• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.1
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• pp.51-56
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• 2009

Purpose: Recently, most hospitals are introducing the PACS system and use of the system continues to expand. But small-scaled PACS called MicroPACS has already been in use through open source programs. The aim of this study is to prove utility of operating a MicroPACS, as a substitute back-up device for conventional storage media like CDs and DVDs, in addition to the full-PACS already in use. This study contains the way of setting up a MicroPACS with open source programs and assessment of its storage capability, stability, compatibility and performance of operations such as "retrieve", "query". Materials and Methods: 1. To start with, we searched open source software to correspond with the following standards to establish MicroPACS, (1) It must be available in Windows Operating System. (2) It must be free ware. (3) It must be compatible with PET/CT scanner. (4) It must be easy to use. (5) It must not be limited of storage capacity. (6) It must have DICOM supporting. 2. (1) To evaluate availability of data storage, we compared the time spent to back up data in the open source software with the optical discs (CDs and DVD-RAMs), and we also compared the time needed to retrieve data with the system and with optical discs respectively. (2) To estimate work efficiency, we measured the time spent to find data in CDs, DVD-RAMs and MicroPACS. 7 technologists participated in this study. 3. In order to evaluate stability of the software, we examined whether there is a data loss during the system is maintained for a year. Comparison object; How many errors occurred in randomly selected data of 500 CDs. Result: 1. We chose the Conquest DICOM Server among 11 open source software used MySQL as a database management system. 2. (1) Comparison of back up and retrieval time (min) showed the result of the following: DVD-RAM (5.13,2.26)/Conquest DICOM Server (1.49,1.19) by GE DSTE (p<0.001), CD (6.12,3.61)/Conquest (0.82,2.23) by GE DLS (p<0.001), CD (5.88,3.25)/Conquest (1.05,2.06) by SIEMENS. (2) The wasted time (sec) to find some data is as follows: CD ($156{\pm}46$), DVD-RAM ($115{\pm}21$) and Conquest DICOM Server ($13{\pm}6$). 3. There was no data loss (0%) for a year and it was stored 12741 PET/CT studies in 1.81 TB memory. In case of CDs, On the other hand, 14 errors among 500 CDs (2.8%) is generated. Conclusions: We found that MicroPACS could be set up with the open source software and its performance was excellent. The system built with open source proved more efficient and more robust than back-up process using CDs or DVD-RAMs. We believe that the operation of the MicroPACS would be effective data storage device as long as its operators develop and systematize it.

• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.4
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• pp.239-246
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• 2005

In this study, a finite element analysis and a vibration test were performed to estimate the natural frequencies of mouse femurs with osteoporosis. Three groups of the femurs include the osteoporotic group, the treated group and the normal group. For the finite element analysis, the micro finite element model of the femur was reconstructed using the Micro-CT images and the Voxel mesh generation algorithm. In the vibration test, the natural frequencies were measured by the mobility test. from the results, the averaged natural frequencies in the osteoporotic group were the highest, followed by those in the treated group. The finite element models were validated within 15% errors by comparing the natural frequencies in the finite element analysis with those in the vibration test. The developed Micro-CT system, the Yokel mesh generation algorithm, the presented finite element analysis, and vibration test could be useful for the investigation of the structural change of the bone tissue, and the diagnosis and the treatment in the osteoporosis.

• Herbal Formula Science
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• v.16 no.2
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• pp.205-217
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• 2008

Objectives : We investigated the effects of Herba Ephedrae and Rhizoma Amorphophalli on high fat diet induced obese male mice. Methods : 8 weeks old, high fat diet induced obese male mice were divided into 5 groups: C57BL/6 normal control, obese vehicle control, GGEx55 (Herba Ephedrae), GGEx61 (Rhizoma Amorphophalli), GGEx62 (Herba Ephedrae + Rhizoma Amorphophalli). After mice were treated with GGEx for 8 weeks, we measured body weight gain, food intake, feeding efficiency ratio, rectal temperature, fat weight, plasma leptin and lipid levels. We also took micro-computerized axial tomography (micro-CT) on the mice. Results : 1. GGEx55 and GGEx62 groups significantly decreased body weight gain and feeding efficiency ratio compared with vehicle control. But they significantly increased rectal temperature. 2. Plasma total cholesterol and LDL-cholesterol concentrations were significantly increased by GGEx55 groups, whereas were significantly decreased by GGEx62 groups compared with vehicle control. 3. GGEx55 and GGEx62 groups significantly decreased total, subcutaneous and visceral fat as well as fat areas in micro-CT analysis of abdomen compared with vehicle control. 4. Plasma GOT and GPT concentrations were significantly increased by GGEx55 groups compared with vehicle control. Conclusions : These results demonstrate that GGEx55 and GGEx62 effectively reduces body weight gain, feeding efficiency ratio in high fat diet induced obese mice, leading to the modulation of obesity. In addition, GGEx55 and GGEx62 decreases visceral adipose tissue mass and improves plasma lipids, suggesting that GGEx55 and GGEx62 may act as a therapeutic agent for obesity.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1320-1323
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• 2003

In this study, the micro-FE analyses were carried out for the plastic behaviour of vertebral trabecular bones. Many researchers have investigated the elastic behaviour of trabecular bones by using the micro-finite element models based on the micro-CT images. However, there was no micro-FE model to account for the plastic behaviour of trabecular bones. Ulrich et at. reported that best results at coarser model were obtained when using 'compensated hexahedron models' with the same relative density. This study indicates that, for the elastic and plastic analysis, 'the compensated hexahedron FE model' is likely to be limited to about 63$\mu\textrm{m}$ image resolution in the vertebra trabecular bones.

