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Linear OPF-based Robust Dynamic Operating Envelopes with Uncertainties in Unbalanced Distribution Networks

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1320-1326页

作者： Bin Liu Julio h.Braslavsky Nariman Mahdavi Energy Centre Commonwealth Scientific and Industrial Research Organisation(CSIRO)Newcastle 2300Australia the Network Planning Division TransgridSydney 2000Australia the Energy Systems Program Energy CentreCommonwealth Scientific and Industrial Research Organisation(CSIRO)Newcastle 2300Australia

Dynamic operating envelopes(DOEs),as key enablers to facilitate distributed energy resource(DER)integration,have attracted increasing attention in the past ***,uncertainties,which may come from load forecasting errors or inaccurate network parameters,have been rarely discussed in DOE calculation,leading to compromised quality of the hosting capacity allocation *** letter studies how to calculate DOEs that are immune to such uncertainties based on a linearised unbalanced three-phase optimal power flow(UTOPF)*** uncertain parameters constrained by norm balls,formulations for calculating robust DOEs(RDOEs)are presented along with discussions on their *** cases,including a 2-bus illustrative network and a representative Australian network,are tested to demonstrate the effectiveness and efficiency of the proposed approach.

关键词： Distributed energy resource(DER) dynamic operating envelope(DOE) feasible region robust optimisation uncertainty modelling unbalanced optimal power flow

Rational design of AggaS/ZnS/ZnS quantum dots with a near-unity photoluminescence quantum yield via double shelling scheme

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Journal of Materials Science & Technology 2024年第2期169卷 235-242页

作者： h.X.Lu h.Liu Z.Z.Fu Y.Y.Chen h.Q.Dai Z.hu W.L.Zhang R.Q.guo Institute for Electric Light Sources School of Information Science and TechnologyFudan UniversityShanghai 200433China Institute of Future Lighting Academy for Engineering and TechnologyFudan UniversityShanghai 200433China Yiwu Research Institute of Fudan University YiwuZhejiang 322000China Zhongshan-Fudan Joint Innovation Center Zhongshan 528437China

In this study,a two-step method was used to synthesize highly luminescent AggaS/ZnS/ZnS quantum dots(QDs).In the first step,an inner ZnS shell was formed via a one-pot method,which resulted in a smaller lattice mismatch between the AggaS core and the outer ZnS shell,thereby facilitating the formation of a thick outer *** the two-step shelling process,the synthesized AggaS/ZnS/ZnS QDs showed an excellent photoluminescence quantum yield(PLQY)of 96.4%with a peak wavelength of 508 nm,repre-senting the highest PLQY reported thus far for AggaS ***,the effect of halogen ions in Zn precursors on the shelling process was *** was proposed that the capacity of halogen ions to coordinate with the QDs influenced the balance between Zn cation diffusion and ZnS shelling ***,the ZnS shelling reaction was dominant when ZnCl_(2)was employed,while Zn cation diffusion was the dominant process under the I^(−)-rich *** work provides insights into the interfacial restructuring during the ZnS shelling and offers a clear map for the tailored synthesis of core/shell QDs.

关键词： AggaS Quantum dots Photoluminescence Core/shell Alloyed core/shell interface

Comparative measurement of CO_(2),Ch_(4)and CO at two traffic interjunctions having inflated vehicular flow in Delhi

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Journal of Environmental Sciences 2024年第7期141卷 314-329页

作者： Komal Daya Soni Khem Singh Shankar g.Aggarwal CSIR-National Physical Laboratory Dr.K.S.Krishnan MargNew Delhi 110012India Academy of Scientific&Innovative Research(AcSIR) Ghaziabad 201002India

