• 대한전자공학회논문지
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• 제26권12호
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• pp.1984-1994
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• 1989

Techniques for approximating digitalcurves by polygonal lines are a valuable tool for image analysis and data compression. S. Shilien proposed a method for segmenting a digital curve into digital straight line segments digital straight line segments which are not satisfied with the structural properties, and have more than one break point by Shilien's method. Here, the structural representation of digital straight lines and digital staight line segments is described. And a method for segmenting a digital curve into digital straight line segments which are not satisfied with the structural properties, and have more than one break point by Shilien's method. Here, the structural representation of digital straight lines and digital staight line segments is described. And a method for segmenting a digital curve into digital straight line segments which may be not satisfied with the structural properties is proposed. The number of break points extracted by this method is less than that by S. Shilien's method from the digital curve which includes the digital straight line segments not satisfied with the structural properties.

• ETRI Journal
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• 제32권4호
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• pp.630-633
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• 2010

In this letter, we propose a novel polygonal approximation of digital curves that preserve original shapes. The proposed method first detects break points, which have two different consecutive vectors, and sets an initial dominant point set. The approximation is then performed iteratively by deleting a dominant point using a novel distance, which can measure both the distance and the angle acuteness. The experimental results show that the proposed method can preserve original shapes and is appropriate for various shapes, including slab-sided shapes.

• 대한공간정보학회지
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• 제17권3호
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• pp.115-120
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• 2009

기존의 도화사 수작업에 의한 기준점기반 항공삼각측량 기법은 전통적인 사진측량에서 유용하게 이용되어 왔으나, 자동화된 수치사진측량 기법이 확산되면서 기존방법의 문제점이 대두되었다. 따라서 본 논문은 보다 발전된 자동화 기술 개발을 위하여 상위 레벨인 선형객체들을 이용한 항공삼각측량 가능성을 제시하고 검증하고자 하였다. 최근에 발달된 선형 객체 추출기법 알고리즘은 보다 정확한 선형 객체 추출기법을 제공하였지만, 포인트 추출기법에 비하여 추출하기 어려운 단점이 존재한다. 따라서 본 논문은 이를 극복하기 위하여 수동 디지타이징이나 에지 연산자를 통하여 쉽게 획득되는 포인트를 이용하여 상위레벨 선형객체를 생성하고, 이를 통해 지형공간정보 이용 가능성을 높이고자 하였다. 본 연구 결과를 통해 진화하고 있는 컴퓨터 환경에 적합한 선형객체를 이용한 항공삼각측량 기법을 발전시킬 것으로 기대된다.

• 대한전자공학회논문지
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• 제27권3호
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• pp.47-53
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• 1990

곡선의 다각형 근사화 방법은 화상분석 또는 데이타 압축등에 많이 사용된다. 다각형 근사화 방법으로, 적은 break point수를 갖고, Sequential Process로 결과를 얻을 수 있는 Cone intersection 방법이 있다. 여기서는 화소간의 거리가 일정한 디지탈 곡선의 경우, 종래의 cone intersection 방법을 정수계산을 이용하여 속도를 향상시키는 방법을 제안한다.

• 천문학회보
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• 제44권1호
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• pp.48.3-48.3
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• 2019

We present analysis results of far infrared (IR) data for 3C 58. We use Herschel observations to measure the IR spectral slope of the source. Our measurements add new IR data points to exisiting high-frequency ones and allow us to improve the IR spectral energy distribution (SED) of 3C 58, and so a cooling break expected in the optical band can be located more precisely. We interpret the SED and the break using a synchrotron+ inverse-Compton model for PWNe and infer flow properties in 3C 58. Because the IR data are contaminated by foregrounds and backgrounds, we discuss impacts of the contamination on our conclusion.

• Journal of Advanced Marine Engineering and Technology
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• 제40권4호
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• pp.342-347
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• 2016

본 논문에서는 실습선과 함정의 광원으로 80 % 이상을 차지하는 백열등 및 형광등기구를 대체하기 위한 선박용 LED 등기구의 경제성 분석에 관하여 기술하였다. 소비전력, 초기투자비용, 유지비용 및 유류비에 대한 절감률을 분석하였고, 탄소배출량과 손익분기점을 산출하였다. 실습선의 초기투자비용은 3.8배 상승하였지만, 5년간 유지비용은 51 % 절감되었다. 40 %, 50 % 및 60 %의 점등률에 따른 손익분기점은 각각 11개월, 9개월 및 7개월로 산출하였다. 함정의 초기 투자비용은 3.5배 상승하였지만, 5년간 유지비용은 55 % 절감되었다. 40 %, 50 % 및 60 %의 점등률에 따른 손익분기점은 각각 15개월, 12개월 및 10개월로 산출하였다. 또한 실습선과 함정의 탄소배출량은 각각 69 % 및 65 % 절감되었다. 이러한 결과를 통하여 실습선과 함정에 LED 등기구를 적용한다면, 50 % 이상의 유지비용 절약과 60 % 이상의 소비전력, 유류비 절감 및 탄소배출량이 감소될 것으로 판단된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1408-1410
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• 1997

Arrhenius plots are useful in predicting long-term use temperatures of organic materials and in choosing parameters for accelerated aging. The effects of antioxidant on the heat resistance and temperature index of EPDM rubber used for electrical insulation were investigated. The short-time points were obtained by 50% retention of elongation at break.

• 한국산업융합학회 논문집
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• 제5권3호
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• pp.255-260
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• 2002

Recently, the occurrences of electrical fire have been suppressed by an earth leakage breaker(ELB), a no fuse breaker(NFB) and a fuse in case of an earth leakage, a short circuit and an over current. But it is impossible for the ELB to break the circuit in the case of the failure of pressure contacts on connecting points and the momentary short circuit. Therefore, it is require to study the constructive problem of the ELB. In this paper, we have developed the auxiliary control device, electrical fire prevention control device(EFPCD), of the ELB. And we have tested the operation characteristics of the ELB according to the load(R, L) As a result of this experiment, we could prevent the electrical fire due to the spark and the overheat occurring in the failure of pressure contacts on connecting points and the momentary short circuit.

• Journal of the Korean Statistical Society
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• 제25권4호
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• pp.471-487
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• 1996

In this paper we propose an efficient scoring type one-step GM-estimator, which has a bounded influence function and a high break-down point. The main point of the estimator is in the weighting scheme of the GM-estimator. The weight function we used depends on both leverage points and residuals So we construct an estimator which does not downweight good leverage points Unider some regularity conditions, we compute the finite-sample breakdown point and prove asymptotic normality Some simulation results are also presented.

• 천문학회지
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• 제52권4호
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• pp.121-131
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• 2019

I investigate the origin of arc degeneracies in satellite microlens parallax ${\pi}_E$ measurements with only late time data, e.g., t > $t_0+t_E$ as seen from the satellite. I show that these are due to partial overlap of a series of osculating, exactly circular, degeneracies in the ${\pi}_E$ plane, each from a single measurement. In events with somewhat earlier data, these long arcs break up into two arclets, or (with even earlier data) two points, because these earlier measurements give rise to intersecting rather than osculating circles. The two arclets (or points) then constitute one pair of degeneracies in the well-known four-fold degeneracy of space-based microlens parallax. Using this framework of intersecting circles, I show that next-generation microlens satellite experiments could yield good ${\pi}_E$ determinations with only about five measurements per event, i.e., about 30 observations per day to monitor 1500 events per year. This could plausibly be done with a small (hence cheap, in the spirit of Gould & Yee 2012) satellite telescope, e.g., 20 cm.