• Journal of Institute of Control, Robotics and Systems
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• v.11 no.7
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• pp.633-643
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• 2005

An unmanned aerial vehicle (UAV) is an aircraft controlled by .emote commands from ground station and/o. pre-programmed onboard autopilot system. A navigation system in the UAV provides a navigation data for a flight control computer(FCC). The FCC requires accurate and reliable position, velocity and attitude information for guidance and control. This paper proposes an ADGPS/INS integrated navigation system for a UAV. The proposed navigation system comprises an attitude determination GPS (ADGPS) receive., a navigation computer unit, and a low-cost commercial MEMS inertial measurement unit(IMU). The navigation algorithm contains a fault detection and isolation (FDI) function fur integrity. In order to evaluate the performance of the proposed navigation system, two flight tests were preformed using a small aircraft. The first flight test was carried out to confirm fundamental operation of the proposed navigation system and to check the effectiveness of the FDI algorithm. In the second flight test, the navigation performance and the benefit of the GPS attitude information were checked in a high dynamic environment. The flight test results show that the proposed ADGPS/INS integrated navigation system gives a reliable performance even when anomalous GPS data is provided and better navigation performance than a conventional GPS/INS integration unit.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.357-360
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• 1997

Abstract: In teleoperation field robotic system such as hydraulically actuated robotic excavator, the maneuverability and convenience is the most important part in the operation of robotic excavator. Particularly the force information is important in dealing with digging and leveling operation in the teleoperated excavator. Excavators are also subject to a wide variation of soil-tool interaction forces. This paper presents a new force reflecting joystick in a velocity-force type bilateral teleoperation system. The master system is electrical joystick and the slave system IS hydraulically actuated cylinder with linear position sensor. Particularly Pneumatic motor is used newly in the master joystick for force reflection and the information of the pressure of salve cylinder is measured and utilized as the force feedback signal. Also force-reflection gain greatly affects the excavation performance of a hydraulically actuated robotic system and it is very difficult to determine it appropriately since slave excavator contacts with various environments such as from soft soil to rock. To overcome this, this paper proposes a force-reflection gain selecting algorithm based on artificial neural network and fuzzy logic.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.9
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• pp.825-831
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• 2015

In this paper, capture motion and visual information from a virtual reality luge simulator to analyze muscular activity in the lower limbs. The Luge Simulator consists of a motion platform with a pneumatic module for weight distribution. We recruited luge athletes and healthy subjects and made real-time surface EMG measurements to estimate the muscular activity in the lower limbs according to the motion protocol of a simulator, and a test was conducted for each subject. The results indicated that the rectus femoris had the highest muscular activity according to the level of the slope and velocity of the luge. The soleus muscle showed a high level of activity during a turn in the luge according to the direction. We found that the development of a virtual reality sports simulator based on physical reaction results could bring positive effects to optimize reality and human cenesthesia.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1841-1848
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• 2010

Electric railway system consist of rolling stock, track, signal and streetcar line system. ATP(Automatic Train Protection) system in railway signaling system is the important one grasping the position and velocity of a train. The wayside transmitter of ATP system is installed between rails. Recently, the research about increasing train speed has been developed in total departments of the railroad systems. The study on the information transmission between on-board transmitter and wayside transmitter is required for increasing the train speed in the ATP system. When the train speed is increased as to same transmissi on distance, the problem on information transmission occurs because the transmission time is decreased. In case that the transmission distance is extended, the transmission time is decreased with respect to the train speed. Therefore, we have to define the standard magnetic intensity as to the train speed in order to transmit correctly telegram. In this paper, the transmission distance for the telegram is suggested on the basis of the train speed. Also, the standard magnetic intensity from the wayside transmitter to on-board transmitter is proposed by using transmission distance regarding the train speed in the ERTMS/ETCS system by using Matlab program.

