• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.147-153
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• 2014

In this paper, we present a non-dyadic lens distortion correction model and image restoration method based on local self-similarity to remove jagging and blurring artifacts in the peripheral region of the geometrically corrected image. The proposed method can be applied in various application areas including vehicle real-view cameras, visual surveillance systems, and medical imaging systems.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.1
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• pp.8-14
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• 2007

X-ray digital tomosynthesis is widely used in the nondestructive testing and evaluation, especially for the printed circuit boards (PCBs). In this study, we propose a simple method to reduce the blur artefact, frequently claimed in the conventional digital tomosynthesis based on SAA (shift-and-add) algorithm, and thus restore the image sharpness. The proposed method is basically based on the SAA, but has a correction procedure by finding blur artefacts from the forward-and back-projection for the firstly obtained, manipulated backprojection data. The manipulation is the replacement of the original data at the POI (plane-of-interest) by zeros. This method has been compared with the conventional SAA algorithm using the experimental measurements and Monte Carlo simulation for the designed PCB phantom. The comparison showed a much enhancement of sharpness in the images obtained from the proposed method.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.11 no.1
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• pp.88-98
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• 2011

Lesch-Nyhan syndrome is a X-linked recessive disorder caused by a deficiency of the enzyme hypoxanthine-guanidine phosphoribosyltransferase (HPRT), enzyme to recycle purines. Case history: born induced vaginal delivery at 40 weeks complicated by premature membrane ruputure, body weight 2.820 gm. He showed failure to thrive showing severe protein aversion like milk products and pink daper. Developmental delay revealing rolling over at 10.5 month, followed by regression. Seizure at 2 months, His poor oral feeding was lifelong problem. Weak crying, spastic, choreoathetoid movement. Self mutilating behavior noted and diagnosed at age 3 years. No family history of consanguinity and neurological disorders. Method: Laboratory test, physical exam, imaging study and molecular. Clinical follow up Treat ment with allopurinol. Result: uric acid 10.5 mg/dL (N 3.5-7.9), APRT 151.1uM/ min/ml pro(25.7-101), HPRT 7.6 (N 233.5-701) and c.151C>T hemizygote (p,Arg51X). Abdominal sonogram showed staghorn calculi in both kidneys, brain MRI brain atrophy. Clinical follow up showed, seizure at 2 mo, developmental delay (head control and, rolling over at at 11mo, pointing body part at 2 yr 7 mo, eye hand coordination at 2 y 11mo,creeping at 3 y 7 mo, speaking words at 6 y 6 mo ),and developmental regression at 3 yr of age. Sleeping problem including insomnia and severe constipation. Self mutilating behavior (lip bite) started at 2.5 yr, neurologic sx including intermittent upward gaze accompanied by swallowing difficulty at 3 y 7 mo grand mal seizure at 4.5 yr and spastic extremity and trunchal hypotonia and choleoathetoid movement and ataxia at 6.5 yr. Scoliosis with severe spasticity at 9 yr 9 mo. Acute life threatening episode with irregular breathing at 9 yr and 9 mo, Emaciation and nephrolithiasis and recurrent pneumonia. Died suddenly at 10 yr 3 mo. Conclusion: life long feeding problem, chronic gut motility dysfunction, sleeping difficulty and progressing neurologic deterioration and nephrolithiasis despite normal serum uric acid maintence by allopurinol treatment.

• Korean Journal of Optics and Photonics
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• v.29 no.3
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• pp.99-103
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• 2018

Optical coherence elastography (OCE) is based on optical coherence tomography (OCT), which is a noninvasive, high-resolution, cross-sectional imaging technique. In this paper, we have developed dynamic optical coherence elastography to measure elasticity, a mechanical property of tissue, by phase difference. A piezoelectric actuator was used for sinusoidal mechanical loading of samples. Before applying this method to biomaterial, we assessed the feasibility of OCE with samples of sponge, eraser, and sharp lead. Cross-sectional and phase-difference images of the sample were obtained under sinusoidal loading. The strain rate was calculated from the phase-difference information. To obtain the envelope of the phase-difference oscillations along the horizontal direction, Hilbert transformation was performed at each depth. The elevation of the envelope was represented by color mapping, and we could measure the relative elasticity within the sample by comparing the elevations. Finally, there was an advantage when we calculated the shear rate using self-interference in the sample arm, instead of the interference between sample and reference arms.

• Anxiety and mood
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• v.14 no.2
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• pp.63-70
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• 2018

It has been suggested that aberrant self-referential processing (SRP) is one of the important components of the explanatory models of social anxiety disorder (SAD). The default mode network (DMN), which reflects intrinsic brain functions, is known to play a critical role in SRP. Recently, resting state functional magnetic resonance imaging (fMRI) research on the functional connectivity in the brain network has gained greater attention as a tool to elucidate the neurobiological basis of various psychiatric disorders. We reviewed resting state fMRI studies that investigated the resting state functional connectivity (RSFC) of the DMN in SAD. Despite of the heterogeneity of the analytic methods and occasional negative findings, most studies consistently reported abnormalities of RSFC within the DMN, suggesting that the DMN may be significant neural correlates of aberrant SRP in SAD. Also, changes in RSFC of the DMN are associated with clinical improvements of therapeutic interventions. Moreover, emerging findings provide the basis for potential use of RSFC as a complementary method in diagnosis of SAD. Ongoing and future research to investigate RSFC of the DMN could broaden our understanding regarding the neurobiological basis of SAD, and contribute to the development of novel treatments for SAD.

