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5. Advanced Thermal Management for High-Power ICs: Optimizing Heatsink and Airflow Design.

Author

Jebelli, Ali, Lotfi, Nafiseh, Zare, Mohammad Saeid, and Yagoub, Mustapha C. E.

Subjects
COMPUTATIONAL fluid dynamics, GALLIUM nitride, SPECIFIC heat, ELECTRONIC systems, POWER amplifiers, THERMAL management (Electronic packaging)
Abstract

In the rapidly advancing field of 5G technology, efficient thermal management is essential for enhancing the performance and reliability of high-power-density integrated circuits (ICs). This paper introduces an innovative approach to cooling these critical components, significantly surpassing traditional methods. Our design optimizes heatsink and fan configurations through systematic experimentation, varying fin shapes, heatsink dimensions, and fan speeds. The results demonstrate that fan velocity is the most critical factor in reducing IC temperatures, as increased airflow dramatically lowers thermal output. Expanding the heatsink surface area further improves heat dissipation by enhancing airflow interaction, while a larger copper heatsink boosts thermal conduction, effectively reducing the final IC temperature. These optimizations streamline the cooling process, minimizing the need for more complex and expensive equipment. This research sets a new benchmark in thermal management, fostering the development of more efficient and reliable electronic systems in the era of advanced wireless communications. Our approach brings a new dimension to existing research by focusing on the optimization of heatsink and airflow designs specifically for ICs. While previous studies have explored broader thermal management strategies, our work addresses specific challenges in heat dissipation by refining geometric configurations and fan speed adjustments. These optimizations result in measurable improvements in both efficiency and scalability, particularly within the context of high-power 5G systems. [ABSTRACT FROM AUTHOR]

Published
2024
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10. Fault-tolerant control of a quadrotor despite the complete rotor failure via adaptive Lyapunov-based control

Author

Jebelli, Ali, Najafiyanfar, Alireza, Yagoub, Mustapha C. E., Jebelli, Ali, Najafiyanfar, Alireza, and Yagoub, Mustapha C. E.

Abstract

In this paper, an efficient method is proposed for the position and altitude tracking control of a quadrotor UAV through a nonlinear dynamic model in case of failure of one or two quadrotor rotors and in the presence of parametric uncertainties. In fact, the system continues its tasks correctly even if one or two rotors of the quadrotor stop working. The proposed method is a combination of the Lyapunov stability theory and the neural network adaptive scheme, in which Lyapunov-based controller was designed for subsystems separately, and their coefficients adaptively tuned by the neural network method. Further, the performances of the proposed control method were evaluated. The simulated results demonstrated that the proposed controller exhibits desirable transient behavior and performance stability, is not sensitive to parameter variations, and has remarkable stability and performance robustness despite the complete rotor failure. Hence, for operational purposes where the stability and continuation of the mission in case of failure of the rotors are of vital importance, using an adaptive Lyapunov-based control approach is recommended., Communication présentée lors du congrès international tenu conjointement par Canadian Society for Mechanical Engineering (CSME) et Computational Fluid Dynamics Society of Canada (CFD Canada), à l’Université de Sherbrooke (Québec), du 28 au 31 mai 2023.

Published
2023

11. Gain-forming effect on optical signal-to-noise ratio in Raman fiber amplifier.

Author

Kazemi, Seyyed Hossein, Jebelli, Ali, and Sirzad, Leila

Subjects
WAVELENGTH division multiplexing, FIBERS, RAMAN effect
Abstract

We have introduced the comprehensive optical-to-noise ratio (OSNR) to investigate simultaneously the effects of all three major linear noise sources in distributed Raman fiber amplifier (DRFA). The total noise power contains double Rayleigh backscattering (DRB) noise, amplified spontaneous emission (ASE) noise, and relative intensity noise (RIN). Also, we have introduced an approximated gain profile approach, which helps in evaluating the OSNR for higher-order pumping (HOP) configuration for backward, forward, and bidirectional DRFA schemes. Finally, by applying the dynamic and static full-numerical computations on a system of eight wavelength division multiplexing (WDM) channels (for amplifier lengths of 70, 140, and 210 km), we demonstrated that for RIN frequencies greater than 100 kHz, the higher-order bidirectional pumping scheme exceeds the backward schemes by 12 dB. [ABSTRACT FROM AUTHOR]

