• Journal of Food Hygiene and Safety
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• v.36 no.4
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• pp.281-288
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• 2021

This study was conducted to analyze and compare the concentrations of heavy metals in 430 different products of 20 types of herbal medicines available in the domestic market in Korea by Graphite Furnace-Atomic Absorption Spectrometry (GF-AAS) and automated mercury analyzer. The accuracy for lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg) was in the range 92.67-102.56%, and the precision was 0.21-6.00 relative standard deviation (RSD%), which was in compliance with the Codex acceptable range. Furthermore, the Food Analysis Performance Assessment Scheme (FAPAS) quality control (QC) material showed a recovery range of 96.7-102.0% and 0.33-4.93 RSD%. The average contents (㎍/kg) of Pb, As, Cd, and Hg in herbal medicines were 254.9 (not detected (N.D.)-2,515.2), 171.0 (N.D.-2,465.2), 99.2 (N.D.-797.1), and 6.0 (N.D.-83.6), respectively. Based on the quantitative analysis results, the heavy metal contents of 20 types of herbal medicines distributed in Korea are within the acceptable range according to the standards issued by the Ministry of Food and Drug Safety (MFDS). By using the manufacturer of herbal products as the standard for QC, the Pb, As, Cd, and Hg contents were investigated in the packaging process just before distribution to determine the actual conditions of residual heavy metals in herbal medicines. Thus, these result may contribute to monitoring the QC of herbal medicines distributed in Korea and could provide basic data for supplying safe herbal medicines to the public.

• Journal of Environmental Science International
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• v.22 no.4
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• pp.471-479
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• 2013

The present study was conducted to judge the applicability of field quality control by children's goods manufacturers by assessing the contents of heavy metals such as Pb and Cd in outdoor play goods for children through measurement using Portable XRF and comparing the results through detailed analyses using ICP. Heavy metal contents of 711 part samples of 505 products were measured using XRF. According to the results, the ratio of products that exceeded the Pb and Cd content standards specified under the Quality Management and Safety Control of Industrial Products Act were 2.4% and 2.6%. Many products certified for self-regulated safety exceeded the standards and thus it was considered that harmful chemical material centered safety management systems would be necessary. Detailed ICP analyses of some products were compared and the results showed deviations of 0.9~80.8% from XRF results. The reasons for this are deviations in the characteristics of measured cross sections and the homogeneity of samples resulting from sample preparation methods, etc. Therefore, it is considered that field quality control will be applicable if measuring methods are efficiently established based on product characteristics and calibration curve preparation methods are established through quality control.

• Analytical Science and Technology
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• v.26 no.1
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• pp.86-90
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• 2013

$^{222}Rn$ concentrations in the groundwater samples without standard material due to the short half-life (3.82 day) were measured through the establishment of the counting efficiency of LSC (Liquid Scintillation Counter) using a standard source of $^{226}Ra$. This study for Quality Assurance/Quality Control (QA/QC) of $^{222}Rn$ analysis was performed to analyze blank samples, duplicate samples, samples of groundwater sampling before and after. In-situ blank samples collected were in the range of 0.44~6.28 pCi/L and laboratory samples were in the range of 1.66~4.95 pCi/L. Their correlation coefficient was 0.9691 and the source contamination from sampling, migration and keeping of samples were not identified. The correlation coefficient between original and duplicate samples from 65 areas was 0.9987. Because radon is an inert gas, in case of groundwater sampling, it is considered to affect the radon concentration. We analyzed samples separately by groundwater sampling before and after using distilled water, but there is no significant difference for $^{222}Rn$ concentrations in distilled waters of two types.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.1-9
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• 2015

