Switched Reluctance Motors(SRMs),outfitted with rugged construction,good speed range,high torque density,and rare earth-free nature that outweigh induction motors(IM)and permanent magnet synchronous motor(PMSM),afford...Switched Reluctance Motors(SRMs),outfitted with rugged construction,good speed range,high torque density,and rare earth-free nature that outweigh induction motors(IM)and permanent magnet synchronous motor(PMSM),afford a broad range of applications in the domain of electric vehicles(EVs).Standard copper magnetic wire and low-carbon steel laminations are used to construct SRMs,which give them high efficiency in the range of 85-95%.Despite SRM's desirable features over traditional motor-speed drives,high torque ripples and radial distortions constrain their deployment in EVs.Precise rotor position is imperative for effective management of the speed and torque of SRMs.This paper provides an illustrative compendium on review of the torque-speed control and ripple mitigation techniques using design enhancements and control methods for SRM drives for EV applications.The various schemes were evaluated on their performance metricsoperational speed range,control complexity,practical realization,need for pre-stored parameters(look-up tables of current,inductance and torque profiles)and motor controller memory requirements.The findings provide valuable insights into balancing the gains and trade-offs associated with EV applications.Furthermore,they pinpoint opportunities for enhancement by analyzing the cost and technical aspects of different SRM controllers.展开更多
As organic thin film transistors(OTFTs)are set to play a crucial role in flexible and cost-effective electronic applica-tions,this paper investigates a high-mobility 6,13-bis(triisopropylsilylethynyl)pentacene(TIPS-pe...As organic thin film transistors(OTFTs)are set to play a crucial role in flexible and cost-effective electronic applica-tions,this paper investigates a high-mobility 6,13-bis(triisopropylsilylethynyl)pentacene(TIPS-pentacene)OTFT for use in flexi-ble electronics.The development of such high-mobility devices necessitates precise device modeling to support technology opti-misation and circuit design.The details of numerical simulation technique is discussed,in which,the electrical behavior of the device is well captured by fine tuning basic semiconductor equations.This technology computer-aided design(TCAD)has been validated with exprimental data.In addition,we have discussed about compact model fitting of the devices as well as parameter extraction procedure employed.This includes verification of Silvaco ATLAS finite element method(FEM)based results against experimental data gained from fabricated OTFT devices.Simulations for p-type TFT-based inverter are also per-formed to assess the performance of compact model in simple circuit simulation.展开更多
Digital content such as games,extended reality(XR),and movies has been widely and easily distributed over wireless networks.As a result,unauthorized access,copyright infringement by third parties or eavesdroppers,and ...Digital content such as games,extended reality(XR),and movies has been widely and easily distributed over wireless networks.As a result,unauthorized access,copyright infringement by third parties or eavesdroppers,and cyberattacks over these networks have become pressing concerns.Therefore,protecting copyrighted content and preventing illegal distribution in wireless communications has garnered significant attention.The Intelligent Reflecting Surface(IRS)is regarded as a promising technology for future wireless and mobile networks due to its ability to reconfigure the radio propagation environment.This study investigates the security performance of an uplink Non-Orthogonal Multiple Access(NOMA)system integrated with an IRS and employing Fountain Codes(FCs).Specifically,two users send signals to the base station at separate distances.A relay receives the signal from the nearby user first and then relays it to the base station.The IRS receives the signal from the distant user and reflects it to the relay,which then sends the reflected signal to the base station.Furthermore,a malevolent eavesdropper intercepts both user and relay communications.We construct mathematical equations for Outage Probability(OP),throughput,diversity evaluation,and Interception Probability(IP),offering quantitative insights to assess system security and performance.Additionally,OP and IP are analyzed using a Deep Neural Network(DNN)model.A deeper comprehension of the security performance of the IRS-assisted NOMA systemin signal transmission is provided by Monte Carlo simulations,which are also carried out to confirm the theoretical conclusions.展开更多
The Tourism Industry plays a critical role in economic growth on the international scene but is equally responsible for contributing to greenhouse gas emissions and energy demand.The research analyzed the global trend...The Tourism Industry plays a critical role in economic growth on the international scene but is equally responsible for contributing to greenhouse gas emissions and energy demand.The research analyzed the global trends of energy consumption(EC)within this industry concerning environmental performance,limits,and prospects of sustained expan-sion.It includes 300 tourism-related businesses across different global economic regions.Key tourism factors include EC,greenhouse gas emissions,renewable energy(RE)use,tourism’s Gross Domestic Product(GDP)contribution,and energy efficiency.Statistical methods such as regression and panel data analysis assess the impact of tourism GDP,carbon emissions and RE.The regression analysis,including linear regression and panel data regression,to assess the influence of factors such as tourism GDP,carbon emissions,RE share,and energy efficiency improvements,providing a data-driven approach to understanding EC in tourism.The findings reveal regional differences,with developed regions consuming more energy per capita,while developing markets show progress in energy-efficient practices.The findings of the linear regression analysis show tourism GDP contribution(β=4,200).The outcomes of the panel data regression analysis show the t-statistic values of carbon emissions(t=5.64).The Difference-in-Differences analysis indicates that tourist GDP is greater in developed regions(β=4,100)compared to developing regions(β=3,500).Carbon emissions(β=4,800)are greater,although RE(β=4,200)and energy efficiency(β=2,500)increase more in developing nations.The research emphasizes expanding use of RE in tourism infrastructure,especially in ecotourism and green hotels.展开更多
