• Journal of Sensor Science and Technology
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• v.32 no.2
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• pp.88-94
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• 2023

Recently, piezoelectric tactile sensors have garnered considerable attention in the field of texture recognition owing to their high sensitivity and high-frequency detection capability. Despite their remarkable potential, improving their mechanical flexibility to attach to complex surfaces remains challenging. In this study, we present a flexible piezoelectric sensor that can be bent to an extremely small radius of up to 2.5 mm and still maintain good electrical performance. The proposed sensor was fabricated by controlling the thickness that induces internal stress under external deformation. The fabricated piezoelectric sensor exhibited a high sensitivity of 9.3 nA/kPa ranging from 0 to 10 kPa and a wide frequency range of up to 1 kHz. To demonstrate real-time texture recognition by rubbing the surface of an object with our sensor, nine sets of fabric plates were prepared to reflect their material properties and surface roughness. To extract features of the objects from the detected sensing data, we converted the analog dataset to short-term Fourier transform images. Subsequently, texture recognition was performed using a convolutional neural network with a classification accuracy of 97%.

• Journal of radiological science and technology
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• v.46 no.3
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• pp.187-195
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• 2023

A shield was made by mixing materials such as bismuth(Bi) and barium(Ba) with silicon to evaluate its shielding ability. Bismuth was made into a shield by mixing a bismuth oxide(Bi₂O₃) colloidal solution and a silicon base and applied to a fibrous fabric, and barium was made by mixing lead oxide(PbO) and barium sulfate(BaSO₄) with a silicon curing agent and solidifying it to make a shield. The test was conducted according to the lead equivalent test method for X-ray protective products of the Korean Industrial Standard. The experiment was conducted by increasing the shielding body one by one from the test condition of 60 kVp, 200 mA, 0.1sec and 100 kVp, 200 mA, 0.1 sec. At 60 kVp, 2 lead oxide-barium sulfate shields, 2 bismuth oxide 1.5 mm shields, and 5 bismuth oxide 0.3 mm shields showed shielding ability equal to or higher than that of lead 0.5 mm. At 100 kVp, 2 lead oxide-barium sulfate shields and 2 bismuth oxide 1.5 mm shields showed shielding ability equal to or higher than that of lead 0.5 mm. It was confirmed that when using 2 pieces of lead oxide-barium sulfate and 1.5 mm of bismuth oxide, respectively, it has shielding ability equivalent to that of lead. Bismuth oxide and lead oxide-barium sulfate are lightweight and have excellent shielding ability, thus they have excellent properties to be used as an apron for radiation protection or other shielding materials.

• Composites Research
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• v.19 no.3
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• pp.1-6
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• 2006

As the structures of the high performance electronic equipments and devices recently become more complex, the electromagnetic interference (EMI) and compatibility (EMC) have been very essential for commercial and military purposes. Thus, sensitive electrical devices and densely packed systems need to be protected from electromagnetic wave. In this research, glass fabric/epoxy composites containing conductive multi-walled carbon nanotube (MWNT) and carbon fiber/epoxy composites as electrical shielding materials were fabricated and electrical properties of the composites were measured. The concerning frequency band is from 300 MHz to 1 GHz. The performances of composite shielding enclosures were predicted using electromagnetic wave 3-D simulation tool, CST Microwave Studio. The shielding enclosure made of carbon fiber/epoxy composites were fabricated and the shielding effectiveness (SE) was measured in the anechoic chamber.

• Textile Coloration and Finishing
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• v.35 no.2
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• pp.128-136
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• 2023

Recently, the automobile industry is developing as the demand for automo- biles increases due to industrial development and population growth. In addition, many studies are being conducted to reduce heat loss inside the automobiles in order to save energy inside the automobiles due to environmental regulations. In this study, alumina, nanosilicon, and aerogel, which are adiabatic materials, were filled in PET to manufacture yarn, identify physical and mechanical properties, and weave into fabric to confirm adiabatic performance. As the content of the adiabatic material increased, the tensile strength of the fibers filled with alumina and nanosilicon decreased greatly, and the adiabatic property slightly increased. The tensile strength of fibers filled with the aerogel decreased slightly, but the adiabatic properties were greatly increased. Therefore, it is considered to be due to the large volume fraction in the PET yarn due to the low density of the aerogel.

