• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.1197-1202
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• 2001

Near-field acoustic holography is a powerful tool to visualize sound sources. This method requires pressure measurement at many points for a good hologram. Thus one has to measure carefully so that errors due to the uncertainty of position, sensor mismatch, and so on are reduced. A method to solve this problem is to use a well-designed measurement system. This paper introduces a sound visualization system at center for noise and vibration control (NOVIC), KAIST, and addresses the advantages in terms of the error reduction. The system consists of array microphones, array jigs, a system to control the position and the velocity of the jigs, a data acquisition system, and a monitoring system. This paper also shows some sound visualization results when the system is applied to a speaker and a computer. The results verifies that the sound visualization system is useful for identifying sound sources.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.1
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• pp.1-9
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• 1998

This paper is focussed on the problem of robustly stabilizing a transformable linear time-varying system. The considered system is a class of state feedback transformable linear systems. First, the real linear time-varying system is transformed into the linear time invariant system composed with the time-invariant linear part and the time-varying uncertainty part. Second, the solution to a quadratic stabilization problem in the transformed linear system is give via' Lyapunov methods. Then this solution is used to construct a stabilizing linear control law for the real linear time-varying system.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.11
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• pp.453-462
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• 2006

This paper evaluates the reliability of KEPCO system using TRELSS, which is a probabilistic reliability evaluation program for large-scaled power system. In order to reflect the characteristic of KEPCO system, the sensitivity of reliability indices such as LOLP, EDLC, EENS and Energy Curtailment for variations of TRELSS parameter and input data was analyzed. Additionally, probabilistic reliability of KEPCO system reflecting sensitivity analysis results was systematically evaluated and simulated. Finally, maximum acceptable FOR of KEPCO system to satisfy reliability criterion, which meet in process of establishing the basic plan for long-term electricity supply and demand is suggested.

• Journal of the Korean Society of Safety
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• v.12 no.2
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• pp.70-79
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• 1997

This paper presents a study on the fuzzy linguistic variable based approach for safety assessment of human body in ELF electromagnetic field considering power system states. To cope with the demand in modern industry, the power system becomes larger in scale, higher in voltage. The advent of high voltage system has increased the relative importance of field effects. The analysis of ELF electromagnetic field based on Quasi-Static Method is introduced while the power system is included to model the expected and/or unexpected uncertainty caused by the load fluctuation and parameter changes. In order to analyze the power system, Monte Carlo simulation method and contingency analysis method are adopted in normal state and alert state, respectively. In the safety assessment of human body, the approach based on fuzzy linguistic variable is employed to overcome the shortcomings resulting from a crisp set concept. The suggested scheme is applied to a sample system(modified IEEE 14 bus system) to validate the usefulness.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.08a
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• pp.119-123
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• 2000

In this paper, authors introduce about Wide Range Vessel Traffic Service (VTS) system using Automatic Identification System (AIS). In order to develop the prototype of Wide Range VIS system, Korean satellite is used for data communication system for AIS. In this system, ship position obtained by using GPS is reported automatically to VTS center through Korean satellite. By using this system, VTS center can cover more wide area than the case using radar only. And the uncertainty of information is decrease. The results of test show the good possibility of VTS using satellite and AIS.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.1
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• pp.63-70
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• 1994

This paper presents manufacturing and evaluation of a non-contact rotational torque measurement system which consists of torque cell, telemeter system, transmitter and receiver coil, transmitter, receiver and telemeter indicator. Static calibration test results show that the system has a maximum uncertaintry of 05% or less. A standar calibration system for rotational torque is used to evaluate the measurement system, As a result, the maximum uncertainty for measuring rotational torque by this system is 2% or less. We may conclude that the measurement system is sufficient to measure rotational torque of shaft in industry.

• The Research Journal of the Costume Culture
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• v.6 no.4
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• pp.149-161
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• 1998

The purpose of this study was to present the effective activation of apparel CAD system and for this, the investigation of actual condition of CAD using companies and comparative inspection with the advanced study were carefully considered. The results were as follows : 1. The investigation result of the system using enterprises is that the direct effect from the operation of the CAD system after its introduction was the promptness, ad the indirect effect of it was the growth of operation level and operating reliance. 2. The problem originated from the system was the uncertainty of employer effectiveness and the financing source for it when introduced, and the lack of consciousness of it when operated. 3. The using level in pattern manufacturing function was lower than that in grading and marking. Therefore, as the full automation in CAD system is a part of CIM construction and the direction to which apparel companies should go, a firmly connected system between management & the persons in charge in apparel companies, facility supplying companies, universities & other educational institutes, and the Government should be duly constructed first of all n order to achieve this aim.

• Journal of Korea Multimedia Society
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• v.13 no.6
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• pp.890-900
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• 2010

The Bayesian networks methods provide an efficient tool for performing information fusion and decision making under conditions of uncertainty. This paper proposes Bayes estimators for the system effectiveness in energy saving of the wireless sensor networks by use of the Bayesian method under the non-informative prior knowledge about means of active and sleep times based on time frames of sensor nodes in a wireless sensor network. And then, we conduct a case study on some Bayesian estimation models for the system energy saving effectiveness of a wireless sensor network, and evaluate and compare the performance of proposed Bayesian estimates of the system effectiveness in energy saving of the wireless sensor network. In the case study, we have recognized that the proposed Bayesian system energy saving effectiveness estimators are excellent to adapt in evaluation of energy efficiency using non-informative prior knowledge from previous experience with robustness according to given values of parameters.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.256-263
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• 1993

The integration of deburring robots into product quality and productivity impact the industrial. In this paper the intelligent system of robotic deburring is proposed integrated with robot system, image processing system, force sensor system and host PC. The size, position, recognition of burr is determined by the information that the image processing system processed. The feed velocity of cutting tool is controlled by the information that the force sensor system processed. The integration of these information can remove the uncertainty of the information of deburring on the cutting path. The result of these technologies is useful for the development of the factory automation and automatic inspection equipments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.5
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• pp.950-960
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• 2010

In this paper, a multi-input multi-output(MIMO) integral variable structure system with an integral-augmented sliding surface is designed for the improved robust control of uncertain multivariable system under the matched persistent disturbance. To effectively remove the reaching phase problems, the integral augmented sliding surface is proposed. Then for its design, the eigenstructure assignment technique is introduced to. To guarantee the designed performance against the persistent disturbance, the stabilizing control for multi-input system is also designed to generate the sliding mode on the integral sliding surface. The stability of the global system together with the existence condition of the sliding mode are investigated and proved for the case of multi input system in the presence of uncertainty and disturbance. The reaching phase is completely removed in proposed MIMO VSS by satisfying the two requirements. An example and computer simulations will be present for showing the usefulness of algorithm.