• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.3
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• pp.216-223
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• 2006

The high efficiency full-bridge LLC resonant converter using a contact-less transformer Is proposed for the photovoltaic power generation system. For the series resonance with a series capacitor, the LLC resonant converter utilizes the leakage inductance and magnetizing inductance of a contact-less transformer Unlike the conventional series resonant converter operated to the continuous resonant current at above resonance frequency, the proposed converter operates to the discontinuous resonant current at the narrow frequency control range below resonance frequency. Due to the discontinuous mode resonant current, the proposed converter can be achieved the zero voltage switching (ZVS) in the primary switches and the zero current switching (ZCS) in the secondary rectification diodes without my auxiliary circuit. In this paper, the experimental results of the proposed full-bridge LLC resonant converter using a contact-less transformer are verified on the simulation based on the theoretical analysis and the 150W experimental prototype.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.5
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• pp.409-416
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• 2006

Operating Characteristics of LLC Series resonant converter with a LLT(Inductor-Inductor-Transformer) transformer is presented. LLT transformer used to combine the inductor and transformer into one unit has the increased leakage inductance in the primary and secondary due to the winging method and the use of the gaped core. The increased leakage inductance in the primary and secondary of LLT transformer can be impacted on the DC voltage gain characteristics of LLC series resonant converter. In the paper, DC gain characteristics and the experimental results of the LLC series resonant converter with a LLT transformer are verified on the simulation based on the theoretical analysis and the 400W experimental prototype.

• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.219-226
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• 2005

This paper describes the open API with integration of semantic web service with PARLAY X based open API in 4G mobile network. It can be expected that the intelligence such as the context-awareness, adaptation and personalization in 4G mobile network will be deployed. But the existing PARLAY based network lacks in considering context-awareness, adaptation and personalization. Therefore, the object of this paper is to support the architecture and the Application Programming Interface (API) of the network service for the context-awareness, adaptation and Personalization in 4G mobile network The open API is to provide users with the adaptive network service to the changing context constraints as well as detecting the changing context and user's Preference. For instance, the open API can Provide users with QoS in network according to the detected context and user's preference, after detecting the context such as location and speed and user's preference.

• Bulletin of the Society of Naval Architects of Korea
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• v.26 no.2
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• pp.32-40
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• 1989

Dynamic ship positioning(DP) system is used to keep the position and heading of a ship, or a floating platform, above a pre-selected site on the seabed by using thrusters. This paper presents a control system based on filtering technique and optimal control theory. The planar motions of a vessel are assumed to consist of low frequency(LF) component and high frequency(HF) one. The former is mainly due to thrusters, current, wind and second order wave forces, while the latter is mainly due to first order oscillatory component of the wave force. Furthermore position measurement signals include the noise. By means of self-tuning filter and Kalman filter techniques, LF motion estimates and HF ones are seperately achieved from the position measurements of the vessel. The estimated LF motions are used as input to the feedback loops. The total thruster power is minimized using the Linear Quadratic Gaussian control theory. The performance of the vessel with the DP system is investigated by computer simulation.

• Journal of Broadcast Engineering
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• v.7 no.2
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• pp.114-125
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• 2002

Although there have been a lot of researches on a video abstraction algorithm, the video abstraction tool is necessary to correctly pick up some important shots in a video because the important shots might vary on the person's subjectivity. This paper proposes a video abstraction and search system for making a video abstraction automatically or manually. Proposed system has two main components, server and client. The server generates the Metadata and makes a video abstraction file. The description for video abstraction file is based on MPEG-7. Since proposed system has a function to manually correct the results of each step, the author could produce a good video abstraction easily and efficiently. The proposed system could be used to build a digital video library.

