• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.665-669
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• 2000

Recently the problem of energy branch become worse increasingly. Therefore many researches about new energy source are processing in several places around are processing in several places around the world. Especially solar energy has many advantages like as purity and infinity. Photovoltaic(PV) system can be classified into two types : One is stand alone type and the other is utility interactive one. Utility interactive type PV system need some technology that Maximum peak power tracking(MPPT) and Anti-islanding and Active Power filter(APF). For APF operation dc-link voltage should be high to supply sufficient output current which needed for harmonic current compensation so usually DC-DC converter is used for boost. In this paper DC-DC converter for PV system and controller for dc-link voltage control are analyzed and designed.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05d
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• pp.797-801
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• 2002

Information network technologies introduce a new education environment. Cyber education is growing rapidly as a field of practice especially in distance education system. The development of multimedia environment based on such technology as graphics, image, voice, and video, personal computer systems use has become the media for interactive teaching-teaming service. These features have made integrated multimedia education feasible. This research suggested a direction for the development of an interactive distance education system. I have developed an education system which cooperate problem bank and learning system. This system support arbitration of the relative difficulty in the problem bank database. An ongoing version of this research was evaluated. Those findings reveal several factors that influence how the proposed system can be tailored to the students' perspectives in order to come up with the enhanced version of this system.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11a
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• pp.85-88
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• 2003

최근 들어 핸드폰이나 PDA 등 휴대용 단말기의 보급이 급격히 늘면서 이를 통한 미디어 감상의 수요가 많이 증가하였다. 또한, 멀티미디어 기술의 발전 방향도 기존의 단방향 서비스를 벗어나 사용자의 기호에 따라 스토리를 전개해나가는 인터렉티브 미디어에 이르렀다. 따라서, 본 연구에서는 본 연구팀이 기존에 진행했던 연구에 이어서 이러한 인터렉티브 미디어를 지원하기 위한 전체 시스템을 설계하였고 이를 PDA 상에 구현하였다. 이때 비디오 코덱으로는 JVT(H.264)를 사용하였으며 컨텐츠제작을 위한 마크업 언어는 자체 정의한 IML(Interactive Media Language)를 사용하였다. 또한, 본 논문에서는 이러한 구현 과정에서 이동 단말기들이 공통적으로 가지는 취약점인 CPU, 메모리 등의 한계를 극복하기 위한 방안도 살펴보았다.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.591-594
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• 1999

The application field of photovoltaic system has been increased widely. In the application of photovoltaic system, the utility interactive photovoltaic system(UIPVS) has benefits of not only the home energy saving in domestic system but also reduction of peak power which threaten the capacity of power plant equipment when the maximum power consumption is occurred in daytime. This paper represents the effect of the nonlinear AC load which connected to the UIPVS with parallel connection and introduces the active power filtering(APF) techniques to the UIPVS for the reactive power compensation. The enhancement of source side power quality using APF algorithm is verified using simulation.

• ETRI Journal
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• v.21 no.4
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• pp.83-93
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• 1999

This paper examines the correlations between user characteristics and their perferences for two selected features of Web-based OPAC systems. User characteristics identified in this study were age, gender, educational status, computer skills and OPAC experience. Usability features included interaction styles, character and image on screen, browsing and navigating style, screen layout, and ease of learning, whereas availability features attended to availability of information, quality of information and up-to-date information. Individual variables and features are described, and the correlation between the variables and the features are explored using Pearson's correlation coefficient(r). Although based on a small-scale sample survey, a considerably large number of statistically significant correlations were found between the users' characteristics and the selected evaluation features of interactive Web-based OPACs. From these observations, it seems to be suitable to recommend that system designers should make a more considered appraisal of the users' demographic characteristics in the design of the new generation of OPAC such as in user-tailored interactive Web-based OPAC systems.

