Digital Commons Network^™

Noise-Robust Automatic Speech Recognition Using A Predictive Echo State Network, Mark D. Skowronski, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

Artificial neural networks have been shown to perform well in automatic speech recognition (ASR) tasks, although their complexity and excessive computational costs have limited their use. Recently, a recurrent neural network with simplified training, the echo state network (ESN), was introduced by Jaeger and shown to outperform conventional methods in time series prediction experiments. We created the predictive ESN classifier by combining the ESN with a state machine framework. In small-vocabulary ASR experiments, we compared the noise-robust performance of the predictive ESN classifier with a hidden Markov model (HMM) as a function of model size and signal-to-noise ratio (SNR). The …

A Review Of Studies In Swarm Robotics, Levent Bayindir, Erol Şahi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

Swarm robotics is a new approach to the coordination of large numbers of relatively simple robots. The approach takes its inspiration from the system-level functioning of social insects which demonstrate three desired characteristics for multi-robot systems: robustness, flexibility and scalability. In this paper we have presented a preliminary taxonomy for swarm robotics and classified existing studies into this taxonomy after investigating the existing surveys related to swarm robotics literature. Our parent taxonomic units are modeling, behavior design, communication, analytical studies and problems. We are classifying existing studies into these main axes. Since existing reviews do not have enough number of …

Aggregation, Foraging, And Formation Control Of Swarms With Non-Holonomic Agents Using Potential Functions And Sliding Mode Techniques, Veysel Gazi̇, Bariş Fi̇dan, Y. Si̇nan Hanay, İlter Köksal

Turkish Journal of Electrical Engineering and Computer Sciences

In this article we consider the aggregation, foraging, and formation control of swarms whose agents are moving in 2-dimensions with non-holonomic unicycle agent dynamics. We approach these problems using artificial potentials and sliding mode control. The main contribution is extension of the recent results (mainly for aggregation) in the literature based on a similar approach for simple integrator agent dynamics models to a significantly more realistic and more difficult setting with non-holonomic unicycle agent dynamics models. In particular, we design continuous-time control schemes via a constructive analysis based on artificial potential functions and sliding mode control techniques. The effectiveness of …

Aggregation In Swarm Robotic Systems: Evolution And Probabilistic Control, Onur Soysal, Erki̇n Bahçeci̇, Erol Şahi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

In this study we investigate two approachees for aggregation behavior in swarm robotics systems: Evolutionary methods and probabilistic control. In first part, aggregation behavior is chosen as a case, where performance and scalability of aggregation behaviors of perceptron controllers that are evolved for a simulated swarm robotic system are systematically studied with different parameter settings. Using a cluster of computers to run simulations in parallel, four experiments are conducted varying some of the parameters. Rules of thumb are derived, which can be of guidance to the use of evolutionary methods to generate other swarm robotic behaviors as well. In the …

Swarm Robot Systems Based On The Evolution Of Personality Traits, Sidney Nascimento Givigi Jr.

Turkish Journal of Electrical Engineering and Computer Sciences

Game theory may be very useful in modeling and analyzing swarms of robots. Using game theory in conjunction with traits of personalities, we achieve intelligent swarm robots. Traits of personality are characteristics of each robot that define the robots' behaviours. The environment is represented as a game and due to the evolution of the traits through a learning process, we show how the robots may react intelligently to changes in the environment. A proof of convergence for the proposed algorithm is offered. The process of selection of traits is discussed and the potential of the modeling is demonstrated in several …

Creating Micro- And Nanostructures On Tubular And Spherical Surfaces, O. Lima, L. Tan, A. Goel, Mehrdad Negahban, Z. Li

Materials Research Science and Engineering Center: Faculty Publications

The authors developed a new technique to create micro- and nanometer scale structures on curved free-standing objects by combining embossing/imprinting lithography approaches with mechanical loadings on elastic films. Embossing/imprinting generates small structures and mechanical loading determines shape or geometry of the final object. As a result, a portion of the tubes with a radius between 0.5 and 3.5 mm and a portion of the spheres with a radius between 2.4 and 7.0 mm were fabricated with grating line features (period of 700 nm) and microlens array features (lens radius of 2.5 µm) atop, respectively. It was found that both static …

