• Journal of the Korea Institute of Building Construction
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• v.7 no.4
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• pp.125-132
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• 2007

The use of Self-Leveling material is increasing recently. This paper assesses the quality of surface layer of concrete floor when Self-Leveling material is defective. The paper shows how to predict the defect of SL material before construction begins. The relationship between the quality of surface layer of concrete floor and the defect of SL material was determined and the quality of surface layer of concrete floor was then estimated. The relations between the quality of surface layer and the defect of SL material were determine considering surface strength, moisture, and consistency of surface layer. Absorbing amount was used as the indicator of consistency and the absorbing amount of test material was measured. Then the relations between the test material and surface strength were determined. Generally concrete floor with greater consistency has greater surface strength, however in this study, we hound that high impact concrete floor could have lower surface strength as the consistency gets bigger. The relations between the level of defect occurred in SL material and the quality of surface layer were examined and we clarified that the surface layer with lower consistency gets higher possibility to occur exfoliation in early stage, one or two weeks after constructing SL material. When the consistency is sufficient, the occurring situation of defect depends upon the moisture of surface layer. Little amount of moisture gets higher possibility not to occur the defect. As the amount increases, fissure generates and early exfoliation may occur. In addition, the level of fissure is highly related with the surface strength.

• Journal of Korean society of Dental Hygiene
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• v.13 no.4
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• pp.631-637
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• 2013

Objectives : The aim of the study is to propose the fundamental data for further developments of the school dental clinic program through evaluating comprehensive improvements of the indices and the oral health status. Methods : This studied was carried out from December 2010 to September 2012. Subjects were 239 elementary school 4th, 5th, 6th grade students having no school dental clinic and 195 elementary school 4th, 5th, 6th grade students having school dental clinic in Busan. They completed self-reported questionnaires after accepting informed consent. The questionnaire included knowledges, attitudes and practices for oral health recognition and supports of the school dental clinic program. Results : Permanent tooth caries prevention rate revealed 59.0%, 53.3%, and 62.0%. in 4th, 5th, and 6th respectively. Rate of Care Group with fissure sealant permanent teeth showed 80.3%, 88.0%, and 88.9% respectively. Index of Care Group with fissure sealant permanent teeth revealed 2.68, 2.90, and 3.97, respectively. DMFT index of Care Group was 1.11, 1.35, and 1.51, respectively. Active D rate of Care Group resulted in 16.7%, 24.1%, and 16.7%, respectively. Dental health education group showed high awareness level of fluoride and sealant effect for caries prevention. Tooth brushing of three times per day was more effective when using rolling tooth brushing. On the other hand, oral health recognition and oral status in the control group was low. Conclusions : Oral health recognition was closely related to good oral care. Expansion of oral health care business is important to prevent dental caries. Systematic approach for oral health education programs and human resources development is very important to improve oral health care.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.243-247
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• 1998

This study was researched the external ocular structure on the korean young age. The results was as follows; 1. On the distance of innercanthus, the average length was 38-40 mm. In the twenties age, the male was longer then the female. 2. On the length of palpebral fissure, the average length was 35-37 mm and right and left eye was similar results. But, the male was longer than the female. 3. On the width of palpebral fissure, the average width was 7-8mm and the male and female was similar results. 4. At the near distance, the average PD was 29-33 mm, but in the twenty age, the left eye of male was longer than the right eye. On the other hand, In the female, the results was reverse. 5. At the distance, the average PD was 31-32 mm, But, In the teens, the male and female was similar results. On the other hand, In the twenties age, the male was longer than the female.

