Engineering Commons^™

Quantitative Correlation Of Rainfall And Earth Surface Displacements For Slope Stability Studies, Chrysanthos Steiakakis, Evangelia Apostolou, Georgia Papavgeri, Zacharias Agioutantis, Achilleas Tripolitsiotis

Mining Engineering Faculty Publications

It is common sense that the possibility of a rockfall increases after an intense rainfall and it is well documented that rainfalls accelerate earth surface displacements such as landslides and rockfalls. This qualitative correlation is highly affected by the geology and climate condition of the area under consideration. The research project entitled "Development of an integrated system for rockfall identification in highways", funded by the Operational Program Competitiveness and Entrepreneurship (co-funded by the European Regional Development Fund (ERDF)) aims to develop an operational system for early warning of rockfalls that occur along transportation corridors. To accomplish this goal the influence …

Detection Of Small-Scale Rockfall Incidents Using Their Seismic Signature, Achilleas Tripolitsiotis, Antonis Daskalakis, Stelios Mertikas, Dionysios Hristopulos, Zacharias Agioutantis, Panagiotis Partsinevelos

Mining Engineering Faculty Publications

Several algorithms have been effectively used to identify the seismic signature of rockfall incidents, which constitute a significant threat for human lives and infrastructure especially when occurring along transportation networks. These algorithms have been mostly evaluated using data from large scale rockfall events that release a large amount of energy. However, low-energy rockfall events (< 100 Joules) triggered by small-sized individual rocks falling from small heights can be severely destructive. In this study, a three-parameter algorithm has been developed to identify low-energy rockfall events. An experimental setup was implemented to 1) validate the results obtained by this algorithm against visual inspection of seismic signals records, 2) define the optimal algorithm parameterization to minimize false alarms, and 3) investigate whether tri-axial vibration monitoring can be replaced by a uniaxial device in order to reduce the installation cost of a real-time rockfall monitoring system. It was found that the success rate of the proposed algorithm exceeds 80% independently of the parameters used, while event identification at a maximum distance with minimal false alarms was achieved when using mean ± 3σ as the threshold criterion and 6 ms and 4 ms as the trigger and event window parameters respectively. Finally, it was found that for the specific experimental setup, a uniaxial device could be used for rockfall event identification.

Estimation Of Optimal Productivity In Labor-Intensive Construction Operations, Krishna Prasad Kisi

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

In an attempt to evaluate the efficiency of labor-intensive construction operations, project managers typically compare actual with historical productivity for equivalent operations. However, this approach toward examining productivity only provides a relative benchmark for efficiency and may lead to the characterization of operations as objectively efficient when in reality such operations might simply be comparably efficient.

Optimal productivity is the highest sustainable productivity achievable under good management and typical field conditions. Optimal productivity is useful in the determination of the absolute efficiency of construction operations because an accurate estimate of optimal labor productivity allows for the comparison of actual vs. …

Common Mode Filtering With Metamaterial-Inspired Structures, Sang G. Kang

Rose-Hulman Undergraduate Research Publications

High-speed digital communication links typically employ differential signaling as an alternative to single ended signaling. The design challenge using these differential lines are that perfect symmetry in the signals sent and in the physical communication line must be maintained to prevent some of the differential mode signal’s energy to be converted to a common-mode signal. The main objective of a common-mode filter is to filter out this common-mode noise while leaving the differential signal intact. Our strategy in this project was to look into past work on common Electric Field Magnetic Field Common Mode Signal Differential Mode Signal Magnetic Field …

A System Dynamics Approach To The Efficacy Of Oxime Therapy In Sub Lethal Exposure To Sarin Gas, Daniel J. Droste

Theses and Dissertations

The 2010 National Security Strategy states, The effective dissemination of a lethal agent would endanger the lives of thousands of people and have unprecedented economic, societal, and political consequences. We must continue to work at home with first responders and health officials to reduce the risk associated with high-consequence threats . Nerve agents, such as Sarin gas, are considered high consequence threats. The threat of use of agents such as Sarin is as much a threat today as any other time in our history. However, the suggested treatment protocol is not as precise as it could be. Debate exists over …