• Journal of Korean Elementary Science Education
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• v.37 no.1
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• pp.66-79
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• 2018

The purpose of this study is to explore how pre-service elementary teachers perceive and use smart learning environments. For this purpose, 23 pre-service elementary teachers who took theory and practice in a science education course were asked to develop lesson materials using smart tools and make a self-report questionnaire. These data were categorized in an instructional, exploratory, and interactive approach, depending on how they guided students to access knowledge and information. As a result of the study, pre-service teachers perceived the smart tools as the exploratory and interactive learning tools to be used for students to actively search for and interact with data and knowledge. But in developing lesson materials, they usually used the smart tools for resource sharing and communication in the instructional manner. In conclusion, the gap between their perception of smart tools and lesson materials, and the educational implications will be discussed.

• Asia pacific journal of information systems
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• v.12 no.4
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• pp.55-75
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• 2002

The purposes of this study are in threefold; to explain the interactivity in web site, to extend the Technology Acceptance Model(TAM) in the WWW context, and to examine its relationship with the existing TAM components. We proposed that the WWW is not just web systems but interactive spaces for virtual community. Web interactivity is represented by the two constructs: system interactivity and social interactivity. We extended and empirically examined the TAM for the web context. An individual's attitude toward the use of the web site is significantly affected by the individual's perception about ease of use, usefulness, and system interactivity. At the same time, behavioral intentions to use the web site is highly related to the social interactivity. The results showed that the system interactivity and social interactivity of a web site are important factors in affecting the user's beliefs and behavior intention of such a web site, So web page providers not only have to make the web site useful and easy to use, but also need to design an interactive web page by putting both systemic aspects and social aspects.

• Journal of Distribution Science
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• v.13 no.4
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• pp.29-33
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• 2015

Purpose - This paper aims to explain the interactive relationship between small and medium-sized enterprises' clusters and regional economic growth, with Jiangsu Province as an illustrative example. It focuses on studying the promotional effects, if any, of small and medium-sized enterprises' cluster-development on regional economic growth, and vice-versa. Research design, data, and methodology - Data were collected from the Jiangsu Statistical Yearbook and the China Industrial Economic Statistical Yearbook, by selecting 26 industries as the research subjects. The sample interval selection is 1981-2012. The data were analyzed with the dynamic panel system using stata 12.0. Results - 1) The small and medium-sized enterprises' cluster degree and Jiangsu's economic growth have a long-term stable equilibrium relationship. 2) In the short term, they have a dynamic adjustment 3) The enterprises' cluster degree leads to regional economic growth in Jiangsu, but not vice-versa. Conclusions - Small and medium-sized enterprises' clusters have an important promotional effect on Jiangsu's economic growth, especially industries with high degree of agglomeration. Therefore, the formation of these clusters can significantly improve economic growth.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.4
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• pp.83-94
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• 2010

Mobile network infrastructure is being completed with the development of hardware and software for mobile devices. Network in mobile devices has evolved for telematics that is expanded much more than its existing concept. Telematics is compound word that is formed from the words "telecommunication" and "informatics". It means that telematics performs control and monitoring service with using mobile device resources. These services provide their services for users' requests through wired or wireless network from mobile devices and server that offers contents and network service collects management information of mobile devices. Map service is one of the preferred services for many telematics users. However, mobile map service has a limit between traffic and information sharing. Therefore it is very important to supply their information for both service provider and terminal user. In this paper, we design a new interactive sketch map using routes and information on the space to be applied effectively, and provide an extended document format that is defined to an extensible and dynamic clustering scheme to have portability map service for mobile device.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.154-159
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• 1998

It is difficult and important for virtual studio systems and media-art products to be designed effective interactions between a performance person, who appears in the studio, and virtual studio equipments, and, an appreciation person and artistic products. The difficulties originate with originate with no even-grained component and no framework of interaction design work. In this article, a layered authoring model is proposed in order to facilitate system designers and artists to construct the system more easily and flexibly using fine-grained media components. And some experimental interactive virtual environments based on the model are shown.