Digital Commons Network^™

Binocular 3d Motion Perception As Bayesian Inference, Martin Lages, Suzanne Heron

MODVIS Workshop

The human visual system encodes monocular motion and binocular disparity input before it is integrated into a single 3D percept. Here we propose a geometric-statistical model of human 3D motion perception that solves the aperture problem in 3D by assuming that (i) velocity constraints arise from inverse projection of local 2D velocity constraints in a binocular viewing geometry, (ii) noise from monocular motion and binocular disparity processing is independent, and (iii) slower motions are more likely to occur than faster ones. In two experiments we found that instantiation of this Bayesian model can explain perceived 3D line motion direction under …

A Critical Evaluation Of Computational Mechanisms Of Binocular Disparity Processing, Junkyung Kim, David A. Mély, Thomas Serre

MODVIS Workshop

The past decades of research in visual neuroscience have generated a large and disparate body of literature on the computation of binocular disparity in the primary visual cortex. Models have been proposed to describe specific phenomena, yet we lack a theoretical framework which is grounded in neurophysiology and also explains the effectiveness of disparity computation. Here, we examine neural circuits that are thought to play an important role in the computation of binocular disparity. Starting with the binocular energy model (Ohzawa et al. 1990), we consider plausible extensions which include suppressive mechanisms from units tuned to different phase disparities (Tanabe …

Formal Aspects Of Non-Rigid-Shape-From-Motion Perception, Vicky Froyen, Qasim Zaidi

MODVIS Workshop

Our world is full of objects that deform over time, for example animals, trees and clouds. Yet, the human visual system seems to readily disentangle object motions from non-rigid deformations, in order to categorize objects, recognize the nature of actions such as running or jumping, and even to infer intentions. A large body of experimental work has been devoted to extracting rigid structure from motion, but there is little experimental work on the perception of non-rigid 3-D shapes from motion (e.g. Jain, 2011). Similarly, until recently, almost all formal work had concentrated on the rigid case. In the last fifteen …

Appearance Controls Interpretation Of Orientation Flows For 3d Shape Estimation, Steven A. Cholewiak, Romain Vergne, Benjamin Kunsberg, Steven W. Zucker, Roland W. Fleming

MODVIS Workshop

The visual system can infer 3D shape from orientation flows arising from both texture and shading patterns. However, these two types of flows provide fundamentally different information about surface structure. Texture flows, when derived from distinct elements, mainly signal first-order features (surface slant), whereas shading flow orientations primarily relate to second-order surface properties (the change in surface slant).

The source of an image's structure is inherently ambiguous, it is therefore crucial for the brain to identify whether flow patterns originate from texture or shading to correctly infer shape from a 2D image. One possible approach would be to use 'surface …

Object Recognition And Visual Search With A Physiologically Grounded Model Of Visual Attention, Frederik Beuth, Fred H. Hamker

MODVIS Workshop

Visual attention models can explain a rich set of physiological data (Reynolds & Heeger, 2009, Neuron), but can rarely link these findings to real-world tasks. Here, we would like to narrow this gap with a novel, physiologically grounded model of visual attention by demonstrating its objects recognition abilities in noisy scenes.

To base the model on physiological data, we used a recently developed microcircuit model of visual attention (Beuth & Hamker, in revision, Vision Res) which explains a large set of attention experiments, e.g. biased competition, modulation of contrast response functions, tuning curves, and surround suppression. Objects are represented by …

Modeling Visual Features To Recognize Biological Motion: A Developmental Approach, Giulio Sandini, Nicoletta Noceti, Alessia Vignolo, Alessandra Sciutti, Francesco Rea, Alessandro Verri, Francesca Odone

MODVIS Workshop

In this work we deal with the problem of designing and developing computational vision models – comparable to the early stages of the human development – using coarse low-level information.

