• 제목/요약/키워드: Non-direct measurement

검색결과 127건 처리시간 0.022초

자기장학 누설자속법을 응용한 직류전류계측법에 관한 연구 (A Study on Direct Current Measurement Using Magneto-Optical LMF Method)

  • 이진이
    • 비파괴검사학회지
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    • 제24권6호
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    • pp.566-572
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    • 2004
  • 금속성 도선 뿐 아니라 기상 또는 액상의 직류전류를 계측하기 위해서는 비접촉으로 전류를 측정할 필요가 있다. 본 논문은 직류전류를 비접촉으로 계측하기 위한 방법 중 하나로써 패러데이효과와 누설자속을 이용하는 방법을 제안하고, 이론적 고찰 및 실험적 검증결과를 보고한다. 공극을 가진 강자성체 코어를 1차 코일에 의하여 자화하면, 공극 주위에는 누설자속이 발생한다. 이러한 누설자속의 수직성분에 의하여 자기광학소자의 자구는 자화되어, 공극의 중심과 자벽은 평행하게 된다. 한편, 2차 코일에 의하여 자기광학소자에 수직한 방향으로 자장을 인가하면, 누설자속분포는 공극의 중심을 기준으로 좌우 대칭이었던 자구의 분포에 편향이 발생한다. 이때 금속, 기체 또는 액체상태의 전류가 코어를 통과하면 자기광학소자의 자벽이 이동하게 된다. 이러한 원리에 의하여 자구 또는 자벽의 이동량을 측정하면, 코어를 통과하는 직류전류의 세기를 알 수 있다.

Disagreement between direct and indirect blood pressure measurements obtained from minipigs

  • Lee, Won-Jae;Park, Lisa Soyeon
    • 대한수의학회지
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    • 제58권3호
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    • pp.131-136
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    • 2018
  • Blood pressure (BP) measurement plays a pivotal role in veterinary medicine for diagnosing cardiovascular disorders and monitoring anesthesia of animals. Although indirect BP measurement has been widely applied to monitor BP because of its convenience and non-invasiveness, it is still unclear whether indirect BP measurement is compatible with direct BP measurement in minipigs. In addition, the effect of animal posture during BP measurement is not well understood in minipigs despite its importance to cardiovascular performance. Therefore, both systolic and diastolic arterial BPs in minipigs were measured via femoral artery catheterization for direct BP measurement and using a compressive cuff as an indirect BP measurement under the dorsal or right lateral recumbent postures. Numerical values were processed by the Bland-Altman method to calculate the bias ${\pm}$ SD and the limits of agreement (LOA). In accordance with the American College of Veterinary Internal Medicine guidelines, the results between direct and indirect BP measurements were determined as apparent disagreements in both systolic and diastolic arterial BPs under all postures because of large bias ${\pm}$ SD and wide LOA. The results of the present will help prevent misinterpretation of the anesthetized patient's condition during monitoring of BP by indirect measurement.

사진측정기의 동향 및 응용사례 (Current status and application of Photogrammetry)

  • 최정수;박응식;김형완;윤용식
    • 항공우주산업기술동향
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    • 제6권2호
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    • pp.80-89
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    • 2008
  • 사진측정기는 2차원 사진 이미지를 사용해 비접촉식으로 3차원 좌표를 측정한다. 사진측정기는 2차원 사진으로부터 3차원 데이터를 재구성하기 위해 삼각측량법을 사용한다. 디지털 사진측정기는 측정사진에 대한 맵핑(mapping)과 비율 조정(scaling) 그리고 번들(bundle) 조정이 소프트웨어로 동시에 계산되며 이를 통해 카메라의 위치와 좌표를 해석해 낸다. 본 연구에서는 대형전파망원경의 구조적인 변형 측정, ISIM 시험 구조체의 사진측정기 결과 분석, 원자로 연료 조립물에 대한 수중 사진측정, 위성 광학 조립부 측정 및 위성 지상지원장비 측정과 같은 특별한 용도로 사용된 사진 측정기에 대해 소개하였다.

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Van der Pauw 측정법을 이용한 금속 도전율의 직류와 교류특성 (DC and AC Characterization of Metals Conductivity using the van der Pauw Measurement Method)

  • 강전홍;한상옥
    • 전기학회논문지P
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    • 제56권4호
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    • pp.157-160
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    • 2007
  • The van der Pauw technique is one of the popular methods for determining the conductivity of flat metal samples. Traceability of the national standard for the conductivity has been achieved by direct current measurement techniques in national measurement institutes of many countries. But recently, alternative current measurement techniques for determining the conductivity of flat metal samples is also interested. In this study, we measured the conductivity of non-ferrous and ferrous flat metals at alternative current using van der Pauw technique. As measurement results, the conductivities of the samples were decreased according to increasing the test frequency even though the decreasing ratio was different.

레이저를 이용한 방전 플라즈마중의 전계측정 기술 동향 (Technical tendency of electric field measurements in glow discharge plasmas using laser spectroscopy)

  • 최영욱;;촌강극기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 E
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    • pp.1663-1665
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    • 1997
  • Direct measurements of electric fields in a glow discharge are difficult because the measurement method should be sensitive to the electric field and non-intrusive. Laser spectroscopy is very suitable in that it is non-intrusive and allow in-situ measurements to be made. In this report, the measurement techniques of electric fields in glow discharge using laser spectroscopy were described.

