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- Title
- Stochastical and neuromimetic aspects of modeling electromagnetic composite materials.
- Creator
- Park, Joseph C., Florida Atlantic University, Neelakanta, Perambur S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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This dissertation is concerned primarily with the analytical modeling of a class of electromagnetic composite materials using the concepts of stochastical mixture theory, principles of electromagnetics and neuromimetic considerations. The global behavior of the test composite is ascertained in terms of the constitutive relations of the material parameters (having stochastical attributions) and the intramaterial hierarchy is modeled as massively interconnected, interacting units depicting such...
Show moreThis dissertation is concerned primarily with the analytical modeling of a class of electromagnetic composite materials using the concepts of stochastical mixture theory, principles of electromagnetics and neuromimetic considerations. The global behavior of the test composite is ascertained in terms of the constitutive relations of the material parameters (having stochastical attributions) and the intramaterial hierarchy is modeled as massively interconnected, interacting units depicting such systems as mimetics of neural networks. Pertinent research efforts enclave the following specific tasks: (i) Modeling a multi-constituent electromagnetic composite medium in terms of the characteristics of its individual constituents and their spatial (random or orderly) dispositions. (ii) Assessment of nonspherical particulate effects (in terms of the stochastical attributes) on the global response of such composite materials. (iii) Evaluation of interparticle interactions and their implicit effects on the effective electromagnetic properties of the composite media. (iv) Assaying the transitional behavior of the test composites and, (v) modeling electromagnetic composites as neuromimetics correlating their effective material characteristics to the corresponding state-transitional response of a massively interconnected neural network. Results arising from these theoretical considerations are compared with data compiled via experimental studies performed (where feasible) or otherwise correlated with theoretical and/or experimental results available elsewhere in the literature. Specific experimental efforts carried out refer to piezoelectric rubber composites and their application in controlling acoustic beamforming via electrical 'pinch off' (which mimics the inhibitory response in a neuronal cell); as well as exclusive experimental tasks to verify the transitional lossy behavior model developed presently using a set of fast-ion conductor composites and dielectric-plus-conductor mixtures. Lastly, inferential conclusions are presented and discussed with an outline on the scope of extensions to the present work.
Show less - Date Issued
- 1994
- PURL
- http://purl.flvc.org/fcla/dt/12359
- Subject Headings
- Composite materials--Electric properties, Composite materials--Magnetic properties, Stochastic processes
- Format
- Document (PDF)
- Title
- Stochastic optimization of energy for multi-user wireless networks over fading channels.
- Creator
- Wang, Di, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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Wireless devices in wireless networks are powered typically by small batteries that are not replaceable nor recharged in a convenient way. To prolong the operating lifetime of networks, energy efficiency is indicated as a critical issue and energy-efficient resource allocation designs have been extensively developed. We investigated energy-efficient schemes that prolong network operating lifetime in wireless sensor networks and in wireless relay networks. In Chapter 2, the energy-efficient...
Show moreWireless devices in wireless networks are powered typically by small batteries that are not replaceable nor recharged in a convenient way. To prolong the operating lifetime of networks, energy efficiency is indicated as a critical issue and energy-efficient resource allocation designs have been extensively developed. We investigated energy-efficient schemes that prolong network operating lifetime in wireless sensor networks and in wireless relay networks. In Chapter 2, the energy-efficient resource allocation that minimizes a general cost function of average user powers for small- or medium-scale wireless sensor networks, where the simple time-division multiple-access (TDMA) is adopted as the multiple access scheme. A class of Ç-fair cost-functions is derived to balance the tradeoff between efficiency and fairness in energy-efficient designs. Based on such cost functions, optimal channel-adaptive resource allocation schemes are developed for both single-hop and multi-hop TDMA sensor networks. In Chapter 3, optimal power control methods to balance the tradeoff between energy efficiency and fairness for wireless cooperative networks are developed. It is important to maximize power efficiency by minimizing power consumption for a given quality of service, such as the data rate; it is also equally important to evenly or fairly distribute power consumption to all nodes to maximize the network life. The optimal power control policy proposed is derived in a quasi-closed form by solving a convex optimization problem with a properly chosen cost-function. To further optimize a wireless relay network performance, an orthogonal frequency division multiplexing (OFDM) based multi-user wireless relay network is considered in Chapter 4., In the OFDM approach, each subcarrier is dynamically assigned to a source- destination link, and several relays assist communication between pairs of source-destination over their assigned subcarriers. Using a class of Ç-fair cost-functions to balance the tradeoff between energy efficiency and fairness, jointly with optimal subcarrier and power allocation schemes at the relays. Relevant algorithms are derived in quasi-closed form. Lastly, the proposed energy-efficient schemes are summarized and future work is discussed in Chapter 5.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3322519
- Subject Headings
- Stochastic processes, Data processing, Wireless communication systems, Mathematical models, Computer network protocols, Signal processing, Digital techniques, Code division multiple access, Waveless division multiplexing, Orthogonalization methods
- Format
- Document (PDF)
- Title
- Studies on Stochastic Multi-user Scheduling in Wireless Communication.
