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\"Numerical simulation models are used in all engineering disciplines for modeling physical phenomena to learn how the phenomena work, and to identify problems and optimize behavior. Smart proxy models provide an opportunity to replicate numerical simulations with very high accuracy and can be run on a laptop within a few minutes, thereby simplifying the use of complex numerical simulations which can otherwise take tens of hours. This book focuses on smart proxy modeling and provides readers with all the essential details on how to develop smart proxy models using artificial intelligence and machine learning, as well as how it may be used in real-world cases. Covers replication of highly accurate numerical simulations using artificial intelligence and machine learning. Details application in reservoir simulation and modeling, and computational fluid dynamics. Includes real case studies based on commercially available simulators. Smart Proxy Modeling is ideal for petroleum, chemical, environmental, and mechanical engineers, as well as statisticians and others working with applications of data-driven analytics\"-- Provided by publisher.

Evidence regarding whether imaging can be used effectively to select patients for endovascular thrombectomy (EVT) is scarce. We aimed to investigate the association between baseline imaging features and safety and efficacy of EVT in acute ischaemic stroke caused by anterior large-vessel occlusion. In this meta-analysis of individual patient-level data, the HERMES collaboration identified in PubMed seven randomised trials in endovascular stroke that compared EVT with standard medical therapy, published between Jan 1, 2010, and Oct 31, 2017. Only trials that required vessel imaging to identify patients with proximal anterior circulation ischaemic stroke and that used predominantly stent retrievers or second-generation neurothrombectomy devices in the EVT group were included. Risk of bias was assessed with the Cochrane handbook methodology. Central investigators, masked to clinical information other than stroke side, categorised baseline imaging features of ischaemic change with the Alberta Stroke Program Early CT Score (ASPECTS) or according to involvement of more than 33% of middle cerebral artery territory, and by thrombus volume, hyperdensity, and collateral status. The primary endpoint was neurological functional disability scored on the modified Rankin Scale (mRS) score at 90 days after randomisation. Safety outcomes included symptomatic intracranial haemorrhage, parenchymal haematoma type 2 within 5 days of randomisation, and mortality within 90 days. For the primary analysis, we used mixed-methods ordinal logistic regression adjusted for age, sex, National Institutes of Health Stroke Scale score at admission, intravenous alteplase, and time from onset to randomisation, and we used interaction terms to test whether imaging categorisation at baseline modifies the association between treatment and outcome. This meta-analysis was prospectively designed by the HERMES executive committee but has not been registered. Among 1764 pooled patients, 871 were allocated to the EVT group and 893 to the control group. Risk of bias was low except in the THRACE study, which used unblinded assessment of outcomes 90 days after randomisation and MRI predominantly as the primary baseline imaging tool. The overall treatment effect favoured EVT (adjusted common odds ratio [cOR] for a shift towards better outcome on the mRS 2·00, 95% CI 1·69–2·38; p<0·0001). EVT achieved better outcomes at 90 days than standard medical therapy alone across a broad range of baseline imaging categories. Mortality at 90 days (14·7% vs 17·3%, p=0·15), symptomatic intracranial haemorrhage (3·8% vs 3·5%, p=0·90), and parenchymal haematoma type 2 (5·6% vs 4·8%, p=0·52) did not differ between the EVT and control groups. No treatment effect modification by baseline imaging features was noted for mortality at 90 days and parenchymal haematoma type 2. Among patients with ASPECTS 0–4, symptomatic intracranial haemorrhage was seen in ten (19%) of 52 patients in the EVT group versus three (5%) of 66 patients in the control group (adjusted cOR 3·94, 95% CI 0·94–16·49; pinteraction=0·025), and among patients with more than 33% involvement of middle cerebral artery territory, symptomatic intracranial haemorrhage was observed in 15 (14%) of 108 patients in the EVT group versus four (4%) of 113 patients in the control group (4·17, 1·30–13·44, pinteraction=0·012). EVT achieves better outcomes at 90 days than standard medical therapy across a broad range of baseline imaging categories, including infarcts affecting more than 33% of middle cerebral artery territory or ASPECTS less than 6, although in these patients the risk of symptomatic intracranial haemorrhage was higher in the EVT group than the control group. This analysis provides preliminary evidence for potential use of EVT in patients with large infarcts at baseline. Medtronic.

