• The Korean Journal of Ecology
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• v.13 no.4
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• pp.321-329
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• 1990

An investigation was performed to elucidate wave character of the timber line on the middle slope of the west side of Paektusan. The Betula ermanii forest, which composes the timber line on about 2, 060m elevation of sea level, is the pure community of B. ermanii. Diffraction pattern of wave distribution of B. eramnii due to boundary condition of alpine temperature gradient was found out on the timber line. Interference patterns of waves of B. ermanii communities produced by environment conditions such as soil layers, whids, snow and relief were shown on a specific area. These facts indicate that the B. ermanii individuals have wave and particle duality, the complementarity principle.

• Journal of Educational Research in Mathematics
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• v.17 no.3
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• pp.253-270
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• 2007

by A.C. Clairaut was written based on the historico-genetic principle such as his . In this paper, by analyzing his we can induce six principles that Clairaut adopted to teach algebra: necessity and curiosity as a motive of studying algebra, harmony of discovery and proof, complementarity of generalization and specialization, connection of knowledge to be learned with already known facts, semantic approaches to procedural knowledge of mathematics, reversible approach. These can be considered as strategies for teaching algebra accorded with beginner's mind. Some of them correspond with characteristics of , but the others are unique in the domain of algebra. And by comparing Clairaut's approaches with school algebra, we discuss about some mathematical subjects: setting equations in relation to problem situations, operations and signs of letters, rule of signs in multiplication, solving quadratic equations, and general relationship between roots and coefficients of equations.

• Journal of the Korean Geographical Society
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• v.41 no.1 s.112
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• pp.22-38
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• 2006

This paper is to explore the cross-border interactions and the formation of trans-boundary regional identity in the Swiss-German-French border region. It begins with a brief review of recent studies on 'boundary and border region', in order to gain a insight into the theoretical debates on this theme and to find out ideal types of the cross-border co-operations. And then it deals with the everyday cross-border movements(working, shopping, living) in 'Regio TriRhena', discussing the development of the trans-boundary co-operations in the EuroRegion 'Upper Rhine'. There are several committees to be defined in trans-boundary co-operation on the 'Upper Rhine', with different scopes of action, structured collectively like Russian dolls(Babushka principle). The economic differences between 3 countries trigger massive cross-border movements. This paper attempts to organize these cross-border interactions around Ullman's 3 bases for spatial interaction(complementarity, transferability, intervening opportunity). In conclusion, this paper shows that the elimination of economic obstacles does not suffice to create trans-boundary identity or a trans-border common regional spirit.