Engineering Commons^™

Energy Benefits Of Reconfigurable Hardware For Use In Underwater Sensor Nets, Bridget Benson, Ali Irturk, Junguk Cho, Ryan Kastner

Electrical Engineering

Small, dense underwater sensor networks have the potential to greatly improve undersea environmental and structural monitoring. However, few sensor nets exist because commercially available underwater acoustic modems are too costly and energy inefficient to be practical for this applications. Therefore, when designing an acoustic modem for sensor networks, the designer must optimize for low cost and low energy consumption at every level, from the analog electronics, to the signal processing scheme, to the hardware platform. In this paper we focus on the design choice of hardware platform: digital signal processors, microcontrollers, or reconfigurable hardware, to optimize for energy efficiency while …

Multi-Objective Design Of Transient Network Models, Bong Seog Jung, Misgana K. Muleta, Paul F. Boulos

Civil and Environmental Engineering

The optimal design of a water distribution system under transient conditions is formulated as a two-objective optimization problem. The objectives are minimization of the total pipe costs and maximization of the hydraulic reliability for the transient network design model. Unlike most optimization models in which demands are set to their end-of-life levels, this approach assumes that the demand loadings vary throughout the design life of the system. Evolutionary algorithms are applied to support efficient search for Pareto optimal solutions to the dual-objective optimization problem. An example application is presented and relevant conclusions are stated.

Theoretical Analysis Of Alendronate And Risedronate Effects On Canine Vertebral Remodeling And Microdamage, Xiang Wang, Antonia M. Erickson, Matthew R. Allen, David B. Burr, R. Bruce Martin, Scott J. Hazelwood

Biomedical Engineering

Bisphosphonates suppress bone remodeling activity, increase bone volume, and significantly reduce fracture risk in individuals with osteoporosis and other metabolic bone diseases. The objectives of the current study were to develop a mathematical model that simulates control and 1 year experimental results following bisphosphonate treatment (alendronate or risedronate) in the canine fourth lumbar vertebral body, validate the model by comparing simulation predictions to 3 year experimental results, and then use the model to predict potential long term effects of bisphosphonates on remodeling and microdamage accumulation. To investigate the effects of bisphosphonates on bone volume and microdamage, a mechanistic biological model …

Linear Analysis Of Ordinary Bridges Crossing Fault-Rupture Zones, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

Rooted in structural dynamics theory, two approximate procedures for estimating peak responses of linearly elastic “ordinary” bridges crossing fault-rupture zones are presented: response spectrum analysis (RSA) procedure and a linear static analysis procedure. These procedures estimate the peak response by superposing peak values of quasi-static and dynamic responses. The peak quasi-static response in both procedures is computed by static analysis of the bridge with peak values of all support displacements applied simultaneously. In RSA, the peak dynamic response is estimated by dynamic analysis including all significant modes, which is simplified in the latter procedure to static analysis of the bridge …

Nonlinear Analysis Of Ordinary Bridges Crossing Fault-Rupture Zones, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

Rooted in structural dynamics theory, three approximate procedures for estimating seismic demands for bridges crossing fault-rupture zones and deforming into their inelastic range are presented: modal pushover analysis (MPA), linear dynamic analysis, and linear static analysis. These procedures estimate the total seismic demand by superposing peak values of quasi-static and dynamic parts. The peak quasi-static demand in all three procedures is computed by nonlinear static analysis of the bridge subjected to peak values of all support displacements applied simultaneously. In the MPA and the linear dynamic analysis procedures, the peak dynamic demand is estimated by nonlinear static (or pushover) analysis …

Validation Of Linearized Flight Models Using Automated System-Identification, Keith Eric Rothman

Master's Theses

Optimization based flight control design tools depend on automatic linearization tools, such as Simulink®’s LINMOD, to extract linear models. In order to ensure the usefulness and correctness of the generated linear model, this linearization must be accurate. So a method of independently verifying the linearized model is needed. This thesis covers the automation of a system identification tool, CIFER®, for use as a verification tool integrated with CONDUIT®, an optimization based design tool. Several test cases are built up to demonstrate the accuracy of the verification tool with respect to analytical results and matches with LINMOD. Several common nonlinearities are …

Comparison And Design Of Simplified General Perturbation Models (Sgp4) And Code For Nasa Johnson Space Center, Orbital Debris Program Office, Nicholas Z. Miura

Master's Theses

This graduate project compares legacy simplified general perturbation model (SGP4) code developed by NASA Johnson Space Center, Orbital Debris Program Office, to a recent public release of SGP4 code by David Vallado. The legacy code is a subroutine in a larger program named PREDICT, which is used to predict the location of orbital debris in GEO. Direct comparison of the codes showed that the new code yields better results for GEO objects, which are more accurate by orders of magnitude (error in meters rather than kilometers). The public release of SGP4 also provides effective results for LEO and MEO objects …

