• Title/Summary/Keyword: Quality assurance system

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Evaluation of Corrected Dose with Inhomogeneous Tissue by using CT Image (CT 영상을 이용한 불균질 조직의 선량보정 평가)

  • Kim, Gha-Jung
    • The Journal of Korean Society for Radiation Therapy
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    • v.18 no.2
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    • pp.75-80
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    • 2006
  • Purpose: In radiation therapy, precise calculation of dose toward malignant tumors or normal tissue would be a critical factor in determining whether the treatment would be successful. The Radiation Treatment Planning (RTP) system is one of most effective methods to make it effective to the correction of dose due to CT number through converting linear attenuation coefficient to density of the inhomogeneous tissue by means of CT based reconstruction. Materials and Methods: In this study, we carried out the measurement of CT number and calculation of mass density by using RTP system and the homemade inhomogeneous tissue Phantom and the values were obtained with reference to water. Moreover, we intended to investigate the effectiveness and accuracy for the correction of inhomogeneous tissue by the CT number through comparing the measured dose (nC) and calculated dose (Percentage Depth Dose, PDD) used CT image during radiation exposure with RTP. Results: The difference in mass density between the calculated tissue equivalent material and the true value was ranged from $0.005g/cm^3\;to\;0.069g/cm^3$. A relative error between PDD of RTP and calculated dose obtained by radiation therapy of machine ranged from -2.8 to +1.06%(effective range within 3%). Conclusion: In conclusion, we confirmed the effectiveness of correction for the inhomogeneous tissues through CT images. These results would be one of good information on the basic outline of Quality Assurance (QA) in RTP system.

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Evaluation of the Modulation Transfer Function for Computed Tomography by Using American Association Physics Medicine Phantom (컴퓨터단층검사에서 AAPM Phantom을 이용한 변조전달함수 평가)

  • Kim, Ki-Won;Choi, Kwan-Woo;Jeong, Hoi-Woun;Jang, Seo-Goo;Kwon, Kyung-Tae;Son, Soon-Yong;Son, Jin-Hyun;Min, Jung-Whan
    • Journal of radiological science and technology
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    • v.39 no.2
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    • pp.193-198
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    • 2016
  • In clinical computed tomography (CT), regular quality assurance (QA) has been required. This study is to evaluate the MTF for analyzing the spatial resolution using AAPM phantom in CT exam. The dual source somatom definition flash (siemens healthcare, forchheim, Germany), the brilliance 64 (philips medical system Netherlands) and aquilion 64 (toshiba medical system, Japan) were used in this study. The quantitative evaluation was performed using the image J (wayne rasband national institutes of health, USA) and chart method which is measurement of modulation transfer function (MTF). In MTF evaluation, the spatial frequencies corresponding to the 50% MTF for the CT systems were 0.58, 0.28, and $0.59mm^{-1}$, respectively and the 10% MTF for the CT systems were 1.63, 0.89, and $1.21mm^{-1}$, respectively. This study could evaluate the characteristic of spatial resolution of MTF using chart method, suggesting the quantitative evaluation method using the data.

A Comparative study among 2nd cycle of Evaluation and Accreditation system on Korean Medicine Education, Global Standards of WFME for Basic Medical Education and WHO guidelines for quality assurance of Traditional Medicine Education in the Western Pacific Region (한의학교육평가원 2주기, 세계의학교육연합회(WFME)의 의학기본교육, WHO 서태평양 지역지부(WHO/WPRO) 인증 기준 간의 비교 연구)

  • Sun, Seung Ho
    • Journal of Society of Preventive Korean Medicine
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    • v.23 no.3
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    • pp.41-57
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    • 2019
  • Objective : The purpose of our study is to compare and analyze the standards for the 2nd cycle of Evaluation and Accreditation system on institute of Korean Medicine Education & Evaluation (2nd IKMEE standards) and WHO guidelines for quality assurance of Traditional Medicine Education in the Western Pacific Region (WHO/WPRO guidelines) around the global standards of World Federation for Medical Education for basic medical education (WFME standard) to identify the shortcomings and improvements of 2nd IKMEE standards. Method : Each article of 2015 revised WFME standard was translated and summarized with focus on its core content. The next step was to review and analyze the corresponding contents of 2nd IKMEE standards in 2016 and the WHO/WPRO guidelines in 2005 for each item, focusing on the WFME standards. Results : All items in the fields of 3. assessment of students and 7. program evaluation in the WFME domain were absent from the 2nd IKMEE standards, and almost none of the WHO/WPRO guidelines. Most items in 1. the mission and outcomes domain, except for some items in the 1.1 mission field, the items of 2.6~2.8 fields in 2. education program domain, the items of 4. student domain except for the items of 4.3 student counseling and support field, and almost all items about quality development in WFME standards did not have a corresponding item in both the 2nd IKMEE standards and the WHO/WPRO standards. Conclusion : 1. The WFME standards are applicable to the criteria development of IKMEE standards. Several items of the WFME standards may need to be modified to apply the educational characteristics of Korean medicine, but consensus or further study is required. 2. Both the 2nd IKMEE standards and the WHO/WPRO standards are very insufficient to meet the WFME standards. In particular, 3. assessment of students and 7. program evaluation in the WFME domain were not in the 2nd IKMEE standards. This standard needs to be supplemented.