Geochemical Controls On Contaminant Uranium In Vadose Hanford Formation Sediments At The 200 Area And 300 Area, Hanford Site, Washington, James Mckinley, John M. Zachara, Jiamin Wan, David Mccready, Steven M. Heald

United States Department of Energy: Publications

Long-term historic spills of uranium at the 300 Area fuel fabrication site (58,000 kg of disposed uranium over 32 yr) and at the 200 East Area BX tank farm (7000 kg of spilled uranium in one event), both within the Hanford formation in the Hanford Site, Washington State, were investigated by subsurface sampling and subsequent microscale investigations of excavated samples. The 200 Area sediments contained uranyl silicate mineralization (sodium boltwoodite) in restrictive microfractures in granitic clasts, in the vadose zone over a narrow range in depth. Well logging and column experiments indicated that tank wastes migrated deeper than observed in …

Hanford Site Vadose Zone Studies: An Overview, G. W. Gee, M. Oostrom, M. D. Freshley, M. L. Rockhold, John M. Zachara

United States Department of Energy: Publications

Large quantities of radioactive and chemical wastes resulting from Pu production for nuclear weapons are located in the vadose zone at the USDOE’s Hanford Site, north of Richland, WA. The vadose zone here is characterized by often highly stratified glacial-fluvial sediments that give rise to complex subsurface-flow paths that contribute to uncertainty of contaminant fate and transport. Research efforts have focused on answering questions of contaminant transport from the viewpoint of geologic, biologic, geochemical, and hydrologic controls. This special section highlights key research topics concerning vadose zone problems at the Hanford Site. Research indicates that some of the contaminant species …

Florida Seagrass Habitat Evaluation: A Comparative Survey For Chemical Quality, Michael A. Lewis, Darrin D. Dantin, Cynthia A. Chancy, Kathryn Abel, Christopher G. Lewis

United States Environmental Protection Agency: Publications

Contaminant concentrations were determined for media associated with 13 Florida seagrass beds. Concentrations of 10 trace metals were more commonly detected in surface water, sediment and two seagrass species than PAHs, pesticides and PCBs. Concentrations of copper and arsenic in surface water exceeded Florida aquatic life criteria more frequently than other trace elements. Total organic carbon, mercury, chromium, zinc, total chlordane, total PAHs, total PCBs, DDD and DDE were significantly greater in seagrass-rooted sediments than adjacent non-vegetated sediments. Total DDT, DDD, DDE, total chlordane, arsenic, copper and nickel exceeded proposed sediment quality guidelines at six of 13 grass beds. Pesticides, …

Convergence Of Peridynamics To Classical Elasticity Theory, S. A. Silling, R. B. Lehoucq

United States Department of Energy: Publications

The peridynamic model of solid mechanics is a nonlocal theory containing a length scale. It is based on direct interactions between points in a continuum separated from each other by a finite distance. The maximum interaction distance provides a length scale for the material model. This paper addresses the question of whether the peridynamic model for an elastic material reproduces the classical local model as this length scale goes to zero. We show that if the motion, constitutive model, and any nonhomogeneities are sufficiently smooth, then the peridynamic stress tensor converges in this limit to a Piola-Kirchhoff stress tensor that …

Kinetics Of Reductive Dissolution Of Hematite By Bioreduced Anthraquinone-2,6-Disulfonate, Chongxuan Liu, John M. Zachara, Nancy Foster, Janae Strickland

United States Department of Energy: Publications

The reductive dissolution of hematite (α-Fe₂O₃) was investigated in a flow-through system using AH2DS, a reduced form of anthraquinone-2,6-disulfonate (AQDS), which is often used as a model electron shuttling compound in studies of dissimilatory microbial reduction of iron oxides. Influent flow rate, pH, and Fe(II) and phosphate concentrations were varied to investigate the redox kinetics in a flow-through reactor. The hematite reduction rates decreased with increasing pH from 4.5 to 7.6 and decreased with decreasing flow rate. The rates also decreased with increasing influent concentration of Fe(II) or phosphate that formed surface complexes at the experimental …

