+publisher:"University of Oklahoma" +contributor:("Runolfsson, Thordur")

University of Oklahoma

1. Lin, Chenxi. Problems in the design and operation of uncertain complex engineering systems.

Degree: PhD, 2011, University of Oklahoma

► In this dissertation, we consider two problems. The first one is a general approach to the optimal design of uncertain dynamical systems, where the uncertainty… (more)

Subjects/Keywords: Differentiable dynamical systems; Mathematical optimization

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Lin, C. (2011). Problems in the design and operation of uncertain complex engineering systems. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/318961

Chicago Manual of Style (16^th Edition):

Lin, Chenxi. “Problems in the design and operation of uncertain complex engineering systems.” 2011. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/318961.

MLA Handbook (7^th Edition):

Lin, Chenxi. “Problems in the design and operation of uncertain complex engineering systems.” 2011. Web. 04 Mar 2021.

Vancouver:

Lin C. Problems in the design and operation of uncertain complex engineering systems. [Internet] [Doctoral dissertation]. University of Oklahoma; 2011. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/318961.

Council of Science Editors:

Lin C. Problems in the design and operation of uncertain complex engineering systems. [Doctoral Dissertation]. University of Oklahoma; 2011. Available from: http://hdl.handle.net/11244/318961

University of Oklahoma

2. BALID, WALID. FULLY AUTONOMOUS SELF-POWERED INTELLIGENT WIRELESS SENSOR FOR REAL-TIME TRAFFIC SURVEILLANCE IN SMART CITIES.

Degree: PhD, 2016, University of Oklahoma

URL: http://hdl.handle.net/11244/51828

► Reliable, real-time traffic surveillance is an integral and crucial function of the 21st century intelligent transportation systems (ITS) network. This technology facilitates instantaneous decision-making, improves… (more)

▼ Reliable, real-time traffic surveillance is an integral and crucial function of the 21st century intelligent transportation systems (ITS) network. This technology facilitates instantaneous decision-making, improves roadway efficiency, and maximizes existing transportation infrastructure capacity, making transportation systems safe, efficient, and more reliable. Given the rapidly approaching era of smart cities, the work detailed in this dissertation is timely in that it reports on the design, development, and implementation of a novel, fully-autonomous, self-powered intelligent wireless sensor for real-time traffic surveillance. Multi-disciplinary, innovative integration of state-of-the-art, ultra-low-power embedded systems, smart physical sensors, and the wireless sensor network—powered by intelligent algorithms—are the basis of the developed Intelligent Vehicle Counting and Classification Sensor (iVCCS) platform. The sensor combines an energy-harvesting subsystem to extract energy from multiple sources and enable sensor node self-powering aimed at potentially indefinite life. A wireless power receiver was also integrated to remotely charge the sensor’s primary battery. Reliable and computationally efficient intelligent algorithms for vehicle detection, speed and length estimation, vehicle classification, vehicle re-identification, travel-time estimation, time-synchronization, and drift compensation were fully developed, integrated, and evaluated. Several length-based vehicle classification schemes particular to the state of Oklahoma were developed, implemented, and evaluated using machine learning algorithms and probabilistic modeling of vehicle magnetic length. A feature extraction employing different techniques was developed to determine suitable and efficient features for magnetic signature-based vehicle re-identification. Additionally, two vehicle re-identification models based on matching vehicle magnetic signature from a single magnetometer were developed. Comprehensive system evaluation and extensive data analyses were performed to fine-tune and validate the sensor, ensuring reliable and robust operation. Several field studies were conducted under various scenarios and traffic conditions on a number of highways and urban roads and resulted in 99.98% detection accuracy, 97.4782% speed estimation accuracy, and 97.6951% classification rate when binning vehicles into four groups based on their magnetic length. Threshold-based, re-identification results revealed 65.25%~100% identification rate for a window of 25~500 vehicles. Voting-based, re-identification evaluation resulted in 90~100% identification rate for a window of 25~500 vehicles. The developed platform is portable and cost-effective. A single sensor node costs only $30 and can be installed for short-term use (e.g., work zone safety, traffic flow studies, roadway and bridge design, traffic management in atypical situations), as well as long-term use (e.g., collision avoidance at intersections, traffic monitoring) on highways, roadways, or roadside… Advisors/Committee Members: REFAI, HAZEM (advisor), Ray, William (committee member), Runolfsson, Thordur (committee member), Tang, Choon Yik (committee member), Imran, Ali (committee member).

Subjects/Keywords: Engineering, Electronics and Electrical; Intelligent Transportation Systems; Wireless Sensor Networks; Smart Cities; Vehicle Counting and Classification; Energy Harvesting; Magnetometer Sesnor; Embedded Systems; Internet of Things; IoT

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

BALID, W. (2016). FULLY AUTONOMOUS SELF-POWERED INTELLIGENT WIRELESS SENSOR FOR REAL-TIME TRAFFIC SURVEILLANCE IN SMART CITIES. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/51828

Chicago Manual of Style (16^th Edition):

BALID, WALID. “FULLY AUTONOMOUS SELF-POWERED INTELLIGENT WIRELESS SENSOR FOR REAL-TIME TRAFFIC SURVEILLANCE IN SMART CITIES.” 2016. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/51828.

MLA Handbook (7^th Edition):

BALID, WALID. “FULLY AUTONOMOUS SELF-POWERED INTELLIGENT WIRELESS SENSOR FOR REAL-TIME TRAFFIC SURVEILLANCE IN SMART CITIES.” 2016. Web. 04 Mar 2021.

Vancouver:

BALID W. FULLY AUTONOMOUS SELF-POWERED INTELLIGENT WIRELESS SENSOR FOR REAL-TIME TRAFFIC SURVEILLANCE IN SMART CITIES. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/51828.

Council of Science Editors:

BALID W. FULLY AUTONOMOUS SELF-POWERED INTELLIGENT WIRELESS SENSOR FOR REAL-TIME TRAFFIC SURVEILLANCE IN SMART CITIES. [Doctoral Dissertation]. University of Oklahoma; 2016. Available from: http://hdl.handle.net/11244/51828

University of Oklahoma

3. Algedir, Amal. The Coexistence of D2D Communication under Heterogeneous Cellular Networks (HetNets).

Degree: PhD, 2019, University of Oklahoma

URL: http://hdl.handle.net/11244/321178

► Device-to-Device (D2D) communication is a promising technique for supporting the stringent requirements of the fifth-generation cellular network (5G). This new technique has garnered significant attention… (more)

▼ Device-to-Device (D2D) communication is a promising technique for supporting the stringent requirements of the fifth-generation cellular network (5G). This new technique has garnered significant attention in cellular network standards for proximity communication as a means to improve cellular spectrum utilization, to decrease user equipment energy consumption, and to reduce end-to-end delay. This dissertation reports an investigation of D2D communication coexistence under 5G heterogeneous cellular network (HetNets) in terms of spectrum allocation and energy efficiency. The work reported herein describes a low-complexity D2D resource allocation algorithm for downlink (DL) resource reuse that can be leveraged to improve network throughput. Notably, cross-tier interference was considered when establishing D2D communication (e.g., macro base station to D2D links; small base station to D2D links; and D2D communication to cellular links served by the macro and small base stations). An allocation algorithm was introduced to reduce interference from D2D to cellular when a single D2D link is sharing cellular resources. Performance of the proposed algorithm was evaluated and compared to various resource allocations. Simulation results demonstrated that the proposed algorithm improves overall system throughput. This allocation algorithm achieved a near-optimal solution when compared with a brute force approach. This dissertation also presents a novel framework for optimizing the energy efficiency of D2D communication coexistence with HetNets in DL transmission. This optimization problem was mathematically formulated in terms of mode selection, power control, and resources allocation (i.e., NP-hard problem). The optimization fraction problem was simplified based on network load and was solved using various optimization methods. An innovative dynamic mode selection based on Fuzzy clustering was also introduced. Proposed scheme performance was evaluated and compared to the standard algorithm. Simulation validated the advantage of the proposed framework in terms of performance gain in both energy efficiency and the number of successfully connected D2D users. Moreover, the energy efficiency of HetNets with D2D compatibility was improved. Finally, this dissertation details a stochastic analytical model for an LTE scheduler with D2D communication. By assuming exponential distributions for users scheduling time, a throughput estimation model was developed using two-dimensional Continuous Time Markov chains (2D-CTMC) of birth-death type. The proposed model will predict the expected number of D2D operated in dedicated and reuse mode, as well as the systems long-term throughput. Advisors/Committee Members: Refai, Hazem (advisor), Runolfsson, Thordur (committee member), Imran, Ali (committee member), Kam Wai Clifford, Chan (committee member), Kisamore, Jennifer (committee member).

Subjects/Keywords: Heterogeneous Cellular Network; Device-to-Device Communication; Energy Efficiency Optimization; Resource Allocation; Throughput Optimization; Continuous Time Markov chains model; Downlink power Control

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Algedir, A. (2019). The Coexistence of D2D Communication under Heterogeneous Cellular Networks (HetNets). (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/321178

Chicago Manual of Style (16^th Edition):

Algedir, Amal. “The Coexistence of D2D Communication under Heterogeneous Cellular Networks (HetNets).” 2019. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/321178.

MLA Handbook (7^th Edition):

Algedir, Amal. “The Coexistence of D2D Communication under Heterogeneous Cellular Networks (HetNets).” 2019. Web. 04 Mar 2021.

Vancouver:

Algedir A. The Coexistence of D2D Communication under Heterogeneous Cellular Networks (HetNets). [Internet] [Doctoral dissertation]. University of Oklahoma; 2019. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/321178.

