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2020

Portland State University

Electrical and Computer Engineering Faculty Publications and Presentations

Articles 1 - 21 of 21

Full-Text Articles in Engineering

Virtual Head Waves In Ocean Ambient Noise: Theory And Modeling, Jie Li, Peter Gerstoft, Martin Siderius, Jun Fan Dec 2020

Virtual Head Waves In Ocean Ambient Noise: Theory And Modeling, Jie Li, Peter Gerstoft, Martin Siderius, Jun Fan

Electrical and Computer Engineering Faculty Publications and Presentations

The Green's function retrieval in media with horizontal boundaries usually only considers the extraction of direct and reflected waves but ignores the virtual head waves, which have been observed experimentally from ocean ambient noise and used to invert for geometric and environmental parameters. This paper derives the extraction of virtual head waves from ocean ambient noise using a vertically spaced sensor pair in a Pekeris waveguide. Ocean ambient noise in the water column is a superposition of direct, reflected, and head waves. The virtual head waves are produced by the cross-correlations between head waves and either reflected waves or other …


Distributed Energy Resource Aggregation Using Customer-Owned Equipment: A Review Of Literature And Standards, Manasseh Obi, Tylor Slay, Robert B. Bass Nov 2020

Distributed Energy Resource Aggregation Using Customer-Owned Equipment: A Review Of Literature And Standards, Manasseh Obi, Tylor Slay, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

Large-scale deployment of renewable energy resources, both utility-scale and distributed, create reliability concerns for electrical power system operators. The weather-dependent, non-dispatchable nature of renewable resources decreases the ability of operators to match supply with demand. Concurrently, distributed energy resources, defined as small-scale loads, generation sources, and storage systems, are becoming ubiquitous within modern electrical systems. This literature review presents the grid services that utilities use to alleviate power systems reliability concerns, particularly those caused by renewable resources, and how aggregations of residential-scale distributed energy resources can be used to provide these services.

By aggregating distributed energy resources en masse to …


A Simplified Accuracy Enhancement To The Saleh Am/Am Modeling And Linearization Of Solid-State Rf Power Amplifiers, Haider Al-Kanan, Fu Li Oct 2020

A Simplified Accuracy Enhancement To The Saleh Am/Am Modeling And Linearization Of Solid-State Rf Power Amplifiers, Haider Al-Kanan, Fu Li

Electrical and Computer Engineering Faculty Publications and Presentations

The Saleh behavioral model exhibits high prediction accuracy for nonlinearity of traveling-wave tube power amplifiers (TWT-PAs). However, the accuracy of the Saleh model degrades when modeling solid-state power amplifiers (SSPAs) technology. In addition, the polynomial expansion of the Saleh model consists of only odd-order terms as analyzed in this work. This paper proposes a novel model accuracy enhancement for the Saleh amplitude-to-amplitude (AM/AM) model when applied to radio frequency (RF) SSPAs. The proposed model enhancement accounts for the second-order intermodulation distortion, which is an important nonlinearity challenge in wideband wireless communications. The proposed static AM/AM model is a three-parameter rational …


Effect Of Bout Length On Gait Measures In People With And Without Parkinson’S Disease During Daily Life, Vrutangkumar Shah, James Mcnames, Graham Harker, Martina Mancini, Patricia Carlson-Kuhta, John G. Nutt, Mahmoud El-Gohary, Carolin Curtze, Fay Horak Oct 2020

Effect Of Bout Length On Gait Measures In People With And Without Parkinson’S Disease During Daily Life, Vrutangkumar Shah, James Mcnames, Graham Harker, Martina Mancini, Patricia Carlson-Kuhta, John G. Nutt, Mahmoud El-Gohary, Carolin Curtze, Fay Horak

Electrical and Computer Engineering Faculty Publications and Presentations

Although the use of wearable technology to characterize gait disorders in daily life is increasing, there is no consensus on which specific gait bout length should be used to characterize gait. Clinical trialists using daily life gait quality as study outcomes need to understand how gait bout length affects the sensitivity and specificity of measures to discriminate pathological gait as well as the reliability of gait measures across gait bout lengths. We investigated whether Parkinson’s disease (PD) affects how gait characteristics change as bout length changes, and how gait bout length affects the reliability and discriminative ability of gait measures …


