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Full-Text Articles in Computer Engineering

Unbiased Federated Learning In Energy Harvesting Error-Prone Channels, Zeynep Çakir, Eli̇f Tuğçe Ceran Arslan May 2023

Unbiased Federated Learning In Energy Harvesting Error-Prone Channels, Zeynep Çakir, Eli̇f Tuğçe Ceran Arslan

Turkish Journal of Electrical Engineering and Computer Sciences

Federated learning (FL) is a communication-efficient and privacy-preserving learning technique for collaborative training of machine learning models on vast amounts of data produced and stored locally on the distributed users. This paper investigates unbiased FL methods that achieve a similar convergence as state-of-the-art methods in scenarios with various constraints like an error-prone channel or intermittent energy availability. For this purpose, we propose FL algorithms that jointly design unbiased user scheduling and gradient weighting according to each user's distinct energy and channel profile. In addition, we exploit a prevalent metric called the age of information (AoI), which quantifies the staleness of …


Intelligent And Secure Fog-Aided Internet Of Drones, Jingjing Yao May 2021

Intelligent And Secure Fog-Aided Internet Of Drones, Jingjing Yao

Dissertations

Internet of drones (IoD), which utilize drones as Internet of Things (IoT) devices, deploys several drones in the air to collect ground information and send them to the IoD gateway for further processing. Computing tasks are usually offloaded to the cloud data center for intensive processing. However, many IoD applications require real-time processing and event response (e.g., disaster response and virtual reality applications). Hence, data processing by the remote cloud may not satisfy the strict latency requirement. Fog computing attaches fog nodes, which are equipped with computing, storage and networking resources, to IoD gateways to assume a substantial amount of …


A Fully Batteryless Multiinput Single Inductor Single Output Energy Harvesting Architecture, Ridvan Umaz Jan 2020

A Fully Batteryless Multiinput Single Inductor Single Output Energy Harvesting Architecture, Ridvan Umaz

Turkish Journal of Electrical Engineering and Computer Sciences

Conventional energy architectures that utilize multiple ambient energy sources are initiated either by an external power supply or through the addition of an extra power source (e.g., battery) to the architecture. However, these interventions compromise the goal of a self-sustainable energy harvesting system. Moreover, conventional architectures are not effective in situations where space is limited (e.g., an artificial heart) or when access to this space is difficult (e.g., human implantable devices), due to their large battery size. Thus, conventional energy combiner circuits that use multiple energy sources are not well suited for supplying power to most applications. This paper presents …


Cooperative Communications With Optimal Harvesting Duration For Nakagamifading Channels, Nadhir Ben Halima, Boujemaa Hatem Jan 2020

Cooperative Communications With Optimal Harvesting Duration For Nakagamifading Channels, Nadhir Ben Halima, Boujemaa Hatem

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we analyze the throughput of cooperative communications with wireless energy harvesting. Relay nodes harvest energy from Radio Frequency (RF) signal transmitted by the source. We derive the packet error probability as well as the throughput for Nakagami fading channels. We also suggest to enhance the throughput by choosing the value of harvesting duration. Our results are valid for both Amplify and Forward (AF) and Decode and Forward (DF) relaying.


Performance Improvement Of Multiuser Cognitive Relay Networks With Full-Duplex Cooperative Sensing And Energy Harvesting, Alieh Moradi, Hamid Farrohki Jan 2019

Performance Improvement Of Multiuser Cognitive Relay Networks With Full-Duplex Cooperative Sensing And Energy Harvesting, Alieh Moradi, Hamid Farrohki

Turkish Journal of Electrical Engineering and Computer Sciences

Energy harvesting cognitive radio has been considered as a promising technology in the fifth generation (5G) of wireless networks to solve the lack of spectrum and energy. In this paper, a novel wireless energy harvesting relay network is proposed for a multiuser cognitive radio to obtain the maximum throughput and decrease the false alarm and misdetection probabilities. The secondary user (SU) can harvest energy from solar sources while utilizing the licensed spectrum of the primary user (PU). Cooperative spectrum sensing is applied to improve the performance of the secondary network and decrease collision and sensing time. In this paper, the …


A Two-Stage Power Converter Architecture With Maximum Power Extraction For Low-Power Energy Sources, Ridvan Umaz Jan 2019

A Two-Stage Power Converter Architecture With Maximum Power Extraction For Low-Power Energy Sources, Ridvan Umaz

Turkish Journal of Electrical Engineering and Computer Sciences

A two-stage power converter with maximum power extraction for energy harvesting is presented. The power converter consists of two stages; a maximum power extraction stage (i.e. first stage) and a regulation stage (i.e. second stage). The first stage consists of a number of charge pumps connected in parallel to extract power from the energy source while the second stage steps up low input voltage level to a usable level for a load. Proposed converter operates as low as 0.3 V and the output up-converts to 3.3 V. The proposed converter is aimed to extract maximum power from either low-power energy …


