+publisher:"Colorado State University" +contributor:("Yang, Liuqing")

Colorado State University

1. Panwar, Mayank. Reliability quantification and visualization for electric microgrids.

Degree: MS(M.S.), Electrical and Computer Engineering, 2012, Colorado State University

► The electric grid in the United States is undergoing modernization from the state of an aging infrastructure of the past to a more robust and… (more)

▼ The electric grid in the United States is undergoing modernization from the state of an aging infrastructure of the past to a more robust and reliable power system of the future. The primary efforts in this direction have come from the federal government through the American Recovery and Reinvestment Act of 2009 (Recovery Act). This has provided the U.S. Department of Energy (DOE) with 4.5 billion to develop and implement programs through DOE's Office of Electricity Delivery and Energy Reliability (OE) over the a period of 5 years (2008-2012). This was initially a part of Title XIII of the Energy Independence and Security Act of 2007 (EISA) which was later modified by Recovery Act. As a part of DOE's Smart Grid Programs, Smart Grid Investment Grants (SGIG), and Smart Grid Demonstration Projects (SGDP) were developed as two of the largest programs with federal grants of 3.4 billion and 600 million respectively. The Renewable and Distributed Systems Integration (RDSI) demonstration projects were launched in 2008 with the aim of reducing peak electricity demand by 15 percent at distribution feeders. Nine such projects were competitively selected located around the nation. The City of Fort Collins in co-operative partnership with other federal and commercial entities was identified to research, develop and demonstrate a 3.5MW integrated mix of heterogeneous distributed energy resources (DER) to reduce peak load on two feeders by 20-30 percent. This project was called FortZED RDSI and provided an opportunity to demonstrate integrated operation of group of assets including demand response (DR), as a single controllable entity which is often called a microgrid. As per IEEE Standard 1547.4-2011 (IEEE Guide for Design, Operation, and Integration of Distributed Resource Island Systems with Electric Power Systems), a microgrid can be defined as an electric power system which has following characteristics: (1) DR and load are present, (2) has the ability to disconnect from and parallel with the area Electric Power Systems (EPS), (3) includes the local EPS and may include portions of the area EPS, and (4) is intentionally planned. A more reliable electric power grid requires microgrids to operate in tandem with the EPS. The reliability can be quantified through various metrics for performance measure. This is done through North American Electric Reliability Corporation (NERC) metrics in North America. The microgrid differs significantly from the traditional EPS, especially at asset level due to heterogeneity in assets. Thus, the performance cannot be quantified by the same metrics as used for EPS. Some of the NERC metrics are calculated and interpreted in this work to quantify performance for a single asset and group of assets in a microgrid. Two more metrics are introduced for system level performance quantification. The next step is a better representation of the large amount of data generated by the microgrid. Visualization is one such form of representation which is explored in detail and a graphical user interface (GUI)… Advisors/Committee Members: Suryanarayanan, Siddharth (advisor), Zimmerle, Daniel (committee member), Yang, Liuqing (committee member).

Subjects/Keywords: data analysis; electric power system; microgrid; reliability; smartgrid; visualization

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APA (6^th Edition):

Panwar, M. (2012). Reliability quantification and visualization for electric microgrids. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/74541

Chicago Manual of Style (16^th Edition):

Panwar, Mayank. “Reliability quantification and visualization for electric microgrids.” 2012. Masters Thesis, Colorado State University. Accessed March 09, 2021. http://hdl.handle.net/10217/74541.

MLA Handbook (7^th Edition):

Panwar, Mayank. “Reliability quantification and visualization for electric microgrids.” 2012. Web. 09 Mar 2021.

Vancouver:

Panwar M. Reliability quantification and visualization for electric microgrids. [Internet] [Masters thesis]. Colorado State University; 2012. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/10217/74541.

Council of Science Editors:

Panwar M. Reliability quantification and visualization for electric microgrids. [Masters Thesis]. Colorado State University; 2012. Available from: http://hdl.handle.net/10217/74541

Colorado State University

2. Yu, Bo. Spectrum efficiency for future wireless communications.

Degree: PhD, Electrical and Computer Engineering, 2015, Colorado State University

URL: http://hdl.handle.net/10217/166861

► Spectrum efficiency has long been at the center of wireless communication research, development, and operation. Today, it is even more so with the explosive popularity… (more)

▼ Spectrum efficiency has long been at the center of wireless communication research, development, and operation. Today, it is even more so with the explosive popularity of mobile internet, social networks, and smart phones that are more powerful than our desktops not long ago. As a result, there is an urgent need to further improve the spectrum efficiency in order to provide higher wireless data capacity. To respond to this demand, the 3rd Generation Partnership Project (3GPP) standardized the radio interface specifications for the next generation mobile communications system, called Long Term Evolution (LTE), in Release 8 specifications in 2008. Then the development continued and an enhanced LTE radio interface called LTE-Advanced (LTE-A) was standardized in Release 10 specifications in 2011. In order to ensure the sustainability of 3GPP radio access technologies over the coming decade, 3GPP standardization will need to continue identifying and providing new solutions that can respond to the future challenges. In this research, we investigate the potential technologies for further spectrum efficiency enhancement in the future steps of the standardization. One key direction is the further enhancement of local area technologies, which play a more and more important role in complementing the wide area networks. Specifically, we investigate two promising techniques for spectrum efficiency improvement in a macro-assisted small cell architecture, called the Phantom cell, which is proposed by DOCOMO. One is the possibility of dynamic allocation of subframes to uplink (UL) or downlink (DL) in time-division duplexing (TDD), called `Dynamic TDD'. The other is the more dynamic and flexible 3-dimensional (3D) beamforming which is facilitated by the adoption of active antenna systems (AAS) in BSs. In addition, full-duplex transmission and cooperative communication are two promising techniques known to enhance the spectrum efficiency of wireless communications. We focus on applying full-duplex in cooperative relaying networks and investigating the optimal resource allocation (both power and relay location) for full-duplex decode-and-forward (DF) relaying systems for spectrum efficiency enhancement. Advisors/Committee Members: Yang, Liuqing (advisor), Luo, Jie (committee member), Morton, Yu (committee member), Wang, Haonan (committee member).

