• 제목/요약/키워드: Large-area

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AKARI INFRARED CAMERA SURVEY OF THE LARGE MAGELLANIC CLOUD

  • Shimonishi, T.;Kato, D.;Ita, Y.;Onaka, T.;AKARI/IRC LMC team
    • Publications of The Korean Astronomical Society
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    • v.32 no.1
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    • pp.83-85
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    • 2017
  • We conducted an unbiased near- to mid-infrared imaging and spectroscopic survey of the Large Magellanic Cloud (LMC) as a part of the AKARI Mission Program "Large-area Survey of the LMC" (LSLMC, PI: T. Onaka). An area of about 10 square degrees of the LMC was observed by five photometric bands (3.2, 7, 11, 15, and $24{\mu}m$) and a low-resolution slitless prism ($2-5{\mu}m$, R ~20) equipped with AKARI /IRC. We constructed and publicly released photometric and spectroscopic catalogues of point sources in the LMC based on the survey data. The catalogues provide a large number of near-infrared spectral data, coupled with complementary broadband photometric data. Combined use of the present AKARI LSLMC catalogues with other infrared point source catalogues of the LMC possesses scientific potential that can be applied to various astronomical studies.

Environmentally Friendly Utilization of the Abandoned Mine Sites As a Recreational Resource (폐광의 환경친화적 관광자원 개발 방안)

  • Choi, Yong-Bok
    • Journal of Environmental Impact Assessment
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    • v.10 no.1
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    • pp.49-57
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    • 2001
  • With reducing coal mining industry the number of coal mine sites between 1988 and 1998 was dropped from 347 to 12. Since the abandoned coal mine sites have been kept without any cares, they have raised various environmental and safety problems. Then, Korean government initiated a special law in 1995 for enhancing economic conditions and solving environmental problems with promoting developmental projects in the abandoned mining sites. As a result, casino business in Chungsun area has been opened to publics, and other large-scale developments such as ski slopes and resorts are planned. In addition, Boryung area in Chungchung province also will launch a large-scale project building golf courses. Based on this developmental trend, it is expected that lots of large-scale developments in other places will be taken place. In general, the large-scale developments have caused various environmental problems, and, thus, environmental aspects should be considered in a decision-making process. This paper examine the status of the abandoned mine sites in Korea and U.S. and suggests the alternatives of its utilization.

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Fracture Mechanics Study on Wear Mechanism of Ceramics -Discussions on Experimental Results of Wear Test- (세라믹의 마멸기구에 관한 파괴역학적 연구 -마멸실험 결과의 고찰-)

  • 김석삼;김재호
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.3
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    • pp.636-645
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    • 1990
  • Analytically induced wear mechanism of elastic body under Hertzian contact is applied in acutual wear test of ceramics. There are two types of wear in ceramics, a large scale wear and a small scale wear. The large scale wear is commensurable with Hertzian contact area and the small scale wear with real contact area. Nondimensional parameter, S$_{c}$, is introduced and fully examined to estimate or predict wear rate of ceramics. Ceramic wear for S$_{c}$.leq.0.8 is in small scale wear and for S$_{c}$;geq.1.6 in large scale wear. wear.

Land Cover Classification Techniques for Large Area using Digital Satellite Data (수치위성자료를 이용한 광역의 토지피복분류 기법)

  • 박병욱
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.14 no.1
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    • pp.39-47
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    • 1996
  • This paper is to provide land cover classification techniques for large area ranged in different pathos by classifying Landsat TM data of Jeonnam province. The analyses proceeded by individual scene because acquired dates are not same in different pathes. In this processing, troubles had happened something like variation of classes can be classified in two scenes and choice problem about overlapped area. Since spatial effects in large area affect data values, it was difficult to make a selection of classes and training fields. we could present a solution about these problems by trial and error method, and found that Bayesian maximum likelihood classification and majority filtering were effective to improve classification accuracy.

