Computer Engineering Commons^™

Generation Of High-Temperature And Low-Density Plasmas For Improved Spectral Resolutions In Laser-Induced Breakdown Spectroscopy, X. N. He, W. Hu, C. M. Li, L. B. Guo, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Improved spectral resolutions were achieved in laser-induced breakdown spectroscopy (LIBS) through generation of high-temperature and low-density plasmas. A first pulse from a KrF excimer laser was used to produce particles by perpendicularly irradiating targets in air. A second pulse from a 532 nm Nd:YAG laser was introduced parallel to the sample surface to reablate the particles. Optical scattering from the first-pulse plasmas was imaged to elucidate particle formation in the plasmas. Narrower line widths (full width at half maximums: FWHMs) and weaker self-absorption were observed from time-integrated LIBS spectra. Estimation of plasma temperatures and densities indicates that high temperature and …

Determination Of Selected Course Management Systems Advantages And Challenges: A Case Study, Dolruedee Suppacheewa

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 of Master of Science by Dolruedee Suppacheewa on May 12, 2011

Public Transit Accessibility And Need Indices: Approaches For Measuring Service Gap, Sha Mamun

Master's Theses

The integration of transit needs into transit accessibility indexing is important for the evaluation of existing transportation systems and, service gaps, and for the identification of priority areas for future investments in transportation infrastructure. This thesis details an accessibility-based transit need indexing model that focuses on the necessity of evaluating transit needs and transit accessibility simultaneously. A need index is developed to identify areas in high need of public transit services using economic and socio-demographic information and a composite accessibility index is developed to identify levels of access to transit services and shortcomings in service provision. The need for transit …

Campus Grids: A Framework To Facilitate Resource Sharing, Derek J. Weitzel

School of Computing: Dissertations, Theses, and Student Research

It is common at research institutions to maintain multiple clusters. These might fulfill different needs and policies, or represent different owners or generations of hard- ware. Many of these clusters are under utilized while researchers at other departments may require these resources. This may be solved by linking clusters with grid mid- dleware. This thesis describes a distributed high throughput computing framework to link clusters without changing security or execution environments. The framework initially keeps jobs local to the submitter, overflowing if necessary to the campus, and regional grid. The framework is implemented spanning two campuses at the Holland Computing …

Examination Of Chaotic Signal Encryption And Recovery For Secure Communication Using Hybrid Acousto-Optic Feedback, Monish Ranjan Chatterjee, Mohammed A. Al-Saedi

Electrical and Computer Engineering Faculty Publications

Generation of chaos from acousto-optic (A-O)Bragg cell modulators with an electronic feedback has been studied for over 3 decades. Since an acousto-optic Bragg cell with zeroth- and first-order feedback exhibits chaotic behavior past the threshold for bistability, such a system was recently examined for possible chaotic encryption of simple messages (such as a low-amplitude sinusoidal signal) applied via the bias input of the sound cell driver. Subsequent recovery of the message signal was carried out via a heterodyne-type strategy employing a locally generated chaotic carrier, with threshold parameters matched to the transmitting Bragg cell.

In this paper, we present numerical …

Joggler: Data Harvest And Analysis Tool, Ondrej Nebesky

Departmental Technical Reports (CS)

Linear-Time Resource Allocation In Security Games With Identical Fully Protective Resources, Octavio Lerma, Vladik Kreinovich, Chris Kiekintveld

Departmental Technical Reports (CS)

Game theory has become an important tools for making resource allocations decision in security domains, including critical infrastructure protection. Many of these games are formulated as Stackelberg security games. We present new analysis and algorithms for a class of Stackelberg security games with identical, fully protective defender resources. The first algorithm has worst-case complexity linear in the number of possible targets, but works only for a restricted case. The second algorithm can find and optimal resource allocation for the general case in time O(n log(n)).

