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Plant-pollinator metanetworks in fragmented landscapes:a simulation study

Ecological Processes 2023年第1期12卷 415-424页

作者： ehsan Rahimi Chuleui Jung Agricultural Science and Technology Institute Andong National UniversityAndong City 36729Republic of Korea Department of Plant Medicals Andong National UniversityAndong CityRepublic of Korea

Background The topology of the plant-pollinator network can be explained by the species’abundance and their random ***-pollinator networks can be studied in the context of a landscape,because each patch can accommodate a certain local *** populations of pollinators in the landscape can be connected through migration and then constitute a metanetwork that is known as a combination of spatial and ecological *** this regard,habitat fragmentation can affect the topology of plant-pollinator metanetworks through changes in the species abundance and limiting their ***,it is not clear what pattern(fragmented or aggregated)of the landscape structure can accommodate networks with a higher degree of *** we created simulated landscapes with different forest proportions scenarios(from 5%to 50%of the total landscape)and degrees of ***,for each landscape,we limited the proportion of pollinators to the forest *** assumed that plants and pollinators are randomly distributed around the landscape and interact *** used landscape metrics to measure different aspects of landscape structure and bipartite metrics for calculating the degree of specialization in plant-pollinator *** The statistical relationship between bipartite and landscape metrics showed that the relationship between the topology of plant-pollinator networks and the landscape structure is affected by the forest amount in the landscape and the degree of forest *** also found that according to the nestedness and H2(a measure of specialization)metrics,fragmented landscapes contain more general plant-pollinator *** Our findings suggest that fragmented landscapes,characterized by scattered forest patches,can promote higher levels of interaction between limited pollinators and diverse flowers,leading to more general plant-pollinator networks.

关键词： Plant–pollinator metanetwork Habitat fragmentation Simulated landscape Landscape metrics Bipartite metrics

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An efficient aerodynamic shape optimization of blended wing body UAV using multi-fidelity models

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Chinese Journal of Aeronautics 2018年第6期31卷 1165-1180页

作者： Parviz MOHAMMAD zadeh Mohsen SAYADI Faculty of New Sciences and Technologies University of Tehran

This paper presents a novel optimization technique for an efficient multi-fidelity model building approach to reduce computational costs for handling aerodynamic shape optimization based on high-fidelity simulation models. The wing aerodynamic shape optimization problem is solved by dividing optimization into three steps—modeling 3D（high-fidelity） and 2D（lowfidelity） models, building global meta-models from prominent instead of all variables, and determining robust optimizing shape associated with tuning local meta-models. The adaptive robust design optimization aims to modify the shape optimization process. The sufficient infilling strategy—known as adaptive uniform infilling strategy—determines search space dimensions based on the last optimization results or initial point. Following this, 3D model simulations are used to tune local meta-models. Finally, the global optimization gradient-based method—Adaptive Filter Sequential Quadratic Programing（AFSQP） is utilized to search the neighborhood for a probable optimum point. The effectiveness of the proposed method is investigated by applying it, along with conventional optimization approach-based meta-models, to a Blended Wing Body（BWB） Unmanned Aerial Vehicle（UAV）. The drag coefficient is defined as the objective function, which is subjected to minimum lift coefficient bounds and stability constraints. The simulation results indicate improvement in meta-model accuracy and reduction in computational time of the method introduced in this paper.

关键词： Adaptive filter sequential quadratic programing(AFSQP) Adaptive robust meta-model Aerodynamic shape optimization Blended wing body(BWB) Move limit strategy Unmanned aerial vehicle(UAV)

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颗粒大小对蔬菜废弃物厌氧发酵过程的影响研究

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中国沼气 2024年第4期42卷 3-9页

作者：李金平张奥博孙永明 Vojislav Novakovic ehsan Gholamian Karkon 甘肃省太阳能与生物质互补多联供系统重点试验室兰州730050 西北低碳城镇支撑技术省部共建协同创新中心兰州730050 兰州理工大学能源与动力工程学院兰州730050 中国科学院广州能源所广州510640 挪威科技大学能源与过程工程系挪威特隆赫姆NO-7491

蔬菜流通环节产生的大量蔬菜废弃物(即尾菜)亟需无害化处理,然而现有尾菜规模化处理采用的“破碎+压榨+厌氧/好氧”处理工艺易出现厌氧发酵酸化问题。为了破解此问题,在分析现有尾菜规模化处理工艺中发现破碎过细是造成厌氧发酵酸化的... 详细信息

