• Title/Summary/Keyword: Short Range Detection

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Obstacle Classification for Mobile Robot Traversability using 2-dimensional Laser Scanning (2차원 레이저 스캔을 이용한 로봇의 산악 주행 장애물 판단)

  • Kim, Min-Hee;Kwak, Kyung-Woon;Kim, Soo-Hyun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.1
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    • pp.1-8
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    • 2012
  • Obstacle detection is much studied by using sensors such as laser, vision, radar and ultrasonic in path planning for UGV(Unmanned Ground Vehicle), but not much reported about its characterization. In this paper not only an obstacle classification method using 2-dimensional LMS(Laser Measurement System) but also a decision making method whether to avoid or traverse the obstacle is proposed. The basic idea of decision making is to classify the characteristics by 2D laser scanned data and intensity data. Roughness features are obtained by range data using a simple linear regression model. The standard deviations of roughness and intensity data are used as measures for decision making by comparing with those of reference data. The obstacle classification and decision making for the UGV can facilitate a short path to the target position and the survivability of the robot.

A Study on Near Cut-In Performance Comparison on Adaptive Cruise Control Stop&Go (ACC Stop&Go 시스템의 근접 Cut-In 성능 비교에 대한 연구)

  • Lee, Dong-Han;Cho, Cheol-Ho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.2
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    • pp.103-109
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    • 2012
  • Adaptive cruise control Stop&Go system has been developed to reduce the driver's workload on highway or public road. This system is characterized by a moderate control of engine and brake actuator. A control system capable of modeling driver's driving characteristics has been constructed to provide natural vehicle behavior in full speed driving. But, ACC Stop&Go system has some limitations. One of the limitations is a detection limitation on near cut-in situation. This paper presents development of the near cut-in test procedure, finding of the limitation value on near cut-in scenario and performance comparisons on ACC Stop&Go system.

Template Synthesis of Nitrogen-Doped Short Tubular Carbons with Big Inner Diameter and their Application in Electrochemical Sensing

  • Cheng, Rui;Zou, Qiong;Zhang, Xiaohua;Xiao, Chunhui;Sun, Longfei;Chen, Jinhua
    • Bulletin of the Korean Chemical Society
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    • v.35 no.8
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    • pp.2423-2430
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    • 2014
  • Nitrogen-doped short tubular carbons (N-STCs) with big inner diameter have been successfully synthesized via carbonization of polydopamine (PDA) wrapped halloysite nanotubes (HNTs). The obtained N-STCs have average length of $0.3{\mu}m$ with big inner diameter (50 nm), thin wall (2-3 nm) and large surface area ($776m^2g^{-1}$), and show excellent electrochemical properties. As an example in electrochemical applications, N-STCs were used to electrochemically detect hydrogen peroxide ($H_2O_2$) and glucose. The results showed that the N-STCs modified glassy carbon (N-STCs/GC) electrode had much better analytical performance (lower detection limit and wider linear range) compared to the acid-treated carbon nanotubes (AO-CNTs) based GC electrode. The unique structure endows N-STCs the enhanced electrochemical performance and promising applications in electrochemical sensing.

Optimum Frequency Analysis for Sonar Transmit Signal design (소나 송신신호 설계를 위한 최적 주파수 분석)

  • Kim, Sunho;Jung, Jangwon;On, Baeksan;Im, Sungbin;Seo, Iksoo
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.5
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    • pp.47-54
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    • 2016
  • In the underwater environment, high resolution can be achieved in the range direction by transmitting and receiving a signal of a particular band and/or waveform. The design of a transmit signal used in the active sonar is very important in order to detect a cylindrical object within a short distance less than 1 km, which is the detection distance of this paper. Designing a transmit signal optimal to a sonar requires appropriate selection of its center frequency and bandwidth, which allows the maximum detection distance of a sonar. In this paper, in terms of maximizing echo excess and signal to noise ratio (SNR), optimum frequency analysis is carried out under various conditions of diverse parameters. In addition, the investigation focused on the determinating a bandwidth is also performed for the purpose of satisfying the performance requirement of range resolution and azimuth resolution.

