Digital Commons Network^™

Image Analysis Using Visual Saliency With Applications In Hazmat Sign Detection And Recognition, Bin Zhao

Open Access Dissertations

Visual saliency is the perceptual process that makes attractive objects "stand out" from their surroundings in the low-level human visual system. Visual saliency has been modeled as a preprocessing step of the human visual system for selecting the important visual information from a scene. We investigate bottom-up visual saliency using spectral analysis approaches. We present separate and composite model families that generalize existing frequency domain visual saliency models. We propose several frequency domain visual saliency models to generate saliency maps using new spectrum processing methods and an entropy-based saliency map selection approach. A group of saliency map candidates are then …

Energy-Efficient Information Inference In Wireless Sensor Networks Based On Graphical Modeling, Wei Zhao

Open Access Dissertations

This dissertation proposes a systematic approach, based on a probabilistic graphical model, to infer missing observations in wireless sensor networks (WSNs) for sustaining environmental monitoring. This enables us to effectively address two critical challenges in WSNs: (1) energy-efficient data gathering through planned communication disruptions resulting from energy-saving sleep cycles, and (2) sensor-node failure tolerance in harsh environments. In our approach, we develop a pairwise Markov Random Field (MRF) to model the spatial correlations in a sensor network. Our MRF model is first constructed through automatic learning from historical sensed data, by using Iterative Proportional Fitting (IPF). When the MRF model …

Hydrogen Loading System Development And Evaluation Of Tritiated Substrates To Optimize Performance In Tritium Based Betavoltaics, Thomas E. Adams

Open Access Dissertations

State-of-the-art hydrogen loading system onto thin metallic films based on differential pressure in calibrated chambers has been developed for conditions pressures and temperatures up to 69 bar and 500°C, respectively. Experiments on hydrogen loading on to palladium films of thickness 50 and 250 nm were conducted at pressure ranging from 0.2 bar to 10 bar at temperature 310°C. For first time film hydrogen loading was carried out at 1 bar and at room temperature which temperature. Beta flux exiting surface of metal tritide films has been modeled with MC-SET (Monte Carlo Simulation of Electron Trajectories in solids). Surface beta flux …

A Nonlinear Interface Formulation For Frictional Contact, Layla K Amaireh

Open Access Dissertations

Finite element simulations of contact problems often involve modeling the interaction of multiple bodies across a non-confirming interface. Non-Confirming Meshes (NCM) are typically associated with large sliding or adaptive refinement on one side of the interface to capture localized nonlinear behavior due to large deformations, damage and inelasticity. The use of NCMs, however, presents a number of numerical issues; the main challenge with such discretizations is to ensure compatibility of the kinematic and traction fields along the non-conforming interface. ^ The Enriched Discontinuous Galerkin Approach (EDGA) (Haikal and Hjelmstad,2010)addresses this challenge by implementing a local enrichment along with an interface …

Integrating Pro-Environmental Behavior With Transportation Network Modeling: User And System Level Strategies, Implementation, And Evaluation, Husain M. Abdul Aziz

Open Access Dissertations

Personal transport is a leading contributor to fossil fuel consumption and greenhouse (GHG) emissions in the U.S. The U.S. Energy Information Administration (EIA) reports that light-duty vehicles (LDV) are responsible for 61\% of all transportation related energy consumption in 2012, which is equivalent to 8.4 million barrels of oil (fossil fuel) per day. The carbon content in fossil fuels is the primary source of GHG emissions that links to the challenge associated with climate change. Evidently, it is high time to develop actionable and innovative strategies to reduce fuel consumption and GHG emissions from the road transportation networks. This dissertation …

A Qualitative Analysis Of The Impact Of The Reform Of The College Of Science Undergraduate Core Curriculum At State University, Dean Ballotti

