• 전기학회논문지
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• 제62권12호
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• pp.1678-1687
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• 2013

This paper describes a prototype of 3-phase 3.3kV/220V 6kVA modular semiconductor transformer developed in the lab for feasibility study. The developed prototype is composed of three single-phase units coupled in Y-connection. Each single-phase unit with a rating of 1.9kV/127V 2kVA consists of a high-voltage high-frequency resonant AC-DC converter, a low-voltage hybrid-switching DC-DC converter, and a low-voltage hybrid-switching DC-AC converter. Also each single-phase unit has two DSP controllers to control converter operation and to acquire monitoring data. Monitoring system was developed based on LabView by using CAN communication link between the DSP controller and PC. Through various experimental analyses it was verified that the prototype operates with proper performance under normal and sag condition. The system efficiency can be improved by adopting optimal design and replacing the IGBT switch with the SiC MOSFET switch. The developed prototype confirms a possibility to build a commercial high-voltage high-power semiconductor transformer by increasing the number of series-connected converter modules in high-voltage side and improving the performance of switching element.

• 대한가정학회지
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• 제31권2호
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• pp.177-188
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• 1993

To obtain a clear understanding of the degree of effect by the food color in diet habits, this study was a survey of the taste for food color. In this study, the term of investigation was tow months(May and Jun. 1992), the object was 10's∼50's women, and the sampling of them at random contain 100 person, respectively. The data-treatment was determinded by frequency, percentage, SD, Chi-square, Spearman's rank order correlation coefficient, Correlation, F-test as measured by SAS program for PC and statistical figures were obtained by GDAS. The results were as follows; 1. Food color in diet habits. : The relationship of food color with appetite by age group was showed to affect all age groups having more then 90%. The concern for food color by age group showed the lowst teenage having 56.7%, showing more then 70% except teenage. When chosen food, The most important characteristics of food was not age group but taste. In the correlation between characteristics, The correlation between color and form, taste and nutrition was showed affirmative. The difference test for the taste of food color and general color was shown, and the level of significance was chosen at 95%. 2. In the correlation between food color and the sense of emotion, The food color of depression and solitude was purple, the color of sadness and crying was white. But in case of only solitude, A statistical significance was shown. 3. In the investigation of taste for food color, the mean of taste degree was high in red, orange, yellow, yellowish green, green, white and low in blue, black. Their statistical significance was shown between colors but, was not shown between age groups. 4. In the relation of food color and associated with food, the colors of associated with food shown a vast difference with natural food color were blue(85.5%), purple(80.0%), pink(41.7%) and yellow(40.0%) but, A red color was not shown the error rate of associated with food color at all. Almost all kinds of associated with food were fruits and vegetables.

• 한국게임학회 논문지
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• 제7권3호
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• pp.39-48
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• 2007

여가는 일상에 지친 피로를 풀어주는데 매우 중요한 요소이다. 특히 주 5일제 근무로 인해 여가를 즐기려는 사람들의 다양한 욕구는 점점 증대되고 있다. 게임은 대학생들에게 하나의 새로운 여가 활동으로 자리 잡고 있다. 과거보다 대학생들은 게임에 대한 욕구가 다양해지고 새로운 것을 추구하지만 개발사들은 비용적인 부분 때문에 대학생들의 욕구를 크게 반영하지 못하고 있다. 이러한 차원에서 본 연구에서는 대학생들의 여가활동 중 게임이용에 대해 어떤 형태를 나타내는지 평가하는데 초점을 맞추었다. 그 결과 하루 평균 3시간미만의 여가활동 중 $1{\sim}2$시간가량 게임을 하고, 재미와 스트레스 해소에 도움이 되기 때문에 많이 이용하는 것으로 나타났다. 온라인 게임과 PC 게임 플랫폼을 좋아하고, 시뮬레이션 게임과 MMORPG를 즐겨하는 것으로 나타났다. 게임 이용시 보통 $1{\sim}2$만원 정도 지불하는 것으로 나타났다. 이와 같은 연구결과를 바탕으로 마케팅 방법을 제안하였다.