Image Object Extraction Based On Semantic Segmentation And Label Loss, Xiaoru Wang, Peirong Xu, Zhihong Yu, Fu Li Aug 2020

Image Object Extraction Based On Semantic Segmentation And Label Loss, Xiaoru Wang, Peirong Xu, Zhihong Yu, Fu Li

Electrical and Computer Engineering Faculty Publications and Presentations

Object extraction refers to the operation of obtaining an object area from an image based on a small amount of mark information given by users, which is a key step in image processing. In order to obtain a complete object profile, current methods usually require a large number of manual annotations, especially for objects with irregular contours. Since traditional algorithms rely on low-level pixel features without semantic information, and are based on obvious mathematical assumptions (ie, strong inductive bias), it is difficult to completely identify objects. At present, in order to improve the integrity of object extraction, semantic segmentation-based methods …


A Unified Spectrum Formulation For Ofdm, Fbmc, And F-Ofdm, Xianzhen Yang, Siyuan Yan, Xiao Li, Fu Li Aug 2020

A Unified Spectrum Formulation For Ofdm, Fbmc, And F-Ofdm, Xianzhen Yang, Siyuan Yan, Xiao Li, Fu Li

Electrical and Computer Engineering Faculty Publications and Presentations

Although orthogonal frequency division multiplexing (OFDM) has been standardized for 5G, filter bank multi-carrier (FBMC) and filtered orthogonal frequency division multiplexing (F-OFDM) remain competitive as candidates for future generations of wireless technologies beyond 5G, due to their reduced spectrum leakage and thus enhanced spectrum efficiency. In this article, we developed a unified spectrum expression for OFDM, FBMC, and F-OFDM, which provides comparative insights into those techniques. A representative sideband quantification is included at the end of this article.


Work-In-Progress: Implementing Sophomore Cornerstone Courses In Electrical And Computer Engineering, Branimir Pejcinovic, Melinda Holtzman, Phillip Wong Jun 2020

Work-In-Progress: Implementing Sophomore Cornerstone Courses In Electrical And Computer Engineering, Branimir Pejcinovic, Melinda Holtzman, Phillip Wong

Electrical and Computer Engineering Faculty Publications and Presentations

Many engineering programs have significant project-based courses in the freshman and senior years. The project component in our freshman year-long sequence evolves from minimally structured projects, like designing and building Rube-Goldberg contraptions, to more complex microcontroller-based projects where formal tools for teamwork and project management are introduced. However, we do not yet enforce strict adherence to procedures and processes in the freshman year. This is unlike the senior capstone, where the expectation is that students will not only be familiar with these methods but will use them effectively throughout their projects. This presents an obvious problem: what happens in the …


Dim: Adaptively Combining User Interests Mined At Different Stages Based On Deformable Interest Model, Xiaoru Wang, Yueli Li, Zhihong Yu, Fu Li, Heng Zhang, Yali Cai, Lixian Li May 2020

Dim: Adaptively Combining User Interests Mined At Different Stages Based On Deformable Interest Model, Xiaoru Wang, Yueli Li, Zhihong Yu, Fu Li, Heng Zhang, Yali Cai, Lixian Li

Electrical and Computer Engineering Faculty Publications and Presentations

User interest mining is widely used in the fields of personalized search and personalized recommendation. Traditional methods ignore the formation of user interest which is a process that evolves over time. This leads to the inability to accurately describe the distribution of user interest. In this paper, we propose the interest tracking model (ITM). To add the timing, ITM uses Dirichlet distribution and multinomial distribution to describe the evolutional process of interest topics and frequent patterns, which well adapts to the evolution of user interest hidden in short texts between different time slices. In addition, it is well known that …


Spectrum Modeling Of Out-Of-Band Intermodulation For Dual-Band Rf Amplifiers In Ofdm Modulation, Xianzhen Yang, Siyuan Yan, Xiao Li, Qiang Wu, Fu Li Apr 2020

