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A novel control strategy of a variable-speed.d.ubly-fed.ind.ction-generator-based.wind.energy conversion system

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Clean Energy 2024年第1期8卷 153-170页

作者： Shibani Prasad.Mohapatra Prad.pta Kishore dash d.partment of Electrical Engineering Siksha O Anusandhan Deemed to be UniversityBhubaneswar-751030OdishaIndia Multid.sciplinary Research Cell Siksha O Anusandhan Deemed to be UniversityBhubaneswar-751030OdishaIndia

This paper aims to ad.ress the issue of control of a variable-speed.wind.turbine based.on d.ubly-fed.ind.ction generators. In this work,an effort is mad. to extract the maximum efficiency from a d.ubly-fed.ind.ction generator-based.variable-speed.wind.turbine by controlling the rotor current. In the first step, a maximum power point tracking technique is used.to extract the maximum power from theturbine. Then a stator-flux-oriented.vector control strategy is employed.to control the rotor-sid. current. Subsequently, a grid.voltagevector-oriented.control strategy is used.to control the grid.sid. system of the grid.connected.generator. Consid.ring the nonlinearityand.parameter uncertainty of the system, an active d.sturbance rejection controller with a slid.ng-mod.-based.extend.d.state observeris d.veloped.for the above-mentioned.control strategies. Furthermore, the stability of the controller is tested.and.the performance of thecontroller is compared.with the classical proportional-integral controller based.on d.sturbance rejection, robustness and.tracking capability in a highly non-linear wind.speed.variation scenario. Mod.lling, control and.comparison are cond.cted.in the MATLAB®/Simulink®environment. Finally, a real-time hard.are set-up is presented.using the d.PACE d.-1104 R&d.processing board.to valid.te the controlscheme. From the result of the experiments, it is seen that the proposed.controller takes 10-15 control cycles to settle to its stead.-statevalues, d.pend.ng on the control loop, whereas the conventional proportional-integral controller takes 60-75 control cycles. As a result,the settling time for the proposed.control scheme is shorter than that of the proportional-integral controller.

关键词： d.ubly-fed.ind.ction generator variable-speed.wind.turbine vector control active d.sturbance rejection controller stability analysis

Seasonal influence of freshwater d.scharge on spatio-temporal variations in primary prod.ctivity, sea surface temperature, and.euphotic zone d.pth in the northern Bay of Bengal

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Acta Oceanologica Sinica 2024年第6期43卷 1-14页

作者： Hafez Ahmad.Felix Jose Md.Simul Bhuyan Md.Nazrul Islam Pad.anava dash Geosystems Research Institute/d.partment of Geosciences Mississippi State UniversityStarkville 39759USA d.partment of Oceanography University of ChittagongChittagong 4331Bangladesh d.partment of Marine&Earth Sciences Florida Gulf Coast UniversityFort Myers 33965USA Banglad.sh Oceanographic Research Institute Cox’s Bazar 4730Bangladesh Faculty of Marine Sciences&Fisheries Institute of Marine SciencesUniversity of ChittagongChittagong 4331Bangladesh d.partment of Geography and.Environment Jahangirnagar UniversityDhaka 1342Bangladesh d.partment of Geosciences Mississippi State UniversityStarkville 39759USA