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APA (6^th Edition):

Yu, B. (2015). Spectrum efficiency for future wireless communications. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/166861

Chicago Manual of Style (16^th Edition):

Yu, Bo. “Spectrum efficiency for future wireless communications.” 2015. Doctoral Dissertation, Colorado State University. Accessed March 09, 2021. http://hdl.handle.net/10217/166861.

MLA Handbook (7^th Edition):

Yu, Bo. “Spectrum efficiency for future wireless communications.” 2015. Web. 09 Mar 2021.

Vancouver:

Yu B. Spectrum efficiency for future wireless communications. [Internet] [Doctoral dissertation]. Colorado State University; 2015. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/10217/166861.

Council of Science Editors:

Yu B. Spectrum efficiency for future wireless communications. [Doctoral Dissertation]. Colorado State University; 2015. Available from: http://hdl.handle.net/10217/166861

Colorado State University

3. Duan, Dongliang. Sensing, communications and monitoring for the smart grid.

Degree: PhD, Electrical and Computer Engineering, 2012, Colorado State University

URL: http://hdl.handle.net/10217/68171

► With the increasing concern for environmental factors, reliability, and quality of service, power grids in many countries are undergoing revolution towards a more distributed and… (more)

Subjects/Keywords: wireless communications; smart grid; wireless sensor network; cognitive radio; power efficiency

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APA (6^th Edition):

Duan, D. (2012). Sensing, communications and monitoring for the smart grid. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/68171

Chicago Manual of Style (16^th Edition):

Duan, Dongliang. “Sensing, communications and monitoring for the smart grid.” 2012. Doctoral Dissertation, Colorado State University. Accessed March 09, 2021. http://hdl.handle.net/10217/68171.

MLA Handbook (7^th Edition):

Duan, Dongliang. “Sensing, communications and monitoring for the smart grid.” 2012. Web. 09 Mar 2021.

Vancouver:

Duan D. Sensing, communications and monitoring for the smart grid. [Internet] [Doctoral dissertation]. Colorado State University; 2012. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/10217/68171.

Council of Science Editors:

Duan D. Sensing, communications and monitoring for the smart grid. [Doctoral Dissertation]. Colorado State University; 2012. Available from: http://hdl.handle.net/10217/68171

Colorado State University

4. Zhang, Wenshu. Cooperative sensing for target estimation and target localization.

Degree: PhD, Electrical and Computer Engineering, 2011, Colorado State University

URL: http://hdl.handle.net/10217/70658

► As a novel sensing scheme, cooperative sensing has drawn great interests in recent years. By utilizing the concept of "cooperation", which incorporates communications and information… (more)

▼ As a novel sensing scheme, cooperative sensing has drawn great interests in recent years. By utilizing the concept of "cooperation", which incorporates communications and information exchanges among multiple sensing devices, e.g. radar transceivers in radar systems, sensor nodes in wireless sensor networks, or mobile handsets in cellular systems, the sensing capability can achieve significant improvement compared to the conventional noncooperative mode in many aspects. For example, cooperative target estimation is inspired by the benefits of MIMO in communications, where multiple transmit and/or receive antennas can increase the diversity to combat channel fading for enhanced transmission reliability and increase the degrees of freedom for improved data rate. On the other hand, cooperative target localization is able to dramatically increase localization performance in terms of both accuracy and coverage. From the perspective of cooperative target estimation, in this dissertation, we optimize waveforms from multiple cooperative transmitters to facilitate better target estimation in the presence of colored noise. We introduce the normalized MSE (NMSE) minimizing criterion for radar waveform designs. Not only is it more meaningful for parameter estimation problems, but it also exhibits more similar behaviors with the MI criterion than its MMSE counterpart. We also study the robust designs for both the probing waveforms at the transmitter and the estimator at the receiver to address one type of a priori information uncertainties, i.e., in-band target and noise PSD uncertainties. The relationship between MI and MSEs is further investigated through analysis of the sensitivity of the optimum design to the out-band PSD uncertainties as known as the overestimation error. From the perspective of cooperative target localization, in this dissertation, we study the two phases that comprise a localization process, i.e., the distance measurement phase and the location update phase. In the first distance measurement phase, thanks to UWB signals' many desirable features including high delay resolution and obstacle penetration capabilities, we adopt UWB technology for TOA estimation, and then translate the TOA estimate into distance given light propagation speed. We develop a practical data-aided ML timing algorithm and obtain its optimum training sequence. Based on this optimum sequence, the original ML algorithm can be simplified without affecting its optimality. In the second location update phase, we investigate secure cooperative target localization in the presence of malicious attacks, which consists of a fundamental issue in localization problems. We explicitly incorporate anchors' misplacements into distance measurement model and explore the pairwise sparse nature of the misplacements. We formulate the secure localization problem as an ℓ1-regularized least squares (LS) problem and establish the pairwise sparsity upper bound which defines the largest possible number of identifiable malicious anchors. Particularly, it is… Advisors/Committee Members: Yang, Liuqing (advisor), Pezeshki, Ali (committee member), Luo, J. Rockey (committee member), Wang, Haonan (committee member).

