Engineering Commons^™

On Decision Making Under Interval Uncertainty: A New Justification Of Hurwicz Optimism-Pessimism Approach And Its Use In Group Decision Making, Van Nam Huynh, Chenyi Hu, Yoshiteru Nakamori, Vladik Kreinovich

Departmental Technical Reports (CS)

If we know the exact consequences of each action, then we can select an action with the largest value of the objective function. In practice, we often only know these values with interval uncertainty. If two intervals intersect, then some people may prefer the alternative corresponding to the first interval, and some prefer the alternative corresponding to the second interval. How can we describe the portion of people who select the first alternative? In this paper, we provide a new theoretical justification for Hurwicz optimism-pessimism approach, and we show how this approach can be used in group decision making.

Three Innovative Concepts For Short Span Steel Bridges, Aaron Jon Yakel, Atorod Azizinamini, Mohammadreza Farimani, Nazzanin Mossahebi

Nebraska Department of Transportation: Research Reports

No abstract provided.

Improved Carrier Injection In Ultrathin-Body Soi Schottky-Barrier Mosfets, M Zhang, Joachim Knoch, Joerg Appenzeller, S Mantl

Other Nanotechnology Publications

The impact of the gate oxide and the silicon-on-insulator (SOI) body thickness on the electrical performance of SOI Schottky-barrier (SB) MOSFETs with fully nickel silicided source and drain contacts is experimentally investigated. The subthreshold swing S is extracted from the experimental data and serves as a measure for the carrier injection through the Sills. It is shown that decreasing the gate oxide and body thickness allows to strongly increase the carrier injection and hence, a significantly improved ON-state of SB-MOSFETs can be obtained.

Rf Sputtered Sixge1-X And Sixge1-Xoy Thin Films For Uncooled Infrared Detectors, Mukti M. Rana

Electrical Engineering Dissertations - Archive

The objective of this work is to find a suitable combination of radio frequency (RF) sputtered SixGe1-x and SixGe1-xOy thin films for uncooled infrared detection. Thus, fabricating and characterizing microbolometers with SixGe1-x and SixGe1-xOy thin films as the sensing material are the ultimate goal of this work. Thin films of SixGe1-x and SixGe1-xOy were deposited by RF magnetron sputtering at room temperature from a single target of SixGe1-x in Ar or Ar : O2 environment. The silicon and oxygen concentrations were varied in a parametric investigation of the dependence of the electrical and optical characteristics of the thin films on …

Dynamic Voltage Restorer For Sensitive Equipment, Yea Zong Kuo

Electrical Engineering Dissertations - Archive

Voltage sags are considered to be the most frequent type of disturbances in the field based on recent power disturbances studies. Their impact on sensitive loads is severe. The impact ranges from load disruptions to substantial economic losses. Despite the technical advances in electronics, there are still some pieces of equipment that are so sensitive that they are unable to withstand voltage sags. An example is the equipment in semiconductor manufacturing. As a result, there is still a search for different ways to manage voltage sags. There are many different methods to mitigate voltage sags, but a CUstom Power Supply …

Acuta Enews March 2007, Vol. 36, No. 3

ACUTA Newsletters

In This Issue

From ACUTA Headquarters Jeri A. Semer, CAE, ACUTA Executive Director

Board Report............... Riny Ledgerwood, San Diego State Univ. ACUTA Sec./Treasurer

Liability When Employees Use Cell Phones White Driving............. Brendan Carr, Wiley Rein LLP

Telecom Managers Profit from VolP Knowledge .................. Gary Audin, Delphi, lnc.