When Is Busemann Product A Lattice? A Relation Between Metric Spaces And Corresponding Space-Time Models, Hans-Peter Künzi, Francisco Zapata, Vladik Kreinovich

Departmental Technical Reports (CS)

The causality relation of special relativity is based on the assumption that the speed of all physical processes is limited by the speed of light. As a result, an event (t,x) occurring at moment t at location x can influence an event (y,s) if and only if s >= t+d(x,y)/c. We can simplify this formula if we use units of time and distance in which c=1 (e.g., by using a light second as a unit of distance). In this case, the above causality relation takes the form s >= t+d(x,y). Since the actual space can be non-Euclidean, H. Busemann generalized …

An Expressive Vocal Midi Controller, Brady Hurlburt

Electrical Engineering Undergraduate Honors Theses

The choice of controller often characterizes the performance obtained from an electronic instrument. Controllers exist that allow electronic musicians to mimic the expressive qualities of keyboard, wind, string, and percussion instruments, but vocalists have been largely neglected. To fill this need, a realtime software vocal MIDI controller named Grove is developed and demonstrated. Grove's pitch and time analyses are shown to be accurate, and it has mappable control signals that go beyond the capabilities of previous audio-to-MIDI converters to facilitate an expressive performance. Grove's source code is available under the GNU GPL v3 license.

Integration Of Communication Constraints Into Physiocomimetic Swarms Via Placement Of Location Based Virtual Particles, Joshua J. Haley

HIM 1990-2015

This thesis describes a change to the Physiocomimetics Robotic Swarm Control framework that implements communication constraints into swarm behavior. These constraints are necessary to successfully implement theoretical applications in the real world. We describe the basic background of swarm robotics, the Physiocomimetics framework and methods that have attempted to implement communications constraints into robotic swarms. The Framework is changed by the inclusion of different virtual particles at a global and local scale that only cause a force on swarm elements if those elements are disconnected from a swarm network. The global particles introduced are a point of known connectivity and …

Computations Under Time Constraints: Algorithms Developed For Fuzzy Computations Can Help, Karen Villaverde, Olga Kosheleva, Martine Ceberio

Departmental Technical Reports (CS)

In usual computers -- that use binary representation of real numbers -- an irrational real number (and even a rational number like 1.3 or 1.2) can only be computed with a finite accuracy. The more accuracy we need, the larger the computation time. It is therefore reasonable to characterize the complexity of computing a real number a by the accuracy D(t) that we can achieve in time t. Once we know this characteristic for two numbers a and b, how can we compute a similar characteristic for, e.g., c = a + b$? In this paper, we show that the …

Uniqueness Of Reconstruction For Yager's T-Norm Combination Of Probabilistic And Possibilistic Knowledge, Nitaya Buntao, Vladik Kreinovich

Departmental Technical Reports (CS)

Often, about the same real-life system, we have both measurement-related probabilistic information expressed by a probability measure P(S) and expert-related possibilistic information expressed by a possibility measure M(S). To get the most adequate idea about the system, we must combine these two pieces of information. For this combination, R. Yager -- borrowing an idea from fuzzy logic -- proposed to use a t-norm f(a,b)$ such as the product f(a,b)=a*b, i.e., to consider a set function f(S)=f(P(S),M(S)). A natural question is: can we uniquely reconstruct the two parts of knowledge from this function f(S)? In our previous paper, we showed that …

Towards Optimal Knowledge Processing: From Centralization Through Cyberinsfrastructure To Cloud Computing, Octavio Lerma, Eric Gutierrez, Chris Kiekintveld, Vladik Kreinovich

Departmental Technical Reports (CS)

One of the most efficient way to store and process data is cloud computing, when we store the data so as to minimize the expenses and increase the efficiency. In this paper, we provide an analytical solution to the corresponding optimization problem.