Open Access Dissertations

The Dean of the College of Science at State University, a large public Midwestern research university, in a memo to the faculty and staff initiated what he called a "review" of the undergraduate science core curriculum. He formed a task force that was to investigate on three issues; a reassessment of the undergraduate core curriculum, the recruitment and retention of qualified undergraduate students with an emphasis on diversity, and strategies that would address these issues. The age of the curriculum, 40 years since the last significant change, was an important factor in the review of the curriculum. This qualitative study …

Transformation Of Biomass Carbohydrates By Transition Metal Catalysts, Christine M Bohn

Open Access Dissertations

By selectively removing functional groups from biomass derived carbohydrates, valuable platform chemicals can be generated from renewable sources. Through dehydration chemistry glucose can be upgraded into 5-(Hydroxymethyl)-2-furfuraldehyde (HMF) and levulinic acid. Iron (III) chloride hexahydrate has shown moderate activity to transform glucose into HMF and has also shown high yields and selectivity for the production of levulinic acid. Typically synthesized from acidic solutions made with mineral acids, levulinic acid has now been produced in high yields with a metal salt. The difference between maximizing production for HMF or levulinic acid from the same catalyst relies on the control of the …

Supersonic Jet Spectroscopy Of Synthetic Foldamers, Multichromophores, And Their Water Containing Clusters, Evan Gardner Buchanan

Open Access Dissertations

A central theme specific to this dissertation concerns the conformation-specific spectroscopy of flexible molecules in an effort to bridge the complexity gap. Generally, molecules in the complexity gap have several flexible coordinates yet conformational isomerization still occurs along a simple reaction coordinate on the potential energy surface. Molecules in this regime benefit greatly from experiments probing the potential energy surfaces and provide a means to develop and test new theories in an effort to explain more complex system. These measurements are possible through the utilization of a supersonic jet expansion to collisionally cool molecules into their vibrational zero-point levels, collapsing …

Project Portfolio Evaluation And Selection Using Mathematical Programming And Optimization Methods, Hugo Caballero

Open Access Dissertations

Project portfolio selection is an essential process for portfolio management and plays an important role in accomplishing organizational goals. This research explores the feasibility of developing a project portfolio selection tool by using mathematical programming and optimization models, specifically 0-1 integer programming (one objective portfolio) and goal programming (multiple objectives portfolio). These methods select the set of projects which deliver the maximum benefit (e.g., net present value, profit, etc.) represented for objective functions subjected to a series of constraints (e.g., technical requirements and/or resources availability) considering the scheduling of selected projects in a planning horizon, interdependence relationship among projects (e.g., …

Beam-Induced Radiation Heating On The Superconducting Undulator At The Advanced Photon Source, Laura Elizabeth Boon

Open Access Dissertations

In January 2013 the Advanced Photon Source (APS), a 7 GeV synchrotron X-ray source, commissioned a Superconducting Undulator (SCU). The superconducting magnet is thermally isolated from the beam vacuum chamber, which absorbs the beam-induced heating. Previous beam induced heat load studies at other laboratories had not included a robust calculation of radiation heating from the upstream dipole magnet. The mitigation of the radiation heating mechanism, and production of photoelectrons to seed an electron cloud was studied for this thesis. ^ An analytical model was developed to predict the radiation heat load on the SCU chamber. This model was benchmarked with …

Aircraft-Based Measurements For The Identification And Quantification Of Sources And Sinks In The Carbon Cycle, Dana R Caulton

Open Access Dissertations

Improved quantification of carbon-cycle sources and sinks is an important requirement for determining mitigation strategies and modeling future climate interactions. Analytically robust measurements require high-precision instrumentation and thoughtful experimental design to produce rigorous and reproducible results despite complex and quickly changing meteorological and environmental conditions. Here, an aircraft platform equipped with a high-precision cavity ring-down spectrometer for CO₂, CH₄ and H₂O quantification was used to acquire data from previously un-sampled sources. The aircraft mass-balance technique was used to quantify CH4 emissions from natural gas well pads in the drilling stage, which were 2-3 orders of …

