Digital Commons Network^™

Expected Length Of The Longest Chain In Linear Hashing, Pongthip Srivarangkul, Hemanta K. Maji

The Summer Undergraduate Research Fellowship (SURF) Symposium

Hash table with chaining is a data structure that chains objects with identical hash values together with an entry or a memory address. It works by calculating a hash value from an input then placing the input in the hash table entry. When we place two inputs in the same entry, they chain together in a linear linked list. We are interested in the expected length of the longest chain in linear hashing and methods to reduce the length because the worst-case look-up time is directly proportional to it.

The linear hash function used to calculate hash value is defined …

Examining The Effects Of Amino And Thiolate Ligands On The Reactivity And Selectivity Of Palladium On Carbon In Hydrogenation Reactions, Eric Liu, Christina Li

The Summer Undergraduate Research Fellowship (SURF) Symposium

Heterogeneous catalysts are used widely by chemical and energy industries because they show high reactivity but often suffer from lack of selectivity. On the other hand, ligands are commonly used in homogeneous catalysts to control the reactivity and selectivity; however, the effects of the ligands on the steric and electronic properties of heterogeneous catalysts are less understood. We examine the effects of four different ligands: 1-adamantanethiol, 1-adamantylamine, 1-dodecanethiol, and 1-dodecylamine, for the commercial hydrogenation catalyst palladium on carbon. Hydrogenation reactions are used as a screening tool to see the behavior that the different catalysts exhibit in the presence of unsaturated …

Stability Of The Interface Between Two Immiscible Liquids During Injection Into A Tapered Hele-Shaw Cell, Zihao Lin, Ivan C. Christov, Daihui Lu

The Summer Undergraduate Research Fellowship (SURF) Symposium

In the early twentieth century, petroleum and mining engineers noticed that water does not displace oil uniformly. This phenomenon, when water penetrates through oil, is now known as viscous fingering. This discovery and the following extensive research have contributed to enhancing oil recovery. In this paper, we describe a numerical study conducted on the stability of the interface between two immiscible liquids in converging and diverging Hele-Shaw cells with varying gradients. Hele-Shaw cells are narrow flow geometries that mimic the properties of a porous medium with fixed permeability. By using computational tools built on the OpenFOAM platform, the multiphase flow …

Incorporating Collisions And Resistance Into The Transition From Field Emission To The Space Charge Regime, Samuel D. Dynako, Adam M. Darr, Allen L. Garner

The Summer Undergraduate Research Fellowship (SURF) Symposium

Advancements in microelectromechanical systems (MEMS) and microplasmas, particularly with respect to applications in combustion and biotechnology, motivate studies into microscale gas breakdown to enable safe system design and implementation. Breakdown at microscale deviates from that predicted by Paschen’s law due to field emission—the stripping of electrons from the cathode in the presence of strong surface field—and follows the Fowler-Nordheim (FN) law. As injected current increases at this length scale, electrons accumulate in the gap and FN electron emission becomes space charge limited, leading to the Child-Langmuir (CL) law at vacuum and the Mott-Gurney (MG) law at high pressure. While theoretical …

A Divide-And-Conquer Approach To Syntax-Guided Synthesis, Peiyuan Shen, Xiaokang Qiu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Program synthesis aims to generate programs automatically from user-provided specifications. One critical research thrust is called Syntax-Guideds Synthesis. In addition to semantic specifications, the user should also provide a syntactic template of the desired program, which helps the synthesizer reduce the search space. The traditional symbolic approaches, such as CounterExample-Guided Inductive Synthesis (CEGIS) framework, does not scale to large search spaces. The goal of this project is to explore a compositional, divide-n-conquer approach that heuristically divides the synthesis task into subtasks and solves them separately. The idea is to decompose the function to be synthesized by creating a set of …

Predict The Failure Of Hydraulic Pumps By Different Machine Learning Algorithms, Yifei Zhou, Monika Ivantysynova, Nathan Keller

The Summer Undergraduate Research Fellowship (SURF) Symposium

Pump failure is a general concerned problem in the hydraulic field. Once happening, it will cause a huge property loss and even the life loss. The common methods to prevent the occurrence of pump failure is by preventative maintenance and breakdown maintenance, however, both of them have significant drawbacks. This research focuses on the axial piston pump and provides a new solution by the prognostic of pump failure using the classification of machine learning. Different kinds of sensors (temperature, acceleration and etc.) were installed into a good condition pump and three different kinds of damaged pumps to measure 10 of …

