• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.505-516
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• 2023

Plastic's ease of processing drives its growing production, resulting in a surge of plastic waste. Addressing this issue, catalytic upcycling emerges as a promising remedy. Various metals (Ru, Pt, etc.) and supports (TiO₂, CeO₂, etc.) have been employed for the chemical recycling of polyolefin plastics. Strategies to enhance liquid fuel selectivity and minimize methane include manipulating particle size, introducing heterogeneous metals, and tuning support characteristics. Simultaneously, endeavors to optimize catalysts by reducing precious metal usage were pursued. This study explores enhancing economic viability in hydrogenolysis and hydrocracking reactions, underscoring the potential of catalystdriven upcycling to tackle plastic waste.

• Journal of Aerospace System Engineering
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• v.17 no.6
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• pp.72-81
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• 2023

Hydrogen-fueled gas turbines are a promising technology that can resolve the carbon dioxide emission issue as future aviation propulsion engines and carbon-free power generations. To achieve high efficiency and stability of gas turbines using 100% hydrogen as fuel, an innovative design of combustor systems is necessary to consider the characteristics of hydrogen, which are different from those of conventional hydrocarbon fuels. Micromix is a combustor design method, which aims to terminate the reaction quickly by intense mixing of fuel and air, consequently reducing NOx and increasing the stability. In this paper, we examine the principles and design process of micromix combustors as a pure-hydrogen combustion technology, and we introduce a design of a 30 kW micromix hydrogen combustor for research.

• Journal of The Korean Association of Information Education
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• v.25 no.4
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• pp.653-664
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• 2021

This study proposes a STEAM (Science, Technology, Engineering, Arts, and Mathematics) program for career exploration of middle school students. The proposed program utilizes VR (Virtual Reality) for new digital technology and webtoon as a popular cultural element. It enables the students to investigate promising fields and experience them virtually for themselves. We design the program based on the 2015 revised curriculum, which enhances the learning effects with existing subjects. In particular, the program provides a hybrid education to combine contact and untact classes considering the COVID-19 situation. The educational goal of the proposed program is to improve creativity and convergence capability. Specifically, it aims to prepare an educational foundation that integrates new digital technologies into education and applies the programs to school education fields. To prove the effectiveness of the developed program, we applied the program to the second graders of A middle school located in Seoul. We expect that the proposed program helps students learn how to utilize new digital technologies and explore future career paths.

• Journal of The Korean Association For Science Education
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• v.23 no.5
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• pp.443-457
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• 2003

The research aimed to compare science curriculum between Korea and Israel and find out characteristics of science curriculum in Israel at middle school level. The middle school 'science' of the 7th revised national curriculum in Korea and middle school 'science and technology' in Israel were compared. Among characteristics of the Israel curriculum of 'science and technology,' distinct ones are as follows: First, 'science and technology' was most highly emphasized with the largest number of time allotment among all subjects at middle school level in Israel. Second, the contents of 'science and technology' were classified into seven areas of 'energy and interaction', 'materials', 'organism', 'earth and the universe', 'technological systems and products' . 'information and communication',and 'ecosystems' rather than four areas of energy, materials, life and earth in Korea. Third, 'organism' was allocated with the highest number of hours among seven areas. Fourth, objectives of each content of 'science and technology' were divided into three categories: scientific aspect, technological aspect, and social value and objectives of each category were related to one another. This characteristic seems to stress STS, multidisciplinary, and interdisciplinary approaches in 'science and technology' in Israel. Such characteristics of the 'science and technology' education in Israel are likely to make significant contributions to establish human resources of highly developing science and technology including IT, BT, NT, ST in the future society. Reflecting upon the characteristics of 'science and technology' education in Israel, Korea might seek for ways to improve its national power based on science and technology through strengthening science and emphasizing science and technology contents among school curriculum.

• Journal of Advanced Technology Convergence
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• v.3 no.1
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• pp.51-58
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• 2024

The reality of this study is that, in accordance with the development trend of human body art, art makeup and semi-permanent makeup are emerging as promising industries in the beauty industry among beauticians, and awareness of professional skill improvement is gradually increasing over time. Accordingly, interest in semi-permanent makeup has increased not only among beauticians who specialize in beauty industry or learn semi-permanent makeup, but also at beauty academies where they learn many beauty techniques, and this trending technology has been promoted at international beauty competitions by holding skill competitions for beauty technicians who specialize in semi-permanent techniques. As a venue for exchanging information about education, it is expected that synergistic effects such as dissemination of the education system can be expected. Korea's rapid industrial development has brought about great changes in the supply and demand of professional and detailed skilled manpower and in the formation of manpower in terms of technical level according to industrial development, and the skills and professional skills of beauty beauticians have improved due to the excellence of the professional education qualifications of beauticians and high skill evaluations. This had a significant impact on self-development and led to a re-recognition of the importance of efforts to achieve skilled skills.

• Convergence Security Journal
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• v.24 no.1
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• pp.83-93
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• 2024

As the paradigm of the global defense industry changes due to the Russia-Ukraine war, Korea's cutting-edge conventional weapons systems are attracting attention from around the world. In 2023, Korea ranked 9th in world arms exports, and is pursuing innovation in the defense industry with the goal of becoming the world's 4th largest defense exporter by 2027. The defense industry is a national strategic industry that requires a long period of time and a large budget, and defense technology is a core technology that has a great impact on the advancement of defense and the national economy. Over the past five years, Korea has suffered economic losses worth approximately 25 trillion won due to the outflow of cutting-edge technology overseas, and there is an urgent need for institutional improvement to prevent the outflow of defense technology. Therefore, this study presented Korea's defense industry development strategy by examining the laws and systems that the three key players in the Indo-Pacific region, the United States, China, and Japan, are promoting to protect defense industry technology. To foster the defense industry as a promising future industry in Korea, it is necessary to respond to the fast-evolving pace of development of advanced science and technology in connection with securing technological sovereignty and protect defense technology, which is a key technology of the country, by improving related laws and systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.192-201
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• 2018

