Control and communication systems for automated vehicles cooperation and coordination

Mención Internacional en el título de doctorThe technological advances in the Intelligent Transportation Systems (ITS) are exponentially improving over the last century. The objective is to provide intelligent and innovative services for the different modes of transportation, towards a better, safer, coordinated and smarter transport networks. The Intelligent Transportation Systems (ITS) focus is divided into two main categories; the first is to improve existing components of the transport networks, while the second is to develop intelligent vehicles which facilitate the transportation process. Different research efforts have been exerted to tackle various aspects in the fields of the automated vehicles. Accordingly, this thesis is addressing the problem of multiple automated vehicles cooperation and coordination. At first, 3DCoAutoSim driving simulator was developed in Unity game engine and connected to Robot Operating System (ROS) framework and Simulation of Urban Mobility (SUMO). 3DCoAutoSim is an abbreviation for "3D Simulator for Cooperative Advanced Driver Assistance Systems (ADAS) and Automated Vehicles Simulator". 3DCoAutoSim was tested under different circumstances and conditions, afterward, it was validated through carrying-out several controlled experiments and compare the results against their counter reality experiments. The obtained results showed the efficiency of the simulator to handle different situations, emulating real world vehicles. Next is the development of the iCab platforms, which is an abbreviation for "Intelligent Campus Automobile". The platforms are two electric golf-carts that were modified mechanically, electronically and electrically towards the goal of automated driving. Each iCab was equipped with several on-board embedded computers, perception sensors and auxiliary devices, in order to execute the necessary actions for self-driving. Moreover, the platforms are capable of several Vehicle-to-Everything (V2X) communication schemes, applying three layers of control, utilizing cooperation architecture for platooning, executing localization systems, mapping systems, perception systems, and finally several planning systems. Hundreds of experiments were carried-out for the validation of each system in the iCab platform. Results proved the functionality of the platform to self-drive from one point to another with minimal human intervention.Los avances tecnológicos en Sistemas Inteligentes de Transporte (ITS) han crecido de forma exponencial durante el último siglo. El objetivo de estos avances es el de proveer de sistemas innovadores e inteligentes para ser aplicados a los diferentes medios de transporte, con el fin de conseguir un transporte mas eficiente, seguro, coordinado e inteligente. El foco de los ITS se divide principalmente en dos categorías; la primera es la mejora de los componentes ya existentes en las redes de transporte, mientras que la segunda es la de desarrollar vehículos inteligentes que hagan más fácil y eficiente el transporte. Diferentes esfuerzos de investigación se han llevado a cabo con el fin de solucionar los numerosos aspectos asociados con la conducción autónoma. Esta tesis propone una solución para la cooperación y coordinación de múltiples vehículos. Para ello, en primer lugar se desarrolló un simulador (3DCoAutoSim) de conducción basado en el motor de juegos Unity, conectado al framework Robot Operating System (ROS) y al simulador Simulation of Urban Mobility (SUMO). 3DCoAutoSim ha sido probado en diferentes condiciones y circunstancias, para posteriormente validarlo con resultados a través de varios experimentos reales controlados. Los resultados obtenidos mostraron la eficiencia del simulador para manejar diferentes situaciones, emulando los vehículos en el mundo real. En segundo lugar, se desarrolló la plataforma de investigación Intelligent Campus Automobile (iCab), que consiste en dos carritos eléctricos de golf, que fueron modificados eléctrica, mecánica y electrónicamente para darle capacidades autónomas. Cada iCab se equipó con diferentes computadoras embebidas, sensores de percepción y unidades auxiliares, con la finalidad de transformarlos en vehículos autónomos. Además, se les han dado capacidad de comunicación multimodal (V2X), se les han aplicado tres capas de control, incorporando una arquitectura de cooperación para operación en modo tren, diferentes esquemas de localización, mapeado, percepción y planificación de rutas. Innumerables experimentos han sido realizados para validar cada uno de los diferentes sistemas incorporados. Los resultados prueban la funcionalidad de esta plataforma para realizar conducción autónoma y cooperativa con mínima intervención humana.Programa Oficial de Doctorado en Ingeniería Eléctrica, Electrónica y AutomáticaPresidente: Francisco Javier Otamendi Fernández de la Puebla.- Secretario: Hanno Hildmann.- Vocal: Pietro Cerr

