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        검색결과 30

        4.
        2015.12 KCI 등재 구독 인증기관·개인회원 무료
        Pulpose : Although diffusion tensor imaging (DTI) has been widely used for the quantitative analyses of the integrity of white matter in the brain in clinical and research fields, quality assurance (QA) for DTI has not been fully established. The purpose of this study suggests a QA guideline for DTI using the American College of Radiology (ACR) Magnetic resonance imaging (MRI) head phantom. Materials and Methods : All experiments were performed using 1.5T and 3.0T scanners (InteraAchiva 1.5T and AchivaTx 3.0T; Philips Medical Systems, Netherlands) equipped with an 8-channel SENSE head coil. The standard axial SE T1-weighted MR images with 6, 15 and 32 directions of DTI were obtained using the standard scanning protocol “Phantom Test Guidance for the ACR MRI Accreditation Program” . Slice thickness and slice gap were set at 5 mm for standard axial SE T1 images and echo planar images, and then both images were compared. Reproducibility was tested with 7 repeat scans in 1.5T scanner and 10 repeat scans in 3.0T scanner. Between the scanning, the ACR MRI phantom was completely removed from coil and was repositioned for each new trial. Parameters for the QA protocol are shown in Table 1. The ACR MRI phantom was stored in the scanner room for at least 24 hours before an experiment, and the room temperature was measured before scanning for DTI. Results : There were statistically significant differences in the geometric accuracy between the 1.5T and 3.0T two scanners across all scan directions. The top-to-bottom diameters had a 11.3 mm error in 1.5T scanner and a 7.2 mm error in 3.0T scanner. Image intensity uniformity tests were significant in 6, 15, and 32 directions at 1.5T and 3.0T comparative analysis (p < 0.001). Additionally, percent signal-ghosting tests were significant in all directions, such as 6, 15 and 32 directions, in both 1.5T and 3.0T scanners (p < 0.001). The DTI images from 1.5T scanner had a ghosting ratio less than 0.025 at 1.5T scanner while 3.0T scanner had a ghosting ratio greater than 0.045. The low-contrast object detectability had a significant differences in 6, 15, 32 directions at 1.5T and 3.0T systems (p < 0.001). The DTI images from 1.5T system showed 2.85 spokes in 6 directions, 14.00 spokes in 15 directions, and 26.14 spokes in 32 directions. The DTI images from 3.0T system had 7.80 spokes in 6 directions, 32.20 spokes in 15 directions, and 37.30 spokes in 32 directions. Image distortion was significant in the anteriorposterior (AP) direction (p <0.001), but was not significant in right-left (RL) direction (p = 0.359). Image distortions in 1.5T scanner were 6.93 mm for the AP direction and 0.26 mm for the RL direction while the same for 3.0T system were 8.55 mm for the AP direction and 0.28 mm for the RL direction. For the FA and the ADC values, we acquired significant results in 6, 15, and 32 directions for 1.5T and 3.0T scanners (p < 0.001). The FA values were relatively lower for 3.0T system than for 1.5T system, and 32 directions for 3.0T scanner had the lowest value. The ADC values of 3.0T system were lower than those of 1.5T system, and 15 and 32 directions had the lowest values. Conclusion : This study is the first trial using the ACR MRI phantom that is easily accessible in most clinical MR centers. Also, the present study using the ACR MRI phantom suggests a QA method for DTI with high reproducibility and easy accessibility.
        5.
        2015.06 구독 인증기관 무료, 개인회원 유료
        This paper will compare two instruments for quality assurance on the internationalization of higher education institutions: The Internationalization Quality Review Process (IQRP) and the International Education Quality Assurance System (IEQAS). Methodologies adopted were ethnography, hermeneutical phenomenology and the cross-cultural comparative approach. Findings show that IQRP was more comprehensive than IEQAS. Three domains -- the nature of the quality assurance, procedural aspect and rewards and sanctions -- were selected, contrasted, compared and analyzed. During the analysis of sanctions, a discernable concept, equity was derived from the IEQAS and an in-depth analysis was undertaken to reveal and interpret the nature of the meaning.