This study intends to find efficient support methods for small and medium-sized businesses (SMBs) especially in the increasingly important mobile sector. We investigated regarding perceptions of mobile sector-specific support programs and their current state of usage, and perceptions of the new mobile market and the present conditions of each stage of production based on analysis of a survey that included 204 respondents in each SMB to achieve this goal. Concretely, detections through this research were the reasons for non-selection of support businesses, the future prospective mobile business area, the company's own first-preference item and the reason for the preference, plus new mobile areas of willingness to apply the company's own product and its own first-preference item, and the reason for the preference. In addition, we found out covering costs and revenue size of the maximum-revenue product for each stage (from the first to the fourth stage), the kind of a product's execution method connected to the product (e.g. self-production, outsourcing to another company to produce a product), and the execution method for pre-products. We can suggest a policy regarding efficient support alternatives for SMBs related to the mobile sector thanks to these findings.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.1
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• pp.113-119
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• 2013

Despite rapid changes in the structure of industry, manufacturing remains a key industry for economic progress, promotion of trade, increased employment, and the creation of new industries. Production technologies are essential for strengthening the competitiveness of small- and medium-sized manufacturing industries. However, it is very difficult to standardize and systematically propagate production technology from an experienced worker to an inexperienced worker because these technologies are generally improved by the skilled people in a workshop. In this study, we introduce a Web-based platform system consisting of a knowledge authoring tool, technology database, semantic database, and Web portal service for sharing production technologies for the exterior housing parts of mobile products. By investigating various cellular phone designs, reference form factors for three types of mobile phone housings were designed based on the standard features. In addition, several manufacturing technologies and considerable information such as reference mold designs and molding conditions optimized using CAE and recent R&D outputs are stored in this system.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.278-279
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• 2012

최근 들어 세계적인 고유가 행진과 화석연료 고갈에 대응하기 위하여 대체 에너지원 발굴에 대한 필요성이 높아지고 있다. 그 중 CIGS 박막 태양전지는 미래 신재생 에너지 자원의 가장 유망한 후보군 중 하나이다. 기존의 Si 기반의 태양전지의 경우 시간경과에 따른 효율 저하, 높은 재료비, 복잡한 공정으로 인하여 대량생산이 힘든 단점을 가지고 있다. 반면 박막 태양전지의 경우 생산 원가를 낮출 수 있는 태양전지 제조기술로서는 2세대 태양전지로 불리우며, 에너지 변환 효율과 생산 원가에서 우월성을 가진다. 그리고 이러한 CIGS 박막 태양전지를 단일 CIGS 타겟을 이용하여 스퍼터링 공정으로 제작하면 기존에 사용되었던 동시 증발법에 비해서 간단하고 대면적 코팅 및 대량 생산이 가능하다. 본 연구에서 사용된 기판으로는 $25{\times}25mm$ 크기의 Soda Lime Glass (SLG) 위에 DC 마그네트론 스퍼터링 공정으로 Mo가 $1{\mu}m$ 증착된 시편을 이용하여, 2 inch 단일 CIGS 타겟 (MATERION, CIGS Target 25-17.5-7.5-50 at%)을 기판 가열하여 증착하였다. RF 파워는 80 W, 기판 온도는 RT, 100, 200, 300, $400^{\circ}C$로 가열 후 증착하였고, CIGS 박막의 두께는 약 $1{\mu}m$로 일정하게 하였다. CIGS/Mo 박막의 파워별 미세구조 분석을 위해 X-ray Diffraction (XRD, BRUKER GADDS)로 측정하였으며, 박막의 결정립 크기를 확인하기 위해 Field Emission Scanning Electron Microscopy (FE-SEM, HITACHI)을 사용하여 측정하였다. 조건별 박막의 조성 분석 및 표면조도는 Energy Dispersive X-ray Spectroscopy (EDS, HORIBA 7395-H)와 Atomic Force Microscopy (AFM)을 이용하여 각각 평가하였다. 마지막으로 광학적 특성을 평가하고 박막의 밴드갭 에너지를 계산하기 위해서 190 nm에서 1,100 nm의 영역 대에서 자외선 광학 측정기(UV-Vis, HP-8453, AGLIENT)로 투과도를 측정하여 밴드갭 에너지를 계산하였다. 증착된 CIGS 박막은 기판 온도가 증가함에 따라 결정립 크기가 커지는 경향을 보였다. 이는 기판 상에 도달한 스퍼터 원자의 확산 에너지 증가로 인한 것으로 생각되어진다. 또한, 기판온도에 따른 결정립 성장 변화는 4성분계의 박막의 조성 및 핵생성 밀도와 관련되어 설명되어질 것이다.

• Korean Journal of Ecology and Environment
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• v.51 no.1
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• pp.105-123
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• 2018

Currently, satellite images act as essential and important data in water resources, environment, and ecology as well as information of geographic information system. In this paper, we will investigate basic characteristics of satellite images, especially application examples in water resources. In recent years, researches on spatial and temporal characteristics of large-scale regions utilizing the advantages of satellite imagery have been actively conducted for fundamental hydrological components such as evapotranspiration, soil moisture and natural disasters such as drought, flood, and heavy snow. Furthermore, it is possible to analyze temporal and spatial characteristics such as vegetation characteristics, plant production, net primary production, turbidity of water bodies, chlorophyll concentration, and water quality by using various image information utilizing various sensor information of satellites. Korea is planning to launch a satellite for water resources and environment in the near future, so various researches are expected to be activated on this field.