Current Search: Power systems (x)
View All Items
Pages
- Title
- Developing a photovoltaic MPPT system.
- Creator
- Bennett, Thomas, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Many issues related to the design and implementation of a maximum power point tracking (MPPT) converter as part of a photovoltaic (PV) system are addressed. To begin with, variations of the single diode model for a PV module are compared, to determine whether the simplest variation may be used for MPPT PV system modeling and analysis purposes. As part ot this determination, four different DC/DC converters are used in conjunction with these different PV models. This is to verify consistent...
Show moreMany issues related to the design and implementation of a maximum power point tracking (MPPT) converter as part of a photovoltaic (PV) system are addressed. To begin with, variations of the single diode model for a PV module are compared, to determine whether the simplest variation may be used for MPPT PV system modeling and analysis purposes. As part ot this determination, four different DC/DC converters are used in conjunction with these different PV models. This is to verify consistent behavior across the different PV models, as well as across the different converter topologies. Consistent results across the different PV models, will allow a simpler model to be used for simulation ana analysis. Consistent results with the different converters will verify that MPPT algorithms are converter independent. Next, MPPT algorithms are discussed. In particular,the differences between the perturb and observe, and the incremental conductance algorithms are explained and illustrated. A new MPPT algorithm is then proposed based on the deficiencies of the other algorithms. The proposed algorithm's parameters are optimized, and the results for different PV modules obtained. Realistic system losses are then considered, and their effect on the PV system is analyzed ; especially in regards to the MPPT algorithm. Finally, a PV system is implemented and the theoretical results, as well as the behavior of the newly proposed MPPT algorithm, are verified.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3356887
- Subject Headings
- Photovoltaic power systems, Design, Electronic circuits, Electric current converters, Power (Mechanics), Renewable energy sources
- Format
- Document (PDF)
- Title
- Predicting failure of remote battery backup systems.
- Creator
- Aranguren, Pachano Liz Jeannette, Khoshgoftaar, Taghi M., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Uninterruptable Power Supply (UPS) systems have become essential to modern industries that require continuous power supply to manage critical operations. Since a failure of a single battery will affect the entire backup system, UPS systems providers must replace any battery before it runs dead. In this regard, automated monitoring tools are required to determine when a battery needs replacement. Nowadays, a primitive method for monitoring the battery backup system is being used for this task....
Show moreUninterruptable Power Supply (UPS) systems have become essential to modern industries that require continuous power supply to manage critical operations. Since a failure of a single battery will affect the entire backup system, UPS systems providers must replace any battery before it runs dead. In this regard, automated monitoring tools are required to determine when a battery needs replacement. Nowadays, a primitive method for monitoring the battery backup system is being used for this task. This thesis presents a classification model that uses data mining cleansing and processing techniques to remove useless information from the data obtained from the sensors installed in the batteries in order to improve the quality of the data and determine at a given moment in time if a battery should be replaced or not. This prediction model will help UPS systems providers increase the efficiency of battery monitoring procedures.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004002
- Subject Headings
- Electric power systems -- Equipment and supplies, Energy storing -- Testing, Lead acid batteries, Power electronics, Protective relays
- Format
- Document (PDF)
- Title
- Maximum power point tracking of photovoltaic systems.
- Creator
- Bennett, Thomas, Zilouchian, Ali, Graduate College
- Date Issued
- 2011-04-08
- PURL
- http://purl.flvc.org/fcla/dt/3164452
- Subject Headings
- Photovoltaic power systems, Solar energy, DC-to-DC converters
- Format
- Document (PDF)
- Title
- Low latency and energy efficient MAC protocols for wireless sensor networks.
- Creator
- Abu-El Humos, Ali M., Florida Atlantic University, Alhalabi, Bassem A., Cardei, Mihaela, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Energy consumption is a critical design issue in Wireless Sensor Networks (WSNs), since sensor nodes are battery operated, and replacing or recharging the battery is usually infeasible. Energy efficient solutions are sought at all network levels, especially at the medium access level. The IEEE 802.11 MAC protocol is optimized for Ad hoc Wireless Networks, but cannot be adopted for WSNs because it has the idle listening problem, which is a major source of energy waste. Several Medium Access...
