• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.206-210
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• 2012

Ground source heat pump is a central heating and cooling system that pumps heat to or from the ground. Building Integrated Geothermal system used in this experiment is one of the Ground Source Heat Pump Systems which utilize energy pile. The purpose of this study is to evaluate heating performance of the system. The building is a low-energy experiment apartment in Yonsei University Songdo Campus and the subject is one of the energy reduced houses in this apartment. In the experiment, indoor temperature, outdoor temperature and the inlet and outlet temperature of ground heat exchanger and subject model, were measured. Then the heat pump's Coefficient of performance(COP) of the heat pump was calculated. As a result, the COP of heat pump is 4-5. Although the depth of the ground heat exchanger in this experiment is shallower than usual heat exchanger, the result of heating performance of this system was good as well.

• 한국유기농업학회지
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• 제23권4호
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• pp.847-858
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• 2015

인삼뿌리썩음병에 길항력이 있는 Bacillus amyloliquefaciens GR4-5 균주 처리 전 후의 토양 내 Bacillus spp. 밀도 변화를 qPCR을 이용하여 분석하였다. 실내배양시험에서는 GR4-5 균주 처리 직후부터 4주째까지 Bacillus sp. group의 유전자 수가 무처리구보다 약 100배 이상으로 유지되는 경향이었다. 실외매몰시험과 포장시험에서는 유의차는 없었지만 경향으로 보아 GR4-5 처리구와 무처리구의 B. subtilis group 유전자 수가 비슷한 수준이 되는데 걸리는 시간은 7일 내외로 나타났다. 토양에 접종된 미생물의 생존에는 환경요인이 큰 영향을 미치며 그 중에서도 온도와 미생물의 격리 정도가 가장 큰 인자로 추정된다. 또한 GR4-5 균주의 생존에는 토양의 수분 함량 변화보다는 균주 처리 방법에 의한 영향이 더 크게 작용하는 것으로 보인다. 본 연구결과를 고려하면, B. amyloliquefaciens GR4-5 균주를 생물적 방제제로 사용하고자 한다면 7일 간격으로 관주 처리하는 것이 식물병원균 억제 및 근권 정착에 유리한 환경을 조성할 수 있을 것으로 판단된다. 또한 본 연구에서 제작한 실외 마이크로코즘 시스템은 제어하기 어려운 외부 환경 요인을 최소로 하여 유용미생물의 토양 내 생존 패턴을 분석하기 위한 간편한 방법으로서 유용하게 사용될 수 있을 것으로 판단된다.

• 한국지열·수열에너지학회논문집
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• 제11권1호
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• pp.1-6
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• 2015

This study presents analysis of the experimental data meeting conditions of several applications in real time. The results of this experimental study are as follows: Respectively in cooling and heating performance, a refrigerant charge tank can take automatic control of variation of the refrigerant quantity by controling pressure and temperature of system and outlet water temperature. The COP shows 3.5 in cooling operation and 3.2 in heating operation. The refrigerant quantity increases 0.69 kJ/h. When the outdoor temperature decreases $1^{\circ}C$, Therefore if the temperature become lower from $25^{\circ}C$ to $-16^{\circ}C$, the refrigerant quantity increases about 9.5%. Compared to the normal state experiment results, the COP in automatic control of the refrigerant quantity rises roughly 10%.

• 한국지열·수열에너지학회논문집
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• 제16권4호
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• pp.16-23
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• 2020

In this study, the control characteristics and effects of control methods on heating performance and energy consumption for the hot water floor radiant heating control system of a residential apartment were research by experiment. As a control method, On-Off control and outdoor reset control methods with GRNN(General Regression Neural Network) and without GRNN are considered. Also, the control performances with regard to improvement of indoor thermal environment and reduction of energy consumption are compared, respectively. Experiment results show that the performance of the control method with GRNN is better than that of conventional on-off control method without GRNN in the responses of room set temperature and energy saving.

• Current Optics and Photonics
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• 제8권4호
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• pp.375-381
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• 2024

In this report, we present the design, fabrication, and experiment of a static solar system for electric vehicle (EV) applications. The static concentration component is composed of compound parabolic concentrators (CPCs) couplings with multi-junction solar cells, where a flat silicon panel is added to the bottom of the CPV structure to maximize power generation. This design allows the system to collect both direct sunlight and diffused sunlight. The CPCs were fabricated with acrylic with a geometric concentration ratio of 4×. We built a prototype with a (3 × 3) cell array of CPCs with a thickness of 25 mm, which is as thin as conventional flat photovoltaic panels, and performed an outdoor experiment that showed that after six hours of operation, the system had an acceptance angle of approximately 43° and an average daily efficiency of 22.85%.

