• Transactions on Control, Automation and Systems Engineering
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• v.1 no.2
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• pp.99-105
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• 1999

This paper presents a fuzzy H$\infty$ filtering problem for a class of uncertain nonlinear systems with time-varying delayed states and unknown inital state on the basis of Takagi-Sugeno(T-S) fuzzy model. The nonlinear systems are represented by T-S fuzzy models, and the fuzzy control systems utilize the concept of the so-called parallel distributed compensation. Using a single quadraic Lyapunov function, the stability and L2 gain performance from the noise signals to the estimation error are discussed. Sufficient conditions for the existence of fuzzy H$\infty$ filters are given in terms of linear matrix inequalities (LMIs). The filtering gains can also be directly obtained from the solutions of LMIs.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1840-1845
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• 2005

The SoC and digital technology development recently enabled the emergence of information devices and control devices because the SoC present many advantages such as lower power consumption, greater reliability, and lower cost. It is required to use an embedded operating system for building control systems. So far, the Real-Time operating system is widely used to implement a Real-Time system since it meets developer's requirements. However, Real-Time operating systems reveal a lack of standards, expensive development, and license costs. Embedded Linux is able to overcome these disadvantages. In this paper, the implementation of control system platform using Real-Time Embedded Linux is described. As a control system platform, we use XScale of a Soc and build Real-Time control platform using RTAI and Real-Time device driver. Finally, we address the feasibility study of the Real-Time Embedded Linux as a Real-Time operating system for mobile robots.

• Journal of the Korean Institute of Intelligent Systems
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• v.7 no.1
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• pp.5-15
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• 1997

This paper mentions a fault tree analysis using not probability but natural language and fuzzy theory, Reliability estimate of each basic event and dependence level estimate among subsystems are expressed by linguistic terms. Analysis results are also expressed by natural language. The meaning of linguistic terms is expressed by a fuzzy set. In the presented analysis approach parametrized operations of fuzzy sets are considered so that analyst's subjectivity can be introduced into the analysis. This paper gives the Chernobyl accident as an example of the fuzzy fault tree analysis using linguistic terms.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.4
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• pp.336-345
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• 1996

The S.O(synchronous osillator) oscillates at its natural frequency without the externa applied signal. But if the external signal is applied, the S.O starts to track the external frequency which can be sinusoidal, pulsed or some other waveform. Thus, the output is synchronized with the wide range of tracking bandwidth to the external frequency. Specifically, the S.O also posses frequency division and multiplication capability. All of these indicate that the S.O can overcome the difficulties of syschronization in coherent digital communication systems. This papers proposed application of DS/SS communication with study on the synchronous properties of S.O.

• Journal of the Korean Society of Systems Engineering
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• v.17 no.1
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• pp.43-52
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• 2021

The aim of this study is to propose the design suitable for sustainability evaluation model of the mobile industry considering system process (SEP). Although a quantitative evaluation was conducted on the link between the national sustainability report and the mobile industry, it was confirmed that it was difficult to identify stakeholders. So it is necessary to develop the design process suitable for the more operator-specific interfaces. The Human System Integration (HSI) methodology was proposed through linkage with work domain analysis. Agile methodology and Resilience engineering methodology were added for sustainable model design. The proposed sustainability system evaluation model is applied so that it can be easily used in all industries.

• International Journal of Contents
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• v.14 no.3
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• pp.17-26
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• 2018

To ensure safety of bridges, it is critical to inspect and assess physical and functional conditions regularly. Presently, most highway bridges in the U.S. are inspected visually. However, this method of inspection is often influenced by the bridge inspector's knowledge and experience. So, reliability and accuracy of inspection results may be problematic. To solve such problems, an extensive number of robotics systems and image processing techniques for bridge inspection methods have been proposed. These robotics systems and image processing techniques are used to measure various bridge conditions, such as apparent damage, displacement and dynamic characteristics. This paper provides a comprehensive review of robotics systems and image processing technologies used in bridge inspection.

• Journal of the Korean Society of Systems Engineering
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• v.1 no.1
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• pp.26-31
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• 2005

In order to care about preserving the environment for future generations, each country has been required to make the laws of the environment. So manufacturers must design, manufacture and sell goods that meet customer's need and must do this while meeting the needs of the environment. In this research we have developed product structure and configuration management system that treats electronic catalogs for recycling of train parts. This research focused on two system. One is JAVA-based electronic catalog that give the information about recycling of train parts. The other is product structure and configuration management system based on electronic catalog and Bill of Materials(B.O.M).

• International Journal of Control, Automation, and Systems
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• v.1 no.1
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• pp.68-75
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• 2003

This paper presents an effective trajectory planning algorithm for industrial robot manipulators. Given the end-effector trajectory in Cartesian space, together with the relevant constraints and task specifications, the proposed method is capable of planning the optimum end-effector trajectory. The proposed trajectory planning algorithm considers the joint acceleration limit, end-effector velocity limits, and trajectory allowance. A feedforward compensator is also incorporated in the proposed algorithm to counteract the delay in joint dynamics. The algorithm is carefully designed so that it can be directly adopted with the existing industrial manipulators. The proposed algorithm can be easily programmed for various tasks given the specifications and constraints. A three-dimensional test trajectory was planned with the proposed algorithm and tested with the Performer MK3s industrial manipulator. The results verified effective manipulator performance within the constraints.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.5
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• pp.602-611
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• 2015

Even though GNSS provides highly accurate navigation information all over the world, it is vulnerable to jamming in the electronic warfare due to its weak signal power. The United States and Korea have plans to use terrestrial navigation systems as back-up systems during outage of GNSS. In order to develop back-up systems of GNSS, an M&S software platform is necessary for performance evaluation of various vehicle trajectories and integrated navigation systems. In this paper a design method of an M&S software is proposed for evaluation of multiple radio positioning integration systems. The proposed M&S software consists of a navigation environment generation part, a navigation algorithm part, a GUI part and a coverage analysis part. Effectiveness of the proposed design method is shown by implementing an M&S software for the GPS, DME and eLoran navigation systems.

• Steel and Composite Structures
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• v.4 no.4
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• pp.317-331
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• 2004

The lateral sway of a multi-storey steel frame should be limited so as to ensure the comfort of the occupants and for the protection of mechanical and architectural systems. This paper investigates the applicability of Schueller's equation for predicting sway of rigid steel frames, and proposes a number of modifications to the equation so that it can produce results that are almost identical to those given by accurate Finite Element (FE) analysis. The behaviour of irregular steel frames has also been studied and proposals are made so that Schueller's Equation can also be used to predict sway of such frames.