• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.4A
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• pp.301-309
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• 2002

In this paper, we propose the effective implementation of various nonlinear combiners using by PS-LFSR: m-parallel memoryless-nonlinear combiner, m-parallel memory-nonlinear combiner, m-parallel nonlinear filter function, and m-parallel clock-controlled function. Finally, we propose m-parallel LILI-128 stream cipher as an example of the parallel implementation, and we determine its cryptographic security and performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.4
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• pp.859-867
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• 2010

In this paper, we propose some parallel structures of the word-based nonlinear combining functions in word-based stream cipher, high-speed versions of general (bit-based) nonlinear combining functions. Especially, we propose the high-speed structures of popular four kinds in word-based nonlinear combiners using by PS-WFSR (Parallel-Shifting or Parallel-Structured Word-based FSR): m-parallel word-based nonlinear combiner without memory, m-parallel word-based nonlinear combiner with memories, m-parallel word-based nonlinear filter function, and m-parallel word-based clock-controlled function. In addition, we propose an implementation example of the m-parallel word-based DRAGON stream cipher, and determine its cryptographic security and performance.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.377-380
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• 2008

본 논문은 시간 지연을 가지는 비선형 상호 결합 시스템에 대한 분산 퍼지 출력 궤환 제어기를 제시한다. Takagi-Sugeno (T-S) 퍼지 모델링을 통하여 비선형 상호 결합 시스템을 퍼지 모델로 표현한다. 상호 결합 시스템의 하위 퍼지 시스템을 안정화 시킬수 있는 분산 출력 궤한 제어기를 설계한다. 폐루프 하위 시스템들의 안정도 조건을 선형 행렬 부등식으로 나태내고, 부등식을 이용하여 제어기의 이득값을 구한다. 모의실험을 통하여 시간 지연이 있는 비선형 상호 결합 시스템에 대한 분산 퍼지 출력 궤한 제어기의 효용성을 평가한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.383-386
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• 2009

In this paper, we propose some parallel structures of the word-based nonlinear combine functions in word-based stream cipher, high-speed versions of general (bit-based) nonlinear combine functions. Especially, we propose the high-speed structures of popular three kinds in word-based nonlinear combiners using by PS-WFSR (Parallel-Shifting or Parallel-Structured Word-based FSR): m-parallel word-based nonlinear combiner without memory, m-parallel word-based nonlinear combiner with memories, and m-parallel word-based nonlinear filter function. Finally, we analyze its cryptographic security and performance.

• Journal of the Korean Institute of Intelligent Systems
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• v.27 no.1
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• pp.15-21
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• 2017

In this paper, the decentralized fuzzy observer design technique is presented for discrete-time nonlinear interconnected systems, which are assumed to be with unknown interconnections. To design the decentralized fuzzy observer, the design problem is considered and the performance function is defined to solve the design problem. Based on the performance function, the sufficient condition is derived for the observer design, and its condition is formulated into linear matrix inequalities. Finally, by the simulation result, the validity of the proposed observer design technique is shown.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 1994.11a
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• pp.132-156
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• 1994

본 논문에서는 비선형 합성 함수를 이용하여 생성된 난수 계열의 특성을 분석한다. 먼저 트레이스 함수 등을 정의하고, 선형 복잡도 및 생성기 구조 분석시 요구되는 관련 이론을 도출하고, 특정 난수 계열이 주어진 경우 이계열을 생성할 수 있는 최소 길이의 LFSR을 합성할 수 있는 USR 합성 알고리듬을 제시한다. 동일한 계열을 위상 천이한 계열간의 비선형 결합으로 생성된 난수 계열과 다른 계열간의 비선형 결합으로 생성된 난수 계열에 대한 주기 및 선형 복잡도 등의 특성을 분석하고 생성기의 구조를 제시한다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.48-51
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• 2007

본 논문에서는 비선형 상호 결합 시스템의 출력 궤환 제어기 설계에 대해서 연구한다. 먼저 퍼지 모델 기법을 이용하여 비선형 상호 연결된 시스템을 Takagi-Sugeno (T-S) 퍼지 모델로 모델링한다. 그 각각의 하위 시스템에 대한 출력 궤한 제어기를 동적 병렬 분산 보상 (DPDC) 기법을 이용하여 퍼지 출력 궤환 제어기로 설계한다. 하위 시스템들의 평형점이 안정화 되는 선형 행렬 부등식 (LMI)를 구하고, 그 부등식을 만족하는 값들로부터 하위 시스템의 제어기 이득을 구한다.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2001.05a
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• pp.77-83
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• 2001

In recent years, the AES in North America and the NESSIE project in Europe have been in progress. Six proposals have been submitted to the NESSIE project including the LILI-128 by Simpson in Australia in the synchronous stream cipher category. These proposals tend towards a design with parallelism of the algorithms in order to facilitate speed-up. In this paper, we consider the PS-LFSR and propose the effective implementation of various nonlinear combiners: memoryless-nonlinear combiner, memory-nonlinear combiner, nonlinear filter function, and clock-controlled function. Finally, we propose m-parallel SUM-BSG and LILI-l28's parallel implementation as examples, and we determine their securities and performances.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.1
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• pp.91-96
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• 2012

Recently, the research of security and its related problems has been received great interested. The research for hper-chaos systems and its synchronization are actively processing as one of method to apply to secure and cryptography communication. In this paper, we propose the synchronization method by coupling coefficient of linear and nonlinear in order to accomplish the synchronization of hyper-chaos system that organized by SC-CNN(State-Controlled Cellular Neural Network). We also verify and confirm the result of synchronization between entire transmitter and receiver, and each subsystem in transmitter and receiver through the phase portrait and difference of time-series by the computer simulation.

• Korean Journal of Optics and Photonics
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• v.10 no.6
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• pp.487-493
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• 1999

In this paper, we studied the characteristics of a soliton coupler using a bent nonlinear waveguide. The bent soliton coupler has very ,harp switching characteristic like the conventional soliton coupler due to the threshold effect of soliton emi,sion from the nonlinear waveguide. By using the bent structure, we can reduce the threshold power for the soliton emission. We consider the saturation effect of nonlinearity and the loss in the medium for more accurate and practical numerical analysis in wave propagation through the bent soliton coupler. The simulation results show that the consideration of the saturation effect and the ]os~ may be very important in the analyses and design of the nonlinear waveguide devices. The bent structure is useful for the emission of the spatial soliton with the low threshold power, when we consider the saturation and the loss effect. ffect.