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A Multi-Objective Particle Swarm Optimization Algorithm Based on Decomposition and Multi-Selection Strategy

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Computers, Materials & Continua 2025年第1期82卷 997-1026页

作者： Li Ma Cai Dai Xingsi Xue Cheng Peng school of Computer Science Shaanxi Normal UniversityXi’an710119China Fujian Provincial Key Laboratory of Big Data Mining and Applications Fujian University of TechnologyFuzhou350118China Information Construction and management Center and Institute of Artificial Intelligence and Educational New Productivity Ningxia Normal UniversityGuyuan756099China

The multi-objective particle swarm optimization algorithm(MOPSO)is widely used to solve multi-objective optimization *** the article,amulti-objective particle swarm optimization algorithmbased on decomposition and multi-selection strategy is proposed to improve the search ***,two update strategies based on decomposition are used to update the evolving population and external archive,***,a multiselection strategy is *** first strategy is for the subspace without a non-dominated *** the neighbor particles,the particle with the smallest penalty-based boundary intersection value is selected as the global optimal solution and the particle far away fromthe search particle and the global optimal solution is selected as the personal optimal solution to enhance global *** second strategy is for the subspace with a non-dominated *** the neighbor particles,two particles are randomly selected,one as the global optimal solution and the other as the personal optimal solution,to enhance local *** third strategy is for Pareto optimal front(PF)discontinuity,which is identified by the cumulative number of iterations of the subspace without non-dominated *** the subsequent iteration,a new probability distribution is used to select from the remaining subspaces to ***,an adaptive inertia weight update strategy based on the dominated degree is designed to further improve the search ***,the proposed algorithmis compared with fivemulti-objective particle swarm optimization algorithms and five multi-objective evolutionary algorithms on 22 test *** results show that the proposed algorithm has better performance.

关键词： Multi-objective optimization multi-objective particle swarm optimization decomposition multi-selection strategy

Practical Options for Adopting Recurrent Neural Network and Its Variants on Remaining Useful Life Prediction

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Chinese Journal of Mechanical Engineering 2021年第3期34卷 32-51页

作者： Youdao Wang Yifan Zhao Sri Addepalli school of Aerospace Transport and ManufacturingCranfield UniversityCranfield MK430ALUK

The remaining useful life(RUL)of a system is generally predicted by utilising the data collected from the sensors that continuously monitor different ***,different deep learning(DL)techniques have been used for RUL prediction and achieved great *** the data is often time-sequential,recurrent neural network(RNN)has attracted significant interests due to its efficiency in dealing with such *** paper systematically reviews RNN and its variants for RUL prediction,with a specific focus on understanding how different components(e.g.,types of optimisers and activation functions)or parameters(e.g.,sequence length,neuron quantities)affect their *** that,a case study using the well-studied NASA’s C-MAPSS dataset is presented to quantitatively evaluate the influence of various state-of-the-art RNN structures on the RUL prediction *** result suggests that the variant methods usually perform better than the original RNN,and among which,Bi-directional Long Short-Term Memory generally has the best performance in terms of stability,precision and *** model structures may fail to produce valid RUL prediction result due to the gradient vanishing or gradient exploring problem if the parameters are not chosen *** is concluded that parameter tuning is a crucial step to achieve optimal prediction performance.

关键词： Remaining useful life prediction Deep learning Recurrent neural network Long short-term memory Bi-directional long short-term memory Gated recurrent unit

Laplace plane and low inclination geosynchronous radar mission design

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Science China(Information Sciences) 2017年第6期60卷 62-71页

作者： Stephen HOBBS Joan Pau SANCHEZ school of Aerospace Transport and Manufacturing Cranfield University

This study is inspired by the Laplace orbit plane property of requiring minimal station-keeping and therefore its potential use for long-term geosynchronous synthetic aperture radar(GEOSAR) imaging. A set of GEOSAR user requirements is presented and analysed to identify significant mission requirements. Imaging geometry and power demand are assessed as a function of relative satellite speed(which is determined largely by choice of orbit inclination). Estimates of the cost of station-keeping as a function of orbit inclination and right ascension are presented to compare the benefits of different orbit choices. The conclusion is that the Laplace plane(and more generally, orbits with inclinations up to 15°) are attractive choices for GEOSAR.

