• Progress in Medical Physics
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• v.22 no.2
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• pp.72-78
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• 2011

The aim of this study is to evaluate the patient's setup errors in TomoTherapy (Hi-Art II, TomoTherapy, USA) Bodyfix system (Medical Intelligence, Ele-kta, Schwabmuchen, Germany) pressure in the vacuum compression, depending on and were evaluated. Bodyfix immobilization system and vacuum pressure was compression applied to the patients who received Tomotherapy thoracic and abdominal area, 21 patients were selected and TomoTehpay treatment total 477 of MVCT images were obtained. The translational (medial-lateral: ML, anterior-posterior: AP, superior-inferior: SI directions) and rolling were recorded and analyzed statistically. Using Pearson's product-moment coefficient and One-way ANOVA, the degree of correlation depending on the different vacuum pressure levels were statistically analyzed for setup errors from five groups (p<0.05). The largest average and standard deviation of systematic errors were 6.00, 5.95 mm in the AP and SI directions, respectively. The largest average of random errors were 4.72 mm in the SI directions. The correlation coefficients were 0.485, 0.244, and 0.637 for the ML-Roll, AP-Vector, and SI-Vector, respectively. SI-Vector direction showed the best relationship. In the results of the different degree of vacuum pressure in five groups (Pressure range: 30~70 mbar), the setup errors between the ML, SI in both directions and Roll p=0.00 (p<0.05) were shown significant differences. The average errors of SI direction in the vacuum pressure of 40 mbar and 70 mbar group were 4.78 mm and -0.74 mm, respectively. In this study, the correlation between the vacuum pressure and the setup-errors were statistically analyzed. The fact that setup-errors in SI direction is dependent in vacuum pressure considerly setup-errors and movement of interal organs was identified. Finally, setup-errors, and it, based on the movement of internal organs in Bodyfix system we should apply more than 50 mbar vacuum pressure. Based on the results of this study, it is suggested that accuracy of the vacuum pressure and the quantitative analysis of movement of internal organs and the tumor should be studied.

• Child Health Nursing Research
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• v.8 no.1
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• pp.32-43
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• 2002

The purpose of this study was to provide basic data on elementary school children's lifestyle and to contribute to developing on the health education program in elementary schools. The subjects were 1,412 children in 4 elementary schools in Gangwon-Do and Chonrabuk-Do area. Data collection was done from September to November 2001 by questionnaire and school health documents. The questionnaire corrected for the purpose of this study which had been developed by Bronson School of Nursing(1991), 'Lifestyle Questionnaire for School-age Children'. The questionnaire consists of 3 categories; 'Activities that promote health', 'Injury prevention', 'Feeling'. Cronbach coefficient alpha for the 29 items was .68. The data analyzed to obtain frequency, mean, percentage, t-test, ANOVA and Pearson correlation coefficient by SPSS Win program. The results of this study were as follows. 1. Females(50.2%) of gender, 6th grade(24.2%) of grade, nuclear family(82.0%) of family type, beyond college graduate(54.5%) of father's school career, under high school graduate(58.1%) of mother's school career, first of birth order(47.1%) were majority. Mean of father's age was 41.2 and mother's age was 38.1. 2. The mean of lifestyle was 66.4, feeling was 73.3, activities that promote health was 60.3 and injury prevention was 64.0. The highest degree of activities that promote health was 「I eat fruits」and injury prevention was 「I look both ways when crossing streets」and feeling was 「I enjoy my family」. The lowest degree of activities that promote health was 「I visit the dentist every tear」 and injury prevention was 「I wear a helmet when I go on bike trips」 and feeling was 「I think it is okay to cry」. 3. There were significant differences in lifestyle of gender(t=4.309, p=.000), grade(F=6.299, p=.000), father's age(t=2.534, p=.011), father's education(t=-4.933, p=.000), mother's education(t=-3.360, p=.001), birth order (t=5.363, p=.000). There were significant differences in activities that promote health of gender(t=-2.462, P=.014), grade(F=4.893, p=.000), father's education(t=-4.480, p=.000), birth order(t=4.343, p=.000), in injury prevention of gender(t=-4.452, p=.000), grade(F=8.636, p=.000), father's age(t=3.386, p=.001), mother's age(t=2.059, p=.040), father's education(t=-6.051, p=.000), mother's education(t=-5.173, p=.000), birth order(t=4.417, p=.000) and in feeling of gender (t=-3.285, p=.001), grade(F=7.526, p=.000), mother's age(t=-3.268, p=.001). 4. Activities that promote health was positively correlated with injury prevention(r=.432, p=.000), feeling(r=.210, p=.000), lifestyle (r=.785, p=.000). Injury prevention was positively correlated with feeling(r=.256, p=.000), lifestyle(r=.854, p=.000) also feeling was positively correlated with lifestyle(r=.504, p=.000). These findings suggest the need to develop nursing strategy to promote elementary school children's health. Because helmet use score in injury prevention marked the lowest score, it is necessary to encourage helmet use when planning injury prevention and health promotion.

