Digital Commons Network^™

Fpga Implementation Of Qr Decomposition For Mimo-Ofdm Using Four Cordic Cores, Bing Han, Zengli Yang, Yahong Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

A low-resource implementation of QR decomposition (QRD) is proposed for MIMO-OFDM systems that employ turbo MMSE-IC (Minimum mean square error interference cancellation) detector. The proposed implementation uses only four CORDIC cores for QR decomposition of complex-valued matrices while existing systolic array architecture requires 15 to 38 CORDIC cores to achieve similar throughput. For 4-by-4 MIMO with 1024 subcarrier OFDM, the turbo MMSE-IC requires 1024 QRD of 4-by-4 complex matrices followed by back substitution. Each matrix QRD is accompanied by rotations of four vectors for the second and subsequent turbo iterations. The proposed architecture implements the multiple vector rotation by multipliers …

Energy And Spectral Efficient Transmissions Of Coded Arq Systems, Jingxian Wu, Gang Wang, Yahong Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

Energy efficiency (EE) and spectral efficiency (SE) feature one of the most fundamental tradeoffs in communication systems. In this paper, we propose an optimum transmission scheme for coded Type-I automatic repeat request (ARQ) systems to balance the EE-SE tradeoff. The optimization is performed with respect to a new design metric, the normalized EE (NEE), which is defined as the energy per bit normalized by the SE. Minimizing NEE means either reducing the energy per bit or increasing the SE, it thus yields a balanced tradeoff between the two. The system design incorporates a wide range of practical system parameters, such …

Neural Network-Based Adaptive Event-Triggered Control Of Affine Nonlinear Discrete Time Systems With Unknown Internal Dynamics, Avimanyu Sahoo, Hao Xu, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the design of a neural network (NN) based adaptive model-based event-triggered control of an uncertain single input single output (SISO) nonlinear discrete time system in affine form is presented. The controller uses an adaptive estimator consisting of a single-layer NN not only to approximate the internal dynamics of an affine nonlinear discrete-time system but also to provide an estimate of the state vector during inter event interval. The NN weights of the adaptive NN estimator are tuned in a aperiodic manner at the event trigger instants unlike periodic updates in standard adaptive neural network (NN) control. A …

Adaptive Event-Triggered Control Of A Uncertain Linear Discrete Time System Using Measured Input And Output Data, Avimanyu Sahoo, Hao Xu, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, an adaptive model-based event-triggered control of an uncertain linear discrete time system is developed. Measured input and output vectors and their history are utilized to express the unknown linear discrete-time system as an autoregressive Markov representation (ARMarkov). A novel adaptive model in the form of AR Markov is proposed and an update law is derived in order to estimate parameters of the ARMarkov model at triggered instants unlike periodic updates in standard adaptive control. Lyapunov method is used to derive the event trigger condition, prove boundedness of the parameter vector and asymptotic convergence of the outputs and …

Neural Network-Based Optimal Control Of Mobile Robot Formations With Reduced Information Exchange, Travis Dierks, Bryan Brenner, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

A novel formation control scheme for mobile robots is introduced in the context of leader-follower framework with reduced communication exchange. The dynamical controller inputs for the robots are approximated from nonlinear optimal control techniques in order to track the designed control velocities generated by the kinematic controller. The proposed nonlinear optimal control technique, referred to as adaptive dynamic programming, uses neural networks (NNs) to solve the optimal formation control problem in discrete time in the presence of unknown internal dynamics and a known control coefficient matrix. A modification to the follower's kinematic controller is used to allow the desired formation …

Harmonic Distortion Optimization Of Cascaded H-Bridge Inverters Considering Device Voltage Drops And Noninteger Dc Voltage Ratios, Bill Diong, Hossein Sepahvand, Keith Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

