Engineering Commons^™

From [0,1]-Based Logic To Interval Logic (From Known Description Of All Possible [0,1]-Based Logical Operations To A Description Of All Possible Interval-Based Logical Operations), Hung T. Nguyen, Vladik Kreinovich

Departmental Technical Reports (CS)

Since early 1960s, we have a complete description of all possible [0,1]-based logical operations, namely of "and"-operations (t-norms) and of "or"-operations (t-conorms). In some real-life situations, intervals provide a more adequate way of describing uncertainty, so we need to describe interval-based logical operations. Usually, researchers followed a pragmatic path and simply derived these operations from the [0,1]-based ones. From the foundational viewpoint, it is desirable not to a priori restrict ourselves to such derivative operations but, instead, to get a description of all interval-based operations which satisfy reasonable properties.

Such description is presented in this paper. It turns out that …

A General Overview Of Multi-Objective Multiple-Participant Decision Making For Flood Management, Taslima Akter, Slobodan P. Simonovic

Water Resources Research Report

Decision-making problems in water resources are often associated with multiple objectives and multiple stakeholders. To enable more effective and acceptable decision outcome, it is required that more participation is ensured in the decision making process. This is particularly relevant for flood management problems where the number of stakeholders could be very large. Although application of multi-objective decision-making tools in water resources is very wide, application with the consideration of multiple stakeholders is much more limited. The solution methodologies adapted for multi-objective multi-participant decision problems are generally based on aggregation of decisions obtained for individual decision makers. This approach seems somewhat …

A Spatial Fuzzy Compromise Approach For Flood Disaster Management, Nirupama, Slobodan P. Simonovic

Water Resources Research Report

Natural disasters affect regions with different intensity and produce damages that vary in space. Topographical features of the region; location of properties that may be exposed to the peril; level of exposure; impact of different mitigation measures; are all variables with considerable spatial variability. A new method for evaluation of disaster impacts has been presented in this report that takes into consideration spatial variability of variables involved and associated uncertainty. Flood management has been used to illustrate the utility of proposed approach.

Floodplain management is a spatial problem. Representation of flood damage mitigation alternatives and objectives in space provides a …

Interval Computations Related To Privacy In Statistical Databases, Luc Longpre, Vladik Kreinovich

Departmental Technical Reports (CS)

We show that the need to maintain privacy in statistical databases naturally leads to interval computations, and provide feasible algorithms for the corresponding interval computation problems.

Correlation Between The Xps Peak Shapes Of Y1bu2cu3o7-X And Film Quality, Paul N. Barnes, Sharmila M. Mukhopadhyay, Timothy J. Haugan, Swaminathan Krishnaswami, Justin C. Tolliver, Iman Maartense

Mechanical and Materials Engineering Faculty Publications

X-ray photoelectron spectroscopy (XPS) depth profiling was used to investigate the compositional and chemical profile of a typical YBCO coated conductor architecture. Results of the process revealed that the Y(3d) photoelectronic peak shape in these films is very different from bulk YBCO. To investigate this, several samples of Y i Ba2Cu307_„ thin films were intentionally created of varying quality. The films were deposited on LaA10 3 by pulsed laser deposition with ./c. values ranging from poorly conducting up to several MA/cm2. Initial results indicated a potential correlation between the Y(3d) XPS peak shape (full-width-half-maximum) of the YBCO and the film …

Numerical Modeling Of Esd-Simulators, Kai Wang, David Pommerenke, Ramachandran Chundru

Electrical and Computer Engineering Faculty Research & Creative Works

ESD generators are widely used for testing the robustness of electronic equipment against human electrostatic discharge via small metal pieces (e.g. key). Presently the IEC 61000-4-2 ESD standard is hotly discussed to improve test result reproducibility. This paper numerically analyzes an ESD simulator and relates its construction parameters to discharge current and field parameters. It uses FDTD method and models the relay (contact mode discharge) as a material with time dependent conductivity. The process is broken down into a charging phase and a stabilization phase until the electrostatic conditions are reached. Then the conductivity of the relay is changed and …

A Fundamental Model Of Cyclic Instabilities In Thermal Barrier Systems, Anette M. Karlsson, J. W. Hutchinson, A. G. Evans

Mechanical Engineering Faculty Publications

Cyclic morphological instabilities in the thermally grown oxide (TGO) represent a source of failure in some thermal barrier systems. Observations and simulations have indicated that several factors interact to cause these instabilities to propagate: (i) thermal cycling; (ii) thermal expansion misfit; (iii) oxidation strain; (iv) yielding in the TGO and the bond coat; and (v) initial geometric imperfections. This study explores a fundamental understanding of the propagation phenomenon by devising a spherically symmetric model that can be solved analytically. The applicability of this model is addressed through comparison with simulations conducted for representative geometric imperfections and by analogy with the …

Ccfss News August 2002, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.

