• Journal of the Korean Society of Radiology
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• v.7 no.5
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• pp.339-345
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• 2013

In foreign countries, the impotance of quality assurance (QA) is increasing, whereas QA evaluation standards are not established properly in Korea. Thus this study was conducted to suggest improved QA evaluation standards and methods by studying/comparing/analyzing the literature in both Korea and foreign countries and prove its suitability through simulated evaluation. result of research in south korea, much check list using the evaluation method subjective, the evaluation of accuracy and reproducibility is meausred in the number of missing. Therefore, attempts to present a clear reference evaluation and objective way to solve the problem, examined the accuracy and reproducibility and 10times of measurement. The results of the simulated evaluation satisfied both proposed evaluation standards and methods. However the QA evaluation standards and methods for the items that are implemented only in Korea and high-contrast spatial resolution could have been established. In this regard, there is a need of further studies on the establishment of QA evaluation standards and methods that suits Korean situation.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.45-47
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• 2006

Cleft palate is a congenital deformity condition with separation of the two sides of the lip resulting in nose deformity. Evaluation of surgical corrections and outcome assessments for nose deformity due to the cleft lip depends mainly on doctor's subjective judgment. An objective method for evaluation of the condition and surgical outcome of nose deformity due to the cleft palate is needed. This study aimed at objective assessment of a cleft palate nose deformity condition by analyzing the following parameters obtained from photographic images of a cleft palate patients: (1) angle difference between two nostril axes. (2) center of the nostril and distance between two centers. (3) overlapped area of two nostrils, and (4) the overlapped area ratio of the two nostrils. A regression equation of doctor's grades was obtained using the eight parameters. Three plastic surgeons gave us the grades for the each photographic image by 10 increments with maximum grade of 100. The average reproducibility of the grades given by the three plastic surgeons and the three laymen using the developed program was $10.8{\pm}4.6%$ and $7.4{\pm}1.8%$, respectively. Kappa values representing the degree of consensus of the plastic surgeons and the three laymen were 0.43 and 0.83. respectively. Correlation coefficient of the grades evaluated by the surgeons and obtained by the neural network was 0.798. In conclusion. the developed neural network model provided us better reproducibility and much better consensus than doctor's subjective evaluation in addition to objectiveness and easy application.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.3
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• pp.157-166
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• 2018

Purpose: This study was aimed to compare the consistency between the custom abutment design and the output in two CAD software programs. Materials and Methods: Customized abutments were designed by using 3Shape Dental System CAD software and Delta9 CAD software on a plaster model with implants (CRM STL file). After milling of the designed abutments, the abutments were scanned with a contact method scanner (Test STL file). We overlaid the Test STL file with each CRM STL file by using inspection software, and then compared the milling reproducibility by measuring the output error of the specimens from each CAD software program. Results: The Delta9 showed better milling reproducibility than 3Shape when comparing the milling errors obtained with a full scan of all specimens (P < .05) and also when comparing the axial wall region specifically according to the axial angle. With 0.9 mm marginal radius, the Delta9 showed better consistency between the design and the output than 3Shape (P < .05). While, anti-rotation form had no significant difference in error between the two systems. When cumulative errors were compared, the Delta9 showed better milling reproducibility in almost cases (P < .05). Conclusion: Delta9 showed a significantly smaller error for most of the abutment design options. This means that it is possible to facilitate generation of printouts with reliable reproducibility and high precision with respect to the planned design.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.71-78
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• 2021

Purpose: To evaluate the inter-fractional position and respiratory reproducibility of lung and liver tumors using pressure conserving type(P-type) abdominal compressor in volumetric modulated arc therapy(VMAT). Materials and methods: Six lung cancer patients and three liver cancer patients who underwent VMAT using a P-type abdominal compressor were included in this study. Cone-beam computed tomography(CBCT) images were acquired before each treatment and compared with planning CT images to evaluate the inter-fractional position reproducibility. The position variation was defined as the difference of position shift values between target matching and bone matching. 4-dimensional cone-beam computed tomography(4D CBCT) images were acquired weekly before treatment and compared with planning 4DCT images to evaluate the inter-fractional respiratory reproducibility. The respiratory variation was calculated by the magnitude of excursions by breathing. Results: The mean ± standard deviation(SD) of overall position variation values, 3D vector in the three translational directions were 1.1 ± 1.4 mm and 4.5 ± 2.8 mm for the lung and liver, respectively. The mean ± SD of respiratory variation values were 0.7 ± 3.4 mm (p = 0.195) in the lung and 3.6 ± 2.6 mm (p < 0.05) in the liver. Conclusion: The use of P-type compressor in lung and liver VMAT was effective for stable control of inter-fractional position and respiratory variation by reproduction of abdominal compression. Appropriate PTV margin must be considered in treatment planning, and image guidance before each treatment are required in order to obtain more stable reproducibility

• Journal of the Korean GEO-environmental Society
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• v.23 no.6
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• pp.19-23
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• 2022

For the substantiation and verification of studies related to the construction of a levee using riverbed soil, real-scale levee construction and experimental studies are essential. One of the most important factors in the experimental study is the reproducibility of the multiple levees with the same initial conditions. Quantitative analysis of the reproducibility should be presented. In this study, a number of physical properties (specific gravity test, sieving test, liquid-plastic limit test, compaction test, on-site Density test) for multiple embankments built with fine-grained bed soil was obtained. The collected data then used to obtain the possibility of reproducing levee through statistical analysis to suggest a process of indicating a numeric initial condition of the real-scale test. As a result of statistical analysis to verify the aforementioned process, it was confirmed that it was possible to quantitatively evaluate the reproducibility of the construction under the same conditions of embankments. This is expected to be a basic data for a full-scale embankment test using riverbed soil including other soil based real-scale tests.

