• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.120.1-120.1
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• 2011

현대 천문학의 주요한 이슈 중 하나인 외계행성은 570개 이상 발견되었는데, 이들 모두 우리 은하내 외계행성들이다. 우리는 KMTNet 광시야 관측시스템을 이용하여 마젤란 은하내 외계행성을 Transit 방법으로 탐색 관측하여 외부은하 최초의 외계행성을 발견하고자 한다. 이제까지 알려진 Transit 행성들의 별표면 통과시간(transit duration)은 대부분 100-300분 사이에 분포하기 때문에, 이 현상의 검출은 최대 10분의 시간분해능을 필요로 한다. 한편, KMTNet 망원경은 마젤란 은하내 21등급의 별을 I 필터에서 10분의 노출로 1%의 측정정밀도를 얻을 수 있고, 8-10미터급 대형망원경을 이용하면 태양질량의 21등급 별을 공전하는 목성형 행성들의 분광후속 관측이 가능하다. 우리는 KMTNet으로 마젤란 은하내 19-21등급에 있는 F-G형 주계열성들과 청색수평가지별들(blue horizontal branch star)을 I 필터(관측 시작, 중간, 끝 시간에는 V 필터도 사용)에서 10분의 노출로 시계열 측광 관측하면, 다수의 Transit 외계행성을 발견할 수 있을 것으로 기대한다. 이와 더불어, 수년의 장시간 관측자료로부터 RR Lyr, ${\delta}$ Sct 및 식변광성의 극대/극심시각을 정밀하게 측정하여 Timing 방법으로 항성계 주위를 공전하는 장주기 외계행성을 발견할 수 있을 뿐만 아니라, 중력렌즈(self-lensing) 현상을 보이는 외계행성도 검출가능하다.

• Journal of Biomedical Engineering Research
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• v.27 no.3
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• pp.89-93
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• 2006

A simple algorithm that can be used to estimate a healthy person's blood pressure using pulse transit time is proposed in this paper. Fifty healthy students participated in the experiment that was conducted in line with the study. The subjects were asked to exercise on several exercise levels using a bicycle ergometer. Their blood pressures during the succeeding rest period were measured. A simple method was proposed to illustrate the relationship between blood pressure and pulse transit time. The systolic blood pressures as well as the heights and weights of the subjects were regarded as the proper parameters, and a second-order regression curve was produced to estimate the subjects' blood pressures. The mean error of estimation was less than 10 mmHg, which was the mean error of manual measurement. Although our estimation model is so simple, it can be used to estimate continuous blood pressure measurement for bicycle ergometer exercise. The electrocardiograms, photoplethysmograms, and blood pressures, however, could not be measured simultaneously As such, their estimation may be slightly different from the results taken from simultaneous measurements.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.56.1-56.1
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• 2013

We have carried out follow-up observations of transiting extrasolar planets using small- to medium-sized reflectors located in Korea. Using the 0.60m telescope stationed at CbNUO (Chungbuk National University Observatory) we have achieved a photometric precision of 1.48 milli-magnitudes (root-mean-square scatter of data) of a HAT-P-09b (transit duration of 3.43 hrs) transit light curve (transit depth ~ 1.3%) with V=12.3 mag for the host star. We expect a photometric precision of 1.0 - 1.2 milli-magnitude for brighter targets (V ~ 10 - 11 mag). The transit technique and its application will be outlined. The results of test observations will be presented and the defocus technique will be discussed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.7
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• pp.1248-1254
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• 2010

Authors conducted a deduction of some parameters using the magnetic equivalent circuit method and a verification study of the thrust force control algorithm of a rotary-typed small-scaled linear induction motor for a railway transit. In a LIM, it is possible to express the parameters of the magnetic equivalent circuit into a function of the shape of the secondary aluminium plate and the airgap between the LIM primary core and the secondary aluminium plate. It means that the LIM properties can be changed considerably by the shape of the secondary aluminium plate and the airgap between the LIM primary core and the secondary aluminium plate. So, authors analyzed a tendency of changes of the magnetic equivalent circuit parameters and the LIM characteristics by changing of the airgap of the secondary aluminium plate of a rotary-typed small-scaled LIM. And authors conducted a verification study of the indirect vector control algorithm with constant slip frequency by using the rotary-typed small-scaled LIM tester set on the basis of the calculated LIM parameters. Finally authors accomplished a research on applicability for LIM railway transit.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.3
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• pp.356-360
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• 2013

The PRT (Personal Rapid Transit) system is a new transportation system in accordance with the requirements of the passengers. Although this PRT system was proposed a long time ago, it did not hold the limelight due to the several limitations in technology. However, the research and development has been active again recently thanks to the development in technology and the review on its applicability as the means of transportation linking to the urban transit system. Although most of these recent studies in relation to the PRT are focused on the hardware such as PRT vehicles or track structures, etc., the operational aspect of it is more important than that of any other means of public transportation. Therefore, among studies on operational aspect of this PRT system, this paper shows the result of study on technology in relation to the movement of vehicle to the station where it was called by the passenger through interface of the wayside control center with the vehicle control system in case where the passenger calls a vehicle at the station.

