• 제목/요약/키워드: 3D-printing

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분말적층용융 기술을 활용한 산업용 중자 제작 (Production of Casting Cores using Powder Bed Fusion Techniques)

  • 최진용;신승중
    • 한국인터넷방송통신학회논문지
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    • 제19권5호
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    • pp.239-244
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    • 2019
  • 기존의 주조 방식은 긴 제작 시간과 많은 비용이 소모되며, 즉각적인 디자인 수정이 불가능하여 다변화하는 현대사회에 대응하기 어려웠다. 때문에 주조 산업은 새로운 대안이 필요했으며 그 중 하나가 적층 제조 기술과의 접목이다. 적층제조기술에는 7가지가 있으나 본 논문에서는 PBF를 활용한 중자 제작을 살펴보려고 한다. 현재의 적층 제조 기술 장비들은 대부분 외산 장비들로 기능 활용과 서비스의 제약이 따르고 있어서 장비의 국산화가 필요하였고 장비의 개발과 함께 기술 활용의 내용을 담았다. 각 장에서는 PBF의 장비 개발 단계 및 소재 적용과 변수 설정에 대해서 서술하고 있으며, 최종적으로 기술을 활용한 산업용 중자 개발의 성공과 특성에 대한 정보를 보여주고 있다.

접착제 분사 기술을 활용한 산업용 중자 제작 (Production of Casting Cores using Powder Binder Jetting Techniques)

  • 최진용;신승중
    • 한국인터넷방송통신학회논문지
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    • 제19권5호
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    • pp.245-250
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    • 2019
  • 현대 주조산업에서는 적층제조기술과 같은 신기술을 도입하면서 과거에는 불가능했던 일들의 실현가능성을 보여주고 있다. 이미 해외에서는 적층제조기술을 활용한 중자 생산 및 적용 사례가 심심치 않게 보도되고 있으며, 정부지원 하에 고유 기술들을 개발하고 시장을 확장해 나가고 있다. 반면 국내에서는 고유장비 기술은커녕 적층제조기술의 활용조차 전무한 실정이다. 이러한 상황에서 적층제조기술의 도입과 국산화는 반드시 필요하다. 본 논문의 각 장에서는 여러가지 적층제조기술 중 접착제 분사 기술에 관련된 적층제조장비의 개발 과정에서부터 개발 장비를 활용한 산업용 중자 생산의 내용을 다루고 있으며, 실제 주조 산업의 적용 가능성에 대해서 언급하고 있다.

CNN 기반 딥러닝을 이용한 인공지지체의 외형 변형 불량 검출 모델에 관한 연구 (A Study on Shape Warpage Defect Detecion Model of Scaffold Using Deep Learning Based CNN)

  • 이송연;허용정
    • 반도체디스플레이기술학회지
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    • 제20권1호
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    • pp.99-103
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    • 2021
  • Warpage defect detecting of scaffold is very important in biosensor production. Because warpaged scaffold cause problem in cell culture. Currently, there is no detection equipment to warpaged scaffold. In this paper, we produced detection model for shape warpage detection using deep learning based CNN. We confirmed the shape of the scaffold that is widely used in cell culture. We produced scaffold specimens, which are widely used in biosensor fabrications. Then, the scaffold specimens were photographed to collect image data necessary for model manufacturing. We produced the detecting model of scaffold warpage defect using Densenet among CNN models. We evaluated the accuracy of the defect detection model with mAP, which evaluates the detection accuracy of deep learning. As a result of model evaluating, it was confirmed that the defect detection accuracy of the scaffold was more than 95%.

