• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2142-2147
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• 2012

This study is aimed at decreasing wrong diagnosis with corrected EF(Ejection Fraction) of 2D echo cardiography by analysing the physical time-resolution difference between Cine MRI and 2D echo cardiography and applying the corrected EF in 2D echocardiography. From February 2010 to December 2011, among the 110 patients who had undergone both 2D echo cardiography and cine MRI only 37 patient were selected suffering aortic valve regurgitation. ED, ES and SV were measured and EF was calculated in each system while normal ranges of Cine MRI and 2D echocardiography were compared to evauate misdiagnosis rate. The correlation of physical time resolution between 2D echocardiography and MRI was evaluated and the differences were corrected with linear regression coefficient which is derived from linear regression analysis. Blandt-Altman plot was used to evaluate the reliability of corrected 2D echo cardiography EF and compare the error among measured values. The values were compared with MRI normal range and misdiagnosis rate was measured again. As a result, misdiagnosis rates of physical time resolution were measured to be 32.4%(12people) before the correction of EF and 18.9%(7people) after the correction. Also, EF confirmed in Blandt-Altman plot were almost the same with MRI EF. In conclusion, when diagnosing aortic regurgitation disease, simply using 2D echocardiography can easily raise the misdiagnosis rates, therefore considering the MRI machine's physical merits, correcting the time resolution difference is important by calculating time resolution wrong diagnosis would decrease and it is considered to be useful in clinical circumstances.

• Restorative Dentistry and Endodontics
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• v.27 no.2
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• pp.142-149
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• 2002

Low-viscosity composite resins may produce better sealed margins than stiffer compositions (KempScholte and Davidson, 1988: Crim, 1989). Plowable composites have been recommended for use in Class V cavities but it is also controversial because of its high rates of shrinkage. On the other hand, in the study comparing elastic moduli and leakage, the microfill had the least leakage (Rundle et at. 1997) Furthermore, in the 1996 survey of the Reality Editorial Team, microfills were the clear choice for abfraction lesions. The purpose of this study was to evaluate the microleakage of 6 compostite resins (2 hybrids, 2 microfills, and 2 flowable composites) with and without load cycling. Notch-shaped Class V cavities were prepared on buccal surface of 180 extracted human upper premolars on cementum margin. The teeth were randomly divided into non-load cycling group (group 1) and load cycling group (group 2) of 90 teeth each. The experimental teeth of each group were randomly divided into 6 subgroups of 15 samples. All preparations were etched, and Single bond was applied. Preparations were restored with the following materials (n=15) : hybrid composite resin [Z250(3M Dental Products Inc. St. Paul, USA), Denfil(Vericom, Ahnyang, Korea)], microfill [Heliomolar RO(Vivadent, Schaan, Liechtenstein), Micronew(Bisco Inc. Schaumburg, IL, USA)], and flowable composite［AeliteFlo(Bisco Inc. Schaumburg, IL, USA), Revolution(Kerr Corp. Orange, CA, USA)]. Teeth of group 2 were subjected to occlusal load (100N for 50,000 cycles) using chewing simulator(MTS 858 Mini Bionix II system, MTS Systems Corp. Minn. USA). All samples were coated with nail polish 1mm short of the restoration, placed in 2％ methylene blue for 24 hours, and sectioned with a diamond wheel. Enamel and dentin/cementum margins were analyzed for microleakage on a sclale of 0 (no leakage) to 3 (3/3 of wall). Results were statistically analyzed by Kruscal-Wallis One way analysis, Mann-Whitney U-test, and Student-Newmann-Keuls method. (p = 0.05) Results : 1. There was significantly less microleage in enamel margins than dentinal margins of all groups (p＜0.05) 2. There was no significant between six composite resin in enamel margin of group 1. 3. In dentin margin of group 1, flowable composite had more microleakage than others but not of significant differences. 4. there was no significant difference between six composite resin in enamel margin of group 2. 5. In dentin margin of group 2, the microleakage were R＞A =H=M＞D＞Z. But there was no significant differences. 6. In enamel margins, load cycling did not affect the marginal microleakage in significant degree. 7. In enamel margins, load cycling did affect the marginal microleakage only in Revolution. (p＜0.05).

