• Journal of the Korean Wood Science and Technology
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• 제39권3호
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• pp.258-268
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• 2011

This study was conducted to investigate the effects of sawdust size and moisture content, pelletizing temperature and time on the durability of the pellets fabricated with larch and tulip tree sawdust. The durability of larch-pellet was significantly higher than that of tulip tree-pellet. For the larch-pellets, the durability of the pellets fabricated with > 18 mesh sawdust was higher than that of 8~18 mesh sawdust. With the increases of pelletizing temperature and time, the durabilities of larch- and tulip tree-pellets steadily improved. The durabilities of larch- and tulip tree-pellets also increased as the moisture content of sawdust increased. In the comparison of durabilities between commercial pellets and larch- or tulip tree-pellets, the pellets fabricated with larch and tulip tree sawdusts in our study were less denser than commercial pellets, but the durability of most larch-pellets was satisfied with the 1st-grade pellet standard designated by Korea Forest Research Institute. In addition, the durability of tulip tree-pellets were higher than that of the 3rd-grade pellet standard. From the scanning electron microscopic observation of larchand tulip tree-pellets, the gap between the sawdusts of each pellet was reduced with the increases of pelletizing temperature and time. In particular, it was visually confirmed that the surface of the pellets made with the pelletizing temperature of $180^{\circ}C$ for 3 min did not differ from that of commercial pellets.

• Journal of The Korean Association For Science Education
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• 제35권5호
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• pp.907-917
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• 2015

Response to Intervention (RTI), which is focused on the gap between pre-interventions and post-interventions, provides an effective intervention program. This study takes under-achievement factors into consideration to determine the overall characteristics of underachievers. The under-achievement factors include cognitive learning factors, affective factors, and environmental factors. This study conducted curriculum-based assessments, achievement tests, and assessments on attitudes toward science and science learning motivation to verify the effects of individually tailored teaching according to the types of under-achievement in science. The experimental group was composed of six students in fourth grade, and the comparison group had 23 students. The findings of the study were as follows. First, the performance and progress of underachievers in the first-stage showed little progress and did not reach grade-level performance. Second, the underachievers in the second-stage greatly improved. In particular, the average of eight sessions in the second-step demonstrated performance beyond that of the regular child. Third, individually tailored teaching according to the types of under-achievement in science positively affected attitudes toward science and science learning motivation. This study will contribute to the improvement of the underachiever by applying individually tailored teaching according to the types of under-achievement in science.

• Journal of the Korean Chemical Society
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• 제57권1호
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• pp.138-146
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• 2013

This study examined the characteristics of the National Assessment of Educational Achievement (NAEA) in Science according to gender. It investigated gender achievement differences in the science section of the 2010 NAEA, the ratio of gender difference in achievement, the ratio of correct answers within each content domain and behavioral domain, and the items which showed high differences between males and females. The results indicate first, that, for 9th graders, females outperformed males in academic achievement in science. Second, with respect to the ratio of correct answers, males outperformed females in the advanced and below basic level groups, but females outperformed males in intermediate level groups. Third, females outperformed males in knowledge and inquiry in the behavior domains, and in chemistry and biology in the content domains. Fourth, an analysis of the items showing the largest gender gap indicated that males outperformed females in interpreting data, while females outperformed males in the items concerned with daily life and items related to the memorization of rules. This research on gender differences in science will allow teachers to complement the weaknesses of students when they study science, and support improved instructional methods in science.

• School Mathematics
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• 제16권2호
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• pp.387-407
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• 2014

Gender differences have been given major attention in mathematics education in the context of pursuing gender equity in instructional and learning environment. It had been traditional belief that male students would outperform female students in mathematics, especially in the areas as geometry. This belief has been given doubts by cumulated empirical evidences that gender differences are gradually diminishing or even reversing its direction as time goes on. In this study, gender differences in geometry were explored using TIMSS 8th grade mathematics data administered in TIMSS 2003, 2007, and 2011, based on a cognitive diagnostic modeling(CDM) approach. Among various CDM models, the Fusion model was employed. The Fusion model has advantages over other CDM models in that it provides more detailed information about gender differences at the attribute level as well as item level and more mathematically tractable. The findings of this study show that Attribute 3(Three-dimensional Geometric Shapes) revealed statistically significant gender differences favoring male students in TIMSS 2003 and 2007, but did not show significant differences in TIMSS 2011, which provides an additional empirical evidence supporting the recent observation that gender gap is narrowing. In addition to the general trends in gender differences in geometry, this study also provided affluent information such as gender differences in attribute mastery profiles and gender differences in relative contributions of each attribute in solving a particular item. Based on the findings of the CDM approach exploring gender differences, instructional implications in geometry education are discussed.

