Engineering Commons^™

Adaptive Motion Pooling And Diffusion For Optical Flow, Naga Venkata Kartheek Medathati, Pierre Kornprobst, Guillaume Masson, Manuela Chessa, Fabio Solari

MODVIS Workshop

We study the impact of local context of an image (contrast and 2D structure) on spatial motion integration by MT neurons. To do so, we revisited the seminal work by Heeger and Simoncelli (HS) [4] using spatio-temporal filters to estimate optical flow from V1-MT feedforward interactions. However, the HS model has difficulties to deal with several problems encountered in real scenes (e.g., blank wall problem and motion discontinuities). Here, we propose to extend the HS model with adaptive processing by focussing on the role of local context indicative of the local velocity estimates reliability. We set a network structure representative …

A Space-Variant Model For Motion Interpretation Across The Visual Field, Guido Maiello, Manuela Chessa, Peter J. Bex, Fabio Solari

MODVIS Workshop

We implement a neural model for the estimation of the focus of radial motion (FRM) at different retinal locations and we assess the model by comparing its results with respect to the precision with which human observers can estimate the FRM in naturalistic, moving dead leaves stimuli. The proposed neural model describes the deep hierarchy of the first stages of the dorsal visual pathway [Solari et al., 2014]. Such a model is space-variant, since it takes into account the retino-cortical transformation of the primate visual system through log-polar mapping that produces a cortical representation of the visual signal to the …

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 …

Measuring The Effectiveness Of Photoresponsive Nanocomposite Coatings On Aircraft Windshields To Mitigate Laser Intensity, Ryan S. Phillips, Hubert K. Bilan, Zachary X. Widel, Randal J. Demik, Samantha J. Brain, Matthew Moy, Charles Crowder, Stanley L. Harriman, James T. O'Malley Iii, Joseph E. Burlas, Steven F. Emmert, Jason J. Keleher

Journal of Aviation Technology and Engineering

In 2004, pilots reported 46 laser illumination events to the Federal Aviation Administration (FAA), with the number increasing to approximately 3,600 in 2011. Since that time, the number of reported laser incidents has ranged from 3,500 to 4,000. Previous studies indicate the potential for flight crewmember distraction from bright laser light being introduced to the cockpit. Compositional variations of the photoresponsive nanocomposite coatings were applied to an aircraft windscreen using a modified liquid dispersion/heating curing process. The attenuating effects of the deposited films on laser light intensity were evaluated using an optical power meter and the resultant laser intensity data …

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 …

The Integration Of Heat Resources In A Solar Thermal-Heat Pump Hydronic System, John Degrove

Purdue Polytechnic Masters Theses

According to the U.S. Department of Energy, roughly 41% of the energy consumed in the U.S. is used the power buildings. Within that number, almost half is used to heat or cool the building. Current technologies allow for consistent thermal management, but most utilize energy harvested from fossil fuels or convert electricity back into thermal energy. Background literature shows that the utilization of alternative heat resources such as heat pumps and solar thermal collectors can greatly reduce the energy used for heat delivery while producing adequate heating performance. A combined hydronic system using a bank of solar thermal collectors in …

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 …

Engineering / Faculty / Sapp Nelson / Purdue University / 2015, Megan R. Sapp Nelson

Data Information Literacy Case Study Directory

These materials were developed to assist a cohort of early career engineering education faculty to critically consider aspects of data management that they may implement in their developing research groups. These materials were used in the context of a two hour workshop and one hour brownbag. In the brownbag, the results of the Data Information Literacy research grant were discussed as they may be relevant to the early career faculty. The faculty then completed a self-assessment to identify their weak areas of data management and their personal priorities for data management. The two hour workshop was then conducted to assist …

Cloud Enabled Attack Vectors, Ryan Jasper

Purdue Polytechnic Directed Projects

The purpose of this directed project and related research was to demonstrate and catalog a new attack vector that utilizes cloud managed infrastructure. Cloud computing is a recent trend that is creating significant hype in the IT sector. Being that cloud computing is a new theme in the computing world, there are many security concerns that remain unknown and unexplored. The product of this directed project provides a documented taxonomy of the new attack vector and how to mitigate risk from this kind of attack.