• Journal of Korean Neurosurgical Society
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• 제29권12호
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• pp.1634-1641
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• 2000

Objective : The cerebrospinal fluid(CSF) pulsates within the craniospinal axis in response to rhythmic cerebral blood volume variation during the cardiac cycle. The aim of this study is to characterize the normal and abnormal CSF flow and its waveforms in the cervical spinal subarachnoid space. Methods : The magnetic resonance(MR) images were obtained with 1.5 T(GE Signa, GE Medical Systems, Milwaukee, USA) unit using the 2 dimensional cine PC(phase contrast) sequence with cardiac gating and gradient recalled echo imaging. This pulse sequence yielded 16 quantitative flow-encoded images per cardiac cycle. Sagittal and axial images of the cervical spinal CSF space were obtained, and target sites were analyzed for characteristic CSF flow (TR=50ms, TE=12.5-15ms). The region of interest(ROI) was 1mm 3 in volume. Twenty six persons were included in this study : 10 healthy volunteers and 16 patients with cervical myelopathy. The post-operative cine MR study were also done in five patients. Results : The normal CSF pulsation dynamics in the cervical spine showed discrete systolic and diastolic components. The CSF flow revealed a sine wave pattern, in which the systolic phase was shorter than the diastolic phase(ratio=2 : 3). The patient group revealed decreased amplitudes of the CSF flow and irregularly distored flow waves. The systolic phase was elongated in the ROI above the stenotic level, whereas the diastolic phase was lengthened below the level. In the postoperative images, the abnormal pattern and amplitude were found to be corrected. Conclusion : From these results, the authors believe that the CSF flow study provides valuable informations regarding the extent of cervical stenosis and may be useful for the surgical planning and post-operative evaluation.

• 정보교육학회논문지
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• 제12권1호
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• pp.99-107
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• 2008

초고속 유선 인터넷의 발달과 더불어 각광을 받고 있는 온라인 학습을 넘어 현재 휴대인터넷 (WiBro)과 UMPC (Ultra Mobile PC)를 비롯한 모바일 환경에서의 학습이 활발해지고 있다. 또한 최근 학생들은 점차 일방적인 주입식 교육보다는 상호작용적이며 즉각적인 피드백을 받을 수 있는 게임적 요소에 큰 관심을 보이고 있다. 본 연구에서는 학습자의 특성을 고려하여 모바일 학습에서 학습자의 학습 동기를 유발, 지속시키기 위한 방안으로써 Keller의 동기 유발 이론에 기초한 게임 전략을 접목시킨 새로운 동기 모형을 제시하여 학교 현장에 적용하였다.

• 한국항해항만학회지
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• 제28권5호
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• pp.449-454
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• 2004

대형여객선을 제외한 대부분의 선박에서는 정확하게 환자를 진단하고 치료할 수 있는 전문의가 없기 때문에 의료환경이 매우 열악하다. 따라서 선원에 대한 복지 및 근무환경의 개선이라는 차원에서 선택용 원적진료가 절실하고, 근무당사자 및 노조의 관심도 높아지고 있다. 본 연구는 원앙 및 연안항해에 종사하는 선박에서 환자 진료 시 중요한 정보로 활용되는 심전도와 청진음을 용이하게 측정하여 육상의 전문의사에게 전송함으로써 원격으로 진료를 수행할 수 있는 시스템을 개발하고자 하는 것이다. 본 논문에서는 기개발한 PC 기반의 디지털 심전도 및 청진기를 통하여 측정된 데이터를 국제해사위성(INMARSAT)을 이용하여 전송할 수 있는 시스템을 설계하였고, 실험을 통하여 전송 전후의 신호를 비교하여 데이터 오류를 검정하였다. 그리고 선박 통신시스템을 이용한 선박 원격의료가 가능함을 확인하였다.

