• 대한공간정보학회지
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• 제7권2호
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• pp.57-68
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• 1999

지형정보의 활용을 위한 기본도 구축은 효율적인 GIS 작업의 성공여부를 좌우할 만큼 매우 중요한 의미를 지니고 있다. 그러므로, 실용적인 기본도 제작을 위해서는 국가지리정보체계와 필지중심토지정보체계를 일원화할 수 있는 지형 및 지적정보의 연계 활용이 이루어져야 한다. 본 연구에서는 1:5,000 항공사진을 이용하여 정사투영 영상지도를 제작하고 map revision을 수행하였다. 그리고 이를 이용하여 기본도를 제작하고 지형 및 지적정보의 중첩정확도를 비교 분석함으로써, 영상지도와 지적정보를 중첩한 통합 데이터베이스의 제공은 물론 정확한 토지현황 파악과 환경 및 도시계획분야에 그 활용 방안을 제시할 수 있었다.

• 자원환경지질
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• 제29권5호
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• pp.615-622
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• 1996

Slope stability analysis was conducted using remote sensing and Geoscientific Information System (GIS) as a part of natural hazard assessment around Chungju area. Landsat TM band 5 and 7 which contain more information about geological structure and geography are chosen and processed to analyse regional geological structure. Through image processing technique such as PCA, HFF, edge detection and enhancement, regional lineament can be mapped and identified. The lineament density map is constructed based on summed length of lineaments per unit area and the study area can be divided into 7 structural domains. Various factors of slope stability analysis such as geology, slope aspect, degree of slope, landcover, water shed as well as characterized structural domain are constructed as a database of GIS. Rating and weighting of each factor for slope stability analysis is decided by considering environmental geological characteristics of study area. Spatial analysis of regional slope stability is examined through overlaying technique of the GIS. The result of areal distribution of slope stability shows that the most unstable area is all over Jaeogae-ni, Hyangsan-ni and Mt. Daedun.

• 환경영향평가
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• 제8권1호
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• pp.51-59
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• 1999

This study was conducted to evaluate the functions of green spaces for the environment amelioration in Chongju City. The results obtained from this study were as follows; 1. Total amounts of $SO_2$ and $NO_2$ which can be absorbed by green spaces in Chongju City from EPA model were calculated as 27,655 tons and l,551 tons per year, respectively. 2. It was estimated that more green spaces were needed to mitigate the effect of air pollutants emitted from industrial complex at Songjung-Dong, Bokdae-Dong and Sachang-Dong in Chongju City. This is acquired as a result of overlaying the map of administrative district, forest state, and $SO_2$ isoline using GIS method. 3. The amounts of green spaces and the selection of their proper location have to be considered at the stage of city planning and in this case, the amounts of air pollutants are also considered.

• 대한조선학회논문집
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• 제50권5호
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• pp.349-354
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• 2013

The blades of flexible propellers are formed by overlaying and adhering many layers of thin glass-fiber fabric sheets, are compressed and dried in the rigid mold. The current manufacturing process can not avoid the rather irregular deformation of the blades composed of non-isotropic non-uniform fabric structures, and inevitably introduces the different shape-forming errors between blades. In this paper, several flexible model propellers are precisely measured with three-dimensional optical instrument and compared with the original design geometry. The model propellers with the as-measured geometry are evaluated with the lifting-surface-theory-based propeller analysis code. The open-water performance are presented and discussed. The importance of the manufacturing accuracy is addressed to be able to apply the flexible propellers for propulsion of marine vehicles.

• Journal of Welding and Joining
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• 제15권5호
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• pp.92-103
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• 1997

The purpose of this study is to improve the wear resistance and hardness of Al alloy by making a formation of the thick surface hardening layers. The thick surface hardening layers were formed by PTAW(Plasma Transferred Arc Welding), with the addition of metal powders (Cu), ceramics powders (NbC, TiC), and mixture powders (Cu+NbC) in Al alloy (A1050, A5083). Mechanical properties of overlaid layers (wear resistance, hardness) were investigated in relation to the microstructure. The results obtained are summarized as follows: The depth of penetration was increased with increasing powder feeding rate. It is considered that these increase were due to the thermal pinch effect by the addition of powders, especially, for the Cu powders, were due to the heat of reaction with the matrix. The hardness and wear resistance of overlaid layers were improved with increasing powder feeding rate. For the Cu powders, it is considered that these increase were due to the increase of the formation of ${\theta}(CuAl_2)$ phase with increasing feeding rate of Cu powers.

