• Journal of the Korean earth science society
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• v.29 no.7
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• pp.531-538
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• 2008

The mode of occurrence of petrified woods from the Tertiary strata of Pohang Basin in Kyeongsangbug-do suggests that the petrified woods are all allochthonous fossils. Petrified woods as well as various types of wood fossils such as carbonized woods and charcoal woods were found. However, some lignified organic remains are rarely found in the bark part of petrified woods. X-ray diffraction analysis showed three types of minerals including Opal-CT, Opal-C, and quartz+cristobalite. The presence of these minerals indicates that silicification occurred under the low temperature. The tuffs are considered to be main source of supply of silica. Analysis of the kind of composing minerals and the condition of tissue preservation can predict that silicification is mainly occurred by replacement.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.12 s.159
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• pp.1788-1799
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• 2006

Assessment of the implementation of a web-based courseware technology application across a merchandising program over a two-year period provides empirical evidence that students believe the technology was easy to use and useful. Results also show that the use of the application was not a hard-ship for the students in terms of time or access, that students in lower class ranks who had not had technology enhanced courses previously were more satisfied with the technology than upper class students, and that perceptions of the technology and satisfaction with it increase with experience using the technology.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.1
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• pp.44-53
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• 2006

In this study, the non-destructive computed tomography was adopted to observe the density profile of the needle-punched Carbon/Carbon(C/C) composites nozzle throat. The density profile of C/C was evaluated within ${\pm}0.01g/cm^3$ with 98.74% confidence when the correction of the image and high signal-to-noise ratio were achieved by the optimization of the beam hardening, the electrical noise and the scattered X-ray. The density variation of C/C with the computed tomography was in good agreement with the results obtained by the water immersion method and the observation with scanning electron microscope.

• Journal of radiological science and technology
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• v.30 no.3
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• pp.281-287
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• 2007

Contrast media may cause tissue injury by extravasation during intravenous automated injection during CT examination. Here, we present a study in which contrast media extravasation was detected and localized in the neck and thorax by three-dimensional(3D) CT data reformation. The CT studies of the extavasation site were performed using a 3D software program with four different display techniques axial, multi planar reformation(MPR), maximum intensity projection(MIP), and volume rendering displays are currently available for reconstructing MDCT data. 3D image reconstructions provide accurate views of high-resolution imaging. This paper introduces extravasation with the MDCT and 3D reformation findings of contrast media extravasation in neck ant thorax. The followed injection of the external jugular vein into an existing intravenous catheter and a large volume of extravasation was demonstrated on by 3D MDCT.

• Journal of Radiation Protection and Research
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• v.36 no.2
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• pp.79-85
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• 2011

OThe purpose of this article was to measure and compare the value of the metal artifact reduction (MAR) algorithm by Dual energy(kVp switching) CT (Computed Tomography) for non using MAR and we introduced new variable Dual energy CT applications through a clinical scan. The used equipment was GE Discovery 750HD with Dual-Energy system(kVp switching). CT scan was performed on the neck and abdomen area subject for patients. Studies were from Dec 20 2010 to Feb 10 2011 and included 25 subject patients with prosthesis. We were measured the HU (Hounsfield Unit) and noise value at metal artifact appear(focal loss of signal and white streak artifact area) according to the using MAR algorithm. Statistical analyses were performed using the paired sample t-test. In patient subject case, the statistical difference of showing HU was p=0.01 and p=0.04 respectively. At maximum black hole artifact area and white streak artifact area according to the using MAR algorithm. However noise was p=0.05 and p=0.04 respectively; and not the affected black hole and white streak artifact area. Dual Energy CT with the MAR algorithm technique is useful reduce metal artifacts and could improve the diagnostic value in the diagnostic image evaluation of metallic implants area.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.90-93
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• 2019

Recently, as SW education has been emphasized in college, interest in Computing Thinking (CT) class at the liberal level has increased. In order to effectively educate students, various methods of teaching and learning are required to reduce the burden on CT education and motivation of students. The purpose of this study is to design teaching and learning using ARCS model to improve learners' learning motivation and learning achievement in CT course as liberal arts education. In this study, the learning elements of CT were selected based on previous research on the characteristics of education in the liberal arts education of the university and analysis of the CT content. In addition, Keller 's ARCS learning motive model was selected to match the instructional tactics according to the motivational factors of Attention, Relevance, Confidence, and Satisfaction. In order to effectively teach these CT contents, detailed strategies based on the ARCS model were designed and presented weekly.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.488-493
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• 2011

The Korean spine geometry and property data for researchers were made by KISTI and Catholic Institute for Applied Anatomy. We took whole spine CT, X-Ray, BMD scan for making high resolution cross-sectional spine images using more 20 donated cadavers(60 - 80 years). Then we constructed 3-dimensional volume model using serial CT images by Mimics software. The major morphometric parameters of vertebrae were measured. Mechanical motion and property data were obtained by the same cadavers using the DEXA for BMD and the spine simulator. The Korean spine geometry and property data could be used for research and development of medical device.

