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A Linear Quadratic Controller Design Incorporating a Parametric Sensitivity Constraint

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International Journal of Automation and computing 2019年第4期16卷 553-562页

作者： mohamed Yagoubi LUNAM University Ecole des Mines de Nantes IRCCyN UMR CNRS 6597(Institut de Recherche en Communications et Cyberntique de Nantes)

The purpose of this paper is to propose a synthesis method of parametric sensitivity constrained linear quadratic (SCLQ) controller for an uncertain linear time invariant (LTI) system. System sensitivity to parameter variation is handled through an additional quadratic trajectory parametric sensitivity term in the standard LQ criterion to be minimized. The main purpose here is to find a suboptimal linear quadratic control taking explicitly into account the parametric uncertainties. The paper main contribution is threefold: 1) A descriptor system approach is used to show that the underlying singular linear-quadratic optimal control problem leads to a non-standard Riccati equation. 2) A solution to the proposed control problem is then given based on a connection to the so-called Lur'e matrix equations. 3) A synthesis method of multiple parametric SCLQ controllers is proposed to cover the whole parametric uncertainty while degrading as less as possible the intrinsic robustness properties of each local linear quadratic controller. Some examples are presented in order to illustrate the effectiveness of the approach.

关键词： Linear quadratic control parametric uncertainties trajectory sensitivity non-standard Riccati equation Lur'e matrix equations linear time invariant (LMI) particle swarm optimization

Oxidation Resistance of the Aluminide Coating Formed on Carbon Steels

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Journal of Materials Science & Technology 1997年第5期13卷 383-388页

作者： Soliman H.M. mohamed K.e. Abd el-Azim M.e. Hammad F.H. Metallurgy Dept. Atomic Energy Authority Cairo Egypt

Low and medium carbon steels were aluminized by the pack aluminizing technique using halideactivated pure-Al and Fe-Al packs. The effect of mixture composition, aluminizing temperatureand time and C content of the steel substrate on the structure and thickness of the aluminidelayer, and on the oxidation resistance was investigated. The optimum oxidation resistance canbe achieved with a low carbon steel substrate when the intermetallic phases Fe3Al and FeAlform the surface of the aluminide layer. In this case, the Al concentration at the surface of thealuminide coating is at least ≥15 wt pct. Formation of high Al concentration phases (FeAl3 andFe2Al5) during aluminizing should be avoided as they tend to embrittle the aluminide layer andreduce its oxidation resistance.

关键词： OO Figure Oxidation Resistance of the Aluminide Coating Formed on Carbon Steels

Distinct and combined impacts of climate and land use scenarios on water availability and sediment loads for a water supply reservoir in northern Morocco

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International Soil and Water Conservation Research 2020年第2期8卷 141-153页

作者： Fatiha Choukri Damien Raclot Mustapha Naimi mohamed Chikhaoui Joao Pedro Nunes Frédéric Huard Cécile Hérivaux mohamed Sabir Yannick Pépin IAV Hassan II Department of Natural Resources and EnvironmentMadinat Al IrfaneRabatMorocco LISAH Univ MontpellierINRAEIRDInstitut AgroMontpellierFrance Ce3C-Centre for ecology Evolution and Environmental ChangesFaculdade de CienciasUniversidade de Lisboa1749-016LisboaPortugal INRAe-AgroClim 228 Route de l’AérodromeCS 4050984914AvignonCedex 9France BRGM Univ Montpellier1039 Rue de Pinville34000MontpellierFrance eNFI bd Moulay YoussefTabriquetSALEMorocco

The objective of this study was to examine the impacts of climate and land use changes on wateravailability and sediment loads for a water supply reservoir in northern Morocco using data-intensive simulation models in a data-scarce region. Impacts were assessed by comparing the simulated water and sediment entering the reservoir between the future period 2031-2050 and the 1983-2010 reference period. Three scenarios of land use change and two scenarios of climate change were developed in the Tleta watershed. Simulations under current and future conditions were performed using the Soil and Water Assessment Tool (SWAT) model. The simulations showed that climate change will lead to a sig-nificant decrease in the annual water supply to the reservoir (-16.9% and -27.5%) and in the annual volume of sediment entering the reservoir (-7.4% and -12.6%), depending on the climate change sce-narios tested. The three scenarios of land use change will lead to a moderate change in annual water inflow into the reservoir (between-6.7% and +6.2%), while causing a significant decrease in sediment entering the reservoir (-37%to-24%). The combined impacts of climate and land use changes will cause a reduction in annual water availability (-9.9%to-33.3%) and sediment supplies (-28.7%to-45.8%). As a result, the lifetime of the reservoir will be extended, but at the same time, the risk of water shortages will increase, especially from July to March. Therefore, alternative water resources must be considered.