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

APA (6^th Edition):

Zhang, W. (2011). Cooperative sensing for target estimation and target localization. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/70658

Chicago Manual of Style (16^th Edition):

Zhang, Wenshu. “Cooperative sensing for target estimation and target localization.” 2011. Doctoral Dissertation, Colorado State University. Accessed March 09, 2021. http://hdl.handle.net/10217/70658.

MLA Handbook (7^th Edition):

Zhang, Wenshu. “Cooperative sensing for target estimation and target localization.” 2011. Web. 09 Mar 2021.

Vancouver:

Zhang W. Cooperative sensing for target estimation and target localization. [Internet] [Doctoral dissertation]. Colorado State University; 2011. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/10217/70658.

Council of Science Editors:

Zhang W. Cooperative sensing for target estimation and target localization. [Doctoral Dissertation]. Colorado State University; 2011. Available from: http://hdl.handle.net/10217/70658

Colorado State University

5. Heydaryanfroshani, Faeze. Distributed medium access control for an enhanced physical-link layer interface.

Degree: PhD, Electrical and Computer Engineering, 2020, Colorado State University

URL: http://hdl.handle.net/10217/219595

► Current wireless network architecture equips data link layer with binary transmission/idling options and gives the control of choosing other communication parameters to the physical layer.… (more)

▼ Current wireless network architecture equips data link layer with binary transmission/idling options and gives the control of choosing other communication parameters to the physical layer. Such a network architecture is inefficient in distributed wireless networks where user coordination can be infeasible or expensive in terms of overhead. To address this issue, an enhancement to the physical-link layer interface is proposed. At the physical layer, the enhanced interface is supported by a distributed channel coding theory, which equips each physical layer user with an ensemble of channel codes. The coding theory allows each transmitter to choose an arbitrary code to encode its message without sharing such a decision with the receiver. The receiver, on the other hand, should decode the messages of interest or report collision depending on whether or not a predetermined reliability threshold can be met. Fundamental limits of the system is characterized asymptotically using a "distributed channel capacity'' when the codeword length can be taken to infinity, and non-asymptotically using an achievable performance bound when the codeword length is finite. The focus of this dissertation is to support the enhanced interface at the data link layer. We assume that each link layer user can be equipped with multiple transmission options each corresponds to a coding option at the physical layer. Each user maintains a transmission probability vector whose entries specify the probability at which the user chooses the corresponding transmission options to transmit its packets. We propose a distributed medium access control (MAC) algorithm for a time-slotted multiple access system with/without enhanced physical-link layer interface to adapt the transmission probability vector of each user to a desired equilibrium that maximizes a chosen network utility. The MAC algorithm is applicable to a general channel model and to a wide range of utility functions. The MAC algorithm falls into the stochastic approximation framework with guaranteed convergence under mild conditions. We developed design procedures to satisfy these conditions and to ensure that the system should converge to a unique equilibrium. Simulation results are provided to demonstrate fast and adaptive convergence behavior of the MAC algorithm as well as the near optimal performance of the designed equilibrium. We then extend the distributed MAC algorithm to support hierarchical primary-secondary user structure in a random multiple access system. The hierarchical user structure is established in the following senses. First, when the number of primary users is small, channel availability is kept above a pre-determined threshold regardless of the number of secondary users that are competing for the channel. Second, when the number of primary users is large, transmission probabilities of the secondary users are automatically driven down to zero. Such a hierarchical structure is achieved without the knowledge of the numbers of primary and secondary users and without direct… Advisors/Committee Members: Luo, Rockey (advisor), Yang, Liuqing (committee member), Pezeshki, Ali (committee member), Wang, Haonan (committee member).

Subjects/Keywords: MAC protocol; distributed wireless networks; wireless communication

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

APA (6^th Edition):

Heydaryanfroshani, F. (2020). Distributed medium access control for an enhanced physical-link layer interface. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/219595

Chicago Manual of Style (16^th Edition):

Heydaryanfroshani, Faeze. “Distributed medium access control for an enhanced physical-link layer interface.” 2020. Doctoral Dissertation, Colorado State University. Accessed March 09, 2021. http://hdl.handle.net/10217/219595.

MLA Handbook (7^th Edition):

Heydaryanfroshani, Faeze. “Distributed medium access control for an enhanced physical-link layer interface.” 2020. Web. 09 Mar 2021.

Vancouver:

Heydaryanfroshani F. Distributed medium access control for an enhanced physical-link layer interface. [Internet] [Doctoral dissertation]. Colorado State University; 2020. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/10217/219595.

Council of Science Editors:

Heydaryanfroshani F. Distributed medium access control for an enhanced physical-link layer interface. [Doctoral Dissertation]. Colorado State University; 2020. Available from: http://hdl.handle.net/10217/219595

Colorado State University

6. Fang, Luoyang. Data mining and spatiotemporal analysis of modern mobile data.

Degree: PhD, Electrical and Computer Engineering, 2019, Colorado State University

URL: http://hdl.handle.net/10217/197361

► Modern mobile network technologies and smartphones have successfully penetrated nearly every aspect of human life due to the increasing number of mobile applications and services.… (more)

