Engineering Commons^™

Adaptive Cutting Force Control For Process Stability Of Micro Ultrasonic Machining, Ala'a M. Al-Okaily

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

The growing demand for miniaturized products motivates the advancement in micromanufacturing processes research and development. Micro Ultrasonic Machining (Micro USM) is a downscaled version of a macro USM process that is developed to fabricate complex features in chemically inert, nonconductive, hard, brittle materials such as quartz, glass, and ceramics. These materials have many applications in various fields such as optics, electronics, MEMS, and biotechnology. The micro USM process stability is hard to accomplish, because it is highly influenced by the accuracy of the machining system and the variation of the process control parameters. The repeatability of micro USM machined features …

Study Of Micro Rotary Ultrasonic Machining, Aarati Sarwade

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

Product miniaturization for applications in fields such as biotechnology, medical devices, aerospace, optics and communications has made the advancement of micromachining techniques essential. Machining of hard and brittle materials such as ceramics, glass and silicon is a formidable task. Rotary ultrasonic machining (RUM) is capable of machining these materials. RUM is a hybrid machining process which combines the mechanism of material removal of conventional grinding and ultrasonic machining. Downscaling of RUM for micro scale machining is essential to generate miniature features or parts from hard and brittle materials.

The goal of this thesis is to conduct a feasibility study and …

Transmitter Localization Using Autonomous Robotic Swarms, Joshua S. Adams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research is to design a proof of concept system that is capable of locating a hidden radio transmitter and to investigate methods of multi-agent formation control with a specific interest in the effectiveness of these methods on the overall objective of locating this transmitter. A system is proposed and developed in which autonomous agents work together to locate this transmitter and their responsiveness is analyzed while using formations based both on a behavioral system and a system derived from centroidal Voronoi tessellations. Many software adaptations to the existing MASnet program are required, as well as some …

The Utah Pilot Bridge, Live Load And Dynamic Testing, Modeling And Monitoring For The Long-Term Bridge Performance Program, Steven M. Petroff

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As part of the Federal Highway Administration's Long-Term Bridge Performance Program, Live Load and Dynamic tests were conducted. A long-term monitoring plan was developed and presented for the Utah Pilot Bridge based on Live Load and Dynamic tests. As one of seven pilot bridges, the Utah Pilot Bridge is one of the first bridges used to initiate the LTBP Program. A formal permit approval process, with the Utah Department of Transportation, was followed to gain permission to conduct the tests and install long-term instrumentation. Analysis provided good results for each test completed, with a summary of test results presented. A …

A Study Of Cause And Effect Relationships Of Snowmelt-Induced Movement For The Skunk Hollow Landslide, Brent P. Randall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Skunk Hollow Landslide (located 1 mile north of Mantua, UT along US-89) was instrumented with an automated monitoring system to aid in the determination of the triggering mechanism of slow moving landslides. Data was transmitted wirelessly through telecommunications to allow year-round, real-time monitoring of the site. Measurements were recorded and analyzed for the first season of landslide movement (fall 2009 to spring 2010) to better understand the correlations between snowmelt and movement initiation. Based on the first year of data, it appears that the Skunk Hollow Landslide is controlled by water infiltrating into the slide mass through cracks and …

Mechanical Behavior Of Alloy 230 At Temperatures Relevant To Ngnp Program, Sudin Chatterjee

UNLV Theses, Dissertations, Professional Papers, and Capstones

Identification and selection of suitable structural materials for heat exchanger application within the purview of the next generation nuclear plant (NGNP) program constitute a major challenge. This challenge stems from the lack of many desired metallurgical and mechanical properties of conventional metallic materials and alloys for applications at temperatures approaching 950 oC. Nickel (Ni)-base Alloy 230 has been highly recommended as a suitable structural material for such application due to its excellent resistance to high-temperature plastic deformation and superior corrosion resistance in many hostile environments. Systematic studies on tensile, fracture toughness, creep, stress-rupture and creep-fatigue behavior of this alloy have …

