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Portland State University

Student Research Symposium

2017

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Articles 1 - 9 of 9

Full-Text Articles in Physical Sciences and Mathematics

Bayesian Optimization For Refining Object Proposals, With An Application To Pedestrian Detection, Anthony D. Rhodes May 2017

Bayesian Optimization For Refining Object Proposals, With An Application To Pedestrian Detection, Anthony D. Rhodes

Student Research Symposium

We devise an algorithm using a Bayesian optimization framework in conjunction with contextual visual data for the efficient localization of objects in still images. Recent research has demonstrated substantial progress in object localization and related tasks for computer vision. However, many current state-of-the-art object localization procedures still suffer from inaccuracy and inefficiency, in addition to failing to successfully leverage contextual data. We address these issues with the current research.

Our method encompasses an active search procedure that uses contextual data to generate initial bounding-box proposals for a target object. We train a convolutional neural network to approximate an offset distance …


An Operational Drought Prediction Framework With Application Of Vine Copula Functions, Mahkameh Zarekarizi May 2017

An Operational Drought Prediction Framework With Application Of Vine Copula Functions, Mahkameh Zarekarizi

Student Research Symposium

Early and accurate drought predictions can benefit water resources and emergency managers by enhancing drought preparedness. Soil moisture memory is shown to contain helpful information for prediction of future values. This study uses the soil moisture memory to predict their future states via multivariate statistical modeling. We present a drought forecasting framework which issues monthly and seasonal drought forecasts. This framework estimates droughts with different lead times and updates the forecasts when more data become available. Forecasts are generated by conditioning future soil moisture values on antecedent drought status. The statistical model is initialized by soil moisture simulations retrieved from …


Find, Build, And Export Information For 3d Printing Of Your Favorite Molecules And Crystal Structures At Two Dedicated Websites, Paul R. Destefano, Peter Moeck May 2017

Find, Build, And Export Information For 3d Printing Of Your Favorite Molecules And Crystal Structures At Two Dedicated Websites, Paul R. Destefano, Peter Moeck

Student Research Symposium

As 3D printers require instructions, the Nano-Crystallography Group at Portland State University is creating two websites (http://nanocrystallography.org/3dconvert/ and http://nanocrystallography.research.pdx.edu/3d-print-files/convert/) where such instructions are created, interactively, for the atomic arrangements of virtually all known molecules and crystals.

We will prepare a "pipeline" into which crystallographic information enters from two curated open access crystallographic databases, is manipulated to create the desired 3D models, and then is exported in either STL format (the standard for monochrome 3D printing) or VRML/X3D (the ISO successor to STL). The two aforementioned databases are the North-American mirror of the Crystallography Open Database (http://nanocrystallography.org) …


Quasi-Optical Measurement For Low Loss Material Characterization In Submillimeter Wave Range, Ha Khiem Tran, Thanh Ngoc Dan Le, Branimir Pejcinovic May 2017

Quasi-Optical Measurement For Low Loss Material Characterization In Submillimeter Wave Range, Ha Khiem Tran, Thanh Ngoc Dan Le, Branimir Pejcinovic

Student Research Symposium

An accurate knowledge of dielectric constant of materials is required in many sub-millimeter wave applications. Free-space measurement of materials has always been one of the first choices due to their non-destructive nature and relatively simple sample preparation. However, free-space measurement systems at sub-millimeter frequency range suffer from two main problems: high loss because of divergent beam pattern and diffraction when the beam waist of the radiated beam is relatively large compared to the size of the sample under tests. In order to mitigate these issues, we set up a quasi-optical system using off-axis parabolic mirrors, which enhance the dynamic range …


Non-Native Mangroves Of Moloka'i, Hawai'i: A Socio-Ecological Analysis, Casey Lewis May 2017

Non-Native Mangroves Of Moloka'i, Hawai'i: A Socio-Ecological Analysis, Casey Lewis

Student Research Symposium

Invasive species are recognized as a leading threat to ecosystems and their management is expensive, time consuming, and labor intensive. Therefore, it is important to review both benefits and detriments of the species to inform appropriate management decisions. Red mangrove was introduced to Moloka'i, Hawaii in 1902 to mitigate the effects of soil erosion and has since spread along the coast and to adjacent islands creating novel habitat. This study assessed both biological services and social attitudes towards Moloka'i's non-native mangroves to provide a comprehensive evaluation of the species. Zooplankton community structure was examined in mangrove and non-mangrove sites and …


Finite Element Method Analysis Of Resonant Cavity For Whispering Gallery Acoustic Sensing Microscopy, Thanh N.D. Le, Ha Tran, Andres H. La Rosa May 2017

Finite Element Method Analysis Of Resonant Cavity For Whispering Gallery Acoustic Sensing Microscopy, Thanh N.D. Le, Ha Tran, Andres H. La Rosa

Student Research Symposium

Whispering Gallery Acoustic Sensing (WGAS) has been studied by Department of Physics at Portland State University as a mean of controlling sample to probe distance in tuning-folk-based scanning probe microscopy (TF-SPM). WGAS uses the microscope frame as a resonance acoustic cavity. The setup shows high potential because of high-quality factor nature of acoustic cavity as well as using mechanical motions of the TF itself instead of electrical signals. However, the analytic solution of the eigenfrequencies of the current microscope frame is very complex due to the asymmetric geometry. The purpose of this study is to use finite element method to …


Performance Analysis Of Droughthpc, Yasodhadevi Nachimuthu May 2017

Performance Analysis Of Droughthpc, Yasodhadevi Nachimuthu

Student Research Symposium

We present our performance analysis of DroughtHPC, a software application being developed by an interdisciplinary effort lead by Dr.Moradkhani in the Civil Engineering department, Dr. Daescu in the Math Department, and Dr. Karavanic in the Computer Science Department.

The DroughtHPC application is used to predict drought conditions for a target geographical area. The data used in the prediction are soil conditions, vegetation layers, canopy cover, snow accumulation information from satellites, and meteorological data. DroughtHPC is written in Python and uses two hydrologic models, PRMS [1] and VIC [2], to simulate soil moisture levels. A larger geographical area such as the …


The Importance Of Urban Habitat Connectivity And Influence On Native Avian Species And Community Science, Kristen S. Gulick May 2017

The Importance Of Urban Habitat Connectivity And Influence On Native Avian Species And Community Science, Kristen S. Gulick

Student Research Symposium

In what ways do small-scale urban backyards contribute to local bird abundance and biodiversity? In what ways might these yards serve as an ‘extension’ of neighboring native forest areas? This project investigates the contribution that a group of backyards, certified through the Backyard Habitat Certification Program, have in the suburb of Hillsdale, Oregon, which is adjacent to the natural area of Keller Woodland. Backyard owners functioning as citizen or community scientists assisted with conducting residential bird point-counts once a week in each backyard and the natural area. Counts were done for a total of 8 weeks during nesting season to …


Cox Processes For Visual Object Counting, Yongming Ma May 2017

Cox Processes For Visual Object Counting, Yongming Ma

Student Research Symposium

We present a model that utilizes Cox processes and CNN classifiers in order to count the number of instances of an object in an image. Poisson processes are well suited to events that occur randomly in space, like the location of objects in an image, as well as to the task of counting. Mixed Poisson processes also offer increased flexibility, however they do not easily scale with image size: they typically require O(n3) computation time and O(n2) storage, where n is the number of pixels. To mitigate this problem, we employ Kronecker algebra which takes advantage of the direct product …