▼ Modern mobile network technologies and smartphones have successfully penetrated nearly every aspect of human life due to the increasing number of mobile applications and services. Massive mobile data generated by mobile networks with timestamp and location information have been frequently collected. Mobile data analytics has gained remarkable attention from various research communities and industries, since it can broadly reveal the human spatiotemporal mobility patterns from the individual level to an aggregated one. In this dissertation, two types of spatiotemporal modeling with respect to human mobility behaviors are considered, namely the individual modeling and aggregated modeling. As for individual spatiotemporal modeling, location privacy is studied in terms of user identifiability between two mobile datasets, merely based on their spatiotemporal traces from the perspective of a privacy adversary. The success of user identification then hinges upon the effective distance measures via user spatiotemporal behavior profiling. However, user identification methods depending on a single semantic distance measure almost always lead to a large portion of false matches. To improve user identification performance, we propose a scalable multi-feature ensemble matching framework that integrates multiple explored spatiotemporal models. On the other hand, the aggregated spatiotemporal modeling is investigated for network and traffic management in cellular networks. Traffic demand forecasting problem across the entire mobile network is first studied, which is considered as the aggregated behavior of network users. The success of demand forecasting relies on effective modeling of both the spatial and temporal dependencies of the per-cell demand time series. However, the main challenge of the spatial relevancy modeling in the per-cell demand forecasting is the uneven spatial distribution of cells in a network. In this work, a dependency graph is proposed to model the spatial relevancy without compromising the spatial granularity. Accordingly, the spatial and temporal models, graph convolutional and recurrent neural networks, are adopted to forecast the per-cell traffic demands. In addition to demand forecasting, a per-cell idle time window (ITW) prediction application is further studied for predictive network management based on subscribers' aggregated spatiotemporal behaviors. First, the ITW prediction is formulated into a regression problem with an ITW presence confidence index that facilitates direct ITW detection and estimation. To predict the ITW, a deep-learning-based ITW prediction model is proposed, consisting of a representation learning network and an output network. The representation learning network is aimed to learn patterns from the recent history of demand and mobility, while the output network is designed to generate the ITW predicts with the learned representation and exogenous periodic as inputs. Upon this paradigm, a temporal graph convolutional network (TGCN) implementing the representation… Advisors/Committee Members: Yang, Liuqing (advisor), Jayasumana, Anura P. (committee member), Luo, Jie (committee member), Wang, Haonan (committee member).

Subjects/Keywords: location privacy; network management; spatiotemporal; mobile big data; cellular networks; prediction

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

APA (6^th Edition):

Fang, L. (2019). Data mining and spatiotemporal analysis of modern mobile data. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/197361

Chicago Manual of Style (16^th Edition):

Fang, Luoyang. “Data mining and spatiotemporal analysis of modern mobile data.” 2019. Doctoral Dissertation, Colorado State University. Accessed March 09, 2021. http://hdl.handle.net/10217/197361.

MLA Handbook (7^th Edition):

Fang, Luoyang. “Data mining and spatiotemporal analysis of modern mobile data.” 2019. Web. 09 Mar 2021.

Vancouver:

Fang L. Data mining and spatiotemporal analysis of modern mobile data. [Internet] [Doctoral dissertation]. Colorado State University; 2019. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/10217/197361.

Council of Science Editors:

Fang L. Data mining and spatiotemporal analysis of modern mobile data. [Doctoral Dissertation]. Colorado State University; 2019. Available from: http://hdl.handle.net/10217/197361

Colorado State University

7. Limo, Chepchumba Soti. Decentralized and dynamic community formation in P2P networks and performance of community based caching.

Degree: MS(M.S.), Electrical and Computer Engineering, 2015, Colorado State University

URL: http://hdl.handle.net/10217/167211

► Distributed Hash Tables (DHT) are commonly used in large Peer-to-Peer networks to increase the efficiently of resolving queries. Minimizing the resource discovery time in P2P… (more)

▼ Distributed Hash Tables (DHT) are commonly used in large Peer-to-Peer networks to increase the efficiently of resolving queries. Minimizing the resource discovery time in P2P networks is highly desirable to improve system-wide performance. Distributed caching is an approach used to reduce the look-up time. File sharing P2P networks have shown that there exists nodes/users who share similar interests based on semantics, geography, etc., and a group of nodes that share similar interests are said to form a community. A Community Based Caching (CBC) algorithm where nodes make caching decisions based on personal interests is investigated. One of CBC’s major contributions is that it alleviates the issue of nodes being limited to caching resources that are popular relative to the entire network. Instead, caching decisions are primarily based on a node's community affiliations and interests. Community discovery algorithms that currently exists either need a centralized source(s) to aid in community discovery or require additional messaging and complicated computations to determine whether to join a group or not. In many cases, nodes are also limited to being members of only one community at a time. A dynamic and decentralized community discovery algorithm, Dynamic Group Discovery (DGD), is proposed. DGD also allows nodes to be members of multiple communities at the same time. DGD's behavior and performance is then evaluated in conjunction with the Community Based Caching algorithm. To aid in group discovery during run time (i.e., dynamically), DGD uses special keys with embedded group identification information. Oversim, a flexible overly network simulation framework is used to evaluate the proposed DGD algorithm. Performance of DGD is compared to Chord and Static Group Allocation (SGA), in which group identification is done only once. Performance is evaluated for different network sizes, community sizes, and asymmetry among communities. Performance results are presented and analyzed when queries are resolved using cache data versus when queries are resolved using non-cache data. The analysis shows that DGD generally improves lookup performance when cache data is used to resolved queries. However, when non-cache data is used, DGD occasionally performs slightly worse than Chord and SGA. For example, in a network with 10,000 nodes, asymmetrical communities and no churn group churn, DGD outperforms Chord by approximately half a hop and 0.1 seconds in latency. When churn was introduced to the same network, DGD performance drops by approximately one hop and 0.15 seconds in latency. The results also show that approximately 90% of the queries are resolved using non-cache data and therefore, even though DGD is guaranteed to reduce lookup time when asymmetrical communities are present and cache records are to used to resolve queries, it is often not enough to significantly improve overall system performance. The results however confirm that caching resources based on personal interests really does reduced lookup performance when… Advisors/Committee Members: Jayasumana, Anura P. (advisor), Yang, Liuqing (committee member), Papadopoulos, Christos (committee member).