A Study on the Application Method of Munition's Quality Information based on Big Data (빅데이터 기반 군수품 품질정보 활용방안에 대한 연구)

  • Jeon, Sooyune;Lee, Donghun;Bae, Manjae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.6
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    • pp.315-325
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    • 2016
  • Due to the expansion of data and technical progress in the military industry, it is important to extract meaningful information for assuring quality and making policies. The analysis of trends and decision making based on big data is helpful for increasing productivity in business and finding new business opportunities. We propose an application to collect reliable quality information for munitions and build a big data platform for using the accumulated information and numerical data. We verified the proposed platform using the Test Report Information Service (TRIS) system and suggest a method that utilizes unstructured and semi-structured data accumulated by TRIS. Thus, we expect that the proposed platform will help in building infrastructure for military data, making efficient strategies, and analyzing trends for assuring munitions quality.

Development of Customer Satisfaction Quality Indicator Considering Producer's Specification Limits (생산자규격을 고려한 소비자만족품질지표의 개발)

  • Kim, Dong-Hyuk;Chung, Young-Bae
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.41 no.4
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    • pp.50-58
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    • 2018
  • Process Capability ($C_{pk}$) is a representative measure of how well the producer manages dispersion and bias for the specifications needed by the consumer. This is expressed as a ratio of 6 times the natural tolerance to the specification. As the producer manages the dispersion small, the capacity index becomes higher. And it is classified into 5 grades according to the degree of management. It is a measure of the quality of processes used in most industrial fields. However, $C_{pk}$ is calculated by only reflecting the mean and dispersion of the process, there is a disadvantage that it can not give information about the economic loss caused by the inconsistency of the process with the target value. Overcoming these drawbacks, process capability indexes reflecting various types of loss functions such as $C_{pm}$, $C^+_{pm}$ and $C_{pl}$ have been developed. However, all of these previous studies have applied the limit to the consumer specification, which is based on the traditional and passive quality perception that the quality characteristic should exist within the limits of the consumer specification. In this study, we will develop 'Customer Satisfaction Quality Indicator (CSQI)' which is a quantitative indicator that can be fully evaluated when the manufacturer's specification limit, which is an aggressive quality strategy, is applied. This is expected to be useful decision information for both producers and consumers.

Computed Radiography applied to the Department of Radiation Oncology (Computed Radiography의 방사선종양학과로의 적용)

  • Hong, Seung-Il;Song, Jong-Nam;Kim, Young-Jae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.10a
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    • pp.547-550
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    • 2011
  • We measured that is Gantry, Collimator Star Shot, Light vs. Radiation, HDR QA with Medical LINAC Then, PACS was implemented on the digital images on the monitor that can be confirmed through the QA. Also, for cooperation with OCS system that is using from present source and impose code that need in treatment in each treatment, did so that Order that connect to network, input to CR may appear, did so that can solve support data mistake of Pinacle and PACS that is Planning System and look at Planning premier in PACS.

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Quality Assurance of Patients for Intensity Modulated Radiation Therapy (세기조절방사선치료(IMRT) 환자의 QA)

  • Yoon Sang Min;Yi Byong Yong;Choi Eun Kyung;Kim Jong Hoon;Ahn Seung Do;Lee Sang-Wook
    • Radiation Oncology Journal
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    • v.20 no.1
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    • pp.81-90
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    • 2002
  • Purpose : To establish and verify the proper and the practical IMRT (Intensity--modulated radiation therapy) patient QA (Quality Assurance). Materials and Methods : An IMRT QA which consists of 3 steps and 16 items were designed and examined the validity of the program by applying to 9 patients, 12 IMRT cases of various sites. The three step OA program consists of RTP related QA, treatment information flow QA, and a treatment delivery QA procedure. The evaluation of organ constraints, the validity of the point dose, and the dose distribution are major issues in the RTP related QA procedure. The leaf sequence file generation, the evaluation of the MLC control file, the comparison of the dry run film, and the IMRT field simulate image were included in the treatment information flow procedure QA. The patient setup QA, the verification of the IMRT treatment fields to the patients, and the examination of the data in the Record & Verify system make up the treatment delivery QA procedure. Results : The point dose measurement results of 10 cases showed good agreement with the RTP calculation within $3\%$. One case showed more than a $3\%$ difference and the other case showed more than $5\%$, which was out side the tolerance level. We could not find any differences of more than 2 mm between the RTP leaf sequence and the dry run film. Film dosimetry and the dose distribution from the phantom plan showed the same tendency, but quantitative analysis was not possible because of the film dosimetry nature. No error had been found from the MLC control file and one mis-registration case was found before treatment. Conclusion : This study shows the usefulness and the necessity of the IMRT patient QA program. The whole procedure of this program should be peformed, especially by institutions that have just started to accumulate experience. But, the program is too complex and time consuming. Therefore, we propose practical and essential QA items for institutions in which the IMRT is performed as a routine procedure.

