• Journal of the Korean association of regional geographers
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• v.23 no.2
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• pp.420-436
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• 2017

This study is to design and apply the Havruta class in the geography class and to investigate the effects of the students' attitude on the geography class and the change of the academic achievement through the Havruta class. As a result, it was found to be effective. The students who experienced the lessons in the class were more interested in the geography class, so they were more active in the class activity and they were useful as the class strategy to turn into the self - leading learner participation class. Through the help of Havruta class, students have been helped to understand the concept of geography, and it can be seen that their interaction with their mates has changed into an active attitude to improve their problem-solving ability and creative thinking ability. But, the students who experienced Havruta class did not get a meaningful difference in the evaluation of academic achievement after the class application. We can expect a positive effect on the application of short-term teaching, but it is necessary to give appropriate grace period to the evaluation of the cognitive domain and to develop a proper evaluation method rather than the existing selective evaluation I knew.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.3
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• pp.25-34
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• 1993

The long-term behavior, such as in excavation problems of weak medium, can be dealt with by the elasto-viscoplasticity models. In this paper, a combined formulation of elasto-viscoplasticity using boundary elements and finite elements without using internal cells is presented. The domain integral introduced due to the viscoplastic stresses is transformed into a boundary integral applying direct integration in cylindrical coordinates. The results of the developed boundary element analysis are compared with those from the explicit solution and from the finite element analysis. It is observed that the boundary element analysis without internal cells results in some error because of its deficiency in handling the nonlinearity in local stress concentration. Therefore, a coupled analysis of boundary elements and finite elements, in which finite elements are used in the area of stress concentration, is developed. The coupled method is applied to a time dependent inelastic problem with semi-infinite boundaries. It results in reasonable solution compared with other methods where relatively higher degree of freedoms are employed. Thus, it is concluded that the combined analysis may be used for such problems in the effective manner.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.2
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• pp.183-189
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• 2018

This study was carried out to investigate the effect of plant growth and production of tomato (Lycopersicon Esculentum Mill cv. Tefunis) according to the water content of non-recycled rockwool culture in high-rise tomato greenhouse. Daily irrigation amount was 3.8 times higher in the irrigation control by Integrated Solar Radiation (ISR) than in the Frequency Domain Reflectometry (FDR) sensor. Water content of ISR and FDR was 90-95 and 60-65%, respectively. Plant height and weight of tomato fruit was 1.2-1.9 times longer and 1.2-2.0 times heavier in the ISR than in the FDR sensor, respectively. No significantly differed to sugar content of tomato by treatments. Marketable fruits were the higher 1.3 times in the ISR compared with the FDR sensor. Cracking percentage in the ISR was also the higher 2.0 times compared with FDR sensor. Therefore, Irrigation control by ISR was appropriate to improve of plant growth and production of tomato with non-recycled rockwool culture in greenhouse during long-term cultivation.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.701-707
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• 2010

To analyze the effectiveness of horticultural therapy reported in research papers, a meta-analysis was carried out with 108 of 377 Korean and overseas research papers on horticultural therapy from 1985 to February 2009 (196 Korean dissertations, 113 Korean journal articles, 5 overseas dissertations, and 63 overseas journal articles). The results revealed a large effect size of 0.71. The effectiveness according to the type, age and number of participants were also analyzed. The therapy was most effective in children, and it was more beneficial for children with special needs and elderly people affected by dementia than for the typical population. The greatest effect was found with group sizes of five people or less, and when carried out by researchers from departments related to horticultural therapy than by researchers from unrelated fields of study. The most effective horticultural therapy programs involved floral decorations; and participants who took part in 21 to 30 sessions or at least 31 sessions benefited the most. Among the main effects of short-term horticultural therapy are cognitive, social, physical and emotional; the greatest effect was observed in the physical domain.