In this study,ten wind turbines and fourteen solar photovoltaic(SPV)modules were employed to compare the potential of hydrogen production from wind and solar energy resources in the six geopolitical zones of Nigeria.T...In this study,ten wind turbines and fourteen solar photovoltaic(SPV)modules were employed to compare the potential of hydrogen production from wind and solar energy resources in the six geopolitical zones of Nigeria.The amount of hydrogen produced was considered as a technical parameter,cost of hydrogen production was considered as an economic index,and the amount of carbon(IV)oxide saved from the use of diesel fuel was considered as an environmental index.The results reveal that ENERCON E-40 turbine yields the highest capacity factor in Lagos,Jos,Sokoto,Bauchi and Enugu sites while FUHRLAENDER,GMBH yields the highest capacity factor in Delta.The mean annual hydrogen production from wind ranged from 2.05 tons/annum at site S6(Delta)to 17.33 tons/annum at site S3(Sokoto),and the mean annual hydrogen production from SPV ranged from 64.33 tons/annum at sites S1(Lagos)to 140.28 tons/annum at site S6(Delta).The cost of hydrogen production from wind was 6.3679 and 25.9007$/kg for sites S3 and S6,respectively,and the cost of hydrogen production from SPV was 5.6659 and 6.1206$/kg for sites S3 and S1,respectively.The amount of CO_(2) saved annually from wind-based hydrogen generation was 137,267 kg/year in site S6 and 504,180 kg/year in site S3,and was used to produce electricity via fuel cells.The amount of CO_(2) saved using hydrogen produced from SPV was 615,400 kg/year and 1,341,899 kg/year in sites S1 and S6,respectively.The results also revealed that 75.55%,88.93%,80.28%,80.54%,85.65%,98.53%more hydrogen could be produced from SPV for sites S1–S6,respectively,compared to the wind resources.This study serves as a source of reliable technical information to relevant government agencies,policy makers and investors in making informed decisions on optimal investment in the hydrogen economy of Nigeria.展开更多
Reconfiguration,as well as optimal utilization of distributed generation sources and capacitor banks,are highly effective methods for reducing losses and improving the voltage profile,or in other words,the power quali...Reconfiguration,as well as optimal utilization of distributed generation sources and capacitor banks,are highly effective methods for reducing losses and improving the voltage profile,or in other words,the power quality in the power distribution system.Researchers have considered the use of distributed generation resources in recent years.There are numerous advantages to utilizing these resources,the most significant of which are the reduction of network losses and enhancement of voltage stability.Non-dominated Sorting Genetic Algorithm II(NSGA-II),Multi-Objective Particle Swarm Optimization(MOPSO),and Intersect Mutation Differential Evolution(IMDE)algorithms are used in this paper to perform optimal reconfiguration,simultaneous location,and capacity determination of distributed generation resources and capacitor banks.Three scenarios were used to replicate the studies.The reconfiguration of the switches,as well as the location and determination of the capacitor bank’s optimal capacity,were investigated in this scenario.However,in the third scenario,reconfiguration,and determining the location and capacity of the Distributed Generation(DG)resources and capacitor banks have been carried out simultaneously.Finally,the simulation results of these three algorithms are compared.The results indicate that the proposed NSGAII algorithm outperformed the other two multi-objective algorithms and was capable of maintaining smaller objective functions in all scenarios.Specifically,the energy losses were reduced from 211 to 51.35 kW(a 75.66%reduction),119.13 kW(a 43.54%reduction),and 23.13 kW(an 89.04%reduction),while the voltage stability index(VSI)decreased from 6.96 to 2.105,1.239,and 1.257,respectively,demonstrating significant improvement in the voltage profile.展开更多
The Dhofar region of Oman,renowned for its unique monsoon-influenced climate and substantial agricultural potential,faces significant challenges in achieving sustainable agricultural practices that balance productivit...The Dhofar region of Oman,renowned for its unique monsoon-influenced climate and substantial agricultural potential,faces significant challenges in achieving sustainable agricultural practices that balance productivity with environmental conservation.This review critically explores a range of sustainable agricultural methods currently im-plemented in the region,including organic farming,water conservation techniques such as drip irrigation and rainwater harvesting,agroforestry systems,crop rotation,and soil conservation measures like terracing and composting.These strategies aim to mitigate pressing environmental concerns such as water scarcity,soil erosion,and land degradation while enhancing crop yield and farm profitability.The review further examines the economic implications of these practices, evaluating their cost-effectiveness, potential for long-term returns, and influence on the growing market demandfor organic and eco-friendly products. Despite their benefits, the broader adoption of these sustainable approaches ishindered by several challenges, including limited access to advanced technologies, inadequate financial resources, lackof technical knowledge, and minimal awareness among local farmers. The article also assesses the role of governmentalpolicies, subsidies, and extension services in promoting the adoption of sustainable agriculture in Dhofar. Finally, it offersstrategic recommendations for future research, policy development, and capacity-building initiatives. This reviewemphasizes the urgent need for continued investment in sustainable solutions to ensure long-term agricultural resilienceand environmental sustainability in the region.展开更多
1 Introduction Amid escalating global climate change,the“dual carbon”goals of carbon peak and carbon neutrality have become a focal point of global attention and an important strategy for sustainable development[1]....1 Introduction Amid escalating global climate change,the“dual carbon”goals of carbon peak and carbon neutrality have become a focal point of global attention and an important strategy for sustainable development[1].With the rapid development of renewable energy technologies and the increasing public demand for environmental protection and low-carbon living,the adoption of new energy vehicles,particularly electric vehicles(EVs).展开更多
The results of mass appraisal in many countries are used as a basis for calculating the amount of real estate tax,therefore,regardless of the methods used to calculate it,the resulting value should be as close as poss...The results of mass appraisal in many countries are used as a basis for calculating the amount of real estate tax,therefore,regardless of the methods used to calculate it,the resulting value should be as close as possible to the market value of the real estate to maintain a balance of interests between the state and the rights holders.In practice,this condition is not always met,since,firstly,the quality of market data is often very low,and secondly,some markets are characterized by low activity,which is expressed in a deficit of information on asking prices.The aim of the work is ecological valuation of land use:how regression-based mass appraisal can inform ecological conservation,land degradation,and sustainable land management.Four multiple regression models were constructed for AI generated map of land plots for recreational use in St.Petersburg(Russia)with different volumes of market information(32,30,20 and 15 units of market information with four price-forming factors).During the analysis of the quality of the models,it was revealed that the best result is shown by the model built on the maximum sample size,then the model based on 15 analogs,which proves that a larger number of analog objects does not always allow us to achieve better results,since the more analog objects there are.展开更多
