Engineering Commons^™

Local Vibrational Modes Competitions In Mn-Doped Zno Epitaxial Films With Tunable Ferromagnetism, Qiang Cao, Maoxiang Fu, Guolei Liu, Huaijin Zhang, Shishen Yan, Yanxue Chen, Liangmo Mei, Jun Jiao

Mechanical and Materials Engineering Faculty Publications and Presentations

We reported spectroscopic investigations of high quality Mn-doped ZnO (ZnMnO) films grown by oxygen plasma-assisted molecular beam epitaxy. Raman scattering spectra revealed two local vibrational modes (LVMs) associated with Mn dopants at 523 and 712cm^-1. The LVMs and magnetic properties of ZnMnO films can be synchronously modulated by post annealing processing or by introducing tiny Co. The relative intensity of two LVMs clearly shows competitions arising from uncompensated acceptor and donor defects competition for ferromagnetic and nonmagnetic films. The experimental results indicated that LVM at 523 cm^-1 is attributed to Mn—(Zinc-vacancy) complexes, while LVM at 712 cm …

Multi-Criteria Decision Modeling For Best Value Selections In Target Value Design Integrated Project Delivery, Brent Patrick Griffis

Master's Theses

Integrated Project Delivery (IPD) combined with Target Value Design (TVD) is a better way to deliver value for the client than traditional guaranteed maximum price (GMP) methods. With traditional GMP delivery methods, the interests of the parties are often at odds. The goal of IPD is to align all party interests in order to achieve a win-win scenario. Due to the aligning nature of IPD and the fact that each party’s success is dependent on achieving the project objectives as a whole; a non-biased, transparent, decision-making process is necessary in order to deliver the project objectives within the constraints of …

High-Speed Mobile Networks For Modern Farming And Agricultural Systems, Santos Najar

Master's Theses

ABSTRACT

High-Speed Mobile Networks for Modern Farming and Agricultural Systems

J.Santos Najar-Ramirez

High-speed mobile networks are necessary for agriculture to inventory individual plant health, maximize yield and minimize the resources applied. More specifically, real-time information on individual plant status is critical to decisions regarding the management of resources reserved and expended. This necessity can be met by the availability of environmental sensors (such as humidity, temperature, and pH) whose data is kept on storage servers connected to static and mobile local area networks. These static and mobile local area networks are connected to cellular, core and satellite networks. For …

Data Chunking In Quasi-Synchronous Ds-Cdma, Trevor Dalke

Master's Theses

DS-CDMA is a popular multiple access technique used in many mobile networks to efficiently share channel resources between users in a cell. Synchronization between users maximizes the user capacity of these systems. However, it is difficult to perfectly synchronize users in the reverse link due to the geographic diversity of mobile users in the cell. As a result, most commercial DS-CDMA networks utilize an asynchronous reverse link resulting in a reduced user capacity. A possible compromise to increase the user capacity in the reverse link is to implement a quasi-synchronous timing scheme, a timing scheme in which users are allowed …

Modification Of The Cal Poly Spacecraft Simulator System For Robust Control Law Verification, Tomoyuki Kato

Master's Theses

The Cal Poly Spacecraft Dynamics Simulator, also known as the Pyramidal Reaction Wheel Platform (PRWP), is an air-bearing four reaction wheel spacecraft simulator designed to simulate the low-gravity, frictionless condition of the space environment and to test and validate spacecraft attitude control hardware and control laws through real-time motion tests. The PRWP system was modified to the new Mk.III configuration, which adopted the MATLAB xPC kernel for better real-time hardware control. Also the Litton LN-200 IMU was integrated onto the PRWP and replaced the previous attitude sensor. Through the comparison of various control laws through motion tests the Mk.III configuration …

Dual High-Voltage Power Supply For Use On Board A Cubesat, Nicholas Weiser

Master's Theses

Since their conception in 1999, CubeSats have come and gone a long way. The first few that went into space were more of a “proof of concept,” and were more focused on sending simple data and photographs back to Earth. Since then, vast improvements have been made by over 40 universities and private firms, and now CubeSats are beginning to look towards interplanetary travel. These small satellites could provide a cost effective means of exploring the galaxy, using off the shelf components and piggy-backing on other launch vehicles with more expensive payloads. However, CubeSats are traditionally launched into Low Earth …

Decafs: A Modular Distributed File System To Facilitate Distributed Systems Education, Halli Elaine Meth

Master's Theses

Data quantity, speed requirements, reliability constraints, and other factors encourage industry developers to build distributed systems and use distributed services. Software engineers are therefore exposed to distributed systems and services daily in the workplace. However, distributed computing is hard to teach in Computer Science courses due to the complexity distribution brings to all problem spaces. This presents a gap in education where students may not fully understand the challenges introduced with distributed systems. Teaching students distributed concepts would help better prepare them for industry development work.