关键词： Laplace plane station-keeping geosynchronous inclination GEOSAR

Micro/nano Indentation and Single Grit Diamond Grinding Mechanism on Ultra Pure Fused Silica

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Chinese Journal of Mechanical Engineering 2011年第6期24卷 963-970页

作者： ZHAO Qingliang GUO Bing STEPHENSIN David CORBETT John school of Mechatronics Engineering Harbin Institute of Technology Harbin 150001 China Materials Department Cranfield University Cranfield Bedford MK43 OAL UK school of Applied Sciences Cranfield University Cranfield Bedford MK43 OAL UK

The existing research about ductile grinding of fused silica glass was mainly focused on how to carry out ductile regime material removal for generating very ＂smoothed＂ surface and investigate the machining-induced damage in the grinding in order to reduce or eliminate the subsurface *** brittle/ductile transition behavior of optical glass materials and the wear of diamond wheel are the most important factors for ductile grinding of optical *** this paper,the critical brittle/ductile depth,the influence factors on brittle/ductile transition behavior,the wear of diamond grits in diamond grinding of ultra pure fused silica（UPFS） are investigated by means of micro/nano indentation technique,as well as single grit diamond grinding on an ultra-stiff machine tool,Tetraform ＂C＂.The single grit grinding processes are in-process monitored using acoustic emission（AE） and force dynamometer *** wear of diamond grits,morphology and subsurface integrity of the machined groves are examined with atomic force microscope（AFM） and scanning electron microscope（SEM）.The critical brittle/ductile depth of more than 0.5 μm is *** compared to the using roof-like grits,by using pyramidal diamonds leads to higher critical depths of scratch with identical grinding ***,the influence of grit shapes on the critical depth is not significant as *** grinding force increased linearly with depth of cut in the ductile removal regime,but in brittle removal regime,there are large fluctuations instead of forces *** SEM photographs of the cross-section profile show that the median cracks dominate the crack patterns beneath the single ***,The SEM photographs show multi worn patterns of diamond grits,indicating an inhomogeneous wear mechanism of diamond grits in grinding of fused silica with diamond grinding *** proposed research provides the basal technical theory for improving the ultra-precision grinding of UPFS.

关键词： ultra pure fused silica (UPFS) micro/nano indentation single grit diamond grinding ductile material removal subsurface integrity diamond grits wear

The impact of anti-corruption measures and risk effects on equity incentives and financial misreporting in China

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China Journal of Accounting Research 2022年第1期15卷 94-121页

作者： Zili Su Constantinos Alexiou school of Finance Central University of Finance and EconomicsBeijingChina TIAS school for Business and Society Tilburg UniversityTilburgNetherlands cranfield school of management Cranfield UniversityCranfield UK

This study examines the effects of anti-corruption and equity incentive risk on financial misreporting in the context of China’s unique corporate ownership structure and governance *** a sample comprising 2,708 cases of financial restatement over the 2007-2017 *** key findings suggest that managers’shareholdings are significantly and positively associated with their firms’financial misreporting,and certain equity risk factors dramatically alter Chinese corporate ***,managers’motivation to misreport is significantly more pronounced in non-state owned enterprises(nonSOEs),suggesting that equity incentive risk effects mitigate the"absence of ownership"problem believed to affect *** in highly competitive industries and firms with low institutional ownership are found to be highly motivated to misreport performance.

关键词： Equity incentives Anti-corruption SOEs Non-SOEs Financial misreporting Risk effects

Deformation Analysis of Micro/Nano Indentation and Diamond Grinding on Optical Glasses

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Chinese Journal of Mechanical Engineering 2012年第3期25卷 411-418页

作者： ZHAO Qingliang ZHAO Lingling GUO Bing STEPHENSIN David CORBETT John school of Mechatronics Engineering Harbin Institute of TechnologyHarbin 150001China Materials Department Cranfield UniversityCranfieldBedford MK43 OALUK school of Applied Sciences Cranfield UniversityCranfieldBedford MK43 OALUK

The previous research of precision grinding optical glasses with electrolytic in process dressing （ELID） technology mainly concentrated on the action of ELID and machining parameters when grinding, which aim at generating very ＂smoothed＂ surfaces and reducing the subsurface damage. However, when grinding spectrosil 2000 and BK7 glass assisted with ELID technology, a deeply comparative study on material removal mechanism and the wheel wear behaviors have not been given yet. In this paper, the micro/nano indentation technique is initially applied for investigating the mechanical properties of optical glasses, whose results are then refereed to evaluate the machinability. In single grit diamond scratching on glasses, the scratching traces display four kinds of scratch characteristics according to different material removal modes. In normal grinding experiments, the result shows BK7 glass has a better machinability than that of spectrosil 2000, corresponding to what the micro/nano indentation vent revealed. Under the same grinding depth parameters, the smaller amplitude of acoustic emission （AE） raw signals, grinding force and grinding force ratio correspond to a better surface quality. While for these two kinds of glasses, with the increasing of grinding depth, the variation trends of the surface roughness, the force ratio, and the AE raw signals are contrary, which should be attributed to different material removal modes. Moreover, the SEM micrographs of used wheels surface indicate that diamond grains on the wheel surface after grinding BK7 glass are worn more severely than that of spectrosil 2000. The proposed research analyzes what happened in the grinding process with different material removal patterns, which can provide a basis for producing high-quality optical glasses and comprehensively evaluate the surface and subsurface integrity of optical glasses.

