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Full-Text Articles in Engineering

Generalized Framework For Similarity Measure Of Time Series, Hongsheng Yin, Honggang Qi, Jingwen Xu, William N. N. Hung, Xiaoyu Song Dec 2014

Generalized Framework For Similarity Measure Of Time Series, Hongsheng Yin, Honggang Qi, Jingwen Xu, William N. N. Hung, Xiaoyu Song

Electrical and Computer Engineering Faculty Publications and Presentations

Currently, there is no definitive and uniform description for the similarity of time series, which results in difficulties for relevant research on this topic. In this paper, we propose a generalized framework to measure the similarity of time series. In this generalized framework, whether the time series is univariable or multivariable, and linear transformed or nonlinear transformed, the similarity of time series is uniformly defined using norms of vectors or matrices.The definitions of the similarity of time series in the original space and the transformed space are proved to be equivalent. Furthermore, we also extend the theory on similarity of …


Simulation Of A Rising Sun Magnetron Employing A Faceted Cathode With A Continuous Current Source, Sulmer Fernandez-Gutierrez, Jim Browning, Ming-Chieh Lin, David N. Smithe, Jack Watrous Nov 2014

Simulation Of A Rising Sun Magnetron Employing A Faceted Cathode With A Continuous Current Source, Sulmer Fernandez-Gutierrez, Jim Browning, Ming-Chieh Lin, David N. Smithe, Jack Watrous

Electrical and Computer Engineering Faculty Publications and Presentations

It has been proposed that gated field emitters could be used in place of conventional thermionic cathodes to control the current injection in a magnetron, both temporally and spatially. Since gated field emitters have to be fabricated on flat surfaces, a faceted cathode would be used to implement this approach. A 2D ten cavity, rising sun magnetron has been modeled using the particle-in-cell code VORPAL. Cylindrical, five-sided, and ten-sided faceted cathodes were modeled to study the variation of magnetron operation due to the cathode shape. This work shows the results of the device performance employing three different cathode geometries with …


Unconventional Computing Catechism, Christof Teuscher Nov 2014

Unconventional Computing Catechism, Christof Teuscher

Electrical and Computer Engineering Faculty Publications and Presentations

What makes a new paradigm or technology promising? What should science, research, and industry invest money in? Is there a life after CMOS electronics? And will the vacuum tube be back? While one cannot predict the future, one can still learn from the past. Over the last decade, unconventional computing developed into a major new research area with the goal to look beyond existing paradigms. In this Perspective, we reflect on the current state of the field and propose a set of questions that anyone working in unconventional computing should be able to answer in order to assess the potential …


Geoacoustic Inversion Of Ship Radiated Noise In Shallow Water Using Data From A Single Hydrophone, Steven E. Crocker, Peter L. Nielsen, James H. Miller, Martin Siderius Nov 2014

Geoacoustic Inversion Of Ship Radiated Noise In Shallow Water Using Data From A Single Hydrophone, Steven E. Crocker, Peter L. Nielsen, James H. Miller, Martin Siderius

Electrical and Computer Engineering Faculty Publications and Presentations

The Centre for Maritime Research and Experimentation conducted a geoacoustic inverse experiment in the Mediterranean Sea in the summer of 2012. Among the objectives was to employ an autono- mous underwater vehicle to collect acoustic data to invert for properties of the seafloor. Inversion results for the compression wave speed in the bottom and the source spectrum of the R/V Alliance during a close approach to the bottom moored vehicle are presented. The estimated wave speed was 1529 m/s (r ¼ 10). The source spectrum of the Alliance was estimated across more than six octaves of frequency.


Noise-Enhanced Information Systems, Hao Chen, Lav R. Varshney, Pramod K. Varshney Oct 2014

Noise-Enhanced Information Systems, Hao Chen, Lav R. Varshney, Pramod K. Varshney

Electrical and Computer Engineering Faculty Publications and Presentations

Noise, traditionally defined as an unwanted signal or disturbance, has been shown to play an important constructive role in many information processing systems and algorithms. This noise enhancement has been observed and employed in many physical, biological, and engineered systems. Indeed stochastic facilitation (SF) has been found critical for certain biological information functions such as detection of weak, subthreshold stimuli or suprathreshold signals through both experimental verification and analytical model simulations. In this paper, we present a systematic noise-enhanced information processing framework to analyze and optimize the performance of engineered systems. System performance is evaluated not only in terms of …


