• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.655-661
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• 2017

Sparse view CT has been widely used to reduce radiation dose to patient in radiation therapy. In this work, we performed sinogram restoration from sparse sampling data by using inpainting method for simulation and experiment. Sinogram restoration was performed in accordance with sampling angle and restoration method, and their results were validated with root mean square error (RMSE) and image profiles. Simulation and experiment are designed to fan beam scan for various projection angles. Sparse data in sinogram were restored by using linear interpolation and inpainting method. Then, the restored sinogram was reconstructed with filtered backprojection (FBP) algorithm. The results showed that RMSE and image profiles were depended on the projection angles and restoration method. Based on the simulation and experiment, we found that inpainting method could be improved for sinogram restoration in comparison to linear interpolation method for estimating RMSE and image profiles.

• Progress in Medical Physics
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• v.24 no.4
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• pp.303-314
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• 2013

Image quality of computed tomography (CT) is very vulnerable to metal artifacts. Recently, the thickness and background normalization techniques have been introduced. Since they provide flat sinograms, it is easy to determine metal traces and a simple linear interpolation would be enough to describe the missing data in sinograms. In this study, we have developed a theory describing two normalization methods and compared two methods with respect to various sizes and numbers of metal inserts by using simple numerical simulations. The developed theory showed that the background normalization provide flatter sinograms than the thickness normalization, which was validated with the simulation results. Numerical simulation results with respect to various sizes and numbers of metal inserts showed that the background normalization was better than the thickness normalization for metal artifact corrections. Although the residual artifacts still existed, we have showed that the background normalization without the segmentation procedure was better than the thickness normalization for metal artifact corrections. Since the background normalization without the segmentation procedure is simple and it does not require any users' intervention, it can be readily installed in conventional CT systems.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.1
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• pp.52-60
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• 2008

Purpose: To establish the methods for sinogram formation and correction in order to appropriately apply the filtered backprojection (FBP) reconstruction algorithm to the data acquired using PET scanner with multiple scintillation crystal layers. Materials and Methods: Formation for raw PET data storage and conversion methods from listmode data to histogram and sinogram were optimized. To solve the various problems occurred while the raw histogram was converted into sinogram, optimal sampling strategy and sampling efficiency correction method were investigated. Gap compensation methods that is unique in this system were also investigated. All the sinogram data were reconstructed using 20 filtered backprojection algorithm and compared to estimate the improvements by the correction algorithms. Results: Optimal radial sampling interval and number of angular samples in terms of the sampling theorem and sampling efficiency correction algorithm were pitch/2 and 120, respectively. By applying the sampling efficiency correction and gap compensation, artifacts and background noise on the reconstructed image could be reduced. Conclusion: Conversion method from the histogram to sinogram was investigated for the FBP reconstruction of data acquired using multiple scintillation crystal layers. This method will be useful for the fast 20 reconstruction of multiple crystal layer PET data.

• Korean Journal of Social Welfare Studies
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• v.43 no.1
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• pp.203-227
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• 2012

This study analyzes the effect on depression of mutual relational aggression experienced by elderly residents at charity nursing home. It also verifies the mediated effect of adaption by the residents to the nursing home. For this end, the researchers conduct a survey for 182 elderly residents in 7 charity nursing homes in Seoul and Kyonggi Province. The statistical methods for the analysis were SPSS version 18.0 and AMOS 7.0program. Following are the findings. First, there turns out to be no statistical significant effect between mutual relational aggression and depression. Second, elderly residents' adaption to the nursing home is proved to serve as a mediated effect between mutual relational aggression and depression. In other words, the more the relational aggression, the more difficult it is for residents to be adapted to the nursing home, and the more depressed the residents are prone to be. Following are suggestions based on the findings. First, nursing home staffs need to establish a system in consideration both of relational aggression and of resident's adaption, to reduce its elderly residents' consequential depression. Second, nursing home staffs need to take measures to help adaption of new residents to prevent or reduce their depression. For example, new residents can be allowed to bring their belongings to the nursing home as much as they want and the nursing home can stand. Third, nursing homes also need to develop programs to prevent or reduce any negative relation, including bullying or casting out, among peer residents in the nursing home.

