• Journal of Korean Society of Forest Science
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• 제32권1호
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• pp.9-15
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• 1976

Financial rotations of Pinus koraiensis stands are calculated and compared on the basis of five basic financial maturity concepts. The rotations given by the forest rent and average annual gross revenue models are in excess of sixty years by adopting zero interest rates of capital and forest lands. IRR model also neglects land value and highly sensitive to the changes of fixed and regeneration costs. The Faustmann doctrine recommands rotation ages of 23-39 years depend upon applied interest rates and site indices, and seems to be most adequate for determining financial maturity. It is however the situation in Korea that economic conditions are changing rapidly, and thus a model which does not require many exogenous variables in calculation process is preferable. The Duerr's solution has a basic simplicity and logic which is appealing from both a theoritical and practical viewpoint, and most adaptable to the Korean situation, even though the model completly neglects the opportunity cost for forest land. There is a tendency to reduce rotation length with the increase of site quality, but the difference is negligible.

• Journal of Industrial Convergence
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• 제22권3호
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• pp.51-65
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• 2024

This study aims to understand positive changes in balance and gait function and difficulties in the instructor's guidance process through repetitive basic motor skill-based physical activities targeting people with cerebellar ataxia. For this purpose, five adults with cerebellar ataxia were selected as research subjects, and their three instructors participated as research participants. To collect quantitative data, the average and standard deviation were examined through pre-and post-evaluation of the research participants' physical activity classes for 16 weeks. The mean and standard deviation of the collected data were calculated using the Shapiro-Wilk test in the SAS 9.1 statistical program (p<.05). As a qualitative data collection method, the cultural description method of developmental research(DSR) proposed by Spradley(1980) was adopted, and the collected data were analyzed inductively according to the analysis method of Mertens(1990). Through this, 31 concepts, 10 subcategories, and 4 categories were discovered. As a result, the difficulties experienced by the research participants included insufficient guidance environment, dissatisfaction of consumers, difficulty in guidance, and non-cooperation of colleagues. Based on these research results, it was found that institutional, legal, and policy support should be provided not only to public institutions but also to private physical activity institutions that can use vouchers in order to maintain the balance of adults with cerebellar ataxia as well as to guide their physical activities.

• Journal of Broadcast Engineering
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• 제15권5호
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• pp.653-664
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• 2010

Generally existing video codec employs entropy coding to deal with residual signals with considering temporal and spatial properties. Scalable Video Coding(SVC) which is extension of H.264/AVC has three technical concepts for removing redundancies between inter-layers. In spite of using novel prediction method between inter-layers in SVC, it is still using same entropy coding method to residual signals. According to the studies, the residual obtained by inter-layer prediction technique has different features of residual signal acquired by spatial or temporal prediction technique. In this paper, we propose an efficient entropy coding method which codes the residual signal obtained by inter-layer prediction with regarding its features adequately. We re-designed the Coded Block Pattern(CBP) table suitably for inter-layer texture prediction. The experiments show that the proposed method can further reduce the BD-Bitrate up to average 2.20% in 4CIF and 1.14% in CIF resolution compared to the existing JSVM 9.18.

• Journal of Science Education
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• 제37권3호
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• pp.417-433
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• 2013

The purpose of this study was to analyze 'how STEAM activities affect students' science process skills and science-related attitudes'. For more accurate, we have set 31 sixth-grade students from Gyeong-gi Province as an experiment group, and another 31 as a comparative group. We developed a STEAM program based on the educational concepts: Creative Design and Emotional Touch. Through pre-post experiment design, we have introduced TSPS, and Test of Affective Aspects. For TSPS, the comparative group scored higher average grade before the process. After the process, however, the experiment group exceeded the other. The result was considerable enough to verify that the science process skills were bolstered through the STEAM program(p<.05), Similar result was derived regarding the science related attitude. Students in the comparative group originally showed higher degree of interest to science. When the STEAM program was carried out, the standing reversed. The increase in the number of science related attitude indicates the program valid(p<.001). Furthermore, when we asked the students who participated in the experiment how they recognized the STEAM activity, we received positive answers: they consider the program efficient and well suited to the class environment. Conclusively, the STEAM program was proven to be effective for improving science process skills and attitude, and was perceived affirmative.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제19권2호
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• pp.413-421
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• 2018