Evaluation And Carbon Fiber Reinforced Polymer Strengthening Of Existing Garage: Case Study, Milan Vatovec, Paul L. Kelley, Tarek Alkhrdaji, Antonio Nanni

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The concrete-repair fiber reinforced polymer technology emerged in the United States during the past 10 years. Since 1995, carbon fiber reinforced polymer (CFRP) has been applied to strengthen concrete decks of a troubled posttensioned garage in Atlanta. During the construction of the garage, design deficiencies were found. A remedial repair, involving heavily reinforced, 7.6 cm (3 in.) thick Gunite (Shotcrete) beams, applied to the underside of the slab between drop panels in the east-west (E-W) direction, was developed in 1984. Since then, delamination of Gunite beams and other structural problems repeatedly occurred. Epoxy injection and other limited repairs were done …

Fuel Consumption Modeling Of A Transport Category Aircraft: A Flight Operations Quality Assurance (Foqa) Analysis, Alan J. Stolzer

All-Inclusive List of Electronic Theses and Dissertations

Fuel is a very large operating cost category for major air carriers - second only to labor costs. Many air carriers have implemented extensive programs to monitor fuel usage. One of several emerging quality assurance programs in the aviation industry, Flight Operations Quality Assurance (FOQA) involves the routine collection and analysis of flight performance data recorded on the airplane for the purpose of improving s~fety and operational procedures. FOQA systems are not constrained by the same data limitations as are traditional aircraft performance monitoring programs and, thus, FOQA may serve as a robust new aircraft performance monitoring tool. The purpose …

Modeling Noise Coupling From Non-Parallel Pcb Trace Routing, Shaofeng Luan, Fengchao Xiao, W. Liu, Jun Fan, Yoshio Kami, James L. Drewniak, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

Coupling between PCB signal traces in proximity is of concern to PCB designers and EMC engineers. The behavior of noise coupling between non-parallel microstrip lines is studied in this paper by a full-wave numerical modeling method CEMPIE, designating a circuit extraction approach based on a mixed-potential integral equation formulation. Good agreement between the numerical results and measurements was obtained.

The Woman's Guide To Navigating The Ph.D. In Engineering & Science [Book Review], Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Transmission Line Modeling Of Vias In Differential Signals, Chen Wang, James L. Drewniak, Jun Fan, James L. Knighten, Norman W. Smith, Ray Alexander

Electrical and Computer Engineering Faculty Research & Creative Works

Signal layer transitions in differential lines are modeled using both FDTD and equivalent circuit methods. The equivalent circuit is developed based on transmission-line reasoning regarding via behavior. Parameters of each transmission-line segment are obtained based on its corresponding physical geometry. The mixed-mode S-parameters from the equivalent circuit and the FDTD modeling are compared. Good agreement is demonstrated in the frequency range from 1 GHz to 20 GHz. The results indicate that vias in differential lines can be modeled as a transmission line for a quick and easy engineering estimation of the differential signal behavior in an environment of signal layer …

Flexural Behavior Of R/C Beams Strengthened With Cfrp Sheets Or Fabric, P. Alagusundaramoorthy, Issam E. Harik, Ching Chiaw Choo

Kentucky Transportation Center Research Report

The resistance to electro-chemical corrosion, high-strength to weight ratio, larger creep strain, fatigue resistance, non-magnetic and non-metallic properties of carbon fiber reinforced polymer (CFRP) composites offer a viable alternative to bonding of steel plates in repair and rehabilitation of reinforced concrete structures. The objective of this investigation is to study the effectiveness of externally bonded CFRP sheets or fabric in increasing the flexural strength of concrete beams. Four-point bending flexural tests are conducted up to failure on nine concrete beams strengthened with different layouts of CFRP sheets and fabric, and three beams with different layouts of anchored CFRP sheets. An …

An Analysis Of Student Progress In Beginning Flight Training: Performance Prediction, Performance Measurement, And Performance Improvement, Ryan Olson