Tech Talk: Time for a Change? Yes, and lt's March 11............... Kevin Tanzillo, Dux PR

DC Update ............ Jeanne Jansenius, Sewanee, The University of the South

lnvite Your Vendors to Join ACUTA

FYI: Useful lnformation from the Campus Student Monitor

Web Tip: New RFI/RFP Web Page............. Aaron Fuehrer, ACUTA lnformation Technology Manager

ACUTA …

Characterization Of Dairy Milk House Waste Water In Kentucky, Anshu Singh, Czarena L. Crofcheck, Gail M. Brion

Biosystems and Agricultural Engineering Faculty Publications

This study focuses on characterization of milk house waste water from eight different farms in Kentucky. The farms were separated into three groups based on the number of cows: small (20-30), medium (30-60), and large (over 60 cows). Samples were collected once a month from four farms and twice a month from the remainder. Samples were analyzed for chemical, biochemical, and microbiological characteristics. Results indicated a large and significant variation in the chemical and microbiological characteristics between the farms. Farm size had a significant effect on the nutrient content of the waste water. Though samples exhibited seasonal variation, there was …

Dairy Waste Utilization Management Tool, José R. Bicudo, Anshu Singh

Agricultural Engineering Extension Publications

Quick tests enabling rapid, on‑farm assessment of manure nutrient content can significantly enhance manure management practices. Rapid or quick tests are less accurate than standard laboratory analyses but can be useful as a manure utilization tool.

Dielectric Response Of Sr Doped Cacu₃Ti₄O₁₂ Ceramics, Wei Li, Robert W. Schwartz, Aiping Chen, Jinsong Zhu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ca1−xSrxCu3Ti4O12 (x=0, 0.1, and 0.2) ceramics were fabricated and their dielectric properties were investigated. It was found that the dielectric constant significantly decreased with the increase of Sr content at low temperature region (<250 K) and remained almost unchanged at high temperature region (>250 K). Three sets of relaxation peaks were observed in electric modulus plots, which were considered to be associated with grains, domain boundaries, and grain boundaries, respectively. Through the analysis of the heights and calculated activation energies of the relaxation peaks, it is strongly believed that the suppressed dielectric constant is related to the change of domain boundaries with Sr doping. ©2007 American Institute of Physics

Multifrequency Eddy Current Inspection Of Corrosion In Clad Aluminum Riveted Lap Joints And Its Effect On Fatigue Life, Shridhar Natarajan, Anthony Chukwujekwu Okafor

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Aging aircraft are prone to corrosion damage and fatigue cracks in riveted lap joints of fuselage skin panels. This can cause catastrophic failure if not detected and repaired. Hence detection of corrosion damage and monitoring its effect on structural integrity are essential. This paper presents multifrequency eddy current (EC) inspection of corrosion damage and machined material loss defect in clad A1 2024-T3 riveted lap joints and its effect on fatigue life. Results of eddy current inspection, corrosion product removal and fatigue testing are presented.

Exploring Effective Methods For Simulating Damaged Structures With Geometric Variation: Toward Intelligent Failure Detection, Daniel A. Mcadams, David Comella, Irem Y. Tumer

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Inaccuracies in the modeling assumptions about the distributional characteristics of the monitored signatures have been shown to cause frequent false positives in vehicle monitoring systems for high-risk aerospace applications. to enable the development of robust fault detection methods, this work explores the deterministic as well as variational characteristics of failure signatures. Specifically, we explore the combined impact of crack damage and manufacturing variation on the vibrational characteristics of beams. the transverse vibration and associated eigenfrequencies of the beams are considered. Two different approaches are used to model beam vibrations with and without crack damage. the first approach uses a finite …

Characterization Of Chlorinated Ethene Degradation In A Vertical Flow Constructed Wetland, James M. Waldron

Theses and Dissertations

Chlorinated solvents, including perchloroethene (PCE) and trichlorethene (TCE), are among the most common groundwater contaminants found in the United States. Once released into the environment, chlorinated solvents are extremely persistent and often require costly and lengthy remedial actions. The use of constructed wetlands has shown promise as an effective and less costly alternative for the treatment of chlorinated solvent contaminated groundwater. This study characterized and evaluated the concentration of chlorinated ethenes within a vertical flow constructed wetland, fed with PCE contaminated groundwater, at Wright-Patterson Air Force Base (WPAFB), Ohio. Chlorinated ethene concentrations were characterized within three distinct layers of the …

