• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.27.1-27.1
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• 2021

I will describe the current progress within the Fifth Generation of SDSS. SDSS-V is an unprecedented all-sky spectroscopic survey of over six million objects. It is designed to decode the history of the Milky Way galaxy, trace the emergence of the chemical elements, reveal the inner workings of stars, and investigate the origin of planets. It will provide the most comprehensive all-sky spectroscopy to multiply the science from the Gaia, TESS and eROSITA missions. SDSS will also create a contiguous spectroscopic map of the interstellar gas in the Milky Way and nearby galaxies that is 1,000 times larger than the state of the art, uncovering the self-regulation mechanisms of galactic ecosystems. It will pioneer systematic, spectroscopic monitoring across the whole sky, revealing changes on timescales from 20 minutes to 20 years. I will highlight key areas of current scientific and technical development as well as opportunities to participate in the survey underway.

• Journal of Electrical Engineering and Technology
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• v.8 no.6
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• pp.1400-1408
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• 2013

This paper proposes a new grid-tied power converter for battery energy storage, which is composed of a 2-stage DC-DC converter and a PWM inverter. The 2-stage DC-DC converter is composed of an LLC resonant converter connected in cascade with a 2-quadrant hybrid-switching chopper. The LLC resonant converter operates in constant duty ratio, while the 2-quadrant hybrid-switching chopper operates in variable duty ratio for voltage regulation. The operation of proposed system was verified through computer simulations. Based on computer simulations, a hardware prototype was built and tested to confirm the technical feasibility of proposed system. The proposed system could have relatively higher efficiency and smaller size than the existing system.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.163-168
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• 2005

In case of rolling stock, SEMS is generally applied in the advanced countries, but is start stage in our country. SEMS is defined the system engineering management system in order to achieve the optimized train performance among the several client requirements aspect of technical engineering management during the design life cycle. And the fire engineering activities in hong kong EMU project are introduced aspect of SEMS in this paper. The fire engineering at rolling stock in view of SEMS controls to apply the satisfied interior material by the fire safety standards (regulation of the commute urban subway safety guideline by the MOCT, BS 6853, NFPA 130, NF F 16-101) and to minimize the fire load in order that passengers egress safe from the fired rolling stock. The rolling stock in the advanced countries is designed to stand for 15-20 minutes in considering the rolling stock to be fired in tunnel. For passenger fire safety, the passenger evacuation provision and progress is set up.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2003.11a
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• pp.195-200
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• 2003

The purpose of this study is to establish the rainwater Utilization for the housing complex through the using rainwater, infiltration and detention. This study focused on the following items. 1) Legal basic conditions for the rainwater utilization in Germany 2) Case study on the rainwater management with examples. As the results of this study, it is necessary to implement these rainwater management system in laws, legal norms and technical regulation.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1623-1624
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• 2015

최근 전기설비의 안전성 확보와 인체감전보호를 위해 저압차단기 관련 국제표준 부합화 및 이에 근거한 관련 전기설비기술기준이 제 개정되었다. 저압차단기의 용도에 따른 안전과 특성기준을 구체화하여 설계, 시공 및 검사 등에 필요한 전기설비기술기준의 판단기준 제 개정 현황을 소개하고자 한다.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.8
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• pp.1313-1323
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• 2004

In accordance with adoption of new convention for the control of ship's ballast water at the diplomatic conference held in London Feb, 2004, every country has to regulate the ballast water and deposit matters. When this Resolution comes into effect in 2009, all vessels engaged in international voyage must have ballast water control program, ballast water records, equipments which are suitable to the standard of exchange and performance for the ballast water. This study estimates objectively their performances, merits and demerits of the ballast water treatment technique and exchanging techniques for safe operation of ships. It is desirable to design an equipment to control the ballast water using the brush-type vacuum suction nonstop reverse cleaning system to overcome the clogging phenomenon and the direct disc filtering to maximize filtering area for the optimum process considering biological availabilities. It will be expected to protect against marine pollution and to maintain clean sea if it is secured to develop new ballast water treatment techniques. And it will also be expected to cope with the Resolution and each regulation of the developed countries from the ballast water.

• Journal of Auto-vehicle Safety Association
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• v.6 no.2
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• pp.43-48
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• 2014

The flexible pedestrian legform impactor(Flex-PLI) consisting of a flexible femur and tibia will be tested for pedestrian protection by global technical regulation(GTR) within the next couple of years as a replacement for the existing transport research laboratory(TRL) legform impactor. In this study, a computer aided engineering(CAE) model was used to perform the effect analysis of each injury with regard to the changes in tolerance factors with the baseline results without tolerance. The tolerance factors were the height of impactor from ground reference line, initial velocity of impactor and rotation of impactor.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.1925-1927
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• 1998

D-STATCON using the multilevel voltage source inverters is presented for voltage regulation and reactive power compensation in distribution system. This cascade M-level inverter consists of (M-1)/2 single phase full bridge inverter(FBI). This multilevel inverter is a natural fit to the flexible ac transmission systems(FACTS) including STATCON, SVC, series compensation and phase shifting, It can solve the problems of conventional transformer-based multipulse inverters and multilevel diode-clamped inverters. From the simulation results, the superiority of D-STATCON with cascade multilevel inverter is shown for high power application.

• Journal of Auto-vehicle Safety Association
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• v.7 no.1
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• pp.40-44
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• 2015

In recent years, WorldSID dummy has been continuously developed and investigated to be a better represent biolfidelic ATD as well as a device for replacement of the current existing EuroSID-2. In Korea, the side impact accident is one of the major severe accidents in terms of numbers of accidents and fatality. Since 2003, 50kph 90degree side crash test has been initiated as a safety standard with EuroSID-1 at the first stage and also same time 55kph impact speed test has been conducted as a part of KNCAP program. Currently only EuroSID-2 is accepted as a regulatory tool for vehicle certification and KNCAP. In order to make use of WorldSID of KNCAP in the distant futuer the tests with WorldSID is conducted experimentally.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1-6
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• 2005

To improve safety management of railway and cope with the factors to threat technical and social safety, we need to establish railway safety management system based on analysis of hazards and assessment of risk for railway system. So we have to conduct PHA(Preliminary Hazard Analysis) first to understand weak points and factors to possibly threat safety using analysis of related data such as past accident/incident data and safety regulation and classification standards of hazards/causes of railway accidents. Therefore in this research, we led types/dangerous events/causes of risks/factors of risks from hazard log developed based on railway accident classification and hazards of railway accident. PHA model for domestic railway system will be used in risk analysis and risk assessment of railway accident.