• Journal of Sensor Science and Technology
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• v.18 no.6
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• pp.423-431
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• 2009

Standard uroflowmetry measures the urine weight using single load cell to evaluate the urinary flow rate. Impact noise should be introduced due to gravity when the urine stream falls down into the container upon the load cell. The present study placed three load cells on the three vertices of a regular triangle and the three signals were ensemble averaged to enhance the signal-to-noise ratio(SNR) regardless of how the urination was made. Simulated urination experiment was performed with three different urine collection methods. In all three methods, SNR of the averaged signal was much higher than each load cell signals. With no urine collection device, the present signal averaging technique resulted in SNR values higher by 10~15 dB than when dual funnels or upper funnel were used to guide the urine stream. Therefore, it was demonstrated that the three point measurement followed by with ensemble averaging could enable accurate uroflowmetric test without any specially made urine collection devices.

• 발명특허
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• v.34 no.7
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• pp.38-42
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• 2009

(주)인벤티오는 신개념 하중측정 기술인 NGWS(Next Generation's Weighing Sensor)를 개발하고 있다. 이 기술은 기존 하중센서인 로드셀(Load Cell)과 마그네틱밸런스용 하중센서(Magnetic Balance)의 장점을 두루갖춰 현재 측정 곤란한 고하중, 고정밀 분야의 측정을 가능케 하는 등 기존 하중센서 시장을 재편할 것이라 예상되고 있다. (주)인벤티오는 이 기술의 완성도를 높이기 위해 기술보증기금으로부터 기술가치평가를 받았으며, 중소기업청에서 추진하는 2007년 신기술아이디어 사업으로 채택되어 기술개발 자금을 지원 받았다.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.1
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• pp.48-57
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• 2013

This paper presents a power management system of the dye-sensitized solar cell (DSSC) for ubiquitous sensor network (USN) applications. The charge pump with a luminance-controlled oscillator regulates the load impedance of the DSSC to track the maximum power point (MPP) under various light intensities. The low drop-out regulator with a hysteresis comparator supplies intermittent power pulses that are wide enough for USN to communicate with a host transponder even under dim light conditions. With MPP tracking, approximately 50% more power is harvested over a wide range of light intensity. The power management system fabricated using $0.13{\mu}m$ CMOS technology works with DSSC to provide power pulses of $36{\mu}A$. The duration of pulses is almost constant around $80{\mu}s$ (6.5 nJ/pulse), while the pulse spacing is inversely proportional to the light intensity.

• International journal of advanced smart convergence
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• v.8 no.4
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• pp.154-160
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• 2019

In this paper, we propose the miniaturization size of wearable Range of Motion(ROM) and a system that can be connected with smart devices in real-time to measure the joint movement range dynamically. Currently, the ROM of the joint is directly measured by a person using a goniometer. Conventional methods are different depending on the measurement method and location of the measurement person, which makes it difficult to measure consistently and may cause errors. Also, it is impossible to measure the ROM of joints in real-life situations. Therefore, the wearable sensor is attached to the joint to be measured to develop a miniaturize size ROM device that can measure the range of motion of the joint in real-time. The sensor measured the resistance value changed according to the movement of the joint using a load cell. Also, the sensed analog values were converted to digital values using an Analog to Digital Converter(ADC). The converted amount can be transmitted wireless to the smart device through the wearable sensor node. As a result, the developed device can be measured more consistently than the measurement using the goniometer, communication with IoT-based smart devices, and wearable enables dynamic observation. The developed wearable sensor node will be able to monitor the dynamic state of rehabilitation patients in real-time and improve the rapid change of treatment method and customized treatment.

• Journal of Sensor Science and Technology
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• v.14 no.1
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• pp.7-15
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• 2005

A sensor and measuring system were implemented to measure both uroflow and urophonography signal during urination for diagnose the lower urinary tract symptom. The implemented system was composed of the uroflow sensor using the load-cell, the urophonography measurement sensor so as stethoscope type, pre-processing part for sensors signal detection, amplifier and filter, system control parts and PC measurement program. A simulator of the lower urinary system that is experimental equipment implemented for evaluate the developed system. The two signals were measured using implemented system and analyzed these signal by means of time domain and frequency domain for extraction of the characteristic parameter which can most effectively reflected by the occlusion of the lower urinary system. Furthermore two signals were measured and analyzed with the subject of 5 healthy adult for clinical application possibility of the implemented system. As a result, the most influence bandwidth of effect according to occlusion of the lower urinary system is $253{\sim}282$ Hz of the urophonography signal.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4C
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• pp.163-174
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• 2009