A Decision Model For Selecting Energy Efficient Technologies For Low -Sloping Roof Tops Using Value-Focused Thinking, Michael J. Mccourt

Theses and Dissertations

The Air Force has a large inventory of low-sloping built up roofs (BURs) and millions of dollars are spent each year retrofitting these systems. The DOD has been directed to reduce non-renewable energy consumption by using energy-efficient technologies. These two details present a great opportunity to use the open roof space to install energy-efficient roofing technologies. The purpose of this research is to provide Air Force decision makers with a tool to assist them in deciding what roofing technologies should be installed on facilities. Value Focused-Thinking is the methodology used to construct the model, in which values were used, instead …

Planning And Assessing Stability Operations: A Proposed Value-Focused Thinking Approach, Gerald D. Fensterer

Theses and Dissertations

Stability operations are vital to establish peace in the aftermath of conflict. The United States is often called in for military support during conflict. The new American military paradigms include establishing peace through stability operations after a military conflict. Due to this new role, military decision makers face many difficulties in conducting successful stability operations. Compounding this problem is the limited number of resources pertaining to stability operations: experts, doctrine, knowledge, and technology. Two overarching challenges of stability operations facing decision makers are planning and prioritizing of stability operations and determining progress. This thesis applies a structured analytical approach to …

An Efficient Metaheuristic For Dynamic Network Design And Message Routing, Robert B. Hartlage

Theses and Dissertations

The implementation of Net-centric warfare presents major challenges in terms of effectively and efficiently delivering critical information across the Global Information Grid. In many cases, the amount of information requested will exceed the capabilities of the network. One challenge is to dynamically design the network (assign transceivers) to maximize the amount of required information that can be transmitted and the quality of service for those transmissions - to best implement the communications tasking order. The problem is as follows: given a list of required message traffic, to include source, destination, size, and priority, design the network to maximize the delivery …

Updating Optimal Decisions Using Game Theory And Exploring Risk Behavior Through Response Surface Methodology, Jeremy D. Jordan

Theses and Dissertations

This thesis utilizes game theory within a framework for updating optimal decisions based on new information as it becomes available. Methodology is developed that allows a decision maker to change his perceived optimal policy based on available knowledge of the opponents strategy, where the opponent is a rational decision maker or a random component nature. Utility theory is applied to account for the different risk preferences of the decision makers. Furthermore, response surface methodology is used to explore good risk strategies for the decision maker to approach each situation with. The techniques are applied to a combat scenario, a football …

Using Relocatable Bitstreams For Fault Tolerance, David P. Montminy

Theses and Dissertations

This research develops a method for relocating reconfigurable modules on the Virtex-II (Pro) family of Field Programmable Gate Arrays (FPGAs). A bitstream translation program is developed which correctly changes the location of a partial bitstream that implements a module on the FPGA. To take advantage of relocatable modules, three fault-tolerance circuit designs are developed and tested. This circuit can operate through a fault by efficiently removing the faulty module and replacing it with a relocated module without faults. The FPGA can recover from faults at a known location, without the need for external intervention using an embedded fault recovery system. …

On-Demand Key Distribution For Mobile Ad-Hoc Networks, Daniel F. Graham

Theses and Dissertations

Mobile ad-hoc networks offer dynamic portable communication with little or no infrastructure. While this has many benefits, there are additional shortcomings specific to wireless communication that must be addressed. This research proposes gossip-based on-demand key distribution as a means to provide data encryption for mobile ad-hoc networks. This technique uses message keys to avoid encrypting and decrypting a message at every node. Other optimizations used include secure channel caching and joint rekey messages. The use of gossip makes the scheme robust to node failure. Experimental results show only a 15% increase in end-to-end delay with a node failure rate of …

Overcoming Tcp Degradation In The Presence Of Multiple Intermittent Link Failures Utilizing Intermediate Buffering, Duane F. Harmon