The contents of this book include chapters on floating point computer arithmetic, natural and generalized interpolating polynomials, uniform approximation, numerical integration, polynomial splines and many more.This book is intended for undergraduate and graduate students in institutes, colleges, universities and academies who want to specialize in this field. The readers will develop a solid understanding of the concepts of numerical methods and their application. The inclusion of Lagrane and Hermite approximation by polynomials, Trapezian rule, Simpsons rule, Gauss methods and Romberg`s methods with illustrative examples is a valuable resource for the readers. Each chapter ends with examples and test questions.

To solve the problems of deep mining safety and ground pressure control in Sanshandao gold mine, a novel ground pressure control mode of deep mining in a subsea metal mine was studied by physical model test and numerical simulation analysis. First, the novel ground pressure control mode was studied by physical model test, the surface deformation characteristics of the physical model were observed by the DIC method, and the deformation and damage characteristics of the rock layer were obtained. Then, the numerical simulation analysis of the novel ground pressure control mode was carried out and verified with the results of the physical model test. Finally, the determined ground pressure control model was verified by engineering. The research results show that the physical model has an obvious disturbance to the surrounding area during the excavation process according to the analysis of the strain monitoring points, and the strain value at the monitoring point was maintained at approximately one ten-thousandth. Meanwhile, the stress change reflected by the strain was consistent with the numerical simulation results, confirming the authenticity of the physical model test results. Additionally, the field industrial test shows that the control mode has a good control effect on the high ground stress in the deep subsea metal mining.

Empirical and probabilistic risk analysis methods can relatively accurately predict the seismic vulnerability of reinforced concrete (RC) structures. Using various intensity measures to estimate and forecast the seismic hazard of RC structures can contribute to the development of typical structural seismic resilience and vulnerability models. However, traditional empirical and analytical vulnerability studies rely more on field observation data and seismic risk algorithms and less on numerical simulation analysis for validation and optimization, resulting in limitations and fuzziness in the accuracy of the developed structural risk models. To explore the damage modes of RC frame structures under different intensities, this paper innovatively combines numerical model algorithms with empirical vulnerability methods to conduct empirical vulnerability and numerical simulation analyses on RC structures. Using probability statistics and nonlinear regression analysis methods, a prediction model for estimating the fragility of RC structures was proposed, and 858 RC structure damage samples from a typical city (Dujiangyan) during the Wenchuan earthquake in China on May 12, 2008, were used for model verification and comparative analysis. Using seismic response analysis theory, 901,530 acceleration records of the Wenchuan earthquake detected by eight actual seismic stations were selected, and nonlinear dynamic time history analysis was conducted. A four-story RC structural model was established using finite element software, and numerical simulation analysis was conducted on the model using 117,863 real earthquake acceleration data points obtained from actual monitoring stations during the Wenchuan earthquake. The acceleration time history curves and incremental dynamic analysis curves of the RC structure under different intensity measures were generated. By combining the moire algorithm and numerical simulation technology, damage stress clouds of steel bars and concrete under different intensity measures were generated, and the accuracy of the developed empirical vulnerability model was verified via numerical simulation results.

The proximal femur’s numerical simulation could give an effective method for predicting the risk of femoral fracture. However, the majority of existing numerical simulations is static, which does not correctly capture the dynamic properties of bone fractures. On the basis of femoral fracture analysis, a dynamic simulation using incremental element deletion (IED)-based finite element analysis (FEA) was developed and compared to XFEM in this study. Mechanical tests were also used to assess it. Different impact speeds, fall postures, and cortical thicknesses were also studied for their implications on fracture types and mechanical responses. The time it took for the crack to shatter was shorter when the speed was higher, and the crack line slid down significantly. The fracture load fell by 27.37% when the angle was altered from 15° to 135°, indicating that falling forward was less likely to cause proximal femoral fracture than falling backward. Furthermore, the model with scant cortical bone was susceptible to fracture. This study established a theoretical foundation and mechanism for forecasting the risk of proximal femoral fracture in the elderly.

