• Journal of Biomedical Engineering Research
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• v.16 no.4
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• pp.499-506
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• 1995

A new numerical method estimated three dimensional shape of the internal surface of the stomach by analyzing the shading data of endoscopic image. First analyzed was the inherent instrumentational characteristics of the endoscope system, followed by the analysis of the stomach surface properties, both of which affected the imaging properties. We employed these prior informations to implement the iterative algorithm of shading analysis based on Hom's variational approach. The present algorithm was validated by performing simulation on a $256{\times}320$ image data chosen from original $512{\times}512$ image of the stomach surface model. The best 3-dimensional estimation of the surface was achieved with the Lagrangian multiplier, of 0.3, when the algorithm best converged showing minimal estimation error.

• Journal of the Korean Society for Railway
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• v.12 no.4
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• pp.472-480
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• 2009

The stability analysis for CWR is difficult in the theory itself because both geometric and material nonlinearity should be considered. Also the analysis results are varied according to the loading history. In contrast to the complexity in the theory, the analysis results for CWR on the railway bridges are quite simple and can be predicted because of a small buckling effect and its negligible nonlinearity. In this study, refined nonlinear analysis methods for the stability analysis of CWR on the railway bridges were developed which consider only material nonlinearity beeause the effects of geometric nonlinearity are nominal. In this study, the analysis results can be found within limited number of iterations with idealized linear force-displacement relationship. From the analysis result comparisons, it was found that the stability analysis for CWR on the railway bridges can be performed effectively by this method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.8
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• pp.803-808
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• 2003

Several dielectric pipes buried in the lossy half space are reconstructed from the scattered fields measured along the interface between the air and the lossy ground. Iterative inversion method by using the hybrid optimization algorithm combining the genetic and the Levenberg-Marquardt algorithm enables us to find the positions, the sizes, and the medium parameters such as the permittivities and the conductivities of the buried pipes as well as those of the background lossy half space even when the dielectric pipes are close together. Illposedness of the inversion caused by the errors in the measured scattered fields are regularized by filtering the evanescent modes of the scattered fields out.

• Geophysics and Geophysical Exploration
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• v.7 no.2
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• pp.148-154
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• 2004

This article reviews the development of three-dimensional (3-D) magnetotelluric (MT) modeling. The 3-D modeling of electromagnetic fields is essential in understanding the physics of MT soundings, and in implementing an inversion method to reconstruct a 3-D resistivity image. Although various numerical schemes have been developed over the last two decades, practical methods have been quite limited. However, the recent rapid improvement in computer speed and memory, as well as the advance in iterative solution algorithms for a large system of equations, makes it possible to model the MT responses of complex 3-D structures, which have been very difficult to simulate before. The use of staggered grids in finite difference method has become popular, conserving a magnetic flux and an electric current and allowing for realistic discontinuous fields. The convergence of numerical solutions has been greatly accelerated by adopting Krylov subspace methods, proper preconditioning techniques, and static divergence corrections. The vector finite-element method using edge elements is also free from the discontinuity problem, and seems a natural choice for modeling complex structures including irregular topography because its flexibility allows one to capture full geometric complexity.

• The Journal of the Korea Contents Association
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• v.11 no.5
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• pp.252-259
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• 2011

To identify the effects of the application of the adaptive statistical iterative reconstruction (ASIR) technique in combination with the other two factors of body mass Index (BMI) and tube potential on radiation dose in cardiac CT. The patient receiving operation the cardiac CT examination was divided four groups into according to kVp.[A group(n=20), Non-ASIR, BMI < 25, 100 kVp; B group(n=20), Non-ASIR, BMI > 25, 120 kVp; C group(n=20), 40% ASIR BMI < 25, 100 kVp; D group(n=20), 40% ASIR, BMI > 25, 120 kVp] After setting up the region of interest in the main artery central part and right coronary artery and left anterior descending artery, the CT number was measured and an average and standard deviation were analyzed. There were A group and the difference which the image noise notes statistically between C. And A group was high so that the noise could note than C group (group A, 494 ${\pm}$ 32 HU; group C, 482 ${\pm}$ 48 HU: P<0.05) In addition, there were B group and the difference noted statistically between D. And B group was high so that the noise could note than D group (group B, 510 ${\pm}$ 45 HU; group D, 480 ${\pm}$ 82 HU: P<0.05). In the qualitative analysis of an image, there was no difference (p>0.05) which a group, B group, C group, and D as to average, A group 4.13${\pm}$0.2, B group 4.18${\pm}$0.1, and C group 4.1${\pm}$0.2 and D group note statistically altogether with 4.15${\pm}$0.1 as a result of making the clinical evaluation according to the coronary artery segments. And the inappropriate image was shown to the diagnosis in all groups. As to the radiation dose, a group 8.6${\pm}$0.9 and B group 14.9${\pm}$0.4 and C group 5.8${\pm}$0.5 and D group are 10.1${\pm}$0.6 mSv.

