• Imaging Science in Dentistry
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• v.37 no.1
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• pp.53-59
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• 2007

Purpose : Bone mineral density (BMD) and bone microarchitecture are important determinants for bone strength. Recently micro-CT have provided possibilities for measuring a variety of structural indices to characterize bone microarchitecture. The objective of this study was to compare the BMD and micro-CT parameters with Young's modulus calculated by finite element analysis (FEA) for the evaluation of bone strength. Materials and Methods Bone specimens were obtained from the 18 female rabbits aged 16 weeks. Of those, 36 samples (right and left femur) were selected for 3D micro-CT analysis $(ANT^{TM},\;SKYSCAN,\;Belgium)$ and BMD by PIXlmus 2 (GE Lunar Co. USA). Five microstructural parameters of micro-CT, such as trabecular thickness (Tb.Th), bone specific surface (BS/BV), percent bone volume (BV/TV), structure model index (SMI) and degree of anisotropy (DOA) were studied. Young's modulus was obtained by software program (ANSYS 9.0, ANSYS Inc, Canonsburg, PA) based on micro-CT three dimensional images. Results : Young's modulus assessed by FEA correlated significantly with Tb.Th, BV/TV, BS/BV and SMI respectively. Young's modulus showed higher correlation with these rnicrostructural parameters of micro-CT than BMD. Microstructural parameters except DOA showed significant correlations within the examined group. Conclusion The microarchitectural parameters o( micro-CT and BMD represented some informations in the evaluation of bone strength assessed by FEA.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.65-65
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• 2011

Early-type galaxies represent the end point of galaxy evolution and, despite pervasive residual star formation, are generally considered "red and dead", that is composed exclusively of old stars with no star formation. Here, their molecular gas content is constrained and discussed in relation to their evolution, supporting the continuing importance of minor mergers and/or cold gas accretion. First, as part of the Atlas3D survey, the first complete, large, volume-limited survey of CO in normal early-type galaxies is presented. At least of 23% of local early-types possess a substantial amount of molecular gas, the necessary ingredient for star formation, independent of mass and environment but dependent on the specific stellar angular momentum. Second, using CO synthesis imaging, the extent of the molecular gas is constrained and a variety of morphologies is revealed. The kinematics of the molecular gas and stars are often misaligned, implying an external gas origin in over a third of all systems, more than half in the field, while external gas accretion must be shot down in clusters. Third, many objects appear to be in the process of forming regular kpc-size decoupled disks, and a star formation sequence can be sketched by piecing together multi-wavelength information on the molecular gas, current star formation, and young stars. Fourth, early-type galaxies do not seem to systematically obey all our usual prejudices regarding star formation (e.g. Schmidt-Kennicutt law, far infrared-radio continuum correlation), suggesting a greater diversity in star formation processes than observed in disk galaxies and the possibility of "morphological quenching". Lastly, a first step toward constraining the physical properties of the molecular gas is taken, by modeling the line ratios of density- and opacity-sensitive molecules in a few objects. Taken together, these observations argue for the continuing importance of (minor) mergers and cold gas accretion in local early-types, and they provide a much greater understanding of the gas cycle in the galaxies harbouring most of the stellar mass. In the future, better dust masses and dust-to-gas mass ratios from Herschel should allow to place entirely independent constraints on the gas supply, while spatially-resolved high-density molecular gas tracers observed with ALMA will probe the interstellar medium and star formation laws locally in a regime entirely different from that normally probed in spiral galaxies.

• Imaging Science in Dentistry
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• v.42 no.3
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• pp.155-161
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• 2012

Purpose: This study was performed to investigate the prevalence, morphology, and calcification pattern of the elongated styloid process in the Mathura population and its relation to gender, age, and mandibular movements. Materials and Methods: The study analyzed digital panoramic radiographs of 2,706 adults. The elongated styloid process was classified with the radiographic appearance based on the morphology and calcification pattern. The limits of mandibular protrusion were evaluated for each subject. The data were analyzed by using a Student's t-test and chi-squared test with significance set at p=0.05. Results: Bilateral elongation having an "elongated" type styloid process with a "partially mineralized" pattern was the most frequent type of styloid process. No correlation was found between styloid process type and calcification pattern on the one hand and gender on the other, although elongated styloid was more prevalent in older and male populations (p<0.05). Further styloid process elongation showed no effect on mandibular protrusive movement (p>0.05). Conclusion: Dentists should recognize the existence of morphological variation in elongated styloid process or Eagle syndrome apparent on panoramic radiographs. We found higher prevalence of elongated styloid process in the population of the Mathura region when compared with other Indian populations. The calcification of the styloid process was more common in the older age group with no correlation to gender, mandibular movement and site. "Type I" with a "partially calcified" styloid process was observed more frequently in the population studied.