Energy storage, such as lead acid batteries, is necessary for renewable energy sources’ autonomy because of their intermittent nature, which makes them more frequently used than traditional energy sources to reduce o...Energy storage, such as lead acid batteries, is necessary for renewable energy sources’ autonomy because of their intermittent nature, which makes them more frequently used than traditional energy sources to reduce operating costs. The battery storage system has to be monitored and managed to prevent serious problems such as battery overcharging, over-discharging, overheating, battery unbalancing, thermal runaway, and fire dangers. For voltage balancing between batteries in the pack throughout the charging period and the SOC estimate, a modified lossless switching mechanism is used in this research’s suggested battery management system. The OCV state of charge calculation, in the beginning, was used in conjunction with the coulomb counting approach to estimate the SOC. The results reveal that correlation factor K has an average value of 0.3 volts when VM ≥ 12 V and an average value of 0.825 when VM ≤ 12 V. The battery monitoring system revealed that voltage balancing was accomplished during the charging process in park one after 80 seconds with a SOC difference of 1.4% between Batteries 1 and 2. On the other hand, the system estimates the state of charge during the discharging process in two packs, with a maximum DOD of 10.8 V for all batteries. The project’s objectives were met since the BMS estimated SOC and achieved voltage balance.展开更多
The latest developments in bio-inspired neuromorphic vision sensors can be summarized in 3 keywords:smaller,faster,and smarter.(1)Smaller:Devices are becoming more compact by integrating previously separated component...The latest developments in bio-inspired neuromorphic vision sensors can be summarized in 3 keywords:smaller,faster,and smarter.(1)Smaller:Devices are becoming more compact by integrating previously separated components such as sensors,memory,and processing units.As a prime example,the transition from traditional sensory vision computing to in-sensor vision computing has shown clear benefits,such as simpler circuitry,lower power consumption,and less data redundancy.(2)Swifter:Owing to the nature of physics,smaller and more integrated devices can detect,process,and react to input more quickly.In addition,the methods for sensing and processing optical information using various materials(such as oxide semiconductors)are evolving.(3)Smarter:Owing to these two main research directions,we can expect advanced applications such as adaptive vision sensors,collision sensors,and nociceptive sensors.This review mainly focuses on the recent progress,working mechanisms,image pre-processing techniques,and advanced features of two types of neuromorphic vision sensors based on near-sensor and in-sensor vision computing methodologies.展开更多
The development of alternative renewable energy technologies is crucial for alleviating climate change and promoting energy transformation.Of the currently available technologies,solar energy has promising application...The development of alternative renewable energy technologies is crucial for alleviating climate change and promoting energy transformation.Of the currently available technologies,solar energy has promising application prospects owing to its merits of being clean,safe,and sustainable.Solar energy is converted into electricity through photovoltaic(PV)cells;however,the overall conversion efficiency of PV modules is relatively low,and most of the captured solar energy is dissipated in the form of heat.This not only reduces the power generation efficiency of solar cells but may also have a negative impact on the electrical parameters of PV modules and the service life of PV cells.To overcome the shortcomings,an efficient approach involves combining a PV cell with a thermoelectric generator(TEG)to form hybrid PV-TEG systems,which simultaneously improve the energy conversion efficiency of the PV system by reducing the operating temperature of the PV modules and increasing the power output by utilizing the waste heat generated from the PV system to generate electricity via the TEGs.Based on a thorough examination of the literature,this study comprehensively reviews 14 maximum power point tracking(MPPT)algorithms currently applied to hybrid PV-TEG systems and classifies them into five major categories for further discussion,namely conventional,mathematics-based,metaheuristic,artificial intelligence,and other algorithms.This review aims to inspire advanced ideas and research on MPPT algorithms for hybrid PV-TEG systems.展开更多
Boron-doped NiO thin films were prepared on glass substrates at 400℃ by airbrush spraying method using a solution of nickel nitrate hexahydrate. Their physical properties were investigated as a function of dopant con...Boron-doped NiO thin films were prepared on glass substrates at 400℃ by airbrush spraying method using a solution of nickel nitrate hexahydrate. Their physical properties were investigated as a function of dopant concentration. From X-ray diffraction patterns, it is observed that the films have cubic structure with lattice parameters varying with boron concentration. The morphologies of the films were examined by using scanning electron microscopy, and the grain sizes were measured to be around 30-50 nm. Optical measurements show that the band gap energies of the films first decrease then increase with increasing boron concentration. The resistivities of the films were determined by four point probe method, and the changes in resistivity with boron concentration were investigated.展开更多
As wind energy is becoming one of the fastestgrowing renewable energy resources,controlling large-scale wind turbines remains a challenging task due to its system model nonlinearities and high external uncertainties.T...As wind energy is becoming one of the fastestgrowing renewable energy resources,controlling large-scale wind turbines remains a challenging task due to its system model nonlinearities and high external uncertainties.The main goal of the current work is to propose an intelligent control of the wind turbine system without the need for model identification.For this purpose,a novel model-independent nonsingular terminal slidingmode control(MINTSMC)using the basic principles of the ultralocal model(ULM)and combined with the single input interval type-2 fuzzy logic control(SIT2-FLC)is developed for non-linear wind turbine pitch angle control.In the suggested control framework,the MINTSMC scheme is designed to regulate the wind turbine speed rotor,and a sliding-mode(SM)observer is adopted to estimate the unknown phenomena of the ULM.The auxiliary SIT2-FLC is added in the model-independent control structure to improve the rotor speed regulation and compensate for the SM observation estimation error.Extensive examinations and comparative analyses were made using a real-time softwarein-the-loop(RT-SiL)based on the dSPACE 1202 board to appraise the efficiency and applicability of the suggested modelindependent scheme in a real-time testbed.展开更多
