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Structural evolution and properties of small-size thiol-protected gold nanoclusters

MOLECULAR PHYSICS 2018年第14期116卷 1804-1811页

作者： Ma, Miaomiao Liu, Liren Zhu, Hengjiang Lu, Junzhe Tan, Guiping Xinjiang Normal Univ Coll Phys & Elect Engn Urumqi 830054 Peoples R China Key Lab Mineral Luminescence Mat & Micro Struct X Urumqi Peoples R China

Ligand-protected gold clusters are widely used in biosensors and catalysis. Understanding the structural evolution of these kinds of nanoclusters is important for experimental synthesis. Herein, based on the particle swarm optimisation algorithm and density functional theory method, we use [Au-1(SH)(2)](n), [Au-2(SH)(3)](n), [Au-3(SH)(4)](n) (n=1-3) as basic units to research the structural evolution relationships from building blocks to the final whole structures. Results show that there is a line-ring-core' structural evolution pattern in the growth process of the nanoclusters. The core structures of the ligand-protected gold clusters consist of Au-3, Au-4, Au-6 and Au-7 atoms. The electronics and optics analysis reflects that stability and optical properties gradually enhance with increase in size. These results can be used to understand the initial growth stage and design new ligand-protected nanoclusters. [GRAPHICS] .

关键词： Thiolated gold clusters particle swarm optimisation algorithm DFT structural evolution

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Hybrid small-signal model parameter extraction for GaN HEMT based on QGA

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INTERNATIONAL JOURNAL OF ELECTRONICS 2024年第4期111卷 729-747页

作者： Wang, Shaowei Zhang, Jincan Yang, Shi Liu, Min Wang, Jinchan Zhang, Juwei Henan Univ Sci & Technol Elect Engn Coll Luoyang 471003 Peoples R China Novaco Microelect Technol Ltd Dept Res & Dev Nantong Peoples R China

A novel algorithm is proposed for optimal extraction of GaN HEMT small-signal model parameters. The proposed Quantum Genetic algorithm (QGA) exploits the superposition, entanglement and interference of quantum states, which solves the problems of high number of iterations and slow convergence when obtaining optimal solutions using Genetic algorithms (GA). Meanwhile, it is solved that the particle swarm optimisation (PSO) algorithm produces premature convergence and easily falls into the local optimum solution. In order to avoid the influence of distributed parasitic effects in large size devices under high-frequency conditions, a suitable frequency range is determined and combined with direct extraction techniques to determine the range of parameter values. The model parameter values are optimised step by step using QGA. In order to verify the superiority of QGA, QGA and PSO algorithms are both used to optimise GaN HEMT small-signal model parameters. By comparing the modelled S-parameter effects of the QGA and the PSO algorithm, it can be found that the QGA has better consistency with the measured data.

关键词： Quantum genetic algorithm genetic algorithm particle swarm optimisation algorithm GaN HEMT small-signal model

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Design of intermediate roll contour and analysis of regulation ability on strip shape of 18-High mill

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INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2024年第12期131卷 6139-6151页

作者： Zhao, Jun Sun, Jing-Na Wu, Tong Guo, Chao-Jian Huang, Hua-Gui Yanshan Univ Natl Engn Res Ctr Equipment & Technol Cold Strip R Qinhuangdao 066004 Hebei Peoples R China

The corresponding objectives and principles of the intermediate roll contour design are proposed to improve the strip edge drop problem in the process of 18-High mill production and enhance the regulation ability on strip shape. The intermediate roll contour is designed using the particle swarm optimisation algorithm to satisfy the production requirements. The elastic-plastic coupling finite element model of roll system-rolling piece integration is established, the application effect of the new roll contour is verified, and the regulation ability on strip shape under the new roll contour is analysed. Results show that, compared with the original roll contour, the strip edge drop phenomenon is remarkably improved. The regulation ability on strip shape is evidently improved compared with that of the original roll contour. The regulation ability on strip shape of the intermediate roll shifting is stronger than that of the intermediate roll bending force under the new roll contour. Finally, combined with field data of rolling, the finite element model is verified on site. The simulation and measured values are high, and the error is within 10%. The research results can provide a good theoretical basis for the improvement of the intermediate roll contour and improvement of the regulation ability on strip shape of 18-High mill.

