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Portland State University

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Articles 1 - 13 of 13

Full-Text Articles in Computer Engineering

Combining Algorithms For More General Ai, Mark Robert Musil May 2018

Combining Algorithms For More General Ai, Mark Robert Musil

Undergraduate Research & Mentoring Program

Two decades since the first convolutional neural network was introduced the AI sub-domains of classification, regression and prediction still rely heavily on a few ML architectures despite their flaws of being hungry for data, time, and high-end hardware while still lacking generality. In order to achieve more general intelligence that can perform one-shot learning, create internal representations, and recognize subtle patterns it is necessary to look for new ML system frameworks. Research on the interface between neuroscience and computational statistics/machine learning has suggested that combined algorithms may increase AI robustness in the same way that separate brain regions specialize. In …


Laser-Scribed Graphene Micro-Supercapacitors, Kimi D. Owens May 2018

Laser-Scribed Graphene Micro-Supercapacitors, Kimi D. Owens

Undergraduate Research & Mentoring Program

M. F. El-Kady and R. B. Kaner, “Scalable fabrication of high-power graphene micro-supercapacitors for flexible and on-chip energy storage,” Nature Communications, vol. 4, p. 1475, Feb. 2013.

Supercapacitors are electrical components that have higher energy density than regular capacitors. Currently, they are large and bulky which makes it hard to be implemented into smaller electronic devices or on-chip. In Scalable Fabrication of High-power Graphene Micro-supercapacitors for Flexible and On-chip Energy Storage, El-Kady and Kaner developed an inexpensive and reliable method for scaling down supercapacitors to be approximately 7.53 x 5.35 mm. To make the laser-scribed graphene (LSG) micro-supercapacitors, an aqueous …


Factors Affecting Big Data Technology Adoption, Nayem Rahman May 2016

Factors Affecting Big Data Technology Adoption, Nayem Rahman

Student Research Symposium

With the advancement of computer science, hardware and software engineering, and computing power, and later with the advent of the internet, social networking tools and other sources such as sensors data growth has increased significantly. These data are called big data which are mostly unstructured, generated in large volumes, data need to be captured in near real-time. To handle big data a completely new set of tools and technologies are being emerged. I have studied big data literature to identify the factors that might influence big data adoption. I was able to list quite a few factors or attributes that …


Evolution And Usage Of The Portal Data Archive: 10-Year Retrospective, Kristin A. Tufte, Robert Bertini, Morgan Harvey Jan 2015

Evolution And Usage Of The Portal Data Archive: 10-Year Retrospective, Kristin A. Tufte, Robert Bertini, Morgan Harvey

Civil and Environmental Engineering Faculty Publications and Presentations

The Portal transportation data archive (http://portal.its.pdx.edu/) was begun in June 2004 in collaboration with the Oregon Department of Transportation, with a single data source: freeway loop detector data. In 10 years, Portal has grown to contain approximately 3 TB of transportation-related data from a wide variety of systems and sources, including freeway data, arterial signal data, travel times from Bluetooth detection systems, transit data, and bicycle count data. Over its 10-year existence, Portal has expanded both in the type of data that it receives and in the geographic regions from which it gets data. This paper discusses the …


System-Wide Performance Analysis For Virtualization, Deron Eugene Jensen Jun 2014

System-Wide Performance Analysis For Virtualization, Deron Eugene Jensen

Dissertations and Theses

With the current trend in cloud computing and virtualization, more organizations are moving their systems from a physical host to a virtual server.

Although this can significantly reduce hardware, power, and administration costs, it can increase the cost of analyzing performance problems. With virtualization, there is an initial performance overhead, and as more virtual machines are added to a physical host the interference increases between various guest machines. When this interference occurs, a virtualized guest application may not perform as expected. There is little or no information to the virtual OS about the interference, and the current performance tools in …


Ranked Similarity Search Of Scientific Datasets: An Information Retrieval Approach, Veronika Margaret Megler Jun 2014

Ranked Similarity Search Of Scientific Datasets: An Information Retrieval Approach, Veronika Margaret Megler

Dissertations and Theses

In the past decade, the amount of scientific data collected and generated by scientists has grown dramatically. This growth has intensified an existing problem: in large archives consisting of datasets stored in many files, formats and locations, how can scientists find data relevant to their research interests? We approach this problem in a new way: by adapting Information Retrieval techniques, developed for searching text documents, into the world of (primarily numeric) scientific data. We propose an approach that uses a blend of automated and curated methods to extract metadata from large repositories of scientific data. We then perform searches over …


A Quantitative Analysis Of Memory Controller Page Policies, Matthew Blackmore Feb 2013

A Quantitative Analysis Of Memory Controller Page Policies, Matthew Blackmore

Dissertations and Theses

Two common goals in computing system design are increasing performance and decreasing power consumption. DRAM-based memory subsystems are a major component of both system performance and power consumption. Memory controllers employ strategies to efficiently schedule DRAM operations to reduce latency and to utilize DRAM low power modes when possible. One of the most important of these is the page policy, which determines when to close pages in DRAM. An effective DRAM memory controller page policy is important to minimizing power consumption and increasing system performance. This thesis explores the impact memory controller page policy has on performance as measured by …


