• Journal of the Korean Society of Industry Convergence
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• v.27 no.4_2
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• pp.973-980
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• 2024

Dependence of dynamic fracture path on loading velocity was observed from experimental results based on the three point bending fracture in cast iron. In this study, 3D and 2D numerical simulations are used to evaluate singular stress fields near crack tip and fracture mechanics parameters. Moving finite element technique, 2D and 3D Delauney automatic mesh generation and contact-noncontact evaluation is introduced into the numerical method. Dynamic fracture thoughness is decreased with increase of impact loading velocity. Fracture mode-ratio corresponds to initial kink angle of fracture path. The numerical result shows that the maximum hoop stress criterion cannot be applied to dynamic fracture of cast iron.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.702-708
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• 2018

3D printing technology is attracting increasing attention as a key technology of the fourth industrial revolution that can change the production paradigm of existing industries. The introduction of construction 3D printing technology has been slower than other industries because of the characteristics of the construction field. On the other hand construction automation using 3D printing is required to reduce the production population, as well as improve productivity and safety. In this study, a construction 3D printing work breakdown structure and link method to a standard estimation system were developed as a preliminary preparation for introducing 3D printing to construction. Based on expert consultation on construction and 3D printing, a hypothetical scenario was developed based on existing construction 3D printing technology. According to the scenario, 16 kinds of works required for 3D printing construction work were derived. The existing work breakdown structure and standard estimation system were analyzed, and the 3D printing work was linked. 3D printing works that were the same as the existing breakdown structure were found, and non-existent works were added to the similar breakdown structure. These results are expected to be helpful for future 3D printing construction management and cost estimation. The actual standard estimation system through 3D printing work will need to be calculated.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.281-283
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• 2022

화물 선박의 전복사고가 매해 발생하고 있음에도 화물을 측정하지 않고 서류에 의존하는 방식으로 화물을 선적하고 있습니다. 우리는 사고의 원인을 사전에 차단할 수 있는 자동 계측 시스템을 연구하였습니다. 본 논문의 시스템은 LiDAR 센서를 이용하여 비규격 화물이 멈추지 않고 자동 계측되어 인력과 시간의 소요를 줄이고 산출된 체적과 3D 모델을 제공합니다. 게다가 화물 차량에 실린 화물을 내리지 않고도 화물의 체적을 산출할 수 있어 항만의 효율성을 향상할 수 있을 것으로 기대합니다.

• The Journal of the Acoustical Society of Korea
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• v.43 no.3
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• pp.285-292
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• 2024

When calculating sonar detection probability, underwater acoustic uncertainty is assumed to be normal distributed with a standard deviation of 8 dB to 9 dB. However, due to the variability in experimental areas and ocean environmental conditions, predicting detection performance requires accounting for underwater acoustic uncertainty based on ocean experimental data. In this study, underwater acoustic uncertainty was determined using measured mid-frequency (2.3 kHz, 3 kHz) noise level and transmission loss data collected in the shallow water of the East Sea. After calculating the predictable probability of detection reflecting underwater acoustic uncertainty based on ocean experimental data, we compared it with the conventional detection probability results, as well as the predictable probability of detection results considering the uncertainty of the Rayleigh distribution and a negatively skewed distribution. As a result, we confirmed that differences in the detection area occur depending on each underwater acoustic uncertainty.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2001.06a
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• pp.193-196
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• 2001

본 논문에서는 3D 패션 코디를 위해 의복의 3D 모델을 개인 캐릭터에 정합하는 방법을 제안한다. 정합 방법은 의복 모델의 변형, 인체와 의복의 역전 부위 검색, 의복 모델의 수정의 3단계로 나누어진다. 먼저, 인체와 의복이 부위별로 대응을 이루도록 각각에 특징점을 설정하고, 의복의 공극을 고려하여 의복 모델의 높이, 넓이, 두께를 부위별로 변형한다. 의복 3D모델의 정합 후에도, 부위에 따라 의복의 표면 위에 인체가 노출되는 역전현상이 일어난다. 이를 위해, z-버퍼를 개량한 거리-버퍼의 개념을 제안하여 역전을 효과적으로 검색한다(Collision Detection ). 검색된 부위에서 삼각형을 분할하여 의복 모델을 수정한다.