Show moreEnergy consumption is a critical design issue in Wireless Sensor Networks (WSNs), since sensor nodes are battery operated, and replacing or recharging the battery is usually infeasible. Energy efficient solutions are sought at all network levels, especially at the medium access level. The IEEE 802.11 MAC protocol is optimized for Ad hoc Wireless Networks, but cannot be adopted for WSNs because it has the idle listening problem, which is a major source of energy waste. Several Medium Access Control (MAC) protocols have been proposed for WSNs to save the transceiver energy by introducing periodic listen/sleep cycles, and thus overcome the idle listing problem. The periodic listen sleep cycles, however, will increase the network latency and require extra overhead to establish and maintain synchronization among nodes in the network. This dissertation introduces a new MAC protocol for WSNs based on the SMAC protocol to improve its latency performance without compromising its energy consumption. The original SMAC provides an efficient solution for the energy consumption problem due to idle listening, but it increases latency especially in low duty cycle applications. TMAC was proposed to further reduce the energy consumption in SMAC and introduced the Forward Request-To-Send (FRTS) packet to solve the early sleep problem observed in TMAC. Later, Adaptive SMAC was proposed to reduce the latency problem in SMAC by at least 50% at light traffic load. Our new protocol, FASMAC, combines the advantages of both adaptive listening and the usage of FRTS packet in TMAC to further reduce the latency of SMAC. In FASMAC, a packet can travel at least three hops away from its source node within one time cycle. This results in at least 67% reduction in latency at light traffic when compared with the original SMAC. We also propose an energy model for performance evaluation of WSNs protocols using the network simulator NS2. The current energy model of NS2 was designed to handle Ad hoc Wireless Networks where the low power consumption sleep mode was not an issue. However, this is not the case in WSNs. We show that NS2 energy model is not suitable to evaluate the performance of WSNs protocols because it does not account for the low power sleep mode. This dissertation proposes a solution to this deficiency and provides simulation results that match real experimental results performed on the actual sensor motes.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/12149
- Subject Headings
- Wireless communication systems, Sensor networks, Power resources--Efficiency
- Format
- Document (PDF)
- Title
- LEARNING AND OPTIMIZATION FOR REAL-TIME MICROGRID ENERGY MANAGEMENT SYSTEMS.
- Creator
- Das, Avijit, Ni, Zhen, Florida Atlantic University, Department of Computer and Electrical Engineering and Computer Science, College of Engineering and Computer Science
- Abstract/Description
-
Microgrid is an essential part of the nation’s smart grid deployment plan, recognized especially for improving efficiency, reliability, flexibility, and resiliency of the electricity system. Since microgrid consists of different distributed generation units, microgrid scheduling and real-time dispatch play a crucial role in maintaining economic, reliable, and resilient operation. The control and optimization performances of the existing online approaches degrade significantly in microgrid...
Show moreMicrogrid is an essential part of the nation’s smart grid deployment plan, recognized especially for improving efficiency, reliability, flexibility, and resiliency of the electricity system. Since microgrid consists of different distributed generation units, microgrid scheduling and real-time dispatch play a crucial role in maintaining economic, reliable, and resilient operation. The control and optimization performances of the existing online approaches degrade significantly in microgrid applications with missing forecast information, large state space, and multiple probabilistic events. This dissertation focuses on these challenges and proposes efficient online learning and optimization-based approaches. For addressing the missing forecast challenges on online microgrid operations, a new fitted rolling horizon control (fitted-RHC) approach is proposed in Chapter 2. The proposed fitted-RHC approach is designed with a regression algorithm that utilizes the empirical knowledge obtain from the day-ahead forecast to make microgrid real-time decisions whenever the intra-day forecast data is unavailable. Simulation results show that the proposed fitted-RHC approach can achieve the optimal policy for the deterministic case study and perform efficiently with the uncertain environment in the stochastic case study.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013671
- Subject Headings
- Microgrids (Smart power grids), Renewable energy, Fuzzy systems
- Format
- Document (PDF)
- Title
- MODELING, PATH PLANNING, AND CONTROL CO-DESIGN OF MARINE CURRENT TURBINES.