Supply Chain Interoperability Measurement, Christos E. Chalyvidis

Theses and Dissertations

Academia recognizes that although supply chains have an inherent need to be validated for their performance, supply chain performance measurement systems are still inadequate and one of the major barriers to successful supply chain collaboration. In this research, theory of Systems Architecture is used to make the first step towards an innovative supply chain performance measure defined as supply chain interoperability. Interoperability is considered a similarity metric with regard to a set of deterministic and stochastic characters (criteria) describing supply chain participants, a methodology that adapts and expands an interoperability measurement tool initially developed in and for a military context. …

Generation Of Strategies For Environmental Deception In Two-Player Normal-Form Games, Howard E. Poston

Theses and Dissertations

Methods of performing and defending against deceptive actions are a popular field of study in game theory; however, the focus is mostly on action deception in turn-based games. This work focuses on developing strategies for performing environmental deception in two-player, strategic-form games. Environmental deception is defined as deception where one player has the ability to change the other's perception of the state of the game through modification of their perception of the game's payoff matrix, similar to the use of camouflage. The main contributions of this research are an expansion of the definition of the stability of a Nash equilibrium …

Analysis Of The Effectiveness Of The F-15e Risk Management During Peacetime Operations, Elliot B. Vasquez

Theses and Dissertations

Human factors are causal or contributory in 80% of Class A mishaps in the Air Force. Risk management tools are used throughout the service in every aircraft to help mitigate the risk of those human factors occurring. The F-15E Strike Eagle community was selected for analysis on the effectiveness of its risk management program but the data was comprised on Class A mishaps from Accident Investigation Boards since 2000 between the F-15 (all models), F-16 (all models), and F-22. Cases were selected if there were human factors root causes or contributory. A fault tree analysis coupled with the Department of …

Exhaust Composition In A Small Internal Combustion Engine Using Ftir Spectroscopy, Kevin P. Horn

Theses and Dissertations

The mission-specific needs of small, remotely piloted aircraft demand lighter, more efficient engines with increased performance for their propulsion systems. A wide range of experimental efforts were undertaken to further the ability to obtain performance data on small engines as well as to develop understanding of their operation. Data were collected to quantify friction losses present in the dynamometer drivetrain on the small engine research bench. A correction and calibration model was developed for brake power collected by the dynamometer. Mechanical efficiencies for 28 cm3, 55 cm3 and 85 cm3 engines were 92.4%, 91.3% and 89.7%, respectively. Maximum fuel conversion …

Effect Of Prior Exposure At Elevated Temperatures On Tensile Properties And Stress-Strain Behavior Of Four Non-Oxide Ceramic Matrix Composites, Sarah M. Wallentine

Theses and Dissertations

Thermal stability of four non-oxide ceramic matrix composites was studied. The materials studied were commercially available composites: SiC/SiNC; C/SiC; C/SiC-B4C (C/HYPR-SiC^TM); and SiC/SiC-B4C (SiC/HYPR-SiC^TM). COI Ceramics manufactured the SiC/SiNC and C/SiC composites using polymer infiltration and pyrolysis (PIP). The C/HYPR-SiC^TM and SiC/HYPR-SiC^TM CMCs were manufactured by Hyper-Therm High-Temperature Composites using chemical vapor infiltration (CVI). All four composites rely on a dense matrix for strength, stiffness, and oxidation protection. Fiber coating provides a fiber-matrix interface that allows fiber-matrix debonding and fiber pullout to occur, imparting fracture toughness to the CMC. The SiC/SiNC, C/SiC, and C/HYPR-SiC …

A Method To Predict Compressor Stall In The Tf34-100 Turbofan Engine Utilizing Real-Time Performance Data, Shuxiang A. Li, Trevor G. Jones

