• Title/Summary/Keyword: Proximity detection

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Target Recognition Triggered Split DNAzyme based Colorimetric Assay for Direct and Sensitive Methicillin-Resistance Analysis of Staphylococcus aureus

  • Jin Xu;Dandan Jin;Zhengwei Wang
    • Journal of Microbiology and Biotechnology
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    • v.34 no.6
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    • pp.1322-1327
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    • 2024
  • The accurate and rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) holds significant clinical importance. This work presents a new method for detecting methicillin-resistant Staphylococcus aureus (S. aureus) in clinical samples. The method uses an aptamer-based colorimetric assay that combines a recognizing probe to identify the target and split DNAzyme to amplify the signal, resulting in a highly sensitive and direct analysis of methicillin-resistance. The identification of the PBP2a protein on the membrane of S. aureus in clinical samples leads to the allosterism of the recognizing probe, and thus provides a template for the proximity ligation of split DNAzyme. The proximity ligation of split DNAzyme forms an intact DNAzyme to identify the loop section in the L probe and generates a nicking site to release the loop sequence ("3" and "4" fragments). The "3" and "4" fragments forms an intact sequence to induce the catalytic hairpin assembly, exposing the G-rich section. The released the G-rich sequence of LR probe induces the formation of G-quadruplex-hemin DNAzyme as a colorimetric signal readout. The absorption intensity demonstrated a strong linear association with the logarithm of the S. aureus concentration across a wide range of 5 orders of magnitude dynamic range under the optimized experimental parameters. The limit of detection was calculated to be 23 CFU/ml and the method showed high selectivity for MRSA.

Development of an Inductive Proximity Sensor in Active Magnetic Bearing System for Magnetically Suspended Centrifugal Blood Pumps (능동 자기 베어링 방식의 자기 부상 원심성 혈액 펌프를 위한 유도성 근접 센서 개발)

  • Kim, H.I.;Kim, H.C.
    • Proceedings of the KOSOMBE Conference
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    • v.1998 no.11
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    • pp.245-246
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    • 1998
  • AMB(Active Magnetic Bearing) systems are popularly used in various areas. In biomedical engineering applications it is a key part of magnetically suspended rotary blood pumps. The special advantage of AMBs is that they enable the rotor to revolve with no physical contact and provide rotary blood pumps with better performances such as low hemolysis level. Fundamentally, AMB systems consist of three parts, proximity sensors for distance detection, microprocessor for control algorithm and power amplifiers for actuating electromagnets. We have developed an inductive type proximity sensor with satisfactory characteristics that can be used in AMB systems. Frequency response was flat at least up to 10 kHz and sensitivity, resolution$(>5{\mu}m)$ and sensing range(<5mm) of the sensor could be adjustable for various purposes. The characteristics of the completed model showed to have satisfactory behaviors compared with the commercially available ones that already appeared to have reliable behaviors in AMB systems.

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Hierarchical Clustering of Symbolic Objects based on Asymmetric Proximity (비대칭적 유사도 기반의 심볼릭 객체의 계층적 클러스터링)

  • Oh, Seung-Joon;Park, Chan-Woong
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.6
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    • pp.729-734
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    • 2012
  • Clustering analysis has been widely used in numerous applications like pattern recognition, data analysis, intrusion detection, image processing, bioinformatics and so on. Much of previous work has been based on the numeric data only. However, symbolic data analysis has emerged to deal with variables that can have intervals, histograms, and even functions as values. In this paper, we propose a non symmetric proximity based clustering approach for symbolic objects. A method for clustering symbolic patterns based on the average similarity value(ASV) is explored. The results of the proposed clustering method differ from those of the existing methods and the results are very encouraging.

Design of a BPSK Transceiver for the Direction Finding Proximity Fuze Sensor for Anti-air missiles (방향 탐지용 대공 근접 신관센서의 BPSK 송수신기 설계에 관한 연구)

  • Choi, Jae-Hyun;Lee, Seok-Woo;Yeom, Kyung-Whan
    • Journal of the Korea Institute of Military Science and Technology
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    • v.16 no.1
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    • pp.81-88
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    • 2013
  • This paper describes the fundamentals, design, realization and test results of a BPSK(Bi Phase Shift Keying) transceiver for the direction finding proximity fuze sensor for anti-aircrafts or air missiles. The BPSK transceiver for the direction finding fuze sensor has been designed to detect a moving target by Doppler signal processing with the code correlation method and to distinguish direction by comparing received powers of each Doppler signal from adjacent three receiving antennas. The electrical and ESS(Environmental Stress Screening) tests of the BPSK transceiver showed satisfactory results and target detection and direction finding performances proved to be successful through dynamic operation tests by 155 mm gun firing.