Published
2023
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23. Design of an Autonomous Underwater Vehicle with Vision Capabilities

Author

Jebelli, Ali

Subjects
Mass Shifter, Autonomous Underwater Vehicle, Virtual Reality, Printed Circuit Board, Fuzzy Logic Controller, Graphical User Interface, Proportional Integral, Local Binary Pattern, Polytetrafluoroethylene, Proportional Integral Differential, Remotely Operated Vehicle
Abstract

At the author’s request, the abstract has been removed due to the confidential nature of the thesis. It will be added once the embargo period has passed.

Published
2016
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26. Gain-forming effect on optical signal-to-noise ratio in Raman fiber amplifier

Author

Kazemi, Seyyed Hossein, Jebelli, Ali, and Sirzad, Leila

Abstract

We have introduced the comprehensive optical-to-noise ratio (OSNR) to investigate simultaneously the effects of all three major linear noise sources in distributed Raman fiber amplifier (DRFA). The total noise power contains double Rayleigh backscattering (DRB) noise, amplified spontaneous emission (ASE) noise, and relative intensity noise (RIN). Also, we have introduced an approximated gain profile approach, which helps in evaluating the OSNR for higher-order pumping (HOP) configuration for backward, forward, and bidirectional DRFA schemes. Finally, by applying the dynamic and static full-numerical computations on a system of eight wavelength division multiplexing (WDM) channels (for amplifier lengths of 70, 140, and 210 km), we demonstrated that for RIN frequencies greater than 100 kHz, the higher-order bidirectional pumping scheme exceeds the backward schemes by 12 dB.

Published
2021
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27. Development of Sensors and Microcontrollers for Underwater Robots

Author

Jebelli, Ali

Subjects
Drag coefficient of the object, Proportional-integral-derivative controller, RPM, PI, Analog to Digital Converter, Thrust coefficient, NN, Sliding mode control Measured thrust, Cd, Force of drag, Height of the fluid above the object, Buoyant mass, Remotely Operated Vehicles, SDO, DOF, ρ, mb, AUV, Proportional controller, T°, Fd, SMC, PID, Density of the fluid, Temperature, Autonomous Underwater Vehicles, Torque coefficient, KQ, Neural network, Serial data output, Proportional-integral controller, ADC, Speed of the object relative to the fluid, ROV, KT, Degree of Freedom, Speed of the motor or propeller, Acceleration of gravity, Torque of the propeller, AV, Advance speed of the propeller
Abstract

Nowadays, small autonomous underwater robots are strongly preferred for remote exploration of unknown and unstructured environments. Such robots allow the exploration and monitoring of underwater environments where a long term underwater presence is required to cover a large area. Furthermore, reducing the robot size, embedding electrical board inside and reducing cost are some of the challenges designers of autonomous underwater robots are facing. As a key device for reliable operation-decision process of autonomous underwater robots, a relatively fast and cost effective controller based on Fuzzy logic and proportional-integral-derivative method is proposed in this thesis. It efficiently models nonlinear system behaviors largely present in robot operation and for which mathematical models are difficult to obtain. To evaluate its response, the fault finding test approach was applied and the response of each task of the robot depicted under different operating conditions. The robot performance while combining all control programs and including sensors was also investigated while the number of program codes and inputs were increased.

Published
2014
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32. Design and Construction of an Underwater Robot Based Fuzzy Logic Controller.

Author

Jebelli, Ali, Yagoub, Mustapha C. E., Rahim, Ruzairi bin HJ. Abdul, and Kazemi, Hossein

Subjects
REMOTE submersibles, FUZZY logic, AUTOMATIC control systems, ROBUST control, MICROCONTROLLERS, PID controllers
Abstract

In this paper, an efficient design control system for autonomous underwater robots is presented. It uses an on-chip RAM rather than a lateral control system for more robustness and a microcontroller-based fuzzy logic controller to better stabilize the robot balancing while moving forward. It was implemented along with a fuzzy proportional integral controller as supervisor and demonstrated through experiments. [ABSTRACT FROM AUTHOR]

Published
2013

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