• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2643-2645
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• 2001

In this paper, a problem of limited sampling time that occurs essentially in digital data acquisition system is discussed. Low sampling frequency and a lot of processed data in micro-controller interferes normal operation of the controller from acquiring information in some case. To settle this problem, we design the sub-system which consists of a new simple micro-controller. which is managed the particular sensor making the trouble to main-controller system.

• Journal of Biomedical Engineering Research
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• v.28 no.3
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• pp.369-376
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• 2007

With the convergence of ubiquitous networking and medical technologies, ubiquitous healthcare(U-Healthcare) service has come in our life, which enables a patient to receive medical services at anytime and anywhere. In the u-Healthcare environment, intelligent real-time biosignal aquisition/analysis techniques are inevitable. In this study, we propose a motion artifact cancelation method in portable photoplethysmography(PPG) signal aquisition using an accelerometer and an adaptive filter. A preliminary experiment represented that the component of the pedestrian motion artifact can be found under 5Hz in the spectral analysis. Therefore, we collected PPG signals under both simulated conditions with a motor that generates circular motion with uniform velocity (from 1 to 5Hz) and a real walking condition. We then reduced the motion artifact using a recursive least square adaptive filter which takes the accelerometer output as a noise reference. The results showed that the adaptive filter can remove the motion artifact effectively and recover peak points in PPG signals, which represents our method can be useful to detect heart rate in real walking condition.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.1
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• pp.47-55
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• 2012

This paper describes the developed HILS and test equipment in order to test the performances of MMW(Millimeter-Wave) seeker which can detect and track a high speed of short-range ballistic missile and aircraft. This system is used to 141 horn antenna array, array switching, and gain and phase control algorithm to simulate various kind of targets and trajectory of high speed and maneuver moving target. In addition, it simulates not only velocity and range for these targets but also clutter and jamming environments. System configuration and implementation and the measurement results of major subsystems such as target motion simulator, simulation signal generator, high speed data aquisition unit, and central control unit are presented. These systems could verify the detection and tracking performance of MMW seeker through dynamic real-time test based on simulation flight scenario.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6A
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• pp.685-692
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• 2008

In this paper, we propose a timing recovery loop for Inmarsat mini-m system downlink receiver. Inmarsat mini-m system requires a timing recovery loop which is robust in frequency offset and has fast acquisition because Inmarsat mini-m system specification requires frequency tolerance is required of ${\pm}924$ Hz (signal bandwidth: 2.4 kHz) and acquisition time of UW (Unique Word) signal duration (15ms).Therefore, we propose a timing recovery loop which is suitable for Inmarsat mini-m system. The proposed timing recovery loop adopted noncoherent UW detector and differential ELD which applied differential UW signal for stability and fast acquisition in frequency offset environment. Simulation results show that the proposed timing recovery loop has stable operation and fast acquisition in frequency offset environment for the system.

• Proceedings of the KSRS Conference
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• v.1
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• pp.196-199
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• 2006

Various communication mechanisms have been developed to acquire a meaningful data from sensors. The key requirement during the sensor data acquisition is determinism and reduction of time dependency. It is a fundermental level of satellite data management for controlling satellite operation software data acquisition from sensors or subsystem. Satellite operation software has various software modules to be operated in addition to data acquisition. Therefore, unnecessary time delay shall be minimized to perform the data acquisition. As the result, interrupt method might be prefered than polling method because the former can decrease the restriction of design during implementation of data acquisition logic. The possible problems while using interrupt method like as interrupt latency caused by delaying of interrupt processing time are analyzed. In this paper, communication mechanism which can be used to interface with satellite computer and subsidary subsystem by using interrupt is presented. As well, time dependency between software scheduling and data acquisition is analyzed.

• Journal of Korea Spatial Information System Society
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• v.5 no.2 s.10
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• pp.91-103
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• 2003

There are currently tremendous amount of geotechnical information saved, which has been qcquired for essential application of site selection, plan, design, constructin, repari in the builing work. However, due to the lack of the location data attribute, there has been a trouble in its analysis and GIS implementation. In this study, the geotechnical information aquisition program(PGeo) for real-time database in the field and geotechnical information reporting program(GeoReport) by Web-GIS for additional data input and its reporting function has been developed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.2
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• pp.159-168
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• 1998

In traditional method, the establishment of database for current data of underground utilities would frequently occur a lot of losses in the time, economic effect and problems of accuracy because the procedure for the generations of transverse and vertical section mapping would be composed of many steps and the establishment of underground utility is inefficiently accomplished. The goals of this study are 1) to obtain digital information and data aquisition simultaneously by realtime in the field, 2) to develop the computer program of generation of transverse and vertical section mapping based on the plan for data transformation. As a result of this study, the establishment of database for underground utilities is able to save the time and improve economic effect and accuracy while minimizing errors in rewriting and acquiring data.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1611-1613
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• 1999

This paper introduces the data processing method and the measurement of the leakage current flowing through polymer insulators. For ageing diagnosis of polymer insulator, data aquisition system was developed to record the leakage current of insulator being tested. Hence, we have gained information for life time from its leakage current. the DAS is protected against over-voltage which would develop in the event of a flashover of the test sample.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.222-222
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• 2009

Currently in electric railways, there are various test standards for catenary systems such as stability assessment standards and maintenance standards for appropriate vehicle operation. In Korea, maintenance vehicles are used to measure height, stagger, and wear of catenaries and various tests are being conducted based on maintenance manuals. In this paper, real-time data aquisition technologies for assessment of electric railway current collection status between catenaries and pantographs that are consistantely being developed from the adoption of electric railways were analyzed based on on-board measurement items.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2405-2407
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• 1999

In recent, the application of polymeric insulators for outdoor is significantly increasing. These materials have shown good performance in service, but had disadvantages under long-term exposure to contamination and moisture, resulting in some problems. Thus, this study concentrated on the development of technique evaluating the insulating status. Experiment was referred to lEC publ. 587, with data aquisition system to monitor leakage current. The components of leakage current investigated were waveform and 3rd harmonic. FFT was conducted for the analysis of harmonic components. The distortion of waveform with application time of voltage was evident, and so the 3rd harmonic component.