• 천문학논총
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• 제30권2호
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• pp.219-221
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• 2015

We present our recent observations of SDSS J102102.25+174439.9, a new eclipsing white dwarf - main sequence WDMS binary with an orbital period of 0.14 days. This system belongs to the post common-envelope binary group as shown by the spectrum from the Sloan Digital Sky Survey. We obtained our data using the ULTRASPEC instrument installed on the 2.4-m telescope at the Thai National Observatory (TNO). Our multi-band observations reveal an unusual and persistent drop in brightness after the primary eclipse. These dips, which appear to show variations in amplitude, also have a complex shape that changes within days. Dips in WDMS systems have been observed on only one other occasion, in the light curve of QS Vir prior to the eclipse of the white dwarf. The dips in SDSS J1021+1744 are unique because they are present at different wavelengths and they occur approximately at similar phases. Hosting a DA white dwarf and an M4 companion star, this system is known to be the only WDMS to show these kind of dips in its light curve. It is possible that these dips are caused by ejected materials from an active companion star, such as in QS Vir. The light curve in the g' filter exhibits deep and narrow features, implying that the material which passes in front of the white dwarf in SDSS J1021 must be dense and small in size. Furthermore, we try to constrain the stellar and orbital parameters of SDSS J1021+1744 using the Binary Maker 3 software. We use g' and r' data for our light curve analysis to have a better approximation for the red dwarf star.

• 한국농공학회논문집
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• 제62권6호
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• pp.63-72
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• 2020

With the implementation of integrated water management policies, the need for information sharing with respect to agricultural water use has increased, necessitating the quantification of irrigation water supply using monitoring data. This study aims to estimate the irrigation water supply amount based on the relationship between the water level and irrigation canal discharge, and evaluate the reliability of monitoring data for irrigation water supply in terms of hydrology. We conducted a flow survey in a canal and reviewed the applicability of the rating curve based on the exponential and parabolic curves. We evaluated the reliability of the monitoring data using a reservoir water balance analysis and compared the calculated results of the supply quantity in terms of the reservoir water reduction rate. We secured 26 readings of measurement data by varying the water levels within 80% of the canal height through water level control. The exponential rating curve in the irrigation canal was found to be more suitable than the parabolic curve. The irrigation water supplied was less than 9.3-28% of the net irrigation water from 2017 to 2019. Analysis of the reservoir water balance by applying the irrigation water monitoring data revealed that the estimation of the irrigation water supply was reliable. The results of this study are expected to be used in establishing an evaluation process for quantifying the irrigation water supply by using measurement information from irrigation canals in agricultural reservoirs.

• 산업경영시스템학회지
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• 제41권2호
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• pp.141-152
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• 2018

Although the 1997 Raw Data of the National Wealth Statistical Survey (South Korea) is timely 20-year-old data, it is meaningful as a benchmarking in the capital stock estimations of Korea, which is estimated by PIM (permanent inventory method). In the case of machinery/equipment, it is the data that can analyze in depth the changes in the industrial structure of Korea. In the case of ASL (average service life) which has economic concept, since the change of ASL is not so large, ASL yielded by the Raw Data of the 1997 National Wealth Statistical Survey is meaningful as reference value for the ASL estimated by the Bank of Korea and the National Statistical Office. As you know Japan has changed its service life due to changes in its industrial structure. However, many of its assets are still used for the years indicated in Showa (before 1989). The same trend with other countries such as Japan. However, the United States is constantly devoted to assessing the useful ASL and value of assets by distinguishing between the Hulten-Wykoff models and those not. Korea has also benchmarked the useful ASL of the United States and Japan when it conducted its own survey every 10 years by due diligence until 1997. In this study, the 'constraint' Iowa curve estimation by the Raw Data of the 1997 National Wealth Statistical Survey is based on the age records of the assets and the maximum age of the assets appropriately derived. And then we made modified Iowa curve by smoothing. From this modified one, we suggested ASL by asset. After 1997, the vintage disposal data directly were collected by the National Statistical Office with Oh Hyun Seung, Cho Jin Hyung, in order to estimate the useful ASL. Since then, the B/S team of the Economic and Statistics Bureau of the Bank of Korea has been working on a new concept of content training.

• 지구물리
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• 제3권3호
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• pp.185-192
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• 2000

미세중력 측정기는 최근 그 중요성이 부각되고 있는 분야로 전통적인 중력측정장치를 기초로 개발되었다. 이 논문에서는 지하 광전 탐사 작업을 위한 미세중력 측정기의 원리와 기술, 그리고 활용법을 소개한다. 몇몇 조사 곡선들은 모델들을 통한 이론적 계산치와 비교하여 볼 때 왜 만족스러운 결과들을 보여주고 있다. 이 방법들은 지하의 왕궁이나 묘지들을 탐사하는데 유용하게 사용될 수 있을 것이다.

