• 제목/요약/키워드: modelling studies

검색결과 464건 처리시간 0.026초

1D AND 3D ANALYSES OF THE ZY2 SCIP BWR RAMP TESTS WITH THE FUEL CODES METEOR AND ALCYONE

  • Sercombe, J.;Agard, M.;Struzik, C.;Michel, B.;Thouvenin, G.;Poussard, C.;Kallstrom, K.R.
    • Nuclear Engineering and Technology
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    • 제41권2호
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    • pp.187-198
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    • 2009
  • In this paper, three power ramp tests performed on high burn-up Re-crystallized Zircaloy2 - UO2 BWR fuel rods (56 to 63 MWd/kgU) within the SCIP project are simulated with METEOR and ALCYONE 3D. Two of the ramp tests are of staircase type up to Linear Heat Rates of 420 and 520 W/cm and with long holding periods. Failure of the 420 W/cm fuel rod was observed after 40 minutes. The third ramp test consisted of a more standard ramp test with a constant power rate of 80 W/cm/min up to 410 W/cm with a short holding time. The tests were first simulated with the METEOR 1D fuel rod code, which gave accurate results in terms of profilometry and fission gas releases. The behaviour of a fuel pellet fragment and of the cladding piece on top of it was then investigated with ALCYONE 3D. The size and the main characteristics of the ridges after base irradiation and power ramp testing were recovered. Finally, the failure criteria validated for PWR conditions and fuel rods with low-to-medium burn-ups were used to analyze the failure probability of the KKL rodlets during ramp testing.

Finite element micro-modelling of RC frames with variant configurations of infill masonry

  • Mohammad, Aslam F.;Khalid, Fatima;Khan, Rashid A.
    • Structural Engineering and Mechanics
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    • 제81권4호
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    • pp.395-409
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    • 2022
  • The presence of infill generally neglected in design despite the fact that infill contribution significantly increase the lateral stiffness and strength of the reinforced concrete frame structure. Several experimental studies and computational models have been proposed to capture the rational response of infill-frame interaction at global level. However, limited studies are available on explicit finite element modelling to study the local behavior due to high computation and convergence issues in numerical modelling. In the current study, the computational modelling of RC frames is done with various configurations of infill masonry in terms of types of blocks, lateral loading and reinforcement detailing employed with material nonlinearities, interface contact issues and bond-slip phenomenon particularly near the beam-column joints. To this end, extensive computational modelling of five variant characteristics test specimens extracted from the detailed experimental program available in literature and process through nonlinear static analysis in FEM code, ATENA generally used to capture the nonlinear response of reinforced concrete structures. Results are presented in terms of damage patterns and capacity curves by employing the finest possible detail provided in the experimental program. Comparative analysis shows that good correlation amongst the experimental and numerical simulated results both in terms of capacity and crack patterns.

Modelling of concrete structures subjected to shock and blast loading: An overview and some recent studies

  • Lu, Yong
    • Structural Engineering and Mechanics
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    • 제32권2호
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    • pp.235-249
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    • 2009
  • The response of concrete structures subjected to shock and blast load involves a rapid transient phase, during which material breach may take place. Such an effect could play a crucial role in determining the residual state of the structure and the possible dispersion of the fragments. Modelling of the transient phase response poses various challenges due to the complexities arising from the dynamic behaviour of the materials and the numerical difficulties associated with the evolving material discontinuity and large deformations. Typical modelling approaches include the traditional finite element method in conjunction with an element removal scheme, various meshfree methods such as the SPH, and the mesoscale model. This paper is intended to provide an overview of several alternative approaches and discuss their respective applicability. Representative concrete material models for high pressure and high rate applications are also commented. Several recent application studies are introduced to illustrate the pros and cons of different modelling options.