Pars plana vitrectomy for tractional diabetic macular edema with or without internal limiting membrane peeling

Background: The effectiveness of internal limiting membrane (ILM) peeling in the surgical treatment of tractional diabetic macular edema (DME), although widely examined, remains controversial. This study aimed to assess the efficacy of pars plana vitrectomy (PPV) in the management of tractional DME and to highlight any benefits of additional ILM peeling. Methods: This was an open-label, prospective, comparative, and interventional study that enrolled 50 eyes with tractional DME that underwent PPV and allocated each to one of two groups: group A consisted of 25 eyes that had no ILM peeling and group B consisted of 25 eyes that underwent ILM peeling. Postoperative assessments of best-corrected distance visual acuity (BCDVA) in the logarithm of minimal angle of resolution (logMAR) notation and central macular thickness (CMT) were performed at 1, 3, and 6 months postoperatively. Results: At baseline, the two groups were comparable in terms of sex ratios, phakic status, insulin use, coexistence of hypertension, and mean (standard deviation [SD]) age, BCDVA, CMT, duration of diabetes mellitus, and glycosylated hemoglobin (HbA1c) levels. In group A, the mean (SD) BCDVA improved significantly from 0.89 (0.12) logMAR preoperatively to 0.64 (0.24) logMAR (P < 0.001), and the mean (SD) CMT declined significantly from 471.28 (80.83) micrometer to 228.20 (26.45) micrometer (P < 0.001), at the 6-month postoperative assessment. Likewise, in group B, the mean (SD) BCDVA improved significantly from 0.83 (0.10) logMAR preoperatively to 0.58 (0.24) logMAR (P < 0.001), and the mean (SD) CMT decreased significantly from 496.84 (89.82) micrometer to 226.20 (18.04) micrometer (P < 0.001), after 6 months. There were no significant differences between groups A and B in the changes in BCDVA (Delta BCDVA) or CMT (Delta CMT) at 1, 3, and 6 months postoperatively with respect to the baseline values (all P > 0.05). Postoperative complications were comparable between the two groups. A significant negative correlation was detected between the preoperative HbA1c level and BCDVA improvement in all participants (r = - 0.82; P < 0.001). Conclusions: PPV is an effective treatment for tractional DME. Additional ILM peeling was not significantly associated with functional and anatomical benefits over a short period. Long-term glycemic control plays a role in vision gain after vitrectomy in patients with diabetes. Further long-term studies are required to verify our findings

Preparation of La0.7Ca0.3Mn0.95Fe0.05O3 perovskites by different methods: Catalytic activity towards the hydroxylation of benzene

Nanoparticles of the La0.7Ca0.3Mn0.95Fe0.05O3 perovskites were synthesized by various wet chemical routes, namely, co-precipitation, oxalate-gel and citrate-gel methods. Phase formation and crystal structure of the synthesized powders were examined by the X-ray diffraction (XRD). The morphology was evaluated by the scan electron microscopy (SEM). Infrared transmission spectroscopy revealed that stretching and bending modes were influenced by the preparation methods. The citrate gel method yielded better powder properties. The prepared perovskite samples were used in the oxidation of benzene. The highest activity for the catalytic oxidation of benzene to phenol in presence of hydrogen peroxide (H2O2) was obtained with the citrate-gel prepared sample

Evaluation of mediastinal lymphadenopathy by diffusion weighted MRI; correlation with histopathological results