Spectrum Modeling Of Out-Of-Band Intermodulation For Dual-Band Rf Amplifiers In Ofdm Modulation, Xianzhen Yang, Siyuan Yan, Xiao Li, Qiang Wu, Fu Li

Electrical and Computer Engineering Faculty Publications and Presentations

Dual-band RF amplifiers play increasingly important roles in next-generation mobile communication systems including 5G, and the out-of-band intermodulation products are often not negligible since they generate interference to adjacent channels. In this article, following our previous modeling of cross-modulation for amplified dual-band signals, an analytical expression of out-of-band intermodulation for dual-band orthogonal frequency-division multiplexing signals is derived using the third-order intercept points IP3. The experimental measurement results validate the proposed analytical expression.


Inversion Of Head Waves In Ocean Acoustic Ambient Noise, Jie Li, Peter Gerstoft, Martin Siderius, Jun Fan Feb 2020

Inversion Of Head Waves In Ocean Acoustic Ambient Noise, Jie Li, Peter Gerstoft, Martin Siderius, Jun Fan

Electrical and Computer Engineering Faculty Publications and Presentations

The virtual head wave is produced through cross-correlation processing of signals containing the real, acoustic head wave. The virtual head wave has the same phase speed as the head wave, but the travel time is offset, thus the term virtual. The virtual head wave, like the real head wave, propagates in a direction corresponding to the seabed critical angle. The virtual head wave travel time varies with array depth and water column depth. However, in a refracting environment, the travel time is also dependent on the depth-dependent sound speed profile. Previously, the virtual head wave was shown as observable from …


Improved Estimation For Saleh Model And Predistortion Of Power Amplifiers Using 1-Db Compression Point, Haider Al Kanan, Xianzhen Yang, Fu Li Jan 2020

Improved Estimation For Saleh Model And Predistortion Of Power Amplifiers Using 1-Db Compression Point, Haider Al Kanan, Xianzhen Yang, Fu Li

Electrical and Computer Engineering Faculty Publications and Presentations

This paper proposes an improved estimation approach for modelling RF power amplifiers (PAs) using the Saleh behavioural model. The proposed approach is appropriate for solid-state PA technologies. The 1-dB compression point of the PA is included in the estimation approach to improve the estimation of the Saleh coefficients. Thus, expressions are derived to describe the relationship between the parameters of the Saleh model and the manufacturing specifications of PAs: gain (G), third-order intercept point (IP3) and 1-dB compression point (P1dB). This method is a simple estimation of a memoryless amplitude-to-amplitude (AM/AM) nonlinearity to benefit RF designers …


A Polarity-Based Approach For Optimization Of Multivalued Quantum Multiplexers With Arbitrary Single-Qubit Target Gates, Kevin Jin, Tahsin Soffat, Justin Morgan, Marek Perkowski Jan 2020

A Polarity-Based Approach For Optimization Of Multivalued Quantum Multiplexers With Arbitrary Single-Qubit Target Gates, Kevin Jin, Tahsin Soffat, Justin Morgan, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Previous work has provided methods for decomposing unitary matrices to series of quantum multiplexers, but the multiplexer circuits created in this way may be highly non-minimal. This paper presents a new approach for optimizing quantum multiplexers with arbitrary single-qubit quantum target functions and ternary controls. For multivalued quantum multiplexers, we define standard forms and two types of new forms: Fixed Polarity Quantum Forms (FPQFs) and Kronecker Quantum Forms (KQFs). Drawing inspiration from the usage of butterfly diagrams, we devise a method to exhaustively construct new forms. In contrast to previous butterfly-based methods, which are used with classical Boolean functions, these …


An Extended Approach For Generating Unitary Matrices For Quantum Circuits, Zhiqiang Li, Wei Zhang, Gaoman Zhang, Juan Dai, Jiajia Hu, Marek Perkowski, Xiaoyu Song Jan 2020