More specifically, we consider a binary classification setting to characterize biological movements with respect to non-biological dynamic events. To this purpose, our model builds on top of the optical flow estimation, and abstract the representation to simulate the limited amount of visual information available at birth. We take inspiration from known biological motion regularities explained by the Two-Thirds Power Law, and design a motion representation that includes different low-level features, …

Assessing Impact Of Exposure To Cyberphysical Systems On Student Interest In Information Technology Careers, Mayari I. Serrano Anazco

Purdue Polytechnic Masters Theses

The main purpose of this project is to determine if the use of Information Technology (IT) tools, specifically cyberphysical devices, in outreach sessions will promote interest of young individuals in pursuing IT careers. The Diversity office of Purdue’s College of Technology offers a number of outreach sessions to a variety of target populations throughout the year. Each department in the college has an opportunity to present a session related to a field of study offered by the department. The research was carried out thru the Spring 2015 semester during the DOiT and Vision outreach programs offered through the college’s Diversity …

Optimal "Big Data" Aggregation Systems - From Theory To Practical Application, William J. Culhane Iv

Open Access Dissertations

The integration of computers into many facets of our lives has made the collection and storage of staggering amounts of data feasible. However, the data on its own is not so useful to us as the analysis and manipulation which allows manageable descriptive information to be extracted. New tools to extract this information from ever growing repositories of data are required.

Some of these analyses can take the form of a two phase problem which is easily distributed to take advantage of available computing power. The first phase involves computing some descriptive partial result from some subset of the original …

Simulations Of Nanoscale Ni/Al Multilayer Foils With Intermediate Ni2al3 Growth, I. E. Gunduz, S. Onel, C. C. Doumanidis, C. Rebholz, Steven F. Son

Purdue Energetics Research Center Articles

Nanoscale multilayers of binary metallic systems, such as nickel/aluminum, exhibit self-propagating exothermic reactions due to the high formation enthalpy of the intermetallic compounds. Most of the previous modelingapproaches on the reactions of this system rely on the use of mass diffusionwith a phenomenological derived diffusion coefficient representing single-phase (NiAl) growth, coupled with heat transport. We show that the reaction kinetics, temperatures, and thermal front width can be reproduced more satisfactorily with the sequential growth of Ni2Al3 followed by NiAl, utilizing independently obtained interdiffusivities. The computational domain was meshed with a dynamically generated bi-modal grid consisting of fine and coarse zones …

An Introduction To The Standards For Preparation And Professional Development For Teachers Of Engineering, Jackson E. Reimers, Cheryl L. Farmer, Stacy S. Klein-Gardner

Journal of Pre-College Engineering Education Research (J-PEER)

The past 30 years have yielded a mature body of research regarding effective professional development for teachers of science and mathematics, leading to a robust selection of professional development programs for these teachers. The current emphasis on connections among science, technology, engineering, and mathematics underscores the need for similar research into the nature of effective professional development for teachers of engineering. With this in mind, this paper completes a review of the literature concerning effective professional development for teachers of engineering, both as a unique discipline and as a context for teaching and learning in other subjects. The results of …

The Promise Of The Maker Movement For Education, Lee Martin

Journal of Pre-College Engineering Education Research (J-PEER)

The Maker Movement is a community of hobbyists, tinkerers, engineers, hackers, and artists who creatively design and build projects for both playful and useful ends. There is growing interest among educators in bringing making into K-12 education to enhance opportunities to engage in the practices of engineering, specifically, and STEM more broadly. This article describes three elements of the Maker Movement, and associated research needs, necessary to understand its promise for education: 1) digital tools, including rapid prototyping tools and low-cost microcontroller platforms, that characterize many making projects; 2) community infrastructure, including online resources and in-person spaces and events; and …

Math, Science, And Engineering Integration In A High School Engineering Course: A Qualitative Study, Clara G. Valtorta, Leema K. Berland

Journal of Pre-College Engineering Education Research (J-PEER)

Engineering in K-12 classrooms has been receiving expanding emphasis in the United States. The integration of science, mathematics, and engineering is a benefit and goal of K-12 engineering; however, current empirical research on the efficacy of K-12 science, mathematics, and engineering integration is limited. This study adds to this growing field, using discourse analysis techniques to examine whether and why students integrate math and science concepts into their engineering design work. The study focuses on student work during a unit from a high school engineering course. Video data were collected during the unit and were used to identify episodes of …

