• 한국산업융합학회 논문집
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• 제19권4호
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• pp.223-230
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• 2016

This paper presents data-driven thermal protection algorithm for preventing overheating of automotive sunroof motor. When a sunroof motor operates abnormally, its coil is overheated and it is failed. Besides, drivers and passengers are damaged. Hence, the sunroof motor observes its temperature and will be stoped when its temperature reach a predefined level. In order to implement low-cost thermal protection function, we drew a knowledge-based temperature increasing and decreasing curve from the result of experimental test. And then, we implemented data-driven thermal protection algorithm which prevents motor's On/Off operation according to motor operating voltage and motor speed. Finally, we implemented experimental test bed and evaluated its feasibility.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.355-359
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• 2001

This paper presents an implementation of digital control system of speed sensorless for Reluctance Synchronous Motor (RSM) drives with DTC. The control system consists of stator flux observer, rotor position/speed/torque estimator, two hysteresis band controllers, an optimal switching look-up table, IGBT voltage source inverter, and TMS320C31 DSP controller by using fully integrated control software. The stator flux observer is based on the combined voltage and current model with stator flux feedback adaptive control that inputs are current and voltage sensing of motor terminal with estimated rotor angle for wide speed range. The rotor position is estimated by observed stator flux-linkage space vector. The estimated rotor speed is determined by differentiation of the rotor position used only in the current model part of the flux observer for a low speed operating area. It does not require the knowledge of any motor parameters, nor particular care for motor starting, In order to prove the suggested control algorithm, we have a simulation and testing at actual experimental system. The developed sensorless control system is shown a good speed control response characteristic results and high performance features in 50/1000 rpm with 1.0Kw RSM having 2.57 ratio of d/q reluctance.

• 정보교육학회논문지
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• 제5권1호
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• pp.133-142
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• 2001

'컴퓨터 교육'이라는 개념은 컴퓨터를 이용한 교육과 컴퓨터를 배우는 교육 두 가지 의미를 동시에 가지고 있기 때문에 사용하는데 주의를 기울여야 한다. 후자의 개념으로서 '컴퓨터 교육'은 전산학에 대한 개론 및 프로그래밍과 관련된 학습이 핵심을 이룬다. 특히 프로그래밍의 학습의 경우는 코딩, 컴파일링, 디버깅등의 복잡한 과정과 함께 운영체제 및 하드웨어에 대한 지식 같은 프로그래밍 외적인 분야에 대해서도 다양한 이해가 요구된다. 기존의 프로그래밍 학습은 프로그래밍 언어의 문법에 대한 기계적 암기나 사용법을 익히는 것에 치중하여 논리적인 사고를 키우는데 적합하지 못했다. 이에 본 논문에서는 프로그래밍에 대한 기본적인 통찰력을 기를 수 있도록 프로그래밍 언어의 기초가 되는 C로 코딩된 게임 소스들을 분석하고자 한다.

• ETRI Journal
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• 제36권3호
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• pp.510-513
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• 2014

A Q-band pHEMT image-rejection low-noise amplifier (IR-LNA) is presented using inter-stage tunable resonators. The inter-stage L-C resonators can maximize an image rejection by functioning as inter-stage matching circuits at an operating frequency ($F_{OP}$) and short circuits at an image frequency ($F_{IM}$). In addition, it also brings more wideband image rejection than conventional notch filters. Moreover, tunable varactors in L-C resonators not only compensate for the mismatch of an image frequency induced by the process variation or model error but can also change the image frequency according to a required RF frequency. The implemented pHEMT IR-LNA shows 54.3 dB maximum image rejection ratio (IRR). By changing the varactor bias, the image frequency shifts from 27 GHz to 37 GHz with over 40 dB IRR, a 19.1 dB to 17.6 dB peak gain, and 3.2 dB to 4.3 dB noise figure. To the best of the authors' knowledge, it shows the highest IRR and $F_{IM}/F_{OP}$ of the reported millimeter/quasi-millimeter wave IR-LNAs.

• 한국보육지원학회지
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• 제15권6호
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• pp.139-167
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• 2019

Objective: This study aims to investigate the effects of a learning cycle model-based early childhood education program using physical motion on young children's scientific inquiry ability, scientific attitude, object manipulation ability and spatial ability. Methods: The subjects of this study were 60 five-year-old children who were attending K-G City Childcare Center. The SPSS Window 21.0 program and content analysis method were used, and post-validation Tukey was conducted to examine the differences between the one-way ANOVA and the group. Results: Activities using body movement were practiced systematically based on the circle learning. Children could revise their pre-concept and concept of error by interacting with other children, teachers and the environment. Furthermore, children were attaining new knowledge while they were doing body movement activities, assessing and applying them to actual activities. Conclusion/Implications: This study is investigated a cyclic learning-based early childhood science education program using physical motion, which has significance in systematic and practical early childhood centered education for young children.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.178-181
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• 2005