Introduction: Diffusion weighted imaging (DWI) has shown its potential as a reliable noninvasive technique for tissue characterization. DWI reflects the tissue specific diffusion capacity which can be used for tissue characterization. Hypercellular tissue (e.g; malignant tumors) had restricted diffusion capacity with increased signals on DWI and low ADC values. Non-tumoral tissues show low cellularity, and diffusion capacity is not restricted resulting in signal loss on DWI and high apparent diffusion coefficient (ADC). Differential diagnosis of mediastinal lymphadenopathy is an issue of debate, especially in malignant benign differentiation. Diffusion weighted imaging with magnetic resonance could improve the diagnostic accuracy in differentiation between benign and malignant mediastinal nodes.Objectives: to determine the efficacy of diffusion weighted MRI in evaluation of mediastinal lymphadenopathy with histopathological correlation to differentiate benign from malignant lymph nodes.Material and methods: 30 patients with mediastinal lymphadenopathy underwent diffusion weighted MRI. ADCs of lymph nodes were derived and constructed from b = 0 and b = 1000 sec/mm2 values by drawing regions of interests (ROI). Consequently, mediastinal nodes were studied, biopsies and histopathological analysis were done after MRI examination.Results: The best cutoff point of ADC to differentiate benign from malignant lesions was 1.15 mm/sec (sensitivity 77%, specificity 92% and AUC 81.4%). Significant negative correlation of ADC by DW MRI and the size of the LNs. The mean ADC values in the lymphoma group was lower than in the sarcoidosis group, and the difference was statistically significant.Conclusion: The study supports that MRI with diffusion weighted images can differentiate benign from malignant mediastinal lymphadenopathy and differentiate lymphoma from sarcoidosis non-invasively

Comparison between P&O and SSO techniques based MPPT algorithm for photovoltaic systems

Solar photovoltaic (SPV) systems are a renewable source of energy that are environmentally friendly and recyclable nature. When the solar panel is connected directly to the load, the power delivered to the load is not the optimal power. It is therefore important to obtain maximum power from SPV systems for enhancing efficiency. Various maximum power point tracking (MPPT) techniques of SPV systems were proposed. Traditional MPPT techniques are commonly limited to uniform weather conditions. This paper presents a study of MPPT for photovoltaic (PV) systems. The study includes a discussion of different MPPT techniques and performs comparison for the performance of the two MPPT techniques, the P&O algorithm, and salp swarm optimization (SSO) algorithm. MATLAB simulations are performed under step changes in irradiation. The results of SSO show that the search time of maximum power point (MPP) is significantly decreased and the MPP is obtained in the shortest time with high accuracy and minimum oscillations in the generated power when compared with P&O

Thermal comparison of mono-facial and bi-facial photovoltaic cells considering the effect of TPT layer absorptivity

With the widespread utilization of solar photovoltaics (PV), it is becoming increasingly important to understand its performance using various configurations to harvest solar energy at the most suitable efficiency, specifically in hot climates. Therefore, this paper compares mono-facial and bi-facial PV cells under the high-temperature desert climate of Sharjah (United Arab Emirates). The optimally tilted and vertical east-west configurations were compared to determine the best orientation for the studied conditions. In addition, new parameter, the rear side layer absorptivity of the mono-facial PV cell, was investigated. The comparative study considered solar radiation, ambient temperature, wind speed, and albedo. The results showed that considering the effect of absorptivity achieves better performance predictions. However, the effect of the absorptivity did not exhibit a significant influence compared to the case with zero absorptivity. As such, the PV cell temperature increased by 0.4°C and 1.4°C at an albedo of 0.2 and 0.7, considering the actual absorptivity value (0.2). On the other hand, it is worth mentioning that improper designs result in considerable temperature rises as the absorptivity value increases. Under the investigated conditions and based on the year-long comparison, the tilted bi-facial performed better than the vertical bi-facial; as the albedo increased from 0.2 to 0.7, the power gain ratio of tilted bi-facial increased from 7.18% to 20.88% and that of vertical bi-facial from -19.4% to 12.65%

Application of the ANOVA method in the optimization of a thermoelectric cooler-based dehumidification system

