Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Purdue University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 601 - 630 of 2869

Full-Text Articles in Physical Sciences and Mathematics

Hyperscaling Violation And Electroweak Symmetry Breaking, Daniel Elander, Robert Lawrence, Maurizio Piai Jun 2015

Hyperscaling Violation And Electroweak Symmetry Breaking, Daniel Elander, Robert Lawrence, Maurizio Piai

Department of Physics and Astronomy Faculty Publications

We consider a class of simplifed models of dynamical electroweak symmetry breaking built in terms of their fve-dimensional weakly-coupled gravity duals, in the spirit of bottom-up holography. The sigma-model consists of two abelian gauge bosons and one real, non-charged scalar feld coupled to gravity in fve dimensions. The scalar potential is a simple exponential function of the scalar feld. The background metric resulting from solving the classical equations of motion exhibits hyperscaling violation, at least at asymptotically large values of the radial direction. We study the spectrum of scalar composite states of the putative dual feld theory by fuctuating the …


Project Barriers To Green Belts Through Critical Success Factors, Chad Laux, Mary E. Johnson, Paul Cada Jun 2015

Project Barriers To Green Belts Through Critical Success Factors, Chad Laux, Mary E. Johnson, Paul Cada

Computer Information Technology Faculty Publications

Purpose The purpose of this paper is to utilize critical success factors (CSF) and identify items Green Belt (GB) practitioners note as barriers to completion of Six Sigma (SS) projects in a major manufacturer setting.

Design/methodology/approach The design of this paper is a descriptive study of a single location of a global manufacturer’s internal data and survey of accredited GBs who have completed an SS project for company accreditation utilizing company focus on CSFs.

Findings The results demonstrate the GB practitioners have competing priorities, have time constraints and lack project management skills that reduce timely completion of SS projects. Top …


Image Segmentation Using Fuzzy-Spatial Taxon Cut, Lauren Barghout May 2015

Image Segmentation Using Fuzzy-Spatial Taxon Cut, Lauren Barghout

MODVIS Workshop

Images convey multiple meanings that depend on the context in which the viewer perceptually organizes the scene. This presents a problem for automated image segmentation, because it adds uncertainty to the process of selecting which objects to include or not include within a segment. I’ll discuss the implementation of a fuzzy-logic-natural-vision-processing engine that solves this problem by assuming the scene architecture prior to processing. The scene architecture, a standardized natural-scene-perception-taxonomy comprised of a hierarchy of nested spatial-taxons. Spatial-taxons are regions (pixel-sets) that are figure-like, in that they are perceived as having a contour, are either `thing-like', or a `group of …


Video Event Understanding With Pattern Theory, Fillipe Souza, Sudeep Sarkar, Anuj Srivastava, Jingyong Su May 2015

Video Event Understanding With Pattern Theory, Fillipe Souza, Sudeep Sarkar, Anuj Srivastava, Jingyong Su

MODVIS Workshop

We propose a combinatorial approach built on Grenander’s pattern theory to generate semantic interpretations of video events of human activities. The basic units of representations, termed generators, are linked with each other using pairwise connections, termed bonds, that satisfy predefined relations. Different generators are specified for different levels, from (image) features at the bottom level to (human) actions at the highest, providing a rich representation of items in a scene. The resulting configurations of connected generators provide scene interpretations; the inference goal is to parse given video data and generate high-probability configurations. The probabilistic structures are imposed using energies that …


Metacognition: Using Confidence Ratings For Type 2 And Type 1 Roc Curves, S A. Klein May 2015

Metacognition: Using Confidence Ratings For Type 2 And Type 1 Roc Curves, S A. Klein

MODVIS Workshop

In the past five years there has been a surge of renewed interest in metacognition ("thinking about thinking"). The typical experiment involves a binary judgment followed by a multilevel confidence rating. It is a confusing topic because the rating could be made either on one's confidence in the binary response (standard rating Type 1 ROC) or on one's confidence sorted by whether the response was correct (Type 2 ROC). Both are metacognition. After a few remarks on challenging aspects of the Type 2 approach, I will present some interesting results for Type 1 ROC for both memory and vision research. …


Two Correspondence Problems Easier Than One, Aaron Michaux, Zygmunt Pizlo May 2015