Development Of Hydrogen Direct Injection For Conversion Of Internal Combustion Engines, Maxwell A. Wilson

UNLV Theses, Dissertations, Professional Papers, and Capstones

The trend toward usage of vehicles that operate on alternative, renewable forms of energy storage has generated areas for development of new products that will facilitate implementation of new automotive fuel systems. As the reality of a hydrogen-fueled economy emerges, intermediate technologies may be necessary for the transition between hydrocarbon fueled internal combustion engines and hydrogen powered fuel cells. The University of Nevada Las Vegas Center for Energy Research has developed a method for converting the common hydrocarbon fueled internal combustion engine to hydrogen direct injected fueling. This thesis describes the second phase of development and involves the design, fabrication …

Design And Analysis Of A Low Temperature Co-Fired Ceramic Micro Combustor, Matthew H. Mccrink

Boise State University Theses and Dissertations

This thesis details the design and construction of a Low Temperature Co-Fired Ceramic (LTCC) micro combustion system. The design of the combustor requires a detailed analysis of the flame’s operational properties and stability. To this end, an analytic model was created to address these concerns. These results were used in conjunction with a detailed numerical analysis to determine the stable operating range of the combustors. The combustion of gaseous fuels requires a device with a lower bound on the channel feature size. This lower limit for combustion corresponds to the minimum quenching distance of the specific fuel being used and …

K-Delta-1-Sigma Modulators For Wideband Analog-To-Digital Conversion, Vishal Saxena

Boise State University Theses and Dissertations

As CMOS technology scales, the transistor speed increases enabling higher speed communications and more complex systems. These benefits come at the cost of decreasing inherent device gain, increased transistor leakage currents, and additional mismatches due to process variations. All of these drawbacks affect the design of high-resolution analog-to-digital converters (ADCs) in nano-CMOS processes. To move towards an ADC topology useful in these small processes a first-order K-Delta-1-Sigma (KD1S) modulator-based ADC was proposed. The KD1S topology employs inherent time-interleaving with a shared integrator and K-quantizing feedback paths and can potentially achieve significantly higher conversion bandwidths when compared to the traditional …

High-Voltage Programmable Delta-Sigma Modulation Voltage-Control Circuit, Lucien Jan Bissey

Boise State University Theses and Dissertations

Modern memory semiconductors require different internal voltages to accomplish the myriad of tasks that are required for operation. These internal voltages are multiples of the external voltage that is applied to the part. This multiple can be greater than one, as is the case with voltage pumps, less than one, as in the case of regulated supplies, and negative, as in the case of negative charge pumps. All of these potentials require control and regulation to ensure proper operation of the die. The control of the supply ensures that the required potentials are available when the die needs it. The …

Using The Continuous Wavelet Transform To Characterize Differences Between Impact Signals From Non-Cleated And Cleated Turf Shoes, Wayne Robert Fischer

Boise State University Theses and Dissertations

The continuous wavelet transform was used to characterize the time-frequency differences between impact forces from non-cleated and cleated turf shoes among male football athletes who perform cut and run activities. This research is significant because it elucidates how athletes experience different impact force and torque frequency content based on the type of shoe they are wearing. The complex Morlet mother wavelet was used to analyze all ground reaction force and vertical ground reaction moment signals to create time-frequency power spectrum plots. For each signal, a statistical confidence interval was calculated and displayed along with the cone of influence caused by …

Gain And Offset Error Correction For Cmos Image Sensor Using Delta-Sigma Modulation, Kuang Ming Yap