Sort Vs. Hash Join On Knights Landing Architecture, Victor L. Pan, Felix Lin

The Summer Undergraduate Research Fellowship (SURF) Symposium

With the increasing amount of information stored, there is a need for efficient database algorithms. One of the most important database operations is “join”. This involves combining columns from two tables and grouping common values in the same row in order to minimize redundant data. The two main algorithms used are hash join and sort merge join. Hash join builds a hash table to allow for faster searching. Sort merge join first sorts the two tables to make it more efficient when comparing values. There has been a lot of debate over which approach is superior. At first, hash join …

Deep Neural Network Architectures For Modulation Classification Using Principal Component Analysis, Sharan Ramjee, Shengtai Ju, Diyu Yang, Aly El Gamal

The Summer Undergraduate Research Fellowship (SURF) Symposium

In this work, we investigate the application of Principal Component Analysis to the task of wireless signal modulation recognition using deep neural network architectures. Sampling signals at the Nyquist rate, which is often very high, requires a large amount of energy and space to collect and store the samples. Moreover, the time taken to train neural networks for the task of modulation classification is large due to the large number of samples. These problems can be drastically reduced using Principal Component Analysis, which is a technique that allows us to reduce the dimensionality or number of features of the samples …

Universality In Viscous Fluid Spreading And Leveling, Zoë S. Penko, Ivan C. Christov, Daihui Lu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Multiphase fluid flows, or flows where the dynamics of an interface between unlike fluids can be observed, require study to further understand the fundamental relationships of the fluids’ properties and their dynamics in multiple applications. The scope of this research project pertains to low Reynolds number flow, a dense fluid spreading through a less dense ambient fluid, with the spreading fluid movement being driven by gravitational buoyancy forces and density differences. The primary investigation involves studying the spreading and leveling of such fluids in shaped geometries, such as subsurface fractures. The objective is to determine the effect of a wide …

Exploring Confidentiality Issues In Hyperledger Fabric Business Applications, Shivam Bajpayi, Pedro Moreno-Sanchez, Donghang Lu, Sihao Yin

The Summer Undergraduate Research Fellowship (SURF) Symposium

The rise of Bitcoin and cryptocurrencies over the last decade have made its underlying technology (blockchain) come into the spotlight. Blockchain is a secure ledger of linked records called blocks. These records are cryptographically immutable and any tampering with the block is evident through a change in the cryptographic signature of the block. Among the blockchains deployed in practice today, Hyperledger Fabric is a platform that allows businesses to make use of blockchains in their applications. However, confidentiality issues arise with respects to the blocks in this blockchain network due to the fact that blocks might contain sensitive information accessible …

Estimating Watershed Residence Times In Artificially-Drained Landscapes And Relation To Nutrient Concentrations, Emma Beck, Lisa Welp, Alexandra L. Meyer

The Summer Undergraduate Research Fellowship (SURF) Symposium

Nutrient runoff from agricultural lands feeds harmful algae blooms that create a variety of problems in freshwater ecosystems. In order to reduce the effects of this nutrient runoff, Best Management Practices (BMPs) are being put in place in agricultural lands. Most of these BMPs focus on slowing down the flow of water through the watershed to give nutrient concentrations time to deplete before the water flows to the stream or river. However, the effectiveness of these BMPs are highly unknown and the process of monitoring nutrient runoff is often complex and costly. The data in this study consists of 7 …

Electronic Effect Of Platinum Alloy Catalysts On Olefin Hydrogenation Kinetics, Colin Reedy, Jeff Miller, Stephen Purdy

The Summer Undergraduate Research Fellowship (SURF) Symposium

Dehydrogenation of alkanes is the first step in transforming light hydrocarbons into liquid fuels and chemicals. This process has traditionally used platinum alloys as catalysts. Alloys are used industrially because they have a greater selectivity than monometallic platinum. Alloying platinum with an inactive promoter modifies the crystalline structure of the surface (geometric effect), and the 5d electrons in platinum responsible for chemistry (electronic effect); both have been suggested to be primarily responsible for dehydrogenation selectivity in platinum alloys. Alloy catalysts have been synthesized using early 3d transition metal promoters with the same Pt₃M crystal structure. X-Ray Absorption Spectroscopy …

