• Journal of Interdisciplinary Genomics
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• v.2 no.1
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• pp.5-9
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• 2020

von Willebrand disease (VWD) is a genetic bleeding disorders caused by a deficiency of von Willebrand factor (VWF). Diagnosis or exclusion of VWD is not an easy task for most clinicians. These difficulties in diagnosis or exclusion of VWD may be due to preanalytic, analytical and postanalytic laboratory issues. Analytical systems to diagnose VWD may produce misleading results because of limitations in their dynamic range of measurement and low sensitivity. However, preanalytical issues such as sample collection, processing, and transportation affect the diagnosis of VWD profoundly. We will review here the common preanlytical issues that may impact the laboratory diagnosis of VWD.

• Transactions of the Korean Society of Mechanical Engineers
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• v.3 no.1
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• pp.27-34
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• 1979

The velocity profiles in the laminar free convection boundary layer on a uniformly heated vertical plate are measured by a Laser Doppler Velocimeter for air in the range of modified Grashof number G $r_{\chi}$*=1.172x10$^{9}$ . The fringe mode, forward scatter type of the LDV system is used and the small magnesium oxide particles are used for the scattering pafticles. The analytical non-dimensionalized velocity profiles are obtained by use of an analog computer for the comparison with the experimental results. The experimental reults are in good agreement with the analytical solution obtained with an aid of the analog computer.er.

• Korean Journal of Optics and Photonics
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• v.4 no.2
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• pp.226-232
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• 1993

A broadband CARS system is constructed for shot by shot measurement of a full CARS spectrum, which consists of a frequency doubled Nd:Yag laser, broadband mode-less laser and optical multi-channel analyzer installed in a double grating monochromator. To increase the accuracy of CARS temperature measurement and get better the fitting goodness, we have measured the slit function of the detection system and determined the analytical functional form of the slit function. Accuracy of the CARS system for temperature measurement is evaluated from the difference between the best-fit temperature of CARS spectrum and temperature of thermocouple reading. The uncertainty of the temperature measurement is found to be less than 1.5% in temperature range from 300 K to 1300 K.

• Journal of the Semiconductor & Display Technology
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• v.14 no.2
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• pp.1-7
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• 2015

In this paper, a new capacitive pressure sensor has been proposed for a displacement measurement. The new sensor is mainly composed of a gap of $5{\mu}m$ and a notch of $1{\mu}m$. And the sensor has the performance as the high sensitivity and capacitance compared with a commercial capacitive sensor. Therefore, the advantages of the new capacitive pressure sensor are good sensitivity in normal range, mechanically robust and large overload protection. The analytical model is induced for confirming the performance of the proposed sensor. In addition, FEM (finite elements method) simulation has been performed to verify the analytical model. Firstly, the displacement characteristics of diaphragm membrane were simulated by the analytical model and FEM in the case of different structure and materials. At last, through this analysis, these simulation results can be predicted the change of the performance when the device parameters are varied. And it is used as a design tool to achieve at a set of performance we desired.

• Analytical Science and Technology
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• v.36 no.5
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• pp.205-215
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• 2023

In the present study, an analytical method was proposed for detecting trifluralin in aquatic products at trace concentrations. The method employed QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) and gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) as the sample preparation and measurement, respectively. The effect of the aqueous phase volume used in the QuEChERS was demonstrated, and the ratio of 10:10 (mL) between water and acetonitrile phase was used for 5 g of sample. Besides, dSPE using C18 and primary-secondary amine (PSA) was applied to remove the potential interferences from the food matrices, indicating no remarkable analyte loss. The linear range was built up from 0.50 ㎍ L^-1 to 3.0 ㎍ L^-1 (R² = 0.9993). Other criteria, i.e., repeatability (RSD_r = 0.86-1.96 %), reproducibility (RSD_R = 1.09-2.01 %), and recovery (over 90 %), were in accordance with Appendix F of AOAC (2016) for method performance. Although no trifluralin was detected for the commercial samples (fish, shrimp, and breaded shrimp), the spiked samples performed favorable recoveries and precision.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.5
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• pp.355-362
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• 2002

There has been relatively a few studies that focused on evaluation of uncertainty for standard methods by which criteria pollutants are analyzed in ambient air. Especially, uncertainty evaluation has not been made yet for sampling and analysis of airborne NO$_2$. Ambient NO$_2$ has been thought to be a major criteria pollutant worldwide because of the potential of ozone formation as well as of its own toxicity. In this study, we tried to assess uncertainties associated with the every step of sampling and of analytical procedure of Griess-Saltzman method. Quality assurance (QA) and quality control (QC) were also emphasized with the uncertainty characterization. The use of Griess-Saltzman method for ambient NO$_2$ analysis showed very uniform daily concentration distribution with the mean of 10.8 ppb and the standard deviation of 1.08ppb during the sampling period. However, seven daily samples collected at the same sampling time and place exhibited highly different concentration distribution. Therefore, we evaluated uncertainties associated with sampling and analysis through the precise application of ISO Guide. Estimates of expanded uncertainties for a total of 62 samples fell in a relatively broad range of 5.17% to 11.85%. On the other hand. the expanded uncertainties were smaller for the high concentration range of greater than 15ppb.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.11
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• pp.2033-2048
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• 1992

