• 전력전자학회논문지
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• 제14권6호
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• pp.504-513
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• 2009

본 논문에서는 조명용 LED 구동 장치를 위한 새로운 방식의 LED 구동 모듈화 방법을 제안한다. 제안된 LED 구동 회로는 플라이백 컨버터를 이용하여 교류 입력 전원의 핫 접지와 LED 구동부의 콜드 접지를 절연한다. LED 전류 제어를 용이하게 하기위해 플라이백 컨버터를 동특성이 뛰어난 불연속 모드로 동작시키고, KIA2431을 이용하여 귀환 루프 제어를 한 후, 그에 대한 특성을 파악한다. 제안된 LED 구동 모듈은 폭넓은 교류 전원 입력 범위와 PWM 제어 IC를 직접 제어하여 버스트 디밍을 구현하고 넓은 범위의 LED 밝기 조절이 가능하게 하였다. 본 논문에서는 제안된 LED 구동 모듈에 대한 동작 원리를 설명하고 LED 구동 모듈을 실제로 구현 및 적용하여 제안된 구동 모듈의 유용성을 입증하였다. 또한, 소형화와 모듈화 된 LED 구동 모듈을 병렬로 연결한 다 채널 LED 구동 장치를 제안하고 그 타당성을 검증하였다.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권1호
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• pp.10-15
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• 2003

This paper presents the digital computer performance evaluations of the three-phase self-excited induction generator (SEIG) driven by the variable speed prime mover such as the wind turbine using the nodal admittance approach steady-state frequency domain analysis with the experimental results. The three-phase SEIG setup is implemented for small-scale rural renewable energy utilizations. The experimental performance results give a good agreement with those ones obtained from the digital computer simulation. Furthermore, a feedback closed-loop voltage regulation of the three-phase SEIG as a power conditioner which is driven by a variable speed prime mover employing the static VAR compensator (SVC) circuit composed of the thyristor phase controlled reactor (TCR) and the thyristor switched capacitor(TSC) is designed and considered herein for the wind-turbine driven the power conditioner. To validate the effectiveness of the SVC-based voltage regulator of the terminal voltage of the three-phase SEIG, an inductive load parameter disturbances in stand-alone are applied and characterized in this paper. In the stand-alone power utilization system, the terminal voltage response and thyristor triggering angle response of the TCR are plotted graphically. The simulation and the experimental results prove the effectiveness and validity of the proposed SVC which is controlled by the Pl controller in terms of fast response and high performances of the three-phase SEIG driven directly by the rural renewable energy utilization like a variable-speed prime mover.

• 전자공학회논문지
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• 제54권3호
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• pp.70-77
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• 2017

최근 IoT 및 딥러닝 관련 기술요소들이 영상보안감시시스템에서도 다양하게 응용되고 있다. 그 중 CCTV를 통해 촬영된 동영상에서 자동으로 특정 객체를 검출, 추적, 분류 하는 감시 기능이 점점 지능화되고 있다. 본 논문에서는 보급형 CPU만 사용하는 PC 환경에서도 실시간 처리가 가능한 알고리즘을 목표로 하였다. GMM(Gaussian Mixture Model)을 이용한 배경 모델링과 헝가리안 알고리즘, 그리고 칼만 필터를 조합한 추적 알고리즘은 전통적이며 복잡도가 비교적 적지만 검출 오류가 높다. 이를 보강하기 위해 대용량 데이터 학습에 적합한 딥러닝을 기술을 적용하였다. 특히 움직임이 있는 사람의 특징을 강조하기 위해 추적된 객체에 대해 SRGB-3 Layer CNN을 사용하였다. 성능 평가를 위해 기존의 HOG와 SVM을 이용한 시스템과 비교했을 때 Move-in은 7.6%, Move-out은 9.0%의 오류율 감소가 있었다.

