Engineering Commons^™

Inferring Undesirable Behavior From P2p Traffic Analysis, Ruben Torres, Mohammad Hajjat, Sanjay G. Rao, Marco Mellia, Maurizio Munafo

Department of Electrical and Computer Engineering Technical Reports

ABSTRACT While peer-to-peer (P2P) systems have emerged in popularity in recent years, their large-scale and complexity make them difficult to reason about. In this paper, we argue that systematic analysis of traffic characteristics of P2P systems can reveal a wealth of information about their behavior, and highlight potential undesirable activities that such systems may exhibit. As a first step to this end, we present an offline and semi-automated approach to detecting undesirable behavior. Our analysis is applied on real traffic traces collected from a Point-of-Presence (PoP) of a national-wide ISP in which over 70% of the total traffic is due …

Experimental And Computational Investigation Of A Rf Plasma Micro-Thruster, J D. Olliges, A D. Ketsdever, W B. Stein, Alina A. Alexeenko, I Hrbud

School of Aeronautics and Astronautics Faculty Publications

A prototype RF plasma micro-thruster has been investigated numerically and experimentally. The experimental results were obtained on a thrust stand capable of micro-Newton resolution. Thrust and mass flow (hence specific impulse) were measured for an argon propellant at mass flows ranging from 0.4 to 5.5 mg/s. An increase over the cold gas thrust of up to 20% was observed for a discharge frequency of 100 MHz and an input power of 77 W. Propulsive efficiency was seen to increase both experimentally and numerically for increasing mass flow and decreasing discharge frequency.

Plasma-Neutral Heat Transfer In Coaxial Rf Argon Discharges, William B. Stein, Alina A. Alexeenko, Ivana Hrbud

School of Aeronautics and Astronautics Faculty Publications

Particle-in-cell/Monte Carlo Collision (PIC/MCC) algorithms comprise a numerical model to assess the discharge characteristics of an RF plasma microthruster concept that exploits an RF capacitively coupled discharge (RFCCD) to heat a propellant. The effects of heat transfer between the discharge and the neutral species on microthruster performance are discussed. Heat transfer within the plasma discharge has been shown to greatly affect the discharge characteristics and thruster performance. Increasing the neutral temperature reduces the amount of power transmitted into the fluid through a reduction of the neutral density, and thus reduces effectiveness of the discharge. The PIC/MCC modeling showed that the …

Experimental And Computational Study Of Area And Perimeter Contributions To Radiometer Forces, N P. Selden, S F. Gimelshein, E P. Muntz, Alina A. Alexeenko, A D. Ketsdever

School of Aeronautics and Astronautics Faculty Publications

The relative contribution to the radiometric force of the area and perimeter of the vane is studied experimentally and numerically. Experimentally, a circular vane, a low-aspect rectangular vane, and a high-aspect rectangular vane were all tested on a force balance, with nano-Newton resolution, placed in a stagnant gas. The computational results were obtained through 2-D simulations using the direct simulation Monte Carlo method, as well as a discrete ordinate solution of the ES model kinetic equation. Gas pressure was varied from 0.006 to 6 Pa, which was a broad enough range to observe the characteristic peak force production of a …

Non-Equilibrium Flow Modeling Using High-Order Schemes For The Boltzmann Model Equations, S Chigullapalli, A Venkattraman, Alina A. Alexeenko, M S. Ivanov

School of Aeronautics and Astronautics Faculty Publications

We consider application of higher-order schemes to the Boltzmann model equations with a goal to develop a deterministic computational approach that is accurate and efficient for simulating flows involving a wide range of Knudsen numbers. The kinetic equations are solved for two non-equilibrium flow problems, namely, the structure of a normal shock wave and an unsteady two-dimensional shock tube. The numerical method comprises the discrete velocity method in the velocity space and the finite volume discretization in physical space with different numerical flux schemes: the first-order, the second-order minmod flux limiter as well as a third-order WENO scheme. The normal …

Comparison Of Two Peer Evaluation Instruments For Project Teams, Kerry Meyers, Stephen Silliman, Matthew Ohland, Leo Mcwilliams, Tracy Kijewski-Correa

