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Robust design of sliding mode control for airship trajectory tracking with uncertainty and disturbance estimation

Journal of Systems Engineering and Electronics 2024年第1期35卷 242-258页

作者： wasim muhammad ALI Ahsan CHOUDHRY Mohammad Ahmad SHAIKH Inam Ul Hasan SALEEM Faisal Department of Aeronautics and Astronautics Engineering Institute of Space TechnologyIslamabad 44000Pakistan Department of Electrical Engineering University of Engineering and TechnologyTaxila 47080Pakistan Department of Measurements and Control Systems Silesian University of TechnologyGliwice 44-101Poland The Joint Doctoral School Silesian University of TechnologyGliwice 44-100Poland

The robotic airship can provide a promising aerostatic platform for many potential *** applications require a precise autonomous trajectory tracking control for *** has a nonlinear and uncertain *** is prone to wind disturbances that offer a challenge for a trajectory tracking control *** paper addresses the airship trajectory tracking problem having time varying reference path.A lumped parameter estimation approach under model uncertainties and wind disturbances is opted against distributed *** uses extended Kalman filter(EKF)for uncertainty and disturbance *** estimated parameters are used by sliding mode controller(SMC)for ultimate control of airship trajectory *** comprehensive algorithm,EKF based SMC(ESMC),is used as a robust solution to track airship *** proposed estimator provides the estimates of wind disturbances as well as model uncertainty due to the mass matrix variations and aerodynamic model *** stability and convergence of the proposed method are investigated using the Lyapunov stability *** simulation results show that the proposed method efficiently tracks the desired *** method solves the stability,convergence,and chattering problem of SMC under model uncertainties and wind disturbances.

关键词： airship chattering extended Kalman filter(EKF) model uncertainties estimation sliding mode controller(SMC)

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Application and comparison of kernel functions for linear parameter varying model approximation of nonlinear systems

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Applied Mathematics(A Journal of Chinese Universities) 2023年第1期38卷 58-77页

作者： Faisal Saleem Ahsan Ali Inam-ul-hassan Shaikh muhammad wasim Department of Measurements and Control Systems Silesian University of TechnologyGliwicePoland Department of Electrical Engineering University of Engineering and TechnologyTaxilaPakistan Department of Aeronautics and Astronautics Engineering Institute of Space TechnologyIslamabadPakistan

In this paper,a comparative study for kernel-PCA based linear parameter varying(LPV)model approximation of sufficiently nonlinear and reasonably practical systems is carried *** matrix inequalities(LMIs)to be solved in LPV controller design process increase exponentially with the increase in a number of scheduling *** kernel functions are used to obtain the approximate LPV model of highly coupled nonlinear *** error to norm ratio of original and approximate LPV models is introduced as a measure of accuracy of the approximate LPV *** examples conclude the effectiveness of kernel-PCA for LPV model approximation as with the identification of accurate approximate LPV model,computation complexity involved in LPV controller design is decreased exponentially.

关键词： kernel-PCA LMIs LPV error to norm ratio computational complexity and control design

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Airship aerodynamic model estimation using unscented Kalman filter

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Journal of Systems Engineering and Electronics 2020年第6期31卷 1318-1329页

作者： wasim muhammad ALI Ahsan Department of Electrical Engineering University of Engineering and TechnologyTaxila 47080Pakistan

An airship model is made-up of aerostatic,aerodynamic,dynamic,and propulsive forces and *** others,the computation of aerodynamic forces and torques is ***,wind tunnel experimentation and potential flow theory are used for their ***,the limitations of these methods pose difficulties in their accurate *** this work,an online estimation scheme based on unscented Kalman filter(UKF)is proposed for their *** proposed method introduces six auxiliary states for the complete aerodynamic *** uses an extended model and provides an estimate of a complete state vector along with auxiliary *** proposed method uses the minimum auxiliary state variables for the approximation of the complete aerodynamic model that makes it computationally less *** estimation performance is evaluated by developing a nonlinear simulation environment for University of Engineering and Technology,Taxila(UETT)*** performance is vali􀅫dated by performing the error analysis based on estimation error and 2-σ uncertainty *** the same problem,the extended Kalman filter(EKF)is also implemented and its results are compared with *** simulation results show that UKF successfully estimates the forces and torques due to the aerodynamic model with small estimation error and the comparative analysis with EKF shows that UKF improves the estimation re􀅫sults and also it is more suitable for the under-consideration problem.