The new attack vector creates efficiencies throughout the lifecycle of an attack and greatly reduces …

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 …

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 …

Seismic In-Plane Response Of Reinforced Concrete Frames With Masonry Infill Walls, Rabab Abdel Karim Al Louzi

Open Access Dissertations

Field data gathered after destructive earthquakes indicate that infill walls interact with reinforced concrete (RC) frames in buildings during an earthquake and could cause failure mechanism different than what the frames are originally designed for. A new method to identify the failure modes of RC frames with infill walls is developed. The method requires only the simple geometric and material properties of the elements involved in the frame- wall assembly. The approach checks various possible failure mechanisms, including those that may evolve depending on how the infill wall may fail during strong shaking, for example, the dynamically evolved captive column …

Near-Congruent Solidification Of Castings, Kevin J Chaput

Open Access Dissertations

A study on the microstructure development of as-cast Cu-Mn alloys based around the congruent minimum at 34.6 wt % Mn and 873 °C was performed. Initially, this was to evaluate the alloy as an alternative to wide freezing range Pb and Sn bronzes that are plagued with porosity. The shallow minimum and associated narrow freezing ranges around the congruent point result in a completely cellular (non-dendritic) solidification morphology for a composition range ~3 wt % Mn about the congruent composition (C _c). The degree of cellular solidification was found to depend on the mold material. Increased mold conductivity lead …

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 …

Magnetic Manipulation And Multimodal Imaging For Single Cell Direct Mechanosensing, Robert L. Wilson

Open Access Theses

The study of internal mechanics of single cells is paramount to understand mechanisms of mechanoregulation. External loading and cell-mediated force generation result in changes in cell shape, rheology, and the deformation of subcellular structures such as the nucleus. Moreover, alterations in the processes that regulate these responses have been further correlated to specific pathologies. Cellular deformation is often studied through application of forces in the environment of the cell, relying on strain and stress transfer through focal adhesions and the cytoskeletal system. However, the transfer of these external forces to internal mechanics can introduce uncertainties in the interpretation of subcellular …

Captured Open Book Image De-Warping And Shading Correction Using 3d Depth Information, Chyuan-Tyng Wu

Open Access Dissertations

Various three dimensional (3D) measuring or capturing devices are introduced to the society recently, and there are abundant possibilities that we can take advantage of this new technology. In this research, we worked on one useful application: to correct the distortion due to the curved shape of the pages of an open book in captured images using of depth information. This work is relevant to camera-based capture devices that can use a projector to cast structured light patterns to provide depth information. In order to improve the visual quality of captured documents, we established our algorithm from two perspectives. First, …

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, …

The Effect Of Maximum Aggregate Size On The Shear Strength Of Geometrically Scaled Reinforced Concrete Beams, Derek Robert Daluga

Open Access Theses

Shear strength of reinforced concrete beams without web reinforcement has been reported to decrease with increases in depth. This is often referred to as a size effect. This reduction in shear strength has been reported to decrease with the use of web reinforcement and increases in maximum aggregate size. ^ The purpose of this study was to test two hypotheses 1) shear strength increases with increases in maximum aggregate size and 2) aggregate gradation affects this increase in shear strength. Maximum aggregate size is defined here as the size of the smallest sieve opening through which all aggregate particles pass. …

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 …

Overcoming Fundamental Barriers In Photovoltaic And Terahertz Generation, Chao Zhou

Open Access Theses

Several fundamental barriers limit the performance of opto-electronic conversion processes below 100%. Two specific examples of current technological interest include photovoltaic conversion of sunlight into electricity (i.e., solar cells), and terahertz generation from optical sources. In particular, solar cells are limited not only by the Carnot limit associated with the second law (approximately 86% at room temperature), but also by radiative recombination, non-reciprocity, carrier thermalization, and sub-bandgap losses. In the case of terahertz generation, the typical process of difference frequency generation relies on two input optical waves with only a small difference between them to generate the desired output; however, …

Synthesis And Characterization Of A Lubricin Mimic (Mlub) To Reduce Friction On The Articular Cartilage Surface, Alexandra May Lawrence