School of Engineering Education Faculty Publications

The College of Engineering at the University of Notre Dame has utilized a paper-pencil instrument for peer evaluations since 2005 as a portion of the assessment of project team efforts (typically 4-5 students per team) in its First Year Engineering Course. The College was considering moving from paper-pencil peer evaluations to an on-line, behaviorally based evaluation instrument, CATME1. The instructors at Notre Dame conducted a comparative study of student feedback on these two instruments during the fall 2007. During the fall semester, the students (~380) within the first year course were divided into two groups, one group using the paper-pencil …

Impact Of Feedback And Revision On Student Team Solutions To Model Eliciting Activities, Matthew Verleger, Heidi Diefes-Dux

School of Engineering Education Graduate Student Series

Helping first-year engineering students to embrace the iterative and open-ended nature of engineering problem solving is a challenge when their prior learning experiences have focused heavily on achieving a correct answer in a single attempt. In this paper, the authors will present a case study of student work from the Fall 2007 implementation of Model-Eliciting Activities (MEAs) to demonstrate the impact of the iterative process of feedback and revision on the quality of student products. They will also discuss some of the future research questions resulting from the iterative process used with MEAs.

Professors’ Instructional Approaches And Students’ Perceptions Of Nanohub Simulations As Learning Tools, Alejandra De Jesus Magana De Leon, George Bodner, Sean B. Brophy

School of Engineering Education Graduate Student Series

No abstract provided.

Implementation Of Station Health Monitoring Procedures For Its Sensors, Volume 2: Implementation Report, Joseph M. Ernst, Darcy M. Bullock

JTRP Technical Reports

No abstract provided.

Assimilating Remote Sensing-Based Et Into Swap Model For Improved Estimation Of Hydrological Predictions, Baburao Kamble, Ayse Kilic

Department of Civil and Environmental Engineering: Faculty Publications

An agro-hydrological simulation model is useful for agriculture monitoring and Remote Sensing provides useful information over large area. Combining both information by data assimilation is used in agro-hydrological modeling and predictions, where multiple remotely sensed data, ground measurement data and model forecast routinely combined in operational mapping procedures. Remote sensing cannot observe input parameters of agro-hydrological models directly. A method to estimate input parameters of such model from Remote Sensing using data assimilation has been proposed by Ines [2002] using the SWAP (Soil, Water, Atmosphere and Plant) model. A Genetic Algorithm (GA) loaded stochastic physically based soil-water-atmosphere-plant model (SWAP) was …

Design And Optimization Of Nanostructured Optical Filters, Jeremiah Brown

Electronic Theses and Dissertations

Optical filters encompass a vast array of devices and structures for a wide variety of applications. Generally speaking, an optical filter is some structure that applies a designed amplitude and phase transform to an incident signal. Different classes of filters have vastly divergent characteristics, and one of the challenges in the optical design process is identifying the ideal filter for a given application and optimizing it to obtain a specific response. In particular, it is highly advantageous to obtain a filter that can be seamlessly integrated into an overall device package without requiring exotic fabrication steps, extremely sensitive alignments, or …

Durability And Retro-Reflectivity Of Pavement Markings (Synthesis Study), Yi Jiang

JTRP Technical Reports

Waterborne paints are used to paint pavement markings (edgelines and centerlines) to provide guidance for motorists. The painted markings need to be repainted periodically as their retro-reflectivity deteriorates. The Indiana Department of Transportation (INDOT) repaints pavement markings at least annually. INDOT engineers would like to determine the feasibility of extending the time intervals of repainting pavement markings on at least some types of roadways. The purpose of this synthesis study is to accomplish the following: (1) to locate and assemble documented information on pavement marking durability; (2) to learn what criteria have been used in other states in measuring retro-reflectivity …

Deck Replacement - Use Of Extra Coating Thickness Epoxy-Coated Bars, J. A. Ramirez, Rachel Elizabeth Henkhaus