DecaFS, Distributed Educational Component Adaptable File System, is a modular distributed file system designed …

Improvements To A Bi-Directional Flyback Dc-Dc Converter For Battery System Of The Dc House Project, Michael Wu

Master's Theses

The DC House project relies primarily on renewable energy sources to provide DC power to the various loads of the house. However, not all renewable sources are capable of providing power at all times of the day. A back-up energy source in the form of a battery storage system must be available to meet the electrical needs of the house. A bi-directional flyback power converter was initially designed to allow a battery to charge from as well as discharge to the 48V bus line of the DC House. The design provided a 35W prototype to demonstrate the converter’s feasibility. Further …

Virtual Reality Engine Development, Varun Varahamurthy

Master's Theses

With the advent of modern graphics and computing hardware and cheaper sensor and display technologies, virtual reality is becoming increasingly popular in the fields of gaming, therapy, training and visualization. Earlier attempts at popularizing VR technology were plagued by issues of cost, portability and marketability to the general public. Modern screen technologies make it possible to produce cheap, light head-mounted displays (HMDs) like the Oculus Rift, and modern GPUs make it possible to create and deliver a seamless real-time 3D experience to the user. 3D sensing has found an application in virtual and augmented reality as well, allowing for a …

A System For Cell Phone Anti-Theft Through Gait Recognition, Cameron P. Cstearns Stearns

Master's Theses

Studies show that smartphone thefts are a significant problem in the United States. [30] With many upcoming proposals to decrease the theft-rate of such devices, investigating new techniques for preventing smartphone theft is an important area of research. The prevalence of new biometric identification techniques for smartphones has led some researchers to propose biometric anti-theft measures for such devices, similar to the current fingerprint authentication system for iOS. Gait identification, a relatively recent field of study, seems to be a good fit for anti-theft because of the non-intrusive nature of passive pattern recognition in walking. In this paper, we reproduce …

Neuromodulation: Action Potential Modeling, Vladimir Ruzov

Master's Theses

There have been many different studies performed in order to examine various properties of neurons. One of the most important properties of neurons is an ability to originate and propagate action potential. The action potential is a source of communication between different neural structures located in different anatomical regions. Many different studies use modeling to describe the action potential and its properties. These models mathematically describe physical properties of neurons and analyze and explain biological and electrochemical processes such as action potential initiation and propagation. Therefore, one of the most important functions of neurons is an ability to provide communication …

Ac Power Combining Strategy With Application To Efficient Linear Power Amplifiers, Rudi Matthew Bendig

Master's Theses

With the ongoing push for wireless systems to accommodate more users and support higher data rates more efficient modulation schemes have been created that are more advanced than simple FM and AM modulation used for radio broadcasting. These modulation schemes, such as orthogonal frequency division multiplexing (OFDM), suffer from high peak to average power ratios. Standard Class A and Class AB amplifiers cannot simultaneously achieve good linearity and efficiency, and therefore there has been an increase in the development of new topologies to combat this issue. Common features to these circuits is power combining of two or more separate transistors. …

Design And Validation Of A Wearable, Continuous, And Non-Invasive Hydration Monitor That Uses Ultrasonic Pulses To Detect Changes In Tissue Hydration Status, Zoie Engman

Master's Theses

Chronic dehydration is an endemic problem for many population groups. Current methods of monitoring hydration status are invasive, time consuming, cannot be performed while exercising, and require lab resources. A proposed solution is a wearable, continuous, and non-invasive device that uses harm-free ultrasonic pulses to detect changes in tissue hydration status over time. Customer and engineering requirements were defined and used to guide the design process. Literature reviews were performed to identify essential information on dehydration, assess current methods, discover state of the art devices, and describe ultrasonic theory. Market research was performed to identify athletes as the target population …

Tspoons: Tracking Salience Profiles Of Online News Stories, Kimberly Laurel Paterson

Master's Theses

News space is a relatively nebulous term that describes the general discourse concerning events that affect the populace. Past research has focused on qualitatively analyzing news space in an attempt to answer big questions about how the populace relates to the news and how they respond to it. We want to ask when do stories begin? What stories stand out among the noise? In order to answer the big questions about news space, we need to track the course of individual stories in the news. By analyzing the specific articles that comprise stories, we can synthesize the information gained from …

Thermal Numerical Analysis Of Vertical Heat Extraction Systems In Landfills, Michael Thomas Onnen

Master's Theses

An investigation was conducted to determine the response of landfills to the operation of a vertical ground source heat pump (i.e., heat extraction system, HES). Elevated landfill temperatures, reported various researchers, impact the engineering performance of landfill systems. A numerical model was developed to analyze the influence of vertical HES operation on landfills as a function of climate and operational conditions.

