• 한국기계가공학회지
• /
• 제21권4호
• /
• pp.91-99
• /
• 2022

By applying METHOD 514.8 of the US military standard MIL-STD-810H, vibration analysis of the winding core automatic feeding device was performed during vehicle transportation. The contact point between the LM guide and main support frame was weak in the vertical axis, transverse axis, and longitudinal axis during the transportation of the automatic winding core feeder vehicle, and the maximum equivalent stress was 236.31 MPa in the longitudinal axis. When random vibration was applied, the safety margin in the longitudinal direction was 0.26, indicating low safety. The safety margin was changed by increasing the damage factor to 0.1. Finally, the safety margin was improved to 3.48 to secure safety. Resonance occurred with a Q factor of 9.34 in the harmonic response to which the RMS value of the ASD data was input, and the vertical axis safety margin was derived as 0.16. When the damping factor was 0.15, the Q factor was 3.37, and resonance was avoided with a safety margin of 6.62.

• 한국산업융합학회 논문집
• /
• 제26권3호
• /
• pp.421-431
• /
• 2023

Recently, the destructive power of typhoons is continuously increasing due to the influence of global warming. In a situation where the installation of floating wind turbines is increasing around the world, concerns about the huge loss and collapse of floating offshore wind turbines due to strong typhoons are deepening. Regarding to the safe operation of the floating offshore wind turbine, the development of a new type of disconnectable mooring system is required. A new fairlead chain stopper considered in this study is devised to more easily attach or detach the floating offshore wind turbine with mooring lines comparing to other disconnectable mooring apparatuses. In order to investigate the structural safety of the initial design of fairlead chain stopper that can be applied to MW-class floating type offshore wind turbine, scale-down structural models were produced using a 3-D printer and structural tests were performed on the models. For the structural tests of the scale-down models, tensile specimens of acrylonitrile butadiene styrene material that was used in the 3-D printing were prepared, and the material properties were evaluated by performing the tensile tests. The finite element analysis of fairlead chain stopper was performed by applying the material properties obtained from the tensile tests and the same load and boundary conditions as in the scale-down model structural tests. Through the finite element analysis, the structural weak parts on the fairlead chain stopper were reviewed. The structural model tests were performed considering the main load conditions of fairlead chain stopper, and the test results were compared to the finite element analysis. Through the results of this study, it was possible to experimentally verify the structural safety of the initial design of fairlead chain stopper. It is also judged that the study results can be usefully used to improve the structural strength of fairlead chain stopper in a detailed design stage.

• 해양환경안전학회지
• /
• 제29권3호
• /
• pp.255-269
• /
• 2023

Surface water temperature of a bay (from the south to the north) increases in spring and summer, but decreases in autumn and winter. Due to shallow water depth, freshwater outflow, and weak current, the water temperature in the central to northern part of the bay is greatly affected by the land coast and air temperature, with large fluctuations. Water temperature variations are large in the north-east coast of the bay, but small in the south-west coast. The difference between water temperature and air temperature is greater in winter and in the south-central part of the bay than that in the north to the eastern coast of the bay where sea dykes are located. As the bay goes from south to north, the range of water temperature fluctuation and the phase show increases. When fresh water is released from the sea dike, the surrounding water temperature decreases and then rises, or rises and then falls. The first mode of empirical orthogonal function (EOF) represents seasonal variation of water temperature. The second mode represents the variability of water temperature gradient in east-west and north-south directions of the bay. In the first mode, the maximum and the minimum are shown in autumn and summer, respectively, consistent with seasonal distribution of surface water temperature variance. In the second mode, phases of the coast of Seosan~Boryeong and the east coast of Anmyeon Island are opposite to each other, bordering the center of the deep bay. Periodic fluctuation of the first mode time coefficient dominates in the one-day and half-day cycle. Its daily fluctuation pattern is similar to air temperature variation. Sea conditions and topographical characteristics excluding air temperature are factors contributing to the variation of the second mode time coefficient.

