• 한국초전도ㆍ저온공학회논문지
• /
• 제26권1호
• /
• pp.25-30
• /
• 2024

High-temperature superconducting rotors offer advantages in terms of output-to-weight ratio and efficiency compared to conventional phase conduction motors or generators. The rotor can be cooled by conduction cooling, which attaches a cryocooler, and by refrigerant circulation, which uses circulating liquid or gas neon, helium and hydrogen. Recent work has focused on environmental issues and on high-temperature superconducting motors cooled with liquid hydrogen that can be combined with fuel cells. However, to ensure smooth supply and return of the cryogenic cooling fluid, a cryogenic rotational coupling between the rotating and stationary parts is necessary. Additionally, the development of a sealing structure to minimize fluid leakage applicable to the coupling is essential. This study describes the design and performance evaluation of a non-contact sealing method, specifically a labyrinth seal, which avoids power loss and heat load caused by friction in contact sealing structures. The seal design incorporates a spiral flow path to reduce leakage using centrifugal force, and computational fluid dynamics (CFD) simulations were conducted to analyze the flow path and rotational speed. A performance evaluation device was configured and employed to evaluate the designed seal. The results of this study will be used to develop a cryogenic rotational coupling with supply and return flow paths for cryogenic applications.

• International Journal of Internet, Broadcasting and Communication
• /
• 제16권1호
• /
• pp.269-279
• /
• 2024

The study explores the evolving landscape of overseas expansion strategies by Korean corporations, focusing on recent geopolitical tensions, the COVID-19 pandemic, and disruptions in global supply chains. It emphasizes the challenges faced by industries producing high-value products and delves into the concept of "Friend-Shoring" policies in the United States, leading major Korean companies to invest in local semiconductor, battery, and automotive factories. Recognizing the potential fragmentation of Korea's manufacturing sector, the paper introduces the "Mother Factory" strategy as a policy initiative, inspired by Japan's model, to establish core production facilities domestically. The discussion unfolds by examining the cases of major companies in Japan and the United States, highlighting the need for Korea to adopt a mother factory strategy to mitigate risks associated with friend-shoring policies. Inspired by Intel's "Copy Exactly" approach, the paper proposes a Korean mother factory model integrating smart factory technology and digital twin systems. This strategic shift aims to enhance responsiveness to geopolitical challenges and fortify the competitiveness of Korean high-tech industries. Finally, the paper proposes a Korean Mother Factory based on smart factory concepts. The suggested model integrates smart factory technology and digital twin frameworks to enhance responsiveness and fortify competitiveness. In conclusion, the paper advocates for the adoption of a comprehensive Korean Mother Factory model to address contemporary challenges, foster advanced manufacturing, and ensure the sustainability and competitiveness of Korean high-tech industries in the global landscape. The proposed strategy aligns with the evolving dynamics of the manufacturing sector and emphasizes technological advancements, collaboration, and strategic realignment.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2012년도 춘계학술대회 논문집
• /
• pp.541-542
• /
• 2012

• 산업경영시스템학회지
• /
• 제41권3호
• /
• pp.176-185
• /
• 2018

With the recent development of manufacturing technology and the diversification of consumer needs, not only the process and quality control of production have become more complicated but also the kinds of information that manufacturing facilities provide the user about process have been diversified. Therefore the importance of big data analysis also has been raised. However, most small and medium enterprises (SMEs) lack the systematic infrastructure of big data management and analysis. In particular, due to the nature of domestic manufacturing companies that rely on foreign manufacturers for most of their manufacturing facilities, the need for their own data analysis and manufacturing support applications is increasing and research has been conducted in Korea. This study proposes integrated analysis platform for process and quality analysis, considering manufacturing big data database (DB) and data characteristics. The platform is implemented in two versions, Web and C/S, to enhance accessibility which perform template based quality analysis and real-time monitoring. The user can upload data from their local PC or DB and run analysis by combining single analysis module in template in a way they want since the platform is not optimized for a particular manufacturing process. Also Java and R are used as the development language for ease of system supplementation. It is expected that the platform will be available at a low price and evolve the ability of quality analysis in SMEs.

• Journal of information and communication convergence engineering
• /
• 제18권1호
• /
• pp.61-68
• /
• 2020

In the era of the fourth industrial revolution, many production plants are gradually evolving into smart factories that apply information and communication technology to manufacturing, distribution, production, and quality management. The conversion from conventional factories to smart factories has resulted in the automation of production sites using the internet and the internet of things (IoT) technology. Thus, labor-intensive production can easily collect necessary information. However, implementing a smart factory required a significant amount of time, effort, and money. In particular, labor-intensive production industries are not automated, and productivity is determined by human skill. A representative industry of such industries is sewing the industry. In the sewing industry, wherein productivity is determined by the operator's skills. This study suggests that production performance, inventory management and product delivery of the sewing industries can be managed efficiently with existing production method by using smart buttons incorporating IoT functions, without using automated machinery.