• Journal of the Korea Convergence Society
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• v.8 no.1
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• pp.89-96
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• 2017

This study is to analyze seven fluoride varnishes remineralizing effects on early carious lesions in the clinical field. While CS, MI, CW, VV, EP, FP and FN were used for permanent teeth, CS, MI, CW and FP were used for primary teeth. The specimens were demineralized for 4 days after forming a $3{\times}3mm^2$ window with nail varnish, applied with varnishes separately, then were stirred in artificial saliva for 1 week. QLF-D analysis of carious lesion size showed that permanent teeth's ${\Delta}F$ value decreased after applying CS(4,64), MI(4.86), CW(4.50), and EP(5.50), while for primary teeth, FP(3.00) and MI(3.00) displayed a remineralizing effect. Thus, MI can be used effectively for preventing caries for both adults and children in the clinical field.

• Journal of Digital Contents Society
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• v.15 no.1
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• pp.113-120
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• 2014

In recent years, devices using the smart ponwa IT service is activated, to research how the fusion of two or more devices will be able to be interest in the soybeans. One of them in the mobile sector through the development of network and hardware digital geo-spatial map of the rapid advances being made and the computer, how do you map data to efficiently simulate a 3D environment, providing services through a virtual environment focused on whether be. In this study, augmented reality and GIS (Geographic Information System), SLM (Static LOD Model) that combines augmented reality technology on the basis of the basic concepts and approaches in geographic space and how Augmented Reality Based on this interpretation of the relevant content What to do in the development and utilization has a purpose. In this study, the conventional SLM 3DS model data structure of a data format conversion of the proposed possibilities for analyzing and, SLM model generation and format of the existing three-dimensional visualization tools SLM model format for converting a format to a model function, and visualization features. In addition, 3D virtual model to propose a format for efficiently making.

• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.135-136
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• 2017

2016년부터 전면 실시된 자유학기제에서 미래 사회를 선도하는 새로운 기술을 접해보는 것은 미래를 살아가는 학생들에게 매우 중요한 부분이 될 것이다. 최근 4차 산업혁명의 일환으로 각광을 받고 있는 3D 프린팅을 다른 기술과 융합하여 학생 중심의 수업을 위한 프로그램을 개발하였다. 개발한 초안에 대하여 전문가 5인의 내용 검토를 통하여 최종 완성되었다. 발된 융합 커리큘럼은 자유학기제의 교과 및 자유학기 활동에서 활용될 수 있는 체험 활동을 중심으로 한 교육과정으로 개발되었으며 향후 자유학기 뿐 아니라 연계 자유학기, 일반학기 및 동아리 활동, 방과 후 활동 등에도 적용될 수 있을 것으로 기대된다.

• Journal of the Korea Convergence Society
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• v.9 no.12
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• pp.189-194
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• 2018

This study is 24 person emergency brake for the structural analysis are described. Recently emerged as a key point of the elevator safety and increase the need for an emergency brake was developed accordingly to ensure the safety of the brake tool for 3D design using Solid Works. ANSYS utilizes 24 person emergency break finite element model for total deformation, strain and stress were obtained.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1416-1417
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• 2013

깊이 정보를 획득하기 위해서 가장 많이 시도되는 방법이 스테레오 정합이다. 스테레오 정합 알고리즘은 다양한 알고리즘의 조합으로 구성되며, 파라메터 또한 다양하다. 일반적으로는 middlebury에서 제공하는 영상과 ground truth를 이용해서 스테레오 정합 알고리즘을 연구하고, 파라메터 최적화 과정을 거친다. 실제 시스템에 알고리즘 및 파라메터를 적용할 때 middlebury 영상으로 선택된 알고리즘과 파라메터가 상이할 수 있다. 본 논문에서는 실제 시스템의 스테레오 카메라를 이용해서 ground truth를 만들 수 있는 방법을 제안하다. 프로젝트를 이용해서 패턴을 투사하고, 스테레오 카메라로 영상을 획득한다. 한 장면에 대해서 다양한 영상으로 스테레오 정합을 수행하여 만들어진 disparity map은 높은 정확성을 가지고 있음으로, 스테레오 정합 알고리즘 검증용 ground truth로 사용이 가능하다.