• Sleep Medicine and Psychophysiology
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• v.7 no.1
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• pp.51-59
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• 2000

Objectives: It is been reported that sleep patterns change significantly during the adolescent years. In Korea, the sleep patterns of adolescents have not been investigated systematically. The authors performed preliminary study about sleep patterns of middle and high school students in Seoul before nationwide study. Methods: The authors selected one of middle and high schools located in typical middle class area in Seoul. The study was performed during the periods when examination or vacation did not affect the sleep cycle. Fifty to one hundred male and female students were selected from one school year each. One of investigators explained the purposes and methods of this study to the students and gave additional explanation to the teachers in charge. We designed a questionnaire for subjects to describe the nap time, bedtime, sleep latency, total sleep time, rise time and sleep efficiency, and the students recorded sleep logs for seven days including weekend. Eight hundred three students answered the questionnaires. Among them, we selected the subjects who recorded sleep logs at least three days and filled up the questionnaires completely. Finally, seven hundred seventy one subjects were included in this study. Weekend was defined as the time from Saturday morning to Sunday morning, and Sunday sleep patterns were treated separately. Results: Across the six school years, school-night bedtimes were delayed one hundred twenty four minutes and school-ight rise times were advanced by thirty five minutes. School-night total sleep times were decreased by one hundred fifty eight minutes, and weekend bedtimes were delayed by one hundred twenty five minutes. The students tended to oversleep on weekends, and the mean of weekend oversleep was ninety six minutes. But, bedtime in weekends was not delayed. Daytime sleep, sleep latency and sleep efficiency were not changed greatly across six school years. Total sleep time of female students was decreased significantly between third middle school year and first high school year, but time of male students was decreased between first and second high school year. Conclusion: It is supposed that sleep deficiency of middle and high school students in Seoul was due to delayed bedtimes and advanced rise times across the school years.

• Tuberculosis and Respiratory Diseases
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• v.55 no.2
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• pp.188-197
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• 2003

Background : Smoke inhalation injury is an important determinant of mortality in burn patients. The early detection of inhalation injury in burn patients is important because the incidence of respiratory failure after inhalation injury was known to be high, with hypoxemia, pneumonia, and prolonged ventilatory support being commonplace. Acute carbon monoxide poisoning was one feature of smoke inhalation. The purpose of our study were to investigate the clinical characteristics of burn patients whose initial arterial carboxyhemoglobin (COHb) level had been elevated, to assess the clinical impact of COHb for smoke inhalation injury. Methods : Among 1,416 burn patients had been admitted at our institution from August 1, 2001 to July 31, 2002, 39 patients whose initial arterial COHb level have been more than 5% were included. We compared clinical scoring system for inhalation injury, percent total body surface area (%TBSA) burn, initial chest X-ray findings, APACHE II scores and SAPS II scores between survivors (n=27) and non-survivors (n=12) retrospectively. Results : COHb level were 9.7(5.71% and 10.3(8.81% in survivors and in non-survivors (p>0.05). Mean %TBSA burn of survivors and non-survivors were $16.6{\pm}17.8%$ and $60.7{\pm}28.8%$ (p<0.001). We did not find any difference in clinical scoring system, initial chest X-ray findings in survivors and in non-survivors. But %TBSA burn, APACHE II and SAPS II scores were high in non-survivors than in survivors significantly. Important factors associated with death were %TBSA burn, APACHE II scores, SAPS II scores, and the most important factor in predicting mortality was %TBSA burn. Conclusion : Burn patients with elevated initial arterial COHb level showed poor prognosis, but further study may be performed to know that the effect of COHb on prognosis in burn patients accompanying smoke inhalation.