Vehicular emissions are considered one of the major anthropogenic sources of greenhouse gases and poor air quality in metropolitan *** study aims to see the correlation of CO_(2),Ch_(4),and CO through monitoring over a period from December 2020 to October 2021 covering three seasons’winter,summer,and monsoon at two different traffic locations of Delhi having different traffic volumes,road patterns,and traffic *** annual average morning concentration of CO_(2),Ch_(4)and CO was found(533±105),(7.3±3.1),(10.7±3.0)ppm at Najafgarh and(480±70),(5.2±1.8),(7.8±2.8)ppm at Rajendra Place,respectively.A relationship between concentration of all three gases and meteorological parameters such as temperature,humidity,wind speed and wind direction has also been investigated using Pearson correlation coefficient and pollution rose diagram.A comparable pattern in concentration was observed for all three gases in spatial(location)and temporal(diurnal)*** concentration trend of CO_(2)in different seasons is winter>summer>monsoon,while in the case of Ch_(4)winter=summer>monsoon but not any seasonal trend was noted in CO *** is observed that CO_(2)has a good relation with CO(a tracer for vehicular emission)in terms of diurnal variation,whereas,Ch_(4)does not represent a relation with CO and CO_(2)diurnally,suggesting that vehicles are the source of CO_(2)but not much contributing to other greenhouse gases like Ch_(4).

关键词： Vehicular emission greenhouse gases harmful pollutants Meteorological parameters

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A study on the seismic behavior of a retrofitted building based on nonlinear static and dynamic analyses

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Earthquake Engineering and Engineering Vibration 2005年第1期4卷 173-180页

作者： Esra Mete güneyisi gülay Altay Department of Civil Engineering Bo■azi■i University Bebek ■stanbul TurkeyResearchAssistantDepartment of Civil Engineering Bo■azi■i University Bebek ■stanbul Turkey Professor

This study describes the seismic performance of an existing five storey reinforced concrete building which represents the typical properties of low-rise non-ductile buildings in Turkey. The effectiveness of shear walls and the steel bracings in retrofitting the building was examined through nonlinear static and dynamic analyses. By using the nonlinear static analysis, retrofitted buildings seismic performances under lateral seismic load were compared with each other. Moreover, the performance points and response levels of the existing and retrofitting cases were determined by way of the capacity-spectrum method described in ATC-40 (1996). For the nonlinear dynamic analysis the records were selected to represent wide ranges of duration and frequency content. Considering the change in the stiffness and the energy dissipation capacities, the performance of the existing and retrofitted buildings were evaluated in terms of story drifts and damage states. It was found that each earthquake record exhibited its own peculiarities, dictated by frequency content, duration, sequence of peaks and their amplitude. The seismic performance of retrofitted buildings resulted in lower displacements and higher energy dissipation capacity depending mainly on the properties of the ground motions and the retrofitting strategies. Moreover, severe structural damage (irreparable or collapse) was observed for the existing building. however, buildings with retrofit alternatives exhibited lower damage levels changing from no damage to irreparable damage states.

关键词： nonlinear static analysis nonlinear time history analysis performance level retrofitting shear wall steel bracing

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Study of hybrid nanofluid flow in a stationary cone-disk system with temperature-dependent fluid properties

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Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 677-694页

作者： A.S.JOhN B.MAhANThESh g.LORENZINI Center for Mathematical Needs Department of MathematicsCHRIST(Deemed to be University)Karnataka 560029India School of Mathematical and Statistical Sciences The University of Texas Rio Grande ValleyTexas 78539U.S.A. Department of Engineering and Architecture University of ParmaParma 43124Italy

Cone-disk systems find frequent use such as conical diffusers,medical devices,various rheometric,and viscosimetry *** this study,we investigate the three-dimensional flow of a water-based Ag-Mg O hybrid nanofluid in a static cone-disk system while considering temperature-dependent fluid *** the variable fluid properties affect the dynamics and heat transfer features is studied by Reynolds's linearized model for variable viscosity and Chiam's model for variable thermal *** single-phase nanofluid model is utilized to describe convective heat transfer in hybrid nanofluids,incorporating the experimental *** model is developed as a coupled system of convective-diffusion equations,encompassing the conservation of momentum and the conservation of thermal energy,in conjunction with an incompressibility condition.A self-similar model is developed by the Lie-group scaling transformations,and the subsequent self-similar equations are then solved *** influence of variable fluid parameters on both swirling and non-swirling flow cases is ***,the Nusselt number for the disk surface is *** is found that an increase in the temperature-dependent viscosity parameter enhances heat transfer characteristics in the static cone-disk system,while the thermal conductivity parameter has the opposite effect.

