• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.4
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• pp.100-106
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• 2022

Topology optimization is applied for the optimal design of various products to ensure weight reduction and productivity improvement. Reducing the weight of the mold while maintaining its rigidity can ensure shortening of the production cycle, stabilization of the mold temperature, and reduction of mold material costs. In this study, a topology optimization technique was applied to the optimal design of the injection mold, and a topology-optimized model of the mold was obtained. First, the injection mold for the square specimens was modeled. Subsequently, a structural analysis was performed by implementing a load condition generated during the injection molding process. Topology optimization was performed based on the structural analysis results, and the models of the initial and topology-optimized designs were manufactured at 1/4 magnification using a 3D printer. Consequently, compared with the existing model, the weight of the topology-optimized model decreased by 9.8%, and the manufacturing time decreased by 7.61%.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.5
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• pp.735-746
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• 2020

Recently, in Korea, various technology developments have been made to utilize 3D space and facility data such as unmanned aerial vehicles (UAV) and laser scanners with the goal of improving productivity at construction sites. However, the lack of related regulations for 3D laser scanner surveying has been a barrier to using the technology across the surveying industry. As a result, owners, contractors, and construction supervisors are reluctant to introduce and apply technology to the site. In this study, the guidelines (drafting and inspection work to be supervised by construction supervisors when constructing earthworks using laser scanners) was developed and presented so that the earth surveying and quantity calculation technology using a laser scanner could be applied and diffused in a construction site. Through the development of this guideline (proposal), it is judged that the supervision and inspection of earthworks quantity using a laser scanner will be activated in the field.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.5
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• pp.937-943
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• 2023

In this study, the mast cover of submarine was reverse engineered and structural analysis was performed. In order to print with the 3D printer, the modeling was reduced to 1/5 size by applying geometric similarity. From the structural analysis results, it was found that the maximum value of equivalent stress generated in the mast cover was 180.9 MPa. This stress value occurs on the inner surface in the major axis. As a result of applying the load condition at a diving depth of 600 m, the mast cover is in a completely elastic state. The 1/5 size model printed on FDM 3D printer with PLA filament was the same as the reverse engineered modeling and it was printed in a perfect shape with no apparent defects. The 1/5 size model printed on PBF 3D printer with SUS316L powder was perfectly manufactured with no apparent defects.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.305-307
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• 2011

최근 3D 입체 영화 및 3D 방송 기술의 개발과 더불어, 사용자의 몰입감을 극대화하기 위하여, 3D 입체영상과 사용자의 인터랙션 효과를 융합하는 3D Interaction 기술이 개발되고 있다. 본 논문에서는 3D 디스플레이에서의 시각안전영역을 고려한 3D 사용자 인터페이스의 구현 방법에 대해서 소개한다. 사용자의 입력에 따라 객체의 변이 정보를 계산하고, 변이 정보가 사람의 시각안정영역 내에서 존재하도록 적응적으로 깊이를 조절하여, 사용자의 시각적 편안함과 3D 객체에 대한 조절 기능을 제공할 수 있다. 무안경 3D 디스플레이 상에서의 구현 결과를 통해 제안하는 기술의 효율성을 보여준다.

• Annual Conference of KIPS
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• 2019.05a
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• pp.226-229
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• 2019

S/W, Coding 3d Print, Aduino, IoT 등은 4차 산업혁명 시대에 주요 산업 분야에서 공통으로 쓰이는 핵심 기술이다. 2018년도부터 코딩 교육 의무화가 되었으며, 4차 산업혁명 시대에 필요한 인재상인 창의 융합형 인재를 육성할 수 있는 교육이 더욱 필요한 때이다. 본 논문에서는 별자리 12궁에 대한 과학적 지식을 탐구하며 Coding, 3D Print, Aduino에 관한 지식을 교육하기 위한 시스템을 만들어 보았다. 메이커 교육을 융합한 창의 융합형 교구인 별 빛 교구와 별자리 무드 등을 제작하였으며, 이 2가지의 교구의 구성 및 교육 내용에 대해 기술하였다.