Boise State University Theses and Dissertations

A delta-sigma modulation analog-to-digital converter (ADC) has many benefits over the use of a pipeline ADC in a CMOS image sensor. These benefits include lower power, noise reduction, ease of maximizing the input range, and simpler signal routing for large arrays. Multiple delta-sigma modulation ADCs are required in a CMOS image sensor, one for each pixel column. Any voltage threshold mismatch between ADCs will introduce gain and offset errors in the ADC's transfer function. These errors will lead to fixed-pattern noise. Correcting gain and offset error for every ADCs in the image sensor will require a complex digital signal processor. …

Impact Of Ground-Level Aviation Emissions On Air Quality In The Western United States, Eric Edward Clark

Boise State University Theses and Dissertations

The aviation industry has experienced sustained growth since its inception result- ing in an increase in air pollutant emissions. Exposure to particulate matter less than 2.5 µm in diameter (PM_2.5) has been linked to respiratory health problems because it penetrates deepest into human lungs.

This thesis focused on the concentrations of three secondary aerosol species (i.e., sulfate, nitrate + ammonium and organic carbon) as they relate to the formation of total PM_2.5. There were three goals of this research: evaluate differences in total PM_2.5 concentration as (1) ground-level aviation emissions (i.e., up to 3,000 …

Point-Based Backup For Decentralized Pompds: Complexity And New Algorithms, Akshat Kumar, Shlomo Zilberstein

Research Collection School Of Computing and Information Systems

Decentralized POMDPs provide an expressive framework for sequential multi-agent decision making. Despite their high complexity, there has been significant progress in scaling up existing algorithms, largely due to the use of point-based methods. Performing point-based backup is a fundamental operation in state-of-the-art algorithms. We show that even a single backup step in the multi-agent setting is NP-Complete. Despite this negative worst-case result, we present an efficient and scalable optimal algorithm as well as a principled approximation scheme. The optimal algorithm exploits recent advances in the weighted CSP literature to overcome the complexity of the backup operation. The polytime approximation scheme …

Open Innovation In Platform Competition, Mei Lin

Research Collection School Of Computing and Information Systems

We examine the competition between a proprietary platform and an open platform,where each platform holds a two-sided market consisted of app developers and users.The open platform cultivates an innovative environment by inviting public efforts todevelop the platform itself and permitting distribution of apps outside of its own appmarket; the proprietary platform restricts apps sales solely within its app market. Weuse a game theoretic model to capture this competitive phenomenon and analyze theimpact of growth of the open source community on the platform competition. We foundthat growth of the open community mitigates the platform rivalry, and balances the developernetwork sizes on …

Towards Finding Robust Execution Strategies For Rcpsp/Max With Durational Uncertainty, Na Fu, Pradeep Varakantham, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

Resource Constrained Project Scheduling Problems with minimum and maximum time lags (RCPSP/max) have been studied extensively in the literature. However, the more realistic RCPSP/max problems — ones where durations of activities are not known with certainty – have received scant interest and hence are the main focus of the paper. Towards addressing the significant computational complexity involved in tackling RCPSP/max with durational uncertainty, we employ a local search mechanism to generate robust schedules. In this regard, we make two key contributions: (a) Introducing and studying the key properties of a new decision rule to specify start times of activities with …

Optimum Failure Truncated Testing Strategies, Erik Kostandyan

Dissertations

Accumulated fatigue damage on mechanical components due to random stress loads eventually causes failure. Therefore products with lower failure rates are more desirable. Testing mechanical components for their intended purpose under predetermined working conditions is a common practice used by industries to prevent failures. Fatigue tests are categorized as Time Truncated or Failure Truncated, known in the literature as Type I and Type II tests, respectively. In failure truncated tests, the mechanical components are tested until the desired number of results is obtained. The parameters of a typical failure truncated test include the capacity of the test facility, the actual …

Developing A Filter Kit System Database: Procedure And Analysis, He Shi

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree Master of Science by He Shi on April 30, 2010.