关键词： hybrid nanofluid cone-disk system laminar flow variable fluid property Nusselt number

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Optimal Control of Service Rates of Discrete-Time(s,Q)Queueing-Inventory Systems with Finite Buffer

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Journal of Systems Science and Systems Engineering 2024年第3期33卷 261-280页

作者： L.Iniya B.Sivakumar g.Arivarignan School of Mathematics Madurai Kamaraj UniversityMaduraiTamilnaduIndia Department of Statistics Manonmaniam Sundaranar UniversityTirunelveliTamilnaduIndia

This article,we develop an optimal policy to control the service rate of a discrete time queueing-inventory system with finite *** customers arrive according to a Bernoulli process and the service time for the customers are *** the buffer size attains its maximum,any arriving new customers are considered to be *** customers are served one by one according to FCFS rule and each customers request random number of *** inventory is replenished according to a(s,Q)inventory policy with geometric lead *** main objectives of this article are to determine the service rates to be employed at each slot so that the long run expected cost rate is minimized for fixed inventory level and fixed buffer size and to minimize the expected waiting time for a fixed inventory level and fixed buffer *** problems are modelled as Markov decision *** establish the existence of a stationary policy and employ linear programming method to find the optimal service *** provide some numerical examples to illustrate the behaviour of the model.

关键词： Queueing-inventory system discrete time batch demand-Markov decision process

An Improved Binary Quantum-based Avian Navigation Optimizer Algorithm to Select Effective Feature Subset from Medical Data:A COVID-19 Case Study

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Journal of Bionic Engineering 2024年第1期21卷 426-446页

作者： Ali Fatahi Mohammad h.Nadimi-Shahraki hoda Zamani Faculty of Computer Engineering Najafabad BranchIslamic Azad UniversityNajafabad ***Iran Big Data Research Center Najafabad BranchIslamic Azad UniversityNajafabad ***Iran

Feature Subset Selection(FSS)is an NP-hard problem to remove redundant and irrelevant features particularly from medical data,and it can be effectively addressed by metaheuristic ***,existing binary versions of metaheuristic algorithms have issues with convergence and lack an effective binarization method,resulting in suboptimal solutions that hinder diagnosis and prediction *** paper aims to propose an Improved Binary Quantum-based Avian Navigation Optimizer Algorithm(IBQANA)for FSS in medical data preprocessing to address the suboptimal solutions arising from binary versions of metaheuristic *** proposed IBQANA’s contributions include the hybrid Binary Operator(hBO)and the Distance-based Binary Search Strategy(DBSS).hBO is designed to convert continuous values into binary solutions,even for values outside the[0,1]range,ensuring accurate binary *** the other hand,DBSS is a two-phase search strategy that enhances the performance of inferior search agents and accelerates *** combining exploration and exploitation phases based on an adaptive probability function,DBSS effectively avoids local *** effectiveness of applying hBO is compared with five transfer function families and thresholding on 12 medical datasets,with feature numbers ranging from 8 to 10,***'s effectiveness is evaluated regarding the accuracy,fitness,and selected features and compared with seven binary metaheuristic ***,IBQANA is utilized to detect *** results reveal that the proposed IBQANA outperforms all comparative algorithms on COVID-19 and 11 other medical *** proposed method presents a promising solution to the FSS problem in medical data preprocessing.

