• 제목/요약/키워드: Precise measurement

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Design of Multisensor Navigation System for Autonomous Precision Approach and Landing

  • Soon, Ben K.H.;Scheding, Steve;Lee, Hyung-Keun;Lee, Hung-Kyu
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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    • pp.377-382
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    • 2006
  • Precision approach and landing of aircraft in a remote landing zone autonomously present several challenges. Firstly, the exact location, orientation and elevation of the landing zone are not always known; secondly, the accuracy of the navigation solution is not always sufficient for this type of precision maneuver if there is no DGPS availability within close proximity. This paper explores an alternative approach for estimating the navigation parameters of the aircraft to the landing area using only time-differenced GPS carrier phase measurement and range measurements from a vision system. Distinct ground landmarks are marked before the landing zone. The positions of these landmarks are extracted from the vision system then the ranges relative to these locations are used as measurements for the extended Kalman filter (EKF) in addition to the precise time-differenced GPS carrier phase measurements. The performance of this navigation algorithm is demonstrated using simulation.

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Time of Flight Resonace Investigation of Amorphous Selenium Films (비정질 셀레늄 필름의 공명 비행시간 조사)

  • 박지군;박성광;이동길;최장용;안상호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집
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    • pp.501-504
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    • 2001
  • We used time-of-flight method to analyse transport properties of charge carrier which is produced by X-ray exposure. It is the research of charge transport and specific property of trap that is performed in direct digital x-ray image receptor. But the results shows us different measurement value of electron and charge drift mobility and it is difficult to precise analysis about charge transport properties and trap mechanism. We measured transit time and drift mobility of charge carriers using time-of-fight method to evaluate the correlation of a-Se thickness change and electric field. We made a testing glass with a-Se of 470 ${\mu}{\textrm}{m}$ thickness on corning glass using thermoevaporation method and built Au electrode with 300nm, 2$\phi$ on both sides of a-Se. As a result of this experiment, electron and hole transit time was each 229.17 $\mu$s and 8.737 $\mu$s at 10V/${\mu}{\textrm}{m}$ electric field and Drift mobility was each 0.00174 $\textrm{cm}^2$/V.s, 0.04584 $\textrm{cm}^2$/V.s.

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Development of a Modified Maxwell Bridge for Precise Measurement of a 10 mH, 100 mH Inductance Standards (10 mH, 100 mH 인덕턴스 표준기 정밀측정용 Modified Maxwell Bridge 개발)

  • Kim, Han-Jun;Lee, Rae-Duk;Kang, Jeon-Hong;Semenov, Yu.P.;Han, Sang-Ok
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2003년도 하계학술대회 논문집 B
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    • pp.840-842
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    • 2003
  • 저 주파수에서 인덕턴스 단위(H, Henry)는 전기용량의 단위(F, Farad)로부터 Maxwell bridge 또는 LC를 이용한 resonance 방법으로써 유도가 된다. 이중 Maxwell bridge 방법은 국가의 단위표준을 유지하는 연구소 또는 기관에서 가장 많이 사용되는 "product arm" 형의 bridge로 잘 알려져 있다. 개발된 bridge는 ratio-transformer를 전압공급 쪽(source)과 신호검출 쪽(detector)에 사용하여 종래의 Maxwell bridge 평형조절 시 main balance와 Wagner balance의 2개 과정을 진행하던 것과는 달리 main balance, source balance, detector balance의 과정을 진행함으로서 기존 bridge의 불안정한 ground admittance들의 영향에 의해 나타나는 불확도를 완전히 제거하였다. 한편 개발된 bridge는 10 mH, 100 mH를 10 nF의 전기용량표준기와 $1\;k{\Omega}$, $10\;k{\Omega}$의 저항표준기로부터 유도 되도록 제작되었으며. 10 mH의 경우 $400\;Hz{\sim}5\;kHz$의 주파수 영역에서 약 $2.2{\times}10^{-6}$(k=1)의 불확도로 인덕턴스 단위를 유도할 수가 있게 되었다.

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Fabrication of a polymerase chain reaction micro-reactor using infrared heating

  • Im, Ki-Sik;Eun, Duk-Soo;Kong, Seong-Ho;Shin, Jang-Kyoo;Lee, Jong-Hyun
    • Journal of Sensor Science and Technology
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    • 제14권5호
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    • pp.337-342
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    • 2005
  • A silicon-based micro-reactor to amplify small amount of deoxyribonucleic acid (DNA) has been fabricated using micro-electro-mechanical systems (MEMS) technology. Polymerase chain reaction (PCR) of DNA requires a precise and rapid temperature control. A Pt sensor is integrated directly in the chamber for real-time temperature measurement and an infrared lamp is used as external heating source for non-contact and rapid heating. In addition to the real-time temperature sensing, PCR needs a rapid thermocycling for effective PCR. For a fast thermal response, the thermal mass of the reactor chamber is minimized by removal of bulk silicon volume around the reactor using double-side KOH etching. The transparent optical property of silicon in the infrared wavelength range provides an efficient absorption of thermal energy into the reacting sample without being absorbed by silicon reactor chamber. It is confirmed that the fabricated micro-reactor could be heated up in less than 30 sec to the denaturation temperature by the external infrared lamp and cooled down in 30 sec to the annealing temperature by passive cooling.