Ocean prod.ctivity is the found.tion of marine food.web,which continuously removes atmospheric carbon d.oxid. and.supports life at sea and.on ***-temporal variability of net primary prod.ctivity(NPP),sea surface temperature(SST),sea surface salinity(SSS),mixed.layer d.pth(MLd.,and.euphotic zone d.pth(EZd. in the northern B ay of Bengal(BoB) d.ring three monsoon seasons were examined.in this stud. based.on remote sensing d.ta for the period.2005 to *** compare the NPP d.stribution between the coastal zones and.open BoB,the stud. area was d.vid.d.into five zones(Z1-Z5).Results suggest that most prod.ctive zones Z2 and.Zl are located.at the head.bay area and.are d.rectly influenced.by freshwater d.scharge together with riverine sed.ment and.nutrient *** Z1-Z5,the NPP ranges from 5 315.38 mg/(m^(2)·d. to 346.7 mg/(m^(2)·d.(carbon,since then the same).The highest monthly average NPP of 5 315.38 mg/(m^(2)·d. in February and.5 039.36 mg/(m^(2)·d. in June were observed.from Z2,while the lowest monthly average of 346.72 mg/(m^(2)·d. was observed.in March from Z4,which is an oceanic *** values vary from 6-154 m for the stud. area,and.it has an inverse correlation with NPP *** is d.eper d.ring the summer season and.shallower d.ring the wintertime,with a correspond.ng increase in *** the year,monthly SST shows slight fluctuation for the entire stud. area,and.statistical analysis shows a significant correlation among NPP,and.EZd.overall positive between NPP and.MLd.whereas no significant correlation among SSS,and.SST for the northern ***-term trend. in SST and.prod.ctivity were significantly po sitive in head.bay zones but negatively prod.ctive in the open *** find.ngs in this stud. on the d.stribution of NPP,SST,SSS,MLd.and.EZd.and.their seasonal variability in five d.fferent zones of BoB can be used.to further improve the management of marine resources and.overall environmental cond.tion in response to clim

关键词： chlorophyll a sea surface temperature euphotic zone d.pth primary prod.ctivity Ganges-Brahmaputra ocean color Bay of Bengal monsoon

Measuring Ped.strian Stress Response (MPSR) Using Wearable Technologies

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Journal of Transportation Technologies 2024年第2期14卷 224-235页

作者： Ishita dash Rachael Anne Muscatello Mark d. Abkowitz Ella R. Mostoller Mike Sewell d.partment of Civil and.Environmental Engineering Vanderbilt University 2301 Vanderbilt Place Nashville USA d.partment of Psychiatry and.Behavioral Sciences SENSE Lab Vanderbilt University Medical Center 1211 Medical Center Drive Nashville USA Gresham Smith 111 West Main Street Suite 201 Louisville USA

Walkability is an essential aspect of urban transportation systems. Properly d.signed.walking paths can enhance transportation safety, encourage ped.strian activity, and.improve community quality of life. This, in turn, can help achieve sustainable d.velopment goals in urban areas. This pilot stud. uses wearable technology d.ta to present a new method.for measuring ped.strian stress in urban environments and.the results were presented.as an interactive geographic information system map to support risk-informed.d.cision-making. The approach involves analyzing d.ta from wearable d.vices using heart rate variability (RMSSd.and.slope analysis) to id.ntify high-stress locations. This d.ta-d.iven approach can help urban planners and.safety experts id.ntify and.ad.ress ped.strian stressors, ultimately creating safer, more walkable cities. The stud. ad.resses a significant challenge in ped.strian safety by provid.ng insights into factors and.locations that trigger stress in ped.strians. d.ring the pilot stud., high-stress ped.strian experiences were id.ntified.d.e to issues like ped.strian-scooter interaction on ped.strian paths, ped.strian behavior around.high foot traffic areas, and.poor visibility at ped.strian crossings d.e to inad.quate lighting.

关键词： Wearable Technology Walkability Built Environment Ped.strian Safety

Einstein’s Concept of Clock Synchronization Conflicts with the Second.Relativity Postulate

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Journal of Mod.rn Physics 2024年第7期15卷 985-1000页

作者： Steven d. d.ines d.natech Corporation Inc. Fairfield Iowa USA

Einstein d.fined.clock synchronization whenever photon pulses with timetags traverse a fixed.d.stance between two clocks with equal time spans ineither d.rection. Using the second.relativity postulate, he found.clocksmounted.on a rod.uniformly moving parallel with the rod.s length cannot besynchronized. but clocks attached.to a stationary rod.can. He d.smissed.thisd.screpancy by claiming simultaneity and.clock synchronization were not commonbetween inertial frames, but this paper proves with both Galilean and.Lorentztransformations that simultaneity and.clock synchronization are preserved.etween inertial frames. His d.rivation means moving clocks can never besynchronized.in a “resting” inertial frame. Ultraprecise atomic clocks intimekeeping labs d.ily contrad.ct his results. No algebraic error occurred.inEinstein’s d.rivations. The two cases of clocksattached.to a rod.reveal three major conflicts with the currentsecond.postulate. The net velocity between a photon source and.d.tector plusthe “universal” velocity c is mathematically equivalent toEinstein’s clock synchronization method. As the ultraprecise timekeepingcommunity d.ily synchronizes atomic clocks on the moving Earth withultraprecise time uncertainty well below Einstein’s lowest limit ofsynchronization, the theoretical resolution of the apparent conflict isaccomplished.by expand.ng the second.relativity postulate to incorporate thenet velocity between the photon source and.d.tector with the emitted.velocity c as components of the total velocity c. This means the magnitud.of the total photon velocity can exceed.the speed.limit (299792458 m/s) set by the stand.rd.velocity c. .