Council of Science Editors:

Algedir A. The Coexistence of D2D Communication under Heterogeneous Cellular Networks (HetNets). [Doctoral Dissertation]. University of Oklahoma; 2019. Available from: http://hdl.handle.net/11244/321178

University of Oklahoma

4. Bozkurt, Fatma. NORM RETRIEVAL FROM SPATIOTEMPORAL SAMPLES.

Degree: PhD, 2018, University of Oklahoma

URL: http://hdl.handle.net/11244/316291

► The goal of this dissertation is to investigate norm retrievable frames having dynamical sampling structure, particularly those that fail the phase retrieval con- dition. We… (more)

Subjects/Keywords: mathematics; norm retrieval; phase retrieval; dynamical sampling

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Bozkurt, F. (2018). NORM RETRIEVAL FROM SPATIOTEMPORAL SAMPLES. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/316291

Chicago Manual of Style (16^th Edition):

Bozkurt, Fatma. “NORM RETRIEVAL FROM SPATIOTEMPORAL SAMPLES.” 2018. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/316291.

MLA Handbook (7^th Edition):

Bozkurt, Fatma. “NORM RETRIEVAL FROM SPATIOTEMPORAL SAMPLES.” 2018. Web. 04 Mar 2021.

Vancouver:

Bozkurt F. NORM RETRIEVAL FROM SPATIOTEMPORAL SAMPLES. [Internet] [Doctoral dissertation]. University of Oklahoma; 2018. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/316291.

Council of Science Editors:

Bozkurt F. NORM RETRIEVAL FROM SPATIOTEMPORAL SAMPLES. [Doctoral Dissertation]. University of Oklahoma; 2018. Available from: http://hdl.handle.net/11244/316291

University of Oklahoma

5. Xiao, Ran. EEG OSCILLATORY ACTIVITIES FROM HUMAN MOTOR BRAIN.

Degree: PhD, 2015, University of Oklahoma

URL: http://hdl.handle.net/11244/23301

► Motor skills are essential in people’s daily life in exploring and interacting with the ambient environment. Impairments to motor functions affect the acquisition of motor… (more)

▼ Motor skills are essential in people’s daily life in exploring and interacting with the ambient environment. Impairments to motor functions affect the acquisition of motor skills, which not only reduce the quality of life, but also impose heavy economic burdens to sufferers and their families. Oscillatory activities in electroencephalography (EEG), such as the mu rhythm, present functional correlation to motor functions, which provide accessible windows to understand underlying neural mechanism in healthy persons and perform diagnoses in patients with various motor impairments. It is thus of significant importance to further investigate classic and/or identify new motor-related EEG oscillatory activities. In this dissertation, EEG oscillations from both infants and adults are investigated to uncover motor-related neural information noninvasively from the human brain regarding their developmental changes and movement representations of body parts, respectively. In typical developing infants at 5-7 months of age, knowledge about mu rhythm development is expanded by capturing subtle developmental changes of its characteristics in a fine age resolution, through the development of new spatio-spectral analysis of EEG data recorded longitudinally on a weekly basis. In adults, motor tasks involving fine body parts are studied to investigate EEG resolutions in decoding movements/motor imageries of individual fingers, which have only been addressed in large body parts in literature. Discriminative information in EEG oscillations about motor tasks of fine body parts is revealed through the discovery of a novel type of spectral structures in EEG, which exhibits better sensitivity to movements of fine body parts than the classic mu rhythm. The findings in this dissertation broaden the scope of neural information in EEG oscillations in relation to motor functions, and contribute to the understanding about human motor functions at various life stages. These results and technologies are promising to be translated to patient studies in the future. Advisors/Committee Members: Ding, Lei (advisor), Runolfsson, Thordur (committee member), Tang, Choon Yik (committee member), Wenger, Michael (committee member), Yu, Tian-You (committee member).

Subjects/Keywords: Engineering, Biomedical.; Engineering, Electronics and Electrical.; Engineering, General.

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Xiao, R. (2015). EEG OSCILLATORY ACTIVITIES FROM HUMAN MOTOR BRAIN. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/23301

Chicago Manual of Style (16^th Edition):

Xiao, Ran. “EEG OSCILLATORY ACTIVITIES FROM HUMAN MOTOR BRAIN.” 2015. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/23301.

MLA Handbook (7^th Edition):

Xiao, Ran. “EEG OSCILLATORY ACTIVITIES FROM HUMAN MOTOR BRAIN.” 2015. Web. 04 Mar 2021.

Vancouver:

Xiao R. EEG OSCILLATORY ACTIVITIES FROM HUMAN MOTOR BRAIN. [Internet] [Doctoral dissertation]. University of Oklahoma; 2015. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/23301.

Council of Science Editors:

Xiao R. EEG OSCILLATORY ACTIVITIES FROM HUMAN MOTOR BRAIN. [Doctoral Dissertation]. University of Oklahoma; 2015. Available from: http://hdl.handle.net/11244/23301

University of Oklahoma

6. Al Kalaa, Mohamad Omar. Practical Extensions to the Evaluation and Analysis of Wireless Coexistence in Unlicensed Bands.

Degree: PhD, 2016, University of Oklahoma

URL: http://hdl.handle.net/11244/47035

► Sharing spectrum resources in unlicensed bands has proven cost effective and beneficial for providing ubiquitous access to wireless functionality for a broad range of applications.… (more)

▼ Sharing spectrum resources in unlicensed bands has proven cost effective and beneficial for providing ubiquitous access to wireless functionality for a broad range of applications. Chipsets designed to implement communication standards in the Industrial, Scientific and Medical (ISM) band have become increasingly inexpensive and widely available, making wireless-enabled medical and non-medical devices attractive to an increased number of users. Consequently, wireless coexistence becomes a concern. In response, the U.S. Food and Drug Administration (FDA) has issued a guidance document to assist medical device manufacturers ensure reasonable safety and effectiveness. Coexistence-testing methods are now being reported in literature, and novel solutions are under consideration for inclusion in the American National Standards Institute (ANSI) C63.27 Standard for Evaluation of Wireless Coexistence. This dissertation addresses practical issues for evaluating and reporting wireless coexistence. During testing, an under-test-system (UTS) is evaluated in the presence of an interfering system (IS). Accordingly, an innovative method is suggested for estimating channel utilization of multiple, concurrent wireless transmitters sharing an unlicensed band in the context of radiated open environment coexistence testing (ROECT). Passively received power measurements were collected, and then a Gaussian mixture model (GMM) was used to build a classifier for labeling observed power samples relative to their source. Overall accuracy was verified at 98.86%. Case studies are presented utilizing IEEE 802.11n as an IS with UTS based on either IEEE 802.11n or ZigBee. Results demonstrated the mutual effect of spectrum sharing on both IS and UTS in terms of per-second channel utilization and frame collision. The process of approximating the probability of a device to coexist in its intended environment is discussed, and a generalized framework for modeling the environment is presented. An 84-day spectrum survey of the 2.4 GHz to 2.48 GHz ISM band in a hospital environment serves as proof of concept. A custom platform was used to monitor power flux spectral density and record received power in both an intensive care unit (ICU) and a post-surgery recovery room (RR). Observations indicated that significant correlation in activity patterns corresponded mainly to IEEE 802.11 channels 1, 6, and 11. Consequently, channel utilization of three non-overlapping channels of 20 MHz bandwidth – relative to IEEE 802.11 channels 1, 6, and 11 – were calculated and fitted to a generalized extreme value (GEV) distribution. Low channel utilization (< 10%), along with sporadic occurrences of higher channel utilization (> 50%), was observed in the surveyed environment. Reported findings can be complementary to wireless coexistence testing. Quantifying the probability of UTS coexistence in a given environment is central to the evaluation of coexistence, as evidenced in the draft of the C63.27 standard. Notably, a method for this calculation is not currently… Advisors/Committee Members: Refai, Hazem H. (advisor), Ford, Timothy (committee member), Imran, Ali (committee member), Runolfsson, Thordur (committee member), Chan, Kam Wai Clifford (committee member).

Subjects/Keywords: Engineering, Electronics and Electrical.; Wireless Coexistence; Wireless Technology; Medical Device

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Al Kalaa, M. O. (2016). Practical Extensions to the Evaluation and Analysis of Wireless Coexistence in Unlicensed Bands. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/47035

Chicago Manual of Style (16^th Edition):

Al Kalaa, Mohamad Omar. “Practical Extensions to the Evaluation and Analysis of Wireless Coexistence in Unlicensed Bands.” 2016. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/47035.

MLA Handbook (7^th Edition):

Al Kalaa, Mohamad Omar. “Practical Extensions to the Evaluation and Analysis of Wireless Coexistence in Unlicensed Bands.” 2016. Web. 04 Mar 2021.

Vancouver:

Al Kalaa MO. Practical Extensions to the Evaluation and Analysis of Wireless Coexistence in Unlicensed Bands. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/47035.

Council of Science Editors:

Al Kalaa MO. Practical Extensions to the Evaluation and Analysis of Wireless Coexistence in Unlicensed Bands. [Doctoral Dissertation]. University of Oklahoma; 2016. Available from: http://hdl.handle.net/11244/47035

University of Oklahoma

7. Rajab, Samer. TOWARD ENHANCED WIRELESS COEXISTENCE IN THE 2.4GHZ ISM BAND VIA TEMPORAL CHARACTERIZATION AND EMPIRICAL MODELING OF 802.11B/G/N NETWORKS A DISSERTATION.

