• Title/Summary/Keyword: laboratory measurement methods

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Machine Vision Technique for Rapid Measurement of Soybean Seed Vigor

  • Lee, Hoonsoo;Huy, Tran Quoc;Park, Eunsoo;Bae, Hyung-Jin;Baek, Insuck;Kim, Moon S.;Mo, Changyeun;Cho, Byoung-Kwan
    • Journal of Biosystems Engineering
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    • v.42 no.3
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    • pp.227-233
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    • 2017
  • Purpose: Morphological properties of soybean roots are important indicators of the vigor of the seed, which determines the survival rate of the seedlings grown. The current vigor test for soybean seeds is manual measurement with the human eye. This study describes an application of a machine vision technique for rapid measurement of soybean seed vigor to replace the time-consuming and labor-intensive conventional method. Methods: A CCD camera was used to obtain color images of seeds during germination. Image processing techniques were used to obtain root segmentation. The various morphological parameters, such as primary root length, total root length, total surface area, average diameter, and branching points of roots were calculated from a root skeleton image using a customized pixel-based image processing algorithm. Results: The measurement accuracy of the machine vision system ranged from 92.6% to 98.8%, with accuracies of 96.2% for primary root length and 96.4% for total root length, compared to manual measurement. The correlation coefficient for each measurement was 0.999 with a standard error of prediction of 1.16 mm for primary root length and 0.97 mm for total root length. Conclusions: The developed machine vision system showed good performance for the morphological measurement of soybean roots. This image analysis algorithm, combined with a simple color camera, can be used as an alternative to the conventional seed vigor test method.

Validation and Measurement Uncertainty Estimation in the Testing Method of Cable-harness Shielding Effectiveness (통신케이블 차폐시험방법의 유효성 확인 및 측정불확도 추정)

  • 김종상;조남호
    • Journal of the Korea Society of Computer and Information
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    • v.7 no.1
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    • pp.8-19
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    • 2002
  • The laboratory shall validate nonstandard methods, laboratory-designed/ /developed methods, standard methods used outside ther intended scope, amplifications and modifications of standard methods to confirm that the methods are fit for the intended use. Therefor in this paper we propose the Validation methods using the statistical analysis and estimating the uncertainty of measurements estimations in the testing method of cable-harness shielding effectiveness

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Removing Lipemia in Serum/Plasma Samples: A Multicenter Study

  • Castro-Castro, Maria-Jose;Candas-Estebanez, Beatriz;Esteban-Salan, Margarita;Calmarza, Pilar;Arrobas-Velilla, Teresa;Romero-Roman, Carlos;Pocovi-Mieras, Miguel;Aguilar-Doreste, Jose-Angel;Commission on Lipoprotein and Vascular Diseases, Sociedad Espanola de Quimica Clinica
    • Annals of Laboratory Medicine
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    • v.38 no.6
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    • pp.518-523
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    • 2018
  • Background: Lipemia, a significant source of analytical errors in clinical laboratory settings, should be removed prior to measuring biochemical parameters. We investigated whether lipemia in serum/plasma samples can be removed using a method that is easier and more practicable than ultracentrifugation, the current reference method. Methods: Seven hospital laboratories in Spain participated in this study. We first compared the effectiveness of ultracentrifugation ($108,200{\times}g$) and high-speed centrifugation ($10,000{\times}g$ for 15 minutes) in removing lipemia. Second, we compared high-speed centrifugation with two liquid-liquid extraction methods-LipoClear (StatSpin, Norwood, USA), and 1,1,2-trichlorotrifluoroethane (Merck, Darmstadt, Germany). We assessed 14 biochemical parameters: serum/plasma concentrations of sodium ion, potassium ion, chloride ion, glucose, total protein, albumin, creatinine, urea, alkaline phosphatase, gamma-glutamyl transferase, alanine aminotransferase, aspartate-aminotransferase, calcium, and bilirubin. We analyzed whether the differences between lipemia removal methods exceeded the limit for clinically significant interference (LCSI). Results: When ultracentrifugation and high-speed centrifugation were compared, no parameter had a difference that exceeded the LCSI. When high-speed centrifugation was compared with the two liquid-liquid extraction methods, we found differences exceeding the LCSI in protein, calcium, and aspartate aminotransferase in the comparison with 1,1,2-trichlorotrifluoroethane, and in protein, albumin, and calcium in the comparison with LipoClear. Differences in other parameters did not exceed the LCSI. Conclusions: High-speed centrifugation ($10,000{\times}g$ for 15 minutes) can be used instead of ultracentrifugation to remove lipemia in serum/plasma samples. LipoClear and 1,1,2-trichlorotrifluoroethane are unsuitable as they interfere with the measurement of certain parameters.