Subjects/Keywords: communities; caching; P2P networks

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APA (6^th Edition):

Limo, C. S. (2015). Decentralized and dynamic community formation in P2P networks and performance of community based caching. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/167211

Chicago Manual of Style (16^th Edition):

Limo, Chepchumba Soti. “Decentralized and dynamic community formation in P2P networks and performance of community based caching.” 2015. Masters Thesis, Colorado State University. Accessed March 09, 2021. http://hdl.handle.net/10217/167211.

MLA Handbook (7^th Edition):

Limo, Chepchumba Soti. “Decentralized and dynamic community formation in P2P networks and performance of community based caching.” 2015. Web. 09 Mar 2021.

Vancouver:

Limo CS. Decentralized and dynamic community formation in P2P networks and performance of community based caching. [Internet] [Masters thesis]. Colorado State University; 2015. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/10217/167211.

Council of Science Editors:

Limo CS. Decentralized and dynamic community formation in P2P networks and performance of community based caching. [Masters Thesis]. Colorado State University; 2015. Available from: http://hdl.handle.net/10217/167211

Colorado State University

8. Giraldez Miner, Julieta. Customer and system impacts of grid support functions for voltage management strategies.

Degree: PhD, Systems Engineering, 2020, Colorado State University

URL: http://hdl.handle.net/10217/211785

► This document describes modeling techniques and methods to study the impacts to the utility and to the customer of using DERs such as advanced inverters… (more)

Subjects/Keywords: curtailment; power system modeling; advanced inverters; voltage control; distributed energy resources

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APA (6^th Edition):

Giraldez Miner, J. (2020). Customer and system impacts of grid support functions for voltage management strategies. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/211785

Chicago Manual of Style (16^th Edition):

Giraldez Miner, Julieta. “Customer and system impacts of grid support functions for voltage management strategies.” 2020. Doctoral Dissertation, Colorado State University. Accessed March 09, 2021. http://hdl.handle.net/10217/211785.

MLA Handbook (7^th Edition):

Giraldez Miner, Julieta. “Customer and system impacts of grid support functions for voltage management strategies.” 2020. Web. 09 Mar 2021.

Vancouver:

Giraldez Miner J. Customer and system impacts of grid support functions for voltage management strategies. [Internet] [Doctoral dissertation]. Colorado State University; 2020. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/10217/211785.

Council of Science Editors:

Giraldez Miner J. Customer and system impacts of grid support functions for voltage management strategies. [Doctoral Dissertation]. Colorado State University; 2020. Available from: http://hdl.handle.net/10217/211785

Colorado State University

9. Wang, Dexin. Simultaneous wireless information and power transfer (SWIPT) in cooperative networks.

Degree: PhD, Electrical and Computer Engineering, 2019, Colorado State University

URL: http://hdl.handle.net/10217/195265

► In recent years, the capacity and charging speed of batteries have become the bottleneck of mobile communications systems. Energy harvesting (EH) is regarded as a… (more)

▼ In recent years, the capacity and charging speed of batteries have become the bottleneck of mobile communications systems. Energy harvesting (EH) is regarded as a promising technology to significantly extend the lifetime of battery-powered devices. Among many EH technologies, simultaneous wireless information and power transfer (SWIPT) proposes to harvest part of the energy carried by the wireless communication signals. In particular, SWIPT has been successfully applied to energy-constrained relays that are mainly or exclusively powered by the energy harvested from the received signals. These relays are known as EH relays, which attract significant attention in both the academia and the industry. In this research, we investigate the performance of SWIPT-based EH cooperative networks and the optimization problems therein. Due to hardware limitations, the energy harvesting circuit cannot decode the signal directly. Power splitting (PS) is a popular and effective solution to this problem. Therefore, we focus on PS based SWIPT in this research. First, different from existing work that employs time-switching (TS) based SWIPT, we propose to employ PS based SWIPT for a truly full-duplex (FD) EH relay network, where the information reception and transmission take place simultaneously at the relay all the time. This more thorough exploitation of the FD feature consequently leads to a significant capacity improvement compared with existing alternatives in the literature. Secondly, when multiple relays are available in the network, we explore the relay selection (RS) and network beamforming techniques in EH relay networks. Assuming orthogonal bandwidth allocation, both single relay selection (SRS) and general relay selection (GRS) without the limit on the number of cooperating relays are investigated and the corresponding RS methods are proposed. We will show that our proposed heuristic GRS methods outperform the SRS methods and achieve very similar performance compared with the optimal RS method achieved by exhaustive search but with dramatically reduced complexity. Under the shared bandwidth assumption, network beamforming among EH relays is investigated. We propose a joint PS factor optimization method based on semidefinite relaxation. Simulations show that network beamforming achieves the best performance among all other cooperative techniques. Finally, we study the problem of power allocation and PS factor optimization for SWIPT over doubly-selective wireless channels. In contrast to existing work in the literature, we take the channel variation in both time and frequency domains into consideration and jointly optimize the power allocation and the PS factors. The objective is to maximize the achievable data rate with constraints on the delivered energy in a time window. Since the problem is difficult to solve directly due to its nonconvexity, we proposed a two-step approach, named joint power allocation and splitting (JoPAS), to solve the problem along the time and frequency dimensions sequentially. Simulations show… Advisors/Committee Members: Yang, Liuqing (advisor), Chong, Edwin K. P. (committee member), Luo, Jie (committee member), Wang, Haonan (committee member).

Subjects/Keywords: full-duplex; relay; SWIPT; network beamforming; energy harvesting; relay selection

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

APA (6^th Edition):

Wang, D. (2019). Simultaneous wireless information and power transfer (SWIPT) in cooperative networks. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/195265

Chicago Manual of Style (16^th Edition):

Wang, Dexin. “Simultaneous wireless information and power transfer (SWIPT) in cooperative networks.” 2019. Doctoral Dissertation, Colorado State University. Accessed March 09, 2021. http://hdl.handle.net/10217/195265.