• Geophysics and Geophysical Exploration
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• v.5 no.3
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• pp.145-149
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• 2002

The static correction, which is classified into refraction based static correction and reflection based residual static correction, removes distortions caused by irregularities of thickness or velocity in near-surface. Generally, refraction statics is a time consuming process because of high dependence on the interpreter's analysis. Therefore, for huge 3D seismic data, automatic static correction which minimizes the interpreter's analysis is required. In this research, we introduce an efficient method of refraction static correction for land 3D seismic survey.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.6
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• pp.1166-1191
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• 2011

This paper presents an adaptive active tracking system with sector based scanning for a single PTZ camera. Dividing sectors on an image reduces the search space to shorten selection time so that the system can cover many targets. Upon the selection of a target, the system estimates the target trajectory to predict the zooming location with a finite amount of time for camera movement. Advanced estimation techniques using probabilistic reason suffer from the unknown object dynamics and the inaccurate estimation compromises the zooming level to prevent tracking failure. The proposed system uses the simple piecewise estimation with a few frames to cope with fast moving objects and/or slow camera movements. The target is tracked in multiple steps and the zooming time for each step is determined by maximizing the zooming level within the expected variation of object velocity and detection. The number of zooming steps is adaptively determined according to target speed. In addition, the iterative estimation of a zooming location with camera movement time compensates for the target prediction error due to the difference between speeds of a target and a camera. The effectiveness of the proposed method is validated by simulations and real time experiments.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.6 s.312
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• pp.9-15
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• 2006

The recent development in robot field shows that service robot which interacts with human and provides specific service to human has been researched continually. Especially, robot for human welfare becomes the center of public concern. At present time, guide robot is priority field of general welfare robot and helps the blind keep safe path when he walks outdoor. In this paper, guide robot provides not only collision avoidance but also the best walking direction and velocity to blind people while recognizing environment information from various kinds of sensors. In addition, it is able to provide the most safe path planing on behalf of blind people.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.9
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• pp.733-739
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• 2017

This paper is a study on PRF selection method to accurately detect the target in the target tracking mode of airborne radar. The proposed methods are an 'optimization' method to select the closest to the center of the allowable zone considering the uncertainty of the target distance and velocity prediction and a 'quasi-optimization' method to improve the real time performance. In addition, the characteristics of the proposed methods are compared and analyzed through cost function and calculation time.

• Journal of Environmental Science International
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• v.22 no.5
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• pp.543-554
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• 2013

Acoustic Doppler Current Profilers (ADCPs) are increasingly popular in the river research and management communities being primarily used for estimation of stream flows. ADCPs capabilities, however, entail additional features that are not fully explored, such as morphological representation of river or reservoir bed based upon multi-beam depth measurements. In addition to flow velocity, ADCP measurements include river bathymetry information through the depth measurements acquired in individual 4 or 5 beams with a given oblique angle. Such sounding capability indicates that multi-beam ADCPs can be utilized as an efficient depth-sounder to be more capable than the conventional single-beam eco-sounders. The paper introduces the post-processing algorithms required to deal with raw ADCP bathymetry measurements including the following aspects: a) correcting the individual beam depths for tilt (pitch and roll); b) filtering outliers using SMART filters; d) transforming the corrected depths into geographical coordinates by UTM conversion; and, e) tag the beam detecting locations with the concurrent GPS information; f) spatial representation in a GIS package. The developed algorithms are applied for the ADCP bathymetric dataset acquired from Han-Cheon in Jeju Island to validate themselves applicability.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1803-1808
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• 2010

Electric railway system consists of rolling stock, track, signal and catenary system. ATP system in railway signaling system is the important one grasping the position and velocity of a train. The wayside device of ATP system is installed between rails. Recently, the research about increasing train speed has been developed in total departments of the railroad systems. The study on the information transmission between on-board device and wayside device is required for increasing the train speed in the ATP system. When the train speed is increased as to same transmission distance, the problem on information transmission occurs because the transmission time is decreased. In case that the transmission distance is extended, the transmission time is decreased with respect to the train speed. Therefore, we have to define the standard magnetic field intensity as to the train speed in order to transmit correctly telegram. In this paper, the transmission distance for the telegram is suggested on the basis of the train speed. Also, the standard magnetic field intensity from the wayside device to on-board device is proposed by using transmission distance regarding the train speed in the ERTMS/ETCS system by using Matlab program. Also, BER according to the train speed is presented by calculating electric field intensity from the magnetic field intensity.