Calibration Of Complex System Dynamics Models: A Practioner's Report, Rod Walker, Wayne W. Wakeland Jul 2011

Calibration Of Complex System Dynamics Models: A Practioner's Report, Rod Walker, Wayne W. Wakeland

Wayne W. Wakeland

This paper is not a typical academic paper that is solidly grounded in the literature. Instead, this paper reports practitioner’s experiences in rebuilding and calibrating a very large system dynamics model. A prior version of this model had been in use for over 10 years in an ongoing executive training simulation. That model had never worked correctly in several key areas, requiring the outputs to be manually adjusted by very experienced facilitators during the course of the simulation. The present project rebuilt the system dynamics model, redesigned the parts that weren’t working, and calibrated the resulting model to match the …


Calibration Of Complex System Dynamics Models: A Practioner's Report, Rod Walker, Wayne Wakeland Jul 2011

Calibration Of Complex System Dynamics Models: A Practioner's Report, Rod Walker, Wayne Wakeland

Systems Science Faculty Publications and Presentations

This paper is not a typical academic paper that is solidly grounded in the literature. Instead, this paper reports practitioner’s experiences in rebuilding and calibrating a very large system dynamics model. A prior version of this model had been in use for over 10 years in an ongoing executive training simulation. That model had never worked correctly in several key areas, requiring the outputs to be manually adjusted by very experienced facilitators during the course of the simulation. The present project rebuilt the system dynamics model, redesigned the parts that weren’t working, and calibrated the resulting model to match the …


Under The Plastic: A Quantitative Look At Dvd Video Encoding And Its Impact On Video Modeling, Wu-Chi Feng, Jin Choi, Wu-Chang Feng, Jonathan Walpole Jan 2003

Under The Plastic: A Quantitative Look At Dvd Video Encoding And Its Impact On Video Modeling, Wu-Chi Feng, Jin Choi, Wu-Chang Feng, Jonathan Walpole

Computer Science Faculty Publications and Presentations

In this paper, we examine the DVD encoding process and the implications this process has video modeling and network traffic analysis. We have assembled a system that allows us to extract the video data from the DVDs as they were encoded for distribution. Analyzing the resulting video trace data, we describe how DVD encodings have evolved over time. In addition, our findings show that the underlying video content is fundamentally different than those produced by basic consumer video capture boards. We demonstrate how this affects current video modeling proposals and their affect on network traffic characterization. This research is based …


A Lessons Learned Repository For Computer Forensics, Warren Harrison, George Heuston, Mark Morrissey, David Aucsmith, Sarah Mocas, Steve Russelle Oct 2002

A Lessons Learned Repository For Computer Forensics, Warren Harrison, George Heuston, Mark Morrissey, David Aucsmith, Sarah Mocas, Steve Russelle

Computer Science Faculty Publications and Presentations

The Law Enforcement community possesses a large, but informal, community memory with respect to digital forensics. Large, because the experiences of every forensics technician and investigator contribute to the whole. Informal because there is seldom an explicit mechanism for disseminating this wisdom except “over the water cooler”. As a consequence, the same problems and mistakes continue to resurface and the same solutions are re-invented. In order to better exploit this informal collection of wisdom, the key points of each experience can be placed into a Repository for later dissemination. We describe a web-based Lessons Learned Repository (LLR) that facilitates contribution …


Entropy Reduction Of English Text Using Variable Length Grouping, Vincent Norman Ast Jr. Jul 1972

Entropy Reduction Of English Text Using Variable Length Grouping, Vincent Norman Ast Jr.

Dissertations and Theses

It is known that the entropy of English text can be reduced by arranging the text into groups of two or more letters each. The higher the order of the grouping the greater is the entropy reduction. Using this principle in a computer text compressing system brings about difficulties, however, because the number of entries required in the translation table increases exponentially with group size. This experiment examined the possibility of using a translation table containing only selected entries of all group sizes with the expectation of obtaining a substantial entropy reduction with a relatively small table.

An expression was …


Saddas; A Self-Contained Analog To Digital Data Acquisition System., Walter Anton Petersen Jan 1972

Saddas; A Self-Contained Analog To Digital Data Acquisition System., Walter Anton Petersen

Dissertations and Theses

SADDAS, a. Self-contained Analog to Digital Data Acquisition System, converts analog voltage inputs to formatted BCD (binary coded decimal digital magnetic tape. SADDAS consists of a 16 channel multiplexer, a 17 bit (4 digits + sign) 40 microsecond analog to digital converter, a 512 byte 8 bit core memory, a 30 IPS (inches per second) digital tape recorder at a density of 556 cpi (characters per inch), and a controller which integrates these instruments into a flexible and easy-to-use system. Sampling rates in excess of 360 samples per second may be used when converting seven channels of data, such as …