The research on cooling electronics devices in workstations, servers, and other devices has become one of the rapidly growing technologies today, with the generation of high heat fluxes associated with component compa...
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The research on cooling electronics devices in workstations, servers, and other devices has become one of the rapidly growing technologies today, with the generation of high heat fluxes associated with component compactness and increased power consumption. Hence, the current study aims to enhance the thermohydraulic performance of a compact mini-channel heat removal system based on a machine learning-based optimization technique. The design variables considered for the optimization study are the channel's Reynolds number (Re), fin thickness (t(f)), fin spacing (s(f)), and fin height (h(f)). Initially, the performance of the heat sink geometry with different fin configurations is computed using 3D-RANS simulations. The generated data are then used to train six regression techniques in machine learning to propose the best approach capable of accurately predicting the heat transfer coefficient and pressure drop data. The selected machine learning model is then coupled with the multi-objective genetic algorithm to find the optimal heat sink geometry. It is found that the multilayered perceptron approach re-designed to a deep neural network model efficiently predicts both the heat transfer coefficient and the pressure drop from the available data. The overall performance of the optimized channel geometry is found up to 2.1 times improved than the best available channel configuration in the data pool. Further, the optimized channel geometry's heat transfer coefficient was 14% higher, and the corresponding pressure drop was five times lower.
Nowadays, the mounting of guns on wheeled/tracked vehicles is increasingly investigated as it enhances gun mobility. To reduce the force imparted by mortars mounted on light vehicles, this paper presents modeling and ...
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Nowadays, the mounting of guns on wheeled/tracked vehicles is increasingly investigated as it enhances gun mobility. To reduce the force imparted by mortars mounted on light vehicles, this paper presents modeling and design optimization of a new recoiling mortar system that potentially replaces traditional towed, fixed-barrel mortars. A concentric recoil system for the mortar was designed, and the recoil cycle has been mathematically modeled using MATLAB software to determine the time histories of recoil force, displacement, and velocity. The mathematical model has been validated by comparing the calculated and measured firing results of a similar recoil system used with a tank gun. Then, multi-objective genetic algorithm (MOGA) optimization technique was utilized to determine the optimum design parameters of the mortar recoil system. It was found that the newly developed recoil system is capable of reducing the force imparted by the mortar by 63.7%. Further reductions of recoil force, recoil track, impact velocity, and recoil cycle time are obtained by applying the optimization technique.
Shell-and-tube heat exchangers are widely used in many research fields and industrial production processes, but little research has been conducted on the use of heat exchangers for drying crops. This study conducted a...
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Shell-and-tube heat exchangers are widely used in many research fields and industrial production processes, but little research has been conducted on the use of heat exchangers for drying crops. This study conducted a numerical simulation of the temperature, velocity, and pressure fields based on the shell-and-tube fluids of a heat exchanger in a biomass particle hot-blast stove. The correctness of the simulation results was verified by test data before simulation, and the mesh was verified to be irrelevant. The application of a multi-objective genetic algorithm in heat exchanger design and optimization was explored, considering five design variables, such as hot tube diameter, transverse pitch, longitudinal pitch, cold flow velocity, and hot flow velocity for optimization. The Nusselt number, friction factor, and comprehensive performance coefficient were used as objective functions for 2D and 3D response surface analysis. The final design variables P1=74.91 mm, P2=104.23 mm, P3=121.37 mm, P4=4.83 m/s, and P5=8.48 m/s were obtained to improve the comprehensive performance coefficient by 16.11%. The heat transfer performance was improved by 9.55% and the resistance performance was reduced by 15%.
This study introduces a new type of fins’ heat sinks, namely the skeleton-based heat exchanger;it combines multi-objective optimization along with the parametric identification of the new design to improve the heat e...
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The real-time reconstruction of the displacement field of a structure from a network of in situ strain sensors is commonly referred to as "shape sensing". The inverse finite element method (iFEM) stands out ...
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The real-time reconstruction of the displacement field of a structure from a network of in situ strain sensors is commonly referred to as "shape sensing". The inverse finite element method (iFEM) stands out as a highly effective and promising approach to perform this task. In the current investigation, this technique is employed to monitor different plate structures experiencing flexural and torsional deformation fields. In order to reduce the number of installed sensors and obtain more accurate results, the iFEM is applied in synergy with smoothing element analysis (SEA), which allows the pre-extrapolation of the strain field over the entire structure from a limited number of measurement points. For the SEA extrapolation to be effective for a multitude of load cases, it is necessary to position the strain sensors appropriately. In this study, an innovative sensor placement strategy that relies on a multi-objective genetic algorithm (NSGA-II) is proposed. This approach aims to minimize the root mean square error of the pre-extrapolated strain field across a set of mode shapes for the examined plate structures. The optimized strain reconstruction is subsequently utilized as input for the iFEM technique. Comparisons are drawn between the displacement field reconstructions obtained using the proposed methodology and the conventional iFEM. In order to validate such methodology, two different numerical case studies, one involving a rectangular cantilevered plate and the other encompassing a square plate clamped at the edges, are investigated. For the considered case studies, the results obtained by the proposed approach reveal a significant improvement in the monitoring capabilities over the basic iFEM algorithm with the same number of sensors.
In the new phase of sustainable development, agriculture is seeking sustainable management of the water-land-energy-economy-environment-food nexus. At present, there are few studies on optimizing crop planting structu...