Development of metal matrix composite is becoming widespread in most engineering applications where excellent mechanical properties are required.Mechanical and microstructural properties of aluminium reinforced with s...Development of metal matrix composite is becoming widespread in most engineering applications where excellent mechanical properties are required.Mechanical and microstructural properties of aluminium reinforced with silicon carbide was investigated.Ingot of aluminium was melted in a furnace at temperature ranging between 650-700℃.Ferrotitanium and silicon carbide were preheated in a muffle furnace before addition to molten aluminium in a crucible furnace.Fixed proportions of magnesium,ferrotitanium and varying proportions of silicon carbide were utilized as reinforcements.Stirring was carried out manually for a minimum of 10 mins after the addition of each weight percent of silicon carbide.Resulting as-cast samples were sectioned for various mechanical and microstructural analysis.Microstructural studies from optical microscopy and scanning electron microscopy(SEM)showed the dispersion of reinforcements in the aluminium matrix.Mechanical properties which includes hardness and tensile strength of fabricated composites were observed to increase,while XRD analysis showed various phases formed from reaction between the matrix and reinforcements.展开更多
This study presents a parametric system identification approach to estimate the dynamics of a chemical plant from experimental data and develops a robust PID controller for the plant.Parametric system identification o...This study presents a parametric system identification approach to estimate the dynamics of a chemical plant from experimental data and develops a robust PID controller for the plant.Parametric system identification of the heat exchanger system has been carried out using experimental data and prediction error method.The estimated model of the heat exchanger system is a time-delay model and a robust PID controller for the time-delayed model has been designed considering weighted sensitivity criteria.The mathematical background of parametric system identification,stability analysis,and H∞ weighted sensitivity analysis have been provided in this paper.A graphical plot has been provided to determine the stability region in the(Kp,Ki),(Kp,Kd)and(KuKd)plane.The stability region is a locus dependent on parameters of the controller and frequency,in the parameter plane.展开更多
In this article,plasma-assisted NH;synthesis directly from N;and H;over packing materials with different dielectric constants(BaTiO_(2),TiO_(2) and SiO_(2))and thermal conductivities(Be O,Al N and Al_(2)O_(2))at room ...In this article,plasma-assisted NH;synthesis directly from N;and H;over packing materials with different dielectric constants(BaTiO_(2),TiO_(2) and SiO_(2))and thermal conductivities(Be O,Al N and Al_(2)O_(2))at room temperature and atmospheric pressure is reported.The higher dielectric constant and thermal conductivity of packing material are found to be the key parameters in enhancing the NH;synthesis performance.The NH;concentration of 1344 ppm is achieved in the presence of BaTiO_(2),which is 106%higher than that of SiO_(2),at the specific input energy(SIE)of 5.4 k J·l^(-1).The presence of materials with higher dielectric constant,i.e.BaTiO_(2) and TiO_(2)in this work,would contribute to the increase of electron energy and energy injected to plasma,which is conductive to the generation of chemically active species by electron-impact reactions.Therefore,the employment of packing materials with higher dielectric constant has proved to be beneficial for NH;synthesis.Compared to that of Al_(2)O_(3),the presence of Be O and Al N yields 31.0%and 16.9%improvement in NH;concentration,respectively,at the SIE of5.4 k J·l^(-1).The results of IR imaging show that the addition of Be O decreases the surface temperature of the packed region by 20.5%to 70.3℃ and results in an extension of entropy increment compared to that of Al_(2)O_(3),at the SIE of 5.4 k J·l^(-1).The results indicate that the presence of materials with higher thermal conductivity is beneficial for NH;synthesis,which has been confirmed by the lower surface temperature and higher entropy increment of the packed region.In addition,when SIE is higher than the optimal value,further increasing SIE would lead to the decrease of energy efficiency,which would be related to the exacerbation in reverse reaction of NH;formation reactions.展开更多
An electrochromic copolymer film of 2-(3,3-dihexyl-3,4-dihydro-2 H-thieno[3,4-b][1,4]dioxepin-6-yl)-7-(3,3-dihexyl-3,4-dihydro-2 H-thieno[3,4-b][1,4]dioxepin-8-yl)-9 H-carbazole(M1) and 4,7-bis(thiophen-2-yl)benzo[c][...An electrochromic copolymer film of 2-(3,3-dihexyl-3,4-dihydro-2 H-thieno[3,4-b][1,4]dioxepin-6-yl)-7-(3,3-dihexyl-3,4-dihydro-2 H-thieno[3,4-b][1,4]dioxepin-8-yl)-9 H-carbazole(M1) and 4,7-bis(thiophen-2-yl)benzo[c][1,2,5]thiadiazole(M2) was prepared via electrochemical technique. The copolymerization was performed with one to one monomer feed ratio. Electrochemical and optical properties of the resulting copolymer film(P3) and the homopolymer films of M1 and M2(P1 and P2) were investigated by using cyclic voltammetry and UV-Vis spectrometry techniques, and the corresponding results were compared. Incorporation of M1 and M2 into copolymer matrix was clearly observed on the resulting cyclic voltammograms and UV-Vis spectra. P3 covered the visible regions coming from both P1 and P2, and exhibited a neutral state darker color than those of homopolymers. P3 film was found to have a multichromic behavior, appearing as brown in its neutral state while changing its color upon oxidation to dark-gray(at about 0.3 V), to blue(at about 0.6 V) and finally to grayish cyan(beyond 0.9 V), with a corresponding optical band gap of 1.65 eV.展开更多
In electrical circuit analysis, it is often necessary to find the set of all direct current （d.c.） operating points （either voltages or currents） of nonlinear circuits. In general, these nonlinear equations are of...In electrical circuit analysis, it is often necessary to find the set of all direct current （d.c.） operating points （either voltages or currents） of nonlinear circuits. In general, these nonlinear equations are often represented as polynomial systems. In this paper, we address the problem of finding the solutions of nonlinear electrical circuits, which are modeled as systems of n polynomial equations contained in an n-dimensional box. Branch and Bound algorithms based on interval methods can give guaranteed enclosures for the solution. However, because of repeated evaluations of the function values, these methods tend to become slower. Branch and Bound algorithm based on Bernstein coefficients can be used to solve the systems of polynomial equations. This avoids the repeated evaluation of function values, but maintains more or less the same number of iterations as that of interval branch and bound methods. We propose an algorithm for obtaining the solution of polynomial systems, which includes a pruning step using Bernstein Krawczyk operator and a Bernstein Coefficient Contraction algorithm to obtain Bernstein coefficients of the new domain. We solved three circuit analysis problems using our proposed algorithm. We compared the performance of our proposed algorithm with INTLAB based solver and found that our proposed algorithm is more efficient and fast.展开更多