Implementation Of Physiologic Flow Conditions In A Blood Vessel Mimic Bioreactor System For The Evaluation Of Intravascular Devices, Marc Cody Dawson

Master's Theses

The prevalence and devastating nature of cardiovascular diseases has led to many advancements in the therapies used to treat the millions of patients that suffer as a result of these conditions. As coronary artery disease (CAD) is the most common of these cardiovascular conditions, it is a major focus of research among the medical industry. Although lifestyle changes and drug therapies can treat early CAD, more advanced cases often require more definitive interventions. In conjunction with angioplasty, stenting of an occluded vessel has shown significant success in preventing restenosis. However, as with nearly every therapeutic process in the medical field, …

An Experiment On Integrated Thermal Management Using Metallic Foam, Derek M. Geiger

Master's Theses

This report details an approach to using metal foam heat exchangers inside an integrated thermal management system on a variable cycle engine. The propulsion system of interest is a variable cycle engine with an auxiliary, variable flow rate fan. The feasibility of utilizing an open-celled metallic foam heat exchanger in the ducting between the constant and variable-fans on this variable cycle engine to cool the avionics was explored using an experimental approach. Two heat exchangers, 6.3 inch width by 6.3 inch length by 0.5 inch thickness, were constructed from 20 and 40 pores per inch (PPI) metal foam and tested. …

A Flight Simulation Study Of The Simultaneous Non-Interfering Aircraft Approach, Brian H. Reel

Master's Theses

Using a new implementation of a NASA flight simulation of the Quiet Short-Haul Research Aircraft, autopilots were designed to be capable of flying both straight in (ILS) approaches, and circling (SNI) approaches. A standard glideslope coupler was sufficient for most conditions, but a standard Proportional-Integral-Derivative (PID) based localizer tracker was not sufficient for maintaining a lateral track on the SNI course. To track the SNI course, a feed-forward system, using GPS steering provided much better results.

NASA and the FAA embrace the concept of a Simultaneous, Non-Interfering (SNI) approach as a way to increase airport throughput while reducing the noise …

Harmonic Analysis Of A Static Var Compensated Mixed Load System, James David Ruckdaschel

Master's Theses

As power electronic based controllers and loads become more prevalent in power systems, there is a growing concern about how the harmonics generated by these controllers and loads affect the power quality of the system. One widely used power electronic based load is the Variable Frequency Drive (VFDs) used to vary the speed of an induction motor; whereas a common example of a power electronic based controller used in power systems is the Static VAR Compensator (SVC) for improving a system’s power factor. In this thesis, the harmonic content and overall performance of a system including both a VFD and …

Design And Control Considerations For A Skid-To-Turn Unmanned Aerial Vehicle, Tanner Austin Sims

Master's Theses

The use of Unmanned Aerial Vehicles (UAVs) are rapidly expanding and taking on new roles in the military. In the area of training and targeting vehicles, control systems are expanding the functionality of UAVs beyond their initially designed purpose. Aeromech Engineering’s NXT UAV is a high speed target drone that is intended to simulate a small aircraft threat. However, in the interest of increasing functionality, enabling NXT to accomplish wings level skidding turns provides the basis for a UAV that can simulate a threat from a missile. Research was conducted to investigate the aerodynamic and performance characteristics of a winged …

Development Of An In-Vitro Tissue Engineered Blood Vessel Mimic Using Human Large Vessel Cell Sources, Dimitri E. Delagrammaticas

Master's Theses

Tissue engineering is an emerging field that offers novel and unmatched potential medical therapies and treatments. While the vast aim of tissue engineering endeavors is to provide clinically implantable constructs, secondary applications have been developed to utilize tissue-engineered constructs for in-vitro evaluation of devices and therapies. Specifically, in-vitro blood vessel mimics (BVM) have been developed to create a bench-top blood vessel model using human cells that can be used to test and evaluate vascular disease treatments and intravascular devices. Previous BVM work has used fat derived human microvascular endothelial cells (EC) sodded on an ePTFE scaffold. To create a more …

Target Tracking Using Various Filters In Synthetic Aperture Radar Data And Imagery, Jessica L. Kiefer

Master's Theses

This thesis explores the use and accuracy of several discrete-time image filters for the purpose of target tracking in Synthetic Aperture Radar imagery. Both extended targets and point targets are used for tracking, showing the need for different types of filters for each target type.