Theses and Dissertations

The Air Force current operations continue to undergo significant changes compelled by decreasing fiscal appropriations, aging aircraft, and personnel drawdown. The Air Force must effectively improve current maintenance operations in part to deal with these challenges. This study will explore the area of the A-10 aircraft fleet's TF34-100 high-pass turbo-fan engine sensor data to seek its deterioration modelling and prognostics capability. In futurity this will allow for achievement of greater confidence in predicting the compressor stall which leads to engine performance deterioration and a costly repair in maintenance. By utilizing an innovative method to forecast the probability of compressor stall, …

Coupling Nuclear Induced Phonon Propagation With Conversion Electron Mössbauer Spectroscopy, Michael J. Parker

Theses and Dissertations

Mössbauer spectroscopy is a very sensitive measurement technique (10^-8 eV) which prompted motivation for the experiment described in this thesis. Namely, can a sensitive detection system be developed to detect nuclear recoils on the order of 10 to 100 of eVs? The hypothesis that this thesis tests is: Nuclear induced phonon bursts caused by Rutherford scattered alphas, decayed from ²⁴¹Am, in a type-310 stainless steel material can couple with 7.3 keV conversion electron Mössbauer events at the other end of the material which will have a statistically significant effect on a Mössbauer spectrum. The phonon bursts produced by …

An Assessment Of The Effectiveness Of Air Force Risk Management Practices In Program Acquisition Using Survey Instrument Analysis, Michael J. Maroney Jr.

Theses and Dissertations

Air Force acquisition programs invest a large amount of resources to develop and field systems. Many of these resources go to risk management in order to help ensure those programs finish successfully with respect to cost, schedule, and technical performance goals. The question arises as to whether this is a sound investment. Although risk management has been shown to be effective in industry, scant empirical evidence exists for its effectiveness within the Air Force. Correlation and regression analysis of survey data show that a positive relationship does exist between specific risk practices and project success. Furthermore, the analysis suggests that …

A Methodology For The Optimization Of Disaggregated Space System Conceptual Designs, Robert E. Thompson

Theses and Dissertations

Optimal design techniques have proven to be an effective systems engineering tool. Using systems architecture as the foundation, this research explores the use of mixed variable optimization models for synthesizing and evaluating disaggregated space system concepts. Model-based conceptual design techniques are used to identify and assess system architectures based upon estimated system cost, performance trades, and cost risk. The Disaggregated Integral System Concept Optimization (DISCO) methodology is introduced, and then applied to representative space-based missions. Several results are obtained that indicate significant cost effectiveness gains from the optimization of multi-orbit and multi-function/multi-orbit disaggregated space systems. The general methodology has broad …

Modal Characterization Of A Piezoelectric Shaker Table, Randall J. Hodkin

Theses and Dissertations

Piezoelectric actuated shaker tables are often used for high frequency fatigue testing. Since natural frequencies can appear in the operating range of these shaker tables, it is necessary to conduct modal characterization of the system before testing. This thesis describes the design and experimental validation of a mechanical model used for modal analysis of a piezoelectric shaker table. A commercially available three-dimensional scanning device was used to produce a point cloud model of the surface geometry, which was converted to a solid model and imported into a Finite Element Analysis (FEA) package for modal analysis. Using a laser vibrometer to …

Simulation Of Metal Particulates In High Energetic Materials, Eduardo Nieto

Theses and Dissertations

This research focused on analyzing the effects of aluminum in high explosives such as PBX9501 using the MPEXS computational simulation code for a wide range of metalized explosive cases. The varying parameters are aluminum particle diameter and mass fraction of aluminum. The addition of metal particulates in explosive mixtures increases the density of the shock wave, causing a higher pressure in the shock. It was concluded that pressure and density steadily increases as the Al particle diameter increases, and pressure and density decreases when Al mass fraction increases. The concentrated pressures will dissipate quickly due to the high density, providing …

Creep Of Sylramic-Ibn Fiber Tows At Elevated Temperature In Air And In Silicic Acid-Saturated Steam, Kevin B. Sprinkle