• Journal of Fashion Business
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• v.27 no.5
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• pp.93-107
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• 2023

This study aimed to design a knee brace with dry electrode EMS (Electrical Muscle Stimulation) for elite badminton players suffering from knee pain and assess its effectiveness in relieving pain and improving mobility. The assessment measured knee joint range of motion (ROM), Sargent jump height, and pain perception using a visual analog scale (VAS). Four experimental groups were established: stability, pain induction after 100 squats, muscle soreness induction with a regular knee brace, and muscle soreness induction with the EMS knee brace. The most suitable knee brace was selected from four samples to design the EMS knee brace. The conductive fabric was integrated into the inner surface of the knee brace to enhance EMS conductivity for the quadriceps muscles. Tensile strength tests showed that the dry electrode did not significantly affect the physical functionality of the knee brace.Regarding knee joint ROM and Sargent jump height, the EMS knee brace outperformed muscle soreness induction with a regular knee brace and wearing a standard knee brace. VAS measurements demonstrated that the EMS braces effectively alleviated pain perception in most cases. The results indicate the potential for developing EMS braces to alleviate pain and prevent injuries for athletes across various sports.

• Geomechanics and Engineering
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• v.37 no.5
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• pp.431-441
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• 2024

A newly developed line-style sand pluviator has been calibrated to prepare repeatable sand specimens of specific statuses of compactness and homogeneity for laboratory tests. Sand is falling via a bottom slot of a fixed hopper, and by moving the sample container under the slot, the container is evenly filled with sand. The pluviator is designed with high flexibility: The falling height of sand, the hopper's opening width and the relative moving speed between the hopper and the sample box can be easily adjusted. By changing these control factors, sand specimens of a wide range of densities can be prepared. A series of specimen preparation was performed using the coarse Merwede River sand. Performance of the pluviator was systematically evaluated by exploring the alteration of achievable density, as well as checking the homogeneity and fabric of the prepared samples by CT scanning. It was found that the density of prepared coarse sand samples has monotonic correlations with none of the three control factors. Furthermore, CT scanning results suggested that the prepared samples exhibited excellent homogeneity in the horizontal direction but periodical alteration of density in the vertical direction. Based on these calibration test results, a preliminary hypothesis is proposed to describe the general working principles of this type of pluviators a priori, illustrating the mechanisms dominating the non-monotonic correlations between control factors and the relative density as well as the vertically prevalent heterogeneity of specimens. Accordingly, practical recommendations are made in a unified framework in order to lessen the load of similar calibration work.

• Journal of the Korean Society of Clothing and Textiles
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• v.17 no.2
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• pp.247-264
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• 1993

This study deals with the manufacturing of the foundation garments for the well-balanced somatotype of the Korean middle-aged womenhood. In order to get hold of the different somatotypes, a survey of a total of 134 middle-aged women in Kwangju area, ranging in their age from 45 through 59 was made. The statistical methods used for the analysis of the basic data were the Pearson's correlation coefficient, Anova, Cluster analysis and Stepwise. Emphasis of the try-on test was placed on (1) the comparison of anthropometric data before and after trying on the foundation garments, (2) sensory evaluation, (3) a rating on fit and performance, (4) the comparison by means of photograph. The conclusions obtained are as follows : 1) The 134 women sampled and measured were classified into the five groups of somatotype : the 52 women (34%) belong to Cluster 1 ; the 22 women(14.5%) belong in Cluster 2 ; the 12 women(7.9%) belong in Cluster 3 ; the 15 women(9.9%) belong in Cluster 4 ; the 33 women(27.7%) belong to Cluster 5. 2) As for the characteristics of the foundation garment design, the V-shaped neckline and chest dart was used. The adjust point is right above the perineum point. The foundation garment length is as far as trochanteric point. The materials used are cotton/polyurethane, lace, 100%cotton. The materials used for corrections were the sponge pad for the chest, and non-woven fabric pad for the back, shoulder and the hip. 3) The comparison of the anthropometric data of the subject when dressed in foundation garments showed a significant difference in bust point height, in bust point length and in nipple-ta-nipple breadth, which proves the foundation garments to be effective in correcting such part as the chest, the hip and the abdomen. 4) As considered in terms of the sensory evaluation, the item except for the shoulder and the armhole coincided with each other in the mean value and in the composite reliability coefficient, which also proves the foundation garments to be effective. 5) Subjects were satisfactory on fit, performance, design, of the foundation garment, and their changed appearance. 6) In the case of the comparison through the photographs, the silhouettes of all the five women subjects were found effectively to be balanced.

