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An efficient hybrid evolutionary optimization algorithm based on PSO and SA for clustering

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第4期10卷 512-519页

作者： Taher NIKNAM Babak AMIRI javad olamaei Ali AREFI Electronic and Electrical Engineering Department Shiraz University of TechnologyShirazIran Information Technology Department Islamic Azad University-Fars Science and Research BranchShiraz Iran Technical Engineering Department Islamic Azad University-South Tehran BranchTehran Iran Power Engineering Group Department of Electrical and Computer Engineering Tarbiat Modares UniversityTehran Iran

The K-means algorithm is one of the most popular techniques in clustering. Nevertheless, the performance of the Kmeans algorithm depends highly on initial cluster centers and converges to local minima. This paper proposes a hybrid evolutionary programming based clustering algorithm, called PSO-SA, by combining particle swarm optimization (PSO) and simulated annealing (SA). The basic idea is to search around the global solution by SA and to increase the information exchange among particles using a mutation operator to escape local optima. Three datasets, Iris, Wisconsin Breast Cancer, and Ripley's Glass, have been considered to show the effectiveness of the proposed clustering algorithm in providing optimal clusters. The simulation results show that the PSO-SA clustering algorithm not only has a better response but also converges more quickly than the K-means, PSO, and SA algorithms.

关键词： Simulated annealing (SA) Data clustering Hybrid evolutionary optimization algorithm K-means clustering Parti-cle swarm optimization (PSO)

Advances and opportunities in wind energy harvesting using plasma actuators: a review

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CLEAN ENERGY 2024年第1期8卷 197-225页

作者： Omidi, javad Columbia Univ Dept Chem Engn New York NY 10027 USA

The dielectric barrier discharge plasma actuator has been recognized as a leading technology for controlling fluid flow and has found remarkable applications in wind energy harvesting over the past decade. Wind turbine aerodynamics are critical in this concept and performance is mainly determined by flow controllers, although significant technical progress is still required. This paper examines all the critical studies to investigate the potential application of plasma actuators for airflow control over wind turbines. This approach has been divided into three categories: wind turbine airfoils, horizontal-axis wind turbines and vertical-axis wind turbines aerodynamic performance and generated power. Finally, the potential functions of plasma actuators in current and future wind turbine generators are discussed. These actuators offer promising solutions to increasing power output, minimizing torque fluctuations and enabling self-starting capabilities, particularly in vertical-axis wind turbines. By adjusting blade pitch angles in conjunction with plasma actuators, significant improvements in airflow optimization and power extraction have been demonstrated. Despite the advancements, challenges persist, such as determining optimal actuator placement and overcoming structural limitations, especially concerning 3D effects and high Reynolds numbers. While plasma actuators enhance aerodynamic efficiency, their complexity needs to be balanced against marginal gains in power production, especially in high-megawatt turbines, for which controlling flow at low wind speeds is challenging. Future research must focus on the sustainable integration of plasma actuators, pitch angle adjustments and active control mechanisms to fully exploit the potential of wind energy for a sustainable future. Incorporating plasma actuators in wind energy systems maximizes efficiency, especially in urban areas and low-wind conditions. This advancement ensures cleaner energy, aligning with eco-friendl

关键词： plasma actuator wind turbine aerodynamic performance generated power DYNAMIC STALL CONTROL FLOW-CONTROL SEPARATION CONTROL TURBINE PERFORMANCE IMPROVEMENT AIRFOIL OPTIMIZATION

Increasing the Maximum Capacity Path in a Network and Its Application for Improving the Connection Between Two Routers

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Tsinghua Science and Technology 2024年第3期29卷 753-765页

作者： Adrian M.Deaconu javad Tayyebi Department of Mathematics and Computer Science Transilvania University of BrasovBrasov 500036Romania Department of Industrial Engineering Birjand University of TechnologyBirjand 000097Iran

Abstract:This paper addresses the problem of improving the optimal value of the Maximum Capacity Path(MCP)through expansion in a flexible network,and minimizing the involved *** only condition applied to the cost functions is to be non-decreasing *** is a non-restrictive condition,reflecting the reality in practice,and is considered for the first time in the ***,the total cost of expansion is a combination of max-type cost(e.g.,for supervision)and sum-type cost(*** building infrastructures,price of materials,price of labor,etc.).For this purpose,two types of strategies are combined:(l)increasing the capacity of the existing arcs,and(l)adding potential new *** different problems are introduced and *** the problems have immediate applications in Internet routing *** first one is to extend the network,so that the capacity of an McP in the modified network becomes equal to a prescribed value,therefore the cost of modifications is minimized.A strongly polynomial-time algorithm is deduced to solve this *** second problem is a network expansion under a budget constraint,so that the capacity of an McP is maximized.A weakly polynomial-time algorithm is presented to deal with *** the special case when all the costs are linear,a Meggido's parametric search technique is used to develop an algorithm for solving the problem in strongly polynomial *** new approach has a time complexity of O(n^(4)),which is better than the time complexity of O(n4 log(n)of the previously known method from literature.

