• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.11
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• pp.941-948
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• 2016

Textile composite materials have been widely applied in aerospace structures due to their various advantages such as high specific stiffnesses and strengths, better out-of-plane performances, impact and delamination resistances, and net shape fabrications. In this paper, a modified geometric model of repeating unit cell (RUC) is suggested based on the Naik's model for 2D plain weave textile composites. The RUC geometry is defined by various parameters. The proposed model considers another parameter which is a gap length between adjacent yarns. The effective stiffnesses are predicted by using the yarn slicing technique and stress averaging technique based on iso-strain assumption. And the stiffnesses of RUC are evaluated by adjusting the gap ratio and verified by comparing with Naik's model and experimental data for 2D plain weave composite specimens.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.552-557
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• 2015

IT technology development and smart appliances due to the increased use of a lot of data on production and consumption has become in the internet. Because this is why importance of information retrieval technology although the growing becoming aware of the difficult techniques to access the required of lot a background knowledge on information retrieval technology. However, the Lucene due to emerge provide to background can implement on search engine by using the Lucene of lack background knowledge for search technology. In this paper, suggest to implement on search engine by using the developed a framework on Lucene-based. Suggest a frameworks are use in the search engines on have guarantee in server environment support on distributed processing and distributed storage, and high availability by using the Hadoop and Nutch, Solr, Zookeeper.

• Journal of Environmental Science International
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• v.21 no.12
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• pp.1495-1501
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• 2012

In this study, an experiment was conducted on influent water with low concentrations of organic matter, such as river water or secondary treatment water of a sewage treatment plant, according to HRT changes by using aerobic biofilm. In the biofilm process, as the biofilm increases in thickness, the inner membrane can be low in oxygen transfer rate and become anaerobic conditions, while the detachment of biomass from biofilm occurs. To overcome these limitations in the detachment of microorganisms in biofilm, the yarn, which was made from poly propylene(PP), was weaved and manufactured into a tube. Then, a test was carried out by injecting air so that the interior of the biofilm could create aerobic conditions. The results of the experiment showed that the removal efficiency of $TCOD_{cr}$ reached 66.1~81.2% by HRT 2hr, and 50.9 ~61.8% after HRT 1 hr. The removal efficiency of $SCOD_{cr}$ was 45.9 to 55.1% by HRT 1hr, and 26.1% in HRT 0.5hr, showing the highest removal efficiency in HRT 1hr. The SS removal efficiency was at 81.8 to 94.6%, and the effluent SS concentration was very low, indicating less than 2.2 mg/L in all HRT's. As a result, the $SCOD_{cr}$ and $NH_4{^+}$-N that were removed per specific surface area and attached to microbial biofilm showed the highest efficiency in HRT 1hr with 8.37 $gSCOD_{cr}/m^2{\cdot}d$, 2.93 $gNH_4{^+}-N/m^2{\cdot}d$. From the result of reviewing the characteristics of biofilm growth, microorganisms were found to be attached, and increased by 36 days. Later, they decreased in number through detachment, but showed a tendency to increase again 41 days later due to microbial reproduction.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.2
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• pp.115-122
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• 2017

Objectives: This study was designed to evaluate the changes in the particle filtration efficiencies of five cloth masks (4 plate types, 1 cup type) with an increasing number of machine washings and the degree of cloth expansion. Methods: NaCl aerosols were generated using an atomizer and passed through cloth masks in a dynamic aerosol chamber. Particle concentrations were measured both before and after for the cloth masks using an optical particle counter (OPC) in the size range of $0.3{\sim}10{\mu}m$. Results: In the original condition, the filtration efficiencies of the five cloth masks were A: 20.1%, B:30.9%, C: 25.0%, D: 26.5%, and E: 40.9%. As the number of washings increased in the order of one, two, and four times, the filtration efficiencies of cloth mask C increased. The filtration efficiency of A, D, and E increased after the first washing. With the exception of B, the filtration efficiency of cloth masks increased after the second washing and those of all cloth masks increased after the fourth washing. This might be caused by the fibers untangling from the yarn and being freed at one end. In this status, the packing density of the textile will not change, but the distances between fibers will increase, which might bring about an increase in filtration efficiency. When the cloth masks were extended by 10% and 20% in one direction, the filtration efficiencies of cloth masks B, D, and E decreased at 10% extension, and those of all cloth masks decreased at 20% extension. When the cloth masks were expanded by 10% and 20% in two directions, the filtration efficiencies of all cloth masks decreased by at least 34.7% at 10% extension, and by at least 60.9% at 20% extension Conclusions: The filtration efficiency of cloth masks could decrease after one to two machine washings, but will increase after four washings in comparison with their original performances. The filtration efficiency of cloth masks will decrease when they are expanded, such as when stretching over the nose during wearing status.