• 한국기계가공학회지
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• 제15권4호
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• pp.51-59
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• 2016

Measurements of the automobile manufacturers are available anywhere and anytime, directly based on the criterion of failure is measured. The maintenance of high-precision production activities is direct evidence of the fact that competitive manufacturing activities are very important in determining the success of companies to recall defective starting from raw material costs. The current manufacturing sites produce calipers and clearance gauge the degree of tool only specific. Therefore, judging the quality, including the number of errors, requires a lot of attention to the dimension failures in day-to-day measurements and measurement tasks and duties repeated in difficult situations. In this paper, we aim to develop a vehicle manufacturing plant site using each of the manufacturing processes while operating a measurement tool. We display it using the Image Processing PC-based S/W with all those visual facts by management and recorded as image information a more accurate and current situation to obtain information and share visual measurements. We carry out research on the design and development vision inspection algorithm applied for pattern-recognition techniques that can help manufacturing site quality control.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 추계학술대회 논문집
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• pp.252-255
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• 2003

Digital environment that is represented to internet is displacing business way of industry and business achievement way with the fast speed being giving great change on life whole, improve existence business process utilizing internet and Web connection technology, information superhighway to tradition industrialist manufacture and e-transformation's propulsion that wish to maximize productivity and administration efficiency is spread vigorously. In this paper, we wish to accomplish generation equipment's heighten stability and believability through remote monitoring and control of BIPV system. This paper describes the design of the monitoring system for sensing the monitoring data and indirect controlling of the BIPV system. Most of the conventional monitoring system depend on the special hardware and software. Basic design goal of monitoring system is to provide the convenience for the user and the portability for the system. In order for the system to fulfill its requirements, it was designed using Labview GUI facility based on the Windows 2000 environment of IBM PC compatible and Add-on card based on the TCP/IP protocol. Advantage of the monitoring system are a personnel expenses curtailment effect, free of the place restriction and unmanned system of the generation plants, etc.

• 디지털융복합연구
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• 제18권10호
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• pp.443-452
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• 2020

현시대의 아동들에게 스마트 모바일 기기들을 활용한 교육은 아동미술교육 분야에서도 이제는 한 부분을 차지하고 있다. 펜이 탑재된 모바일 기기들과 스마트 태블릿PC들이 출시되면서 드로잉과 컬러링이 디지털 기기들로 가능해졌기 때문이다. 오늘날 아동들을 위한 컬러링 게임 콘텐츠들은 언제든지 애플리케이션 형태로 다운로드 받아 아동미술교육 현장에서 사용할 수 있게 되었다. 하지만 아동들을 위한 미술교육 효과를 가진 컬러링 기능성 게임들은 극히 적으며, 게임 안에 들어있는 미술 콘텐츠 요소들 또한 서비스되고 있는 모든 게임들이 대부분 비슷하며, 아동미술 표현기법 기능들도 부족한 상황이다. 본 연구는 아동들의 컬러링 활동을 도와주며 창의성과 상상력을 높일 수 있는 아동미술교육용 컬러링 기능성 게임 콘텐츠 개발의 중요성을 인지하고 기존 오프라인 아동미술교육 현장에서 시행되는 검증된 대표적인 미술표현기법들을 분석하여 아동미술 교육용 컬러링 게임 디지털 융복합 표현기법 콘텐츠의 개발방향과 요소들을 중심으로 연구하여 제시하고자 한다.

• Food Science and Biotechnology
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• 제16권6호
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• pp.1035-1040
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• 2007

Epidemiologic studies have shown important relationships between oxidative stress and Alzheimer's disease (AD) brain. In this study, free radical scavenging activity and neuronal cell protection effect of aqueous methanol extracts of Acanthopanax senticosus (A. senticosus) were examined. $H_2O_2$-induced oxidative stress was measured using 2',7'-dichlorofluorescein diacetate (DCF-DA) assay. Pretreatment with the phenolics of A. senticosus prevented oxidative injury against $H_2O_2$ toxicity. Since oxidative stress is known to increase neuronal cell membrane breakdown, leading to cell death, lactic dehydrogenase release, and trypan blue exclusion assays were utilized. We found that phenolics of A. senticosus have neuronal cell protection effects. It suggests that the phenolics of A. senticosus inhibited $H_2O_2$-induced oxidative stress and A. senticosus may be beneficial against the oxidative stress-induced risk in AD.