For the digitization of turbocharger, the prediction of compressor working state is essential. How to build a model with accurate prediction and less time-consuming is the premise of studying the digitization of turbo...
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作者:
Morgan, Sarah J.McGrath, Ciara N.de Weck, Olivier L.Aerosp Corp
Performance Modeling & Anal Dept 14745 Lee Rd Chantilly VA 20151 USA Univ Manchester
Dept Mech Aerosp & Civil Engn Aerosp Syst Oxford Rd Manchester M13 9PL England MIT
Dept Aeronaut & Astronaut Apollo Program Astronaut & Engn Syst 77 Massachusetts Ave Cambridge MA 02139 USA
This paper presents a method of planning spacecraft maneuvers for mobile target tracking. Agile, maneuverable spacecraft have been proposed as a means of modifying satellite orbits to observe discrete targets on the E...
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This paper presents a method of planning spacecraft maneuvers for mobile target tracking. Agile, maneuverable spacecraft have been proposed as a means of modifying satellite orbits to observe discrete targets on the Earth on demand. This work adapts this concept to propose a method of using maneuverable spacecraft to observe a mobile target as it moves across the Earth. Previous work has shown the potential of such an approach to increase persistence of coverage of a moving target. This work applies a suitable optimizer to select possible maneuvers for a spacecraft, or a constellation of spacecraft, to repeatedly observe a moving target. A biased random key genetic algorithm is used, which adjusts the delta V for each maneuver to minimize the total delta V used and maximize target coverage over the full sequence of maneuvers. The developed method is applied to two case studies concerning monitoring of tropical storms. The results indicate that, using relatively small maneuvers, spacecraft orbits can be adjusted to improve the quantity and quality of views of a moving target. In the Typhoon Megi case study, a single spacecraft using less than 2.5 m/s delta V is shown to double the access time and provide two additional observations of the storm eye compared with a nonmaneuvering spacecraft in an identical initial orbit. Opportunities for observations increase as the number of maneuverable spacecraft are increased, with a three-spacecraft constellation able to provide five complete observations of the storm eye for a total change in velocity of 12 m/s.
The usage of a single dielectric barrier discharge plasma actuator (SDBD-PA) device for improving a aerodynamic performance of a locally developed horizontal axis wind turbine blade section is studied with one of the ...
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The usage of a single dielectric barrier discharge plasma actuator (SDBD-PA) device for improving a aerodynamic performance of a locally developed horizontal axis wind turbine blade section is studied with one of the most recent electrostatic models. To characterize this blade section behavior over a wide range of operating conditions of SDBD-PA and to advance its performance with a fully automated optimization algorithm, a computationally cost efficient direct regression model is proposed. In this paper, 512 comprehensive numerical simulations are carried out to derive the direct regression model for aerodynamic performance calculation when the PA is in use. However, to obtain highly accurate results, two different models for angle of attacks higher and less than 21 degrees are suggested. The proposed mathematical model within the specified boundary limits allows for a rapid linkage between aerodynamic performance and genetic algorithm which canbe made to acquire optimum results for each case without requiring burdensome numerical simulations. It is identified that superimpose input parameters effects onto each other is not explanatory of the final effect on aerodynamic performance and interaction effects should be seriously taken into consideration at the proposed regression model.
Harris Hawks optimizer (HHO) is a new swarm intelligence optimization algorithm proposed in recent years. It seeks the optimal solution by simulating the predation strategy of Harris hawks and many previous experiment...
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Harris Hawks optimizer (HHO) is a new swarm intelligence optimization algorithm proposed in recent years. It seeks the optimal solution by simulating the predation strategy of Harris hawks and many previous experiments show that HHO has a good effect on solving optimization problems. However, HHO also has the shortcomings of low convergence accuracy and easy to fall into local optimum. In order to improve the performance of HHO, an improved HHO hybridized with extremal optimization (IHHO-EO) is proposed. Aiming at the defect of insufficient information utilization and excessive randomization in the exploration phase of the algorithm, the own historical optimal position of Harris hawks is introduced to better guide the individuals to search for better positions and improve the global search ability. Secondly, a nonlinear prey energy escaping factor is proposed to better balance the exploration and exploitation phases. Thirdly, refracted opposition-based learning (ROBL) with a dynamic parameter is proposed and combined with HHO, which can improve the quality of solutions and convergence speed. Finally, the exploitation ability is improved by performing EO operation which has strong local search ability. The proposed algorithm is applied to 23 classical benchmark test functions and 29 CEC2017 test functions. IHHO-EO is compared with HHO, other newly proposed optimization algorithms and some improved variants of HHO. The experimental results verify the effectiveness of the added strategies. In addition, the proposed approach is applied to solving the pressure vessel design problem. The results show that IHHO-EO has an excellent performance in terms of accuracy, reliability and statistical tests.
Effective management of construction project portfolios demands informed decisions driven by data and mathematical models, aiming to enhance decision-making and address complex decision problems. This article introduc...
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ISBN:
(纸本)9783031782374;9783031782381
Effective management of construction project portfolios demands informed decisions driven by data and mathematical models, aiming to enhance decision-making and address complex decision problems. This article introduces an innovative approach that prioritizes sustainability criteria selection, utilizing data-driven insights and mathematical optimization to optimize project portfolio management. Through multi-objective optimization, our study targets improved resource efficiency, time reduction, and minimized environmental impact, offering portfolio managers a powerful tool for decision-making.
