• Proceedings of the Korean Society of Medical Physics Conference
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• 2006.08a
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• pp.126-126
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• 2006

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.41
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• pp.167-175
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• 1997

This study is concerned with Quality Maintenance System in Total Productive Maintenance. The important factor in manufacturing process is to attain the uniformity of quality Also quality assurance system is defined such as manufacturing process and products. In this paper, the design of quality maintenance system is considered to manufacturing process elements. Especially the manufacturing process is oriented to machinery equipments, repair and maintenance system is wide principal factor. And quality in manufacturing field is influenced by equipment maintenance system. So in the article, maintenance system for quality is given in a view of quality assurance. And the analysis of Physical Mechanism is explored in real field example.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.113-116
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• 2006

After laws for recycling promotion of construction wastes was established on December, 2003, successive technical and institutional measures related to construction wastes are driven. Typically quality standards for recycled aggregate were enacted and officially announced, and recently the quality assurance system for recycled aggregate is promoted to be established. In relation, this study reviewed major factors affecting certification examination necessary to carry out quality assurance system for recycled aggregate and related standards to guarantee the quality of recycled aggregate. More specifically it is suggested that working place examination related to manufacturing facility and planning, quality control manpower and system, environmental and safety control, etc, and quality inspection with classified by for road construction, for concrete, and for asphalt concrete are used as quality assurance standards.

• Progress in Medical Physics
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• v.14 no.3
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• pp.184-188
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• 2003

It is strongly recommended that periodic quality assurance should be carried out in the Gamma Knife that is used in radiosurgery since high radiation is delivered in one session. Since the protocols for Gamma Knife recommended by associations or agencies on quality assurance are absent in Korea, hospitals possessing the Gamma Knife have developed their own protocols. In order to develop a quality assurance protocol suitable for Korea, we reviewed the protocols of the Gamma Knife manufacturer, USA and Japan. we categorized the periodic items into three parts,: radiation dose, mechanical and safety part. The USA recommended and regulated more strict than the manufacturer. Japan recommended the items and frequency based on the USA. In conclusion, we tried to suggest a basic Gamma Knife quality assurance protocol suitable for Korea.

• Journal of radiological science and technology
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• v.41 no.1
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• pp.39-45
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• 2018

The purpose of this study is to evaluate the usefulness of a software-based quality assurance system based on Volumetric Modulated Arc Therapy treatment plan. Evaluate treatment plan through the D VH analysis, PTV mean dose ($D_{mean}$) and PTV 95% dose($D_{95}$) compare the MFX based on original treatment plan, Average error rate was $0.9{\pm}0.6%$, $1.0{\pm}0.8%$, respectively. Measuring point dose using phantom and ion chamber, the average error rate between the ionization chamber and MFX was $0.9{\pm}0.7%$, $1.1{\pm}0.7%$ (high dose region), $1.1{\pm}0.9%$, $1.2{\pm}0.7%$ (low dose region). The average gamma though of MFX and $Delta^{4PT}$ is $98.7{\pm}1.2%$, $98.4{\pm}.3%$, respectively. Through this study, A software based QA system that simplifies hardware based QA procedures that involve a lot of time and effort. It can be used as a simple and useful tool in clinical practice.

• Progress in Medical Physics
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• v.32 no.4
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• pp.107-115
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• 2021

Purpose: The purpose of this study was to compare the clinical quality assurance results of portal dosimetry using an electronic portal imaging device, a method that is extensively used for patient-specific quality assurance, and the newly released Mobius3D for intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT). Methods: This retrospective study includes data from 122 patients who underwent IMRT and VMAT on the Novalis Tx and VitalBeam linear accelerators between April and June 2020. We used a paired t-test to compare portal dosimetry using an electronic portal imaging device and the average gamma passing rates of MobiusFX using log files regenerated after patient treatment. Results: The average gamma passing rates of portal dosimetry (3%/3 mm) and MobiusFX (5%/3 mm) were 99.43%±1.02% and 99.32%±1.87% in VitalBeam and 97.53%±3.34% and 96.45%±13.94% in Novalis Tx, respectively. Comparison of the gamma passing rate results of portal dosimetry (3%/3 mm) and MobiusFX (5%/3 mm as per the manufacturer's manual) does not show any statistically significant difference. Conclusions: Log file-based patient-specific quality assurance, including independent dose calculation, can be appropriately used in clinical practice as a second-check dosimetry, and it is considered comparable with primary quality assurance such as portal dosimetry.