Thienoisatin Oligomers As N-Type Molecular Semiconductors, Natalie M. Kadlubowski, Xuyi Luo, Jianguo Mei

The Summer Undergraduate Research Fellowship (SURF) Symposium

Organic field effect transistors (OFETs) offer many advantages compared to traditional inorganic transistors, such as flexibility and solution processability. In this study we design and synthesize two thienoisatin-based organic semiconducting small molecules, then investigate their electronic properties in n-type OFETs. To introduce n-type charge transport, electron-withdrawing dicarbonitrile moieties were installed on thienoisoindigo and bis-thienoisatin molecules, which led to a quinoidal conjugation on thienoisoindigo, while maintaining an aromatic conjugation on the bis-thienoisatin. Following the syntheses, the molecules were characterized to determine highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels via cyclic voltammetry, as well as any potential …

Majorana Spin-Flip Transition In The Alpha Magnetic Trap, Miguel Alarcon, Colin Riggert, Francis Robicheaux

The Summer Undergraduate Research Fellowship (SURF) Symposium

The main purpose of the ALPHA collaboration is to trap antihydrogen atoms so that the Charge Conjugation-Parity Transformation-Time Reversal (CPT) symmetry can be tested. The trapping mechanism consists on an octupole magnet that traps the atoms near the magnetic field minima. Once trapped, due to the Majorana spin-flip effect, atoms can escape by changing the orientation of its spin. The magnetic field generated by the octupole magnet present in the trap has multiple zeroes of different orders. These zeroes could affect the probability of a spin flip, and therefore alter the number of escaped atoms. The main problem tackled by …

Efvs Effects On Pilot Performance, Michael Campbell, Nsikak Udo-Imeh, Steven J. Landry

The Summer Undergraduate Research Fellowship (SURF) Symposium

Flight tests have been conducted at Purdue University using a computer-based flying simulator in an attempt to determine and measure the effects of Enhanced Flight Vision Systems (EFVS) on the performance of pilots during landing. Knowledge of these effects could help guide future design and implementation of EFVS in modern commercial aircraft, and further increase pilots’ ability to control the aircraft in low-visibility conditions. The problem that has faced researchers in the past has revolved around the difficulty in interpreting the data which is generated by these tests. The difficulty in making a generalized conclusion based on the large amount …

Short-Term Organic Carbon Release And Chlorine Disinfectant Decay For Cross-Linked Polyethylene (Pex) Plumbing Pipes, Miriam Tariq, Christian J. Ley, Maryam Salehi, Andrew J. Whelton

The Summer Undergraduate Research Fellowship (SURF) Symposium

The use of cross-linked polyethylene (PEX) plumbing pipes has grown in popularity for residential applications. However, PEX pipes can leach organic materials into water that can enable biofilm growth, cause off-tastes and -odors, and may react with disinfectants to form disinfection by-products (DBP). Varied manufacturing processes that are applied to create PEX pipes add to the complexity of understanding organic materials released. In this study, organic carbon release from three PEX pipe brands was monitored for up to five days using a series of stagnation periods. Seven stagnation periods of 1, 2, 4, 8, 24, 72, and 120 hours were …

Steady-State Method To Measure The In-Plane Thermal Conductivity Of Thin Sheet Materials, Evgeny Pakhomenko, Andrew James Wildridge, Abraham Mathew Koshy, Souvik Das, Andreas Jung

The Summer Undergraduate Research Fellowship (SURF) Symposium

A new generation of silicon pixel detectors is required to cope with the unprecedented luminosities at the high-luminosity phase of the Large Hadron Collider (HL-LHC) in 2025. The HL-LHC provides a high radiation, high interaction rate environment for the innermost detector region of the CMS detector. This can lead to an uncontrolled increase in temperature of the detector that can destroy the silicon pixels. Moreover, too high operating temperature can add noise to the data obtained from the detector and can slow the read out cheap down. Therefore, the Phase II upgrade to the Compact Muon Solenoid (CMS) experiment requires …

Assessing Potential Winter Weather Response To Climate Change And Implications For Tourism In The U.S. Great Lakes And Midwest, Natalie Chin, Kyuhun Byun, Alan F. Hamlet, Keith A. Cherkauer

School of Agricultural & Biological Engineering Faculty Publications

Study Region: Eight U.S. states bordering the North American Laurentian Great Lakes.