关键词： Maximum Capacity Path(MCP) network expansion Internet routing polynomial-time algorithms

Changes in climatic conditions drive variations in arbuscular mycorrhizal fungi diversity and composition in semi-arid oak forests

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Journal of Forestry Research 2024年第5期35卷 106-119页

作者： Nahid Jafarian javad Mirzaei Reza Omidipour Yahya Kooch Department of Forest Science Faculty of AgricultureIlam UniversityIlam 69315-516Iran Department of Range and Watershed Management Faculty of AgricultureIlam UniversityIlam 69315-516Iran Faculty of Natural Resources and Marine Sciences Tarbiat Modares UniversityNoor 46417-76489MazandaranIran

Arbuscular mycorrhizal fungi(AMF)play a vital role in plant productivity and ecosystem ***,their responses to abiotic factors(i.e.,climate,physiography,and soil properties)are unknown,especially across climatic gradients and slope aspects in arid and semi-arid *** this study,using 60 composite soil samples,direct and indirect effects of climate factors and slope aspects on AMF diversity,composition and spore density were *** findings indicate that climate has a more direct influ-ence on soil properties(P<0.001)in comparison to slope aspect(P=0.449).In contrast,climate significantly affected AMF diversity and composition,with the highest diversity in dryer *** pH had the highest correlation with different facets of AMF *** equation modeling(SEM)indicated that only a small part of the variation in AMF diversity and spore density could be explained by climate characteristics,slope aspect and soil *** on SEM results,climate was the most important determinant of AMF diversity and spore density;slope aspect had a less critical *** outputs suggest that variations in AMF diversity are derived by the direct effects of climate and the indirect effect of soil chemical *** addition,with increasing dryness,sporulation and AMF diversity increased.

关键词： AMF diversity and composition Physiographic factors Semi-arid ecosystems Zagros forest

Modelling rapid non-destructive test using light weight deflectometer on granular soils across different degrees of saturation

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2732-2748页

作者： javad Ghorbani Arooran Sounthararajah Troyee Tanu Dutta Jayantha Kodikara ARC Smart Pavements Hub Dept.of Civil EngineeringMonash UniversityVIC3800Australia

This study introduces an advanced finite element model for the light weight deflectometer(LWD),which integrates contact mechanics with fully coupled *** simulating LWD tests on granular soils at various saturation levels,the model accurately reflects the dependence of the LWD modulus on dry density,water content,and effective *** model addresses and overcomes the limitations of previous finite element models for this specific ***,this research presents the first experimentally validated fully coupled contact impact ***,the research provides a comparative assessment of elastoplastic and nonlinear elastic models and contrasts an enriched node-tosegment method(developed in this study)with the more precise mortar technique for contact *** comparisons reveal unique advantages and challenges for each ***,the study underscores the importance of careful application of the LWD modulus,emphasising the need for sophisticated tools to interpret soil behaviour accurately.

关键词： Granular soils Plasticity Finite element analysis Contact mechanics Modulus Degree of saturation

Suspended particulate matter promotes epithelial-to-mesenchymal transition in alveolar epithelial cells via TGF-β1-mediated ROS/IL-8/SMAD3 axis

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Journal of Environmental Sciences 2024年第7期141卷 139-150页

作者： Shahrzad Molavinia Dian Dayer Mohammad javad Khodayar Gholamreza Goudarzi Maryam Salehcheh Cellular and Molecular Research Center Medical Basic Sciences Research InstituteAhvaz Jundishapur University of Medical SciencesAhvazIran Department of Toxicology School of PharmacyAhvaz Jundishapur University of Medical SciencesAhvazIran Student Research Committee Ahvaz Jundishapur University of Medical SciencesAhvazIran Toxicology Research Center Medical Basic Sciences Research InstituteAhvaz Jundishapur University of Medical SciencesAhvazIran Air Pollution and Respiratory Diseases Research Center Ahvaz Jundishapur University of Medical SciencesAhvazIran Iranian Scientific Association of Clean Air TehranIran

Epidemiological evidence presents that dust storms are related to respiratory diseases,such as pulmonary fibrosis(PF).However,the precise underlying mechanisms of SPM-elicited adverse effects still need to be ***-mesenchymal transition(EMT)process is a characteristic of *** discussed whether suspended particulate matter(SPM)is involved in EMT induction via transforming growth factor-β1(TGF-β1).In this study,a detailed elemental analysis(55 elements),particle size,and morphology were *** investigate the toxicity of SPM,an MTT test was performed to detect cell ***,A549cells were exposed to selected concentrations of SPM(20 and 40μg/mL)for single and repeated *** DCFH-DA assay showed that exposure to SPM could produce reactive oxygen species(ROS).The ELISA assay demonstrated increased levels of interleukin-8(IL-8)and TGF-β1 in the *** blot was used to detect the expression of proteins associated with EMT and the SMAD3-dependent *** of western blot demonstrated that E-cadherin was reduced,whereas p-SMAD3,vimentin,andα-smooth muscle actin were *** findings indicated that SPM triggered EMT by induction of oxidative stress,inflammation,and the TGF-β1/SMAD3 pathway activation.