Importance measures are used to prioritize the system components for achieving high efficiency and economy of reliability optimization. The existing importance measures pay more attention to evaluating the impact of c...
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Importance measures are used to prioritize the system components for achieving high efficiency and economy of reliability optimization. The existing importance measures pay more attention to evaluating the impact of component performance changes on the objective function (such as system reliability, cost and so on). Still, these importance measures do not consider the influence of constraints in the system reliability optimization models during the ranking process of components, which may leave the component with the largest importance measure almost no space to improve its reliability. For the cost-constrained reliability optimization model (ROM), this paper proposes a cost-constrained ROM-based importance measure (CRIM) by comprehensively considering the objective function and constraints, and several properties of CRIM are discussed. Then, the CRIM-based genetic algorithm (CRIGA) is developed to solve the cost-constrained ROM. The numerical experiment for different scale systems is implemented to evaluate the performance of CRIGA by comparing it with other optimization algorithms. Experimental results show that CRIGA can get better solutions with faster convergence speed and better robustness. Finally, the case on the coal transportation system of the thermal power plant is introduced to illustrate the application of CRIM and CRIGA in reliability optimization.
This article presents a new two-axis solar tracker based on an online optimization algorithm so as to track the position of the sun without using its movement *** this research,four well-known optimization algorithms ...
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This article presents a new two-axis solar tracker based on an online optimization algorithm so as to track the position of the sun without using its movement *** this research,four well-known optimization algorithms are employed to find the two unknown parameters named azimuth and zenith angles,which determine the position of the *** magnitude of the sunray is considered as the cost function of all ***,several experiments are carried out to find the best optimization algorithm with optimal population size,number of iterations,and also the best initialization *** initialization leads to faster convergence compared to random *** results clearly show that the particle swarm optimization algorithm with a population size of 15 and 7 iterations using uniform initialization method has better performance than the other algorithms,with a convergence time of less than 40 *** average fitness value or voltage received by the tracker is 2.4 Volts in this method,which is higher than other *** also performs well with a population size of 15 and 7 ***,the artificial neural network with one hidden layer and 20 neurons is employed to predict these two parameters in each day and moment in a year in Shiraz city according to the experimental data extracted from *** of the day from January and the time are inputs and zenith and azimuth angles are considered the output of neural network *** performance of the proposed ANN model is evaluated using regression plots,demonstrating a strong correlation between predicted and target ***,the outcomes reveal the feasibility of using online optimization algorithms and neural network modeling in an effort to bypass the complex mathematical model of mechatronic systems and predict the movement of the sun automatically.
Diagnosing heart disease is considered a difficult task as it provides a digital estimation of the seriousness of the disease. As a result, the quickest treatment can be done. So, heart diagnosis has attracted a lot m...
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Diagnosing heart disease is considered a difficult task as it provides a digital estimation of the seriousness of the disease. As a result, the quickest treatment can be done. So, heart diagnosis has attracted a lot more attention in the medical industry throughout the globe, and along with excellence in efficacy, the optimization algorithm plays a crucial role in the detection of heart disease. Here, to predict the cardiac illness an improvised CatBoost algorithm and Multi-layer Perceptron classifier are used. Also, proper hyperparameter tweaking is needed for the successful implementation of the classifier. In order to optimize the hybrid model's hyperparameters, the Mayfly optimization algorithm is deployed for effective hyperparameter optimization. In order to increase prediction accuracy, the Harris-Hawks optimization technique is used to choose the essential features from the dataset. Z-Alizadeh Sani and Cleveland heart disease datasets are utilized to detect heart disease. Also, it is compared with the existing models. To validate the efficiency of a model, six various measures are used: precision, accuracy, recall, the F- 1 measure, specificity, and loss. Here, when compared to the previous studies, the proposed model yields better performance, i.e., 98.7% accuracy with Cleveland and 99.2% with Alizadeh Sani Datasets.
Steel reinforcing bar (SRB) engineering is a very professional, complex, massive, and neglected project, which affects the structural performance and cost of building. Traditional SRB engineering is a labor-intensive ...
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Steel reinforcing bar (SRB) engineering is a very professional, complex, massive, and neglected project, which affects the structural performance and cost of building. Traditional SRB engineering is a labor-intensive project, often accompanied by the quality of SRB construction and the waste of material. At present, information tech-nology is undergoing a revolution. With the rise and optimization of Building Information Modeling (BIM) technology and the continuous improvement of artificial intelligence-based optimization algorithms, new solu-tions have been put forward to solve these traditional SRB engineering problems. This study combines two different fields of BIM and optimization algorithms to establish a process of BIM-based SRB detail construction design and picking optimization that provides a reference for traditional SRB engineering. It is also an explo-ration and application of BIM technology to practical engineering. This study classified and analyzed the SRB crash nodes problems classified into four crash nodes classification and proposed a BIM-based SRB designing process. For the problem of the SRB connection position, a general segmental formula for SRB (for example, Longitudinal SRB on columns and beams) was studied, and a set of processes was established to determine the unknowns of the segment formula to locate the connection position of SRB. Besides, this study utilizes BIM's coherent information transfer and visualization technologies that select Revit software to create new information such as "SRB shape family," "component family," "annotated family," and so on. The application of BIM in SRB is carried out through the transfer, transformation, and expression of information in the forms of SRB design drawings, SRB processing schedules, SRB construction schedules, and SRB construction partition charts, and so on. in addition, the problem of one-dimensional blanking of single-size and multiple-size raw materials is discussed with the minimum numb
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