- Creator
- Wang, Di, Morgera, Salvatore D., Wang, Xin, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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We developed a cross layer design which combines retransmission diversity and multi-user diversity for wireless communication. To this end, a joint design of adaptive modulation and coding with retransmission-based automatic repeat request protocol is outlined. This design is applied to devise multi-user scheduling schemes, which can optimally capture the available multi-user and retransmission diversities. In addition, the proposed on-line scheduling algorithms can operate even when the...
Show moreWe developed a cross layer design which combines retransmission diversity and multi-user diversity for wireless communication. To this end, a joint design of adaptive modulation and coding with retransmission-based automatic repeat request protocol is outlined. This design is applied to devise multi-user scheduling schemes, which can optimally capture the available multi-user and retransmission diversities. In addition, the proposed on-line scheduling algorithms can operate even when the underl ying fading channel distribution is unknown, while asymptotically converging to the offline benchmark with guarantees on prescribed fairness and rate requirements. Numerical results are provided to verify the merits of our novel schemes for multi-user transmissions over Nakagami block fading channels.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/fau/fd/FA00012568
- Subject Headings
- Stochastic processes--Data processing, Wireless communication systems, Computer network protocols, Code division multiple access, Modulation (Electronics), Signal processing--Digital techniques
- Format
- Document (PDF)
- Title
- Stochastic processes in the social sciences: markets, prices and wealth distributions.
- Creator
- Romero, Natalia E., Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
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The present work uses statistical mechanics tools to investigate the dynamics of markets, prices, trades and wealth distribution. We studied the evolution of market dynamics in different stages of historical development by analyzing commodity prices from two distinct periods : ancient Babylon, and medieval and early modern England. We find that the first-digit distributrions of both Babylon and England commodity prices follow Benford's Law, indicating that the data represent empirical...
Show moreThe present work uses statistical mechanics tools to investigate the dynamics of markets, prices, trades and wealth distribution. We studied the evolution of market dynamics in different stages of historical development by analyzing commodity prices from two distinct periods : ancient Babylon, and medieval and early modern England. We find that the first-digit distributrions of both Babylon and England commodity prices follow Benford's Law, indicating that the data represent empirical observations typically arising from a free market. Further, we find that the normalized prices of both Babylon and England agricultural commodities are characterized by stretched exponential distributions, and exhibit persistent correlations of a power law type over long periods of up to several centuries, in contrast to contemporary markets. Our findings suggest that similar market interactions may underlie the dynamics of ancient agricultural commodity prices, and that these interactions may remain stable across centuries. To further investigate the dynamics of markets, we present the analogy between transfers of money between individuals and the transfer of energy through particle collisions by means of the kinetic theory of gases. We introduce a theoretical framework of how micro rules of trading lead to the emergence of income and wealth distribution. Particularly, we study the effects of different types of distribution of savings/investments among individuals in a society and different welfare/subsidies redistribution policies. Results show that while considering savings propensities, the models approach empirical distributions of wealth quite well. The effect of redistribution better captures specific features of the distributions which earlier models failed to do. Moreover, the models still preserve the exponential decay observed in empirical income distributions reported by tax data and surveys.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3352825
- Subject Headings
- Stochastic processes, Mathematical models, Consumption (Economics), Mathematical models, Business cycles, Mathematical models, Statics and dynamics (Social sciences), Mathematical models
- Format
- Document (PDF)
- Title
- A generalized stochastic birth/death population model based on Indian RiverLagoon dolphins.
- Creator
- Stonger, Jon, Noonburg, Erik G., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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For over a decade, researchers at Harbor Branch Oceanographic Institute (HBOI) have conducted surveys of the bottlenose dolphin (Tursiops truncatus) population of Indian River Lagoon (IRL) in Florida. I have constructed a 4-stage population model using the statistical program R. The model is used to conduct a viability analysis by analyzing the relationship between birth, calf and adult survival rates. The power analysis compares survey frequency to expected confidence intervals in estimating...
Show moreFor over a decade, researchers at Harbor Branch Oceanographic Institute (HBOI) have conducted surveys of the bottlenose dolphin (Tursiops truncatus) population of Indian River Lagoon (IRL) in Florida. I have constructed a 4-stage population model using the statistical program R. The model is used to conduct a viability analysis by analyzing the relationship between birth, calf and adult survival rates. The power analysis compares survey frequency to expected confidence intervals in estimating abundance. The sensitivity analysis shows that the population is most sensitive to changes in adult survival, followed by birth rate and calf survival. The model shows a strong chance of viability over a 50 year time span. The population is vulnerable to long periods of decline if birth, calf or adult survival rates fall below certain thresholds. Overall, the model simulates the future impacts of demographic change, providing a tool for conservation efforts.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004163, http://purl.flvc.org/fau/fd/FA00004163
- Subject Headings
- Animal populations -- Estimates, Bottlenose dolphin -- Florida -- Indian River Lagoon -- Geographical distribution, Indian River (Fla : Lagoon), Marine mammal populations -- Estimates -- Florida -- Mathematical models, Population biology, Stochastic processes
- Format
- Document (PDF)