- Creator
- Hasankhani, Arezoo, Tang, Yufei, VanZwieten, James, Florida Atlantic University, Department of Computer and Electrical Engineering and Computer Science, College of Engineering and Computer Science
- Abstract/Description
-
Marine and hydrokinetic (MHK) energy systems, including marine current turbines and wave energy converters, could contribute significantly to reducing reliance on fossil fuels and improving energy security while accelerating progress in the blue economy. However, technologies to capture them are nascent in development due to several technical and economic challenges. For example, for capturing ocean flows, the fluid velocity is low but density is high, resulting in early boundary layer...
Show moreMarine and hydrokinetic (MHK) energy systems, including marine current turbines and wave energy converters, could contribute significantly to reducing reliance on fossil fuels and improving energy security while accelerating progress in the blue economy. However, technologies to capture them are nascent in development due to several technical and economic challenges. For example, for capturing ocean flows, the fluid velocity is low but density is high, resulting in early boundary layer separation and high torque. This dissertation addresses critical challenges in modeling, optimization, and control co-design of MHK energy systems, with specific case studies of a variable buoyancy-controlled marine current turbine (MCT). Specifically, this dissertation presents (a) comprehensive dynamic modeling of the MCT, where data recorded by an acoustic Doppler current profiler will be used as the real ocean environment; (b) vertical path planning of the MCT, where the problem is formulated as a novel spatial-temporal optimization problem to maximize the total harvested power of the system in an uncertain oceanic environment; (c) control co-design of the MCT, where the physical device geometry and turbine path control are optimized simultaneously. In a nutshell, the contributions are summarized as follows:
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013991
- Subject Headings
- Marine turbines, Modeling dynamic systems, Ocean wave power
- Format
- Document (PDF)
- Title
- Design of a power management model for a solar/fuel cell hybrid energy system.
- Creator
- Melendez, Rosana., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This thesis proposes a Power Management Model (PMM) for optimization of several green power generation systems. A Photovoltaic/Fuel cell Hybrid Energy System (PFHES) consisting of solar cells, electrolyzer and fuel cell stack is utilized to meet a specific DC load bank for various applications. The Photovoltaic system is the primary power source to take advantage of renewable energy. The electrolyzer-fuel cell integration is used as a backup and as a hydrogen storage system with the different...
Show moreThis thesis proposes a Power Management Model (PMM) for optimization of several green power generation systems. A Photovoltaic/Fuel cell Hybrid Energy System (PFHES) consisting of solar cells, electrolyzer and fuel cell stack is utilized to meet a specific DC load bank for various applications. The Photovoltaic system is the primary power source to take advantage of renewable energy. The electrolyzer-fuel cell integration is used as a backup and as a hydrogen storage system with the different energy sources integrated through a DC link bus. An overall power management strategy is designed for the optimization of the power flows among the different energy sources. Extensive simulation experiments have been carried out to verify the system performance under PMM governing strategy. The simulation results indeed demonstrate the effectiveness of the proposed approach.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2705074
- Subject Headings
- Electric power systems, Building-integrated photovoltaic systems, Renewable energy sources, Hydrogen as fuel, Research
- Format
- Document (PDF)
- Title
- Modern power distribution and conversion in undersea systems.
- Creator
- Tusting, Robert F., Taylor, Lawrence D.
- Date Issued
- 1991
- PURL
- http://purl.flvc.org/FCLA/DT/3351947
- Subject Headings
- Remote submersibles--Design and construction, Submersibles--Design and construction, Power systems, Electric current converters
- Format
- Document (PDF)
- Title
- Applications of pulse width modulation to LEDs, fuel cells and battery technology.
- Creator
- Watt, Wayne W., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
It has become a case of great desire and, in some instances, a requirement to have systems in engineering be energy efficient, in addition to being effectively powerful. It is rare that there is a single technique that has the range to make this possible in a wide collection of areas in the field. The work done in this thesis exhibits how Pulse Width Modulation (PWM) bridges LEDs, plug in vehicles, fuel cells and batteries, all seemingly different sub categories of electrical engineering. It...