An Extended Approach For Generating Unitary Matrices For Quantum Circuits, Zhiqiang Li, Wei Zhang, Gaoman Zhang, Juan Dai, Jiajia Hu, Marek Perkowski, Xiaoyu Song

Electrical and Computer Engineering Faculty Publications and Presentations

In this paper, we do research on generating unitary matrices for quantum circuits automatically. We consider that quantum circuits are divided into six types, and the unitary operator expressions for each type are offered. Based on this, we propose an algorithm for computing the circuit unitary matrices in detail. Then, for quantum logic circuits composed of quantum logic gates, a faster method to compute unitary matrices of quantum circuits with truth table is introduced as a supplement. Finally, we apply the proposed algorithm to different reversible benchmark circuits based on NCT library (including NOT gate, Controlled-NOT gate, Toffoli gate) and …


Introduction To The Design And Simulation Of Reflectionless Filters, G. Lemire, Branimir Pejcinovic Jan 2020

Introduction To The Design And Simulation Of Reflectionless Filters, G. Lemire, Branimir Pejcinovic

Electrical and Computer Engineering Faculty Publications and Presentations

One novel approach to improving filter performance is to use so-called reflectionless filters which have recently been proposed. In this paper we demonstrate how to design, simulate and manufacture a reference reflectionless low-pass filter with the corner frequency of 188 MHz. We have found very good agreement between measurements, simulations, and published data, which validates our implementation of the design procedure. We have also designed a comparable diplexer so that we can examine the relative advantages and disadvantages of the reflectionless filters vs. diplexers. Measurements, simulations and published data, all agree very well in this case as well. This agreement …


Design Of Rubrics For Student Outcomes In 2019-2020 Abet Criteria, Branimir Pejcinovic Jan 2020

Design Of Rubrics For Student Outcomes In 2019-2020 Abet Criteria, Branimir Pejcinovic

Electrical and Computer Engineering Faculty Publications and Presentations

ABET is the main accreditation body for engineering programs in the United States and they have recently introduced a new set of Student Outcomes. This set was reduced from 11 to 7 items by combining several outcomes into one and adding some new ones. In our electrical and computer engineering programs we decided to design a set of seven general rubrics, one for each ABET outcome. These rubrics could then be used unaltered if course content fits them, or they can be adjusted to fit a particular course. To use a common description for rubrics, we wanted to keep the …


Defending Against Adversarial Attacks In Transmission- And Distribution-Level Pmu Data, Jun Jiang, Xan Liu, Eduardo Cotilla-Sanchez, Robert B. Bass, Xinghui Zhao Jan 2020

Defending Against Adversarial Attacks In Transmission- And Distribution-Level Pmu Data, Jun Jiang, Xan Liu, Eduardo Cotilla-Sanchez, Robert B. Bass, Xinghui Zhao

Electrical and Computer Engineering Faculty Publications and Presentations

Phasor measurement units (PMUs) provide highfidelity data that improve situation awareness of electric power grid operations. PMU datastreams inform wide-area state estimation, monitor area control error, and facilitate event detection in real time. As PMU data become more available and increasingly reliable, these devices are found in new roles within control systems, such as remedial action schemes and early warning detection systems. As with other cyber physical systems, maintaining data integrity and security pose a significant challenge for power system operators. In this paper, we present a comprehensive analysis of multiple machine learning techniques to detect malicious data injection within …


Resource Study Of Large-Scale Electric Water Heater Aggregation, Kevin Marnell, Conrad Eustis, Robert B. Bass Jan 2020

Resource Study Of Large-Scale Electric Water Heater Aggregation, Kevin Marnell, Conrad Eustis, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

Residential-scale distributed energy assets, like residential electric water heaters, individually present a negligible load to the power grid. When aggregated, however, these assets can impart significant effects within a balancing area; they may be dispatched en masse to provide grid services. An aggregation of water heaters may be controlled to assume generator-like functions with the ability to effectively “decrement power” through dispatch of load. This resource study examines the capabilities of a 10,000 unit water heater aggregation by subjecting the aggregate to dispatch requests of various size and duration, then analyzing how the aggregate responds to and recovers from these …


