• Journal of Astronomy and Space Sciences
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• v.30 no.3
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• pp.145-152
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• 2013

Rotation-powered pulsars are excellent laboratories for studying particle acceleration as well as fundamental physics of strong gravity, strong magnetic fields and relativity. Particle acceleration and high-energy emission from the polar caps is expected to occur in connection with electron-positron pair cascades. I will review acceleration and gamma-ray emission from the pulsar polar cap and associated slot gap. Predictions of these models can be tested with the data set on pulsars collected by the Large Area Telescope on the Fermi Gamma-Ray Telescope over the last four years, using both detailed light curve fitting, population synthesis and phase-resolved spectroscopy.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.666-669
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• 1993

The space charge fields, including intermode apace charge fields in photorefractive material with two impurities are obtained for the small light intensity at large modulation depth, and their implication of high-capacity volume holographic interconnection are presented. In the following data regions the effect of intermode space charge fields are suppresed and the criteria for optimal implementation of volume holographic interconnections are satisfied.

• Korean Institute of Interior Design Journal
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• no.34
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• pp.106-113
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• 2002

Certosa, a representative Monastic Architecture of Renaissance era, has been well preserved. And it has worked as a symbol of the space form & style revealed by monad, sell, arcade and court, which are characteristic of a monastery. A court is divided into large court and small one, and it connects each units and each sells through the annex with clarifying each space identities. And arcade and pillar is not only to derive a unitary space from entire space, but also to try openness and extension applying a different height in spite of physical closure of style. Especially planned by monad and cell, the routine space of monks, a structure of rational space is a yardstick of moderation and frugality, showing affluent space which occupy essential areas without extra space. And the space appears self-sufficiency, honest poverty, and affluence with order and eternity based on elementary principles of the Cartusio order in composition and plan of the space. Keeping strong linking with entire sells in the monastery, Each sell symbolizes entire sells, and the inverse is the same. And it is the universe advocating eternity and it is also a small city which provides the monks with accurate modules and scales in the very recluse space.

• Korean Institute of Interior Design Journal
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• v.16 no.6
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• pp.224-231
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• 2007

Superyachts are passenger vessels whose hull exceeds 24m. They are a kind of luxurious leisure ships. Interior designers can contribute in the field of space design of superyachts. This study is intended to investigate the space elements and their organization of superyachts for putting the base of superyachts interior design. Especially it is focused on the interior space division by structural elements such as the watertight bulkheads and decks. In this study we analyze general arrangements, floor plans of decks, of 31 superyachts and extract space elements and their disposition in three dimension. On the basis of the space arrangement we classify the types of space organization of superyachts. And then we inquire the interior space division of superyachts, which is characterized by the structural elements of the ship. The watertight compartments made by the bulkheads and decks have a great effect on interior space design in super yachts. The results of this study are summed up as follows: At first, the small-size superyacht has 3 decks and the midium or large-size superyachts has 4decks. Secondly, depending on the number of decks the superyachts has several typical patterns of space organization. Thirdly, in general there are 5-6 watertight compartments on a deck depending on the superyachts scale. Finally, there are distinct separation between the passenger's movement and the crew's movement on the ship.

• Korean Institute of Interior Design Journal
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• v.22 no.5
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• pp.33-41
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• 2013

It is not surprising that senior centers are widely used nationwide as Korea becomes an aging society. This study attempts to figure out senior citizens' needs and evaluations of senior centers in terms of characteristics of their usage and spatial composition. A face to face interview using a questionnaire was conducted on 255 senior citizens who has been using senior centers located in Jangyu new city apartment housing complex. The questionnaire is composed of questions asking characteristics of their usage, evaluations of spatial composition, and respondents' demographic data. Findings are: First, it is found that many respondents visit senior centers everyday and spend 4 to 6 hours a day. Their main activities are meeting friends, taking hobbies, and dining. That is, senior centers play a pivotal role in daily lives of senior citizens. Such characteristics should be taken into account in space design when planning to build a future senior center; Second, it is found that senior centers play a role of auxiliary space for building their sense of belonging and familarity. It is found that furnitures in senior centers are worn out and safety measures are not sufficiently considered; Third, it is found that they highly evaluate flexible spacial composition that could be partitioned or extended depending on occasions even though they prefer independent space; Fourth, it is found that kitchen facilities are not large enough considering the fact that more that half of the respondents have their lunches in senior centers. Even though they do not cook for themselves kitchen space should be large enough for preparing meals simultaneously for a large number people.