• Tuberculosis and Respiratory Diseases
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• v.59 no.6
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• pp.625-630
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• 2005

Background : Determining the cause of an exudative pleural effusion is sometimes quite difficult, especially between malignant and tuberculous effusions. Twenty percent of effusions remain undiagnosed even after a complete diagnostic evaluation, including pleural biopsy. The activity of tumor necrosis factor-alpha (TNF-${\alpha}$), which is the one of proinflammatory cytokines, is increased in both infectious and malignant effusions. The aim of this study was to investigate the diagnostic efficiency of TNF-${\alpha}$ activity in distinguishing tuberculous from malignant effusions. Methods : 46 patients (13 with malignant pleural effusion, 33 with tuberculous pleural effusion) with exudative pleurisy were included. TNF-${\alpha}$ concentrations were measured in the pleural fluid and serum samples using an enzyme-linked immunosorbent assay (ELISA). In addition, TNF-${\alpha}$ ratio (pleural fluid TNF-${\alpha}$ : serum TNF-${\alpha}$) was calculated. Results : TNF-${\alpha}$ concentration and TNF-${\alpha}$ ratio in the pleural fluid were significantly higher in the tuberculous effusions than in the malignant effusions (p<0.05). However, the serum levels of TNF-${\alpha}$ in the malignant and tuberculous pleural effusions were similar (p>0.05). The cut off points for the pleural fluid TNF-${\alpha}$ level and TNF-${\alpha}$ ratio were found to be 136.4 pg/mL and 6.4, respectively. The sensitivity, specificity and area under the curve were 81%, 80% and 0.82 for the pleural fluid TNF-${\alpha}$ level (p<0.005) and 76%, 70% and 0.72 for the TNF-${\alpha}$ ratio (p<0.05). Conclusion : We conclude that pleural fluid TNF-${\alpha}$ level and TNF-${\alpha}$ ratio can distinguish a malignant pleural effusion from a tuberculous effusion, and can be additional markers in a differential diagnosis of tuberculous and malignant pleural effusion. The level of TNF-${\alpha}$ in the pleural fluid could be a more efficient marker than the TNF-${\alpha}$ ratio.

• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.503-510
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• 2005

In this research, composite alumina was prepared to add the various promoters by sol-gel method and examined its thermal stability. After sintering at $1,200^{\circ}C$, the thermal stability resulted in following order, $Si{\fallingdotseq}La$ > Ti > $Ba{\fallingdotseq}Ce$ > Y > $Zr{\fallingdotseq}Mg$, in accordance with adding the promoters. Especially in case of silica-added alumina, a phase transformation temperature to ${\alpha}$-alumina increased about $150^{\circ}C$ and after sintering at $1,200^{\circ}C$, it showed to maintain in ${\gamma}$-form and ${\delta}$-form alumina phase. Also it showed an increase of surface area from $3m^2/g$ to $71m^2/g$ compared with pure ${\alpha}$-alumina. In the case of silicaadded alumina, the characterization change of this alumina particle resulted in a delay of phase transformation because Si-O-Al bond was increased when sintered at high temperature. In case of lanthanum-added alumina, there was a sintering delay phenomenon in inter-particles as $LaAlO_3$ structure existed. The existence of lanthanum structure was confirmed by XRD and XPS analysis. It appeared on the alumina surface as $La_2O_3$ structure when it was sintered under $1,000^{\circ}C$, as the perovskite structure of $LaAlO_3$ at above $1,000^{\circ}C$ and as the magneto-plumbite structure of $LaAl_{11}O_{18}$ at above $1,300^{\circ}C$.