Formalization Of Matrix Theory In Hol4, Zhiping Shi, Yan Zhang, Zhenke Liu, Xinan Kang, Yong Guan, Jie Zhang, Xiaoyu Song Aug 2014

Formalization Of Matrix Theory In Hol4, Zhiping Shi, Yan Zhang, Zhenke Liu, Xinan Kang, Yong Guan, Jie Zhang, Xiaoyu Song

Electrical and Computer Engineering Faculty Publications and Presentations

Matrix theory plays an important role in modeling linear systems in engineering and science. To model and analyze the intricate behavior of complex systems, it is imperative to formalize matrix theory in a metalogic setting. This paper presents the higherorder logic (HOL) formalization of the vector space and matrix theory in the HOL4 theorem proving system. Formalized theories include formal definitions of real vectors and matrices, algebraic properties, and determinants, which are verified in HOL4. Two case studies, modeling and verifying composite two-port networks and state transfer equations, are presented to demonstrate the applicability and effectiveness of our work.


Compact Verilog-A Modeling Of Silicon Traveling-Wave Modulator For Hybrid Cmos Photonic Circuit Design, Kehan Zhu, Vishal Saxena, Wan Kuang Aug 2014

Compact Verilog-A Modeling Of Silicon Traveling-Wave Modulator For Hybrid Cmos Photonic Circuit Design, Kehan Zhu, Vishal Saxena, Wan Kuang

Electrical and Computer Engineering Faculty Publications and Presentations

A compact Verilog-A model of silicon-based junction traveling-wave Mach-Zehnder modulator (MZM) is developed for hybrid CMOS and photonic system-level simulation in Cadence environment. Critical device functions such as the voltage dependent change of refractive index, small-signal RLGC parameters for the MZM arms are extracted from the photonic device characterization from OpSIS foundry. Thermo-optical coefficient is also considered in the model. Simulation results including electro-optic S21 is characterized for the phase modulator's bandwidth. Also, transient MZM operation with non-return to zero (NRZ) data transmission at 10 Gb/s and 20 Gb/s rates are demonstrated.


Passive Localization Of Noise-Producing Targets Using A Compact Volumetric Array, John Gebbie, Martin Siderius, Peter L. Nielsen, James Miller Jul 2014

Passive Localization Of Noise-Producing Targets Using A Compact Volumetric Array, John Gebbie, Martin Siderius, Peter L. Nielsen, James Miller

Electrical and Computer Engineering Faculty Publications and Presentations

A technique is presented for passively localizing multiple noise-producing targets by cross-correlating the elevation beams of a compact volumetric array on separate bearings. A target’s multipath structure inherently contains information about its range; however, unknown, random noise waveforms make time separation of individual arrivals difficult. Ocean ambient noise has previously been used to measure multipath delays to the seabed by cross-correlating the beams of a vertical line array [Siderius, Song, Gerstoft, Hodgkiss, Hursky, and Harrison, J. Acoust. Soc. Am. 127, 2193–2200 (2010)], but this methodology has not been applied to distant noise sources having non-vertical arrivals. The technique presented in …


Coherence Extrapolation For Underwater Ambient Noise, Jorge Quijano, Stan E. Dosso, Martin Siderius, Lanfranco Muzi Jun 2014

Coherence Extrapolation For Underwater Ambient Noise, Jorge Quijano, Stan E. Dosso, Martin Siderius, Lanfranco Muzi

Electrical and Computer Engineering Faculty Publications and Presentations

This paper considers extrapolation of the vertical coherence of surface-generated oceanic ambient noise to simulate measurements made on a longer sensor array. The extrapolation method consists of projecting the noise coherence measured with a limited aperture array into the domain spanned by prolate spheroidal wave functions, which are an orthogonal basis defined by array parameters and the noise frequency. Using simulated data corresponding to selected multi-layered seabeds as ground truth, the performance of the extrapolation method is explored. Application of the technique is also demonstrated on experimental data.


