• School Mathematics
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• v.3 no.2
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• pp.447-473
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• 2001

Since the greater part of mathematical concepts have been developed in the direction of “from the concrete and realistic aspects to the abstract level”, children should be secured to learn mathematics genetically with various manipulative materials. The aim of this study is to instigate the active use of geoboards in mathematics classroom. To achieve this arm, we first embodied the several significances on the use of geoboards in mathematics instruction. And we then performed an instruction that children discover and justify the formula related to the area of trapezoid by exploring with geoboards, and analyzed the instructional episode to support our assertion about some secure merit accompanied by using geoboards. From this study, we obtained the conclusion that geoboard activity contains many significances such as children can explore congruence, symmetry, similarity, fundamental properties of figures, and pattern. Futhermore, geoboard activity enable children to transform a figure into other equivalently, develop spatial sense, have basic experiences for coordinate geometry, build a concrete model to explain abstract ideas, and foster the ability of problem solving and mathematical thinking.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.4
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• pp.108-117
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• 2009

Leissa claimed in his article that the Rayleigh method is not the same as the Ritz method for determining natural frequencies and its corresponding mode shapes and contended that Rayleigh's name should not be attached to the method. The present article examines the methods in viewpoint of admissible functions and its minimization process, and of the historical developments. It concludes that Leissa's assertion is relevant, although Rayleigh did apply a conceptual theory systematized from the Lagrange method, and given 38 years earlier than Ritz's 'masterly exposition of theory'.

• Bulletin of the Korean Mathematical Society
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• v.54 no.1
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• pp.289-298
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• 2017

Let R denote a commutative Noetherian (not necessarily local) ring and let I be an ideal of R of dimension one. The main purpose of this note is to show that the category ${\mathfrak{M}}(R,\;I)_{com}$ of I-cominimax R-modules forms an Abelian subcategory of the category of all R-modules. This assertion is a generalization of the main result of Melkersson in [15]. As an immediate consequence of this result we get some conditions for cominimaxness of local cohomology modules for ideals of dimension one. Finally, it is shown that the category ${\mathcal{C}}^1_B(R)$ of all R-modules of dimension at most one with finite Bass numbers forms an Abelian subcategory of the category of all R-modules.

• Kyungpook Mathematical Journal
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• v.55 no.4
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• pp.817-826
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• 2015

Let R be a commutative ring with total quotient ring K. Each monomorphic R-module endomorphism of a cyclic R-module is an isomorphism if and only if R has Krull dimension 0. Each monomorphic R-module endomorphism of R is an isomorphism if and only if R = K. We say that R has property (${\star}$) if for each nonzero element $a{\in}R$, each monomorphic R-module endomorphism of R/Ra is an isomorphism. If R has property (${\star}$), then each nonzero principal prime ideal of R is a maximal ideal, but the converse is false, even for integral domains of Krull dimension 2. An integral domain R has property (${\star}$) if and only if R has no R-sequence of length 2; the "if" assertion fails in general for non-domain rings R. Each treed domain has property (${\star}$), but the converse is false.

• Korean Journal of Child Studies
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• v.23 no.2
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• pp.107-120
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• 2002

This study compared the social skills and affective perspective taking of institutionalized and home-reared children. The subjects were 59 institutionalized and 60 home-reared children in Seoul. Results showed that institutionalized children were lower in cooperation, self-assertion and self-control than home-reared children. Institutionalized children were lower in delight, sadness, fear, and anger than home-reared children. As skills in self-control increased, the level of affective perspective taking about fear increased.

• International Commerce and Information Review
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• v.11 no.1
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• pp.465-484
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• 2009

Since the launch of the GATT system, one of the most controversial topics in trade liberalization has been the conflict between culture and trade. The sticking point has been the necessity of cultural exceptions in trade rules. Some countries do not wish to allow further exceptions to basic principles even in cultural industry, while many other countries make their efforts to obtain "cultural safety valve." The latter group asserts that it is indispensable for the protection of cultural identity, whereas the former seems to doubt the truth of the assertion. That is because cultural policy measure possibly constitute a means of arbitrary or unjustifiable discrimination between countries, or a disguised barriers to trade in cultural products. Unfortunately, cultural exceptions still remain unresolved in the WTO, the successor to the GATT. This paper is to review the history and rules of multilateral trading system on cultural industry, address the critical issues to deal with in the DDA negotiations, and lastly provide some perspectives on the appropriate shape of the cultural safety valve.

• Journal of the Korean Home Economics Association
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• v.49 no.9
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• pp.1-13
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• 2011

This study examined whether preschool children's meta-socialization (conceptions of social situations) and their responses differed according to the children's gender. The participants were 78 preschool children living in Seoul, Korea. The results showed gender differences in the children's conceptions of social situations and in their responses to social situations. Firstly, a girl's conceptual judgments about social situations were more developed and dependent on the teacher's authority. Secondly, the boys showed direct and physical responses, while girls showed indirect, linguistic, and emotional responses in moral and social-conventional situations. In addition, girls made more frequent responses to 'Choice Assertion' in personal situations than boys.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.298-302
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• 2009

This paper proposes a single sign-on scheme in which a mobile user offers his credential information to a home network running the OSGi (Open Service Gateway Initiative) service platform, to obtain user authentication and control a remote device through a mobile device using this authentication scheme, based on SAML (Security Assertion Markup Language). Especially by defining the single sign-on profile to overcome the handicap of the low computing and memory capability of the mobile device, we provide a clue to applying automated user authentication to control a remote device via a mobile device for distributed mobile environments such as a home network based on OSGi.

• Kyungpook Mathematical Journal
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• v.51 no.1
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• pp.1-10
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• 2011

Let (R, T) be a normal pair of commutative rings (i.e., R ${\subseteq}$ T is a unita extension of commutative rings, not necessarily integral domains, such that S is integrally closed in T for each ring S such that R ${\subseteq}$ S ${\subseteq}$ T) such that the total quotient ring of R is a von Neumann regular ring. Let P be one of the following ring-theoretic properties: going-down ring, extensionally going-down (EGD) ring, locally divided ring. Then R has P if and only if T has P. An example shows that the "if" part of the assertion fails if P is taken to be the "divided domain" property.

• Language and Information
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• v.2 no.2
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• pp.53-79
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• 1998

This paper is an attempt to give an account of presupposition inheritance (henceforth PI) in conditionals from a functional-discourse perspective. The focus of study is on how to evaluate the embedded presupposition (EP) nested in the hypothetical world. I propose the view that if the EP satisfies the condition on the presupposition satisfaction, it becomes background information in the relevant world, arguing against the theories which employ simple cancellation or disappearance of those EPs. The discourse processing among discourse participants is to be considered in the light of functional significance for the explication of the contrastive mechanism of presupposition and assertion. I advance a revised model of PI in conditionals and analyze several problematic cases of conditionals, with a particular attention to their DRSs.