关键词： airship unscented Kalman filter(UKF) extend Kalman filter(EKF) state estimation aerodynamic model estimation

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Analysis of the effect of passive measures on the energy consumption and zero-energy prospects of residential buildings in Pakistan

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Building Simulation 2021年第4期14卷 1325-1342页

作者： muhammad wasim Anwar Zaib Ali Abdullah Javed Emad Ud Din muhammad Sajid School of Mechanical and Manufacturing Engineering National University of Sciences and TechnologyIslamabadPakistan

Climate change can adversely impact the thermal comfort and energy efficiency of the buildings stock. The South Asian countries are particularly vulnerable to the adverse impacts of climate change specially in the form of rising temperatures and increasing frequency of heat waves. The passive building design measures can be useful in mitigating and adapting to the climate change by increasing energy efficiency and reducing greenhouse gas (GHG) emissions. In this study various passive climate change adaptation measures (PCAMs) have been used individually and in form of combinations in order to analyze their impact on the energy efficacy of residential buildings in Pakistan. It has been found that the natural ventilation and front green wall are the most efficient options for reducing the overall energy consumption. By implementation of these PCAMs, cooling demand can be decreased by 27.75% while heating demand can be reduced by 35%. Secondly, the prospect of net zero-energy building and reduced CO2 emissions are also studied. It has been shown that building can achieve net-zero energy on an annual basis at every orientation and it can attain the status of nearly zero-energy building on a monthly basis. Moreover, emitted CO2 can be reduced by 31% by using the renewable energy.

关键词： building energy simulations net zero-energy passive climate adaptation measures climate change energy consumption Pakistan

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Adipose-derived regenerative therapies for the treatment of knee osteoarthritis

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World Journal of Stem Cells 2024年第4期16卷 324-333页

作者： Ilias E Epanomeritakis wasim S Khan Division of Trauma and Orthopaedic Surgery Addenbrooke’s HospitalCambridge University Hospitals NHS Foundation TrustCambridge CB20QQUnited Kingdom Division of Trauma and Orthopaedic Surgery Department of SurgeryUniversity of CambridgeCambridge CB20QQUnited Kingdom

Knee osteoarthritis is a degenerative condition with a significant disease burden and no disease-modifying *** treatment ultimately requires joint *** capable of regenerating cartilage could significantly reduce financial and clinical *** regenerative potential of mesenchymal stromal cells(MSCs)has been extensively studied in the context of knee *** has yielded promising results in human studies,and is likely a product of immunomodulatory and chondroprotective biomolecules produced by MSCs in response to ***-derived MSCs(ASCs)are becoming increasingly popular owing to their relative ease of isolation and high proliferative *** vascular fraction(SVF)and micro-fragmented adipose tissue(MFAT)are produced by the enzymatic and mechanical disruption of adipose tissue,*** avoids expansion of isolated ASCs ex vivo and their composition of heterogeneous cell populations,including immune cells,may potentiate the reparative function of *** this editorial,we comment on a multicenter randomized trial regarding the efficacy of MFAT in treating knee *** discuss the study’s findings in the context of emerging evidence regarding adipose-derived regenerative *** underlying mechanism of action of ASCs is proposed while drawing important distinctions between the properties of isolated ASCs,SVF,and MFAT.