        5,800원
        6.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        According as radiation therapy technique develops, standardization of radiation therapy has been complicated by the plan QA(Quality Assurance). However, plan QA tools are two type, OADT (opposite accumulation dose tool) and 3DADT (3 dimensional accumulation dose tool). OADT is not applied to evaluation of beam path. Therefore tolerance error of beam path will establish measurement value at OADT. Plan is six beam path, five irradiation field at each beam path. And beam path error is 0 degree, 0.2 degree, 0.4 degree, 0.6 degree, 0.6 degree, 0.8 degree. Plan QA accomplishes at OADT, 3DADT. The more path error increases, the more plan QA error increases. Tolerance error of OADT path is 0.357 using tolerance error of conventional plan QA. Henceforth plan QA using OADT will include beam path error. In addition, It will increase reliability through precise and various plan technique.
        4,000원
        7.
        2015.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper is concerned with the quality assurance of recliner chair frame. It is necessary for recliner chair frame that is endurable for the repeated load and sudden impact of human sitting and general use. And this paper studies the quality assurance of recliner chair frame that is newly designed and made in the regional company. The procedures of quality assurance are composed of the stress analysis using computer simulation and results by test equipments. Theoretical survey is composed with the stress analysis results from ANSYS program and quality assurance procedures are composed of static load test, reciprocal load test of spring and impact test of locking frame. The results from the mechanical tests satisfy the safety criteria of the Korean national standard. This research assures the quality of new designed recliner chair frame and can be used as quality assurance procedures of concerned structures
        4,000원
        8.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Aging of the fire organizations, typical disaster response agencies also will be in serious problems with aging society. It is expected that the ratio of more than fifties will reach 31~40% after 10~15 years in Seoul fire organization. This Aging of firefighters can bring about a serious problem in disaster and safety management, since firefighters require robust fitness and healthy bodies in disaster situations. In this study, after the analysis of aging status and trend of firefighters in Seoul, I have an empirical analysis about the impact this aging has on organization effectiveness and QA. As a result, the increase of the elderly reduced organization effectiveness and QA. In addition, in the group consisting of less than 50, it is expected to increase the organization's effectiveness and QA activities through field activity to improve the professional skills with age, but could not be confirmed. In the group consisting of more than fifties, it was found that aging had a significant negative impact on organizational effectiveness and QA activities as factors, including physical deterioration by aging.
        4,500원
        9.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A prerequisite for improving the quality of a product is to enhance the quality of its parts supplied from outsourced enterprises. An enterprise certified by ISO 9001 Quality Management System is expected to develop their effective quality assurance system and maintain it through continuous control and improvement, thereby ensuring the good quality of products that they produce. However, it is reported that small and medium–sized enterprises certified by ISO 9001 have difficulty establishing an effective quality assurance system. This study aims to propose a new method of improving a quality assurance system that can be more effective in small and medium–sized enterprises. This study collectively considered requirements specified in several international standards on quality system and the results of expert group brainstorming to identify evaluation areas and items for assessing a quality assurance system. Based on these evaluation areas and items, a set of checklists for diagnosing and improving a quality assurance system was developed. In order to demonstrate the usefulness of the proposed method, this study applied it to ten small and medium-sized enterprises and could identify four approaches for improving their current quality assurance system. The presented improvement method, which consists of establishment of quality goals and quality innovation plan, defective products corrective activities, 4M and design change process, improvement of customer quality information management, is expected to be utilized as a useful tool for the enhancement of the quality assurance system of small and medium-sized enterprises.
        4,300원
        10.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To estimate weld quality of the resistance spot-welding, the acoustic emission features are investigated from the total acoustic emission signal at the single-spot weld. Typically, the resistance spot welding process consists of several stages: set-down of the electrodes, squeeze, current flow, forging, hold time, and lift-off. Various types of acoustic emission response corresponding to each stage can be separately analyzed by using back-propagation neural network classifier and wavelet transform technique. The presented machine learning results provide a validation for using back-propagation neural network and wavelet transform technique as a valuable insights into the resistance spot-welding process. Especially, a wavelet transform technique is demonstrated and the plots are very powerful in the recognition of the acoustic emission features
        4,000원
        11.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        기후 자료를 정확히 분석하고 미래 환경을 예측하기 위해서는 이들 자료에 대한 검증과 품질 관리 과정이 필요하다. 본 연구에서는 우리나라에서 구축한 기후 자료의 품질을 효과적으로 관리하기 위하여, 기후 자료의 시각화 도구를 개발하고, 이를 이용한 품질 관리 방안을 제시하였다. 본 연구에서 개발한 HTML5 기반의 시각화 도구를 이용하여, 인터넷 환경에서 다수의 전문가들이 효과적으로 기후 자료를 관리할 수 있게 되었다. 기후자료의 시각화 도구를 활용하여 기후자료의 품질 관리 업무에 적용한 결과, 다양한 종류의 품질 관리 검사를 효과적으로 수행할 수 있었다. 본 연구의 결과는 향후 기상청의 기후 자료 품질 관리 업무에 활용될 수 있을 것으로 예상된다.