This paper considers achieving the minimum total harmonic distortion (THD) or frequency-weighted THD (WTHD) of the staircase-modulated output voltage of single-phase multilevel inverters, with or without elimination of the lowest order harmonics. The minimal THD values, together with the corresponding step angles and dc voltage source ratios, have been obtained for the 5-, 7-, 9-, 11-, and 13-level cases; accounting for the device voltage drops when the load is resistive or is moderately inductive is described. Similarly, the minimal WTHD values, together with the corresponding step angles and dc source voltage ratios, have been obtained for the five-, seven-, and …

Convex Cones Of Generalized Positive Rational Functions And Nevanlinna-Pick Interpolation, Daniel Alpay, Izchak Lewkowicz

Mathematics, Physics, and Computer Science Faculty Articles and Research

Scalar rational functions with a non-negative real part on the right half plane, called positive, are classical in the study of electrical networks, dissipative systems, Nevanlinna-Pick interpolation and other areas. We here study generalized positive functions, i.e with a non-negative real part on the imaginary axis. These functions form a Convex Invertible Cone, cic in short, and we explore two partitionings of this set: (i) into (infinitely many non-invertible) convex cones of functions with prescribed poles and zeroes in the right half plane and (ii) each generalized positive function can be written as a sum of even and odd parts. …

Representation Formulas For Hardy Space Functions Through The Cuntz Relations And New Interpolation Problems, Daniel Alpay, Palle Jorgensen, Izchak Lewkowicz, Itzik Marziano

Mathematics, Physics, and Computer Science Faculty Articles and Research

We introduce connections between the Cuntz relations and the Hardy space H2 of the open unit disk D. We then use them to solve a new kind of multipoint interpolation problem in H2, where for instance, only a linear combination of the values of a function at given points is preassigned, rather than the values at the points themselves.

Comments On Alrc Discussion Paper 79, Copyright And The Digital Economy, June M. Besek, Jane C. Ginsburg, Philippa Loengard

Faculty Scholarship

We provide these comments in connection with the Australian Law Reform Commission’s ongoing study of copyright and the digital economy, and in particular its request for comments on the recommendations put forth in its Discussion Paper 79 (June 2013). We focus on US law, and how the US experience bears on the possibility of an open-ended uncompensated "fair use" type exception in Australia, and other related issues.

The fair use doctrine in the US provides great flexibility, but that flexibility in many instances comes at the cost of certainty and predictability. We are not suggesting that reasonable judgments cannot be …

Multi Geophysical Parameters For Earthquake Forecasting, Ramesh P. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

This article focuses on the importance of keeping the public aware of earthquake forecasting. This article also encourages proper seismic codes to design buildings in the seismic-prone regions because such practice can save lives and property associated with an earthquake.

Inter- And Intra-Annual Variability Of Vegetation In The Northern Hemisphere And Its Association With Precursory Meteorological Factors, Boksoon Myoung, Yong-Sang Choi, Seungbum Hong, Seon Ki Park

Mathematics, Physics, and Computer Science Faculty Articles and Research

Determination of phenological variation is one of the most critical challenges in dynamic vegetation modeling, given the lack of a strong theoretical framework. Previous studies generally focused on the timing of a phenological event (e.g., bud-burst or onset of growing season) and its atmospheric prompts, but not on the interactive variations across phenological stages. This study, therefore, investigated the inter- and intra-annual variability existing in all the phenological stages and the relations of the variability with four meteorological variables (surface temperature (Ts), shortwave radiation (SW ), vapor pressure deficit (VPD), and precipitation (PRCP)) using a 25-year (1982-2006) dataset of leaf …

Commentary Rethinking Airport Land-Cover Paradigms: Agriculture, Grass, And Wildlife Hazards, Travis L. Devault, Michael J. Begier, Jerrold L. Belant, Bradley F. Blackwell, Richard A. Dolbeer, James A. Martin, Thomas W. Seamans, Brian E. Washburn

Human–Wildlife Interactions

No abstract provided.