Fuzzy Sensor Algorithm for Measuring Traffic Information using Analytic Hierarchy Process (계층 분석방법을 이용한 교통량검지를 위한 퍼지센서 알고리즘)

  • Jin, Hyun-Soo
    • Journal of the Korean Institute of Intelligent Systems
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    • 제12권3호
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    • pp.193-201
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    • 2002
  • For measuring a traffic symbolic confusion Quantity and symbolic air pleasantness, we use fuzzy sensor algorithm maded by symbolic information Quantity. Hut for implementation of fuzzy sensor, we use some symbolic information item, this method cannot produce precise output because we use vague fuzzy rule method and we cannot abundance fuzzy for precision of fuzzy rule method. For this reason, this paper introduce new fuzzy sensor algorithm composed of not fuzzy rule method but using Analytic Hierachy Process. To prove that new method is good, two type of fuzzy sensor applied to traffic signal controller and through much passing vehicle, two fuzzy sensor compared each other.

Remote Real-Time Uranium Concentration Measurement Using the Nitrogen Laser and optode (질소레이저와 광섬유를 이용한 원격제어 실시간 우라늄 농도 측정)

  • Lee, Sang-Mock;Shin, Jang-Soo;Lee, Su-Mi;Koh, Kwang-Nak;Kang, Shin-Won
    • Journal of Sensor Science and Technology
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    • 제6권5호
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    • pp.362-368
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    • 1997
  • The remote real-time uranium concentration analysis using nitrogen laser, optode, photomultiplier and optical fiber is studied. The optode for the remote collection of uranium fluorescence is designed. The fluorescence intensity at time zero is calculated in order to exclude the quenching effect and the temperature fluctuation and used for more precise estimation. The fluorescence change is very sensitive to the uranium concentration change. The method shows the detection limit of 0.06ppm and the linearity between 0.1ppm and 2ppm of the aqueous uranium concentration.

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Mobile u-healthcare system in IEEE 802.15.4 WSN and CDMA network environments

  • Toh, Sing-Hui;Lee, Seung-Chul;Lee, Hoon-Jae;Do, Kyeong-Hoon;Chung, Wan-Young
    • Journal of Sensor Science and Technology
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    • 제18권5호
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    • pp.337-342
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    • 2009
  • This paper describes a robust mobile u-healthcare system with multiple physiological signs measurement capability in real time with integration of WSN(wireless sensor network) technology and CDMA(code division multiple access) network. A cellular phone receives health data in WSN and performs local physiological signs analysis at a phone processor, and then transmits abnormal data to server for further detail or precise health signal evaluation by a medical doctor over a CDMA network. Physiological signs of the patients are continuously monitored, processed and analyzed locally at cellular phone process to produce useful medical information for diagnosis and tracking purposes. By local simple analysis in cellular phone processor we can save the data transmission cost in CDMA network. By using the developed integrate ubiquitous healthcare service architecture, patients can realize self-health checking so that the prevention actions can be taken earlier. Appropriate self-monitoring and self-management can cure disease and relieve pain especially for patients who suffer from chronic diseases that need long term observation.

A Study on the Observation of IRR Camera in Surface Discharge Image (표면방전 현상의 적외선 카메라 관측에 관한 연구)

  • Lim, Jang-Seob;Kim, Jin-Gook;Kim, Hyun-Jong;Lee, Woo-Sun;Lee, Jin;Kim, Duck-Keun;Lee, Hack-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.563-566
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    • 2003
  • The conventional testing as IEC-60587 is widely used in suface aging measurement of outside insulator those testing can carry out very short time in Lab testing. Also IEC-60587 testing is able to offer the standard judgement of relative degradation level of out side HV machine. Therefore it is very useful method compare to previous conventional tracking testing method and effective Lab testing method, But surface discharges(SD) have very complex characteristics of discharge pattern so it is required estimation research to development of precise analysis method. In recent, the study of IRR Camera is carrying out discover of temperature of power equipment through condition diagnosis and system development of degradation diagnosis.

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Development of a Signal Conditioner to Improve the Measurement Reliability of a Microseismic Monitoring System (미소진동 모니터링 시스템의 측정 신뢰도 향상을 위한 시그널 컨디셔너 개발)

  • Cheon, Dae-Sung;Han, Cheol-Min;Lee, Jang Baek
    • Tunnel and Underground Space
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    • 제30권1호
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    • pp.1-14
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    • 2020
  • Microseismic monitoring is utilized for the performance verification and safety management of the structure by detecting fine levels of damage. In order to construct a highly reliable microseismic monitoring system, the role of signal conditioner is critical. The signal conditioner helps with accurate data collection and precision control of the device, and performs additional functions such as signal conversion, linearization, and amplification. In this technical report, noise reduction signal conditioner suitable for mining sites was developed and reviewed for the purpose of implementing more precise monitoring by supplementing the previously developed microseismic monitoring system.

A Study on Grip Force and Angular Kinematics during Golf Putting Stroke (그립악력과 각운동학을 이용한 골프 퍼팅 분석)

  • Choi, Jin-Seung;Kim, Hyung-Sik;Lim, Young-Tae;Yi, Jeong-Han;Tack, Gye-Rae
    • Korean Journal of Applied Biomechanics
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    • 제17권3호
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    • pp.125-131
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    • 2007
  • The purpose of this study was to evaluate the difference in grip force and angular kinematic variables between elite (handicap${\leq}2$) and novice golfers. Three-dimensional motion analysis system with synchronized grip force measurement system was used. The participants consisted of two groups based on their playing ability: 10 elite golfers and 10 novice golfers. Each subject performed 5 putting strokes at the distance of 1, 3, and 5m with randomly selected order. During entire putting phase, elite group showed relatively constant grip force but novice group showed continuously increasing grip force pattern. There existed a clear difference in the trajectory of shoulder line between two groups. As for novice group the rotational center did not converge into one point, for elite group the rotational center converged into precise single point. And there was a clear difference pattern in anterior-posterior directional movement at shoulder between two groups. These difference might be helpful for improving consistent putting skills.