蔬菜流通环节产生的大量蔬菜废弃物(即尾菜)亟需无害化处理,然而现有尾菜规模化处理采用的“破碎+压榨+厌氧/好氧”处理工艺易出现厌氧发酵酸化问题。为了破解此问题,在分析现有尾菜规模化处理工艺中发现破碎过细是造成厌氧发酵酸化的主要原因,因以尾菜为主要原料的厌氧发酵,常因为其水解过快,体系内有机酸过度积累出现酸化现象,导致产气失败。为了进一步研究颗粒大小对尾菜厌氧发酵过程的影响,提高其能源利用率,文章选取白菜作为试验底物,比较了高有机负荷下不同颗粒大小白菜(2 cm见方小块、完整叶片、1/4棵)对产沼气性能的影响。结果表明:较小颗粒大小会导致出现酸化现象。颗粒大小为整片和1/4棵条件下累积产气量分别为68.1 L、69.2 L,发酵过程处于稳定状态;颗粒大小为2 cm小块试验组出现酸化产气停止,各基础指标出现停滞或累积现象。试验可为尾菜规模化快速处理提供数据参考。

关键词：蔬菜废弃物处理利用颗粒大小厌氧消化酸抑制

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Investigation of Poly(ether-b-amide)/Nanosilica Membranes for CO_2/CH_4 Separation

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Chinese Journal of Polymer Science 2014年第4期32卷 402-410页

作者： ehsan Seddigh Morteza Azizi ehsan Shirzaei Sani Davod Mohebbi-Kalhori Department of Chemical Engineering University of Sistan and Baluchestan

The results of molecular dynamics （MD） simulations on transport process of CO2 and CH4 gases in poly（ether-b- amide）（PEBAX）/nanosilica membranes are discussed. The diffusion coefficients for CH4 and CO2 gases at 6 cases with different amounts of nanosilica loading in the simulation boxes are presented. The results show that diffusion coefficients for CO2 gas in all cases are larger than those for the CH4 one. Moreover 10% nanosilica loading case shows maximum effects on diffusion coefficients and improves them by more than 68% and 157% for CO2 and CH4 gases, respectively. Additionally, the results of 3-D Cartesian trajectories and displacements curves are presented and the jumping attempt of CO2 is significantly more than that of CH4. Due to the rubbery state of PEBAX membranes in ambient temperature, the results confirm that channel lifetimes are very short and then back diffusion is not observed for this polymer.

关键词： Gas separation Polymeric membrane Molecular dynamics Diffusion coefficient.

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Catalytic process modeling and sensitivity analysis of alkylation of benzene with ethanol over MIL-101(Fe) and MIL-88(Fe)

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Frontiers of Chemical Science and Engineering 2020年第6期14卷 1100-1111页

作者： ehsan Rahmani Mohammad Rahmani Department of Chemical Engineering Amirkabir University of TechnologyTehran 158754413Iran

A solvothermal method was used to synthesize MIL-101(Fe)and MIL-88(Fe),which were used for alkylation of *** synthesized catalysts were characterized by X-ray diffraction,Fourier transform infrared spectroscopy,field emission scanning electron microscope,dynamic light scattering,and BET ***-organic frameworks(MOFs)were modeled to investigate the catalytic performance and existence of mass transfer *** effectiveness factors revealed absence of internal a nd external mass *** analysis revealed best operating conditions over MIL-101 at 120℃ and 5 bar and over MIL-88 at 142℃ and 9 bar.

关键词： MOFs alkylation ethylbenzene catalysts pellet model kinetic model sensitivity analysis

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A Test Approach for Look-Up Table Based FPGAs

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Journal of Computer Science & Technology 2006年第1期21卷 141-146页

作者： ehsan Atoofian Zainalabedin Navabi Department of Electrical and Computer Engineering University of Tehran 14399 Tehran Iran

This paper describes a test architecture for minimum number of test configurations in test of FPGA （Field Programmable Gate Array） LUTs （Look Up Tables）. The test architecture includes a TPG （Test Pattern Generator） that is tested while it is generating test data for LEs （Logic Elements） that form the CUT （Circuit Under Test）. This scheme eliminates the need for switching LEs between CUT, TPG and ORA （Output Response Analyzer） and having to perform many more reconfiguratioas of the FPGA. An external ORA locates faults of the FPGA under test. In addition to the LUTs, a scheme is presented for testing other parts of LEs. Compared with other methods, the presented scheme uses the least number of reconfigurations of an FPGA for its LUT testing.

关键词： FPGA testing BIST LUT testing memory testing TPG with LE

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Texture evolution and mechanical anisotropy of an ultrafine/nano-grained pure copper tube processed via hydrostatic tube cyclic expansion extrusion

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International Journal of Minerals,Metallurgy and Materials 2022年第12期29卷 2241-2251页

作者： Seyed Moien Faregh Ghader Faraji Mahmoud Mosavi Mashhadi Mohammad eftekhari School of Mechanical Engineering College of EngineeringUniversity of TehranTehran 11155-4563Iran