JTRP Technical Reports

The results of this study were implemented in the form of design recommendations for bond of epoxy-coated bars with thicker coatings up to 18 mils. The scope of the work included evaluation of AASHTO LRFD (2004) and ACI 318 design recommendedations for the development and splice length of extra epoxy-coating thinkness reinforcing bars in normal-weight concrete bridge decks and a proposed monitoring plan for a generic concrete bridge deck in Indiana where epoxy-coated bars with thicker coatings might be emeployed. The use of the current provisions for development and splice length of epoxy-coated bars in tension in both the AASHTO …

Acquisition And Analysis Of Earthwork Pay Quantity Verification Data, Sharvil Saurabh Shah, Makarand Hastak

JTRP Technical Reports

This research identifies technologies and methods that can be used by INDOT in earthwork data collection and earthwork quantity calculation process on large construction projects that could result in timely completion of the projects with less labor and resultant cost. In order to achieve the above stated objective, several tasks were performed, i.e., literature review, data collection, data analysis, and recommendations. INDOT engineers were interviewed to determine their current state of practice. Also, all the state DOTs, professional companies in Indiana and vendors of earthwork data collection equipment and software products were contacted through questionnaire surveys and personal interviews. Two …

Spotlight On Construction: Expansion And Renovation Of Georgia Southern University’S Henderson Library Spurred By Quintupling Of Student Body, Ann Hamilton, Mark Holland

Georgia Library Quarterly

The article reports on the expansion and renovation of Georgia Southern University's Henderson Library. The Zach S. Henderson Library has been the hub of academic life at Georgia Southern University for more than 30 years. The library has been the focus of an extensive expansion and renovation to help meet the needs of the university's growing student body. The first phase of the $22.75 million project opened on October 1, 2006. The original building included 109,515 square feet of space. The additional building will feature seating on the first, second and third floors and a balcony on the fourth floor …

Fabrication Of High Aspect Ratio Metal Nanotips By Nanosecond Pulse Laser Melting, Bo Cui, Lin Wu, Stephen Y. Chou

Department of Mechanical and Materials Engineering: Faculty Publications

The authors have developed an approach to fabricate sharp and high aspect ratio metal tips using nanosecond pulse laser melting. A quartz wafer covered with a thin chromium (Cr) film was placed on top of a second wafer with a sub-micrometer gap between them and the Cr film facing the second wafer. Then an excimer laser pulse (308 nm wavelength, 20 ns pulse duration) was shone from the back of the quartz wafer and melted the Cr film momentarily (several hundred nanoseconds). It is found that the molten Cr films can self-form discrete metal pillars connecting the two wafers. After …

Control Of The Nanoscale Crystallinity And Phase Separation In Polymer Solar Cells, Chih-Wei Chu, Hoichang Yang, Wei-Jen Hou, Jinsong Huang, Gang Li, Yang Yang

Department of Mechanical and Materials Engineering: Faculty Publications

Grazing-incidence x-ray diffraction and atomic force microscopy were performed on bulk heterojunction regioregular poly(3-hexylthiophene) (RR-P3HT) [6,6]-phenyl-C₇₁-butyric acid methyl esters spin-cast films with different film processing conditions to correlate the crystalline nanostructure of P3HT with the corresponding solar cell performance. The increase in long wavelength absorption for solvent annealed films is related to highly conjugated crystal structure of RR-P3HT phase-separated in the active layer. Upon thermal annealing, the solvent annealed 50-nm-thick device shows high solar cell performance with fill factor up to 73% and power conversion efficiency of 3.80%.