• Restorative Dentistry and Endodontics
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• v.32 no.2
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• pp.151-161
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• 2007

Dental caries is the most common disease in the oral cavity However, the mechanism and treatment of dental caries is not completely understood since many complex factors are involved. Especially the effect of pH on remineralization of early stage of dental caries is still controversial In this study, dental caries in dentin was induced by using lactic acidulated buffering solutions and the loss or inorganic substance was measured. Also decalcified specimens were remineralized by three groups of solution with different pH (group of pH 4.3, 5.0, and 5.5). Then, the amount and the area of inorganic substance precipitation was quantitatively analyzed with microradiograph. Also a qualitative comparison of the normal phase the demineralized phase, and the remineralized phase of hydroxyapatite crystal was made under SEM. The results were as follows, 1. In microradiograghic analysis, as the pH increased, the amount of remineralization in decalcified dentin tended to increase significantly As the pH decreaced, deeper decalcification, however, occurred along with remineralization. The group of pH 5.5 had a tendency to be remineralized without demineralization (p<0.05). 2. In SEM view, the remineralization in dentine caries occurred from the hydroxyapatite crystal surface surrounding the mesh of organic matrix, and eventually filled up the demineralized area. 3. 5 days after remineralization, hydroxyapatite crystal grew bigger with deposition of inorganic substance in pH 4.3 and 5.0 group, and the crystal in the remineralized area appeared to return to normal. After 10 days, the crystals in group of pH 4.3 and 5.0, which grew bigger after 5 days of remineralization, turned back to their normal size, but in group of pH 5.5, some crystals were found to double their size. In according to the results of this experiment, the decalcifying and remineralizing process of dentine is neither simple nor independent, but a dynamic process in which decalcification and remineralization occur simultaneously. The remineralization process occurred from the hydroxyapatite crystal surface.

• Proceedings of the KACD Conference
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• 2008.05a
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• pp.177-183
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• 2008

It was reported that esthetic composite resin restoration reinforces the strength of remaining tooth structure with preserving the natural tooth structure. However, it is unknown how much the strength would be recovered. The purpose of this study was to compare the fracture resistance of three types of undermined cavity filled with composite resin with that of non-cavitated natural tooth. Forty sound upper molars were allocated randomly into four groups of 10 teeth. After flattening occlusal enamel. undermined cavities were prepared in thirty teeth to make three types of specimens with various thickness of occlusal structure (Group $1{\sim}3$). All the cavity have the 5 mm width mesio-distally and 7 mm depth bucco-lingually. Another natural 10 teeth (Group 4) were used as a control group. Teeth in group 1 have remaining occlusal structure about 1 mm thickness, which was composed of mainly enamel and small amount of dentin. In Group 2, remained thickness was about 1.5 mm, including 0.5 mm thickness dentin. In Group 3, thickness was about 2.0 mm, including 1 mm thickness dentin. Every effort was made to keep the remaining dentin thickness about 0.5 mm from the pulp space in cavitated groups. All the thickness was evaluated with radiographic Length Analyzer program. After acid etching with 37% phosphoric acid, one-bottle adhesive (Single $Bond^{TM}$, 3M/ESPE, USA) was applied following the manufacturer's recommendation and cavities were incrementally filled with hybrid composite resin (Filtek $Z-250^{TM}$, 3M/ESPE, USA). Teeth were stored in distilled water for one day at room temperature, after then, they were finished and polished with Sof-Lex system. All specimens were embedded in acrylic resin and static load was applied to the specimens with a 3 mm diameter stainless steel rod in an Universal testing machine and cross-head speed was 1 mm/min. Maximum load in case of fracture was recorded for each specimen. The data were statistically analyzed using one-way analysis of variance (ANOVA) and a Tukey test at the 95% confidence level. The results were as follows: 1. Fracture resistance of the undermined cavity filled with composite resin was about 75% of the natural tooth. 2. No significant difference on fracture loads of composite resin restoration was found among the three types of cavitated groups. Within the limits of this study, it can be concluded the fracture resistance of the undermined cavity filled with composite resin was lower than that of natural teeth, however remaining tooth structure may be supported and saved by the reinforcement with adhesive restoration, even of that portion consists of mainly enamel and a little dentin structure.

