• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.559-561
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• 2008

본 논문에서는 실용적이며 신뢰성 있는 고전압 대용량 유도전동기 구동용 H-브릿지 멀티레벨 인버터를 개발하여 산업 현장에 적용한 내용을 소개하였다. 실용적인 PWM (Pulse Width Modulation)과 PEBB (Power Electronics Building Blocks)에 기초한 신뢰성 있는 분산 제어를 적용하였으며, H-브릿지 멀티레벨 인버터를 이용한 유도 전동기 벡터 제어시의 위상지연을 보상하여 제어 성능을 향상시켰다. 또한, Power Cell 고장 발생시 시스템을 정지하지 않으면서 효율적 운전을 가능하게 하는 3상 불평형 제어를 이용하여 잉여성을 확보하였다. 다양한 전압과 용량의 H-브릿지 멀티레벨 인버터를 설계 및 제작하여 각종 부하 실험, 산업 현장 적용을 통해 적용된 방법의 타당성과 실용성을 입증하였다. 또한 실제 제품 설계, 생산, 판매, 유지 보수 과정을 통해 설계의 유연성, 생산의 효율성, 유지 보수의 편리함, 그리고 사용자 요구에 대한 대응성이 우수함을 확인하였다.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.155-156
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• 2015

본 논문은 마이크로그리드의 seamless mode transfer 를 위한 부하 위치에 따른 고조파 보상 기능을 가진 간접 전류 제어기법을 다루고 있다. 분산 발전 기반의 마이크로그리드는 계통 연계 모드와 독립 운전 모드시 각각 전류 제어기와 전압 제어기로 정의되며 각 모드에서 고품질의 전력공급을 위하여 강인한 제어기가 필요되어진다. 이때 계통 왜곡이나 비선형 부하의 연결등은 시스템의 전력 품질 악화를 초래할 수 있으며 이러한 문제를 해결하고자 많은 연구가 진행되었다. 본 논문에서는 계통연계 모드 뿐만 아니라 독립 운전 모드에서도 사용 가능한 비례공진 제어 기반의 간접 전류 제어기법을 제안하였고 부하 위치에 따른 고조파 보상 기법과 안정적인 모드변환을 동시에 고려하였다. 또한 비례 공진 제어기의 실용적인 모델을 사용함으로 인해 때때로 야기되는 독립 운전시의 전압 크기 감소에 대한 대책으로 적용이 간편한 전압 회복 기법도 추가되었다. 결과적으로 비선형 부하를 공급하기 위한 제안된 방식은 계통 연계와 독립 운전 모드에서 안정적인 전력 공급과 모드 절환 특성을 가짐을 PSIM 시뮬레이션을 통해 입증되었다.

• Journal of the Korean Geotechnical Society
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• v.28 no.5
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• pp.13-25
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• 2012

Ground anchor method is one of the most popular reinforcing technology for slope in Korea. For the health monitoring of slope which is reinforced by permanent anchor for a long period, monitoring of the tension force of ground anchor is very important. However, since electromechanical sensors such as strain gauge and V/W type load cell are also subject to long-term risk as well as suffering from noise during long distance transmission and immunity to electromagnetic interference (EMI), optical FBG sensors embedded tendon was developed to measure strain of 7-wire strand by embedding FBG sensor into the center king cable of 7-wire strand. This FBG sensors embedded tendon has been successfully applied to measuring the short-term anchor force. But to adopt this tendon to long-term monitoring, temperature compensation of the FBG sensors embedded tendon should be done. In this paper, we described how to compensate the effect in compliance with the change of underground temperature during long-term tension force monitoring of ground anchors by using optical fiber sensors (FBG: Fiber Bragg Grating). The model test was carried out to determine the temperature sensitivity coefficient (${\beta}^{\prime}$) of FBG sensors embedded tendon. The determined temperature sensitivity coefficient ${\beta}^{\prime}=2.0{\times}10^{-5}/^{\circ}C$ was verified by comparing the ground temperatures predicted from the proposed sensor using ${\beta}^{\prime}$ with ground temperatures measured from ground thermometer. Finally, temperature compensations were carried out based on ${\beta}^{\prime}$ value and ground temperature measurement from KMA for the tension force monitoring results of tension type and compression type anchors, which had been installed more than 1 year before at the test site. Temperature compensated tension forces are compared with those measured from conventional load cell during the same measuring time. Test results show that determined temperature sensitivity coefficient (${\beta}^{\prime}$) of FBG sensors embedded tendon is valid and proposed temperature compensation method is also appropriate from the fact that the temperature compensated tension forces are not dependent on the change of ground temperature and are consistent with the tension forces measured from the conventional load cell.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.2
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• pp.163-169
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• 2000

From the viewpoint of the cost effective design of power conversion systems, it is very important to fully u utilize the CillTent capacity of power devices over all circumstances. Therefore this paper deals with the l practical design of digital CillTent controller to meet the requirements of fast and overshoot free control r response over the varying control voltage bOlmds, the accompanied computational delay, and the system U W1certainties. The proposed controller consists of high gain PI control schemes using both the conditional i integrator and the modified delay compensator. The simulation and experimental results show the validity of t the proposed controller.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.546-547
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• 2019

본 논문은 증강현실 기술과 GPS 기능을 합친 여행 어플리케이션으로 사용자가 어플리케이션 내에 지정된 장소로 가서 화면을 비췄을 때 화면 내에서 관광지에 대한 정보를 얻을 수 있고, 그 장소에 실제로 다녀간 사용자들이 남긴 다양한 주변 정보들 까지 한눈에 볼 수 있도록 개발하였다. 증강현실을 통해 여행정보와 현장에서 작성한 후기를 제공하고 여행지에서의 증강현실 퀘스트 수행에 따라 경험치와 훈장 등의 보상으로 RPG(Role-Playing Game)성장 방식의 몰입감과 재미요소를 제공함으로써 사용자가 실용적인 정보를 실시간 현장 화면과 함께 몰입할 수 있는 서비스를 제공한다.

