• Title/Summary/Keyword: systems-theory

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Development of Vision Based Steering System for Unmanned Vehicle Using Robust Control

  • Jeong, Seung-Gweon;Lee, Chun-Han;Park, Gun-Hong;Shin, Taek-Young;Kim, Ji-Han;Lee, Man-Hyung
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1700-1705
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    • 2003
  • In this paper, the automatic steering system for unmanned vehicle was developed. The vision system is used for the lane detection system. This paper defines two modes for detecting lanes on a road. First is searching mode and the other is recognition mode. We use inverse perspective transform and a linear approximation filter for accurate lane detections. The PD control theory is used for the design of the controller to compare with $H_{\infty}$ control theory. The $H_{\infty}$ control theory is used for the design of the controller to reduce the disturbance. The performance of the PD controller and $H_{\infty}$ controller is compared in simulations and tests. The PD controller is easy to tune in the test site. The $H_{\infty}$ controller is robust for the disturbances in the test results.

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A study on process-plan selection via multiple attribute decision-making approach and fuzzy quantification theory (다속성 의사결정법과 퍼지정량화 이론을 이용한 공정계획 선택에 관한 연구)

  • Leem, Choon-Woo;Lee, Noh-Sung
    • Journal of Institute of Control, Robotics and Systems
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    • v.3 no.5
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    • pp.490-496
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    • 1997
  • This paper describes a new process-plan selection method using a modified Fuzzy Quantification Theory(FQT). The problem of process-plan selection can be characterized by multiple attributes and used subjective, uncertain information. Fuzzy Quantification Theory is used for handling such information because it is a useful tool when human judgment or evaluation is quantified via linguistic variables, and the proposed method is concerned with the selection of a process plan by derivation of the values of categories for each attribute. In this paper, a modified Fuzzy Quantification Theory(FQT) is described and the procedure of this approach is explained and examples illustrated.

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An Integrated Computer Security Model Based on the General Trust Theory (신뢰성이론을 바탕으로 한 통합 컴퓨터 보안 모형에 관한 연구)

  • Lee, Sang-Gun;Yoo, Sang-Jin
    • Asia pacific journal of information systems
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    • v.12 no.1
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    • pp.123-138
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    • 2002
  • For the last two decades, there has been much research on computer abuse from the perspective of the general deterrence theory based on objectism, which covers security policy, security awareness programs, and physical security system. The traditional view offered by the general deterrence theory indicates that security policy, security awareness, and security system play a major role in preventing computer abuse. In spite of continuous organizational efforts and investments based on these systematic factors, the incidence of computer abuse in organizations is still rapidly increasing. This paper proposes another perspective-the social control theory based on subjectism-in preventing computer abuse. According to the social control theory, organizational trust, which comprises organizational attachment, commitment, involvement and norms, can prevent computer abuse by reducing insider's computer abuse. The aim of this article is to assess the role of organizational trust come from attachment, commitment, involvement, norms in preventing computer abuse. The results indicate that both organizational trust and deterrent factors are effective in preventing computer abuse.

A Coherent Model in Upholding General Deterrence Theory and Impact to Information Security Management

  • Choi, Myeong-Gil;Ramos, Edwin R.;Kim, Man-Sig;Kim, Jin-Soo;Whang, Jae-Hoon;Kim, Ki-Joo
    • Journal of Information Technology Applications and Management
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    • v.16 no.3
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    • pp.73-86
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    • 2009
  • To establish an effective security strategy, business enterprises need a security benchmarking tool. The strategy helps to lessen an impact and a damage in any threat. This study analyses many aspects of information security management and suggests a way to deal with security investments by considering important factors that affect security manager's decision. To address the different threats resulting from a major cause of accidents inside an enterprise, we investigate an approach that followed ISO17799. We unfold a criminology theory that has designated many measures against the threat as suggested by General Deterrence Theory. The study proposes a coherent model of the theory to improve the security measures especially in handling and protecting company assets and human lives as well.

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Knowledge Management Research Based on Social Network Theories: A Review with Future Directions

  • Tae Hun Kim
    • Asia pacific journal of information systems
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    • v.32 no.1
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    • pp.168-190
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    • 2022
  • This review aims to synthesize social network theories by drawing on the importance of social network perspectives in understanding knowledge management with technology in organizations. I provide an overview of prior social network research with the following core ideas: the primacy of relations between organizational actors, the utility of actors' embeddedness in social fields, the social utility of network connections, and the structural patterning of social life. On top of that, I summarize critical social perspectives (the social capital theory, the structural hole theory, the embeddedness perspective, the social exchange theory, the organizational learning theory, and the innovation diffusion theory) to suggest potential research questions for future studies in social network research in the knowledge management discipline.

Operations on Generalized Intuitionistic Fuzzy Soft Sets

  • Park, Jin-Han
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.11 no.3
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    • pp.184-189
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    • 2011
  • Generalized intuitionistic fuzzy soft set theory, proposed by Park et al. [Journal of Korean Institute of Intelligent Systems 21(3) (2011) 389-394], has been regarded as an effective mathematical tool to deal with uncertainties. In this paper, we prove that certain De Margan's law hold in generalized intuitionistic fuzzy soft set theory with respect to union and intersection operations on generalized intuitionistic fuzzy soft sets. We discuss the basic properties of operations on generalized intuitionistic fuzzy soft sets such as necessity and possibility. Moreover, we illustrate their interconnections between each other.

Time-optimal multistage controllers from the theory of dynamical cell-to-cell mappings

  • Yoon, Joong-Sun
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.118-123
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    • 1989
  • This work deals with fast-to-compute global control laws for time-optimal motion of strongly nonlinear dynamic systems like resolute robots. the theory of cell-to-cell mappings for dynamical systems offer the possibility of doing the vast majority of the control law computation offline in case of time optimization with constrained inputs. These cells result from a coarse discretization of likely swaths of state space into a set of nonuniform, contiguous volumes of relatively simple shapes. Once the cells have been designed, the bang-bang schedules for the inputs are determined for all likely starting cells and terminating cells. the resulting control law is an open-loop optimal control law with feedback monitoring and correction.

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Robust Adaptive Control for a Sort of Uncertain Systems (일련의 불확실한 시스템에 대한 강인한 적응제어)

  • 김진환;이정휴;함운철
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.30B no.3
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    • pp.22-30
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    • 1993
  • In this paper, robust adaptive control algorithms which can be applied to unknown uncertain systems are suggested. Transform matrix for dividing states into "uncontrolled" states and "controlled" states and general searching procedure for the transform matrix which assign arbitrary n-1 eigen values for the uncontrolled subsystem of n-th orther single-input single-output systems of which state variables can be observable are also studied and utilized for the design of new-type controllers. We drived new-type control laws by using adaptive control theory and variable structure system and its stability is proved by using Lyapunov stability theory.

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Fuzziness in Radiation Protection and Nuclear Safety (Human Factors and Reliability)

  • Nishiwaki, Yasushi
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.1047-1050
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    • 1993
  • In radiation protection and nuclear safety, there are many uncertainties or fuzziness due to subjective human judgement. It is desirable to have a theory by which both non-probabilistic uncertainties, or fuzziness, of human factors and the probabilistic properties of machines can be treated consistently. Fuzzy set theory seems to be an effective tool for analyzing the risk and safety of complex man-machine systems such as nuclear power plants.

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