© 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).In recent studies, Thermo-Electric Coolers (TEC) have been utilized for dehumidification purposes, which is mainly based on the extraction of moisture from humid atmospheric air. The reviewed literature showed that the rate of water collection from the TEC-based system can be affected by various parameters such as the module’s input voltage, the heat sink orientation, and tilt angles. In this research, the analysis of variance (ANOVA) was used to examine the significance of these factors and their interaction within the system on the TEC-based dehumidification system. Four levels were investigated for both, the Peltier’s input voltage and the rotation angle, and three levels for the tilt angle. This study indicated the significance of the studied factors and their interactions within the dehumidification system along with performing an overall numerical optimization. The experiments were conducted under the same working conditions in an enclosed environment to minimize errors. According to the overall numerical optimization, which was validated experimentally, the optimum system performance was predicted to be obtained at approximately 6.8V Peltier input volt, 65° rotation angle, and 90° tilt angles, with predicted optimum productivities of 0.32278 L/kWh and 13.03 mL/hr. For the same set of parameters, the variation between the experiment and the numerical optimization was less than 4%. The experiments show that when optimizing water collection rates for thermoelectric cooling heat sinks​ under high humidity conditions, the orientation of the heat sink should be considered.Peer reviewe

Thermohydraulic analysis of covalent and noncovalent functionalized graphene nanoplatelets in circular tube fitted with turbulators

© The Author(s) 2022. This article is licensed under a Creative Commons Attribution 4.0 International. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Covalent and non-covalent nanofluids were tested inside a circular tube fitted with twisted tape inserts with 45° and 90° helix angles. Reynolds number was 7000 ≤ Re ≤ 17,000, and thermophysical properties were assessed at 308 K. The physical model was solved numerically via a two-equation eddy-viscosity model (SST k-omega turbulence). GNPs-SDBS@DW and GNPs-COOH@DW nanofluids with concentrations (0.025 wt.%, 0.05 wt.% and 0.1 wt.%) were considered in this study. The twisted pipes' walls were heated under a constant temperature of 330 K. The current study considered six parameters: outlet temperature, heat transfer coefficient, average Nusselt number, friction factor, pressure loss, and performance evaluation criterion. In both cases (45° and 90° helix angles), GNPs-SDBS@DW nanofluids presented higher thermohydraulic performance than GNPs-COOH@DW and increased by increasing the mass fractions such as 1.17 for 0.025 wt.%, 1.19 for 0.05 wt.% and 1.26 for 0.1 wt.%. Meanwhile, in both cases (45° and 90° helix angles), the value of thermohydraulic performance using GNPs-COOH@DW was 1.02 for 0.025 wt.%, 1.05 for 0.05 wt.% and 1.02 for 0.1 wt.%.Peer reviewe

New CPW-Fed Broadband Circularly Polarized Planar Monopole Antenna Based On A Couple Of Linked Symmetric Square Patches

A new broadband circularly polarized planar monopole antenna with coplanar waveguide feeding (CPW-fed) is proposed. This antenna consists of a couple of linked symmetric square patches (CLSSP), an asymmetric ground plane and two strips connected to the left ground plane by the CLSSP radiator and a straight strip. A broad impedance bandwidth (IBW) is achieved. Moreover, a broad axial ratio bandwidth (ARBW) is obtained by using an asymmetric ground plane and an inverted L-shaped strip. Simulation results demonstrate that IBW reaches 119% (1.56-6.18 GHz) and ARBW is 88.9% (2-5.2 GHz). The latter is completely overlapped by the simulated IBW. In addition, antenna performance is investigated by studying different parameters

Compact CPW-Fed Broadband Circularly Polarized Monopole Antenna With Inverted L-Shaped Strip And Asymmetric Ground Plane

The design of a coplanar waveguide-fed (CPW-fed) broadband circularly polarized printed monopole antenna is proposed. The antenna consists of a simple rectangular radiator monopole, an inverted L-shaped strip, a horizontal stub, and a modified asymmetric ground plane. Simulation results indicate that the impedance bandwidth (IBW) is 121% (1.575-6.4 GHz), and the axial ratio bandwidth (ARBW) is 64.3% (2.85-5.55 GHz). A parametric study is performed for verification. Results: indicate that the proposed antenna is suitable for different wireless communications systems