A Study on the Traffic Information System Development Using DSRC (DSRC를 이용한 교통정보시스템 개발 연구)

  • Kwon, Han-Joon;Lee, Jae-Jun;Lee, Seung-Hwan;Lee, Jin-Kweon;Kim, Yong-Deak
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.8 no.6
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    • pp.13-22
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    • 2009
  • Recently, DSRC technology is used in the various fields such as parking system, BIS, ETC, etc. This paper suggests a traffic information system using this DSRC technology. The traffic information processing based on point detection using existing vehicle detection equipment is the system in which a collection and a service are operated separately while the traffic information system based on the link detection using DSRC is able to collect and provide the traffic information through the communication between RSE and OBU. The speed of a traffic congestion is high on the process converted from a point passing speed to a link average speed because the vehicle detection equipment makes the link traffic information into the point information. When the condition of traffic is deteriorated, traffic speed of the vehicle detection equipment becomes higher than DSRC. Especially, in this system, deflection by data of the traffic speed of the traffic information system is much decreased, and the unexpected condition detection and traffic condition are provided promptly.

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Design and Implementation of the Magnetic Detection System Using the Geological Magnetic Filter (자기환경필터를 이용한 자기표적 검출 시스템의 설계 및 제작)

  • Kim, Won-Ho;Choi, In-Kyu;Park, Jong-Sik
    • Journal of Sensor Science and Technology
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    • v.8 no.2
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    • pp.148-153
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    • 1999
  • In this paper, we developed and implemented the geological magnetic filter for the improvements of the signal to noise ratio of the magnetic detection system. Using the geological magnetic filter, we can remove the coherent noises in the time domain and improve the signal to noise ratio of the magnetic detection system. Numerical simulation results show that geological magnetic filter can excellently remove the sensor misalignment effects and the regular short range local noise as well as it delete the coherent noises. We confirmed that the geological magnetic filter improved the signal to noise ratio about 19dB and deleted the coherent noises with restoring the source magnetic signal through experiments by implemented system.

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Electrochemical Detection of Self-Assembled Viologen Modified Electrode as Mediator of Glucose Sensor

  • Lee, Dong-Yun;Choi, Won-Suk;Park, Sang-Hyun;Kwon, Young-Soo
    • Journal of Electrical Engineering and Technology
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    • v.4 no.1
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    • pp.106-110
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    • 2009
  • An amperometric glucose biosensor has been developed using viologen derivatives as a charge transfer mediator between a glucose oxidase (GOD) and a gold electrode. A highly stable self-assembled monolayer (SAM) of thiol-based viologen was immobilized onto the gold electrode of a quartz crystal microbalance (QCM) and GOD was immobilized onto the viologen modified electrode. This biosensor response to glucose was evaluated amperometrically in the potential of -300mV. Upon immobilization of the glucose oxidase onto the viologen modified electrode, the biosensor showed rapid response towards glucose. Experimental conditions influencing the biosensor performance, such as pH potential, were optimized and assessed. This biosensor offered excellent electrochemical responses for glucose concentration below ${\mu}$ mol level with high sensitivity and selectivity and short response time. The levels of the RSDs (<5%) for the entire analyses reflected the highly reproducible sensor performance. A linear calibration range between the current and the glucose concentration was obtained up to $4.5{\times}10^{-4}M$. The detection limit was determined to be $3.0{\times}10^{-6}M$.

