• International Journal of Computer Science & Network Security
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• 제23권1호
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• pp.17-24
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• 2023

The objective of this paper is to use Geographical Information Systems for identifying Digital Divide in Riyadh Neighborhoods, Saudi Arabia. Geo-database was created that includes Streets, Neighborhoods, ICT Access Data and Coverage Map for Riyadh. We used QGIS and overlay for analysis, intersection selected as tool for this paper. The results indicate that after analyzing the use of information communication technology in all regions of the Kingdom it turns that Riyadh, Ash Sharqiyyah and Makkah in average with percentage 50%, While Al Jawf, Al Madinah, and Najran are the least with percentage 42%. Then we focused on Riyadh to analyze the digital divide because it is the capital of Saudi Arabia and occupations the highest percent of communications towers in the KSA due to population density. Regarding coverage of the 4G, the neighborhoods at the center have recorded very high coverage score. While neighborhoods at the edges of the city have low values of coverage score. Same for 3G, it is more intense in the center and the coverage percentage is higher than 4G. For 2G we found it had the highest coverage compared to 3G or 4G

• Journal of Positioning, Navigation, and Timing
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• 제13권2호
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• pp.131-136
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• 2024

This paper deal with a method for calculating the continuity of Korea Augmentation Satellite System (KASS), which was completed in Korea in December 2023, and a plan to respond in the event that a continuity hazard situation occurs during operation. For this purpose, the International Civil Aviation Organization (ICAO) Satellite Based Augmentation System (SBAS) continuity standards, Wide Area Augmentation System (WAAS), and European Geostationary Navigation Overlay Service (EGNOS) continuity cases are examined in this paper. According to the measures recommended by the ICAO, when the number of continuity risks exceeds a certain level and the level drops drastically, various mitigation operations by country are implemented. Through this, if KASS does not meet ICAO continuity standards in the future, such measures can be referred to. In addition, this paper computes the short-term KASS continuity during the test broadcast period. Although continuity does not meet the ICAO standards, although this test period is too short, further meaningful analysis in the future is required. Additionally, this paper carried out an analysis of the timing and period to systematically calculate the meaningful value of continuity.

• 한국지리정보학회지
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• 제3권3호
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• pp.31-44
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• 2000

본 연구의 결과에 의하면, 첫째, 수치지도 개발이 완결되고, 센서스트랙제도가 채택되고, 각종 연관자료들이 전산화되면 GIS의 갖가지 표현, 연산, 중첩기능을 통하여 지형, 인구, 주택을 비롯한 각종 경제, 사회자료들이 센서스트랙 내지는 블락그룹 등 소규모 지역 단위의 주제도 혹은 주소 단위의 점묘도로 알아보기 쉽게 화면에 나타내어져 각종 도시현황분석에 신뢰성 있게 쓰일 수 있다. 둘째, 시설물의 입지결정은 사회가 다원화 될수록 시간이 오래 걸리고 구설수를 피할 수 없는데, GIS는 수치지도를 포함한 도시의 각종 자료들을 그대로, 변형하여, 모델링시키며, 또한 다양한 의사결정방법들과 결합하여 화면상에 표현하며 신속하고도 과학적인 의사결정을 이루는데 큰 역할을 담당할 수 있다고 본다. 결론적으로, GIS와 센서스를 비롯한 각종 도시정보들이 이와같이 결합되고 활용된다면 신속하고도 신뢰성 있는 도시현황분석과 시설물입지분석을 가능케하고, 궁극적으로 보다 나은 행정서비스를 이룰 수 있다고 본다.

• 한국지리정보학회지
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• 제12권2호
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• pp.23-33
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• 2009

위성영상은 도시의 물리적 확장 및 변화를 예측하고 분석하는데 있어 매우 유용하게 활용되고 있다. 도시의 물리적 확장 및 변화는 도시의 토지이용과 밀접하게 관련되어 있으며, 지속 가능한 도시성장을 위해서는 토지이용을 중심으로 한 지속적인 성장관리가 필수적이다. 본 연구에서는 인공위성에 의한 원격자료를 기초 입력 자료로 1985년~2000년 사이의 토지피복과 토지이용의 변화를 분석하였다. 또한 토지이용 전환율을 파악하여 부산시 시가화지역의 확산동향과 확산지역의 토지이용특성을 파악하였다. 그 결과, 첫째, 도시지역의 면적은 지속적으로 늘어난 반면 농업, 산림, 수계지역의 면적은 연도별로 부산시 행정구역개편으로 인해 면적의 변화가 상이함을 알 수 있었다. 둘째 부산시의 도시화 지역 면적이 1985년도 $92.5km^2$에서 2000년도에는 $167.5km^2$로 3.8% 증가한 것을 알 수 있었다. 셋째 토지이용의 전환율을 분석한, 결과 농경지 나지가 도시화 지역으로 가장 많이 전환 되었고, 다음이 산림의 순서로 나타났다. 넷째, 2001년에 구축된 부산시건물 database와의 overlay 분석결과 농업지역 나지는 제1, 2종 근린생활시설(45.63%), 산림지역은 공동주택(18.49%), 수계지역은 공장(31.84%)등의 비율이 높음을 알 수 있었다.

