• Title/Summary/Keyword: Measurement Angle

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Measurement of Phasor Angles of Power System using Synchronized Phasor Measurement System (동기위상 측정장치를 이용한 전력계통 위상각 측정)

  • Yi, Kyung-Keuk;Lee, Jae-Wook;Wang, Jae-Myung;Choo, Jin-Boo
    • Proceedings of the KIEE Conference
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    • 2000.11a
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    • pp.55-57
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    • 2000
  • This paper presents the measurement of phasor angle of power system using Synchronized Phasor Measurement System(SPMS). SPMS includes the GPS receiver, so it can add the exact time information to the data acquired from the power system by SPMS. Using that data, we can compare the difference of phasor angles of voltages currents acquired at the exactly same time, and monitor the RMS values of voltage and current. In this paper, we present the difference of voltage angles between 345kV Sinjechon S/S and 345kV Asan S/S, where two SPMS were installed separately, and prove their performance by comparing to simulation result of PSS/E.

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Enhanced Representation for Object Tracking (물체 추적을 위한 강화된 부분공간 표현)

  • Yun, Frank;Yoo, Haan-Ju;Choi, Jin-Young
    • Proceedings of the IEEK Conference
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    • 2009.05a
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    • pp.408-410
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    • 2009
  • We present an efficient and robust measurement model for visual tracking. This approach builds on and extends work on subspace representations of measurement model. Subspace-based tracking algorithms have been introduced to visual tracking literature for a decade and show considerable tracking performance due to its robustness in matching. However the measures used in their measurement models are often restricted to few approaches. We propose a novel measure of object matching using Angle In Feature Space, which aims to improve the discriminability of matching in subspace. Therefore, our tracking algorithm can distinguish target from similar background clutters which often cause erroneous drift by conventional Distance From Feature Space measure. Experiments demonstrate the effectiveness of the proposed tracking algorithm under severe cluttered background.

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A Study on the Character for the Foot and Calf Growth of Primary School Children (초등학생의 발과 하퇴부 성장특성 연구)

  • Park, Myoung-Ae
    • Fashion & Textile Research Journal
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    • v.4 no.2
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    • pp.163-168
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    • 2002
  • For the purpose of investigating the factor of foot and calf growth of primary-school children who are fast-growing during this period a group of the 1st graders of primary-school had been the subject of this measurement in 1995 and there after they became the subject again in 1997, 1999 when they were the 3th, 5th graders measurement was carried out in 30 items including status and weight and marthin-type measure and foot-print were used for this measurement as the result, stature is correlated with height items and length items of foot and calf weight is correlated with width and circumference items of foot and calf angle of the first toe showed the highest growth like 3rd graders, heel circumference had rapidly grown rather than in the part of foot circumference in the factor analysis df foot measurement of 10-year, the first, second factors, appeared the size of shoes, in case of 12-year the first factor with status appeared the size of shoes.

Self-Calibration of a Robot Manipulator by Using the Moving Pattern of an Object (물체의 운동패턴을 이용한 로보트 팔의 자기보정)

  • Young Chul Kay
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.5
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    • pp.777-787
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    • 1995
  • This paper presents a new method for automatically calibrating robot link (Kinematic) parameters during the process of estimating motion parameters of a moving object. The motion estimation is performed based on stereo cameras mounted on the end-effector of a robot manipulator. This approach significantly differs from other calibration approaches in that the calibration is achieved by simply observing the motion of the moving object (without resorting to any other external calibrating tools) at numerous and widely varying joint-angle configurations. A differential error model, which expresses the measurement errors of a robot in terms of robot link parameter errors and motion parameters, is developed. And then a measurement equation representing the true measurement values is derived. By estimating the above two kinds of parameters minimizing the difference between the measurement equations and the true moving pattern, the calibration of the robot link parameters and the estimation of the motion parameters are accomplished at the same time.