The Composition Of First-Year Engineering Curricula And Its Relationships To Matriculation Models And Institutional Characteristics, Xingyu Chen

Open Access Dissertations

The preparation of technically excellent and innovative engineering graduates urges for a reform of the engineering curriculum to meet critical challenges in society (National Academy of Engineering, 2005). An examination of the current engineering curricula is needed to offer a baseline to further discuss if the curriculum reform meets the critical challenges. Meanwhile, concern about engineering retention prioritizes a review of the first-year engineering curricula. The existing literature does not include a nationwide examination of the first-year engineering curricula and introductory engineering courses. This study aspired to fill the gap by providing a detail description of the composition of first-year …

Effects Of Energetic Irradiation On Materials And Devices Based On Graphene And Topological Insulators, Isaac Childres

Open Access Dissertations

This report focuses on the optical and electronic properties of graphene and topological insulators and how these Dirac fermion systems interact with energetic irradiation. We first present data exploring the effects of electron-beam and oxygen plasma induced disorder on the electronic properties and Raman spectra of graphene. These initial investigations were important for relating Raman peak intensities and weak localization features to each other and to an average disorder length in graphene, L_D. ^ We then integrate gate-effect measurements into the Raman spectroscopy study to fully explore the relationships between carrier density, disorder and Raman spectrum signatures. We …

Energy Conservation And Efficiency In Manufacturing: Employee Decisions And Actions, Marla Dee Corson

Open Access Dissertations

Energy conservation and intensity reduction efforts are becoming increasingly more prevalent and ultimately necessary, especially for energy-intensive manufacturing companies in particular to stay in business. Typical actions are to change technology, and thus, realize an energy cost savings in overall utilities. However, in today's competitive market, with climate change and other environmental impacts as well, it is necessary for the cost of energy to be valued as a cost of making a product, and thus, managed at the same level as the cost of labor or materials. This research assessed human behavior at the individual and organizational levels both at …

Irrigation With Treated Wastewater: Potential And Limitations, Anne Dare

Open Access Dissertations

As the world population increases and resources become more coveted, water emerges as a key component to global food security. The Middle East and North Africa (MENA) is among the driest regions in the world: containing just one percent of the world's freshwater resources. An increasing population creates greater quantities of wastewater and demands greater quantities of food, so an obvious connection arises. However logical wastewater reuse may be for bridging the irrigation supply-demand gap in this arid region, significant limitations prevent widespread adoption. The overall goal of this research is to take a holistic view of the limitations facing …

Diagnosing Undergraduate Biology Students' Experimental Design Knowledge And Difficulties, Annwesa Dasgupta

Open Access Dissertations

Experimental design is an important component of undergraduate biology education as it generates knowledge of biology. This dissertation addresses the challenge undergraduate educators face for assessing knowledge of experimental design in biology by examining knowledge of, and difficulties with, experimental design in the context of first-year undergraduate biology students at Purdue. The first chapter reviews several recent reports that highlight the necessity to increase understanding of the experimental research process as a core scientific ability (for e.g., AAAS, 2011; AAMC-HHMI, 2009; NRC, 2007). Despite its importance, there is limited information about what students actually learn from designing experiments. In the …

Transport Studies Of Reentrant Integer Quantum Hall States Forming In The Two-Dimensional Electron Gas, Nianpei Deng

Open Access Dissertations

The two dimensional electron gas subjected to a magnetic field has been a model system in contemporary condensed matter physics which generated many beautiful experiments as well as novel fundamental concepts. These novel concepts are of broad interests and have benefited other fields of research. For example, the observations of conventional odd-denominator fractional quantum Hall states have enriched many-body physics with important concepts such as fractional statistics and composite fermions. The subsequent discovery of the enigmatic even-denominator ν=5/2 fractional quantum Hall state has led to more interesting concepts such as non-Abelian statistics and pairing of composite fermions which can be …

