• Progress in Medical Physics
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• v.28 no.3
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• pp.111-121
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• 2017

Verification of dose distribution is an essential part of ensuring the treatment planning system's (TPS) calculated dose will achieve the desired outcome in radiation therapy. Each measurement have uncertainty associated with it. It is desirable to reduce the measurement uncertainty. A best approach is to reduce the uncertainty associated with each step of the process to keep the total uncertainty under acceptable limits. Point dose patient specific quality assurance (QA) is recommended by American Association of Medical Physicists (AAPM) and European Society for Radiotherapy and Oncology (ESTRO) for all the complex radiation therapy treatment techniques. Relative and absolute point dose measurement methods are used to verify the TPS computed dose. Relative and absolute point dose measurement techniques have a number of steps to measure the point dose which includes chamber cross calibration, electrometer reading, chamber calibration coefficient, beam quality correction factor, reference conditions, influences quantities, machine stability, nominal calibration factor (for relative method) and absolute dose calibration of machine. Keeping these parameters in mind, the estimated relative percentage uncertainty associated with the absolute point dose measurement is 2.1% (k=1). On the other hand, the relative percentage uncertainty associated with the relative point dose verification method is estimated to 1.0% (k=1). To compare both point dose measurement methods, 13 head and neck (H&N) IMRT patients were selected. A point dose for each patient was measured with both methods. The average percentage difference between TPS computed dose and measured absolute relative point dose was 1.4% and 1% respectively. The results of this comparative study show that while choosing the relative or absolute point dose measurement technique, both techniques can produce similar results for H&N IMRT treatment plans. There is no statistically significant difference between both point dose verification methods based upon the t-test for comparing two means.

• Journal of the Korean Society of School Health
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• v.4 no.2
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• pp.119-135
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• 1991

The study was designed to gain necessary basic data order to grasp health knowledge, attitude, practice level of middle and high school students and to analyse th problem and to point out the method of improvement in the field of school health education. The survery was carried out through this reporter's interview for 2,400 students who attend to ten schools in Young Nam area during the period of a month from 25 the June to 25th July 1989. The result of this study can be summaried as follows. 1. The total number of answers on the question was 2,346. As for general characteristics the percent of female middle school students was 60.6% and the percent of male students was 77.7%, 45.9% of high school students was evening school students. 52.9% of middle school students and 42.3% of high school students were borne in rural area. 2. The percentage of unknown and misunderstanding for Epidemic Hepatitis infection was 46.3% of middle school students and 29.6% of high school students. 3. The percentage of unknown and misunderstanding for Epidemic Hemorrhage fever infection was 85.6% of middle school students and 66.9% of high school students. 4. The percentage of right knowledge for AIDS infection was 66.0% of middle school students and 90.4% of high school students. 5. The percentage of right knowledge for Typhoid infection was 47.8% of middle school students and 69.4% of high school students. 6. The percentage of unknown and misunderstanding for Tuberculosis infection was 71.6% of middle school students and 62.2% of high school students. 7. As for personal hygiene, the percentage of toothbrushing after every meal was high level : 44.2% of middle school students and 42.0% of high school students. 8. 60.9% of middle school students take a bath twice a week, 49.2% oh high school students take a bath a week. Times of bath of middle school students was higher than that of high school students. 9.The percentage of washing hand after using toilet was 42.1% of middle school students and 35.1% of high school students. 49.0% of middle school students and 55.1% of high school students wash hand sometimes after using toilet. 10. The percentage of change of underwear twice a week was 57.6% of middle school students and 49.8% of high school students. 11. The percentage of habit of unbalanced diet was 30.% of middle school students and 27.6% of high school students. 50.8% of middle school students and 51.7% of high school students have balanced diet. 12. Index of health practice of personal hygiene can be summarized as follows. A. A case of middle school students. 1) The percentage of health practice index in male and female was 49.6% and 48.1% respectively. Index of female students was higher than that of male students. 2) As for parent's occupation, public servants and company emplyee was upper level. Farming was low level. 3) As for income level, middle, level with 56.5% was highest in high income level and low level with 27.4% was highest in low income level. B. A case of high school students. 1) Middle level of health practice index was 46.0% of male students, upper and low level was 32.4% and 28.0% of female students respectively. 2) Middle level of health practice index was high in farming and company employee and upper level was high in commerce and service, low level with 60.0% was high in unemployed. 3) Upper practice index 35.7% appears in the rich and low practice index 38.3% appears in the poor. 13. Average points of Health practice about personal hygiene were as follows. (Full marks at 4). A. A case of middle school. Female (1.87 point) was higher than male (1.26 point). Night time (2.03 point) was higher than day time (1.66 point) and middle or small cities (2.17 point) are high than any other places. As for parent's occupation, students whose parents are company clerk get high marks (2.32) and ten students whose parent's job are service get next high marks (2.20). B. A case of high school. Female (1.53 point) was higher than male (1.22 point), as parents educational level were higher the point were higher, and as income level was higher, the points of health practice (1.78) were higher, and as for parents occupation, service get highest point (1.93) and commerce get next high point (1.86) public servant get low point (1.66). 14. The percentage of experience in smoking was 11.9% of middle school students and 60.9% of high school students. 15. The percentage of experience in inhalation of bond and administrating LSD was 4.3% of male middle school students, 8.4% of female middle school students, 6.9% of male high school students and 4.2% of female high school students. The knowledge level of communicable disease infection are very low in middle and high school students and practice level of personal hygiene are also very low. As a whole we can evaluate that middle and high school students are low level of health knowledge and practice. In conclusion, we must consider preparation for school health education program through establishing of health subjects in the carriculum, and securing of health education teachers and using materials and media program of health education. It is very important to establish macroscopic policy and strategy for public health education and to get people have right knowledge and practice for health.