• The Journal of the Korea Contents Association
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• v.15 no.4
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• pp.350-356
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• 2015

The aim of this study is to perform simulations to design the detector module with crystal array by Monte Carlo simulation. For this purpose, a small animal PET scanner, employing module with 1~8 crystal array discrimination scheme, was designed. The proposed scanner has an inner diameter of 100 mm with detector modules in crystal array. Each module is composed of a 5.0 mm LSO crystal with a $2.0{\times}2.0mm^2$ sensitive area with a pitch 2.1 mm and 10.0 mm thickness. The LSO crystals are attached to the SiPM which has a dimension of $2.0{\times}2.0mm^2$. The detector module with crystal array of the designed PET detector was simulated using the Monte Carlo code GATE(Geant4 Application for Tomographic Emission). The detector is enough compensation for the loss of data in sinogram due to gaps between modules. The results showed that the high sensitivity and effectively reduced the problem about the missing data were greatly improved by using the detector module with 1 crystal array.

• Journal of Science and Technology Studies
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• v.18 no.2
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• pp.135-179
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• 2018

How do robots interact with the elderly? In this paper, we analyze the contexts of interaction between robots and the elderly and the role of mediators in initiating, facilitating, and maintaining the interaction. We do not attempt to evaluate the robot's performance or measure the impact of robots on the elderly. Instead, we focus on the circumstances and contexts within which a robot is situated as it interacts with the elderly. Our premise is that the success of human-robot interaction does not depend solely on the robot's technical capability, but also on the pre-arranged settings and local contingencies at the site of interaction. We select three television shows that feature robots for the elderly and one "dementia-prevention" robot in a regional healthcare center as our sites for observing robot-elderly interaction: "Grandma's Robot"(tvN), "Co-existence Experiment''(JTBC), "Future Diary"(MBC), and the Silbot class in Suwon. By analyzing verbal and non-verbal interactions between the elderly and the robots in these programs, we point out that in most cases the robots and the elderly do not meet one-to-one; the interaction is usually mediated by an actor who is not an old person. These mediators are not temporary or secondary components in the robot-elderly interaction; they play a key role in the relationship by arranging the first meeting, triggering initial interactions, and carefully observing unfolding interactions. At critical moments, the mediators prevent the interaction from falling apart by intervening verbally or physically. Based on our observation of the robot-elderly interaction, we argue that we can better understand and evaluate the human-robot interaction in general by paying attention to the existence and role of the mediators. We suggest that researchers in human-robot interaction should expand their analytical focus from one-to-one interactions between humans and robots to human-robot-human interactions in diverse real-world situations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1684-1689
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• 2012

This research is performed for the elderly patients who have knee osteoarthritis joint and who are applied to complex exercise program to know that how the complex exercise affects on pain and muscle activation. This research is tested 23 elderly patients who have knee osteoarthritis in hospital B. It divided into exercise group(n=2) and control group(n=1), by doing general physical therapy for each case three times a week, 40 minutes, among 10 weeks and measured before and after VAS and muscle activation. For the case exercise group, supplementally, applied to complex exercise program three times a week, 40 minutes, among 10 weeks and also measured before and after VAS and muscle activation. After the test is performed in 10 weeks, the results of this test are as follows. First, both exercise group and control group, they have more in pain after experiment rather than before, respectively(p<0.05). but There was no significant statistical difference between two groups(p>0.05). Second, exercise group have in muscle activation after experiment rather than before(p<0.05). and There was significant statistical difference between two groups(p<0.05). The test is implied that if the people who has knee osteoarthritis wants to get more good effects with complex exercise, they should get more opportunities to complex exercise. as well as fitness, resistance exercise and grafted to the easily create an exciting program to improve the quality of life of seniors in the program will be studied in future study.