Two Correspondence Problems Easier Than One, Aaron Michaux, Zygmunt Pizlo

MODVIS Workshop

Computer vision research rarely makes use of symmetry in stereo reconstruction despite its established importance in perceptual psychology. Such stereo reconstructions produce visually satisfying figures with precisely located points and lines, even when input images have low or moderate resolution. However, because few invariants exist, there are no known general approaches to solving symmetry correspondence on real images. The problem is significantly easier when combined with the binocular correspondence problem, because each correspondence problem provides strong non-overlapping constraints on the solution space. We demonstrate a system that leverages these constraints to produce accurate stereo models from pairs of binocular images …


Binocular 3d Motion Perception As Bayesian Inference, Martin Lages, Suzanne Heron May 2015

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 …


Formal Aspects Of Non-Rigid-Shape-From-Motion Perception, Vicky Froyen, Qasim Zaidi May 2015

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 …


Object Recognition And Visual Search With A Physiologically Grounded Model Of Visual Attention, Frederik Beuth, Fred H. Hamker May 2015

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 May 2015

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, …


Optimal "Big Data" Aggregation Systems - From Theory To Practical Application, William J. Culhane Iv May 2015

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 May 2015

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 …


Privacy-Preserving Social Network Analysis, Christine Marie Task Apr 2015

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 …


Parallel Symmetric Eigenvalue Problem Solvers, Alicia Marie Klinvex Apr 2015

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 …


Video Advertisement Mining For Predicting Revenue Using Random Forest, Yuan Hsin Huang Apr 2015

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 …


Mathematical Approaches To Food Nutrient Content Estimation With A Focus On Phenylalanine, Jieun Kim Apr 2015

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 …


Non-Covalent Affinity Materials For Protein Structure Determination Via Single Particle Reconstruction Analysis Cryo-Electron Microscopy, Minji Ha Apr 2015

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 Apr 2015

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 …


Laboratory Studies On The Production Of Alpha-Pinene-Derived Organic Nitrates And Their Atmospheric Fate, Joel David Rindelaub Apr 2015

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 NOx. To lower this uncertainty, we quantified the organic nitrate yield from the OH radical oxidation of α-pinene under high NOx 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 NOx. The hydrolysis of organic nitrates was found to be …


Architectural Techniques To Extend Multi-Core Performance Scaling, Hamza Bin Sohail Apr 2015

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 …


Climate Change Impact Assessments Using The Water Erosion Prediction Project Model, Joseph Trotochaud Apr 2015

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 …


Partition Density Functional Theory, Jonathan R. Nafziger Apr 2015

Partition Density Functional Theory, Jonathan R. Nafziger

Open Access Dissertations

Partition density functional theory (PDFT) is a method for dividing a molecular electronic structure calculation into fragment calculations. The molecular density and energy corresponding to Kohn Sham density-functional theory (KS-DFT) may be exactly recovered from these fragments. Each fragment acts as an isolated system except for the influence of a global one-body 'partition' potential which deforms the fragment densities. In this work, the developments of PDFT are put into the context of other fragment-based density functional methods. We developed three numerical implementations of PDFT: One within the NWChem computational chemistry package using basis sets, and the other two developed from …


Evaluating Breast Cancer Stem Cell Response To Antiangiogenic Therapy, Connor J. Holloway Apr 2015

Evaluating Breast Cancer Stem Cell Response To Antiangiogenic Therapy, Connor J. Holloway

Open Access Theses

Angiogenic inhibitors function by blocking tumor cell signals used to recruit host tissue vasculature to the tumor site, thereby depriving the cancer of the nutriment needed for further expansion. The development and implementation of angiogenic inhibitors in conjunction with standard chemotherapy agents has increased progression-free survival but not overall patient survival. It is hypothesized that chronic exposure to large doses of AAT drugs worsens hypoxic conditions within the tumor mass, selectively stimulating aggressive cancer stem cell populations to grow and proliferate. ^ In this study, the expression of the CSC biomarkers ALDH1, DLL1, and EpCAM were evaluated in breast cancer …


Spatial Analysis Of Passenger Vehicle Use And Ownership And Its Impact On The Sustainability Of Highway Infrastructure Funding, Matthew Volovski Apr 2015

Spatial Analysis Of Passenger Vehicle Use And Ownership And Its Impact On The Sustainability Of Highway Infrastructure Funding, Matthew Volovski

Open Access Dissertations

Across the United States, the sustainability of highway funding is at risk due to increasing need and uncertainty in the factors that drive revenue. Past studies on highway funding sustainability have identified that the root cause of changing highway revenue are the shifts in social demographics and economic characteristics. Unfortunately, from the revenue perspective (the focus of this dissertation), the ability of previous research to account for these factors has been rather limited in two ways; first, the inability to accurately assess current regional vehicle use (a typical prerequisite for statistical modeling of highway revenues) due to difficulties associated with …


