• Science of Emotion and Sensibility
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• v.24 no.2
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• pp.49-56
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• 2021

In this study, we investigated the necessary mechanical properties of conductive multifilament yarns for fabricating the electrodes of biosignal measurement pressure and stretch textile sensors using embroidery. When electrodes and circuits for smart wearable products are produced through the embroidery process using conductive multifilament yarns, unnecessary material loss is minimized, and complex electrode shapes or circuit designs can be produced without additional processes using a computer embroidering machine. However, because ordinary missionary threads cannot overcome the stress in the embroidery process and yarn cutting occurs, herein, we analyzed the S-S curve, thickness, and twist structure, which are three types of silver-coated multifilament yarns, and measured the stress in the thread of the embroidery simultaneously. Thus, the required mechanical properties of the yarns in the embroidery process were analyzed. In the actual sample production, cutting occurred in silver-coated multifilament rather than silver-coated polyamide/polyester, which showed the lowest S-S curve. In the embroidery process, the twist was unwound through repetitive vertical movement. Further, we fabricated a piezoresistive pressure/tension sensor to measure gauge factor, which is an index for measuring biological signals. We confirmed that the sensor can be applied to the fabrication of embroidery electrodes, which is an important process in the mass production of smart wearable products.

• Conservation Science in Museum
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• v.31
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• pp.1-20
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• 2024

The "Buseoksa Temple Gwaebul" (1684, K969) in the possession of the National Museum of Korea is a large Buddhist hanging scroll produced for outdoor rituals (gwaebul) at the eponymous temple. The painting demonstrates the most complex composition among the existing Buddhist hanging scrolls as it depicts the Shakyamuni Buddha in the lower middle, surrounded by the Vairocana Buddha, Medicine Buddha, and Amitabha Buddha. This study examines the characteristics of the background fabric and the production methods of the scroll from Buseoksa Temple and explores the characteristics of the coloring techniques by integrating the results of a non-destructive analysis to determine the materials used for coloring. The gwaebul comprises a total of 13 panels, with 11 panels arranged side by side and one panel each added to the top and bottom. The background fabric of the painting consist of semi-transparent silk tabby for the nine panels in the center, and silk tabby for the four panels surrounding the four sides. The coloring materials used to paint the scroll were analyzed using X-ray fluorescence, and were confirmed to be inorganic pigments of red, yellow, green, blue, and white. For some parts painted in yellow and blue, the colors were expressed by first applying light white pigment before adding organic pigments. In addition, ink was used for the black lines and gold leaf was used for the patterns of the Buddhist robes. X-ray irradiation enabled the determination of the location and technique of coloring according to each pigment color by highlighting the difference in brightness depending on the main component and the thickness of each pigment.

• Journal of Navigation and Port Research
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• v.38 no.6
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• pp.623-627
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• 2014

In recent years, wireless communication technologies in human body have received an increasing attention and the research on an antenna that can be worn also has been actively conducted. In this paper, an wearable antenna that can receive GPS signal frequency is proposed. The antenna was manufactured by using a copper polyester fabric with thickness of 0.08mm as a radiator and a ground plate, and a goatskin with thickness of 0.7mm as dielectric substrate. Cutting edges placed in diagonal direction of square patch in order to obtain a circular polarization characteristic, and the conductive cloth and leather was laminated by using a conductive epoxy. First, goatskin dielectric constant was obtained through the simulation and measurement of resonance frequency of the three square patch antennas with different size. On the basis of the results, an antenna operating in the GPS band was designed and the performance of the antenna was validated by making the experiment. The change of the characteristic of the antenna that is located on the shoulder parts of the clothing and wearing person were measured. And it was confirmed that the reception sensitivity has a similar level as compared to the commercially produced ceramic GPS antenna.