关键词： 18-High mill Intermediate roll contour particle swarm optimisation algorithm Strip shape Regulation ability

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Increasing the ampacity of underground cable lines by optimising the thermal environment and design parameters for cable crossings

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IET GENERATION TRANSMISSION & DISTRIBUTION 2022年第11期16卷 2309-2318页

作者： Perovic, Bojan Klimenta, Dardan Tasic, Dragan Raicevic, Nebojsa Milovanovic, Milos Tomovic, Milan Vukasinovic, Jovan Univ Pristina Kosovska Mitrovica Fac Tech Sci Kneza Milosa St 7 RS-38220 Kosovska Mitrovica Serbia Univ Nis Fac Elect Engn Nish Serbia Kosovo & Metohija Acad Appl Studies Dept Zvecan Zvecan Serbia

The problem of optimising the thermal environment and design parameters of underground cable lines for cable crossings with the aim of increasing the ampacities of cables is considered in this paper. particle swarm optimisation (PSO) algorithm, formulated as a continuous non-linear optimisation problem with constraints, for solving this hot spot problem is applied. It is found, using the PSO algorithm, that there are a suitable size of cable bedding and an arrangement of cables within that bedding, which can eliminate or significantly mitigate the hot spot effect without the use of any additional cooling equipment. In this manner, the ampacities of both crossing cable lines increase by about 15% on average with respect to the case of a similar crossing with installation parameters commonly used. In addition, it is shown how the cross-sectional areas of the conductors and metal screens and the metal screen bonding methods affect the optimal solution.

关键词： thermal environment conductors (electric) design parameters particle swarm optimisation algorithm hot spot problem power cables underground cables particle swarm optimisation cable bedding hot spot effect installation parameters crossing cable lines cross-sectional areas PSO algorithm metal screen bonding methods underground cable lines cooling continuous nonlinear optimisation problem

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Backstepping fractional sliding mode voltage control of an islanded microgrid

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IET GENERATION TRANSMISSION & DISTRIBUTION 2019年第12期13卷 2464-2473页

作者： Delavari, Hadi Naderian, Sina Hamedan Univ Technol Dept Elect Engn Hamadan 65155 Iran

Distribution networks include thousands of sensors and a large number of controllable devices such as flexible loads, batteries and distributed generators with an arbitrary configuration that can be parametrically uncertain or topologically unknown. In this study, a new robust non-linear voltage-control strategy based on backstepping and fractional-order (FO) sliding mode control (SMC) is presented for an islanded microgrid (MG). Then for the problem of determining the controller parameters, particle swarm optimisation algorithm is used. The primary objective in this study is to improve robust performance and disturbance rejection of the closed-loop control system. A FO backstepping SMC is proposed in this study. The proposed controller robustly regulates the MG voltages in the presence of parametric uncertainties, unmodelled dynamics, imbalanced and non-linear loads with harmonic. Finally, the performance of the proposed technique is investigated under disturbance in an islanded MG. An in-depth comparative study is done to highlight the merits of the proposed controller. Simulation results revealed that the total harmonic distortion and the steady-state error of the output voltage are successfully decreased and the dynamic performance and the capability of perturbation rejection are efficiently improved.

关键词： power generation control distributed power generation harmonic distortion nonlinear control systems uncertain systems closed loop systems particle swarm optimisation variable structure systems robust control voltage control control nonlinearities backstepping fractional sliding mode voltage control islanded MG MG voltages FO backstepping SMC closed-loop control system particle swarm optimisation algorithm islanded microgrid robust nonlinear voltage-control strategy distribution networks

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Synthesis of flat-top beam pattern of linear antenna arrays with restricted side lobe level, VSWR and independent nulls using Flower Pollination algorithm

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INTERNATIONAL JOURNAL OF ELECTRONICS 2019年第12期106卷 1964-1977页

作者： Patidar, Hemant Mahanti, Gautam Kumar Muralidharan, R. Oriental Univ Dept Elect & Elect Engn Indore Madhya Pradesh India Natl Inst Technol Dept Elect & Commun Engn Durgapur India NUST Coll Engn Dept Elect & Comp Engn Muscat Oman

Inspired by the biological evolution and the natural selection, evolutionary algorithms have already shown their success in obtaining the solutions for many complex optimisation problems. The aim of this paper is to study the performance of Flower Pollination algorithm for the synthesis of the flat-top beam pattern in linear antenna arrays with restrictions on the peak side lobe level, ripple in the flat-top portion, and maximum Voltage Standing Wave Ratio along with the two independent nulls. Mutual coupling is considered between the parallel dipole antennas. This synthesis is obtained by the generation of current amplitudes with binary phase shifters of 0 and 180 degrees for the antenna elements. Matlab software is used for the simulations. The values of the different antenna parameters as well as the statistical parameters such as the global best fitness value, worst fitness value, mean and standard deviation from the optimisation process generated by the simulations are obtained. Two examples are presented in this paper with different number of antenna elements. The obtained results show the superiority of the Flower Pollination algorithm over particle swarm optimisation algorithm. Moreover, the results obtained from simulations are validated by using FEKO software.