Evaluation Method For Strategic Investments, Olabode Alabi

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

Real Options Analysis (ROA) has become a complimentary tool for engineering economics. It has become popular due to the limitations of conventional engineering valuation methods; specifically, the assumptions of uncertainty. Industry is seeking to quantify the value of engineering investments with uncertainty. One problem with conventional tools are that they may assume that cash flows are certain, therefore minimizing the possibility of the uncertainty of future values. Real options analysis provides a solution to this problem, but has been used sparingly by practitioners. This paper seeks to provide a new model, referred to as the Beta Distribution Real Options Pricing …

2010 Spring Engr333 Project Seminar Presentation, Eric Ledy, Rachel Jelgerhuis, Jasper Gondhi, Michael Gondhi, Steve Brink, John Mantel, Kyle Harvey, Jim Vanleeuwen, Jacob Speelman, Mitch Brummel, Tyler Van Dongen, Nathan Van Heukelum, Lynette Hromada, Jen Meneely, Matthew Brouwer, Marc Eberlein, Steve Demaagd, Tim Opperwall, Andrew Dejong, Joel Love, Alex Boelkins, Amanda Hollinger, Betsy Huyser, Jason Dornbos, Jason Handlogten, Justin Karsten, Matt Milan

ENGR 333

File for student presentation, given by students in the Spring 2010 class of ENGR333.

Hydrogen Fuel Cell Analysis: Lessons Learned From Stationary Power Generation Final Report, Scott E. Grasman, John W. Sheffield, Fatih Dogan, Sunggyu Lee, Umit O. Koylu, Angie Rolufs

Materials Science and Engineering Faculty Research & Creative Works

This study considered opportunities for hydrogen in stationary applications in order to make recommendations related to RD&D strategies that incorporate lessons learned and best practices from relevant national and international stationary power efforts, as well as cost and environmental modeling of pathways. The study analyzed the different strategies utilized in power generation systems and identified the different challenges and opportunities for producing and using hydrogen as an energy carrier. Specific objectives included both a synopsis/critical analysis of lessons learned from previous stationary power programs and recommendations for a strategy for hydrogen infrastructure deployment. This strategy incorporates all hydrogen pathways and …

College Of Engineering Senior Design Competition Spring 2010, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Each student in his or her senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. The senior design project encourages the student to use everything learned in the engineering program to create a practical, real-world solution to an engineering challenge.

A highlight of the year-long senior design project is the senior design competition. This competition, which usually takes place the week before finals each semester, helps focus the senior students on increasing the quality and potential for commercial application for their design projects.

Judges from local industry evaluate the projects on innovation, commercial …

Signal Processing On Waveform Data From The Eyesafe Ladar Testbed (Elt), K.D. Neilsen, Scott E. Budge, R.T. Pack

Electrical and Computer Engineering Faculty Publications

The Eyesafe Ladar Test-bed (ELT) is a raster scanning, single-beam, energy-detection ladar with the capability of digitizing and recording the return pulse waveform at 2 GHz in the field for off-line 3D point cloud formation research in the laboratory. The ELT serves as a prime tool in understanding the behavior of ladar waveforms. Signal processing techniques have been applied to the ELT waveform in an effort to exploit the signal with respect to noise reduction, range resolution improvement, and ability to discriminate between two surfaces of similar range. This paper presents a signal processing method used on the ELT waveform. …

Computer Program And Method For Detecting And Predicting Valve Failure In A Reciprocating Compressor, Ming-Chuan Leu, Jagannathan Sarangapani, Raghuram Puthall Ramesh

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Embodiments of the present invention provide a method implemented by a computer program for detecting and identifying valve failure in a reciprocating compressor and further for predicting valve failure in the compressor. Embodiments of the present invention detect and predict the valve failure using wavelet analysis, logistic regression, and neural networks. A pressure signal from the valve of the reciprocating compressor presents a non-stationary waveform from which features can be extracted using wavelet packet decomposition. The extracted features, along with temperature data for the valve, are used to train a logistic regression model to classify defective and normal operation of …