Avian Diets In A Saline Ecosystem: Great Salt Lake, Utah, Usa, Anthony J. Roberts

Human–Wildlife Interactions

Saline lakes provide a prey-rich, predator-free environment for birds to utilize during migration and stopover periods. The Great Salt Lake (GSL), Utah is the largest salt lake in North America and is utilized by millions of migratory birds. It also is host to multiple commercial endeavors. Proposed expansion of commercial use of the GSL would result in increased impounded area and water extraction for mineral production, which may increase the GSL’s salinity and negatively impact invertebrate abundance. I review previous literature and synthesize diets of avian species utilizing the GSL to determine the importance of each invertebrate species, including brine …

Recommended Management Strategies To Limit Anthropogenic Noise Impacts On Greater Sage-Grouse In Wyoming, Gail L. Patricelli, Jessica L. Blickley, Stacie L. Hooper

Human–Wildlife Interactions

Recent research has demonstrated that noise from natural gas development negatively impacts sage-grouse (Centrocercus urophasianus) abundance, stress levels, and behaviors. Other types of anthropogenic noise sources are similar to gas-development noise and, thus, the response by sage-grouse is likely to be similar. The results of research suggest that effective management of the natural soundscape is critical to the conservation and protection of sage-grouse. The goals of this review are to discuss current approaches in the management of new and existing noise sources in Wyoming and recommend research priorities for establishing effective noise management strategies. We make 4 interim …

Copyright 1992-2012: The Most Significant Development?, Jane C. Ginsburg

Faculty Scholarship

On the occasion of the twentieth anniversary of the Fordham Intellectual Property Law & Policy Conference, its organizer, Professor Hugh Hansen, planned a session on “U.S. Copyright Law: Where Has It Been? Where Is It Going?” and asked me to look back over the twenty years since the conference’s inception in order to identify the most important development in copyright during that period. Of course, the obvious answer is “the Internet,” or “digital media,” whose effect on copyright law has been pervasive. I want to propose a less obvious response, but first acknowledge that digital media and communications have presented …

Ensemble Forecasting Of Coronal Mass Ejections Using The Wsa-Enlil With Coned Model, D. Emmons, Ariel O. Acebal, A. Pulkkinen, A. Taktakishvili, Peter Macneice, D. Odstrcil

Faculty Publications

The combination of the Wang‐Sheeley‐Arge (WSA) coronal model, ENLIL heliospherical model version 2.7, and CONED Model version 1.3 (WSA‐ENLIL with CONED Model) was employed to form ensemble forecasts for 15 halo coronal mass ejections (halo CMEs). The input parameter distributions were formed from 100 sets of CME cone parameters derived from the CONED Model. The CONED Model used image processing along with the bootstrap approach to automatically calculate cone parameter distributions from SOHO/LASCO imagery based on techniques described by Pulkkinen et al. (2010). The input parameter distributions were used as input to WSA‐ENLIL to calculate the temporal evolution of the …

Automated Extraction And Classification Of Time-Frequency Contours In Humpback Vocalizations, Hui Ou, Whitlow W.L. Au, Lisa M. Zurk, Marc O. Lammers

Electrical and Computer Engineering Faculty Publications and Presentations

A time-frequency contour extraction and classification algorithm was created to analyze humpback whale vocalizations. The algorithm automatically extracted contours of whale vocalization units by searching for gray-level discontinuities in the spectrogram images. The unit-to-unit similarity was quantified by cross-correlating the contour lines. A library of distinctive humpback units was then generated by applying an unsupervised, cluster-based learning algorithm. The purpose of this study was to provide a fast and automated feature selection tool to describe the vocal signatures of animal groups. This approach could benefit a variety of applications such as species description, identification, and evolution of song structures. The …

A Transformation-Based Approach To Implication Of Gste Assertion Graphs, Gouwu Yang, William N. N. Hung, Xiaoyu Song, Wensheng Guo