• Journal of the korean Society of Automotive Engineers
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• v.26 no.1
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• pp.76-82
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• 2004

In this paper, the trend of quality management system that suppliers in the automotive industry are adopting, the classification system of suppliers and car manufacturers requirements for quality are described. Due to the complexity of the requirements for quality, the introduction of an active quality management system which can meet all conditions is a difficult task. Thus, to cope with this difficulty, this paper shows the optimal requirements that suppliers have to consider when they are introducing quality management system and the discriminated strategies to assure parts quality by supplier model.

• Journal of Korean Society for Quality Management
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• v.51 no.2
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• pp.155-170
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• 2023

Purpose: Nowadays, the risk assessment system is widely used in many industrial and public areas to reduce the possible risks. The system is used to determine the priorities of the government quality assurance works in Defense Agency for Technology and Quality. However, as the risk assessment system is used for other purposes, there are some items that need improvement, and in this study, we propose improvement plans by benchmarking the risk assessment systems of other institutions. Methods: In this paper, first, the procedures of risk assessment system used in many industrial sites were reviewed, and how each institution specialized and applied the system. Afterwards, by benchmarking various risk assessment systems, an improvement plan on how to operate the risk assessment system in the case of government quality assurance for centrally procured military supplies was presented, and practical application cases were presented to prove the usefulness of the improvement plan. Results: The proposed risk assessment system differs from the existing system in five major aspects. First, inputs, outputs, and key performance indicators were specified from the systematic point of view. Second, risk analysis was analyzed in four dimensions: probability of occurrence, impact, detection difficulty. Third, risk mitigation measures were classified, control, transfer, and sharing. Fourth, the risk mitigation measures were realized through document verification, product verification, process verification, and quality system evaluation. Finally, risk mitigation measures were implemented and the effectiveness of the risk mitigation measures was evaluated through effectiveness evaluation. Conclusions: In order for the risk assessment procedure proposed in this study to be applied to actual work, it is necessary to obtain the consent of the person involved in the work due to the increased time for risk identification and preparation of the government quality assurance log, and a change in the information system that performs the actual work is required. Therefore, the authors of this study plan to actively perform internal seminar presentations and work improvement suggestions to apply these research outputs to actual work.

• Research in Plant Disease
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• v.23 no.4
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• pp.314-321
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• 2017

Acidovorax valerianellae had been reported a causal agent of bacterial black spot disease on corn salad in France, 2003 and on watermelon in Korea 2011. In this study, difference in host specificity between 2 groups, corn salad strains and watermelon strains, of Acidovorax valerianellae was recognized and compared. In the pathogenicity test, all 5 watermelon strains showed pathogenicity on the 6 Cucurbitaceae plants but not on corn salad, whereas 4 corn salad strains showed pathogenicity only on the corn salad. Utilization of Biolog substrates was different between watermelon strains and corn salad strains on 4 substrates, Malonic Acid, ${\alpha}-Hydroxybutyric$ Acid, ${\alpha}-Keto$ Butyric Acid, and Glycyl-L Glutamic Acid. The phylogenetic tree built with the 16S rDNA sequences showed that all of A. valerianellae stains was grouped into 1 clade separating from the other species of Acidovorax genus. Within A. valerianellae clade, watermelon strains and corn salad strains were separated into 2 sub-groups. REP-PCR analysis also separated the two groups. Host specificity, substrate utilization, and some genetic characteristics suggested that there are two pathogenic groups, watermelon group and corn salad group in A. valerianellae.

• Progress in Medical Physics
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• v.21 no.1
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• pp.99-112
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• 2010

In Republic of Korea, there are many Quality Assurance protocol for general radiation treatment machine such as linac. However, Quality Assurance protocol for radiosurgery treatment system is not ready perfectly. One of the radiation treatment machine for radiosurgery, novalis system needs to suitable Quality Assurance protocol for using it right way during radiation treatment and maintaining suitable accuracy for daily, weekly, monthly and annually periods. Therefore, in this article, we develop Quality Assurance protocol for novalis system. We collected and analysed domestic and foreign novalis Quality Assurance protocol. After that, we selected essential QA items and each tolerance range for developing proper QA protocol, and we made anatomical phantom for execution of selected QA items and evaluation of overall state of QA, and then, we use this measured value as a reference. Quality Assurance items are consisted of Mechanical accuracy QA part and Radiation delivery QA part. Mechanical accuracy QA part is comprised of radiation generation machine part, assistive devices part and multi-leaf collimator part. Radiation delivery QA part is divided into radiation isocenter accuracy and dosimetric evaluation. After that, developed novalis QA tables are made by using these QA items. These novalis QA tables would be used to good standard in order to maintain apt accuracy for radiosurgery in daily, weekly, monthly and annually periods.