Show moreIt has become a case of great desire and, in some instances, a requirement to have systems in engineering be energy efficient, in addition to being effectively powerful. It is rare that there is a single technique that has the range to make this possible in a wide collection of areas in the field. The work done in this thesis exhibits how Pulse Width Modulation (PWM) bridges LEDs, plug in vehicles, fuel cells and batteries, all seemingly different sub categories of electrical engineering. It stems from an undergraduate directed independent study supervised by Dr. Zilouchian that encircled LEDs and electric vehicles and how they contribute to a smart electric grid. This thesis covers the design and development of a prototype board that test how PWM saves energy, prolongs lifespan and provides a host of customizable features in manufactured LED lights that are used in the marine industry. Additionally, the concept of charging batteries that provide power to electric vehicles was explored. It is stressed that consumers who are interested in electric vehicles are concerned about refueling and recharge times. It is natural that a competing product, such as the electric vehicle in a world dominated by internal combustion engines, will perform on par if not better than existing choices. Tests are conducted to investigate the methods of fast battery charging and the challenges this technique creates. Attention is also given to the development of a pulsed Proton Exchange Membrane (PEM) fuel cell, specifically to prove whether pulse modulation is more efficient in a hydrogen producing fuel cell as opposed to direct-driven voltage and current alternatives.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3174313
- Subject Headings
- Power electronics, Digital control systems, Electric current converters, Fuel cells, Economic aspects
- Format
- Document (PDF)
- Title
- Reliable, energy-aware cross-layer protocol for wireless sensor networks.
- Creator
- Badi, Ahmed., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This research addresses communication reliability in the highly constrained wireless sensor networks environment. We propose a cross-layer, reliable wireless sensor protocol design. The protocol benefits from the body of research in the two areas of wireless sensors reliability research and wireless sensors energy conservation research. The protocol introduces a new energy saving technique that considers reliability as a design parameter and constraint. The protocol also introduces a new back...
Show moreThis research addresses communication reliability in the highly constrained wireless sensor networks environment. We propose a cross-layer, reliable wireless sensor protocol design. The protocol benefits from the body of research in the two areas of wireless sensors reliability research and wireless sensors energy conservation research. The protocol introduces a new energy saving technique that considers reliability as a design parameter and constraint. The protocol also introduces a new back-off algorithm that dynamically adjusts to the data messages reliability needs. Other cross-layer techniques that the protocol introduces are dynamic MAC retry limit and dynamic transmission power setting that is also based on the messages reliability requirements. Cross layer design is defined as the interaction between the different stack layers with the goal of improving performance. It has been used in ad hoc wireless systems to improve throughput, latency, and quality of service (QoS). The improvements gained in performance come at a price. This includes decreased architecture modularity and designs may be hard to debug, maintain or upgrade. Cross-layer design is valuable for wireless sensor networks due to the severe resource constraints. The proposed protocol uses cross-layer design as a performance and energy optimization technique. Nevertheless, the protocol avoids introducing layer interdependencies by preserving the stack architecture and optimizes the overall system energy and reliability performance by information sharing. The information is embedded as flags in the data and control messages that are moving through the stack. Each layer reads these flags and adjusts its performance and handling of the message accordingly. The performance of the proposed protocol is evaluated using simulation modeling. The reference protocol used for evaluation is APTEEN., We developed simulation programs for the proposed protocol and for APTEEN protocol using the JiST/SWANS simulation tool. The performance evaluation results show that the proposed protocol achieves better energy performance than the reference protocol. Several scalability experiments show that the proposed protocol scales well and has better performance for large networks. Also, exhaustive bandwidth utilization experiments show that for heavily-utilized or congested networks, the proposed protocol has high reliability in delivering messages classified as important.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/359921
- Subject Headings
- Computer network protocols, Wireless communication systems, Technological innovations, Sensor networks, Power resources, Efficiency
- Format
- Document (PDF)
- Title
- Energy-efficient routing in ad hoc wireless networks.