This study is intended to look into the effects of children's forest experience activities on parent-child relationship and child attitude change. To achieve this, a survey was empirically carried out to 185 children. The results were as follows. First, the normality of parent-child relationship before and after forest experience activities showed that the parent-child relationship increased from 3.229 points before participation in forest experience activities to 3.841 points after participation in forest experience activities on average. And the child attitude increased from 3.226 points before participation in forest experience activities to 3.765 points after participation in forest experience activities, which there was a change of mean value before and after forest experience activities in both concepts. Second, the difference in parent-child relationship and child attitude change before and after forest experience activities showed that both parent-child relationship(Z=-10.98, p<.001) and child attitude(Z=-11.05, p<.001) did have significant differences before and after forest experience activities in the significant level of .05. As for the above-mentioned findings, children's forest experience activities improves the parent-child relationship and changes their behaviors outside the kindergarten. Consequently, nature-friendly forest experience education can provide emotional stability for children and help them build a positive rapport between teacher, parent and peer.

• Journal of Korean Elementary Science Education
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• 제24권4호
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• pp.337-344
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• 2005

The purpose of this study is to analyze field trip activities in the elementary school science textbook developed under the 7th national curriculum. The results indicated there was an average of 4.25 field trip activities each semester presented in the textbook from the 3rd to 6th grade, mostly related to earth science and biology. The places for field trips were limited to in-school environment and natural sites in communities, and mostly purported to gain understanding of rudimentary concepts. Field trip activities were intended to facilitate science knowledge and understanding in order to integrate with the textbook content rather than offering students simple one-time activities. Most activities in the textbook guided students step by step. The starting or follow-up activities in the fields trips and reminder for cautions were not clearly presented. In order for the field trips to integrate with the content of the curriculum in the text book, they have to be presented in the textbook systematically. It is also imperative to find out various fold trip places related to the content in the curriculum, develop efficient activities dealing with science at the appropriate level for students and increasing interests in science and its teaming.

• KSCE Journal of Civil and Environmental Engineering Research
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• 제28권5D호
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• pp.655-664
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• 2008

Lean Construction recommends implementing site production management by measuring the reliability of daily production tasks, collecting the causes for failure of incomplete tasks, and identifying problems in the existing process based on the collected data. Although many research projects have been performed to introduce Lean Construction in Korea, there are not many cases in which day-to-day site production operations has been stringently evaluated based on such methods. This paper introduces three cases in which such techniques were implemented on a residential, civil infrastructure and plant project. On each project, process maps were created with the superintendents and daily production meetings were held for two weeks. Consequently, the average PPC for the three projects was 79% for PPC and 16% for PAT. In addition, the majority of the failures were due to 'Directive/Plan' and 'Prerequisites.' The results show that project stakeholders (owners, contractors, etc.) lack the ability to plan ahead and keep to their plans, and also lack the capability to synchronize workflow between themselves. The results also reveal that project participants need to be more proactive in solving process problems on site and also need to be better educated in Lean concepts and methodologies.

• Journal of the Korean Institute of Landscape Architecture
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• 제47권1호
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• pp.88-103
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• 2019

