• Radiation Oncology Journal
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• v.20 no.1
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• pp.41-52
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• 2002

Purpose : 3D conformal radiotherapy, the optimum dose delivered to the tumor and provided the risk of normal tissue unless marginal miss, was restricted by organ motion. For tumors in the thorax and abdomen, the planning target volume (PTV) is decided including the margin for movement of tumor volumes during treatment due to patients breathing. We designed the respiratory gating radiotherapy device (RGRD) for using during CT simulation, dose planning and beam delivery at identical breathing period conditions. Using RGRD, reducing the treatment margin for organ (thorax or abdomen) motion due to breathing and improve dose distribution for 3D conformal radiotherapy. Materials and Methods : The internal organ motion data for lung cancer patients were obtained by examining the diaphragm in the supine position to find the position dependency. We made a respiratory gating radiotherapy device (RGRD) that is composed of a strip band, drug sensor, micro switch, and a connected on-off switch in a LINAC control box. During same breathing period by RGRD, spiral CT scan, virtual simulation, and 3D dose planing for lung cancer patients were peformed, without an extended PTV margin for free breathing, and then the dose was delivered at the same positions. We calculated effective volumes and normal tissue complication probabilities (NTCP) using dose volume histograms for normal lung, and analyzed changes in doses associated with selected NTCP levels and tumor control probabilities (TCP) at these new dose levels. The effects of 3D conformal radiotherapy by RGRD were evaluated with DVH (Dose Volume Histogram), TCP, NTCP and dose statistics. Results : The average movement of a diaphragm was 1.5 cm in the supine position when patients breathed freely. Depending on the location of the tumor, the magnitude of the PTV margin needs to be extended from 1 cm to 3 cm, which can greatly increase normal tissue irradiation, and hence, results in increase of the normal tissue complications probabiliy. Simple and precise RGRD is very easy to setup on patients and is sensitive to length variation (+2 mm), it also delivers on-off information to patients and the LINAC machine. We evaluated the treatment plans of patients who had received conformal partial organ lung irradiation for the treatment of thorax malignancies. Using RGRD, the PTV margin by free breathing can be reduced about 2 cm for moving organs by breathing. TCP values are almost the same values $(4\~5\%\;increased)$ for lung cancer regardless of increasing the PTV margin to 2.0 cm but NTCP values are rapidly increased $(50\~70\%\;increased)$ for upon extending PTV margins by 2.0 cm. Conclusion : Internal organ motion due to breathing can be reduced effectively using our simple RGRD. This method can be used in clinical treatments to reduce organ motion induced margin, thereby reducing normal tissue irradiation. Using treatment planning software, the dose to normal tissues was analyzed by comparing dose statistics with and without RGRD. Potential benefits of radiotherapy derived from reduction or elimination of planning target volume (PTV) margins associated with patient breathing through the evaluation of the lung cancer patients treated with 3D conformal radiotherapy.

• Informatization Policy
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• v.28 no.3
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• pp.3-22
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• 2021

This article reviews previous literature on the metaverse and attempts to provide a refined definition for this phenomenon. Metaverse has recently been in the spotlight among discussions by the industry and the media while a consensus on the exact definition of metaverse is yet to be determined. Since Neal Stephenson first coined the term metaverse in his novel "Snow Crash" in 1992, the Acceleration Studies Foundation (ASF) was the first to analyze the concept of metaverse in 2007. While ASF's effort did not receive much spotlight it may have deserved, metaverse gained much attention in the fall of 2020 when NVIDIA announced its real-time simulation and collaboration platform for 3D production named "Omniverse" as a next-generation alternative for the Internet along with Roblox defining its service as metaverse during its IPO. Since then, metaverse has been commonly recognized as a world where we can cross over reality and virtuality. Based on the two axes and four scenarios proposed by the ASF, we review the literature across four realms as follows - virtual reality, mirror world, augmented reality, and lifelogging. Then, we examine the issues with the existing definition of metaverse and propose an alternative explanation by focusing on human behavior and user experience. Finally, we reassess the concept of metaverse and incorporate human communication, reality-based and virtual-based activities, and eXtended reality as elements to properly define metaverse.

