무선 전력 전송용 고출력 주파수 가변 공진기 설계

박재수(Jaesu Park),최재훈(Jaehoon Choi) 한국전자파학회 2013 한국전자파학회논문지 Vol.24 No.3

본 논문에서는 자기 공명 방식의 무선 전력 전송 시스템을 위한 고출력 가변 공진기를 제안하였다. 공진 코일에는 스파이럴 구조를 사용하였으며, 공진 코일의 양 끝단에 고출력용 가변 트리머 커패시터를 연결하여 주파수 가변이 용이하도록 설계하였다. 3D 시뮬레이션 툴과 등가 회로 모델링 기법을 이용하여 커패시터 용량 변화에 따른 공진 주파수 변화와 전달특성을 예측하였다. 무선 전력 전송 시제품을 제작하여 측정한 결과, 송/수신 코일이 160 mm의 거리로 이격되어 있을 때, 3.0~4.5 MHz 범위의 공진 주파수 가변이 용이하였으며, 50%이상의 전송 효율을 얻을 수 있었다. In this paper, a high power tuneable resonator for a wireless power transfer system based on magnetic resonance is proposed. A spiral structure is used for a self-resonant coil and tuneable trimmer capacitors are added at the edges of resonant coils such that the frequency can be easily tuned. 3D simulation tools and equivalent circuit modeling method are used for predicting self-resonant frequency and scattering parameters according to the change of capacitor values. From the measurement of the prototype WPT system, the resonant frequency could be controlled from 3.0 MHz to 4.5 MHz and the transmission efficiency way over 50 % when the distance between transmitting coil and receiving coil was 160 mm.

동남아화교의 對중국 투자에서 홍콩의 입지

박재수(Park JaeSue),김은숙(Kim EunSook) 전남대학교 글로벌디아스포라연구소 2009 디아스포라 연구 Vol.3 No.2

본 연구는 동남아화교와 중국 간의 자본이동을 홍콩의 역할에 주목하여 살펴보고자 하였다. 연구방법은 특정 주체(다국적기업 등)의 국제적 이동 현상을 잘 설명해주고 있는 더닝(Dunning)의 소유권우위, 입지우위, 내부화(Ownership, Location, Internalization), 즉 OLI패러다임을 적용해 보았다. 다만 패러다임 중에서 홍콩의 입지를 중점적으로 파악해 보고자 하였다. 동남아화교는 투자동기 측면에서는 에스닉, 자본확대, 그리고 자본회피가 전형적이며, 그 관계 하에서 홍콩의 입지특성이 나타난다. 환언하면, 홍콩자본은 대부분 동남아 화교자본에 근원을 두고 있으며, 그 자본을 중국으로 투자하였다. 그리고 동남아 국가의 배타적 화교정책을 기회로 전환시켰으며, 홍콩을 중심으로 자본을 회피시키는 특징이 나타났다. Overseas Chinese in Southeast Asia have been playing a leading role in the Southeast countries business through the extensive interpenetration of capital flows and business networks. The recent East Asian Regionalism also has seriously depended the investment to mainland china of Overseas Chinese business in Southeast Asia. Moreover, through the ethnic network of chinese that is, their cross-border investments and global trade networks in Hong-Kong, Overseas Chinese have also facilitated the rearticulation of mainland China into the global economy.

Study on the Natural Light Condensing and Transmission Device for Smart Farm

( Jaesu Lee ),( Youngsin Hong ),( Pyoungwoo Yang ),( Jeonghyun Baek ),( Jiseob Lim ),( Jongwon Park ),( Hyundong Lee ),( Jeongwook Heo ),( Hyunhwan Kim ),( Gookhwan Kim ),( Kilsu Han ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

Smart farm (plant factory) technology is evolving into various farms of convergence technology through linkage with bio & IT industry, and urban agriculture. Particularly, it can serve as a key solution to societal issues, such as rural aging, rural migration settlement and rural job creation for young people. However, the level of technology and industrialization of the plant factories in domestic smart farms is still growing. For example, plant factories are centered on production of leaf vegetables due to limited technology to maintain light quality and intensity of artificial light sources. Therefore, it is important to acquire core technology necessary to design an automated system that enhances modeling and industrializing Korean smart farms. In this study, a natural light condensing and transmission device was designed to develop a next-generation light supply system that uses both natural and artificial light. The prototype of the natural light condensing and transmission device consisted of a condenser lens, an optical sensor, a light source tracking device, and an optical fiber. The condenser lens has increased the efficiency of the optical fiber by focusing more natural light on the optical fiber in the form of an aspherical convex lens. The optical sensor maximizes the efficiency of light collection by sensing from the sunrise. The light source tracking device enables more precise tracking of light sources as it uses an optical sensor system. The optical fiber has the highest degree of freedom among optical transmission technologies and it can transmit more than 200 m light sources with a low attenuation rate (0.06%/m). In the future, The spectroscopic measurement of light source and light efficiency (loss rate) will test using a spectrophotometer (FieldSpec 4, ASD Inc., USA) having a measurement range of 350 ~ 2,500 nm.