• Imaging Science in Dentistry
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• v.40 no.4
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• pp.179-185
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• 2010

Purpose : Cortical bone thickness is one of the important factor in mini-implant stability. This study was performed to investigate the buccal cortical bone thickness at every interdental area as an aid in planning mini-implant placement. Materials and Methods : Two-dimensional slices at every interdental area were selected from the cone-beam computed tomography scans of 20 patients in third decade. Buccal cortical bone thickness was measured at 2, 4, and 6 mm levels from the alveolar crest in the interdental bones of posterior regions of both jaws using the plot profile function of $Ez3D2009^{TM}$ (Vatech, Yongin, Korea). The results were analyzed using by Mann-Whitney test. Results : Buccal cortical bone was thicker in the mandible than in the maxilla. The thickness increased with further distance from the alveolar crest in the maxilla and with coming from the posterior to anterior region in the mandible (p<0.01). The maximum CT value showed an increasing tendency with further distance from the alveolar crest and with coming from posterior to anterior region in both jaws. Conclusion : Interdental buccal cortical bone thickness varied in both jaws, however our study showed a distinct tendency. We expect that these results could be helpful for the selection and preparation of mini-implant sites.

• Korean Journal of Oriental Medicine
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• v.4 no.1 s.4
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• pp.27-45
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• 1998

$\ulcorner$Euibangyoochui醫方類聚$\lrcorner$ (1445) is regarded as a treasure-house of the knowledge of traditional oriental medicine which contains over 50,000 prescriptions and enormerous amount of medical information. Despite the importance and information contained in this book, it has been rarely used since it was not convenient to use this book. In this study, therefore, the establishment of database on $\ulcorner$Euibangyoochui$\lrcorner$ was carried out. Before the database establishment of $\ulcorner$Euibangyoochui$\lrcorner$ , basic works such as correction, interpretation, proofreading and translation of original text should be done. The results obtained in this study are summaried as follows : 1) During the course of studying the original text of $\ulcorner$Euibangyoochui$\lrcorner$ , the editing process and transmission of medical books in early Chosun dynasty was figured out. 2) For better correction, interpretation, proofreading and translation of $\ulcorner$Euibangyoochui$\lrcorner$ , $\ulcorner$Euibangyoochui$\lrcorner$ microfilms which are the collection of Japanese Royal Library (宮內廳 圖書寮) were obtained in this study. Through this process, the errors in the republication were able to be corrected. 3) Analyzing the organization and compilatory method of $\ulcorner$Euibangyoochui$\lrcorner$ is one of the basic requirements of understanding the scale of the whole. book and establishing database as a result. So the analysis results were used for the basic structuring of database. 4) $\ulcorner$Euibangyoochui$\lrcorner$ CD- ROM was designed in a way that the images of microfilms, original text and Korean translation can be compared by 3-D device. In addition, the convenience and proficiency of imaging the information and prescriptions of the text is one of the remarkable features of this CD-ROM.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.142-146
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• 1996

In this paper, we present the main research results on the 2 Tesla class - superconducting MRI magnet which we have developed. Multi section type superconducting MRI main coil and various superconducting shims were designed and fabricated for obtaining the high field homogeneity, which is requested in the MR imaging. After assembling the magnet with room temperature bore cryostat field homogenity has been measured and analyzed by NMR field mapping system. According to this, field homogeneity of 22 ppm / 30 cm dsv was confirmed.