• Textile Coloration and Finishing
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• v.33 no.4
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• pp.210-219
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• 2021

It was intended to conduct basic research to reduce development lead time and cost consumed in DTP process technology development. For the simulation of HTPE fabric, virtual engineering software was used to generate fiber model, yarn model, fabric model, and finite element model of HTPE fiber. The purpose of this study is to analyze the correlation and error rate between the stiffness numerical analysis results according to the direct DTP process parameters using reactive dyes in the generated finite element model and the stiffness measurements of the actual sample ac- cording to ASTM D1388. And, after dyeing the HTPE plain fabric according to the direct DTP process parameters, we want to analyze the dyeability of the HTPE fabric fabrics according to the direct DTP process parameters through the color fastness analysis. When looking at the results of the analysis of the finite element model, a higher value was shown when the distance between the nozzle and the fabric was 3mm than when the distance was 10mm. When the distance between the nozzle and the fabric was 10mm and 7mm, the reactive dye did not penetrate sufficiently, resulting in poor clarity when viewed with the naked eye.

• Journal of KIBIM
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• v.6 no.3
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• pp.49-56
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• 2016

As project opportunities for the Architecture, Engineering and Construction (AEC) industry have grown more complex and larger, the utilization of Building Information Modeling (BIM) technologies for three-dimensional (3D) design and simulation practices has been increasing significantly; the typical applications of the BIM technologies include clash detection and design alternative based on 3D planning, which have been expanded over to the technology of construction management in the AEC industry for virtual design and construction. As for now, commercial BIM software has been operated under a single-user environment, which is why initial costs for its introduction are very high. Cloud computing, one of the most promising next-generation Internet technologies, enables simple Internet devices to use services and resources provided with BIM software. Recently in Korea, studies to link between BIM and cloud computing technologies have been directed toward saving costs to build BIM-related infrastructure, and providing various BIM services for small- and medium-sized enterprises (SMEs). This study addressed development of the usage metering functions of BIM software under cloud computing architecture in order to archive and use BIM data and create an optimal revenue structure so that the BIM services may grow spontaneously, considering a demand for cloud resources. For the reason, we surveyed relevant cases, and then analyzed needs and requirements from AEC industry. Based on the relevant cases, customizing for cloud BIM and design for the development was performed. We also surveyed any related-law to support cloud computing-based BIM service. Finally, we proposed herein how to optimally design and develop the usage metering functions of cloud BIM software.

• Journal of Advanced Navigation Technology
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• v.26 no.3
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• pp.166-171
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• 2022

In this paper, we propose an algorithm to improve DoA(direction of arrival) estimation performance of the subspace-based method by generating high robustness correlation matrix of the signals incident on the uniformly linear array antenna. The existing subspace-based DoA estimation method estimates the DoA by obtaining a correlation matrix and dividing it into a signal subspace and a noise subspace. However, the component of the correlation matrix obtained from the low SNR and small number of snapshots inaccurately estimates the signal subspace due to the noise component of the antenna, thereby degrading the DoA estimation performance. Therefore a robust correlation matrix is generated by arranging virtual signal vectors obtained from the existing correlation matrix in a sliding manner. As a result of simulation using MUSIC and ESPRIT, which are representative subspace-based methods,, the computational complexity increased by less than 2.5% compared to the existing correlation matrix, but both MUSIC and ESPRIT based on RMSE 1° showed superior DoA estimation performance with an SNR of 3dB or more.

• Korean Journal of Human Ecology
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• v.23 no.6
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• pp.1191-1204
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• 2014