Applications Of Femtosecond Coherent Anti-Stokes Raman Scattering In Combustion, Claresta Nicole Dennis

Open Access Dissertations

The dissertation deals with the further development of chirped-probe-pulse femtosecond coherent anti-Stokes Raman spectroscopy (CPP fs-CARS) for applications of gas phase thermometry and extension to methane concentration measurements. The main effort has been to assess the usefulness and robustness of the technique in turbulent combustors of practical interest. A primary aim has been to evaluate the use of CPP fs-CARS for vibrational N₂ thermometry in a highly turbulent environment. It has been suggested that due to the laser beam temporal overlap required for fs-CARS signal generation, the technique would be unsuccessful due to beam propagation retardation effects from density …

Using Energy-Efficient Technologies To Produce Bedding Plants And Microgreens In Protected And Controlled Environments, Joshua R. Gerovac

Open Access Theses

Gerovac, Joshua R. M.S., Purdue University, December 2014. Using Energy-Efficient Technologies to Produce Bedding Plants and Microgreens in Protected and Controlled Environments. Major Professor: Roberto G. Lopez. Production of bedding plants in commercial greenhouses (GHs) located in northern latitudes begins in late winter and continues through late spring when low outdoor temperatures generally necessitate active heating to maintain temperatures suitable for growth and development. Meanwhile, year-round production of microgreens using multi-layer systems requires sole-source (SS) photosynthetic lighting for production. Energy used to provide active heating in commercial GHs or SS lighting in multi-layer systems is second only to labor as …

Evaluation Of Collapse Indicators For Seismically Vulnerable Reinforced Concrete Buildings, Nicholas R. Skok

Open Access Theses

Older reinforced concrete buildings can be prone to column shear and compression failures during earthquakes because of inadequate transverse reinforcement. Cities in seismic areas still have large inventories of older and potentially deficient buildings. To analyze every building and estimate its vulnerability in detail is costly. A simple method to rank quickly older buildings according to their seismic vulnerability is needed to help engineers prioritize the use of resources for rehabilitating the most vulnerable buildings.

Four indicators of building damage or collapse were evaluated using numerical analysis and prior data from building surveys: column index (Hassan & Sozen, 1997), R …

Realization And Evaluation Of A 3-Degrees-Of-Freedom Mouse Model, Udayan Umapathi

Open Access Theses

Kinesiology research has shown that translation and rotation are inseparable actions in the real world. Motivated by this fact, this thesis explores a model for the computer mouse, the new addition being rotational input about vertical axis of a mouse. We realize our model through Mushaca, a 3-degrees-of-freedom mouse (3DOF mouse) that can sense rotation, in addition to sensing XY planar translation. The thesis presents two realizations of Mushaca - namely a MEMS version that uses accelerometer and gyroscope, and an optical sensor version that uses two optical sensors. Through a controlled user study we try to find out if …

Usability Of Immersive Virtual Reality Input Devices, Christopher G. Mankey

Open Access Dissertations

This research conducts a usability analysis of human interface devices within an Immersive Virtual Reality Environment. The analysis is carried out for two different interface devices, a commercially available Intersense ^© Wand and a home built pinch glove and wireless receiver. Users were asked to carry out a series of minor tasks involving placement of shaped blocks into corresponding holes within an Immersive Virtual Reality Environment. Performance was evaluated in terms of speed, accuracy and precision via the collection of completion times, errors made and the precision of motion during the experiment.

Evaluating Optimum Levels Of Detail For 3d Interactive Aviation Maintenance Instructions, Nicholas Rohe

Open Access Theses

With the aviation industry shifting from paper based maintenance instructions to digital maintenance instructions, there needs to be a standard for what goes into creating the digital instructions. This study was done to determine what the optimum level of detail for 3D interactive aviation maintenance instructions. The definition of optimum for this study was: lowest amount of geometrical data with lowest rendering needed for comprehension and ease of use.