Dissertations

The current project was designed to explore potential strategies for reducing the risk of accidents and incidents with beginning flight students (V = 28) by: (a) evaluating the CogScreen™ Aeromedical Edition (CogScreen-AE) test as a predictor of performance, (b) investigating patterns in student performance using expanded data collection procedures, including more extensive measurement of landings, and (c) evaluating the effects of early supplemental training on a personal computer-based aviation training device (PCATD). The experimental manipulation employed a matched pairs research design and exposed a treatment group (rt = 14) to six trials of “skill pattern” practice on a PCATD, with …

Numerical Studies Of Transition For Flows Around Multi-Element Airfoils, Fengjun Liu

Dissertations

The transition of flows around a multi-element airfoil has been numerically studied using RANS with a k - e two-equation transition model, LST and DNS. The transition model uses an effective eddy-viscosity by coupling an intermittence-like correction to a turbulence eddy-viscosity that can be obtained via solving a parent k - e turbulence model. The transition model is truly predictive in that it is able to predict transition onset locations without having to specify prior knowledge of the targeted transition process. The predicted transition onset locations for all the cases studied were compared with the measured data. The results suggest …

Multicast Routing Algorithms And Failure Analyses For Low Earth Orbit Satellite Communication Networks, Jae Soong Lee

Theses and Dissertations

In the rapidly changing environment of mobile communications, the importance of the mobile satellite (e,g,, low earth orbit satellites (LEOsats)) networks will increase due to their global visibility and connection. Multicasting is an effective communication method in terms of frequency spectrum usage for a LEO network. It is devised to provide lower network traffic (i,e,, one-to-many transmissions). This research examines the system performance of two dissimilar terrestrially-based multicasting protocols: the Distance Vector Multicast Routing Protocol (DVMRP) and the On Demand Multicast Routing Protocol (ODMRP). These two protocols are simulated in large group membership density and in the presence of satellite …

Surface Switching Characteristics Of Variable Permittivity Dielectrics, Wayne Huebner, Eric J. Carleton

Materials Science and Engineering Faculty Research & Creative Works

Flashover voltage, lifetimes, and switch performance of insulators utilizing square thin and thick film electrodes were examined to determine the viability of using thin electrodes for reliable surface discharge switching. Gold, silver, and platinum were sputtered (0.25 µm) and screen printed (15 µm) onto Al₂O₃, TiO₂, and modified BaTiO₃ (MBT), then tested in air at 10⁵ Pa, under vacuum (10^-3/ torr), and while immersed in an insulating fluid, SF-2 (manufactured by 3M). For the measured range of 0.5 to 3 mm in air, the flashover voltage for all three insulators …

Shear Strength Of R/C Beams Wrapped With Cfrp Fabric, P. Alagusundaramoorthy, Issam E. Harik, Ching Chiaw Choo

Kentucky Transportation Center Research Report

The emergence of high strength epoxies has enhanced the feasibility of increasing the shear strength of concrete beams by wrapping with carbon fiber reinforced polymer (CFRP) fabric. The objective of this investigation is to evaluate the increase in shear strength of concrete beams wrapped with different configurations of CFRP fabric. Shear tests are conducted up to failure on two reinforced concrete control beams and twelve reinforced concrete beams wrapped with four different configurations of CFRP fabric. An analytical procedure is presented to predict the shear strength of beams wrapped with CFRP fabric. Comparisons are made between the test results and …

Forensics And Case Studies In Civil Engineering Education: State Of The Art, Norbert J. Delatte, Kevin L. Rens

Civil and Environmental Engineering Faculty Publications

This paper reviews the state of the art in the use of forensic engineering and failure case studies in civil engineering education. The study of engineering failures can offer students valuable insights into associated technical, ethical, and professional issues. Lessons learned from failures have substantially affected civil engineering practice. For the student, study of these cases can help place design and analysis procedures into historical context and reinforce the necessity of lifelong learning. Three approaches for bringing forensics and failure case studies into the civil engineering curriculum are discussed in this paper. These are stand-alone forensic engineering or failure case …

Agricultural Product Loads And Warehouse Failures, Norbert J. Delatte

Civil and Environmental Engineering Faculty Publications

Two manufactured metal building warehouses loaded with agricultural products failed in service. Inspection revealed considerable damage to the structure and the foundation. The building owner filed suit against the building supplier, the building erector, and the soils testing laboratory whose engineer had designed the foundation. The agricultural product imposed substantial outward lateral pressures on the walls of the structures. Review of the available design documents indicated that these loads had not been accounted for in design. A structural analysis revealed that elements of the structure were underdesigned for the agricultural product loads. In addition, the foundation did not have any …