• Korean Journal of Environmental Agriculture
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• 제37권3호
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• pp.207-212
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• 2018

BACKGROUND: Recently, the need for a method to cultivate 'Haryejosaeng' Satsuma mandarin has been increasing. However, there is limited information available as this is a new Satsuma mandarin cultivar, which was bred by the RDA in 2004. Many farmers who cultivate this cultivar follow the cultivation method similar to that used for 'Miyagawa' Satsuma mandarin, and suffer low production of optimum-sized fruits. METHODS AND RESULTS: This study was conducted to find out the optimum ratio of leaf-to-fruit for the stable production of high quality 'Haryejosaeng' Satsuma mandarin fruits in a non-heated plastic film house. Seven-year-old 'Haryejosaeng' Satsuma mandarin trees were used in the study. Before the treatment, the leaf-to-fruit ratio ranged from 5.7 to 17.9. The treatments included 10, 20, 30, and 40 leaves per fruit. The fruits were removed if over fruiting was observed at day 60 after full bloom. We investigated the fruit size and quality on the day of harvest. Flowering and fruiting patterns in each treatment were recorded for the following year. In the experiments, the flower-to-leaf ratio was 1.12 to 1.74. As the leaf-to-fruit ratio decreased, the fruit size and weight also decreased. Contrarily, the higher the ratio of leaf-to-fruit, the higher fruit size and weight were. It was noted that the ratio of 20:1 was ideal to produce the M grade optimum-sized Satsuma mandarin fruits on the day of harvest. However, higher ratio might result in fruits weighting above 100 g. There was no difference among the treatments in terms of fruit quality, such as total soluble solid contents, titratable acid, and color. In the subsequent years, flowering and fruiting in the treatments were lowered when the leaf number per fruit was 10, but they were improved when the leaf number per fruit was above 20. CONCLUSION: Based on the above results, the optimum ratio of leaf-to-fruit was found to be 20:1 for flowering and fruiting of 'Haryejosaeng' Satsuma mandarin. It is important that optimum ratio of leaf-to-fruit is set as a standard to produce good grade and quality of 'Haryejosaeng' Satsuma mandarin fruits.

• The Mathematical Education
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• 제60권4호
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• pp.529-542
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• 2021

The purpose of this research is to compare the mathematical beliefs that directly or indirectly affect the mathematics learning of Korean languge learners with those of non-Korean languge learners and identify the characteristics. To this end, an analytical comparative research was conducted through a questionnaire survey on perceptions of mathematics learning for 6th grade students of elementary school with different cultural and linguistic backgrounds in the same mathematics classroom. As a result of the analysis, Korean languge learners and non-Korean languge learners gave different meanings to learning mathematics, and they recognized various meanings of success in mathematics. In addition, the math learning ability of non-Korean learners was evaluated higher than that of Korean learners. Based on their positive beliefs, they decided how to resolve conflict situations with different problem-solving results. It will be necessary to prepare a teaching/learning plan that can fully implement multicultural mathematics education in the mathematics classroom where Korean language learners with different cultural and linguistic backgrounds belong. The results of this research can contribute to raising awareness of the need for follow-up researches to find ways to reduce the learning gap between Korean languge learners and non-Korean languge learners. It is expected that this research will contribute to understanding the perceptive characteristics of Korean language learners about learning mathematics and to prepare a plan to utilize them in mathematics lessons.

• Radiation Oncology Journal
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• 제18권1호
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• pp.27-31
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• 2000

Purpose : The aim of this study was to investigate treatment results, toxicity and efficacy of hypefractionated radiation therapy combined with paclitaxel for paraaortic node recurrence in cervix cancer. Materials and Methods: Between September 1997 to March 1999, 12 patients with paraaortic node recurrence in cervix cancer who previously received radical or postoperative radiotherapy were treated with hypefractionated radiation therapy combined with paclitaxel. Of these, 2 patients who irradiated less than 30 Gy were excluded, 10 patients were eligible for this study. Median age was 51 years. Initial FIGO stage was 1 stage IBI, 2 stage IIA, 7 stage IIB. For initial treatment, 7 patients received radical radiotherapy and 3 received postoperative radiotherapy. The paraaortic field encompassed the gross recurrent disease with superior margin at T12, and inferior margin was between L5 and S1 with gap for previously pelvic radiation field. The radiation field was initially anterior and posterior opposed field followed by both lateral field. The daily dose was 1.2 Gy, twice daily fractions, and total radiotherapy dose was between 50.4 and 60 Gy(median, 58.8 Gy). Concurrent chemotherapy was done with paclitaxel as a radiosensitizer. Dose range was from 20 mg/m$^{3}$ to 30 mg/m$^{3}$ (median, 25 mg/m$^{3}$), and cycle of chemotherapy was from 3 to 6 (median, 4.5 cycle). Follow-up period ranged from 3 to 21 months. Results : Interval between initial diagnosis and paraaortic node recurrence was range from 2 to 63 months (median, 8 months). The 1 year overall survival rate and median survival were 75$\%$ and 9.5 months, respectively. The 1 year disease free survival rate and median disease free survival were 30$\%$ and 7 months, respectively. At 1 month after treatment, 4 (40$\%$) achieved a complete response and 6 (60$\%$) experienced a partial response and all patients showed response above the partial response. There was distant metastasis in 6 patients and pelvic node recurrence In 2 patients after paraaortic node irradiation. There was 2 patients with grade 3 to 4 leukopenla and 8 patients with grade 1 to 2 nausea/ vomiting which was usually tolerable with antlemetic drug. There was no chronic complication in abdomen and pelvis during follow up period. Conclusion : hypefractionated radiation therapy combined with paclitaxel chemotherapy diosensitizer showed high response rate and few complication rate in paraaortic node recurrence in cervix cancer Therefore, present results suggest that hypefractionated radiation therapy combined with paclitaxel chemotherapy can be used as optimal treatment modality in this patients.