Intra-body communication (IBC) is a new,emerging,short-range and human body based communication methodology.It is a technique to network various devices on human body,by utilizing the conducting properties of human ti...Intra-body communication (IBC) is a new,emerging,short-range and human body based communication methodology.It is a technique to network various devices on human body,by utilizing the conducting properties of human tissues,suitable for currently fast developing Body area network (BAN)/Body sensor network (BSN).IBC is believed to have advantages in power consumption,electromagnetic radiation,interference from external electromagnetic noise,security,and restriction in spectrum resource.In this article,the authors develop two models,which are analytical and empirical approaches,for comparing the performance and accuracy of IBC on a human limb.Through in vivo experiment of five volunteers,both models basically match with the experimental result with equivalent circuit model superior than electromagnetic model in term of maximum error.展开更多
基金supported in part by the Universitat Politècnica de València under grant PAID-10-21supported through AMRITA Seed Grant(Proposal ID:ASG2022188)。
文摘Switched Reluctance Motors(SRMs),outfitted with rugged construction,good speed range,high torque density,and rare earth-free nature that outweigh induction motors(IM)and permanent magnet synchronous motor(PMSM),afford a broad range of applications in the domain of electric vehicles(EVs).Standard copper magnetic wire and low-carbon steel laminations are used to construct SRMs,which give them high efficiency in the range of 85-95%.Despite SRM's desirable features over traditional motor-speed drives,high torque ripples and radial distortions constrain their deployment in EVs.Precise rotor position is imperative for effective management of the speed and torque of SRMs.This paper provides an illustrative compendium on review of the torque-speed control and ripple mitigation techniques using design enhancements and control methods for SRM drives for EV applications.The various schemes were evaluated on their performance metricsoperational speed range,control complexity,practical realization,need for pre-stored parameters(look-up tables of current,inductance and torque profiles)and motor controller memory requirements.The findings provide valuable insights into balancing the gains and trade-offs associated with EV applications.Furthermore,they pinpoint opportunities for enhancement by analyzing the cost and technical aspects of different SRM controllers.
基金The DST government of India is appreciated by the researchers for giving them the early career research grant under the project ECR/2017/000179。
文摘As organic thin film transistors(OTFTs)are set to play a crucial role in flexible and cost-effective electronic applica-tions,this paper investigates a high-mobility 6,13-bis(triisopropylsilylethynyl)pentacene(TIPS-pentacene)OTFT for use in flexi-ble electronics.The development of such high-mobility devices necessitates precise device modeling to support technology opti-misation and circuit design.The details of numerical simulation technique is discussed,in which,the electrical behavior of the device is well captured by fine tuning basic semiconductor equations.This technology computer-aided design(TCAD)has been validated with exprimental data.In addition,we have discussed about compact model fitting of the devices as well as parameter extraction procedure employed.This includes verification of Silvaco ATLAS finite element method(FEM)based results against experimental data gained from fabricated OTFT devices.Simulations for p-type TFT-based inverter are also per-formed to assess the performance of compact model in simple circuit simulation.
基金supported in part by Vietnam National Foundation for Science and Technology Development(NAFOSTED)under Grant 102.04-2021.57in part by Culture,Sports and Tourism R&D Program through the Korea Creative Content Agency grant funded by the Ministry of Culture,Sports and Tourism in 2024(Project Name:Global Talent Training Program for Copyright Management Technology in Game Contents,Project Number:RS-2024-00396709,Contribution Rate:100%).
文摘Digital content such as games,extended reality(XR),and movies has been widely and easily distributed over wireless networks.As a result,unauthorized access,copyright infringement by third parties or eavesdroppers,and cyberattacks over these networks have become pressing concerns.Therefore,protecting copyrighted content and preventing illegal distribution in wireless communications has garnered significant attention.The Intelligent Reflecting Surface(IRS)is regarded as a promising technology for future wireless and mobile networks due to its ability to reconfigure the radio propagation environment.This study investigates the security performance of an uplink Non-Orthogonal Multiple Access(NOMA)system integrated with an IRS and employing Fountain Codes(FCs).Specifically,two users send signals to the base station at separate distances.A relay receives the signal from the nearby user first and then relays it to the base station.The IRS receives the signal from the distant user and reflects it to the relay,which then sends the reflected signal to the base station.Furthermore,a malevolent eavesdropper intercepts both user and relay communications.We construct mathematical equations for Outage Probability(OP),throughput,diversity evaluation,and Interception Probability(IP),offering quantitative insights to assess system security and performance.Additionally,OP and IP are analyzed using a Deep Neural Network(DNN)model.A deeper comprehension of the security performance of the IRS-assisted NOMA systemin signal transmission is provided by Monte Carlo simulations,which are also carried out to confirm the theoretical conclusions.
文摘The Tourism Industry plays a critical role in economic growth on the international scene but is equally responsible for contributing to greenhouse gas emissions and energy demand.The research analyzed the global trends of energy consumption(EC)within this industry concerning environmental performance,limits,and prospects of sustained expan-sion.It includes 300 tourism-related businesses across different global economic regions.Key tourism factors include EC,greenhouse gas emissions,renewable energy(RE)use,tourism’s Gross Domestic Product(GDP)contribution,and energy efficiency.Statistical methods such as regression and panel data analysis assess the impact of tourism GDP,carbon emissions and RE.The regression analysis,including linear regression and panel data regression,to assess the influence of factors such as tourism GDP,carbon emissions,RE share,and energy efficiency improvements,providing a data-driven approach to understanding EC in tourism.The findings reveal regional differences,with developed regions consuming more energy per capita,while developing markets show progress in energy-efficient practices.The findings of the linear regression analysis show tourism GDP contribution(β=4,200).The outcomes of the panel data regression analysis show the t-statistic values of carbon emissions(t=5.64).The Difference-in-Differences analysis indicates that tourist GDP is greater in developed regions(β=4,100)compared to developing regions(β=3,500).Carbon emissions(β=4,800)are greater,although RE(β=4,200)and energy efficiency(β=2,500)increase more in developing nations.The research emphasizes expanding use of RE in tourism infrastructure,especially in ecotourism and green hotels.
