• International Journal of Computer Science & Network Security
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• v.23 no.1
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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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• v.13 no.2
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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.

• Journal of the Korean Association of Geographic Information Studies
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• v.3 no.3
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• pp.31-44
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• 2000

The purpose of this study is to show how could GIS along with digital maps and census data be used for scientific urban analysis and location analysis for a proposed project. Results are summarized as follows. First. after digital maps being completed, the census tract system being adopted, and major urban data being inputted in the computer file, GIS could be used intensively for various reliable urban analysis. With graphic statistical, and overlay functions of GIS, various physical and socio-economic characteristics of urban areas could be presented for analysis in the form of thematic and datapoint maps on the computer screen. Second, the locational analysis for a proposed project is a major part in the building permit review process, which tends to become disputable and time consuming as society become pluralized. Along with various GIS functions scientific decision-making methods could be developed, and the methods could play an important role for faster and scientific location analysis. As such, GIS would play an important role for faster and reliable urban analysis and location analysis and these functions finally would play important roles to improve public services and administration of local governments.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.23-33
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• 2009

Satellite image is very usefully practiced to predict and analyze physical expansion and change of city. Physical expansion and change of city is closely related to the use of land, and continuous growth management focused on the use of land is essential for sustainable city growth. In this research, the change of land cover and land-use were analyzed with basic input data from 1985 to 2000 according to artificial satellite. Moreover, the land-use turnover rate was understood and expansion trend of urban sprawl in Busan metropolitan city and land-use characteristics of the expansion area. The results are, first, the area for urban region was expanded continuously but areas for agriculture area, forest area, and water area had different changes due to administrative district reform of Busan by each year. Second, the urbanization area in Busan was increased by 3.8% from $92.5km^2$ in 1985 to $167.5km^2$ in 2000. Third, the result of analysis on land-use turnover rate showed that agriculture area was turned into urbanized area the most, and forest area was followed by. Fourth, the result of analysis on database and overlay of buildings in Busan established in 2001 showed that agriculture area are had type 1 and 2 neighborhood living facilities (45.63%), apartment house in forest area (18.49%), and factory in water area (31.84%) with high ratio.

• Korean Journal of Remote Sensing
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• v.27 no.1
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• pp.43-49
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• 2011

In the face of growing concern about global warming, increasing attention has been focused on the reduction of carbon dioxide emissions. One method to mitigating the release of carbon dioxide is Carbon Capture and Storage (CCS). CCS includes separation of carbon dioxide from industrial emission in plants, transport to a storage site, and long-term isolation in underground. It is necessary to conduct analyses on optimal site selection, surface monitoring, and additional effects by the construction of CCS facility in Gyeongsang basin, Korea. For the optimal site selection, necessary data; geological map, landcover map, digital elevation model, and slope map, were prepared, and a weighted overlay analysis was performed. Then, surface monitoring was performed using high resolution satellite image. As a result, the candidate region was selected inside Gyeongnam for carbon storage. Finally, the related regulations about CCS facility were collected and analyzed for legal question of selected site.

• Journal of Advanced Navigation Technology
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• v.22 no.5
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• pp.384-390
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• 2018

This paper introduces a MATLAB graphical user interface (GUI) based software for analysis of korea augmentation satellite system (KASS) availability performance. This software uses minimum variance (MV) estimator and Kriging algorithm to generate integrity information such as user differential range error (UDRE) and grid ionospheric vertical error (GIVE). The information is offered to ground and aviation users in Korean region. The software also gives accuracy data, protection level data and availability map about each user position by using the integrity information. In particular the software calculates the protection level along a path of aircraft. We verified the result of protection level of aviation user by comparing them with the results of SBASimulator#2, which is a simulation tool of european geostationary navigation overlay service (EGNOS). As a result, the protection level error between the result of our software and the SBASimulator#2 was about 2% which means that the result of our software is accurate.

• Journal of Environmental Impact Assessment
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• v.14 no.5
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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.

• Journal of Surface Science and Engineering
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• v.52 no.6
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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.

• Journal of Environmental Science International
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• v.17 no.6
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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.

• Korean Institute of Interior Design Journal
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• v.17 no.6
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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.