• 대한환경공학회지
• /
• 제39권9호
• /
• pp.527-533
• /
• 2017

제조공정이 기술 집약적인 반면 제품 수명이 짧아 다량으로 버려지는 스마트폰의 환경영향에 관심이 커지고 있다. 이 연구에서는 전과정평가 기법을 기반으로 스마트폰의 다양한 환경영향을 정량적으로 분석, 평가하였다. ISO 14040 시리즈 표준에 의거한 전과정평가를 수행하였고, 스마트폰의 제조전, 제조, 유통, 사용 및 폐기를 포함하는 전과정 단계를 시스템경계에 포함하였다. 평가한 10개 환경영향범주 모두에서 제조전단계가 가장 큰 환경영향을 나타내었다. 지구온난화 영향은 제조전단계, 유통단계, 사용단계, 제조단계, 폐기단계경우 각각 52.6%, 23.9%, 15.7%, 7.0% 및 0.8% 이었다. 스마트폰 제조전단계의 부품별 환경영향은 PCB, 배터리, 디스플레이 모듈 순이었다. 따라서 스마트폰의 전과정 환경영향 저감을 위해서는 스마트폰 소형/경량화를 통해 자원사용량을 줄이고, 자원순환성을 높일 수 있는 친환경 소재를 적용하여 제조전단계의 환경영향을 줄이려는 노력이 필요하다.

• Journal of the Optical Society of Korea
• /
• 제19권6호
• /
• pp.687-694
• /
• 2015

A photoluminescence (PL) imaging method using a vision camera was employed to inspect InGaN/GaN quantum-well light-emitting diode (LED) epi-wafers. The PL image revealed dark spot defective regions (DSDRs) as well as a spatial map of integrated PL intensity of the epi-wafer. The Shockley-Read-Hall (SRH) nonradiative recombination coefficient increased with the size of the DSDRs. The high nonradiative recombination rates of the DSDRs resulted in degradation of the optical properties of the LED chips fabricated at the defective regions. Abnormal current-voltage characteristics with large forward leakages were also observed for LED chips with DSDRs, which could be due to parallel resistances bypassing the junction and/or tunneling through defects in the active region. It was found that the SRH nonradiative recombination process was dominant in the voltage range where the forward leakage by tunneling was observed. The results indicated that the DSDRs observed by PL imaging of LED epi-wafers were high density SRH nonradiative recombination centers which could affect the optical and electrical properties of the LED chips, and PL imaging can be an inspection method for evaluation of the epi-wafers and estimation of properties of the LED chips before fabrication.

• 융합정보논문지
• /
• 제7권5호
• /
• pp.177-182
• /
• 2017

IoT, 클라우드 컴퓨팅, 빅데이터와 같은 주요 ICT 기술이 제조 분야에 적용되기 시작하면서 스마트 공장 구축이 본격화 되고 있다. 스마트 공장 구현의 핵심은 공장 내외부의 데이터 확보 및 분석력에 있다. 따라서 빅데이터 분석 플랫폼에 대한 필요성이 증가하고 있다. 본 연구의 목적은 제조 공정 빅데이터 분석을 위한 플랫폼을 구성하고, 분석을 위한 통합 메소드를 제안하는데 있다. 제안하는 플랫폼은 대량의 데이터 셋을 분산 처리하기 위해 분석도구 R과 하둡을 통합한 RHadoop 기반 구조로서 자동화 시스템의 단위 공정 및 공장 내에서 수집되는 빅데이터를 하둡 HBase에 직접 저장 및 분석이 가능하다. 또한 기존 RDB 기반 분석의 한계점을 보완하였다. 이러한 플랫폼은 스마트 공장을 위한 단위 공정 적합성을 고려하여 개발되어야 하며, 제조 공정에 스마트 공장을 도입하고자 하는 중소기업에 IoT 플랫폼 구축의 가이드가 될 수 있을 것으로 전망된다.

• 한국산업정보학회논문지
• /
• 제25권2호
• /
• pp.73-85
• /
• 2020

우리나라는 최근까지 양적투입 위주의 제조업 성장 방식을 취해왔을 뿐만 아니라 Fast-follower 전략으로 제조 강국 반열에 올라섰지만 선진국의 제조업 부흥 정책과 신흥국의 산업구조 고도화로 인해 한계에 직면하게 되었다. 최근 4차산업혁명의 도래와 수요의 복잡화로 인해 시장의 변화를 사전에 빠르게 감지해 생산전략에 반영하는 체제가 요구됨에 따라 ICT를 활용하여 제조업의 경쟁력 강화를 위해 스마트 팩토리를 도입은 선택이 아닌 필수가 되어가고 있다. 본 연구는 정보기술혁신 제품인 스마트 팩토리의 지속사용의도에 영향을 미치는 주요 요인들이 무엇인지를 기술수용모형을 토대로 살펴보고자 한다. 이를 위해 본 연구는 스마트 팩토리를 운영 중인 기업들을 대상으로 온라인과 오프라인으로 설문조사를 실시하였으며 122부의 표본으로 분석하였다. 구체적으로 CEO의 리더십, 조직학습, 지각된 전환비용이 기술수용모형의 주요 신념변수인 지각된 사용 용이성과 지각된 유용성을 매개하여 지속사용의도에 미치는 영향을 살펴보았다.

• 한국포장학회지
• /
• 제29권3호
• /
• pp.203-209
• /
• 2023

The increasing saturation challenges in storage facilities for Low- and Intermediate-Level Radioactive Waste call for a more efficient storage approach. Consequently, we have developed a square-structured container that features a storage capacity approximately 20% greater than that of conventional drum-type containers. Considering the need to contain various radioactive wastes from nuclear power usage securely until they no longer pose a threat to human health or the environment, this study focuses on evaluating the sealing efficacy of the newly designed rectangular container using finite element analysis. Since radioactive waste containers typically do not experience external forces except under special circumstances, our analysis simulated the impact of an external force, assuming a fall scenario. After fastening the bolts, we examined the vertical stress distribution on the container by applying the calculated external force. The analysis confirms the container's stable seal.