• Journal of Digital Contents Society
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• v.18 no.6
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• pp.1151-1156
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• 2017

It is common to achieve lower performance in traversing tree data structures in GPU than one expects. In this paper, we analyze the reason of lower-than-expected performance in GPU tree traversal and present that the warp divergences is caused by the branch instructions ("if${\ldots}$ else") which appear commonly in tree traversal CUDA codes. Also, we compare the parallel shifted sort algorithm which can reduce the number of warp divergences with a kd-tree CUDA implementation to show that the shifted sort algorithm can work faster than the kd-tree CUDA implementation thanks to less warp divergences. As the analysis result, the shifted sort algorithm worked about 16-fold faster than the kd-tree CUDA implementation for $2^{23}$ query points and $2^{23}$ data points in $R^3$ space. The performance gaps tend to increase in proportion to the number of query points and data points.

• Journal of the Korean Society of Costume
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• v.59 no.6
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• pp.118-125
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• 2009

Goryeong Jeesandong tombs No.73 from the 5th century located in Gyeongsangbookdo is the most representative remains of the Daegaya. They were excavated and examined by the Daedong Research Center for Cultural Properties. In this study, the textiles in the Goryeong Jeesandong tomb No.73 is identified and their features are examined through scientific analysis. Due to the fact that the remains were not treated for preservation, we were able to observe many samples under the microscope. Within the hemp textiles both hemp and ramie were made using s-twist threads and the thread count distribution is calculated to be 8.0${\sim}$20.0/$cm^2$. Among the silk, the taffeta was categorized into five types. First, there was plain woven silk which the thickness of the warp and the weft is the same and their rate of threadcount was the same. The second type was thin tabby which is spacious between threads. The third kind was woven by warp and weft which had very different thickness. The fourth type used two threads for each warp. The fifth kind used two threads for the warp threads and used thick threads for the weft for a modified plain weave, and it is the first of its kind to be found. Also, there was a compound weave with warp-faced compound weave among silk.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.5
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• pp.109-116
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• 2016

Polymethyl methacrylate is commonly used in the outer lens of automotive rear lamps. However, if the lens warps above the allowable limit, it may lead to faulty connection with the housing, and failure of the assembly. This study investigated the effects of gate diameter and cooling line distance in the mold design for automotive outer lens. The optimal gate diameter and cooling line distance to minimize the warp of the outer lens were derived as 3.0 mm and 50-60 mm respectively, and the cooling temperature to minimize warp was shown to be $60-80^{\circ}C$ (mold surface temperature $48-67^{\circ}C$). A higher cooling temperature may somewhat mitigate the warp, but is undesirable because it may cause injection molding problems, such as sinks. A mold was constructed matching the optimal design and the produced lens properties, particularly the degree of warp, were comparable with the CAE predictions.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.6
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• pp.978-985
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• 2021

This study aims to propose a prediction model for the drape coefficient using artificial neural networks and to analyze the nonlinear relationship between the drape properties and physical properties of fabrics. The study validates the significance of each factor affecting the fabric drape through multiple linear regression analysis with a sample size of 573. The analysis constructs a model with an adjusted R² of 77.6%. Seven main factors affect the drape coefficient: Grammage, extruded length values for warp and weft (m_warp, m_weft), coefficients of quadratic terms in the tensile-force quadratic graph in the warp, weft, and bias directions (c_warp, c_weft, c_bias), and force required for 1% tension in the warp direction (f_warp). Finally, an artificial neural network was created using seven selected factors. The performance was examined by increasing the number of hidden neurons, and the most suitable number of hidden neurons was found to be 8. The mean squared error was .052, and the correlation coefficient was .863, confirming a satisfactory model. The developed artificial neural network model can be used for engineering and high-quality clothing design. It is expected to provide essential data for clothing appearance, such as the fabric drape.

• Journal of the Korean Society of Costume
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• v.33
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• pp.217-228
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• 1997

The purpose of this study was to investigate influence of the construction method of the circular skirt on drapability and shape of static silhouette and length variation. In made 24 types of skirts giving the variations (six kinds of peach skin-like finished fabrics two types of cutting method two types of machine stitch method of hem), The results were as follows: 1. Analysis of drapability In the cutting method thre was similarity between warp direction and true bias direc-tion. In the machine stitch method of hem there was similarity between blind stitch and blind stitch machine. According to the fabrics analysis of drapability was excellent in the order N/P 80/20(fabric 1)>P 100(fabric 5)>P 100(fabric 6)>P 100 (fabric 2)>P 100 (fabric 4)>N/C 50/50(fabric 3). 2. Analysis of the characteristics values of static silhouette shape In the cutting method shape of static sil-houette became wide in the warp direction. In the machine stitch method of hem shape of static silhouette became wide in the blind stitch. According to the fabrics shape of static silhouette became most wide in the N/C 50/50(fabric 3) and shape of static sil-houette become most narrow in the P 100(fabric 2,5) 3. Analysis of the length variation In the cutting method the true bias direc-tion was longer than the warp direction. In the machine stitch method of hem there was simi-machine stitch method of hem there was simi-larity between blind stitch and blind stitch ma-chine. In fabrics the P 100(fabric 6) showed the longest the N/C 50/50(fabric 3) showed most slight. Interaction between the cutting and messure-ment part of skirt lengh. In the warp diretion parts that showed longest length variation were C. G, K, O in the true bias diretion parts that showed most slight length variation were A, E, M, I.