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In the new phase of sustainable development, agriculture is seeking sustainable management of the water-land-energy-economy-environment-food nexus. At present, there are few studies on optimizing crop planting structure and analyzing its spatial layout with consideration of natural and socio-economic factors. Herein, we proposed a framework for addressing this issue. In this framework, the NSGA-II algorithm was used to construct the multi-objective optimization model of crop planting structures with consideration of water and energy consumption, greenhouse gas (GHG) emissions, economic benefits, as well as food, land, and water security constraints, while the model for planting spatial layout optimization was established with consideration of crop suitability using the MaxEnt model and the improved Hungarian algorithm. This framework was further applied in the Black Soil Region of Northeast China (BSRNC) for analyzing optimized crop planting structures and spatial layouts of three main crops (rice, maize, and soybean) under various scenarios. This study showed that the sown area of rice in the BSRNC decreased by up to 40.73 % and 35.30 % in the environmental priority scenario and economic-environmental balance scenario, respectively, whereas that of soybean increased by up to 112.44 % and 63.31 %, respectively. In the economic priority scenario, the sown area of rice increased by up to 93.98 %. Expanding the sown area of soybean was effective in reducing GHG emissions. On the contrary, rice production led to greater environmental costs though it provided higher economic returns. Among the three crops, maize exhibited an advantage in balancing environmental and economic benefits. Hegang-Jixi area in the northeast of the BSRNC was identified as the key area with the most intense crop planting transfer among different scenarios. Overall, this framework provides a new methodology for optimizing crop planting structures and spatial layouts with consideration of the nexus
The design of new products is now influenced by shifting consumer demands and technological advancements. Products must satisfy high-quality standards and have a low environmental impact. New phenomena such as distrib...
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The design of new products is now influenced by shifting consumer demands and technological advancements. Products must satisfy high-quality standards and have a low environmental impact. New phenomena such as distributed and urban manufacturing are emerging to cope with this. A new manufacturing era is coming where methods that prevent waste, support small workshops and encourage do-it-yourself are crucial. In the early design stage, the process knowledge is minimal, and the decision taken is vital. For this reason, it is essential to support designers in anticipating the impact of decisions on the final product. This paper establishes the groundwork for decision-support methodologies for sustainable design in One-of-a-Kind additive manufacturing prototyping. Our proposed method is applied to a Fused Filament Fabrication case study, wherein we evaluate the impact of nine variables on factors such as process time, energy and material consumption, environmental footprint, and product quality. The initial step aims to generate fresh insights through Taguchi experimentation, while the subsequent step formulates and resolves a multi-objective optimization problem using the NSGA-II algorithm. The resulting Pareto-optimal solutions serve as the basis for a novel visual-based design support tool. The proposed approach can evaluate the trade-offs between product quality and environmental impact by offering users a visual heatmap based on quantitative data. This heatmap can guide the user in the material and production parameter selection. Integrating the decision support tool into the product design process can empower designers to create environmentally responsible products while fostering innovation.
The ever-increasing water demand has not only disrupted the demand-supply balance, causing conflicts among multiple stakeholders, but has also led to environmental impacts due to aquifer depletion. Today, agent-based ...
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This paper presents a two-phase hierarchical classifier for determining the different states in Alzheimer's disease (AD). In the first phase, an evolutionary system is developed to determine the most relevant slic...
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ISBN:
(纸本)9783031574290;9783031574306
This paper presents a two-phase hierarchical classifier for determining the different states in Alzheimer's disease (AD). In the first phase, an evolutionary system is developed to determine the most relevant slices (in both X-axis and Y-axis) of the magnetic resonance imaging (MRI) for the construction of a classifier. To obtain the image features, the biorthogonal wavelet transform 3.3 was used at level 2. Due to the high number of coefficients, a dimensionality reduction is performed using minimum Redundancy - Maximum Relevance algorithm (mRMR) and Principal Component Analysis (PCA). An evolutionary algorithm on a high-performance computer with GPU was used to optimize the slides. Support vector machine (SVM) was used in the fitness function to estimate the features of the classifier in a computationally simple way. In the second phase, using the different solutions of the Pareto front obtained by the evolutionary algorithm, a multiple deep learning system was developed, each of the systems having as input one of the selected slices of the analyzed solution. The solution with three slices (trade-off between complexity and accuracy) was used as the solution. The obtained hierarchical deep learning system fused the information from each system and analyzed the probabilities obtained for each class. As a final result, an accuracy of 92% was obtained for the six classes. A total of 1,200 patients from the Alzheimer's disease neuroimaging initiative (ADNI) database were used, corresponding to six different classes of patients (with varying degrees of dementia).
In semiconductor manufacturing process, the wafer direct bonding, so-called die-to-wafer hybrid bonding, still has unexpected voids on the boning surface which decreases the bonding efficiency. Therefore, this paper p...
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In semiconductor manufacturing process, the wafer direct bonding, so-called die-to-wafer hybrid bonding, still has unexpected voids on the boning surface which decreases the bonding efficiency. Therefore, this paper proposes a design approach for the bonding head guiding platform (BHGP) based on compliant mechanism for the die-to-wafer hybrid bonding. Firstly, a bridge amplification module (BAM) is designed and simulated. Secondly, a dual parallelogram module (DPM) is designed and analyzed. Then, the BAM is combined with the DPM to create a full design of the BHGP. To investigate the parametric effect of the geometric inputs on the output behaviors of the platform, the parameter sensitivity is conducted. The multi-objective optimization study is performed using multi-objective genetic algorithm. The results determined the displacement can gain up to 191.88 mu m, the parasitic error has a small value of 1.47 mu m, and the von Mises stress is minimal value of 52 MPa. The crosstalk of the platform is about 3.82%, and this ratio ensures a linear characteristic of the platform. A small value of stress allows a high safety factor during operation. The result of this study is expected be utilized for removing voids in the die-to-wafer hybrid bonding process.
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