关键词： Antenna array flat-top beam pattern Flower Pollination algorithm ripple side lobe level particle swarm optimisation algorithm voltage standing wave ratio

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optimisation model for power system restoration with support from electric vehicles employing battery swapping

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IET GENERATION TRANSMISSION & DISTRIBUTION 2016年第3期10卷 771-779页

作者： Sun, Lei Wang, Xiaolei Liu, Weijia Lin, Zhenzhi Wen, Fushuan Ang, Swee Peng Salam, Md. Abdus Zhejiang Univ Sch Elect Engn Hangzhou 310027 Zhejiang Peoples R China Inst Teknol Brunei Dept Elect & Elect Engn BE-1410 Bandar Seri Begawan Brunei

The energy stored in the batteries of electric vehicles (EVs) could be employed for starting generators when a blackout or a local outage occurs. Considering the feature of the battery swapping mode, an available capacity model of the batteries in a centralised charging station is first developed. Then, the authors analyse the start-up characteristics of a generator powered by batteries and propose a bi-level optimisation-based network reconfiguration model to determine the restoration paths with an objective of maximising the overall generation capability. In the upper-level optimisation model, the generator start-up sequence is optimised, whereas the restoration paths are optimised in the lower-level one. Moreover, they consider the uncertainties associated with the available capacity of the batteries. The bi-level optimisation model for the network reconfiguration is developed in the chance-constrained programming framework and solved by the well-established particle swarm optimisation algorithm. Finally, case studies are employed to demonstrate the effectiveness of the presented model. Simulation results show that a centralised EV charging station could act as a power source to effectively restore a power system without black-start (BS) generators or with insufficient cranking power from BS generators, and the presented model could be used to guide actual system restorations.

关键词： power system restoration battery powered vehicles secondary cells power generation reliability particle swarm optimisation electric vehicles power system restoration blackout EV battery swapping mode starting generator start-up characteristics centralised charging station outage bilevel optimisation-based network reconfiguration upper-level optimisation model chance-constrained programming framework particle swarm optimisation algorithm black start generator BS generator

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Application of PMUs for adaptive protection of overcurrent relays in microgrids

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IET GENERATION TRANSMISSION & DISTRIBUTION 2018年第18期12卷 4061-4068页

作者： Zanjani, Mohsen Ghalei Monfared Mazlumi, Kazem Kamwa, Innocent Univ Zanjan Dept Elect Engn Zanjan Iran Hydroquebec Res Inst IREQ Power Syst & Math Quebec City PQ Canada

This study proposes a new application of micro-phasor measurement units (mu PMUs) for adaptive coordination of overcurrent relays in microgrids. Mis-coordination of overcurrent relays usually arising from the variation of relays fault current and it can cause damage to equipment of network and raise operating costs. Fault current injection and direction to microgrid are highly dependent on network uncertainties;therefore, fault current is affected by line and power plant outages. This study proposes an algorithm to detect these uncertainties in online operation. Then, microgrid overcurrent relays coordination is optimised again. Uncertainties are line and power plant outages in transmission network and microgrid side and two distinct methods are used for each. For online detection of uncertainties in the transmission side, it is assumed that a mu PMU is installed between transmission network and microgrid point of common coupling;so, the topology changes such as line outage is detected by monitoring of Thevenin impedance estimation that is obtained by mu PMU measurements. Uncertainties detection in a microgrid is done by signals that are sent by mu PMUs and installed all over the microgrid. All data are gathered and analysed in phasor data concentrators and then overcurrent relays coordination is updated with such changes.