• The Journal of Korean Society for Radiation Therapy
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• v.25 no.1
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• pp.41-47
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• 2013

Purpose: To evaluate the usefulness of Integrated PET/CT and compare the gloss tumor volume (GTV) identified on CT, PET, PET/CT to that obtained from fluorodeoxyglucose (FDG). Materials and Methods: This experimental study was obtained using GE Discovery 690 (General Electric Healthcare, Milwaukee, MI, USA) PET/CT simulator with Gammex Laser System for five non-small cell lung cancer (NSCLC) patients. In order to increase the reproducibility of the patient setup, We have to fixed to patients using the Extended Wing Board. GTV delineation was painted using the EclipseTM ver.10 contouring program for CT, PET, PET/CT images. And then, We were to compare the changes in the GTV. Results: These results are drawn from 5 patients who have atelectasis or pneumonitis. Compared to CT defined GTV, PET was decreased by 10.5%, 11.8% and increased by 67.9%, 220%, 19.4%. PET/CT was decreased by 7.7%, 6.7%, 28% and increased by 232%, 24%. Conclusion: We were able to determine the usefulness of PET/CT simulator for NSCLC. PET/CT simulator in radiation therapy is useful to define the target volume and It is possible to delineate Objective and accurate target volume. It seems to be applicable to other areas in the near future.

• Journal of Veterinary Clinics
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• v.32 no.6
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• pp.508-510
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• 2015

A 7-year-old castrated male Boston terrier dog was referred due to dyspnea and unilateral cervical mass. On physical examination, mass on left submandibular region was palpated. CT findings revealed this case could be the tumor originated from left lingual vein. The client refused further treatment and the patient expired because of respiratory failure 10 days after presentation. On necropsy, a well-defined firm mass which located in the left side of larynx was detected. Histopathological findings for the mass indicated polygonal tumor cells arranged in nest and separated by fibrovascular septa. We performed immunohistochemisry to evaluate of chromogranin A and tumor cells showed positive immunoreactivity for chromogranin A. Based on computed tomography (CT), histopathological and immunohistochemical findings, this case was definitely diagnosed to paraganglioma of the body on the lingual vein. This report describes the clinical findings, CT imaging characteristics, histopathologic and immunohistochemical features of paraganglioma arised from lingual vein in a dog.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.408-413
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• 2010

Purpose : We aimed to prove the relative limitation of $^{99m}Tc-DMSA$ scintigraphy (DMSA) compared to computed tomography (CT) in diagnosing acute pyelonephritis (APN) in children. Methods : Since September 2006, after a 64-channel CT was imported, 10 DMSA false-negative patients have been identified: these patients underwent a CT scan for acute abdomen or acute febrile symptoms and were diagnosed as having APN; however, their DMSA scans were clear. We focused on these 10 DMSA false-negative patients and analyzed their clinical findings and CT results. We used Philips Brilliance Power 64-channel CT scanner for the CT scan and Siemens Orbitor Nuclear Camera 60 Hz for the DMSA scan. Results : The 10 DMSA false-negative patients were mostly males (80%) and infants (80%). They had fever for a mean of 1.1-day duration before admission and showed increase in acute reactants: leukocyte, erythrocyte sedimentation rate, and C-reactive protein. The CT findings of renal lesions were focal in 6 (60%) cases and diffuse in 4 (40%) cases, and most of the lesions were unilateral in 80% of patients. CT proved that 22 renal lesions were neglected by DMSA. Differential renal function test by DMSA was also of no use in the evaluation of renal lesions. Conclusion : In this study, DMSA scan showed limitation in finding renal cortical lesions of CT-proven APN patients. DMSA false-negative results seem to occur at early-phase disease of infantile age, but more prospective studies are needed to determine the reasons and their prevalence.