关键词： Climate change Land use change SWAT Runoff Reservoir management Morocco

Comprehensive evaluation of machine learning algorithms applied to TBM performance prediction

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Underground Space 2022年第1期7卷 37-49页

作者： Jie Yang Saffet Yagiz Ying-Jing Liu farid Laouafa Zhongtian Construction Group Co.Ltd HangzhouChina Department of Civil and environmental engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina School of Mining and Geosciences Nazarbayev UniversityNur-Sultan 010000Kazakhstan National Institute for Industrial environment and Risks(INeRIS) Verneuil-en-HalatteFrance

To date,the accurate prediction of tunnel boring machine(TBM)performance remains a considerable challenge owing to the complex interactions between the TBM and *** evolutionary polynomial regression(ePR)and random forest(RF),this study devel-ops two novel prediction models for TBM *** models can predict the TBM penetration rate and field penetration index as outputs with four input parameters:the uniaxial compressive strength,intact rock brittleness index,distance between planes of weakness,and angle between the tunnel axis and planes of weakness(a).First,the performances of both ePR-and RF-based models are examined by comparison with the conventional numerical regression method(i.e.,multivariate linear regression).Subsequently,the performances of the RF-and ePR-based models are further investigated and compared,including the model robustness for unknown datasets,interior relationships between input and output parameters,and variable *** results indicate that the RF-based model has greater prediction accuracy,particularly in identifying outliers,whereas the ePR-based model is more convenient to use by field engineers owing to its explicit *** ePR-and RF-based models can accurately identify the relationships between the input and output *** ensures their excellent generalization ability and high prediction accuracy on unknown datasets.

关键词： Tunnel boring machine evolutionary polynomial regression Random forest Optimization Regularization

Non-isolated Step-up DC-DC Converter Based on Switched Capacitor Cells

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CSee Journal of Power and energy Systems 2023年第3期9卷 1161-1172页

作者： farid Mohammadi Gevork B.Gharehpetian Hasan Rastegar Mohammad Farhadi-Kangarlu Amirkabir university of technology TehranIran Faculty of electrical and Computer engineering Urmia UniversityUrmiaIran

A non-isolated high gain step-up DC-DC converter for low power applications is suggested in this *** the designed transformerless converter,the main switch current and voltage stress is reduced while maintaining high voltage *** instance,with a duty cycle of 0.5 a voltage gain equal to 5 is achieved while the normalized switch voltage stress is ***,it decreases power losses of active and passive *** the proposed converter design,the switched-capacitor(SC)technique is used to obtain maximum voltage transfer gain using only one *** three modes of operation,i.e.,continuous conduction mode(CCM),boundary conduction mode(BCM),and discontinuous conduction mode(DCM),are studied in *** small signal analysis(SSA)of the designed converter is investigated,and its steady-state model is examined under *** of the proposed converter proposed in this study is assessed and tested using a *** of the converter is recorded above 94%in a wide range of output ***,compared to the other converters,the results suggest satisfactory performance of the designed *** issue of the proposed converter is that its input current is not smooth due to using the switched-capacitor cell in its *** issue is alleviated by using input filters.

关键词： DC-DC converter high voltage gain nonisolated switched capacitor cell voltage stress

Problems of drinking water treatment along Ismailia Canal Province, egypt

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第3期9卷 232-242页

作者： mohamed H.GeRIeSH Klaus-Dieter BALKe Ahmed e.eL-RAYeS Geology Department Faculty of ScienceSuez Canal UniversityP.C.41522IsmailiaEgypt Institute of Geosciences Teubingen University72076 TeubingenGermany

The present drinking water purification system in egypt uses surface water as a raw water supply without a preliminary filtration *** the other hand,chlorine gas is added as a disinfectant agent in two steps,pre-and *** to these reasons most of water treatment plants suffer low filtering effectiveness and produce the trihalomethane(THM) species as a chlorination *** Ismailia Canal represents the most distal downstream of the main Nile *** its water contains all the proceeded pollutants discharged into the *** addition,the downstream reaches of the canal act as an agricultural drain during the closing period of the High Dam gates in January and February every ***,the wide industrial zone along the upstream course of the canal enriches the canal water with high concentrations of heavy *** obtained results indicate that the canal gains up to 24.06×106 m3 of water from the surrounding shallow aquifer during the closing period of the High Dam gates,while during the rest of the year,the canal acts as an influent stream losing about 99.6×106 m3 of its water *** reduction of total organic carbon(TOC) and suspended particulate matters(SPMs) should be one of the central goals of any treatment plan to avoid the disinfectants *** combination of sedimentation basins,gravel pre-filtration and slow sand filtration,and underground passage with microbiological oxidation-reduction and adsorption criteria showed good removal of parasites and bacteria and complete elimination of TOC,SPM and heavy ***,it reduces the use of disinfectants chemicals and lowers the treatment ***,this purification system under the arid climate prevailing in egypt should be tested and modified prior to application.

