• 센서학회지
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• 제31권5호
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• pp.312-317
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• 2022

Piezoelectric energy harvesting has attracted increasing attention over the last decade as a means for generating sustainable and long-lasting energy from wasted mechanical energy. To develop self-powered wearable devices, piezoelectric materials should be flexible, stretchable, and bio-eco-friendly. This study proposed the fabrication of stretchable piezoelectric composites via dispersing perovskite-structured BaTiO₃ nanoparticles inside an Ecoflex polymeric matrix. In particular, the stretchable piezoelectric sensor array was fabricated via a simple and cost-effective spin-coating process by exploiting the piezoelectric composite comprising of BaTiO₃ nanoparticles, Ecoflex matrix, and stretchable Ag coated textile electrodes. The fabricated sensor generated an output voltage of ~4.3 V under repeated compressing deformations. Moreover, the piezoelectric sensor array exhibited robust mechanical stability during mechanical pushing of ~5,000 cycles. Finite element method with multiphysics COMSOL simulation program was employed to support the experimental output performance of the fabricated device. Finally, the stretchable piezoelectric sensor array can be used as a self-powered touch sensor that can effectively detect and distinguish mechanical stimuli, such as pressing by a human finger. The fabricated sensor demonstrated potential to be used in a stretchable, lead-free, and scalable piezoelectric sensor array.

• 센서학회지
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• 제14권5호
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• pp.357-361
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• 2005

Low-stress silicon nitride (LSN) thin films with embedded metal line have been developed as free standing structures to keep microspheres in proper locations and localized heat source for application to a chip-based sensor array for the simultaneous and near-real-time detection of multiple analytes in solution. The LSN film has been utilized as a structural material as well as a hard mask layer for wet anisotropic etching of silicon. The LSN was deposited by LPCVD (Low Pressure Chemical Vapor Deposition) process by varing the ratio of source gas flows. The residual stress of the LSN film was measured by laser curvature method. The residual stress of the LSN film is 6 times lower than that of the stoichiometric silicon nitride film. The test results showed that not only the LSN film but also the stack of LSN layers with embedded metal line could stand without notable deflection.

• 센서학회지
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• 제25권1호
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• pp.13-19
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• 2016

Nowadays, most major automobile manufacturers are very interested, and actively involved, in developing driver alcohol detection system for safety (DADSS) that serves to prevent driving under the influence. DADSS measures the blood alcohol concentration (BAC) from the driver's breath and limits the ignition of the engine of the vehicle if the BAC exceeds the reference value. In this study, to optimize the sensor array of the DADSS, we selected sensors by using three different methods, configured the sensor arrays, and then compared their performance. The Wilks' lambda, stepwise elimination and filter method (using a principal component) were used as the sensor selection methods [2,3]. We compared the performance of the arrays, by using the selectivity and sensitivity as criteria, and Sammon mapping for the analysis of the cluster type of each gas. The sensor array configured by using the stepwise elimination method exhibited the highest sensitivity and selectivity and yielded the best visual result after Sammon mapping.

• JSTS:Journal of Semiconductor Technology and Science
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• 제5권1호
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• pp.11-16
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• 2005

This paper presents fabrication process and experimental results of two different types of flexible MEMS biosensors based on polymer/metal multilayer processing techniques. One type of a biosensor is a microelectrode array (MEA) for nerve signal monitoring through implanting the MEA into a living body, and another is a tactile sensor capable of being mounted on an arbitrary-shaped surface. The microelectrode array was fabricated and its electrical characteristics have been examined through in vivo and in vitro experiment. For sensitive skin, flexible tactile sensor array was fabricated and its sensitivity has been analyzed. Mechanical flexibility of these biosensors has been achieved by using a polymer, and it is verified by implanting a MEA to an animal and mounting the tactile sensor on an arbitrary-shaped surface.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.857-860
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• 2014

본 논문에서는 서모파일 어레이 센서를 이용한 무선 인체 감지 시스템을 제안한다. 제안한 시스템은 천정에 센서를 부착하여 온도 분포라고 불리는 공간의 온도를 측정한다. 시스템은 $4{\times}4$ 픽셀의 온도 분포를 측정하여 인체의 움직임을 추출할 수 있도록 분석된다. 실험 결과에서 제안한 시스템은 인체 움직임을 성공적으로 감지하였다.

