• Fashion & Textile Research Journal
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• v.21 no.4
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• pp.480-487
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• 2019

This study used 3D technology to develop a multi-functional sports brassiere with increased comfort and fit that can be worn as a base layer during exercise or as underwear. A 75A size industrial lingerie figure was used to develop a standard pattern. 3D tools for scanning and pattern making, such as Vivid 910, Geomagic Design X, 2C-AN and Yuka CAD were used. The sports brassiere was designed as a tank top style with dual structure and linings attached to a pad utilized with a sport brassiere mold cup. 3D outer and lining's pattern was differently developed in consideration of the body's curvature with pad's shape and structure. Shoulder and neck part reduction rates were adjusted to increase the neck areas fit that considered the nude pattern's structure due to uncomfortableness felt by wearers who were uncomfortable with the neck areas fit on existing brand products. The reduction rate was also set differently on each part. For example, the reduction rate on outer side panel was set strongly to increase the breast's volume. Two products, developed by a 3D sports brassiere and previously released product, were worn on 8 subjects in their 20's to evaluate fit, comfort, and purchase preferences. The evaluation proved that newly developed 3D products were superior to comparative products. The results of the clothing pressure measurement indicate that the newly developed sports brassiere's front part had less pressure on upper bust and shoulder areas compared to comparative products as well as showed less pressure on the back side, which shows improved wearing comfort compared to comparative products.

• Journal of Astronomy and Space Sciences
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• v.26 no.4
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• pp.693-702
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• 2009

A computational fluid analysis was performed on an LOx line system of a liquid rocket engine. The model was created with 3D CAD and imbedded to the 3D CFD program. Before the full scale analysis on the system was carried out, each components with simplified models was analyzed to save time and cost. As a result, the inlet pressure of the gas generator should be compensated with a certain device unless the inlet pressure of the line system is sufficiently high. The flow pattern of the exit of the system was dependant upon the location of the orifice as well as the size. As a whole the line system analyzed met the requirements, and will be tested and confirmed after being manufactured.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.4
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• pp.429-436
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• 2018

The RCS value of maritime ship is indicator of ship's stealth performance and it should be particularly measured for navy ship to ensure survivability on the battlefield. In the design phase of the navy ship, a RCS prediction should be performed to reduce RCS value and achieve ROC(Required Operational Capability) of the ship through configuration control. In operational phase, the RCS value of the ship should be measured for verifying the designed value and obtaining tactical data to take action against enemy missile. During the measurement of RCS for the ship, ship motion can be affected by roll and pitch in accordance with sea state, which should be analyzed into threat elevation from view point of enemy missile. In this paper, we propose a method to measure and analyze RCS of ship in 3-dimensions using a ship motion measuring instrument and a fixed RCS measurement system. In order to verify the proposed method, we conducted a marine experiment using a test ship in sea environment and compared the measurement data with RCS prediction value which is carried by prediction SW($CornerStone^{TM}$) using CAD model of the ship.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.4
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• pp.101-108
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• 2016

Endmill fillet cutting at the corner was conducted with the online measurement of cutting forces and tool deflection by a tool dynamometer and an eddy current sensor system. The profile of the machined surface was also compared with the CAD profile with a Coordinate Measuring Machine (CMM) and CALYPSO software. It was found that the end mill cutter with four blades has a better surface profile than that with two blades, and the cutting forces and tool deformation were increased as the cutting speed was increased. When the tool located at the degree $45^{\circ}$ corner was found to conduct the maximum cutting force than started to the point of the workpiece. As it was compared with the CMM and ANOVA analysis result in the case that the cutting force and tool deformation was the maximum, it was found that the result was affected by the spindle speed and the number of blades.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.147-151
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• 2008

Construction project is completed through several stages and problems of each stage affect directly not only now but also next. Defect of 2D drawings influence in construction phase, and it make many loss on project. Nowadays we practically use real Mock-up test in construction sites to solve the problems. But it also has many problems which are waste much money and time. Therefore, this study tries to analyze effect that is occurred by appling BIM Mock-up simulation instead of real Mock-up execution. These analysis is conducted by comparing two construction building site. These have same shape but one is made for BIM Mock-up, and another is real Mock-up. Comparison points of view are cost, time and operator's satisfaction. It is expect that BIM Mock-up is more effective at low cost and on shorter time. But our analysis show that each are conducted different part of function. So new Mock-up type is required. Hybrid Mock-up is combine real mock-up with BIM simulation and it can minimize risk of project.