• Journal of The Korea Institute of Healthcare Architecture
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• v.22 no.2
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• pp.35-44
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• 2016

Purpose: Recently, Universal design has been applied to a variety of concepts of social integration in the national legislation and institutions, however, the applying to urban railway station is not satisfied. Most of cases, the handicapped can not work continuously, universal design must be provided. Methods: This study derives the detailed criteria through comparing and analyzing an national and international universal design-related system in transit zone. And the status is investigated in transit zone of domestic urban railway station. Improved national standard requirements are derived considering the type of the handicapped and universal design principles. Result: The domestic status shows that the most lacking entry criteria is not specified in national standards or the design is a lowest-level required by criteria through comparing detailed criteria drawn into domestic analysis. Therefore, in order to provide a pedestrian environment to meet the universal design principles and requirements for the handicapped, there is a need to re-establish with a specific national standards. Implications: This study will draw on universal design standards for seamless transfer in transit zone of urban railway station. The next studies are needed to target the overall paths ranging from outside to landing in urban railway station.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.2
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• pp.99-106
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• 2004

Train control system in LRT (Light Rail Transit) is developed as a part of "Light Rail Transit System Development Project". But there was no specific requirement representing the system safety. Because system safety must be ensured before the customization, we applied the system to a officially recognized specific procedure, such as "A Guideline to Ensure the Safety of Train Control System in Korea" that was officially announced by KNR (Korea National Railroad) in 2001. We should draw system safely requirement to guarantee system safety for the first time. In this paper, the hazard identification and analysis to derive the safety requirement on LRT train control system are carried out following the KNR guideline. To analyze hazard, we have to deduce system functions, identify related hazards, derive the effects of the hazards, analyze current risk, define the target risk of the system, and deduce the alternative plans to reduce the effects of the hazards. After the hazard analysis following the upper procedure, 30 hazards are identified and analysed. Especially detailed analysis on train collision that is a main hazard of the train control of system is specially carried out.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.11
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• pp.1578-1586
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• 2015

Personal rapid transit (PRT) is getting attention as a new form of transportation. It is energy efficient and provides the high level of passenger service. In this study, the dynamic PRT dispatching and routing problem is dealt with. Passengers request transportation service on a complex network, and an operating system monitors passenger arrivals and coordinates vehicles in real time. A new online dispatching and routing algorithm is proposed, which minimizes the total travel distance of vehicles and the waiting time of passengers. The algorithm dispatches vehicles by considering multiple vehicles' state and multiple passengers at the same time. In particular, finding the shortest-time path is attempted by taking into account the future congestion on lanes. Discrete-event simulation is employed to validate the performance of the proposed algorithm. The results show the algorithm in this study outperforms others.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1181-1182
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• 2007

Light Rail Transit (LRT) System is an urban transit system which has approximately an intermediate transportation capacity between conventional subway and bus ($5,000{\sim}25,000$ persons per hour and per direction). It is a high-tech system which operational capacity, punctuality and mobility are remarkably improved. There are some types of LRT systems such as monorail, tramway, AGT(Automated Guideway Transit), and so on. The LRT systems have been applied and being operated in about a hundred lines around the world and many projects that apply the LRT systems in Korea are being proceeded and scheduled. For the efficient management, economical construction, and safe operation of various LRT systems, the establishment of national standard is necessary such as vehicle standardized specification, vehicle performance test standard, vehicle safety standard, construction guide, operation regulation, etc. of LRT systems. This paper presents the standard specification of electrical equipment of linear induction motor type light rail vehicle, that is LIM AGT(AGT system propelled with linear induction motor) vehicle. The LIM AGT system has been applied in Japan subway and ART(Advanced Rapid Transit) system of Canada and Yongin LRT is currently under construction.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1183-1184
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• 2007

Light Rail Transit (LRT) is optimized vehicle system for complex urban circumstance. LRT systems have many merits such as improved accuracy and safety. There are many LRT systems such as monorail, tram, automated guideway transit, linear induction motor propulsion and so on. These systems have been operated in Japan and other advanced countries. In Korea, local government has many projects to apply the advanced LRT system. But there are no standards regulation, performance test regulation and construction regulation for monorail system, linear induction motor system and tram in Korea. We expect that standardization brings economical construction and safety. The linear induction motor system has been usually applied to subway in Japan and ART(Advanced Rapid Transit) in Canada. In Korea, the linear induction motor system has been adopted for Yong-In LRT and currently under construction. This paper presents signalling system and TCMS(train control and monitoring system) of linear induction motor system.