Theses and Dissertations

It is well documented that assumptions made in the popular Transmission Control Protocol's (TCP) development, while essential in the highly reliable wired environment, are incompatible with today's wireless network realities in what we refer to as a challenged environment. Challenged environments severely degrade the capability of TCP to establish and maintain a communication connection with reasonable throughput. This thesis proposes and implements an intermediate buffering scheme, implemented at the transport layer, which serves as a TCP helper protocol for use in network routing equipment to overcome short and bursty, but regular, link failures. Moreover, the implementation requires no modifications to …

Hardware Realization Of A Transform Domain Communication System, Marshall E. Haker

Theses and Dissertations

The purpose of this research was to implement a Transform Domain Communication System (TDCS) in hardware and compare experimental bit error performance with results published in literature. The intent is to demonstrate the effectiveness or ineffectiveness of a TDCS in communicating binary data across a real channel. In this case, an acoustic channel that is laden with narrowband interference was considered. A TDCS user pair was constructed to validate the proposed design using Matlab™ to control a PC sound card. The proposed TDCS design used the Bartlett method of spectrum estimation, the spectral notching algorithm found in TDCS literature, quadrature …

Quantifying Non-Equilibrium In Hypersonic Flows Using Entropy Generation, Ryan W. Carr

Theses and Dissertations

The constitutive relations traditionally used for finding shear stress and heat flux in a fluid become invalid in non-equilibrium flow. Their derivation from kinetic theory only demonstrates they are valid only for small deviations from equilibrium. Because it is fundamentally linked to non-equilibrium, entropy generation is used to investigate the limits of the continuum constitutive relations. However, the continuum equations are inherently limited to near equilibrium conditions due to the constitutive relations; thus kinetic theory must be used as a basis for comparison. Direct Simulation Monte Carlo (DSMC), a particle method alternative to continuum methods, is based on kinetic theory …

Experimental Characterization Of Turbulent Flow Around Cylinder Arrays, Adam D. Harder

Theses and Dissertations

This research was done as part of an effort to develop alternative fire suppressant technologies for aircraft engine nacelles. A circular cylinder array was designed, built, and placed in the AFIT roll-around low speed wind tunnel to model generic clutter inside an engine nacelle. A turbulence grid was fabricated to enable measurements of the effects of turbulence level, independent of airspeed, on the flow over different model configurations. The wind tunnel test section was 12 inches wide x 12 inches high x 24 inches long. Pressure differential measurements were taken on various cylinder configurations. The configurations included one cylinder as …

Simulation Of The Dynamically Coupled Kc-135 Tanker And Refueling Boom, Jeremy J. Smith

Theses and Dissertations

Future Air Force requirements for the use of unmanned aircraft will require Automated Aerial Refueling (AAR). Current AAR research requires a precision model to simulate the refueling process of a KC-135 tanker and a UAV. There are existing high fidelity models of the tanker aircraft, refueling boom and proposed receiver aircraft. However, none of the models are coupled. Since boom orientation and motion is known to change the trim of the tanker aircraft, which in turn influences all other aspects of the refueling process, a new model is needed. The new model was created by integrating an existing KC-135 tanker …

The Aerodynamic Performance Of The 24 Inch Houck Configuration, Michael M. Walker

Theses and Dissertations

Fuel efficiency of aircraft is of great importance to the military and private sector. A more efficient wing design for UAVs would lead to improvements in mission support while reducing fuel costs for the Air Force. An experimental investigation of one candidate design, the Houck Aircraft Configuration, has been conducted in the AFIT low speed wind tunnel. This aircraft shares similarities to other joined-wing aircraft, but includes curved flow-guides of varying spanwise camber connecting the upper and lower wingtips. Experimental results that the addition of flow guides on the 24" Houck Configuration results in a 2.5% reduction in L/D(sub max) …

Characterization Of A Hall Effect Thruster Using Thermal Imaging, James W. Tomaszewski

Theses and Dissertations

A Hall thruster uses ionized xenon as a propellant for space propulsion applications. The heat produced by thruster components and the xenon plasma transfers to space and the spacecraft, impacting thruster and spacecraft design, as well as thruster efficiency and lifetime. Therefore, thermal information was gathered and analyzed in order to better understand the thermal characteristics of an operating thruster and to provide data applicable to improving the thruster efficiency and lifetime. This paper contains analysis of thruster temperatures obtained using a commercially available FLIR A40M thermographic imager in order to characterize a Busek Inc. 200W Hall Effect Thruster operating …