• The Korean Journal of Emergency Medical Services
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• v.19 no.3
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• pp.19-32
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• 2015

Purpose: This study examined the effect of wearing personal protective equipment (PPE) on cardiopulmonary resuscitation (CPR), positive airway pressure, and the posture of emergency medical technicians (EMTs) when conducting CPR. Methods: Twenty 119 EMTs performed 30:2 CPR on a manikin for 4 min. Imaging data were digitized with Kwon3D XP (version 4.0). Data were collected by analyzing the motion when starting in one cycle, such as pressing to the maximum and in the final position (relaxed), and were analyzed with SPSS 18.0. Results: The angle of the elbow joints was significantly reduced (p < .05). The trunk angle was statistically significantly (p < .01, p < .001) increased. The angular velocities of the shoulder joint and left elbow joint were reduced (p > .05). The angular velocity of the trunk was significantly reduced in the starting and maximum compression postures. The hand-escape time was increased. The average compression depth was increased but not significantly (p > .05). The positive airway pressure was reduced (p > .05). Conclusion: The angle of the elbow joints and the angular velocity of the trunk were reduced, and the angle of the trunk was increased. The success of CPR and positive airway pressure was reduced.

• Journal of the Korean Society of Radiology
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• v.15 no.3
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• pp.281-291
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• 2021

This study aimed to measure the quantitative changes in images according to the use of compressed sensing in expressing the slow flow rate in TOF MRA test using magnetic resonance imaging. This study set different blood flow rate sections by using auto-injector and flow phantom and compared changes in the SNR, CNR, SSIM, and RMSE measurements by different CS factors between TOF with CS and TOF without CS. One-way ANOVA was performed to test the effect on the image induced by the increase of the CS factor. The results revealed that TOF MRA with CS significantly decreased scan time without significantly affecting SNR and CNR compared to TOF MRA with CS. On the other hand, the differences in SSIM and RMSE between TOF with CS and TOF without CS increased as the CS factor increased. Therefore, it is necessary to efficiently reduce scan time by adapting the CS technique while considering the appropriate range of the CS factor. Additionally, more studies are needed to evaluate CS factors and the similarity precision of images further.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.2
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• pp.626-643
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• 2023

As mobile forensics has emerged as an essential technique, the demand for technology development, education and training is increasing, wherein images are used. Academic societies in South Korea and national institutions in the US and the UK are leading the Mobile Forensic Image development. However, compared with disks, images developed in a mobile environment are few cases and have less active research, causing a waste of time, money, and manpower. Mobile Forensic Images are also difficult to trust owing to insufficient verification processes. Additionally, in South Korea, there are legal issues involving the Telecommunications Business Act and the Act on the Protection and Use of Location Information. Therefore, in this study, we requested a review of a standard model for the development of Mobile Forensic Image from experts and designed an 11-step development model. The steps of the model are as follows: a. setting of design directions, b. scenario design, c. selection of analysis techniques, d. review of legal issues, e. creation of virtual information, f. configuring system settings, g. performing imaging as per scenarios, h. Developing a checklist, i. internal verification, j. external verification, and k. confirmation of validity. Finally, we identified the differences between the mobile and disk environments and discussed the institutional efforts of South Korea. This study will also provide a guideline for the development of professional quality verification and proficiency tests as well as technology and talent-nurturing tools. We propose a method that can be used as a guide to secure pan-national trust in forensic examiners and tools. We expect this study to strengthen the mobile forensics capabilities of forensic examiners and researchers. This research will be used for the verification and evaluation of individuals and institutions, contributing to national security, eventually.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.655-668
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• 2023

In radiography, an antiscatter grid is a well-known device for eliminating unexpected x-ray scatter. We investigate a new stationary grid artifact suppression method based on a nonsubsampled contourlet transform (NSCT) incorporated with Gaussian band-pass filtering. The proposed method has an advantage that extracts the Moiré components while minimizing the loss of image information and apply the prior information of Moiré component positions in multi-decomposition sub-band images. We implemented the proposed algorithm and performed a simulation and an experiment to demonstrate its viability. We did this experiment using an x-ray tube (M-113T, Varian, focal spot size: 0.1 mm), a flat-panel detector (ROSE-M Sensor, Aspenstate, pixel dimension: 3032 × 3800 pixels, pixel size: 0.076 mm), and carbon graphite-interspaced grids (JPI Healthcare, 18 cm × 24 cm, line density: 103 LP/inch and 150 LP/inch, ratio: 5:1, focal distance: 65 cm). Our results indicate that the proposed method successfully suppressed grid artifacts by reducing them without either reducing the spatial resolution or causing negative side effects. Consequently, we anticipate that the proposed method can improve image acquisition in a stationary grid x-ray system as well as in extended x-ray imaging.