• 대한원격탐사학회지
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• 제27권1호
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• pp.43-49
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• 2011

지구온난화의 주범인 이산화탄소가 국제적으로 문제가 되고 있는 가운데, 이산화탄소의 농도 증가를 억제시키기 위해 이산화탄소를 포집하여 장기간 안정적으로 저장시킬 수 있는 탄소 포집 및 저장(Carbon Capture and Storage: CCS) 기술의 개발이 요구되고 있다. CCS 기술은 이산화탄소 저감 방안 중 가장 직접적이고 현실적인 방안으로 각광을 받고 있으나, 이산화탄소 최적 저장지의 선정 및 이산화탄소 지중저장이 야기할 수 있는 부수적인 영향에 대한 분석이 요구된다. 본 연구에서는 경상분지를 대상으로 GIS 기법을 이용하여 CCS 설비를 위한 적지 분석을 수행하고, 현황분석 및 법적분석을 수행하였다. 적지분석에는 지질도, 수치표고모형, 경사도, 토지피복도를 이용한 경중률 분석이 사용되었으며, 현황분석에는 고해상도 위성영상을 활용하였다. 그 결과 연구대상지내 이산화탄소 저장시설 설치를 위한 최적후보지가 선정되었으며, 마지막으로 법적분석에서는 탄소 저장과 관련된 현행 규정 및 탄소 저장시설의 설비 시 문제가 될 수 있는 각종 법적 사항을 조사하였다.

• 한국항행학회논문지
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• 제22권5호
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• pp.384-390
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• 2018

본 논문에서는 KASS (korea augmentation satellite system) 의 가용성 성능 평가를 위한 MATLAB GUI (graphical user interface)기반의 소프트웨어에 대해 소개한다. 본 소프트웨어는 MV (minimum variance) estimator 와 Kriging 알고리즘을 이용해 한반도 지역의 지상 사용자 및 항공기 사용자에 대해 UDRE (user differential range error) 와 GIVE (grid ionospheric vertical error) 와 같은 무결성 정보를 생성한다. 또한 본 소프트웨어는 생성한 정보를 이용하여 사용자의 각 위치에 대해 정확도, 보호 수준, 가용성 지도를 제공한다. 특히 항공기 경로에 대해 경로에 따른 보호 수준 값을 계산하는 기능을 수행한다. 항공기 사용자에 대한 보호 수준 값 계산 결과는 EGNOS (european geostationary navigation overlay service) 의 시뮬레이션 툴인 SBASimulator#2의 결과와 비교하여 검증하였다. 그 결과 본 소프트웨어가 생성한 보호 수준의 값의 오차가 약 2% 정도로 정확하게 나온 것을 확인하였다.

• 환경영향평가
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• 제14권5호
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• pp.305-315
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• 2005

The scheme to classify pollution sources in Korean TMDL planning has been pointed out too much complex to implement practically because of requiring a wide range of items to be collected from a field. Within a deficient situation to collect field data, the mathematical scheme that focuses only on counting an uniform area ratio of the different land uses to estimate of pollutant loads from individual sub-catchments has been used without taking into account of the spatial characteristics of major land uses as well as the locations of pollution sources in each sub-catchment. It would cause to significant level of errors to estimate the pollution loads. Therefore, this study proposes a renovated scheme that can be adopted more easily to classify pollution sources in the watershed and reduce the estimation errors in the spatial distribution of pollution sources by introducing a spatial analysis based on digital land cover maps. In order to estimate a unit area to calculate the uniform pollution load, the pollution response unit area that is locating spatially at the same place and having same land use is identified through the application of GIS overlay technique. Unlikely existing conventional method to calculate the pollution load based on equal distribution of pollutants for each administrative boundary, it is assumed that the pollution load from household and livestock sources are generated and washed off from only residential areas. While, pollution from business population comes from commercial area and industrial load from wastewater discharge facilities are from industrial areas. From comparison of the calculated results from the existing the method and the proposed one, it is found that although the estimation of pollution load from sub-catchment in the case of the existing conventional method application results in negligible difference in total pollution amounts from the whole area of Wangsook watershed as a study area, significant difference of pollution load among sub-catchment in which pollution response unit areas are diverse, however, appears in the case of the application of the renovated scheme.

