• Journal of the Korean Data and Information Science Society
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• 제21권5호
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• pp.935-944
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• 2010

In this paper, we develop the noninformative priors for the reliability in a stress-strength model where a strength X and a stress Y have independent exponential distributions with different scale parameters and a common location parameter. We derive the reference priors and prove the propriety of joint posterior distribution under the general prior including the reference priors. Through the simulation study, we show that the proposed reference priors match the target coverage probabilities in a frequentist sense.

• 한국철도학회논문집
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• 제9권6호
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• pp.766-771
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• 2006

Railway stations are important facilities for transport of passengers and freights. The location of station have an effect on the efficiency of railway transport and operation. In this study, an inspection of the primary factors for station spacing in urban railway has been performed and a review for the propriety of the present states and further improvement has been carried. It may be helpful for proper decisions on the route planning in urban railway. Primary factors for station spacing are 1)train capacity, 2)competitiveness with other transportation, 3)accessibility and 4)construction cost, which is out of consideration in the inspection. From the result of this study, the proper station spacing is about 600m for the accessibility, more over 1.03km for the train capacity and more over 1.4km for the competitiveness with other transportation.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.399-404
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• 2004

Recently GPS has been playing an increasingly important role in geodesy and positioning, for example, car navigation system, surveying, ITS(intelligent transport systems), LBS(Location Based Service) and so on. For telematics application, reception conditions of GPS signal are important. In some situation, such as in areas between buildings, metropolitan areas or areas with large skyscraper complexes, there are situations whereby the satellite signal is seriously restricted by various obstacles. Before the signal arrives at the receiver, it may be blocked, reflected, delayed, attenuated or scattered by terrestrial obstacles such as buildings. In this paper, we present satellite imagery data for telematics application. Therefore, for propriety of this studies, we made a GPS satellite visibility experiments in Bun-Dang on same time. This paper describes an approach to calculate building level using 0.6m, 1m, 6.6m resampling aerial polo imagery in stead of the satellite imagery and make a comparative study of accuracy. This paper tests the simulation of GPS signal using the building level.

• 한국정밀공학회지
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• 제17권11호
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• pp.141-150
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• 2000

Continuously variable transmission(CVT) combined differential gear unit has many advantages, which are the decrease of CVT size, the increase of overall efficiency, the extension of speed ratio range, and the generation of geared neutral. It is known that such CVT can be classified into the input coupled type and the output coupled type according to the coupling location of continuously variable unit(CVU). In this paper, six different configurations of input coupled type CVT combined V-belt CVU and 2K-H I type differential gear unit are proposed. Some useful theoretical formula related to speed ratio, power flow and efficiency are derived and analyzed. The propriety of derived formula and theoretical analysis are proven by various experiments.

• 한국정보통신학회논문지
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• 제19권12호
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• pp.2836-2843
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• 2015

일반적인 선박 내 통신은 재질의 특성상 기존 RF기반 무선통신 기술을 적용하는 데 제약이 따른다. 가시광통신 기술은 가시광을 통신수단으로 하기 때문에 전파제약이나 간섭 같은 기존 무선통신 기술의 문제점을 해결할 수 있으며, LED조명을 활용한 통신과의 융합으로 추가적인 설비 요구가 상대적으로 낮고, 가시광을 이용함에 따라 인체에도 무해하다는 장점이 있다. 본 논문에서는 256Kbps급, 5m 전송 거리 급의 가시광통신 기술을 선박 내 통신에 적용함으로써 일반적인 RF통신기기 적용이 어려운 여건에서의 응급호출 시스템 솔루션을 제안하고, 제안 시스템의 실제구현과 시험을 통하여 그 타당성을 검증한 결과를 제시하였다.

• 한국생활과학회지
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• 제17권3호
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• pp.413-423
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• 2008

The purpose of this study was to consider the evaluations of curriculum and young children by kindergarten teachers. The investigation subjects for questionnaire were 637 (the directors, vice-directors, the head teachers, and teachers) who were selected by proportional stratified sampling method for population and the subjects for interview were 11 teachers out of previous subjects who have worked at Jeolla-Do. The questionnaire was based on preceding studies and the propriety of contents was validated. The followings are results of this study. First, according to the purpose of curriculum, more than half of kindergarten teachers answered that they do perform evaluation to validate the young children's developmental process and there were statistically no significant differences by variables of kindergarten teachers. This study was to see whether they perform the evaluation results of curriculum or not, they relatively perform and there were statistically differences by kindergarten teacher's working location, establishment type, level of education and age. This study was to see whether they reflect the evaluation results of curriculum, and it was revealed as they relatively reflect. Also, there were statistically significant differences by kindergarten teacher's working location. And, kindergarten teachers requested the appropriate evaluation curriculum that also requires the adequate education for teachers and organized supporting system as a implication plan. Second, as of material types for children's portfolio evaluation, teachers collect activity products at most, then activity picture, observation, standardized test, teacher's journal, recording or tape-recording, post-interview and data that were collected at home. And, kindergarten teachers requested the appropriate evaluation method and the supply of human resources as a implication plan for young children's evaluation.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.810-813
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• 2004

