• 한국지리정보학회지
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• 제11권2호
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• pp.1-12
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• 2008

버스와 지하철 등 대중교통수단은 승용차가 없는 시민들에게는 유일한 이동수단으로써 생활필수 서비스에 속한다. 또한 스마트성장을 비롯한 바람직한 도시성장유형들은 예외없이 대중교통수단 위주의 개발 (transit-oriented development)을 권장하고 있다. 그러므로 대중교통서비스는 모든 시민들에게 가용한 기본서비스가 되어야 함과 동시에 도시정책의 주요수단이 된다. 본 연구는 대중교통서비스 취약지역을 파악하고 그 분포특성을 분석함으로써 도시 대중교통정책 수립에 기여함을 목적으로 한다. 이를 위해 대구광역시를 사례지역으로 하여 통계청의 기초단위구 자료와 위성영상을 이용하여 분석단위를 세분화하고 이를 기준으로 버스 및 지하철 정류장과의 거리를 계산하였다. 그리고 정류장으로부터 300m이상 격리된 지역을 대중교통서비스 취약지역으로 간주하였다. 이 기준에 따라 대중교통서비스 취약지역의 특성을 면적, 인구, 주택유형 등의 측면에서 파악하였다. 분석결과 대중교통서비스는 지역별로 큰 차이가 나는 가운데 특히 교외지역과 농촌지역에서 취약계층이 많음이 입증되었다. 특히 본 연구는 이동성이 낮은 노인인구중 대중교통서비스를 이용하기 쉽지 않는 계층을 파악하고 공간적 분포를 제시하였다.

• 대한디지털의료영상학회논문지
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• 제10권2호
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• pp.23-31
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• 2008

Computed radiography(CR) has been widely used in the field of diagnostic radiography since digital X-ray image was introduced. The imaging performance of CR system was studied by analyzing the digital image data of the CR images which are the outcomes of the whole imaging system composed of image plate(IP), laser digitizer, analoge-digital convertor, and a given image processing unit. In this study, we used a conventional CR system made by Agfa. From the flat field image of 150$\times$150 image pixels, signal-to-noise ratio(SNR) was calculated. SNR of the CR image increases in proportion to logarithm value of the X-ray exposure irradiated on the IP. SNR is less than about 6 at the exposure below 0.2mR and is more than 10 at the exposure above 0.54mR. In our study, most of images obtained by the smaller exposures less than 2.0mR can not be readable. In general, the minimum value of the SNR ranges from 3 to 5. We obtained modulation transfer function(MTF) by analyzing the bar pattern image which was made under conditions as follows: X-ray tube potential was 55kVp, the IP exposure was 0.54 mR, and the distance between X-ray source to IP was 2m, where bar pattern was located on the IP. MTF is 23% at 2.5lp/mm spatial frequency. Provided that the MTF of noise equivalent modulation is 10%, the CR system has the limiting spatial resolution of 3.2lp/mm. If the image sharpness is evaluated by the spatial frequency where MTF is 50%. the corresponding spatial frequency is 0.5$\sim$0.75lp/mm. MTFA(Modulation Transfer Function Area) is 1.0lp/mm. Compared with the Fuji CR whose MTFA is 1.1lp/mm, Agfa CR in this study shows almost same MTFA performance.

• 농촌계획
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• 제15권4호
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• pp.213-220
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• 2009

Farmland spatial data are needed as a basic information in conducting rational use of farmlands in regional scale. This study develops a method that can be used to make up such farmland spatial data in a simple way and to develop a technique to manage them in a unitary way, and examines the effectiveness of the technique by applying it to the case area. A method that Web-Service Raster Image and Digital Cadastal Map can be utilized as a base map was devised. It was designed applying the vector system, in which one lot of farmland is area unit. Raster image and field survey data were combined to increase the accuracy of data. The lot boundaries of the existing boundary map were adjusted to the shapes of actual farmlands using GIS edition function. A proper farmland use classification system to the area characteristics was established and data obtained from the field survey were coded. Usually it is very difficult to identify the size of one lot of actual farmland in the existing space data, based on the results of the case study, the result map showed actual topography very realistically. Also the frequently occurring lot divisions and the serious topographical modifications by natural disasters frequently have made it impossible to survey farmlands on the catastral map in the field. But the final map had a great usefulness in that it may solve such problems by expressing the filed survey results graphically.

