• Steel and Composite Structures
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• v.7 no.4
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• pp.279-301
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• 2007

When coupling beams are proportioned appropriately in coupled core wall (CCW) systems, the input energy from ground motions is dissipated primarily through inelastic deformations in plastic hinge regions at the ends of the coupling beams. It is desirable that the plastic hinges form at the beam ends while the base wall piers remain elastic. The strength and stiffness of the coupling beams are, therefore, crucial if the desired global behavior of the CCW system is to be achieved. This paper presents the results of nonlinear response history analysis of two 20-story CCW buildings. Both buildings have the same geometric dimensions, and the components of the buildings are designed based on the equivalent lateral force procedure. However, one building is fitted with steel coupling beams while the other is fitted with diagonally reinforced concrete coupling beams. The force-deflection relationships of both beams are based on experimental data, while the moment-curvature and axial load-moment relationships of the wall piers are analytically generated from cross-sectional fiber analyses. Using the aforementioned beam and wall properties, nonlinear response history analyses are performed. Superiority of the steel coupling beams is demonstrated through detailed evaluations of local and global responses computed for a number of recorded and artificially generated ground motions.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.1
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• pp.1-10
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• 1993

A brief description on the greenhouse gases, the greenhoue effect, sea level changes, forcing of climate, the history of Earth's changing climate based on the IPCC REPORT and the records of the recent variation of the climate in the Republic of Kore is presented here for help enhancing awareness of the issues. The climate of the Earth has the potential to be changed on all timescales by the fluctuations of the concentrations of radioactively active greenhouse gases, solar radiation, aerosols and albedo. However, the rate of the recent global warming seems to be larger and rapid than any have occurred thorughout recorded history enough to draw the world-wide attention and worry concerned with the theme of environment and development. There are still uncertainties in the predictions relating to the timing, magnitude and the pattern of the climatic change due to the current incomplete understanding of various aspects of the complex processes. Nonetheless, the scientific results avaliable is sufficient to allow for decisive precautionary measures to be taken.

• Journal for History of Mathematics
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• v.17 no.4
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• pp.37-44
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• 2004

Homological algebra has emerged and developed since 1950s. However, in 1890's Hilbert investigated the resolutions in his Syzygy Theorem which is a vital ingredient in homological algebra. In 1956 Serre has proved the finite global dimension of regular local rings. His result give a basic tool in homological algebra. This paper also deals with the depth formula that was raised by Auslander in 1961.

• Earthquakes and Structures
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• v.10 no.3
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• pp.589-611
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• 2016

This paper presents an analytical study aimed at evaluating the seismic performance of steel moment resisting frames (MRFs) retrofitted with different approaches. For this, 3, 6 and 12 storey MRFs having four equal bays of 5 m were selected as the case study models. The models were designed with lateral stiffness insufficient to satisfy code drift and hinge limitations in zones with high seismic hazard. Three different retrofit strategies including traditional diagonal bracing system and energy dissipation devices such as buckling restrained braces and viscoelastic dampers were used for seismic upgrading of the existing structures. In the nonlinear time history analysis, a set of ground motions representative of the design earthquake with 10% exceedance probability in fifty years was taken into consideration. Considering the local and global deformations, the results in terms of inter-storey drift index, global damage index, plastic hinge formations, base shear demand and roof drift time history were compared. It was observed that both buckling-restrained braces and viscoelastic dampers allowed for an efficient reduction in the demands of the upgraded frames as compared to traditional braces.

