• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.4
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• pp.495-503
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• 2001

In a functionally graded materials(FGM), two constituent material particles are mixed up according to a specific volume fraction distribution so that its thermoelastic behavior is definitely characterized by such a material composition distribution. Therefore, the designer should determine the most suitable volume fraction distribution in order to design a FGM that optimally meets the desired performance against the given constraints. In this paper, we address a numerical optimization procedure, with employing interior penalty function method(IPFM) and FDM, for optimizing 2D volume fractions of heat-resisting FGMs composed of metal and ceramic. We discretize a FGM domain into finite number of homogenized rectangular cells of single design variable in order for the optimization efficiency. However, after the optimization process, we interpolate the discontinuous volume fraction with globally continuous bilinear function in order to enforce the continuity of volume fraction distributions.

• Korean Journal of Construction Engineering and Management
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• v.5 no.6 s.22
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• pp.154-161
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• 2004

The term 'well-being' which becomes a popular trend in various industries has been introduced in the housing market as well. This trend could be understood as an emerging trend rooted to customers' preference for apartment enabling residents to live comfortably and healthy in 2000s. The housing industry has attempted to meet customers' requirements by presenting' well-being apartments' emphasizing healthy and natural-friendly aspects. For instance, suppliers in the industry has adopted master plans and unit plans to support well-being residence. In addition, they introduced less-toxic-emission materials to interior However, it has been unknown that customers in the housing market also agree to well-being functions presented by suppliers and, if then, which aspects they consider mon important In order to answer questions stated above, a research to investigate perceptions of potential customers in Busan towards well-being apartments is designed and this paper is a summarized result. Based on the real-world investigations, the important functions or concepts relevant to well-being apartments perceived by customers are defined and suppliers' approach to meet these Is presented.

• Fire Science and Engineering
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• v.20 no.1 s.61
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• pp.43-49
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• 2006

In this paper, we are studied on the temperature characteristics and fire progress of an incandescent electric lamp at 220V/100W. In the case of stationary state, the ignition possibility of the incandescent electric lamp due to the heat generation was low because the temperature was measured at $161.9^{\circ}C$ the temperature was increased at $538.1^{\circ}C$ in the airtight chamber, but it does not generated the fire because the oxygen was not exist in the airtight chamber. When the lamp is broken, the filament of lamp was melted in the air. The gas of lamp interior spurted to the weakest part by external flame. Thus, the incandescent electric lamp is high possibility of fire when oxygens from airtight space. Also, it is known that the possibility of ignition is very high if combustion materials(sawdust) exists on surrounding. These experimental results will be utilized for the data in the investigation electrical fire cause.

• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.449-456
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• 2020

When you move to a new home, or when you change the wallpaper or flooring of your home, office, etc., you can enjoy the joy of opening your new home with the sick house syndrome, such as the stinging smell and stinging eyes that may appear after the interior work. It is only a moment. Volatile organic compounds from building materials, adhesives, wallpaper, and paints used in new buildings or new furniture cause residents' health and discomfort in indoor life. These volatile organic compounds include benzene, toluene, acetone, and styrene, as well as the representative formaldehyde, and these substances are slowly released over a long period of time, causing acute or chronic diseases to residents. As a method for removing organic volatile substances, physical methods using adsorption, chemical methods for converting volatile substances to other substances, or a mixture of the two are mainly used. In this paper, a sustained release chlorine dioxide gel pack obtained by a method for controlling the reaction rate of a reactant and the release of a product is mixed with a zeolite adsorbent having an optimized hole diameter to adsorb and decompose and remove formaldehyde suspended in the air. I would suggest an effective method.

• Journal of the Korean Home Economics Association
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• v.48 no.1
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• pp.97-110
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• 2010

The purpose of this study was to identify development strategies of high value-added cultural products in order to help promote Jeonnam cultural tourism festivals. In order to achieve this purpose, we carried out a market survey of cultural products sold in cultural tourism festivals held successfully within the Jeonnam area.The subjects of this study were local festivals which were labeled as cultural tourism festivals by the Ministry of Culture, Sports and Tourism from 2000 to 2008. The results of this study were as follows: Firstly, a store survey was conducted to analyze the categories of products on offer. As a result, the most frequent product was accessories (46.2%), followed by clothing and miscellaneous goods (25.2%), ceramic products (14.8%), interior decoration products (9.1%), and stationery (4.6%). Secondly, in the design motif used for cultural products, most products did not contain festival or local images. Cultural products with festival images made up 47.2% of the range, while only 2.3% of products on offer contained local imagery. The remaining 50.3% of cultural products for sale did not use festival or local images. Finally, in terms of materials used, most products used metal (36.7%), followed by textiles (32.9%), ceramic (13.8%), wood (6.2%), plastic (6.2%), paper (3.6%), and leather (0.2%). For price range, 52.4% of product were equal to or below 10,000 won, followed by 33.1% between 10,000-30,000 won. The results of this study showed that the cultural products of Jeonnam festivals lacked symbolism of the region or festival itself. Furthermore, items and the price ranges were not diverse enough. A possible solution would be to address this short coming, but more importantly, design a marketing and commercial strategy tailored towards the promotion of cultural products which contain both regional and festival imageries.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.5
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• pp.585-596
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• 2012