• Journal of Korea Multimedia Society
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• v.18 no.9
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• pp.997-1007
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• 2015

In this paper, we propose a method for automatically analyzing the bone formation in a mouse model of frontal bone defect. We perforate two holes of 0.8mm diameter in the frontal bone and observe the bone formation process using a micro CT. Because the conventional analysis software of the micro CT does not support automatic analysis of the bone formation status, we have to use a manual analysis method. However the manual analysis is very cumbersome and requires a lot of time, we propose an automatic analysis method. It rotates the image around three axes directions so that the mouse's skull come into regular position. It calculates the cumulative image of the voxel values for the perforated bone surface. It estimates the hole location by finding the darkest point in the cumulative image. The proposed method was applied to 24 CT images of saline administration group and PTH administration group and hole location was estimated. BV/TV index was calculated for the estimated hole to evaluate the bone formation status. Experimental results showed that bone formation process is more active in PTH administration group. The method proposed in this paper could replace successfully the cumbersome and time consuming manual job.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.808-809
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• 2006

The decrease of the distance between particle centers due to the growth of the sinter necks can be explained by the well known two-particle model. Unfortunately this model fails to provide a comprehensive description of the processes for 3D specimens. Furthermore, there is a significant discrepancy between the calculated and the measured shrinkage because particle rearrangements are not considered. Only the recently developed analysis of the particle movements inside of 3D specimens using micro focus computed tomography $({\mu}CT)$, combined with photogrammetric image analysis, can deliver the necessary experimental data to improve existing sintering theories. In this work, ${\mu}CT$ analysis was applied to spherical copper powders. Based on photogrammetric image analysis, it is possible to determine the positions of all particle centers for tracking the particles over the entire sintering process and to follow the formation and breaking of the particle bonds. In this paper, we present an in-depth analysis of the obtained data. In the future, high resolution synchrotron radiation tomography will be utilized to obtain in-situ data and images of higher resolution.

• Journal of Radiation Industry
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• v.17 no.3
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• pp.233-238
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• 2023

This study was conducted to confirm the safety of the operator's radiation exposure in the micro PET-CT image acquisition experiment using the ¹⁸F-FDG. The usage of ¹⁸F-FDG and the exposure dose of handlers were measured at University B in Metropolitan City A, which uses ¹⁸F-FDG for micro PET-CT image acquisition. As a result of the measurement, the exposure dose is far below the effective dose limit of radiation workers, 50 mSv per year, and the equivalent dose limit of 500 mSv per year for hands, feet, and skin. has been measured Since these exposure doses can be further increased according to the number of times of use of ¹⁸F-FDG, it is judged that the exposure dose compared to the handling amount of ¹⁸F-FDG shown in this study can be used as reference data. In addition, as changed environments such as the use of materials other than unopened RI are occurring in education and research environments, such as the use of ¹⁸F-FDG at University B, radiation exposure with more interest in safety management by checking the factors of radiation exposure of the handler concerned We will always do our best to reduce it.

• International Journal of Oral Biology
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• v.41 no.2
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• pp.83-88
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• 2016

Periodontitis is an inflammatory disease, which destroys the connective tissue and the alveolar bone. Recently, it has been suggested that the effect of natural substances could be induced into an anti-inflammatory environment. However, the effect of Safflower seed extract (SAF-M) associated with periodontitis has not been investigated yet. Therefore, the purpose of this study was to assess the anti-inflammatory effects of SAF-M. Cytotoxicity was assessed through MTS analysis using hGF and hPDL cells. Periodontitis was induced by injecting LPS into gingival tissue on the maxillary molars of rats ($45{\mu}g$ LPS/one time, 3 times a week for 3 weeks). SAF-M was administered daily at 30 mg/kg and 100 mg/kg. Alveolar bone resorption was evaluated through the micro-CT. hGF and hPDL cells showed differential cytotoxicity in response to SAF-M at 5 mg/ml and 1 mg/ml concentrations. Micro-CT showed reduction of the alveolar bone resorption in the SAF-M treatment group. These results suggested that SAF-M is a potential therapeutic agent for periodontitis.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.5
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• pp.323-330
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• 2023

The development of an analysis model that reflects the microstructure characteristics of polyvinyl alcohol (PVA) fiber-reinforced cementitious composites, which have a highly complex microstructure, enables synergy between efficient material design and real experiments. PVA fiber orientations are an important factor that influences the mechanical behavior of PVA fiber-reinforced cementitious composites. Owing to the difficulty in distinguishing the gray level value obtained from micro-CT images of PVA fibers from adjacent phases, fiber segmentation is time-consuming work. In this study, a micro-CT test with a voxel size of 0.65 ㎛³ was performed to investigate the three-dimensional distribution of fibers. To segment the fibers and generate training data, histogram, morphology, and gradient-based phase-segmentation methods were used. A U-net model was proposed to segment fibers from micro-CT images of PVA fiber-reinforced cementitious composites. Data augmentation was applied to increase the accuracy of the training, using a total of 1024 images as training data. The performance of the model was evaluated using accuracy, precision, recall, and F1 score. The trained model achieved a high fiber segmentation performance and efficiency, and the approach can be applied to other specimens as well.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.128-131
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• 2002

Several FE models were developed based on micro-CT images of a mandibular specimen. A new dental implant model was suggested from parameter study for the relation between shape and interfacial stress of dental implants. It is found that the proposed model is highly beneficial.