关键词： Feature subset selection Optimization Binary metaheuristic algorithms Bioinspired Machine learning Medical datasets

The great catastrophe: causes of the Permo-Triassic marine mass extinction

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National Science Review 2024年第1期11卷 37-50页

作者： Paul B.Wignall David P.g.Bond School of Earth & Environment University of Leeds School of Environmental Sciences University of Hull

The marine losses during the Permo-Triassic mass extinction were the worst ever experienced. All groups were badly affected, especially amongst the benthos(e.g. brachiopods, corals, bryozoans, foraminifers,ostracods). Planktonic populations underwent a fundamental change with eukaryotic algae being replaced by nitrogen-fixing bacteria, green-sulphur bacteria, sulphate-reducing bacteria and prasinophytes. Detailed studies of boundary sections, especially those in South China, have resolved the crisis to a ～55 kyr interval straddling the Permo-Triassic boundary. Many of the losses occur at the beginning and end of this interval painting a picture of a two-phase extinction. Improved knowledge of the extinction has been supported by numerous geochemical studies that allow diverse proposed extinction mechanisms to be studied. A transition from oxygenated to anoxic-euxinic conditions is seen in most sections globally, although the intensity and timing shows regional variability. Decreased ocean ventilation coincides with rapidly rising temperatures and many extinction scenarios attribute the losses to both anoxia and high *** kill mechanisms include ocean acidification for which there is conflicting support from geochemical proxies and, even less likely, siltation(burial under a massive influx of terrigenous sediment) which lacks substantive sedimentological evidence. The ultimate driver of the catastrophic changes at the end of the Permian was likely Siberian Trap eruptions and their associated carbon dioxide emissions with consequences such as warming, ocean stagnation and acidification. Volcanic winter episodes stemming from Siberian volcanism have also been linked to the crisis, but the short-term nature of these episodes(he overwhelming evidence for rapid warming during the crisis makes this an unlikely cause. Finally, whilst the extinction is well studied in equatorial latitudes, a different history is found in northern Boreal latitudes

关键词： ocean anoxia ocean acidification siltation productivity collapse volcanic winter

Study on the dynamic contact relationship between layers under temperature gradients in CRTSⅢ ballastless track

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high-speed Railway 2024年第3期2卷 133-142页

作者： Zhao L. Zhao g. Yang g. Jin h. Li C. Railway Engineering Research Institute China Academy of Railway Sciences Co. Ltd Beijing 100081 China China State Railway group Co. Ltd. Beijing 100844 China School of Transportation Southeast University Nanjing 211189 China School of Traffic and Transportation Beijing Jiaotong University Beijing 100081 China

In areas with large temperature differences, the uneven distribution of temperatures in the CRTS III ballastless track slab due to daytime sunlight can cause warpage deformation, leading to periodic rail irregularities that increase the wheel-rail impact of high-speed vehicles and accelerate track structure damage. Therefore, it is necessary to study the dynamic contact relationship between the composite slab and the base plate during vehicle running. The results of the study show that: 1) Under the influence of temperature gradients, the composite slab tends to deform elliptically. With a positive temperature gradient, the middle part of the track slab bulges upward, causing the slab to be supported by its four corners. Conversely, with a negative temperature gradient, the four corners of the track slab bulge upward, resulting in the slab being supported by its center. 2) Temperature gradients can lead to separation between the composite slab and the base plate, reducing the contact area between layers. During vehicle running, the contact area between layers gradually increases, but the separation cannot be completely closed. 3) The temperature gradient significantly affects the vertical displacement of the track. The vertical displacement in the middle of the slab increases with a positive temperature gradient. In contrast, the vertical displacement at the ends of the slab increases with a negative temperature gradient. 4) The stress of self-compacting concrete at the side position significantly increases under a positive temperature gradient, with the vertical stress increasing by 2.7 times when the temperature gradient increases from 0 to 90 ℃·m−1. © 2024

关键词： Ballastless track high-speed railway Interlayer contact Periodic irregularities Temperature gradient