PURPOSES : The objective of this study is to propose a quality control and quality assurance method for use during asphalt pavement construction using non-destructive methods, such as ground penetrating radar (GPR) and an infrared (IR) camera. METHODS : A 1.0 GHz air-coupled GPR system was used to measure the thickness and in situ density of asphalt concrete overlay during the placement and compaction of the asphalt layer in two test construction sections. The in situ density of the asphalt layer was estimated based on the dielectric constant of the asphalt concrete, which was measured as the ratio of the amplitude of the surface reflection of the asphalt mat to that of a metal plate. In addition, an IR camera was used to monitor the surface temperature of the asphalt mat to ensure its uniformity, for both conventional asphalt concrete and fiber-reinforced asphalt (FRA) concrete. RESULTS : From the GPR test, the measured in situ air void of the asphalt concrete overlay gradually decreased from 12.6% at placement to 8.1% after five roller passes for conventional asphalt concrete, and from 10.7% to 5.9% for the FRA concrete. The thickness of the asphalt concrete overlay was reduced from 7.0 cm to 6.0 cm for the conventional material, and from 9.2 cm to 6.4 cm for the FRA concrete. From the IR camera measurements, the temperature differences in the asphalt mat ranged from $10^{\circ}C$ to $30^{\circ}C$ in the two test sections. CONCLUSIONS : During asphalt concrete construction, GPR and IR tests can be applicable for monitoring the changes in in situ density, thickness, and temperature differences of the overlay, which are the most important factors for quality control. For easier and more reliable quality control of asphalt overlay construction, it is better to use the thickness measurement from the GPR.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.3
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• pp.673-681
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• 2007

The integration of Quality Circles and Six-Sigma has gained attentions for the attainment of enhanced customer satisfaction, costs reduction, and improved business performance. The purpose of this paper is to verify the benefit from the integration of Quality Circles and Six-Sigma by applying the integrated process for an alcohol manufacturing line. In the integrated process, we used the first three steps of Six-Sigma of Define, Measure, and Analyze(D-M-A) and then applied the concept of Quality Circle, which has good performance in the Improvement and Control(I-C) process. For the selection of the theme of quality circles, Analytic Hierarch Process(AHP) is used, and we also employed the experimental design, which is designed to find an optimal operating condition. Furthermore, the results of the economic analysis confirm that the integration process would be successful in reducing the incidence of defects and the quality cost.

• Journal of radiological science and technology
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• v.41 no.6
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• pp.595-602
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• 2018

Quality control (QC) of Computed Tomography (CT) devices is based on image quality measurement on AAPM CT phantom which is a standard phantom. Although it is possible to control the accuracy of the CT apparatus, it is expensive and has a disadvantage of low penetration rate. Therefore, in this study, we make image quality measurement phantom at low cost using FFF (Fused Filament Fabrication) type three-dimensional printer and try to analyze the usefulness, compare it with existing standard phantom. To print a phantom, We used three-dimensional printer of the FFF system and PLA (Poly Lactic Acid, density: $1.24g/cm^3$) filament, and the CT device of 64 MDCT (Aquilion CX, Toshiba, Japan). In addition, we printed a phantom using three-dimensional printer after design using various tool based on existing standard phantom. For image quality evaluation, AAPM CT phantom and self-generated phantom were measured 10 times for each block. The measured data were analyzed for significance using the Mannwhiteney U-test of SPSS (Version 22.0, SPSS, Chicago, IL, USA). As a result of the analysis, phantom fabricated with three-dimensional printer and standard phantom showed no significant difference (p>0.05). Furthermore, we confirmed that image quality measurement performance of a phantom using three-dimensional printer is similar to the existing standard phantom. In conclusion, we confirmed the possibility of low cost phantom fabrication using three dimensional printer.

• Proceedings of the KSRS Conference
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• v.2
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• pp.647-650
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• 2006

Compact Airborne Spectrographic Imager (CASI) hyperspectral imagery was acquired over the Little Miami River Watershed (1756 square miles) in Ohio, U.S.A., which is one of the largest hyperspectral image acquisition. For the development of a 4m-resolution land cover dataset, a hierarchical approach was employed using two different classification algorithms: 'Image Object Segmentation' for level-1 and 'Spectral Angle Mapper' for level-2. This classification scheme was developed to overcome the spectral inseparability of urban and rural features and to deal with radiometric distortions due to cross-track illumination. The land cover class members were lentic, lotic, forest, corn, soybean, wheat, dry herbaceous, grass, urban barren, rural barren, urban/built, and unclassified. The final phase of processing was completed after an extensive Quality Assurance and Quality Control (QA/QC) phase. With respect to the eleven land cover class members, the overall accuracy with a total of 902 reference points was 83.9% at 4m resolution. The dataset is available for public research, and applications of this product will represent an improvement over more commonly utilized data of coarser spatial resolution such as National Land Cover Data (NLCD).