• Journal of the Korean School Mathematics Society
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• 제10권3호
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• pp.353-367
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• 2007

The purpose of this study was to examine what errors students made in solving word problems with figures and to compare the problem-solving abilities of boys and girls for each type of word problems with figures. It's basically meant to provide information on effective teaching-learning methods about world problems with figures that were given the greatest weight among different sorts of word problems. The findings of the study were as fellows: First, there was no difference between the boys and girls in the types of error they made. Both groups made the most errors due to a poor understanding of sentences, and they made the least errors of making the wrong expression. And the students who gave no answers outnumbered those who made errors. Second, as for problem-solving ability, the boys outperformed the girls in problem solving except variable problems. There was the greatest gap between the two in solving combining problems. Third, they made the average or higher achievement in solving the types of problems that were included much in the textbooks, and made the least achievement in relation to the types of problems that were handled least often in the textbooks.

• Steel and Composite Structures
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• 제33권6호
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• pp.823-836
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• 2019

Spiral welded tubes (SWTs) are fabricated by helically bending a steel plate and welding the resulting abutting edges. The cost-effectiveness of concrete-filled steel tube (CFST) columns can be enhanced by utilising such SWTs rather than the more conventional longitudinal seam welded tubes. Even though the steel-concrete interface bond strength of such concrete-filled spiral-welded steel tubes (CF-SWSTs) is an important consideration in relation to ensuring composite behaviour of such elements, especially at connections, it has not been investigated in detail to date. CF-SWSTs warrant separate consideration of their bond behaviour to CFSTs of other tube types due to the distinct weld seam geometry and fabrication induced surface imperfection patterns of SWTs. To address this research gap, axial push-out tests on forty CF-SWSTs were carried out where the effects of tube material, outside diameter (D), outside diameter to wall thickness (D/t), length of the steel-concrete interface (L) and concrete strength grade (f'_c) were investigated. D, D/t and L/D values in the range 102-305 mm, 51-152.5 and 1.8-5.9 were considered while two nominal concrete grades, 20 MPa and 50 MPa, were used for the tests. The test results showed that the push-out bond strengths of CF-SWSTs of both mild-steel and stainless-steel were either similar to or greater than those of comparable CFSTs of other tube types. The bond strengths obtained experimentally for the tested CF-SWSTs, irrespective of the tube material type, were found to be well predicted by the guidelines contained in AISC-360.

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6481-6484
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• 2012

Background: In 2008, the Health Authority in Abu Dhabi (the capital of the United Arab Emirates) introduced HPV vaccine free of charge for high school girls entering grade 11, becoming the first state in the Middle East to do so. The objectives of this study were to assess the knowledge, attitude and practice of school nurses in the Emirate of Abu Dhabi about HPV infection and the vaccine. Materials and Methods: A quantitative study was designed and conducted from June to August 2012 in Emirate of Abu Dhabi. Data were collected through direct face to face interviews. from one hundred and twenty five nurses. Results: Knowledge of HPV infection and HPV vaccine was almost universal among the school nurses (97%). The majority of the participants (71%) thought that the HPV vaccine was good. Cultural unacceptability (45%) and lack of women's concern about their own health (21%) were rated as the top barriers for the successful introduction of the vaccine in the UAE. More than half of the sampled nurses (58%) have either given this vaccine to school girls or taken it themselves. The majority (95%) did not come across any side effects from the vaccine. The level of qualification and the place of work did not significantly affect the correct knowledge of HPV infection or cervical cancer prevention methods. Conclusions: The knowledge and attitude of the sampled school nurses in Abu Dhabi State about HPV infection and vaccine is very good in both the public and private sectors. However, a knowledge gap in cervical cancer screening methods was identified.