MLA Handbook (7^th Edition):

Wang, Dexin. “Simultaneous wireless information and power transfer (SWIPT) in cooperative networks.” 2019. Web. 09 Mar 2021.

Vancouver:

Wang D. Simultaneous wireless information and power transfer (SWIPT) in cooperative networks. [Internet] [Doctoral dissertation]. Colorado State University; 2019. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/10217/195265.

Council of Science Editors:

Wang D. Simultaneous wireless information and power transfer (SWIPT) in cooperative networks. [Doctoral Dissertation]. Colorado State University; 2019. Available from: http://hdl.handle.net/10217/195265

Colorado State University

10. Zhang, Lyuou. Non-asymptotic properties of spectral decomposition of large gram-type matrices with applications to high-dimensional inference.

Degree: PhD, Statistics, 2020, Colorado State University

URL: http://hdl.handle.net/10217/219574

► Jointly modeling a large and possibly divergent number of temporally evolving subjects arises ubiquitously in statistics, econometrics, finance, biology, and environmental sciences. To circumvent the… (more)

▼ Jointly modeling a large and possibly divergent number of temporally evolving subjects arises ubiquitously in statistics, econometrics, finance, biology, and environmental sciences. To circumvent the challenges due to the high dimesionality as well as the temporal and/or contemporaneous dependence, the factor model and its variants have been widely employed. In general, they model the large scale temporally dependent data using some low dimensional structures that capture variations shared across dimensions. In this dissertation, we investigate the non-asymptotic properties of spectral decomposition of high-dimensional Gram-type matrices based on factor models. Specifically, we derive the exponential tail bound for the first and second moments of the deviation between the empirical and population eigenvectors to the right Gram matrix as well as the Berry-Esseen type bound to characterize the Gaussian approximation of these deviations. We also obtain the non-asymptotic tail bound of the ratio between eigenvalues of the left Gram matrix, namely the sample covariance matrix, and their population counterparts regardless of the size of the data matrix. The documented non-asymptotic properties are further demonstrated in a suite of applications, including the non-asymptotic characterization of the estimated number of latent factors in factor models and related machine learning problems, the estimation and forecasting of high-dimensional time series, the spectral properties of large sample covariance matrix such as perturbation bounds and inference on the spectral projectors, and low-rank matrix denoising from temporally dependent data. Next, we consider the estimation and inference of a flexible subject-specific heteroskedasticity model for large scale panel data, which employs latent semiparametric factor structure to simultaneously account for the heteroskedasticity across subjects and contemporaneous and/or serial correlations. Specifically, the subject-specific heteroskedasticity is modeled by the product of unobserved factor process and subject-specific covariate effect. Serving as the loading, the covariate effect is further modeled via additive models. We propose a two-step procedure for estimation. Theoretical validity of this procedure is documented. By scrupulously examining the non-asymptotic rates for recovering the latent factor process and its loading, we show the consistency and asymptotic efficiency of our regression coefficient estimator in addition to the asymptotic normality. This leads to a more efficient confidence set for the regression coefficient. Using a comprehensive simulation study, we demonstrate the finite sample performance of our procedure, and numerical results corroborate the theoretical findings. Finally, we consider the factor model-assisted variable clustering for temporally dependent data. The population level clusters are characterized by the latent factors of the model. We combine the approximate factor model with population level clusters to give an integrative group factor model as… Advisors/Committee Members: Zhou, Wen (advisor), Wang, Haonan (advisor), Breidt, Jay (committee member), Meyer, Mary (committee member), Yang, Liuqing (committee member).

Subjects/Keywords: gram-type matrices; non-asymptotic analysis; spectral decomposition; high dimensional time series; dynamic factor model; principal component analysis

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APA (6^th Edition):

Zhang, L. (2020). Non-asymptotic properties of spectral decomposition of large gram-type matrices with applications to high-dimensional inference. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/219574

Chicago Manual of Style (16^th Edition):

Zhang, Lyuou. “Non-asymptotic properties of spectral decomposition of large gram-type matrices with applications to high-dimensional inference.” 2020. Doctoral Dissertation, Colorado State University. Accessed March 09, 2021. http://hdl.handle.net/10217/219574.

MLA Handbook (7^th Edition):

Zhang, Lyuou. “Non-asymptotic properties of spectral decomposition of large gram-type matrices with applications to high-dimensional inference.” 2020. Web. 09 Mar 2021.

Vancouver:

Zhang L. Non-asymptotic properties of spectral decomposition of large gram-type matrices with applications to high-dimensional inference. [Internet] [Doctoral dissertation]. Colorado State University; 2020. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/10217/219574.

Council of Science Editors:

Zhang L. Non-asymptotic properties of spectral decomposition of large gram-type matrices with applications to high-dimensional inference. [Doctoral Dissertation]. Colorado State University; 2020. Available from: http://hdl.handle.net/10217/219574

Colorado State University

11. Mohanpurkar, Manish. Computation of loop flows in electric grids with high wind energy penetration.

Degree: PhD, Electrical and Computer Engineering, 2013, Colorado State University

URL: http://hdl.handle.net/10217/81399

► In a deregulated electricity market, the financial transmission rights (FTRs) and the bid-sell principle for energy trades are used to determine the expected power flows… (more)