Degree: PhD, 2016, University of Oklahoma

URL: http://hdl.handle.net/11244/33191

► This dissertation presents an extensive experimental characterization and empirical modelling of 802.11 temporal behavior. A detailed characterization of 802.11b/g/n homogeneous and heterogeneous network traffic patterns… (more)

▼ This dissertation presents an extensive experimental characterization and empirical modelling of 802.11 temporal behavior. A detailed characterization of 802.11b/g/n homogeneous and heterogeneous network traffic patterns is featured, including idle time distribution and channel utilization. Duty cycle serves as a measure for spectrum busyness. Higher duty cycle levels directly impact transceivers using the spectrum, which either refrain from transmission or suffer from increased errors. Duty cycle results are provided for 802.11b, g and n Wi-Fi technologies at various throughput levels. Lower values are observed for 802.11b and g networks. Spectrum occupancy measurements are essential for wireless networks planning and deployment. Detailed characterization of 802.11g/n homogeneous and heterogeneous network traffic patterns, including activity and idle time distribution are presented. Distributions were obtained from time domain measurements and represent time fragment distributions for active and inactive periods during a specific test. This information can assist other wireless technologies in using the crowded ISM band more efficiently and achieve enhanced wireless coexistence. Empirical models of 802.11 networks in the 2.4 GHz Industrial, Scientific, and Medical (ISM) band are also presented. This information can assist other wireless technologies aiming to utilize the crowded ISM band more efficiently and achieve enhanced wireless coexistence. In this work models are derived for both homogeneous and heterogeneous 802.11 network idle time distribution. Additionally, two applications of 802.11 networks temporal characterization are presented. The first application investigates a novel method for identifying wireless technologies through the use of simple energy detection techniques to measure the channel temporal characteristics including activity and idle time probability distributions. In this work, a wireless technology identification algorithm was assessed experimentally. Temporal traffic pattern for 802.11b/g/n homogeneous and heterogeneous networks were measured and used as algorithm input. Identification accuracies of up to 96.83% and 85.9% are achieved for homogeneous and heterogeneous networks, respectively. The second application provides a case study using 802.15.4 ZigBee transmitter packet size on-line adjustments is also presented. Packet size is adaptively modified based on channel idle time distribution obtained using simple channel power measurements. Results demonstrate improved ZigBee performance and significant enhancement in throughput as a result of using adaptive packet size transmissions. Advisors/Committee Members: Refai, Hazem H. (advisor), Adams, Curts (committee member), Dyer, John (committee member), Imran, Ali (committee member), Runolfsson, Thordur (committee member).

Subjects/Keywords: Wireless communication; Spectrum Utilization Analysis; Time domain Spectrum modeling; ISM Band; Machine learning

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Rajab, S. (2016). TOWARD ENHANCED WIRELESS COEXISTENCE IN THE 2.4GHZ ISM BAND VIA TEMPORAL CHARACTERIZATION AND EMPIRICAL MODELING OF 802.11B/G/N NETWORKS A DISSERTATION. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/33191

Chicago Manual of Style (16^th Edition):

Rajab, Samer. “TOWARD ENHANCED WIRELESS COEXISTENCE IN THE 2.4GHZ ISM BAND VIA TEMPORAL CHARACTERIZATION AND EMPIRICAL MODELING OF 802.11B/G/N NETWORKS A DISSERTATION.” 2016. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/33191.

MLA Handbook (7^th Edition):

Rajab, Samer. “TOWARD ENHANCED WIRELESS COEXISTENCE IN THE 2.4GHZ ISM BAND VIA TEMPORAL CHARACTERIZATION AND EMPIRICAL MODELING OF 802.11B/G/N NETWORKS A DISSERTATION.” 2016. Web. 04 Mar 2021.

Vancouver:

Rajab S. TOWARD ENHANCED WIRELESS COEXISTENCE IN THE 2.4GHZ ISM BAND VIA TEMPORAL CHARACTERIZATION AND EMPIRICAL MODELING OF 802.11B/G/N NETWORKS A DISSERTATION. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/33191.

Council of Science Editors:

Rajab S. TOWARD ENHANCED WIRELESS COEXISTENCE IN THE 2.4GHZ ISM BAND VIA TEMPORAL CHARACTERIZATION AND EMPIRICAL MODELING OF 802.11B/G/N NETWORKS A DISSERTATION. [Doctoral Dissertation]. University of Oklahoma; 2016. Available from: http://hdl.handle.net/11244/33191

University of Oklahoma

8. Li, Xin. DESIGN OF TRANSIENT ENERGY AUTOMATON AND STUDY OF ENERGY FLOWS ON LATTICE GRAPH.

Degree: PhD, 2018, University of Oklahoma

URL: http://hdl.handle.net/11244/299784

► The effort of this doctoral dissertation research is devoted to the design of an automaton system and corresponding computer experiments for studying the dynamics of… (more)

▼ The effort of this doctoral dissertation research is devoted to the design of an automaton system and corresponding computer experiments for studying the dynamics of energy flow on lattice graphs. Such a Transient Energy Automaton (TEA) is a computational system that automates dynamic energy exchanges on a graph once triggered by disturbances similar to those used in the analysis of the dynamics of multi-machine power model system. The differences between TEA and other automata are: 1) TEA considers all of the vertices in the lattice graphs that are connected with each other; 2) TEA supposes the energy exchange processing by two specific actions; 3) TEA defines the governing rules of those actions. The TEA enables two fundamental actions of energy exchange at each vertex: a slow action to absorb a certain fraction of the energy received from the site of initial disturbance or the neighboring vertices, and a fast action to reflect the rest of the received energy to the rotors or oscillators at neighboring vertices on the graph. These two fundamental actions coupled together to enable the energy flow of TEA. In order to simplify the coupling of the two actions in the TEA, we let these two fundamental actions at local site or vertex be governed by the following rules: 1. For each vertex, the amount of energy received at a local site in the reflection action, which is defined as dispersion ratio, is a function of the graph geometry including the structure of lattice and value configuration of edges; 2. The fraction of energy that can be absorbed by each vertex in the absorption action, which is defined as absorption ratio, is based on the capability of the vertex; 3. We suppose at a particular time instant, all the vertices are in one same action, either fast action or slow action; 4. Such rules are functions of the geometry and value configuration of graph and the property of vertices, which ultimately enable the TEA to create time evolution of energy distribution, that may affect the dynamics of the system. The two governing rules apply to the fast and slow actions at the local site or vertex-level by the ratios of dispersion and absorption. The ratios are defined by two major intrinsic factors for the global energy exchange: 1) geometry of graph and its value configuration, and 2) property of vertex. The geometry controls the energy dispersion among vertices according to their propinquities and centralities configured by graph lattice, while the property of vertex is the capability to absorb or reflect the energy received. The energy distribution among vertices on a graph and its time evolution are computed recursively using the computational formula of the two actions under the governing rules. Moreover, the computation of the accumulated energy at each vertex satisfies an “additive superposition” principle to obtain the homogeneity of energy distribution on graph for each time step and for the time evolution of the process. The global properties of energy flow on a graph can then be investigated by… Advisors/Committee Members: Jiang, John N. (advisor), Barker, Kash A. (committee member), Runolfsson, Thordur (committee member), Thulasiraman, Krishnaiyan (committee member), Barnes, Ronald D. (committee member).

Subjects/Keywords: Engineering, System Science.; Computer Science.

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Li, X. (2018). DESIGN OF TRANSIENT ENERGY AUTOMATON AND STUDY OF ENERGY FLOWS ON LATTICE GRAPH. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/299784

Chicago Manual of Style (16^th Edition):

Li, Xin. “DESIGN OF TRANSIENT ENERGY AUTOMATON AND STUDY OF ENERGY FLOWS ON LATTICE GRAPH.” 2018. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/299784.

MLA Handbook (7^th Edition):

Li, Xin. “DESIGN OF TRANSIENT ENERGY AUTOMATON AND STUDY OF ENERGY FLOWS ON LATTICE GRAPH.” 2018. Web. 04 Mar 2021.

Vancouver:

Li X. DESIGN OF TRANSIENT ENERGY AUTOMATON AND STUDY OF ENERGY FLOWS ON LATTICE GRAPH. [Internet] [Doctoral dissertation]. University of Oklahoma; 2018. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/299784.

Council of Science Editors:

Li X. DESIGN OF TRANSIENT ENERGY AUTOMATON AND STUDY OF ENERGY FLOWS ON LATTICE GRAPH. [Doctoral Dissertation]. University of Oklahoma; 2018. Available from: http://hdl.handle.net/11244/299784

University of Oklahoma

9. Asghar, Ahmad. A New Paradigm for Proactive Self-Healing in Future Self-Organizing Mobile Cellular Networks.

Degree: PhD, 2019, University of Oklahoma

URL: http://hdl.handle.net/11244/316814

► Mobile cellular network operators spend nearly a quarter of their revenue on network management and maintenance. Remarkably, a significant proportion of that budget is spent… (more)

▼ Mobile cellular network operators spend nearly a quarter of their revenue on network management and maintenance. Remarkably, a significant proportion of that budget is spent on resolving outages that degrade or disrupt cellular services. Historically, operators have mainly relied on human expertise to identify, diagnose and resolve such outages while also compensating for them in the short-term. However, with ambitious quality of experience expectations from 5th generation and beyond mobile cellular networks spurring research towards technologies such as ultra-dense heterogeneous networks and millimeter wave spectrum utilization, discovering and compensating coverage lapses in future networks will be a major challenge. Numerous studies have explored heuristic, analytical and machine learning-based solutions to autonomously detect, diagnose and compensate cell outages in legacy mobile cellular networks, a branch of research known as self-healing. This dissertation focuses on self-healing techniques for future mobile cellular networks, with special focus on outage detection and avoidance components of self-healing. Network outages can be classified into two primary types: 1) full and 2) partial. Full outages result from failed soft or hard components of network entities while partial outages are generally a consequence of parametric misconfiguration. To this end, chapter 2 of this dissertation is dedicated to a detailed survey of research on detecting, diagnosing and compensating full outages as well as a detailed analysis of studies on proactive outage avoidance schemes and their challenges. A key observation from the analysis of the state-of-the-art outage detection techniques is their dependence on full network coverage data, susceptibility to noise or randomness in the data and inability to characterize outages in both spacial domain and temporal domain. To overcome these limitations, chapters 3 and 4 present two unique and novel outage detection techniques. Chapter 3 presents an outage detection technique based on entropy field decomposition which combines information field theory and entropy spectrum pathways theory and is robust to noise variance. Chapter 4 presents a deep learning neural network algorithm which is robust to data sparsity and compares it with entropy field decomposition and other state-of-the-art machine learning-based outage detection algorithms including support vector machines, K-means clustering, independent component analysis and deep auto-encoders. Based on the insights obtained regarding the impact of partial outages, chapter 5 presents a complete framework for 5th generation and beyond mobile cellular networks that is designed to avoid partial outages caused by parametric misconfiguration. The power of the proposed framework is demonstrated by leveraging it to design a solution that tackles one of the most common problems associated with ultra-dense heterogeneous networks, namely imbalanced load among small and macro cells, and poor resource utilization as a consequence. The… Advisors/Committee Members: Imran, Ali (advisor), Runolfsson, Thordur (committee member), Ford, Timothy (committee member), Cheng, Samuel (committee member), Chan, Kam Wai (committee member).

