• Proceedings of the KAIS Fall Conference
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• 2007.05a
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• pp.143-146
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• 2007

컴퓨터 네트워크에서 전송제어 프로토콜 상에서 다중시간 간격으로 혼잡제어의 지연을 피드백 루프의 시간간격을 조정하여 명시적 예측을 실행해 제어의 단점을 개선하는데 연구한다. 먼저 TCP의 모둘 형 확장에서 Tahoe, Reno, Vegas등 다양한 버전의 TCP에 적용되는 간단한 인터페이스를 통한 함수 호출을 정의하고, 이것이 성능을 크게 향상시는 것을 입증한다. 두 번째로, 광대역 WAN에서 지연-대역폭의 곱이 높을 경우 더욱 심각해지는 사후 제어의 불확실성 차이를 해소함으로써 MTS TCP가 기반 피드백 제어에 사전성을 부여한다는 것을 입증한다. 세번째는 트래픽 제어의 3가지 차원인, 즉 추적 능력, 연결 지속 기간, 공정성이 성능에 미치는 영향 등을 비교 분석하여 입증한다.

• Progress in Medical Physics
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• v.3 no.2
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• pp.67-81
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• 1992

Lots of physical phenomena which deteriorate the faithfulness of radiological images exist. The most common types of degradation are a loss of resolution and an increase in noise. This article deals with resolution. factors that influence it. and its characterisation. The problem of resolution failure due to a generic blurring phenomenum is described diagramatically and mathematically. for both one dimensional and two dimensional signals. The definition of the point spread function. the line spread function. the convolution integral and the modulation transfer function are made. The concept of frequency domain operations using the Fourier Transform is also discussed.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.290-293
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• 2013

본 연구에서는 최근 각광받고 있는 융합기술 중의 하나인 가시광 통신 기술을 개발하고 실제 시제품을 구현하기 위한 시스템 기술에 대해서 기술한다. 전 세계적으로 LED조명 시장이 급성장하고 있고 또한 이를 활용한 가시광통신(visible light communication:VLC) 기술이 화두가 되고 있다. 이에 따라서 본 논문에서는 현재 개발중인 LED기반 VLC 시스템 기술을 송신 및 수신 모듈로 분류하고 개별 모둘에 대한 구체적인 개발 시스템에 대해서 소자 및 주요 부품의 특성을 기반으로 제시한다. 또한 실제 개발된 시스템을 통해 약 0.5m 거리에서 약 12Mbps의 데이터 전송이 가능함을 보인다. 개발된 기술은 가정 내 또는 실내 주차장 등과 같이 실내 측위 또는 데이터 서비스 등에서 중요한 역할을 할 것으로 기대된다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.453-453
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• 2009

Wafer 태양전지와 Back sheet 및 기타 소재를 사용하는 기존의 Photovoltaic Module은 투과성이 존재하지 않으므로 본 논문에서는 태양전지 모듈의 투과특성을 발휘할 수 있는 Glass to Glass (GtG) Type의 Photovoltaic module에 대해 그 투과 특성 및 효율과의 관계를 분석하였다. 먼저 Module용 소재 중 Poly vinyl butyral (PVB) 및 Ethylene vinyl acetate(EVA) sheet의 Transmittance와 Haze 특성을 분석하였다. GtG 타입의 Photovoltaic Module은 약 90%정도의 투과율을 갖는 강화유리 및 Haze가 없는 PVB sheet를 사용하여 1m $\times$ 1m 크기로 제작하였다. GtG 타입으로 제조한 모둘 중 Cell 16EA를 사용한 모듈은 Cell 25EA를 사용한 모듈에 비해서 36% 투과율이 증가하였으나 효율 면에서 38%감소하였다. 최종적으로 GtG 타입 Module의 효율과 투과율에 관련된 식을 각각 정립하였다.

• Korean Institute of Interior Design Journal
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• v.19 no.5
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• pp.83-94
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• 2010