• Trans-
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• v.7
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• pp.49-80
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• 2019

As ageing society rapidly unfolds, it is becoming an even more important issue to secure wellbeing and happiness of senior citizens and the society as a whole. Growing talks on how culture and art positively affect the elderly led to more demands from the public on culture and art institutions to increase their social participations. Art museums too, as an art and cultural institution and a social education entity, are requested to play a bigger role in the effort to tackle the concerns derived from the ageing society. Korean art museums came up with senior programs since 2000, which makes it a relatively recent phenomenon. The consensus on the importance and needs of such programs has been around for a while in our society. However, effect measurement of these programs needs further research and discussion. This thesis examined the effect of senior programs using the Museum Wellbeing Measures Toolkit published in 2013. With the service quality research model, correlations were analyzed among program components, wellbeing effect, participant satisfaction and their willingness to re-enroll in order to produce a practical guidance on how to plan and operate the programs. To measure effect of senior programs and to analyze influencing factors would provide us with important data to prove the social responsibility and benefit art museums offer in our society. At the same time, such researches would contribute to enhancing the quality of current programs run by museums and give methodological suggestions on how to assess and improve senior programs.

• Progress in Medical Physics
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• v.23 no.4
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• pp.309-316
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• 2012

Multimodal-imaging technique has been rapidly developed for improvement of diagnosis and evaluation of therapeutic effects. In despite of integrated hardware, registration accuracy was decreased due to a discrepancy between multimodal image and insufficiency of count in accordance with different acquisition method of each modality. The purpose of this study was to improve the PET image by event data resampling through analysis of data format, noise and statistical properties of small animal PET list data. Inveon PET listmode data was acquired as static data for 10 min after 60 min of 37 MBq/0.1 ml $^{18}F$-FDG injection via tail vein. Listmode data format was consist of packet containing 48 bit in which divided 8 bit header and 40 bit payload space. Realigned sinogram was generated from resampled event data of original listmode by using adjustment of LOR location, simple event magnification and nonparametric bootstrap. Sinogram was reconstructed for imaging using OSEM 2D algorithm with 16 subset and 4 iterations. Prompt coincidence was 13,940,707 count measured from PET data header and 13,936,687 count measured from analysis of list-event data. In simple event magnification of PET data, maximum was improved from 1.336 to 1.743, but noise was also increased. Resampling efficiency of PET data was assessed from de-noised and improved image by shift operation of payload value of sequential packet. Bootstrap resampling technique provides the PET image which noise and statistical properties was improved. List-event data resampling method would be aid to improve registration accuracy and early diagnosis efficiency.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.10
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• pp.377-382
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• 2018

This study deals with internal state and tissue density analysis methods for red ginseng grade determination. For internal measurement of red ginseng, there have been various studies on nondestructive testing methods since the 1990s, It was difficult to grasp the most important inner hole and inside whites in the grading. So in this study, we developed a closed capturing device for infra-red illumination environment, and developed an internal measurement system that can detect the presence and diameter of inner hole and inside whites. Made devices consisted of infrared lights with a high transmission rate of red ginseng in 920 nanometer wave band, a infra-red camera and a Y axis actuator with a red ginseng automatically controlled focus on the camera. The proposed algorithm performs an auto-focus system on the Y-axis actuator to automatically adjust the sharp focus of the object according to the size and thickness. Then red ginseng is rotated $360^{\circ}$ at $1^{\circ}$ intervals and 360 total images are acquired, and reconstructed as a sinogram through Radon transform and Back-projection algorithm was performed to acquire internal images of red ginseng. As a result of the algorithm, it was possible to acquire internal cross-sectional image regardless of the thickness and shape of red ginseng. In the future, if more than 10,000 different shapes and sizes of red ginseng internal cross-sectional image are acquired and the classification criterion is applied, it can be used as a reliable automated ginseng grade automatic measurement method.