Control of Culture Mediums on Hydroponic Growth of Ledebouriella Seseloides Seedlings under the Smart Greenhouse of Artificial Light Type

( Jeongwook Heo ),( Kyounghoon Park ),( Chanheum Park ),( Jaesu Lee ),( Jeonghyun Baek ),( Seouggil Hong ),( Gongin Lee ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

In hydroponic culture, several nutrient solutions were used for plant growth and development under smart greenhouse (Plant factory system) conditions with artificial lights instead of sun light. The conventional solutions are automatically irrigated for leafy plants production under controlled EC and pH conditions. Researches on the nutrient solution control were focused on the cool-season leafy plants such as lettuce spp. growing for 4~5 weeks after seedling transplantation on hydroponic culture bed. However, investigations on the effects of nutrient solutions for long term culture crops compared to the leafy plants have not been conducted. It was conducted to investigate the effect of conventional culture mediums on long-term growth of Ledebouriella seseloides seedlings under smart greenhouse conditions. Conventional Japan Wonsi standard (JW), Yamazaki Leaf lettuce (YL), and Yamazaki Padeudeuk (YP) solutions were used for hydroponic culture. The seedlings with a longer growth period than leafy plants were considered as a plant material. The seedlings which developed 2~3 true leaves were grown in the smart greenhouse with Light-Emitting Diodes (LEDs) lights of blue, red and white of 1:2:1 mixture in energy ratio. The three nutrient solutions were regularly irrigated by the deep flow technique (DFT) system on the culture gutters for 350 days. Long term culture of Ledebouriella seseloides seedlings with a longer growth period was established by the nutrient solutions which conventionally used for hydroponic culture of leafy plants inside the smart greenhouse conditions. There was no significance in the leaf growth of the seedlings such as fresh weight, leaf extension and leaf pigmentation among the mediums. From the results, it is suggested that the type of culture mediums was not crucial factor in long-term growth of the seedlings under controlled environments such as smart greenhouse conditions although average leaf number of the seedlings grown under MJ or YP treatment significantly increased.

서울의 상업용 부동산 시장에서 자본환원율을 이용한 시장 효율성과 CAPM의 검증

박종권,이재수,전재범,Park, Jongkwon,Lee, Jaesu,Jun, Jaebum 한국건설관리학회 2017 한국건설관리학회 논문집 Vol.18 No.1

본 연구는 서울의 상업용 부동산인 오피스 빌딩 및 소매용 부동산 자산을 대상으로 체계적 위험과 자본환원율 간의 관계를 실증분석함으로써 시장의 효율성과 CAPM의 적용여부를 검증하는 것을 목적으로 한다. 이를 위하여 본 연구에서는 투자의 위험을 수반하는 자본자산의 기대수익률 결정이론인 자본자산가격결정모형(CAPM)을 토대로 서울의 3대 오피스 빌딩 시장인 강남권, 여의도 마포권, 도심권 그리고 기타권역과 소매용 부동산의 3대 시장인 강남권, 신촌 마포권, 도심권 그리고 기타 권역에 대하여, 시장포트폴리오인 증권시장선과 권역별 초과자본환원율로 산정된 증권특성선을 비교 및 분석하였으며 그 결과, 오피스 빌딩 시장에서 GBD 권역을 제외한 나머지 권역들(YBD 권역, CBD 권역 그리고 기타 권역), 소매용 부동산 시장에서는 SBD 권역 및 CBD 권역에서 체계적 위험이 증가할수록 분기초과자본환원율이 감소하여 시장이 효율적이지 않음을 알 수 있었다. 이와 함께, 오피스 빌딩 시장의 4개 권역(강남권의 GBD 권역, 마포 여의도권의 YBD 권역, 도심권의 CBD 권역, 그리고 기타 권역)과 소매용 부동산 시장의 4개 권역(강남권의 GBD 권역, 마포 신촌권의 SBD권역, 도심권의 CBD 권역, 그리고 기타 권역) 모두에서 CAPM이 성립하지 않음도 확인할 수 있었다. This paper is to understand the impact of systematic risk on capitalization rate at office building market and retail real estate market in Seoul and to see if CAPM(Capital Asset Pricing Model) is applicable. For this, this paper considers eight different office building and retail real estate markets in Seoul city area, called GBD, YBD, CBD, and Other Business District, and GBD, SBD, CBD, and Other Business District, to find out if there is any positive-linearity between systematic risk and capitalization rate for each business district not. Then, this paper tries to verify applicability of CAPM to four office building markets and four retail real estate markets with Black, Jensen, and Scholes(1972)'s statistical methodology. At last, the result shows that there is positive linearity between systematic risk and capitalization rate only GBD except Others(YBD, CBD, and other business district) in office building market. In addtion, SBD and CBD, they could be figured out that it is not efficient market because increasing systematic risk declines capitalization rate in retail real estate market. However, CAPM is not applicable in all office building(GBD, YBD, CBD, and other business district) and retail real estate markets(GBD, SBD, CBD, and other business district) in Seoul.