• Composites Research
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• v.25 no.1
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• pp.19-25
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• 2012

The study investigated the buckling behavior of sandwich composite columns with different hole sizes and hole positions when they were applied to a compressive load. The columns consisted of 1.7mm thick faces of glass fabric/epoxy and 23mm, 37mm, 48mm, and 61mm thick cores of urethane-foam. Different hole sizes with the diameter of 25mm and 38mm were considered in this experiment. To evaluate the effect of hole position on the buckling behavior, we considered three types of hole position: 25mm diameter hole located at the center, 25mm diameter hole at 1/4 position from the center to the end of the column, and 25mm diameter hole at 1/2 position from the center to the end of the column. According to the results, buckling and maximum loads of the column having 25mm diameter hole were lower by 10% compared to those of the column without hole, whereas the loads for the column having 38mm diameter hole were 30% less than those of the column without hole. Hole position appeared to have no effect on buckling and maximum loads. Major failure modes were observed as follows: the core shear failure for the thin columns having 23mm and 37mm thick cores, and the face-core debonding for the thick columns having 48mm and 61mm thick cores.

• Korean Journal of Heritage: History & Science
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• v.39
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• pp.243-280
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• 2006

At the Bujang-ri Site, Seosan, South Chungcheong Province, around 220 archaeological features, including semi-subterranean houses and pits of Bronze Age and semi-subterranean houses, pits, and burials of Baekje period had been identified and investigated. In Particular, mound burials No. 5 of 13 of Baekje mound burials yielding a gilt-bronze cap along with other valuable artifacts drew international scholarly attention. The gilt-bronze cap from the mound burial No. 5 is a significant archaeological data not only in the study of Baekje archaeology but also in the study of international affairs and exchange at that time. At the time of exposure, the gilt-bronze cap was already broken into a number of pieces and seriously damaged by corrosion, and hardening and urethane foam were necessary in the process of collecting its pieces. Ahead of main conservational treatments on cap, X-ray photograph and CT(computerizes tomography) were taken in order to examine interior structure of the cap and to decide appropriate treatments. In the five layers identified in the profile of cap, a textile layer was set between a metal and a layerof bark of paper birch for avoiding direct contact of the metal and the bark of paper birch. Analyses were executed for examining textile layer and a layer of fibroid material. According to microscopic analysis, while the textile layer consisted of the simplest plain fabric with one fold among three kinds of textile structures, the layer of fibroid material was mixed with two or three kinds of fibers. A comparative analysis with standard sample using FT-IR (Fourier Transform Infrared Spectroscopy) announced that both textiles and fabrics were hemp. Analysis of kind of the paper birch resulted in barks of paper birch with 15 fold. A metallographic microscope, SEM, and WDS were used for the analysis of microscopic structures of plated metal pieces. While amalgam plating was treated as a plating method, the thickness of the plated layer, a barometer of plating technique, was ranged from $1.72{\mu}m$ to $8.67{\mu}m$. The degree of purity of gold (Au) used in plating was 98% in average, and less than 1% of silver (Ag) was included.

• Journal of the Korean Home Economics Association
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• v.12 no.1
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• pp.459-471
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• 1974

This study was carried out on the thermal transmission on account of variation of weaves and researched on the selection of the most suitable weaves for warmth. Also the interrelation among the density, thickness and thermal transmission by different weaves was studied, the author has woven three fundamental weaves, five weaves derived from the fundamental weaves and two special weaves for the purpose of experiment. In weaving of fabrics for experiments the lever type hand loom was used. Testing of texture was carried out according to KS and ASTM. The thermal transmission was also tested by as cooling method which were developed by the author. The conclusions of experiments were as follows. 1. Matt weaves, honey comb weaves and satin weaves having long floating yarns have large cover factor and were thicker. these structures of the weaves were good in warmth. 2. Thermal transmission was reciprocated to the cover factor, thickness and value of cover factor multiplied by thickness : It was found that the weaves of woven fabrics for warmth had better use of satin weaves, Matt weaves, Granite weaves and Honey comb weaves. In the time of warmth is not the first purpose, had better use of Rib weaves. Plain weaves and Twill weaves with thin thickness and high thermal transmission.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.8
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• pp.1338-1346
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• 2003