• Journal of the Korean Society for Library and Information Science
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• v.57 no.2
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• pp.31-50
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• 2023

The aim of this study is to explore the purpose and method of reading by examining relevant research from various academic fields. According to the reading theory in the Cho-seon Dynasty, reading was classified as either a way of gaining fame, becoming a gentle man, or solving problems. However, this views have been largely replaced by the belief that reading serves two main purposes: self-discipline and practical usage in this study (Confucian perspectives have been excluded from this approach). The traditional reading method, known as sukookdok-jeongsa, influenced by Chu-tzu's reading, emphasized a fluent reading and a deep reading. A fluent reading (sukookdok) method involved a reading aloud, memorizing, and a repeated reading for the literal decoding. After decoding, a deep reading (jeongsa) involved a reading while taking notes, a reading with reference and a repeated reading for the optimal comprehension. A fluent reading in the traditional reading theory is succeeded by 'a reading for liberal arts' and a deep reading is succeeded by 'a reading for learning'. The sukookdok-jeongsa's various reading methods are useful enough to apply to reading education in the school library. But 'a reading for fun' did not appear in the traditional reading theory.

• Korean Journal of Social Welfare
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• v.63 no.1
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• pp.5-28
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• 2011

This study, based on the research on the history of life, aimed to recompose and analyze into what life progressive structure the life experience by the mentally ill, after the onslaught of the disease, developed in a bid to understand the risk progress in the mentally ill's life, and to determine what contributed to the current stabilized recovery and adjustment. Five mentally ill persons participated in the study, and Sch$\ddot{u}$tze's narrative interview was used to gather data. The gathered data were analyzed according to Sch$\ddot{u}$tze's process structure of life. The interviewees' life experiences were chronologically organized as understood, and significant stories were recomposed that not only brought about changes but also helped overcome their disabilities in the process of treatment and rehabilitation after the onslaught of the disease. As a result, their experiences were recomposed into the stage of onslaught of the mental illness and confusion, and into the stage of intensive treatment and rehabilitation. The former was categorized into suppression by the disease, repetition and endurance of the painful life, and separation from their family and frustration. The latter was categorized into the rediscovery of self through social role change, others who helped realize the life potential, the expansion of mental health services in the community, obstacle to the integration of communities, re-integration of family relationships, re-analysis of experience of the disease through the examination of the life prior to onslaught of the disease, and expectation for the future. Also, these themes were comparatively examined so as to examine the crisis progress in the mentally ill's life after the onslaught of the disease, as well as the life transfer process through positive rehabilitation. Lastly, on the basis of these results, important areas of mental health services for the mentally ill were discussed.

• Cartoon and Animation Studies
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• s.36
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• pp.375-391
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• 2014

Animation movie is a non-photorealistic animated art that consists of formative language forming a frame based on a story and cuts describing frames that form the cuts. Therefore, in expressing an image, artistic expression methods and devices for a formative space are should be provided in a frame while cuts have the images between frames faithfully. Short animation movie is produced by various image experiments with unique image expressions rather than narration for expressing subjective discourse of a writer. Therefore, image style that forms unique images and various image directions are important factors. This study compared the experimental image directions of and , both of which showed a production method of film manipulation. First, while uses pixilation that produces images obtained from live images through painting and many optical disclosure process on a cell mat, was made with diverse collage techniques such as tearing, cutting, pasting, and folding hundreds of scenes from action movies. Second, expresses non-causal relationship of characters by their repetitive behaviors and circulatory image structure through a fixed camera angle, resisting typical scene transition. On the other hand, has an advancing structure that progresses antagonistic relationship of characters through diverse camera angles and scene transition of unique images. Third, in terms of editing, uses a long-take short cut technique in which the whole image consists of one short cut, though it seems to be many scenes with the appearance of various characters. On the other hand, maximizes visual fun and commitment by image reconstruction with hundreds of various short cuts. That is, both works have common features of an experimental work that shows expansion of animated image expressions through film manipulation that is different form general animation productions. On top of that, delivers routine life of diverse human beings without clear narration through image of conceptualized spaces. expresses it in a new image space through image reconstruction with collage technique and speedy progress, setting a binary opposition structure.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.67-70
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• 2013