A Label-Free Fluorescent Amplification Strategy for High-Sensitive Detection of Pseudomonas aeruginosa based on Protective-EXPAR (p-EXPAR) and Catalytic Hairpin Assembly

  • Lu Huang;Ye Zhang;Jie Liu;Dalin Zhang;Li Li
    • Journal of Microbiology and Biotechnology
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    • v.34 no.7
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    • pp.1544-1549
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    • 2024
  • This study presents a fluorescent mechanism for two-step amplification by combining two widely used techniques, exponential amplification reaction (EXPAR) and catalytic hairpin assembly (CHA). Pseudomonas aeruginosa (P. aeruginosa) engaged in competition with the complementary DNA in order to attach to the aptamer that had been fixed on the magnetic beads. The unbound complementary strand in the liquid above was utilized as a trigger sequence to initiate the protective-EXPAR (p-EXPAR) process, resulting in the generation of a substantial quantity of short single-stranded DNA (ssDNA). The amplified ssDNA can initiate the second CHA amplification process, resulting in the generation of many double-stranded DNA (dsDNA) products. The CHA reaction was initiated by the target/trigger DNA, resulting in the release of G-quadruplex sequences. These sequences have the ability to bond with the fluorescent amyloid dye thioflavin T (ThT), generating fluorescence signals. The method employed in this study demonstrated a detection limit of 16 CFU/ml and exhibited a strong linear correlation within the concentration range of 50 CFU/ml to 105 CFU/ml. This method of signal amplification has been effectively utilized to create a fluorescent sensing platform without the need for labels, enabling the detection of P. aeruginosa with high sensitivity.

Characteristics of the Fault Current and the Protection for Superconducting and Normal Conducting Limiter combined with a Transformer (상용변압기와 결합된 초전도체 및 상전도체 한류기의 고장전류 및 보호기기 동작특성)

  • Im, In-Gyu;Choi, Hyo-Sang;Jung, Byung-Ik
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.9
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    • pp.1313-1317
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    • 2013
  • With increasing demand of power, the equipment of power system is enlarging and the absolute capacity is going up. As a result, when a fault occurs, the fault current is consistently increasing. Therefore, I suggested some solution for limiting the fault current more efficiently. This study shows the characteristics of superconducting limiting elements and normal conducting elements combined with a transformer. We performed a short-circuit test about the fault current by using SCR switching control system operated from a CT. When short circuit accidents happened in the secondary side of a transformer, fault currents flowed and a SCR switching control system was operated. It resulted in a decrease of the fault current in the limited elements of third winding connected in parallel. For this test, we used YBCO thin films and normal conducting elements as the limited elements. Within a cycle, a superconducting fault current limiter with YBCO thin films reduced more than 90% of fault current because the resistance of superconducting elements sustainedly grew. On the other hand, the limiter with normal conductors limited as much as a set value because its resistance characteristic was linear. Consequently, in case of the limiter with superconductor, limiting range of the circuit was wide but the range of protective detection was undefined. In contrast, as for the limiter with normal conductors, limiting range and protection duty were appropriate.

MLP-A(Multi Link Protection for Airborne Network Verifying) algorithms and implementation in multiple air mobile/verification links (다중 공중 이동/검증 링크에서의 MLP-A 알고리즘 및 구현)

  • Youn, Jong-Taek;Jeong, Hyung-jin;Kim, Yongi;Jeon, Joon-Seok;Park, Juman;Joo, Taehwan;Go, Minsun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.3
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    • pp.422-429
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    • 2022
  • In this paper, the intermediate frequency transmission signal level between the network system-based baseband and RF unit consisting of multi-channel airborne relay devices and a lot of mission devices, which are currently undergoing technology development tasks, is kept constant at the reference signal level. Considering the other party's receiving input range, despite changes in the short-range long-range wireless communication environment, it presents a multi-link protection and MLP-A algorithm that allows signals to be transmitted stably and reliably through signal detection automatic gain control, and experiments and analysis considering short-distance and long-distance wireless environments were performed by designing, manufacturing, and implementing RF units to which MLP-A algorithms were applied, and applying distance calculation equations to the configuration of multiple air movements and verification networks. Through this, it was confirmed that a stable and reliable RF communication system can be operated.