Investigating Hastily-Formed Collaborative Networks, Joshua S. Campbell, Stanley L. Cooley, Matthew F. Durkin, Brian K. Maddocks

Theses and Dissertations

This research explores both the human and technical aspects of the network centric environment in the context of a major disaster or incident of national significance. The National Incident Management System (NIMS) is viewed by the authors as a social network, and an organizational topology is developed to improve its effectiveness. A rapid Network Deployment Kit (RNDK) using commercial off the shelf (COTS) wireless networking technology is also proposed that facilitates immediate NIMS implementation. The integration of logical and technical analyses forms a comprehensive systems engineering proposal to facilitate collaboration in a net-centric environment. It is envisioned that the methodology …

A Reconfigurable Stacked Microstrip Patch Antenna For Satellite And Terrestrial Links, Mohammod Ali, Abu T.M. Sayem, Vijay K. Kunda

Faculty Publications

A reconfigurable stacked microstrip patch antenna is proposed. The antenna operates at an upper frequency f(u) with a broadside pattern, 7.5-dBi right-hand circularly polarized gain, and 15.8% bandwidth. At a lower frequency f(1), the antenna operates as a planar inverted-F antenna (7.3% bandwidth and 3.9-dBi peak gain) with the main beam directed close to the horizon. Switching between the two regimes of operation is achieved using p-i-n diodes. antenna operation in the upper frequency hand is suitable for low-earth-orbit or medium-earth-orbit satellite communications, and in the lower frequency band, the antenna is useful for terrestrial land-mobile or other wireless applications.

A Distributed Model Of Carbohydrate Transport And Metabolism In The Liver During Rest And High-Intensity Exercise, E Chalhoub, L. Xie, V. Balasubramanian, Joanne M. Belovich

Chemical & Biomedical Engineering Faculty Publications

A model of reaction and transport in the liver was developed that describes the metabolite concentration and reaction flux dynamics separately within the tissue and blood domains. The blood domain contains equations for convection, axial dispersion, and transport to the surrounding tissue; and the tissue domain consists of reactions representing key carbohydrate metabolic pathways. The model includes the metabolic heterogeneity of the liver by incorporating spatial variation of key enzymatic maximal activities. Simulation results of the overnight fasted, resting state agree closely with experimental values of overall glucose uptake and lactate output by the liver. The incorporation of zonation …

Evaluation Of Linking Pavement Related Databases, Yuhong Wang, David L. Allen

Kentucky Transportation Center Research Report

In general, the objectives of this study were to identify and solve various issues in linking pavement performance related database. The detailed objectives were: to evaluate the state-of-the-art in information technology for data integration and data mining, to review the existing KyTC databases and study their potentiality for being linked for pavement performance evaluation, to prepare data linking alternatives for the KyTC’s review, to prepare an implementation plan for linking pavement related databases. The study reviewed the current practices of data integration by other organizations that face the similar challenges as KyTC. In addition, a review was conducted of the …

Evaluation Of Geophysical Methods And Geophysical Contractors On Four Projects In Kentucky, David L. Allen

Kentucky Transportation Center Research Report

This report details four geophysical testing projects that were conducted in Kentucky for the Kentucky Transportation Cabinet. The four projects were as follows: KY 101, Edmonson and Warren Counties, US 31-W, Elizabethtown Bypass, Hardin County, KY 61, LaRue County, and US 27, Pulaski County.

Two contractors conducted the investigations for this study and they were as follows: KY 101 – (PELA) Electrical Resistivity and Microgravity, US 31-W – (CCKS) Microgravity, KY 61 – (CCKS) Electrical Resistivity and Microgravity, and US 27 – (CCKS) Electrical Resistivity and Microgravity.

These two methods preformed well and this report recommends that these geophysical methods …