Integration Of Z-Depth In Compositing, Kayla Steckel

Open Access Theses

It is important for video compositors to be able to complete their jobs quickly and efficiently. One of the tasks they might encounter is to insert assets such as characters into a 3D rendered environment that has depth information embedded into the image sequence. Currently, a plug-in that facilitates this task (Depth Matte®) functions by looking at the depth information of the layer it's applied to and showing or hiding pixels of that layer. In this plug-in, the Z-Depth used is locked to the layer the plug-in is applied. This research focuses on comparing Depth Matte® to a custom-made plug-in …

The Scientific Theories Of Michael Faraday And James Clerk Maxwell, Shannon P. Israelsen

The Purdue Historian

This paper explores the role of mathematical formalism in physics theories through an analysis of the work of physicists Michael Faraday and James Clerk Maxwell in the field of electromagnetism. After a brief description of the educational backgrounds of each scientist, their views on the nature of physics theory and its relationship to mathematics are contrasted. Faraday sought a mathematics-free theory to describe the results of his experiments, producing a family of concepts that became the roots of electromagnetic field theory. Maxwell built upon these concepts, giving them robust mathematical expression and incorporating them into one unified theoretical picture. An …

Keynote: Can We Coexist With Superintelligent Machines?, James Barrat

Dawn or Doom Conference

Within the next few decades, machine intelligence will match then surpass human intelligence. Can we share the planet with smarter-than-human machines and survive?

Understanding Ourselves Is The "Holy Grail" Of The Human-Kind, Zygmunt Pizlo

Dawn or Doom Conference

Richard Feynman once said 'what I cannot create, I do not understand'. It follows, that building intelligent robots that emulate us is the best way to understand the human mind.

Developing Professional Skills In Stem Students: Data Information Literacy, Lisa Zilinski, Megan R. Sapp Nelson, Amy S. Van Epps

Libraries Faculty and Staff Scholarship and Research

Undergraduate STEM students are increasingly expected to have some data use skills upon graduation, whether they pursue post-graduate education or move into industry. This project was an initial foray into the application of data information literacy competencies to training undergraduate students to identify markers of data and information quality. The data consumer training appeared within two courses to help students evaluate data objects, including databases and datasets available on the Internet. The application of the Data Credibility Checklist provides a foundation for developing data reuse competencies. Based upon the initial presentation of the content, it became obvious that students need …

Sorting Reality From What We Think We Know About Breast Cancer In Africa, Sulma I. Mohammed, Joe B. Harford

Department of Comparative Pathobiology Faculty Publications

Much attention has been paid to the features of breast cancer in Africa and the parallels between breast cancer in indigenous Africans and in African American women, including a shift toward earlier onset; a tendency toward poorer outcomes; and an increased likelihood for the tumors to be negative for the estrogen receptor (ER), the progesterone receptor (PR), and/or the human epidermal growth factor receptor-2 (HER2) [1,2]. One of the more aggressive forms of breast cancer is termed ‘‘triple negative,’’ i.e., ER2, PR2, HER22 [3]. Patients with triple negative breast cancer tend to be younger than patients with other forms of …

An Efficient Certificateless Encryption For Secure Data Sharing In Public Clouds, Seung-Hyun Seo, Mohamed Yoosuf Mohamed Nabeel, Xiaoyu Ding, Elisa Bertino

Cyber Center Publications

We propose a mediated certificateless encryption scheme without pairing operations for securely sharing sensitive information in public clouds. Mediated certificateless public key encryption (mCL-PKE) solves the key escrow problem in identity based encryption and certificate revocation problem in public key cryptography. However, existing mCL-PKE schemes are either inefficient because of the use of expensive pairing operations or vulnerable against partial decryption attacks. In order to address the performance and security issues, in this paper, we first propose a mCL-PKE scheme without using pairing operations. We apply our mCL-PKE scheme to construct a practical solution to the problem of sharing sensitive …