This paper presents the theoretical development and qualitative evaluation of a new concept in the mathematical modeling of dynamic structures. We use both test data and analytical approximations to identify the parameters of an incomplete model. The model has the capability of predicting the response of the points of interest on the structure over the frequency range of interest and can be used to predict the changes in natural frequencies and normal modes due to structural changes. The theory was tested by running simulated tests on a relatively simple structure, identifying the parameters of the incomplete model, and using this model to predict the effects on frequency and mode shapes of several mass and stiffness changes. The conditions of the tests were varied by selecting different numbers of points of measurement, varying the frequency range, and by including assumed measurement error. It is recommended that the theoretical development be continued and that applications to more complex structures be carried out in order to develop a better understanding of the limitations and capabilities of the method. A successful, more definitive sevaluation could lead to immediate practical applications.

• Mass Spectrometry Letters
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• v.8 no.4
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• pp.109-113
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• 2017

Single analytical procedure including extraction, liquid chromatography, and mass spectrometric analysis was evaluated for the simultaneous measurement of lysophospholipids (LPLs). LPLs, particularly, lysophosphatidic acids (LPA) and sphingosine 1-phosphate (S1P) are lipid messengers ubiquitously found in various biological matrix. The molecular species mediate important physiological roles in association with many diseases (e.g. cancer, inflammation, and neurodegenerative disease), which emphasize the significance of the simple and reliable analytical method for biomarker discovery and molecular mechanistic understanding. Thus, we developed analytical method mainly focusing on, but not limited by those lipid species S1P and LPA using reverse phase liquid chromatography-tandem mass spectrometry (RPLC-ESI-MS-MS). Extraction method was modified based on Folch method with optimally minimal level of ionization additive (ammonium formate 10 mM and formic acid). Reverse-phase liquid-chromatography was applied for chromatographical separation in combination with negative ionization mode electrospray-coupled Orbitrap mass spectrometry. The method validation was performed on human blood plasma in a non-targeted lipid profiling manner with full-scan MS mode and data-dependent MS/MS. The proposed method presented good inter-assay precision for primary targets, S1P and LPA. Subsequent analysis of other types of LPLs identified a broad range of lysophosphatidylcholines (LPCs) and lysophosphatidyl-ethanolamines (LPEs).

• Biomedical Science Letters
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• v.22 no.3
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• pp.83-97
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• 2016

The measurement of viral load in HIV-1 infected patients is essential for the establishment of a therapeutic strategy. Several commercial assays have shown shortcomings in quantifying rare genotypes of HIV-1 such as minor groups of N and O. In this study, the HIV-1 RT-qPCR assay was developed. The primers and probe of HIV-1 were designed to target the pol gene and to increase the detection efficiency of various subtypes including group N and O. The HIV-1 quantitative RT-qPCR assay was assessed for its analytical performance and clinical evaluation. The LoD was determined to 33.9 IU/ml. The LoD of several subtypes including A, C, D, CRF_01AE, F, CRF_02AG, G and H, were determined to less than 40 IU/ml. The HIV-1 quantitative RT-qPCR assay was evaluated using the China National Reference Panel of HIV-1 RNA to determine the analytical performance. The results were all within the acceptable range. The clinical evaluation was performed at Hunan CDC in China. The clinical evaluation results were compared with those of the China domestic commercial kit. A significant correlation (fresh samples; $R^2=0.84$, P<0.001, frozen samples; $R^2=0.76$, P<0.001) between the two systems was observed for 64 fresh samples and 76 frozen samples with viral loads, and the Bland-Altman plot showed good agreement (98.4%, 96.1%, respectively). In conclusion, the HIV-1 quantitative RT-qPCR assay had comparable analytical performance with several commercial kits. The study provides basic data for the research of HIV-1 diagnosis and the development of P < HIV-1 molecular diagnostic assay.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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• pp.279-284
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• 1992

This paper presents the theoretical development and qualitiative evaluation of a new concept in the mathematical modeling of dynamicstructures. We use both test data and analytical approximations to identify the parameters of an incomplete model. The model has the capability of prodicting the response of the points of interest on the structure over the frequency range of interest and can be used to predict the changes in natural frequencies and normal modes due to structural changes. The theory was tested by running simulated tests on a relatively simple structure, identifying the parameters of the incomplete model, and using this model to predict the effects on frequency and mode shapes of several mass and stiffness changes. The conditions of the test were varied by selecting different numbers of points of meansurement, varying the frequency range, and by including assumed measurement error. It is recommended that the theroetical development be continued and that applications to more complex structures be carried out in order todevelop a better understanding of the limitations and capabilites of the method. A successful, more definitive evaluation could lead to immediate practical applications.