Engineering Commons^™

Design For Manufacturability And Assembly Of An Assistive Technician Creeper, Including Single Drive Control Of A Multi-Degree Of Freedom Kinematic Mechanism, Larry T. Wilde Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In 2011, a team of engineering students at Utah State University designed and built an assistive technician creeper to assist persons with lower-extremity physical disabilities to work in low-clearance areas. In order to put this technology on the market, a complete product redesign was needed to address safety and functionality concerns. This thesis outlines the specific design needs, presents the detailed design approach, and summarizes the final creeper solution. The mechanisms of the initial prototype were modified to independently incline or recline the upper body, and raise or lower the seat surface with a single motor. This will be especially …

Best Practices For Volume Flow Rate Measurements Using Piv At The Exit Of A Turbulent Planar Jet, Rick Cressall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Particle image velocimetry (PIV) is used to make volume-flow-rate measurements at the exit of a turbulent, planar nozzle. The objective of this report is to assess a range of data acquisition and processing parameters. Data is acquired for volume flow rates of Reynolds numbers between 10,000 and 100,000 for both two-component (2C) and stereo PIV. The parameters are systematically changed one at a time and evaluated using differences in uncertainty, calculation time, and volume- flow-rate deviation. Data acquisition parameters follow the trends of previous work. A multitude of processing parameters were varied for several PIV processing methods. Recommendations for each …

Orienteering Problem: A Survey Of Recent Variants, Solution Approaches And Applications, Aldy Gunawan, Hoong Chuin Lau, Pieter Vansteenwegen

Research Collection School Of Computing and Information Systems

Duplicate record, see https://ink.library.smu.edu.sg/sis_research/3271. The Orienteering Problem (OP) has received a lot of attention in the past few decades. The OP is a routing problem in which the goal is to determine a subset of nodes to visit, and in which order, so that the total collected score is maximized and a given time budget is not exceeded. A number of typical variants has been studied, such as the Team OP, the (Team) OP with Time Windows and the Time Dependent OP. Recently, a number of new variants of the OP was introduced, such as the Stochastic OP, the …

Orienteering Problem: A Survey Of Recent Variants, Solution Approaches And Applications, Aldy Gunawan, Hoong Chuin Lau, Pieter Vansteenwegen

Research Collection School Of Computing and Information Systems

The Orienteering Problem (OP) has received a lot of attention in the past few decades. The OP is a routing problem in which the goal is to determine a subset of nodes to visit, and in which order, so that the total collected score is maximized and a given time budget is not exceeded. A number of typical variants has been studied, such as the Team OP, the (Team) OP with Time Windows and the Time Dependent OP. Recently, a number of new variants of the OP was introduced, such as the Stochastic OP, the Generalized OP, the Arc OP, …

Managing Egress Of Crowd During Infrastructure Disruption, Teck Hou Teng, Shih-Fen Cheng, Trong-Nghia Truong, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

In a large indoor environment such as a sports arena or convention center, smooth egress of crowd after an event can be seriously affected if infrastructure such as elevators and escalators break down. In this paper, we propose a novel crowd simulator known as SIM-DISRUPT for simulating egress scenarios in non-emergency situations. To surface the impact of disrupted infrastructure on the egress of crowd, SIM-DISRUPT includes features that allow users to specify selective disruptions as well as strategies for controlling the distribution and egress choices of crowd. Using SIM-DISRUPT, we investigate effects of crowd distribution, egress choices and infrastructure disruptions …

Traffic Simulation Model For Port Planning And Congestion Prevention, Baoxiang Li, Kar Way Tan, Trong Khiem Tran

Research Collection School Of Computing and Information Systems

Effective management of land-side transportation provides the competitive advantage to port terminal operators in improving services and efficient use of limited space in an urban port. We present a hybrid simulation model that combines traffic-flow modeling and discrete-event simulation for land-side port planning and evaluation of traffic conditions for a number of what-if scenarios. We design our model based on a real-world case of a bulk cargo port. The problem is interesting due to complexity of heterogeneous closed-looped internal vehicles and external vehicles traveling in spaces with very limited traffic regulation (no traffic lights, no traffic wardens) and the traffic …

From Footprint To Evidence: An Exploratory Study Of Mining Social Data For Credit Scoring, Guangming Guo, Feida Zhu, Enhong Chen, Qi Liu, Le Wu, Chu Guan

