• Progress in Medical Physics
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• v.17 no.3
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• pp.131-135
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• 2006

A commercial ion chamber matrix was examined the characteristics and its performance for radiotherapy qualify assurance. The device was the I'mRT 2D-MatriXX (Scanditronix-Wellhofer, Schwarzenbruck, Germany). The 2D-MatriXX device consists of a 1020 vented ion chamber array, arranged in $24{\times}24cm^2$ matrix. Each ion chamber has a volume of $0.08cm^3$, spacing of 0.762 cm and minimum sampling time of 20 ms. For the investigation of the characteristics, dose linearity, output factor, short-term reproducibility and dose rate dependency were tested. In the testing of dose linearity. It has shown a good signal linearity within 1% in the range of $1{\sim}800$cGy. Dose rate dependency was found to be lower than 0.4% (Range: 100-600 Mu/min) relative to a dose rate of 300 Mu/min as a reference. Output factors matched very well within 0.5% compared with commissioned beam data using a ionization chamber (CC01, Scanditronix-Wellhofer, Schwarzenbruck, Germany) in the range of field sizes $3{\times}3{\sim}24{\times}24cm^2$. Short-term reproducibility (6 times with a interval of 15 minute) was also shown a good agreement within 0.5%, when the temperature and the pressure were corrected by each time of measurement. in addition, we compared enhanced dynamic wedge (EDW, Varian, Palo Alto, USA) profiles from calculated values in the radiation planning system with those from measurements of the MatriXX. Furthermore, anon-uniform IMRT dose fluence was tested. All the comparison studies have shown good agreements. In this study, the MatriXX was evaluated as a reliable dosimeter, and it could be used as a simplistic and convenient tool for radiotherapy qualify assurance.

• Journal of The Korean Association For Science Education
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• v.40 no.2
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• pp.177-189
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• 2020

In this study, we implemented an education program to improve the responsive teaching ability of pre-service science teachers, and analyzed the responsive teaching practices revealed during the program process. Through this, we derived the types and characteristics of responsive teaching practice, identified factors that made it difficult for pre-service teachers to practice, and obtained empirical data on under what conditions the responsive teaching capacity of pre-service teachers was developed. For this purpose, a practice-based teacher education program was designed and carried out for 14 pre-service teachers who had no experience in responsive teaching. The program consists of four steps; observation of class, practice through rehearsal, application in practicum, and post-reflection on educational practice. In particular, qualitative analysis was conducted on the types of responsive teaching and their detrimental factors revealed during application in practicum. As a result of the analysis, four types were derived; discriminator type, communicator type, guide type, and facilitator type. Each type was identified as having a common responsive teaching step element. The education program implemented in this study was effective for pre-service teachers to recognize the importance of student-participation class and the educational effect of responsive teaching. However, three barriers that prevented pre-service teachers from responsive teaching practice were also analyzed. First was the pressure to achieve specific learning goals within a given class time. Second was the rigid belief of the fixed curriculum. Third was the obsession that the teacher should lead the class. Based on these results, it was suggested that in order to improve the responsive teaching ability of pre-service teachers, it is necessary to support the recognition of breaking out of the thinking the time constraint, the flexibility of the curriculum, and the role of teacher as a class supporter.

• Journal of Chest Surgery
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• v.36 no.12
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• pp.904-910
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• 2003

Thoracoscopic bullectomy (VATS-B) is now the preferred treatment for spontaneous pneumothorax despite of higher recurrence rate than open thoracotomy. Several methods have been used to prevent this problem. The effectiveness of staple line reinforcement (SLR) in VATA-B using endostaplers was assessed by clinical and experimental study. Meterial and Method: In experimental study, canine lungs were harvested immediately (group I N=5) and 48 hours (group II N=5) after stapling. The pressures at which initial air leaks occurred were measured. In clinical study from February 1997 to March 1999, 106 procedures in 104 patients undergoing VATS-B for spontaneous pneumothorax were classified into two groups according to the presence of SLR and were compared. Result: The average pressure of the initial air leakage was significantly higher in SLR than that of staples alone (18$\pm$1.6 vs 48$\pm$3 mm Hg in group I; 23.8$\pm$1.9 vs 54$\pm$4.6 mm Hg in group II, p<0.001). In the clinical data, there were significant differences seen in the duration of drainage, the total length of endostaplers used, and the duration of the postoperative hospital stay between patients with staple alone and patients with SLR (4.4$\pm$1.4 vs 3.1$\pm$1.1 days in duration of drainage, 92.3$\pm$28.1 vs 71.1$\pm$30.6 mm in total length of endostaplers used, 5.9$\pm$1.9 vs 4.6$\pm$1.7 days in postoperative hospital stays, p<0.001). Conclusion: SLR was effective for preventing prolonged air leakage and responsible for shorter hospital stays after VATS-B for the treatment of spontaneous pneumothorax.