关键词： Knee osteoarthritis Mesenchymal stromal cells Adipose tissue Stromal vascular fraction Micro-fragmented adipose tissue Regeneration

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Sunflower-Like SrCo_(2)S_(4)@f-MWCNTs Hybrid Wrapped by Engineering N-Reduced Graphene Oxide for High Performance Dye-Sensitized Solar Cells

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Journal of Renewable Materials 2020年第4期8卷 431-446页

作者： Weiming Zhang muhammad wasim Khan Xueqin Zuo Qun Yang Huaibao Tang Shaowei Jin Guang Li School of Physics and Materials Science Anhui UniversityHefei230601China Anhui Key Laboratory of Information Materials and Devices Hefei230601China Institute of Physical Science and Information Technology Anhui UniversityHefei230601China

A novel sunflower-like nanocomposite of SrCo_(2)S_(4)nanoflakes and functionalized multiwall carbon nanotubes(f-MWCNTs)entanglement enveloped in nitrogen-reduced graphene oxide(N-RGO)is prepared by a cheap *** unique entanglement structure of the material exhibits higher specific surface area,better electrical conductivity and other *** helps to reduce the transfer resistance in the photoelectric process of the battery and improve the electrochemical activity,thus increasing the photoelectric conversion efficiency of the *** new ternary cobalt-based sulfide material can replace platinum as the counter electrode(CE)material loaded on dye-sensitized solar cells(DSSCs).DSSCs with SrCo_(2)S_(4)@f-MWCNTs@N-RGO(SCS@f-M@N-R)as CE material show excellent photoelectric conversion efficiency(PCE,8.06%),even surpassing than that of Pt CE material(7.51%).The low cost,excellent electrocatalytic performance and simple preparation method of SCS@f-M@N-R nanomaterial provide feasibility for replacing platinum material as the CE material of DSSCs,which is of great significance and persuasion.

关键词： Dye-sensitized solar cells sunflower-like multiwall carbon nanotubes SrCo_(2)S_(4) counter electrode

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磁流变弹性体的性能研究

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橡胶工业 2023年第11期70卷 845-849页

作者：王静 muhammad wasimAsim 危银涛清华大学车辆与运载学院北京100084

以天然橡胶为基体制备磁流变弹性体(MRE),研究MRE的Payne效应及磁感应强度和磁流变效应。扫描电子显微镜分析得出,对于羰基铁粉质量分数最大(81.67%)的MRE,羰基铁粉分布密集,出现羰基铁粉团聚现象。流变仪测试结果表明:随着羰基铁粉质... 详细信息

以天然橡胶为基体制备磁流变弹性体(MRE),研究MRE的Payne效应及磁感应强度和磁流变效应。扫描电子显微镜分析得出,对于羰基铁粉质量分数最大(81.67%)的MRE,羰基铁粉分布密集,出现羰基铁粉团聚现象。流变仪测试结果表明:随着羰基铁粉质量分数的增大,MRE的Payne效应和磁流变效应增强;随着应变的增大,MRE的储能模量减小,损耗因子增大。

关键词：磁流变弹性体羰基铁粉天然橡胶磁流变效应

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Influence of rainfall infiltration on the stability of unsaturated coal gangue accumulated slope

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Journal of Mountain Science 2021年第6期18卷 1696-1709页

作者： Kaleem Ullah Jan KHAN WANG Chang-ming muhammad wasim Jan KHAN LIANG Zhu LI Shuo LI Bai-long College of Construction Engineering Jilin UniversityChangchun 130021China Department of Management Sciences University College of Zhob(Sub-Campus BUITEMS)Balochistan 85200Pakistan