Respiration Of Metal (Hydr)Oxides By Shewanella And Geobacter: A Key Role For Multihaem C-Type Cytochromes, Liang Shi, Thomas C. Squier, John M. Zachara, James K. Fredrickson

United States Department of Energy: Publications

Dissimilatory reduction of metal (e.g. Fe, Mn) (hydr)oxides represents a challenge for microorganisms, as their cell envelopes are impermeable to metal (hydr)oxides that are poorly soluble in water. To overcome this physical barrier, the Gram-negative bacteria Shewanella oneidensis MR-1 and Geobacter sulfurreducens have developed electron transfer (ET) strategies that require multihaem c-type cytochromes (c-Cyts). In S. oneidensis MR-1, multihaem c-Cyts CymA and MtrA are believed to transfer electrons from the inner membrane quinone/quinol pool through the periplasm to the outer membrane. The type II secretion system of S. oneidensis MR-1 has been implicated in the reduction of metal …

Diversifying Biological Fuel Cell Designs By Use Of Nanoporous Filters, Justin C. Biffinger, Ricky Ray, Brenda Little, Bradley R. Ringeisen

United States Navy: Publications

The use of proton exchange membranes (PEMs) in biological fuel cells limits the diversity of novel designs for increasing output power or enabling autonomous function in unique environments. Here we show that selected nanoporous polymer filters (nylon, cellulose, or polycarbonate) can be used effectively in place of PEMs in a miniature microbial fuel cell (mini-MFC, device cross-section 2 cm²), generating a power density of 16 W/m³ with an uncoated graphite felt oxygen reduction reaction (ORR) cathode. The incorporation of polycarbonate or nylon membranes into biological fuel cell designs produced comparable power and durability to Nafion-117 membranes. Also, …

Influence Of Van Der Waals Forces On Increasing The Strength And Toughness In Dynamic Fracture Of Nanofibre Networks: A Peridynamic Approach, Florin Bobaru Ph.D.

Department of Engineering Mechanics: Faculty Publications

The peridynamic method is used here to analyse the effect of van der Waals forces on the mechanical behaviour and strength and toughness properties of three-dimensional nanofibre networks under imposed stretch deformation. The peridynamic formulation allows for a natural inclusion of long-range forces (such as van der Waals forces) by considering all interactions as ‘long-range’. We use van der Waals interactions only between different fibres and do not need to model individual atoms. Fracture is introduced at the microstructural (peridynamic bond) level for the microelastic type bonds, while van der Waals bonds can reform at any time. We conduct statistical …

Using Adaptive Management To Meet Conservation Goals, Thomas M. Franklin Franklin, Ronald Helinski Helinski, Andrew Manale Manale

United States Environmental Protection Agency: Publications

Natural resource professionals should know whether or not they are doing an effective job of managing natural resources. Their decision-making process should produce the kind of results desired by the public, elected officials, and their agencies’ leadership. With billions of dollars spent each year on managing natural resources, accountability is more important than ever. Producing results is the key to success. Managers must have the necessary data to make enlightened decisions during program implementation—not just at the conclusion of a program. Adaptive management is described as an adapt-and-learn methodology as it pertains to implementing Farm Bill conservation practices. Four regional …

Quantifying Kinematics Of Purposeful Movements To Real, Imagined, Or Absent Functional Objects: Implications For Modelling Trajectories For Robot-Assisted Adl Tasks, Kimberly J. Wisneski, Michelle J. Johnson

Biomedical Engineering Faculty Research and Publications

Background

Robotic therapy is at the forefront of stroke rehabilitation. The Activities of Daily Living Exercise Robot (ADLER) was developed to improve carryover of gains after training by combining the benefits of Activities of Daily Living (ADL) training (motivation and functional task practice with real objects), with the benefits of robot mediated therapy (repeatability and reliability). In combining these two therapy techniques, we seek to develop a new model for trajectory generation that will support functional movements to real objects during robot training. We studied natural movements to real objects and report on how initial reaching movements are affected by …

