• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제48권4호
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• pp.311-321
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• 2020

With the recent breakthrough in technology for micro-satellite, small satellite, and mega constellation missions, and the cost of accessing space from recycled space launch vehicles sharply lowered. Thus, space development is set to make a transition to a new space age that is different from before. Accordingly, the problem of worsening space environment conditions due to the increase in space debris, an inevitable adjunct to active space development, is also emerging as an international concern. In this paper, the contents and trends of international organizations for the protection of the space environment and space debris mitigation guidelines of each country were reviewed and forecast the future movement of the international community. In addition, it is suggested example of guidelines that fit the reality of Korea and how to apply them.

• Journal of Biosystems Engineering
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• 제24권4호
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• pp.335-342
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• 1999

Air and flue gas temperature distributions in the space heater for greenhouse were measured to develop a thermal design technology for the space heater. Also, the characteristics of the fan supplying air to the space heater were investigated. The temperature of the flue gas inside the flue gas tube was linearly decreased as the lenght of than those of the flue gas with the oxygen concentration of 8.25% at the last exit of the second flue gas tube. Thus, the operating efficiency of the space heater could be increased with low air ratio decreased exhausting gas temperature and saved the energy consumption with decreased excess air flow. The temperature of the air supplied by fan was increased slowly around the first flue gas tube, meanwhile, increased sharply around the second flue gas tube due to large LMTD (Logarithmic Mean Temperature Difference) at the first flue gas tube than which of the second flue gas tube.

• Proceedings of the SAREK Conference
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.527-532
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• 2009

Recently, the size of Large Space has been gradually enlarged, according to the development of technology, and because they're used not only for indoor events, but also for various outdoor sports, for example, baseball or soccer. Therefore, there are more demands for developing indoor environment control technology to establish indoor thermal-environment which is proper for different events held in Large Space. This study aims at offering some basic data which can be referred to as the construction guide for the full-scaled construction of Large Space in Korea by arranging the matters to be attended to in designing, and controlling technologies for efficient Large Space design.

• Journal of applied mathematics & informatics
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• 제18권1_2호
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• pp.339-350
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• 2005

A space-time fractional advection-dispersion equation (ADE) is a generalization of the classical ADE in which the first-order time derivative is replaced with Caputo derivative of order $\alpha{\in}(0,1]$, and the second-order space derivative is replaced with a Riesz-Feller derivative of order $\beta{\in}0,2]$. We derive the solution of its Cauchy problem in terms of the Green functions and the representations of the Green function by applying its Fourier-Laplace transforms. The Green function also can be interpreted as a spatial probability density function (pdf) evolving in time. We do the same on another kind of space-time fractional advection-dispersion equation whose space and time derivatives both replacing with Caputo derivatives.

• Journal of the Korean Society of Industry Convergence
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• 제12권3호
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• pp.121-128
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• 2009

This study is for getting sacrificial service, discussing process of sacrificial rituals and understanding the composition of space in Dong-gok Jaesa. For these things, we're arranged for exact blueprint through actual survey and analyzed the architectural features. Dong-gok Jaesa has features which show centripetal space organization with strong closing sparsely. This is intended for sincerity during ritual which is processed without obstruction. This is a mixed form which is unified both straight dwelling and Jung Dang Hyeop Sil type. And this is for all functions which is necessary for Jaesa architecture in only one building. And this is used with organizing technique for space utility with connection of compartments and various enlargement and partition. Through these things, even though it is not a big Jaesa, it shows that this is Korea traditional composition of space technique according to several purposes.

• Journal of Communications and Networks
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• 제14권2호
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• pp.206-212
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• 2012

In this paper, in order to effectively apply unitary space-time modulation to the direct-sequence spread-spectrum multiple-access (DSSS-MA) networks, we propose a low-rate, noncoherent, unitary, and space-time modulated DSSS system supporting any number of transmit antennas based on Walsh matrices. The proposed scheme simultaneously performs bandwidth spreading and space-time coding and outperforms those using high-rate, conventional unitary space-time constellations. Furthermore, the proposed scheme allows for a simple detector structure based on fast Walsh transforms.

• Proceedings of the Korean Institute of Interior Design Conference
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• 한국실내디자인학회 2007년도 추계학술발표대회 논문집
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• pp.89-92
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• 2007

Media art has been differentiated and evolved depending on the development of digital technology and the growing of pop culture. Finally experiential ways, which make much of communication with human beings, bring themselves into relief in media art, and these various ways broke lines between virtual reality and reality with the elevation of digital technology, and that has a direct effect on expressing actual space. For this reason, diversified expressions of media art can be an important guideline for studying how to express modern space. This research analyzes expressing features in media art establishing a link with modern industrial interior space and offers new future-oriented space.

• Bulletin of the Korean Space Science Society
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• 한국우주과학회 2009년도 한국우주과학회보 제18권1호
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• pp.64.2-64.2
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• 2009

• Journal of Information Technology Services
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• 제2권1호
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• pp.145-156
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• 2003

This paper presents and analyzes urban planning process to be adopted to create ubiquitous space in city environment, using City of Seoul's Digital Media Street Project as a case study. The Digital Media Street will become the main pedestrian thoroughfare in the Digital Media City (DMC) in Sangam area, planned to become the world's first ubiquitous environment in full urban scale. Ubiquitous space is reinterpreted from an urban planning perspective, and a new approach to planning such a space is introduced, including strategies to couple technology, space, and human activities. Methodology, role of different actors, planning process, and institutional arrangement are examined in turn, and this yields further agenda for improvements that can be made in planning ubiquitous spaces in the future.

• Honam Mathematical Journal
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• 제45권2호
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• pp.316-324
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• 2023

The P-curvature tensor has been studied in the space-time of general relativity and it is found that the contracted part of this tensor vanishes in the Einstein space. It is shown that Rainich conditions for the existence of non-null electro variance can be obtained by P_𝛼𝛽. It is established that the divergence of tensor G_𝛼𝛽 defined with the help of P_𝛼𝛽 and scalar P is zero, so that it can be used to represent Einstein field equations. It is shown that for V₄ satisfying Einstein like field equations, the tensor P_𝛼𝛽 is conserved, if the energy momentum tensor is Codazzi type. The space-time satisfying Einstein's field equations with vanishing of P-curvature tensor have been considered and existence of Killing, conformal Killing vector fields and perfect fluid space-time has been established.