• The Korean Journal of Applied Statistics
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• v.14 no.1
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• pp.201-210
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• 2001

스포츠에서 통계적 개념이 부적절하게 사용되고 있는 몇 가지의 경우들을 살펴보고, 이를 바로잡기 위한 방안을 제시한다. 먼저 야구의 경우를 자세히 살펴본 뒤 축구와 권투의 경우에 관해서도 논의한다.

• Journal of the Korean Wood Science and Technology
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• v.10 no.2
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• pp.22-27
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• 1982

This experiment was carried out to evaluate the results of fire retardancy of sealer coated plywood by Building material combustibility tester and Inclined panel tester. At this study, weight loss percentage, flame exhausted time, burning point and smoke yield coefficient were examined. The findings of this study lead to conclusions as listed below. 1. It was obvious that weight loss percentage and flame exhausted time of Inclined panel tester had more remarkable tendency than those of Building material combustibility tester. 2. Burning point was determined by Inclined panel tester while smoke yield coefficient by Building material combustibility tester. 3. Weight loss percentage decreased remarkably with proportion to the increase of sealer coated amount during 5 minutes burning. 4. Flame exhausted time decreased with proportion to the increase of sealer coated amount during 3 minutes burning. 5. Burning point indicated increasing tendency with proportion to the increase of sealer coated amount. 6. Smoke yield coefficient of urea scaler showed definite inclination decreasing with the increase of sealer coated amount.

• Radiation Oncology Journal
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• v.2 no.1
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• pp.101-106
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• 1984

Various methods are available for determination of exposure time in intracavitary radiotherapy of the carcinoma of the uterine cervix. To determine the accuracy of dose calculation with isodose curve for TAO applicator, comparison with results calculated by computer for radiotherapy treatment Planning was done in 24 procedures done in 12 consecutive patients with the carcinoma of the uterine cervix from May to December, 1983. The results are as follows: 1. The average dose rate Per hour of Point A was 87.70 rad, being 89.91 rad ana 85.49 rad in left and right, respectively. 2. The average percentage of dose rate of point A calculated by isodose curve method over that by computer was $101.28\%$ and the difference was less than $5\%$ in 17 Procedures and over $10\%$ in only 3 procedures. 3. The average percentage in case of point B was $108.67\%$. In conclusion, in most cases the difference was less than 200 rad for point A and less than 100 rad for point B during 2 courses of intracavitary radiotherapy. And so the dose rate calculation with isodose curve for TAO applicator is comparatively accurate.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.768-779
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• 1995

This study was performed to investigate the effect of root canal shaping techniques on the change of the shape of prepared root canal. 40 mesiobuccal canals of recently extracted mandibular 1st and 2nd molars were divided into 4 groups and shaped by step-down/balanced force technique, step-down/step-back technique, step-back technique and conventional technique respectively. The change of the shape of root canal was traced by superimposing the radiographs obtained before and after shaping of each root canal. The results were as follows. 1. By the experimented techniques except conventional technique, the root canals were more shaped in convex side of apical area and in concave side of most curved and coronal area than in the other sides(P<0.05). By conventional technique, the root canals were more shaped in convex side than in convave side from apex to orifice(P<0.05). 2. By step-down/balanced force technique, the cancave sides at C and D points of proximal view and C point of clinical view were more shaped than the convex side(P<0.05). Through the entire canal, the concave side was more shaped than the convex side in proximal view(P<0.01). But there was no statistical difference between both sides in clinical view. 3. By step-down/step-back technique, the change of root canal shape was not statistically different in concave and convex sides at each point of both views(P>0.05). And through the entire canal in proximal view, there was no statistical difference in shaping percentage between both sides. But through the entire canal in clinical view, the concave side was more shaped than the convex side(P<0.1). 4. By step-back technique, the convex side at B point of clinical more shaped than the other sides(P<0.05). Through the entire canal in proximal and clinical views, there was no statistical difference in shaping percentage between both sides. 5. Comparing the total shaping percentage among techniques, that in conventional technique was the greatest numerically, and followed by the percentages in step-down/step-back, step-down/balanced force and step-back technique. But, in proximal view, shaping percentages were not statistically different among techniques(P>0.05, ANOVA test). In clinical view, shaping percentages in step-back and conventional techniques were statistically different(P<0.01, ANOVA test). * Proximal view: radiograph taken in mesiodistal direction. * Clincal view: radiograph taken in faciolingual direction. A point : 1mm point from radiographic apex B point : center point between A and C points C point : most curved point of root canal D point : center point between C point and canal oriffice.