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Methodology of the Spatial Boundary Determination for Trade Area of Large-scale Discount Stores Using GIS and Road Connectivity (GIS와 도로연결성을 이용한 대형할인점 상권의 공간적 범위 설정 방법)

  • Lee, Yong-Ik;Hong, Sung-Eon;Park, Soo-Hong
    • Spatial Information Research
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    • v.18 no.1
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    • pp.11-17
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    • 2010
  • The present study attempts to provide the practical methodology to determine the spatial boundary of trade area, not depending on conventional circle-based regional analysis, but adopting dimension-diverging conception based on GIS and road connectivity by exemplifying a large-scale discount store with an outlook to enhance accuracy and reliability in trade area analyzing. Unlike the preliminary researches frequently relying on circular form of interpretation which were not likely to exclude obstacles blocking the accessibility to trade areas, the method suggested by the study is to suggest an alternative way for demarcating the trade areas more practically with better access by excluding in-between obstacles. Finally, we show verification of proposed cost models and performance by join strategy.

A Study on the Characteristics of House Arrangement of Unified Silla Period - Focused on the Capital Remains of Silla in Gyeongju - (통일신라시대 주택의 배치특성 - 경주 신라왕경 발굴유구를 중심으로 -)

  • Han, Ji-Man;Lee, Jeong-Mee
    • Journal of the Korean housing association
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    • v.27 no.3
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    • pp.23-30
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    • 2016
  • Among the unearthed House ruins in Gyeongju of the capital of Silla period, the ruins to see the overall appearance of building arrangement is the ruins of Silla capital S1E1 area, Inwangdong 412, and the Jaemaejeong. In this study, the characteristics of urban house arrangement of the Unified Silla period was analyzed that, through a review of the arrangement relationship between the gate and the individual buildings found in these ruins. The urban house of the Unified Silla period was surrounded with wall, and the way to distinguish between functional areas within it are shown differently, depending on the size of the house. In other words, the small house was divided each area by installation of inner fence, and the large house was by arranging attached buildings. Thai is, the central area is not divided by inner fence is the Characteristics that is different from the small house. And in all houses, a large courtyard is located in the front of main building. Conatruction of the courtyard determines the location and direction of the main building. And the each area has external space of courtyard in the center.

A Framework for Wide-area Monitoring of Tree-related High Impedance Faults in Medium-voltage Networks

  • Bahador, Nooshin;Matinfar, Hamid Reza;Namdari, Farhad
    • Journal of Electrical Engineering and Technology
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    • v.13 no.1
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    • pp.1-10
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    • 2018
  • Wide-area monitoring of tree-related high impedance fault (THIF) efficiently contributes to increase reliability of large-scaled network, since the failure to early location of them may results in critical lines tripping and consequently large blackouts. In the first place, this wide-area monitoring of THIF requires managing the placement of sensors across large power grid network according to THIF detection objective. For this purpose, current paper presents a framework in which sensors are distributed according to a predetermined risk map. The proposed risk map determines the possibility of THIF occurrence on every branch in a power network, based on electrical conductivity of trees and their positions to power lines which extracted from spectral data. The obtained possibility value can be considered as a weight coefficient assigned to each branch in sensor placement problem. The next step after sensors deployment is to on-line monitor based on moving data window. In this on-line process, the received data window is evaluated for obtaining a correlation between low frequency and high frequency components of signal. If obtained correlation follows a specified pattern, received signal is considered as a THIF. Thereafter, if several faulted section candidates are found by deployed sensors, the most likely location is chosen from the list of candidates based on predetermined THIF risk map.

Development and performance evaluation of large-area hybrid gamma imager (LAHGI)

  • Lee, Hyun Su;Kim, Jae Hyeon;Lee, Junyoung;Kim, Chan Hyeong
    • Nuclear Engineering and Technology
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    • v.53 no.8
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    • pp.2640-2645
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    • 2021
  • We report the development of a gamma-ray imaging device, named Large-Area Hybrid Gamma Imager (LAHGI), featuring high imaging sensitivity and good imaging resolution over a broad energy range. A hybrid collimation method, which combines mechanical and electronic collimation, is employed for a stable imaging performance based on large-area scintillation detectors for high imaging sensitivity. The system comprises two monolithic position-sensitive NaI(Tl) scintillation detectors with a crystal area of 27 × 27 cm2 and a tungsten coded aperture mask with a modified uniformly redundant array (MURA) pattern. The performance of the system was evaluated under several source conditions. The system showed good imaging resolution (i.e., 6.0-8.9° FWHM) for the entire energy range of 59.5-1330 keV considered in the present study. It also showed very high imaging sensitivity, successfully imaging a 253 µCi 137Cs source located 15 m away in 1 min; this performance is notable considering that the dose rate at the front surface of the system, due to the existence of the 137Cs source, was only 0.003 µSv/h, which corresponds to ~3% of the background level.