Functional Verification Of Class Invariants In Cleanjava, Carmen Avila, Yoonsik Cheon

Departmental Technical Reports (CS)

In a Cleanroom-style functional program verification, a program is viewed as a mathematical function from one program state to another, and a verification is done by comparing two functions, the implemented and the expected behaviors of a program. The technique requires a minimal mathematical background and supports forward reasoning, but it doesn't support assertions such as class invariants. However, assertions such as class invariants are not only a practical programming tool but also play a key role in the correctness proof of a program by specifying conditions and constraints that an object has to satisfy and thus defining valid states …

Estimating Probability Of Failure Of A Complex System Based On Partial Information About Subsystems And Components, With Potential Applications To Aircraft Maintenance, Christelle Jacob, Didier Dubois, Janette Cardoso, Martine Ceberio, Vladik Kreinovich

Departmental Technical Reports (CS)

An Empirical Study Of Student Programming Bugs, Amy Hansen

Undergraduate Honors Capstone Projects

Students in introductory computer science courses often have difficulty with coding and problem solving, which results in bugs. These bugs cause both student frustration and attrition of many of our CS majors. In this work, we seek to understand the bugs that students encounter. We have two sources of data. First, we collect and analyze 450 bugs that were brought to our tutor lab by our CS 1 and CS2 students. Second, we analyze bugs in CS I homework assignments. The results show that the majority of the problems are due to problem solving skills, while the remaining problems involve …

Clustering Educational Digital Library Usage Data: Comparisons Of Latent Class Analysis And K-Means Algorithms, Beijie Xu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

There are common pitfalls and neglected areas when using clustering approaches to solve educational problems. A clustering algorithm is often used without the choice being justified. Few comparisons between a selected algorithm and a competing algorithm are presented, and results are presented without validation. Lastly, few studies fully utilize data provided in an educational environment to evaluate their findings. In response to these problems, this thesis describes a rigorous study comparing two clustering algorithms in the context of an educational digital library service, called the Instructional Architect.

First, a detailed description of the chosen clustering algorithm, namely, latent class analysis …

Field-Programmable Gate Array Implementation Of A Scalable Integral Image Architecture Based On Systolic Arrays, Juan Alberto De La Cruz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The integral image representation of an image is important for a large number of modern image processing algorithms. Integral image representations can reduce computation and increase the operating speed of certain algorithms, improving real-time performance. Due to increasing demand for real-time image processing performance, an integral image architecture capable of accelerating the calculation based on the amount of available resources is presented. Use of the proposed accelerator allows for subsequent stages of a design to have data sooner and execute in parallel. It is shown here how, with some additional resources used in the Field Programmable Gate Array (FPGA), a …

Design And Performance Analysis Of Mac Schemes For Wireless Sensor Networks Powered By Ambient Energy Harvesting, Zhi Ang Eu, Hwee-Pink Tan, Winston K. G. Seah

Research Collection School Of Computing and Information Systems

Energy consumption is a perennial issue in the design of wireless sensor networks (WSNs) which typically rely on portable sources like batteries for power. Recent advances in ambient energy harvesting technology have made it a potential and promising alternative source of energy for powering WSNs. By using energy harvesters with supercapacitors, WSNs are able to operate perpetually until hardware failure and in places where batteries are hard or impossible to replace. In this paper, we study the performance of different medium access control (MAC) schemes based on CSMA and polling techniques for WSNs which are solely powered by ambient energy …

Exploration Of Spatial Diversity In Multi-Antenna Wireless Communication Systems, Shichuan Ma

Department of Computer Electronics and Engineering: Dissertations, Theses, and Student Research

With increasing demand on wireless internet and personal multimedia, the data rate of wireless communications is expected to increase dramatically. Future wireless networks face challenges of supporting data rates higher than one gigabits per second. Among various technologies, multi-antennas, also known as multiple-input multiple-output (MIMO), are undoubtedly the most promising to enable higher data rates. By employing the extra degrees of freedom in the spatial domain, multi-antenna techniques enhance the wireless communication systems through array gain, spatial diversity, and spatial multiplexing. Although multi-antenna systems have been utilized for more than ten years, a thorough analysis of various aspects of multi-antenna …