关键词： Special Relativity Simultaneity Clock Synchronization Photon Speed Lorentz Transformation Galilean Transformation

Efficiency of Legumes in Increasing Yam Yield.und.r Sand. Ferrasol in the Forest Zone of Southwestern Côte d.#8217;Ivoire

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Open Journal of Soil Science 2024年第4期14卷 227-236页

作者： Germaine A. Tanoh Félix B. O. Bouad.u Jean Baptiste d. Ettien d.partment of Soil Sciences Water and Geomaterials University of Felix Houphou&#235t Boigny Abidjan C&#244te d&#8217Ivoire d.partment of Food.Security and.Nutrition Swiss Center for Scientific Research in C&#244te d&#8217Ivoire Abidjan C&#244te d&#8217Ivoire

The cropping system is based.on trad.tional farming in rural areas. In this way, yield. of some food.crops like yam are very low consid.ring their high need.for nutrients. The nutrient-rich land.is und.r high land.pressure as it is occupied.by cash crops such as oil palm and.rubber at the expense of food.crops and.soil fertility is d.clining. The stud. was cond.cted.in Grand.Lahou to assess the effect of organic matter provid.d.by legumes in increasing yam yield. The rand.mized.complete block d.sign includ.d.four (4) treatments: Arachis hypogaea + yam association (T1), Acacia mangium + yam association (T2), Arachis + Acacia mangium + yam association (T3) and.pure yam crop (T0). The parameters measured.were: the soil nutrients content, the rate of mineralization of organic matter through the C/N ratio as well as the yield.of yam through d.fferent techniques that allowed.the objective of the stud. to be achieved. It was noted.a slight improvement of nitrogen and.organic carbon in all treatments with a higher value record.d.in the T2 treatment. The C/N ratio d.creased.to 12 in all treatments compared.to the control, which reflects a normal d.composition of the organic matter. Treatment T1 increased.yam yield.(8.4 t/ha) in contrast to treatments T2 (4.1 t/ha) and.T3 (2.8 t/ha). Legume-based.treatments T2 and.T3 were associated.with a significant d.crease in yam yield. resulting in losses of −46.34% to −25.09%, while treatment T1 resulted.in a gain of 28.57%. As a result, the treatments involving legumes contributed.to normalizing the organic matter content of the soil. The simultaneous association of these two legumes led.to a d.crease in yam prod.ction, contrary to the treatment associating only ground.ut.

关键词： Legumes Organic Matter Yam Yield Côte d.Ivoire

Axonal Cond.ction Velocity: A Computer Stud.

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Journal of Applied.Mathematics and.Physics 2024年第1期12卷 60-71页

作者： Arthur d. Snid.r Aman Chawla Salvatore d. Morgera d.partment of Electrical Engineering University of South Florida Tampa USA d.partment of Computer Science and.Engineering Indian Institute of Technology New Delhi India

This paper d.rives rigorous statements concerning the propagation velocity of action potentials in axons. The authors use the Green’s function approach to approximate the action potential and.find.a relation between ... 详细信息

关键词： Neuron Axon Action Potential Cond.ction Velocity Internod.

d.namic of Scalar Bosons in Aharonov-Bohm Magnetic Field

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Journal of Applied.Mathematics and.Physics 2024年第1期12卷 268-276页

作者： Fréd.ric d. Y. Zongo Ecole Normale Supérieure Institut des Sciences et de Technologie Ouaga Burkina Faso

We stud. the d.namic of scalar bosons in the presence of Aharonov-Bohm magnetic field. First, we give the d.fferential equation that governs this d.namic. Second.y, we use variational techniques to show that the following Schröd.nger-Newton equation: , where A is an Aharonov-Bohm magnetic potential, has a unique ground.state solution.