• Korean Journal of Optics and Photonics
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• v.14 no.3
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• pp.312-320
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• 2003

The basic mechanistic aspects of the interaction and practical considerations related to polymer ablation were briefly reviewed. Photochemical and photothermal effects, which highly depend on laser wavelength have close correlation with each other. In this study, multi-scanning laser ablation processing of polymer with a DPSS (Diode Pumped Solid State) 3rd harmonic Nd:YVO$_4$ laser (355 nm) was developed to fabricate a three-dimensional micro shape. Polymer fabrication using DPSSL has some advantages compared with the conventional polymer ablation process using KrF and ArF laser with 248 nm and 193 nm wavelength. These advantages include pumping efficiency and low maintenance cost. And this method also makes it possible to fabricate 2D patterns or 3D shapes rapidly and cheaply because CAD/CAM software and precision stages are used without complex projection mask techniques. Photomachinability of polymer is highly influenced by laser wavelength and by the polymer's own chemical structure. So the optical characteristics of polymers for a 355 nm laser source is investigated experimentally and theoretically. The photophysical and photochemical parameters such as laser fluence, focusing position, and ambient gas were considered to reduce the plume effect which re-deposits debris on the surface of substrate. These phenomena affect the surface roughness and even induce delamination around the ablation site. Thus, the process parameters were tuned to optimize for gaining precision surface shape and quality. This maskless direct photomachining technology using DPSSL could be expected to manufacture tile prototype of micro devices and molds for the laser-LIGA process.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.2
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• pp.181-189
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• 2021

In order to increase the practical usability of the virtual reality(VR)-based BIM object in the construction site, the difference between the virtual image and the real image should be resolved, and when it is applied to the construction schedule management function, it is necessary to reduce the image gap between the virtual completion and the actual completion. In this study, in order to solve this problem, a prototype of 4D model is developed in which augmented reality (AR) and 3D printing technologies are linked, and the practical usability of a 4D model linked with two technologies is verified. When a schedule simulation is implemented by combining a three-dimensional output and an AR object, it is possible to provide more intuitive information as a tangible image-based schedule information when compared to a simple VR-based 4D model. In this study, a methodology and system development of an AR implementation system in which subsequent activities are simulated in 4D model using markers on 3D printing outputs are attempted.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.4
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• pp.66-74
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• 1996

In this paper, a 3-dimensional ship structural model which includes the longitudinals and stiffeners is constructed. This model can be constructed from the well-defined data structure which represents the ship structural members and their relationship. So the object-oriented concept for the data structure is introduced. The structural analysis model is automatically generated by extracting the necessary information for structural analysis from the ship structural model : Users need to handle the ship structural model only when any design change occurs because the structural analysis model is automatically generated.

• Journal of Technologic Dentistry
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• v.42 no.1
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• pp.35-41
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• 2020

Purpose: The purpose of this study was to evaluate the accuracy of the DLP 3D printer by conducting 3-dimensional assesment of resin provisional restorations. Methods: The first premolar of the maxillary was prepared for the abutment. The abutment was scanned by using a scanner. The provisional restoration was designed by using CAD software. A total of 16 resin provisional restorations were produced using ZD200 and Veltz DLP 3D printer. Scanning was done of resin provisional restorations and 3-dimensional measurement was conducted for accuracy. The mean (SD) of RMS was reported for each group. Independent t-test was used to assess the statistical significance of the results. All analyses were done using SPSS 22.0. Results: The mean ± SD of RMS value for the accuracy of the resin provisional restorations that was fabricated by using ZD200 and Veltz DLP 3D printer were 50.85.±4.64㎛ and 70.33±6.31㎛. Independent t-test showed significant differences between groups(p<0.001). Conclusion: The resin provisional restorations made with DLP 3D printers showed clinically acceptable accuracy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.1
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• pp.1-6
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• 2003

A novel Solid Freeform Fabrication System, which makes prototype by cutting tapes at the boundary of object and accumulating the tapes, has been developed. In order to overcome the staircase shape at the surface of prototype, the laser beam is irradiated tangent to the surface. Five axis cutting system and the tangent cutting trajectory generation algorithm have been developed.