Dr. Gerald K Ijemaru

Wireless rechargeable sensor networks (WRSNs) have emerged as a critical infrastructure for monitoring and collecting data in large-scale and dynamic environments. The energy autonomy of sensor nodes is crucial for the sustained operation of WRSNs. This paper presents a comprehensive survey on the state-of-the-art approaches and technologies in on-demand energy provisioning in large-scale WRSNs. We explore various energy harvesting techniques, storage solutions, and energy management strategies tailored to the unique challenges posed by the dynamic and resource-constrained nature of WRSNs. This survey categorizes existing literature based on energy harvesting sources, including solar, kinetic, and ambient energy, and discusses advancements in energy storage technologies such as supercapacitors and rechargeable batteries. Furthermore, we investigate energy management techniques that adaptively balance energy consumption and harvesting, optimizing the overall network performance. In addition to providing a thorough overview of existing solutions, this paper identifies opportunities and challenges in the field of on-demand energy provisioning for large-scale WRSNs. By synthesizing current research efforts, this survey aims to provide insight to researchers and policymakers in understanding the landscape of on-demand energy provisioning in large-scale WRSNs. The insights gained from this study pave the way for future innovations and contribute to the development of sustainable and self-sufficient wireless sensor networks, critical for the advancement of applications such as environmental monitoring, precision agriculture, and smart cities.

The main objective of reliability-centered maintenance is the cost-effectiveness of the maintenance strategy. These strategies, rather than the different components of reliability-centered maintenance being applied independently, are optimally integrated to take advantage of their respective strengths to optimize equipment reliability and life-cycle costs. The article uses reliability parameters to define the type of maintenance strategy and time to perform maintenance on gas compressors. This article presents a methodology using the gas compressor's reliability parameters to model reliability-centered maintenance procedure for the gas compressors. The approach is based on reliability parameters gotten from the liner regression carried out on the gas compressors. The shape parameter (beta) from the Weibull linear regression shows that most components in the two gas compressors were experiencing early failure with their beta < 1 and the distribution that best fits the data is the lognormal distribution, whose parameters are the shape parameter (sigma') and the scale parameter (').

Recent studies have shown the efficacy of mobile elements in optimizing the energy consumption of sensor nodes. Current data collection approaches for waste management applications focus on exploiting IoT-enabled technologies. However, these techniques are no longer sustainable in the context of smart city (SC) waste management applications due to the emergence of large-scale wireless sensor networks (LS-WSNs) in smart cities with sensor-based big data architectures. This paper proposes an energy-efficient swarm intelligence (SI) Internet of Vehicles (IoV)-based technique for opportunistic data collection and traffic engineering for SC waste management strategies. This is a novel IoV-based architecture exploiting the potential of vehicular networks for SC waste management strategies. The proposed technique involves deploying multiple data collector vehicles (DCVs) traversing the entire network for data gathering via a single-hop transmission. However, employing multiple DCVs comes with additional challenges including costs and network complexity. Thus, this paper proposes analytical-based methods to investigate critical tradeoffs in optimizing energy consumption for big data collection and transmission in an LS-WSN such as (1) finding the optimal number of data collector vehicles (DCVs) required in the network and (2) determining the optimal number of data collection points (DCPs) for the DCVs. These critical issues affect efficient SC waste management and have been overlooked by previous studies exploring waste management strategies. Simulation-based experiments using SI-based routing protocols validate the efficacy of the proposed method in terms of the evaluation metrics.

Wireless Rechargeable Sensor Networks (WRSNs) have emerged with strong potentials to address the bottlenecks of energy/lifetime of a WSN. Recent techniques have shown the efficacy of multiple mobile elements (MMEs) in terms of energy consumption optimization. However, new challenges for energy efficient MMEs scheme have emerged due to the emergence of large-scale WRSNs with big sensor-based data systems. Thus, large-scale deployments are currently limited owing to the bottlenecks of energy/lifetime, and mode of deployments of the sensor nodes. This paper proposes a deadline-based multiple mobile elements (DB-MMEs) model exploiting the efficacies of MMEs scheme to optimize energy consumption and provisioning. The DB-MMEs scheme exploits multifunctional wireless Mobile Charging Vehicles (MCVs) for both wireless charging and data collection via a single-hop transmission. The scheme is specifically designed for delay-intolerant applications. None of the existing techniques have considered this approach to minimize latency and optimize energy consumption and provisioning for LS-WRSNs scenarios. The proposed scheme first organizes the sensors into several clusters for wireless charging and data collection. To optimize energy consumption and provisioning and address the challenges of energy/lifetime for LS-WRSNs scenarios, this paper proposes analytical-based approaches to address some critical trade-offs including: (1) determining the optimal amount of energy available for the MCVs; (2) finding the optimal number of MCVs deployed within a given deadline; and (3) finding the optimal number of data collection and charging points (DCCPs). Lastly, the performance of the proposed approach is evaluated through experimental simulations, and the results validate the efficacy of the analytical-based method.

