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Fast Finite-Time Composite Controller for Vehicle Steer-by-Wire Systems with Communication Delays
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The modern steer-by-wire (SBW) systems represent a revolutionary departure from traditional automotive designs, replacing mechanical linkages with electronic control mechanisms. However, the integration of such cutting-edge technologies is not without its challenges, and one critical aspect that demands thorough consideration is the presence of nonlinear dynamics and communication network time delays. Therefore, to handle the tracking error caused by the challenge of time delays and to overcome the parameter uncertainties and external perturbations, a robust fast finite-time composite controller (FFTCC) is proposed for improving the performance and safety of the SBW systems in the present article. By lumping the uncertainties, parameter variations, and exterior disturbance with input and output time delays as the generalized state, a scaling finite-time extended state observer (SFTESO) is constructed with a scaling gain for quickly estimating the unmeasured velocity and the generalized disturbances within a finite time. With the aid of the SFTESO, the robust FFTCC with the scaling gain is designed not only for ensuring finite-time convergence and strong robustness against time delays and disturbances but also for improving the speed of the convergence as a main novelty. Based on the Lyapunov theorem, the closed-loop stability of the overall SBW system is proven as a global uniform finite-time. Through examination across three specific scenarios, a comprehensive evaluation is aimed to assess the efficiency of the suggested controller strategy, compared with active disturbance rejection control (ADRC) and scaling ADRC (SADRC) methods across these three distinct driving scenarios. The simulated results have confirmed the merits of the proposed control in terms of a fast-tracking rate, small tracking error, and strong system robustness.

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Publication Date
Mon Mar 23 2020
Journal Name
Journal Of Engineering
Experimental and Numerical Study on CFRP-Confined Square Concrete Compression Members Subjected to Compressive Loading
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Strengthening of the existing structures is an important task that civil engineers continuously face. Compression members, especially columns, being the most important members of any structure, are the most important members to strengthen if the need ever arise. The method of strengthening compression members by direct wrapping by Carbon Fiber Reinforced Polymer (CFRP) was adopted in this research. Since the concrete material is a heterogeneous and complex in behavior, thus, the behavior of the confined compression members subjected to uniaxial stress is investigated by finite element (FE) models created using Abaqus CAE 2017 software.

The aim of this research is to study experime

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Publication Date
Wed Feb 01 2023
Journal Name
Journal Of Engineering
Evaluation of Seepage Force and Overall Stability Factor Along Proposed Baghdad Metro Tunnel Across Tigris River
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Baghdad Metro is a vital project to fulfill the rapidly increased traffic volume requirements. The proposed metro will connect both sides of Baghdad City, passing under the Tigris River. This study is employed finite elements software (PLAXIS 3D) to evaluate the seepage force developed around the sub-river segment during different construction stages and for other water levels of Tigris. The study found that when the water level changes from maximum to minimum, the developed seepage force decreases by (8 to 13%) and (22 to 27%) respectively. The seepage forces were found to be maximum during the excavation stage. The concrete lining process led to a noticeable reduction in seepage forces at all locations. The study also

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Publication Date
Thu Apr 01 2021
Journal Name
Chaos, Solitons & Fractals
Modeling and analysis of an <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si7.svg"><mml:mrow><mml:mi>S</mml:mi><mml:msub><mml:mi>I</mml:mi><mml:mn>1</mml:mn></mml:msub><mml:msub><mml:mi>I</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi>R</mml:mi></mml:mrow></mml:math> epidemic model with nonlinear incidence and general recovery functions of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si8.svg"><mml:msub><mml:mi>I</mml:mi><mml:mn>1</mml:mn></mml:msub></mml:math>
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Publication Date
Tue Jul 01 2025
Journal Name
المجلة العراقية للعلوم الاقتصادية
Using the Hybrid ARDL–GRU Model in Investigating the Dynamic Relationship between Dinar Deposits and US Dollar Payments at the Central Bank of Iraq
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This research examines the relationship between dinar deposits and U.S. dollar payments at the Central Bank of Iraq using monthly data for the period 2016–2025. The ARDL model, the GRU neural network, and a hybrid ARDL–GRU model are applied. The results show that dollar payments are stationary at level, while dinar deposits become stationary after first differencing, with a significant positive long-run cointegrating relationship. The linear ARDL model has limited ability to capture sudden shocks, whereas the hybrid ARDL–GRU model achieves superior forecasting performance both in-sample and out-of-sample. The findings confirm the Central Bank of Iraq’s efficiency in managing domestic and foreign liquidity and maintaining market stab

