• Journal of Bio-Environment Control
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• v.27 no.1
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• pp.20-26
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• 2018

This study was conducted to develop a device for measuring the air flow by space variation through monitoring program, which acquires data by each point from each environmental sensor located in the greenhouse. The distribution of environmental factors(air temperature, humidity, wind speed, etc.) in the greenhouse is arranged at 12 points according to the spatial variation and a large number of measurement points (36 points in total) on the X, Y and Z axes were selected. Considering data loss and various greenhouse conditions, a bit rate was at 125kbit/s at low speed, so that the number of sensors can be expanded to 90 within greenhouse with dimensions of 100m by 100m. Those system programmed using MATLAB and LabVIEW was conducted to measure distributions of the air flow along the greenhouse in real time. It was also visualized interpolated the spatial distribution in the greenhouse. In order to verify the accuracy of CFD modeling and to improve the accuracy, it will compare the environmental variation such as air temperature, humidity, wind speed and $CO_2$ concentration in the greenhouse.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.7176-7181
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• 2015

This thesis is about the system where the solar module is attached to the high functional guardrail posts with anti-weed, anti-plant, and road-kill applied to produce internal power, enabling the integrated control and real-time monitoring of appearance of wildlife and road conditions using the USN. The whole system consists of a photovoltaic module(PV), a detection sensor(pyroelectric), a controller(operation select and motion sensor), the USN system, the DB(sound and flash), an output unit of sound and flash, and the control system of road-kill prevention and safety induction for vehicles. Thus this study aims to address the remote control and monitoring system of multipurpose guardrails to improve road environment, prevent road-kills, protect wild animals, and guide cars safely by using the USN which is combined with new renewable energy and IT convergence technology. As a result of the study on the remote control and monitoring system using the USN, it was ascertained that the response time of the unmanned sensing system was within 5.1 ms with the current consumption of 0.328 mA, and the data transmission speed of the remote control system was 250 kbps with the current consumption of 0.283 mA.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.131-131
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• 2009

최근 환경규제가 강화되면서 친환경적인 전력생산 요구 등의 외부환경 변화에 따른 우리나라의 전력구조가 기존의 중압 집중형 발전을 탈피한 분산전원 발전에 대한 관심이 증대되고 있는 실정이다. 특히, 분산전원으로서의 전력생산은 공급의 안전성, 경쟁력 및 에너지의 지속성 등이 요구되어지는데, 재생에너지가 가지고 있는 에너지 지속성의 한계 및 설치의 제약성을 탈피할 수 있는 시스템으로 현재 연료전지시스템이 가장 근접해 있는 실정이다. 즉, 도시가스 인프라가 우수하고 인구조밀 지역이 많은 우리나라의 특성상 각 가정 및 건물에 쉽게 설치하고 공급의 안전성을 갖는 건물용 연료전지는 최근 가장 각광받고 있는 분산전원 시스템 중의 하나이다. 올해부터 모니터링사업의 일환으로 수용가에 설치 될 연료전지 시스템이 얼마나 안정적으로 전기와 열을 각 가정에 공급하고 시스템의 안전성을 확보하는 가는 건물용 연료전지의 분산전원으로서의 가능성 및 국민의 수용성을 증대시키는 중요한 역할을 할 것이다. 연료전지시스템은 상용전력과 연계되어 있기 때문에 시스템의 안정성 뿐만 아니라 상용전력의 변화에 대응하여 안정적인 운전을 하는지에 대한 평가가 필수적이다. 이에 따라 본 연구에서는 가정용 연료전지시스템의 성능 및 안전성평가의 일환으로 계통연계형 전력변환장치의 성능 및 안전성을 평가 하고자 한다. 연료전지 검사를 위한 계통연계형 전력변환장치의 시험평가 항목으로는 크게 정상특성성능시험, 보호기능성능시험, 과도응답특성성능시험 및 외부사고성능시험 등으로 나뉘어진다. 본 연구에서는 외부사고 성능시험 항목들인 출력측 단락시험, 계통전압 순간정전?순간강하시험 및 부하차단 시험 등을 통하여 외부사고에 대한 성능 및 안전성을 평가하였다. 외부사고 성능시험의 주 목적은 시스템의 이상 운전이 아니라 외부의 영향에 따른 시스템의 안전성 및 전력품질을 평가한다. 출력측 단락시험을 수행하기 위해서 전력변환장치를 정격 출력 전압, 정격 출력 주파수 및 정격 출력에서 운전한 후, 교류 전원장치는 단락 전류를 검출하여, 사고 발생 후 0.3초 이내에 개방하도록 설정하였다. 여기서, 단락 저항 Rsc를 정격 전류의 10배 이상에 해당하는 부하와 같은 값으로 설정하였다. 스위치 SWSC를 폐로하여 단락 상태를 만들며, 이 때 전력변환장치의 출력전류와 차단 또는 정지 시간을 측정하였다. 실험 결과에 대한 판정기준은 단락전류를 검출하여 0.5초 이내에 개폐기 개방 또는 게이트 블록 기능이 동작하여 시스템을 안정하게 정지시키고 시스템 어떤 부위에도 손상이 없어야 한다. 실험 결과 파워컨디셔너의 출력전류 및 차단 또는 정지된시간이 40ms로 나타났고, 출력전류의 파형도 매우 안정함을 볼 수 있었다. 이와 같이 모든 실험을 수행한 결과 외부사고에 대하여 시스템이 안전하게 정지하는 등 연료전지 시스템의 안전성을 확인하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.266-271
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• 1999

