• 전자통신동향분석
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• 제36권1호
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• pp.54-63
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• 2021

Since the recent COVID-19 pandemic, countries have been strengthening trade protection for their security, and the importance of securing strategic materials, such as food, is drawing attention. In addition to the cultural aspects, the global preference for food produced in Korea is increasing because of the Korean Wave. Thus, the Korean food industry can be developed into a high-value-added export food industry. Currently, Korea has a low self-sufficiency rate for foodstuffs apart from rice. Korea also suffers from problems arising from population decline, aging, rapid climate change, and various animal and plant diseases. It is necessary to develop technologies that can overcome the production structures highly dependent on the outside world of food and foster them into export-type system industries. The global agricultural industry-related technologies are actively being modified via data accumulation, e.g., environmental data, production information, and distribution and consumption information in climate and production facilities, and by actively expanding the introduction of the latest information and communication technologies such as big data and artificial intelligence. However, long-term research and investment should precede the field of living organisms. Compared to other industries, it is necessary to overcome poor production and labor environment investment efficiency in the food industry with respect to the production cost, equipment postmanagement, development tailored to the eye level of field workers, and service models suitable for production facilities of various sizes. This paper discusses the flow of domestic and international technologies that form the core issues of the site centered on the 4th Industrial Revolution in the field of agriculture, livestock, and fisheries. It also explains the environmental awareness production technologies centered on sustainable intelligence platforms that link climate change responses, optimization of energy costs, and mass production for unmanned production, distribution, and consumption using the unstructured data obtained based on detection and growth measurement data.

• 한국습지학회지
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• 제23권3호
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• pp.234-241
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• 2021

본 논문은 자유수면을 갖는 와류수차의 성능에 풀리의 영향을 이해하는 것이다. 실험은 개수로 유입구 유량 0.0069 ~ 0.0077 m³/s 범위에서 물리적 인자(와류높이, 유속, 유효낙차 등)에 따른 수차의 회전수, 전압 및 전류를 측정해 분석하였다. 실험결과에 따르면 와류수차의 전압, 전류 및 회전수는 블레이드 형태와 상관없이 풀리비가 증가할 경우 감소하였다. 직선형 블레이드와 비틀린 블레이드의 효율은 풀리비 0.45 지점에서 52 %인 반면 소형 비틀린 블레이드의 효율은 풀리비 0.21 지점에서 54 %이다. 와류수차의 최대 발전량은 풀리비 0.5 지점 내에서 발생했다. 와류수차의 효율은 풀리비에 따라 0.2 ~ 58 % 범위에서 관찰되었다.

• Design & Manufacturing
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• 제15권4호
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• pp.24-31
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• 2021

In this study, an artificial neural network model was constructed to convert CAE analysis data into similar experimental data. In the analysis and experiment, the injection molding data for 50 conditions were acquired through the design of experiment and random selection method. The injection molding conditions and the weight, height, and diameter of the product derived from CAE results were used as the input parameters for learning of the convert model. Also the product qualities of experimental results were used as the output parameters for learning of the convert model. The accuracy of the convert model showed RMSE values of 0.06g, 0.03mm, and 0.03mm in weight, height, and diameter, respectively. As the next step, additional randomly selected conditions were created and CAE analysis was performed. Then, the additional CAE analysis data were converted to similar experimental data through the conversion model. An artificial neural network model was constructed to predict the quality of injection molded product by using converted similar experimental data and injection molding experiment data. The injection molding conditions were used as input parameters for learning of the predicted model and weight, height, and diameter of the product were used as output parameters for learning. As a result of evaluating the performance of the prediction model, the predicted weight, height, and diameter showed RMSE values of 0.11g, 0.03mm, and 0.05mm and in terms of quality criteria of the target product, all of them showed accurate results satisfying the criteria range.

• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.899-908
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• 2021

It is expected that the global market for vessel repair and remodeling will grow up to the scale of about 25 billion dollars by 2023. Korea's shipbuilding industry is leading the world with its international competitiveness in design and production technology. The actual status of vessel repair industry, however, is poor as there are only two or three companies for vessel repair that can deal with large vessels in the area of Gyeongnam. The reason is that civil complaints are filed severely about environmental problems and environment-related regulations are so strict that it is fairly hard to get governmental approval for the operation of a vessel repair workplace. Domestic vessel repair companies mainly target small- and medium-sized vessels. There are only few workplaces that can carry out regular examination or repair work on large vessels such as LNG vessels, and due to the high price of vessel repair, most of the domestic repair work on large vessels including LNG vessels tends to be snatched by markets in Southeast Asia or China. Despite the tremendous domestic demand of Korea that has established the world's first shipbuilding industry and world's sixth biggest harbor infrastructure, its vessel repair industry can be said to be in very poor condition. In order to vitalize vessel repair industry, this study is aimed to analyze the environmental influence of vessel repair workplaces in Gyeongnam where vessel repair companies are concentrated and suggest standard processes by analyzing vessel repair processes precisely.

• 센서학회지
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• 제30권6호
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• pp.388-394
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• 2021

The conventional microelectromechanical system (MEMS) process has been used to fabricate sensors with high costs and high-volume productions. Emerging 3D printing can utilize various materials and quickly fabricate a product using low-cost equipment rather than traditional manufacturing processes. 3D printing also can produce the sensor using various materials and design its sensing structure with freely optimized shapes. Hence, 3D printing is expected to be a new technology that can produce sensors on-site and respond to on-demand demand by combining it with open platform technology. Therefore, this paper reviews three standard 3D printing technologies, such as Fused Deposition Modeling (FDM), Direct Ink Writing (DIW), and Digital Light Processing (DLP), which can apply to the sensor fabrication process. The review focuses on strain/load sensors having both sensing material features and structural features as well. NCPC (Nano Carbon Piezoresistive Composite) is also introduced as a promising 3D material due to its favorable sensing characteristics.

• 한국항공우주학회지
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• 제50권10호
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• pp.739-745
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• 2022

전투기의 여러 가지 환경 요구도 중 폭발성 대기는 항공기 체계와 승무원의 안전을 위해 군수품의 점화 여부를 확인하는 시험이다. 시험은 한국생산기술연구원(KITECH)에서 보유하고 있는 폭발성 대기 시험장비를 활용하였고, 보수적으로 시험을 수행하기 위해 일반 연료보다 점화 특성이 민감한 n-hexane을 사용하였다. 미 군용 환경시험 규격서인 MIL-STD-810G w/Change 1, Method 511.6, Procedure I을 바탕으로 적용 범위와 테일러링(Tailoring) 가이드, 세부 시험절차를 확인하고 전투기의 각 계통에 대한 본 시험의 필요성을 고찰한다. 본 연구를 통해 전투기에 장착되는 구성품에 대한 폭발성 대기 시험 결과를 분석하고, 도출한 주안점을 공유하여 올바른 테일러링 방안을 제시한다.

• 한국의류산업학회지
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• 제23권2호
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• pp.261-272
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• 2021

The purpose of the present study was to evaluate the thermal insulation of air-filled winter jackets according to the amount of air-filler using a thermal manikin. The insulation of these jackets' was compared to a down padded jacket with an identical design and size. The amounts of air-filler were 100% (26,219 cm³), 70% (18,645 cm³), 50% (13,110 cm³), and 0% (0 cm³). The results showed that a clothing insulation (Icl) of 0%, 50%, 70%, and 100% air, and 100% down jackets was 0.208, 0.243, 0.207, 0.176, and 0.315 clo, respectively. In addition, the down jacket with waisttaped had a clothing insulation of 0.369 clo. However, the highest value of clothing insulation per clothing weight was the 50% air-filled jacket in all conditions. In terms of regional power consumption of the thermal manikin, the down jacket consumed less power for the shoulder and chest than the air-filled jackets. In conclusion, in order to maximize the thermal insulation of air-filled jackets, an optimal amount of air-filler, that is, an amount which does not compromise (break) the layer of inner air between the surface of manikin and the lining of the jacket, should be explored. Further studies on lining materials, end-closed design, and changes in thermal insulation under the conditions of strong wind or heavy snow are recommended.