• Journal of Fashion Business
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• v.23 no.6
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• pp.27-36
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• 2019

This study aimed to analyze the color differences by warp direction of textile mosaics by focusing on two representative textile wallcovering types, woven and string. Mosaics made of string can be expressed as having three-dimensionality based on color differences resulting from the warp direction of the string. String wallcoverings, unlike woven or non-woven wallcoverings, only have vertically oriented warp lamination on the backing paper without weft, and therefore, the reflection and backing color can be expressed differently depending on the angle of the mosaic. In this study, two identical wallcoverings were manufactured using the same materials but using different textile types, woven and string. The wallcoverings underwent die-cutting by each angle and were deployed in cube form. The analysis was based on ISO 5631-1:2015. The color difference between the two wallcoverings, woven and string, was shown as ΔE* 9.29. Based on the standard deviation of the color difference for each mosaic angle, woven ranged from ΔE* 0.09 to 0.94 and string ranged from ΔE* 1.92 to 3.74, showing a larger color difference. Thus, using the color differences of string to create a mosaic wallcovering improved dimensionality.

• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.9-21
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• 2013

Due to increased computing power and flexibility of GPU, recent GPUs execute general purpose parallel applications as well as graphics applications. Programmers can use GPGPU by using the APIs from GPU vendors. Unfortunately, computational resources of GPU are not fully utilized when executing general purpose applications because of frequent branch instructions. To handle the branch problem, several warp formations have been proposed. Intuitively, we expect that the warp formations providing higher computational resource utilization show higher performance. Contrary to our expectations, according to simulation results, the performance of the warp formation providing better utilization is lower than that of the warp formation providing worse utilization. This is because warp formation providing high utilization causes serious memory bottleneck due to increased memory request. Therefore, warp formation providing high computation utilization cannot guarantee high performance without proper hardware resources. For this reason, we will analyze the correlation between hardware configuration and warp formation. Our simulation results present the guideline to solve the underutilization problem due to branch instructions when designing recent GPU.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.3
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• pp.453-463
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• 2021

The lengthwise and widthwise deformation of warp-knitted fabrics with different sizes and loading modes were evaluated. Moreover, five tricot samples cut in three directions were compared under four test conditions (A-D). In tests A and B, 500 and 250 g loads were applied on a layer of 20 × 20 and 5 × 10 cm² samples, respectively. In test C, a 20 × 20 cm² sample was folded in half over a rod, and 500 g load was applied to each half. In test D, a 20 × 20 cm² sample was sewn in a loop and subjected to a 500 g load. The lengthwise extension and widthwise contraction analysis results indicate that test B affords the largest values. However, analysis results of the warp-knitted fabric normalized through conversion to a 1 g load and 1 cm sample width indicate that the largest values are afforded for test D. Therefore, pattern reduction may vary depending on the measurement method and properties of the knitted fabric used for the compression wear production, causing variations in the finished product. Thus, an appropriate measurement method must be adopted based on the compression wear design and knitted fabric to be used.

• Journal of the Korean Society of Costume
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• v.57 no.1 s.110
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• pp.93-104
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• 2007

This study is considered about the fabrics culture of Baekje Period by analyzing the fabrics pieces at a inner part of the It-bronze shoes found at the tomb of King Mu-ryeong in 1971 AD. The analysis methods of the fabrics pieces are a photographing of fabrics pieces surface by VMS, Digital camera(Nikon Coolpix 995) and the analysis of samples by SEM, XRD and FT-IR. It is assumed this fabrics pieces are the inner shoes, which consisted of compound woven silk at outward, some of tabby and a hemp at inward and the braids for decoration, of the gilt-bronze shoes. The features are as follows. 1. All of compound woven silk are the warp-faced compound tabby of plain fabrics and the density is various from high to low one. Compound woven silk which is attached the gilt-bronze shoes of the tomb of King Mu-ryeong weaves in high density by a thick thread. The fibers material of compound woven silk prove to be a silk by the analysis of wrap samples by SEM, XRD and FT-IR. 2. Tabby are excavated under the condition which attached on reverse side of compound woven silk. Those ran classify two types. First, the fine weaving by high density of wrap and weft. Second, the loose warp weaving with one warp and some of weft. 3. Hemp is almost ramie by SEM analysis and the density is different. Ramie which supposed to be attached Guem has the very low density. In addition to, Ramie pieces, excavated in condition and weaved finely, proved the conspicuous weaving skill in Baekje period. 4. Various kinds of braid are found and these ones classifies by fiber material and entwining way. Two types out of these are the one of silk thread, decorates the upper, middle parts of compound woven silk shoes and the other of hemp thread, decorates the lower parts.

• Fashion & Textile Research Journal
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• v.1 no.4
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• pp.387-392
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• 1999

The effects of the ratio of warp diameter to filling diameter (${\beta}$-ratio) and warp thread crash on the crimp factor and the yarn curvature were studied theoretically in this paper. The models of 2/2 twill fabric derived square cloth and sinusoidal curved cloth were used for the theoretical analysis. The crimp factors (C) for the models were given theoretically as follows; (1) Derived square cloth(general equation for b) $$C=\frac{(1+{\beta})({\theta}-sin{\theta})}{(1+{\beta})sin{\theta}+{\alpha}}$$ (2) Sihusoidal curved cloth $$C=\frac{(1+{\beta})sin{\theta}\[1+\{\frac{{\pi}(1-cos{\theta})}{4sin{\theta}}\}^2\]+{\alpha}}{(1+{\beta})sin{\theta}+{\alpha}}-1$$ The curvatures(${\kappa}$) for the models were given theoretically as follows; (1) Derived square cloth $${\kappa}=\frac{2}{d_w+d_f}$$ (2) Sinusoidal curved cloth $${\kappa}=\|{^{\;\;\prime\prime} \atop r}(s)\| \\ where \;s=\frac{p^'}{{\pi}}\(u+\frac{k^2u}{4}+\frac{k^2}{8}sin2u\)$$.