• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.9 s.252
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• pp.1160-1165
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• 2006

In this paper, the 2-dimensional uniaxial force sensors array is introduced to detect the distributed force using fiber Bragg gratings. Uniaxial force transducer was designed to avoid the chirping and micro bending which degrade the performance of the sensor. The Brags wavelength shift of the sensor was estimated using the finite element analysis. Using this uniaxial force sensor, the uniaxial force sensors array $(3{\times}3)$ was fabricated, and the Performance of this sensors array was evaluated. The Presented sensors may has very simple configuration and its wiring is very simple compared with any other force sensors arrays.

• Journal of Sensor Science and Technology
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• v.20 no.4
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• pp.279-285
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• 2011

This study was carried out to apply chemical gas sensors for the identification of bad breath which is one of the important sensitive problem for the humans' daily life. Seven sensors, including five semiconductor sensors and two electrochemical sensors, were tested for the three panels three times in several conditions. The results showed that the reproducibility of sensors were generally good, and electrochemical sensors showed better reproducibility while semiconductor sensors showed better sensitivity. No rinsing before measurement showed relatively better results in terms of both sensitivity and reproducibility. Semiconductor gas sensors for hydrogen sulfide shows the highest sensitivity, and it was recommended to use the odor-free bag for the measurement of bad breath.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.10
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• pp.3554-3570
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• 2021

With the rapid development of the Chinese water project, the safety monitoring of dams is urgently needed. Many drawbacks exist in dams, such as high monitoring costs, a limited equipment service life, long-term monitoring difficulties. MEMS sensors have the advantages of low cost, high precision, easy installation, and simplicity, so they have broad application prospects in engineering measurements. This paper designs intelligent monitoring based on the collaborative measurement of dual MEMS sensors. The system first determines the endpoint coordinates of the sensor array by the coordinate transformation relationship in the monitoring system and then obtains the dam settlement according to the endpoint coordinates. Next, this paper proposes a dual-MEMS sensor collaborative measurement algorithm that builds a mathematical model of the dual-sensor measurement. The monitoring system realizes mutual compensation between sensor measurement data by calculating the motion constraint matrix between the two sensors. Compared with the single-sensor measurement, the dual-sensor measurement algorithm is more accurate and can improve the reliability of long-term monitoring data. Finally, the experimental results show that the dam subsidence monitoring system proposed in this paper fully meets the engineering monitoring accuracy needs, and the dual-sensor collaborative measurement system is more stable than the single-sensor monitoring system.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.37.4-37
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• 2002

$\textbullet$ Feature extraction method for robot application $\textbullet$ Using ultrasonic sensor arrays $\textbullet$ Differentiate the target as plane, corner and edge $\textbullet$ Neural network approach

• Proceedings of the Korean Ceranic Society Conference
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• 2000.10a
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• pp.156.1-156
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• 2000

• The Journal of the Acoustical Society of Korea
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• v.30 no.3
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• pp.129-135
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• 2011

An algorithm is presented for estimating the 3-D location (i.e., azimuth angle, elevation angle, and range) of multiple sources with a uniform circular array (UCA) consisting of an even number of sensors. Recently the rank reduction (RARE) algorithm for partly-calibrated sensor arrays was developed. This algorithm is applicable to sensor arrays consisting of several identically oriented and calibrated linear subarrays. Assuming that a UCA consists of M sensors, it can be divided into M/2 identical linear subarrays composed of two facing sensors. Based on the structure of the subarrays, the steering vectors are decomposed into two parts: range-independent 2-D direction-of-arrival (DOA) parameters, and range-relevant 3-D location parameters. Using this property we can estimate range-independent 2-D DOAs by using the RARE algorithm. Once the 2-D DOAs are available, range estimation can be obtained for each source by defining the 1-D MUSIC spectrum. Despite its low computational complexity, the proposed algorithm can provide an estimation performance almost comparable to that of the 3-D MUSIC benchmark estimator.

• Journal of Power Electronics
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• v.11 no.2
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• pp.218-227
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• 2011

The subject of variable step size maximum power point tracking (MPPT) algorithms has been addressed in the literature. However, most of the addressed algorithms tune the variable step size according to two variables: the photovoltaic (PV) array voltage ($V_{PV}$) and the PV array current ($I_{PV}$). Therefore, both the PV array current and voltage have to be measured. Recently, maximum power point trackers that arc based on a single variable ($I_{PV}$ or $V_{PV}$) have received a great deal of attention due to their simplicity and ease of implementation, when compared to other tracking techniques. In this paper, two methods have been proposed to design a variable step size MPPT algorithm using only a single current sensor for stand-alone battery storage PV systems. These methods utilize only the relationship between the PV array measured current and the converter duty cycle (D) to automatically adapt the step change in the duty cycle to reach the maximum power point (MPP) of the PV array. Detailed analyses and flowcharts of the proposed methods are included. Moreover, a comparison has been made between the proposed methods to investigate their performance in the transient and steady states. Finally, experimental results with field programmable gate arrays (FPGAs) are presented to verify the performance of the proposed methods.

• Journal of IKEEE
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• v.19 no.1
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• pp.52-57
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• 2015

The disease diagnosis system has been developed using the thin nitride(Si3N4) cantilever arrays which can measure the difference of capacitances between sensor and reference. The system consists of 32-bits RISC(Reduced Instruction Set Computer), RAM/Flash, bus, communication IP's, ADC(Analog Digital Converter) board, and LCD display. The marker selection method, which give us the good accuracy from reasonal numbers of markers, is suggested. The developed system has the resolution under 1fF and can detect 10nM concentration of Thrombin.

• Composites Research
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• v.20 no.6
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• pp.21-27
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• 2007

Low-velocity impact damage in a composite stiffened panel was detected using built-in piezoelectric active sensor arrays. Using these piezoelectric active sensors, various diagnostic signals were generated to propagate Lamb waves through the structure and the responses were picked up to detect changes in the structure's vibration signature due to the damage. Three algorithms - ADI(Active Damage Interrogation), TD RMS (Time Domain Root Mean Square) and STFT (Short Time Fourier Transform) - were examined to express the features of the signal changes as one damage index. From damage detecting tests, two impact induced delaminations were detected and the location was estimated with the algorithms and diagnostic signals.

• Journal of Sensor Science and Technology
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• v.5 no.2
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• pp.9-14
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• 1996

We have fabricated the vacuum magnetic sensor with a lateral field emitter arrays constructed on n-Si substrate, and investigated its magnetic characteristics. The device consists of 100 field-emitter tips with a $10{\mu}m$ pitch, gate, and split-anodes which are laterally structured. The electron-emission characteristics from the emitter followed the Fowler-Nordheim tunnelling theory. The sensor has good linear characteristics and high sensitivity of 825 %/T.