• Journal of the Korea Fashion and Costume Design Association
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• v.14 no.2
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• pp.127-145
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• 2012

In an effort to investigate the overall trends of knit fabrics in fashion trends books, this study analyzed the components(fabric, yarn, gauge, thickness, knitting structure, pattern, dyeing and finishing) of knit fabrics in fashion trends books by the years and seasons from the S/S season of 2002 to the F/W season of 2011. Analyzed in the study were total 883 knit fabrics including the knit samples in Nelly Rodi Knitwear and Promostyl Fabrics. Collected data were put to frequency analysis with SPSS 12.0. Group mean analysis was also performed for thickness. The research results were as follows: As for knit fabrics in fashion trend books by the years and seasons, knit fabrics were most used in 2004 with similar frequency of knit fabrics among the seasons. As for fabric composition of knit fabrics, the uses of blend fabrics were considerably prominent both in S/S and F/W seasons and recorded the highest level in the S/S season of 2003 and the F/W season of 2002. As for gauge composition of knit fabrics, S/S seasons saw the most uses of fine G of 20G or higher, while F/W seasons saw the many uses of 12G-18G, which showed the highest frequency in 2002. As for knitting structure of knit fabrics, the plain stitch was used most both in S/S and F/W seasons and recorded the highest level in the S/S season of 2011 and the F/W season of 2007. As for pattern of knit fabrics, stripes and solid patterns were used most regardless of seasons. As for dyeing and finishing of knit fabrics, non-processed fabrics were used most, recording high frequency in the early 2000s.

• Journal of the Korean Society of Costume
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• v.36
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• pp.53-75
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• 1998

The kind, the structure, and the motif of the Chosun dynasty's fabrics found mainfy within the Buddhist statues were studied. The total of 62 pieces of fabrice can be classified chronologically as follows ; 27 pieces in the year of 1431, 20 pieces of 1550, 9 pieces of 1664, and 6 pieces of 1735. These 62 fabrics also categorized by the weaving method as follows; 27 plain weaved, 17 twill weaved, 10 pieces of satine weaved, 7 pieces of Leno weaved, and 1 piece of double weaved fabrics. Most of the studied fabrics were silk, the rest were 2 pieces of yam and 1 piece of cotton, Kyun, Chu, and Cho were the plain weaved silk as Nung and Ki were the twill weaved silk, Satine weaved silk was called as Dan and double weaved silk was called Chikum in the Chosun dynasty. 1. The antique fabrics were composed of mainly silk. This is believed due to the utmost devotion to the buddhist statue as an object of worship. 2. In the fabric's structural point of view, th ecrossed 4-ply threads of warp yarn which is one of Leno weaved can be observed fre-quently in the period of Korea dynasty's fabrics. But it started to disappear in the beginning of Chosun dynasty, since only one piece of Ra could be found in the 1431's fabrics. Keum, one of the double weaved structure is assumed to be extinct from the Korea dynasty. Satin weaved fabrics started to be woven from the latter period of Korea dynasty and was very popular in Chosun dynasty. 3. The widths of fabrics in the Chosun dynasty gradually decreased compared with those of Korea dynasty.

• Journal of the Korean Society of Costume
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• v.57 no.2 s.111
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• pp.1-10
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• 2007

This study aims at the improvement of sewing function through understandings of dynamic property about the sewing methods and the thread material selection in knitwear. The tensile strength and shear of KES-FB and the Instron were measured for the analysis of the mechanical properties. The knit cloth was structured In the plain stitch, $1\times1$ rib stitch and $2\times1$ rib stitch with the combination of wool and cotton. With regard to the sewing method, intralooping and interlacing were applied. For thread materials, polyester, cotton, wool and silk were used. Since silk has the lowest extension and similar values regardless of its construction in intralooping, it is available knit apparel with uniform elastic recoverv. It also has small shearing resistance. It can be used in apparel which needs big mobility, but it causes rutting problem. Therefore, it is suitable to use intralooping. When the same sewing yarn and textile are use, it can lower shearing resistance and extension in intralooping, Since wool needs a lot of extension energy and it can be cut, intralooping is more suitable than interlacing in sewing of wool. In interlacing using polyester, extension and shearing resistance are high. Therefore, it is suitable for knit sewing with high massing. Silk is not suitable for interlacing since it can be rut. Even though knit materials are different, the RT values of polyester and cotton are similar in same construction. Therefore, they can be substituted each other considering resilience after sewing.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.1
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• pp.173-182
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• 2001