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Flow Velocity Measurement for Laminar Diffusion Flames Utilizing LII Signal from Soot Particles (매연입자의 LII 신호를 이용한 충류확산화염 유동속도 측정)

  • Lee, Jung-Soo;Nam, Youn-Woo;Lee, Won-Nam
    • 한국연소학회:학술대회논문집
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    • 2006.04a
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    • pp.157-163
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    • 2006
  • A new technique utilizing LII signal for the measurement of flow velocities of laminar diffusion flames has been investigated. Soot particles in ethylene diffusion flames are heated by a modulated Ar-ion laser beam. LII signals and their phase angles are measured using a lock-in amplifier at the different flame heights and the axial flow velocity are obtained from the measured phase angle delay. The measured velocities are similar to those from LDV measurements under the same operating conditions. The effects of laser power, LII signal wavelength, and modulation frequency are not sensitive to the velocity measurement. However, the choice of an optical chopper blade type could affect the measurement result. The use of a 6/5 chopper blade showed the better result that is possibly due to the square shape of modulated laser beam. This study successfully demonstrated that axial flow velocities of laminar diffusion flames can be measured by a new technique utilizing LII signal, which does not need particle seeding unlikely to LDV or PIV techniques.

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Consideration on the Experimental Measurement of Flaw Height of Welds by Ultrasonic Testing (초음파(超音波) 탐상법(探傷法)에 의(依)한 용접부(熔接部)의 결함(缺陷)높이 측정(測定)에 관한 연구(硏究))

  • Ahn, Il-Young;Yin, Tong-Kyu;Han, Eung-Kyo
    • Journal of the Korean Society for Nondestructive Testing
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    • v.2 no.1
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    • pp.10-16
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    • 1982
  • This study was carried out to measure the flaw height of welds in consideration of the effective probe angle in ultrasonic oblique detection. Specimens with inserted artificial flaws were made and flaw heights were estimated from detecting these specimens. Two different methods were applied to estimate flaw heights. From the result of the experiment, flaw height could be measured within the accuracy of 15% percent error and the difference between the probe distance method and beam path method is about 5% relatively small. It is considered that the results obtained this experimental study could be helpful informal ions for measuring flaw height.

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Effect of Mutual Coupling Between Test Leads on Ground Impedance Measurement (측정선의 상호유도작용이 접지임피던스의 측정에 미치는 영향)

  • Lee, Bok-Hee;Eom, Ju-Hong;Cho, Sung-Chul
    • Proceedings of the KIEE Conference
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    • 2003.11a
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    • pp.71-74
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    • 2003
  • Fall-of-potential method is used usually to measure the ground impedance of large scale grounding system exactly. Because the interlinked magnetic flux between closed loops to inject test current and to measure potential rise is existed in E-P-C straight line arrangement, mutual(or inductive) coupling influences greatly on the measurement correctness. Measurement errors produced from inductive coupling could be reduced by the arrangement methods of auxiliary electrodes. Right angle or P-E-C order arrangement methods were effective to reduce the inductive coupling and the decrease degree of measurement error was analysed as quantitative through an experiment.

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A Study of the Characteristics of Thickness Distribution of Liquid Sheet Formed by Two Low Speed Impinging Jets (저속 충돌 제트로 생성되는 액막의 두께 분포 특성 연구)

  • Han, M.J.;Jeon, Y.U.;Seo, T.W.;Kang, B.S.
    • Journal of ILASS-Korea
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    • v.26 no.1
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    • pp.26-32
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    • 2021
  • In this study, the thickness of the liquid sheet formed by two low speed impinging jets was measured by the direct contact method. The effects of jet velocity and liquid viscosity on the thickness were analyzed and the results were compared with theoretical modeling and optical thickness measurement results. The liquid film thickness decreased as the radius and circumferential angle increased. The jet velocity did not affect the liquid film thickness as predicted in theoretical modeling. In the theoretical modeling, there was no influence of the fluid properties on thickness, but in the case of low viscosity liquids, the thickness was predicted high, and it was well matched in high viscosity liquids. The direct measurement results showed no significant difference from the optical measurement results, thus confirming the reliability of the optical measurement method.