Mechanical device using the load cell or strain gage sensor can be influenced by tempearute changes because temperature change can cause a shift in the load cell or straing gage output at zero loading. In this paper, micro cone penetrometers with 1~7mm in diameter, are developed by using an optical fiber sensor (FBG: Fiber Bragg Grating) to compensate the continous temperature change during cone penetration test. Note the temperature compensated method using optical fiber sensor which has hair-size in diameter, and is not affected by environmental conditions because the measured data is the wavelength shifting of the light instead of the intensity of the electric voltage. Temperature effect test shows that the output voltage of strain gage changes and increases with an increase in the temperature. A developed FBG cone penetrometer, however, achieves excellent temperature compensation during penetration, and produces continuous change of underground temperature. In addition, the temperature compensated FBG cone shows the excellent sensitivity and detects the interface of the layered soils with higher resolution. This study demonstrates that the fiber optic sensor renders the possibility of the ultra small size cone and the new fiber optic cone may produce more reliable temperature compensated tip resistance.

• Journal of the Korean Society for Nondestructive Testing
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• v.12 no.4
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• pp.9-17
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• 1993

Three types of piezoelectric sensors to detect acoustic emission signals were developed and characterized. Epicentral displacement and velocity of a plate to have infinite boundary were calculated by convolution between a Green's function and a simulated source time function to show parabolic rising characteristic. The sensor calibration system set up was composed of a steel plate, a glass capillary, an indentor and a load cell indicator The transient elastic signals were detected by the sensors. The results were compared with the theoretical results and Fast Fourier Transformed. As the results, the sensor fabricated using a disk shape of a piezoelectric PZT element showed resonant characteristics. The sensors fabricated using a conical shape PZT element and a PVDF polymer film showed the wide band characteristics for particle displacement and velocity, respectively. The calculated results showed good agreements with the transient responses in the cases of the wide band sensors and it was confirmed that the simulated source time function had been properly assumed.

• ETRI Journal
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• v.32 no.5
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• pp.722-728
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• 2010

This paper presents the design and fabrication model of a touchpad based on a contact-resistance-type force sensor. The touchpad works as a touch input device, which can sense contact location and contact force simultaneously. The touchpad is 40 mm wide and 40 mm long. The touchpad is fabricated by using a simple screen printing technique. The contact location is evaluated by the calibration setup, which has a load cell and three-axis stages. The location error is approximately 4 mm with respect to x-axis and y-axis directions. The force response of the fabricated touchpad is obtained at three points by loading and unloading of the probe. The touchpad can detect loads from 0 N to 2 N. The touchpad shows a hysteresis error rate of about 11% and uniformity error rate of about 3%.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.4
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• pp.359-365
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• 2003

This paper describes the on-line readymixed concrete production system using CAN network, which is a leading industrial control network. The CAN network interface circuits for moisture sensor and load cell sensor we designed for CAN network of readymixed concrete production system, respectively, and also the method for networking 2-states devices such as limit switch and lamp is suggested. The operating status of a overall remicon production system is monitored, and also the system is controlled with host computer through the network. The CAN network interface method is applied to the real readymixed concrete production system to verify the performance of proposed method.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2554-2556
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• 2000

기존의 게임기를 포함한 여러 입력장치들의 대부분이 미세한 조작과 변위의 변화, 특히 가속도와 변위의 세분화가 어려웠다. 또한 외부의 충격에 내구성이 약한 단점들이 있었다. 본 연구에서는 최근 게임기 산업에서 3차원 입력장치를 필요로 함에 따라 기존의 2차원 변위에 더해서 3차원 입력장치의 구현을 기반으로 저가형의 소형 다축load cell 센서방식을 채택하여 부분 변위의 조작, 내구성과 기존 하드웨어의 단순화 등 여러 면에서 개선이 되었으며, 보다 정밀하고 다양한 입력에 대응하기 위하여 센싱 신호처리 회로의 개선과 디지털 통신방식을 부가하였다. 본 논문에서는 이 구현을 위한 하드웨어와 소프트웨어에 대한 연구결과를 소개하고자 한다.