The purpose in this study has to development the system on increasing operation of old-typed transceiver for solve the question that limited allocation frequencies and continuesly icreasment of traffic. Therefore, we are desigened the remote control system that has the function for variable channels, PTT and monitoring of transmission power and frequencies. Exchange of control data is to hold in common the twist two-wire or telephone line for the voice transmission. The H/W is consist of FSK and MCS-51 processor which are up-down control of channel, n control and monitoring display by serial data transmission. According to the simplex traffic operation is designed the algorithm of serial data transmission by sequential transmission sequence and protocol. The S/W of sequential transmission sequence is designed to usefully the intergrated communications system which is able to connection between the multi-transceiver and multi-terminal by master processor.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.3
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• pp.208-214
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• 2003

Because the digital control includes microprocessor different from an analog control, the digital control enables to monitor internal parameters of DC-DC converter and to control output voltage remotely by communicating with a Window based PC and also to monitor whether exact voltage is output or not. These things are impossible in an analog control. In this paper, a simple buck converter controlled by DSP(TMS320C31) is implemented. This converter outputs 0V to 5V from 15V input voltage and is controlled by a PD algorithm using DSP. Finally the response characteristics of a step reference voltage and in a steady state are analyzed to verify the usefulness of this digital controlled converter.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.5
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• pp.400-408
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• 2007

In this paper, development of the 8kW parallel module converter is presented. For a effective configuration of FB-PWM converter, this paper proposes 4-parallel operation of 2 kw-module. FB converter of 2-kW module is controlled by phase shut PWM and in order to achieve ZVZCS, the simple auxiliary circuit is applied in secondary side. In order to achieve ZCS, control logic for auxiliary circuit operation is designed to reset the primary current during free-wheeling period. For output current sharing of 4-modules, the charge control is employed. The charge control logic is designed with phase shift PWM logic. Voltage controller is implemented by using DSP(TMS320LF2406) with A/D conversion data of the output current and voltage of each module. The developed converter is installed in PCU(Power Conditioning Unit) for HSG(High Speed Generator) in a vehicle and health monitoring system is implemented for vehicle operation test. Finally, performance of the developed converter is proved under practical operation of HSG.

• Korean Journal of Optics and Photonics
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• v.19 no.3
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• pp.175-181
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• 2008

We develop a fiber optic acceleration sensor with LED, PD, POF, and a cantilever beam, having film grating at the edge of the beam. Light is transmitted from LED to PD through the film grating. When the cantilever beam moves by external vibration, output light is modulated as sinusoidal signals. The characteristics of output signals are dominated by the spacing of the film grating and also by the size and the elasticity of the beam. Two output signals, having constant initial phase difference, are obtained by two gratings with 90 degree phase difference. Those two signals are used to determine phase angle, which is proportional to the displacement of the beam. Finally, the acceleration is determined from conversion equation between displacement and acceleration. This sensor is designed for monitoring the vibration of large and complex building in the low frequency range of below 7 Hz, and is particularly suitable to measure acceleration in electromagnetic environments.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.4
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• pp.759-764
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• 2020

As the paradigm of manufacturing and production is also changing in line with the fourth industrial revolution, the social demands and directions for Industry 4.0 cannot be reversed, and the scalability and universality of 3D printing technology are attracting attention. 3D printer is a technology developed for the purpose of reducing product development costs, and with the recent expiration of 3D printer technology patent, related technology has been revealed and various technologies applied are being researched and developed, and various singularities have been discovered and supplemented. Thus, to compensate for the inconvenience of the current output method, which requires direct offline adjustment of the machine in the use of 3D printers and 3D printing through direct input of modeling data, the design of the IoT system is proposed to perform real-time online output requests for multiple 3D printers, monitoring functions that can expect normal outputs, and online real-time remote management functions for multiple 3D printers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.577-580
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• 2014

In this paper an auto-switching dual-input energy harvesting circuit is proposed. Since the maximum power points of a thermoelectric generator(TEG) output and a vibration device(PEG) output is 1/2 of their open-circuit voltage, an identical MPPT controller can be used for both energy sources. The proposed circuit monitors the outputs of the TEG and PEG, and chooses the energy source generating a higher output using an auto-switching controller, and then harvests the maximum power from the selected device using a MPPT controller. The harvested energy is boosted through a charge pump and stored in a storage capacitor. The stored energy is provided to a load through a PMU(Power Management Unit). The proposed circuit is designed in a $0.35{\mu}m$ CMOS process and its functionality has been verified through extensive simulations. The designed chip occupies $1.4mm{\times}1.2mm$ including pads.

• Journal of Digital Policy
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• v.2 no.4
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• pp.33-39
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• 2023

With a continuous occurrence of right-turn traffic accidents at intersections, there is an increasing demand for measures to address these incidents. In response, a technology has been developed to detect the presence of pedestrians through object detection in CCTV footage at right-turn areas and display warning messages on the screen to alert drivers. The YOLO (You Only Look Once) model, a type of object detection model, was employed to assess the performance of object detection. An algorithm was also devised to address misidentification issues and generate warning messages when pedestrians are detected. The accuracy of recognizing pedestrians or objects and outputting warning messages was measured at approximately 82%, suggesting a potential contribution to preventing right-turn accidents