【Background and Objective】Under large-scale new energy integration, hydraulic units often deviate from optimal working conditions, leading to deteriorated internal flow, uneven stress distribution, and increased risk of turbine blade fatigue crack. However, the internal and external factors causing turbine fatigue cracks under different working conditions remain unclear and comprehensive analysis of turbine fatigue damage is lacking. This study aims to unveil the underlying mechanism and find strategy to prevent turbine blade fatigue cracks under large-scale new energy integration. 【Method】Based on the internal and external factors responsible for runner blade cracks, the basic principle of turbine blade fatigue was elaborated by combining stress characteristics under different operating conditions. Current research methods, progress in blade fatigue studies, and emerging fatigue research approaches based on intelligent algorithms were systematically reviewed and analysed.【Result】Our study identified prominent bottlenecks in existing research in three areas: ①Theoretical analysis. The highly complex internal structure of turbines and the lag in model-prototype similarity rate theory are the main obstacles, leading to significant research challenges. ②Numerical simulation: Insufficient research depth (predominantly phenomenological descriptions lacking in-depth analysis), limited research scope (neglect of optimizing turbine start-stop rules), and low research efficiency (scarce application of single-channel pressure fluctuation analysis) hinder research advances. ③Field tests: Missing key dynamic stress data, inadequate in-depth analysis of test data, unevaluated impacts of strain gauge protection devices on data reliability, unbalanced focus on blades (ignoring guide vanes) limit research validity. Additionally, machine learning technology was found to be potential in addressing these challenges, promising a new paradigm for fatigue research.【Conclusion】Existing research on runner fatigue cracks, based on theoretical analysis, numerical simulation and experimental measurement, has yielded achievements but faces challenges. Future research is needed to integrate machine learning with traditional methods to develop more cost-effective and efficient fatigue analysis for turbine blades.

Aiming at the problem that the Harris hawk optimization (HHO) algorithm does not have high optimization accuracy and is prone to fall into local optimum, an improved Harris hawk optimization (SHHO) algorithm based on multi-strategy synergy mechanism is proposed. Firstly, in the initialization stage, out adopts the good point set method to create the population, and draws on the topology theory to divide the population into two different populations to enhance the connection between the populations. Second, a multi-strategy synergy mechanism was designed to randomly divide individuals into two categories: leader eagles and non-leader eagles using the clan topology. The grouping was based on the ordering of fitness values. In addition, a search strategy was constructed for each category to ensure a balance between exploration and exploitation capabilities. Finally, to validate the performance of SHHO, ordinary functions and CEC test set and benchmark functions of CEC test set were selected for simulation and SHHO was compared with other optimization algorithms using ANOVA, Wilcoxon and Friedman tests. Meanwhile, three classical engineering problems are selected to verify the effectiveness of SHHO in real engineering. The results show that SHHO has significant improvement in convergence accuracy and speed, and has high practical value and advantages in engineering optimization applications.

Aircraft continuously change their flight attitudes during actual operations. If a constant attitude is maintained during wind tunnel tests, the aerodynamic characteristics obtained may significantly deviate from the actual performance of the aircraft. Such discrepancies hinder the optimal design of aircraft and can adversely affect safety. The dual-rotating shaft mechanism is a commonly used model support system in wind tunnel testing, playing a crucial role in simulating various flight attitudes of the aircraft. The paper integrates the structural characteristics of a newly designed dual rotating shaft mechanism to perform a numerical analysis of its aerodynamic shape and evaluate its impact on the quality of the wind tunnel flow field. Multiple rounds of numerical simulations and comparative analyses were carried out on mechanisms with different structural configurations, leading to an optimized structural design. Subsequently, corresponding experiments were conducted to validate the design results. The results indicate that reducing the axial width and thickness of the front shaft crutch arm and positioning it further from the rotor center can alleviate upstream interference. The research provides a valuable reference for the future development of dual rotating shaft mechanisms.