Impact Of Biogenic Volatile Organic Compounds On Peroxyacetyl Nitrate Production In The Southeast United States, Christopher John Groff Apr 2015

Impact Of Biogenic Volatile Organic Compounds On Peroxyacetyl Nitrate Production In The Southeast United States, Christopher John Groff

Open Access Theses

Our atmosphere is arguably the fundamental entity that has made life on Earth possible. Knowledge of the delicate nature of our atmosphere continues to spread as "green" initiatives promote awareness of human influence on the environment. However, many climate scientists fear that unless immediate mitigation occurs, the reversal of human impact on our planet will be impossible, leading to unknown consequence. Perturbations to natural processes are likely to cause drastic change to the planet as we know it and ultimately result in significant health issues. It is important to push the boundaries of our understanding of atmospheric processes with intent …


Trajectory Generation For Lane-Change Maneuver Of Autonomous Vehicles, Ashesh Goswami Apr 2015

Trajectory Generation For Lane-Change Maneuver Of Autonomous Vehicles, Ashesh Goswami

Open Access Theses

Lane-change maneuver is one of the most thoroughly investigated automatic driving operations that can be used by an autonomous self-driving vehicle as a primitive for performing more complex operations like merging, entering/exiting highways or overtaking another vehicle. This thesis focuses on two coherent problems that are associated with the trajectory generation for lane-change maneuvers of autonomous vehicles in a highway scenario: (i) an effective velocity estimation of neighboring vehicles under different road scenarios involving linear and curvilinear motion of the vehicles, and (ii) trajectory generation based on the estimated velocities of neighboring vehicles for safe operation of self-driving cars during …


Securing Communication Within The Harms Model For Use With Firefighting Robots, Maxwell D. Dewees Apr 2015

Securing Communication Within The Harms Model For Use With Firefighting Robots, Maxwell D. Dewees

Open Access Theses

Humans and robots must work together in increasingly complex networks to achieve a common goal. In this research, firefighting robots are a part of a larger, decentralized system of humans, agents, robots, machines, and sensors (HARMS). Although communication in a HARMS model has been utilized in previous research, this new study looks at the security considerations of the communications layer of the HARMS model. A network attack known as a man-in-the-middle attack is successfully demonstrated in this paper. Then, a secure communications protocol is proposed to help provide confidentiality and authentication of HARMS actors. This research is applied to any …


Improving Product Design Phase For Engineer To Order (Eto) Product With Knowledge Base Engineering (Kbe), Hanhdung Thi Dinh Apr 2015

Improving Product Design Phase For Engineer To Order (Eto) Product With Knowledge Base Engineering (Kbe), Hanhdung Thi Dinh

Open Access Theses

In industry currently Computer Aided Design (CAD) is an important tool for the modification, analysis, or optimization of the 3D virtual environment that replicates the physical product. CAD software is an efficient and reliable tool. However, as globalization increases customer demands, this process needs to be faster and more efficient to accommodate changing product design situations, especially for Engineer-to- Order (ETO) products. ^ The traditional method of product design process is to operate CAD software without argumentation. Design engineers create CAD prototypes and drawings based on available knowledge and information which comes from engineering experts, company standards, industrial practices as …


Password Strength Analysis: User Coping Mechanisms In Password Selection, Brian Thomas Curnett Apr 2015

Password Strength Analysis: User Coping Mechanisms In Password Selection, Brian Thomas Curnett

Open Access Theses

The security that passwords provide could be seriously flawed due to the way people cope with having to memorize and recall their passwords. The National Institute of Standards and Technology (NIST) standard that is used to measure the password strength, known as entropy, is designed for a single use and does not consider that users may choose to keep parts of their password across password changes. This study shows that a portion of users keep some information from previous passwords across changes. These habits which will be called coping mechanisms that over time serve to erode the protection provided by …


Digital Forensics And Community Supervision: Making A Case For Field Based Digital Forensics Training, Christopher Michael Flory Apr 2015

Digital Forensics And Community Supervision: Making A Case For Field Based Digital Forensics Training, Christopher Michael Flory

Open Access Theses

In this paper I will review the literature concerning investigator digital forensics models and how they apply to field investigators. A brief history of community supervision and how offenders are supervised will be established. I will also cover the difference between community supervision standards and police standards concerning searches, evidence, standards of proof, and the difference between parole boards and courts. Currently, the burden for digital forensics for community supervision officers is placed on local or state law enforcement offices, with personnel trained in forensics, but may not place a high priority on outside cases. Forensic field training for community …