• Journal of Broadcast Engineering
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• v.11 no.3 s.32
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• pp.284-301
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• 2006

In this paper, we present a design and implementation of a TV-Anytime metadata authoring tool for providing personalized data-broadcasting services. The TV-Anytime specifies metadata schema, metadata coding and delivery, and provides service models to provide personalized broadcasting content services at anytime when users want to consume using metadata including ECG (Electronic Content Guide) and content descriptive information in a PDR (Personal Digital Recorder)-centric environment. In spite of a useful services based on TV-anytime metadata, the metadata authoring still remains as a harassing and time consuming task. For easy metadata authoring, the proposed metadata authoring provides the following key functionalities: metadata visualization, media access, and semi-automatic method for editing segment related metadata.

• Journal of The Korean Association of Information Education
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• v.19 no.3
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• pp.373-384
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• 2015

Computer education is gradually focusing on a wide variety of areas of expertise such as production of visual media and software development, instead of on the use of ICT like before. Particularly, computer courses related to production of image media require a complex practice procedure and repeated practice, making the future hands-on work difficult. Therefore, this study tried to verify the effect of the change in running methods of the "computer graphic" course from offline to blended learning. This analyzed the students' lecture satisfaction survey results of before and after the change. As a result, blended learning was well received and led to the small variations in the scores of the satisfaction surveys between the lecturers. Additionally, many students responded that the blended learning was more effective in their satisfaction surveys.

• Journal of Korean Public Health Nursing
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• v.15 no.2
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• pp.412-427
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• 2001

The purpose of this study is to provide a basis to recognize the health behaviors of middle-aged men that are constructive to a healthy life style. Data were collected from interview of questionnaires completed by 160 middle aged men living in Incheon from November 1 to 30, 2000. The questionnaires used in this study were obtained from publications on health related topics shown in literature review. These topics included : health concept, diseases, use of tobacco, alcohol, caffeine, drug, exercise and diet, cause of stress and stress management. The data were analyzed by descriptive statistics using the SPSS program. The results of this study were as follows. 1. $47.5\%$ of Middle aged men thought of concept of health as a doing daily living pattern. 2. $38.5\%$ of the middle aged men had illness or disease, which included hypertension, gastritis, disc, peptic ulcer, indigestion and DM. 3. $55.6\%$ of the middle aged men smoked cigarettes. Most of them the began to smoke due interest. 4. $72.5\%$ of the middle aged men drank alcohol. Most of them began drinking due to peer pressure. 5. $81.2\%$ of the middle aged men consumed caffeine-containing products. 6. $59.4\%$ of the middle aged men took drugs. Most of the drugs were digestant. vitamins and analgesics. 7. $25.2\%$ of the middle aged men exercised more than 2 times per week. 8. Most of causes of stress were economic difficulties and sickness. The method of stress management were alcolhol and use of tobacco mostly.

• Journal of the Korea Convergence Society
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• v.9 no.8
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• pp.265-272
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• 2018

This study is a descriptive study to investigate the factors influencing the level of cognitive function among elderly living alone according to the presence of dementia risk factors. We conducted a simple questionnaire, GDS-K and MMSE-DS tests to investigate the risk of dementia among 143 elderly people living alone in the community. The results showed that the major factors influencing the cognitive function of the elderly people living alone were education, age, depression status, smoking, leisure activities, and gender. In order to develop strategies for the prevention of dementia in the elderly people living alone, it is necessary to change lifestyle and provide various management methods to identify risk factors that negatively affect cognitive function and to help cognitive health.

• Journal of the Korean Geographical Society
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• v.37 no.2
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• pp.161-176
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• 2002

The Landscape of the Bibo Geomancy is generally showed in Korean traditional settlement. The tradition of the Bibo Geomancy was given much weight in the Korean geographic history of life, so it could be a important research theme. The discussion in my dissertation, 1 insist on that, a comment of the Bibo together with a comment of the selection of proper sites composed as axis in Korean geomancy. As a grounds basis of an argument, 1 described on the concept and the composition of the Bibo Geomancy, the backgrounds of the theory, the historical changes of the Bibo Geomancy in Korea, the form and the function of the Bibo and the comparison with the Bibo-Geomancy of the north-east Asia.