• Journal of Biomedical Engineering Research
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• v.24 no.5
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• pp.401-410
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• 2003

This study investigates the biomechanical efficacies of various cement augmentation techniques with or without pressurization for varying degrees of osteoporotic femur. For this study, a biomechanical analysis using a finite element method (FEM) was undertaken to evaluate surgical procedures, Simulated models include the non-cemented(i.e., hip screw only, Type I), the cement-augmented(Type II), and the cemented augmented with pressurization(Type III) models. To simulate the fracture plane and other interfacial regions, 3-D contact elements were used with appropriate friction coefficients. Material properties of the cancellous bone were varied to accommodate varying degrees of osteoporosis(Singh indices, II∼V). For each model. the following items were analyzed to investigate the effect surgical procedures in relation to osteoporosis of varying degrees : (a) von Mises stress distribution within the femoral head in terms of volumetric percentages. (b) Peak von Mises stress(PVMS) within the femoral head and the surgical constructs. (c) Maximum von Mises strain(MVMS) within the femoral head, (d) micromotions at the fracture plane and at the interfacial region between surgical construct and surrounding bone. Type III showed the lowest PVMS and MVMS at the cancellous bone near the bone-construct interface regardless of bone densities. an indication of its least likelihood of construct loosening due to failure of the host bone. Particularly, its efficacy was more prominent when the bone density level was low. Micromotions at the interfacial surgical construct was lowest in Type III. followed by Type I and Type II. They were about 15-20% of other types. which suggested that pressurization was most effective in limiting the interfacial motion. Our results demonstrated the cement augmentation with hip screw could be more effective when used with pressurization technique for the treatment of intertrochanteric fractures. For patients with low bone density. its effectiveness can be more pronounced in limiting construct loosening and promoting bone union.

• Journal of Korean Home Economics Education Association
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• v.15 no.4
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• pp.115-132
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• 2003

The purpose of this study is aimed at giving proof that helps the elementary practical arts education system accomplish as the effects are turned out experimentally. Two classes of the sixth grade of J elementary school in Dae-gu have been selected in order to be experimented. One was chosen as an experimental group, the other was done as a comparative group. The creative-problem-solving learning-model was applied to the experimental group, and the traditional way of teaching was applied to the comparative group. For four classes of the sixth grades, ‘chapter 8: Making with recycled materials’ was proceeded as the content. Then. tests about the way of environmental awareness and creativity were carried out twice. After that, the results of pre and after-test in the comparative and experiment groups were compared using the t-test method. Following the analysis of the data collected in this study. the following major observations were obtained: First, children who were educated the creative problem-solving in a practical arts education achieved higher scores than before. Therefore, it turns out that the CPS method is an effective way to improve the environmental awareness in children. It showed that it included lots of daily habits connected with daily life and it made the intention to carry out the environment-preservation stronger and children´s attitude towards the environment improved. Moreover, making with recycled materials was used to solve an environmental problem, affecting in a positive way in our life. It also made the positive recognition about the environment. Second. the application of the creative problem-solving class of the practical arts education can make positive results to children. It helped children to have more interest in the environment around them. Children´s fluency, flexibility and originality in their ideas were improved as much as possible while they were solving problems. Consequently, the application of the creative problem-solving class model of elementary practical arts environmental education lets children expand environment consciousness and creativity.

• Journal of Korean Home Economics Education Association
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• v.18 no.4 s.42
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• pp.67-84
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• 2006

This study was carried out to investigate nutrient intake, dietary self-efficacy, and physical activity self-efficacy of elementary school students by obesity index in Gyeongbuk area. The survey was conducted from June 7 to June 18 in 2005. The study was peformed by analyzing a questionnaire answered by 523 elementary school student in 5th and 6th grade. The obesity index was gained by height and weight data. Nutrient intakes was evaluated by 24hr-dietary record. Statistical data analysis were completed using the SPSS 12.0 program. The results were summarized as follows; The result of the body measurement was that 31.7% of underweight group, 45.1% of normal group, 12.8% of overweight group, 10.3% of obese group. 13.9% of underweight group experienced weight control, and 17.5% of the subject respond they will try the weight control in the future. Male students showed significantly higher exercise frequency than female students(p<0.001). Male underweight group and female obese group show the highest exercise frequency. Daily energy intake of the subject showed 80.1% in male students and 87.5% in female students revealed under the recommended dietary allowance(RDA) for Korean. The intake ratio of energy nutrients was identical in male and female of underweight group and obese group, so this showed that intake style was similar in two groups. By investigating through MAR(mean adequacy ratio), underweight group of male students and both normal and overweight group of female students were lowest, while overweight group of male students and underweight group of female students were the highest. Physical activity self-efficacy of male students was higher than female students, and physical activity self-efficacy by obesity index was higher in underweight group of male students and obese group in female.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.2
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• pp.35-45
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• 2010