A 1-D model of the vertical profile of a landfill was developed to approximate fluid temperatures in the HES. A 2-D model was then analyzed over a 40 year time period using the approximate fluid temperatures to determine the …

Toward General Purpose 3d User Interfaces: Extending Windowing Systems To Three Dimensions, Forrest Freiling Reiling

Master's Theses

Recent growth in the commercial availability of consumer grade 3D user interface devices like the Microsoft Kinect and the Oculus Rift, coupled with the broad availability of high performance 3D graphics hardware, has put high quality 3D user interfaces firmly within the reach of consumer markets for the first time ever. However, these devices require custom integration with every application which wishes to use them, seriously limiting application support, and there is no established mechanism for multiple applications to use the same 3D interface hardware simultaneously. This thesis proposes that these problems can be solved in the same way that …

Atrengine: An Orientation-Based Algorithm For Automatic Target Recognition, Justin Ting-Jeuan Kuo

Master's Theses

Automatic Target Recognition (ATR) is a subject involving the use of sensor data to develop an algorithm for identifying targets of significance. It is of particular interest in military applications such as unmanned aerial vehicles and missile tracking systems. This thesis develops an orientation-based classification approach from previous ATR algorithms for 2-D Synthetic Aperture Radar (SAR) images. Prior work in ATR includes Chessa Guilas’ Hausdorff Probabilistic Feature Analysis Approach in 2005 and Daniel Cary’s Optimal Rectangular Fit in 2007.

A system incorporating multiple modules performing different tasks is developed to streamline the data processing of previous algorithms. Using images from …

The Effect Of Clay, Cement And Fibers On The Strength And Durability Of Compressed Earth Blocks, Wyatt Adair Banker-Hix

Master's Theses

This Thesis examines the effect of soil characteristics, cement content and fibers on the strength and durability of compressed earth blocks (CEBs). This work expands on the available information regarding the constituent properties which affect the compressive and tensile strengths and durability of CEBs. Additionally, little research on the subject of synthetic fibers and their effect on strength and durability of CEBs is available and this work provides an initial study in this area.

To study the effects of fibers, as well as confirm the trends of previous research regarding the effects of clay and cement, 27 unique batches of …

Optimizing Lempel-Ziv Factorization For The Gpu Architecture, Bryan Ching

Master's Theses

Lossless data compression is used to reduce storage requirements, allowing for the relief of I/O channels and better utilization of bandwidth. The Lempel-Ziv lossless compression algorithms form the basis for many of the most commonly used compression schemes. General purpose computing on graphic processing units (GPGPUs) allows us to take advantage of the massively parallel nature of GPUs for computations other that their original purpose of rendering graphics. Our work targets the use of GPUs for general lossless data compression. Specifically, we developed and ported an algorithm that constructs the Lempel-Ziv factorization directly on the GPU. Our implementation bypasses the …

A Comparison Of Image Processing Techniques For Bird Detection, Elsa Reyes

Master's Theses

Orchard fruits and vegetable crops are vulnerable to wild birds and animals. These wild birds and animals can cause critical damage to the produce. Traditional methods of scaring away birds such as scarecrows are not long-term solutions but short-term solutions. This is a huge problem especially near areas like San Luis Obispo where there are vineyards. Bird damage can be as high as 50% for grapes being grown in vineyards. The total estimated revenue lost annually in the 10 counties in California due to bird and rodent damage to 22 selected crops ranged from $168 million to $504 million (in …

Future Of Payment Platforms, Salim Benjamin Youssefzadeh

Master's Theses

With the vast increase in smartphones, there have been an increasing number of opportunities growing in the app industry. One in particular is the way we deal with money. There are huge overheads in the current payment systems around the world particularly in the United States, many of which include large transaction fees. Many new businesses have grown to solve these inefficiencies and create a new platform that provides a new user experience, security, and convenience among many other things. However, many of these platforms are still centralized, making them more susceptible to attacks. This thesis goes over the various …

Coffee: Context Observer For Fast Enthralling Entertainment, Anthony M. Lenz

Master's Theses

Desktops, laptops, smartphones, tablets, and the Kinect, oh my! With so many devices available to the average consumer, the limitations and pitfalls of each interface are becoming more apparent. Swimming in devices, users often have to stop and think about how to interact with each device to accomplish the current tasks at hand. The goal of this thesis is to minimize user cognitive effort in handling multiple devices by creating a context aware hybrid interface. The context aware system will be explored through the hybridization of gesture and touch interfaces using a multi-touch coffee table and the next-generation Microsoft Kinect. …

A Set Union Based Formulation For Course Scheduling And Timetabling, Jesse Paul Bukenberger