Theses and Dissertations

Stressed oxidation experiments on Sylramic-iBN fiber tows were performed to evaluate the novel fiber's mechanical performance, creep behavior, and creep mechanisms. This research effort investigated creep response of Sylramic-iBN fiber tows at elevated temperatures in both air and in silicic acid-saturated steam environments. Creep experiments were conducted at creep stresses ranging from 127 to 762 MPa at 400°C and 500°C in order to examine the mechanical behavior of the Sylramic-iBN fiber tows at temperatures below and above the melting point of boria (450°C). Sylramic-iBN fibers are known to have excellent creep resistance, better than most other non-oxide fibers and significantly …

Orbit Estimation Of Non-Cooperative Maneuvering Spacecraft, Gary M. Goff

Theses and Dissertations

Due to the ever increasing congestion of the space environment, there is an increased demand for real-time situation awareness of all objects in space. An unknown spacecraft maneuver changes the predicted orbit, complicates tracking, and degrades estimate accuracies. Traditional orbit estimation routines are implemented, tested, and compared to a multiple model format that adaptively handles unknown maneuvers. Multiple Model Adaptive Estimation is implemented in an original way to track a non-cooperative satellite by covariance inflation and filtering-through a maneuver. Parameters for successful instantaneous maneuver reconstruction are analyzed. Variable State Dimension estimation of a continuously maneuvering spacecraft is investigated. A requirements …

Topology Optimization Of An Aircraft Wing, David L. Walker

Theses and Dissertations

A Topology Optimization (TO) was conducted on an aircraft wing in order to mathematically determine an ideal structural case for future aircraft. TO generally involves iteratively reducing individual elemental density until the desired mass or volume constraint is met. Two different TO styles where approached: a global three-dimensional concept and a more traditional two-dimensional rib and spar optimization which more closely mimics the baseline model. All optimizations were compared against a baseline wing for von-Mises stress, displacement, and buckling. The objective of this research was to develop a design procedure maintaining the baseline structural integrity of the wing while reducing …

Interview With Conrad Haber, Rca Heritage Program

RCA Oral History Transcripts

Interview with Conrad Haber for the RCA Heritage Program Oral History grant.

Interview With Herb And Sandy Schwartz, Rca Heritage Program

RCA Oral History Transcripts

Interview with Herb and Sandy Schwartz for the RCA Heritage Program Oral History grant.

Interview With Carl Haslett, Rca Heritage Program

RCA Oral History Transcripts

Interview with Carl Haslett for the RCA Heritage Program Oral History grant.

Using Opensim To Predict Knee Joint Moments During Cycling, Karim C. Dudum, Jake E. Deschamps, Juan D. Gutierrez-Franco, Luke I. Kraemer, Alejandro M. Gonzalez-Smith, Eshan M. Dandekar, S. J. Hazelwood, Stephen M. Klisch

Biomedical Engineering

Cycling is a relatively low impact activity conventionally recommended as a rehabilitative or fitness sustaining exercise for patients at a high risk for knee osteoarthritis (OA) [1,2]. Expanding our understanding of knee joint loads is necessary to develop and improve evidence-based prescriptions for cycling as a rehabilitative and fitness therapy that limits the risk for knee OA.

OpenSim (www.simtk.org) is an open source biomechanical analysis software that can partition predictions of external joint loads (or net muscle moments) into muscle and joint contact loads [3]. Joint contact loads more accurately represent cartilage tissue loading and hence risk for cartilage damage …

Diffusion Of A Janus Nanoparticle In An Explicit Solvent: A Molecular Dynamics Simulation Study, Ali Kharazmi, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

Molecular dynamics simulations are carried out to study the translational and rotational diffusion of a single Janus particle immersed in a dense Lennard-Jones fluid. We consider a spherical particle with two hemispheres of different wettabilities. The analysis of the particle dynamics is based on the time-dependent orientation tensor, particle displacement, as well as the translational and angular velocity autocorrelation functions. It was found that both translational and rotational diffusion coefficients increase with decreasing surface energy at the nonwetting hemisphere, provided that the wettability of the other hemisphere remains unchanged. We also observed that in contrast to homogeneous particles, the nonwetting …