Research Collection School Of Computing and Information Systems

With the booming popularity of online social networks like Twitter and Weibo, online user footprints are accumulating rapidly on the social web. Simultaneously, the question of how to leverage the large-scale user-generated social media data for personal credit scoring comes into the sight of both researchers and practitioners. It has also become a topic of great importance and growing interest in the P2P lending industry. However, compared with traditional financial data, heterogeneous social data presents both opportunities and challenges for personal credit scoring. In this article, we seek a deep understanding of how to learn users’ credit labels from social …

Unsupervised Feature Selection For Outlier Detection By Modelling Hierarchical Value-Feature Couplings, Guansong Pang, Longbing Cao, Ling Chen, Huan Liu

Research Collection School Of Computing and Information Systems

Proper feature selection for unsupervised outlier detection can improve detection performance but is very challenging due to complex feature interactions, the mixture of relevant features with noisy/redundant features in imbalanced data, and the unavailability of class labels. Little work has been done on this challenge. This paper proposes a novel Coupled Unsupervised Feature Selection framework (CUFS for short) to filter out noisy or redundant features for subsequent outlier detection in categorical data. CUFS quantifies the outlierness (or relevance) of features by learning and integrating both the feature value couplings and feature couplings. Such value-to-feature couplings capture intrinsic data characteristics and …

Hot Ductility And Hot-Shortness Of Steel And Measurement Techniques: A Review, G Sahoo, M Deepa, B Singh, A Saxena

Journal of Metals, Materials and Minerals

Usage of steel scrap has become important in steel making from the view points of resource conservation and preventing environmental problems. High levels of steel scraps are used in the production of steel, especially, via electric arc furnaces (EAF). However, Copper, which is mainly contained in the scrap of cars and home electronic appliance, is problematic in mechanical workings at elevated temperatures and limits the usage of scrap iron. It is enriched at steel/scale interface by preferential oxidation of Fe, which leads to liquid embrittlement or surface cracking during hot working. This type of defect is well known as surface …

Petrographic Analysis Of Ceramic Artifacts From Ban Di Kiln, Pattani Province, Thailand, W Dhanmanonda, S Hongrittipun, D Aussavamas

Journal of Metals, Materials and Minerals

This research paper aims to investigate the components of archaeological ceramic artifacts collected from Ban Di kiln, Pattani province, Thailand. The procedure involves the petrographic examination of fragments of ceramic artifacts, focusing on raw materials, sources of materials, and production techniques. Ban Di ceramics date back to 16th and 17th centuries, the period in which ancient Patani had enjoyed its prosperity in domestic and foreign trade. This study shows that alluvial soils from coastal plains, with high content of sand, are predominant materials in the manufacture. The production process involves jiggering and hot pressing at the firing temperatures between 400-550 …

Dependence Of Electrical Resistivity On Plastic Deformation In Copper-Aluminum Alloy Cu0.975al0.025, J G Miranda Ramos, E Medrano Atencio, M Quiroga Agurto, F A Reyes Navarro

Journal of Metals, Materials and Minerals

We measure changes of electrical resistivity after a plastic deformation. We supposed that the changes are due to a large density of dislocation present in the polycrystalline samples; therefore, we also measure the amount of dislocations after the plastic deformation. Thus, for our aim, we elaborated copper-aluminum alloys Cu0.975Al0.025; next, with them, we fabricated metallographic specimens, which were submitted to traction subsequently. We measured the electrical resistivity before and after the traction. The obtained results are discussed in a theoretical framework of dislocations.

Dual Role Of Sb Ions As Electron Traps And Hole Traps In Photorefractive Sn2P2S6 Crystals, Brant E. Kananen, Eric M. Golden, Sergey A. Basun, D. R. Evans, A. A. Grabar, I. M. Stoika, John W. Mcclory, Nancy C. Giles, Larry E. Halliburton

Faculty Publications

Doping photorefractive single crystals of Sn₂P₂S₆ with antimony introduces both electron and hole traps. In as-grown crystals, Sb³⁺ (5s²) ions replace Sn²⁺ ions. These Sb³⁺ ions are either isolated (with no nearby perturbing defects) or they have a charge-compensating Sn²⁺ vacancy at a nearest-neighbor Sn site. When illuminated with 633 nm laser light, isolated Sb³⁺ ions trap electrons and become Sb²⁺ (5s²5p¹) ions. In contrast, Sb³⁺ ions with an adjacent Sn vacancy trap holes during illumination. The hole is primarily …

Implementation And Performance Evaluation Of Acoustic Denoising Algorithms For Uav, Ahmed Sony Kamal Chowdhury

