• Journal of the Institute of Convergence Signal Processing
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• v.20 no.2
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• pp.99-104
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• 2019

Recently, modern people are increasing the incidence of various musculoskeletal diseases due to wrong posture. Prevention is possible through proper posture habit, but it is not easy to recognize posture by oneself. Various studies have been conducted to monitor persistent posture in daily life, but most studies using constrained measurement methods and high-cost measurement equipment are not suitable for daily life. In this paper, we implemented a posture discrimination system using a FSR sensor array that can induce posture correction spontaneously through sitting posture monitoring in daily life. The implemented system is designed as a cushion type so it is easy to apply to existing chair. In addition, it can identify five most common postures in everyday life, and can monitor real-time through Android-based smart-phone monitoring application. For the performance evaluation of the implemented system, each posture was measured 50 times repeatedly. As a result, 97.6% accuracy was confirmed.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.1
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• pp.15-20
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• 2023

In general, maintaining an incorrect sitting posture for a long time is widely known to adversely affect the spine. Recently, several researchers have been interested in the causal relationship between incorrect sitting posture and spinal diseases, and have been studying methods to precisely measure changes in sitting or standing posture to prevent spinal diseases. In previous studies, we have developed a sensor device capable of measuring real-time posture change, applied a momentum calculation algorithm to improve the accuracy of real-time posture change measurement, and verified the accuracy of the postural change measurement sensor. In this study, we developed a posture measurement and analysis device that considers changes in the center of body pressure through the developed sitting pressure measurement, and it confirmed the sensor as an auxiliary tool to increase the accuracy of posture correction training with improving the user's visual feedback.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.3
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• pp.555-562
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• 2007

In order to display Bayer input stream received from CMOS image sensor to the display device, image signal processing must be performed. That is, the hardware performing the image signal processing for Bayer data is called ISP(Image Signal Processor). We can see real image through ISP processing. ISP executes functionalities for gamma correction, interpolation, color space conversion, image effect, image scale, AWB, AE and AF. In this paper, we obtained the optimum algorithm through software verification of ISP module for CMOS camera image sensor and described using VHDL and verified in ModelSim6.0a simulator. Also we downloaded into Xilinx XCV-1000e for the designed ISP module and completed the board level verification using PCI interface.

• Journal of Sensor Science and Technology
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• v.5 no.3
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• pp.9-16
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• 1996

This paper deals with the capacitive voltage divider which can measure a transient voltages generated by operating a high voltage impulse generator. The transient voltage measuring system using the capacitive electric field sensor consists of the planar-type electric field sensor having a fast response characteristic and the wide-bandwidth voltage follower, and the input impedance of which is extremely high, about $10^{12}{\Omega}$. In order to analyze the response characteristics to a step input, the newly developed calibration method is proposed, and the error of voltage dividing ratio associated with set-up condition is investigated. Also the optimal set-up condition that is to be maintained within the range of 0.5 % is taken. From the calibration experiment, the frequency bandwidth of the transient voltage measuring system whose response time to a step input is about 15.8 ns, is from 6.37 Hz to 27.3 MHz. Therefore it is possible to measure the commercial frequency voltages as well as the transient over voltages without signal distortions.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.223-228
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• 2018

In this paper the water sensor using a coaxial cavity resonator is designed and manufactured. The water sensor which can sense water drop linearly has been constructed with voltage controlled oscillator(VCO), coaxial cavity resonator, RF switch, RF detector, A/D converter, DAC and micro controller. The operating frequency range of the designed water sensor is from 2.5GHz to 3.2GHz and the input voltage and current source are 24[V/DC] and 1[A]. The designed sensor circuit includes VCO, RF switch, RF detector which varies the frequency characteristics of the devices in the high frequency of 3GHz. And so we should correct the error of the frequency characteristics of those devices in the sensor circuit. To do this, we make the reference path which switches the signals to the RF detector directly without sending it to the resonator. According to the result of simulation and measurement, we can see that there is 0-50MHz difference between simulated resonator frequency and manufactured resonator frequency.

• Journal of Sensor Science and Technology
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• v.5 no.2
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• pp.47-54
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• 1996

This paper deals with the electric field sensor and automatic measuring system of the time-varying space electric field produced by lightning discharges. The theoretical principle and the design rule of the measuring devices are investigated, and the semisphere-type electric field sensor and the signal process system are fabricated. From the calibration experiments, the frequency bandwidth of the measuring system ranges from 200 [Hz] to 1.56 [MHz] and the sensitivity is 0.96 [m V/V/m] as the amplification gain is 10. In addition, the electric field waveforms produced by lightning discharges are observed by the proposed electric field measuring system from June to August in 1995. The data is sampled with the time interval of 200 [ns] and is automatically recorded by transient signal analyzer(Necolet Pro 30), the resolution of which is 12 bit. And it is registered at personal computer. The electric field waveforms produced by intracloud discharge tend to be bipolar, with two or three narrow and fast rising pulses superimposed on the initial half-cycle.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.778-779
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• 2016

In This paper, We designed the scintillation detector for measuring radiation signals in units of pixels for a radiation source that is distributed in the space. And we carried out a study to design a radiation imaging by the module for obtaining the detection signal. For measuring radiation distribution we configure a radiation detector combining CsI(Tl) scintillator and a photodiode. In addition, its performance was verified via gamma irradiation test.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1558-1560
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• 2001

네트워크 분석기를 이용하여 GIS용 UHF 부분방전 검출장치가 CIGRE 권고안을 만족시킴을 보일 수 있는 방법을 제안하였다. 이 방법은 운전중인 GIS에서도 활용이 가능하며 주파수 영역에서 GIS 내 부분방전신호의 감쇠율을 정확히 측정할 수 있고 측정 시스템의 개별부품에 대한 교정이 필요치 않다. 또한 측정한 GIS의 구간별 감쇠율을 이용해 센서의 종류와 부분방전검출장치 및 GIS의 구성에 따라 센서의 위치를 손쉽게 결정할 수 있다.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.92-98
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• 2003

A wind turbine monitoring system is essential equipment fur the performance evaluation and mechanical load analysis of a wind turbine. A monitoring system using LabVIEW is developed in this study. This system monitors signals from a meteorological mast, wind turbine generator, and tower. The discrete signals which are sampled at t Hz are automatically saved on a data file in the unit of a day. Besides these basic functions, the developed monitoring system has the other several capabilities. One of them is the information access from a remote PC through the internet. A vision image of the test site area and data files that are produced by LabVIBW software can be uploaded to the main computer located in a remote site. An emergency backup system using UPS fur the power loss on the monitoring HW is also prepared, A detail explanation for the developed wind turbine monitoring system is presented in this study.

• Aerospace Engineering and Technology
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• v.4 no.2
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• pp.21-26
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• 2005

In airframe structural tests, a control system which has many control channels and a data acquisition system which has many data acquisition channels are used. The more it is used many channels in airframe structural test, the more hardware resources are added in test system. Before test load is applied in test article, test engineer must check test system and components. Therefore, many problems which be likely to happen to system can be minimized. The checking method of test system and components is calibration verification. In this paper, it is described that calibration verification concept and method in relation to airframe structural test controller components.(MTS Aero90 Multifunction Input Output Processor and 497.22 Dual DC Conditioner)