Mercury Blast Dictionaries: Analysis And Performance Measurement, Jeremy Buhler

All Computer Science and Engineering Research

This report describes a hashing scheme for a dictionary of short bit strings. The scheme, which we call near-perfect hashing, was designed as part of the construction of Mercury BLAST, an FPGA-based accelerator for the BLAST family of biosequence comparison algorithms. Near-perfect hashing is a heuristic variant of the well-known displacement hashing approach to building perfect hash functions. It uses a family of hash functions composed from linear transformations on bit vectors and lookups in small precomputed tables, both of which are especially appropriate for implementation in ardware logic. We show empirically that for inputs derived from genomic DNA sequences, …

Determining Alpha-Helix Correspondence For Protein Structure Prediction From Cryo-Em Density Maps, Master's Thesis, May 2007, Sasakthi S. Abeysinghe

All Computer Science and Engineering Research

Determining protein structure is an important problem for structural biologists, which has received a significant amount of attention in the recent years. In this thesis, we describe a novel, shape-modeling approach as an intermediate step towards recovering 3D protein structures from volumetric images. The input to our method is a sequence of alpha-helices that make up a protein, and a low-resolution volumetric image of the protein where possible locations of alpha-helices have been detected. Our task is to identify the correspondence between the two sets of helices, which will shed light on how the protein folds in space. The central …

Dna Repair In Incipient Alzheimer's Disease, Monika Ray, Weixiong Zhang

All Computer Science and Engineering Research

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder currently with no cure. Understanding the pathogenesis in the early stages of late-onset AD can help gain important mechanistic insights into this disease as well as aid in effective drug development. The analysis of incipient AD is steeped in difficulties due to its slight pathological and genetic differences from normal ageing. The difficulty also lies in the choice of analysis techniques as statistical power to analyse incipient AD with a small sample size, as is common in pilot studies, can be low if the proper analytical tool is not employed. In this …

Control Of A Robotic Arm Using Low-Dimensional Emg And Ecog Biofeedback, Timothy M. Blackely, William D. Smart

All Computer Science and Engineering Research

In this dissertation we describe a system that uses a low dimensional input derived from electromyography and electrocorticography data to control a robot. The work involves creating a system that allows signals recorded directly from a human body to allow control of a small robot arm. We compare direct joystick control with electromyogram (EMG) input to determine if one input system is superior, or if the quality of control between them is comparable. We also verify the system that is used to record the electromyogram signals is adaptable to other forms of biosignal input; in particular, direct connection to a …

Roadmap Analysis Of Protein-Protein Interactions. Master's Thesis, August 2007, Brian C. Haynes

All Computer Science and Engineering Research

The ability to effectively model the interaction between proteins is an important and open problem. In molecular biology it is well accepted that from sequence arises form and from form arises function but relating structure to function remains a challenge. The function of a given protein is defined by its interactions. Likewise a malfunction or a change in protein-protein interactions is a hallmark of many diseases. Many researchers are studying the mechanisms of protein-protein interactions and one of the overarching goals of the community is to predict whether two proteins will bind, and if so what the final conformation will …

Dynamic Modeling And Simulations Of Solid Oxide Fuel Cells For Grid-Tied Applications, Nagasmitha Akkinapragada

Masters Theses

"As energy consumption rises, one must find suitable alternative means of generation to supplement conventional existing generation facilities. In this regard, distributed generation (DG) will continue to play a critical role in the energy supply-demand realm. The common technologies available as DG are micro-turbines, solar photovoltaic systems, fuel cells stack and wind energy systems. In this thesis, a dynamic model of solid oxide fuel cell (SOFC) is presented. Fuel cells operate at low voltages and hence need to be boosted and inverted in order to be connected to the utility grid. The interconnection of the SOFC with a DC-DC converter …

Advanced Controller Design Using Neural Networks For Nonlinear Dynamic Systems With Application To Micro/Nano Robotics, Qinmin Yang

Doctoral Dissertations

"The dissertation focuses on neural network (NN) control designs for nonlinear systems with application to micro/nano robotic. Critical problems in nano scale including thermal drift are also addressed"--Abstract, page iv.

