Faculty Research Seminars

Faculty Research Seminars

The slides from these seminars will be uploaded soon.

 

Inverse Problems, Constraint Satisfaction, Reversible Logic, Invertible Logic and Grover Quantum Oracles for Practical Problems

Dr. Marek Perkowski

May 29th, 2020

Slides for Dr Perkowski's presentation.

Material characterization of microwave absorbers and ferroelectrics + what’s going on in engineering education research

Dr. Branimir Pejčinović

April 17th, 2020

In this presentation I will address three different research topics, mainly to pique people’s interest and curiosity. Two deal with the material characterization of a) microwave absorbers, and b) ferroelectrics. For the third one, I will argue that there are many areas of engineering education that are worthy of exploration for which I am seeking collaborators.  

A. The shielding of electronic devices is important for reasons ranging from regulatory to proper device functioning, and in applications from defense to consumer electronics. I will discuss the development and characterization of a novel microwave absorber material (MF-RAM) based on micron-sized ferrite beads and mm-length carbon fibers which are deposited electrostatically using the flocking process. The material is thin, lightweight, broadband and customizable with respect to frequency and amount of absorption. It was developed by Tangitek and at PSU we have characterized it in free space and in waveguides. We have demonstrated that MF-RAM exhibits losses associated with both electric and magnetic fields and could be more than competitive with commercially available solutions. I will also explain the basics of material characterization techniques used.

B. Despite their name, ferroelectrics have nothing to do with the magnetic field. Instead, they exhibit a behavior that is reminiscent of magnetic field hysteresis, i.e., they can maintain two different polarization states inside the material, depending on the signal trajectory (or history). Because they can have two different states when the electric field is zero they can be utilized as simple memory elements. However, their scaling to very thin layers is difficult and not well understood. I will present some recent measurement results on structures developed by a local startup.

C. Potential research topics engineering education will be illustrated with a couple of examples: 1. Investigating the time and effort that students spend studying, 2. Investigating how well students are prepared for life-long-learning. These are complex problems and I will discuss some tools and recent observations that could be turned into research projects.

An Introduction to the Research being Conducted in the Portland State University Magnetomechanical Energy Conversion and Controls Laboratory

Dr. Jonathan Bird

February 28th, 2020

In this presentation I will discuss three exciting research topics that are being investigated in the PSU’s laboratory for magnetomechanical energy conversion and control: (1) magnetic gears for improved power conversion, (2) negative stiffness resonant ocean power generators and (3) maglev vehicle transportation using electrodynamic wheels.

 

Leveraging Signal Structure for Efficient and Adaptive Machine Learning

Dr. John Lipor

January 24th, 2020

Abstract: Many major contributions to signal processing theory have centered around recognizing structure in signals of interest, with prominent examples being the Shannon-Nyquist sampling theorem for bandlimited signals and compressed sensing for signals that are sparse in some domain. In both examples, a key theme is that the structure in these signals can be leveraged to make the most efficient use of the available sampling resources. In this talk, I discuss how this general approach can be extended to the problems of data clustering and level set estimation. In the former case, high-dimensional signals can be effectively sorted (clustered) by recognizing the low-dimensional structure inherent in data from different clusters. In the latter, smoothness in the level set boundary or correlations between points can be harnessed to estimate level sets while minimizing the number of measurements taken, the distance between sampled points, or other costs associated with sampling. In all cases, the underlying structure allows for efficient signal reconstruction with a variety of theoretical guarantees.

Machine Learning for Anomaly Detection in Multi-Dimensional Data

Dr. Stanley R. Rotman, Harold Schnitzer Visiting Scholar from Ben-Gurion University of the Negev

November 22nd, 2019

Abstract: Multi-dimensional signals, such as Hyperspectral or Temporal Synthetic Aperture Radar, have very complicated distributions; machine learning promises to be a reasonable approach to determining structure in the data without any prior assumptions.  In this talk, we will consider Non-Negative Matrix Factorization (NNMF) as a method to both determine trends in the data and to significantly reduce the number of redundant dimensions. We will use this transformed data for advanced anomaly detection.

Slides for presentation part 1

Slides for presentation part 2

Achieving and Exploiting Fairness in the N-player Ultimatum Game

Dr. Garrison Greenwood

October 18th, 2019

The Ultimatum Game is studied to see how people respond in bargaining situations. In the 2-player version each round a player can be a proposer or a responder. A proposer makes an offer on how to split a monetary amount and responder either accepts or rejects the offer. If accepted, the money is split as proposed; if rejected both players get nothing. N-player models suggest offers decrease over time but are still accepted. However, in human experiments players acted irrationally and rejected offers they deemed unfair. In this talk it is shown a (μ/μ,λ)-evolution strategy can evolve offer and acceptance thresholds that promote fairness. Then a single self-interested player is added who ignores fairness and instead exploits the other players by maximizing his payoffs. Monte Carlo Tree Search (MCTS) is used to adaptively control this self-interested player's offer levels during the game. Our results indicate MCTS can produce payoffs for this player as much as 40% higher than the population average payoff.