• 한국정보전자통신기술학회논문지
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• 제12권6호
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• pp.582-590
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• 2019

우리나라는 저출산·고령화가 진행함에 따라 전체 인구의 14%를 웃도는 고령사회에 진입함으로써 1인 세대의 증가라는 사회변화에 직면해 있다. 고령사회에서 1인 세대 증가로 인한 가스화재 사고를 예방할 수 있는 효과적인 방법은 컨트롤 밸브를 설치하여 설정시간이 지나면 강제적으로 가스를 차단하는 방법이다. 본 연구에서는 밸브 핸들을 돌리지 않고 택트 스위치를 눌러 모터를 이용하여 웜기어와 헬리컬 기어로 동력을 전달하여 밸브를 좌우 회전하여 개폐 할 수 있게 개발하였고, 컨트롤러와 탈부착이 쉽게 전용 밸브를 개발함으로써 조립 및 검사가 용이하고, 부품 수 및 제품 사이즈를 줄여 원가 절감을 통해 경쟁력을 강화할 수 있도록 개발하였다. 또한 내구성 시험을 통해 12초에 한 번씩 ON/OFF 반복하여 34시간 동안 10,000번을 수행하는 동안 안정적으로 동작 할 수 있도록하여 9년 이상을 사용할 수 있도록 개발하였다. 개발 방법은 Solid works와 Altium Designer 툴을 활용하여 기구 및 PCB 설계를 진행하였고, Firmware 개발은 IAR Embedded Workbench 환경에서 개발하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권1호
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• pp.177-185
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• 2020

Objective: The study was conducted to establish a relationship between inclusion level of Vachellia tortilis (V. tortilis) leaf meal and time spent on different behavioral activities by finishing pigs. Methods: A total of forty-eight male Large White×Landrace finishing pigs with a mean (±standard deviation) body weight of 63.8±3.28 kg aged 14 wks were assigned to individual pens in a completely randomized design. Pigs were fed on diets containing 0, 30, 60, 90, 120, and 150 g/kg dry matter of V. tortilis leaf meal ad libitum with fresh water provided throughout the trial. There were eight pigs in each experimental diet. The behavior of pigs was observed for three wks twice a wk from 0600 to 1800 h using six closed circuit television cameras. Results: Increasing levels of V. tortilis leaf meal caused a linear decrease (p<0.05) in time spent eating, lying down and the number of visit to the feeder. Time spent standing and biting objects increased linearly (p<0.05) with increasing inclusion level of V. tortilis leaf meal. The was a negative linear relationship (p<0.05) between condensed tannins versus time spent eating, lying down and number of feeder visits. Condensed tannins showed a positive linear relationship (p<0.05) with time spent standing and biting objects. Neutral detergent fiber caused a linear decrease (p<0.05) in number of feeder visits, time spent eating, time spent standing. Conclusion: Inclusion level of V. tortilis leaf meal reduces time spent eating, lying down and the number of feeder visit while prolonging time spent standing and biting of objects. Condensed tannins and dietary fiber are among nutritional factors affecting behavioral activities displayed by finishing pigs.

• Journal of Power Electronics
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• 제13권4호
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• pp.679-691
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• 2013

High-power electromagnetic transmitter power supplies are an important part of deep geophysical exploration equipment. This is especially true in complex environments, where the ability to produce a highly accurate and stable output and safety through redundancy have become the key issues in the design of high-power electromagnetic transmitter power supplies. To solve these issues, a high-frequency switching power cascade based emission power supply is designed. By combining the circuit averaged model and the equivalent controlled source method, a modular mathematical model is established with the on-state loss and transformer induction loss being taken into account. A triple-loop control including an inner current loop, an outer voltage loop and a load current forward feedback, and a digitalized voltage/current sharing control method are proposed for the realization of the rapid, stable and highly accurate output of the system. By using a new algorithm referred to as GAPSO, which integrates a genetic algorithm and a particle swarm algorithm, the parameters of the controller are tuned. A multi-module cascade helps to achieve system redundancy. A simulation analysis of the open-loop system proves the accuracy of the established system and provides a better reflection of the characteristics of the power supply. A parameter tuning simulation proves the effectiveness of the GAPSO algorithm. A closed-loop simulation of the system and field geological exploration experiments demonstrate the effectiveness of the control method. This ensures both the system's excellent stability and the output's accuracy. It also ensures the accuracy of the established mathematical model as well as its ability to meet the requirements of practical field deep exploration.

• 시큐리티연구
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• 제60호
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• pp.91-111
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• 2019

꾸준히 늘어나고 있는 강력범죄의 예방은 언제나 인류의 중요 화두 중 하나이다. 최근의 대표적인 예방법은 도시에 범죄예방환경설계(CPTED)을 적용해 설계하는 것이다. 이 개념에서 가장 중요한 것이 감시와 접근통제인데, 그 중 일반적으로 많이 사용되는 방법은 기계적 감시에 속하는 것이지만 새로운 흐름에 맞추어 공공데이터를 활용한 다른 관점에서의 클래식 범죄예방 정책 제안이 필요하다. 이에 본 연구에서는 활용하는 공공데이터로 한국의 중심지인 서울시 데이터 포탈에서 제공되는 최근 년도의 자치구별 5대 범죄 발생현황통계를 중심으로 범위를 설정, 가장 개선이 필요한 부분에 범죄예방정책을 제안하도록 한다. 데이터 분석 및 시각화 방법으로는 오픈소스인 Python 분석 프로그램을 사용하였다.