The positioning accuracy of the Global Positioning System (GPS) has been improved considerably during the past two decades. The main error sources such as ionospheric refraction, orbital uncertainty, antenna phase center variation, signal multipath, and tropospheric delay have been reduced substantially, if not eliminated. In this study, the GPS data collected by the GPS receivers that were established as continuously operating reference stations by International GNSS Service (IGS), Ministry of the Interior (MOl), Central Weather Bureau (CWB), and Industrial Technology Research Institute (ITRI) Of Taiwan are utilized to investigate the impact of atmospheric water vapor on GPS positioning determination. The surface meteorological measurements that were concurrently acquired by instruments co-located with the GPS receivers include temperature, pressure and humidity data. To obtain the influence of the GPS height on the proposed impact study. A hydrodynamic ocean tide model (GOTOO.2 model) and solid earth tide were used to improve the GPS height. The surface meteorological data (pressure, temperature and humidity) were introduced to the data processing with 24 troposphere parameters. The results from the studies associated with different GPS height were compared for the cases with and without a priori knowledge of surface meteorological measurements. The finding based on the measurements in 2003 is that the surface meteorological measurements have an impact on the GPS height. The associated daily maximum of the differences is 1.07 cm for the KDNM station. The impact is reduced due to smoothing when the average of the GPS height for the whole year is considered.

• 전기학회논문지P
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• 제66권4호
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• pp.213-218
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• 2017

The DC electrolytic capacitor for DC-link of power converter is widely used in various power electronic circuits and system application. Its functions include, DC Bus voltage stabilization, conduction of ripple current due to switching events, voltage smoothing, etc. Unfortunately, DC electrolytic capacitors are some of the weakest components in power electronics converters. Many papers have proposed different algorithms or diagnosis method to determinate the ESR and tan ${\delta}$ capacitance C for fault alarm system of the electrolytic capacitor. However, both ESR vary with frequency and temperature. Accurate knowledge of both parameters at the capacitors operating conditions is essential to achieve the best reference data of fault alarm. According to parameter analysis, the capacitance increases with temperature and the initial ESR decreases. Higher frequencies make the reference ESR with the initial ESRo value to decrease. Analysis results show that the proposed DC Bus electrolytic capacitor reference ESR model setting technique can be applied to advanced reference signal of capacitor diagnosis systems successfully.

• 한국정보통신학회논문지
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• 제3권4호
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• pp.715-722
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• 1999

본 연구는 노인복지정책을 위한 정보통신시스템을 어떠한 방향으로 개발해야 하는지를 분석하기 위해 연구하였으며, 연구방법으로는 문헌자료와 현장방문 면담조사를 병행하여 실시하였다. 문헌자료는 주로 이론적 배경을 중심으로 연구하였으며, 면담조사는 1999년 9월 15일에서 16일 양일간에 무작위적 방법에 의해 노인들을 면담하여 노인들이 지금 필요로 하는 것이 무엇인지를 파악하는데 이용하였다. 면담결과를 분석해 보면, 노인들이 가장 많이 요구하는 것이 경제적 요구 의료요구 주택요구ㆍ문화요구ㆍ교통요구ㆍ교육요구 순으로 나타내고 있다. 노인들의 요구에 의한 정보통신시스템의 개발은 경제적 요구에는 재택근무시스템ㆍ홈쇼핑시스템ㆍ홈뱅킹시스템이 필요하며, 의료요구에는 의료지원시스템ㆍ의료정보시스템ㆍ원격의료지원시스템, 주택요구에는 가정자동화시스템ㆍ인터넷시스템, 문화요구에는 이벤트정보시스템ㆍ여가정보시스템, 교통요구에는 자동교통지리시스템ㆍ자동운전시스템, 교육요구에는 원격교육시스템ㆍ지식학습지원시스템 등의 개발이 필요하다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2007년도 추계학술대회 및 제23회 정기총회
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• pp.307-308
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• 2007

일반적으로 대부분의 실제 시스템은 복잡하고, 외란이나 불완전한 지식에 영향을 받으며, 비선형 특성을 가지고 있다. 이러한 시스템을 제어하기 위해 현대제어 이론에 기초한 제어기가 연구되고 있다. 그러나 이러한 제어이론과 제어기를 산업현장에 검증 없이 곧 바로 적용하면 시스템의 손상이 발생할 수 있으므로 모의실험을 통한 검증이 반드시 필요하다. 본 논문에서는 산업현장의 불안정과 비선형성을 대표할 수 있는 시소시스템을 모형대상으로 설정하여 RCGA기반의 상태피드백 제어기와 상태관측기를 설계하여 이들을 결합한 제어시스템을 설계한다. 다양한 초기조건과 외란에 대한 시뮬레이션을 통해 제어시스템의 유효성을 확인한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.240-243
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• 2003

Sensorless Vector control of the permanent magnet synchronous motor(PMSM) typically requires knowledge of the PMSM structure and parameters, which in some situations are not readily available or may be difficult to obtain. In this paper, by measuring the currents of the PMSM drive, a neural-network-based rotor position and speed estimation method for PMSM is described. Because the proposed estimator treats the estimated motor speed as the weights, it is possible to estimate motor speed to adapt back propagation algorithm with 2 layered neural network. The proposed control algorithm is applied to PMSM drive system. The operating characteristics controlled by neural networks control are examined in detail.