• 마이크로전자및패키징학회지
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• 제28권4호
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• pp.73-77
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• 2021

신체 착용 및 부착이 가능한 웨어러블 기기용 유연 전극은 외력에 대한 기계적/전기적 내구성을 확보하고 동시에, 다양한 기능성을 부여하는 방향으로 연구가 활발히 진행되고 있다. 본 연구는 Carbon black를 전도성 필러로 적용하여 Carbon/PDMS 기반 유연 복합체를 제조하고 carbon black의 함량에 따른 복합체의 유연전극, 온도 센서 및 히터용 소재로서의 적용 가능성에 대해 고찰해 보았다. Carbon black의 함량 증가에 따른 비저항 감소를 관찰하였고, 반복인장에 따른 전기저항 변화율 실험을 통해 유연전극으로서의 적용 가능성을 확인하였다. 온도 변화에 따른 carbon/PDMS 복합체의 전기적 특성 평가를 통해 온도센서로서 적용이 가능한 정온도계수 특성을 관찰하였고, carbon black 함량에 따라 정온도계수 특성 조절이 가능함을 확인할 수 있었다. 전압 인가에 따른 Carbon/PDMS 복합체의 발열 특성 관찰을 통해 히터용 소재로서의 적용가능성 역시 확인할 수 있었다.

• 마이크로전자및패키징학회지
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• 제28권4호
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• pp.31-39
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• 2021

본 논문에서는 FEM(유한요소법)을 사용하여 PoP (Package on Package)용 PCB를 unit(유닛)과 substrate(서브스트레이트)로 분리한 warpage 해석과 warpage에 미치는 층별 두께의 영향도 분석과 층별 두께 조건을 다구찌법에 의한 SN비(Signal-to-Noise ratio)로 분석하였다. 해석 결과에 의하면 유닛 PCB는 회로층의 영향이 대단히 높았는데 특히 외층의 영향도가 높았다. 반면에 서브스트레이트 PCB는 회로층의 영향도가 높았으나 유닛 PCB에 비해 상대적으로 낮았으며 오히려 솔더 레지스트의 영향도가 증가하였다. 따라서 유닛 PCB와 서브스트레이트 PCB를 동시에 고려하여 PoP PCB의 층별 구조는 외부와 내부 회로층은 두껍게, 윗면 솔더 레지스트는 얇게 설계하고 바닥면 솔더 레지스트의 두께를 5 ㎛와 25 ㎛ 사이의 두께를 선정하는 바람직하다.

• 해양환경안전학회지
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• 제28권2호
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• pp.354-360
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• 2022

해양플랜트 상구구조물의 중량 절감을 위한 알루미늄 핸드레일 적용을 위하여, 소재의 항복강도 향상 및 관련 국제기준에 부합한 강도평가를 통하여 설계가 이루어지고 있다. 기존에 해양프로젝트에 설치된 알루미늄 핸드레일은 플랫폼에 설치 시 소켓에 볼트 연결되며, 소켓의 설계 정도에 따라서 핸드레일 처짐 량이 크게 좌우된다. 그러나 국제기준에서는 소켓에 대한 중요성 언급이 없으며, 별도의 평가 절차나 기준도 모호하다. 따라서 본 연구를 통해서 핸드레일 소켓 설계 시 고려해야 하는 주요 인자들에 대한 강도 해석을 수행하고, 최적의 치수를 도출하였다. 개발모델의 구조 안전성을 확보하기 위하여, 실험을 통한 검증을 수행하였고, 국제기준에서 요구하는 허용 처짐 이내에서 모두 만족함을 확인하였다. 개발된 국산화 모델은 기존 외국 제조사와 비교하여 가볍고, 생산성이 향상되어 향후 많은 분야에서 사용이 될 것으로 판단된다.