• The Journal of the Korean dental association
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• v.50 no.12
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• pp.743-754
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• 2012

urpose : The purpose of this study was to evaluate the US II plus/GS II Osstem$^{(R)}$ implants through the study for the clinical success rate during the installation of the Osstem¢Á implants after bone graft. Materials and Methods : This study was researched in the 4 medical institutions: Chonnam National University, Chosun University, Bundang Seoul National University Hospital, and FM dental clinic from May, 2002 to September, 2009. Based on the total number of 60 patients whose treatment was the installation of the US II plus/GS II Osstem¢Á implants after bone graft, we evaluated success rate of implants. We analysis the distribution of patient's age and gender, edentulous area, bone type, fixture length and diameter, installation and loading time, donor site, bone graft material and method, antagonistic teeth, and survival and success rate. From these analyses we got the following results. Results : 1. In this study, the total number of patients who have been installed with US II plus implant was 27, and total of 52 implants were installed. The average age was 38.9, with 16 male, and 11 female patients. 2. The total number of patients who have been installed with GS II implant was 33, and total of 54 implants were installed. The average age was 49.7, with 24 male, and 9 female patients. 3. As for bone graft method, either autogenous bone or a mix of autogenous and heterogenous bone was used(88.4%) for US II plus. Chin, iliac, and Maxillary tuberosity were the donor sites for autogenous bone graft, and onlay method of bone graft was performed. 4. Allogenic bone or a mix of autogenous and heterogenous bone was used(77.8%) for GS II. Chin, ramus, and tibia were the donor sites for autogenous bone graft, and GBR method of bone graft was performed. 5. The duration from the installation of implants to setting of final prosthesis was average of 16 months and 10 months for US II plus and GS II respectively. Also, the final follow up period was average of 31 months and 28 months respectively. During this period, one GS II implant was removed from 1 patient due to failure of early osteointegration. 6. The survival rates were 100% and 98.1%, and success rates were 94.2% and 94.4% for US II plus and GS II implant respectively. Conclusion : On the evaluation of our clinical study, both US II plus and GS II Osstem¢Á implants showed the excellent clinical results after bone graft.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.6
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• pp.469-477
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• 2009

Purpose: This study was performed to evaluate the effect of various graft materials used with a titanium cap on the ability of new bone formation in the rabbit calvarium. Materials and Methods: A total of 32 sites of artificial bony defects were prepared on the calvaria of sixteen rabbits by using a trephine bur 8 mm in diameter. Each rabbit had two defect sites. 0.2 mm deep grooves were formed on the calvaria of sixteen rabbits by using a trephine bur 8 mm in diameter for the fixation of a titanium cap. The treatments were performed respectively as follows: without any graft for the control group (n=8), autogenous iliac bone graft for experimental group 1 (n=8), alloplastic bone graft ($SynthoGraft^{(R)}$, USA) for experimental group 2 (n=8), and xenogenic bone graft ($NuOss^{(R)}$, USA) for experimental group 3 (n=8). After the treatments, a titanium cap (8 mm in diameter, 4 mm high, and 0.2 mm thick) was fixed into the groove. At the third and sixth postoperative weeks, rabbits in each group were sacrificed for histological analysis. Results: 1. In gross examination, the surgical sites showed no signs of inflammation or wound dehiscence, and semicircular-shaped bone remodeling was shown both in the experimental and control groups. 2. In histological analysis, the control group at the third week showed bone remodeling along the inner surface of the cap and at the contact region of the calvarium without any specific infiltration of inflammation tissue. Also, there was no soft tissue infiltration. Bone remodeling was observed around the grafted bone and along the inner surface of the titanium cap in experimental group 1, 2, and 3. 3. Histologically, all groups at the sixth week showed the increased area of bone remodeling and maturation compared to those at the third week. In experimental group 2, the grafted bone was partially absorbed by multi nucleated giant cells and new bone was formed by osteoblasts. In group 3, however, resorption of the grafted bone was not observed. 4. Autogenous bone at the third and sixth week showed the most powerful ability of new bone formation. The size of newly formed bone was in decreasing order by autogenous, alloplastic, and heterogenous bone graft. There was no statistically significant difference among autogenous, alloplastic, and heterogenous bones(p>0.05). Summary: This result suggests that autogenous bone is the best choice for new bone formation, but when autogenous bone graft is in limited availability, alloplastic and xenogenic bone graft also can be an alternative bone graft material to use with a suitably guided membrane.