히어 캠 임베디드 플랫폼 설계 (HearCAM Embedded Platform Design)

  • 홍선학;조경순
    • 디지털산업정보학회논문지
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    • 제10권4호
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    • pp.79-87
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    • 2014
  • In this paper, we implemented the HearCAM platform with Raspberry PI B+ model which is an open source platform. Raspberry PI B+ model consists of dual step-down (buck) power supply with polarity protection circuit and hot-swap protection, Broadcom SoC BCM2835 running at 700MHz, 512MB RAM solered on top of the Broadcom chip, and PI camera serial connector. In this paper, we used the Google speech recognition engine for recognizing the voice characteristics, and implemented the pattern matching with OpenCV software, and extended the functionality of speech ability with SVOX TTS(Text-to-speech) as the matching result talking to the microphone of users. And therefore we implemented the functions of the HearCAM for identifying the voice and pattern characteristics of target image scanning with PI camera with gathering the temperature sensor data under IoT environment. we implemented the speech recognition, pattern matching, and temperature sensor data logging with Wi-Fi wireless communication. And then we directly designed and made the shape of HearCAM with 3D printing technology.

Selective Laser Melting을 이용한 코발트-크롬 가철성 국소의치의 수복 증례 (Cr-Co removable partial denture treatment fabricated by selective laser melting: a case report)

  • 임지훈;신수연
    • 구강회복응용과학지
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    • 제37권1호
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    • pp.39-47
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    • 2021
  • 의치의 금속구조물을 selective laser melting을 통하여 제작하는 경우 기존의 제작 방식에 비해 여러 기공 과정이 생략되어 시간이 절약되고 간편해진다. 또한 균질한 밀도의 금속구조물을 얻을 수 있어 우수한 기계적 성질, 특히 피로 파절에 대한 높은 저항성을 기대할 수 있다. 본 증례에서는 부분 무치악 환자에서 기존의 방식으로 최종인상을 채득하여 주모형을 제작하였고 이를 스캔하여 데이터화 하였다. 스캔 데이터 상에서 금속구조물을 디자인한 뒤 selective laser melting 방식으로 가철성 국소의치를 제작하였으며 기능적 및 심미적으로 만족스러운 결과를 보였기에 이를 보고하는 바이다.

제4차 산업혁명과 미래 약사 직능의 변화 (The Fourth Industrial Revolution and Changes of Pharmacists' Roles in the Future)

  • 김유경;윤정현
    • 한국임상약학회지
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    • 제30권4호
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    • pp.217-225
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    • 2020
  • The fourth industrial revolution, with its characteristics of "hyper-connectivity", "hyper-intelligence" and "automation", is a hot topic worldwide. It will fundamentally change industry, economy, and business models through technological innovations, such as big data, cloud computing, Internet of Things (IoT), artificial intelligence (AI), and 3D printing. In particular, the development of highly advanced information technology (IT) and AI is expected to replace human roles, thereby changing employment and occupation prospects in the future. Based on this, some predict that the profession of the pharmacist will soon disappear. To counter this, pharmacists' attention and efforts are required to seek innovative transformations in their functions by responding sensitively and promptly to changes of the fourth industrial revolution. It is also necessary to recognize the new roles of pharmacists and to develop the competencies to perform them. The fourth industrial revolution is an inevitable change of the times. At this time, we should take comprehensive and open perspectives on how the future society will change economically, culturally, and socially, and use it as an opportunity to shape the new future of pharmacists.

적층가공 방식으로 제작한 전치와 구치 임시보철물의 적합도 비교 (Comparative evaluation of the fitness of anterior and posterior interim crowns fabricated by additive manufacturing)

  • 박영대;강월
    • 대한치과기공학회지
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    • 제43권4호
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    • pp.153-159
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    • 2021
  • Purpose: The purpose of this study was to assess the fitness of anterior and posterior interim crowns fabricated by three different additive manufacturing technologies. Methods: The working model was digitized, and single crowns (maxillary right central incisor and maxillary right first molar) were designed using computer-aided design software (DentalCad 2.2; exocad). On each abutment, interim crowns (n=60) were fabricated using three types of additive manufacturing technologies. Then, the abutment appearance and internal scan data of the interim crown was obtained using an intraoral scanner. The fitness of the interim crowns were evaluated by using the superimposition of the three-dimensional scan data (Geomagic Control X; 3D Systems). The one-way analysis of variance and Tukey posterior test were used to compare the results among groups (α=0.05). Results: A significant difference was found in the fitness of the interim crowns according to the type of additive manufacturing technology (p<0.05). The posterior interim crown showed smaller root mean square value than the anterior interim crown. Conclusion: Since the fitness of the posterior interim crown produced by three types of additive manufacturing technology were all within clinically acceptable range (<120 ㎛), it can be sufficiently used for the fabrication of interim crowns.