A Model-Based Transformation Framework For Designing And Analyzing Wireless Sensor Networks, Raoudha Saida, Yessine Hadj Kacem, Mohammed Sulaiman Bensaleh, Mohamed Abid Jan 2018

A Model-Based Transformation Framework For Designing And Analyzing Wireless Sensor Networks, Raoudha Saida, Yessine Hadj Kacem, Mohammed Sulaiman Bensaleh, Mohamed Abid

Turkish Journal of Electrical Engineering and Computer Sciences

Wireless sensor networks (WSNs) comprise resource-constrained (e.g., memory, processing, and energy) sensor nodes that are deployed in different areas and are able to monitor environmental conditions. Simulation has been widely used in order to evaluate the network performance. In this context, software designers need to evaluate, refine, and validate high-level models for WSN applications at early stages of development via simulation tools, in particular for WSN applications supporting energy-harvesting devices. In the present paper, we propose a model-based transformation framework that allows the modeling and simulation of a WSN system supporting energy-harvesting capabilities. In this proposal, we start from a …


Electrostrictive Polymers For Mechanical-To-Electrical Energy Harvesting, William G. Kaval, Ronald A. Coutu Jr., Robert A. Lake Jul 2016

Electrostrictive Polymers For Mechanical-To-Electrical Energy Harvesting, William G. Kaval, Ronald A. Coutu Jr., Robert A. Lake

Electrical and Computer Engineering Faculty Research and Publications

Research of electrostrictive polymers has generated new opportunities for harvesting energy from the surrounding environment and converting it into usable electrical energy. Piezoelectric ceramic based devices have long been used in energy harvesting for converting mechanical motion to electrical energy. Nevertheless, those materials tend to be unsuitable for low-frequency mechanical excitations such as human movement. Since organic polymers are typically softer and more flexible, the translated electrical energy output is considerably higher under the same mechanical force. Currently, investigations in using electroactive polymers for energy harvesting, and mechanical-to-electrical energy conversion, are beginning to show potential for this application. In this …


Energy Harvesting And Storage: The Catalyst To The Power Constraint For Leveraging Internet Of Things (Iot) On Trains, Kelechi Nwogu May 2015

Energy Harvesting And Storage: The Catalyst To The Power Constraint For Leveraging Internet Of Things (Iot) On Trains, Kelechi Nwogu

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

The success of Wireless Sensor Networks is heavily constrained by its reliance on storage technology like batteries, which are a finite resource. Whilst the number of transistors in an IC doubles every 18 months, the energy density of batteries is relatively flat during the same time period. This is a key challenge in leveraging the Internet of Things on trains.

The gravity of this problem is increased by an order of magnitude when the network is to be scaled up to hundreds or thousands of nodes. Comprehensive research and development efforts have been devoted to building ultra-low power sensors. These …


Optimal Joint Transmission And Harvested Energy Scheduling For Renewable Energy Harvesting Enabled Cellular Network Under Coordinated Multi-Point Transmission, Zejue Wang, Hongjia Li, Dan Hu, Song Ci Jan 2015

Optimal Joint Transmission And Harvested Energy Scheduling For Renewable Energy Harvesting Enabled Cellular Network Under Coordinated Multi-Point Transmission, Zejue Wang, Hongjia Li, Dan Hu, Song Ci

Department of Electrical and Computer Engineering: Faculty Publications

On-grid energy consumption of base stations (BSs) contributes up a significant fraction of the total carbon dioxide (CO2) emissions of cellular networks, among which remote radio units (RRUs) absorb most of the energy consumption. To eliminate the on-grid energy consumption and the corresponding CO2 emission, we propose a new transmission framework, in which all RRUs and associated power amplifiers (PAs) are powered by hybrid energy sources including on-grid energy source and off-grid renewable energy source. Based on the framework, we pursue a systematic study on the joint transmission and harvested energy scheduling algorithm for the hybrid energy …


A Statistical Analysis Of Wind Speed Data Using Burr, Generalized Gamma, And Weibull Distributions In Antakya, Turkey, İlker Mert, Cuma Karakuş Jan 2015

A Statistical Analysis Of Wind Speed Data Using Burr, Generalized Gamma, And Weibull Distributions In Antakya, Turkey, İlker Mert, Cuma Karakuş

Turkish Journal of Electrical Engineering and Computer Sciences

The wind energy potential of the Antakya area was statistically analyzed based 8 years of wind data sets (2002--2009). The 4-parameter Burr, 3-parameter generalized gamma, and conventional Weibull distributions were regarded as suitable statistical models for describing wind speed profiles. The suitability of the models was tested by $R^{2}$, \textit{RMSE}, chi-squared, and Kolmogorov--Smirnov analysis. According to goodness-of-fit tests, the Burr distribution was found to be more suitable than the generalized gamma or Weibull distributions for representing the actual probability of wind speed data for Antakya. Based on the capacity factors estimated by the Burr model at a hub height, the …