Electrical and Computer Engineering Faculty Publications and Presentations

Generalized symbolic trajectory evaluation (GSTE) is a model checking approach and has successfully demonstrated its powerful capacity in formal verification of VLSI systems. GSTE is an extension of symbolic trajectory evaluation (STE) to the model checking of -regular properties. It is an alternative to classical model checking algorithms where properties are specified as finite-state automata. In GSTE, properties are specified as assertion graphs, which are labeled directed graphs where each edge is labeled with two labeling functions: antecedent and consequent. In this paper, we show the complement relation between GSTE assertion graphs and finite-state automata with the expressiveness of regular …

Intelligent Modeling And Verification, Gangming Luo, Graziano Chesi, Xiaoyu Song, Xiaojing Yang

Electrical and Computer Engineering Faculty Publications and Presentations

System modeling tends to have many complex features, and uncertainties often lead to numerous complications and influence many important aspects related to its applications. Intelligent modeling merges mathematical and computer based approaches, and it utilizes pioneering new scientific methods and cutting-edge technologies.

Characterization Of Evaporative Metal Bonding In Superalloys For Use In Gasified Coal Turbine Generators, Joshua Elliot Braband

Theses and Dissertations

The diffusion bonding of Kanthal APMT, CM247LC, and Rene 80 was studied. The objective of the first part of this work was to create diffusion bonded test samples of Kanthal APMT, CM247LC, and Rene 80 using a 25μm thick zinc interlayer at varying times and temperatures. Then, using scanning electron microscopy to determine the profile of the zinc diffusing into the parent materials, the diffusion coefficients of the zinc interlayer into the materials were determined for each of the materials at each bonding time and temperature. The next objective was to create a finite element model of the bonding process …

Optimization Of The Garch Model Parameters Using A Genetic Algorithm, Jonathon Patrick Cummings

Theses and Dissertations

Financial time series are often characterized by nonlinearity and volatility bunching. Standard regression analysis models cannot capture changing volatilities, potentially leading to erroneous results. The need to more completely model the characteristic volatilities inherent to financial time series eventually led to the creation of the GARCH model. Typical GARCH parameters are (1,1) incorporating a 1-period lag of the regression residual as well as a 1-period lag of the regression volatility. The primary question investigated in this paper is whether the typical GARCH(1,1) parameters are in fact optimal over all time periods and attempts to improve on the typical parameters by …

Determination Of Optimum Polymer Dose For Grand Forks Wastewater Treatment Plant Lagoon Sludge Dewatering, Dipesh Das

Theses and Dissertations

The Grand Forks Waste Water Treatment Plant (GFWWTP) is currently sending its waste activated sludge (WAS) from the activated sludge treatment process to an existing on-site wastewater treatment lagoon which has been in operation since 2003. The plant produces approximately 65,000 gallons of WAS per day. Because of this high level of loading, the existing lagoon system is no longer considered as a treatment option for the produced sludge. The Plant Authority is trying to find a sustainable solution for sludge disposal and for this reason the GFWWTP is interested in introducing screw press system for the dewatering process. As …

Does Google Search Data Aid In Predicting Unemployment?, Brennan Dyk

Theses and Dissertations

The unemployment rate is typically forecasted in the literature using initial claims for unemployment, a lagged value of unemployment, and an autoregressive component. This paper looks to improve upon existing models by adding Google search data to traditional models using initial claims or replacing initial claims with Google searches. One hypothesis is that Google searches may improve forecast accuracy due to employees knowing or getting a sense when they may become unemployed and be searching for jobs prior to filing for unemployment. Study of this is important to improve the accuracy of models and to provide more accurate out-of-sample forecasts …

A Framework For The Integration Of Technology Into Curricula Development And Student Assessment, Washington Helps

Theses and Dissertations

The purpose of this work is to amalgamate technology and education in a manner which will prove to be beneficial to all stakeholders involved and which will allow for an improvement in the ubiquitous process of curriculum development in the teaching and learning sphere. The primary motivation surrounds the issue of limited human resources in terms of teachers and expert knowledge as well as available physical resources such as computer equipment or other classroom artifacts. It should be duly noted that it is in many developing countries where the student-teacher ratio is very high and where such a framework will …