Open Access Theses

The lubricating proteoglycan, lubricin, facilitates the remarkable low friction and wear properties of articular cartilage in the synovial joints of the body. Lubricin lines the joint surfaces and plays a protective role as a boundary lubricant in sliding contact; down-regulation of lubricin is associated with cartilage degradation and the pathogenesis of osteoarthritis. An unmet need for early osteoarthritis treatment is the development of therapeutic molecules that mimic lubricin function and yet are also resistant to enzymatic degradation common in the damaged joint. Here, we engineered a lubricin mimic (mLub) that resists enzymatic degradation and binds to the articular surface to …

Optimizing Electrode Thickness And Material For Laser-Induced Electrothermal Flow, Jian Wei Khor

Open Access Theses

In this article, the material dependence of electrothermal flow is studied to optimize an optoelectric particle manipulation technique called Rapid Electrokinetic Patterning (REP). REP utilizes a heat source to produce temperature gradients, which, in this study, are induced by the application of a 1064 nm cw laser. The simultaneous application of an uniform AC electric field assemble colloids on the surface of an electrode that can be moved by translating the laser. The temperature gradients produced from the heat source are crucial in REP as the higher the temperature gradient the faster the electrothermal flow. Thus, optimization of temperature gradients …

Smart V-Belt, Kyle J. Mosier

Open Access Theses

The purpose of this research was to develop a method for detecting premature failure in a v-belt using capacitance and resistance readings. Another goal of the research was to detect tension values on the belt using the same readings. Materials of current belts and possible materials for a prototype belt were tested. Materials were chosen, and prototype belts were built. Pulley system configurations were developed and built. Sections of the belt designs were tested for capacitance and resistance before and after various methods of damage. Capacitance was chosen as the better sensing method. Certain layered belt configurations and sheave configurations …

Delamination Of C/Pekk I-Beam Using Virtual Crack Closure Technique And Cohesive Zone Method, Greeshma Ramakrishna

Open Access Theses

A damage study is conducted on a carbon epoxy/PEKK (poly-ether-ketone-ketone) thermoplastic composite I-Beam, with a pre crack of 100 mm modeled between the top flange and the filler (butt joint between filler and web). This project is in collaboration with Fokker Aerostructures, Netherlands and is part of the Thermoplastic Primary Aircraft Structure innovation program (TAPAS). The C/PEKK I-Beam is modeled after a section of the Gulfstream G650 aircraft's centre beam, which was previously a carbon fiber/epoxy hat-stiffened skin construction. The objective of the thesis is to identify if the crack propagates in the I-Beam within the load range that act …

Development And Application Of Quantitative Methods For Ecosystem Services, Rebecca A. Logsdon

Open Access Dissertations

Ecosystem services are benefits that people receive from the environment. Despite recent exponential increases in ecosystem service research, the ecosystem service framework has made little impact on policy and land management decisions, especially in the United States. Two of the main limitations for a lack of ecosystem service considerations in both policy and land management decisions are a need for more advanced quantification methods and the lack of engagement of key stakeholders who are responsible for making land management decisions. This research seeks to address these two limitations by testing and improving quantification methods of ecosystem services and by evaluating …

An Experimental Study On The Effects Of Blade Row Interactions On Aerodynamic Loss Mechanisms In A Multistage Compressor, Natalie Rochelle Smith

Open Access Dissertations

While the gas turbine engine has existed for nearly 80 years, much of the complex aerodynamics which governs compressor performance is still not well understood. The unsteady flow field consists of periodic blade row interactions from the wakes and potential fields of each blade and vane. Vane clocking is the relative circumferential indexing of adjacent vane rows with the same vane count, and it is one method to change blade row interactions. Though the potential of performance benefits with vane clocking is known, the driving flow physics have yet to be identified. ^ This research examines the effects of blade …

Modeling On Single-Sided Wind-Driven Natural Ventilation, Haojie Wang

Open Access Dissertations

Buildings use 40% of the total primary energy in the United States, with a significant part of this energy being used for ventilation and cooling. Despite the large amount of energy used in buildings, reports have shown that the indoor air quality (IAQ) and thermal comfort are not satisfactory. The lowered productivity due to the bad IAQ could cause $125 billion loss per year and the sick building syndromes could cause $32 billion direct healthcare costs. Most of the problems related to IAQ are caused by insufficient fresh outdoor air supply or lack of maintenance with traditional mechanical ventilation systems. …

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 …