and axis-direction velocity vector fields based on the grid-dependency tests. The mixing time analysis depending on the multiphase flow conditions indicates that the utilization of a two-stepped impeller with a smaller size provides less time for mixing. This study's results are expected to be utilized as the preliminary data to develop the mixing and integrating equipment of the onshore drilling mud system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권10호
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• pp.4883-4901
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• 2016

Energy efficiency in Wireless Sensor Networks (WSNs) is very appealing research area due to serious constrains on resources like storage, processing, and communication power of the sensor nodes. Due to limited capabilities of sensing nodes, such networks are composed of a large number of nodes. The higher number of nodes increases the overall performance in data collection from environment and transmission of packets among nodes. In such networks the nodes sense data and ultimately forward the information to a Base Station (BS). The main issues in WSNs revolve around energy consumption and delay in relaying of data. A lot of research work has been published in this area of achieving energy efficiency in the network. Various techniques have been proposed to divide such networks; like grid division of network, group based division, clustering, making logical layers of network, variable size clusters or groups and so on. In this paper a new technique of group based WSNs is proposed by using some features from recent published protocols i.e. "Energy-Efficient Multi-level and Distance Aware Clustering (EEMDC)" and "Energy-Efficient Multi-level and Distance Aware Clustering (EEUC)". The proposed work is not only energy-efficient but also minimizes the delay in relaying of data from the sensor nodes to BS. Simulation results show, that it outperforms LEACH protocol by 38%, EEMDC by 10% and EEUC by 13%.