Finite element modelling of GFRP reinforced concrete beams

  • Stoner, Joseph G.;Polak, Maria Anna
    • Computers and Concrete
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    • 제25권4호
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    • pp.369-382
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    • 2020
  • This paper presents a discussion of the Finite Element Analysis (FEA) when applied for the analysis of concrete elements reinforced with glass fibre reinforced polymer (GFRP) bars. The purpose of such nonlinear FEA model development is to create a tool that can be used for numerical parametric studies which can be used to extend the existing (and limited) experiment database. The presented research focuses on the numerical analyses of concrete beams reinforced with GFRP longitudinal and shear reinforcements. FEA of concrete members reinforced with linear elastic brittle reinforcements (like GFRP) presents unique challenges when compared to the analysis of members reinforced with plastic (steel) reinforcements, which are discussed in the paper. Specifically, the behaviour and failure of GFRP reinforced members are strongly influenced by the compressive response of concrete and thus modelling of concrete behaviour is essential for proper analysis. FEA was performed using the commercial software ABAQUS. A damaged-plasticity model was utilized to simulate the concrete behaviour. The influence of tension, compression, dilatancy, mesh, and reinforcement modelling was studied to replicate experimental test data of beams previously tested at the University of Waterloo, Canada. Recommendations for the finite element modelling of beams reinforced with GFRP longitudinal and shear reinforcements are offered. The knowledge gained from this research allows for the development of a rational methodology for modelling GFRP reinforced concrete beams, which subsequently can be used for extensive parametric studies and the formation of informed recommendations to design standards.

AI-Enabled Business Models and Innovations: A Systematic Literature Review

  • Taoer Yang;Aqsa;Rafaqat Kazmi;Karthik Rajashekaran
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제18권6호
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    • pp.1518-1539
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    • 2024
  • Artificial intelligence-enabled business models aim to improve decision-making, operational efficiency, innovation, and productivity. The presented systematic literature review is conducted to highlight elucidating the utilization of artificial intelligence (AI) methods and techniques within AI-enabled businesses, the significance and functions of AI-enabled organizational models and frameworks, and the design parameters employed in academic research studies within the AI-enabled business domain. We reviewed 39 empirical studies that were published between 2010 and 2023. The studies that were chosen are classified based on the artificial intelligence business technique, empirical research design, and SLR search protocol criteria. According to the findings, machine learning and artificial intelligence were reported as popular methods used for business process modelling in 19% of the studies. Healthcare was the most experimented business domain used for empirical evaluation in 28% of the primary research. The most common reason for using artificial intelligence in businesses was to improve business intelligence. 51% of main studies claimed to have been carried out as experiments. 53% of the research followed experimental guidelines and were repeatable. For the design of business process modelling, eighteen AI mythology were discovered, as well as seven types of AI modelling goals and principles for organisations. For AI-enabled business models, safety, security, and privacy are key concerns in society. The growth of AI is influencing novel forms of business.

Trends in research and development of Evacuation modelling at Korea and Overseas (국내외 Evacuation modelling 연구 및 개발의 연구 동향)

  • Gu, Ji Won;Oh, Ryun Seok;Choi, Jun Ho
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 한국건축시공학회 2022년도 봄 학술논문 발표대회
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    • pp.233-234
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    • 2022
  • In order to minimize casualties in case of a fire in a building, it is necessary to anticipate the time required for evacuation of occupants and the delay in evacuation in advance, and prepare countermeasures for possible occurrences. In fact, various factors that cannot be predicted exist and cannot be considered by excluding them, so the risk is predicted and evaluated through quantitative evacuation modeling. In order to understand this, we analyzed domestic and international evacuation modeling research trends. For about 40 years, starting with the characteristics of human movement, an evacuation modeling technique based on scientific methods has been developed through actual fire accident cases and various real-world experiments with humans. Then, in order to analyze the natural reaction of humans, which has a decisive influence in the recognition and decision-making phase, evacuation modelling studies have been conducted in depth using psychological and physical experimental methods.