The Blue Lights: Stories, Brian Douglas Maxwell

Theses and Dissertations

The Blue Lights is a collection of episodic short stories that looks at life along Florida's Space Coast, a strip of beach best known for its shuttle launches and proximity to Disney World. Most of the stories are set along the Atlantic, and all of them chronicle the day-to-day activities of an insular and antiquated beach culture. The stories are unhurried, subtle in construction and inward rather than dramatic, meant to represent a pre-Internet, pre-cell phone Florida where characters stumble into small yet illuminating moments of self-realization set in recognizable, though run-down, places.

Though the stories vary stylistically, The Blue …

Exploring The Impact Of Zebra Mussels (Dreissena Polymorpha) On Residental Lakeshore Property Values In Otter Tail And Becker Counties, Minnesota, Spencer Crowley Mcgrew

Theses and Dissertations

Aquatic invasive species are a major problem in Minnesota. Aquatic invasive species disrupt ecosystems, limit lake recreation, and reduce lakeshore property values. They are expensive to manage, and often impossible to eradicate once established. In this study, I am asking this question: What is the economic impact, in terms of residential shoreline property values, of the introduction of the invasive zebra mussel (Dreissena polymorpha) into large and popular freshwater lakes in west central Minnesota?

Past studies comparing lakeshore property values based on environmental factors such as water quality, clarity, lake size, and depth have shown that these environmental amenities are …

Tanzania Higher Education-Fifty Years After Independence, Godfrey Magoti Mnubi

Theses and Dissertations

As Tanzania celebrates fifty years of independence at the crossroads of globalization, the country has experienced a changing landscape and a major transformation in higher learning education with spectacular expansion in student enrollment rates. This requires its higher education institutions, particularly universities, to function effectively as a source of knowledge and to serve as an important partner in sustainable development by promoting effective teaching, research and service in Tanzania.

To understand the pace of globalization and the multitude of social challenges that have faced Tanzania higher education since 1961, how the policies and practices of higher education have evolved over …

Towards More Efficient Enhanced Sampling Methods To Study Phase Transitions, Kenneth Ndumbe Ngale

Theses and Dissertations

The most familiar phase transitions observed in nature are associated with a change in the state of matter (solid, liquid, and gas). In some rare cases this may involve the plasma phase. Such transitions are often referred to as first order phase transitions and often occur commonly such as during the melting of snow or freezing of lakes and rivers during winter. This project focuses on the most ubiquitous phase changes such as, liquid-solid and vapor-liquid as well as the less prevalent vapor-solid transitions. These types of phase transitions are also known as classical phase transitions. They usually involve symmetry …

Epileptic Seizure Detection And Prediction From Electroencephalogram Using Neuro-Fuzzy Algorithms, Ahmed Fazle Rabbi

Theses and Dissertations

This dissertation presents innovative approaches based on fuzzy logic in epileptic seizure detection and prediction from Electroencephalogram (EEG). The fuzzy rule-based algorithms were developed with the aim to improve quality of life of epilepsy patients by utilizing intelligent methods. An adaptive fuzzy logic system was developed to detect seizure onset in a patient specific way. Fuzzy if-then rules were developed to mimic the human reasoning and taking advantage of the combination in spatial-temporal domain. Fuzzy c-means clustering technique was utilized for optimizing the membership functions for varying patterns in the feature domain. In addition, application of the adaptive neuro-fuzzy inference …

Machine Speech, Tim Wu

Faculty Scholarship

Computers are making an increasing number of important decisions in our lives. They fly airplanes, navigate traffic, and even recommend books. In the process, computers reason through automated algorithms and constantly send and receive information, sometimes in ways that mimic human expression. When can such communications, called here “algorithmic outputs,” claim First Amendment protection?