Subjects/Keywords: Mobile Cellular Networks; Information and Communication Technology; Artificial Intelligence; Data Analytics

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Asghar, A. (2019). A New Paradigm for Proactive Self-Healing in Future Self-Organizing Mobile Cellular Networks. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/316814

Chicago Manual of Style (16^th Edition):

Asghar, Ahmad. “A New Paradigm for Proactive Self-Healing in Future Self-Organizing Mobile Cellular Networks.” 2019. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/316814.

MLA Handbook (7^th Edition):

Asghar, Ahmad. “A New Paradigm for Proactive Self-Healing in Future Self-Organizing Mobile Cellular Networks.” 2019. Web. 04 Mar 2021.

Vancouver:

Asghar A. A New Paradigm for Proactive Self-Healing in Future Self-Organizing Mobile Cellular Networks. [Internet] [Doctoral dissertation]. University of Oklahoma; 2019. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/316814.

Council of Science Editors:

Asghar A. A New Paradigm for Proactive Self-Healing in Future Self-Organizing Mobile Cellular Networks. [Doctoral Dissertation]. University of Oklahoma; 2019. Available from: http://hdl.handle.net/11244/316814

University of Oklahoma

10. Farooq, Hasan. A PARADIGM SHIFTING APPROACH IN SON FOR FUTURE CELLULAR NETWORKS.

Degree: PhD, 2018, University of Oklahoma

URL: http://hdl.handle.net/11244/316230

► The race to next generation cellular networks is on with a general consensus in academia and industry that massive densification orchestrated by self-organizing networks (SONs)… (more)

▼ The race to next generation cellular networks is on with a general consensus in academia and industry that massive densification orchestrated by self-organizing networks (SONs) is the cost-effective solution to the impending mobile capacity crunch. While the research on SON commenced a decade ago and is still ongoing, the current form (i.e., the reactive mode of operation, conflict-prone design, limited degree of freedom and lack of intelligence) hinders the current SON paradigm from meeting the requirements of 5G. The ambitious quality of experience (QoE) requirements and the emerging multifarious vision of 5G, along with the associated scale of complexity and cost, demand a significantly different, if not totally new, approach to SONs in order to make 5G technically as well as financially feasible. This dissertation addresses these limitations of state-of-the-art SONs. It first presents a generic low-complexity optimization framework to allow for the agile, on-line, multi-objective optimization of future mobile cellular networks (MCNs) through only top-level policy input that prioritizes otherwise conflicting key performance indicators (KPIs) such as capacity, QoE, and power consumption. The hybrid, semi-analytical approach can be used for a wide range of cellular optimization scenarios with low complexity. The dissertation then presents two novel, user-mobility, prediction-based, proactive self-optimization frameworks (AURORA and OPERA) to transform mobility from a challenge into an advantage. The proposed frameworks leverage mobility to overcome the inherent reactiveness of state-of-the-art self-optimization schemes to meet the extremely low latency and high QoE expected from future cellular networks vis-à-vis 5G and beyond. The proactiveness stems from the proposed frameworks’ novel capability of utilizing past hand-over (HO) traces to determine future cell loads instead of observing changes in cell loads passively and then reacting to them. A semi-Markov renewal process is leveraged to build a model that can predict the cell of the next HO and the time of the HO for the users. A low-complexity algorithm has been developed to transform the predicted mobility attributes to a user-coordinate level resolution. The learned knowledge base is used to predict the user distribution among cells. This prediction is then used to formulate a novel (i) proactive energy saving (ES) optimization problem (AURORA) that proactively schedules cell sleep cycles and (ii) proactive load balancing (LB) optimization problem (OPERA). The proposed frameworks also incorporate the effect of cell individual offset (CIO) for balancing the load among cells, and they thus exploit an additional ultra-dense network (UDN)-specific mechanism to ensure QoE while maximizing ES and/or LB. The frameworks also incorporates capacity and coverage constraints and a load-aware association strategy for ensuring the conflict-free operation of ES, LB, and coverage and capacity optimization (CCO) SON functions. Although the resulting optimization problems are… Advisors/Committee Members: Imran, Ali (advisor), Runolfsson, Thordur (committee member), Refai, Hazem (committee member), Chan, Kam Wai Clifford (committee member), Adams, Curt (committee member).

Subjects/Keywords: Mobility Prediction; 5G; Proactive SON; Self Optimization; Self Healing

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Farooq, H. (2018). A PARADIGM SHIFTING APPROACH IN SON FOR FUTURE CELLULAR NETWORKS. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/316230

Chicago Manual of Style (16^th Edition):

Farooq, Hasan. “A PARADIGM SHIFTING APPROACH IN SON FOR FUTURE CELLULAR NETWORKS.” 2018. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/316230.

MLA Handbook (7^th Edition):

Farooq, Hasan. “A PARADIGM SHIFTING APPROACH IN SON FOR FUTURE CELLULAR NETWORKS.” 2018. Web. 04 Mar 2021.

Vancouver:

Farooq H. A PARADIGM SHIFTING APPROACH IN SON FOR FUTURE CELLULAR NETWORKS. [Internet] [Doctoral dissertation]. University of Oklahoma; 2018. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/316230.

Council of Science Editors:

Farooq H. A PARADIGM SHIFTING APPROACH IN SON FOR FUTURE CELLULAR NETWORKS. [Doctoral Dissertation]. University of Oklahoma; 2018. Available from: http://hdl.handle.net/11244/316230

University of Oklahoma

11. Petrich, Erik. Real-time 3-D Scene Reconstruction.

Degree: PhD, 2016, University of Oklahoma

URL: http://hdl.handle.net/11244/34689

► This dissertation describes a complete system that captures image data from multiple stereoscopic camera pairs and reconstructs a 3-D model of the imaged scene in… (more)

▼ This dissertation describes a complete system that captures image data from multiple stereoscopic camera pairs and reconstructs a 3-D model of the imaged scene in real-time. To achieve real-time rates, the system is organized in a distributed hierarchical fashion to maximize parallelism and uses algorithms that, in many instances, are suitable for direct implementation in digital hardware rather than software on a general purpose computer. At the lowest level of the hierarchy, image data is acquired from a single camera and processed to compensate for lens distortion and to apply rectification in preparation for stereo image processing. At the next level, data from pairs of cameras is matched to compute a dense stereoscopic disparity map from which 3-D surfaces are inferred and a mesh model is constructed. Finally, at the top level all of the individual 3-D mesh models are merged into a single 3-D model. If desired, the camera image data can be applied to the resultant 3-D model as a texture and the model re-rendered from a virtual camera viewpoint. Previous 3-D research focuses on individual steps in this process (lens distortion correction, image rectification, stereoscopic disparity computation, and model building). This dissertation considers them instead in the context of a complete end-to-end system. Traditional approaches to model building begin with an unstructured "point cloud" that is neutral with respect to how the data was acquired; this allows model building to be studied independent of data acquisition but may miss some opportunities available in a more tightly coupled interface. By taking a broader view of the problems faced by the entire system, a novel algorithm for 3-D model building has been developed that takes advantage of the organization in the dense stereoscopic disparity map to efficiently build its model. The core of this novel algorithm is a method of evaluating linear regression error to fit a series of line segments to data points in a way that can be efficiently implemented directly in hardware. Advisors/Committee Members: Sluss, James Jr (advisor), Tull, Monte (advisor), Runolfsson, Thordur (committee member), Havlicek, Joseph (committee member), Özaydin, Murad (committee member).

Subjects/Keywords: Stereoscopic Computer Vision; 3D modeling; Real-time image processing

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Petrich, E. (2016). Real-time 3-D Scene Reconstruction. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/34689

Chicago Manual of Style (16^th Edition):

Petrich, Erik. “Real-time 3-D Scene Reconstruction.” 2016. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/34689.

MLA Handbook (7^th Edition):

Petrich, Erik. “Real-time 3-D Scene Reconstruction.” 2016. Web. 04 Mar 2021.

Vancouver:

Petrich E. Real-time 3-D Scene Reconstruction. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/34689.

