• Radiation Oncology Journal
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• v.10 no.2
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• pp.171-180
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• 1992

The precise role of radiotherapy for low grade gliomas including the optimal radiation dose and timing of treatment remains unclear. The information given by a retrosepctive analysis may be useful in the design of prospective randomized studies looking at radiation dose and time of surgical and radiotherapeutic treatment. The records of 56 patients (M:F = 29:27) with histologically verified cerebral low grade gliomas (47 cases of grade 1 or 2 astrocytomas and 9 oligodendrogliomas) diagnosed between 1979 and 1989 were retrospectively reviewed. The extent of surgical tumor removal was gross total or radical subtotal in 38 patients ($68\%$) and partial or biopsy only in the remaining 18 patients ($32\%$). Postooperative radiation therapy was given to 36 patients ($64\%$) of the total 56 patients with minimum dose of 5000 cGy (range=1250 to 7220 cGy). The 5-and 10-year survival rates for the total 56 patients were $44\%$ and $32\%$ respectively with a median survival of 4.1 years. According to the histologic grade the 5- and 10-year survivals were $52\%$ and $35\%$ for the 24 patients respectively with grade I astrocytomas compared to $20\%$ and $10\%$ for the 23 patients with grade II astrocytomas. Survival of oligodendroglioma patients was greater than those with astrocytoma ($65\%$ vs $36\%$ at 5 years), and the difference was also remarkable in the long term period of follow up ($54\%$ vs $23\%$ at 10 years). Those who received high-dose radiation therapy ($\geq$5400 cGy) had significant better survival than those who received low-dose radiation (< 5400cGy) or surgery alone (p<0.05). The 5- and 10-year survival rates were, respectively $59\%$ and $46\%$ for the 23 patients receiving high-dose radiation, $36\%$ and $24\%$ for the 13 patients receiving low-dose radiation, and $35\%$ and $26\%$ for the 20 patients with surgery alone. Survival rates by the extent of surgical resection were similar at 5 years ($46\%$ vs $41\%$), but long term survival was quite different (p<0.01) between total/subtotal resection and partial resection/biopsy ($41\%$ and $12\%$, resepctively). Previously published studies have identified important prognostic factors in these tumor: age, extent of surgery, grade, performance status, and duration of symptoms. But in our cases statistical analysis revealed that grade I histology (p<0.025) and young age (p<0.001) were the most significant good prognostic variables.

• The Journal of the Korean bone and joint tumor society
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• v.10 no.2
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• pp.130-133
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• 2004

Low-grade fibromyxoid sarcoma (LGFMS) is very rarely seen, and it commonly arises from the deep soft tissues of the lower extremities. Histologically, it is characterized by the presence of bland spindle cells with mainly storiform pattern of growth, set in alternating areas with a myxoid or fibrous stroma. The immunohistochemical reaction of this tumor permits a positive diagnosis of low grade fibromyxoid sarcoma and allows its distinction from a number of other benign and malignant soft tissue tumor. We report this rare case together with the review of the literature.

• Journal of the Korean Wood Science and Technology
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• v.38 no.2
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• pp.85-93
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• 2010

Japanese cedar has low density and poor mechanical performance. Manufacturing glue-laminated timber (glulam) is the best way to compensate for its poor mechanical performance. The Korean Standard (KS) confines outermost lamina of glulam to higher grade than E8, but the yield of higher than grade E8 from logs is only 6.5%. Therefore, the aim of this study is to investigate the possibility of non-Korean-Standard glulam in structural applications. Allowable stresses determined by both hand-calculation and Monte-Carlo simulation show a higher allowable stress than that of the KS-standard glulam of 6S-22B. In the Korean Standard (KS), knot characteristics are not taken into account. Japanese cedar has relatively small knots. We believe that the small knots in Japanese cedar contribute to a higher allowable stress than the KS-standard glulam would predict. The species classification of KS is required to be further subdivided into sub-species groups based on knot characteristics.

• Journal of Power System Engineering
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• v.19 no.5
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• pp.45-51
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• 2015

Grade 91 steel is used for the major structural components of Generation-IV reactor systems such as a very high temperature reactor (VHTR) and sodium-cooled fast reactor (SFR). Since these structures are designed for up to 60 years at elevated temperatures, the prediction of long-term creep life is very important to determine an allowable design stress of elevated temperature structural component. In this study, a large body of creep rupture data was collected through world-wide literature surveys, and using these data, the long-term creep life was predicted in terms of three methods: Larson-Miller (L-M), Manson-Haferd (M-H) and Wilshire methods. The results for each method was compared using the standard deviation of error. The L-M method was overestimated in the longer time of a low stress. The Wilshire method was superior agreement in the long-term life prediction to the L-M and M-H methods.