• 융합보안논문지
• /
• 제22권1호
• /
• pp.61-69
• /
• 2022

대규모 사이버공격이나 테러가 발생하여 국가가 막대한 피해를 보거나 안보에 치명적인 위협이 되었을 때에서야 비로소 사이버보안 인력 양성에 대한 사회적 관심은 높아진다. 또한, 정부에서는 사이버보안 인력 양성과 확보 정책을 제시하곤 한다. 하지만, 양성된 사이버보안 인력이 관련 기관이나 기업에 취업한 이후에 이들을 체계적으로 관리할 수 있는 시스템은 아직 미약하다. 소프트웨어 인력은 표준화된 자격등급 모델이 있어서 각 등급별로 적합한 직무를 설정하여 관리하고 있다. 사이버보안 인력도 경력, 학력, 교육훈련 실적 등을 고려한 특화된 자격등급 모델이 필요하다. 자격등급을 부여함으로써 각 등급별로 수행할 수 있는 직무를 설정하고 부서의 직책과 직위도 등급을 고려하여 부여해야 한다. 따라서 본 논문에서는 사이버보안 인력의 효율적으로 관리하기 위한 자격등급 모델을 제안한다.

• 융합보안논문지
• /
• 제22권2호
• /
• pp.59-66
• /
• 2022

최근 스마트 홈(smart home) 기술은 홈 오토메이션(home automation)의 편리함으로 큰 호응을 얻으며 발전하고 있다. 특히 스마트 홈은 홈 네트워크(home network)에 여러 IoT(Internet of Things) 및 센서들을 유·무선 네트워크로 연결하여 다양한 서비스를 제공하고 있다. 그리고 스마트 홈 서비스는 월패드(wall pad)를 통해 조명이나 에너지, 환경, 도어 카메라 등을 쉽고 편리하게 제어하고 있다. 그러나 최근 월패드의 해킹사고로 인해 사회적 이슈가 되고 있는 가운데, 개인정보의 유출 및 사생활 침해가 예상된다. 이에 월패드 보안에 대한 실질적인 예방과 대응책 마련이 필요한 실정이다. 따라서 본 연구에서는 월패드와 관련한 취약 원인을 고찰하고 대응 방안을 제안함으로써, 향후 스마트 홈의 대응 기술 개발에 기초 자료로 활용될 수 있을 것으로 기대한다.

• 전자통신동향분석
• /
• 제39권4호
• /
• pp.42-53
• /
• 2024

Mathematical modeling is the process of representing physical phenomena using equations, and it often describes various scientific phenomena through differential equations. Numerical analysis, which is capable of approximating solutions to partial differential equations representing physical phenomena, is widely utilized. However, in high-dimensional or nonlinear systems, computational costs can substantially increase, leading to potential numerical instability or convergence issues. Recently, Physics-Informed Neural Networks (PINNs) have emerged as an alternative approach. A PINN leverages physical laws even with limited data to provide highly reliable predictive performance and can address the convergence issues and high computational costs associated with numerical analysis. This paper analyzes the weak signals, research trends, patent trends, and case studies of PINNs. On the basis of this analysis, it proposes directions for the development of PINN techniques in the agricultural field. In particular, the application of PINNs in agriculture is expected to be more effective than in other industries because of their ability to reflect real-time changes in biological processes. While the technology readiness level of PINNs remains low, the potential for model training with minimal data and real-time prediction capabilities suggests that PINNs could replace traditional numerical analysis models. It is anticipated that the research and industrial applications of PINN will develop at an increasing pace while focusing on addressing the complexity of mathematical models in agriculture, mathematical modeling and the application of various biological processes; securing key patents related to PINNs; and standardizing PINN technology in the field of agriculture.