Council of Science Editors:

Petrich E. Real-time 3-D Scene Reconstruction. [Doctoral Dissertation]. University of Oklahoma; 2016. Available from: http://hdl.handle.net/11244/34689

University of Oklahoma

12. Mai, Anh. GAIT PERFORMANCE AND CONTROL OF A PROSTHETIC ANKLE JOINT FOR BELOW-KNEE AMPUTEES.

Degree: PhD, 2015, University of Oklahoma

URL: http://hdl.handle.net/11244/15496

► Traumatic events such as accidents or vascular and circulatory disorders often lead to amputation of the lower limb below the knee joint. The surgery is… (more)

▼ Traumatic events such as accidents or vascular and circulatory disorders often lead to amputation of the lower limb below the knee joint. The surgery is followed by fitting of a prosthetic device and rehabilitation process to help the individual recover mobility. The recovered gait of the individual depends to a large extent on his/her health, the amputation technique, and the functional level of the prosthesis. Prior research in amputee gait has focused mostly on assessing gait symmetry, movement of the healthy joints, activities of the unaffected muscles, and the metabolic energy consumption in individuals who had undergone traditional amputation. Very little research has been carried out on the performance of individuals with non-traditional amputation procedures designed to maximize the ability of the residual limb to support body weight at the extremity and to maintain the ability of the affected muscles. Moreover, majority of the studies were limited to gait tests in laboratory environments which restricted the mobility of the individuals. Current ankle/foot prostheses for people with below-knee amputation are primarily passive devices whose performance cannot be adapted or optimized to meet the requirements of different users. The adverse consequences of wearing poorly functioning prosthetic feet include asymmetric gait, increased metabolic consumption, limited blood flow, instability, and pain. Over the long term, the amputees, especially ones with diabetes, might have to undergo hip replacement procedure and use wheel-chair on a daily basis. There exists a high and increasing demand for an advanced prosthetic foot that is comfortable and able to replicate the function of the biological foot. Some of the factors hindering the development and performance validation of such an actively controlled foot are the lack of complete understanding of the gait, the interaction between the residual limb and the controller, presence of human in the control loop, unknown interaction between the terrain and the foot, and stringent requirements on the mechanical power and rigidity of the foot. This dissertation aims to address these shortcomings in a systematic fashion in order to develop an intelligent ankle/foot prosthesis system. The following are the key steps in the process adopted in this dissertation. • First, a gait monitoring device and algorithms for gait analysis will be developed to study the gait of people with below-knee amputation in real time during work-related activities. Experimental protocols are then designed to collect gait data from individuals with below-knee amputation in order to understand the activity of the residual muscles and the ability of the prosthetic device to support body weight during gait. • The dependence of the interfacial socket forces and electromyography signals from the muscles in the residual limb on the type of the gait and gait-related events will then be studied. The use of this dependence to recognize user gait and the corresponding ankle displacement pattern for the… Advisors/Committee Members: Commuri, Sesh (advisor), Zaman, Musharraf (committee member), Runolfsson, Thordur (committee member), Tang, Choon Yik (committee member), Yu, Tian-You (committee member).

Subjects/Keywords: Gait Analysis; Prosthetic Foot; Intelligent Control

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Mai, A. (2015). GAIT PERFORMANCE AND CONTROL OF A PROSTHETIC ANKLE JOINT FOR BELOW-KNEE AMPUTEES. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/15496

Chicago Manual of Style (16^th Edition):

Mai, Anh. “GAIT PERFORMANCE AND CONTROL OF A PROSTHETIC ANKLE JOINT FOR BELOW-KNEE AMPUTEES.” 2015. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/15496.

MLA Handbook (7^th Edition):

Mai, Anh. “GAIT PERFORMANCE AND CONTROL OF A PROSTHETIC ANKLE JOINT FOR BELOW-KNEE AMPUTEES.” 2015. Web. 04 Mar 2021.

Vancouver:

Mai A. GAIT PERFORMANCE AND CONTROL OF A PROSTHETIC ANKLE JOINT FOR BELOW-KNEE AMPUTEES. [Internet] [Doctoral dissertation]. University of Oklahoma; 2015. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/15496.

Council of Science Editors:

Mai A. GAIT PERFORMANCE AND CONTROL OF A PROSTHETIC ANKLE JOINT FOR BELOW-KNEE AMPUTEES. [Doctoral Dissertation]. University of Oklahoma; 2015. Available from: http://hdl.handle.net/11244/15496

University of Oklahoma

13. Yang, Mu. Distributed Computation of Graph Spectrum, Eigenvector Centrality, and Solution to Linear Equations.

Degree: PhD, 2017, University of Oklahoma

URL: http://hdl.handle.net/11244/53080

► This dissertation is devoted to the development of distributed algorithms, with which nodes in a large decentralized network can accomplish tasks that are seemingly difficult… (more)

▼ This dissertation is devoted to the development of distributed algorithms, with which nodes in a large decentralized network can accomplish tasks that are seemingly difficult without an omniscient central node. The tasks include estimating the graph spectrum, from which each node can draw its own conclusion about the network structure, computing the eigenvector centrality, from which every node can judge its own importance in the network, and solving a system of linear equations whose data are scattered across the network or discovering that no solution exists. The ability to perform these tasks enhances the capability of existing and emerging networks such as smart power grids, social networks, and ad hoc sensor networks, potentially allowing them to function in ways that are not previously thought to be possible. We begin with the design of a novel, two-stage distributed algorithm that enables nodes in an undirected and connected graph to jointly estimate the spectrum of a matrix associated with the graph, which includes the adjacency and Laplacian matrices as special cases. In the first stage, the algorithm uses a discrete-time linear iteration and the Cayley-Hamilton theorem to convert the problem into one of solving linear equations, where each equation is known to a node. In the second stage, if the nodes happen to know that said matrix is cyclic, the algorithm uses a Lyapunov approach to asymptotically solve the equations with an exponential rate of convergence. Otherwise, it uses a random perturbation approach and a structural controllability result to approximately solve the equations with an error that can be made small. We then consider the fundamental problem of cooperatively solving a general system of linear equations over a network, for which a continuous-time distributed algorithm is devised. We show that the algorithm enables the nodes to asymptotically agree on a solution when there are infinitely many solutions, determine the solution when there is exactly one, and detect that no solution exists when there are none. We also establish that the algorithm is globally exponentially convergent, derive an explicit lower bound on its convergence rate that it can do no worse than, and prove that the larger the network's algebraic connectivity, or the further away from being singular the system of equations, the larger this lower bound. Finally, we address the open question of whether it is possible to calculate eigenvector centrality over a network. We provide an affirmative answer by presenting a class of continuous-time distributed algorithms and an asynchronous gossip algorithm, which allow every node i in a graph to compute the ith entry of the Perron-Frobenius eigenvector of a symmetric, Metzler, and irreducible matrix induced by the graph, as well as the corresponding eigenvalue, when node i knows only row i of the matrix. We show that each continuous-time distributed algorithm is a nonlinear networked dynamical system with a skew-symmetric structure, whose state is guaranteed to… Advisors/Committee Members: Tang, Choon Yik (advisor), Cruz, J. R. (committee member), Lakshmivarahan, S. (committee member), Thulasiraman, Krishnaiyan (committee member), Runolfsson, Thordur (committee member).

Subjects/Keywords: Control; Distributed Algorithm; Network System; Dynamic System

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Yang, M. (2017). Distributed Computation of Graph Spectrum, Eigenvector Centrality, and Solution to Linear Equations. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/53080

Chicago Manual of Style (16^th Edition):

Yang, Mu. “Distributed Computation of Graph Spectrum, Eigenvector Centrality, and Solution to Linear Equations.” 2017. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/53080.

MLA Handbook (7^th Edition):

Yang, Mu. “Distributed Computation of Graph Spectrum, Eigenvector Centrality, and Solution to Linear Equations.” 2017. Web. 04 Mar 2021.

Vancouver:

Yang M. Distributed Computation of Graph Spectrum, Eigenvector Centrality, and Solution to Linear Equations. [Internet] [Doctoral dissertation]. University of Oklahoma; 2017. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/53080.

Council of Science Editors:

Yang M. Distributed Computation of Graph Spectrum, Eigenvector Centrality, and Solution to Linear Equations. [Doctoral Dissertation]. University of Oklahoma; 2017. Available from: http://hdl.handle.net/11244/53080

University of Oklahoma

14. Tajik, Elham. MODELING AND CONTROL OF MICROGRID COMPONENTS.

Degree: PhD, 2018, University of Oklahoma

URL: http://hdl.handle.net/11244/316764

► Due to the increase in the integration of renewable energy resources into electrical power systems, there are various challenges that modern power systems are facing.… (more)

▼ Due to the increase in the integration of renewable energy resources into electrical power systems, there are various challenges that modern power systems are facing. A lot of issues in this subject are discussed under the concept of microgrid and their operational and control concerns. Power electronic interfaces (converters, inverters) are necessary for connecting generation units based on renewable energy resources to the power grid. Consequently, inverter control is a primary issue in operating microgrids. Fast dynamics of power electronic interfaces results in different operating concerns and strategies for inverter-based generation units as compared to large conventional synchronous generators. To provide simplicity in operating inverter-based generation units, there are various control strategies based on emulating the critical properties of a conventional synchronous generator such as inertia and damping. This dissertation designs a novel operational and control model for controlled power electronic loads and inverter-based generators inspired by synchronous generators' equations and stated in port-Hamiltonian systems' formulation. This inverter generator controller is added to the inverter switching controller to enable the generator to behave in a manner similar to a synchronous generator. We develop a control methodology based on Interconnection and Damping Assignment Passivity Based Control (IDA-PBC) strategy for the proposed inverter-based generator dynamics. We prove the stability of the designed closed loop system and develop a simulation model for the projected control strategy that includes an example system consisting of a constant impedance load, a π-modeled line and an inverter-based generator. We also develop a generic port-Hamiltonian model for loads that allows through the appropriate selection of structure and controls the mimicking of the behavior of complex loads that are connected to the grid through controlled power electronic interfaces. Advisors/Committee Members: Runolfsson, Thordur (advisor), Petrov, Nikola (committee member), Tang, Choon Yik (committee member), Jiang, John (committee member), Moses, Paul (committee member).

Subjects/Keywords: Power Systems; Microgrid; Port-Hamiltonian systems; Constant Power Loads; Virtual Machine; Engineering, Electronics and Electrical.

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Tajik, E. (2018). MODELING AND CONTROL OF MICROGRID COMPONENTS. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/316764

Chicago Manual of Style (16^th Edition):

Tajik, Elham. “MODELING AND CONTROL OF MICROGRID COMPONENTS.” 2018. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/316764.

MLA Handbook (7^th Edition):

Tajik, Elham. “MODELING AND CONTROL OF MICROGRID COMPONENTS.” 2018. Web. 04 Mar 2021.