• 대한공간정보학회지
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• 제1권1호
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• pp.217-225
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• 1993

지형공간정보체계에 대한 투자의 타당성을 조사하는 방법으로 비용효과분석을 하는 경우가 많다. 경제학분야의 비용/효과 분석기법을 일반적인 정보체계도입의 타당성조사에 대해서 많이 활용하여 왔으며 최근 GSIS에 대해서도 적용시키려는 노력이 많이 진행되고 있다. 본 연구에서는 국내 GSIS에 적합한 비용/효과 모델을 확립시키고 이모델을 시설물관리 업무에 적용시켰다. GSIS의 구축에 필요한 비용의 항목을 결정하고 각각의 항목에 필요한 단가를 조사하여 결정하므로서 국내실정에 맞는 비용모형을 제시하였으며 효과모형의 확립에서는 지형공간정보체계를 도입하므로서 얻을 수 있는 효과를 특성에 따라 분류하였으며 분류된 항목 중 정량화 가능한 항목을 세부적으로 분류하였다. 확립된 비용/효과 모형을 국내의 대규모의 도시가스공금 업체에 적용시켜 100명 이상의 직원수와 300,000 가구이상의 수용가를 관리하는데 필요한 GSIS를 설계하였으며 이러한 GSIS를 구축할 때의 비용과 GSIS의 도입 없이 수동식으로 운영하는 비용을 계산하여 비교하였다.

• 한국실내디자인학회논문집
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• 제24권5호
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• pp.117-127
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• 2015

This paper depicts a case study of the BIM (Building Information Modeling)-enabled evaluation of design alternatives for an actual remodeling project in Yeongwol, Korea. The increase of urban population and income followed by the growth of economy has derived massive supply of grand scale housing project in Korea since 1970s. Consequently, building remodeling became one of the feasible resolutions for renovating such old housings in these days. This paper aims to introduce a technical approach to such remodeling projects based on BIM-enabled applications focusing on quantitative analysis of design alternatives. Among the technical issues of such building remodeling projects, this paper focuses on the BIM-enabled area analysis and comparison between design alternatives to support decision-making even in early phase of remodeling design process. BIM and its variety of applications have broadly influenced the domain of AEC-FM (Architecture, Engineering, Construction, and Facility Management) within the lifecycle of buildings. As one of the applications facilitated by BIM, the automated area calculation and scenario-based comparison between alternatives can play an important role in the early phase of remodeling project. We modeled three design alternatives (buildings) and three housing modules (units) based on the actual case in Yeongwol city, Korea using a BIM design authoring tool. Nine combinatorial BIM models were demonstrated for the BIM-enabled review process described in this paper. To determine the most optimal design scenario among nine alternatives, this paper demonstrates a result of the conducted spatial program review. The main subject includes specific spatial program issues on; 1) the number of unit spaces; and 2) area of individual/grouped and private/shared spaces.

• 한국농림기상학회지
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• 제3권1호
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• pp.37-43
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• 2001

Crop status monitoring and yield prediction at higher spatial resolution is a valuable tool in various decision making processes including agricultural policy making by the national and local governments. A prototype crop forecasting system was developed to project the size of rice crop across geographic areas nationwide, based on daily weather pattern. The system consists of crop models and the input data for 1,455 cultivation zone units (the smallest administrative unit of local government in South Korea called "Myun") making up the coterminous South Korea. CERES-rice, a rice crop growth simulation model, was tuned to have genetic characteristics pertinent to domestic cultivars. Daily maximum/minimum temperature, solar radiation, and precipitation surface on 1km by 1km grid spacing were prepared by a spatial interpolation of 63 point observations from the Korea Meteorological Administration network. Spatial mean weather data were derived for each Myun and transformed to the model input format. Soil characteristics and management information at each Myun were available from the Rural Development Administration. The system was applied to the forecasting of national rice production for the recent 3 years (1997 to 1999). The model was run with the past weather data as of September 15 each year, which is about a month earlier than the actual harvest date. Simulated yields of 1,455 Myuns were grouped into 162 counties by acreage-weighted summation to enable the validation, since the official production statistics from the Ministry of Agriculture and Forestry is on the county basis. Forecast yields were less sensitive to the changes in annual climate than the reported yields and there was a relatively weak correlation between the forecast and the reported yields. However, the projected size of rice crop at each county, which was obtained by multiplication of the mean yield with the acreage, was close to the reported production with the $r^2$ values higher than 0.97 in all three years.

