This research was conducted to reduce the defect rate caused by nozzle clogging of printing heads used in binder jet 3D printers. The binder jet 3D printing technology may adhere to the printing head nozzle by dispersing powder due to mechanical operation such as transferring the printing head and supplying powder, and may cause nozzle clogging by natural curing at the nozzle end depending on the type of binder used. To solve this problem, this study created a cleaning module exclusively for printing heads to check whether the durability of printing heads is improved through analysis of printing results before and after using the cleaning module. To this end, this research used a thermal bubble jet printing head, and the used powder was studied using gypsum powder.

본 논문에서는 웹툰 캐릭터 영상에 대해서 심층학습에 기반한 3D 안면 재구성 기술을 제안한다. 본 연구에서 제안하는 방법은 기본 사항 모듈과 상세 사항 모듈로 구성된다. 입력 받은 웹툰 캐릭터 영상에 대해서 기본 사항 모듈의 요소인 Albedo 모듈을 적용해서 안면에 들어오는 빛의 양을 계산하여 Albedo 맵을 생성한다. 그 리고 기본 사항 모듈의 다른 구성 요소인 FLAME 모듈에서는 입력 영상에 대한 기본적인 3D 안면 형태를 생 성한다. 이와 동시에 상세사항 모듈을 적용해서 실제 사람과 다르게 이목구비가 변형된 웹툰 캐릭터 영상의 표정이나 얼굴 깊이와 같은 특징을 살리는 세부사항을 추출한다. 계산한 세부사항들을 토대로 세부사항 맵을 생성하여 앞서 FLAME 모듈에서 생성된 3D 안면 형태와 결합하여 세부사항 안면 형태를 생성한다. 그 후 Albedo 모듈에서 생성된 Albedo 맵까지 적용하면 최종적으로 웹툰 캐릭터 영상에 대한 3D 안면 재구성이 완 료된다. 본 연구에서는 웹툰 캐릭터뿐만 아니라 안면이 스타일화된 애니메이 션 캐릭터에 대해서도 결과를 생성하고, 이를 기존 연구와 비교하여 그 우수성을 입증한다.

VR 및 AR은 대중들이 접근하기 어려운 기술이 아닌, 개인용 스마트 폰 하나로 체험 및 활용 할 수 있는 시 대가 되었다. 최근 이런 개인용 스마트 폰의 다양한 센서를 활용한 AR 콘텐츠가 개발되고 서비스 되고 있다. AR 콘텐츠의 수요가 커지면서Software교육의 수요도 커지게 되었다. 하지만, 비전공자들도 배우기 쉬운 Python 언어를 중심으로 SW 교육이 활발해졌음에도, 아직까지 AR 콘텐츠 개발에서는 Python을 적극적으로 사용할 수 없다. AR 콘텐츠는 기술 분야 뿐 아니라 인터렉티브 아트 분야에서도 활발하게 사용되고 있다. 최근 인터 렉티브 아티스트들은 Python을 이용하여 인공지능을 활용한 작품을 개발 및 전시하고 있다. Python을 통한 SW 교육은 SW 분야의 취업에만 필요한 것이 아니라 아트 분야에서도 필요한 교육이 되었다. 본 논문에서는 AR 콘텐츠 개발 교육을 위한 Python과 Unity 3D Engine을 이용한 네트워크 기반 AR 프레임 워크를 제안한다. 제 안한 AR 프레임 워크는 Web 기반 브라우저에서 개인용 스마트 폰의 카메라에 접근하여 카메라 정보를 Main Server에 전송하고 Python에서 Mark를 분석한다. Mark 정보에 맞춰 Unity 3D Engine에서 3D 오브젝트를 렌더 링하고, 카메라 정보화 합성 후, MJPEG 스트리밍으로 개인용 스마트 폰 화면에 렌더링 된다. 본 논문에서 제 안한 AR 프레임 워크는 SW 교육 플랫폼과 비대면 교육 플랫폼의 요구사항을 반영하며, 인터렉티브 아티스트 들의 다양한 도전에 필요한 기술적 제한을 낮춰 줄 것으로 기대한다.

Aluminum alloys are widely utilized in diverse industries, such as automobiles, aerospace, and architecture, owing to their high specific strength and resistance to oxidation. However, to meet the increasing demands of the industry, it is necessary to design new aluminum alloys with excellent properties. Thus, a new method is required to efficiently test additively manufactured aluminum alloys with various compositions within a short period during the alloy design process. In this study, a combinatory approach using a direct energy deposition system for metal 3D printing process with a dual feeder was employed. Two types of aluminum alloy powders, namely Al6061 and Al-12Cu, were utilized for the combinatory test conducted through 3D printing. Twelve types of Al-Si-Cu-Mg alloys were manufactured during this combinatory test, and the relationship between their microstructures and properties was investigated.

Metal additive manufacturing (AM) has transformed conventional manufacturing processes by offering unprecedented opportunities for design innovation, reduced lead times, and cost-effective production. Aluminum alloy, a material used in metal 3D printing, is a representative lightweight structural material known for its high specific strength and corrosion resistance. Consequently, there is an increasing demand for 3D printed aluminum alloy components across industries, including aerospace, transportation, and consumer goods. To meet this demand, research on alloys and process conditions that satisfy the specific requirement of each industry is necessary. However, 3D printing processes exhibit different behaviors of alloy elements owing to rapid thermal dynamics, making it challenging to predict the microstructure and properties. In this study, we gathered published data on the relationship between alloy composition, processing conditions, and properties. Furthermore, we conducted a sensitivity analysis on the effects of the process variables on the density and hardness of aluminum alloys used in additive manufacturing.