• 한국측량학회지
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• 제30권6_1호
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• pp.567-574
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• 2012

최근 영상감시시장은 공공부문과 민간보안부문 등에서 CCTV 수요확대로 큰 성장세를 보이고 있다. 공공부문과 민간보안부분에 CCTV의 활용은 확대되고 있으나, 재난 재해분야에 CCTV의 활용은 아직까지 미흡한 것이 현실이다. 본 연구에서는 재난 재해 상황 변화를 감시자의 눈으로 담아내는 CCTV의 역할을 재조명하여 상습적으로 내수침수가 발생하고 있는 강남역 일대를 중심으로 재난원인분석을 위한 사례분석을 수행하였다. 먼저, 강남역 일대의 주요 침수지점에 대한 CCTV영상자료를 수집하고 영상 분석 및 현장조사를 통해 강우발생에 따른 침수시간과 침수심을 산정하였다. 또한 과거침수이력과 AWS(Automatic Weather System)강우자료를 이용하여 강우분석을 수행하였다. 강우분석결과와 CCTV영상에서 추출한 침수시간과 침수심 정보의 비교분석을 통해 과거 침수이력을 바탕으로 한 강남역 침수발생 강우량과 대응방안을 제시하였다. 이 결과는 상습침수지역인 강남역의 침수피해를 상당히 절감할 수 있을 것으로 판단된다.

• 한국자동차공학회논문집
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• 제19권6호
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• pp.140-147
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• 2011

The injection nozzle of an electro-hydraulic injector for the common rail Diesel fuel injection system is being opened and closed by movement of a injector's needle which is balanced by pressure at the nozzle seat and at the needle control chamber, at the opposite end of the needle. In this study, the slenoid actuator was considered as a prime movers in high pressure Diesel injector. Namely a solenoid-driven Diesel injector with different driving current types, as a general method driven by solenoid coil energy, has been applied with a purpose to develop the analysis model of the solenoid actuator to predict the dynamics characteristics of the hydraulic component (injector) by using the AMESim code. Aimed at simulating the hydraulic behavior of the solenoid-driven injector, the circuit model has been developed as a unified approach to mechanical modeling in this study. As this analytic results, we know the suction force and first order time lag for driving force can be endowed in solenoid-driven injector in controlling the injection rate. Also it can predict that the input current wave exerted on solenoid coil is the dominant factor which affects on the initial needle behavior of solenoid-driven injector than the hydraulic force generated by the constant injection pressure.

• PNF and Movement
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• 제5권2호
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• pp.63-71
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• 2007

Objective : Respiratory muscle weakness and decreased chest mobility has been suggested to result from the deconditioning that accompanied activity level in chronic elderly stokes. The benefits of respiratory exercise programmes on exercise capacity and muscle strength in hemiplegia. This study aimed to determine the effects of selective inspiratory and expiratory muscles training and chest mobility exercise on patients with strokes to establish if an improved exercise capacity can be obtained in patients that are not limited in their daily activities. Methods & Intervention : Twelve patients were assigned to the intensive respiratory exercise group participated in a measures design that evaluated the subjects with pre-treatment and post-treatment. Thirteen subjects who were assigned to a control group received training with breathing exercise and resistance exercise of skeletal muscles. The subjects performed spirometry then undertook a 6-week programme of respiratory muscle and chest mobility training. Training for the two groups was carried out 2 times a week for 6 weeks. Measurements and Results : Spirometry(Forced Vital Capacity: FVC and Closed Circuit Spiromety: CCS) and thoracic mobility were measured before and after the 6 weeks. The experimental group improved significantly compared to control group in FVC, $FEV_1$, MVV, IRV and ERV, and upper chest wall expansion(p<0.05). No significant improvement was seen in thoracic mobility or lung function in control group(p>0.05). Conclusion : The major findings in this study were that a intensive 6week exercise programme of resistive breathing and chest mobility in patients with hemiplegia led to an increase in lung capacity. The resistive breathing exercise programme used here resulted in a significant increase in the chest excursion during breathing.