关键词： phasor measurement relay protection distributed power generation power generation protection overcurrent protection power generation faults power transmission protection power transmission faults particle swarm optimisation fault currents power generation reliability power transmission reliability PMU adaptive overcurrent relay protection microgrid overcurrent relays coordination microphasor measurement units relays fault current operating costs fault current injection network uncertainties line outages power plant outages transmission network online uncertainty detection Thevenin impedance estimation microgrid point-of-common coupling data analysis phasor data concentrators particle swarm optimisation algorithm IEEE 9-bus system DigSILENT software package MATLAB software package

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High-performance Brillouin distributed temperature sensor using Fourier wavelet regularised deconvolution algorithm

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IET OPTOELECTRONICS 2014年第6期8卷 203-209页

作者： Pradhan, Himansu Shekhar Sahu, Prasant Kumar Indian Inst Technol Bhubaneswar Sch Elect Sci Bhubaneswar 751013 Odisha India

In this study, the authors presented a distributed optical fibre temperature sensor whose performance is improved using the optimisation techniques and Fourier wavelet regularised deconvolution (ForWaRD) method. As the input power launched into the sensing fibre is critical, the authors have considered both conventional optimisation technique and evolutionary optimisation techniques namely: genetic algorithm, differential evolution algorithm and particle swarm optimisation algorithm to increase the stimulated Brillouin scattering (SBS) threshold power. Using the optimised value of the parameters and employing evolutionary computing techniques, the proposed 50 km long temperature sensing system offers a 4.7 dB improvement in SBS threshold power over the design of experiment based system. It is being verified that power of the backscattered signals approximately are the convolution of the input pulsed power and corresponding backscatter optical fibre impulse responses. The Fourier wavelet regularised deconvolution (ForWaRD) method is employed to improve the spatial resolution of the proposed sensing system without reducing the pulse width of the input pulse. Employing ForWaRD technique a 10 m better spatial resolution observed as compared with the Fourier deconvolution technique. The proposed 50 km long temperature sensing system exhibits a temperature resolution of 1.85 K because of suppression of SBS threshold and noise reduction.

关键词： fibre optic sensors temperature sensors stimulated Brillouin scattering Fourier transform optics wavelet transforms deconvolution genetic algorithms particle swarm optimisation distributed sensors optical information processing signal denoising high-performance Brillouin distributed temperature sensor Fourier wavelet regularised deconvolution algorithm optical fibre temperature sensor ForWaRD method evolutionary optimisation techniques genetic algorithm differential evolution algorithm particle swarm optimisation algorithm stimulated Brillouin scattering SBS threshold power input pulsed power convolution backscatter optical fibre impulse responses spatial resolution SBS threshold suppression noise reduction

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Multi-objective robust optimisation model for MDVRPLS in refined oil distribution

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INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH 2022年第22期60卷 6772-6792页

作者： Xu, Xiaofeng Lin, Ziru Li, Xiang Shang, Changjing Shen, Qiang China Univ Petr Sch Econ & Management Qingdao Peoples R China Beijing Univ Chem Technol Sch Econ & Management Beijing 100029 Peoples R China Aberystwyth Univ Fac Business & Phys Sci Dept Comp Sci Aberystwyth Dyfed Wales

At depots with refined oil shortage, arranging a reasonable distribution scheme with limited supply affects operation costs, demand satisfaction rate of gasoline stations (hereafter, 'station satisfaction'), and overtime penalty. This study considers the refined oil distribution problem with shortages using a multi-objective optimisation approach from the perspective of decision makers of oil marketing companies. The modelling and solving process involves (i) formulation of a crisp multi-depot vehicle routing model with limited supply (MDVRPLS) which considers station priority and soft time windows, (ii) development of a robust optimisation model (ROM) to manage uncertainty in demand, and (iii) the proposal of a multi-objective particle swarm optimisation (MOPSO)algorithm. Results of numerical experiments show that (i) the crisp model can better balance operation costs, station satisfaction, and overtime penalty, which produces 3.33% and 4.60% increase in station satisfaction at an increased unit cost and overtime penalty respectively;(ii) ROM successfully addresses uncertainty in demand compared to the crisp model, which requires an additional 8.81% in cost and 12.85% in penalty;and (iii) the MOPSO manages these MDVRPLS models more effectively than other heuristic algorithms. Therefore, applying ROM of refined oil supply shortage to the management significantly improves the efficiency and resists the disturbance caused by external uncertainties, providing scope for efficient distribution of scarce resources.

关键词： MDVRPLS refined oil distribution robust optimisation multi-objective optimisation particle swarm optimisation algorithm

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