This paper aims to identify planting design for the renewal of Okgu Park, located in Siheung, Gyeonggi-do. I designate planting concept fit spatial functions and also suggest planting designs that are proper for a growth environment. The spatial functions of the research site are divided on the basis of the park facilities, its surroundings, and usage. To understand the planting concept, this paper looks into the distribution of plant species and the precise planting structure. To understand the planting concept and the current usage of shade space in the park, I examine the distribution of plant species and the precise planting structure. There are 48 kinds of plants, with Zoysia japonica area (28.84%), Prunus yedoensis (8.0%), Pinus thunbergii (6.73%) and Zelkova serrata (6.38%) taking up the majority. 27 places were chosen for researching the precise planting structure. The research shows that the average green coverage ratio is 38.14% and the average green capacity coefficient is $0.72m^3/m^2$. The growth defective rate of trees in the shade areas is estimated by averaging the classified growth conditions of individual trees per block of shade areas. Areas with an inferior environment for growth and low spatial usage in Okgu Park are selected as subjects for planting design. After comparing the spatial functions with planting concepts and analyzing the growth of plants, I identify $36,236m^2$ areas with inferior growth condition. I also examine structures and the surrounding areas to find areas that require urgent planting improvement, specifically identifying landscape space and shade space around the fountain and the buffer space nearby the North gate. I rearrange spatial functions in the selected areas to devise a planting design considering the existing vegetation, layer structure, and its usage. I set the planting concept and direction to improve the landscape of the selected areas through implementing a planting design so the park users can be satisfied with each space.

• Journal of the Korean Society of Earth Science Education
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• 제15권2호
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• pp.213-223
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• 2022

The purpose of this study is to identify the types of essential inquiry activities presented in elementary science textbooks for grades 5-6, and to find out what difficulties teachers have in the actual teaching process. To this end, the essential research activities presented in the textbook were analyzed into six types: experimentation/observation, investigation/discussion and presentation, data interpretation, discussion/discussion, simulation activity, and expression. In addition, 108 elementary school teachers were investigated for the suitability of inquiry activity achievement standards, suitability at the student's level, student interest, and difficulty in teaching instruction. To summarize the research results, the most frequently suggested type was the experiment/observation type, followed by simulation activity type and data interpretation type. It was analyzed that there was no discussion/discussion type in the 5th grade textbooks, and the 6th graders did not present research activities that correspond to the research/discussion/presentation type and the expression type in the textbook. In the results of teachers' responses to the suitability of achievement standards for inquiry activities presented in textbooks and the suitability of the student's level, 5th graders showed lower average scores than 6th graders, and showed similar average scores in student interest and instructional difficulty. Also, it was confirmed that improvement was required for a total of 17 inquiry activities. Specifically, teachers responded that they had difficulty in guiding inquiry activities when the experimental results did not appear as intended in the textbook, when students' interest in inquiry activities was low, and when students and teachers had low understanding of related science concepts. Teachers pointed out practical problems such as difficulties in long-term observation in astronomy-related units, and students in upper elementary school not actively participating in dynamic play activities.

• Korean Journal of Cognitive Science
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• 제27권2호
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• pp.159-219
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• 2016

Mathematical ability is important for academic achievement and technological renovations in the STEM disciplines. This study concentrated on the relationship between neural basis of mathematical cognition and its mechanisms. These cognitive functions include domain specific abilities such as numerical skills and visuospatial abilities, as well as domain general abilities which include language, long term memory, and working memory capacity. Individuals can perform higher cognitive functions such as abstract thinking and reasoning based on these basic cognitive functions. The next topic covered in this study is about individual differences in mathematical abilities. Neural efficiency theory was incorporated in this study to view mathematical talent. According to the theory, a person with mathematical talent uses his or her brain more efficiently than the effortful endeavour of the average human being. Mathematically gifted students show different brain activities when compared to average students. Interhemispheric and intrahemispheric connectivities are enhanced in those students, particularly in the right brain along fronto-parietal longitudinal fasciculus. The third topic deals with growth and development in mathematical capacity. As individuals mature, practice mathematical skills, and gain knowledge, such changes are reflected in cortical activation, which include changes in the activation level, redistribution, and reorganization in the supporting cortex. Among these, reorganization can be related to neural plasticity. Neural plasticity was observed in professional mathematicians and children with mathematical learning disabilities. Last topic is about mathematical creativity viewed from Neural Darwinism. When the brain is faced with a novel problem, it needs to collect all of the necessary concepts(knowledge) from long term memory, make multitudes of connections, and test which ones have the highest probability in helping solve the unusual problem. Having followed the above brain modifying steps, once the brain finally finds the correct response to the novel problem, the final response comes as a form of inspiration. For a novice, the first step of acquisition of knowledge structure is the most important. However, as expertise increases, the latter two stages of making connections and selection become more important.