Study Focus: Variable Infiltration Capacity (VIC) model simulations, based on data from an en- semble of atmospheric-ocean general circulation models (AOGCMs) used for the Intergovernmental Panel on Climate Change's (IPCC's) Fifth Assessment Report (AR5), were used to quantify potential climate change impacts on winter weather and hydrology in the study re- gion and understand implications for its tourism sector.

New Hydrologic Insights for the Region: By the 2080s, climate change could result in winters that are shorter by over a month, reductions of over a month in days …

Zooming Into A Tinkering Project: The Progression Of Learning Through Transitional Objects, Priyanka Parekh, Elisabeth R. Gee

Interdisciplinary Journal of Problem-Based Learning

The Maker Movement has been received by the field of K–12 education with great enthusiasm as a way of teaching STEM content to children. We call attention to and identify learning opportunities in children’s projects created in a playful, informal environment with easily available materials. In keeping with research in the field of maker education and learning sciences, we describe tinkering as a constructionist learning activity in which meaning making is captured through transitional objects (Bamberger, 1995). First, we examine one specific tinkering project and identify transitional objects within the project. Next, we discuss the process of meaning making as …

Investigation Of The Effects Of Oxidizer Temperature On The Stability Of A Gas-Centered Swirl Coaxial Injector, William Zach Hallum

Open Access Dissertations

Rocket engines achieve extraordinary high energy densities within the chamber in the form of high pressure turbulent combustion. Successful design of these engines requires sustained, stable operation of a combustor exposed to extreme thermal loads. Slight deviations in operating conditions can then incur consequences ranging from reduced performance up to catastrophic failure in the face of excess heat loading. Sustained periodic oscillations, termed combustion instabilities, are often encountered during development, as fluctuations produced by combustion noise couple with heat release modes by way of modulation of the feed system, injector hydrodynamics, chemical kinetics, and mixing and atomization process. Successful development …

System Architecture, Calibration, And Control For Lidar Systems Onboard Unmanned Vehicles, Tamer Shamseldin

Open Access Dissertations

The development of Unmanned Aerial Vehicles (UAVs) as a mobile platform for deploying portable systems has benefited several applications in the civilian and military fields in the past few decades. Also, the parallel advances in peripheral technology such as the enhancement of GNSS/INS modules have resulted in a remarkable development of both UAVs as well as UAVs applications. Such development leads to the establishment of a system architecture for UAV design that will be the basis of all discussion in this dissertation. Centrally, this dissertation introduces a generic framework for UAVs equipped with a GNSS/INS positioning and orientation module as …

Multi-Dimensional Data Analytics And Deep Learning Via Tensor Networks, Wenqi Wang

Open Access Dissertations

With the booming of big data and multi-sensor technology, multi-dimensional data, known as tensors, has demonstrated promising capability in capturing multidimensional correlation via efficiently extracting the latent structures, and drawn considerable attention in multiple disciplines such as image processing, recommender system, data analytics, etc. In addition to the multi-dimensional nature of real data, artificially designed tensors, referred as layers in deep neural networks, have also been intensively investigated and achieved the state-of-the-art performance in imaging processing, speech processing, and natural language understanding.

However, algorithms related with multi-dimensional data are unfortunately expensive in computation and storage, thus limiting its application when …

Producing Nanoscale Laser Spot And Its Applications, Anurup Datta

Open Access Dissertations

Driven by the exponential growth in the field of nanotechnology in the last few decades, there has been a huge impetus in the design and production of subwavelength nanoscale laser spot which has found wide range of applications in different fields such as nanofabrication and data storage, among others. Limited by the diffraction limit of light when using conventional optics, generally metallic nano-apertures and nano-antennas are used for producing sub-100 nm spots. Design of such types of nano structures typically involves the use of surface plasmons to effectively collect and concentrate light below the diffraction limit. This work discusses the …

Graphic Design Students' Development Of Adaptive Expertise In Ideation Strategies, Shih-Ping Kuo