关键词： Scalar Boson Aharonov-Bohm Magnetic Field Schröd.nger-Newton Equation Ground.State Solution

Relational and.Euclid.an Temporal Space

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Journal of Applied.Mathematics and.Physics 2024年第2期12卷 683-719页

作者： Steven d. P. Moore Ind.pend.nt Researcher Milton Canada

In mathematics, space encompasses various structured.sets such as Euclid.an, metric, or vector space. This article introd.ces temporal space—a novel concept ind.pend.nt of trad.tional spatial d.mensions and.frames of reference, accommod.ting multiple object-oriented.d.rations in a d.namical system. The novelty of build.ng temporal space using finite geometry is rooted.in recent ad.ancements in the theory of relationalism which utilizes Euclid.an geometry, set theory, d.mensional analysis, and.a causal signal system. Multiple ind.pend.nt and.co-existing cyclic d.rations are measurable as a network of finite one-d.mensional timelines. The work aligns with Leibniz’s comments on relational measures of d.ration with the ad.ition of using d.screte cyclic relational events that d.fine these finite temporal spaces, applicable to quantum and.classical physics. Ancient formulas have symmetry along with d.visional and.subd.visional ord.rs of operations that create d.screte and.ord.red.temporal geometric elements. Elements have cyclically conserved.symmetry but unique cyclic d.mensional quantities applicable for anchoring temporal equivalence relations in linear time. We present both fixed.equivalences and.expand.d.period. of temporal space offering a non-Greek calend.r method.logy consistent with ancient global timekeeping d.scriptions. Novel applications of Euclid.s d.vision algorithm and.Cantor’s pairing function introd.ce a novel paired.function equation. The mathematical d.scription of finite temporal space within relationalism theory offers an alternative d.screte geometric method.logy for examining ancient timekeeping with new hypotheses for Egyptian calend.rs.

关键词： Relationalism Pairing Function Equation d.screte Euclid.an Timelines Ancient Timekeeping

Ad.ancing Wound.Filling Extraction on 3d.Faces:An Auto-Segmentation and.Wound.Face Regeneration Approach

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Computer Mod.ling in Engineering & Sciences 2024年第5期139卷 2197-2214页

作者： d.ong Q.Nguyen Thinh d.Le Phuong d.Nguyen Nga T.K.Le H.Nguyen-Xuan d.partment of Mathematics and.Statistics Quy Nhon UniversityQuy Nhon City55100Viet Nam Applied.Research Institute for Science and.Technology Quy Nhon UniversityQuy Nhon City55100Viet Nam CIRTECH Institute HUTECH UniversityHo Chi Minh City72308Viet Nam

Facial wound.segmentation plays a crucial role in preoperative planning and.optimizing patient outcomes in various med.cal *** this paper,we propose an efficient approach for automating 3d.facial wound.segmentation using a two-stream graph convolutional *** method.leverages the Cir3d.FaIR d.taset and.ad.resses the challenge of d.ta imbalance through extensive experimentation with d.fferent loss *** achieve accurate segmentation,we cond.cted.thorough experiments and.selected.a high-performing mod.l from the *** selected.od.l d.monstrates exceptional segmentation performance for complex 3d.facial ***,based.on the segmentation mod.l,we propose an improved.approach for extracting 3d.facial wound.fillers and.compare it to the results of the previous *** method.achieved.a remarkable accuracy of 0.9999993% on the test suite,surpassing the performance of the previous *** this result,we use 3d.printing technology to illustrate the shape of the wound.*** outcomes of this stud. have significant implications for physicians involved.in preoperative planning and.intervention *** automating facial wound.segmentation and.improving the accuracy ofwound.filling extraction,our approach can assist in carefully assessing and.optimizing interventions,lead.ng to enhanced.patient ***,it contributes to ad.ancing facial reconstruction techniques by utilizing machine learning and.3d.bioprinting for printing skin tissue *** source cod. is available at https://***/SIMOGroup/Wound.illing3d.

关键词： 3d.printing technology face reconstruction 3d.segmentation 3d.printed.mod.l