• Journal of Industrial Technology
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• v.25 no.B
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• pp.3-10
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• 2005

Since in 1970, the length of concrete pavements(JCP, JRCP and CRCP) are growing rapidly at both of main highways and local roads. Many of them are deteriorated and old enough to be repaired or replaced. The pavement is more important than the other infrastructures and it is very difficult to go around or block the traffic during the rehabilitation. The very-early strength latex-modified concrete(VES-LMC)may offer the advantages of high-early-strength, higher flexural strength, higher bond strength, and improved durability. The VES-LMC could be used at a kind of fast track ofr early opening to the traffic after 3 hours of concrete placement. The installation of VES-LMC overlay at Jung-Boo highway was successfully done from April 28 to 29, 2005. The traffic was closed at 07:00 PM and opened to traffic at 08:30 AM. The compressive and flexural strength of VES-MC were more than 28MPa, 6.2MPa after 4 hours, respectively.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.793-795
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• 2007

The present study investigates the effect of the flight path of military aircraft on noise map and its WECPNL distribution. Aircraft noise modeling and simulation are made on a Korean military airport by INM(Integrated Noise Model) 6.2 version, and the flight path of military aircraft is modeled by combining takeoff, overfly, approach and touch-and-go modes. The present INM simulations are conducted for two cases with different overfly modes and show that the change of overfly mode remarkably affects the noise influence region and the WECPNL distribution around the aircraft.

• Journal of the military operations research society of Korea
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• v.30 no.1
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• pp.153-167
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• 2004

This study focuses on building the wartime air operation model to evaluate the airfield capability. There are some uncertainties in the process of air operation such as mission flying time, turn around time, mission damage or kill rate, weather condition, and so on. Airplanes, on the way to the airbase after completing mission flight, may have been in queue on the holding point due to the unusable condition of airfield. And then, they may sometimes need to go other airbases due to the shortage of fuel. Under those uncertainties, this model is to evaluate the airfield capability in the wartime air operation using simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.10
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• pp.1738-1743
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• 2008

Environmental issue is one of the key factors to industry area using fossil fuels, because it accelerates the global warming. So it is supposed to reduce greenhouse gases around the developed nations of the world at times go. This issue is especially for the power industry. Under this background, MicroGrid system that consists of Distributed Energy Resources (DER) system, such as natural power system (wind, solar) and fuel-cell, co-generation, also known as CHP (Combined heat and power), has been developed greatly during the last 10 years. This paper adopts optimal model using GAMS to develop methods for conducting an integrated assessment of MicroGrid system.

• Journal of Environmental Impact Assessment
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• v.18 no.3
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• pp.143-150
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• 2009

The present study investigates the effects of the flight paths of military aircraft on noise map and its WECPNL(Weighted Equivalent Continuous Perceived Noise Level) distribution. Aircraft noise modeling and simulation have been performed on a Korean military air base by means of INM(Integrated Noise Model) with the input data of airfield location, aircraft specifications, flight paths and aircraft's operation schedules. The result of noise modelling has been verified in comparison with the result of measured noise level. The flight path of military aircraft, as the key parameter of the present study, was modeled by combining takeoff, overfly, approach and touch-and-go modes. The present INM simulations have been conducted for various flight path cases with different takeoff, approach modes and overfly modes. The simulation results showed that the change of flight path can remarkably affect the noise influence region and the WECPNL distribution around the airfield.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.437-439
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• 2006

Actually, The present traffic accident detection system is subsisting limitation of accurate distinction under the crowded condition at intersection because the system defend upon mainly the image information at intersection and digital image processing techniques nearly all. To complement this insufficiency, this article aims to estimate the level of present technology and a realistic possibility by analyzing the acoustic characteristic of crash sound that we have to investigate for improvement of traffic accident detection rate at intersection. The skid sound of traffic accident is showed the special pattern at 1[kHz])${\sim}$3[kHz] bandwidth when vehicles are almost never operated in and around intersection. Also, the frequency bandwidth of vehicle crash sound is showed sound pressure difference oyer 30[dB] higher than when there is no occurrence of traffic accident below 500[Hz].

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.626-629
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• 2008

The present study investigates the effect of the flight patterns of military aircraft for takeoff and approach on noise map. Aircraft noise modeling and simulation have been made on a Korean military airport by INM(Integrated Noise Model). The flight path of a military aircraft is modeled with takeoff, overfly, approach and touch-and-go modes. The present INM simulations are conducted for various cases with change of different takeoff and approach modes. It show that the change of takeoff and approach modes can cause considerable noise effects on the noise influence region around the airport.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.7
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• pp.679-685
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• 2006

In this paper, development of an omni-directional mobile robot with rocker-bogie link structure is addressed. The overall mobile robot system consists of the robot mechanism with embedded control architecture, wireless communication with host graphic monitoring system, and the joy stick tole-controller. In the cluttered environment with various sizes of obstacles, the omni-directionality and the traversality are required for a mobile robot, so that the robot call go around or climb over the obstacles according to the size. The mobile robot mechanism developed in this paper has both of the omni-directionality and the traversality by 4 steerable driving wheels and the 2 additional passive omni-directional wheels linked with the rocker-bogie structure. The kinematic modeling for the mobile robot is described based on the well-known Sheth-Uicker convention and the instantaneous coordinate system.

• Nuclear Engineering and Technology
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• v.41 no.3
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• pp.237-246
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• 2009

Digitalization of not only non-safety but also safety-grade I &C systems with full computerized Main Control Room (MCR) is the recent trend of I&C systems of nuclear power plants (NPP) around the world, while plant maintenance has been shifting from traditional time based maintenance to condition based maintenance. In order to cope with the new trend of operation and maintenance in NPP, a concept of online distributed diagnostic system for both plant operation and maintenance has been proposed in order to further improve both the plant efficiency and the work environment of plant operation staff members by organizational learning. In this respect, the research subjects of human machine interface (HMI) for the online distributed diagnostic system are also discussed for supporting the plant personnel at both MCR and local working places in the plant by the application of advanced ICT (Information and Communication Technologies).

• Journal of Mechanical Science and Technology
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• v.15 no.3
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• pp.339-350
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• 2001

To overcome problems in tracking error related to the unmodeled dynamics in the high speed operation of industrial robots, many researchers have used sliding mode control, which is robust against parameter variations and payload changes. However, these algorithms cannot reduce the inherent chattering which is caused by excessive switching inputs around the sliding surface. This study proposes a fuzzy-sliding mode control algorithm to reduce the chattering of the sliding mode control by fuzzy rules within a pre-determined dead zone. Trajectory tracking simulations and experiments show that chattering can be reduced prominently by the fuzzy-sliding mode control algorithm compared to a sliding mode control with two dead zones, and the proposed control algorithm is robust to changes in payload. The proposed control algorithm is implemented to the SCARA (selected compliance articulated robot assembly) robot using a DSP (digital signal processor) for high speed calculations.