• 한국수학교육학회지시리즈B:순수및응용수학
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• 제16권3호
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• pp.271-276
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• 2009

We study the geometry of screen conformal light like hypersurfaces M of a semi- Riemannian manifold M. The main result is a characterization theorem for screen conformal lightlike hypersurfaces of a semi-Riemannian space form.

• 한국조경학회지
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• 제31권1호
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• pp.23-33
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• 2003

The purpose of this study is to analyse six different factors of water space that influence interior landscape architecture of officers and commercial spaces. Six different factors of water space that influence interior landscape architecture are the height of the water space, the design form, the blending with the location environment, location, general satisfaction with the water space, and general satisfaction with whole space. The results of this study are as follows: 1. Water space of commercial space was bigger than office space. The satisfaction is the highest in 0∼0.6M(B2) of office space and 3.5M(C6) of commercial space. The cascade form in the office space and large water volume design in commercial areas, which supplies abundant sound and water volume, were the highest. 2. In the analysis of preferences, the design form and the general design of the office space influences satisfaction levels. The height of the water space, and a combination of other factors influence general satisfaction. Water space influences commercial areas in higher degrees. 3. The items were most desired or satisfactory for interior landscape architecture were a cascade, water fall, and small water fountain. 4. A place introduced with water space had higher satisfaction levels. Water space produces higher than general satisfaction and indicates water, space alone cannot make general interior space satisfactory, although it can make interior landscape architecture space satisfactory. 5. There is more general satisfaction in commercial space than in office space. 6. The design of water space influences overall satisfaction: a rest area of office space needs an impressive and aggressive approach, while the office space should harmonize with its surroundings, as a commercial space.

• 교육녹색환경연구
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• 제3권1호
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• pp.15-23
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• 2003

Focusing on both the form of open classroom and that of independent one which have been most planned and being built, this study was designed to see if the educational environment of their inner space, structure, and facilities gives a proper support to classroom activities during the various classes based on open education. Selecting representative teaching methods in elementary school, such as open simultaneous learning, learning through a medium, learning in the corner, subject learning, team teaching and learning hardening basics, this study surveyed problems and improvements using literature works, questionnaires, observing, and interviews. Through the study on learning space for open education, it has been known that the form of independent classroom fits into one classroom learning and open classroom into small group learning and individual learning, and that the form of open classroom connecting open space with a classroom are more desirable when there is change from large to small group.

• 대한수학회지
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• 제46권5호
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• pp.979-995
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• 2009

As warped product manifolds provide an excellent setting to model space time near black holes or bodies with large gravitational field, the study of these manifolds assumes significance in general. B. Y. Chen [4] initiated the study of CR-warped product submanifolds in a Kaehler manifold. He obtained a characterization for a CR-submanifold to be locally a CR-warped product and an estimate for the squared norm of the second fundamental form of CR-warped products in a complex space form (cf [6]). In the present paper, we have obtained a necessary and sufficient conditions in terms of the canonical structures P and F on a CR-submanifold of a nearly Kaehler manifold under which the submanifold reduces to a locally CR-warped product submanifold. Moreover, an estimate for the second fundamental form of the submanifold in a generalized complex space is obtained and thus extend the results of Chen to a more general setting.

• 호남수학학술지
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• 제27권4호
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• pp.595-602
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• 2005

Comtrans algebras are modules equipped with two trilinear operations: a left alternative commutator and a translator satisfying the Jacobi identity, the commutator and translator being connected by the so-called comtrans identity. These identities have analogues for trilinear forms. On a given vector space, the set of all comtrans algebra structures itself forms a vector space. In this paper, the dimension of the space of comtrans algebra structures on a finite-dimensional vector space is determined.