Distributed sensor networks have emerged as part of the advancements in sensing and wireless technologies and currently support several applications, including continuous environmental monitoring, surveillance, tracking, and so on which are running in wireless sensor network environments, and large-scale wireless sensor network multimedia applications that require large amounts of data transmission to an access point. However, these applications are often hampered because sensor nodes are energy-constrained, low-powered, with limited operational lifetime and low processing and limited power-storage capabilities. Current research shows that sensors deployed for distributed sensor network applications are low-power and low-cost devices characterized with multifunctional abilities. This contributes to their quick battery drainage, if they are to operate for long time durations. Owing to the associated cost implications and mode of deployments of the sensor nodes, battery recharging/replacements have significant disadvantages. Energy harvesting and wireless power transfer have therefore become very critical for applications running for longer time durations. This survey focuses on presenting a comprehensive review of the current literature on several wireless power transfer and energy harvesting technologies and highlights their opportunities and challenges in distributed sensor networks. This review highlights updated studies which are specific to wireless power transfer and energy harvesting technologies, including their opportunities, potential applications, limitations and challenges, classifications and comparisons. The final section presents some practical considerations and real-time implementation of a radio frequency–based energy harvesting wireless power transfer technique using Powercast™ power harvesters, and performance analysis of the two radio frequency–based power harvesters is discussed. Experimental results show both short-range and long-range applications of the two radio frequency–based energy harvesters with high power transfer efficiency.

This paper proposes energy-efficient swarm intelligence (SI)-based approaches for efficient mobile wireless charging in a distributed large-scale wireless sensor network (LS-WSN). This approach considers the use of special multiple mobile elements, which traverse the network for the purpose of energy replenishment. Recent techniques have shown the advantages inherent to the use of a single mobile charger (MC) which periodically visits the network to replenish the sensor-nodes. However, the single MC technique is currently limited and is not feasible for LS-WSN scenarios. Other approaches have overlooked the need to comprehensively discuss some critical tradeoffs associated with mobile wireless charging, which include: (1) determining the efficient coordination and charging strategies for the MCs, and (2) determining the optimal amount of energy available for the MCs, given the overall available network energy. These important tradeoffs are investigated in this study. Thus, this paper aims to investigate some of the critical issues affecting efficient mobile wireless charging for large-scale WSN scenarios; consequently, the network can then be operated without limitations. We first formulate the multiple charger recharge optimization problem (MCROP) and show that it is N-P hard. To solve the complex problem of scheduling multiple MCs in LS-WSN scenarios, we propose the node-partition algorithm based on cluster centroids, which adaptively partitions the whole network into several clusters and regions and distributes an MC to each region. Finally, we provide detailed simulation experiments using SI-based routing protocols. The results show the performance of the proposed scheme in terms of different evaluation metrics, where SI-based techniques are presented as a veritable state-of-the-art approach for improved energy-efficient mobile wireless charging to extend the network operational lifetime. The investigation also reveals the efficacy of the partial charging, over the full charging, strategies of the MCs.

With the recent increase in urban drift, which has led to an unprecedented surge in urban population, the smart city (SC) transportation industry faces a myriad of challenges, including the development of efficient strategies to utilize available infrastructures and minimize traffic. There is, therefore, the need to devise efficient transportation strategies to tackle the issues affecting the SC transportation industry. This paper reviews the state-of-the-art for SC transportation techniques and approaches. The paper gives a comprehensive review and discussion with a focus on emerging technologies from several information and data-driven perspectives including (1) geoinformation approaches; (2) data analytics approaches; (3) machine learning approaches; (4) integrated deep learning approaches; (5) artificial intelligence (AI) approaches. The paper contains core discussions on the impacts of geo-information on SC transportation, data-driven transportation and big data technology, machine learning approaches for SC transportation, innovative artificial intelligence (AI) approaches for SC transportation, and recent trends revealed by using integrated deep learning towards SC transportation. This survey paper aimed to give useful insights to researchers regarding the roles that data-driven approaches can be utilized for in smart cities (SCs) and transportation. An objective of this paper was to acquaint researchers with the recent trends and emerging technologies for SC transportation applications, and to give useful insights to researchers on how these technologies can be exploited for SC transportation strategies. To the best of our knowledge, this is the first comprehensive review that examines the impacts of the various five driving technological forces—geoinformation, data-driven and big data technology, machine learning, integrated deep learning, and AI—in the context of SC transportation applications.