• 국토계획
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• 제54권2호
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• pp.93-108
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• 2019

This study examines the relationship between three-dimensional urban built environment and urban surface temperature using LANDSAT 8 satellite image data in Seoul city. The image was divided into 600m×600m grid units as an unit of analysis. Due to the high level of spatial dependency in surface temperature, this study uses spatial statistics to take into account spatial auto-correlation. The spatial error model shows the best goodness of fit. The analysis results show that the three-dimensional built environment and transport environment as well as natural environment have statistically significant associations with surface temperature. First, natural environment variables such as green space, streams and river, and average elevation show statistically significant negative association with surface temperature. Second, the building area shows a positive association with surface temperature. In addition, while sky view factor (SVF) has a positive association with surface temperature, surface roughness (SR) shows a negative association with it. Third, transportation related variables such as road density, railway density, and traffic volume show positive associations with surface temperature. Moreover, this study finds that SVF and SR have different effects on surface temperature in regard to the levels of total floor areas in built environment. The results indicate that interactions between floor area ratio (FAR) and three-dimensional built environmental variables such as SVF and SR should be considered to reduce urban surface temperature.

• 한국지진공학회논문집
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• 제25권5호
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• pp.223-232
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• 2021

The spatial variation characteristics of seismic motions at the nuclear power plant's site and structures were analyzed using earthquake records obtained at the Fukushima nuclear power plant during the Great East Japan Earthquake. The ground responses amplified as they approached the soil surface from the lower rock surface, and the amplification occurred intensively at about 50 m near the ground. Due to the soil layer's nonlinear characteristics caused by the strong seismic motion, the ground's natural frequency derived from the response spectrum ratio appeared to be smaller than that calculated from the shear wave velocity profile. The spatial variation of the peak ground acceleration at the ground surface of the power plant site showed a significant difference of about 0.6 g at the maximum. As a result of comparing the response spectrums at the basement of the structure with the design response spectrum, there was a large variability by each power plant unit. The difference was more significant in the Fukushima Daiichi site record, which showed larger peak ground acceleration at the surface. The earthquake motions input to the basement of the structure amplified according to the structure's height. The natural frequency obtained from the recorded results was lower than that indicated in the previous research. Also, the floor response spectrum change according to the location at the same height was investigated. The vertical response on the foundation surface showed a significant difference in spectral acceleration depending on the location. The amplified response in the structure showed a different variability depending on the type of structure and the target frequency.

• 한국인터넷방송통신학회논문지
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• 제22권1호
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• pp.35-43
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• 2022

본 논문에서는 10W급 MMIC를 결합하여 20W급으로 상향시킨 단위 전력 증폭기를 8-way 공간결합기와 결합하여 100W급 SSPA를 제작하는 연구를 진행하였다. SSPA는 TWTA에 비해 상대적으로 낮은 단일 소자의 출력으로 높은 출력을 충족하기 위해 저손실, 고효율의 결합 기술을 필요로 한다. 본 논문에서 설계 및 제작된 SSPA는 20dB 이상의 반사 손실과 94% 이상의 우수한 결합효율을 갖는 8-way 공간결합기에 20W급 고출력증폭모듈 8대를 장착하여 100W급 SSPA로 제작되었다. -10dBm 인가시 20kHz 20%에서 112.2~169.8W, 400kHz 40%에서 125.9~173.8W, 800kHz 40%에서 117.5~162.2W로 나타나 PRF 3가지 조건에서 모두 이득 60dB 이상과 100W 이상의 성능을 보였다.

• 농촌계획
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• 제29권4호
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• pp.153-163
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• 2023

This study was conducted to review data utilization plans and suggest solutions based on the need for tools that can objectively diagnose problems in rural areas. The study extracted items through prior research and was carried out as a process of reviewing data capable of constructing spatial data. The results performed in the above manner are as follows. First, prior research and expert surveys were conducted to select diagnostic items to derive details of a total of three items that should be considered for rural space plans such as regional revitalization and regeneration using regional characteristics such as environment, society, and culture. Second, as a result of listing data available for regional diagnosis, 6 types of environment, 15 types of society, and 18 types of culture were selected out of a total of 529. Finally, it was suggested to establish a national standard spatial unit by grasping the limitations of public data such as omission of spatial data and accuracy. This study is significant in that it presented implications for data utilization as well as selection of items for rural diagnosis and reviewed data utilization based on rural specialized districts of "The Act on Support for Restructuring and Regeneration of Rural Spaces" to be implemented in 2024. This is considered to be valuable as a study for sustainable rural diagnosis if processes such as spatial data construction and weight setting are carried out in the future.