• Journal of Korean Medicine Rehabilitation
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• v.33 no.1
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• pp.97-108
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• 2023

The purpose of this study is to investigate the effectiveness of integrative Korean medicine treatment for patients who were diagnosed as acute fracture on pelvis. The patients were treated by Korean medicine as conservative management including acupuncture, pharmacopuncture, herbal medication and cupping for hospitalization periods. Numerical rating scale (NRS), EuroQol-5 dimensions (EQ-5D), Oswestry disability index (ODI), patient global impression of change (PGIC), self-walking distance and the changes of symptoms were measured to assess patients' improvement. NRS, ODI scores and EQ-5D definitely improved on 4 patients of 5 cases. NRS decreased from 6~7 to 3~5, ODI scores decreased from 62~75.11 to 40~52 and EQ-5D increased from 0.013~0.331 to 0.47~0.773. PGIC and self-walking distance were also enhanced after treatments. In conclusion, this study suggests that integrative Korean medicine could be effective treatment for acute pelvic fracture.

• Korean Journal of Social Welfare Studies
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• v.42 no.2
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• pp.235-274
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• 2011

The purpose of this study is to understand suffering of torture for victims with suspicion of espionage under the military government in Korea by knowing meaning and structure of empirical phenomena. Methods is to applied to Phenomenological and heuristic Human Becoming Methodology, and the subjects of this study are text for three tortured victims. Results is the structure that the victims accepted their act of espionage under the torture and horror, living with retribution from heaven, surviving pressured times, and fighting for human rights upon release from prison. The conceptual integration of relationship issues were: valuing, imaging, languaging with powering and transforming under the process of revealing-concealing and enabling-limiting. Finally, discussion and practical meaning was reviewed.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.3
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• pp.361-366
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• 2018

Ice crushing occurs in many situations that involve a sliding frictional component such as sports involving ice-contact, ice interaction with ship hulls, and ice-on-ice sliding/crushing within glaciers and between interacting sea ice floes. Ice crushing-friction tests were conducted in the lab at $-10^{\circ}C$ using a set of acrylic ice-crushing platens that included a flat smooth surface and a variety of high-roughness surfaces with regular arrays of small prominences. The experiments were part of Phase II tests of the Blade Runners technology for reducing ice-induced vibration. Ice was crushed against the platens where the ice movement had both a vertical and a horizontal component. High-speed imaging through the platens was used to observe the ice contact zone as it evolved during the tests. Vertical crushing rates were in the range 10-30 mm/s and the horizontal sliding rates were in the range 4.14-30 mm/s. Three types of freshwater ice were used. Friction coefficients were extraordinarily low and were proportional to the ratio of the tangential sliding rate and the normal crushing rate. For the rough surfaces all of the friction coefficient variation was determined by the fluid dynamics of a slurry that flowed through channels that developed between leeward-facing facets of the prominences and the moving ice. The slurry originated from a highly-lubricating self-generating squeeze film of ice particles and melt located between the encroaching intact ice and the surfaces.

• The Journal of the Korea Contents Association
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• v.18 no.7
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• pp.628-634
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• 2018

In an examination of the temporomandibular joint disc, MRI(Magnetic Resonance Imaging) is a useful method, and it is necessary to conduct an examination with one's mouth open for a long time to observe the accurate position change of the disc. Thus, this study would produce a TMJ device, using the 3-D printing technology, which would maintain the state of opening the mouth and would evaluate its usefulness as compared to the existing fixed device. As compared to the image using the existing TMJ device, the image taken with the self-produced TMJ device with a 3-D printer showed a somewhat lower SNR, but there was no defect for a clinical use. It is judged that benefits to costs would increase, since it can be customized for the individual patient and can contribute to the production of similar tools by utilizing the 3-D printing technology.

• Journal of Korean Neurosurgical Society
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• v.48 no.1
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• pp.53-58
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• 2010

Objective : The purpose of this study was to review the safety and durability of aneurysms treated with stent-assisted coiling of ruptured anterior communicating artery aneurysms with small parent vessels (< 2.0 mm). Methods : Retrospective review of all ruptured aneurysm treated with stent assisted endovascular coiling between March 2005 and March 2009 at our institution was conducted. We report 11 cases of the Neuroform stent placement into cerebral vessels measuring less than 2.0 mm in diameter (range, 1.3-1.9 mm) in anterior cerebral artery. Clinical follow-up ranged from 3 to 12 months and imaging follow-up was performed with cerebral angiography at 6 months and 12 months after discharge. Results : Complete occlusion was achieved in 10 patients, and a remnant neck was evident in one. No stent displacement or no dislodgement occurred during stent placement. There was no evidence of thromboembolic complication, arterial dissection and spasm during procedure. We performed follow-up angiography in all patients at 6 months and/or 12 months from the first procedure. The follow-up angiographic data showed successfully results except one in-stent stenosis case. All patients improved clinical performances except one patient with severe vasospasm who showed poor clinical condition initially. Conclusion : We have safely and successfully treated 11 vessels smaller than 2.0 mm in diameter with self-expanding stents with good short and intermediate term results. More clinical data with longer follow-ups are needed to establish the role of stent-assisted coiling in ruptured aneurysms with small parent vessels.