• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.166-172
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• 2004

An underwater motion measurement system was constructed for applications to the model basin. A commercial motion capture system, FALCON of Motion Analysis Corp., which corrects automatically the distortion caused by refraction of the light passing through water and air, was adopted for underwater motion measurement. The modifications of FALCON system were performed: waterproofing camera housings, markers, connectors, and a new blue ring lighter. the accuracy of the motion measurement was obtained within the calibration error of 0.87mm in average and 0.89mm in standard deviation for the distance of 500mm between two markers on the calibration device. the volume of $2100mm(length)\times2100mm(breadth)\times2300mm(Height)$ was covered with 4 cameras of the underwater motion measurement system. For the performance verification, motion measurement test of a vertical mooring chain model excited at the top end was carried out. The 3D motions of mooring model were measured with variable amplitude and period of the forced excitation. Higher order motions of the mooring model were observed as the excitation period decreases. the performance of the system was verified by successfully measuring 3D motion of mooring model.

• ETRI Journal
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• v.24 no.6
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• pp.435-442
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• 2002

Antenna Passive Intermodulation (PIM) level measurement results are rarely credited to be due to external signal receiving characteristics of the antennas or serious effects from external PIM sources, such as the anechoic chamber absorber and antenna tower. This paper presents an antenna PIM model for a reflected PIM measurement method. Based on the findings of null point generation and the behavior of the third order PIM values obtained by theoretical predictions and experimental results, we concluded that the results of the antenna PIM level test were influenced by the external PIM sources generated by the anechoic chamber absorber and the path differences of PIM signals coming into the antenna.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.723-726
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• 2002

This paper describes the design, fabrication, and measurement of a sequential-rotation microstrip-array antenna for the Electronic Toll Collection System (ETCS). The ETCS is made possible by using roadside equipment with radiation pattern that can accurately pinpoint the designated communication area, without interference from other lanes. The sequential-rotation microstrip-array antenna was applied to the absorber to reduce the side lobe level (SLL). Results showed that the antenna yields a return loss at a center frequency of -20.675 dB, an axial ratio of 1.15 dB, and a gain of 20.26 dBi.

• Atmosphere
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• v.28 no.2
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• pp.113-121
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• 2018

In order to monitor greenhouse gases including $CO_2$, various types of surface-, aircraft-, and satellite-based measurement projects have been conducted. These data help understand the variations of greenhouse gases and are used in atmospheric inverse modeling systems to simulate surface fluxes for greenhouse gases. CarbonTracker is a system for estimating surface $CO_2$ flux, using an atmospheric inverse modeling method, based on only surface observation data. Because of the insufficient surface observation data available for accurate estimation of the surface $CO_2$ flux, additional observations would be required. In this study, a system that assimilates aircraft $CO_2$ measurement data in CarbonTracker (CT2013B) is developed, and the estimated results from this data assimilation system are evaluated. The aircraft $CO_2$ measurement data used are obtained from the Comprehensive Observation Network for Trace gases by the Airliner (CONTRAIL) project. The developed system includes the preprocessor of the raw observation data, the observation operator, and the ensemble Kalman filter (EnKF) data assimilation process. After preprocessing the raw data, the modeled value corresponding spatially and temporally to each observation is calculated using the observation operator. These modeled values and observations are then averaged in space and time, and used in the EnKF data assimilation process. The modeled values are much closer to the observations and show smaller biases and root-mean-square errors, after the assimilation of the aircraft $CO_2$ measurement data. This system could also be used to assimilate other aircraft $CO_2$ measurement data in CarbonTracker.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1997.12a
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• pp.206-212
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• 1997

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.300-301
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• 2014

Measurement of beam deflection is a common procedure to determine proper behavior of the structure. Either LVDT (Linear Variable Displacement Transformer) or strain gauge is usually used in experiments. A newly developed coordinate reading measurement system can be also applied for the deflection measurements. In this study, an experimental measurement was made on a laboratory size beam specimen to examine the possibility of the use of such coordinate measurement system. Results have shown the possibility of utilizing the new system for beam deflection measurement.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.859-860
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• 2006

We developed a cuffless and noninvasive measurement technique of blood pressure using tonometric pressure sensor. With observation that the maximum value of pulse pressure is not obtained at mean arterial pressure(MAP), we have figured out MAP based on the physiological characteristic including the elasticity of wrist tisse. Detecting only one part of the body and using only one device are quite advantageous over other BP measurement techniques. Our technique makes new way for the cuffless BP measurement.

• Proceedings of the Korean Magnestics Society Conference
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• 2004.12a
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• pp.193-193
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• 2004

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.568-569
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• 2005

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.4
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• pp.436-440
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• 2013

An haptic tactile interface (HTI) is presented with its modeling. Its design is dedicated to perform friction coefficient measurement to characterize reachable feelings with that kind of interface. Friction measurements are presented and discussed.