폐쇄형 식물생산 시스템에서 태양광 채광시스템 연구

이상규 ( Sanggyu Lee ),이재수 ( Jaesu Lee ),이현동 ( Hyundong Lee ),백정현 ( Jeonghyun Baek ),노시영 ( Siyoung Rho ),홍영신 ( Youngsin Hong ),박종원 ( Jongwon Park ) 한국환경과학회 2019 한국환경과학회지 Vol.28 No.5

In this study, a solar light collector that collects and transmits solar light required for crop production in a closed plant production system was developed. The solar light collector consisted of a Fresnel lens for collecting solar light, and a tracking actuator for tracking solar light from sunrise to sunset to increase the light collection efficiency. The optical fiber that transmitted solar light was made of Glass Optical Fiber (GOF), and it had an excellent optical transmission rate. After collecting the solar light, the amount of light was measured at 5, 10, 15, 20, 25, and 30 cm distances from the GOF through the darkroom by using a light sensor logger connected to a quantum and pyranometer sensor. Compared with solar light, the light intensity of pyranometer sensor measured at 5 cm was 114% higher than solar light, and 61% at 10 cm. In addition, it was observed that it is possible to transmit the necessary amount of light for growing crops up to about 15 cm (as over 22%) through GOF. Therefore, adding diffusers to the solar light collector should be expected to replace artificial light in plant factories or plug seedlings nurseries for leafy vegetables. More studies on the solar light collection devices and the light transmission devices that have high light collection efficiency should be conducted.

Peroxynitrite Scavenging Mechanism of Alaternin and Nor-rubrofusarin glucose from Cassia tora

Chung HaeYoung,Choi JaeSue,Jung HyunAh,Park TaeHyun 大韓藥學會 2002 大韓藥學會 總會 및 學術大會 Vol.2002 No.2

무선 전력 전송용 고효율 공진기 설계

장요한(Yohan Jang),권재순(Jaesoon Kwon),박재수(Jaesu Park),최재훈(Jaehoon Choi) 한국전자파학회 2011 한국전자파학회논문지 Vol.22 No.9

본 논문에서는 자기 공명 방식의 무선 전력 전송 시스템에서 효율 향상 방안을 제시하였다. 공진 코일은 헬리컬과 스파이럴 형태가 결합된 구조를 제안하였으며, 소스와 디바이스 코일은 단일 원형 루프 형태로 설계하였다. 측정 결과, 송수전 코일이 120 mm의 거리로 이격되어 있을 때 헬리컬과 스파이럴 구조를 결합한 공진기는 기존의 헬리컬 구조의 공진기보다 효율이 13 % 향상되는 결과를 보였다. 뿐만 아니라, 크기도 기존 공진기에 비해 33 % 소형화할 수 있었다. In this paper, an efficiency improvement method in the wireless power transfer system based on magnetic resonance is proposed. A combined helical-spiral structure is adopted for self-resonant coil and source and device coils are designed using circular loop structure. The proposed resonator utilizing combined helical-spiral structure yields 13 % efficiency improvement over that of an existing helical type resonator when the transmitting and receiving coils are separated by 120 mm. In addition, the size can be reduced by 33 % comparing to the previous resonator.

Analysis and Design Guide of Active EMI Filter in a Compact Package for Reduction of Common-Mode Conducted Emissions

Dongil Shin,Sungnam Kim,Geunseok Jeong,Jaesu Park,Joungwook Park,Ki Jin Han,Jingook Kim [Institute of Electrical and Electronics Engineers 2015 IEEE transactions on electromagnetic compatibility Vol.57 No.4

<P>A common-mode (CM) active filter was designed in a compact package to suppress CM conducted emissions at a switching mode power supply (SMPS). Based on the analytical expressions considering both stability and performance, the design and optimization rules for the proposed active filter have been presented. After verifying its performance by measurements using vector network analysis, the proposed filter was installed in a 200-W SMPS board with 64 and 110 kHz switching frequencies, demonstrating its usefulness by experiments. The performance degradation due to the magnetic saturation and the AEF grounding impedance was also analyzed and investigated.</P>

Common Mode Noise Reduction for an LLC Resonant Converter by Using Passive Noise Cancellation

Younggon Ryu,Sungnam Kim,Geunseok Jeong,Jaesu Park,Duil Kim,Jongwook Park,Jingook Kim,Ki Jin Han 한국전자파학회JEES 2015 Journal of Electromagnetic Engineering and Science Vol.15 No.2

This paper describes the application of a passive noise cancellation method to a prototype inductor-inductor-capacitor (LLC) resonant converter by placing a compensation winding in a transformer to reduce common mode noise. The connection method for the compensation winding is investigated. A circuit analysis is implemented for the displacement currents between the primary and secondary windings in the transformer. The analyzed displacement currents are verified by performing a circuit simulation and a proper compensation winding connection that reduces common mode noise is found. The measurement results show that common mode noise is reduced effectively up to 20 dB in the 1 to 7 MHz frequency region for the prototype LLC resonant converter by using the proposed passive noise cancellation method.