Vancouver:

Tajik E. MODELING AND CONTROL OF MICROGRID COMPONENTS. [Internet] [Doctoral dissertation]. University of Oklahoma; 2018. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/316764.

Council of Science Editors:

Tajik E. MODELING AND CONTROL OF MICROGRID COMPONENTS. [Doctoral Dissertation]. University of Oklahoma; 2018. Available from: http://hdl.handle.net/11244/316764

University of Oklahoma

15. Mayeli, Ahmad. Advancing Multimodal Approaches to Study Human Brain: Improvements in Simultaneous EEG-fMRI Acquisition.

Degree: PhD, 2019, University of Oklahoma

URL: http://hdl.handle.net/11244/323236

► The primary aim of the study detailed in this dissertation was improving the quality of simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) experiments.… (more)

▼ The primary aim of the study detailed in this dissertation was improving the quality of simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) experiments. Two common challenges to use concurrent EEG-fMRI tests are addressed herein. The first is the presence of EEG artifacts during simultaneous EEG-fMRI, which require more consideration than EEG data recorded outside the scanner. To mitigate this issue, a fully automated artifact correction pipeline was developed. In the proposed pipeline, magnetic resonance (MR) environmental (i.e., gradient and ballistocardiogram [BCG]) artifacts were reduced using optimal basis sets (OBS) and average artifact subtraction (AAS). Subsequently, independent component analysis (ICA) was leveraged for reducing physiological artifacts (e.g., eye blinks, saccade and muscle artifacts), in addition to residual BCG artifacts. To validate pipeline performance, both resting-state (time/frequency and frequency analysis) and task-based (event related potential [ERP]) EEG data from eight healthy participants were tested. This data was compared with the time/frequency and frequency results achieved by matching meticulously, manually corrected EEG data to the automatically corrected EEG data. No significant difference was found between results. A comparison between ERP results (e.g., amplitude measures and SNR) also showed no differences between manually corrected and fully automated EEG corrected data. The second challenge addressed in this work is the low experimental control over the subject's actual behavior during the eyes-open resting-state fMRI (rsfMRI). This technique has been widely used for studying the (presumably) awake and alert human brain using multimodal EEG-fMRI; however, objective and verified experimental measures to quantify the degree of alertness (e.g., vigilance) are not readily available. To this end, the study reported in this dissertation investigated whether simultaneous multimodal EEG, rsfMRI and eye-tracker experiments could be used to extract objective and robust biomarkers of vigilance in healthy human subjects (n = 10) during cross fixation. Frontal and occipital beta power (FOBP) were found to correlate (r = 0.306, p<0.001) with pupil size fluctuation, which is an indirect index for locus coeruleus activity implicated in vigilance regulation. Moreover, FOBP was also correlated with heart rate (r = 0.255, p<0.001) and several brain regions in an anti-correlated network, including the bilateral insula and inferior parietal lobule. Results support the conclusion that FOBP is an objective and robust biomarker of vigilance in healthy human subjects. Advisors/Committee Members: Refai, Hazem (advisor), Bodurka, Jerzy (advisor), Sluss, James J (committee member), Runolfsson, Thordur (committee member), Lake, Vickie (committee member).

Subjects/Keywords: Engineering, Electronics and Electrical.; Engineering, Biomedical.; Biology, Neuroscience.

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Mayeli, A. (2019). Advancing Multimodal Approaches to Study Human Brain: Improvements in Simultaneous EEG-fMRI Acquisition. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/323236

Chicago Manual of Style (16^th Edition):

Mayeli, Ahmad. “Advancing Multimodal Approaches to Study Human Brain: Improvements in Simultaneous EEG-fMRI Acquisition.” 2019. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/323236.

MLA Handbook (7^th Edition):

Mayeli, Ahmad. “Advancing Multimodal Approaches to Study Human Brain: Improvements in Simultaneous EEG-fMRI Acquisition.” 2019. Web. 04 Mar 2021.

Vancouver:

Mayeli A. Advancing Multimodal Approaches to Study Human Brain: Improvements in Simultaneous EEG-fMRI Acquisition. [Internet] [Doctoral dissertation]. University of Oklahoma; 2019. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/323236.

Council of Science Editors:

Mayeli A. Advancing Multimodal Approaches to Study Human Brain: Improvements in Simultaneous EEG-fMRI Acquisition. [Doctoral Dissertation]. University of Oklahoma; 2019. Available from: http://hdl.handle.net/11244/323236

University of Oklahoma

16. Soltani, Hoda. Development of Soil-Pile Interaction Models in Improved Soils Using Centrifuge Test Data and System Identification Methods.

Degree: PhD, 2016, University of Oklahoma

URL: http://hdl.handle.net/11244/34641

► Documented distresses in pile foundations in soft soils during past earthquakes have shown that piles founded in soft soils undergo large lateral deformations during seismic… (more)

▼ Documented distresses in pile foundations in soft soils during past earthquakes have shown that piles founded in soft soils undergo large lateral deformations during seismic loading. Improving the soil surrounding the piles is an effective strategy to improve the behavior of pile foundations in soft soils. Many fundamental mechanisms determining the interaction between the improved soil and piles have, however, not been fully understood. This has led to limited applications of soil improvement around piles in seismic regions and excessive conservatism in designs. This dissertation assessed the static and seismic responses of single piles in improved and unimproved soft clays using data from a series of centrifuge tests. The centrifuge model contained a number of single piles embedded in a soft clay layer overlying a dense sand layer. The soft clay near the ground surface surrounding some of the piles was improved to various dimensions with cement. Experimental results were used to extract the p-y curves for both the improved and unimproved soils and these curves were compared with the curves currently used in practice. A new feature was added to the traditional bending moment curve fitting methods accounting for the discontinuities in the distributions of shear force and soil reaction along the piles at the interface between the improved and unimproved soil. The p-y curves currently used in practice were found to be accurate for cases with medium and large improved zones. Although the theory assumes that the p-y curve at a given depth is entirely controlled by soil at that depth, influence of adjacent soil layers were observed on the experimentally derived p-y curves. System identification methods were employed to extract the natural frequencies, damping ratios, and mode shapes of the unimproved soil system. The identified parameters were validated against those estimated from analytical methods and employed to synthesize prediction models which were subsequently used to simulate the soil response for three successive base motions. The identified models captured acceleration time-histories reasonably well in the small and moderate shaking events. The influence of the improved zone size was reflected on the identified natural frequencies of the soil-pile-top mass systems. Seismic interactions between the soil and pile were simulated by adapting a hysteretic model that integrated phenomena such as soil-pile separation, material degradation, and radiation damping. The developed interaction elements calibrated for one shaking event were deployed to predict the soil reactions in another shaking event. The predicted soil reactions compared reasonably well with those obtained from the measured results. Advisors/Committee Members: Muraleetharan, Kanthasamy (advisor), Runolfsson, Thordur (committee member), Miller, Gerald (committee member), Cerato, Amy (committee member), Sivalingam, Sritharan (committee member).

Subjects/Keywords: Pile Foundations; Soil Improvement; Modal Analysis; Hysteresis; Lateral Loads

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Soltani, H. (2016). Development of Soil-Pile Interaction Models in Improved Soils Using Centrifuge Test Data and System Identification Methods. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/34641

Chicago Manual of Style (16^th Edition):

Soltani, Hoda. “Development of Soil-Pile Interaction Models in Improved Soils Using Centrifuge Test Data and System Identification Methods.” 2016. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/34641.

MLA Handbook (7^th Edition):

Soltani, Hoda. “Development of Soil-Pile Interaction Models in Improved Soils Using Centrifuge Test Data and System Identification Methods.” 2016. Web. 04 Mar 2021.

Vancouver:

Soltani H. Development of Soil-Pile Interaction Models in Improved Soils Using Centrifuge Test Data and System Identification Methods. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/34641.

Council of Science Editors:

Soltani H. Development of Soil-Pile Interaction Models in Improved Soils Using Centrifuge Test Data and System Identification Methods. [Doctoral Dissertation]. University of Oklahoma; 2016. Available from: http://hdl.handle.net/11244/34641

University of Oklahoma

17. Kaadan, Asaad. Modular Optical Wireless Elements.

Degree: PhD, 2016, University of Oklahoma

URL: http://hdl.handle.net/11244/47111

► Optical wireless has gained attention in recent years as an e cient and secure way to provide broadband connectivity to mobile platforms, isolated communities, and… (more)

Subjects/Keywords: Engineering; Electronics and Electrical. Optical wireless. Optical arrays.

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Kaadan, A. (2016). Modular Optical Wireless Elements. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/47111

Chicago Manual of Style (16^th Edition):

Kaadan, Asaad. “Modular Optical Wireless Elements.” 2016. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/47111.

MLA Handbook (7^th Edition):

Kaadan, Asaad. “Modular Optical Wireless Elements.” 2016. Web. 04 Mar 2021.

Vancouver:

Kaadan A. Modular Optical Wireless Elements. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/47111.

Council of Science Editors:

Kaadan A. Modular Optical Wireless Elements. [Doctoral Dissertation]. University of Oklahoma; 2016. Available from: http://hdl.handle.net/11244/47111

University of Oklahoma

18. Hashmi, Umair Sajid. NOVEL USER-CENTRIC ARCHITECTURES FOR FUTURE GENERATION CELLULAR NETWORKS: DESIGN, ANALYSIS AND PERFORMANCE OPTIMIZATION.