• Asia-Pacific Journal of Business
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• v.13 no.3
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• pp.361-373
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• 2022

Purpose - This paper analyzes the student determinants of college non-completion and estimates the effects of each determinant on college non-completion. Design/methodology/approach - We use student panel data from a large Korean university from 2011 to 2021. Our results are from estimation of fixed-effects logit model. Findings - The results show that grade point average, participation in extracurricular activities, the number of counseling sessions with teachers, and financial aid are the main determinants of college non-completion. Academic probation, which is defined as any person who has a cumulative grade point average below a one point seven five, increases the non-completion rate by 2.6 percentage points and an one-point rise in extracurricular activities index reduces the rate by 0.1 percentage points. The effects of each determinant are heterogeneous across student sub-groups which are separated by gender, nationality, and academic discipline. Research implications or Originality - Tailored support programs for academically discouraged students that incorporate student characteristics and backgrounds are necessary to increase college completion rates and degree attainment.

• Archives of design research
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• v.17 no.4
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• pp.319-326
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• 2004

This festival study is based on visitors' evaluation on the Danwon art festival. It was founded as follows; The major visitors of this festival were family and they were interested in educational programs. This festival was evaluated as the art and educational type experience oriented event for family. Visitors satisfied about organization of this event with 4.86 on Likert 7 point and positive percentage was 61.7%. The accessbility was evaluated the secondly satisfied program among 13 evaluation items. The average point was high with 5.34 and positive percentage was high with 79.3%. The highest satisfaction was educational evaluation with average point of 5.37 which was the highest satisfaction. Also the positive percentage was 84% which showed the highest positive opinion. The satisfaction of program interesting was average point of 4.84 which was relatively positive satisfaction. Visitors' positive percentage was 57.3% and negative percentage is only 8.3% which showed satisfaction of program interesting. But visitors unsatisfied about event variety, guiding facility, guiding pamphlet, guider service, parking facility, and foods service. there should be more improvement on the programs. Especially, improvement on public relationship, food quality, and parking for visitors should be implemented. in terms of interesting programs, visitors were most interested in the experience of blacksmith's shop among programs. It was founded that experience based festival programs were popular among this festival visitors and most festivals here in Korea at the moment. So more experience based programs are recommended for this festival.

• Korean Journal of Animal Reproduction
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• v.21 no.2
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• pp.191-195
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• 1997

The objective of this study were to compare two methods of analysis of milk urea nitrogen (MUN) and to relate conentration of MUN to pregnancy rate in dairy cows. The Azotest and Sigma method for MUN analysis were compared. The Azotest consistently underestimated the Sigma values for same samples, except for those in rank 3. The CV for the Azotest, within each rank, were less than 15%, demonstrating acceptable repeatability of the Azotest within a rank. Concentrations of MUN higher or lower than MUN in rank 3 and 4 were associated with decreased pregnancy rate. Mun concentrations in rank 5 and 6 were associated with a, pp.oximately a 16 percentage point decrease in pregnancy rate. Mun concentrations in rank 5 and 6 were associated with a, pp.oximately a 16 percentage point decrease in pregnancy rate after AI in dairy cow. This results suggest that Azotest may be benificial to dairy producers to monitor urea nitrogen concentration in their herd in efforts to maintain or improve reproductive efficiency.

• KIEAE Journal
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• v.7 no.5
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• pp.135-142
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• 2007

This is an experimental study on the structural characteristics of reinforced concrete beams using of the oyster shells as a substitute fine aggregate of concrete. In this study, the main factors consist of the grain sizes and the percentage of substitution of oyster shells to fine aggregate in the equal water cement ratio. The results of the study showed as followed. The initial load value of them represented similar constant within 10% of the maximum load value in each test beam. But the maximum load value and the ultimate load value decreased with increased grain size and the rate of substitution. As the grain size of oyster shells became smaller, the load values of them were somewhat higher. The deflection among deformation properties of reinforced concrete beams with oyster shells represented typical curves like that of normal reinforced concrete. In the deformation of steel and concrete, the deformation was proportionated to the load till yield point and from yield point until approaching the ultimate load point. One type was typical curve of the load and the deformation and the other type irregularly was changed to very small deformation for the load increase centering around load axis. After the analyzing structural behaviors and the properties of reinforced concrete test beams with oyster shells, the most excellent grain size of oyster shells represented 1.0mm and less or 5.0mm and less with taking uniformly, and the percentage of practicable substitution of them to fine aggregate was about 30%.