• Journal of Fashion Business
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• v.16 no.2
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• pp.151-162
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• 2012

The industry-wide development of digital technologies has also affected the textile and fashion industries immensely. The applications of 3D technology, virtual reality, and/or augmented reality systems have helped to create novel fashion brands based on the marriage of IT and textile/fashion industries. 3D digital virtual clothing systems have been developed to help the textile and fashion industries in terms of the planning, manufacturing, marketing and sales sectors. So far, most of the development effort for the 3d virtual clothing systems has been focused on the woven fabrics. The characteristics of woven fabrics differ from those of knitted fabric. Since the physical structures and mechanical properties of the knitted fabrics are definitely different from those of woven fabrics, the simulation process for the knitted fabrics should follow different approaches. The loops in a knitted fabric deform easily. The deformation results in a readily stretchable fabric appearance. Cloth simulation mostly employs models that approximate the mechanical properties of linear elastic planes. This simulation scheme does not, however, describe well enough the behavior of knitted fabrics, which deviate largely from the linear isotropic material characteristics. This study aims at characterizing the tensile deformation and surface textures of a knitted fabric product. Tensile deformation curves for the wale, course, and bias direction are analyzed. The surface texture of the knitted fabric is analyzed by using a 3-dimensional scanning device.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.6
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• pp.345-351
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• 2019

Recently, ink-jet printing technology has been applied for various industries such as semiconductor, display, ceramic tile decoration. Ink-jet printing has advantages of high resolution patterning, fast printing speed, high ink efficiency and many attempts have been made to apply functional materials with excellent physical and chemical properties for the ink-jet printing process. Due to these advantages, research scope of ink-jet printing is expanding from conventional two-dimensional printing to three-dimensional printing. In order to expand the application of ink-jet printing, it is necessary to optimize the rheological properties of the ink and the interaction with the substrate. In this study, photo curable ceramic complex ink containing nano silica particles were synthesized and its printability was characterized. Contact angle of the photo curable silica ink were modified by control of the ink composition and the surface property of the substrate. Effects of contact angle on printing resolution and three-dimensional printability were investigated in detail.

• Journal of radiological science and technology
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• v.41 no.1
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• pp.61-66
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• 2018

The recent 3D printing technology is used in various medical, manufacturing, and education fields and is more efficient in terms of production process, time, and cost than existing production. Especially in fracture surgery, interest and research have been focused on improving accuracy, shortening of operation time and recovery time, and reducing reoperation. However, because of the financial and technical problems of the 3D printer and the file conversion program, the 3D printing is made directly at the hospital, and it is not generally used for diagnosis of fracture and surgical research. In this study, to solve those problems, clavicle CT imaging was switched into Osirix Open Source DICOM Viewer, Stereolithography file conversion programs and commercial Terarecon 3D DICOM Viewer, file conversion programs, and then clavicle fracture model was directly made through 3D printer of fused filament fabrication wire additive processing method, and then the accuracy of the shape was compared and analyzed. Clavicle fracture models printed in two methods were blind-tested on clinicians of general hospitals' orthopedics and radiologic technicians with over 10 years of experiences, and then their analysis opinions of resolution reviews were analyzed. The result showed no difference. The 3D printing model with open source DICOM STL file conversion program used was applicable to clinical, so it is considered useful in precision diagnosis of fracture and operation plans.

• Composites Research
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• v.34 no.6
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• pp.426-433
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• 2021

The carbon fiber reinforced plastic manufacturing process has a problem in that a dimensional error occurs due to thermal deformation such as residual stress, spring-in, and warpage. The main causes of thermal deformation are various, including the shape of the product, the chemical shrinkage, thermal expansion of the resin, and the mold effect according to the material and surface condition of the mold. In this study, a viscoelastic model was applied to the plate model to predict the thermal deformation. The effects of chemical shrinkage and thermal expansion of the resin, which are the main causes of thermal deformation, were analyzed, and the analysis technique of the 3-D viscoelastic model with and without mold was also studied. Then, the L-shaped mold effect was analyzed using the verified 3D viscoelastic model analysis technique. The results show that different residual deformation occurs depending on the surface condition even when the same mold is used.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.4
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• pp.289-296
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• 2014

The rebar detailing is an important work influencing the final performance and quality of RC structures. But it is one of the most irrational and illogical activity in construction site. Many groups of workers, including main contractors, structural engineers, shop drawers, rebar fabricators, and etc., participate in this activity. A loosely-organized process for this activity is apt to produce a big amount of rebar loss or even degraded structures. A 3-dimensional rebar auto-placing system, called as Rebar Hub, has been designed and implemented in this research. Rebar Hub provides a totally integrated service from 3D structural modeling of buildings to rebar auto-placing considering anchorage, splice, and the length of ordered rebar. In addition, Rebar Hub can recognize the 2D drawing CAD files and then build 3D structural models which are used for the start point of 3D rebar auto-placing. After rebar auto-placing, each members of the 3D structural model have rebar information belonging to them. It means that the rebar information can be used for the afterward works such as quantity-survey, manufacturing and fabrication of rebars. Rebar Hub is showing outstanding performance while applying to practical projects. It has almost five times productivity and reduces the rebar loss up to 3~8% of the initially-surveyed amount of rebar.