- Creator
- Dai, Qing., Florida Atlantic University, Wu, Jie
- Abstract/Description
-
The ad hoc wireless network is an infrastructureless network, where mobile stations are typically powered by batteries. Energy conservation has therefore becomes a very important issue. In this thesis, we discuss our work on several problems in energy-efficient routing. Chapter 3 focuses on how to compute the minimum uniform broadcast transmission power in an ad hoc wireless network. Several algorithms are proposed and their running time compared through simulation. It is shown that Prim's...
Show moreThe ad hoc wireless network is an infrastructureless network, where mobile stations are typically powered by batteries. Energy conservation has therefore becomes a very important issue. In this thesis, we discuss our work on several problems in energy-efficient routing. Chapter 3 focuses on how to compute the minimum uniform broadcast transmission power in an ad hoc wireless network. Several algorithms are proposed and their running time compared through simulation. It is shown that Prim's Minimum Spanning Tree (MST) has better performance than Kruskal's MST and the two binary search algorithms. In the following two chapters, routing algorithms are studied for specific situations, when directional antenna is used (Chapter 4) or when partial signal could be collected, stored and integrated (Chapter 5). Different algorithms are discussed and their energy performance illustrated by simulation study. Their application and limitation are also discussed in the thesis.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13077
- Subject Headings
- Wireless communication systems, Routers (Computer networks), Electronic digital computers--Power supply, Mobile computing
- Format
- Document (PDF)
- Title
- Performance analysis of multitaper spectrum estimation.
- Creator
- Skoro Kaskarovska, Violeta, Florida Atlantic University, Erdol, Nurgun, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
We characterize the Multitaper Spectral Estimation method as a tool for stationary signal analysis. We compare its performance to the conventional periodogram, the parametric autoregressive and multitaper autoregressive spectral estimates. We analyze single and two frequency sinusoids with additive Gaussian white noise and autoregressive processes of orders 2, 4 and 24. We extend its application to non-stationary signals and develop the multitaper spectrogram. We test the spectrograms with...
Show moreWe characterize the Multitaper Spectral Estimation method as a tool for stationary signal analysis. We compare its performance to the conventional periodogram, the parametric autoregressive and multitaper autoregressive spectral estimates. We analyze single and two frequency sinusoids with additive Gaussian white noise and autoregressive processes of orders 2, 4 and 24. We extend its application to non-stationary signals and develop the multitaper spectrogram. We test the spectrograms with simulated non-stationary autoregressive process of order 2 as the magnitude of its poles vary between 0 and 1 and the angle of the poles vary between 0 and pi. Our results show that the multitaper spectral estimate can be parameterized and is more accurate than others tested for non-sinusoidal signals. We also show applications to aero-acoustic data analysis.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13235
- Subject Headings
- Spectral theory (Mathematics), Signal processing--Mathematics, System identification, Power spectra
- Format
- Document (PDF)
- Title
- Power system modeling and optimization methods vis-a-vis integrated resource planning (IRP).
- Creator
- Arsali, Mohammad H., Florida Atlantic University, Neelakanta, Perambur S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The state-of-the-art restructuring of power industries is changing the fundamental nature of retail electricity business. As a result, the so-called Integrated Resource Planning (IRP) strategies implemented on electric utilities are also undergoing modifications. Such modifications evolve from the imminent considerations to minimize the revenue requirements and maximize electrical system reliability vis-a-vis capacity-additions (viewed as potential investments). IRP modifications also provide...
Show moreThe state-of-the-art restructuring of power industries is changing the fundamental nature of retail electricity business. As a result, the so-called Integrated Resource Planning (IRP) strategies implemented on electric utilities are also undergoing modifications. Such modifications evolve from the imminent considerations to minimize the revenue requirements and maximize electrical system reliability vis-a-vis capacity-additions (viewed as potential investments). IRP modifications also provide service-design bases to meet the customer needs towards profitability. The purpose of this research as deliberated in this dissertation is to propose procedures for optimal IRP intended to expand generation facilities of a power system over a stretched period of time. Relevant topics addressed in this research towards IRP optimization are as follows: (1) Historical prospective and evolutionary aspects of power system production-costing models and optimization techniques; (2) A survey of major U.S. electric utilities adopting IRP under changing socioeconomic environment; (3) A new technique designated as the Segmentation Method for production-costing via IRP optimization; (4) Construction of a fuzzy relational database of a typical electric power utility system for IRP purposes; (5) A genetic algorithm based approach for IRP optimization using the fuzzy relational database.
