• Journal of the Korean Mathematical Society
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• v.34 no.2
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• pp.321-336
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• 1997

Let S be the Ricci curvature of an n-dimensional compact minimal totally real submanifold M of a quaternion projective space $HP^n (c)$ of quaternion sectional curvature c. We proved that if $S \leq \frac{16}{3(n -2)}c$, then either $S \equiv \frac{4}{n - 1}c$ (i.e. M is totally geodesic or $S \equiv \frac{16}{3(n - 2)}c$. All compact minimal totally real submanifolds of $HP^n (c)$ satisfy in $S \equiv \frac{16}{3(n - 2)}c$ are determined.

• Journal of the Korean Society of Clothing and Textiles
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• v.18 no.5
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• pp.602-614
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• 1994

The purpose of this study was to suggest the proper ease of total crotch length concerning both appearance and comfort. The research processes as follows. 1) For the purpose of obtaining the necessary ease of slacks in body movement, experimental slacks of no ease of total crotch length were made. Three college girls putting on these experimental slacks were examined on their back middle waist lines using cross-cut method. 2) Experimental slacks for suggesting the proper ease consist of 7 types; slacks CO, Wl, W3, W5, W7, C3, C5. The sensory evaluation for appearance and comfort was applied to evaluate the 7 slacks. The results can be summarized as follows. 1. As the leg-movement angle increased, the vertical space increased and the horizontal space decreased. There was negative relationship between vertical and horizontal space. And as the leg.movement angle increased, the area of space increased. The shapes of space showed the amounts of space and the direction of force by the movements. 2. The appearances of slacks C3, W3, C5 were better than the other slacks. The eases of the crotch were better than those of the waist line in appearance. And slakcs W7 was better than any other , ;lacks in comfort. When the amount of each part of eases was same, the comfort in eases of crotch was not as good as that of waist line. 3. In slacks, the proper ease of total crotch length was 3% and 5% of total crotch length.

• Bulletin of the Korean Mathematical Society
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• v.35 no.3
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• pp.503-514
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• 1998

We want to treat this problem for real hypersurfaces in a complex hyperbolic space $J_n(C)$. Thus it seems to be natural to consider some problems concerned with the estimation of the Ricci tensor for real hypersurfaces in $H_n(C)$. In this paper we will find a new tensorial formula concerned with the Ricci tensor and give it a characterization of horospheres and geodesic hyperspheres in a complex hyperbolic space $H_n(C)$.

• Bulletin of the Korean Mathematical Society
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• v.36 no.4
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• pp.717-722
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• 1999

The set of continuous maps of a space X to real usual space R equipped with the toplogy of pointwise convergence will be denoted by $C_p$(X). In this paper, we prove that; $C_p$(X) is hereditarily separable and hereditary Lindelof if and only if $X^n$ is hereditarily separable and hereditary Lindelof.

• Bulletin of the Korean Mathematical Society
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• v.39 no.2
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• pp.327-332
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• 2002

In this paper we prove that if M is a J-invariant sub-manifold of codimension 2 in a complex projective space $P_{n+1}(C)$, and the second fundamental tensor is cyclic-parallel or M has harmonic curvature, then M is locally complex quadric Q$_n$(C) or P$_n$(C).

• Journal of Astronomy and Space Sciences
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• v.13 no.2
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• pp.1-19
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• 1996

Satellite Technology Research Center(SaTReC) of Korean Advanced Institute of Science and Technology(KAIST) has started a collaborative research, development, and training program in the field of space technology. As the result of that, SaTReC has successfully developed and operated the KISTAT-1, which is the first Korean satellite system. From the experience gained. SaTReC has developed the KITSAT-2 with its own technology and man-power and acquired the capability to design and to manufacture small satellite systems. In this paper, an overview of KITSAT-1/2 microsatellite systems and operational results are introduced.

• Communications of the Korean Mathematical Society
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• v.18 no.4
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• pp.695-701
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• 2003

In this paper, we have characterizations of almost P-spaces which are analogous characterizations of P-spaces and we will show that if X is an almost P-space such that it is $C^{*}-embedded$ in every almost P-space in which X is embedded, then $$\mid${\upsilon}X-X$\mid${\leq}1$ and that if $$\mid${\upsilon}X-X$\mid${\leq}1$ and ${\upsilon}X$ is Lindelof, then for any almost P-space Y in which X is dense embedded, then X is $C^{*}-embeded$ in Y.

• Journal of the Chungcheong Mathematical Society
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• v.23 no.1
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• pp.109-117
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• 2010

In this paper, we define the concept of a c-net and study the convergence of c-nets. Also we show that a c-net in a topological space X has a convergent sub-c-net if and only if X is a $Lindel{\ddot{o}}f$ space, if every $G_{\delta}$ set is open in X.

• The Research Journal of the Costume Culture
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• v.7 no.6
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• pp.170-181
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• 1999

The purpose of this study is to suggest the possibility of futurism as original design pursuing newness in approaching 21C by studying how futurism having a great effect on fashion as innovatory ideology in early 20C did became paradigm in 20C fashion and the common peculiarity of the dress and its ornaments in this time before 21C. The Space Age Fashion and Techno-Cyber Fashion are representative futurism fashion of 20C. The common inner inclination in both Space Age Fashion and Techno-Cyber fashion are ; First, a future-oriented character. Second, a surrealism character, Third, an anti-cultural character. The greatest peculiarity in the common outer shape in both Space Age Fashion and Techno-Cyber Fashion is material. First, a innovatory choice. Second, an active motion. Third, a diverse effects. Future dress and its ornaments of 21C may be changed greatly by the development of technique, and this fact supports the forecast that the change of paradigm resulted from the development of science may have an effect on future dress and its ornaments as well as modern one. The paradigm change of futurism fashion would be continued, and its influence would work as main source shaping the form of design in 21C.

• Kyungpook Mathematical Journal
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• v.55 no.2
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• pp.355-372
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• 2015

In the present paper, by using the Fibonacci difference matrix, we introduce the almost convergent sequence space $\hat{c}^f$. Also, we show that the spaces $\hat{c}^f$and $\hat{c}$ are linearly isomorphic. Further, we determine the ${\beta}$-dual of the space $\hat{c}^f$ and characterize some matrix classses on this space. Finally, Fibonacci core of a complex-valued sequence has been introduced, and we prove some inclusion theorems related to this new type of core.