• 한국지능시스템학회논문지
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• 제24권4호
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• pp.424-429
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• 2014

본 논문에서는 발광광고물의 휘도를 측정하는 영상기반 휘도측정시스템을 제안한다. 제안하는 휘도측정시스템은 DSLR 카메라의 영상을 이용하여 점휘도계의 효율성과 면휘도계의 휴대성 및 경제성의 단점을 보완하며, 대상의 전체적인 휘도를 측정하는 시스템으로 영상을 입력받아 휘도분석 알고리즘을 통해 실시간으로 휘도값이 출력되도록 설계하였다. 측정 대상인 발광광고물은 설치 위치, 크기, 모양이 다양하며, 발광광고물의 휘도는 측정 거리, 각도, 색 등 다양한 조건에 따라 측정값이 달라진다. 따라서 정확한 휘도를 측정하기 위하여 측정대상물과의 거리에 따른 휘도값의 변화를 측정하였고, 측정 거리가 증가하면 휘도값이 변화하는 것을 고찰하였다. 실험을 통하여 측정 위치와 휘도값의 연관성을 수식으로 나타내었고, 제안한 방법을 평가하기 위해 점휘도계를 이용한 측정값과 비교 실험을 진행하였다.

• 한국태양에너지학회 논문집
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• 제25권3호
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• pp.37-45
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• 2005

Higher requirement of advanced building design code and the development of construction technique have resulted in more thermal and air tight buildings. This has caused the sick building syndrome in a indoor air quality has been relatively getting worse. A new concept with a solar fresh air heating and electrostatic precipitator or called as STCC(Solar Transpired Collector and Cyclone) has been proposed to solve this IAQ issue. This paper describes the assessment study of STCC system under different outdoor airflow rates. The experiment was carried out under real condition with 30CMM STCC system test facility. Incense smoke was used to study the particle concentration decay trends under outdoor airflow rates 0CMM, 10CMM, 20CMM, 30CMM, with applied voltages of 5kV and 15kV for collecting and discharging electrodes of an Electrostatic Precipitator. Result shows that the particle decay increases by increasing the outdoor airflow rates. The collection efficiency, dust cleaning effectiveness(P) and application area calculation result comparisons have also been studied. This factors could be used to estimate how a dust of indoor air quality(IAQ) and removed for a building space with a STCC system.

• 정보교육학회논문지
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• 제14권4호
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• pp.527-536
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• 2010

유비쿼터스 컴퓨팅과 모바일 기술은 식물원, 공원, 박물관이나 교실 등과 같은 다양한 실내외 공간에서의 참신한 학습 경험들을 가능하게 하는 새로운 기술이다. 본 연구에서는 체험학습자들이 유비쿼터스 환경의 실내외 공간에서 RFID 리더기가 부착된 모바일기기를 가지고 체험학습이 가능한 시스템을 개발하였다. 개발된 시스템은 학습자가 학습자의 학습 수준에 따라 학습 내용을 제공하여 개인별 학습 활동이 가능하도록 설계하였다. 실험결과 학습자들은 RFID 태그가 부착된 체험학습장에서의 체험학습에 적극적으로 흥미를 느꼈다.

• 정보과학회 논문지
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• 제44권7호
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• pp.733-741
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• 2017

LPWAN(Low Power Wide Area Network) 기술은 사물인터넷을 위한 M2M(Machine to Machine) 네트워킹 기술이다. 이 기술의 목적은 저전력, 장거리, 저속 통신을 지원하는 것이며 대표적으로 LoRaWAN(Long Range Wide Area Network)가 있다. LoRaWAN를 이용하여 사물들 간의 정보를 교환하기 위해서는 다양한 환경에 대하여 링크의 성능을 알아야 하는데 실증적인 환경을 기반으로 한 성능 분석 연구는 활발하게 진행되고 있지 않다. 따라서 본 논문은 실내, 실외 환경에서 링크 품질에 영향을 끼칠 수 있는 다양한 변수에 대하여 LoRaWAN의 물리적 통신 기술인 LoRa(Long Range) 링크의 성능을 실증적으로 평가한다. 이를 위해 물리적인 성능 모니터링 시스템을 설계하고 구현하였으며, 이후 통신 실험 환경을 실내, 실외 기반으로 구성하였으며 설정 파라미터 및 거리에 따른 SNR(Signal to Noise Ratio), RSSI(Received Signal Strength Indication), PDR(Packet Delivery Ratio)의 성능을 평가하였다.

• 한국해양공학회지
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• 제21권3호
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• pp.46-51
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• 2007

A multi-purpose environmental monitoring system has been developed as a commercially available standard using the technique of hetero-core spliced fiber optic sensors, for the purposes of monitoring large-scale structures and preserving natural environments. The monitoring system has been tested and evaluated in a possible outdoor condition, in view of the full-scale operation at actual sites to be monitored. Additionally, the developed system in this work conveniently provides us with various options of sensor modules intended for monitoring such physical quantities as displacement, distortion, pressure, binary states, and liquid adhesion. Two channels of optical fiber line were monitored in each channel, three displacement sensor modules were connected in series, in order to examine the performance to a pseudo-cracking experiment in the outdoor situation and to clarify temperature influences an the system, in terms of the coupling of optical connectors and the OTDR stability. The results from the pseudo-cracking experiment agreed with the actual cracks, by means of calculation, based an the detected displacement values and their geometrical arrangement of the used sensor modules. The temperature change, ranging from 10 to $20^{\circ}C$ resulting from the 10-days free running operation, was found to influence the system stability of ${\pm}10{\mu}m$, primarily due to the coupling instability of the used optical connectors. It was found that fusion splicing, rather than the use of connectors, reduced the fluctuation dawn to ${\pm}2{\mu}m$. The specification and performance of various option modules have been demonstrated to show the capability of inspecting various physical quantities by use of the single system, which would be suitable for multi-purpose environmental monitoring.