Show less - Date Issued
- 1998
- PURL
- http://purl.flvc.org/fcla/dt/12567
- Subject Headings
- Electric utilities--United States, Electric power system--United States
- Format
- Document (PDF)
- Title
- Power-aware broadcasting and activity scheduling in ad hoc wireless networks using connected dominating sets.
- Creator
- Wu, Bing., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In mobile ad hoc wireless networks (MANET), due to host mobility, broadcasting is expected to be frequently used to find a route to a particular host, to page a host, and to alarm all hosts. A straightforward broadcasting by flooding is usually very costly and results in substantial redundancy and more energy consumption. Power consumption is an important issue since most mobile hosts operate on battery. Broadcasting based on a connected dominating set (CDS) is a promising approach, where...
Show moreIn mobile ad hoc wireless networks (MANET), due to host mobility, broadcasting is expected to be frequently used to find a route to a particular host, to page a host, and to alarm all hosts. A straightforward broadcasting by flooding is usually very costly and results in substantial redundancy and more energy consumption. Power consumption is an important issue since most mobile hosts operate on battery. Broadcasting based on a connected dominating set (CDS) is a promising approach, where only nodes inside CDS need to relay the broadcast packet. Wu and Li proposed a simple distributed algorithm for calculating CDS in MANET. In general, nodes inside CDS consume more energy to handle various bypass traffics than nodes outside the set. To prolong the life span of each node and, hence, the network by balancing the energy consumption in the system, nodes should be alternated in being chosen to form a CDS. Activity scheduling deals with the way to rotate the role of each node among a set of given operation modes. In thesis I propose to apply power-aware CDS notions to broadcasting and activity scheduling. I also introduce distance rule and extended rules to further reduce broadcasting energy consumption. The effectiveness of the proposed method are confirmed through my simulation experiment.
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/12958
- Subject Headings
- Mobile computing, Wireless communication systems, Electronic digital computers--Power supply
- Format
- Document (PDF)
- Title
- Tool wear monitoring using artificial neural networks.
- Creator
- Kurapati, Venkatesh., Florida Atlantic University, Masory, Oren, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
An on-line scheme for monitoring tool wear in unmanned machining operations using artificial neural networks (ANNs) is proposed. Various configurations of ANNs are studied to increase the accuracy of tool wear estimation. With this aim three configurations of the ANNs namely, an ANN without memory, an ANN with one phase memory, and an ANN with two phase memory are considered. Each ANN is trained to associate an input vector which consists of values of cutting conditions, with an output vector...
Show moreAn on-line scheme for monitoring tool wear in unmanned machining operations using artificial neural networks (ANNs) is proposed. Various configurations of ANNs are studied to increase the accuracy of tool wear estimation. With this aim three configurations of the ANNs namely, an ANN without memory, an ANN with one phase memory, and an ANN with two phase memory are considered. Each ANN is trained to associate an input vector which consists of values of cutting conditions, with an output vector containing flank wear as a single output. The training data and evaluation data is generated using the popular analytical tool wear model. The performance of all the ANNs are compared by considering four different cases of evaluation data. The proposed scheme of tool wear modeling using ANNs is easily extendible to include other cutting parameters and can be implemented in real-time.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/14868
- Subject Headings
- Neural networks (Computer science), Flexible manufacturing systems, Power tools, Machine tools--Data processing
- Format
- Document (PDF)
- Title
- Local construction of connected dominating sets in wireless ad hoc networks.
- Creator
- Dai, Fei., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Wireless ad hoc networks are infrastructure-less multi-hop networks consisting of mobile (such as in mobile ad hoc networks) or stationary (such as in wireless sensor networks) wireless devices. These networks involve several challenges, including limited bandwidth and energy resources, frequent topology changes, and a lack of central control. Local acting, self-organizing, and self-healing algorithms (also called localized algorithms) are essential to the design of wireless ad hoc networks....