Intensity Modulated Radiation Therapy Commissioning and Quality Assurance: Implementation of AAPM TG119 (세기조절방사선치료(IMRT)의 Commissioning 및 정도관리: AAPM TG119 적용)

  • Ahn, Woo-Sang;Cho, Byung-Chul
    • Progress in Medical Physics
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    • v.22 no.2
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    • pp.99-105
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    • 2011
  • The purpose of this study is to evaluate the accuracy of IMRT in our clinic from based on TG119 procedure and establish action level. Five IMRT test cases were described in TG119: multi-target, head&neck, prostate, and two C-shapes (easy&hard). There were used and delivered to water-equivalent solid phantom for IMRT. Absolute dose for points in target and OAR was measured by using an ion chamber (CC13, IBA). EBT2 film was utilized to compare the measured two-dimensional dose distribution with the calculated one by treatment planning system. All collected data were analyzed using the TG119 specifications to determine the confidence limit. The mean of relative error (%) between measured and calculated value was $1.2{\pm}1.1%$ and $1.2{\pm}0.7%$ for target and OAR, respectively. The resulting confidence limits were 3.4% and 2.6%. In EBT2 film dosimetry, the average percentage of points passing the gamma criteria (3%/3 mm) was $97.7{\pm}0.8%$. Confidence limit values determined by EBT2 film analysis was 3.9%. This study has focused on IMRT commissioning and quality assurance based on TG119 guideline. It is concluded that action level were ${\pm}4%$ and ${\pm}3%$ for target and OAR and 97% for film measurement, respectively. It is expected that TG119-based procedure can be used as reference to evaluate the accuracy of IMRT for each institution.

A Method to Calculate a Pass Rate of the ${\gamma}$-index Analysis in Tomotherapy Delivery Quality Assurance (DQA) (단층치료기를 이용한 방사선 치료의 환자별 정도관리 평가를 위한 감마인덱스의 정량화 방법)

  • Park, Dahl;Kim, Yong-Ho;Kim, Won-Taek;Kim, Dong-Won;Kim, Dong-Hyun;Jeon, Ho-Sang;Nam, Ji-Ho;Lim, Sang-Wook
    • Progress in Medical Physics
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    • v.21 no.4
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    • pp.340-347
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    • 2010
  • DQA, a patient specific quality assurance in tomotherapy, is usually performed using an ion chamber and a film. The result of DQA is analysed with the treatment planning system called Tomo Planning Station (TomoPS). The two-dimensional dose distribution of film measurement is compared with the dose distribution calculated by TomoPS using the ${\gamma}$-index analysis. In ${\gamma}$-index analysis, the criteria such as 3%/3 mm is used and we verify that whether the rate of number of points which pass the criteria (pass rate) is within tolerance. TomoPS does not provide any quantitative information regarding the pass rate. In this work, a method to get the pass rate of the ${\gamma}$-index analysis was suggested and a software PassRT which calculates the pass rate was developed. The results of patient specific QA of the intensity modulated radiation therapy measured with I'mRT MatriXX (IBA Dosimetry, Germany) and DQA of tomotherapy measured with film were used to verify the proposed method. The pass rate was calculated using PassRT and compared with the pass rate calculated by OmniPro I'mRT (IBA Dosimetry, Germany). The average difference between the two pass rates was 0.00% for the MatriXX measurement. The standard deviation and the maximum difference were 0.02% and 0.02%, respectively. For the film measurement, average difference, standard deviation and maximum difference were 0.00%, 0.02% and 0.02%, respectively. For regions of interest smaller than $24.3{\times}16.6cm^2$ the proposed method can be used to calculate the pass rate of the gamma index analysis to one decimal place and will be helpful for the more accurate DQA in tomotherapy.

An Integrative Method of Fault Tree Analysis and Fault Modes and Effect Analysis for Security Evaluation of e-Teaching and Learning System (전자 교수학습 시스템의 보안성 평가를 위한 결함트리분석과 고장유형에 대한 영향분석의 통합적 방법)

  • Jin, Eun-Ji;Kim, Myong-Hee;Park, Man-Gon
    • KIPS Transactions on Software and Data Engineering
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    • v.2 no.1
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    • pp.7-18
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    • 2013
  • These days, the teaching and learning system has been increasing for the rapid advancement of the information technologies. We can access education systems of good quality anytime, anywhere and we can use the individually personalized teaching and learning system depending on developing the wireless communication technology and the multimedia processing technology. The more the various systems develop, the more software security systems become important. There are a lot kind of fault analysis methods to evaluate software security systems. However, the only assessment method to evaluate software security system is not enough to analysis properly on account of the various types and characteristic of software systems by progressing information technology. Therefore, this paper proposes an integrative method of Fault Tree Analysis (FTA) and Fault Modes and Effect Analysis(FMEA) to evaluate the security of e-teaching and learning system as an illustration.