PVDF(poly vinylidene fluoride) and P(VDF-TrFE)(poly vinylidene fluoride-tetrafluoroethylene) are the typical piezoelectric polymers with unique properties. Even they are inferior to conventional piezoelectric ceramics PZT in electromechanical conversion efficiency and interior loss, though they are superior in receiving sensitivity and frequency bandwidth. Their acoustic impedances are relatively close to water or biological tissue and it is easier to make thin film than other piezoelectric materials. Futhermore, the film is so flexible that it is easy to attach on a complex surface. Those properties are suitable for the ultrasound transducers which are useful for medical and biological application, so that various types of polymer transducers have been developed. In this paper, several important considerations for design and fabrication of piezoelectric polymer transducers were described and their effect on the transducer performance were demonstrated through the KLM model analysis. Then, it was briefly reviewed about the structures of the polymer transducers developed for obtaining images as well as the characteristics of the images in several important medical and biological application fields.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.289-303
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• 2019

This paper presents research on furniture making based on Hojangjul, which is an engraving technique that highlights the wooden patterns of traditional furniture. Somokbang, one of the 12 workshops in Tongyeong, has used Hojangjul as an engraving technique since Imjinwaeran. It was inherited by the late Cheon Sang-won, who was No. 59 of National Important Intangible Cultural Properties, and developed into Samhojang, Ohojang, Seongtoinoimun, Hotguinoimun, and Gyeopguinoimun. It was then spread to Masan, Ulsan, and Gwangyang via marine routes and further into the inland areas via land routes, developing in various patterns and forms. The present study investigated and examined the making techniques and characteristics of Hojangjul engraved in joinery furniture in Tongyeong, Masan, and Ulsan in the Gyeongsang region and Gwangyang and Dongbok in the Jeolla region, thus shedding new light on the traditional techniques that have been gradually disappearing and promoting the transmission, inheritance, and development of the traditional techniques.

• Composites Research
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• v.34 no.1
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• pp.47-50
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• 2021

In this paper, the Curing process for Epoxy Molding Compound (EMC) Package was developed by comparing the performance of the EMC/Cu Bi-layer package manufactured by the conventional Hot Press process system and Carbon Nanotubes (CNT) Heater process system of the surface heating system. The viscosity of EMC was measured by using a rheometer for the curing cycle of the CNT Heater. In the EMC/Cu Bi-layer Package manufactured through the two process methods by mentioned above, the voids inside the EMC was analyzed using an optical microscope. In addition, the interfacial void and warpage of the EMC/Cu Bi-layer Package were analyzed through C-Scanning Acoustic Microscope and 3D-Digital Image Correlation. According to these experimental results, it was confirmed that there was neither void in the EMC interior nor difference in the warpage at room temperature, the zero-warpage temperature and the change in warpage.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.2
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• pp.145-166
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• 2021

For several decades, sediment traps have served as one of the key tools for constraining the biological carbon pump (BCP), a process that vertically exports particulate organic carbon (POC) and associated biogenic materials from marine primary production in surface waters to the deep ocean interior. In this paper, I introduced the general methods, the current status of global sediment trap studies, and importance of it to understand the deep ocean carbon cycling. Recent studies suggest that sinking POC in the deep ocean are more complex and spatio-temporally heterogeneous than we considered. Especially researches those studied resuspended and laterally transported particles are presented. Researches that used organic (radiocarbon; ¹⁴C) and inorganic (Al) tracers to understand the oceanic POC cycling and the significance of resuspended particles are reviewed, and the importance of radiocarbon study by using MICADAS (Mini radioCarbon Dating Systems) is emphasized.

• Journal of the Korean Wood Science and Technology
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• v.32 no.1
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• pp.88-95
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• 2004

The purpose of this study is to identify the species of wood members used in the Keunjungjeon Hall, main building of the Kyungbok palace in Seoul. The total 144 samples consist of 52 from pillars and 92 from other wood members. Only two species were identified, which were Abies holophylla Max. (needle fir) and Pinus densiflora Sieb. et Zucc. (Japanese red pine). For the pillars, A. holophylla were more abundantly used than P. densiflora. Among 20 outer pillars ('Pyeongju'), 11 were A. holophylla, and 9 were P. densiflora. Among 12 inner pillars ('Naejinkoju'), 7 were A. holophylla, and 5 were P. densiflora. Among 4 inner corner pillars ('Gwikoju'), 3 were A. holophylla and 1 was P. densiflora. For 92 other wood members, only 2 purlins were A. holophylla and the others were all P. densiflora. The results suggest that the common opinion 'Palace buildings of Korea are made from red pine woods' should be corrected. We think that fir logs might be used for the pillars instead of pines because long and straight pines were not available during 1860s due to heavy utilization of pines as construction and fuel materials in the late Chosun period.