Multiobjective Optimization Method For Identifying Modular Product Platforms And Modules That Account For Changing Needs Over Time, Patrick K. Lewis

Theses and Dissertations

Natural and predictable changes in consumer needs often require the development of new products. Providing solutions that anticipate, account for, and allow for these changes over time is a significant challenge to manufacturers and design engineers. Products that adapt to these changes through the addition of modules reduce production costs through product commonality and provide a set of products that cater to customization and adaptation. In this thesis, a multiobjective optimization design method using s-Pareto frontiers – sets of non-dominated designs from disparate design models - is developed and used to identify a set of optimal adaptive product designs that …

A Concise Model Of 3x7 Wire Rope Used In Cable Guardrail Systems, Cody S. Stolle

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Wire rope is a versatile, flexible, high-strength member that is used in many mechanical systems. However, due to the complexity of wire rope, analytical investigations have been relatively limited. Previous attempts to create simplified models of wire rope were not validated with physical testing and used a cumbersome beam-and-shell or beam-and-solid method for simulating the wire rope. An improved LS-DYNA model of 19-mm diameter 3x7 wire rope commonly used in roadside cable guardrail installations has been developed. A Belytschko-Schwer beam element was selected along with material *MAT_166. Since wire rope displays internal damping due to friction of strands and wires, …

An Efficient Implementation Of An Exponential Random Number Generator In A Field Programmable Gate Array (Fpga), Smitha Gautham

Theses and Dissertations

Many physical, biological, ecological and behavioral events occur at times and rates that are exponentially distributed. Modeling these systems requires simulators that can accurately generate a large quantity of exponentially distributed random numbers, which is a computationally intensive task. To improve the performance of these simulators, one approach is to move portions of the computationally inefficient simulation tasks from software to custom hardware implemented in Field Programmable Gate Arrays (FPGAs). In this work, we study efficient FPGA implementations of exponentially distributed random number generators to improve simulator performance. Our approach is to generate uniformly distributed random numbers using standard techniques …

Adverse Elevator Effect In Landing Flare, Nihad E. Daidzic

Aviation Department Publications

No abstract provided.

Difference Between The Second-Brewster And Pseudo-Brewster Angles When Polarized Light Is Reflected At A Dielectric–Conductor Interface, A. Alsamman, R. M.A. Azzam

Electrical Engineering Faculty Publications

For a given pseudo-Brewster angle ϕpB of minimum reflectance ∣∣rp∣∣ of p-polarized light at a dielectric-conductor interface, the second-Brewster angle ϕ2B of minimum reflectance ratio |ρ|=∣∣rp∣∣/|rs| of the p and s polarizations is determined for all possible values of the complex relative dielectric function ϵ that lead to the same ϕpB . The difference ϕ2B−ϕpB is considered as a function of ϕpB and θ=arg(ϵ) . For any given ϕpB , the difference ϕ2B−ϕpB=0 atθ=0(ϵr>0,ϵi=0) increases monotonically as a function of θ and reaches maximum value {ϕ2B−ϕpB}max in the limit as θ→180° (ϵr<0,ϵi=0) . This maximum difference {ϕ2B−ϕpB}max has an upper limit of 15.701° whenϕpB=28.195° .

Sdm Propagation Model For Multiple Channels Using Ray Theory, Syed H. Murshid, Ebad Zahir, Abhijit Chakravarty

Electrical Engineering and Computer Science Faculty Publications

Spatial Domain Multiplexing (SDM) is a novel optical fiber multiplexing technique where multiple channels of the same wavelength are launched at specific angles inside a standard step index multimode carrier fiber. These channels are confined to specific locations inside the fiber and they do not interfere with each other while traversing the length of the fiber. Spatial filtering techniques are employed at the output end to separate, route and process the individual channels. These skew ray channels inside the SDM system follow a helical trajectory along the fiber. The screen projection of the skew rays resembles a circular polygon. A …