Beyond Blackboards: Engaging Underserved Middle School Students In Engineering, Sarah Blanchard, Justina Judy, Chandra Muller, Richard H. Crawford, Anthony J. Petrosino, Christina K. White, Fu-An Lin, Kristin L. Wood

Journal of Pre-College Engineering Education Research (J-PEER)

Beyond Blackboards is an inquiry-centered, after-school program designed to enhance middle school students’ engagement with engineering through design-based experiences focused on the 21st Century Engineering Challenges. Set within a predominantly lowincome, majority-minority community, our study aims to investigate the impact of Beyond Blackboards on students’ interest in and understanding of engineering, as well as their ability to align their educational and career plans. We compare participants’ and nonparticipants’ questionnaire responses before the implementation and at the end of the program’s first academic year. Statistically significant findings indicate a school-wide increase in students’ interest in engineering careers, supporting a shift in …

Motivational Influences Of Using Peer Evaluation In Problem-Based Learning In Medical Education, Sara Abercrombie, Jay Parkes, Teresita Mccarty

Interdisciplinary Journal of Problem-Based Learning

This study investigates the ways in which medical students’ achievement goal orientations (AGO) affect their perceptions of learning and actual learning from an online problem-based learning environment, Calibrated Peer Review^TM. First, the tenability of a four-factor model (Elliot & McGregor, 2001) of AGO was tested with data collected from medical students (N = 137). Then, a structural regression model relating the factors of AGO to students’ perceptions of grading fairness, judgments of learning, and scoring accuracy was tested. The results indicate that student engagement and success in diagnosing a patient’s presentation using a peer feedback-rich web-based PBL environment …

Social Constructivism And Case-Writing For An Integrated Curriculum, Alison F. Doubleday, Blase Brown, Philip A. Patston, Pamela Jurgens-Toepke, Meaghan Driscoll Strotman, Anne Koerber, Colin Haley, Charlotte Briggs, G. William Knight

Interdisciplinary Journal of Problem-Based Learning

Case-writing within an integrated, systems-based health professions education curriculum presents many unique challenges. Specifically, case-writing in this context must consider integration of multidisciplinary learning objectives and synthesis of biomedical and clinical sciences. Establishing an effective process for content integration and determining who should be involved in the case-writing process can be a daunting task and this specific context requires a new model for effective casewriting. This paper provides a model for the cycle of case development, implementation, evaluation and modification in an integrated, systems-based health professions curriculum. We highlight how this collaborative case-writing model parallels the social constructivist approach promoted …

Privacy-Preserving Social Network Analysis, Christine Marie Task

Open Access Dissertations

Data privacy in social networks is a growing concern that threatens to limit access to important information contained in these data structures. Analysis of the graph structure of social networks can provide valuable information for revenue generation and social science research, but unfortunately, ensuring this analysis does not violate individual privacy is difficult. Simply removing obvious identifiers from graphs or even releasing only aggregate results of analysis may not provide sufficient protection. Differential privacy is an alternative privacy model, popular in data-mining over tabular data, that uses noise to obscure individuals' contributions to aggregate results and offers a strong mathematical …

Mechanism And Kinetics Of Homogeneous Catalysis, Silei Xiong

Open Access Dissertations

A model-based approach using a diverse set of data including monomer consumption, evolution of molecular weight, and end-group analysis was employed to determine each of the reaction specific rate constants involved in 1-hexene polymerization process catalyzed by a family of group IV single-site catalysts. The primary set of elementary reaction steps included initiation, normal propagation, misinsertion, recovery from misinsertion, monomer independent and dependent chain transfer. Robust determination of kinetic constants and reaction mechanisms for a series of Group IV amine bis-phenolate complexes led to the development of several structure−activity relationships.^ For some of the catalysts of the bis-phenolate family the …

Parallel Symmetric Eigenvalue Problem Solvers, Alicia Marie Klinvex

Open Access Dissertations

Sparse symmetric eigenvalue problems arise in many computational science and engineering applications: in structural mechanics, nanoelectronics, and spectral reordering, for example. Often, the large size of these problems requires the development of eigensolvers that scale well on parallel computing platforms. In this dissertation, we describe two such eigensolvers, TraceMin and TraceMin-Davidson. These methods are different from many other eigensolvers in that they do not require accurate linear solves to be performed at each iteration in order to find the smallest eigenvalues and their associated eigenvectors. After introducing these closely related eigensolvers, we discuss alternative methods for solving the saddle point …