Texture evolution and mechanical anisotropic behavior of an ultrafine-grained(UFG)pure copper tube processed by recently introduced method of hydrostatic tube cyclic expansion extrusion(HTCEE)was *** the UFG tube,different deformation behavior and a significant anisotropy in tensile properties were recorded along the longitudinal and peripheral *** HTCEE process increased the yield strength and the ultimate strength in the axial direction by 3.6 and 1.67 times,***,this process increased the yield strength and the ultimate strength in the peripheral direction by 1.15 and 1.12 times,*** ratio of ultimate tensile strength in the peripheral direction to that in the axial direction,as a criterion for mechanical anisotropy,are 1.7 and 1.16 for the as-annealed coarse-grained and the HTCEE processed UFG tube,*** results are indicative of a reducing effect of the HTCEE process on the mechanical ***,after HTCEE process,a low loss of ductility was observed in both directions,which is another advantage of HTCEE *** measurements revealed a slight increment of hardness values in the peripheral direction,which is in agreement with the trend of tensile *** analysis was conducted in order to determine the oriental distribution of the *** obtained{111}pole figures demonstrate the texture evolution and reaffirm the anisotropy observed in mechanical *** electron microscopy micrographs showed that different modes of fracture occurred after tensile testing in the two orthogonal directions.

关键词： severe plastic deformation ultrafine grained hydrostatic tube cyclic expansion extrusion anisotropy texture

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Teaching the User By Learning From the User:Personalizing Movement Control in Physical Human-robot Interaction

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IEEE/CAA Journal of Automatica Sinica 2017年第4期4卷 704-713页

作者： Ali Safavi Mehrdad H.zadeh Department of Electrical and Computer Engineering Kettering UniversityFlintMI 48504USA

This paper proposes a novel approach for physical human-robot interactions(pHRI), where a robot provides guidance forces to a user based on the user performance. This framework tunes the forces in regards to behavior of each user in coping with different tasks, where lower performance results in higher intervention from the robot. This personalized physical human-robot interaction(p2HRI) method incorporates adaptive modeling of the interaction between the human and the robot as well as learning from demonstration(LfD) techniques to adapt to the users' performance. This approach is based on model predictive control where the system optimizes the rendered forces by predicting the performance of the user. Moreover, continuous learning of the user behavior is added so that the models and personalized considerations are updated based on the change of user performance over time. Applying this framework to a field such as haptic guidance for skill improvement, allows a more personalized learning experience where the interaction between the robot as the intelligent tutor and the student as the user,is better adjusted based on the skill level of the individual and their gradual improvement. The results suggest that the precision of the model of the interaction is improved using this proposed method,and the addition of the considered personalized factors to a more adaptive strategy for rendering of guidance forces.

关键词： Haptic guidance learning from demonstration(LfD) personalized physical human-robot interaction(p2HRI) user performance

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ECG beat classification using particle swarm optimization and support vector machine

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Frontiers of Computer Science 2014年第2期8卷 217-231页

作者： Ali KHAZAEE A. E. zadeh Department of Electrical Engineering Bojnourd Branch Islamic Azad University Bojnourd *** Iran Faculty of Electrical and Computer Engineering B abol University of Technology Bobo*** Iran

In this paper, we propose a novel ECG arrhythmia classification method using power spectral-based features and support vector machine （SVM） classifier. The method extracts electrocardiogram＇s spectral and three timing inter- val features. Non-parametric power spectral density （PSD） estimation methods are used to extract spectral features. The proposed approach optimizes the relevant parameters of SVM classifier through an intelligent algorithm using parti- cle swarm optimization （PSO）. These parameters are： Gaus- sian radial basis function （GRBF） kernel parameter o- and C penalty parameter of SVM classifier. ECG records from the MIT-BIH arrhythmia database are selected as test data. It is observed that the proposed power spectral-based hybrid par- ticle swarm optimization-support vector machine （SVMPSO） classification method offers significantly improved perfor- mance over the SVM which has constant and manually ex- tracted parameter.

关键词： ECG arrhythmia classification SVM PSO op-timization PSD

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Estimating Network Connectedness of Financial Markets and Commodities

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Journal of Systems Science and Systems Engineering 2020年第5期29卷 572-589页

作者： ehsan Bagheri Seyed Babak Ebrahimi Financial Engineering Group Faculty of Industrial EngineeringK.N.Toosi University of TechnologyTehranIran

We investigate the directional volatility and return network connectedness among stock,commodity,bond,currency and cryptocurrency *** period of study covers Feb 2006 until August *** utilize and expand Diebold and Yilmaz(20142015)connectedness measurement;accordingly,in the variance decomposition structure,we use Hierarchical Vector Autoregression(HVAR)to estimate high dimensional networks more *** empirical results show that markets are highly connected,especially during *** stock markets are the net receiver of shocks,while European and American stock markets are the net transmitter of shocks to other *** pairwise connectedness results suggest that among stock markets,DAX-CAC 40,FTSE 100-CAC 40 and S&P 500-S&P_TSX index are more integrated through connectedness than the *** other markets,WTI crude oil-Brent crude oil,30-Year bond and 10-Year bond,Dollar Index futures-EUR/USD have notable *** terms of cryptocurrencies,they contribute insignificantly to other markets and are highly integrated with each *** and cryptocurrencies seem to be good choices for investors to hedge during a crisis.

关键词： Financial markets network connectedness econometrics commodity

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