Laboratory Versus Daily Life Gait Characteristics In Patients With Multiple Sclerosis, Parkinson’S Disease, And Matched Controls, Vrutangkumar Shah, James Mcnames, Martina Mancini, Patricia Carlson-Kuhta, Rebecca I. Spain, John G. Nutt, Mahmoud El-Gohary, Carolin Curtze, Fay Horak Jan 2020

Laboratory Versus Daily Life Gait Characteristics In Patients With Multiple Sclerosis, Parkinson’S Disease, And Matched Controls, Vrutangkumar Shah, James Mcnames, Martina Mancini, Patricia Carlson-Kuhta, Rebecca I. Spain, John G. Nutt, Mahmoud El-Gohary, Carolin Curtze, Fay Horak

Electrical and Computer Engineering Faculty Publications and Presentations

Background and purpose: Recent findings suggest that a gait assessment at a discrete moment in a clinic or laboratory setting may not reflect functional, everyday mobility. As a step towards better understanding gait during daily life in neurological populations, we compared gait measures that best discriminated people with multiple sclerosis (MS) and people with Parkinson’s Disease (PD) from their respective, age-matched, healthy control subjects (MS-Ctl, PD-Ctl) in laboratory tests versus a week of daily life monitoring.

Methods: We recruited 15 people with MS (age mean ± SD: 49 ± 10 years), 16 MS-Ctl (45 ± 11 years), 16 …


Quantum Algorithms And Experiment Implementations Based On Ibm Q, Wenjie Liu, Junxui Chen, Yinsong Xu, Jiahao Tang, Lain Tong, Xiaoyu Song Jan 2020

Quantum Algorithms And Experiment Implementations Based On Ibm Q, Wenjie Liu, Junxui Chen, Yinsong Xu, Jiahao Tang, Lain Tong, Xiaoyu Song

Electrical and Computer Engineering Faculty Publications and Presentations

With the rapid development of quantum theory and technology in recent years, especially the emergence of some quantum cloud computing platforms, more and more researchers are not satisfied with the theoretical derivation and simulation verification of quantum computation (especially quantum algorithms), experimental verification on real quantum devices has become a new trend. In this paper, three representative quantum algorithms, namely Deutsch-Jozsa, Grover, and Shor algorithms, are briefly depicted, and then their implementation circuits are presented, respectively. We program these circuits on python with QISKit to connect the remote real quantum devices (i.e., ibmqx4, ibmqx5) on IBM Q to verify these …


A Quantum Algorithm For Automata Encoding, Edison Tsai, Marek Perkowski Jan 2020

A Quantum Algorithm For Automata Encoding, Edison Tsai, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Encoding of finite automata or state machines is critical to modern digital logic design methods for sequential circuits. Encoding is the process of assigning to every state, input value, and output value of a state machine a binary string, which is used to represent that state, input value, or output value in digital logic. Usually, one wishes to choose an encoding that, when the state machine is implemented as a digital logic circuit, will optimize some aspect of that circuit. For instance, one might wish to encode in such a way as to minimize power dissipation or silicon area. For …


Multi-Scale Decision Network With Feature Fusion And Weighting For Few-Shot Learning, Xiaoru Wang, Bing Ma, Zhihong Yu, Fu Li, Yali Cai Jan 2020

Multi-Scale Decision Network With Feature Fusion And Weighting For Few-Shot Learning, Xiaoru Wang, Bing Ma, Zhihong Yu, Fu Li, Yali Cai

Electrical and Computer Engineering Faculty Publications and Presentations

Learning from limited labelled examples is key a research hotspot with excellent scenarios and potential applications. Currently, most of metric learning-based few-shot models still have the problem of low recognition accuracy. This is mainly because that they only use the top-layer abstract feature with semantic information, which ignores the low-layer features that are also critical for the few-shot recognition. Therefore, the extracted features do not have abundant representation ability, and it is difficult to recognize easily confusing objects. Moreover, they usually adopt a fixed distance function or train a comparable network to measure features. These methods lack adaptability, cannot sufficiently …