• 한국표면공학회지
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• 제52권6호
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• pp.283-288
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• 2019

MCrAlY overaly coatings are used as oxidation barrier coatings to prevent degradation of the underlying substrate in high temperature and oxidizing environment of the hot section of gas turbines. Therefore, oxidation resistance in high temperature is important property of MCrAlY coatings. Also, coefficients of thermal expansion (CTE) of MCrAlY have middle value of that of Ni-based superalloys and oxides, which have the effect of preventing the delamination of the surface oxides. Cyclic oxidation test is one of the most useful methods for evaluating the high temperature durability of coatings used in gas turbines. In this study, NiCoCrAlY overlay coatings were formed on Inconel 792(IN 792) substrates by vacuum plasma spraying process. Vacuum plasma sprayed NiCoCrAlY coatings and IN 792 susbstrates were exposed to 1000℃ one-hour cyclic oxidation environment. NiCoCrAlY coatings showed lower weight gain in short-term oxidation. In long-term oxidation, IN 792 substrates showed higher weight loss due to delamination of surface oxide but NiCoCrAlY coatings showed lower weight loss. X-ray diffraction (XRD) analysis showed α-Al2O3 and NiCr₂O₄ was formed during the cyclic oxidation test. Through cross-section observation using scanning electron microscopy (SEM) and electron back scatter diffraction (EBSD) analysis, thermally grown oxide (TGO) layer composed of α-Al₂O₃ and NiCr₂O₄ was formed and the thickness of TGO increased during 1000℃ cyclic oxidation test. β phase in upper side of NiCoCrAlY coating was depleted due to oxidation of Al and outer beta depletion zone thickness also increased as the cyclic oxidation time increased.

• 한국환경과학회지
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• 제17권6호
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• pp.679-687
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• 2008

In this study, we implemented landslide distribution of Jeju Island using ANN and GIS, respectively. To do this, we first get the counter line from 1:2,5000 digital map and use this counter line to make the DEM. for the evaluate the land slide susceptibility. Next, we abstracted slop map and aspect map from the DEM and get the land use map using ISODATA classification method from Landsat 7 images. In the computation processes of landslide analysis, we make the class to the soil map, tree diameter map, Isohyet map, geological map and so on. Finally, we applied the ANN method to the landslide one and calculated its weighted values. GIS results can be calculated by using Acrview program and produced Jeju landslide susceptibility map by usign Weighted Overlay method. Based on our results, we found the relatively weak points of landslide ware concentrated to the top of Halla mountains.

• 한국실내디자인학회논문집
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• 제17권6호
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• pp.30-40
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• 2008

Adolf Loos showed important directionality in the thought of modem culture and architecture. The thought about the architecture of Adolf Loos was gathered by "Raumplan". It is the solution of the plan in space. But the concept and method of the "Raumplan" had not been synthesized until near the end of Loos's life. Loos's first reference to the "Raumplan" appears in 1929. I think that "Raumplan" became the solution of the plan in space with a formation process of the thought about the architecture and culture of Adolf Loos. Therefore, the purpose of this paper derived a characteristic of "Raumplan" from the relations between the architectural thought of Adolf Loos and "Raumplan". The processes of the study are as follows. (1)Consideration about the growth background of Adolf Loos and the social situation of Vienna. (2)Analysis about architecture and the cultural critic of Adolf Loos. (3)Analysis of "Raumplan" based on architectural thought of Adolf Loos. As a result, I got the four characteristics of "Raumplan" as follows. (1) Separation and continuation of "Raum". (2) Fragment of "Raum". (3) Overlay and transmission by the axis of multiplex eyes. (4) Structural adjustment of the "Raum" by Hierarchy. Finally, I understood the architecture which Adolf Loos pursued in "Raumplan" had a high function and contained the clear meaning and contents which had practical use and economic value, and it were not a results of the simple logic.