        4,200원
        13.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since commercial operation of Kori-1 nuclear power plant in 1978, twenty units are under operation and six units are under construction at 2011 present. Nuclear power become a main energy source in our country. However, the plant was constructed by a USA
        4,200원
        14.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Traditionally Nuclear Research and Development (R&D) result has been big influence on other industries and societies and it requires large scale investments and study period. So it is essential to apply Quality Assurance (QA) for systematic R&D management
        4,000원
        15.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        온라인 게임의 품질 관리는 게임의 완성도를 결정하는 중요한 단계 중 하나이다. 본 논문에서는 대학 수업을 통해 게임의 품질 관리를 효과적으로 운영하기 위한 포커스 그룹 테스트(Focus Group Test) 프로세스를 제안한다. 이를 위해 게임 테스팅 업체에서 시행하는 테스트 항목들을 검토하여 포커스 그룹 테스트를 통해 게임 품질 관리를 효과적으로 하기 위한 테스트 그룹과, 그룹별 세부 테스트 내용을 제안한다. 다음으로 대학 수업을 통해 포커스 그룹 테스트를 효 과적으로 운영하기 위한 운영 시스템을 제안한다. 마지막으로 개발 중인 상용 온라인 게임을 의뢰받아 포커스 그룹 테스트를 수행한 사례를 소개함으로서 제안한 내용이 효과적으로 운영될 수 있음을 검증한다. 제안한 방식의 수업 운 영을 통해 실무 지향적으로 수업이 가능하며 개발사와 대학 간의 효과적인 산학 협력이 가능할 것으로 판단된다
        4,000원
        16.
        2009.05 구독 인증기관 무료, 개인회원 유료
        A institute developed Quality Assurance(QA) program for nuclear R&D projects to meet the demands of its customers' requirements for recognized quality standards and nuclear industry accepted practices. It was implemented by project quality assurance plan as a new process. This paper is designed to introduce the process of establishment and execution of nuclear quality assurance programs for R&D as a case study. This QA program can be used as a reference to other organization on implementation of QA for R&D projects.
        4,000원
        17.
        2009.05 구독 인증기관 무료, 개인회원 유료
        A success of network integration project depends on how well we are able to provide a network implementation fulfilled with customer's requirements within an established budge. As its environment have become enlarged and distributed, the interested parties will be increased and as its customer's technologies have become generalized through a lot of learning opportunities, the requirements will be increased and its qualities will be better. Therefore, it is getting difficult to satisfy their requirements and maintain its qualities. Effectively managing conditions that are able to have effects on resources and schedule at the early requirement analysis stage due to the requirement changes at the end of the project, we are about to offer a service quality and requirement management that can fulfill with customer's requests.
        4,000원
        18.
        2008.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 콘크리트 도로 포장의 고품질을 확보하기 위한 방안으로 지불규정을 개발하는 과정의 일환으로 수행되었으며 지불규정 적용을 위한 합리적인 품질측정방법의 개발 방안을 모색하고 품질에 따라 지불계수를 결정하는 기법을 개발하는 것이 목적이다. 우선 콘크리트 포장의 지불규정 인자인 슬래브 두께에 대하여 통계적인 기법을 이용하여 측정 자료를 분석함으로써 측정자에 따른 읽음오차를 감안하여 지불규정의 기준에 대한 허용오차를 결정하는 방법을 제시하였으며 두께 측정 시 측정 간격 및 위치 등의 측정빈도를 결정하는 방법도 제시하였다. 또한 지불계수를 합리적으로 결정하는 방법을 제시하기 위하여 슬래브 두께와 콘크리트 철강도 등의 지불규정 인자에 대하여 미국에서 사용하고 있는 PWL 방법을 이용한 지불계수를 산정하여 정규분포와 t분포를 이용하여 구한 지불계수와 비교분석함으로써 국내에 적용하기 적절한 지불계수를 산정하는 방안을 제시하였다.
        4,000원
        19.
        2006.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
          Many producers put sampling inspection policy into the way of their convenience. Examples of the convenience are irregular lot size and too small sample size. Because they don"t use a standard sampling inspection policy, they can not guarantee the quali
        4,000원
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