• 대한건축학회논문집:계획계
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• 제34권9호
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• pp.9-20
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• 2018

There are many large and small spaces in the interior of the building, and these spaces are arranged and connected to form a systematic spatial structure. A structure is a collection of several parts to form a whole. In other words, the spatial structure in architecture can be seen as a whole organized and organized as individual unit spaces are gathered together. Therefore, in order to understand the spatial structure, we first need to define the unit spaces that form part, how they are interconnected and arranged, and then understand how and how these unit spaces are organized to form a whole. The main purpose of this study is to study the structural system of space based on the shape information of space on architectural plane. This means interpreting the process and method of how the unit spaces defined as a certain shape on the architectural plane are organized step by step, integrated into a higher level, and eventually integrated into one whole. In this paper, the shape and layout of the unit space are identified in the architectural plan, the connection relation is defined, and expressed in the network form. And suggests a new methodology for interpreting the organizational process in which the following spaces are integrated as a whole. This new methodology is based on human perceptual characteristics. When people recognize an object, they recognize the object partly and completely. We want to explain the relationship between parts of space and the whole according to their characteristics.

• 대한수학회논문집
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• 제11권1호
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• pp.201-207
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• 1996

If a torus has $L^p$-bounded second fundamental form then it is included in the lower part of the moduli space. That is, its conformal class is bounded.

• 한국실내디자인학회논문집
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• 제16권6호
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• pp.65-76
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• 2007

This research is progressed on the premise that there is a basic rule to organize a space in form generation process. In this study first, antecedent researches are inquired, and formal vocabularies related with form generation in space design are founded. Generally in the organizing process of spatial form designer could have selectively combined formal vocabularies consciously or unconsciously, and these formal vocabularies related with form generation are classified with 'formal elements' and 'spatial relationships'. First, as formal elements '2-dimensional line elements(rectilinear, oblique-linear, curvilinear)' are chosen. Second, formal vocabularies of 'spatial relationships' are 37 extracted from literatures related with architectural language or spatial language. Among them there are several vocabularies with similar or same meaning, they are unitized to representative one. Thereupon 20 vocabularies are finally selected as the formal vocabularies of 'spatial relationships', they are addition, subtraction, intersection, superimposition, juxtaposition, shifting, rotation, reflection, scaling, stretching, shear, bending, folding, distortion, articulation, deconstruction, symmetry, repetition, proportion, and asymmetry.

• 호남수학학술지
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• 제43권2호
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• pp.289-304
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• 2021

In this paper, we establish several geometric characterizations focusing on the relationship between the squared norm of the second fundamental form and the warping function of SCR-lightlike warped product submanifolds in an indefinite Kaehler manifold. In particular, we find an estimate for the squared norm of the second fundamental form h in terms of the Hessian of the warping function λ for SCR-lightlike warped product submanifolds of an indefinite complex space form. Consequently, we derive an optimal inequality, namely $${\parallel}h{\parallel}^2{\geq}2q\{{\Delta}(ln{\lambda})+{\parallel}{\nabla}(ln{\lambda}){\parallel}^2+\frac{c}{2}p\}$$, for SCR-lightlike warped product submanifolds in an indefinite complex space form. We also provide one non-trivial example for this class of warped products in an indefinite Kaehler manifold.

• East Asian mathematical journal
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• 제37권1호
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• pp.41-77
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• 2021

Let M be a semi-invariant submanifold of codimension 3 with almost contact metric structure (��, ξ, η, g) in a complex space form Mn+1(c), c ≠ 0. We denote by Rξ = R(·, ξ)ξ and A(i) be Jacobi operator with respect to the structure vector field ξ and be the second fundamental form in the direction of the unit normal C(i), respectively. Suppose that the third fundamental form t satisfies dt(X, Y ) = 2��g(��X, Y ) for certain scalar ��(≠ 2c)and any vector fields X and Y and at the same time Rξ is ��∇ξξ-parallel, then M is a Hopf hypersurface in Mn(c) provided that it satisfies RξA(1) = A(1)Rξ, RξA(2) = A(2)Rξ and ${\bar{r}}-2(n-1)c{\leq}0$, where ${\bar{r}}$ denotes the scalar curvature of M.