• Advances in concrete construction
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• 제10권1호
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• pp.81-92
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• 2020

Flexural and splitting strength behavior of conventional concrete can significantly be improved by incorporating the fibers in it. A significant number of research studies have been conducted on various types of fibers and their influence on the tensile capacity of concrete. However, as an important property, tensile capacity of fiber reinforced concrete (FRC) is not modelled properly. Therefore, this paper intends to formulate a model based on experiments that show the relationship between the fiber properties such as the aspect ratio (length/diameter), fiber content, compressive strength, flexural strength and splitting strength of FRC. For the purpose of modeling, various FRC mixes only with steel fiber are adopted from the existing research papers. Automated neural network search (ANS) is then developed and used to investigate the effect of input parameters such as fiber content, aspect ratio and compressive strength to the output parameters of flexural and splitting strength of FRC. It is found that the ANS model can be used to predict the flexural and splitting strength of FRC in a sensible precision.

• 드라이브 ㆍ 컨트롤
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• 제18권2호
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• pp.1-8
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• 2021

In this work, a circuit with a hydraulic power unit is formulated as a means of predicting the behavior of the prefill valve in the future. The behavior of the prefill valve can be examined by the measurements of the configured power unit, and the performance is determined by using hydraulic pumps, relief valves, and hydraulic hoses that make up the power unit. In particular, pressure/flow pulsation generated by hydraulic pumps can cause instability in the prefill valve and cause noise-induced degradation of the overall performance and reliability of the hydraulic system containing the prefill valve. Therefore, to study the behavior and performance of the prefill valve in a relatively accurate manner, the prediction of the characteristics of the hydraulic power unit driving the prefill valve is very important. In this study, the pulsation characteristics of the hydraulic pump were analyzed to theoretically demonstrate its relationship with different settings of the power unit, such as relief valve pressure settings and the presence/absence of the hose.

• 융합정보논문지
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• 제11권4호
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• pp.83-101
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• 2021

본 연구는 우리나라 중소기업들에게 4차 산업혁명 대응과 스마트 기업으로의 변화를 위해서는 어떠한 기술들을 우선적으로 적용하여야 하는가에 대한 내용을 AHP를 활용하여 규명하는 것이다. 이를 위하여 4차 산업혁명 관련 기술들을 종합하고, 김대훈 외(2019)의 분류기준을 준용하지만 전문가들의 의견을 추가로 수렴하여 관련 기술들을 분류하였다. 인공지능(AI), Big Data, Cloud Computing을 디지털 기반기술로, 모바일, 사물인터넷(IoT), Block Chain을 초연결 기술로, 무인운송(자율주행), 로봇(Robot), 3D 프린팅, 드론을 융합기술로, 스마트 제조 및 물류, 스마트 헬스케어, 스마트 교통, 스마트 금융을 스마트 산업기술로 구분하였다. AHP 분석과 종합가중치를 계산하는 방식으로 기술적용 우선순위를 확인한 결과 제조기업은 모바일, 인공지능(AI), Big Data, 로봇(Robot)의 순위가 높으며, 서비스기업은 Big Data, 로봇(Robot), 인공지능(AI), 스마트 헬스케어의 순위가 높고 전체기업에서는 Big Data, 인공지능(AI), 로봇(Robot), 모바일의 순서이다. 본 연구를 통해 4차 산업혁명 대응과 스마트 기업으로의 변화를 위해서는 어떠한 기술들을 우선적으로 적용하여야 하는가를 명확하게 규명하였다.