• Korean Journal of Digital Imaging in Medicine
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• v.9 no.1
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• pp.53-65
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• 2007

PACS has been run at the Kyung Hee University Medical Center(KHMC) since 2001, and the installation and operation of PACS have contributed to automation and quantification of KHMC's medical environment During these five years our greatest concern is how to make our own guiding principle of diagnostic monitor QA which is adapted to international standards. In accordance with the terms of 'KHMC QA Guideline', 'AAPM TG18', 'SMPTE RP133', 'DICOM Part14', 'DIN V 6868-57', 'JESRA X-0093', 'JIS Z4752-2-5' and 'KCARE', concern about quality assurance of medical images are on the increase. With the investigation of acceptance testing and quality control of international standards for medical display devices, and data collection and analysis for recommended guideline, it is reported that acceptance testing(quality control), including geometrical distortion, display reflection, luminance response, luminance uniformity, display resolution, display noise, veiling glare and color chromaticity being adequate and effective to domestic hospital environments for medical display devices and assessment methods according to each performance. Accordingly, KHMC classified the checkpoint items by period, at the time of monitor setting, monthly, quarterly, half-yearly and annually. Periodic classification of checkpoint items for monitor QA makes a good guideline for image QA/QC and useful guideline for persistent good quality of monitor.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.108-114
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• 2012

Purpose: Immunosorbent assay most commonly used in the laboratory and commercial third-party quality control material is a substance that provided by BIO-RAD. However, in Reference Sheet by radioimmunoassay test kit or a measuring device for the mention of Acceptable Range is somewhat lacking. Radioimmunoassay for the inspection of test results by setting Acceptable Range to increase the objectivity of the recommendations on the data accumulated by the manufacturer listed in the Reference Sheet is to be issued. Materials and Methods : In our hospital since 2009 partially BIO-RAD using quality control materials in 2011, excluding certain items, some items were most of the BIO-RAD third-party quality control materials are used. Thus, internal quality control data accumulated BIO-RAD's Unity Real Time program by using the items were measured. Results : BIO-RAD using quality control material items were about 50 of the 20 Point Data averages, standard deviations, variation coefficients were calculated to measure the Acceptable Range of kit, automated immunoassay attributed Roche Elecsys / E170 / cobas e Systems the measures and compared. Conclusions : BIO-RAD QC materials commonly used hospital and peer group by setting the measurement kit, suitable for laboratory equipment for radioimmunoassay of Acceptable Range manufacturer recommendation to increase the objectivity of the test results by national and international recognition for radioimmunoassay should seek to increase.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1963-1966
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• 2007

본 연구에서는 기존의 IIR 필터가 아닌 장기간의 누적 반사도자료를 활용하여 실제 레이더 반사도의 감쇄정도를 정량적으로 파악하고 차폐지역 후면의 반사도를 보정하여 강우산정시 기초자료인 반사도 자료처리에서 개선된 품질관리기법을 적용하여 그 결과를 분석해보고자 하였다. 개발된 품질관리기법을 적용한 사례분석 결과, 기 IIR필터에 의한 지형에코제거에 비해 강수에코의 제거현상 등의 오차발생이 줄어들고 차폐보정으로 반사도 강도도 향상되었다. 실제 C밴드에 비해 감쇄의 영향이 적은 광덕산 S밴드 레이더와 비교한 결과에서도 차폐보정을 통하여 완전차폐를 제외한 부분차폐지역의 경우 상당히 개선된 결과를 보여주었다.