• 대한디지털의료영상학회논문지
• /
• 제14권2호
• /
• pp.47-56
• /
• 2012

Amount of radiation exposure by seeing through fluoroscopy examination while is many patient exposure administration and unprepared misgovernment be. In this study, abdominal fluoroscopy during the scan, the dose and image quality change according to the use of grid and added filter optimized by measuring the test condition is proposed. Uses seeing through fluoroscopy examination equipment of Image Intensifier of Easy Diagnost Eleva (Philips), under tube type and uses Human phantom and measures average area dose according to grid insertion existence and nonexistence and added filter kind change. Measure sum of 29 organ dose and effective dose through PCXMC imagination simulation program and image J program through noise, SNR, image distortion was measured. Resolution, sharpness, and analyzed using the MTF curves. Fluorography the grid to insert the filter thickness and thickening and increased the average area dose and organ doses and effective dose. In the case of spot examination, when inserted grid, average area dose and organ dose and effective dose increased. Filter thickens the average area dose decreased, but the organ doses and effective dose were increased when use 0.2mmCu+1mmAl filter, decreased slightly. Noise and SNR measurements without inserting the gird, if you do not use the added filter was the lowest and when measure the distortion, 0.1mmCu+1mmAl filter was no difference of image quality in case insert grid was judged that when did not use occasion added filter that do not use grid, difference of image quality does not exist. Did not show a big difference, according to the grid and uses of the added filter sharpness, and resolution. Patient dose increases with factors that reduce the quality of the image so reckless grid and the use of the added filter when abdominal fluoroscopy examination should be cautious in using.

• International Journal of Contents
• /
• 제6권3호
• /
• pp.15-18
• /
• 2010

Grid system is based on the Grid Security Infrastructure (GSI). GSI uses user's proxy to guarantee availability among multi-trust domains. Since grid system has been developed focusing on availability, GSI provides authentication and authorization performed by systems, but there are lacks of privacy consideration. For this reason, some researchers decide to use their own cluster system and do not want to use public grid systems. In this paper, we introduce a new privacy enhanced security mechanism for grid systems. With this mechanism, user can participate in resource allocation and authorization to user's contents more actively. This mechanism does not need to change previous middleware and minimize the computational overheads.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
• /
• pp.585-588
• /
• 2002

Grid provides integral ing system that enables to use distributed computing resource and services as adapts traditional infrastructures to overcome the distributed computing environments. But, computing today is moving away from a restriction of the desktop, becoming diffused into our surrounding and onto our personal digital devices. In such mobile computing environments, users expects to access resource and services at any time from anywhere in such Mobile-Grid computing. This expectation results security issues, since the computing environments is expanded. This paper describes the security challenges in Mobile-Grid computing, explaining why traditional security mechanism fail to meet the demands of these environments. This paper describes policy driven security mechanism enabled entity to use service and data in trust Mobile-Grid environments and a set of security service module that need to be realized in the Mobile-Grid security architecture presents a set of use pattern that show hew these modules can be used for billing service in a secure Mobile-Grid environments.

• 디지털산업정보학회논문지
• /
• 제9권2호
• /
• pp.23-32
• /
• 2013

The purpose of this study is to make effective mobile grid considered general environment, which can be summarized as irregular mobility, service exploration, data sharing, variety of machines, limit to the battery duration, etc. The data was extracted from the Dartmouth College. We analysed mobile use pattern of a specific group and applied pattern using hybrid method. As a result, we could adjust infra usage effectively and appropriately and cost cutting and increase satisfaction of user. In this study, by applying weighting method based on access time interval, we analysed use pattern added time variation with association rule during users in mobile grid environment. We proposed more stable way to manage patterns in a mobile grid environment that is being used as a hybrid form to process the data value received from the server in real time. Further studies are needed to get appropriate use pattern by group using use patterns of various groups.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 컴퓨터소사이어티 추계학술대회논문집
• /
• pp.219-222
• /
• 2003

Increasingly, Grid technics are developed and demonstrated widely. These days, a point to be considered is that clients use Grid resources more easily. Grid Portals, based on standard Web technologies, are increasingly used to provide user interfaces for using Grid resources. But, due to lack of delegation capabilities in using Grid resources through Grid Portals, it is requested of the security mechanisms. That solution is to using Myproxy Server. Myproxy Server allows Grid user to use Grid resources being interact with Grid Portals. But, while users log in Grid Portals, we are faced with over the overlap of users credentials. This paper describes relationship between Portals and Myproxy, and proposes the way to solve the problem of the overlap of users credentials.