• Journal of Educational Research in Mathematics
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• v.9 no.1
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• pp.81-109
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• 1999

This study aims to reflect the basic principles and teaching-teaming principles of Realistic Mathematics Education in order to suppose an way in which mathematics as an activity is carried out in primary school. The development of what is known as RME started almost thirty years ago. It is founded by Freudenthal and his colleagues at the former IOWO. Freudenthal stressed the idea of matheamatics as a human activity. According to him, the key principles of RME are as follows: guided reinvention and progressive mathematisation, level theory, and didactical phenomenology. This means that children have guided opportunities to reinvent mathematics by doing it and so the focal point should not be on mathematics as a closed system but on the process of mathematisation. There are different levels in learning process. One should let children make the transition from one level to the next level in the progress of mathematisation in realistic contexts. Here, contexts means that domain of reality, which in some particular learning process is disclosed to the learner in order to be mathematised. And the word of 'realistic' is related not just with the real world, but is related to the emphasis that RME puts on offering the students problem situations which they can imagine. Under the background of these principles, RME supposes the following five instruction principles: phenomenological exploration, bridging by vertical instruments, pupils' own constructions and productions, interactivity, and interwining of learning strands. In order to reflect how to realize these principles in practice, the teaming process of algorithms is illustrated. In this process, children follow a learning route that takes its inspiration from the history of mathematics or from their own informal knowledge and strategies. Considering long division, the first levee is associated with real-life activities such as sharing sweets among children. Here, children use their own strategies to solve context problems. The second level is entered when the same sweet problems is presented and a model of the situation is created. Then it is focused on finding shortcomings. Finally, the schema of division becomes a subject of investigation. Comparing realistic mathematics education with constructivistic mathematics education, there interaction, reflective thinking, conflict situation are many similarities but there are alsodifferences. They share the characteristics such as mathematics as a human activity, active learner, etc. But in RME, it is focused on the delicate balance between the spontaneity of children and the authority of teachers, and the development of long-term loaming process which is structured but flexible. In this respect two forms of mathematics education are different. Here, we learn how to develop mathematics curriculum that respects the theory of children on reality and at the same time the theory of mathematics experts. In order to connect the informal mathematics of children and formal mathematics, we need more teachers as researchers and more researchers as observers who try to find the mathematical informal notions of children and anticipate routes of children's learning through thought-experiment continuously.

• Lingua Humanitatis
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• v.1 no.1
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• pp.235-251
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• 2001

According to Chomskyan grammar, humans can generate and understand an unbounded number of grammatical sentences. Against the background of pure and idealized linguistic competence, this linguistic productivity is argued and understood. In actual utterances, however, there are many limitations of productivity but they are said to come from the general constraints on performances such as capacity of short term memory or attention. In this paper I discuss a problem raised against idealized productivity. I argue that linguistic productivity idealizes our linguistic competence too much. By separating idealized competence from the various constraints of performance, Chomskyan theorists can argue for unlimited productivity. However, the absolute distinction between grammar (pure competence) and parser (actual psychological processes) makes little sense when we explain the low acceptability(intelligibility) of center embedded sentences. Usually, the problem of center embedded sentence is explained in terms of memory shortage or other performance constraints. To explain the low acceptability, however, we need to assume specialized memory structure because the low acceptability occurs only with a specific type of syntactic pattern. 1 argue that this special memory structure should not be considered as a general performance constraint. It is a domain specific (specifically linguistic) constraints and an intrinsic part of human language processing. Recent development of Chomskyan grammar, i.e., minimalist approach seems to close the gap between pure competence and this type of specialized constraints. Chomsky's earlier approach of generative grammar focuses on end result of the generative derivation. However, economy principle (of minimalist approach) focuses on actual derivational processes. By having less mathematical or less idealized grammar, we can come closer to the actual computational processes that build syntactic structure of a sentence. In this way, we can have a more concrete picture of our linguistic competence, competence that is not detached from actual computational processes.

• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.381-388
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• 2020

This paper discusses English Hedges or Hedging Expressions on the basis of their morphosyntactic-pragramatic properties within the perspective of sociolinguistics. The term, 'Hedges' for the past decades since Lakoff(1973), has received little attention from the English grammar circles such as morphosyntax and the generative grammar theories. This paper presents a more comprehensive approach to the identification, distributions, functions, and the morphosyntactic properties of English Hedges. The earlier research on English Hedges in the 70's show that hedges are metalinguistic or mitadiscourse expressions which constitute a means for executing Politeness strategy in pragmatics. Nonetheless, research from the interface of syntactic-pragmatics has been scarce. This article suggests a more complex body of English hedges that have not been extensively discussed in the literature. Additionally, their configurational domain is to be proposed as part of the PolP with [±hedged] above CP⁺ (or CP beyond). The ramifications of the current study are suggested in terms of comparative linguistics, EFL/ESL studies of English for global communication, and pragmatics-sensitive machine translation studies in the forseeable future.

• Journal of the Korean Chemical Society
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• v.57 no.6
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• pp.801-812
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• 2013

In this study, we analyzed the analogies in the chemistry domain of 27 middle school science textbooks and 8 high school chemistry textbooks developed under the 2009 Revised National Curriculum. A total of 284 analogies (science, 143; chemistry, 141) were identified from the textbooks, which means that 8.11 analogies (science, 5.3; chemistry, 17.6) per textbook and 0.68 analogy (science, 0.66; chemistry, 0.70) per 10 pages were used on average. Compared with previous curricula that the number of analogies gradually increased, the use of analogy was found to be somewhat decreased in the 2009 Revised National Curriculum. The number of analogies found in each textbook considerably varied depending on course, unit, and publishing company. One hundred ninety one different kinds of analogies were used, among which 38(19.9%) were used over twice. Further analyses of the types of analogies indicated that verbal and pictorial analogy, analogy with abstract target and concrete analog, and enriched analogy were frequently used. However, the term 'analogy' and the description about the limitation of the analogy were rarely mentioned. Artificial analogy, teacher-centered analogy, and analogy with low systematicity were also found to be frequently used. Educational implications of these findings are discussed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.4
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• pp.213-221
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• 2018

South Korea has been reluctant to open its geospatial information overseas to ensure security as a divided country. However, this cannot continue as the domestic and international environments related to geospatial information and the industrial ecosystem of information and communication technologies have been changing dramatically. Within this context, this study aims to analyze the causal relations among relevant variables and how they change and interact with time using a systems thinking process. First, causal maps were created for the domains of national security, map-based convergence service, and corporate competition. Then, the causal maps for each domain were integrated, based on which the points for policy intervention and dominant feedback loops were identified. The analysis results showed that securing the self-sufficiency of domestic geospatial businesses is a key element to determine the whole causal map, and the variable that changes the dominant feedback loop from a vicious circle to a virtuous one is the decision to open geospatial information overseas. In this study, I found the policy leverage that is a policy intervention point that can produce a great effect with little input by building a causal map of the interactions between major variables. This study is significant in that it identified and analyzed the dominant feedback loop as to which causal structure would dominate the system in the long term. The results of this study can be used to discuss not only the impacts of map data overseas opening on the national security and geospatial information industry, but also the interactions in the future when Google or other global companies request to release the geospatial information.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.581-587
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• 2004

Conventional power spectrum methods based on FFT, AR method are not appropriate for analyzing biomedical signals whose spectral characteristics change rapidly. On the other hand, time-frequency analysis has more desirable characteristics of a time-varying spectrum. In this study, we investigated the spectral components of heart rate variability(HRV) in time-frequency domain using time frequency analysis methods. In the various time-frequency kernels functions, we studied the suitable kernels for the analysis of HRV using synthetic HRV signals. First, we evaluated the time/frequency resolution and cross term reduction of various kernel functions. Then, from the instantaneous frequency, obtained from time-frequency distribution, the method extracting frequency components of HRV was proposed. Subjects were 17 healthy young men. A coin-stacking task was used to induce mental stress. For each subjects, the experiment time was 3 minutes. Electrocardiogram, measured during the experiment, was analyzed after converted to HRV signal. In the results, emotional stress of subjects produced an increase in sympathetic activity. Sympathetic activation was responsible for the significant increase in the LF/HF ratio. Subjects were divided into two groups with task ability. Subjects who have higher mental stress have lack of task ability.