Show moreWireless ad hoc networks are infrastructure-less multi-hop networks consisting of mobile (such as in mobile ad hoc networks) or stationary (such as in wireless sensor networks) wireless devices. These networks involve several challenges, including limited bandwidth and energy resources, frequent topology changes, and a lack of central control. Local acting, self-organizing, and self-healing algorithms (also called localized algorithms) are essential to the design of wireless ad hoc networks. A connected dominating set (CDS) is frequently used in wireless ad hoc networks as a virtual backbone to support efficient routing, service discovery, and area monitoring. In addition, efficient broadcasting (i.e., finding a small set of forward nodes to ensure full delivery) can be viewed as forming a CDS on-the-fly. The periodically maintained virtual backbone is called a static CDS, and the temporarily formed forward node set is called a dynamic CDS. For efficiency and robustness, the ideal CDS construction algorithm is lightweight, has fast convergence, and minimizes the CDS size. This dissertation focuses on providing a generic framework to unify localized CDS construction schemes, including both static and dynamic CDS constructions, for wireless ad hoc networks. The goal is to provide insights on how to form a small CDS (forward node set) in dynamic networks with affordable overhead and high robustness. A classification of CDS construction algorithms for wireless ad hoc networks has been provided at the beginning. An efficient scheme, called Rule K, has been proposed for static CDS construction. Rule K achieves a probabilistic constant upper bound on the expected CDS size, which is currently the best known performance guarantee for localized CDS algorithms. Rule K has been extended to a unified framework, called the coverage condition, which contains most existing localized virtual backbone construction and efficient broadcast algorithms as its special cases. The coverage condition has been further extended to construct a k-connected k-dominating set for higher robustness, and integrated in an iterative process that further reduces the CDS size while maintaining the same level of robustness.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/12144
- Subject Headings
- Wireless communication systems, Electronic digital computers--Power supply, Mobile computing, Sensor networks
- Format
- Document (PDF)
- Title
- APIS: A SOFTWARE AND HARDWARE TOOLKIT FOR FEDERATED POWER MANAGEMENT IN ENERGY HARVESTING APPLICATIONS.
- Creator
- Prey, Adam, Hallstrom, Jason O., Florida Atlantic University, Department of Computer and Electrical Engineering and Computer Science, College of Engineering and Computer Science
- Abstract/Description
-
Embedded systems and Internet of Things (IoT) devices have been limited in application by constraints posed by batteries. Batteries add size, weight, and upkeep costs, while also limiting the lifetime of devices that are preferred to be small, lightweight, and long-lasting. We present Apis, a software and hardware toolkit for federated power management in energy harvesting applications. By replacing batteries with rapid charging storage capacitors, circuitry to control federated energy...
Show moreEmbedded systems and Internet of Things (IoT) devices have been limited in application by constraints posed by batteries. Batteries add size, weight, and upkeep costs, while also limiting the lifetime of devices that are preferred to be small, lightweight, and long-lasting. We present Apis, a software and hardware toolkit for federated power management in energy harvesting applications. By replacing batteries with rapid charging storage capacitors, circuitry to control federated energy storage, and software support to make this architecture useful to developers, embedded devices can potentially run inde nitely with limited maintenance. We present the Apis hardware design for controlling federated energy storage, supporting software for controlling this hardware, and the results of experiments performed to validate the Apis model. The system is named after the taxonomy genus for the honey bee, a creature dedicated to the harvesting and federated storage of energy resources.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013405
- Subject Headings
- Internet of things, Energy harvesting, Embedded systems (Computer systems), Telecommunication--Power supply, Application program interfaces (Computer software)
- Format
- Document (PDF)
- Title
- Developing interpretive turbulence models from a database with applications to wind farms and shipboard operations.
- Creator
- Schau, Kyle A., Gaonkar, Gopal H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This thesis presents a complete method of modeling the autospectra of turbulence in closed form via an expansion series using the von Kármán model as a basis function. It is capable of modeling turbulence in all three directions of fluid flow: longitudinal, lateral, and vertical, separately, thus eliminating the assumption of homogeneous, isotropic flow. A thorough investigation into the expansion series is presented, with the strengths and weaknesses highlighted. Furthermore, numerical...