UNLV Theses, Dissertations, Professional Papers, and Capstones

Unmanned Aerial Vehicles (UAVs) have become popular alternative for wildlife monitoring and border surveillance applications. Elimination of the UAV’s background noise and classifying the target audio signal effectively are still a major challenge. The main goal of this thesis is to remove UAV’s background noise by means of acoustic denoising techniques. Existing denoising algorithms, such as Adaptive Least Mean Square (LMS), Wavelet Denoising, Time-Frequency Block Thresholding, and Wiener Filter, were implemented and their performance evaluated. The denoising algorithms were evaluated for average Signal to Noise Ratio (SNR), Segmental SNR (SSNR), Log Likelihood Ratio (LLR), and Log Spectral Distance (LSD) metrics. …

Stationary Nonimaging Concentrators – A Comprehensive Study And Design Improvements, Srikanth Madala

UNLV Theses, Dissertations, Professional Papers, and Capstones

Most places on our planet receive an annual average radiation between 800-1000 W/m2. In the man-made world, this radiation is largely incident on stationary structures such as buildings, roads, monuments, bridges etc. Moreover, in the natural world also, there are large tracts of barren land which can be put to good use given their solar energy potential. The vision of the current research is to concentrate all this available solar energy to a more readily usable form. Therefore, stationary nonimaging solar concentrator technologies are sought after. This dissertation work is an exhaustive research on the nonimaging concentrating mechanisms with stationary …

Alkali-Activated Natural Pozzolan/Slag Binder For Sustainable Concrete, Meysam Najimi

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study aimed to fully replace Portland cement (PC) with environmentally friendly binders capable of improving longevity of concrete. The new binders consisted of different proportions of natural Pozzolan and slag which were alkaline-activated with various combinations of sodium hydroxide and sodium silicate. A step-by-step research program was designed to (1) develop alkali-activated natural Pozzolan/slag pastes with adequate fresh and strength properties, (2) produce alkali-activated natural Pozzolan/slag mortars to assess the effects of dominant variables on their plastic and hardened properties, and (3) finally produce and assess fresh, mechanical, dimensional, transport and durability properties of alkali-activated natural Pozzolan/slag concretes. The …

A Business Intelligence Framework For Network-Level Traffic Safety Analyses, Naveen Kumar Veeramisti

UNLV Theses, Dissertations, Professional Papers, and Capstones

Currently, there are both methodological and practical barriers that together preclude a substantial use of theoretically sound approaches, such as the ones recommended by the Highway Safety Manual (HSM), for traffic safety management. Although the state-of-the-art provides theoretically sound approaches such as the Empirical Bayes method, there are still various important capabilities missing. Methodological barriers include among others (i) lack of a theoretically sound approach for corridor-level network screening, (ii) lack of a comprehensive approach for estimation of Safety Performance Functions based on a simultaneous consideration of both crash patterns and associated explanatory variables, and (iii) lack of theoretically sound …

Direct Quadrature Method Of Moments With Delumping For Modeling Multicomponent Droplet Vaporization, Simcha L. Singer

Mechanical Engineering Faculty Research and Publications

A multicomponent droplet vaporization model which combines the computational efficiency of continuous thermodynamic approaches with the detailed species information provided by discrete component models has been developed. The Direct Quadrature Method of Moments (DQMoM) is used to efficiently solve for the evolution of the nodes and weights of the equivalent liquid-phase mole fraction distribution without assuming any functional form. The novelty of the approach is an inexpensive delumping procedure that is used to reconstruct the time-dependent mole fractions and fluxes for all discrete species. When applied to a vaporizing kerosene droplet, agreement between the full discrete component model, which solves …

Integrated Design Of Downwind Land-Based Wind Turbines Using Analytic Gradients, Andrew Ning, Derek Petch

Faculty Publications

Wind turbines are complex systems where component-level changes can have significant system-level effects. Effective wind turbine optimization generally requires an integrated analysis approach with a large number of design variables. Optimizing across large variable sets is orders of magnitude more efficient with gradient-based methods as compared to gradient-free method, particularly when using exact gradients. We have developed a wind turbine analysis set of over 100 components where 90% of the models provide numerically exact gradients through symbolic differentiation, automatic differentiation, and adjoint methods. This framework is applied to a specific design study focused on downwind land-based wind turbines.