Purpose: Surge in patients with hepatocellular carcinoma, hepatic artery chemical embolization is one of the effective interventional procedures. The PET/CT examination plays an important role in determining the presence of residual cancer cells and metastasis, and prognosis after embolization. The other hand, the hepatic artery chemical embolization of embolic material used lipiodol produced artifacts in the PET/CT examination, and these artifacts results in quantitative evaluation influence. This study, the radioactivity density and the percentage error was evaluated by the extent of the impact of lipiodol in the image of PET/CT. Materials and Methods: 1994 NEMA Phantom was acquired for 2 minutes and 30 seconds per bed after the Teflon, water and lipiodol filled, and these three inserts into the enough to mix the rest behind radioactive injection with $20{\pm}10MBq$. Phantom reconfigure with the iterative reconstruction method the number of iterations for two times by law, a subset of 20 errors. We set up region of interest at each area of the Teflon, water, lipiodol, insert artifact occurs between regions, and background and it was calculated and compared by the radioactivity density(kBq/ml) and the% Difference. Results: Radioactivity density of the each region of interest area with the teflon, water, lipiodol, insert artifact occurs between regions, background activity was $0.09{\pm}0.04$, $0.40{\pm}0.17$, $1.55{\pm}0.75$, $2.5{\pm}1.09$, $2.65{\pm}1.16 kBq/ml$ (P <0.05) and it was statistically significant results. Percentage error of lipiodol in each area was 118%, compared to the water compared with the background activity 52%, compared with a teflon was 180% of the difference. Conclusion: We found that the error due to under the influence of the attenuation correction when PET/CT scans after lipiodol injection performed, and the radioactivity density is higher than compared to other implants, lower than background. Applying the nonattenuation correction images, and after hepatic artery chemical embolization who underwent PET/CT imaging so that the test should be take the consideration to the extent of the impact of lipiodol be.

• The Journal of the Korea Contents Association
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• v.17 no.6
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• pp.81-85
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• 2017

The aim of this study was to evaluate the usability of applied Low dose Computed Tomography(LDCT) protocol in examining urinary calculus using computed tomography. The subjects of this study were urological patients who visited a medical institution located in Busan from June to December 2016 and the protocol used in this study was Adaptive Statistical Iterative Reconstruction: low-dose CT with 50% Adaptive Statistical Iterative Reconstruction (ASIR). As results of quantitative analysis, the mean pixel value and standard deviation within kidney region of image(ROI)of the axial image were $26.21{\pm}7.08$ in abdomen CT pre scan and $20.03{\pm}8.16$ in low-dose CT. Also the mean pixel value and standard deviation within kidney ROI of the coronal image were $22.07{\pm}7.35$ in abdomen CT pre scan and $21.67{\pm}6.11$ in low dose CT. The results of qualitative analysis showed that four raters' mean values of observed kidney artifacts were $19.14{\pm}0.36$ when using abdomen CT protocol and $19.17{\pm}0.43$ in low-dose CT, and the mean value of resolution and contrast was $19.35{\pm}0.70$ when using abdomen CT protocol and $19.29{\pm}0.58$ in low-dose CT. Also the results of a exposure dose analysis showed that the mean values of CTDIvol and DLP in abdomen CT pre scan were 18.02 mGy and $887.51mGy{\cdot}cm$ respectively and the mean values of CTDIvol and DLP when using low-dose CT protocol were 7.412 mGy and $361.22mGy{\cdot}cm$ respectively. The resulting dose reduction rate was 58.82% and 59.29%, respectively.