• Title/Summary/Keyword: Non-direct measurement

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

  • Lee, Jin-Yi
    • Journal of the Korean Society for Nondestructive Testing
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    • v.24 no.6
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    • pp.566-572
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    • 2004
  • It is necessary to measure the direct current with a non-contact methodology for the liquid or gas phase, as welt as the conducting metals. This paper described a theoretical consideration and experimental verification for a non-contact quantitative direct current measurement system using the Faraday effect and magnetic flux leakage. The leakage of magnetic flux occurs around a gap when a ferromagnetic core including the discontinuous gap is magnetized. Two large anisotropic domains in a magneto-optical film are occurred by the vertical component of leaked magnetic flux and the domain walls are paralleled to the center of the gap. Here, the symmetrical arrangement of domains are deflected when a vertical magnetic field is applied to the magneto-optical film. The domain wall of the magneto-optical film are relocated when a measuring current passes through the ferromagnetic core. Therefore, a direct current passing through the core can be determined quantitatively by the measurement of moving distance of the domain wall.

Disagreement between direct and indirect blood pressure measurements obtained from minipigs

  • Lee, Won-Jae;Park, Lisa Soyeon
    • Korean Journal of Veterinary Research
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    • v.58 no.3
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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.

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

  • Choi, Jung-Su;Park, Eung-Sik;Kim, Hyung-Wan;Yoon, Yong-Sik
    • Current Industrial and Technological Trends in Aerospace
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    • v.6 no.2
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    • pp.80-89
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    • 2008
  • Photogrammetry is a non-direct 3-dimensional coordinate measurement technique using 2-dimensional photographic images. For reconstruction 3-dimensional data from the 2-dimensional photos, photogrammetry uses the fundamental principle of triangulation. Digital photogrammetry solve for the camera location and coordinates simultaneously through the mapping, scaling and bundle processing in software processing. In this paper, several applications for photogrammetry measurement are introduced, such as 'photogrammetric measurement of the gravity deformation of a cassegrain type antenna', 'analysis of photogrammetry data from ISIM mockup', 'underwater photogrammetric verification of nuclear fuel assemblies', 'spacecraft optical bench measurement' and 'spacecraft ground support equipment measurement'.

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

  • Kang, Jeon-Hong;Han, Sang-Ok
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.56 no.4
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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.

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

  • Choi, Y.W.;Bowden, M.;Muraoka, K.
    • Proceedings of the KIEE Conference
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    • 1997.07e
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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
    • Korean Journal of Clinical Laboratory Science
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    • v.45 no.2
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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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A Study on Measurement Technique of Insulation Resistance for Non-interrupting Inspection Using Non-contact Voltage Phase Detection Technology (비접촉 전압위상 검출 기술을 이용한 무정전 절연저항 측정 방법에 관한 연구)

  • Lee, Ki-Yeon;Moon, Hyun-Wook;Kim, Dong-Woo;Lim, Young-Bae;Choi, Dong-Hwan;Kim, Yong-Hyeok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.8
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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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    • v.18 no.E4
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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.

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

  • Ahn, Kuk-Hyun;Song, Jae-Bok
    • The Journal of Korea Robotics Society
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    • v.14 no.4
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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.