• Korean Journal of Digital Imaging in Medicine
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• v.14 no.2
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• pp.47-56
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• 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
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• v.6 no.3
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• pp.15-18
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• 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.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.585-588
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• 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.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.2
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• pp.23-32
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• 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.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.219-222
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• 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.

• Journal of radiological science and technology
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• v.33 no.4
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• pp.341-348
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• 2010

By accessing the current status of FPD system use in the hospitals located in Seoul and Gyeonggi Province as well as the entrance skin dose and the image quality evaluation realized by C-D Phantom, and the image assessment by the medical professionals regarding the radiography for the extremity, the following results were derived. 1. According to the evaluation made in the actual use of FPD system (12 machines), the grid ratio varied from 8:1 to 13:1, and 6 machines used the grid ratio with 12:1, realizing the largest number. Among the machines, there were 8 machines that allowed a removable grid while 3 machines did use a removable grid (25.0%). 2. When it came to the equipments used for the experiment, it showed that the amount of the entrance skin dose increased from 4.13 times up to 4.79 times with the grid use. 3. The difference in the entrance skin dose depending on the changes in the exposure condition(0.5times or 2.0times) was not significantly different regardless of the patients' thickness. 4. In terms of the image quality depending on C-D Phantom, the grid use was distinguished well. However, the images were well distinguishable as the exposure condition got increased. 5. In the clinical assessment, the grid use was less effective for the Hand PA, which was considered to shoot a thin body part. It was evaluated that the grid use was preferred for the Knee AP, which was shooting for a relatively thick body part. Nonetheless, 3 out of 5 people said that they would not use the grid if the entrance skin dose to reduced.

• Education of Primary School Mathematics
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• v.22 no.1
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• pp.13-27
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• 2019

The use of grid paper in elementary mathematics textbooks is used in numbers and calculations, figures and measurement areas. Among them, it is used most in the figure area. In spite of this utilization, it is necessary to supplement it because it is difficult to revise or supplement the trial and error that often occurs in the course of the course, as the process of using the textbook paper in the actual class. The use of grid paper in elementary mathematics textbooks is used in numbers and calculations, figures and measurement areas. Among them, it is used most in the figure area. In spite of this utilization, it is necessary to supplement it because it is difficult to revise or supplement the trial and error that often occurs in the course of the course, as the process of using the textbook paper in the actual class. In this study, we tried to find out the usability of grid paper boards which can be used more effectively than the grid paper among the teaching aids presented in the 'Development of teaching aids standards for math class' of Korea Foundation for the Advancement of Science & Creativity(2017). A questionnaire survey was conducted on the use of grid paper and grid paper board for teachers who actually use grid paper in elementary mathematics. As a result, we found out the achievement criteria of grid paper board utilization and investigated the study subject which is effective to use grid paper board. In particular, we have identified specific learning topics that are effective in each area and presented specific activities.

• Journal of radiological science and technology
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• v.15 no.2
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• pp.31-36
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• 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
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• 2003.10a
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• pp.86-87
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• 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.

• The KIPS Transactions:PartA
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• v.11A no.1
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• pp.75-80
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• 2004

To interact database data with GRID system, implementation and installation of data manipulation module which manipulates database data and its index is required. Developing a search system searching data on web-based database, and integrating it with grid system, it is possible that searching data on web and use it directly on GRID system without independent data module. So, we can build easy and effective grid system, and the system could have more flexible architecture adapting data change. In this paper, we propose a searching system which interacting web-based database with GRID systems. We integrated the searching system with a bio god system which runs virtual screening jobs. As a result, UB Grid (Universal Bio Grid) is constructed. Developer could reduce time and effort required to integrate web data to GRID system, and user could use UB Grid system easily and effectively.