Control Oriented Concentrating Solar Power (Csp) Plant Model And Its Applications, Qi Luo

Open Access Dissertations

Solar receivers in concentrating solar thermal power plants (CSP) undergo over 10,000 start-ups and shutdowns, and over 25,000 rapid rate of change in temperature on receivers due to cloud transients resulting in performance degradation and material fatigue in their expected lifetime of over 30 years. The research proposes to develop a three-level controller that uses multi-input-multi-output (MIMO) control technology to minimize the effect of these disturbances, improve plant performance, and extend plant life. The controller can be readily installed on any vendor supplied state-of-the-art control hardware.^ We propose a three-level controller architecture using multi-input-multi-output (MIMO) control for CSP plants that …

Video Advertisement Mining For Predicting Revenue Using Random Forest, Yuan Hsin Huang

Open Access Theses

Shaken by the threat of financial crisis in 2008, industries began to work on the topic of predictive analytics to efficiently control inventory levels and minimize revenue risks. In this third-generation age of web-connected data, organizations emphasized the importance of data science and leveraged the data mining techniques for gaining a competitive edge. Consider the features of Web 3.0, where semantic-oriented interaction between humans and computers can offer a tailored service or product to meet consumers' needs by means of learning their preferences. In this study, we concentrate on the area of marketing science to demonstrate the correlation between TV …

Adult Learners' Perceptions Of Mooc Motivation, Success, And Completion: A Virtual Ethnographic Study, Jamie Lynn Loizzo

Open Access Dissertations

Massive open online courses (MOOCs) have been credited with disrupting the traditional classroom and challenging distance education models in higher education. MOOCs were developed with the intention of opening up education to the masses, specifically those in developing countries who could not readily access educational resources or opportunities. However, early quantitative reports have shown that MOOC participants tend to be adult learners who already possess bachelor's or master's degrees. Additionally, MOOC completion rates have been reported to be significantly low with less than 15% of enrolled students actually completing them. This has led to questions about who the true target …

Mathematical Approaches To Food Nutrient Content Estimation With A Focus On Phenylalanine, Jieun Kim

Open Access Dissertations

Managing the intake of a certain nutrient can be an effective treatment for some inherited metabolic disorders. An example of such dietary treatments is for phenylketonuria (PKU), for which patients must follow a low-phenylalanine diet for life. Some food databases provide the phenylalanine (Phe) content for a large number of unprocessed foods, and a limited number of composite foods; however, they are not exhaustive. As an attempt to complete this list, we introduce three mathematical approaches to estimate a bound for the Phe content based on the available nutritional information. The first approach is based on the statistical distribution of …

Investigations Of Carbon Nanotube Catalyst Morphology And Behavior With Transmission Electron Microscopy, Sammy M. Saber

Open Access Dissertations

Carbon nanotubes (CNTs) are materials with significant potential applications due to their desirable mechanical and electronic properties, which can both vary based on their structure. Electronic applications for CNTs are still few and not widely available, mainly due to the difficulty in the control of fabrication. Carbon nanotubes are grown in batches, but despite many years of research from their first discovery in 1991, there are still many unanswered questions regarding how to control the structure of CNTs. This work attempts to bridge some of the gap between question and answer by focusing on the catalyst particle used in common …

Non-Covalent Affinity Materials For Protein Structure Determination Via Single Particle Reconstruction Analysis Cryo-Electron Microscopy, Minji Ha

Open Access Theses

Single particle analysis (SPA) by cryogenic electron microscopy (Cryo-EM) is one of the powerful tools for determining biological macromolecule structure, particularly when combined with computational methods or X-ray crystallography. However, the SPA is challenged by sample processing efficiency. In this work, polyrotaxane (PRTx) was designed and synthesized such that laterally and rotationally mobile lysine nitrolicacetic acid (Lys-NTA) modified α-cyclodextrins (α-CD) were threaded onto a polyethylene glycol (PEG) core. Polyrotaxanes threaded with amine modified α-CD were also designed and synthesized for stoichiometric control of His-tagged protein capture by PRTx. For higher efficiency of single particle analysis along a single strand of …