基金supported by Abiola Ajimobi Technical UniversityUniversity of Ibadan
文摘In this study,ten wind turbines and fourteen solar photovoltaic(SPV)modules were employed to compare the potential of hydrogen production from wind and solar energy resources in the six geopolitical zones of Nigeria.The amount of hydrogen produced was considered as a technical parameter,cost of hydrogen production was considered as an economic index,and the amount of carbon(IV)oxide saved from the use of diesel fuel was considered as an environmental index.The results reveal that ENERCON E-40 turbine yields the highest capacity factor in Lagos,Jos,Sokoto,Bauchi and Enugu sites while FUHRLAENDER,GMBH yields the highest capacity factor in Delta.The mean annual hydrogen production from wind ranged from 2.05 tons/annum at site S6(Delta)to 17.33 tons/annum at site S3(Sokoto),and the mean annual hydrogen production from SPV ranged from 64.33 tons/annum at sites S1(Lagos)to 140.28 tons/annum at site S6(Delta).The cost of hydrogen production from wind was 6.3679 and 25.9007$/kg for sites S3 and S6,respectively,and the cost of hydrogen production from SPV was 5.6659 and 6.1206$/kg for sites S3 and S1,respectively.The amount of CO_(2) saved annually from wind-based hydrogen generation was 137,267 kg/year in site S6 and 504,180 kg/year in site S3,and was used to produce electricity via fuel cells.The amount of CO_(2) saved using hydrogen produced from SPV was 615,400 kg/year and 1,341,899 kg/year in sites S1 and S6,respectively.The results also revealed that 75.55%,88.93%,80.28%,80.54%,85.65%,98.53%more hydrogen could be produced from SPV for sites S1–S6,respectively,compared to the wind resources.This study serves as a source of reliable technical information to relevant government agencies,policy makers and investors in making informed decisions on optimal investment in the hydrogen economy of Nigeria.
文摘Reconfiguration,as well as optimal utilization of distributed generation sources and capacitor banks,are highly effective methods for reducing losses and improving the voltage profile,or in other words,the power quality in the power distribution system.Researchers have considered the use of distributed generation resources in recent years.There are numerous advantages to utilizing these resources,the most significant of which are the reduction of network losses and enhancement of voltage stability.Non-dominated Sorting Genetic Algorithm II(NSGA-II),Multi-Objective Particle Swarm Optimization(MOPSO),and Intersect Mutation Differential Evolution(IMDE)algorithms are used in this paper to perform optimal reconfiguration,simultaneous location,and capacity determination of distributed generation resources and capacitor banks.Three scenarios were used to replicate the studies.The reconfiguration of the switches,as well as the location and determination of the capacitor bank’s optimal capacity,were investigated in this scenario.However,in the third scenario,reconfiguration,and determining the location and capacity of the Distributed Generation(DG)resources and capacitor banks have been carried out simultaneously.Finally,the simulation results of these three algorithms are compared.The results indicate that the proposed NSGAII algorithm outperformed the other two multi-objective algorithms and was capable of maintaining smaller objective functions in all scenarios.Specifically,the energy losses were reduced from 211 to 51.35 kW(a 75.66%reduction),119.13 kW(a 43.54%reduction),and 23.13 kW(an 89.04%reduction),while the voltage stability index(VSI)decreased from 6.96 to 2.105,1.239,and 1.257,respectively,demonstrating significant improvement in the voltage profile.
文摘The Dhofar region of Oman,renowned for its unique monsoon-influenced climate and substantial agricultural potential,faces significant challenges in achieving sustainable agricultural practices that balance productivity with environmental conservation.This review critically explores a range of sustainable agricultural methods currently im-plemented in the region,including organic farming,water conservation techniques such as drip irrigation and rainwater harvesting,agroforestry systems,crop rotation,and soil conservation measures like terracing and composting.These strategies aim to mitigate pressing environmental concerns such as water scarcity,soil erosion,and land degradation while enhancing crop yield and farm profitability.The review further examines the economic implications of these practices, evaluating their cost-effectiveness, potential for long-term returns, and influence on the growing market demandfor organic and eco-friendly products. Despite their benefits, the broader adoption of these sustainable approaches ishindered by several challenges, including limited access to advanced technologies, inadequate financial resources, lackof technical knowledge, and minimal awareness among local farmers. The article also assesses the role of governmentalpolicies, subsidies, and extension services in promoting the adoption of sustainable agriculture in Dhofar. Finally, it offersstrategic recommendations for future research, policy development, and capacity-building initiatives. This reviewemphasizes the urgent need for continued investment in sustainable solutions to ensure long-term agricultural resilienceand environmental sustainability in the region.
基金supported by Yunnan Provincial Basic Research Project(202401AT070344)National Natural Science Foundation of China(62263014).
文摘1 Introduction Amid escalating global climate change,the“dual carbon”goals of carbon peak and carbon neutrality have become a focal point of global attention and an important strategy for sustainable development[1].With the rapid development of renewable energy technologies and the increasing public demand for environmental protection and low-carbon living,the adoption of new energy vehicles,particularly electric vehicles(EVs).
基金financed as part of the project“Development of a methodology for instrumental base formation for analysis and modeling of the spatial socio-economic development of systems based on internal reserves in the context of digitalization”(FSEG-2023-0008)funded by the Russian Science Foundation(Agreement 23-41-10001,https://doi.org/https://rscf.ru/project/23-41-10001/).
文摘The results of mass appraisal in many countries are used as a basis for calculating the amount of real estate tax,therefore,regardless of the methods used to calculate it,the resulting value should be as close as possible to the market value of the real estate to maintain a balance of interests between the state and the rights holders.In practice,this condition is not always met,since,firstly,the quality of market data is often very low,and secondly,some markets are characterized by low activity,which is expressed in a deficit of information on asking prices.The aim of the work is ecological valuation of land use:how regression-based mass appraisal can inform ecological conservation,land degradation,and sustainable land management.Four multiple regression models were constructed for AI generated map of land plots for recreational use in St.Petersburg(Russia)with different volumes of market information(32,30,20 and 15 units of market information with four price-forming factors).During the analysis of the quality of the models,it was revealed that the best result is shown by the model built on the maximum sample size,then the model based on 15 analogs,which proves that a larger number of analog objects does not always allow us to achieve better results,since the more analog objects there are.