Sparsity-Based Edge Noise Removal From Bilevel Graphical Document Images, Thai V. Hoang, Elisa H. Barney Smith, Salvatore Tabbone Jun 2014

Sparsity-Based Edge Noise Removal From Bilevel Graphical Document Images, Thai V. Hoang, Elisa H. Barney Smith, Salvatore Tabbone

Electrical and Computer Engineering Faculty Publications and Presentations

This paper presents a new method to remove edge noise from graphical document images using geometrical regularities of the graphics contours that exist in the images. Denoising is understood as a recovery problem and is accomplished by employing a sparse representation framework in the form of a basis pursuit denoising algorithm. Directional information of the graphics contours is encoded by atoms in an overcomplete dictionary which is designed to match the input data. The optimal precision parameter used in this framework is shown to have a linear relationship with the level of the noise that exists in the image. Experimental …


Phase Control And Fast Start-Up Of A Magnetron Using Modulation Of An Addressable Faceted Cathode, J. Browning, S. Fernandez-Gutierrez, M. C. Lin, D. N. Smithe, J. Watrous Jun 2014

Phase Control And Fast Start-Up Of A Magnetron Using Modulation Of An Addressable Faceted Cathode, J. Browning, S. Fernandez-Gutierrez, M. C. Lin, D. N. Smithe, J. Watrous

Electrical and Computer Engineering Faculty Publications and Presentations

The use of an addressable, faceted cathode has been proposed as a method of modulating current injection in a magnetron to improve performance and control phase. To implement the controllable electron emission, five-sided and ten-sided faceted planar cathodes employing gated field emitters are considered as these emitters could be fabricated on flat substrates. For demonstration, the conformal finite-difference time-domain particle-in-cell simulation, as implemented in VORPAL, has been used to model a ten-cavity, rising sun magnetron using the modulated current sources and benchmarked against a typical continuous current source. For the modulated, ten-sided faceted cathode case, the electrons are injected from …


An Eigenvector-Based Test For Local Stationarity Applied To Array Processing, Jorge Quijano, Lisa M. Zurk Jun 2014

An Eigenvector-Based Test For Local Stationarity Applied To Array Processing, Jorge Quijano, Lisa M. Zurk

Electrical and Computer Engineering Faculty Publications and Presentations

In sonar array processing, a challenging problem is the estimation of the data covariance matrix in the presence of moving targets in the water column, since the time interval of data local stationarity is limited. This work describes an eigenvector-based method for proper data segmentation into intervals that exhibit local stationarity, providing data-driven higher bounds for the number of snapshots available for computation of time-varying sample covariance matrices. Application of the test is illustrated with simulated data in a horizontal array for the detection of a quiet source in the presence of a loud interferer.


Energy-Efficient Stdp-Based Learning Circuits With Memristor Synapses, Xinyu Wu, Vishal Saxena, Kristy A. Campbell May 2014

Energy-Efficient Stdp-Based Learning Circuits With Memristor Synapses, Xinyu Wu, Vishal Saxena, Kristy A. Campbell

Electrical and Computer Engineering Faculty Publications and Presentations

It is now accepted that the traditional von Neumann architecture, with processor and memory separation, is ill suited to process parallel data streams which a mammalian brain can efficiently handle. Moreover, researchers now envision computing architectures which enable cognitive processing of massive amounts of data by identifying spatio-temporal relationships in real-time and solving complex pattern recognition problems. Memristor cross-point arrays, integrated with standard CMOS technology, are expected to result in massively parallel and low-power Neuromorphic computing architectures. Recently, significant progress has been made in spiking neural networks (SNN) which emulate data processing in the cortical brain. These architectures comprise of …


Low-Current Sensing Circuit And Topology For Portable Gamma Radiation Sensor, M. S. Ailavajhala, M. R. Latif, M. Mitkova Apr 2014

Low-Current Sensing Circuit And Topology For Portable Gamma Radiation Sensor, M. S. Ailavajhala, M. R. Latif, M. Mitkova

Electrical and Computer Engineering Faculty Publications and Presentations

A sensing circuit is presented for a portable/handheld semiconductor based radiation sensor, which senses low current changes without the inclusion of transistor noise issues. This circuit design block was implemented using supporting circuit architectures to enable sensing between 33pA to 1nA using low voltages. Additionally, a unique circuit topology is presented by which the effect of radiation damage to the silicon substrate and any devices on the substrate is reduced.