Downwind machines …

The Impacts Of Arterial Occlusion, Sex, And Exercise On Arteriogenesis And Functional Vasodilation, Megan Tze-Mei Chu

Master's Theses

The most frequent clinical presentation of peripheral arterial occlusive disease (PAOD) is intermittent claudication, which may be caused by impaired vasodilation. Patients demonstrate both local and systemic impairments in vasodilation, but as the collateral circulation is the primary site of resistance to the ischemic zone, impaired collateral vasodilation would have the greatest potential to induce claudication. Collateral function following arterial occlusion is not well defined, but immature collaterals may demonstrate impaired vasodilation in animal models, although this is potentially improved with exercise training. Furthermore, as females exhibit poorer physical function with ischemia and less improvement with therapeutic exercise, there appears …

Assessment Of Asymmetric Flight On Solar Uas, Eric Belfield

Master's Theses

An investigation was conducted into the feasibility of using an unconventional flight technique, asymmetric flight, to improve overall efficiency of solar aircraft. In this study, asymmetric flight is defined as steady level flight in a non-wings-level state in- tended to improve solar incidence angle. By manipulating aircraft orientation through roll angle, solar energy collection is improved but aerodynamic efficiency is worsened due to the introduction of additional trim drag. A point performance model was devel- oped to investigate the trade-off between improvement in solar energy collection and additional drag associated with asymmetric flight. A mission model with a focus on …

Design, Analysis, And Simulation Of A Jitter Reduction Circuit (Jrc) System At 1ghz, Run Bin Yu

Master's Theses

The clock signal is considered as the “heartbeat” of a digital system yet jitter which is a variation on the arrival time of the clock edge, could undermine the overall performance or even cause failures on the system. Deterministic jitter could be reduced during the designing process however random jitter during operation is somehow less-controllable and unavoidable. Being able to remove jitter on the clock would therefore play a vital role in system performance improvement.

This thesis implements a 1GHz fully feedforward jitter reduction circuit (JRC) which can be used as an on-chip IP core at clock tree terminals to …

Development Of Cal Poly's Shock Table, Christopher D. Risner

Master's Theses

Shock is one of the environmental tests that a spacecraft must pass before being cleared for launch. Shock testing poses a challenging data acquisition issue and careful selection of equipment is crucial to creating a successful shock test facility. Cal Poly’s CubeSat programs can currently perform all environmental testing other than shock themselves, so a quality shock table would be useful. Previous groups of students had developed a shock table, and this paper details the improvement and characterization of that shock table’s behavior. Several adjustable parameters were tested and documented to discover trends in the shock table’s response to an …

Quantifying Parkinson's Disease Symptoms Using Mobile Devices, Charles R. Aylward

Master's Theses

Current assessments for evaluating the progression of Parkinson’s Disease are largely qualitative and based on small sets of data obtained from occasional doctor-patient interactions. There is a clinical need to improve the techniques used for mitigating common Parkinson’s Disease symptoms. Available data sets for researching the disease are minimal, hindering advancement toward understanding the underlying causes and effectiveness of treatment and therapies. Mobile devices present an opportunity to continuously monitor Parkinson’s Disease patients and collect important information regarding the severity of symptoms. The evolution of digital technology has opened doors for clinical research to extend beyond the clinic by incorporating …

Nanoindentation Techniques For The Evaluation Of Silicon Nitride Thin Films, Weston T. Mangin

Master's Theses

Silicon nitride thin films are of interest in the biomedical engineering field due to their biocompatibility and favorable tribological properties. Evaluation and understanding of the properties of these films under diverse loading and failure conditions is a necessary prerequisite to their use in biomedical devices. Three wafers of silicon nitride-coated silicon were obtained from Lawrence Livermore National Laboratory and used to create 96 samples. Samples were subjected to nanoindentation testing to evaluate the mechanical properties of the film. Samples were subjected to nanoimpact testing to compare the damage resistance of the film to separate nanoimpact types. Samples were subjected to …

Evaluation Of Efficiency Of Various Materials To Shield From Radiation In Space Using The Monte Carlo Transport Code Called Fluka, Roman Savinov

Master's Theses

The purpose of this study is to improve spacecraft shielding from radiation in space. It focuses on the evaluation of shielding efficiency of different materials. The efficiency of a shield is evaluated by the dose profile within the shield and the amount of dose absorbed by a target using the Monte Carlo transport code called FLUKA. The output of this code is validated by recreating the experiments from published papers and comparing the results. Once the FLUKA’s output is validated, the efficiency of sixteen materials, subject to SPE and GCR sources, are evaluated. The efficiency comparison is made by fixing …