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Publication Date
Fri Jan 15 2021
Journal Name
Obstetrics &amp; Gynecology Science
Effects of excessive tea consumption on pregnancy weight gain and neonatal birth weight
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Objective Tea lovers are increasing worldwide. We hope that this report is the first to discuss the possible impacts of high black tea consumption on gestational weight gain (GWG) and birth parameters. Methods Throughout one year, a total of 7,063 pregnant ladies coming for first antenatal visit were screened in a major tertiary center. Of them, 1,138 were involved and divided according to their preference into 3 groups: excessive tea (ET), usual tea (UT), and mixed beverages group. The study included women who gave birth to healthy neonates. Results The rate of ET consumption was 4.13% with a total of 41 cases. The UT group (controls) comprised 94 women. ET was significantly associated (P<0.05) with maternal age, parity, occupation, smokin

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Publication Date
Sun Jun 05 2016
Journal Name
Baghdad Science Journal
Corrosion, Passivity and Pitting of Inconel (600) in Sulphuric Acid
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A potentiostatic study of the behaviour of Inconel (600) in molar sulphuric acid has been carried out over the temperature range 293-313 K. Values have been established for the potentials and current densities of the corrosion, active-passive transition, passivity and transpassive states. For corrosion, the current density (ic) and potential (Ec) have been determined from well-defined Tafel lines. The potential and current density prior to the commencement of passivity have been obtained corresponding respectively to the critical potential (Ecr( and to the current density (icr) for the active-passive transition state. The passive range was defined by the respective potentials and current densities for passive film formation and dissolutio

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Publication Date
Thu Nov 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Marketing decisions as an intermediary variable of the nature of the relationship between Environmental Turbulence and marketing effectiveness exploratory study of Carrefour branches in Erbil Governorate
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The organizations, represented by its Management, are working hard in various ways to identify the environmental disturbances that occur in their environment and to investigate and follow up the movement of these disturbances and to respond to them through the decisions they make in an attempt to keep pace with the work and sustainability of their activities, including those decisions, marketing decisions taken by the environmental disturbulence in the market of the organization, the inability of these organizations to read the indicators of these disturbulence correctly displays their marketing effectiveness to vibration and decline in the negative.The current research is based on a fundamental problem that envi

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Publication Date
Fri Aug 10 2018
Journal Name
Ceramics International
Application of zirconia surface coating to improve fracture resistance and stress distribution of zirconia ceramic restorations
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Zirconia ceramic restoration (ZCR) has a higher fracture incidence rate than metal ceramic restoration. Different surface treatments were used to improve fracture performance of ZCR such as grit blasting (GB) by aluminium oxide powder. This type of surface treatment generate residual stresses on veneering ceramic causing crack initiation and ending with a fracture. In order to overcome the stress generated by GB, zirconia surface coating is used as a surface treatment to improve fracture resistance and to accommodate stresses along the ZCR layers. Fifty zirconia ceramic crowns were fabricated and divided according to the type of surface treatment into three groups; the first group is (ZG), involving 20 cores were coated with a mixture of pa

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Publication Date
Mon Jun 01 2015
Journal Name
Journal Of Engineering
Theoretical Investigations on the Structural Behavior of Biaxial Hollow Concrete Slabs
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This paper presents a numerical analysis using ANSYS finite element program to simulate the reinforced concrete slabs with spherical voids. Six full-scale one way bubbled slabs of (3000mm) length with rectangular cross-sectional area of (460mm) width and (150mm) depth are tested as simply supported under two-concentrated load. The results of the finite element model are presented and compared with the experimental data of the tested slabs. Material nonlinearities due to cracking and crushing of concrete and yielding of reinforcement are considered. The general behavior of the finite element models represented by the load-deflection curves at midspan, crack pattern, ultimate load, load-concrete strain curves and failure m

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Publication Date
Fri May 31 2019
Journal Name
Journal Of Engineering
Numerical Investigation of Heat Transfer Enhancement of Double Pipe Heat Exchanger Using Metal Foam Fins
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The influence of adding metal foam fins on the heat transfer characteristics of an air to water double pipe heat exchanger is numerically investigated. The hot fluid is water which flows in the inner cylinder whereas the cold fluid is air which circulates in the annular gap in parallel flow with water. Ten fins of metal foam (Porosity = 0.93), are added in the gap between the two cylinder, and distributed periodically with the axial distance. Finite volume method is used to solve the governing equations in porous and non-porous regions. The numerical investigations cover three values for Reynolds number (1000 ,1500, 2000), and Darcy number (1 x10-1, 1 x10-2, 1x10-3). The comparison betwee

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