• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 춘계종합학술대회
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• pp.769-772
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• 2007

Quantum cryptography is considered as a promising solution towards absolute security in long term cryptosystems. While the application of quantum cryptography in fiber networks has significant advances, research on the application of quantum cryptography in mobile networks is still prematures. In this paper, we analyses the interests of using quantum technique.

• 응용통계연구
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• 제15권2호
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• pp.433-448
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• 2002

탐색적 자료분석에서는 자료를 통계적 모형에 바로 적합시키기 보다 자료를 있는 그대로 보려는 데 중점을 두므로 현시성을 강조한다. 따라서, 다양한 그래프가 사용되는데. 본 논문에서는 이러한 그래프들을 이용하여 탐색적 자료분석의 몇 가지 유용한 사례들을 보이고자 한다.

• ETRI Journal
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• 제35권3호
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• pp.448-458
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• 2013

This paper presents a generalized post-processing technique for enhancing the pseudorandomness of digital chaotic oscillators through a nonlinear XOR-based operation with rotation and feedback. The technique allows full utilization of the chaotic output as pseudorandom number generators and improves throughput without a significant area penalty. Digital design of a third-order chaotic system with maximum function nonlinearity is presented with verified chaotic dynamics. The proposed post-processing technique eliminates statistical degradation in all output bits, thus maximizing throughput compared to other processing techniques. Furthermore, the technique is applied to several fully digital chaotic oscillators with performance surpassing previously reported systems in the literature. The enhancement in the randomness is further examined in a simple image encryption application resulting in a better security performance. The system is verified through experiment on a Xilinx Virtex 4 FPGA with throughput up to 15.44 Gbit/s and logic utilization less than 0.84% for 32-bit implementations.

• 한국정보전자통신기술학회논문지
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• 제9권5호
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• pp.445-450
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• 2016

In this paper we study the effect of chaos in nonuniform instability with optical fiber based IoT networks. The transient response of optically controlled fiber has also described. Nonlinear optical fiber effects especially fiber scattering in networks has emerged as the essential means active optical devices. The paradigm instability in fiber Internet serves as a test for fundamental study of chaos and its suppression and exploitation in practical application in optical communication. This paper attempts to present a survey and some of our research findings on the nature of chaotic effect on Internet based optical communication. The transient response in optical fiber has been evaluated theoretically by calculating the variation of the scattering function. The lines has used under open ended termination containing optically induced region. The scattered optical waves in a fiber used in optic communications are temporally unstable above certain threshold intensity.

• KIEE International Transactions on Electrophysics and Applications
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• 제11C권2호
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• pp.6-11
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• 2001

Abstract- In this paper, a new Partial Discharge (PD) detection using Pockels cell was proposed and considerable apparent chaotic characteristics were discussed. For this purpose, PD was generated from needle-plane electrode in air and detecte by optical measuring system using Pockels cell, based on Mach-Zehner interferometer, consisting of He-Ne laser, single mode optical fiber, 50/50 beam splitter and photo detector. In addition, the presence of chaos of the PD signals has been investigated by examining their means of qualitative and quantitative information. For the former, return map and 3-dimensional strange attractor have been drawn in order to investigate the presence of chaotic characteristics relevant to PD signals, detected through CT and Peckels sensor respectively, in the normalized time series. The presence of strange attractor indicates the existence of fractal structures in it's phase space. For the latter, several dimension values of strange attractor were verified sequentially. Throughout this paper, it is likely that the chaotic characteristics regarding the PD signals under air are verified.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.2000-2003
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• 2002

In this paper, an IC chip of a cell- network type circuit constructed with 1-dimensional chaos circuits is reported. The circuit, is designed by sing switched-current (Sl) techniques. In the proposed circuit, by controlling connections of cells, an S- dimensional circuit (S ＝ 1, 2, 3,…) and a synchronization system can be constructed easily. Furthermore, in spite of faults of a few cells, the circuit can reconstruct above-mentioned systems only to change connections of cells. This feature will open up new vista for engineering applications which are used in a distance place such as space, deep sea, etc. since it is difficult to repair faults of these application systems. To investigate the characteristics of the circuit, SPICE simulations are performed. The VLSI chip is fabricated from the layout design using a CAD tool, MAGIC. The proposed circuit is integrable by a standard 1.2 $\mu\textrm{m}$ CMOS technology.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.567-570
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• 2003