• ALGAE
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• v.31 no.4
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• pp.303-315
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• 2016

Compsopogon specimens collected in China were examined based on morphology and DNA sequences. Five molecular markers from different genome compartments including rbcL, COI, 18S rDNA, psbA, and UPA were identified and used to construct a phylogenetic relationship. Phylogenetic analyses indicated that two different morphological types from China clustered into an independent clade with Compsopogon specimens when compared to other global samples. The Compsopogon clade exhibited robust support values, revealing the affiliation of the samples to Compsopogon caeruleus. Although the samples were distributed in a close geographical area, unexpected sequence divergences between the Chinese samples implied that they were introduced by different dispersal events and from varied origins. It was speculated that Compsopogon originated in North America, a portion of the Laurentia landmass situated in the Rodinia supercontinent at approximately 573.89-1,701.50 million years ago during the Proterozoic era.Although Compsopogonhad evolved for a rather long time, genetic conservation had limited its variability and rate of evolution, resulting in the current monospecific global distribution. Additional global specimens and sequence information were required to increase our understanding of the evolutionary history of this ancient red algal lineage.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.1-7
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• 2022

Korean medical device industry has laid the foundation for full-fledged growth and development with the G7 medical engineering technology development project that started in 1995, and the medical device production in 2020 increased by 8.52 times and the export by 13.94 times, compared to those in 2001. In early years, electronic medical devices such as ultrasound imaging device contributed greatly to Korean medical industry, but top ranks in medical device production and export in Korea has shifted recently to in vitro diagnostic medical devices and dental implants. However, the share of imported medical devices in the Korean medical device market have not changed much; it still ranges in 60 to 70%, as the Korean medical device industry produces and exports mid- to low-priced medical devices, and technology-intensive and capital-intensive high-priced medical devices are mainly imported. In this paper, we compare the leading medical devices produced by major Korean companies and those by global top medical device companies to suggest strategies for the Korean medical device companies to enter the global market.

• Asian review of World Histories
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• v.3 no.2
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• pp.171-200
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• 2015

At its simplest, this essay provides a narrative of migration in Asia since the arrival of Homo sapiens some 70,000 years ago. More fully, it presents the case for conducting long-term, world-historical interpretation for Asia with attention to multiple perspectives, which has become increasingly central to global historical analysis. Following an introductory articulation of the benefits of long-term interpretation, the second section presents a balance of three perspectives-empire, exchange, and migration-as frameworks for interpreting the Asian past. The third section presents further detail on migration in long-term Asian history. The concluding section identifies four changes in patterns of migration during the past two centuries and emphasizes the underlying importance of cross-community migration in long-term human biological and social evolution.

• Asian review of World Histories
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• v.1 no.1
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• pp.85-116
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• 2013

The theory of terrestrial impact which has been developed by the astronomy scientists since 1970s is employed for this article in a new angle that atmospheric conditions of our planet should be adopted in the interpretation of the history of mankind. Large and small terrestrial impacts must be acknowledged as key tasks in terms of the study of 'world history'. The Society of Interdisciplinary Studies has already advocated that the 'Bronze Age Civilization' was strongly influenced by the long term terrestrial impact phenomena. Based on historical materials from Korea, the present study was able to identify the years 680-880, 1100-1220, 1340-1420, and 1490-1760 as periods in which territorial impacts occurred.

• Journal of the Korea Furniture Society
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• v.13 no.1
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• pp.61-69
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• 2002

Compared to the fields of Interior Design and Architecture, there have been very few research studies peformed to analyze the history of furniture design in Korea. If our Country wishes to become a participant in the world of global furniture design, it will be necessary to perform more offensive research in both the design of furniture, as well as a complete documentation of our Country's history of furniture design. This study aims to detail the method of chair design by analyzing two examples of chair design. The study, once complete, will be a reference for furniture designers as a practical method, and will become basic material for ongoing studies of the Programming for chair design.

• Journal of Fashion Business
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• v.7 no.3
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• pp.54-59
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• 2003

Asia has the potential of becoming a center of power in fashion. Japan has worked hard to build images of beauty and serenity. The Chinese people already have enriched their business sense throughout history. China is considered as the next powerhouse of fashion. The Asian "mosaic" including Korea should be very colorful, deep, spiritual and beautiful. It is essential we upgrade and update the training and education of fashion leaders. It is possible to find a niche in a global market through maximizing our strength based upon a great and long history in manufacturing textiles.