Show moreThis thesis presents a complete method of modeling the autospectra of turbulence in closed form via an expansion series using the von Kármán model as a basis function. It is capable of modeling turbulence in all three directions of fluid flow: longitudinal, lateral, and vertical, separately, thus eliminating the assumption of homogeneous, isotropic flow. A thorough investigation into the expansion series is presented, with the strengths and weaknesses highlighted. Furthermore, numerical aspects and theoretical derivations are provided. This method is then tested against three highly complex flow fields: wake turbulence inside wind farms, helicopter downwash, and helicopter downwash coupled with turbulence shed from a ship superstructure. These applications demonstrate that this method is remarkably robust, that the developed autospectral models are virtually tailored to the design of white noise driven shaping filters, and that these models in closed form facilitate a greater understanding of complex flow fields in wind engineering.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004058
- Subject Headings
- Fluid mechanics, Renewable energy sources, Von Kármán, Theodore -- 1881-1963, Wind energy conservation systems, Wind power, Wind turbines -- Aerodynamics
- Format
- Document (PDF)
- Title
- Adaptive power control in 802.11 networks.
- Creator
- Dural, Serkan., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
IEEE 802.11 networks successfully satisfy high data demands and are cheaper compared to cellular networks. Modern mobile computers and phones are equipped with 802.11 and are VoIP capable. Current network designs do not dynamically accommodate changes in the usage. We propose a dynamic power control algorithm that provides greater capacity within a limited geographic region. Most other power algorithms necessitate changes in 802.11 requiring hardware changes. Proposed algorithm only requires...
Show moreIEEE 802.11 networks successfully satisfy high data demands and are cheaper compared to cellular networks. Modern mobile computers and phones are equipped with 802.11 and are VoIP capable. Current network designs do not dynamically accommodate changes in the usage. We propose a dynamic power control algorithm that provides greater capacity within a limited geographic region. Most other power algorithms necessitate changes in 802.11 requiring hardware changes. Proposed algorithm only requires firmware updates to enable dynamic control of APs transmit power. We use earlier studies to determine the limit of the number of users to optimize power. By lowering transmit power of APs with large number of users, we can effectively decrease the cell size. The resulting gap is then covered by dynamically activating additional APs. This also provides greater flexibility and reduces the network planning costs.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/221941
- Subject Headings
- IEEE 802.11 (Standard), Computer networks, Security measures, Computer network protocols, Mobile communication systems, Power supply
- Format
- Document (PDF)
- Title
- Design and Implementation of a Solar Platform and a Fuel Cell System on an Electric Utility Vehicle.
- Creator
- Saelzer, Max W., Zilouchian, Ali, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In thesis work, an innovative design and implementation of a "trybrid" system is carried out. This new "trybrid" system is the continuation of the solar electric vehicle which was designed and developed as an undergraduate independent study under the supervision of Dr. Roger Messenger. The work done on this thesis consists in the implementation of the existing solar electric vehicle outfitted with a fuel cell system. For this, two fuel cell systems were analyzed as possible candidates for the...
Show moreIn thesis work, an innovative design and implementation of a "trybrid" system is carried out. This new "trybrid" system is the continuation of the solar electric vehicle which was designed and developed as an undergraduate independent study under the supervision of Dr. Roger Messenger. The work done on this thesis consists in the implementation of the existing solar electric vehicle outfitted with a fuel cell system. For this, two fuel cell systems were analyzed as possible candidates for the retrofit. Also, different hydrogen storage methods are analyzed in terms of efficiency and safety. This thesis also covers the control system utilized to manage the energy from the two different energy sources. Special attention is devoted to the method of determining the state of charge of the batteries which controls fuel cell turn on time. This first prototype shows the different functionalities and optimized features that maximize the solar energy production, and determines exactly when to turn on the fuel cell for minimum hydrogen usage.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fau/fd/FA00012546
- Subject Headings
- Electric power systems, Hybrid electric vehicles, Fuel cells--Technological innovations, Automobile industry and trade--Forecasting
- Format
- Document (PDF)