Architecting System Of Systems: Artificial Life Analysis Of Financial Market Behavior, Nil Hande Ergin

Doctoral Dissertations

"This research study focuses on developing a framework that can be utilized by system architects to understand the emergent behavior of system architectures. The objective is to design a framework that is modular and flexible in providing different ways of modeling sub-systems of System of Systems. At the same time, the framework should capture the adaptive behavior of the system since evolution is one of the key characteristics of System of Systems. Another objective is to design the framework so that humans can be incorporated into the analysis. The framework should help system architects understand the behavior as well as …

Modeling Network Traffic On A Global Network-Centric System With Artificial Neural Networks, Douglas K. Swift

Doctoral Dissertations

"This dissertation proposes a new methodology for modeling and predicting network traffic. It features an adaptive architecture based on artificial neural networks and is especially suited for large-scale, global, network-centric systems. Accurate characterization and prediction of network traffic is essential for network resource sizing and real-time network traffic management. As networks continue to increase in size and complexity, the task has become increasingly difficult and current methodology is not sufficiently adaptable or scaleable. Current methods model network traffic with express mathematical equations which are not easily maintained or adjusted. The accuracy of these models is based on detailed characterization of …

Terahertz Data Processing For Standoff Detection Of Improvised Explosive Devices, Amit Bipin Shah

Masters Theses

"Improvised Explosive Devices (IEDs) are homemade, non-conventional explosive devices, which are used to destruct and incapacitate individuals and property. IEDs are becoming a popular weapon of attack among terrorists and insurgents due to their easy of making and capability to cause major damage. Hence, is has become necessary to develop efficient systems for detecting and disarming these devices. The Terahertz technology which uses electromagnetic radiations between 0.3 THz to 10 THz for imaging is one of the most recently developed detection techniques and is ideally suitable for detection of IEDs and similar devices. Although a lot of work has been …

Fine Particle Classification Using Dilute Fluidized Beds, Rajasekharan Pillai Annapoorneswari

Masters Theses

"The main objective of this project is to classify spherical soda-lime glass particles based on their size using a dilute fluidized bed system. The influence of inclined plates in the column, plate separation, plate inclination, and number of plates on the overall separation efficiency of particles will be investigated. The effect of column shape on the classification efficiency will also be assessed"--Introduction, page 3.

Vapor Phase Uptake Of Volatile Organic Contaminants By Hybrid Poplar Trees, Sally Rebecca Breite

Masters Theses

"Phytoremediation, the use of plants to immobilize, degrade or remove contaminants from the environment, shows great promise as a remediation technique for many contaminated sites. Phytovolatilization in particular is of great interest for sites contaminated with chlorinated solvents and other volatile organic compounds (VOCs), many of which are recalcitrant to biodegradation. Hybrid poplar trees have been shown to uptake, translocate and volatilize numerous aqueous-phase VOCs, however vapor phase uptake of such compounds has only recently been observed and for only one contaminant, tetrachloroethylene (PCE). One semi-volatile and five volatile compounds were dosed to poplar trees in aqueous and vapor phase …

Microfluidic Biosensors For Intelligent Metabolite Monitoring, Nitin Radhakrishnan

Masters Theses

"Baseline (zero-value) drift and sensitivity degradation are two common problems related with biosensors. In order to overcome these problems, there is a great need for integrating an on-demand, in situ self-diagnosis and self-calibration unit along with the sensor. Utilizing the microfluidic technology, it is possible to explore the feasibility of implementing this function without any externally coupled bulky apparatus. A microsystem including a microfluidic channel and calibration electrodes are prepared by microfabrication techniques"--Abstract, page iv.

The Effect Of Object Color On Depth Ordering, Reynold Bailey, Cindy Grimm, Christopher Davoli, Richard Abrams

All Computer Science and Engineering Research

The relationship between color and perceived depth for realistic, colored objects with varying shading was explored. Background: Studies have shown that warm-colored stimuli tend to appear nearer in depth than cool-colored stimuli. The majority of these studies asked human observers to view physically equidistant, colored stimuli and compare them for relative depth. However, in most cases, the stimuli presented were rather simple: straight colored lines, uniform color patches, point light sources, or symmetrical objects with uniform shading. Additionally, the colors were typically highly saturated. Although such stimuli are useful for isolating and studying depth cues in certain contexts, they leave …