• 천문학회보
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• 제43권1호
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• pp.31.2-31.2
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• 2018

The progenitor star properties of supernovae (SNe) are not fully understood though a large number of SNe have been discovered so far. One of the promising ways to understand the properties of progenitor stars is to study SN early light curve where the shock heated emission after explosion is imprinted in. We have performed Intensive Monitoring Survey of Nearby Galaxies (IMSNG) using a global network of telescopes with the aim to snatch the very early moments of SNe explosion. As one of the fruits of our project, we present the result on the type Ic SN, SN 2017ein which was discovered at 2017 May 25 in NGC 3938. We will present the physical properties of the type Ic SN progenitor star that are obtained from the analysis of early epoch data.

• 한국측량학회지
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• 제17권3호
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• pp.197-203
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• 1999

GPS의 이동측량 방법을 사용하여 위치정보와 속성정보를 취득하는 경우, 대상지의 지형학적 위치와 여러가지 오차요인에 의해 이상점이 발생하게 된다. 본 연구에서는 절사평균 방법과 1차 미분을 이용한 이상점 검출 알고리즘을 작성하고, 선형보간법과 다항식보간법을 사용하여 이상점 보간을 하였다. 또한 정확하게 보간된 데이터를 이용하여 국도 30 km구간에 대해 수치지도를 제작하였으며 수치지도를 제작하는 과정에서 발생될 수 있는 문제점들을 고찰하고 문제점들의 해결을 통해 정확한 GIS 커버리지 맵을 작성하였다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 추계학술발표대회
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• pp.1408-1410
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• 2015

Information about the painted road markings and other painted road objects play an important part in keeping safety of drivers. Some researchers have presented research approaches and dealt with road markings detection. In this paper, we present comprehensive survey of these techniques, and review some of them like a machine learning method, template matching method for road markings detection and classification, method of detection and classification of road markings using curve-based prototype fitting, signed edge signature method.

• 수산해양교육연구
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• 제23권4호
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• pp.642-647
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• 2011

In order to analyze the influence of floating marine debris (FMD) in the East China Sea (ECS), a sighting survey was conducted from July 1st to July 14th, 2009 navigating about 966 km using a training vessel "Kaya (1,737 ton)" of Pukyong National University. The sampled zones are divided into 5 transect by observation day during the survey days and again specified with 45 segments per unit hour on the survey routes. The results of distribution of FMD are as follows: 1. The quantities of FMD at the central China Sea(CE) and northern part of Taiwan(NT) were found as total mean of 90.8 ea/hr, 56.7 ea/hr, respectively, and also 36.8 ea/hr, western part of Kyushu district(WJ), 10.7 ea/hr, 8.0 ea/hr, western(OK1) and northern part(OK2) of Okinawa, respectively. 2. Temporal variation of FMD is represented by depicting the sinusoidal curve as shape as tide in CE and OK1. 3. The higher sea surface temperature (SST) is as likely as if Kuroshio current exists strongly, the less quantities are decreased. On the other hand, the coastal zone of ECS and near of Yellow Sea are increased by lower SST.

• 천문학회보
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• 제45권1호
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• pp.36.2-36.2
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• 2020

Intensive Monitoring Survey of Nearby Galaxies (IMSNG) has been managed over 6 years. It aimed to constrain the progenitor system and explosion mechanism of SNe by detection of very early signal from shock heated emission. We have conducted monitoring observation of nearby bright galaxies those were carefully selected using global network of 1-m class telescopes. More than 20 SNe have occured in our target fields. As One of result of the survey, we present light curve analysis of type Ia SN 2018kp, which was discovered in NGC 3367. Based on photometric analysis, we calculated explosion parameters and set constraints of physical conditions of this supernova. We compared the results with theoretical model progenitor systems to find out which scenario is the most fitted to SN 2018kp case. Moreover, we estimate the distance to the galaxy and look into the relation between SNe and galactic physical parameters.

• 대한교통학회지
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• 제20권1호
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• pp.131-139
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• 2002

본 연구는 도로의 설계일관성 평가를 위해 지방부 2차로 도로의 평면 곡선부 85백분위 주행속도 예측모형을 기존의 회귀모형에 비해 보다 효율적이고 신뢰성 높은 인공신경 망 이론을 적용하여 개발하였다. 곡선반경, 곡선길이, 교차각, 시거, 차로폭, 차선(안쪽, 바깥쪽)과 같은 기하구조 특성에 의해 속도가 결정된다는 가정하에 30개 조사지점을 통해 얻어진 자료를 모형의 입력층 자료로 이용하였고, 입력층 변수에 따라 네 가지 유형의 신경망 모형을 제시하였다. 신경망 모형 중 다층신경 망 모형을 적용하여 은닉충의 유니트 수, 학습계수, 모멘텀계수, 학습횟수의 변화에 따른 최적 모형 구조를 도출하였다. 신경망 모형의 학습성능을 검증하기 위하여 선정된 30개 조사지점에서 20개 지점을 모형의 학습자료로 나머지 학습되지 않은 10개 지점을 예측자료로 활용하였다. 분석결과, 네 가지 유형의 신경망 모형 중에서 모형 D가 통계적 검증결과 $R^2$값이 85%이며, %RMSE=0.0204로 가장 실제값에 유사한 모형으로 평가되었다.