• Journal of Environmental Science International
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• v.30 no.3
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• pp.235-243
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• 2021

This study was conducted to investigate the growth of Dendranthema zawadskii in damaged soils when they are treated with improvement agents. The treatments consisted of a control (unamended field soil) and the application of a loess ball of 1 cm to the field soil. According to the degree of damage the de-icing agent had caused, the soils were divided into 3 areas (based on the yellowing of Pinus densiflora for. multicaulis in soil surveys): H (high saline), M (medium saline), and L (low saline). A total of six treatments were performed: D. zawadskiia plant without soil amendment (H; high saline soil, M; medium saline soil, L; low saline soil), and a D. zawadskiia plant with loess ball on the soil surface (H.L; high saline soil with loess ball, M.L; medium saline soil with loess ball, L.L; low saline soil with loess ball). The results showed that D. zawadskiia growth went from highest to lowest in the order: M.L > L.L > M > L > H.L > H. Plant growth results showed that soils treated with soil amendments (loess ball) were better for D. zawadskii growth than untreated soils.

• Journal of Sensor Science and Technology
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• v.32 no.2
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• pp.110-117
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• 2023

Reconstructing underwater geometry in real time with forward-looking sonar is critical for applications such as localization, mapping, and path planning. Geometrical data must be repeatedly calculated and overwritten in real time because the reliability of the acoustic data is affected by various factors. Moreover, scattering of signal data during the coordinate conversion process may lead to geometrical errors, which lowers the accuracy of the information obtained by the sensor system. In this study, we propose a three-step data processing method with low computational cost for real-time operation. First, the number of data points to be interpolated is determined with respect to the distance between each point and the size of the data grid in a Cartesian coordinate system. Then, the data are processed with a nonlinear interpolation so that they exhibit linear properties in the coordinate system. Finally, the data are transformed based on variations in the position and orientation of the sonar over time. The results of an evaluation of our proposed approach in a simulation show that the nonlinear interpolation operation constructed a continuous underwater geometry dataset with low geometrical error.

• The Korean Journal of Mycology
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• v.12 no.4
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• pp.164-169
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• 1984

Interspecific heterokaryons were obtained between auxotrophic mutants of Pleurotus ostreatus and Pleurotus florida by polyethylene $glycol-Ca^{++}$ induced fusion of somatic protoplasts. The fusion products produced colonies of dense growing mycelium after 10-14 days culture on hypertonic Mushroom Minimal Medium. When they were transferred to Mushroom Minimal Medium plates, the sectors showed normal vegetative morphology but the colonies of irregular shape varied in growth rate. All of the colonies produced fruit body of normal pilei. Some heterokaryon colonies bearing none or only a small amounts of basidiospores were isolated. Fusion products, generally, gave higher basidiocarp yields than the parents.

• The Research Journal of the Costume Culture
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• v.31 no.1
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• pp.124-140
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• 2023

This study analyzes traditional women's Hu costumes of the Tang dynasty, and deploys a creative fashion design to converge contemporary and traditional styles. In this costume, women wear a robe with striped or plain patterns in the lower part of the pants, and it appears frequently in red and yellow colors. Depending on the sleeve, it is either a round collar or a turn down collar robe. In the Hu hat, the huntuomao and juanyanxumao were leather and mili and weimao were used to prevent the sand from flowing. This study uses the CLO 3D program with the "moment" theme based on the Hu costume for women to deploy 4 pairs of fashion design and to produce works for 2 pairs. The 3D virtual clothing program demonstrates important effects in design deployment and pattern arrangement through its efficiency and convenience of clothing production. The CLO 3D program was closely combined with the 2D design and the 3D affect, and it heightened the efficiency in saving the processing time and energy of the sample clothes. Through facilitating the 3D digital fashion design, the production may reduce time needed and contribute to an effective economy, and it may compare digital fashion design to actual products as well as illustrate the potential of digital fashion design.

• Convergence Security Journal
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• v.23 no.2
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• pp.67-74
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• 2023

An elevator is a mechanical and electronic device composed of about 20,000 various parts, and is systematically operated with a close relationship with each other. By intuitively understanding this complex elevator structure and efficiently recognizing the operating model, it will be possible to increase the understanding of the elevator system and the efficiency of maintenance. The existing elevator management system is a process of collecting and understanding information based on data generated from elevators, and has a structure that lacks efficiency in expressing and managing real-world information during elevator maintenance. Therefore, this paper proposes a simulator framework that can operate efficiently based on the actual elevator model. By constructing the recognition of specific objects through a 3D-based service model and visualizing the operation process, it will be possible to enhance the understanding of the structure and operation required for elevator operation. To this end, the core components of the elevator system are identified, the relationship between them and the operating method are visualized, and a simulator is implemented. Based on this, it will be possible to provide a realistic information management and operating environment in virtual space and real platform.