Fractal mathematics is being highlighted as a research method for classification of image. But the application of Fractal dimension(FD) has been required the complicated calculation method because of its complex repetition progressing. In this paper, it has been developed the new approach method to express the Fractal Dimension(FD) for aging level calculation and estimation system of outside insulator using special image processing algorithm. As a result after FD testing, the recognized aging estimation of FD has a very characteristics compared to the conventional visual inspection.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.124-131
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• 2000

In this study, the NEURAL NETWORK (hereinafter referred to as NN) was applied to control of the nonlinear factors for turning movement of the crawler vehicle and experiment was carried out using a small model of crawler vehicle in order to inspect an application of NN. Furthermore, CHAOS NEURAL NETWORK (hereinafter referred to as CNN) was also applied to this control so as to compare with conventional NN. CNN is especially effective for plane in many variables with local minimum which conventional NN is apt to fall into, and it is relatively useful to nonlinear factors. Experiment of turning on the slope of crawler vehicle was performed in order to estimate an adaptability of nonlinear problems by NN and CNN. The inclination angles of the road surface which the vehicles travel on, were respectively 4deg, 8deg, 12deg. These field conditions were selected by the object for changing nonlinear magnitude in turning phenomenon of vehicle. Learning of NN and CNN was carried out by referring to positioning data obtained from measurement at every 15deg in turning. After learning, the sampling data at every 15deg were interpolated based on the constructed learning system of NN and CNN. Learning and simulation programs of NN and CNN were made by C language ("Association of research for algorithm of calculating machine (1992)"). As a result, conventional NN and CNN were available for interpolation of sampling data. Moreover, when nonlinear intensity is not so large under the field condition of small slope, interpolation performance of CNN was a little not so better than NN. However, when nonlinear intensity is large under the field condition of large slope, interpolation performance of CNN was relatively better than NN.

• 한국산업정보학회논문지
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• 제11권1호
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• pp.29-37
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• 2006

오늘날 컴퓨터 네트워크의 발전과 휴대통신의 광범위한 보급으로 연예 오락, 영상 문화콘텐츠, 전자상거래 또는 의료분야에 이르기 까지 멀티미디어 자료의 응용은 매우 중요한 위치를 차지하고 있다. 그러나 실제 이들 자료들이 발달된 통신망을 통하여 효율적으로 전파, 활용되기 위해서는 무엇보다도 이들을 저장하거나 전송하는 과정에서 충분한 안정성이 전제되어야 할 것이다. 이를 위하여 오늘날 많은 암호화 방법들이 개발되어 응용되고 있다. 그러나 대부분 원문에 대한 자료를 텍스트에 기반으로 하게 됨으로, 영상과 같이 자료의 양이 방대하고 실시간 처리하는데 제약이 존재하는 멀티미디어 자료에 직접 적용하기는 문제점이 많다. 이에 본 논문에서는 먼저 복잡성과 초기 조건에 대한 민감성 등 카오스적 특성을 지닌 Logistic 함수를 이용한 암호화 기법을 도입하고 다음으로 비트평면상에서 Boolean 행렬의 기본 연산을 이용한 대수적 암호화 알고리즘을 수행함으로써 효과적인 영상 암호화 방법을 제시하였다.

• 한국컴퓨터정보학회논문지
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• 제18권3호
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• pp.97-105
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• 2013

재난으로 인해 초토화 상황이 발생하면 전기 단절로 기지국을 이용하는 통신 수단이 두절된다. 공공 안전 및 재난 구조 전파 통신 표준 관련 시스템을 사용하기 위해서 사용자는 전용 장비를 사용해야 하고, 운영을 위한 전문 지식이 필요하다. 또한, 인프라를 구축하기 위한 막대한 투자비용이 드는 단점을 가지고 있다. 이는 재난 상황에서 신속하고 효율적인 재난 통신으로는 부족하며, 국가 자원이 투입되긴 전 국민들에게 큰 혼란이 발생할 수 있다. 이 문제를 해결하기 위해 본 논문에서는 일반인도 바로 사용할 수 있는 모바일 응용의 설계를 제안하고, 개념 증명을 위해 이를 안드로이드 폰 응용으로 구현한다.