关键词： Drinking water treatment Hazardous by-products Natural attenuation Ismailia Canal egypt

early Cretaceous Tectonostratigraphic evolution of the Southern Tunisian Margin Based on Gravity,Seismic and Potential Field Data:New Insights into a Geodynamic evolution in a Tethyan and Mesogean Rifting Context

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Journal of earth Science 2023年第3期34卷 879-899页

作者： mohamed Ben Chelbi Faculty of Sciences of Tunis Laboratory of GeodynamicGeonumeric and Geomaterials(L3G)LR18ES37University of Tunis El ManarTunisTunisia

Many geophysical and geological data have been used to interpret the tectonic evolution of the south-eastern part of the Tunisian margin and to analyze the dominant structures in the *** Menzel Habib Plain(MHP)and surroundings,targeted by this study,exhibits thick siliciclastic and carbonate formations attributed to the early Cretaceous *** of seismic and gravimetric data coupled with analysis of the syndepositional faults affecting these formations prove that the Tunisian margin is dominated,during this period,by N-S to Ne-SW extensional *** geodynamic evolution of the MHP is mainly due to the irregular normal movement of the N-S faults,which represents the southernmost branch of the N-S Axis(NSA)and of the NW-Se faults,which constitutes the Se segment of the South Atlasic fault corridor(SAFC).In addition,the Ne-SW and e-W oriented faults contributed to this *** extensive periods,this network of faults determines horst and grabens basin geometry or tilted blocks inducing formation of several distinct areas with different subsidence ***,the normal activity of the major faults promotes the vertical mobilization of the Triassic salt resulting in the individualization of several diapiric bodies,some of which pierced their sedimentary *** dynamics reflect echoes of the sinistral drifting of Africa with respect to europe,integrated in a long Tethyan rifting cycle,and the beginning of opening of the Mesogean Sea,respectively.

关键词： Tunisian margin early Cretaceous extensive tectonics Tethyan and Mesogean rifting geodynamics

Coverless Image Steganography Based on Jigsaw Puzzle Image Generation

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Computers, Materials & Continua 2021年第5期67卷 2077-2091页

作者： Al Hussien Seddik Saad M.S.mohamed e.H.Hafez Department of Computer Science Faculty of ScienceMinia UniversityMinya61519Egypt Department of Mathematics College of ScienceTaif UniversityTaif21944Saudi Arabia Department of Mathematics Faculty of ScienceAl-Azher UniversityNasr City11884Egypt Department of Mathematics Faculty of ScienceHelwan UniversityCairoEgypt

Current image steganography methods are working by assigning an image as a cover file then embed the payload within it by modifying its pixels,creating the stego ***,the left traces that are caused by these modifications will make steganalysis algorithms easily detect the hidden payload.A coverless data hiding concept is proposed to solve this *** does not mean that cover is not required,or the payload can be transmitted without a ***,the payload is embedded by cover generation or a secret message mapping between the cover file and the *** this paper,a new coverless image steganography method has been proposed based on the jigsaw puzzle image generation driven by a secret ***,the image is divided into equal rows then further divided into equal columns,creating blocks(i.e.,sub-images).Then,according to secret message bits and a proposed mapping function,each block will have tabs/blanks to get the shape of a puzzle piece creating a fully shaped jigsaw puzzle *** that,the generated jigsaw puzzle image is sent to the *** results and analysis show a good performance in the hiding capacity,security,and robustness compared with existing coverless image steganography methods.

关键词： Coverless information hiding Jigsaw puzzle image image steganography data hiding

Fe modeling of concrete beams and columns reinforced with FRP composites

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Defence Technology（防务技术） 2021年第1期17卷 1-14页

作者： farid Abed Chahmi Oucif Yousef Awera Haya H.Mhanna Hakem Alkhraisha Department of Civil engineering American University of SharjahP.O.Box 26666United Arab Emirates Institute of Structural Mechanics(ISM) Bauhaus-Universitat WeimarMarienstraße 15D-99423WeimarGermany

Compression and flexure members such as columns and beams are critical in a structure as its failure could lead to the collapse of the *** the present work,numerical analysis of square and circle short columns,and reinforced concrete(RC)beams reinforced with fiber reinforced polymer composites are carried *** work is divided into two *** the first part,numerical study of axial behavior of square and circular concrete columns reinforced with Glass Fiber Reinforced Polymer(GFRP)and Basalt Fiber Reinforced Polymer(BFRP)bars and spiral,and Carbon Fiber Reinforced Polymer(CFRP)wraps is *** results of the first part showed that the axial capacity of the circular RC columns reinforced with GFRP increases with the increase of the longitudinal reinforcement *** addition,the results of the numerical analysis showed good correlation with the experimental *** interaction diagram for BFRP RC columns is also developed with considering various *** results of numerical modeling of RC columns strengthened with CFRP wraps revealed that the number and the spacing between the CFRP wraps provide different levels of ductility enhancement to the *** the cases considered in this study,column with two middle closely spaced CFRP wraps demonstrated the best *** the second part of this research,flexural behavior of RC beams reinforced with BFRP,GFRP and CFRP bars is investigated along with validation of the numerical model with the experimental *** results resembled the experimental observations that indicate significant effect of the FRP bar diameter and type ont he flexural capacity of the RC *** was also shown that Increasing the number of bars while keeping the same reinforcement ratio enhanced the stiffness of the RC beam.

关键词： Numerical analysis BRFP GFRP CFRP Columns Beams experimental tests