The objective of this study is to verify the positional accuracy by performing the orthometric corrections on the high resolution satellite images and to analyze the band correlation between the high resolution images corrected with orthometric correction. The objectives also included an analysis on the correlation of NDVI. For the orthometric correction of images from KOMPSAT2 and IKONOS, systematic errors were removed in use of RPC data, and non-planar distortions were corrected with GPS surveying data. Also, by preempting the image points at the same positions within ortho images, a comparison was performed on positional accuracies between image points of each image and GPS surveying points. The comparison was also made on the positional accuracies of image points. between the images. For correlation of band and correlation of NDVI, the descriptive statistics of DN values were acquired for respective bands by adding the Quickbird images and Aerial Photographs undergone through orthometric correction at the time of purchase. As result, from a comparison on positional accuracies of Orthoimages from KOMPSAT2 and Ortho Images of IKONOS was made. From the comparison the distance between the image points within each image and GPS surveying points was identified as 3.41m for KOMPSAT2 and as 1.45m for IKONOS, presenting a difference of 1.96m. Whereas, RMSE between image points was identified as 1.88m. The level of correlation was measured by using Quickbird, KOMPSAT2, IKONOS and Aerial Photographs between inter-image bands and NDVI, showing that there were high levels of correlation between Quickbird and IKONOS identified from all bands as well as from NDVI, except a high level of correlation that was identified between the Aerial Photographs and KOMPSAT2 from Band 2. Low levels of correlation were also identified between Quickbird and Aerial Photographs from Band 1. and between KOMPSAT2 and IKONOS from Band 2 and Band 4, whereas, KOMPSAT2 showed low correlations with Aerial Photographs from Band 3. For NDVI, KOMPSAT2 showed low level of correlations with both of QuickBird and IKONOS.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.3
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• pp.47-56
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• 2014

Recently, the velocity of sea-level rising has increased due to the global warming and the natural disasters have been occurred many times. Therefore, there are various demands for the integration of vertical reference datums for the ocean and land areas in order to develop a coastal area and prevent a natural disaster. Currently, the vertical datum for the ocean area refers to Local Mean Sea Level(LMSL) and the vertical datum for the land area is based on Incheon Mean Sea Level(IMSL). This study uses 31 points of Tidal Gauge Bench Mark (TGBM) in order to compares and analyzes the geometric heights referring LMSL, IMSL, and the nationally determined geoid surface. 11 points of comparable data are biased more than 10 cm when the geometric heights are compared. It seems to be caused by the inflow of river, the relocation of Tidal Gauge Station, and the topographic change by harbor construction. Also, this study analyze the inclination of sea surface which is the difference between IMSL and LMSL, and it shows the inclination of sea surface increases from the western to southern, and eastern seas. In this study, it is shown that TGBM can be used to integrate vertical datums for the ocean and land areas. In order to integrate the vertical datums, there need more surveying data connecting the ocean to the land area, also cooperation between Korea Hydrographic and Oceanographic Administration and National Geographic Information Institute. It is expected that the integrated vertical datum can be applied to the development of coastal area and the preventative of natural disaster.

• Journal of Nutrition and Health
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• v.43 no.2
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• pp.114-122
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• 2010

Se and Fe are trace minerals acting as antioxidant scavenging free radicals. Iron deficiency is the most frequently reported nutritional deficiency in females. Body iron status are known to be dependent not only upon dietary iron intake, but also upon micro-mineral nutrition and obesity. Antioxidants such as selenium are reported to play an important role on the regulation of erythropoiesis by protecting RBC membrane from antioxidative damage. In this study, iron status in young females and its relationships with selenium status and physique were examined. Serum selenium and iron concentrations were measured by HANARO research reactor using neutron activation analysis method (NAA-method). The proportion with iron deficiency and anemia were 27.1% and 8.6%, respectively in young females, but the proportion with iron deficient anemia was 1.4%. The mean serum selenium level was $12.0\;{\mu}g/dL$ and in normal range in the young women. The study participants were tertiled according to BMI and serum selenium levels. Serum ferritin and iron levels inclined with increasing BMI tertiles. Serum iron and RBC count were higher in middle selenium group than low selenium group. Individuals had significantly lower hematocrit level in the lowest tertile for their serum selenium levels compared with the highest tertile. The serum ferritin level was predicted 25% by BMI and RBC count 26.2% by the serum selenium level and body fat%. In conclusion, this study shows that body iron status in young adult females are influenced by obesity and body selenium status.