A Power Line Proximity Detecter for Mobile Crane (크레인의 고압 전선로 접근 경보장치)

  • Choi, Sam-Jin;Kim, Hyun-Sik;Lee, Jong-Ho;Kim, Il-Hwan;Park, Chan-Won
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.2374-2376
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    • 2001
  • In this paper we have developed a Power Line Proximity Detecting device for Mobile Crane by using a Derivation Electric-Potential Detection method. A mobile crane worker can be easily exposed to a dangerous electrical shock and the electrocution while they are working at near the high-voltage electrical lines. The derivation electric-potential of the power lines have been simulated in our experiment, Also, microprocessor-based detecting device and transmitter/receiver modules are introduced to show a solution for the dangerous mobile crane working environment. As a result, It has been shown a good functional field test.

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Rapid detection microfluidic immunosensor for food safety using static light scattering

  • Kim, Kee-Sung
    • 한국환경농학회:학술대회논문집
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    • 2009.07a
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    • pp.187-199
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    • 2009
  • We present real.time, rapid detection of Mycoplasma pneumonia in phosphate buffered saline (PBS) inside a Y.channel polydimethylsiloxane (PDMS) microfluidic device by means of optical fiber monitoring of latex immunoagglutination. The latex immunoagglutination assay was performed with serially diluted Mycoplasma pneumonia solutions using highly carboxylated polystyrene particles of 390nm and 500nm diameter conjugated with monoclonal anti. Mycoplasma pneumonia . Proximity optical fibers were located around the viewing cell of the device, which were used to measure the increase in 45${\b{o}}$ forward light scattering of the immunoagglutinated particles. The detection limit was less than 50 $pgml^{-1}$ both for 390nm and 500nm microspheres with the detection time less than 90 seconds.

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Proximity Measurement between Communication Objects (통신 객체들 간의 친밀도 측정)

  • Kwon, Jeong-Eun;Song, Ji-Hwan;Kim, Myoung-Ho
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.4
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    • pp.275-279
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    • 2009
  • Many countries including the US and ED oblige telecommunication service providers to retain communication logs for a certain amount of time. The retained data are used for the purpose of the investigation, detection, or prosecution of serious crimes, but of huge size. In order to efficiently extract information such as a correlation between criminals and suspects, we must eliminate unnecessary data that occupy a large portion of communication logs. In this paper, we propose how to measure the proximity between communication objects using communication logs. The proximity let the collected data be analyzed efficiently: analyzing the data in the decreasing order of proximities or removing the data with low proximities before analyzing. The experimental results show that there is a correlation between proximities of our proposed measurement and estimation by people.

Indoor Zone Detection based on Bluetooth Low Energy (블루투스를 이용한 실내 영역 결정 방법)

  • Frisancho, Jorge;Lee, Jemin;Kim, Hyungshin
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2015.07a
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    • pp.279-281
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    • 2015
  • Location awareness is an important capability for mobile-based indoor services. Those indoor services have motivated the implementation of methods that need high computational load cost and complex mechanisms for positioning prediction. These mechanisms, such as opportunistic sensing and machine learning, require more energy consumption to achieve accuracy. In this paper, we propose the Bluetooth Low Energy indoor zone detection (BLEIZOD) technique. This method exploits the concept of proximity zone to reduce the load cost and complexity. Our proposed method implements the received signal strength indicator (RSSI) function more effectively to gain accuracy and reduce energy consumption.

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A Study on the Coordinate Transformation by Using the Analog Signal Processing (아날로그 신호처리에 의한 좌표변환에 관한 연구)

  • Che, Woo-Seong;Park, Seo-Wook;Oh, Jun-Ho
    • Journal of the Korean Society for Precision Engineering
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    • v.6 no.4
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    • pp.119-125
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    • 1989
  • This paper presents a method of analog signal processing for a coordinate transformation. Through the proposed method, two-dimensional position information obtanided from any type of null-detector can be transformed into the information with repect to world coordinate system. In order to implement the method, a null- detection device which consists of four optical proximity sensor is developed. Through the experiments for performance evaluation, the effectiveness of the proposed method has been demonstrated.

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A Study on the Enhanced Filtering for the Removal of BEMF in BLDC Motors

  • Moon, Yu-Sung;Choi, Jae-Hyun;Kim, Jung-Won
    • Journal of IKEEE
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    • v.23 no.1
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    • pp.310-313
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    • 2019
  • This paper used the majority function to digitally filter back-electromotive force as an explanation of the Brushless DC MOTOR control algorithm. The cause and improvement of motor noise, which are operating in close proximity to high frequency sources, did not use conventional low pass filter and comparator elements. Also, they repeatedly output a noise-free BEMF signal for the input value of the majority detection filtering. These filtering steps can help reduce costs and minimize the area of a PCB by requiring relatively little hardware.