• Journal of Digital Contents Society
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• v.16 no.1
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• pp.33-41
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• 2015

Since bitmap indices are useful for OLAP queries over low-cardinality data columns, they are frequently used in data warehouses. In many data warehouse applications, the domain of a column tends to be hierarchical, such as categorical data and geographical data. When the domain of a column is hierarchical, hierarchical bitmap index is able to significantly improve the performance of queries with conditions on that column. This strategy, however, has a limitation in that when a large scale hierarchy is used, building a bimamp for each distinct node leads to a large space overhead. Thus, in this paper, we introduce the way to build hierarchical bitmap index on an attribute whose domain is organized into a large-scale hierarchy in space-constrained environments. Especially, in order to figure out space overhead of hierarchical bitmap indices, we propose the cut-selection strategy which divides the entire hierarchy into two exclusive regions.

• Journal of Korean Association for Spatial Structures
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• v.18 no.1
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• pp.93-100
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• 2018

The retractable roof structures have actions of various types of loads and external forces depending on the retraction and operation conditions of the roof in terms of efficiency of control and maintenance as the aspect of structural plan. In particular, there is a need for studies on the establishment of retraction controlled wind velocity to maintain the stable control and usability of roof structure against strong winds or sudden gusts during the retraction of the roof. In this paper, it was intended to provide basic materials for the development of guidelines on the operation and maintenance of domestic retractable buildings with large space by analyzing the factors affecting the retraction controlled wind velocity for the overseas stadiums with the large spatial retractable roof structures where the sliding system was applied on the steel retractable systems. As a result, the controlled wind velocity tends to decrease as the retractable roof area increases. On the other hand, the controlled wind velocity tends to increase as the retraction time increases. In addition, in the space-grid roof structures, the spherical roof structures type showed the average controlled wind velocity of 10m/sec lower than that of 17.3m/sec for curved-roof structure type, and in the curved-roof structure type, the truss roof structure showed the average controlled wind velocity of 8.9m/sec which is lower than that of 17.3m/sec for the space for the space-grid roof structure.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.4
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• pp.347-360
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• 2014

Recently construction of large sewer tunnels used also as underground sluiceways/storages is increasing in order to prevent urban inundation, untreated sewage flow into rivers from combined sewer overflows and consequential river pollution due to climate change. Most of these large sewer tunnels are constructed with concrete and the concrete lining should be protected from corrosion caused by hydrogen sulfide($H_2S$). This paper introduced popular concrete corrosion protection methods for large sewer tunnels with 100-plus years of life cycle, and pros and cons of each corrosion protection methods were described by giving specific examples. However, it is difficult to objectively assess corrosion protection alternatives because of insufficient track record of corrosion protection methods applied to large sewer tunnels. In this paper, the evaluation process for selecting a corrosion protection alternative was introduced for large sewer tunnels using a case study.

• Journal of applied mathematics & informatics
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• v.30 no.3_4
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• pp.647-653
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• 2012

In this paper, we consider fuzzy random sets as (measurable) mappings from a probability space into the set of fuzzy sets and prove a uniform strong law of large numbers for sequences of independent and identically distributed fuzzy random sets. Our results generalize those of Bass and Pyke(1984)and Jang and Kwon(1998).

• Proceedings of the Korean Statistical Society Conference
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• 2002.11a
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• pp.215-220
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• 2002

In this paper, we establish weak laws of large numbers for weighted sums of convex-compactly uniformly integrable fuzzy random variables taking values in the space of upper-semicontinuous fuzzy sets in R$^{p}$.