The physical properties and biodegradability of cellulose fabrics, such as cotton and rayon, are expected to vary with textile care. In this study cotton and rayon fabrics were washed repeatedly with detergents, bleaches, or softeners. The changes of physical properties were investigated by measuring retention of breaking strength, shrinkage, handle, and the fiber surface was observed by SEM. The biodegradability of fabrics was also estimated by soil burial test. The results were as follows. Cotton fabrics laundered repeatedly by detergents and bleaches lost virtually no strength. The breaking strength of the rayon fabrics decreased by about 17%∼25% after repeated launderings. Shrinkage in weft direction was much larger than that in warp direction. Bending rigidities of both fabrics decreased remarkably within 10 wash cycles. Shear rigidity in cotton fabrics increased continuously with repeated washing cycles, however, that in rayon fabrics did not show any change as washing went on. Friction coefficient increased in both fabrics after 10 wash cycles, and this is thought to be attributed to the wrinkle, interlocking of hairs, surface damage resulted from repeated washings. In cotton fabrics made of staple yarns, short hairs on the yarn surface entangled together with repeated launderings. This resulted in the continuous increase in % shrinkage, shear rigidity, friction coefficient. Rayon fabrics made of filament yarns, however, did not show this phenomenon. Softener treated fabrics showed the lowest values in bending rigidity, shear rigidity and friction coefficient because the cationic surfactants adsorbed on the fiber surface behaved like lubricants. The biodegradability of fabrics was noticeably affected by the composition of washing solutions. The fabrics washed with detergents and bleaches were decomposed faster than those washed with the others were and the cotton fabrics washed with detergents and softeners hardly degraded. The fabrics soiled with milk were decomposed almost completely and those soiled with Palmitic acid did not degrade greatly.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.11
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• pp.1318-1329
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• 2003

The purpose of this study was to examine the effects of the structural characteristics of men's suit fabrics on the texture image and the preference, and to analyze the relationship between the preference and the practical sales ratio. In addition, the texture images and the preference of fabric and jackets made of the same fabrics were compared. As specimen, jackets for men's suit of 2002' S/S and their fabrics were collected. Questionnaires composed of 22 sensibility related and 21 fabric image related adjectives were developed. For the subjective evaluation of the texture image, both jackets and fabric samples were tested. Tests were performed with 100 female subjects in clothing department and apparel industry. For the objective evaluation, structural characteristics such as fiber contents, yarn twist, fabric count, thickness and weight were analyzed. Total Hand Value were calculated from mechanical properties determined by the KES-FB system. Factor analysis showed sensibilities were classified into 6 categories; "surface roughness", "weight", "density", "stiffness", "elasticity" and "wetness". Fabric images were classified into 4 categories; "classic", "original", "practical", and "stuffy". Depending on the method to show the specimen to the subjects, whether it is suit or fabric, statistically significant differences were observed with a number of adjectives for sensibilities and fabric images. The results of THV of KES did not agree with the preference of subjects, which suggests that we should be careful when using the KES system, which was developed for Japanese people. Price was considered to be another factor besides the texture image that influenced on purchase.

• Journal of the Korean Society of Clothing and Textiles
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• v.20 no.1
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• pp.157-169
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• 1996

Polyester yarns and fabrics containing three levels of $TiO_2$ delusterant were hydrolyzed with NaOH and examined for physical and morphological changes. The mechanical propertis and hand values of alkaline hydrolyzed polyester fabrics were measured using KES-FB system. Also, the relationship between the morphology and the mechanical property of alkaline hydrolyzed polyester fabrics was analyzed. The results are as follows: 1. At an initial stage of alkaline treatment, the concentration of $TiO_2$ did not affect the weight loss of the treated yarns. But by increasing treatment time, the effect of the concentration of $TiO_2$ on the weight loss of the fiber became more pronounced. The weight loss were increased in the following order; fulldull> semidull> clear 2. The effect of hydrolysis on yarn tensile strength seems to be more related to the size of the pits on the fibers rather than the number of pits. 3. Axially oriented pits occurred along the hydroyzed, delustered fiber surfaces, while such pitting was absent on hydrolyzed fiber containing no $TiO_2$. The number of voids across the surface of a fiber increased with an increase in the amount of TiOa incorporated into the fibers. The size of the voids depended on the treatment time of hydrolysis rather than the concentration of TiOa. 4. The mechanical properties and hand values of polyester fabrics were changed by alkaline treatment but were identical regardless of the concentration of TiOa. While the mechanical properties of polyester fabrics depended on the structural change of the fibers and the yarns within the fabrics as the fiber diameter became progressively smaller rather than the size and number of pits.