Conventionally, ornament has developed around linear thinking based on Euclidean geometry, and been explained as simple and lucid natural Euclidean geometrical phenomena. The modular arrangement with vertical, horizontal and diagonal grids has been an organizing principle of classical ornament, but in digital era ornament is found not to be explained only with the principle of traditional arrangement due to the seemingly irregular complex forms. In that sense, this study presents the concept of digital ornament and examined the backgrounds of ornament in digital age, that are complex system and non-Euclidean geometry. Accordingly, the present study takes an approach by dividing new formal types of ornament into algorithmic form, hybrid form and dynamic form to find out a principle of pattern organization. Lately, architects who actively use computer for their architectural designs take the algorithmic strategies in nature and create various and complex patterns by simple rules. The patterns are not the repetition of the same, but the production of singularities. In addition, hybrid form by morphing shows a topologically flexible evolutionary transformation, and is used to create in-between transitional shapes from the source to target. Finally, the patterns by the interaction between the system components which are corresponded to the embedded forces emerge from dynamic simulation of the natural environment. Rather than objects itself, focus is given to the process of generating forms, and the ornamental patterns as the revelation of such implicit order provide not just the formal beauty but also spatial pathways for lights and air, maximizing the effects of lights.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.11
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• pp.2739-2749
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• 1996

This aper introduces the multiple Neocognitron module approach for the effective target reognition. The Neocognitron which is designed to classify a pattern by extracting the local features from it, seems to be an unique method that can perform a pattern recognition using the neural networks. But due to its rigid structure, the Neocognitron must be reconstructed whenever there exists a variation on the number of classes. This is a quite difficult problem for the target recognition application that needs huge amount of computation and numerous classes to be classified. In this paper, we construct several smaller Necognitrom modules and train each module to adapt each class. After construction of the mulules, we integrate them in parallel so as to adaopt input at the same time and to produce each score that shold be matched to be learned class. This approach can reduce the sizes of the networks and is adaptive to the increase of classes as well as the authentic distortion, shift, scale variation and slight rotation invariant properties of general Neocognitron. This paper show the effectiveness of the proposed approach through some experience and performs analysis of the inhibitory interconnections in the architecture of the multiple module structure.

• Journal of The Korean Association of Information Education
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• v.16 no.3
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• pp.299-307
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• 2012

Even though there are many models for educational curriculum of giftedness for children, there is little model for educational methodology and curriculum of information science giftedness of children. A curriculum model for information science giftedness of children is proposed on this study. This model's characteristics is a modular integrated curriculum model combined the mathematics, natural science, and information science. Because there is no regular curriculums of information science at elementary school. this model is valided. Also, There is also need to train multiple areas in the field of information science to expose information science giftedness of the children, This model is to minimize the relationship between modules, and to maximize the cohesion in the each module. As for result of statistics analysis for 60 giftedness students during three years, we know the effectiveness of this model.

• The KIPS Transactions:PartC
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• v.11C no.2
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• pp.163-170
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• 2004

The additional mechanism Is required to set up a secure connection among the communication subjects in the internet environment. Each entity should transfer and receive the encrypted and hashed data to guarantee the data integrity. Also, the mutual authentication procedure should be processed using a secure communication protocol. The SSL/TLS is a protocol which creates the secure communication channel among the communication subjects and sends/receives a data. Although the OpenSSL which implements the TLS is using by many developers and its stability and performance are proved, it has a difficulty in using because of its large size. So, this Paper designs and implements the secure communication which the users can use easily by modification works of OpenSSL library API. We proved the real application results using the DRM client/server case which supports a secure communication using the implemented API.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.137-143
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• 2009

Through the development of techniques, robots are becomes smaller, and many of robots needed for application are greater and greater. Method of coordinating large number of autonomous robots through local interactions has becoming an important research issue in robot community. Swarm Robot System is a system that independent autonomous robots in the restricted environment infer their status from preassigned conditions and operate their jobs through the coorperation with each other. Within the SRS,a robot contains sensor part to percept the situation around them, communication part to exchange information, and actuator part to do a work. Specially, in order to cooperate with other robots, communicating with other robot is one of the essential elements. In such as Bluetooth has many adventages such as low power consumption, small size module package, and various standard procotols, it is rated as one of the efficent communcating system for autonomous robot is developed in this paper. and How to construct and what kind of procedure to develop the communicatry system for group behavior of the SRS under intelligent space is discussed in this paper.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.6
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• pp.558-567
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• 1997

Linear power amplifier modules with high-efficiency have been developed for PCS handy phone. These modules were designed using extracted large-signal models of MESFETs and harmonic balance simulation. The modules are intended for low-tier and high-tier at the operation frequency range of 1750 ~ 1780 MHz. For low-tier module, the output power and $IMD_3$ were 23.2 dBm and 31 dBc, respectively, at power-added efficiency of 34% with the supply drain bias of 3.6 V. For high-tier module, the output power and $IMD_3$ were 272.2 dBm and 31 dBc, respectively, at power-added efficiency of 33% with the supply drain bias of 4.2 V. These linear power amplifier modules are suitable for PCS handy phone.