文摘Energy storage, such as lead acid batteries, is necessary for renewable energy sources’ autonomy because of their intermittent nature, which makes them more frequently used than traditional energy sources to reduce operating costs. The battery storage system has to be monitored and managed to prevent serious problems such as battery overcharging, over-discharging, overheating, battery unbalancing, thermal runaway, and fire dangers. For voltage balancing between batteries in the pack throughout the charging period and the SOC estimate, a modified lossless switching mechanism is used in this research’s suggested battery management system. The OCV state of charge calculation, in the beginning, was used in conjunction with the coulomb counting approach to estimate the SOC. The results reveal that correlation factor K has an average value of 0.3 volts when VM ≥ 12 V and an average value of 0.825 when VM ≤ 12 V. The battery monitoring system revealed that voltage balancing was accomplished during the charging process in park one after 80 seconds with a SOC difference of 1.4% between Batteries 1 and 2. On the other hand, the system estimates the state of charge during the discharging process in two packs, with a maximum DOD of 10.8 V for all batteries. The project’s objectives were met since the BMS estimated SOC and achieved voltage balance.
基金This work was supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.NRF-2019R1A2C2002447)This research also was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.NRF-2014R1A6A1030419)This work also was supported by Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea Government(MOTIE)(P0020967,Advanced Training Program for Smart Sensor Engineers).
文摘The latest developments in bio-inspired neuromorphic vision sensors can be summarized in 3 keywords:smaller,faster,and smarter.(1)Smaller:Devices are becoming more compact by integrating previously separated components such as sensors,memory,and processing units.As a prime example,the transition from traditional sensory vision computing to in-sensor vision computing has shown clear benefits,such as simpler circuitry,lower power consumption,and less data redundancy.(2)Swifter:Owing to the nature of physics,smaller and more integrated devices can detect,process,and react to input more quickly.In addition,the methods for sensing and processing optical information using various materials(such as oxide semiconductors)are evolving.(3)Smarter:Owing to these two main research directions,we can expect advanced applications such as adaptive vision sensors,collision sensors,and nociceptive sensors.This review mainly focuses on the recent progress,working mechanisms,image pre-processing techniques,and advanced features of two types of neuromorphic vision sensors based on near-sensor and in-sensor vision computing methodologies.
基金This work was supported by National Natural Science Foundation of China(61963020,62263014)Yunnan Provincial Basic Research Project(202201AT070857).
文摘The development of alternative renewable energy technologies is crucial for alleviating climate change and promoting energy transformation.Of the currently available technologies,solar energy has promising application prospects owing to its merits of being clean,safe,and sustainable.Solar energy is converted into electricity through photovoltaic(PV)cells;however,the overall conversion efficiency of PV modules is relatively low,and most of the captured solar energy is dissipated in the form of heat.This not only reduces the power generation efficiency of solar cells but may also have a negative impact on the electrical parameters of PV modules and the service life of PV cells.To overcome the shortcomings,an efficient approach involves combining a PV cell with a thermoelectric generator(TEG)to form hybrid PV-TEG systems,which simultaneously improve the energy conversion efficiency of the PV system by reducing the operating temperature of the PV modules and increasing the power output by utilizing the waste heat generated from the PV system to generate electricity via the TEGs.Based on a thorough examination of the literature,this study comprehensively reviews 14 maximum power point tracking(MPPT)algorithms currently applied to hybrid PV-TEG systems and classifies them into five major categories for further discussion,namely conventional,mathematics-based,metaheuristic,artificial intelligence,and other algorithms.This review aims to inspire advanced ideas and research on MPPT algorithms for hybrid PV-TEG systems.
文摘Boron-doped NiO thin films were prepared on glass substrates at 400℃ by airbrush spraying method using a solution of nickel nitrate hexahydrate. Their physical properties were investigated as a function of dopant concentration. From X-ray diffraction patterns, it is observed that the films have cubic structure with lattice parameters varying with boron concentration. The morphologies of the films were examined by using scanning electron microscopy, and the grain sizes were measured to be around 30-50 nm. Optical measurements show that the band gap energies of the films first decrease then increase with increasing boron concentration. The resistivities of the films were determined by four point probe method, and the changes in resistivity with boron concentration were investigated.
文摘As wind energy is becoming one of the fastestgrowing renewable energy resources,controlling large-scale wind turbines remains a challenging task due to its system model nonlinearities and high external uncertainties.The main goal of the current work is to propose an intelligent control of the wind turbine system without the need for model identification.For this purpose,a novel model-independent nonsingular terminal slidingmode control(MINTSMC)using the basic principles of the ultralocal model(ULM)and combined with the single input interval type-2 fuzzy logic control(SIT2-FLC)is developed for non-linear wind turbine pitch angle control.In the suggested control framework,the MINTSMC scheme is designed to regulate the wind turbine speed rotor,and a sliding-mode(SM)observer is adopted to estimate the unknown phenomena of the ULM.The auxiliary SIT2-FLC is added in the model-independent control structure to improve the rotor speed regulation and compensate for the SM observation estimation error.Extensive examinations and comparative analyses were made using a real-time softwarein-the-loop(RT-SiL)based on the dSPACE 1202 board to appraise the efficiency and applicability of the suggested modelindependent scheme in a real-time testbed.
文摘Development of metal matrix composite is becoming widespread in most engineering applications where excellent mechanical properties are required.Mechanical and microstructural properties of aluminium reinforced with silicon carbide was investigated.Ingot of aluminium was melted in a furnace at temperature ranging between 650-700℃.Ferrotitanium and silicon carbide were preheated in a muffle furnace before addition to molten aluminium in a crucible furnace.Fixed proportions of magnesium,ferrotitanium and varying proportions of silicon carbide were utilized as reinforcements.Stirring was carried out manually for a minimum of 10 mins after the addition of each weight percent of silicon carbide.Resulting as-cast samples were sectioned for various mechanical and microstructural analysis.Microstructural studies from optical microscopy and scanning electron microscopy(SEM)showed the dispersion of reinforcements in the aluminium matrix.Mechanical properties which includes hardness and tensile strength of fabricated composites were observed to increase,while XRD analysis showed various phases formed from reaction between the matrix and reinforcements.
