• 전자공학회논문지A
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• 제32A권8호
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• pp.11-18
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• 1995

This paper proposes a nonlinear adaptive equalizer which is based on fuzzy rules and fuzzy inference of several affine mapping for the received channel data. The proposed nolonlinear adaptive equalizers with the significantly lower computational complexity. Also it can be applied to the on-line adaptation environments owing to its fast convergence characteristics and the lower computational load. When using the decision feedback vectors, this equaalizer can be easily realized in the form of the DFE structure with out the requirement for the perfect channel knowledge as in the case of the fuzzy adaptive filter.

• 대한전기학회논문지
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• 제35권12호
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• pp.573-578
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• 1986

The adaptive control of a plant in the presence of disturbance is considered. In sevral papers, it was shown that bounded disturbance made the basic adaptive scheme unstable. For achieving robust stability in adaptive control system in the presence of disturbance, the pureintegration in the adaptive law is limited by means of an additional feedback term. In this paper, the suggested adaptive control law has property that the output error converges to zero whether the disturbance exist or not, without the priori knowledge. The adaptive controller suggested assure the boundness of all signal in the overall system. Finally, computer simulation show the effectiveness of the suggested adaptive control law.

• 한국콘텐츠학회논문지
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• 제10권10호
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• pp.479-493
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• 2010

지식기반 환경의 변화와 더불어 이-러닝은 매우 보편화된 교수.학습 방법의 하나가 되었으며, 이와 관련한 여러 연구들이 진행되고 있다. 이-러닝의 주요 연구 분야 중의 하나는 학습자의 다양한 상황들을 반영하여 학습자 개개인의 특징에 맞게 학습내용을 지원하기 위한 적응형 학습 시스템에 관한 연구이다. 이와 관련하여 최근에는 적응적 학습내용을 보다 효과적으로 지원하기 위하여 온톨로지를 기반으로 한 적응형 학습 시스템에 대한 연구들이 활발히 진행되고 있다. 본 논문에서는 FCA의 개념 망을 기반으로 온톨로지의 접근 방법과 목적은 같이하지만, 특정 영역의 학습에 적합한 사용자가 보다 자유롭고 쉽게 자신의 적응형 학습 시스템을 구축하여 사용할 수 있는 적응형 학습 시스템을 설계하여 제안한다. 제안된 시스템은 학습영역에 존재하는 학습객체와 학습개념들 사이의 연관 관계에 따라 이들을 개념 망 구조 안에 자동으로 계층화한다. 또한 학습자의 지식수준, 학습선호도, 학습스타일 및 학습개념의 학습상태에 따라 개념 망 학습구조를 적응적으로 구성하여 제시한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.271-273
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• 2001

This paper presents a adaptive speed controller for field oriented controlled (FOC) permanent magnet synchronous motor (PMSM) drives. However, achieving FOC requires machine specific knowledge, and tracking of drifting motor parameters in order to maintain control. The proposed controller based on Minimum Controller Syntheses (MCS) algorithm does not require exact knowledge of motor parameters. This controller structure simplifies the design and implementation of the adaptive controller requiring less effort to synthesis than a standard MRAC system. Simulation results using Matlab/Simulink show that the proposed controller has good dynamic performances and it is insensitive to parameter variations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권1호
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• pp.287-304
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• 2012

Spectrum sensing is an important functionality for cognitive users to look for spectrum holes before taking transmission in dynamic spectrum access model. Unlike previous works that assume perfect knowledge of the SNR of the signal received from the primary user, in this paper we consider a realistic case where the SNR of the primary user's signal is unknown to both fusion center and cognitive radio terminals. A Kalman filter based adaptive Takagi and Sugeno's fuzzy system is designed to make the global spectrum sensing decision based on the observed energies from cognitive users. With the capacity of adapting system parameters, the fusion center can make a global sensing decision reliably without any requirement of channel state information, prior knowledge and prior probabilities of the primary user's signal. Numerical results prove that the sensing performance of the proposed scheme outperforms the performance of the equal gain combination based scheme, and matches the performance of the optimal soft combination scheme.

• 지식경영연구
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• 제7권2호
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• pp.53-68
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• 2006

Knowledge has become an important resource for organization. The manufacturing industry is usually operated on the basis of business processes, and most workers are familiar with their own processes. The process-based approach, therefore, can provide an efficient way to capture and navigate knowledge. In this study, we focus on knowledge which may be missed during knowledge transfer among workers. For this, we propose a method for analyzing knowledge flow, which is passed among business processes. We propose a process-based knowledge management framework for analyzing knowledge flow, which employs a two-phase analysis: process analysis and knowledge flow analysis. A knowledge flow model, represented by Knowledge Flow Diagram, is proposed as a tool for representing knowledge. We formulate several semantics for knowledge flow modeling. We build the three-level schema: conceptual, logical, and physical in order to automate the knowledge model adaptive to knowledge management systems. The proposed approach is verified and illustrated through a case study on the manufacturing process of A Company.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.7-12
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• 1993

This paper presents a generalized truncated least, squares adaptive algorithm and a two-stage design method. The proposed algorithm is directly derived from the normal equation of the generalized truncated least squares method (GTLSM). The special case of the GTLSM, the truncated least squares (TLS) adaptive algorithm, has a distinct features which includes the case of minimum steps estimator. This algorithm seemed to be best in the deterministic case. For real applications in the presence of disturbances, the GTLS adaptive algorithm is more effective. The two-stage design method proposed here combines the adaptive control system design with a conventional control design method and each can be treated independently. Using this method, the validity of the presented algorithms are examined by the simulation studies of an indirect adaptive control.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.101-106
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• 1997

This paper proposes a stable adaptive neural network control(NNC) for fixable joint manipulators. For designing the stable adaptive NNC, the flexible system dynamics is separated into fast and slow subdynamics according to singular perturbation concept. For the slow subdynamics, an adaptive NNC is designed to warrant the system stability and NN learning by lyapunov stability criterion. And to stabilize the fast dynamics, derivative control loop is installed. Through numerical simulation, the performance of the proposed NNC was compared to that of an adaptive controller designed based on the knowledge of the system dynamics. The proposed NNC shows much improvement over the conventional adaptive controller.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.185-189
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• 1987

The controller with robustness described in this paper is designed for processes with variable time-delays. This adaptive mechanism includes servo and stabilizing compensators. In the proposed multivariable controller. knowledge of the system time-delay is not required.

• Journal of Information Technology Applications and Management
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• 제18권1호
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• pp.15-39
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• 2011

A deeper understanding of how organizations behave as social complex adaptive systems is needed. In this paper we demonstrate how the Leadership Invigorating Flows of Energies model can help with this understanding. The model highlights the role of emergent leadership as a force encouraging the creation, diffusion, and utilization of knowledge through self-organizing mechanisms. We illustrate our approach by examining Wikipedia and show how it can be described as a social CAS. Our analysis of Wikipedia describes how emerging intrapreneurship behaviors result in dynamic flows of knowledge and self-organizing feedback mechanisms across the organization. We provide implications for organization studies and present evidence to support claims made by advocates of complexity theory. We conclude by proposing that Wikipedia can be seen as a new form of organization, and finish with a brief note highlighting a possible way forward.