Open Access Dissertations

This exploratory study uses the convergent design of mixed methods to integrate adaptive expertise theory to study how individual student participant from graphic design or non-graphic-design majors to solve a novel ideation problem in graphic design. Adaptive expertise includes six dimensions: metacognition, flexibility, dynamic knowledge, ability to welcome challenges, efficiency and deep understanding of the domain knowledge, and multiple perspectives. Those are desired qualities for a learner to stand out in the global market that are constantly changing with complex challenges. Thirty undergraduate students participated in this study. This study aims to answer four questions: types of graphic design tool …

The Mathematical Content Preparation Of Elementary Teachers, Brooke Max

Open Access Dissertations

Prospective elementary teachers’ (PTs) preparation often includes courses focused on deepening K–8 mathematical content knowledge and, in some cases, considering the content from a teacher’s perspective. Standards and recommendations from professional organizations have included attention to mathematical content (e.g., Mathematical Education of Teachers II [MET II]), mathematical processes (e.g., Common Core State Standards for Mathematics: Standards for Mathematical Practice [CCSSM SMPs]), and mathematical proficiency (e.g., Adding It Up). The publication of these documents has raised questions about how mathematics teacher educators (MTEs) incorporate these standards and recommendations in PTs’ coursework, particularly in Mathematics Content for Elementary Teachers (MCfET) courses, which …

Analysis Of Metallic Shielding For Reduction Of Rf Induced Heating Of Electrode During Mri For Active Implants, Krishna M. Singhal

Open Access Dissertations

The options available to patients with implantable devices are limited. It is because there are multiple interactions between the MRI environment and the implantable medical devices. The three main components of MRI systems- static magnet, RF coil, and a gradient coil- interact with the implantable medical devices. These interactions can cause force, torque, device vibrations and RF-induced heating. Among all these potential hazards is the heating caused by the RF electromagnetic field. The lead wires of the implants can act as antennas and pick up the electric field generated by the RF coil. This results in the induced current traveling …

Guided Data Fusion, Romila Pradhan

Open Access Dissertations

While the volume and variety of data furnished by disparate data sources has rocketed over the years, often there is little to no restraint over the quality of data available on the Internet; data sources often provide conflicting information for the same data item (a real-world entity or event).

Recent years have witnessed a number of data fusion systems that propose solutions to consolidate multiple instances of a data item, distinguish correct from incorrect information and present a unified, consistent and meaningful record to users. Most of these fusion systems are focused on automatically identifying correct information for data items. …

Micropropulsion Trade Study And Investigation For Attitude Control Of Nanosatellites, Katherine L. Fowee

Open Access Theses

Since their inception two decades ago, CubeSats have become dominant in the small satellite market, enabling new mission architectures, technology development, and education opportunities. However, the limited mass, power, and volume inherent in this small platform, constrains the on board subsystems and thus the capabilities compared to larger satellites. Attitude control is essential to maximizing the potential of CubeSats and other nanosatellites, though traditional momentum control systems such as reaction wheels are not feasible on the smallest CubeSats. Micropropulsion is an intriguing alternative to traditional methods, and many miniaturization efforts have been made for chemical and electrical propulsion systems. One …

Designing Agricultural Input Subsidy Programs: A System Dynamics Informed Optimization Approach For Zambia, Mrunal Shah

Open Access Theses

Input subsidies have been introduced in many of the sub-Saharan countries to increase the agricultural productivity. However, these programs are very expensive and they continue to operate with no end in sight. There have been many studies evaluating of the subsidy programs, but there is a need to develop a formal design model for input subsidies. This Thesis provides a proof of concept design model for a time-bounded input subsidy program. A system dynamic framework was developed based on the in depth literature review of the learnings from the past subsidy programs. Using the relationships in the system dynamic framework, …

Three Essays On Skill Heterogeneity In Frictional Labor Markets, Jacklyn R. Buhrmann

Open Access Dissertations

This dissertation is composed of three essays using labor search models to explore the role of skill mismatch in the labor market. The first, “Skill Mismatch in Frictional Labor Markets”, provides theory and evidence on pair-specific skill mismatch in the labor market, defined as the gap between an individual’s skills and the requirements of her job. Employment data from the NLSY97 display some degree of positive sorting into occupations on the basis of cognitive skills, but skill mismatch is pervasive and costly. I develop and estimate a labor search model featuring heterogeneity in worker skills and firm skill requirements that …