• Journal of Biosystems Engineering
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• v.28 no.3
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• pp.253-260
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• 2003

In this study, the feasibility of magnetic resonance techniques for nondestructive internal quality evaluation of Korean red ginseng was examined. Relaxation time constants were measured using various grades of red ginsengs. Solid state magnetic resonance imaging technique was applied to image dried red ginsengs which have low moisture contents (about 13%). A 7 tesla magnetic resonance imaging system operating at a proton resonant frequency of 300 ㎒ was used for acquiring MR images of dried Korean red ginseng. The comparison test of cross cut digital images and magnetic resonance images of heaven grade, good grade with cavity inside, and good grade with white part inside red ginseng suggested the feasibility of the internal quality evaluation of Korean red ginsengs using MRI techniques. A good grade red ginseng included abnormal tissues such as cavities or white parts inside was observed by the signal intensity of MR image based on magnetic resonance properties of proton nucleus. Analysis on an one dimensional profile of acquired MR image of Korean red ginseng showed easy discrimination of normal and abnormal tissues. MR techniques suggested ways to detect internal defects of red ginsengs effectively.

• Korean Journal of Human Ecology
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• v.23 no.6
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• pp.969-980
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• 2014

This paper reports on a study that examined the longitudinal and concurrent effects of the home literacy environment(HLE) on first grade language performance, and the effect of language performance on school adjustment. Study subjects were 469 first graders of 6 elementary schools. The parents' and teacher's reports were used to investigate the subjects' language performance, school adjustment, and the HLE before and after the elementary school entry. Findings from the study show that there is an association between the HLE during the preschool period and the HLE in first grade, and the HLE in first grade positively affects children's language performance. Also the children's language performance had a positive influence on their school adjustment. Therefore, it can be concluded that the HLE during the preschool period is a significant feature that lingers to affect children's language performance and school adjustment.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.37-47
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• 2009

This study analyzes the effect of alternatives and estimates alternatives evaluation index (AEI) using PCSWMM and weighted summation method. PCSWMM considering combined sewer overflows (CSOs) in the Mokgamcheon watershed was used and effectiveness analysis of alternative was conducted to develop not only flowrate but also the pollutant of BOD and SS. Indicators of AEI are selected using sustainability evaluation concept, driver-pressure-state-impact-response (DPSIR) framework and calculated by weighted summation method. After estimating AEI, alternatives was classified into three groups G (Good), A (Acceptable) and P (Poor) grade. As a results, it is analyzed that alternatives applied to Oryucheon were G grade and those of Yeokgokcheon were P grade and the remainings were 'A' grade. This result will be effective to the integrated watershed management for sustainablility.

• Korean Journal of Health Education and Promotion
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• v.22 no.1
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• pp.41-54
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• 2005

Purpose : This study was undertaken in order to find out the actual condition and barriers of health education in elementary school after introduction of 7th curriculum modification. Method: A questionaire was sent by mail on November 1, 2003, and received a total of 230 till November 30, 2003. Among them, 198 were included in fmal analysis. The collected data was analyzed through frequency, percentage, mean and standard deviation. Results : The results of this study were as follows: Among of the school health task, the most time spending task was emergency treatment and medication. The health education content which now being taught was sex education and prevention of drug abuse in the 6th grade, prevention of obesity in the 5th grade, emergency treatment, safety education in the 4th grade and prevention of disease of teeth in the 3rd grade. The most difficult problem in health education was pointed to no subject, no hour about health education by policy. Conclusion : It was necessary to formalize the health education subject, to ensure of health education hour by policy and to establish of extra health education room to improve health education at elementary school.

• The Korean Journal of Community Living Science
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• v.17 no.4
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• pp.137-149
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• 2006

The purpose of this study was to examine the relation of middle school students' stress in relation to certain variables, those of grade, gender, academic achievement, coping behavior and self-concept. The subjects were 574 students selected from 4 middle schools in the Incheon area. The instruments included a stress index, coping behavior questionnaire and self-concept inventory. The statistics used from this data were t-test, one-way ANOVA (Scheff test), correlation analysis and multiple regression analysis. This study showed that middle school students' stress was influenced significantly by the grade, gender and achievement in school. Also, coping behavior and self-concept were influenced significantly by the grade, gender, and achievement in school. Correlation analysis indicated that student's stress and certain coping behavior were postively correlated, especially avoidance coping behavior indicated a higher correlation to students' stress than active coping behavior. The relationship between stress and self-concept indicated a negative high correlation. It was also found that avoidance coping behavior, family self-concept, general self-concept, school and class self-concept, grade and academic achievement were significant predictors of middle school students' stress.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.1038-1043
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• 1997

To adapt the neural network proess for the purpose of determination of optimal utting onditions (optimal cutting speed and feed rate), some selection strategies for the machining factors are necessary, which is considered planning cutting process. In this case, factors that have both nonlinearity and strong relationship must be selected. Although tool grade and chemical properties of workpiece material have strong effect to cutting speed, it's not easy to find a analytic relation between them. In this paper, a mathematical method for determining the optimal amount of cutting (depth of cut, feed rate) is presented by tool goemetry and heat generation during cutting process. And various tool grade and workpiece material groups ase classified based on its chemical properties. Thier chemical composition and hardness are used as input pattern for neural network learnig. The result of learning shows the relationship between tool grade and workpiece material and it is proved that it can be used as a sub-system for automatic process planning system.