• Journal of Korean Society of societal Security
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• v.3 no.2
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• pp.41-46
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• 2010

This study focuses on two points. First, I have examined the difference on combustion between flame-retardant and non flame-retardant products including vertical blinds and roll screens that are widely used as a substitute for fabric curtains. The second point is to see how long flame-retardant goods can be durable, that is, flame retardant durability after washing in liquid. the experiment on the flame-retardant ability before and after washing of vertical blinds and roll screens that have been used for a long time in fire protection construct. Comparing and analyzing domestic and foreign laws on flame-retardant after the experiment on durability of these products. I aim to draw necessity for increased application of internal laws and regulations on flame-retardant and show how to improve the point at issue. According to the result, clear differences in performance and safety were observed between flame-retardant and non flame-retardant products. flame-retardant materials can prevent things from fire spread without igniting but melting when they've met flame and burnt, In contrast, non flame-retardant material for experiment which size is 120cm long takes less than 3 minutes only to be completely destroyed by fire. However, it was expected for flame-retardant durability of flame-retardant blinds which are not washable to decrease flame-retardant durability after being washed with water, there was no sharp difference. so it is demonstrated that flame-retardant blinds can keep flame-retardant durability. accordingly through the strict course of product we are concerned about keeping durability.

• Science of Emotion and Sensibility
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• v.19 no.4
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• pp.83-94
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• 2016

The aim of this study was to investigate effective expression method of performance information of functional clothing and preferred alternatives for the categorized consumer groups according to the perception about the functional outdoor jacket. 472 males and females in their 20s-60s' were surveyed and their answers were analysed and categorized by using SPSS 21.0 statistical program. For the study, four different expression methods for waterproof & breathable fabric, 'illustration only', 'illustration+Korean text', 'illustration+foreign text', and 'chart with Korean text', were presented and asked for finding correct answers. The analysis was done for three categorized consumer groups from the former study, 'unconversant/brand & design pursuing group', 'conversant/function pursuing group' and 'high price/high function preferring group'. The results showed that regardless of groups, 'picture only' was the most preferred method and 'graph' was the least. However, the percentage of correct answers for the 'graph' was the biggest, especially for 'conversant/function pursuing group'. It implied that the effective expression method should be differentiated depending on the target consumer groups. 'Conversant/function pursuing group' more agreed on the need for additional information, such as 'after-washed performance', than other two groups.

• Smart Media Journal
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• v.12 no.7
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• pp.43-51
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• 2023

As online transactions increase, the image of clothing has a great influence on consumer purchasing decisions. The importance of image information for clothing materials has been emphasized, and it is important for the fashion industry to analyze clothing images and grasp the materials used. Textile materials used for clothing are difficult to identify with the naked eye, and much time and cost are consumed in sorting. This study aims to classify the materials of textiles from clothing images based on deep learning algorithms. Classifying materials can help reduce clothing production costs, increase the efficiency of the manufacturing process, and contribute to the service of recommending products of specific materials to consumers. We used machine vision-based deep learning algorithms ResNet and Vision Transformer to classify clothing images. A total of 760,949 images were collected and preprocessed to detect abnormal images. Finally, a total of 167,299 clothing images, 19 textile labels and 20 fabric labels were used. We used ResNet and Vision Transformer to classify clothing materials and compared the performance of the algorithms with the Top-k Accuracy Score metric. As a result of comparing the performance, the Vision Transformer algorithm outperforms ResNet.