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Validity for Use of Non-HDL Cholesterol Rather than LDL Cholesterol

  • Kwon, Se-Young;Na, Young-Ak
    • 대한임상검사과학회지
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    • 제45권2호
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    • pp.54-59
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    • 2013
  • NonHDL cholesterol values have been suggested as a risk marker for cardiovascular disease. NonHDL cholesterol values were calculated, using a very simple measurement [nonHDL cholesterol=serum total cholesterol-HDL cholesterol]. This formula is very useful as a screening tool for identifying dyslipoproteinemias, risk assessment, and assessing the results of hypolipidemic therapy. The data from the 2009 Korean National Health and Nutrition Examination Survey were used. Analysis was done for 1,992 subjects with lipid panels (Cholesterol, HDL, LDLdirect and Triglycerides) results. We studied the relationship between nonHDL cholesterol and LDL cholesterol. As a result, nonHDL cholesterol values were plotted against the LDL direct and calculated values. The linear regression equation for nonHDL cholesterol and direct LDL cholesterol was $nonHDLchol=23.60+1.03{\times}LDLdirect$ (p<0.0001, $r^2=0.80$) in all subjects. The subjects were classified into triglyceride values. When triglycerides are below 400 mg/dL, the linear fit to LDL direct is found to be $[nonHDLchol=17.34+1.07{\times}LDLdirect]$ (p<0.0001, $r^2=0.88$) and to the Friedewald LDL calculation is $[nonHDLchol=23.10+1.02{\times}LDLcalc]$ (p<0.0001, $r^2=0.82$). For triglycerides above 400 mg/dL, the linear fit equation is $[nonHDLchol=87.57+0.92{\times}LDLdirect]$ (p<0.0001, $r^2=0.50$) and to the LDL calculated, it is $[nonHDLchol=142.70+0.50{\times}LDLcalc]$ (p<0.0001, $r^2=0.32$). This study provides examples of the utility of nonHDL cholesterol concentrations in clinical medicine.

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비접촉 전압위상 검출 기술을 이용한 무정전 절연저항 측정 방법에 관한 연구 (A Study on Measurement Technique of Insulation Resistance for Non-interrupting Inspection Using Non-contact Voltage Phase Detection Technology)

  • 이기연;문현욱;김동우;임용배;최동환;김용혁
    • 전기학회논문지
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    • 제67권8호
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    • pp.1106-1112
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    • 2018
  • In this paper, measurement techniques are presented to test the performance of insulation without interruption if it is difficult to measure insulation resistance. Especially, non-contact voltage phase detection techniques have been developed that can be applied in environments where it is difficult to find voltage measurement locations such as component receptors. The performance verification of the non-interrupting insulation resistance measuring devices has been tested against existing products using standard calibration equipment and test jigs. The validation confirmed performance within 2 % for direct contact type and within 10 % for non-contact type. In addition, the procedure to make continuous insulation test using the equipment was proposed.

Development of Direct Measurement Device for Alveolar Breath Carbon Monoxide

  • Jo, Wan-Kuen;Oh, Jee-Won
    • Journal of Korean Society for Atmospheric Environment
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    • 제18권E4호
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    • pp.181-190
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    • 2002
  • A novel portable device for the direct measurement of alveolar breath carbon monoxide (CO) was developed. The major components of the device include a mouthpiece, non-rebreathing two-way valve, Teflon tube, and CO dosimeter. An alveolar CO measurement can be completed within 1.5 min when using the proposed device and measurement protocol. Measurements could be read to the nearest 0.1 ppm. Humidity did not influence the CO measurements taken by the CO dosimeter, plus there were no problems associated with the recovery and carryover of CO through the device. The criterion for significance in statistical analyses was p< 0.05. The average recovery was 103 and 99% for recovery and carryover experiments, respectively. Test results using the proposed alveolar CO measurement system reflected a good reproducibility. This reproducibility was also supported by the finding that the relative standard deviations (RSDs) of the data sets were less than 7% for the loss experiment and less than 8% for the carryover experiment. Consequently, it would appear that the proposed device can be effectively applied to measure CO levels found in breath, thereby overcoming several disadvantages associated with the conventional bag and adsorbent tube sampling methods.

센서리스 협동로봇의 직관적인 교시를 위한 직교공간 직접교시 (Cartesian Space Direct Teaching for Intuitive Teaching of a Sensorless Collaborative Robot)

  • 안국현;송재복
    • 로봇학회논문지
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    • 제14권4호
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    • pp.311-317
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    • 2019
  • Direct teaching is an essential function for collaborative robots for easy use by non-experts. For most robots, direct teaching is implemented only in joint space because the realization of Cartesian space direct teaching, in which the orientation of the end-effector is fixed while teaching, requires a measurement of the end-effector force. Thus, it is limited to the robots that are equipped with an expensive force/torque sensor. This study presents a Cartesian space direct teaching method for torque-controlled collaborative robots without either a force/torque sensor or joint torque sensors. The force exerted to the end-effector is obtained from the external torque which is estimated by the disturbance observer-based approach with the friction model. The friction model and the estimated end-effector force were experimentally verified using the robot equipped with joint torque sensors in order to compare the proposed sensorless approach with the method using torque sensors.