• 대한전자공학회논문지SD
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• 제37권11호
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• pp.9-17
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• 2000

폭발성 가스의 종류 및 그 양을 검지하기 위한 10개의 개별 센서가 한 기판위에 집적된 센서어레이를 개발했다. 이 센서어레이는 각종 가스에 대해 다양한 감도 패턴을 가지며, $SnO_2$를 모물질로 하는 10개의 산화물 반도체 가스센서로 구성하였다. 나노사이즈이며 큰 비표면적을 가진 모물질에 서로 다른 첨가물을 첨가하여 감지물질를 제작함으로써 저농도에 대한 감도 및 재현성을 높였고, 센서어레이 전반에서 균일한 온도 분포가 되도록 설계하였다. $400^{\circ}C$에서 동작하는 센서어레이로부터 얻은 감도를 이용하여 주성분 분석 기법을 통해 폭발 하한값의 범위에서 부탄, 프로판 그리고 메탄 등과 같은 폭발성 가스의 종류 및 양을 신뢰성 있게 식별할 수 있었다.

• Current Optics and Photonics
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• 제1권6호
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• pp.573-578
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• 2017

Position estimation of a sound source based on time difference of arrival at an array of three acousto-optic sensors is introduced. Each sensor consists of a Mach-Zehnder interferometer including a sensing part in one arm that is a piece of fiber surrounded by membrane in order to enhance the acousto-optic effect. Estimation error of a recorded gunshot sound signal was evaluated with the theoretically calculated values for two different locations.

• 전자공학회논문지 IE
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• 제48권1호
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• pp.25-29
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• 2011

Ryu 등은 방위각 이노베이션을 효율적으로 구할 수 있는 계산식을 가진 다중표적 방위각 추적 알고리즘을 제안하였으며, 이 알고리즘은 데이터연관 문제가 발생하지 않는다는 장점을 가지고 있다. Ryu 알고리즘의 효율적인 방위각 이노베이션 계산식은 선배열센서를 사용하는 경우에 대하여 유도하였기 때문에, Ryu 알고리즘은 선배열센서에만 적용이 가능하다. 다중표적 방위각 추적 문제를 연구하는 많은 분야에서 다양한 형태의 배열센서를 사용하고 있다. 특히, 소나(Sonar)에서는 선배열센서 뿐만 아니라 원통형 배열센서도 많이 사용되고 있으며, 원통형 배열센서를 사용하는 대표적인 소나로 선체고정형 소나(Hull Mounted Sonar)가 있다. 본 논문에서 Ryu의 다중표적 방위각 추적 알고리즘을 원통형 배열센서에 적용할 수 있도록 수정하고, 다양한 컴퓨터 시뮬레이션을 통해서 수정된 알고리즘의 추적성능을 확인한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권10호
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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.

• 센서학회지
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• 제22권4호
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• pp.286-291
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• 2013

This paper presents to analyze patterns from single and complex malodors using gas sensor array based on metal oxide semiconductors. The aim of research is to identify and discriminate single malodors such as $NH_3$, $CH_3SH$ and $H_2S$ and their mixtures according to concentration levels. Measurement system for analyzing patterns from malodors is constructed by an array of metal oxide semiconductor sensors which are available commercially together with associate electronics. The patterns from sensory system are analyzed by Principal Component Analysis (PCA) which is simple statistical pattern recognition technique. Throughout the experimental trails, we confirmed the experimental procedure for measurement system such as sensors calibration time and gas flow rate, and discriminated malodors using pattern analysis technique.