Three-dimensional formability of the thermoplastic laminar composite was studied according to manufacturing conditions. Five different types of the plain weave fabric were used as reinforcement with PET matrix. The square blank was made by press consolidation technique and formed in the type hemisphere. B-factor defined as the ratio of width of yarn and distance between yarns was used as the factor of formability in the type of plain weave fabric. The formability of PET/Glass fabric laminar composite was estimated in terms of forming rate and B-factor with the thickness distribution, area ratio of blank, and intra-ply shear angle. The thickness distribution across hemisphere was strongly affected by the B-factor, forming rate and blank thickness. The area ratio of blank was increased with B-factor, forming rate and blank thickness. Also, it was found that the intra-ply shear angle depends on the B-factor and forming rate.

• Composites Research
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• v.22 no.6
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• pp.52-62
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• 2009

This paper is for the state of the art of the lightweight protective clothing against the mine, and it covers the preliminary work focused on the appropriate protection, ballistics, convenience, and wearability. It is suggested that the lightweight protective clothing should be fabricated with the laminated materials of high strength woven and non-woven fabrics to reduce the weight and thickness, thus improving the wearability. And partial reinforcement of the protective clothing is necessary to prevent the mortal wound near the important parts of the body without disturbing the arbitrary activity. The composition of the protective clothing should be designed in consideration of easy putting-on and taking-off in addition to easy divesture, which require little motion of the body is in case of serious injury. Additionally, status of the practical technique for high performance and ultra-light hybrid armor material were also described.

• Conservation Science in Museum
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• v.15
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• pp.78-95
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• 2014

To examine the materials, production techniques, and key features of Goryeo wooden lacquerwares, scientific analysis was conducted on six relevant lacquerware items. All of the items, except for a lacquered bowl ^{duksu 4123}, were found to have been made by first covering the surface of the wood with cloth and then varnishing with lacquer. The wooden frames of flower-shaped lacquered case and pine leaves shape lacquered case were made by wrapping thin wood around either the lid or bottom panel. In most cases, microscopic analysis revealed a lower layer of lacquer mixed with bone ash and bone dust, followed by an upper varnish layer of lacquer. SEM-EDS analysis and μ-XRF ^{Micro-X-ray Fluorescence} analysis showed that vermilion lacquer mixed with cinnabar was used on the surface. A lid decorated with a dot pattern was made by first varnishing the surface with yellow lacquer mixed with orpiment, and then irregular dot pattern with a mixture of black lacquer and soot. The vermilion lacquer used to varnish the side of the lacquered bowls was composed of lacquer mixed with cinnabar and minium ^{Red Lead}.

• Analytical Science and Technology
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• v.30 no.5
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• pp.270-278
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• 2017

The absorption of blood onto the surfaces of white cotton, polyester, rayon, and nylon fabrics was studied. Different categories of fabrics (woven and knitted) with diverse thickness, were manually folded twice to obtain four fabric layers, and $100{\mu}L$ of human blood was dropped onto the surface of the fabrics. The amount of blood that penetrated the fabric layer and the shape of bloodstain observed on the fabrics were influenced by the chemistry, thickness, and texture of the fabric. The blood bearing fabrics were left to dry for 3 days, washed by hand using tap water, and Lumiscene was then sprayed onto the fabrics to enhance the latent bloodstain for comparison of the shape of the bloodstain before and after washing by hand. The features of the bloodstain after washing varied greatly with the recipient fabrics. Additionally, stronger luminescence was observed at the surface where the blood was deposited compared to the background. However, it was confirmed that physical contact during the washing can deform the original shape of the bloodstain. The effect of the drying time on the bloodstain after hand washing was also studied. $100{\mu}L$ of blood was dropped on the surfaces of the fabrics and dried for 0, 1, 12, 24, 72 h, and 7 days, then washed by hand, before the bloodstain was enhanced with Lumiscene. The results of this experiment indicated that the increased drying time induces stronger chemiluminescence of Lumiscene. However, after drying of the bloodstain for 7 days, the luminescence of the bloodstain was decreased at the blood deposited site and increased around the blood deposited site.