Monte Carlo analysis is performed on the results of the extended target filter results to determine the absolute mean-squared error between the filter prediction of the target centroid and the actual location of the target centroid. Two different filters were chosen for the extended target: Kalman and H Infinity.

Both the Kalman and H Infinity …

Design Simulation Of Top Ito Gratings To Improve Light Transmission For Gallium Nitride Leds, Xiaomin Jin, Simeon Trieu, Fei Wang, Bei Zhang, Tao Dai, Xiangning Kang, Guoyi Zhang

Electrical Engineering

We present simulation results of the indium tin oxide (ITO) top diffraction grating using a rigorous couple wave analysis (RCWA) for GaN LEDs. We study three different nano-structure patterns: cylindrical pillar grating, conical pillar grating, and cylindrical nano-hole grating. We show the light transmission improvement with nano-grating designs and present design-charts for the nano-hole grating.

Dynamics Simulation And Malfunction Diagnosis Of Heavy Machinery Using Msc Adams, Dewen Kong, Jim M. Meagher, Xi Wu

Mechanical Engineering

No abstract provided.

Integrating Adams Software Into An Upper Division Mechanical Design And Analysis Course, Xi Wu, Dewen Kong, Jim Meagher

Mechanical Engineering

No abstract provided.

A Numerical Approach For Predicting The Impact Of Vascular Architecture On Blood Flow During Ischemic Repair, Stephanie Ann Wood, Shilpi Ghosh, Kevin Jones, Gabriel Gruionu, Trevor R. Cardinals

Biomedical Engineering

Abstract of conference presentation.

Functional Vasodilation Following Murine Chronic Hindlimb Ischemia, Matthew David Yocum, Trevor R. Cardinal

Biomedical Engineering

Abstract of conference presentation.

Fatigue Strength Of Common Tibial Intramedullary Nail Distal Locking Screws, Lanny V. Griffin, Robert M. Harris, Joseph J. Zubak

Biomedical Engineering

Premature failure of either the nail and/or locking screws with unstable fracture patterns may lead to angulation, shortening, malunion, and IM nail migration. Up to thirty percent of all unreamed nail locking screws can break after initial weight bearing is allowed at 8–10 weeks if union has not occurred. The primary problem this presents is hardware removal during revision surgery. The purposes of our study was to evaluate the relative fatigue resistance of distal locking screws and bolts from representative manufacturers of tibial IM nail systems, and develop a relative risk assessment of screws and materials used. Evaluations included quantitative …

Housing Market Outlook: San Luis Obispo, Ca And Surrounding Area, Gabe Randall, Scott D. Kelting

Construction Management

Starting between 1999 and 2000, national home prices began a period of unprecedented growth, increasing at a pace more than 8 times their annual average until peaking in early 2006. National home prices appreciated over 100% on average during the 6 year period before declining 27% from 2006 through Q4 2008. Markets across the sunbelt, namely Florida, Southern California, and Arizona saw prices appreciate as much as 180 % from 2000 to their peak in 2006; these areas have also declined the fastest and hardest, falling as much as 50% and boasting the highest foreclosure rates in the country.

Architectural Optimization Of Decomposition Algorithms For Wireless Communication Systems, Ali Irturk, Bridget Benson, Nikolay Laptev, Ryan Kastner

Electrical Engineering

Matrix decomposition is required in various algorithms used in wireless communication applications. FPGAs strike a balance between ASICs and DSPs, as they have the programmability of software with performance capacity approaching that of a custom hardware implementation. However, FPGA architectures require designers to make a countless number of system, architectural and logic design decisions. By performing design space exploration, a designer can find the optimal device for a specific application, however very few tools exist which can accomplish this task. This paper presents automatic generation and optimization of decomposition methods using a core generator tool, GUSTO, that we developed to …

Design-An Opportunity In Reducing Corrugated Fiberboard Carbon Footprint, Jay Singh, R. Kisch, J. Chhun, Eric Olsen

Industrial Technology and Packaging

Telescoping Half Slotted Containers (HSC) and Diagonal Corner Bliss style containers are popular choices for packaging agricultural products such as apples, pears, citrus, potatoes, garlic and most vegetables. This study evaluated two unique corrugated container designs, Kisch Full Circle Tray (FCT) and Single V Kisch Bliss, which are both viable designs available to replace the presently used styles of boxes for produce distribution. This paper presents the compression strength results of Telescoping HSC containers as compared to two possible replacements and the Diagonal Corner Bliss designs when stored under standard, refrigerated and tropical conditions. It also compares the material savings …

Flexography Printing Performance Of Pla Film, J. Jacobson, Malcom Keif, Xiaoying Rong, Jay Singh, Keith Vorst