Field Emissions Of (Hydro)Chlorofluorocarbons And Methane From A California Landfill, Alexander H. Sohn

Master's Theses

A comprehensive field investigation was conducted at Potrero Hills Landfill (PHL) located in Suisun City, California to quantify emissions of twelve (hydro)chlorofluorocarbons (i.e. F-gases). The specific target constituents for this study included CFC-11, CFC-12, CFC-113, CFC-114, HCFC-21, HCFC-22, HCFC-141b, HCFC-142b, HCFC-151a, HFC-134a, HFC-152a, and HFC-245fa. The majority of the F-gas emission studies have been conducted outside of the United States and very limited field landfill emission data are available in the United States. Because of historical usage of blowing agents in insulation foams including CFC-11, HCFC-142b, HFC-134a, and HFC-245fa, models reported in literature predicted high F-gas emissions from a landfill …

Repeat Exposure To Leg Swing Perturbations During Treadmill Training Induces Long-Term Retention Of Increased Step Length In Human Sci: A Pilot Randomized Controlled Study, Ming Wu, Jill M. Landry, Janis Kim, Brian D. Schmit, Sheng-Che Yen, Jillian Mcdonald, Yunhui Zhang

Biomedical Engineering Faculty Research and Publications

Objective: To determine whether repeat exposure to force perturbations during treadmill training can induce long-term retention of improved step length and overall improvements in locomotor function in persons with spinal cord injury.

Design: Fourteen patients with spinal cord injury were recruited and randomly assigned to swing resistance or swing assistance training groups. A controlled swing resistance or assistance force, for resistance or assistance training groups, respectively, was applied to both legs through a cable-driven robotic system during treadmill training. Each participant trained 3 times per week for 6 weeks. Step length, walking speed, 6-minute walking distance, and other clinical assessments …

Transient Local Bone Remodeling Effects Of Rhbmp-2 In An Ovine Interbody Spine Fusion Model, Hyun W. Bae, Vikas V. Patel, Zeeshan M. Sardar, Jeffrey Badura, Ben B. Pradhan, Howard Seim, Anthony S. Turner, Jeffrey M. Toth

Biomedical Engineering Faculty Research and Publications

Background: Recombinant human bone morphogenetic protein-2 (rhBMP-2) is a powerful osteoinductive morphogen capable of stimulating the migration of mesenchymal stem cells (MSCs) to the site of implantation and inducing the proliferation and differentiation of these MSCs into osteoblasts. Vertebral end-plate and vertebral body resorption has been reported after interbody fusion with high doses of rhBMP-2. In this study, we investigated the effects of 2 rhBMP-2 doses on peri-implant bone resorption and bone remodeling at 7 time points in an end-plate-sparing ovine interbody fusion model. Methods: Twenty-one female sheep underwent an end-plate-sparing discectomy followed by interbody fusion at L2-L3 and L4-L5 …

Investigation Of Polymer–Plasticizer Blends As Sh-Saw Sensor Coatings For Detection Of Benzene In Water With High Sensitivity And Long-Term Stability, Pintu Adhikari, Laura Jeanne Alderson, Florian Bender, Antonio J. Ricco, Fabien Josse

Electrical and Computer Engineering Faculty Research and Publications

We report the first-ever direct detection of benzene in water at concentrations below 100 ppb (parts per billion) using acoustic wave (specifically, shear-horizontal surface acoustic wave, SH-SAW) sensors with plasticized polymer coatings. Two polymers and two plasticizers were studied as materials for sensor coatings. For each polymer–plasticizer combination, the influence of the mixing ratio of the blend on the sensitivity to benzene was measured and compared to commercially available polymers that were used for BTEX (benzene, toluene, ethylbenzene, and xylene) detection in previous work. After optimizing the coating parameters, the highest sensitivity and lowest detection limit for benzene were found …

Nanomanufacturing Outside Of The Lab: An Academic-Industry Partnership Case Study, Ann E. Delaney

Boise State University Theses and Dissertations

In 2003, policy entrepreneur Dr. Mihail Roco wrote in Nature Biotechnology, “The key goals of nanotechnology are advances in molecular medicine, increased working productivity, extension of the limits of sustainable development and increased human potential.” From initial visions like Roco’s until now, there has been significant investment and research progress in the field of nanotechnology. According to the White House, over $20 billion has been invested in nanotechnology research and development by the United States government since 2000.¹ There is now a growing emphasis on transitioning from a focus on fundamental research towards a focus on overcoming …