• Clinical and Experimental Pediatrics
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• v.52 no.8
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• pp.869-874
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• 2009

Purpose : Short attacks of headache are present in the pediatric age group. Short-lasting headaches (SLH) have been infrequently reported in children and adolescents. This study aims to assess the prevalence, clinical characteristics, treatment, and prognosis of short-lasting headaches in children and adolescents. Methods : One hundred twenty-three consecutive patients attended the Chosun University Hospital Headache Center between March 2006 and July 2007. Among 123 headache patients, 44 patients with one key criterion, namely, recurrent headaches episodes of a few seconds to less than 30 minutes, were selected. Results : Of the 123 headache patients, 44 (35.8%, males 18, females 26) had SLH. The mean age was 9.24 years (range 2.3-14.2). The mean headache frequency was $11.50{\pm}10.30$ per month, mean severity was $4.86{\pm}1.36$ out of 10, and the mean PedMIDAS score was $7.97{\pm}17.51$. SLH was significantly more common in children <6 years old (10/22, 45.5%) than in ${\geq}6$ years old (34/101, 33.7%) (P=0.015). The nature of pain was pressure in 30.2%, stabbing in 27.9%, throbbing in 18.6%, and dull in 11.7%. In 52.4% patients, the pain occurred in the front, one side of the temple in 28.5%, both sides of the temple in 7.1%, and back in 4.8% patients. The duration of attacks was <6 minutes in 38% and ${\geq}6$ minutes in 61.4%. The intensity of the pain was 4-6 out of 10 in 75.0%, in 13.6% 1-3, and in 11.4% 7-10. Treatment was significantly effective in reducing the frequency, duration, and severity of headaches and the PedMIDAS score after 3 months (P<0.05). Conclusion : Short attacks of headache are common (35.8%) in children and adolescents. These are difficult to classify according to International Headache Society criteria. The outcome, after a period of 3 months to 2 years, was favorable in most patients. Further studies are needed to gather more data and to obtain a better description of these forms of headache in the pediatric group.

• Tunnel and Underground Space
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• v.28 no.5
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• pp.400-425
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• 2018

This study presents the research results and current status of the DECOVALEX-2019 project Task B. Task B named 'Fault slip modelling' is aiming at developing a numerical method to simulate the coupled hydro-mechanical behavior of fault, including slip or reactivation, induced by water injection. The first research step of Task B is a benchmark simulation which is designed for the modelling teams to familiarize themselves with the problem and to set up their own codes to reproduce the hydro-mechanical coupling between the fault hydraulic transmissivity and the mechanically-induced displacement. We reproduced the coupled hydro-mechanical process of fault slip using TOUGH-FLAC simulator. The fluid flow along a fault was modelled with solid elements and governed by Darcy's law with the cubic law in TOUGH2, whereas the mechanical behavior of a single fault was represented by creating interface elements between two separating rock blocks in FLAC3D. A methodology to formulate the hydro-mechanical coupling relations of two different hydraulic aperture models and link the solid element of TOUGH2 and the interface element of FLAC3D was suggested. In addition, we developed a coupling module to update the changes in geometric features (mesh) and hydrological properties of fault caused by water injection at every calculation step for TOUGH-FLAC simulator. Then, the transient responses of the fault, including elastic deformation, reactivation, progressive evolutions of pathway, pressure distribution and water injection rate, to stepwise pressurization were examined during the simulations. The results of the simulations suggest that the developed model can provide a reasonable prediction of the hydro-mechanical behavior related to fault reactivation. The numerical model will be enhanced by continuing collaboration and interaction with other research teams of DECOLVAEX-2019 Task B and validated using the field data from fault activation experiments in a further study.