A System For Automatically Annotating Traditional Irish Music Field Recordings, Bryan Duggan, Brendan O'Shea, Padraig Cunningham

Conference papers

This paper presents MATT2 (Machine Annotation of Traditional Tunes). MATT2 is a novel system which can automatically annotate field recordings of traditional Irish music with useful metadata such as tune name, key signature, time signature, composer and discography. MATT2 works by using a number of algorithms to automatically transcribe digital audio to be annotated to the ABC music notation language. It then compares these transcriptions against a corpus of 860 human made transcriptions in ABC using a variation of the edit distance algorithm. Results using MATT2 to annotate fifty recordings of flute and fiddle tunes demonstrate a high success rate …

Dedication To Pierre Lallemand On The Occasion Of His Retirement, Dominque D'Humieres, Manfred Krafczyk, Li-Shi Luo, Robert Rubinstein

Mathematics & Statistics Faculty Publications

The fourth international conference for mesoscopic methods in engineering and science (http://www.icmmes. org), held in Munich, Germany, 16–20 July 2007, was closed with a celebration honouring Dr Pierre Lallemand on the occasion of his retirement from the Centre National de la Recherche Scientifique (CNRS) after more than 40 years of service.

Dual Bypass Gas Metal Arc Welding Process And Control, Xiaopei Liu

University of Kentucky Doctoral Dissertations

GMAW (Gas Metal Arc Welding) is one of the most important arc welding processes being adopted in modern manufacturing industry due to its advantages in productivity, energy efficiency and automation. By monitoring and improving some of the important properties of GMAW such as production rate, metal transfer and base metal heat input, researchers could bring the process efficiency and stability to a new level. In recent years, some innovative modifications of GMAW such as Twins, Tandem and laser-MIG hybrid welding have been adopted into many industrial applications for better productivity.

In this dissertation, a novel GMAW called DB-GMAW (Dual Bypass …

Evaluation Of An Image Processing Algorithm For Scene Change Detection, Daniel Flores

Open Access Theses & Dissertations

Despite the efforts to reduce traffic accidents by government entities and automobile manufactures, the numbers of accidents are not considerably reduced. An evaluation of an algorithm based on the fly's eye is done on this research applying its principles to detect scene change on images for printed circuit boards providing initial steps to implement this algorithm on vehicular traffic to keep track of objects moving on the field for collision avoidance purposes. The effectiveness of the algorithm is addressed through a comparison of its performance with that found in experimental data.

Analysis Of Number And Mass Concentration Of Coarse And Fine, Nancy Garcia

Open Access Theses & Dissertations

There is currently much concern over particles suspended in the ambient air, their effects on people and the environment throughout the world. The suspended particles can cause adverse health effects, reduce visibility and over the course of time wear buildings. Primary air quality concerns are of particles, their effects and their key characteristics. Particle number concentration (NC) of traffic emissions is an important element of the study, specifically heavy duty diesel engine emissions. Particle number concentration is the number of particles of a specific size in a unit of air; in this study they are measured by the number of …

Guidelines For Using Local Material For Roadway Base And Subbase, Biraj Gautam

Open Access Theses & Dissertations

Flexible base materials that meet TxDOT specifications are getting more difficult to purchase in many TxDOT Districts. As a result, higher quality materials have to be hauled long distances, sometimes from other States. This act would significantly increase the costs associated with the construction of roads and subsequent maintenance and rehabilitation of them. Lower quality (i.e., out-of-specification) materials are normally available. If through appropriate modifications of the materials (adjusting the gradation or/and stabilization) or structural design (specifying thicker layers of base and/or hot mix) the use of the local materials can be permitted, the construction can be accelerated and significant …

Allocating Emergency Response Vehicles To Cover Critical Infrastructures, Hao Lei

Open Access Theses & Dissertations

Optimal deployment of limited emergency response service units in a metropolitan area is of interests to public agencies. The limited emergency units not only have to respond to the demand for service by residents and businesses, but also cover Critical Infrastructures (CIs). This Thesis formulates an improved optimization model to allocate different types of Emergency Response Service (ERS) units among their candidate base stations. The allocation of units must ensure maximum coverage to CIs, subject to the capacities of the base stations, service standard in terms of time to reach the CIs, and the availability of the ERS units (when …

Assessment Of Human Muscle Fatigue From Surface Emg Signals Recorded During Isometric Voluntary Contractions By Using A Cosine Modulated Filter Bank, Cristhian Mauricio Potes