• 대한방사선기술학회지:방사선기술과학
• /
• 제33권4호
• /
• pp.341-348
• /
• 2010

상 하지 촬영 시 서울 경기지역 병원의 FPD(Flat Pannel Detector) System 사용 실태와 격자 사용에 따른 환자 선량 및 C-D Phantom에 의한 화질평가, 임상 평가자들에 의한 영상평가를 한 결과 다음과 같은 결론을 얻었다. 1. FPD system(12대)의 사용 실태 조사결과 격자비는 8 : 1에서 13 : 1까지이며, 12 : 1이 6대로 가장 많았다. 이 중 격자의 탈 부착이 가능한 장비는 8대이지만, 사용하지 않는 것이 5대(62.5%)로 격자를 그대로 사용하는 곳이 9곳(75.5%)이었다. 2. 실험에 사용된 장비에서 격자사용으로 환자가 받은 선량이 4.13배에서 4.79배까지 많이 받는 것으로 나타났다. 3. 노출조건(mAs)의 변화(0.5배나 2.0배)에 따라 환자가 받는 선량의 차이는 환자 두께에 따라 크게 차이 나지는 않았다. 4. C-D Phantom에 따른 영상의 화질평가는 격자 사용 시와 노출량이 많아질 때 영상의 식별은 잘 되었다. 5. 임상 평가는 두께가 얇은 Hand PA 영상에서는 격자사용을 하지 않는 것이 더 좋았다. 두께가 두꺼운 Knee AP 영상에서는 격자를 사용하는 것이 좋다는 평가를 받았다. 그러나 환자선량이 적어진다면 격자를 사용하지 않겠다는 의견이 5명 중 3명으로 더 많았다.

• 한국수학교육학회지시리즈C:초등수학교육
• /
• 제22권1호
• /
• pp.13-27
• /
• 2019

초등 수학 교과서에서 모눈종이의 활용은 수와 연산, 도형, 측정 영역에서 사용하고, 이 중에서 도형 영역에서 가장 많이 사용하고 있다. 이러한 사용에도 불구하고 실제 초등 수학 교과서의 모눈종이를 활용한 수업 과정을 보면 모눈종이 사용에 따른 시행착오의 수정이나 보완이 어려워서 보다 효과적인 방안이 필요해보였다. 이에 본 연구에서는 한국과학창의재단(2017)의 '수학 수업용 교구 표준안'에서 제시한 교구 중에서 모눈종이보다 더 효과적인 모눈종이판 교구의 활용성을 설문 조사 하였다. 조사는 초등 수학 교과서에서 모눈종이를 활용하고 있는 차시별 학습주제 중에서 모눈종이와 모눈종이판에서 어느 것이 더 효과적인지를 교사들에게 조사한 후, 모눈종이판의 활용이 더 효과적인 학습주제의 성취기준을 찾아 분석하고, 영역별로 가장 효과적인 학습 주제의 구체적인 활동 과정을 제시하였다.

• 대한방사선기술학회지:방사선기술과학
• /
• 제15권2호
• /
• pp.31-36
• /
• 1992

Grids can improve the diagnostic quality of chest radiography by trapping the greater part of scattered radiation thus providing more detailed. chest radiographic images. It is most effective mathod of reduce the scatter ratio but must increase the expour factor. The benefit of use of grid is improve the contrast and the loss is increase of patient dose. In chest radiography especially hard quality high voltage radiography it will have to be considered to select the optimum grid with view point of benefit and loss. In this experiment, author got some result of characteristics about 4 different grids with film method. 1. There was no difference the scatter ratio in case of no grid and the scatter ratio was about 60%. 2. 16 : 1 grid was excellent of scatter reduction factor in high voltage chest radiography, next was 10 : 1, CROSS, MICRO FINE grid have low scatter reduction rate compare to 16:1, 10:1 grid. 3. The bucky factor of CROSS grid in accordance of kVp was find out the highest in 4 grids, on the contraly 10 : 1 grid was profitable to the exposure does. 4. With careful consideration in the point of scatter reducion rate and bucky factor, author suggest the 10 : 1 linear grid on the use of chest radiography in $80{\sim}120\;kVp$, 16 : 1 grid in $120{\sim}140\;kVp$.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
• /
• pp.86-87
• /
• 2003

Unstructured grid system is suitable for flows of complex geometries. For problems with moving boundary walls, the grid system must be changed and deformed with time if we use a body fitted grid system. In this paper, a new moving-grid finite-volume method on unstructured grid system is proposed and developed for unsteady compressible flows with shock waves. To assure geometric conservation laws on moving grid system, a control volume on the space-time unified domain is adopted for estimating numerical flux. The method is described and applied for two-dimensional flows.

• 정보처리학회논문지A
• /
• 제11A권1호
• /
• pp.75-80
• /
• 2004

데이터베이스에 저장되어 있는 데이터를 그리드 시스템에서 사용하기 위해서는 먼저 시스템에 필요한 데이터를 수집하여 데이터베이스나 파일 시스템에 저장한 후, 데이터베이스의 데이터 및 그 인덱스를 관리하는 전용의 모듈을 별도로 구현하고, 그리드 시스템에 연동시켜야 한다. 웹 기반의 데이터 검색 시스템을 구현하여 데이터베이스에 있는 데이터들을 그리드 시스템에서 바로 사용할 수 있다면, 전용의 데이터 모듈 없이 그리드 시스템에서 바로 데이터를 처리할 수 있으므로, 보다 효율적이고 사용하기 쉬우며, 데이터베이스의 변경에 유연하게 대처한 수 있을 것이다. 본 논문에서는 웹 기반 데이터베이스의 데이터를 바로 그리드 시스템과 연계시켜 사용한 수 있는 검색 시스템을 제안한다. 이 검색 시스템을 이용하여 버추얼 스크리닝 작업을 수행하는 바이오 그리드 시스템에 적용하여 UB Grid (Universal Bio Grid)를 구축하였다. 개발자는 웹에서 제공되는 데이터론 그리드 시스템에 통합시키기 위한 시간과 노력을 줄일 수 있었으며, 사용자는 보다 쉽게 효율적으로 UB Grid 시스템을 사용한 수 있었다.