• Journal of Preventive Medicine and Public Health
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• v.29 no.3 s.54
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• pp.439-449
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• 1996

This study was conducted to evaluate the relationship between change in obesity indices and change in serum lipids in adult male workers. Two-hundred-eight adult male workers of an industry in Taegu city were followed-up from 1991 to 1995. Height, weight, circumferences of hip and waist, blood pressure were measured and serum lipids were analysed. Data on life style were obtained using self-administered questionnaires. Mean differences of anthropometric measurements between 1991 and 1995 were as follows: 1.63kg in weight, 3.61cm in waist circumferences, 4.23cm in hip circumferences, $0.52kg/m^2$ in BMI and -0.021 in WHR. Those of lipids were as follows; 15.09mg/dl in total cholesterol, 20.43mg/dl in triglyceride, 9.40mg/dl in HDL-cholesterol, 2.87 in MI - index (p<0.01) and 350mg/dl in LDL-cholesterol. The changed value of BMI and Katsura index were strongly correlated with that of total cholesterol(r=0.174, p<0.05), the changed value of BMI correlated with that of triglyceride(r=0.374, p<0.01) and the changed value of weight correlated with that of MI index(r=-0.173, p<0.05). The changed value of WHR was signifiantly correlated with that of total cholesterol(r=0.162, p<0.05), however, was not significantly correlated with HDL-cholesterol, LDL-cholesterol, triglyceride and MI index. The changed value of weight, BMI and Katsura index were correlated with that of triglyceride (r=0.262, p<0.01; r=0.267, p<0.01; r=0.258, p<0.01) and the changed value of MI index(r=0.143, p<0.05; r=-0.158; r=-0.144, p<0.01), adjusting the pattern of change in life style. The changed values of HDL - cholesterol and MI index between 1991 and 1995 in low WHR group were significantly higher than those in high WHR group(p<0.05, p<0.01), adjusting the baseline value of them. Similar pattern was observed when considering Katsura index. When stratifying by BMI value of 1991, in low BMI group, the changed value of HDL - cholesterol and MI index showed the same pattern as above, however that of triglyceride was statistically higher in obese group than in non obese group(p<0.05). In conclusion BMI might be a better indicator to predict serum lipids change than other obesity indices.

• Childhood Kidney Diseases
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• v.9 no.2
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• pp.137-142
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• 2005

Purpose : Acute poststreptococcal glomerulonephritis(APSGN) follows infection of group A$\beta$-hemolytic streptococci. The prognosis of APSGN has been reported as favorable. However, several studies have reported that some patients progress to chronic renal failure. In an attempt to clarify this, we analyzed the clinical course of patients with APSGN. Methods : Between January 2000 and December 2004, a total of 48 children who were diagnosed with APSGN according to the presence of hematuria, transient hypocomplementemia and evidence of group A $\beta$-hemolytic streptococcal infection were evaluated. Results : Six(12.5$\%$) patients showed elevation of serum creatinine level but there was no patient with Persistent renal dysfunction. Blood pressure was controlled with ease in all patients and there was no case of persistent hypertension. Renal biopsy was done in 5 patients who showed heavy proteinuria or renal insufficiency and the outcomes showed findings consistent with ordinary APSGN except one with findings of rapidly progressive glomerulonephritis(RPGN). Serum complement levels normalized within 8 weeks(92.9$\%$). Hematuria disappeared within 6 months(79$\%$) and proteinuria within 6 months(100$\%$) from the disease onset. Conclusion : Prolonged renal dysfunction or heavy proteinuria found in five patients(10.4$\%$) led to renal biopsy. All these problems resolved within 6 months. Our data support that the prognosis of childhood APSGN is favorable without any serious sequoia. (J Korean Soc Pediatr Nephrol 2005;9:137-142)

• The Journal of Korean Society for School & Community Health Education
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• v.3
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• pp.59-78
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• 2002