• International Commerce and Information Review
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• v.15 no.1
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• pp.3-34
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• 2013

This research, which was experimented by dividing tangible and intangible products, established the influence that affects recovery for consumers' complaint behavior and behavioral intention as per each different compensation program. In Experiment 1, the consumers, who experienced complaint behavior owing to company's mistake, have preferably recovered through the compensation program offered by the company. However, there was a significant difference in preference recovery between products that caused complaint behavior. According to the study result, the more clear preference recovery was shown in the case of purchasing laptop than the case of dining in family restaurant. Additionally, the consumers' emotion recovery was possible through compensation.; There was a emotion recovery disparity depending on product type between purchasing laptop case and dining in family restaurant case. The consumers, who experienced complaints, were only able to recover their preference, emotion, and behavioral intention through compensation of which recovery was greater in tangible product case than ordinary service. Meanwhile, there was no distinct difference between recovery compensation types even though the products were identical-type ones whereas it appeared that such tangible product which showed greater purchasing effort as laptop computer was more effective in stimulating emotion response. In Experiment 2, the purpose was to find out the difference between complaint behavior and its recovery process shown after purchase by Korean and Japanese college students, who have different consumer purchasing habits. The both consumers of the two countries, who experienced complaint behavior, demonstrated precise difference in preference recovery while the emotion and behavioral intention exhibited no disparity between the two consumer groups. In this experiment, it was learned that Korean college students were show-off purchase type consumers while on the other hand, the Japanese college students were famous product purchase type consumers. Thus, there was a clear difference in laptop computer purchase process and post-purchase evaluation between these two groups. In particular, the Korean college students had quicker preference recovery through compensation than the Japanese college students on account of their tendency to be consciousness of others. Nevertheless, there was no difference between the emotion recovery and re-purchase recovery and therefore, the compensation program for complaints was proven to affect the emotion and behavioral intention.

• Convergence Security Journal
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• v.20 no.2
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• pp.85-90
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• 2020

The purpose of this study was to provide information necessary for development of the applications that could facilitate the prevention and management of obesity in children with intellectual disabilities and to present improvement measure for development of practical applications. Mobile applications for prevention and management of obesity for children with intellectual disabilities need to be configured to enable effective flow of information and services delivered between parents and children with disabilities through applications. This configuration is expected to allow effective obesity control to be derived through parental involvement in the process of motivation.. The composition of contents consists of three parts: nutrition, exercise(physical activity), and lifestyle. It is desirable for each content to be applied in a simple but easy-to-understand method, reflecting the characteristics of an intellectually disabled child. In addition, this study presented the user expansion and their continuous involvement through interface simplification, alert function, reward, voice recognition and subtitle support strategies in consideration of the characteristics of the children with intellectual disabilities.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.9
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• pp.735-738
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• 2018

The accuracy of extracting the azimuth angle of a target is significantly affected by the error in the mono-pulse ratio of the air-borne antenna hybrid mono-pulse Radar system. This error is strongly induced by the phase imbalance between the channels of the system. In this paper, a method is proposed for effectively calibrating the phase imbalance caused by physical differences between the RF channels from the antenna to the $180^{\circ}$ hybrid. Through a flight test, it was confirmed that the accuracy of the azimuth angle of the target is improved by using the proposed method.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.433-434
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• 2017

기존의 전력 시스템에서 큰 부피를 차지하는 계통 주파수(50/60Hz) 변압기를 대체하기 위해서, 최근 전력용 반도체 변압기 SST(Solid State Transformer)에 대한 연구가 많이 수행되고 있다. AC/DC 컨버터는 높은 시스템 입력 전압에 대응 가능한 기존의 다양한 멀티레벨 컨버터 중 CHB (Cascaded H-bridge) 컨버터는 시스템 모듈화의 용이성과 상용 소자의 정격전압을 고려했을 때 반도체 변압기 시스템에 가장 많이 적용되고 있는 토폴로지이지만 각각의 H-bridge 컨버터 DC-link 전압의 불평형 문제가 발생한다. 본 논문에서는 CHB 컨버터의 전압 불평형을 해결하기 위하여 추가적인 센서가 필요없는 간단하고 실용적인 전압 불평형 보상 제어기를 제안한다.

• The Journal of the Korea Contents Association
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• v.19 no.5
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• pp.484-496
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• 2019

The purpose of this study is to identify the factors influencing conflict transition through the conflict transition process experienced by college graduates with early careers. The participants of this study were in-depth interviews with a total of 8 young people aged 25-34 who graduated from college and found their common subjects in all cases. As a result, the topics such as 'lack of recognition and compensation', 'unfairness of supervisor', 'characteristics of job (interdependence, autonomy)' were derived. 'Lack of recognition and compensation' brought about a sense of skepticism about the idea that even though they worked hard, they could not be recognized. And it caused a conflict transition. When the participants felt the 'unfairness of the supervisor', the task conflicts were further amplified and it transfer to relationship conflict. Among the characteristics of 'job characteristics', when highly interdependent occupations were carried out, conflict transition was shown and conflict levels were high. On the other hand, the work environment with job autonomy showed job satisfaction and did not show conflict transition. This study has an academic significance in that it revealed the types of conflicts and conflict transfer factors experienced in early career status of college graduates. In addition, this research have the practical implications to improves the participants' understanding of the conflict transfer through actual scene in the workplace.