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Semi-Rigid connections in steel structures: State-of-the-Art report on modelling, analysis and design

  • Celik, Huseyin Kursat;Sakar, Gokhan
    • Steel and Composite Structures
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    • 제45권1호
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    • pp.1-21
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    • 2022
  • In the structural analysis of steel frames, joints are generally considered as rigid or hinged considering their moment transfer ability. However, the first studies conducted with the beginning of the 20th century showed that the joints do not actually fit these two definitions. In reality, a joint behaves between these two extreme points and is called semi-rigid. Including the actual state of the joint in the structural analysis provides significant economic advantages, so the subject is an intense field of study today. However, it does not find enough application area in practice. For this reason, a large-scale literature published from the first studies on the subject to the present has been examined within the scope of the study. Three important points have been identified in order to examine a joint realistically; modelling the load-displacement relationship, performing the structural analysis and how to design. Joint modelling methods were grouped under 7 main headings as analytical, empirical, mechanical, numerical, informational, hybrid and experimental. In addition to the moment-rotation, other important external load effects like axial force, shear and torsion were considered. Various evaluations were made to expand the practical application area of semi-rigid connections by examining analysis methods and design approaches. Dynamic behaviour was also included in the study, and besides column-beam connections, other important connection types such as beam-beam, column-beam-cross, base connection were also examined in this paper.

Feasibility Analysis on the Attack Graph Applicability in Selected Domains

  • Junho Jang;Saehee Jun;Huiju Lee;Jaegwan Yu;SungJin Park;Su-Youn Hong;Huy Kang Kim
    • Journal of the Korea Society of Computer and Information
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    • 제28권5호
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    • pp.57-66
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    • 2023
  • In this paper, a research trend of attack graph studies for Cyber-Physical System (CPS) environments is surveyed, and we analyse the limitations of previous works and prospect the future directions. 35 among around 150 attack graph studies conducted within 5 years target CPS, and we inspect key features of CPS environment in the security aspect. Also, we categorize and analyze target studies in the aspect of modelling physical systems and considering air gaps, which are derived as key features of the security aspects of CPS. Half of 20 research that we surveyed do not reflect those two features, and other studies only consider one of the two features. In this circumstance, we examine challenges that attack graph studies on CPS environment face. Finally, we expect state-led studies or studies targeting open-spec commercial CPS will dominate.

Homology Modelling of Chemerin like Receptor-1 (CMKLR1): Potential Target for Treating Type II Diabetes

  • B, Sathya.
    • Journal of Integrative Natural Science
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    • 제10권1호
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    • pp.20-26
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    • 2017
  • Chemerin receptor, which predominantly expressed in immune cells as well as adipose tissue, was found to stimulate chemotaxis of dendritic cells and macrophages to the site of inflammation. Chemerin is a widely distributed multifunctional secreted protein implicated in immune cell migration, adipogenesis, osteoblastogenesis, angiogenesis, myogenesis, and glucose homeostasis. Recent studies suggest chemerin may play an important role in the pathogenesis of obesity and insulin resistance and it becomes a potential therapeutic target for treating type II diabetes. The crystal structure of chemerin receptor has not yet been resolved. Therefore, in the present study, homology modelling of CMKLR1 was done utilizing the crystal structure of human angiotension receptor in complex with inverse agonist olmesartan as the template. Since the template has low sequence identity, we have incorporated both threading and comparative modelling approach to generate the three dimensional structure. 3D models were generated and validated. The reported models can be used to characterize the critical amino acid residues in the binding site of CMKLR1.

A Study on the Information Modeling of Defense R&D Process Using IDEF Methodology (IDEF 방법론을 이용한 국방 연구개발 프로세스의 정보모델링 연구)

  • Kim, Chul-Whan
    • The Journal of Society for e-Business Studies
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    • 제10권1호
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    • pp.41-60
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    • 2005
  • IDEF(Integrated Definition) method, a standard methodology of CALS process modelling, was applied to the weapon system R&D process to provide information modelling by analysing about goal, input, output and constraints in the R&D process. The information to be managed in R&D institutes was identified by using SmartER which is the automation program of IDEF1/1X and obtained information modelling for TO-BE model. The work process of weapon system R&D consists of the concept study phase, the exploration development phase, the system development phase, the prototype manufacturing phase, and the report writing of R&D results phase. The information modelling of weapon system R&D is the R&D work process with information sharing by means of IWSDB Since IDEF is suitable for large scale system development like weapon system R&D, further studies on IDEF would be required to achieve the goal of defense CALS.

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