In this paper, a background initialization for video surveillance proposed. The proposed algorithm is that the background images are sampled n frames during ${\Delta}t$ All Sampling frames are divided by $M{\times}N$ size block every frame. Average values of pixels for same location block of the sampling frames during ${\Delta}t$t are taken. then the maximum intensity $\alpha$ and the minimun intensity $\beta$ is obtained, respecticely. The intial by $M{\times}N$ size block, then average intensity $\eta$ of pixels for the block is obtained. If the average intensity $\eta$ is out of the initial range of the background image, it is decided the moving object image, and if the average intensity $\eta$ is included in the initial range of the background image. it is decided the background image. To examine the propriety of the proposed algorithm in this paper, the accuracy and robustness evaluation results for human and car in the indoor and outdoor enviroment. the error rate of the proposed method is less than the existing methods and the extraction rate of the proposed method is better than the existing methods.

• 한국환경과학회지
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• 제17권4호
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• pp.385-396
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• 2008

The air quality data is important for understanding and analyzing a surrounding influence. In that light, it is positively necessary for a propriety assessment to determine a location of the air quality monitoring sites. In this study, the climate analysis about temperature and wind, using the meteorological data in the Pohang, is conducted to do that. In the next stage, we distinguished the wind by east-west or north-south component, which has less correlation than temperature, analyzed and divided the wind sector. As the result, the wind circumstance of the Pohang is divided into major 5 wind sector; that is the urban area, the northeast coastal area, the east ocean and the west mountainous area. We think that an analysis on detailed wind sector by utilizing the numerical simulation is needed.

• 한국통신학회논문지
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• 제33권10B호
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• pp.894-903
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• 2008

일반적으로 센서들의 위치는 감시 정찰 센서 네트워크의 적용 범위, 데이터 전송 비용, 그리고 자원 관리에 영향을 미치기 때문에, 최적의 위치에 센서를 배치해야 한다. 그러나 산악 지대나 도심 지역과 같은 실 환경에 센서 노드를 배치할 경우, 센서에 영향을 미치는 다양한 지형 및 기후 요소들을 고려하기 어렵다. 따라서 이러한 다양한 환경에 센서를 배치할 경우 감시 영역 측면에서 목표 대상을 효율적으로 탐지할 수 있는 센서 배치 방법이 필요하다. 이를 위해 본 논문에서는 센서 배치와 관련된 다양한 기후와 지형 등의 환경 요소들을 분석하고, 이들 영향 요소들이 센서 노드 배치 시 활용될 수 있도록 정량화한다. 이를 바탕으로 센서 탐지 영역 측면에서 정량화된 영향 요소들을 고려함으로써 보다 실효적인 센서 배치 방법론을 제안한다. 또한 본 논문에서 제안한 센서 배치 방법론을 따르는 센서 배치 관리 시스템을 구현함으로써 제안된 방법론의 타당성을 입증한다.

• 대한환경공학회지
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• 제27권11호
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• pp.1228-1237
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• 2005

퇴적물 내에 포함되어 있는 오염물질이 장기적으로 수질에 미치는 영향을 예측하고, 준설에 따른 수질개선 효과를 예측하여 준설규모나 위치를 선정하는데 적용할 수 있는 수환경 모형을 개발하였다. 대상수역의 수질수문자료를 중심으로 구역을 분획하고 매개변수를 추정하여 모의한 후, 변수에 대한 민감도 분석을 통하여 최적의 값들을 결정하였다. 이를 토대로 시범수역 A의 PCBs 농도를 장기간 모니터링 한 결과, 가장 오염되어 있는 구간의 수층 PCBs 농도는 30년 후 $3.1\;{\mu}g/L$에서 $2.4\;{\mu}g/L$로 감소하는 것으로 예측되었다. 이는 퇴적층의 오염물질이 수층의 오염공급원으로 존재하는 한, 장시간이 지나더라도 수층의 농도는 크게 감소하지 않아 퇴적물로부터의 오염원의 공급을 원천적으로 차단하지 않고는 수질개선효과는 기대하기 어려울 것으로 나타났다. 따라서 심각한 오염지역의 오염물질을 선택적으로 준설함으로써 수층의 수질개선 효과를 얻을 수 있을 것으로 판단되었다.