• 디지털산업정보학회논문지
• /
• 제11권2호
• /
• pp.141-152
• /
• 2015

Our agriculture and rural villages have faced negative conditions in many reasons. To overcome this situation, a new change is needed by the 6th industrialization. Many agriculture and rural villages in Korea are pursuing the 6th industrialization through the convergence of the primary, secondary, and tertiary industries to vitalize agriculture and rural villages. But there are several problems with the 6th industrialization. There is a limit to the capacity building of the members of the rural organization and Korean agricultural base primary, secondary, and tertiary industries are weak all. In addition, it has been insufficient research for value chain management of the region as a whole; there has been no study of information sharing across the region for the 6th industrialization. This study is about value chain management model for successful the 6th industry with Quick Response System and the big data technology. In this study to provide the efficiency of 6th industry value chain management with customer's needs analysis using big data and research for the information share between the industries in the region through the information pipeline theory of the QR System. We hope that our study is helped to proceed successfully on the 6th industrialization in Korea.

• 디지털융복합연구
• /
• 제10권10호
• /
• pp.423-430
• /
• 2012

이 연구는 폐 PE/PET/TPE 상용화에 따른 특성에 초점을 맞추었다. 재활용 PET/HDPE blend의 단점인 내열특성과 충격강도 특성이 개선되었고, 내열특성은 polyester계 폐TPE를 첨가한 것이 HDPE가 첨가된것 보다 $50^{\circ}C$ 이상 높은 $150^{\circ}C$이상을 나타내었다. Elastomer의 적용으로 충격강도가 현저히 증가되어 내열 및 탄성이 요구되는 산업분야에 적용할 수 있는 안전소재로의 적용가능성을 확인할 수 있었다. 또한 상용화제를 이용하여 PET를 블렌드 함으로써 폴리올레핀계 수지의 강도를 향상시켰다. 폐HDPE와 폐PET blend의 기계적 물성이 크게 향상되었으며, morphology 특성에서도 상용화제의 첨가에 따라 분산상의 크기가 감소하고 균일해짐이 관찰되었다.

• 디지털융복합연구
• /
• 제10권9호
• /
• pp.449-456
• /
• 2012

초보자들은 프로그래밍 입문 수업을 통해 프로그래밍 언어의 문법적 지식뿐만 아니라, 알고리즘 구상과 프로그램 작성을 위한 문제해결력을 키우는 과정이 필요하다. 문제를 해결하기 위한 문제해결력을 키우는 과정 없이 프로그래밍언어의 지식과 문법위주의 교육이 주가 되는 현실에서 기초 학력수준이 상대적으로 낮은 전문대학의 컴퓨터전공 학생들이 프로그래밍언어 수업에서 느끼는 어려움은 더 크다고 할 수 있다. 본 연구에서는 교육용 프로그래밍언어인 스크래치를 활용한 학생들이 활용하지 않은 반 학생들에 비해 문제 해결력, 프로그래밍 작성 능력, 수업의 만족도면에서 크게 향상되었음을 비교 분석하였다.

• 디지털융복합연구
• /
• 제10권6호
• /
• pp.61-69
• /
• 2012

오늘날 스마트융합이 급속도로 진척되면서 소프트웨어(software : SW)의 시장이 크게 성장하고 있다. 그러나 세계시장에서 우리나라의 SW가 차지하는 비중은 2.2%에 불과하다. 특히 패키지SW는 글로벌 기업의 그것에 비해 매우 취약한 실정이며, 임베디드SW에 비해서도 그 비중이 낮은 수준에 머물러 있다. 이는 국산 패키지SW의 취약한 경쟁력에 기인하지만, 정부의 정책적 지원도 상대적으로 미약한 실정이다. 이에 본 연구는 국산 패키지SW산업 실태를 자료 및 사례연구를 통해 파악하고 패키지SW 지원정책의 개선 과제를 도출한 다음, 이를 토대로 국산 패키지SW산업의 육성에 관한 정책 대안을 제언하고자 한다.