Degree: PhD, 2019, University of Oklahoma

URL: http://hdl.handle.net/11244/321126

► Ambitious targets for aggregate throughput, energy efficiency (EE) and ubiquitous user experience are propelling the advent of ultra-dense networks. Inter-cell interference and high energy consumption… (more)

▼ Ambitious targets for aggregate throughput, energy efficiency (EE) and ubiquitous user experience are propelling the advent of ultra-dense networks. Inter-cell interference and high energy consumption in an ultra-dense network are the prime hindering factors in pursuit of these goals. To address this challenge, we investigate the idea of transforming network design from being base station-centric to user-centric. To this end, we develop mathematical framework and analyze multiple variants of the user-centric networks, with the help of advanced scientific tools such as stochastic geometry, game theory, optimization theory and deep neural networks. We first present a user-centric radio access network (RAN) design and then propose novel base station association mechanisms by forming virtual dedicated cells around users scheduled for downlink. The design question that arises is what should the ideal size of the dedicated regions around scheduled users be? To answer this question, we follow a stochastic geometry based approach to quantify the area spectral efficiency (ASE) and energy efficiency (EE) of a user-centric Cloud RAN architecture. Observing that the two efficiency metrics have conflicting optimal user-centric cell sizes, we propose a game theoretic self-organizing network (GT-SON) framework that can orchestrate the network between ASE and EE focused operational modes in real-time in response to changes in network conditions and the operator's revenue model, to achieve a Pareto optimal solution. The designed model is shown to outperform base-station centric design in terms of both ASE and EE in dense deployment scenarios. Taking this user-centric approach as a baseline, we improve the ASE and EE performance by introducing flexibility in the dimensions of the user-centric regions as a function of data requirement for each device. So instead of optimizing the network-wide ASE or EE, each user device competes for a user-centric region based on its data requirements. This competition is modeled via an evolutionary game and a Vickrey-Clarke-Groves auction. The data requirement based flexibility in the user-centric RAN architecture not only improves the ASE and EE, but also reduces the scheduling wait time per user. Offloading dense user hotspots to low range mmWave cells promises to meet the enhance mobile broadband requirement of 5G and beyond. To investigate how the three key enablers; i.e. user-centric virtual cell design, ultra-dense deployments and mmWave communication; are integrated in a multi-tier Stienen geometry based user-centric architecture. Taking into account the characteristics of mmWave propagation channel such as blockage and fading, we develop a statistical framework for deriving the coverage probability of an arbitrary user equipment scheduled within the proposed architecture. A key advantage observed through this architecture is significant reduction in the scheduling latency as compared to the baseline user-centric model. Furthermore, the interplay between certain system design parameters… Advisors/Committee Members: Imran, Ali (advisor), Imran, Ali (committee member), Runolfsson, Thordur (committee member), Refai, Hazem (committee member), Chan, Kam Wai Clifford (committee member), Adams, Curt (committee member).

Subjects/Keywords: Artificial Intelligence.; Telecommunications; Electrical and Computer Engineering

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Hashmi, U. S. (2019). NOVEL USER-CENTRIC ARCHITECTURES FOR FUTURE GENERATION CELLULAR NETWORKS: DESIGN, ANALYSIS AND PERFORMANCE OPTIMIZATION. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/321126

Chicago Manual of Style (16^th Edition):

Hashmi, Umair Sajid. “NOVEL USER-CENTRIC ARCHITECTURES FOR FUTURE GENERATION CELLULAR NETWORKS: DESIGN, ANALYSIS AND PERFORMANCE OPTIMIZATION.” 2019. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/321126.

MLA Handbook (7^th Edition):

Hashmi, Umair Sajid. “NOVEL USER-CENTRIC ARCHITECTURES FOR FUTURE GENERATION CELLULAR NETWORKS: DESIGN, ANALYSIS AND PERFORMANCE OPTIMIZATION.” 2019. Web. 04 Mar 2021.

Vancouver:

Hashmi US. NOVEL USER-CENTRIC ARCHITECTURES FOR FUTURE GENERATION CELLULAR NETWORKS: DESIGN, ANALYSIS AND PERFORMANCE OPTIMIZATION. [Internet] [Doctoral dissertation]. University of Oklahoma; 2019. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/321126.

Council of Science Editors:

Hashmi US. NOVEL USER-CENTRIC ARCHITECTURES FOR FUTURE GENERATION CELLULAR NETWORKS: DESIGN, ANALYSIS AND PERFORMANCE OPTIMIZATION. [Doctoral Dissertation]. University of Oklahoma; 2019. Available from: http://hdl.handle.net/11244/321126

University of Oklahoma

19. Hosseini, Seyed Hossein. REVEALING ADDITIONAL INFORMATION ABOUT ELECTRICITY MARKET UNDERLYING POWER SYSTEM USING POWER SYSTEM PRINCIPLES AND PUBLISHED MARKET RESULTS.

Degree: PhD, 2014, University of Oklahoma

URL: http://hdl.handle.net/11244/13388

► In this dissertation we provide a novel estimation framework designed and structured on duality theory for estimation of some key parameters in electricity markets. Specifically,… (more)

Subjects/Keywords: Engineering; Electronics and Electrical.

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Hosseini, S. H. (2014). REVEALING ADDITIONAL INFORMATION ABOUT ELECTRICITY MARKET UNDERLYING POWER SYSTEM USING POWER SYSTEM PRINCIPLES AND PUBLISHED MARKET RESULTS. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/13388

Chicago Manual of Style (16^th Edition):

Hosseini, Seyed Hossein. “REVEALING ADDITIONAL INFORMATION ABOUT ELECTRICITY MARKET UNDERLYING POWER SYSTEM USING POWER SYSTEM PRINCIPLES AND PUBLISHED MARKET RESULTS.” 2014. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/13388.

MLA Handbook (7^th Edition):

Hosseini, Seyed Hossein. “REVEALING ADDITIONAL INFORMATION ABOUT ELECTRICITY MARKET UNDERLYING POWER SYSTEM USING POWER SYSTEM PRINCIPLES AND PUBLISHED MARKET RESULTS.” 2014. Web. 04 Mar 2021.

Vancouver:

Hosseini SH. REVEALING ADDITIONAL INFORMATION ABOUT ELECTRICITY MARKET UNDERLYING POWER SYSTEM USING POWER SYSTEM PRINCIPLES AND PUBLISHED MARKET RESULTS. [Internet] [Doctoral dissertation]. University of Oklahoma; 2014. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/13388.

Council of Science Editors:

Hosseini SH. REVEALING ADDITIONAL INFORMATION ABOUT ELECTRICITY MARKET UNDERLYING POWER SYSTEM USING POWER SYSTEM PRINCIPLES AND PUBLISHED MARKET RESULTS. [Doctoral Dissertation]. University of Oklahoma; 2014. Available from: http://hdl.handle.net/11244/13388

University of Oklahoma

20. Al Zoubi, Obada. The Use of EEG-fMRI Features for Characterizing Mental Disorders.

Degree: PhD, 2019, University of Oklahoma

URL: http://hdl.handle.net/11244/321134

► Determining clinically relevant biomarkers of mental disorders for reliably indicating pathophysiological processes or predicting therapeutic responses remains a major challenge, despite decades of research. Identifying… (more)

▼ Determining clinically relevant biomarkers of mental disorders for reliably indicating pathophysiological processes or predicting therapeutic responses remains a major challenge, despite decades of research. Identifying such biomarkers can help patients significantly improve their quality of life and alleviate their suffering. Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) are non-invasive tools to investigate neurobiological mechanisms underlying mental disorders. Extracting and leveraging informative features from the high temporal resolution EEG and high spatial resolution fMRI may offer a more comprehensive understanding of brain spatial and temporal activities in health and disease. More importantly, this information can lead to a better understanding of the neurobiology of mental illness. This dissertation investigates the analyses and applications of extracting and combining informative features from EEG and fMRI, along with applying machine learning (ML) and computational methods for building biomarkers of mental illnesses. Several methodological challenges in the extraction of informative and reproducible features are also addressed. First, two types of EEG features obtained from resting state EEG-fMRI measurements were extracted: 1) broadband-multichannel EEG dynamical features, called EEG microstates (EEG-ms); and 2) heterogeneous, static EEG features. Using EEG features only, results elucidate that: 1) EEG-ms characteristics and information theoretical properties can successfully differentiate individuals with mood and anxiety disorders from healthy comparison subjects with potential applications for other clinical groups; and 2) heterogeneous static EEG features can successfully predict “brain aging,” noted here as BrainAGE from 468 EEG datasets, achieving a correlation of r=0.61 between predicted age and chronological age. Next, extracted EEG features were leveraged with fMRI to enhance the predictivity of BrainAGE and localizing the associated EEG-ms brain regions. More specifically, static EEG features were combined with resting state fMRI features to construct a multimodal BrainAGE predictor as a case study. Notably, it was found that EEG and fMRI contain a large portion of shared information about age, although each modality has its fingerprint of the aging process. The developed approach is a general purpose and be applied to predict other outcomes from brain imaging data. Similarly, EEG-ms features were integrated with fMRI to localize associated brain regions within fMRI space, revealing functional brain connectivity changes in individuals with mood and anxiety disorders as a case study. As a result, harnessing combined EEG-fMRI methods have enriched our knowledge some mental disorders and broadened our understanding of them with potential applications for other clinical groups and outcomes. Finally, this work evaluated the reproducibility and replication of EEG-ms analysis to address technical issues that have thus far been overlooked in the literature. In… Advisors/Committee Members: Refai, Hazem (advisor), Bodurka, Jerzy (advisor), Runolfsson, Thordur (committee member), Sluss, James (committee member), Cheng, Samuel (committee member), Feinstein, Justin (committee member), Adams, Curt (committee member).

Subjects/Keywords: Engineering; Biomedical.

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Al Zoubi, O. (2019). The Use of EEG-fMRI Features for Characterizing Mental Disorders. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/321134

Chicago Manual of Style (16^th Edition):

Al Zoubi, Obada. “The Use of EEG-fMRI Features for Characterizing Mental Disorders.” 2019. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/321134.

MLA Handbook (7^th Edition):

Al Zoubi, Obada. “The Use of EEG-fMRI Features for Characterizing Mental Disorders.” 2019. Web. 04 Mar 2021.

Vancouver:

Al Zoubi O. The Use of EEG-fMRI Features for Characterizing Mental Disorders. [Internet] [Doctoral dissertation]. University of Oklahoma; 2019. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/321134.