Empirical millimeter-wave wideband propagation characteristics of high-speed train environments

  • Park, Jae-Joon;Lee, Juyul;Kim, Kyung-Won;Kwon, Heon-Kook;Kim, Myung-Don
    • ETRI Journal
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    • v.43 no.3
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    • pp.377-388
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    • 2021
  • Owing to the difficulties associated with conducting millimeter-wave (mmWave) field measurements, especially in high-speed train (HST) environments, most propagation channels for mmWave HST have been studied using methods based on simulation rather than measurement. In this study, considering a linear cell layout in which base stations are installed along a railway, measurements were performed at 28 GHz with a speed up to 170 km/h in two prevalent HST scenarios: viaduct and tunnel scenarios. By observing the channel impulse responses, we could identify single- and double-bounced multipath components (MPCs) caused by railway static structures such as overhead line equipment. These MPCs affect the delay spread and Doppler characteristics significantly. Moreover, we observed distinct path loss behaviors for the two scenarios, although both are considered line-of-sight (LoS) scenarios. In the tunnel scenario, the path loss exponent (PLE) is 1.3 owing to the waveguide effect, which indicates that the path loss is almost constant with respect to distance. However, the LoS PLE in the viaduct scenario is 2.46, which is slightly higher than the free-space loss.

A Comparative Analysis of Test Methods of Measuring d- and q-Axes Inductances for Interior Permanent Magnet Synchronous Motor (매입형 영구자석 동기전동기의 인덕턴스 측정법 비교 분석)

  • Kim, Seung-Joo;Kim, Cherl-Jin;Lee, Ju
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.5
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    • pp.923-928
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    • 2009
  • The performance analysis and robust control of the interior permanent magnet synchronous motor(IPMSM) greatly depend on accurate value of its parameters. To achieve the high performance of torque control, it is necessary to consider exact inductance values because the inductances are nonlinear parameters of operating the IPMSM. Therefore many different methods have been performed for analysis of the methodology for the exact measurement of synchronous inductances. None of them is considered standard, and accuracy levels of all these methods are also not consistent. Among these experimental methods, the DC current decay test and the vector current control test are ideal for a laboratory environment. In this paper, these two test methods are compared by applying inductances to the IPMSM. The paper analyzes the measured inductances of the two methods and their differences with inductances obtained from the finite element method(FEM).

Development of Wall-Thinning Evaluation Procedure for Nuclear Power Plant Piping-Part 1: Quantification of Thickness Measurement Deviation

  • Yun, Hun;Moon, Seung-Jae;Oh, Young-Jin
    • Nuclear Engineering and Technology
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    • v.48 no.3
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    • pp.820-830
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    • 2016
  • Pipe wall thinning by flow-accelerated corrosion and various types of erosion is a significant and costly damage phenomenon in secondary piping systems of nuclear power plants (NPPs). Most NPPs have management programs to ensure pipe integrity due to wall thinning that includes periodic measurements for pipe wall thicknesses using nondestructive evaluation techniques. Numerous measurements using ultrasonic tests (UTs; one of the nondestructive evaluation technologies) have been performed during scheduled outages in NPPs. Using the thickness measurement data, wall thinning rates of each component are determined conservatively according to several evaluation methods developed by the United States Electric Power Research Institute. However, little is known about the conservativeness or reliability of the evaluation methods because of a lack of understanding of the measurement error. In this study, quantitative models for UT thickness measurement deviations of nuclear pipes and fittings were developed as the first step for establishing an optimized thinning evaluation procedure considering measurement error. In order to understand the characteristics of UT thickness measurement errors of nuclear pipes and fittings, round robin test results, which were obtained by previous researchers under laboratory conditions, were analyzed. Then, based on a large dataset of actual plant data from four NPPs, a quantitative model for UT thickness measurement deviation is proposed for plant conditions.