• Journal of the Society of Disaster Information
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• v.9 no.3
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• pp.249-258
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• 2013

Recieved Mar. 06, 2013 Revised Mar. 29, 2013 Accepted Sep. 11, 2013In this study, we evaluated the method performance and the optimum sample injection method of the portable GC/MS(HAPSITE) which were designed to operate on scene of chemical accidents. Chemicals used for performance test were vinyl chloride(VC), methyl chloride(MC), benzene(Bz), toluene(Tol). CRM(Certified Reference Material) Manufactured by KRISS(Korea Research Institute of Standards and Science) was used as the standard gas. The results showed that 1) Among three sample injection methods(Cylinder, Silico canister, and Bag), bag was identified as the most appropriate sample injection method. Bag material and capacity did not significantly affect the results. The most ideal reproducibility occurred at the 2-minute point of the purge time in the loop and tenax methods. 2) Performance evaluation of HAPSITE was conducted. Evaluation items were reproducibility, linearity, method detection limit, etc. Tenax concentration method was appropriate for larger molecules and Carbopack concentration method was suitable for smaller molecules.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.177-180
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• 2001

This paper describes the calibration method and the evaluation method of relative expanded uncertainty for a multi-axis force/moment sensor. This sensor should be calibrated to be use in the industry. Now, the confidence of the calibration result is expressed with interference error. But it is no inaccurate, because an interference error, besides, a reproducibility error of the sensor, a error of this six-axis force/moment sensor calibrator, and so on. Thus, in order to accurately evaluate the relative expanded uncertainty of it, the concept of the uncertainty should be induced, and these errors must be contained in the relative expanded uncertainty. In this paper, the calibration method is exhibited and the evaluation method of the relative expanded uncertainty is also exhibited. And, a six-axis force/moment sensor was calibrated and the relative expanded uncertainty was evaluated.

• Transactions of Materials Processing
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• v.17 no.5
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• pp.356-363
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• 2008

An evaluation system of the thermal properties of exothermic & insulating materials was developed. By measuring the power supply of the induction furnace, the thermal property of exothermic & insulating materials could be evaluated with high reproducibility at elevated temperature of molten steel. The thermal properties of exothermic & insulating materials were affected by mixing condition of raw materials. The effect of main components of exothermic & insulating materials such as metallic aluminum and $Fe_2O_3$ powder on the exothermic and insulating properties was examined. It could be expected to design and develop various exothermic & insulating materials by means of the evaluation system of the thermal properties.

• Journal of the Korea Safety Management & Science
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• v.11 no.3
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• pp.209-216
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• 2009

A development in method of evaluating the measurement precisions using approximate F tests and variance components from expected mean square (EMS) is investigated. The research proposes three-factor mixed measurement models with the fixed and random factors. Unrestricted and unconstrained design work was rarely studied, while restricted and constrained designs have been significantly discussed. The unrestricted and unconstrained designs assume to be an independence of interaction. The proposed evaluation method about the measurement precisions can be extended to four-factor random measurement model or mixed measurement model. The study also presents the three evaluation indexes of precisions such as R&RTR (Reproducibility & Repeatability-To-Total Precision Ratio), PTR (Precision-To-Tolerance Ratio), and SNR (Signal-To-Noise Ratio). Numerical examples are proposed to evaluate the approximate F tests with Satterthwaite degrees of freedom and three indexes using the measurement precisions from EMS.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.6
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• pp.628-634
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• 2008

The purpose of this study is to examine reproducibility of operation plan and 3-dimentional jaw movement patterns by comparing jaw position of STO with post-operative jaw position. Twenty patients with class III dental and skeletal malocclusion who were treated with Le-Fort I osteotomy and B-SSRO were reviewed. Lateral cephalometric radiographs were taken within two weeks before operation and two days after operation. Cephalometric radiographs were compared and analyzed with orthognathic computer program '$V-Ceph^{TM}$'. Post-operative maxillary advancement was insufficient compared to maxillary advancement through STO. Post-operative setback movement was over compared to mandibular setback movement through STO. But statistically this is not significant. Maxillary vertical location is insignificant on the whole. Especially post-operative maxillary clockwise rotation is significant compared to maxillary rotation through STO. Post-operative maxillary clockwise rotation tendency is generally observed in all patients. So surgeons and staffs must consider this tendency when operation plan is established ans operation is being performed. Using intra or extra oral marking points, face bow, and bite plate will make exact surgery possible.