Open Access Theses & Dissertations

Human muscle fatigue involves both a decrease in the frequency and increase in the amplitude of a surface electromyographic (EMG) signal. Muscle fatigue is also related to a decrease of the force impeding to reach the same initial level of the maximum voluntary contraction (MVC). To determine muscle fatigue indices, a method is proposed by decomposing a surface EMG signal into 32-subbands. This decomposition was attained by using a cosine modulated filter bank. The

surface EMG signals analyzed during this research were recorded during isometric voluntary contractions. Both the instantaneous mean frequency (IMF) and the instantaneous amplitude (IA) are estimated …

A Study Of The Interaction Of Thioindigo Dye, With Several Inorganic Host Materials, Alejandra Ramirez

Open Access Theses & Dissertations

Maya Blue has been the focus of numerous studies and is believed to be a mixture of palygorskite clay and indigo dye.^1,2 Several derivatives of this pigment have been developed with intriguing properties. For instance, the dye thioindigo reacts with the palygorskite clay to exhibit a broad range of colors from red to blue under UV-Vis excitation. Based on FT-Raman and computer simulation, previous work performed in our group could relate indigo and thioindigo interaction to the aluminum sites in the framework. super>3,4

The work performed with other inorganic host materials such as, layer structures and zeolites have …

Zinc Telluride Deposition Using Close Space Sublimation, Luis Carlos Romo

Open Access Theses & Dissertations

This thesis presents the optimization process of the close space sublimation (CSS) technique to deposit zinc telluride (ZnTe) on thin-film cadmium telluride (CdTe) solar cells. Previous research has demonstrated that creating a heavily doped ZnTe intermediate layer between the absorber-CdTe and the back contacts produces low-resistive CdTe contacts that overcome the Schottky barrier created at the interface of a metal and a semiconductor [11]. ZnTe interlayer forms a tunnel barrier at the contact interface so the positive charges created at the p-CdTe/n-cadmium sulfide (CdS) junction can be easily collected at the back contact maximizing the current collection process. However, ZnTe …

Quality Evaluation Of Portland Cement Concrete At Early Age With Free-Free Resonant Column, Gilberto Wenglas

Open Access Theses & Dissertations

At early age, the behavior and mechanical properties of portland cement concrete changes rapidly with time due to hydration. The hydration process consists of a series of chemical reactions that accelerate nonlinearly with the rise in temperature. The hydration process consists of three stages: the dormant period, the setting time, and the hardening time. Timely opening of roads and resumption of constructions depend of the knowledge of these stages. The initial and final setting times are arbitrarily determined by a standard test (ASTM C 403). Although the setting time has been studied for many decades, the new technologies allow making …

Numerical Analysis Of Respiratory Aerosol Deposition: Effects Of Exhalation, Airway Constriction And Electrostatic Charge, Samir C. Vinchurkar

Theses and Dissertations

The dynamics of particle laden flows are integral to the analysis of toxic particle deposition and medical respiratory aerosol delivery. Computational fluid-particle dynamics (CFPD) can play a critical role in developing a better understanding of particle laden flows, especially in a number of under-explored areas. The applications considered in this study include both the numerical aspects and the physical phenomena of respiratory aerosol transport. Objective I: Considering the effects of mesh type and grid convergence, four commonly implemented mesh styles were applied to a double bifurcation respiratory geometry and tested for flow patterns and aerosol deposition. Results indicated that the …

Remote Forensics May Bring The Next Sea Change In E-Discovery: Are All Networked Computers Now Readily Accessible Under The Revised Federal Rules Of Civil Procedure?, Joseph J. Schwerha, Scott Inch

Journal of Digital Forensics, Security and Law

The recent amendments to Rule 26 of the Federal Rules of Civil Procedure created a two-tiered approach to discovery of electronically stored information (“ESI”). Responding parties must produce ESI that is relevant, not subject to privilege, and reasonably accessible. However, because some methods of storing ESI, such as on magnetic backup tapes and within enormous databases, require substantial cost to access and search their contents, the rules permit parties to designate those repositories as “not reasonably accessible” because of undue burden or cost. But even despite the difficulty in searching for ESI, the party’s duty to preserve potentially responsive evidence …