Effects of changing position on cardiac output & on patient's discomforts after cardiac surgery (개심술을 받은 환자의 체위에 따른 심박출량 및 불편감에 관한 연구)

  • Yu Mi;Kwon Eun-Ok;Choi Yun-Kyoung;Kang Hyun-Ju;Oh Se-Eun
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.7 no.2
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    • pp.256-270
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    • 2000
  • Invasive hemodynamic monitoring has become a valuable assessment parameters in critical care nursing in patients undergoing open heart surgery patients. During cardiac surgery, the Swan Ganz catheter is placed in the pulmonary artery. Critical care nurses routinely obtain cardiac output, cardiac index, and pulmonary arterial pressure in these patients. Traditionally, patients are positioned flat and supine for cardiac output measurement. Numerous studies have dealt with the effects of changing position on the hemodynamic variables. However, there are a few studies dealing with patients who undergo cardiac surgery in Korea. Thus, the purpose of this study was to determine the effects of changing position on cardiac output, PAP, CVP, BP, HR and discomfort in patients after cardiac surgery. A sample of 21 adults who had CABG and/or valve replacement with Swan Ganz catheters in place was studied. The data were collected in the cardiac ICU of a university hospital in Seoul during the period from July 28, 1999 to August 30. 1999. In this study, the independent variable is patient position in the supine, 30 degree, and 45 degree angles. Dependent variables are C.O., C.I., CVP, PAP, MAP, HR and patients' perceived discomforts. Subject discomfort was measured subjectively by visual analogue scale. Other hemodynamic data where collected by the thermodilution method and by direct measurement. The data were analyzed by percentile, t-test, ANOVA, Linear regression analysis using SPSS-/WIN program. The results are as follows : 1) Changes in cardiac output were absent in different angle positions, 0, 30. 45 degrees(F=.070, P=.932). Changes in cardiac index were absent in different angle positions, 0. 30, 45 degrees(P>.05). 2) Changes in central venous pressure were absent in different angle positions, 0, 30, 45 degree(P>.05). 3) PAP had no change in different angle 0, 30, 45 degree positions; systolic PAP(P>.05), diastolic PAP(P>.05). 4) Changes in systolic blood pressure were absent in different angle positions, 0, 30, 45 degree(P>.05). 5) Changes in heart rates were absent in different angle positions, 0, 30, 45 degree(P>.05). 6) Patients' perceived discomfort was absent in different angle positions, 0, 30, 45 degree(p<.05). In conclusion, critical care nurses can measure C.O., C.I., PAP, BP, & CVP in cardiac surgery patients at 30 degree or 45 degree positions. This can improve the patients' comfort.

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In-Situ Gamma Spectrometry Research Analysis and Radiation Efficiency Sensitivity Evaluation (감마핵종 In-Situ 측정 연구 동향 분석 및 방사능 측정 효율 민감도 평가)

  • Hyun Jun Na;Hyeok Jae Kim;Seong Yeon Lee;Min Woo Kwak;Kwang Pyo Kim
    • Journal of Radiation Industry
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    • v.17 no.1
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    • pp.1-9
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    • 2023
  • Since a large amount of radioactive waste is expected to be generated due to permanent shutdown of many nuclear power plants, it is necessary to prepare efficient management methods for radioactive waste. Therefore, there is a need for a based study to apply the In-Situ gamma spectrometry, which can simplify the measurement procedure. The purpose of this study is to analyze research cases of In-Situ gamma spectrometry and to analyze the sensitivity of measurement according to influencing factors on In-Situ gamma spectrometry. Research cases of five institutions, including the CERN and the Imperial College Reactor Centre (ICRC), were selected as the institutions to be investigated. Research on the In-Situ gamma spectrometry was conducted on the satisfaction of the acceptance criteria for radioactive waste and the analysis of residual radioactivity in the site. In-Situ Objective Counting System (ISOCS) was used as a major measuring device. Sampling and computer code were used to verify the analysis results. For evaluation of measuring sensitivity according to influencing factors on In-Situ gamma spectrometry, the thickness of the measurement target, the distance between the detector and the target, the angle of the collimator, and the contamination location were performed using ISOCS's Geometry Composer. In every case, based on 122 keV, the efficiency decreased as the energy increased in the high energy region, and the efficiency decreased as the energy decreased in the low energy region. As the target thickness increased, the efficiency decreased, and as the distance between target and detector increased, the efficiency decreased. As the distance between contamination and detector increased, the efficiency decreased, and as the angle of the collimator increased, the measurement efficiency increased. However, when simulating the measurement situation using Geometry Composer, the background is not considered, and the probability of incident in the background increases as the angle increases, so further research needs to be conducted in consideration of these. This study can be utilized when applying the In-Situ gamma spectrometry of radioactive waste clearance in the future.