Human Knee Joint Finite Element Model Using A Two Bundle Anterior Cruciate Ligament: Validation And Gait Analysis, Nicholas A. Czapla, Meghan K. Sylvia, Zachary F. Lerner, David J. Tuttle, Otto J. Schueckler, S. J. Hazelwood, Stephen M. Klisch

Biomedical Engineering

Anterior cruciate ligament (ACL) deficient individuals are at a much higher risk of developing osteoarthritis (OA) compared to those with intact ACLs, likely due to altered biomechanical loading [1]. Research indicates the ACL is comprised of two “bundles”, the anteromedial (AM) and posterolateral (PL) bundles [2]. Although the function of both bundles is to restrain anterior tibial translation (ATT), each bundle has their own distinct range of knee flexion where they are most effective [3].

Articular cartilage contact stress measurements are difficult to measure in vivo. An alternative approach is to use knee joint finite element models (FEMs) to predict …

Brief Look At The Environment Of Space, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Brief Look at the Environment of Space" from June 17, 2015.

Development Of A Human Knee Joint Finite Element Model To Investigate Cartilage Stress During Walking In Obese And Normal Weight Adults, Meghan K. Sylvia, Nicholas A. Czapla, Zachary F. Lerner, David J. Tuttle, Otto J. Schueckler, Scott Hazelwood, Stephen M. Klisch

Biomedical Engineering

Osteoarthritis (OA) is a degenerative condition characterized by the breakdown and loss of joint articular cartilage. While the cause of OA is not precisely known, obesity is a known risk factor [1]. Particular effort has gone towards understanding the relationship between obesity and knee OA because obesity is more strongly linked to OA at the knee than at any other lower extremity joint [2]. Although the relationship between obesity and knee OA is well established, the mechanism of pathogenesis is less understood. Excess body weight generates greater joint contact forces at the knee. However, obese individuals alter their gait, resulting …

Design And Implementation Of An Instrumented Pedal For Cycling Biomechanics Research, Luke I. Kraemer, Juan D. Gutierrez-Franco, Jake E. Deschamps, Karim C. Dudum, Eshan M. Dandekar, Scott Hazelwood, Hemanth Porumamilla, Stephen M. Klisch

Biomedical Engineering

Cycling is a common, low-impact activity used for recreation, exercise, and rehabilitation. Knee joint loading can be predicted using inverse dynamic analyses of pedal load cell and kinematic data measured during cycling biomechanics experiments. Several studies have successfully measured foot loading at the pedals, e.g. by using custom instrumented pedal spindles outfitted with strain gauges and a potentiometer to measure crank angle [1-3]. Such designs are relatively complex, requiring difficult machining and component fabrication, and require post-processing of strain gauge data.

The long-term goal of this study is to calculate knee joint loading and, ultimately, cartilage tissue stress to provide …

Blended Classes: Expectations Vs. Reality, Susan L. Murray, Julie Phelps, Kelly L. Jones

Engineering Management and Systems Engineering Faculty Research & Creative Works

Blended courses, also called hybrid, have a portion of the course taught face-to-face in a classroom, and at least one-third of the course work is online. Some instructors consider this format to be "the best of both worlds." Students receive the personal contact and interaction with the instructor during the classroom portion. They also have flexibility in the pace, access, and repetition of the online content. In this paper, we explore 49 graduate students' expectations for a required operations management course that was delivered in a blended format. The same students were also surveyed at the completion of the course …

Implementation Of Compressive Sensing Algorithms On Arm Cortex Processor And Fpgas, Dinesh Veeramachaneni

Electrical Engineering Theses

Nowadays, communication systems require huge amounts of data to be processed. Some examples of these systems include radar systems, video streaming, and many other multimedia applications. These systems require large amounts of bandwidth to satisfy the Nyquist rate. Compressive Sensing is proposed as a way to reduce their bandwidth requirements. Compressive Sensing algorithms are generally implemented at the receiver to reconstruct the original signal from a reduced set of samples. This methodology eliminates data which is relatively insignificant. It possesses the potential to eliminate the use of large bandwidth, cost effective matched filters, and high-frequency analog-todigital converters at the receiver …