The purpose of this study was based on students in high school to find out how interest eating and controlling weight on normal time by sex to let them get a better sense's of view on weight controlling so they can get healthy, and healthy school life and concentrate on studying, As a result of analyzing the data collected for the subject of high school students, the conclusions were as follows; First, out of 325 students, 44.6% were male students, and 179 were female students, Compared to the BMI, normal mass were 50.8%, which were 165 students, less weighted were 39.7%, which were 129 students, and over weighted were 9.5%, which were 31 student. Also average height for male students were 173.8 cm, for female students were 161.5 cm, average weight were 67.2 kg for male students, and for female students were 53.2kg. Using BMI analysing the results and the male students had an average of 22.2%, and the female students had an average of 20.3%, so male students were a little higher than the female students. Second, the interest rate for weight control were 82.2%, that's 267 students for, 'interested' and 7.8%, which were 58 student for 'not interested', so most students were interested, in controlling weight. Interest rate were 83.6% for male students, 81.0% were female students. BMI told that group of less weighted were 82.9%, group of normal were 79.4% and group of over weighted were 93.5%. The rate were all high not relating to BMI. Third, compared to the past, more people said 'normal'(41.3%), people who said 'a little fat'(36.3%) decreased, but they still think they are fat even though they are not, also when they are less weighted they still think they are fat. Fourth, for 'weight control, and food' both male and female said they were related, and for 'weight control and exercising' they also said they were related, but more male said that they were related, However for relations between' controlling weight and school's physical education class' the answers were usually disagree. Fifth, for the 'satisfaction of their present weight', both BMI and the students answered and this results were mostly same as the past result, so most students prefer to lose weight. Also, both male and female think that the reason they have this weight now is, because of 'the amount of exercises' and 'the amount of food they eat', so they find that it's related to each other. Sixth, for the experience on weight control, both male and female had experiences, and they answered 'exercising and food treatment' is the good way to control weight. Also for 'the reason they started to control there weight', both male and female answered, 'they thought there weight were not normal'. Seventh, 'Do you pick on food to control weight?' and 'Do you feel nervous before you eat?' and for last 'control of drinking water' the answer was all different, and both male and female answered negatively. Eighth, time wasted on exercising per day, for less than 30 minute were 81.5%, the form of exercises that students did were 'not much or walking on the way to school and way to home'. Usually for their free time, male students spend on exercising however female student did not. Also both female and male students showed that they like to exercise, but majority of female student disliked to exercise. To everyone's point of view 'like'(32.9%), 'like a lot'(20.9%), so everyone agrees. The knowledge information on controlling weight, they answered, usually found from commercials, newspaper or magazines and from parents or friend. From the past many high school students wanted to control their weight, so there should had been a good education on this, however there wasn't any of those education and still it doesn't exist. Also most school's education are arranged to entrance pressure so they have a lot of knowledge and informations to it, but for real they don't have any activity or actions on it. Through this research, we felt that, we should correct students with wrong understanding on controlling weight and wrong knowledge. Also we suggest to make an activity program for this.

• Journal of the Korean Society of School Health
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• v.12 no.1
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• pp.149-167
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• 1999

To investigate the actual conditions of smoking in middle and high school students in Chinan County, I used a sturctured questionnaire for 1,579 students attending twelve middle-high schools from December 1, 1998 to December 20, 1998. I collected and data correlated the using an $SPSS-PC^+$ 1. The smoking rate of middle-high schoo1 students in Chinan County was 17.9%, relatively high. This smoking rate was different according to the gender, grade, religion, and economic situation. In mals, high school students, non-religious, students low income family students, the smoking rate was higher. The smoking rate of high school students was almost the same as the smoking rate of adults, generally higher than that of foreign teenagers. Because the smoking rat of studinets in the third grade of middle school and in the first grade of high School was six times higher, increased education should be conducted during this time in an attempt to curb the sudden increase of the smoking rate. The smoking rate of girl students was 5.0%; this has increased mor than three times from ten years ago. Consequently, counter measures should be taken against the smoking of female students as well as juvenile smoking in general. In addition, the smoking rate of middle-high school students showed interesting differences when correnated with enviornmental factors. Students with low grades, who are not satisfied with school life, who don't have both parents, who have uncaring parents who nare too strict or too arbitary, who have smoking parents, or who have experienced smoking commonly smoked. Therefore, to lower the smoking rate we should improve the school environment, improve a student's interest in school life. And parents or siblings should lead by example and quit smoking at home. Schools should educate students more effectively concerning the harmful effects of smoking and create an accurate understanding of its dancers. From the beginning, we should teach students never ever to touch cigaretts. 2. The surve discovered that most students started out of curiosity, or solicitantion from friends or elders at middle school, and had been smoking one to five cigarettes for more than a year. They obtained cigarettes at stores and most of them have friends who smoke. As a result anti-smoking education should be conducted at elementary schools prior to middle school. More than 95% of the teenagers who smoke had friends who smote and smoked out of curiosity or the recommendation of elders. Thus, we must focus on teenagers who smoke in group, rather than individually. Fuyrthermore, the strict application of the regulation of tobacco sales as well as tobacco cooperation from retailers are needed. While students did not show any mood or academic achievement difference after beginning smoking, 58.1% of the students a health situdation that was worse. Juvenile smoking is more harmful to the juvenile than adult smoking is to the adult. This should be focused on in an anti-smoking campaign. 3. Students who smoke hada more positive attitude toward smoking than students who don't smoke. Students who smoke had a tendency to have a nuetral position and are not concerned about smoking compared to non-smoking students. The survey showed that the great number of students had a nuetral position. Because this nuetrality may increase Juvenile smoking, education that provides an exact understanding of smoking should be performed to build the correct attidude toward smoking. 4. Middle school students smoke when angry, gloomy, anxious, a lone and when they have some problems to solve, on when they feel inconveniened in other wores, they smoke to reliver stress. They also smok due to addiction. Because smoking is not a praetical method to relieve stress, a program which helps to acquire positive relief stress should be provided to help reduce smoking. 5. About 65% of students who smoke want to quit smoking because of health problem, 78% of them have tried mor than once to quit but failed due to weak will power and peer pressure from friends who smoke. Juvenile smoking is group, oriented. Thus, the program that advances less smoking will be the one that focuseds on groups. 6. As for advice to students who want to quit smoking, "persuasion" was used most commonly, followed by a "presentation on how to quit smoking". Another method were severe punishment. About 70% of the students wanted the anti-smoking guide at school. 7. Most students (73.5%) had a position that more anti-smoking education at school is needed. Obriously, then, anti-smoking education at middle-high schools should be reinfoced. Although the education which explains the harmful influence of tobacco is known as an efficient way prevent smoking; it does not influence students who already smoke. Therefore, for students who smoke, multi-dimensional approaches must be attempted that include physical training, phychokogical approache, consultation and discussion, medical chek-ups, audio-visual education technigues, and professonal instructors, in addition, because smoking students have more negative on lukewarm attitude to anti-smoking education anti-smoking education should be conducted through a communicative style by dedicated teachers who care about students. In order to increase the effectiveness of this program.