전기화학-기계적 평탄화에 관한 연구 동향 분석 (Analysis of Research Trends on Electrochemical-Mechanical Planarization)

  • 이현섭;김지훈;박성민;추동엽
    • Tribology and Lubricants
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    • 제37권6호
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    • pp.213-223
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    • 2021
  • Electrochemical mechanical planarization (ECMP) was developed to overcome the shortcomings of conventional chemical mechanical planarization (CMP). Because ECMP technology utilizes electrochemical reactions, it can have a higher efficiency than CMP even under low pressure conditions. Therefore, there is an advantage in that it is possible to reduce dicing and erosions, which are physical defects in semiconductor CMP. This paper summarizes the papers on ECMP published from 2003 to 2021 and analyzes research trends in ECMP technology. First, the material removal mechanisms and the configuration of the ECMP machine are dealt with, and then ECMP research trends are reviewed. For ECMP research trends, electrolyte, processing variables and pads, tribology, modeling, and application studies are investigated. In the past, research on ECMP was focused on basic research for the development of electrolytes, but it has recently developed into research on tribology and process variables and on new processing systems and applications. However, there is still a need to increase the processing efficiency, and to this end, the development of a hybrid ECMP processing method using another energy source is required. In addition, ECMP systems that can respond to the developing metal 3D printing technology must be researched, and ECMP equipment technology using CNC and robot technology must be developed.

Selective Laser Sintering of Co-Cr Alloy Powders and Sintered Products Properties

  • Dong-Wan Lee;Minh-Thuyet Nguyen;Jin-Chun Kim
    • 한국분말재료학회지
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    • 제30권1호
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    • pp.7-12
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    • 2023
  • Metal-additive manufacturing techniques, such as selective laser sintering (SLS), are increasingly utilized for new biomaterials, such as cobalt-chrome (Co-Cr). In this study, Co-Cr gas-atomized powders are used as charge materials for the SLS process. The aim is to understand the consolidation of Co-Cr alloy powder and characterization of samples sintered using SLS under various conditions. The results clearly suggest that besides the matrix phase, the second phase, which is attributed to pores and oxidation particles, is observed in the sintered specimens. The as-built samples exhibit completely different microstructural features compared with the casting or wrought products reported in the literature. The microstructure reveals melt pools, which represent the characteristics of the scanning direction, in particular, or of the SLS conditions, in general. It also exposes extremely fine grain sizes inside the melt pools, resulting in an enhancement in the hardness of the as-built products. Thus, the hardness values of the samples prepared by SLS under all parameter conditions used in this study are evidently higher than those of the casting products.

저비용 수제 연신레오미터 개발 및 성능 평가 (Development and performance evaluation of a low-cost custom-made extensional rheometer)

  • 김시현;박한별;김정현
    • 한국가시화정보학회지
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    • 제21권1호
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    • pp.110-118
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    • 2023
  • Characterizing the extensional rheological properties of non-Newtonian fluids is crucial in many industrial processes, such as inkjet printing, injection molding, and fiber engineering. However, educational institutions and research laboratories with budget constraints have limited access to an expensive commercial extensional rheometer. In this study, we developed a custom-made extensional rheometer using a CO2 laser cutting machine and 3D printer. Furthermore, we utilized a smartphone with a low-cost microscopic lens for achieving a high spatial resolution of images. The aqueous polyethylene-oxide (PEO) solutions and a Boger fluid were prepared to characterize their extensional properties. A transition from a visco-capillary to an elasto-capillary regime was observed clearly through the developed rheometer. The extensional relaxation time and viscosity of the aqueous PEO solutions with a zero-shear viscosity of over 300 mPa·s could be quantified in the elasto-capillary regime. The extensional properties of the solutions with relatively small zero shear viscosity could be calculated using a smartphone's slow-motion feature with increasing temporal resolution of the images.