This paper presents a new approach to simplify the design of class-E power amplifier (PA) using hybrid artificial neural-optimization network modeling. The class-E PA is designed for wireless power transfer (WPT) applications to be used in biomedical or internet of things (IoT) devices. Artificial neural network (ANN) models are combined with optimization algorithms to support the design of the class-E PA. In several amplifier circuits, the closed form equations cannot be extracted. Hence, the complicated numerical calculations are needed to find the circuit elements values and then to design the amplifier. Therefore, for the first time, ANN modeling is proposed in this paper to predict the values of the circuit elements without using the complex equations. In comparison with the other similar models, high accuracy has been obtained for the proposed model with mean absolute errors (MAEs) of 0.0110 and 0.0099, for train and test results. Moreover, root mean square errors (RMSEs) of 0.0163 and 0.0124 have been achieved for train and test results for the proposed model. Moreover, the best and the worst-case related errors of 0.001 and 0.168 have been obtained, respectively, for the both design examples at different frequencies, which shows high accuracy of the proposed ANN design method. Finally, a design of class-E PA is presented using the circuit elements values that, first, extracted by the analyses, and second, predicted by ANN. The calculated drain efficiencies for the designed class-E amplifiers have been obtained equal to 95.5% and 91.2% by using analyses data and predicted data by proposed ANN, respectively. The comparison between the real and predicted values shows a good agreement.

Big sensor-based data systems and the emergence of large-scale wireless sensor networks (LS-WSNs), which are spatially distributed across various geographical areas in smart cities (SCs) have thrown new challenges for energy-efficient data collection. The traditional approach utilizing IoT-based techniques for data collection and transmission for waste management applications is not energy-efficient and currently infeasible for such LS-WSNs, thus necessitating the need for a transformation to an IoV-based technique, where vehicular networks can be opportunistically exploited for efficient data collection for waste management strategies in SCs. This paper gives two contributions to research in waste management for SCs. First, a comprehensive study of the various IoT-based techniques for waste management in SCs is presented. Survey studies present energy consumption of the sensor-nodes due to high routing/transmission/control overheads as a major challenge. Several IoT-based techniques have been used to optimize the energy efficiency of the sensor-nodes. However, none has effectively addressed the challenges of energy consumption and optimization. The second contribution proposes an IoV-based technique for data collection for waste management in SCs. To the best of our knowledge, this is the first of such a proposed scheme for SC waste management strategies. Thus, this paper is the first attempt to propose a novel IoV-based model for SC waste management strategies. This technique involves the use of vehicles as opportunistic MDCs to optimize energy efficiency. The paper also proposes using swarm-intelligence-based methods to increase energy efficiency and data collection for SC waste management application. An energy-efficient routing model is very critical to IoT-based applications. Hence, the paper presents an energy-efficient opportunistic model utilizing the ant-based routing algorithms for LS-WSN SC waste management applications. The paper also provides some analytical approaches to determine the energy consumption of the network model. The final part presents experiments in different application scenarios to evaluate the performance of the proposed model. The results present the proposed approach in good performance in terms of the performance metrics compared to the conventional techniques for waste management strategies.

Recent advancements in technological research have seen the use of mobile data collectors (MDCs) or data MULEs for wireless sensor network (WSN) applications. In the context of smart city (SC) waste management scenarios, vehicular networks or the internet of Vehicles (IoV) can be exploited as MDCs or data MULEs for data collection and transmission purposes from the sparsely distributed smart sensors that are attached to the smart bins to an access point or sink node and further deployed for waste management operations. A major challenge with the traditional methods of data collection using static sink nodes is the high energy consumption of the sensor-nodes. The use of MDCs has been well studied and shown to be energy efficient. To the best of the authors' knowledge, this scheme has not been exploited for waste management operations in a SC. Compared to the centralized schemes, the data MULE scheme presents several advantages for data collection in WSN applications. This chapter proposes an energy-efficient model for opportunistic data collection in IoV-enabled SC waste management operations