▼ In a deregulated electricity market, the financial transmission rights (FTRs) and the bid-sell principle for energy trades are used to determine the expected power flows on transmission lines. Expected power flows are calculated by applying the superposition theorem on the approved electronic tags (e-tags). Multiple parallel paths in interconnected networks lead to division of power flows determined by the impedances of the parallel paths and the physical laws of electricity. The actual power flows in the network do not conform to the market expectations leading to unscheduled flows (USF) on transmission lines. USF have historically been estimated and accommodated deterministically for a given set of e-tags. However, wide-area interconnections experience variability and uncertainty due to a significant penetration of wind energy connected at the transmission level, thus imparting a stochastic nature to USF. A linear model, from the literature, has been adopted to model USF using a mathematical artifact called `minor loop flows'. This research develops an automated framework that provides accurate estimates of loop flows suitable for both market and network level accommodation of variable USF. This generic framework will be applicable to any power transmission network with intermittent energy resources. A loop detection algorithm (LDA) based on graph theory is proposed to detect loops in a transmission network of any size. The LDA is formulated as a modification of the A-star (A*) algorithm, the lowest ancestor theorem, and Dijkstra's algorithm. The LDA has an order of complexity of V2, where V is the total number of vertices or buses in the network under consideration. An application of a geographical information systems (GIS) technique has been established to obtain the transmission line layouts. The outcome of the LDA (i.e., minor loops) and line layouts (i.e., azimuth) are processed to compute the incidence matrix of the estimator. The variability due to the penetration of wind energy is accounted in the proposed framework using the probabilistic load flow analysis based on Monte Carlo simulations. Three techniques - ordinary least squares (OLS), analytic ridge regression (RR), and robust regression (M-estimators) - are used to estimate minor loop flows. The estimation techniques adhere to the auto-correction of the quality of estimates in case of ill-conditioning of the incidence matrix. Accuracy of loop flow estimates is highly significant, as they may be used for assigning economic responsibility of USF in electricity markets. Wind power generation companies (WGENCOs) employ forecasting models to participate in the primary electricity markets. Forecasting models used to predict the output of wind power plants are inherently erroneous and hence, their impacts on USF are studied. The impact of forecasting errors associated with the output of wind plants is investigated using the concept of prediction intervals rather than point accurate forecasts. Loop flow estimates corresponding to the prediction… Advisors/Committee Members: Suryanarayanan, Siddharth (advisor), Yang, Liuqing (committee member), Young, Peter M. (committee member), Zimmerle, Daniel J. (committee member).

Subjects/Keywords: loop flows; wind energy; unscheduled flows; power systems; electricity markets; loop detection algorithm

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

APA (6^th Edition):

Mohanpurkar, M. (2013). Computation of loop flows in electric grids with high wind energy penetration. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/81399

Chicago Manual of Style (16^th Edition):

Mohanpurkar, Manish. “Computation of loop flows in electric grids with high wind energy penetration.” 2013. Doctoral Dissertation, Colorado State University. Accessed March 09, 2021. http://hdl.handle.net/10217/81399.

MLA Handbook (7^th Edition):

Mohanpurkar, Manish. “Computation of loop flows in electric grids with high wind energy penetration.” 2013. Web. 09 Mar 2021.

Vancouver:

Mohanpurkar M. Computation of loop flows in electric grids with high wind energy penetration. [Internet] [Doctoral dissertation]. Colorado State University; 2013. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/10217/81399.

Council of Science Editors:

Mohanpurkar M. Computation of loop flows in electric grids with high wind energy penetration. [Doctoral Dissertation]. Colorado State University; 2013. Available from: http://hdl.handle.net/10217/81399

Colorado State University

12. Cheng, Xilin. Reliable and energy-efficient cooperative OFDM communications over underwater acoustic channels.

Degree: PhD, Electrical and Computer Engineering, 2015, Colorado State University

URL: http://hdl.handle.net/10217/170321

► Underwater acoustic sensor networks (UWASN) have been attracting growing research interests in recent decades due to various promising applications. Underwater acoustic communications (UAC), which adopts… (more)

Subjects/Keywords: cooperative communications; energy efficiency; OFDM; reliability; underwater acoustic communications

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

APA (6^th Edition):

Cheng, X. (2015). Reliable and energy-efficient cooperative OFDM communications over underwater acoustic channels. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/170321

Chicago Manual of Style (16^th Edition):

Cheng, Xilin. “Reliable and energy-efficient cooperative OFDM communications over underwater acoustic channels.” 2015. Doctoral Dissertation, Colorado State University. Accessed March 09, 2021. http://hdl.handle.net/10217/170321.

MLA Handbook (7^th Edition):

Cheng, Xilin. “Reliable and energy-efficient cooperative OFDM communications over underwater acoustic channels.” 2015. Web. 09 Mar 2021.

Vancouver:

Cheng X. Reliable and energy-efficient cooperative OFDM communications over underwater acoustic channels. [Internet] [Doctoral dissertation]. Colorado State University; 2015. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/10217/170321.

Council of Science Editors:

Cheng X. Reliable and energy-efficient cooperative OFDM communications over underwater acoustic channels. [Doctoral Dissertation]. Colorado State University; 2015. Available from: http://hdl.handle.net/10217/170321

Colorado State University

13. Waddington, Chad. Synthetic aperture source localization.

Degree: PhD, Mathematics, 2018, Colorado State University

URL: http://hdl.handle.net/10217/191271

► The detection and localization of sources of electromagnetic (EM) radiation has many applications in both civilian and defense communities. The goal of source localization is… (more)