• 산업기술연구
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• 제25권A호
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• pp.49-56
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• 2005

Recently, very-early strength latex-modified concrete(below ; VES-LMC) has been developed for repairing and overlaying the old concrete bridge deck. VES-LMC provides the advantage of very-early-strength, as well as high flexural strength, bond strength, durability, resistance to corrosion, reduced water permeability and resistance to damage from freeze-thaw cycles. The compressive and flexural strength of VES-LMC are 21 MPa and 4.5 MPa at 3 hours after concrete placing, respectively. However, VES-LMC would have a relatively large shrinkage at early-age because of reduced water-cement ratio, big water self-dissipation, and rapid hydration reaction. Therefore, the purpose of this study was to evaluate the early-age and restrained shrinkage of VES-LMC, having an experimental variables such as latex contents and cement types. The latex contents included 0%, 5%, 10%, 15% and 20%, and the cement types included ordinary portland cement and very-early strength cement.

• 설비공학논문집
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• 제25권1호
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• pp.37-42
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• 2013

Double pipe system in which PB pipe is inserted in CD pipe buried in the concrete slab is widely used for cold and hot water supplies in apartment housings. The system, however becomes complicated and the overlaying pipes in the concrete slab weaken the compressive strength of the slab. Also, insufficient insulation increases energy loss. In this work, the problems of the double pipe system are studied and plans A, B, and C are suggested for improvement. In terms of compressive strength of the concrete slab, plan A(total pipe length 73 m) was the weakest and plan B(2 m) was the strongest. Energy loss of plan A was the largest with 558.9 W and plan B was the lowest with 220.7 W. However, considering the combined effect of strength and heat loss, plan C becomes the best choice, which retains the advantage of the double pipe system.

• 한국전기전자재료학회논문지
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• 제24권8호
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• pp.609-615
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• 2011

This paper is studied for the improvement of the characteristics of gate oxide with 3-nm-thick gate oxide by deuterium ion implantation methode. Deuterium ions were implanted to account for the topography of the overlaying layers and placing the D peak at the top of gate oxide. A short anneal at forming gas to nitrogen was performed to remove the damage of D-implantation. We simulated the deuterium ion implantation to find the optimum condition by SRIM (stopping and range of ions in matter) tool. We got the optimum condition by the results of simulation. We compare the electrical characteristics of the optimum condition with others terms. We also analyzed the electrical characteristics to change the annealing conditions after deuterium ion implantation. The results of the analysis, the breakdown time of the gate oxide was prolonged in the optimum condition. And a variety of annealing, we realized the dielectric property that annealing is good at longer time. However, the high temperature is bad because of thermal stress.

• 대한원격탐사학회지
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• 제11권1호
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• pp.1-17
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• 1995

원격탐사자료(MOS-1)를 이용하여 라오스 북부 남칸유역분지의 토지이용형태를 분류하 고, 항공사진과 지형도 및 현지조사에 의한 자료를 기초로 하여 Arc/Info 시스템에서 10종류의 주 제도를작성하였다. 이가운데 취락, 소유역분지, 지형고도, 사면경사를 기준으로하여 토지이용분포 의 특성을 각 주제도면을 중첩 분석하여 규명하였다. 더욱이 화전지역의 분포특성을 파악하고, 휴 경지와 화전지역에 대하여 미작이 가능한 영구농지로 전환할 수 있는 적지를 추출하여 유역관리 를 위한 기초자료를 산출하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권4호
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• pp.1884-1903
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• 2019

Device-to-Device (D2D) communications can provide proximity based services in the future 5G cellular networks. It allows short range communication in a limited area with the advantages of power saving, high data rate and traffic offloading. However, D2D communications may reuse the licensed channels with cellular communications and potentially result in critical interferences to nearby devices. To control the interference and improve network throughput in overlaid D2D cellular networks, a novel channel assignment approach is proposed in this paper. First, we characterize the performance of devices by using Poisson point process model. Then, we convert the throughput maximization problem into an optimal spectrum allocation problem with signal to interference plus noise ratio constraints and solve it, i.e., assigning appropriate fractions of channels to cellular communications and D2D communications. In order to mitigate the interferences between D2D devices, a cluster-based multi-channel assignment algorithm is proposed. The algorithm first cluster D2D communications into clusters to reduce the problem scale. After that, a multi-channel assignment algorithm is proposed to mitigate critical interferences among nearby devices for each D2D cluster individually. The simulation analysis conforms that the proposed algorithm can greatly increase system throughput.