Ion Beam Effect On Ge-Se Chalcogenide Glass Films: Non-Volatile Memory Array Formation, Structural Changes And Device Performance, M. R. Latif, T. L. Nichol, M. Mitkova, D. A. Tenne, I. Csarnovics, S. Kokenyesi, A. Csik Apr 2014

Ion Beam Effect On Ge-Se Chalcogenide Glass Films: Non-Volatile Memory Array Formation, Structural Changes And Device Performance, M. R. Latif, T. L. Nichol, M. Mitkova, D. A. Tenne, I. Csarnovics, S. Kokenyesi, A. Csik

Electrical and Computer Engineering Faculty Publications and Presentations

In this work a scheme for fabricating a conductive bridge non-volatile memory arrays, using ion bombardment through a mask, is demonstrated. Blanket films and devices have been created to study the structural changes, surface roughness and device performance. Ar+ ions interaction on thin films of GexSe1−x system have been studied using Raman Spectroscopy, Atomic Force Microscopy (AFM) and Energy Dispersive X-Ray Spectroscopy (EDS). The performance of the memory devices has been analyzed based on the formation of vias and damage accumulation due to Ar+ ion interactions with GexSe1−x(x=0.25, 0.3 and 0.4) …


A Reference System For Animal Biometrics: Application To The Northern Leopard Frog, D. Petrovska-Delacrétaz, A. Edwards, J. Chiasson, G. Chollet, D. Pilliod Mar 2014

A Reference System For Animal Biometrics: Application To The Northern Leopard Frog, D. Petrovska-Delacrétaz, A. Edwards, J. Chiasson, G. Chollet, D. Pilliod

Electrical and Computer Engineering Faculty Publications and Presentations

Reference systems and public databases are available for human biometrics, but to our knowledge nothing is available for animal biometrics. This is surprising because animals are not required to give their agreement to be in a database. This paper proposes a reference system and database for the northern leopard frog (Lithobates pipiens). Both are available for reproducible experiments. Results of both open set and closed set experiments are given.


A 1 Gs/S, 31 Mhz Bw, 76.3 Db Dynamic Range, 34 Mw Ct-Δς Adc With 1.5 Cycle Quantizer Delay And Improved Stf, Sakkarapani Balagopal, Kehan Zhu, Vishal Saxena Feb 2014

A 1 Gs/S, 31 Mhz Bw, 76.3 Db Dynamic Range, 34 Mw Ct-Δς Adc With 1.5 Cycle Quantizer Delay And Improved Stf, Sakkarapani Balagopal, Kehan Zhu, Vishal Saxena

Electrical and Computer Engineering Faculty Publications and Presentations

A 1 GS/s continuous-time delta-sigma modulator (CT- ΔΣM) with 31 MHz bandwidth, 76.3 dB dynamic range and 72.5 dB peak-SNDR is reported in a 0.13 μm CMOS technology. The design employs an excess loop delay (ELD) of more than one clock cycle for achieving higher sampling rate. The ELD is compensated using a fast-loop formed around the last integrator by using a sample-and-hold. Further, the effect of this ELD compensation scheme on the signal transfer function (STF) of a feedforward CT- ΔΣ architecture has been analyzed and reported. In this work, an improved STF is achieved by using a combination …


A Low-Cost Wireless Portable Particulate Matter Monitoring System, Sin Ming Loo, James A. Hall, Joshua Kiepert, Michael Pook, Nicholas Terrell Jan 2014

A Low-Cost Wireless Portable Particulate Matter Monitoring System, Sin Ming Loo, James A. Hall, Joshua Kiepert, Michael Pook, Nicholas Terrell

Electrical and Computer Engineering Faculty Publications and Presentations

This paper describes a portable sensor system design for environmental research. The designed system has been deployed in many environments and has been EMI/EMC approved for operation in commercial aircraft cabins. The sensor suite includes particulate matter, CO, CO2, temperature, humidity, pressure, light intensity, and sound sensors. Multiple sensor systems can be deployed at once to form a wireless sensor network. Each sensor node is powered either with six AA batteries or via a transformer and standard outlet. The data collected by a node can be stored locally on the device and/or sent through the integrated ZigBee mesh network to …


Timing And Carrier Synchronization With Channel Estimation In Af Two-Way Relaying Networks, Ali A. Nasir, Hani Mehrpouyan, Salman Durrani, Steven D. Bolstein, Rodney A. Kennedy Jan 2014

Timing And Carrier Synchronization With Channel Estimation In Af Two-Way Relaying Networks, Ali A. Nasir, Hani Mehrpouyan, Salman Durrani, Steven D. Bolstein, Rodney A. Kennedy