▼ The detection and localization of sources of electromagnetic (EM) radiation has many applications in both civilian and defense communities. The goal of source localization is to identify the geographic position of an emitter of some radiation from measurements of the elds that the source produces. Although the problem has been studied intensively for many decades much work remains to be done. Many state-of-the-art methods require large numbers of sensors and perform poorly or require additional sensors when target emitters transmit highly correlated waveforms. Some methods also require a preprocessing step which attempts to identify regions of the data which come from emitters in the scene before processing the localization algorithm. Additionally, it has been proven that pure Angle of Arrival (AOA) techniques based on current methods are always suboptimal when multiple emitters are present. We present a new source localization technique which employs a cross correlation measure of the Time Dierence of Arrival (TDOA) for signals recorded at two separate platforms, at least one of which is in motion. This data is then backprojected through a Synthetic Aperture Radar (SAR)-like process to form an image of the locations of the emitters in a target scene. This method has the advantage of not requiring any a priori knowledge of the number of emitters in the scene. Nor does it rest on an ability to identify regions of the data which come from individual emitters, though if this capability is present it may improve image quality. Additionally we demonstrate that this method is capable of localizing emitters which transmit highly correlated waveforms, though complications arise when several such emitters are present in the scene. We discuss these complications and strategies to mitigate them. Finally we conclude with an overview of our method's performance for various levels of additive noise and lay out a path for advancing study of this new method through future work. Advisors/Committee Members: Cheney, Margaret (advisor), Pinaud, Oliver (committee member), Mueller, Jennifer (committee member), Given, James (committee member), Yang, Liuqing (committee member).

Subjects/Keywords: synthetic aperture radar; source localization

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

APA (6^th Edition):

Waddington, C. (2018). Synthetic aperture source localization. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/191271

Chicago Manual of Style (16^th Edition):

Waddington, Chad. “Synthetic aperture source localization.” 2018. Doctoral Dissertation, Colorado State University. Accessed March 09, 2021. http://hdl.handle.net/10217/191271.

MLA Handbook (7^th Edition):

Waddington, Chad. “Synthetic aperture source localization.” 2018. Web. 09 Mar 2021.

Vancouver:

Waddington C. Synthetic aperture source localization. [Internet] [Doctoral dissertation]. Colorado State University; 2018. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/10217/191271.

Council of Science Editors:

Waddington C. Synthetic aperture source localization. [Doctoral Dissertation]. Colorado State University; 2018. Available from: http://hdl.handle.net/10217/191271

14. Tang, Yanru. Distributed wireless networking with an enhanced physical-link layer interface.

Degree: PhD, Electrical and Computer Engineering, 2019, Colorado State University

URL: http://hdl.handle.net/10217/195248

► This thesis focuses on the cross-layer design of physical and data link layers to support efficient distributed wireless networking. At the physical layer, distributed coding… (more)

▼ This thesis focuses on the cross-layer design of physical and data link layers to support efficient distributed wireless networking. At the physical layer, distributed coding theorems are proposed to prepare each transmitter with an ensemble of channel codes. In a time slot, a transmitter chooses a code to encode its messages and such a choice is not shared with other transmitters or with the receiver. The receiver guarantees either reliable message decoding or reliable collision report depending on whether a predetermined reliability threshold can be met. Under the assumption that the codeword length can be taken to infinity, the distributed capacity of a discrete-time memoryless multiple access channel is derived and is shown to coincide with the classical Shannon capacity region of the same channel. An achievable error performance bound is also presented for the case when codeword length is finite. With the new coding theorems, link layer users can be equipped with multiple transmission options corresponding to the physical layer code ensemble. This enables link layer users to exploit advanced wireless capabilities such as rate and power adaptation, which is not supported in the current network architecture. To gain understandings on how link layer users should efficiently exploit these new capabilities, the corresponding link layer problem is investigated from two different perspectives. Under the assumption that each user is provided with multiple transmission options, the link layer problem is first formulated using a game theoretic model where each user adapts its transmission scheme to maximize a utility function. The condition under which the medium access control game has a unique Nash equilibrium is obtained. Simulation results show that, when multiple transmission options are provided, users in a distributed network tend to converge to channel sharing schemes that are consistent with the well-known information theoretic understandings. A stochastic approximation framework is adopted to further study the link layer problem for the case when each user has a single transmission option as well as the case when each user has multiple transmission options. Assume that each user is backlogged with a saturated message queue. With a generally-modeled channel, a distributed medium access control framework is proposed to adapt the transmission scheme of each user to maximize an arbitrarily chosen symmetric network utility. The proposed framework suggests that the receiver should measure the success probability of a carefully designed virtual packet or a set of virtual packets, and feed such information back to the transmitters. Given channel feedback from the receiver, each transmitter should obtain a user number estimate by comparing the measured success probability with the corresponding theoretical value, and then adapt its transmission scheme accordingly. Conditions under which the proposed algorithm should converge to a designed unique equilibrium are characterized. Simulation results are provided to… Advisors/Committee Members: Luo, Rockey (advisor), Yang, Liuqing (committee member), Pezeshki, Ali (committee member), Wang, Haonan (committee member).

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

APA (6^th Edition):

Tang, Y. (2019). Distributed wireless networking with an enhanced physical-link layer interface. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/195248

Chicago Manual of Style (16^th Edition):

Tang, Yanru. “Distributed wireless networking with an enhanced physical-link layer interface.” 2019. Doctoral Dissertation, Colorado State University. Accessed March 09, 2021. http://hdl.handle.net/10217/195248.

MLA Handbook (7^th Edition):

Tang, Yanru. “Distributed wireless networking with an enhanced physical-link layer interface.” 2019. Web. 09 Mar 2021.

Vancouver:

Tang Y. Distributed wireless networking with an enhanced physical-link layer interface. [Internet] [Doctoral dissertation]. Colorado State University; 2019. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/10217/195248.

Council of Science Editors:

Tang Y. Distributed wireless networking with an enhanced physical-link layer interface. [Doctoral Dissertation]. Colorado State University; 2019. Available from: http://hdl.handle.net/10217/195248

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