Industrial Technology and Packaging

During the past decade polylactide acid (PLA) polymer has been the subject of numerous researches aimed at comparing it with traditional petroleum based polymers for many packaging applications. PLA is biodegradable and derived from agricultural by-products such as corn starch or other starch-rich substances like maize, sugar or wheat.While PLA is currently being used in many packaging applications with well documented performance, little work has been done comparing printing processes and performance. This study presents PLA printing performance and sustainability findings using the common flexography printing process. Various analytical methods were used to evaluate performance and provide recommendations for optimized …

Simulating The Growth Of Articular Cartilage Explants In A Permeation Bioreactor To Aid In Experimental Protocol Design, Timothy P. Ficklin, Andrew Davol, Stephen M. Klisch

Mechanical Engineering

Recently a cartilage growth finite element model (CGFEM) was developed to solve nonhomogeneous and time-dependent growth boundary-value problems (Davol et al., 2008, “A Nonlinear Finite Element Model of Cartilage Growth,” Biomech. Model. Mechanobiol., 7, pp. 295–307). The CGFEM allows distinct stress constitutive equations and growth laws for the major components of the solid matrix, collagens and proteoglycans. The objective of the current work was to simulate in vitro growth of articular cartilage explants in a steady-state permeation bioreactor in order to obtain results that aid experimental design. The steady-state permeation protocol induces different types of mechanical stimuli. When the specimen …

Case Study In Implementing A Service-Learning Class In A Construction Management Curriculum, Philip L. Barlow

Construction Management

Service-learning is a pedagogical approach which gives the students an opportunity to develop professional and social skills in concert with learning and reflecting on curricular material. This is achieved through a student’s active participation in a meaningful community service project, open and interactive reflection, formal class lectures, and discussions. This case study discusses the results of implementing a pilot service-learning undergraduate class in a state university construction management program. The course was offered as a two-credit hour voluntary technical elective in the Spring quarter of 2008. The organization of this study first puts service-learning into context by giving a brief …

Shielding Effectiveness Of Superalloy, Aluminum, And Mumetal Shielding Tapes, Cindy Suit Cheung

Master's Theses

Using MIL-HDBK-419A, MATLAB and Nomographs, Shielding Effectiveness for the Magnetic Field, Electric Field, and Plane Wave were calculated over a frequency range from 10 Hz to 1 GHz. The three shielding tapes used included superalloy, aluminum, and mumetal. Calculations for Shielding Effectiveness involve the computation of Absorption Loss, Reflection Loss, and Re-Reflection Correction Factor. From the outcome of the calculations, it was suitable to conclude that all three metals fulfill the 40 dB Shielding Effectiveness requirements for SGEMP fields for frequencies greater or equal to 1 MHz. Accordingly, all three shielding tapes provide at least 40 dB of shielding to …

Bottom-Up Ontology Creation With A Direct Instance Input Interface, Charles C.H. Wei

Master's Theses

In general an ontology is created by following a top-down, or so called genus-species approach, where the species are differentiated from the genus and from each other by means of differentiae [8]. The superconcept is the genus, every subconcept is a species, and the differentiae correspond to roles. To complete it a user organizes data into a proper structure, accompanied with the instances in that domain in order to complete the construction of an ontology. It is a concept learning procedure in a school, for example. Students first learn the general knowledge and apply it to their exercise and homework …

Development Of An Imager System Optimized For Low-Power, Limited-Bandwidth Space Applications, Kalia R. Glassey

Master's Theses

A relatively new picosatellite standard, CubeSats have traditionally been used for simple educational missions. As CubeSats become more complex and utilize more complex sensors such as imagers, they gain enhanced credibility as satellite platforms.

Imaging systems on CubeSats have the potential to be used for a variety of uses, such as earth and weather monitoring, attitude determination, and remote sensing. However the size and power limitations of CubeSats pose an interesting challenge to the design of a capable, robust imaging system.

This thesis outlines the objectives and requirements of CP-3’s imaging system, and describes the development process and methods. Test …

The Effect Of The Fastener Of Different Configuration Composite Panels On Failure Analysis, Robert Austin

Master's Theses

This study presents the effect of the stacking sequence and fiber orientation on a composite sandwich panel subjected to static in-plane bolt loading. Six plates were constructed with laminates of unidirectional carbon fiber and cross ply weaves of fiberglass. The orientations that were examined included 0, +/- 45, and 90 degrees. Half of the plates had fiberglass lamina on the outside of the laminate while the other three plates had the carbon fiber on the outside. Experimental and analytical tests were performed to determine the best orientations and stacking sequence.

For the numerical analysis, plates with fibers oriented at +/- …