关键词： Particulate matter TGF-β1 Oxidative stress Epithelial-mesenchymal transition Pulmonary fibrosis Cells

Effects of heat stress and long photoperiod on the prostate of rats

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Asian pacific Journal of Reproduction 2024年第4期13卷 187-196页

作者： Hamid Reza Ghaffari javad Poursamimi Department of Basic Sciences School of MedicineZabol University of Medical SciencesZabolIran Department of Immunology Faculty of MedicineZabol University of Medical SciencesZabolIran

Objective:To examine light and heat effects on the morphological,histological,and micrometric structure of the prostate of ***:Thirty adult male rats were divided into three *** control group was kept under 20℃-22℃ and an artificial 12 h/12 h day/night cycle;the temperature group was under normal light and at(42±1)℃ heat for 4 to 5 h daily,and the light group was exposed to 8 h/16 h day/night cycle with 20℃-22℃.Rats were weighed five times(at the beginning of the study and every seven days).Five milliliters(mL)of their peripheral blood were *** tissue staining was performed using the hematoxylin-eosin(H&E)stain and periodic acid-Schiff(PAS).In the following,tissue and cellular reactions to the PAS were ***:Folds were located entirely on the surface of the anterior lobe and periphery of the other *** secretory units in the anterior lobe were more than the lateral lobe.A strong reaction of the secretory cells to the PAS was *** serum levels of the light group also significantly increased compared to the control group(P<0.05).The most histometric changes of the lobes were established in the lateral *** stress resulted in a significant decrease in testosterone levels and transformed prostate *** epithelium and parenchyma to scaffold ratio in the temperature group ***:Maximum and minimum changes in the ventral lobe happened under the ascent of temperature and light,*** ventral lobe in the study of prostatic hyperplasia should be more considered.

关键词： Prostate Heat stress Photoperiod Histology Testosterone Rat

Temperature-jump tensile tests to induce optimized TRIP/TWIP effect in a metastable austenitic stainless steel

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International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 2025-2036页

作者： Mohammad javad Sohrabi Hamed Mirzadeh Saeed Sadeghpour Abdol Reza Geranmayeh Reza Mahmudi School of Metallurgy and Materials Engineering College of EngineeringUniversity of Tehran14395-515TehranIran Centre for Advanced Steels Research Materials and Mechanical EngineeringUniversity of Oulu90014 OuluFinland

In the present work,plastic deformation mechanisms were initially tailored by adjusting the deformation temperature in the range of 0 to 200℃ in AISI 304L austenitic stainless steel,aiming to optimize the strength-ductility *** was shown that the combined twinning-induced plasticity(TWIP)/transformation-induced plasticity(TRIP)effects and a wider strain range for the TRIP effect up to higher strains by adjusting the deformation temperature are good strategies to improve the strength-ductility synergy of this metastable stainless *** this regard,by consideration of the observed temperature-dependency of plastic deformation,the controlled sequence of TWIP and TRIP effects for archiving superior strength-ductility trade-off was intended by the pre-designed temperature jump tensile ***,the optimum tensile toughness of 846 MJ/m^(3) and total elongation to 133% were obtained by this strategy via exploiting the advantages of the TWIP effect at 100℃ and the TRIP effect at 25℃ at the later stages of the ***,a deformation-temperature-transformation(DTT)diagram was developed for this metastable ***,based on work-hardening analysis,it was found that the main phenomenon constraining further improvement in the ductility and strengthening was the yielding of the deformation-induced α′-martensite.

关键词： metastable stainless steels transformation-induced plasticity twinning-induced plasticity stacking fault energy mechanical properties

A Stacking Machine Learning Model for Student Performance Prediction Based on Class Activities in E-Learning

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Computer Systems Science & Engineering 2024年第5期48卷 1251-1272页

作者： Mohammad javad Shayegan Rosa Akhtari Department of Computer Engineering University of Science and CultureTehran***Iran

After the spread of COVID-19,e-learning systems have become crucial tools in educational systems worldwide,spanning all levels of *** widespread use of e-learning platforms has resulted in the accumulation of vast amounts of valuable data,making it an attractive resource for predicting student *** this study,we aimed to predict student performance based on the analysis of data collected from the OULAD and Deeds *** stacking method was employed for modeling in this *** proposed model utilized weak learners,including nearest neighbor,decision tree,random forest,enhanced gradient,simple Bayes,and logistic regression *** a trial-and-error process,the logistic regression algorithm was selected as the final learner for the proposed *** results of experiments with the above algorithms are reported separately for the pass and fail *** findings indicate that the accuracy of the proposed model on the OULAD dataset reached 98%.Overall,the proposed method improved accuracy by 4%on the OULAD dataset.

关键词： Stacking e-learning student performance prediction machine learning classification