Flexible camera series network for deformation measurement of large scale structures

  • Yu, Qifeng;Guan, Banglei;Shang, Yang;Liu, Xiaolin;Li, Zhang
    • Smart Structures and Systems
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    • v.24 no.5
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    • pp.587-595
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    • 2019
  • Deformation measurement of large scale structures, such as the ground beds of high-rise buildings, tunnels, bridge, and railways, are important for insuring service quality and safety. The pose-relay videometrics method and displacement-relay videometrics method have already presented to measure the pose of non-intervisible objects and vertical subsidence of unstable areas, respectively. Both methods combine the cameras and cooperative markers to form the camera series networks. Based on these two networks, we propose two novel videometrics methods with closed-loop camera series network for deformation measurement of large scale structures. The closed-loop camera series network offers "closed-loop constraints" for the camera series network: the deformation of the reference points observed by different measurement stations is identical. The closed-loop constraints improve the measurement accuracy using camera series network. Furthermore, multiple closed-loops and the flexible combination of camera series network are introduced to facilitate more complex deformation measurement tasks. Simulated results show that the closed-loop constraints can enhance the measurement accuracy of camera series network effectively.

Destripe Hyperspectral Images with Spectral-spatial Adaptive Unidirectional Variation and Sparse Representation

  • Zhou, Dabiao;Wang, Dejiang;Huo, Lijun;Jia, Ping
    • Journal of the Optical Society of Korea
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    • v.20 no.6
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    • pp.752-761
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    • 2016
  • Hyperspectral images are often contaminated with stripe noise, which severely degrades the imaging quality and the precision of the subsequent processing. In this paper, a variational model is proposed by employing spectral-spatial adaptive unidirectional variation and a sparse representation. Unlike traditional methods, we exploit the spectral correction and remove stripes in different bands and different regions adaptively, instead of selecting parameters band by band. The regularization strength adapts to the spectrally varying stripe intensities and the spatially varying texture information. Spectral correlation is exploited via dictionary learning in the sparse representation framework to prevent spectral distortion. Moreover, the minimization problem, which contains two unsmooth and inseparable $l_1$-norm terms, is optimized by the split Bregman approach. Experimental results, on datasets from several imaging systems, demonstrate that the proposed method can remove stripe noise effectively and adaptively, as well as preserve original detail information.

Piezoelectric 6-dimensional accelerometer cross coupling compensation algorithm based on two-stage calibration

  • Dengzhuo Zhang;Min Li;Tongbao Zhu;Lan Qin;Jingcheng Liu;Jun Liu
    • Smart Structures and Systems
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    • v.32 no.2
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    • pp.101-109
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    • 2023
  • In order to improve the measurement accuracy of the 6-dimensional accelerometer, the cross coupling compensation method of the accelerometer needs to be studied. In this paper, the non-linear error caused by cross coupling of piezoelectric six-dimensional accelerometer is compensated online. The cross coupling filter is obtained by analyzing the cross coupling principle of a piezoelectric six-dimensional accelerometer. Linear and non-linear fitting methods are designed. A two-level calibration hybrid compensation algorithm is proposed. An experimental prototype of a piezoelectric six-dimensional accelerometer is fabricated. Calibration and test experiments of accelerometer were carried out. The measured results show that the average non-linearity of the proposed algorithm is 2.2628% lower than that of the least square method, the solution time is 0.019382 seconds, and the proposed algorithm can realize the real-time measurement in six dimensions while improving the measurement accuracy. The proposed algorithm combines real-time and high precision. The research results provide theoretical and technical support for the calibration method and online compensation technology of the 6-dimensional accelerometer.

Comparison of Methods for Measuring Histamine by ELISA and HPLC-MS Assay In Vitro (In Vitro에서 히스타민 측정 시 ELISA법과 HPLC-MS 분석법의 비교)

  • Lee, In Hee;Kim, Yoo Hyun
    • Korean Journal of Clinical Laboratory Science
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    • v.47 no.4
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    • pp.306-312
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    • 2015
  • The measurement of histamine is to determine the degree of allergy because the allergic reaction can lead to the release of histamine. In general, the antigen-antibody reaction was quantified by measuring absorbance using a microplate reader. In this study, we compare the method using a general antigen-antibody reaction and the method using a high performance liquid chromatography mass spectrometer (HPLC-MS) of chemical analysis in the measurement of histamine secretion. The cell line used was RBL-2H3, an allergic reaction was induced by stimulation with C48/80 (compound 48/80). Allergy-induced cells degranulation rate was confirmed by measurement of ${\beta}$-hexosaminidase and cytotoxicity was performed for the validity of the experiment. The quantitative determination of histamine showed a significant difference, since the quantitative limit of the measurement by the antigen-antibody reaction was 10.257 ppm while the quantitative limit of the measurement by HPLC-MS was 0.020 ppm. Measurement of histamine in allergic activity and anti-allergy tests showed that the HPLC-MS analysis rather than the analysis of the antigen-antibody reaction is a more precise and accurate test.