关键词： optical glasses micro/nano indentation single grit diamond scratching material removal mode surface integrity electrolytic in process dressing (ELID)

Power plant selection in a carbon constrained world the TERA(technoeconomic environmental risk analysis)

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航空动力学报 2009年第4期24卷 896-902页

作者： Stephen Ogaji Pericles Pilidis Vishal Sethi Department of Power and Propulsion school of Engineering cranfield University

There is an increasing concern that current trends of consumption of natural resources cannot *** is imperative that major targeted investments are made into economical and reliable environment friendly propulsion and power *** novel and promising concepts are being *** selection of the best candidates to pursue for investment becomes a very difficult choice.A detailed TERA(techno-economic environmental risk analysis) framework is described here to quantify risks and to compare and rank competing schemes on a formal and consistent *** technique is based on detailed and rigorous thermodynamic representations of power plants.A layer of environment,economic,weather and other models to describe the appropriate local conditions is superimposed to *** outcome is a techno-economic environmental risk analysis framework with appropriate detail of each power plant as applied to the appropriate *** results for each concept can then be compared and contrasted to make appropriate selections.

关键词： TERA(techno-economic environmental risk analysis) techno-economic risk analysis gas turbine multi-disciplinary optimisation(MDO)

Optimal Feedback Control of Oil Reservoir Waterflooding Processes

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International Journal of Automation and computing 2016年第1期13卷 73-80页

作者： A.S.Grema Yi Cao school of Energy Environment & Agrifood Cranfield University

Waterfiooding is a process where water is injected into an oil reservoir to supplement its natural pressure for increment in productivity. The reservoir properties are highly heterogeneous, its states change as production progresses which require varying injection and production settings for economic recovery. As water is injected into the reservoir, more oil is expected to be produced. There is also likelihood that water is produced in association with the oil. The worst case is when the injected water meanders through the reservoir, it bypasses pools of oil and gets produced, Therefore, any effort geared toward finding the optimal settings to maximize the value of this venture can never be over emphasized. Waterflooding can be formulated as an optimal control problem. However, traditional optimal control is an open-loop solution, hence cannot cope with various uncertainties inevitably existing in any practical systems. Reservoir models are highly uncertain. Its properties are known with some degrees of certainty near the well-bore region only. In this work, a novel data-driven approach for control variable （CV） selection was proposed and applied to reservoir waterflooding process for a feedback strategy resulting in optimal or near optimal operation. The results indicated that the feedback control method was close to optimal in the absence of uncertainty. The loss recorded in the value of performance index, net present value （NPV） was only 0.26%. Furthermore, the new strategy performs better than the open-loop optimal control solution when system/model mismatch was considered. The performance depends on the scale of the uncertainty introduced. A gain in NPV as high as 30.04% was obtained.

关键词： Oil reservoir management intelligent wells optimal control theory feedback control geological uncertainty.

Automatic interval management for aircraft based on dynamic fuzzy speed control considering uncertainty

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Chinese Journal of Aeronautics 2023年第11期36卷 354-372页

作者： Jie YUAN Yang PEI Yan XU Xiaochen LI Yuxue GE school of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China school of Aerospace Transport and ManufacturingCranfield UniversityCranfield MK430ALUnited Kingdom

A novel real-time autonomous Interval management System(IMS)is proposed to automate interval management,which considers the effect of wind uncertainty using the Dynamic Fuzzy Velocity Decision(DFVD)*** membership function can be generated dynamically based on the True Air Speed(TAS)limitation changes in real time and the interval criterion of the adjacent aircraft,and combined with human cognition to formulate fuzzy rules for speed adjusting *** groups of experiments were conducted during the en-route descent stage to validate the proposed IMS and DFVD performances,and to analyze the impact factors of the *** verification experimental results show that compared with actual flight status data under controllers’command,the IMS reduces the descent time by approaching 30%with favorable wind uncertainty suppression *** analysis shows that the ability improvement of DFVD is mainly affected by the boundary value of the membership ***,the dynamic generation of the velocity membership function has greater advantages than the static method in terms of safety and *** the analysis of influencing factors,we found that the interval criterion and aircraft category have no significant effect on the capability of *** a higher initial altitude scenario,the initial interval should be appropriately increased to enhance safety and efficiency during the descent *** prototype system could evolve into a realtime Flight-deck Interval management(FIM)tool in the future.

关键词： Air traffic control Air transportation Fuzzy logic Safety interval Wind uncertainty