• Journal of the Korean Society of Safety
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• v.31 no.6
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• pp.84-92
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• 2016

Since the mankind started its space mission, the number of artificial space objects has been increasing exponentially. It contains not just the space machines which are in use but the machines which are out of order. Meantime, those dead machines are being a serious danger, a real threat to human's lives and property because of it could re-enter into the earth's atmosphere and fall to the ground causing mega-disaster. As the number of space activities gets growing so far, the re-entry of the space objects will be a lot more happened in the future. Therefore, not just natural space object like asteroids but the artificial space object like artificial satellite and space station can cause the disaster by falling to the ground. To protect our nation and our property, the government has set up the space disaster management center in Korea astronomy and Space science Institute. In this study, we surveyed public's recognition of the space object's re-entry situation and analyzed it to contribute building national space disaster management policy.

• Journal of the Korean Mathematical Society
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• v.56 no.5
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• pp.1387-1401
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• 2019

Consider a finite measure space (${\Omega}$, ${\Sigma}$, ${\mu}$) and a Banach space $X({\mu})$ consisting of (equivalence classes of) real measurable functions defined on ${\Omega}$ such that $f{\chi}_A{\in}X({\mu})$ and ${\parallel}f{\chi}_A{\parallel}{\leq}{\parallel}f{\parallel}$, ${\forall}f{\in}({\mu})$, $A{\in}{\Sigma}$. We prove that if it satisfies the subsequence property, then it is an ideal of measurable functions and has an equivalent norm under which it is a Banach function space. As an application we characterize norms that are equivalent to a Banach function space norm.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.251-257
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• 1998

Spherical space frame structure with triangular network pattern, which has the various characteristics for the mechanic property, a funtional property, an aesthetic property and so on, has often been used as one of the most efficient space structures. It is expected that this type will be used widely in large-span structural roofs. But because this structure is made of network by combination of line elements there me many nodes therefore, the structure behavior is very complicated and there can be an overall collapse of structure by buckling phenomenon if the external force reaches a limitation. This kind of buckling is due to geometric shape, network pattern, the number of layer and so on, of structure. Therefore spherical space frame with triangle network pattern have attracted many designers and researchers attention all over the world. The number of layer of space frame is divided in to the simgle, double, multi layer. That is important element which is considered deeply in the beginning of structural design. The buckling characteristics of single-layer model and double-layer model for the spherical space frame structure with triangular network pattern are evaluated and the buckling loads of these types are compared with investigation their structural efficiency in this study.

• Journal of the Chungcheong Mathematical Society
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• v.33 no.2
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• pp.287-292
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• 2020

In this paper, we prove that a distal homeomorphism f of a compact connected metric space X does not have the eventual pseudo orbit tracing property.

• Bulletin of the Korean Mathematical Society
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• v.52 no.1
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• pp.69-83
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• 2015

In this paper we introduce and study the separable weak bounded approximation properties which is strictly stronger than the approximation property and but weaker than the bounded approximation property. It provides new sufficient conditions for the metric approximation property for a dual Banach space.

• Communications of the Korean Mathematical Society
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• v.25 no.3
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• pp.477-484
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• 2010

In this paper, we introduce a new property (*) of a topological space and prove that if X satisfies one of the following conditions (1) and (2), then compactness, countable compactness and sequential compactness are equivalent in X; (1) Each countably compact subspace of X with (*) is a sequential or AP space. (2) X is a sequential or AP space with (*).

• Journal of the Chungcheong Mathematical Society
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• v.13 no.2
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• pp.81-86
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• 2001

In this paper, we present the proof of the property for interior metric space and geodesic space.

• International Commerce and Information Review
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• v.6 no.1
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• pp.249-265
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• 2004

In the current digital age, most of the countries in the world recognize the electronic business to be a very prospective area in the future and plan to activate for the preoccupation of the business. As a result, this led a rapid increase of the electronic business volume. Electronic business takes place in the cyber space, using internet. However, the intellectual property rights have a high degree of possibility of being infringed as the digitalized intellectual property is easy to receive, copy and transmit in the cyber space. The language structure on the web, represented by HTML, makes easier to copy the intellectual property. And, as the internet has no national boundary, the infringement of the intellectual property rights is easier regardless of country, which could lead to the commercial disputes between the concerned countries. There are in fact many legal disputes nowadays on the infringement of the intellectual property rights in such field as computer programming, infringement of the copyright, business model patent and infringement of the trademark right on the registered name of the domain. It is, therefore, time now to prepare a new theory or legal system to protect the intellectual property rights on copyright, patent and trademark right so as to comply with the digital environment together with such a splendid growth of "electronic business." USA and Germany are nowadays making a significant movement on the legislation of the electronic business, and this study will focus on the legislative contents, judicial precedents and interpretation of law in the above countries.

• Bulletin of the Korean Mathematical Society
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• v.38 no.4
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• pp.663-668
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• 2001

X and Y are Banach spaces for which K(X, Y), the space of compact operators from X to Y, is an M-ideal in L(X, Y), the space of bounded linear operators form X to Y. If Z is a closed subspace of Y such that L(X, Z) has property SU in L(X, Y) and d(T, K(X, Z)) = d(T, K(X, Y)) for all $T \in L(X, Z)$, then K(X, Z) is an M-ideal in L(X, Z) if and only if it has property SU is L(X, Z).

• Korean Institute of Interior Design Journal
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• v.18 no.5
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• pp.128-136
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• 2009

This study analyzed and defines the property of visual perception throughout the revision of the observation time of the original space and the rotating space. The conclusions of this study are as fellows: First, based on the existing theory and experiment, the study obtained the basis which decides the sector data originating fixation-gaze after staring the specific sector over 300ms time. It will become the turning point hereafter for our research to fix the time in this way. Second, in analyzing the minute data, the study built a revision method of the observation time by analyzing the meanings and the reasons of the revision of the original data. Third, according to the difference of revision quantity, female testee have more increases in the amount of data than male testee from the original screen. On the other hand, the opposite tendency appears from the previous data. This shows there is a difference in the observation properly by sex. Last, we could grasp Information about the property of the observation time throughout eyeball fixations, and the revision and analysis of the 'controlled observation data'. These data can be used in design element arrangement of interior space, hereafter.