Council of Science Editors:

Al Zoubi O. The Use of EEG-fMRI Features for Characterizing Mental Disorders. [Doctoral Dissertation]. University of Oklahoma; 2019. Available from: http://hdl.handle.net/11244/321134

University of Oklahoma

21. Imran, Syed. MODELING AND ANALYSIS OF THE INTERACTION BETWEEN ROLLER DRUM AND PAVEMENT MATERIAL DURING COMPACTION.

Degree: PhD, 2016, University of Oklahoma

URL: http://hdl.handle.net/11244/34624

► The problem of ensuring real time control of compaction quality during pavement construction is considered in this dissertation. Asphalt pavements are complex, multilayer, heterogeneous structures… (more)

▼ The problem of ensuring real time control of compaction quality during pavement construction is considered in this dissertation. Asphalt pavements are complex, multilayer, heterogeneous structures where different layers of asphalt mixes are often placed on top of and supported by a base subgrade layer. In order to ensure long term performance of these pavements, it is imperative to ensure proper quality in both the subgrade and the asphalt layer during their construction. Compaction is one of the important steps in pavement construction that significantly affects the quality and long term performance of the pavement. Proper and uniform compaction of the subgrade and asphalt layers during construction is necessary for the pavement to support the expected traffic load over its lifetime. Inadequate compaction of asphalt layers could result in a pavement with insufficient stiffness leading to problems such as reduced fatigue life, accelerated aging/decreased durability, rutting, raveling, and moisture damage. The underlying subgrade also needs sufficient compaction to ensure adequate load bearing capacity of the pavement and reduce its susceptibility to moisture and other weather-related distresses. Although the impact of compaction on the performance and longevity of pavements is well understood, addressing compaction issues during construction is not easy given the limitations in the available quality control tools. The traditional QC methods rely on in situ measurement devices that provide an estimate of compaction quality at discrete test locations and generally cover less than 1% of the entire pavement area. Therefore, it is not possible to address under-compaction in areas other than those identified at the test locations. Besides, the tests are time consuming, expensive, and often destructive in nature. In order to overcome these limitations, ‘Intelligent Compaction (IC)’ methods have been proposed to provide 100% coverage of the pavement surface during compaction. These methods analyze the vibrations of roller drum and provide an estimate of the stiffness of the compacted pavement material. Further, these systems have integrated Global Position Sensors (GPS) and computational devices that record the spatial location of the roller and the stiffness values continuously during compaction. One major limitation in the available IC technologies is that they provide the estimation of pavement quality in terms of vendor specific values and do not provide estimates in terms of any of the parameters used in the design of the pavement. The relationship between these measurement values and accepted measures such as modulus or pavement density is also not well established. Limitations in the understanding on the coupled dynamics between a vibratory roller and lack of mathematical framework hamper the research and validation of the IC technologies. In this dissertation, the limitations of the IC technologies in quality control of asphalt compaction are addressed through the development of a mathematical model to study… Advisors/Committee Members: Commuri, Sesh (advisor), Zaman, Musharraf (committee member), Beainy, Fares (committee member), Runolfsson, Thordur (committee member), Sluss, James (committee member), Tang, Choon Yik (committee member).

Subjects/Keywords: Pavement Engineering; Signal Processing; Mathematical Modeling

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Imran, S. (2016). MODELING AND ANALYSIS OF THE INTERACTION BETWEEN ROLLER DRUM AND PAVEMENT MATERIAL DURING COMPACTION. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/34624

Chicago Manual of Style (16^th Edition):

Imran, Syed. “MODELING AND ANALYSIS OF THE INTERACTION BETWEEN ROLLER DRUM AND PAVEMENT MATERIAL DURING COMPACTION.” 2016. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/34624.

MLA Handbook (7^th Edition):

Imran, Syed. “MODELING AND ANALYSIS OF THE INTERACTION BETWEEN ROLLER DRUM AND PAVEMENT MATERIAL DURING COMPACTION.” 2016. Web. 04 Mar 2021.

Vancouver:

Imran S. MODELING AND ANALYSIS OF THE INTERACTION BETWEEN ROLLER DRUM AND PAVEMENT MATERIAL DURING COMPACTION. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/34624.

Council of Science Editors:

Imran S. MODELING AND ANALYSIS OF THE INTERACTION BETWEEN ROLLER DRUM AND PAVEMENT MATERIAL DURING COMPACTION. [Doctoral Dissertation]. University of Oklahoma; 2016. Available from: http://hdl.handle.net/11244/34624

University of Oklahoma

22. XUE, YUZHEN. IDENTIFICATION AND ESTIMATION OF MULTI-MODAL COMPLEX DYNAMIC SYSTEM.

Degree: PhD, 2009, University of Oklahoma

URL: http://hdl.handle.net/11244/319254

► In this dissertation we study identification of complex dynamic systems as well as hybrid system estimation. For the identification part, we propose a scheme to… (more)

▼ In this dissertation we study identification of complex dynamic systems as well as hybrid system estimation. For the identification part, we propose a scheme to identify an autonomous complex stochastic dynamic system based on a black-box model, that is, the system is modeled based on output data only. The system under study is a system whose underlying space is the union of strong attraction domains. The system exhibits a behavior such that it spends a long time in one strong attraction domain before transitioning to another one. Systems showing this behavior can be found in many applications ranging from biology to power systems to chemical processes. Considering the nature of this type of a system, we model it as a hybrid system. In particular, it is a strong attraction domain featured hybrid system (SAFHS). Two principal features of this type of a hybrid system are that the boundaries between the modes (strong attraction domains) are nonlinear and the dynamic behavior within each mode can be highly nonlinear, e.g. limit cycle. Identification algorithms for this kind of hybrid system are not well developed. In this dissertation we propose our first result for identification of this type of system. The resulting model is hybrid in nature. We detect the multi-modal dynamics as well as local dynamics within each mode, thus providing a complete unified approach of identification of the system dynamics. The approach developed in this dissertation is based on finite dimensional approximations of compact operators, spectral theory for non-reversible Markov chains, identification techniques for hidden Markov models (HMM), and identification techniques for linear and non-linear dynamics. Examples are carried out to verify our analysis and to illustrate the effectiveness of the proposed algorithms. In the estimation part, we present a high accuracy, low computational load method for a nonlinear/non-Gaussian hybrid system, motivated by the need to get a better trade-off between efficiency and accuracy which is a crucial issue in real time estimation problems. The efficiency and accuracy of the proposed algorithm are illustrated by examples. Moreover, its good performance makes it practical and robust for tracking a target in a complex situation, as we demonstrate by a simulated maneuvering target tracking example. Advisors/Committee Members: Runolfsson, Thordur (advisor).

Subjects/Keywords: System identification; Control theory; Hybrid systems

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

XUE, Y. (2009). IDENTIFICATION AND ESTIMATION OF MULTI-MODAL COMPLEX DYNAMIC SYSTEM. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/319254

Chicago Manual of Style (16^th Edition):

XUE, YUZHEN. “IDENTIFICATION AND ESTIMATION OF MULTI-MODAL COMPLEX DYNAMIC SYSTEM.” 2009. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/319254.

MLA Handbook (7^th Edition):

XUE, YUZHEN. “IDENTIFICATION AND ESTIMATION OF MULTI-MODAL COMPLEX DYNAMIC SYSTEM.” 2009. Web. 04 Mar 2021.

Vancouver:

XUE Y. IDENTIFICATION AND ESTIMATION OF MULTI-MODAL COMPLEX DYNAMIC SYSTEM. [Internet] [Doctoral dissertation]. University of Oklahoma; 2009. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/319254.

Council of Science Editors:

XUE Y. IDENTIFICATION AND ESTIMATION OF MULTI-MODAL COMPLEX DYNAMIC SYSTEM. [Doctoral Dissertation]. University of Oklahoma; 2009. Available from: http://hdl.handle.net/11244/319254

University of Oklahoma

23. Ma, Yong. MULTI-MODAL BEHAVIOR AND CLUSTERING IN DYNAMICAL SYSTEM WITH APPLICATIONS TO WIND FARMS.

Degree: PhD, 2009, University of Oklahoma

URL: http://hdl.handle.net/11244/318885

► The dissertation then presents a novel methodology for clustering wind turbines of a wind farm into different groups. The method includes creation of a Markov… (more)

Subjects/Keywords: Hybrid systems; Wind power plants; Markov processes

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Ma, Y. (2009). MULTI-MODAL BEHAVIOR AND CLUSTERING IN DYNAMICAL SYSTEM WITH APPLICATIONS TO WIND FARMS. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/318885

Chicago Manual of Style (16^th Edition):

Ma, Yong. “MULTI-MODAL BEHAVIOR AND CLUSTERING IN DYNAMICAL SYSTEM WITH APPLICATIONS TO WIND FARMS.” 2009. Doctoral Dissertation, University of Oklahoma. Accessed March 04, 2021. http://hdl.handle.net/11244/318885.

MLA Handbook (7^th Edition):

Ma, Yong. “MULTI-MODAL BEHAVIOR AND CLUSTERING IN DYNAMICAL SYSTEM WITH APPLICATIONS TO WIND FARMS.” 2009. Web. 04 Mar 2021.

Vancouver:

Ma Y. MULTI-MODAL BEHAVIOR AND CLUSTERING IN DYNAMICAL SYSTEM WITH APPLICATIONS TO WIND FARMS. [Internet] [Doctoral dissertation]. University of Oklahoma; 2009. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/11244/318885.

Council of Science Editors:

Ma Y. MULTI-MODAL BEHAVIOR AND CLUSTERING IN DYNAMICAL SYSTEM WITH APPLICATIONS TO WIND FARMS. [Doctoral Dissertation]. University of Oklahoma; 2009. Available from: http://hdl.handle.net/11244/318885

		in
And / Or
		in
And / Or
		in
And / Or
		in

Open Access Theses and Dissertations