文摘This study presents a parametric system identification approach to estimate the dynamics of a chemical plant from experimental data and develops a robust PID controller for the plant.Parametric system identification of the heat exchanger system has been carried out using experimental data and prediction error method.The estimated model of the heat exchanger system is a time-delay model and a robust PID controller for the time-delayed model has been designed considering weighted sensitivity criteria.The mathematical background of parametric system identification,stability analysis,and H∞ weighted sensitivity analysis have been provided in this paper.A graphical plot has been provided to determine the stability region in the(Kp,Ki),(Kp,Kd)and(KuKd)plane.The stability region is a locus dependent on parameters of the controller and frequency,in the parameter plane.
基金the financial support from National Natural Science Foundation of China(No.51976093)K C Wong Magna Fund in Ningbo University。
文摘In this article,plasma-assisted NH;synthesis directly from N;and H;over packing materials with different dielectric constants(BaTiO_(2),TiO_(2) and SiO_(2))and thermal conductivities(Be O,Al N and Al_(2)O_(2))at room temperature and atmospheric pressure is reported.The higher dielectric constant and thermal conductivity of packing material are found to be the key parameters in enhancing the NH;synthesis performance.The NH;concentration of 1344 ppm is achieved in the presence of BaTiO_(2),which is 106%higher than that of SiO_(2),at the specific input energy(SIE)of 5.4 k J·l^(-1).The presence of materials with higher dielectric constant,i.e.BaTiO_(2) and TiO_(2)in this work,would contribute to the increase of electron energy and energy injected to plasma,which is conductive to the generation of chemically active species by electron-impact reactions.Therefore,the employment of packing materials with higher dielectric constant has proved to be beneficial for NH;synthesis.Compared to that of Al_(2)O_(3),the presence of Be O and Al N yields 31.0%and 16.9%improvement in NH;concentration,respectively,at the SIE of5.4 k J·l^(-1).The results of IR imaging show that the addition of Be O decreases the surface temperature of the packed region by 20.5%to 70.3℃ and results in an extension of entropy increment compared to that of Al_(2)O_(3),at the SIE of 5.4 k J·l^(-1).The results indicate that the presence of materials with higher thermal conductivity is beneficial for NH;synthesis,which has been confirmed by the lower surface temperature and higher entropy increment of the packed region.In addition,when SIE is higher than the optimal value,further increasing SIE would lead to the decrease of energy efficiency,which would be related to the exacerbation in reverse reaction of NH;formation reactions.
文摘An electrochromic copolymer film of 2-(3,3-dihexyl-3,4-dihydro-2 H-thieno[3,4-b][1,4]dioxepin-6-yl)-7-(3,3-dihexyl-3,4-dihydro-2 H-thieno[3,4-b][1,4]dioxepin-8-yl)-9 H-carbazole(M1) and 4,7-bis(thiophen-2-yl)benzo[c][1,2,5]thiadiazole(M2) was prepared via electrochemical technique. The copolymerization was performed with one to one monomer feed ratio. Electrochemical and optical properties of the resulting copolymer film(P3) and the homopolymer films of M1 and M2(P1 and P2) were investigated by using cyclic voltammetry and UV-Vis spectrometry techniques, and the corresponding results were compared. Incorporation of M1 and M2 into copolymer matrix was clearly observed on the resulting cyclic voltammograms and UV-Vis spectra. P3 covered the visible regions coming from both P1 and P2, and exhibited a neutral state darker color than those of homopolymers. P3 film was found to have a multichromic behavior, appearing as brown in its neutral state while changing its color upon oxidation to dark-gray(at about 0.3 V), to blue(at about 0.6 V) and finally to grayish cyan(beyond 0.9 V), with a corresponding optical band gap of 1.65 eV.
文摘In electrical circuit analysis, it is often necessary to find the set of all direct current （d.c.） operating points （either voltages or currents） of nonlinear circuits. In general, these nonlinear equations are often represented as polynomial systems. In this paper, we address the problem of finding the solutions of nonlinear electrical circuits, which are modeled as systems of n polynomial equations contained in an n-dimensional box. Branch and Bound algorithms based on interval methods can give guaranteed enclosures for the solution. However, because of repeated evaluations of the function values, these methods tend to become slower. Branch and Bound algorithm based on Bernstein coefficients can be used to solve the systems of polynomial equations. This avoids the repeated evaluation of function values, but maintains more or less the same number of iterations as that of interval branch and bound methods. We propose an algorithm for obtaining the solution of polynomial systems, which includes a pruning step using Bernstein Krawczyk operator and a Bernstein Coefficient Contraction algorithm to obtain Bernstein coefficients of the new domain. We solved three circuit analysis problems using our proposed algorithm. We compared the performance of our proposed algorithm with INTLAB based solver and found that our proposed algorithm is more efficient and fast.
基金supported by The Science and Technology Development Fund of Macao under grant 014/2007/A1,063/2009/A and 024/2009/A1the Research Committee of the University of Macao under Grants UL012/09-Y1/EEE/VMI01/FST,RG077/09-10S/ VMI/FST,RG075/07-08S/10T/VMI/FST,and RG072/09-10S/ MPU/FSTthe Funds of Fujian Provincial Department of Science & Technology as 2007Y0024,2007T0009,2007I0018 and 2008J1005
文摘Intra-body communication (IBC) is a new,emerging,short-range and human body based communication methodology.It is a technique to network various devices on human body,by utilizing the conducting properties of human tissues,suitable for currently fast developing Body area network (BAN)/Body sensor network (BSN).IBC is believed to have advantages in power consumption,electromagnetic radiation,interference from external electromagnetic noise,security,and restriction in spectrum resource.In this article,the authors develop two models,which are analytical and empirical approaches,for comparing the performance and accuracy of IBC on a human limb.Through in vivo experiment of five volunteers,both models basically match with the experimental result with equivalent circuit model superior than electromagnetic model in term of maximum error.