Electrical and Computer Engineering Faculty Publications and Presentations

Two-way relaying networks (TWRNs) allow for more bandwidth efficient use of the available spectrum since they allow for simultaneous information exchange between two users with the assistance of an intermediate relay node. However, due to superposition of signals at the relay node, the received signal at the user terminals is affected by multiple impairments, i.e., channel gains, timing offsets, and carrier frequency offsets, that need to be jointly estimated and compensated. This paper presents the system model for amplify-and-forward (AF) TWRNs in the presence of multiple impairments and proposes least squares and differential evolution based algorithms for joint estimation …


Rt-Dsp Using ”See Through”, Cameron H. G. Wright, Thad B. Welch, Michael G. Morrow Jan 2014

Rt-Dsp Using ”See Through”, Cameron H. G. Wright, Thad B. Welch, Michael G. Morrow

Electrical and Computer Engineering Faculty Publications and Presentations

Engineering educators teaching digital signal processing (DSP) have found that using hands-on exercises for students can smooth the transition from theory to practical real-time DSP. However, before significant learning can begin using such exercises, students must build their confidence in the hardware and software platforms. When using audio signals, a “talk-through” project accomplishes this. For introducing more complicated signals such as video, the authors propose the use of a “see-through” project. This paper provides a description of a see-through project on a high-performance real-time DSP platform, discusses how such a project can lead to better follow-on learning using more advanced …


Simulation Of Electron Hop Funnels Using Version 9.2 Of Lorentz-2e, Tyler Rowe, Marcus Pearlman, Jim Browning Jan 2014

Simulation Of Electron Hop Funnels Using Version 9.2 Of Lorentz-2e, Tyler Rowe, Marcus Pearlman, Jim Browning

Electrical and Computer Engineering Faculty Publications and Presentations

Electron hop funnels have been simulated using the new version of the particle trajectory simulation software, Lorentz-2E. Simulations were conducted to determine the validity of the version 9.2 results and the consistency of the results to a previous version of the software, version 8.0. In addition, a new method of injecting a uniform current with all rays of equal charge is discussed, and the results of the method are presented. Version 9.2 of the software was successfully implemented and a new emission model tested. The transition of the software version will allow for faster simulation times of the electron hop …


Functional Verification Of High Performance Adders In Coq, Qian Wang, Xiaoyu Song, Ming Gu, Jiaguang Sun Jan 2014

Functional Verification Of High Performance Adders In Coq, Qian Wang, Xiaoyu Song, Ming Gu, Jiaguang Sun

Electrical and Computer Engineering Faculty Publications and Presentations

Addition arithmetic design plays a crucial role in high performance digital systems. The paper proposes a systematic method to formalize and verify adders in a formal proof assistant COQ. The proposed approach succeeds in formalizing the gate-level implementations and verifying the functional correctness of the most important adders of interest in industry, in a faithful, scalable, and modularized way. The methodology can be extended to other adder architectures as well.


Reliability Analysis For Chain Topology Wireless Sensor Networks With Multiple-Sending Transmission Scheme, Jie Cai, Xiaoyu Song, Jinyuan Wang, Ming Gu Jan 2014

Reliability Analysis For Chain Topology Wireless Sensor Networks With Multiple-Sending Transmission Scheme, Jie Cai, Xiaoyu Song, Jinyuan Wang, Ming Gu

Electrical and Computer Engineering Faculty Publications and Presentations

Reliability analysis is a key problem in wireless sensor networks (WSNs). The primary contribution of this paper is an in-depth study of the reliability of a chain topology wireless sensor network with multiple-sending scheme. We study the wireless link reliability for the fading channels. The node energy availability for the source and relay nodes is investigated in terms of the limited node energy. The instantaneous network reliability and the mean time to failure are derived. Finally, the initial node energy allocation scheme is proposed to balance the lifetime of each sensor node, thus reducing the total energy consumption. The simulation …


Cost Minimization Approach To Synthesis Of Linear Reversible Circuits, Ben Schaeffer, Marek Perkowski Jan 2014

Cost Minimization Approach To Synthesis Of Linear Reversible Circuits, Ben Schaeffer, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

This paper presents a heuristic cost minimization approach to synthesizing linear reversible circuits. Two bidirectional linear reversible circuit synthesis methods are introduced, the Alternating Elimination with Cost Minimization method (AECM) and the Multiple CNOT Gate method (MCG). Algorithms, example syntheses, and extensions to these methods are presented. An MCG variant which incorporates line reordering is introduced. Tests comparing the new cost minimization methods with the best known method for large circuits are presented. Results show that of the three methods MCG had the lowest average CNOT gate counts for linear reversible circuits up to 24 lines, and that AECM had …