• Economic and Environmental Geology
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• v.28 no.3
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• pp.185-197
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• 1995

Tungsten skarns in the Chungju mine which consists mainly of strata-bound type iron ore deposits are found in the vicinity of the contact between the age-unknown Kyemeongsan Formation and granitic rock intrusions of Mesozoic age($134{\pm}2Ma$). Tungsten skarns were formed extensively from alumina and silica-rich schistose rocks by the introduction of calcium and iron from hydrothermal solution. The skarns comprise a metasomatic column and are subdivided into four facies; garnet facies, wollastonite facies, epidote facies and chlorite facies. The skarn process in time-evolutional trend can be divided broadly into the four facies in terms of the paragenetic sequence of calc-silicates and their chemical composition. Skarn and ore minerals were formed in the following sequence; (1) garnet facies, adjacent to biotite granite, containing mainly garnet(>Ad96) and magnetite, (2) wollastonite facies containing mainly wollastonite and garnet(Ad95~60), (3) epidote facies, containing mainly epidote(Ps35~31), quartz, andradite-grossular(Ad63~50), and scheelite, (4) chlorite facies, adjacent to and replacing schist, containing mainly chrolite, muscovite, quartz, calcite, epidote(Ps31~25), hematite and sulfides. The mineral assemblage and mineral compositions. suggest that the chemical potentials of Ca and Fe increased toward the granitic rock, and the component Al, Mg, K, and Si decreased from the host rock to granitic rock. The homogenization temperature and salinity of fluid inclusion in scheelite, quartz and epidote of epidote facies skarn is $300-400^{\circ}C$ and 3-8wt.% eqiv. NaCl, respectively. ${\delta}^{34}S$ values of pyrite and galena associated with chlorite facies skarn is $9.13{\sim}9.51%_{\circ}$ and $5.85{\sim}5.96%_{\circ}$, respectively. The temperature obtained from isotopic com· position of coexisting pyrite-galena is $283{\pm}20^{\circ}C$. Mineral assemblages and fluid inclusion data indicate that skarn formed at low $X_{CO_2}$, approximately 0.01. Temperature of the skarn mineralization are estimated to be in the range of $400^{\circ}C$ to $260^{\circ}C$ and pressure to be 0.5 kbar. The oxygen fugacity($fo_2$) of the skarn mineralization decreased with time. The early skarn facies would have formed at log $fo_2$ values of about -25 to -27, and late skarn facies would have formed at log $fo_2$ values of -28 to -30. The estimated physicochemical condition during skarn formation suggests that the principal causes of scheelite mineralization are reduction of the ore·forming fluid and a decrease in temperature.