• Korean Chemical Engineering Research
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• v.55 no.3
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• pp.322-331
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• 2017

District heating was first introduced in Korea in 1985. As the service life of the underground thermal piping network has increased for more than 30 years, the maintenance of the underground thermal pipe has become an important issue. A variety of complex technologies are required for periodic inspection and operation management for the maintenance of the aged thermal piping network. Especially, it is required to develop a model that can be used for decision making in order to derive optimal maintenance and replacement point from the economic viewpoint in the field. In this study, the analysis was carried out based on the repair history and accident data at the operation of the thermal pipe network of five districts in the Korea District Heating Corporation. A failure probability model was developed by introducing statistical techniques of qualitative analysis and binomial logistic regression analysis. As a result of qualitative analysis of maintenance history and accident data, the most important cause of pipeline damage was construction erosion, corrosion of pipe and bad material accounted for about 82%. In the statistical model analysis, by setting the separation point of the classification to 0.25, the accuracy of the thermal pipe breakage and non-breakage classification improved to 73.5%. In order to establish the failure probability model, the fitness of the model was verified through the Hosmer and Lemeshow test, the independent test of the independent variables, and the Chi-Square test of the model. According to the results of analysis of the risk of thermal pipe network damage, the highest probability of failure was analyzed as the thermal pipeline constructed by the F construction company in the reducer pipe of less than 250mm, which is more than 10 years on the Seoul area motorway in winter. The results of this study can be used to prioritize maintenance, preventive inspection, and replacement of thermal piping systems. In addition, it will be possible to reduce the frequency of thermal pipeline damage and to use it more aggressively to manage thermal piping network by establishing and coping with accident prevention plan in advance such as inspection and maintenance.

• Korean Chemical Engineering Research
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• v.55 no.3
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• pp.436-442
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• 2017

Fischer-Tropsch synthesis is the technology of converting a syngas (CO+$H_2$) derived from such as coal, natural gas and biomass into a hydrocarbon using a catalyst. The catalyst used in the Fischer-Tropsch synthesis consists of active metal, promoter and support. The types of these components and composition affect the reaction activity and product selectivity. In this study, we manufactured an iron catalyst using ${\gamma}-Al_2O_3/SiO_2$ mixed support (100/0 wt%, 75/25 wt%, 50/50 wt%, 25/75 wt%, 0/100 wt%) by an impregnation method to investigate how the composition of ${\gamma}-Al_2O_3/SiO_2$ mixed support effects on the reaction activity and product selectivity. The physical properties of catalyst were analyzed by $N_2$ physical adsorption and X-Ray diffraction method. The Fischer-Tropsch synthesis was conducted at $300^{\circ}C$, 20bar in a fixed bed reactor for 60h. According to the results of the $N_2$ physical adsorption analysis, the BET surface area decreases as the composition of ${\gamma}-Al_2O_3$ decreases, and the pore volume and pore average diameter increase as the composition of ${\gamma}-Al_2O_3$ decreases except for the composition of ${\gamma}-Al_2O_3/SiO_2$ of 50/50 wt%. By the results of the X-Ray diffraction analysis, the particle size of ${\alpha}-Fe_2O_3$ decreases as the composition of ${\gamma}-Al_2O_3$ decreases. As a result of the Fischer-Tropsch synthesis, the CO conversion decreases as the composition of ${\gamma}-Al_2O_3$ decreases, and the selectivity of C1-C4 decreases until the composition of ${\gamma}-Al_2O_3$ was 25 wt%. In contrast, the selectivity of C5+ increases until the composition of ${\gamma}-Al_2O_3$ is 25 wt%.