Even though a Han-bok, or traditional Korean costume, should be inherited since it is invaluable part of our culture, research on Han-bok is scarce. Since the development of a Jeogori pattern, the upper garment of Korean traditional clothes, is done mostly based on the chest size, the design does not completely consider on wearer's body shape. Moreover, unless made by an expert, trial and error is almost always necessary to improve the fit of the clothes. In this research, a Jeogori pattern was suggested that improves the fit based on the shape of the upper back(straight or bent) of a female in her late 20s who often wears a Han-bok and is comfortable when moving. Using a 3D virtual clothing system, the optimum pattern was selected based on the body shape. The final selection was made, and each subjects tried the garment on to evaluate the comfort when moving, along with its appearance, based on a seven point Likert scale. As a result, for a straight body shape, the optimum ease for the front bust width was 2.5cm, and that for the back bust width was 2.0cm. The optimum center back dart was 1.0cm. The optimum Geodae width was 7.6cm, and the optimum back Geodae point was 2.0cm. For the bent body shape, the optimum ease for the front and back bust was 2.0cm. The optimum Geodae width was 8.4cm, and the optimum back Geodae point was 1.5cm. Furthermore, if the Hwajang slope was set at half of the vertical distance between the laterals of the neck and shoulder, a fitted silhouette appeared, which is preferred nowadays. In the appearance evaluation, the final pattern designed in this research received higher scores than the original design(straight; p<.001, bent; p<.05). The results of the evaluation of the comfort when moving also showed higher scores for the final pattern that was designed.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.1
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• pp.122-129
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• 2015

Excessive overheating to a manual transmission clutch system under operating conditions can be considered the main reason of its performance degradation. The clutch system has to be ensured with its service life by showing that it passes the extreme tests called anti-fade test and hill start test in a certain design step. In general, design feedbacks from these kinds of the experiments are adapted to the system to enhance its performance. However, it usually takes much time and costs a lot due to the repetition of the tests. In this research, a process to calculate temperature of the clutch system was developed to determine whether the design can be passed the anti-fade test and hill start test in the design phase. The process incorporates many CAE techniques such as heat transfer analysis using 1D dynamic simulation method, system dynamics, CFD and parametric optimization. CFD is utilized to analyze 3-dimensional heat transfer of the clutch system and fluid dynamics of air in the clutch housing. The process was applied for the clutch systems in several vehicle models. The results was compared with those of the experiment. The applicability of the developed process was verified by comparing the predicted results with experimental results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.3083-3093
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• 2010

The number of Free-Form construction projects are increased by development of 3D parametric modeling technology. The reason of Free-Form Architecture's appearance is advance of digital technology. BIM simulation decision making support is inefficient because it is used in virtual reality. In this study, we developed "AR naviX" which is the digital contents of construction management based on AR for effective decision making support to Free-Form construction project. It reflects construction site by using site picture and video, or Laser scanning data. User feel high reality and is absorbed in augmented reality. So they can reduce the time of decision.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.5
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• pp.2051-2054
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• 2015

Background: Radiation therapy is a key part of the combined modality treatment for Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL), which can achieve locoregional control of disease. The 3D-conformal radiation oncology can be extended-field (EFRT), involved-field (IFRT) and involved node (INRT). New techniques have resulted in a smaller radiation field and lower dose for critical organs such as lung heart and breast. Materials and Methods: In our research, we made a virtual simulation for one patient who was treated in four different radiotherapeutic techniques: mantle field (MFRT), EFRT, IFRT and INRT. After delineatiion we compared dose-volume histograms for each technique. The fusion of CT for planning radiotherapy with the initial PET/CT was made using Softver Xio 4.6 in the Focal program. The dose for all four techniques was 36Gy. Results: Our results support the use of PET/CT in radiation therapy planning. With IFRT and INRT, the burden on the organs at risk is less than with MFRT and EFRT. On the other hand, the dose distribution in the target volume is much better with the latter. Conclusions: The aim of modern radiotherapy of HL and NHL is to reduce the intensity of treatment and therefore PET/CT should be used to reduce and not increase the amount of tissue receiving radiation.

• Journal of Korea Game Society
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• v.9 no.5
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• pp.95-104
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• 2009

Recently, increasing numbers of games and simulators are being implemented by employing the physically-based modeling techniques for better realism. In this paper, we propose the implementation techniques for overhead crane simulator based on ODE, the well-known open source dynamic engine. By comparing the dynamic behavior of the proposed system with a commercial engine based simulator, the physical plausibility and the effectiveness of the ODE based OHC simulator are verified. We expect the proposed the OHC simulator can be successfully utilized for virtual training in various educational institutes.