A person who performs or plans to conduct a physical protection inspection as stipulated by the law, the act on physical protection and radiological emergency, should obtain an inspector’s ID card certified and authorized by Nuclear Safety and Security Commission Order No.137 (referred to as Order 137). In addition, according to Order 137, KINAC has been operating some training courses for those with the inspector’s ID card or intending to acquire it. Also, strenuous efforts have been put to incrementally elevate their inspection related expertise. Since Republic of Korea has to import uranium enriched less than 20% in order to manufacture fuels of nuclear reactors in domestic and abroad, the physical protection for categorization III nuclear material in transit is significantly important along with an increase in transport. The expertise of inspectors should be constantly needed to strengthen as the increase in transport leads to an increase in inspection of nuclear material in transit. We have suggested a special way to improve the inspector’s capacities through Virtual Reality technology (VR). A 3-Dimensional virtual space was designed and developed using a 3-axis simulator and VR equipment for practical training. HP’s Reverb G2 product, which was developed in collaboration with VALVE Corporation and MicroSoft, was used as VR equipment, and the 3-axis motion simulator was developed by M-line STUDIO corp. in Korea for the purpose of realizing virtual reality. The training scenarios of transport inspection consist of three parts: preparation at the shipping point, transport in route including stops and handover at the receiving point. At the departure point, scenario of the transport preparation is composed with the contents of checking the transport-related documents which should be carried by shipper and/or carrier during transport and confirming who the shipper and/or carrier is. Second, scenario is designed for inspector to experience how carrier and/or shipper protect the nuclear material during transport or stops for rests or contingency and how they communicate with each other during transport. Lastly, scenario is developed focusing on key check items during handover of responsibilities to the facility operator at the destination. Those training scenarios can be adopted to strengthen the capabilities of those with inspector’s ID card of physical protection in accordance with Order 137 and to help new inspectors acquire inspectionrelated expertise. In addition, they can be used for domestic education to promote understanding of nuclear security, or may be used for education for people overseas for the purpose of export of nuclear facilities.

3D printing is widely used in product development and prototype manufacturing, and is expected to become universal across various industries with the development of 3D printing-related technologies. However, parts made by Fused Deposition Modeling(FDM) 3D printing using the commonly used stacking manufacturing process, show low tensile strength and hardness. The decreased mechanical properties of these parts limit their use as structural elements. In this study, we aim to investigate the relationship between ultrasonic treatment of PLA parts produced by FDM 3D printing and their mechanical properties. Specifically, we analyze the effects of ultrasonic annealing on the mechanical properties of PLA parts using the tensile test specimen.

Recently, hollow carbon spheres (HCS) have aroused great interests in the field of energy storage and conversion owing to their unique morphology, structure and other charming properties. Nevertheless, unsatisfactory electrical conductivity and relatively poor volumetric energy density caused by inevitable gaps between discrete carbon spheres greatly impede the practical application of HCS. In this work, for the first time we propose a novel dual-template strategy and successfully fabricate interconnected 3D hollow N-doped carbon network (HNCN) by a facile and scalable pyrolysis process. By systematical characterization and analysis, it can be found that HNCN is assembled by HCS and lots of mesoporous carbon. Compared to the counterparts, the obtained HNCN exhibits unique 3D interconnected architecture, larger specific surface area, hierarchical meso/macropore structure, higher structure defects, higher N doping amount and more optimized N configurations (especially for pyridinic-N and graphitic-N). As a result, these advantageous features endow HNCN with remarkably promoted electrochemical performance for supercapacitor and oxygen reduction reaction. Clearly, our proposed dual-template strategy provides a good guidance on overcoming the intrinsic shortcomings of HCS, which undoubtedly broadens their application in energy storage and conversion.

Among the Additive Manufacturing (AM) technologies, the Binder-Jetting printing technology is a method of spraying an adhesive on the surface of powder and laminate layer by layer. Recently, this technique has become a major issue in the production of large casting products such as ship-building, custom vehicles and so on. In this study, we performed research to make actual mold castings and increase mechanical property by using special sand and water-based binders. For use as a mold, it has a strength of more than 3MPa and permeability. Various experiments were carried out to obtain suitable them. The major process parameters were binder jetting volume, binder types, layer thickness and heat treatment condition. As a result of this study, the binder drop quantity was measured to be about 60 pico-liter, layer thickness was 100μm and the heat treatment condition was measured about 1,000℃ and compressive strength were measured to be more than 5MPa. The optimum condition of this experiment was established through actual casting of aluminum. The equipment used in this study was a Freeforms T400 model (SFS Co., Ltd.), and the printing area of 420 * 300 * 250mm and resolution of 600dpi can be realized.

We attempted to provide an overview of the laws and current state of the 3D printing industry in South Korea and around the world, using the annual industry surveys and the Wohler report. Additionally, we reviewed articles relating to the potential exposure to hazards associated with 3D printing using metal materials. In South Korea, there were 406 3D printing-related businesses, employing 2,365 workers, and the market size was estimated at 455.9 billion won in 2021. Globally, the average growth rate of the 3D printing industry market over the past 10 years was 27.4%, and the market size was estimated at $11.8 billion in 2019. The United States had the highest cumulative installation ratio of industrial 3D printers, followed by China, Japan, Germany, and South Korea. A total of 6,168 patents related to 3D printing were registered in the US between 2010 and 2019. Harmful factors during metal 3D printing was mainly evaluated in the powder bed fusion and direct energy deposition printing types, and there is a case of material extrusion type with metal additive filaments. The number, mass, size distribution, and chemical composition of particles were mainly evaluated. Particle concentration increases during the opening of the chamber or post-processing. However, operating the 3D printer in a ventilated chamber can reduce particle concentration to the background level. In order to have a safe and healthy environment for 3D printing, it is necessary to accumulate and apply knowledge through various studies.