The slope instability is associated with increasing rate of rainfall infiltration which cause shear strength reduction and suction loss and the slope tend to failure. The influences of rainfall infiltration on the stability of clayey and sandy slopes have been analyzed but the effect of rainfall infiltration on the stability of unsaturated coal gangue accumulated slope was needed to study. Therefore, a coal gangue accumulated slope prone to failure in Fuxin area of Northeast China was considered to evaluate its failure mechanism under different rainfall events. The effects after five different rainfall events on slope stability were physically analyzed, numerically investigated and the results from both uncoupled(hydraulic) and coupled(hydromechanical) responses were compared using finite element analysis. It was observed that the decisive soaking and leaching under different rainfall conditions caused maximum deformation at the crest of slope due to maximum value of permeability coefficient of coal gangue. The critical duration of moderate intensity(147 mm/day) of rainfall for the instability of coal gangue accumulated slope is declared as five days. The results from finite element analysis in this paper further clarifies that increase in duration of rainfall infiltration process cause hysteretic change in positive pore-water pressure causing decrease in factor of safety and increase in deformation. It is concluded that the stability of unsaturated coal gangue accumulated slope is greatly influence by the coupled effect of stress and porewater pressure in comparison of uncoupled(hydraulic) analysis as the obtained factor of safety values after five days of rainfall infiltration were 0.9 and 1.1 respectively.

关键词： Hydro mechanical coupling Factor of safety Ground water table Rainfall infiltration Matric suction Coal gangue

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Utilisation of green urban space for food sufficiency and the realisation of the sustainable development goals-UK stakeholders perspective

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Geography and Sustainability 2024年第1期5卷 13-18页

作者： Alex Opoku Anna Duff Moohammed wasim Yahia Samuel Ekung Department of Architectural Engineering College of EngineeringUniversity of SharjahUAE UCL Bartlett School of Sustainable Construction University College LondonLondonUK Department of Quantity Surveying University of UyoUyoNigeria

The exponential growth of food demand due to the increasing global population has the potential to seriously threaten the quality and quantity of food supplies due to climate *** study explores the utilisation of green urban spaces for achieving food self-sufficiency by investigating the extent to which sustainable urban farms could be used to reduce the consumption of imported produce in the *** also examines urban farming stakeholders'perspective on how food self-sufficiency can help realise the SDGs especially SDG 2(Zero hunger)and SDG 13(Climate action).The study adopts a mixed method approach through a survey with 115 respondents and semi-structured interviews conducted with 12 respondents from 4 different urban farming stakeholder *** findings of this study presented a strong correlation between stakeholders who had concerns about where their food came from and the carbon footprint of imported *** research shows that,urban farms will no doubt play a vital role in the future of food security in our cities/communities and that the SDGs could be realised through sustainable urban farms implemented within the relevant planning regulations/policies.

关键词： Cities Food sufficiency Green urban space Urban farms SDGS

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Enhancing PDF Malware Detection through Logistic Model Trees

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Computers, Materials & Continua 2024年第3期78卷 3645-3663页

作者： muhammad Binsawad Department of Information Systems King Abdulaziz UniversityP.O.Box 80217Jeddah21589Saudi Arabia

Malware is an ever-present and dynamic threat to networks and computer systems in cybersecurity,and because of its complexity and evasiveness,it is challenging to identify using traditional signature-based detection *** study article discusses the growing danger to cybersecurity that malware hidden in PDF files poses,highlighting the shortcomings of conventional detection techniques and the difficulties presented by adversarial *** article presents a new method that improves PDF virus detection by using document analysis and a Logistic Model *** a dataset from the Canadian Institute for Cybersecurity,a comparative analysis is carried out with well-known machine learning models,such as Credal Decision Tree,Naïve Bayes,Average One Dependency Estimator,Locally Weighted Learning,and Stochastic Gradient *** traditional structural and JavaScript-centric PDF analysis,the research makes a substantial contribution to the area by boosting precision and resilience in malware *** use of Logistic Model Tree,a thorough feature selection approach,and increased focus on PDF file attributes all contribute to the efficiency of PDF virus *** paper emphasizes Logistic Model Tree’s critical role in tackling increasing cybersecurity threats and proposes a viable answer to practical issues in the *** results reveal that the Logistic Model Tree is superior,with improved accuracy of 97.46%when compared to benchmark models,demonstrating its usefulness in addressing the ever-changing threat landscape.

关键词： Malware detection PDF files logistic model tree feature selection cybersecurity

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