• Journal of Korean Society of Steel Construction
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• v.11 no.1 s.38
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• pp.33-42
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• 1999

In the present study, crack initiation criteria, static failure and tensile mode fatigue behavior for a rail steel are evaluated to assure the railway vehicle's safety. The transverse fissure, which is the most critical damage in the rail, is initiated by the maximum shear stress and its location is subsurface. In addition, the possibility of transition from the shear mode to the mixed mode increases with increasing the length of subsurface crack. Because of the brittleness by the welding, the fracture toughness of the welded part is lower than of the base metal. For low ${\Delta}K$, the stage II fatigue crack growth rates of the welded part is slower than of the base metal but, for high ${\Delta}K$, this different behavior for fatigue crack growth rate is nearly diminished. These trends are more remarkable for low stress ratio, R=0.1. It is believed that this behavior is caused by the change of the microstructure which that of the welded part is coarser than of base metal.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.1
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• pp.135-143
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• 2004

The Human body is subject to two patterns of senescence, both of which are represented in the eye and vision. This article discusses the anatomical and physiological changes in anterior and posterior segments which occur with age. The areas covered include the globe, lids, tears, conjunctiva, cornea, sclera, anterior chamber angle, iris, lens, choroid, vitreous and retina. A sample of 219 individuals between the ages of 50 and 79 years was tested with case history, slit lamp examination, palpebral fissure, horizontal visible iris diameter(HVID) and pupil size. The palpebral fissure decreases with age while HVID remains constant in all age classes. This study suggests that an understanding of anatomical and physiological changes which occur with age is helpful to all eye clinicians because the aging process affects all of the ocular tissues.

• Journal of Integrative Natural Science
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• v.11 no.3
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• pp.139-147
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• 2018

Hippocampal atrophy is a well-established imaging biomarker of Alzheimer disease (AD). However, hippocampus is a non-homogenous structure with cytoarchitecturally and functionally distinct sub-regions or subfield, with each region performing distinct functions. Certain regions of the subfield have shown selective vulnerability to AD. Here, we are interested in studying the effects of normal aging and mild cognitive impairment on these sub-regional volumes. With a reliable automated segmentation technique, we segmented these subregions of the hippocampus in 101 cognitively normal (CN), 135 early mild cognitive impairment (EMCI), 67 late mild cognitive impairment (LMCI) and 48 AD subjects. Thereby, dividing the hippocampus into hippocampal tail (tail), subiculum (SUB), cornu ammonis 1 (CA1), hippocampal fissure (fissure), presubiculum (PSUB), parasubiculum (ParaSUB), molecular layer (ML), granule cells/molecular layer/dentate gyrus (GCMLDG), cornu ammonis 3(CA3), cornu ammonis 4(CA4), fimbria and hippocampal-amygdala transition area (HATA). In this cross sectional study of 351 ADNI subjects, no differences in terms of age, gender, and years of education were observed among the groups. Though, the groups had statistically significant differences (p < 0.05 after the multiple comparison correction) in the Mini-Mental State Examination (MMSE) scores. There was asymmetrical volume loss in the early stages of AD with the left hemisphere showing volume loss in regions that were unaffected in the right hemisphere. Bilateral parasubiculum, right cornu ammonis 1, 3 and 4, right fimbria and right HATA regions did not show any volume loss till the late MCI stages. Our findings suggest that the hippocampal subfield regions are selectively vulnerable to AD and also that these vulnerabilities are asymmetrical especially during the early stages of AD.

• Korean Journal of Veterinary Pathology
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• v.7 no.1
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• pp.59-62
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• 2003

A two-year-old pointer dog showed a liver failure for long duration. By radiographic examination, barium or gas filled intestine was detected in the pericardium. Although liver function was bad, surgery was tried to repair hernia due to the poor prognosis. Intestine, omentum, and liver with gall bladder were dislocated in the pericadial sac by peritoneopericardial diaphragmatic hernia (PPDH). Intestine was easily removed from pericardial sac but omentum and liver were not because of strong adhesion to the pericardial sac. Postmortem examination was performed because the patient was died after surgery. Grossly, herniated liver whose right medial lobe was strongly adhered to the pericardial sac was severely congested with fibrin adhesion on the surface. Hypoplastic abnormally up-located heart had a fissure in the outside of lower right venticulum bordered apex and depressed large vessels including vena cava and aortic arch into the base of heart. It was suggested that formation of a fissure and depression of vessels might be due to the pressure of herniated organs. In the veterinary literature as far as we knew, PPDH associated with liver failure due to adhesion of liver to the pericardial sac has not been reported.

