• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.157-159
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• 2023

In order to promote the historicity of Eoryongdo Lighthouse, which was designated as a lighthouse cultural heritage in August 2023, and to utilize it as a water-friendly space, the facilities were improved to maintain the function of the lighthouse smoothly, and the buildings were reinforced to utilize it as a water-friendly space. We want to inform the public of the historical value of the lighthouse and make every effort to ensure maritime traffic safety, which is the original role of the lighthouse.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.1
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• pp.1226-1230
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• 2001

Multi-target tracking systems need to tracking several targets simultaneously. To track a target among the measurements of several targets, data association is needed. In this paper, a method using the cou-pled confidence region of predicted target position is proposed. The proposed method shows good performance in simulations of multi-target tracking systems.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1758-1763
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• 2004

This paper focuses on congestion control for ATM network with uncertain time-variant delays. The time-variant delays can be distinguished into two distinct components. The first one is represented by time-variant queueing delays in the intermediate switches that are occurred in the return paths of RM cells. The next one is a forward path delay. It is solved by the VBR model which quantifies the data propagation from the sources to the switch. Robust $H_8$ control is studied for solving congestion problem with norm-bounded time-varying uncertain parameters. The suitable robust $H_8$ controller is obtained from the solution of a convex optimization problem through LMI technique.

• Journal of Power System Engineering
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• v.21 no.1
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• pp.24-29
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• 2017

Studies in liquid-vapor ejector, which performs a great efficiency in refrigeration cycle is highly concerned. This paper is based on basic refrigeration cycle and three ejector refrigeration cycles and the comparison and contrasts about when 6 different refrigerants are applied to such refrigeration cycles. All cycles had a percentage increase of COP from 4 to 74% when ejector was applied, and the source of increasement was the decrease of total work done due to ejector's pressure recovery function. When R-245fa is applied to cycle (d), results showed that COP was the most superior in such cycle, R-245fa showed high volume entrainment ratio in all cycles. Future studies in refrigeration cycles will require more knowledge and experiments on ejector's appliance to refrigeration cycles and the actuation of such functions.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.1
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• pp.30-36
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• 2009

Cracking of scored or creased lines on boards is a serious problem in converting process of corrugated fiberboard. It is important to reduce the possibility of score crack in advance by controlling the related quality factors of linerboard. To find out the key properties affecting score crack, we carried out the correlation analysis between score crack and physical properties of linerboards. Score crack was evaluated by visual rating on surface crack after folding a linerboard using laboratory folding resistance tester. Thickness of linerboard was the most important factor to score crack. The critical limits of thickness and strain can be determined by correlation analysis for reducing the possibility of score crack.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.1
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• pp.8-15
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• 2001

Presence of small amount of old newsprints printed with waterbased flexographic inks leads to a significant loss brightness of the deinked pulp by flotation process. Recently there has been an increased interest in employing neutral deinking processes to solve the problems associated with waterbased flexo ink. A comparative experimental study was performed to evaluate the efficiency of neutral deinking and conventional alkaline deinking for ONP furnishes contaminated with flexo ink. It was shown that neutral deinking provides significant improvements in brightness, yield and freeness as compared with alkaline deinking. Flotation efficiency was different depending upon the type of surfactants used in neutral deinking. The result of this study showed that alcohol type surfactant is superior to fatty acid type surfactant in neutral deinking efficiency.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.496-499
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• 1991

Photovoltaic system has very low energy conversion efficiency and the output characteristics of solar cell is varied by the Insolation quantity and the temperature. In order to improve the efficiency of photovoltaic system, the energy which has got from solar cell must be use maximum. In this paper, it was stimultaneous executed both MPPT control and instrumentation in order that the operating point of solar cell is located maximum power point, using the PWM inverter and micro-computer, which is for the purpose of acquiring maximum power from the solar cell. As a result, maximum power point tracking had carried out and the efficiency of photovoltaic system improved, even if insolation quantity and the temperature are varied.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.296-299
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• 2003

The conventional DTC strategy provides a fast torque response even though it has very simple scheme consisted with only two hysteresis band comparators and a switching table for torque and flux control. Drawbacks of the conventional DTC are relatively high torque ripple at low speed and variation of the switching frequency according to motor speed. In this paper, the new direct torque control(DTC) schemes are proposed. Those schemes are based on the torque slope and enable to reduce the torque ripple and maintain the switching frequency constantly.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.4
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• pp.73-80
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• 2007

Modern aircraft are required to carry various external stores mounted at different locations on the wing. Sometimes the attachment of stores to an aircraft wing leads to flutter speed reduction, which is a very severe aeroelastic problem. In order to suppress structural vibration and expand the flutter boundary of the aircraft with stores, it is necessary to investigate the main problems and characteristics of them. In addition, active vibration control may be required because passive vibration isolators show limited capabilities for the various wing/store configuration. In this paper, therefore, the flutter stability to the various wing/store configurations was investigated and active vibration control of wing/store model was performed using a piezoelectric actuator.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.566-571
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• 2007

In this study, it is investigated the thermal post-buckling characteristics of step-formed FG panel under the heat and supersonic flow. Material properties are assumed to be temperature dependent as well as continuously varying in the thickness direction of the panel according to a simple power law distribution in terms of the volume fraction of the constituent. First-order shear deformation theory(FSDT) of plate is applied to model the panel, and the von Karman strain-displacement relations are adopted to consider the geometric nonlinearity due to large deformation. Also, the first-order piston theory is used to model the supersonic aerodynamic load acting on a panel. Numerical results are summarized to reveal the thermal post-buckling behaviors of FG panels with various volume fractions, temperature conditions and aerodynamic pressures in detail.