Applications Of Microlocal Analysis To Some Hyperbolic Inverse Problems, Andrew J Homan

Open Access Dissertations

This thesis compiles my work on three inverse problems: ultrasound recovery in thermoacoustic tomography, cancellation of singularities in synthetic aperture radar, and the injectivity and stability of some generalized Radon transforms. Each problem is approached using microlocal methods. In the context of thermoacoustic tomography under the damped wave equation, I show uniqueness and stability of the problem with complete data, provide a reconstruction algorithm for small attenuation with complete data, and obtain stability estimates for visible singularities with partial data. The chapter on synthetic aperture radar constructs microlocally several infinite-dimensional families of ground reflectivity functions which appear microlocally regular when …

Undergraduate Engineering Students' Experiences Of Interdisciplinary Learning: A Phenomenographic Perspective, Ming-Chien Hsu

Open Access Dissertations

Engineers are expected to work with people with different disciplinary knowledge to solve real-world problems that are inherently complex, which is one of the reasons that interdisciplinary learning has become a common pedagogical practice in engineering education. However, empirical evidence on the impact of interdisciplinary learning on undergraduates is lacking. Regardless of the differences in the scope of methods used to assess interdisciplinary learning, frameworks of interdisciplinary learning are imperative for developing attainable outcomes as well as interpreting assessment data. Existing models of interdisciplinary learning have been either conceptual or based on research faculty members' experiences rather than empirical data. …

Laboratory Studies On The Production Of Alpha-Pinene-Derived Organic Nitrates And Their Atmospheric Fate, Joel David Rindelaub

Open Access Dissertations

Currently, the formation yields of organic nitrates from the oxidation of biogenic volatile organic compounds, such as α-pinene, is highly uncertain, negatively impacting our knowledge on tropospheric ozone production and the fate of atmospheric NO_x. To lower this uncertainty, we quantified the organic nitrate yield from the OH radical oxidation of α-pinene under high NO_x conditions. The α-pinene- derived nitrates created in chamber experiments readily partitioned to the aerosol phase and underwent particle phase hydrolysis, indicating that these processes are likely a sink for atmospheric NO_x. The hydrolysis of organic nitrates was found to be …

Architectural Techniques To Extend Multi-Core Performance Scaling, Hamza Bin Sohail

Open Access Dissertations

Multi-cores have successfully delivered performance improvements over the past decade; however, they now face problems on two fronts: power and off-chip memory bandwidth. Dennard's scaling is effectively coming to an end which has lead to a gradual increase in chip power dissipation. In addition, sustaining off-chip memory bandwidth has become harder due to the limited space for pins on the die and greater current needed to drive the increasing load . My thesis focuses on techniques to address the power and off-chip memory bandwidth challenges in order to avoid the premature end of the multi-core era. ^ In the first …

Bayesian Global Optimization Approach To The Oil Well Placement Problem With Quantified Uncertainties, Zengyi Dou

Open Access Theses

The oil well placement problem is vital part of secondary oil production. Since the calculation of the net present value (NPV) of an investment depends on the solution of expensive partial differential equations that require tremendous computational resources, traditional methods are doomed to fail. The problem becomes exceedingly more difficult when we take into account the uncertainties in the oil price as well as in the ground permeability. In this study, we formulate the oil well placement problem as a global optimization problem that depends on the output of a finite volume solver for the two-phase immiscible flow (water-oil). Then, …

Climate Change Impact Assessments Using The Water Erosion Prediction Project Model, Joseph Trotochaud

Open Access Theses

This study was conducted to develop a simplified method of obtaining future climate data inputs for natural resource models and apply that method to three locations within the continental United States to assess the effect of climate change on soil erosion, runoff, and fire risk. A method was developed for quickly obtaining future climate data over a wide range of scenarios, General Circulation Models (GCMs), and timescales from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) and Fifth Assessment Report (AR5) model families using the MarkSim^® DSSAT Weather Generator and a Microsoft Excel VBA Macro, the …