Master's Theses

The Course Timetabling Problem is a widely studied optimization problem where a number of sections are scheduled in concert with the assignment of students to sections in order to maximize the desirability of the resulting schedule for all stakeholders. This problem is commonly solved as a linear program with variables for each student or group of students with identical schedules. In this paper we explore an alternative formulation that aggregates binary student variables into integer variables denoting the number of students enrolled in a course. Our solution method assumes decomposition of the general schedule into time blocks, and applies a …

Addition Of A Stanton Gauge To The Boundary Layer Data System, Brittany Reanne Kinkade

Master's Theses

The Stanton gauge technique provides an indirect method for measurement of skin friction on a smooth aerodynamic surface in which a pressure tap is available. This thesis presents the design and evaluation of a new type of skin friction measurement gauge based on the Stanton gauge concept but not requiring a surface pressure tap. This new skin friction measurement gauge, called a "Flow Tab", can therefore be used on an aerodynamic model or aircraft surface without alteration of the surface. The Flow Tab is thus particularly well-suited to use with Cal Poly's Boundary Layer Data System (BLDS), a small, self-contained …

Development Of A Finite Element Model For Predicting The Impact Energy Absorbing Performance Of A Composite Structure, Matthew Lowell Roberts

Master's Theses

Because of their high strength-to-weight ratio, Fiber Reinforced Composite (FRC) materials are well suited for use in high performance racing applications where weight must be kept to a minimum. Formula SAE (FSAE) race cars are designed and built by college students, roughly following the model of a scaled down Formula One car. Strict regulations are placed on specific components of the car in the interest of equalizing competition and ensuring the safety of the drivers. Students are required to construct a survival cell (the chassis), which can resist large amounts of energy in the event of a crash, with an …

Incorporating Active Learning Into The Graphical Communications Course, Lulu Sun

Publications

Active learning, is a student-centered learning strategy which has recently gained considerable attention in higher education. The literature has shown that active learning has led to better student attitudes and improvements in their thinking, communication, leadership, and writing skills. The core elements of active learning are student activities and engagement in the learning process. As more faculty look for alternatives to traditional teaching methods they have strongly advocated active learning. However, the potential challenges for faculty with such an approach cannot be ignored such as increased class preparation time, the risks of student dissatisfaction, the use of instructional technology, and …

Is Biofuel A Feasible Long-Term Chief Energy Source? A Global Perspective, Rajee Olaganathan, Aston Lee, Debra Tong, Mameegate Zheng Jun Cheston, Zack Ho Xuan Yi

Publications

This scientific paper examines the feasibility of officiating biofuels as the future chief energy source of the world. It weighs the pros and cons of the four different generations of biofuels that have been discovered over time, explaining how the raw materials used in each generation determines each individual level of long-term sustainability. It then further analyses both general advantages and disadvantages, comprising of economic, social, health and environmental impacts; giving the reader an unbiased perspective. Few case studies have also been reviewed to better understand the implications of drawing energy from biofuels, as well as the current state of …

An Eigenvector-Based Test For Local Stationarity Applied To Array Processing, Jorge Quijano, Lisa M. Zurk

Electrical and Computer Engineering Faculty Publications and Presentations

In sonar array processing, a challenging problem is the estimation of the data covariance matrix in the presence of moving targets in the water column, since the time interval of data local stationarity is limited. This work describes an eigenvector-based method for proper data segmentation into intervals that exhibit local stationarity, providing data-driven higher bounds for the number of snapshots available for computation of time-varying sample covariance matrices. Application of the test is illustrated with simulated data in a horizontal array for the detection of a quiet source in the presence of a loud interferer.

Wake Interaction And Power Production Of Variable Height Model Wind Farms, M. H. Vested, N. Hamilton, J. N. Sørensen, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Understanding wake dynamics is an ongoing research topic in wind energy, since wakes have considerable effects on the power production when wind turbines are placed in a wind farm. Wind tunnel experiments have been conducted to study the wake to wake interaction in a model wind farm in tandem with measurements of the extracted power. The aim is to investigate how alternating mast height influences the interaction of the wakes and the power production. Via the use of stereo-particle image velocimetry, the flow field was obtained in the first and last rows of the wind turbine array as a basis …

The Effect Of Fiber Depth On The Estimation Of Peripheral Nerve Fiber Diameter Using Group Delay And Simulated Annealing Optimization, Nam Tran

Master's Theses

Peripheral neuropathy refers to diseases of or injuries to the peripheral nerves in the human body. The damage can interfere with the vital connection between the central nervous system and other parts of the body, and can significantly reduce the quality of life of those affected. In the US, approximately between 15 and 20 million people over the age of 40 have some forms of peripheral neuropathy. The diagnosis of peripheral neuropathy often requires an invasive operation such as a biopsy because different forms of peripheral neuropathy can affect different types of nerve fibers. There are non-invasive methods available to …