• Korean Journal of Optics and Photonics
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• v.33 no.4
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• pp.137-145
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• 2022

A directional coupler device, one of the fundamental components of photonic integrated circuits, distributes optical power by evanescent field coupling between two adjacent optical waveguides. In this paper, the design process for manufacturing a directional coupler device is reviewed, and the accuracy of the design results, as seen from the characteristics of the actual fabricated device, is confirmed. When designing a directional coupler device through a two-dimensional (2D) beam-propagation-method (BPM) simulation, an optical structure is converted to a two-dimensional planar structure through the effective index method. After fabricating the directional coupler device array, the characteristics are measured. To supplement the 2D-BPM results that are different from the experimental results, a 3D-BPM simulation is performed. Although 3D-BPM simulation requires more computational resources, the simulation result is closer to the experimental results. Furthermore, the waveguide core refractive index used in 3D-BPM is adjusted to produce a simulation result consistent with the experimental results. The proposed design procedure enables accurate design of directional coupler devices, predicting the experimental results based on 3D-BPM.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.3
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• pp.96-109
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• 2011

Recently, the geographic information system(GIS) is generally used in various fields with the development of information and communication technology, with expansion of its applications and utilization scope. Especially, utilizing GIS is expected to have positive effects on the geography learning and more helpful for the geographic information observation compared to the picture or 2D based media. The effective visualization of complex geographic data does not only take realization of its visual information but also increases the human ability in analysis and understanding to use the geographic information. In this paper, we examine a method to develop the geography learning contents based on the technology with augmented reality and GIS, and then we have a case study for various kinds of visualization techniques and examples to use in geography learning situation. Moreover, we introduce an example of the manufacturing process from the existing GIS data to augmented reality based geography learning system. From the above, we show that the usefulness of our method is applicable for effective visualization of the three-dimensional geographic information in the geography learning environment.

• Journal of Welding and Joining
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• v.20 no.3
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• pp.122-128
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• 2002

The laser welding in the automotive industries has been used widely for the butt joint of blank sheets rather than the lap joint of automotive body panels. But as a substitute far the spot welding of automotive body panels, the so called three dimensional laser welding will be important far the body panel engineers. Specially the laser welding of body panels with a smooth weld line is applied increasingly, for example, to the side panels. So far, some criteria of the laser weld quality was suggested by in-house regulations or national standards from experiences and/or rule of thumbs. In the manufacturing places, a go or no-go criterion is adopted because of the simplicity or a lack of rational criteria. It is true specially for the selection of the process parameters, which gives the basic causes for the good quality of laser welds. In this study, the effects of joint combination, gap and welding speed on the lap joint $CO_2$ laser welding of two mild steel sheets with different thicknesses are obtained through a $2{\times}3{\times}7$ factorial experiment. The results of the weld quality are statistically analysed using analysis of variance (ANOVA) and compared between two characteristic zones, which are separated by the type of sectional shapes and the level of input energy per volume. The thickness combinations are 0.8mm/1.2mm, 1.2mm/0.8mm of mild steel sheets. The welding speed covers from the deep penetration to the partial penetration. The gap size has three levels of no-gap, 0.16m, and 0.26mm. The bead width, penetration depth and input energy per volume are measured and used as the weld quality criteria.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.3
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• pp.409-422
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• 2021

A doctor's coat worn by Seo Jae-pil (1864-1951)-National Registered Cultural Heritage No. 607-was conserved with wet cleaning to remove thick wrinkles and brown stains that had been present for a long time. This paper also applied microscopic observation and infrared spectrophotometric analysis to obtain scientific investigation data on the cotton fabric of this doctor's coat. Information about Seo Jae-pil's time as a doctor, the process of changing his English name, and C.D.Williams & Co., which produced the medical coat, revealed that this doctor's coat was worn by Seo Jae-pil between 1892 and 1898 or 1926 and 1939. Additionally, this paper proposes a pad for filling relics that can protect the shape of modern and contemporary clothing, such as Seo Jae-pil's doctor's coat, for display at a museum site. Specifically, this research provides detailed information on the manufacturing of filling pads that can prevent damage to modern and contemporary jackets and coats so that they can be used in the cultural heritage field by developing filling materials for three-dimensional costume artifacts.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.88-91
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• 2002

The two dimensional size effect of specimen gauge section (length x width) was investigated on the compressive behavior of a T300/924 [45/-45/0/90]3s, carbon fiber-epoxy laminate. A modified ICSTM compression test fixture was used together with an anti-buckling device to test 3mm thick specimens with a 30$\times$30, 50$\times$50, 70$\times$70, and 90mm$\times$90mm gauge length by width section. In all cases failure was sudden and occurred mainly within the gauge length. Post failure examination suggests that $0^{\circ}$ fiber microbuckling is the critical damage mechanism that causes final failure. This is the matrix dominated failure mode and its triggering depends very much on initial fiber waviness. It is suggested that manufacturing process and quality may play a significant role in determining the compressive strength. When the anti-buckling device was used on specimens, it was showed that the compressive strength with the device was slightly greater than that without the device due to surface friction between the specimen and the device by pretoque in bolts of the device. In the analysis result on influence of the anti-buckling device using the finite element method, it was found that the compressive strength with the anti-buckling device by loaded bolts was about 7% higher than actual compressive strength. Additionally, compressive tests on specimen with an open hole were performed. The local stress concentration arising from the hole dominates the strength of the laminate rather than the stresses in the bulk of the material. It is observed that the remote failure stress decreases with increasing hole size and specimen width but is generally well above the value one might predict from the elastic stress concentration factor. This suggests that the material is not ideally brittle and some stress relief occurs around the hole. X-ray radiography reveals that damage in the form of fiber microbuckling and delamination initiates at the edge of the hole at approximately 80% of the failure load and extends stably under increasing load before becoming unstable at a critical length of 2-3mm (depends on specimen geometry). This damage growth and failure are analysed by a linear cohesive zone model. Using the independently measured laminate parameters of unnotched compressive strength and in-plane fracture toughness the model predicts successfully the notched strength as a function of hole size and width.