• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.5
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• pp.454-462
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• 2006

To enhance the competitive edge of the material cost, various techniques lowering the material cost of inverter to drive Cold Cathode Fluorescent Lamp (CCFL) have been developed. In this paper, the theoretical analysis has been done for the existing techniques such as Jin Balance and O2Micro technique. Especially, How to design the value of magnetizing inductance to meet the specification of the lamp current tolerance between lamps has been disclosed. Based on this result, two kinds of hybrid type balancing techniques have been proposed and analyzed mathematically, Also, the accuracy of the proposed techniques has been verified through Pspice simulation.

• Journal of The Korean Association of Information Education
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• v.5 no.1
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• pp.83-100
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• 2001

A survey about uses of internet was conducted for elementary, middle and high school mathematics teachers in Seoul to determine the accessibility, level of usage, expertise, and general attitudes towards using internet for educational purposes. The survey indicated that only half of the teachers had computers in the classroom and less than 10% of the teachers had access to the internet in the classroom. The survey suggests that in order to quickly incorporate internet into mathematics education, teachers need help in getting the hardware, training for technology application, and Korean based resources on the internet. The survey also suggests that the teachers need to recognize the power of the internet usage and to do research to find a better way to integrate technology into their teaching.

• Journal of The Korean Association of Information Education
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• v.9 no.1
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• pp.99-112
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• 2005

In this research, we analyze chatting language of elementary school students, present the properties which are a result of this analysis and propose the method to solve it. Analysis on the chatting language considering organic relation of sentences is classified into syntactic, semantic and statistical characteristics. As a result of analysis, new characteristics is discovered writing by the way children pronounce their words, writing by switching the order of syllable's frontal and rear ends, inarticulate conversation of the other man. To minimize language misuse and to establish a chatting culture that is favorable to the development of children's emotional development, we propose the methods of computer system.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.475-480
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• 2008

In this paper, I will propose a Custom-made Suit Production System. The system does not only help the customers to edit and measure their size by creating the landmarks in the 2D human body images which is taken from the camera, but it also visualizes the virtual cloth by using the landmarks and the modeling data of the virtual cloth. In this system is a new technology for the digital and the automation which is not handmade way of using Custom-made Suit industry. It will be generally useful in the various contents of the clothing industry.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.629-634
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• 2008

디지털 영상 매체들이 등장한 후부터 장면전환 검출은 영상의 편집과 검색, 요약 등 여러 작업에 적용되기 위해 활발히 연구되어 왔다. 특히 디지털 방송이 MPEG2방식으로 송신되기 시작한 이후로 이러한 연구는 더욱 활발히 진행되었다. 그 결과로 MPEG2 영상에서 장면전환을 검출하기 위해서 압축영역에서의 검출법과 비압축영역에서의 검출법이 제시되었다. 특히 압축영역에서의 장면전환 검출방법은 전체를 디코딩하지 않고 장면전환을 빠르게 검색할 수 있는 방법들이 주로 등장되었다. 하지만, 이 방법들은 정확도가 떨어지거나 속력저하가 극심한 등 여러 가지 문제를 보였다. 따라서 우리는 좀 더 빠르고 정확도가 높은 장면전환 시점 검출을 위해서 GOP의 길이와 B 프레임의 용량 변화를 이용하고자 한다. 우리의 방법은 B 프레임의 용량 변화를 이용하여 장면 전환을 보다 빠르게 검색하고 보다 높은 정확도를 위해서 GOP 길이의 변화가 심한 곳을 추가로 지정하여 정확도를 보강한다. 이러한 방법은 기존의 장면전환 검출 방법보다 빠른 해결책이 된다. 그 뿐 아니라 정확도 면에서도 만족할만한 결과를 보여주고 있다. 본 논문에서 제시한 이러한 방법은 기존의 획일적인 방법에서 벗어나 MPEG2 영상내에서 좀 더 빠르고 정확한 장면검출을 위한 새로운 아이디어를 제공한다.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.6
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• pp.510-515
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• 2001

Generally, there are (1)Words for conversation (2)Tone (3)Pitch (4)Formant frequency (5)Speech speed, etc as the element for emotional recognition from speech signal. For human being, it is natural that the tone, vice quality, speed words are easier elements rather than frequency to perceive other s feeling. Therefore, the former things are important elements fro classifying feelings. And, previous methods have mainly used the former thins but using formant is good for implementing as machine. Thus. our final goal of this research is to implement an emotional recognition system based on pitch, formant, speech speed, etc. from speech signal. In this paper, as first stage we foun specific features of feeling angry from his words when a man got angry.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.12
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• pp.1933-1940
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• 2013

Recently, due to improvement of computer performance and development of information devices, technology of mobile augmented reality is proliferating rapidly. However, because most of contents are passive or limitary, user can not feel interest and immersion. This paper designs interaction user interface system of 2 dimensional drawing based on mobile augmented reality to make bi-directional communication between the real world and the virtual world possible by using the vision based augmented reality and the database system.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.4
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• pp.619-625
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• 1997

$Si_3N_4$ powder with 2 wt% $Al_2O_3$ and 6 wt% $Y_2O_3$additives was gas pressure sintered (GPS). Characterization of the mechanical properties was compared with sintering conditions (temperature, pressure, time). Based on experimental result , the optimal condition of gas pressure sintering was found at $1900^{\circ}C$, 3 MPa for 1 hour. It is assumed that mechanical properties were degraded due to the grain coasening effects with increasing temperature or holding time. However, the grain size was decreased with increasing pressure, resulted in better strength, but lower fracture toughness. Present results suggested that optimization of processing parameters was impotant for better mechanical properties of $Si_3N_4$.

• Archives of design research
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• v.17 no.2
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• pp.463-470
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• 2004

This paper studied tangible interaction design of VR platform and its applications that are economic In development process and cost, flexible by contents and installation conditions, and that has business potential for consumer market. The design solution uses video based virtual world and tangible interaction by motion tracking. Our platform enables a user to monitor their action and to collaborate with other users of remote place within attractive interaction feedback. We developed two design applications, Glass Xylophone 2003 and VR Class, in our platform. Glass Xylophone 2003 provides interactive music performance and helps self practice of glass xylophone. VR Class gives more serious distance learning experience with tutoring and group collaboration. They are presented in public exhibitions and tested by exhibition visitors. They showed application potential of this design solution in interactive game, distance learning, and entertainment field.

• Journal of Internet Computing and Services
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• v.10 no.3
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• pp.151-157
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• 2009

A lot of E-Learning system is supplying the existent item difficulty based learning information to learner. And learner is doing learning contents according to the fixed learning course. It is difficult for learner to get efficient learning effect. Because learner has to belong to fixed item difficulty and learning course even thought learner has different degree that understand studying in learning course. This research proposed the learner adaptive E-learning system that is able to control the item difficulty and learning course to analyze the understanding degree of learner in learning course. In this result, learner is able to improve learning effect to get rid of fixed learning course using bi-directed learning such as off-line learning.