• Restorative Dentistry and Endodontics
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• v.16 no.1
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• pp.200-208
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• 1991

The purpose of this study was to observe shear bond strength of composite resin to dentin following surface treatment. Freshly extracted forty-eight sound human molars were used in this study. They were stored at $4^{\circ}C$ physiologic saline solution before experiment. The teeth was then mounted with self curing acrylic resin in brass mold. The buccal surfaces of the teeth were grinding approximately 1.5mm by means of water-irrigated grinding wheel to expose the flattened fresh dentin surfaces. The specimens were divided into 6 groups according to preparation and treatment procedures on dentin surfaces; Group 1: Untreated after preparation with No.301 diamond point Group 2: Treated with primer for 60 seconds after preparation with No.301 diamond point Group 3: Untreated after preparation with No.700 fissure carbide bur Group 4: Treated with primer for 60 seconds after preparation with No.700 fissure carbide bur Group 5: Untreated after grinding with 600 grit silicon carbide paper Group 6: Treated with primer for 60 seconds after grinding with 600 grit silicon carbide paper Light cure dental adhesive was applicated to each specimen. Silux plus(3M) was inserted then into polyethylene tube of 3mm diameter and 3mm height, and polymerized to dentin surface. All of the specimens were stored in distilled water at $35.6^{\circ}C$ for 24 hours prior to testing. The shear bond strength was measured using an Instron Universal Testing Machine. The results obtained from this study were as follows: 1. The shear bond strength to dentin was the highest in group II. 2. The shear bond strength to dentin was the lowest in group III. 3. There was no significant difference in shear bond strength to dentin according to preparation instrument. 4. The primer treatment group showed significantly greater shear bond strength than untreated group.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.3
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• pp.491-498
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• 2005

Occlusal fissures and pits are ideal places for the development of caries. Pit and fissure sealants are now considered as a very effective means to prevent dental caries. The purpose of this investigation was to examine the effect on the sealant penetration of the elapse of time from the application of sealant until exposure to visible light, and to examine the effect of the filler content and tooth position on the sealant penetration. 192 extracted human premolars were used to this experiment. Following enamel conditioning, a light-polymerized sealant was applied and 4 different periods of time(3, 5, 10, 20 seconds) were allowed until exposure to the light source. The results obtained were as follows; 1. According to time, in both unfilled sealant and filled sealant penetration increases deeply through mindfulness. 2. Sealant that apply to mandiblar premolar penetrated deeply through than to maxillay teeth. 3. Penetration difference according to filler content, unfilled sealant penetrated deeply through than filled sealant. The result from this study indicated that unfilled sealant penetrated most deeply in mandible when at least 20s time elapsed.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.211-215
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• 2001

Objective : The present study was performed to analyze treatment results for 22 cases of arachnoid cyst and to have appropriate surgical method in our department. Material and Methods : We performed a retrospective study in 22 cases in 11 years between 1989 to 2000 that could be followed up. The analysis was based on the results of patients age, sex distribution, developed area, clinical symptom, treatment method, and complication. Results : The age range of cyst development was between 7 months to 60 years with the average age of 21 years. As for sex distribution, 20 were male and 2 were female, with significantly more cyst development in males than females. Thirteen cases were developed in the sylvian fissure, 3 cases in the posterior fossa, 4 cases in the cerebral convexity of the supratentorial area, 1 case in the suprasella and 1 case in interhemiphere. Those cases with the sylvian fissure involvement included 6 cases of Type I, 4 cases of Type II, and 3 cases of Type III. As for the distribution according to hemisphere, more arachnoidal cysts were seen in the right hemisphere. The most common clinical symptom was headache, followed by seizure and speech disturbance. As for the treatment method in 22 cases, surgery was performed in 17 cases and conservative treatment in 5 cases. Fenestration was performed in 14 cases. 13 cases of them showed good outcome, and 1 case with delayed development showed no improvement. Cyst-peritoneal shunt was done in 2 cases. Both fenestration and cyst-peritoneal shunt were done in 1 case. Conclusion : Patients who perforemed fenestration were showed good outcome with few complication. We concluded that fenestration is the most appropriate surgical method for arachnoid cyst.