• Kyungpook Mathematical Journal
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• 제56권3호
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• pp.993-1002
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• 2016

In this paper we give some non-existence theorems for parallel normal Jacobi operator of real hypersurfaces in real, complex and quaternionic space forms, respectively.

• 대한가정학회지
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• 제42권2호
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• pp.1-18
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• 2004

The purpose of this study was to investigate the degree of relationship satisfaction and self-disclosure in real-space friend relations and cyber-space friend relations. The sample was 248 middle and high school students, and 107 undergraduates. The main findings of this study are as follows: 1) Relationship satisfaction is significantly higher in cyber-space friend relations than in real-space friend relations. 2) In contrast to relationship satisfaction, self-disclosure is significantly higher in real-space friend relations than in cyber-space friend relations. 3) Self-disclosure differs significantly in terms of grade, gender, number of friends, communication method, and daily internet usage.

• 한국실내디자인학회논문집
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• 제16권5호
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• pp.126-133
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• 2007

This study is intended to set the concept of becoming meaning of digital space through digital technology and to study the influence of digital space on becoming of real space through derived keyword. The results of this study are summarized as follows. First, the digital concept is created in the process that the virtual space is changed into the real space with a priority given to form, space and time. Digital expression concept and image concept the structural becoming, and idea concept and creative concept creates the time becoming. Second, the concept of digital becoming exposes a physical visibility through the digital's virtual image, and non-space spatiality through the space simulation. It also continuously reveals a consecutive time and non-consecutive time through a statable progress, incremental progress, and dynamic progress. Third, as the influence of digital on becoming of real space, the digital visibly not only expresses the new and difficult becoming problem through conceptual virtuality, but also can review the real space's space concept with virtuality in the digital non-area. Digital's durability expresses the new space's existence by physically combining with the existing space through the virtual form creation.

• 충청수학회지
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• 제21권1호
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• pp.29-48
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• 2008

We deal with the classification problem of real hypersurfaces in a complex hyperbolic space. In order to classify real hypersurfaces in a complex hyperbolic space we characterize a real hypersurface M in $H_n(\mathbb{C})$ whose structure vector field is not principal. We also construct extrinsically homogeneous real hypersurfaces with four distinct curvatures and their structure vector fields are not principal.

• 대한수학회지
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• 제32권2호
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• pp.161-170
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• 1995

A complex $n(\geq 2)$-dimensional Kaehlerian manifold of constant holomorphic sectional curvature c is called a complex space form, which is denoted by $M_n(c)$. A complete and simply connected complex space form is a complex projective space $P_nC$, a complex Euclidean space $C^n$ or a complex hyperbolic space $H_nC$, according as c > 0, c = 0 or c < 0. Takagi [12] and Berndt [2] classified all homogeneous real hypersufaces of $P_nC$ and $H_nC$.

• 한국실내디자인학회논문집
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• 제14권4호
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• pp.19-26
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• 2005

Digital technology continually makes a space evolves. The real-time behavior design communicates the data with the situation of circumference of the space(visitors moving, interior and exterior situations). The space form was changed because it interfaces in real time. The purpose of this study was finding out the characteristics of real-time behavior space design through the analysis of space formative languages, sensorium, S-R and material. This study will be the one of basic references for the digital space design. The boundary of this study set limits to the works of digital space designer who applies the real-time exchanging data to their design among the digital space design works from 1996 to 2004. But it excepted from the real-time behavior space in virtual realty. Therefore, the objects of this study were the works of onl and NOX(paraSITE, Trans-port 2001, Muscle, MotormeCCa, Handdrawspace, Saltwater Pavilion, Son-O-House, H2O Expo). The method was the contents analysis of space formative languages(Greg Lynn's ten space formative languages; bleb, blob, branch, flower, fold, lattice, teeth, shred, skins and strand), sensorium, S-R and material. The results of the study are as follows: 1) The organizational elements; Space formative languages(bleb, blob, fold, shred, skins, strand), stimulation(Human Participation, Human Moving, Weather Conditions), and response(Spatial Moving, Sound Pattern, Lighting Pattern, color Pattern, Activating Particles, Moving Picture, Virtual Friend) 2) The material Use; Sound, lights, and network have been used in the space. Immaterial matter will be used the main material of space design in 21"'century, 3)The spatial types; formal changing of space, projecting immaterial elements, and changing the sound.

• Kyungpook Mathematical Journal
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• 제52권3호
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• pp.271-278
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• 2012

We study some functions defined on the unit tangent space, which are formed with the second fundamental form of submanifolds of a real space form. These give an exact expression of isotropy of submanifolds in a real space form and a relationship between intrinsic invariants and extrinsic ones.

• 대한수학회보
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• 제41권4호
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• pp.609-618
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• 2004

Pseudo-parallel real hypersurfaces in complex space forms can be defined as an extrinsic analogues of pseudo-symmetric real hypersurfaces, that generalize the notion of semi-symmetric real hypersurface. In this paper a classification of the pseudo-parallel real hypersurfaces in a non-flat complex space forms is obtained.

• 한국컴퓨터그래픽스학회논문지
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• 제25권3호
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• pp.115-122
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• 2019

본 연구에서는 사용자 참여를 유도하는 가상공간 스토리 북을 기획하고 구현하여 연구 실험 하였다. 구현한 스토리북은 시나리오를 진행하기 위해서 사용자가 적극적으로 시나리오상의 미션을 수행해야 시나리오가 진행이 되는 것이다. 가상공간 스토리 북의 시나리오를 진행하는 절차는 다음과 같다. 첫 번째, 프로젝션으로 가상공간을 구현한다. 두 번째, 시나리오에 맞추어 사용자는 실제 물체를 가져와 가상의 공간에 실제 물체를 삽입한다. 세 번째, 실제 물체와 대응되는 3D모델이 증강한다. 마지막으로 사용자는 증강된 이미지와 실제 물체를 자유롭게 제어함으로 가상공간에서 이루어지는 시나리오를 체험한다. 구현한 결과물은 3명의 5살 어린이들에게 유저 스터디를 진행하였다. 실험에 참여한 어린이는 가상공간 스토리북을 매우 잘 이해하는 모습을 보였으며 실제 물체를 가상의 공간에 집어넣는 과정을 이해하는 모습이 관찰되었다. 또한 어린이는 현실과 가상을 혼돈하지 않고 실제 물체와 가상 이미지를 구분하는 모습을 확인할 수 있었다. 결과적으로 가상공간 스토리 북을 통해 가상의 공간위에 실제 물체를 증강시키는, 방식을 가진 가상공간 스토리북의 가능성을 확인 할 수 있었다.

• 호남수학학술지
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• 제30권3호
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• pp.535-550
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• 2008

Let M be a real hypersurface of a complex space form with almost contact metric structure $({\phi},{\xi},{\eta},g)$. In this paper, we study real hypersurfaces in a complex space form whose structure Jacobi operator $R_{\xi}=R({\cdot},{\xi}){\xi}$ is ${\xi}$-parallel. In particular, we prove that the condition ${\nabla}_{\xi}R_{\xi}=0$ characterize the homogeneous real hypersurfaces of type A in a complex: projective space $P_n{\mathbb{C}}$ or a complex hyperbolic space $H_n{\mathbb{C}}$ when $g({\nabla}_{\xi}{\xi},{\nabla}_{\xi}{\xi})$ is constant and not equal to -c/24 on M, where c is a constant holomorphic sectional curvature of a complex space form.