Toward Enhancing Estimates Of Kentucky’S Heavy Truck Tax Liabilities, Andrew V. Mcneill, Suzanne Perkins, Merl Hackbart

Kentucky Transportation Center Research Report

Kentucky has established a Road Fund tax structure that is partially based on the principle that the system users pay their fair share of the costs associated with maintaining a safe and efficient highway system in Kentucky. Several of the most important sources of Kentucky’s road fund revenues derived from commercial trucking are dependent on the self-reported tax liabilities submitted by trucking firms. Self- reporting and the interstate nature of this industry allows for the possibility of tax evasion either due to fraudulent behavior or processing errors. To ensure the integrity of the system, the Revenue and Transportation Cabinets have …

Contractor Performed Quality Control On Kytc Projects, Donn E. Hancher, Yuhong Wang, Kamyar C. Mahboub

Kentucky Transportation Center Research Report

This report addresses issues related to transferring the responsibility for quality control from the Kentucky Transportation Cabinet (KyTC) to construction contractors. Surveys of the KyTC, other state departments of transportation, and Kentucky highway contractors were done to identify the advantages, concerns, and modifications of the Contractor Performed Quality Control (CPQC) program. An advisory committee of experienced KyTC engineers, FHWA representatives, and contractor representatives met periodically to identify approaches for handling key issues of the program.

Several key topics related to CPQC are presented in this report, with emphasis on quality control (QC) /quality assurance (QA) administration, QC/QA procedures, quality acceptance …

Analysis Of Traffic Crash Data In Kentucky (1997-2001), Kenneth R. Agent, Jerry G. Pigman, Monica L. Barrett, Eric R. Green

Kentucky Transportation Center Research Report

This report documents an analysis of traffic crash data in Kentucky for the years of 1997 thro ugh 2001. A primary objective of this study was to determine average crash statistics for Kentucky highways. Average and critical numbers and rates of crashes were calculated for various types of highways in rural and urban areas. These data can be used in Kentucky’s procedure to identify locations that have abnormal rates or numbers of crashes.

The other primary objective of this study was to provide data, which can be used in the preparation of the problem identification portion of Kentucky’s Annual Highway …

Correlation And Prediction Of Fatigue Crack Growth Rate For Different R-Ratios, Sudip Dinda

Masters Theses

The prediction of fatigue crack growth rate of a structural material is an important aspect by which we can predict the critical or safe crack length and, therefore, avoid the sudden failure of components and structures.

There are numerous models which claim to predict the fatigue crack growth rate, but with the exception of the highly published "crack closure methodology" no other model lived up to the expectation of correlating the fatigue crack growth data or predicting the fatigue crack growth rate for different R-ratios.

In order to find an effective solution to the above problem a study has been …

Flight Physician - August, 2002, Civil Aviation Medical Association

Browse all Civil Aviation Medical Association Newsletters

A sixteen page newsletter of the Civil Aviation Medical Association. The newsletter provided news about civil aviation medicine and information related to the organization.

Anticipating Full Vehicle Radiated Emi From Module-Level Testing In Automobiles, Geping Liu, Chingchi Chen, Yuhua Tu, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

EMI due to common-mode currents on cables routed in automobiles was studied using a test device designed to mimic a vehicle. Both experimental work and Finite-Difference Time-Domain (FDTD) modeling were employed in this paper. The good agreement between the measurements and modeling results indicates that the numerical tools can be a useful aid in predicting vehicle-level EMI by developing vehicle transfer functions and measuring the module-level EMI characteristics on the bench top.

Temporal Modeling Of Software Test Coverage, Sahra Sedigh, Arif Ghafoor, Raymond A. Paul

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a temporal model for the coverage achieved by software testing. The proposed model, which is applicable at any level of the testing hierarchy, can determine the value of test coverage at any given time, as well as predicting future values. The model is comprised of two main components: coverage functions, and the coverage matrix. The coverage functions represent the coverage of a single entity as a function of time and reflect the test environment through their stochastic parameters. The coverage matrix utilizes the coverage functions to depict the coverage attained for each entity by each test within …

Field Extraction From Near Field Scanning For A Microstrip Structure, Lin Zhang, Kevin P. Slattery, Chen Wang, Masahiro Yamaguchi, K.-I. Arai, Richard E. Dubroff, James L. Drewniak, David Pommerenke, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

Currents associated with high-speed digital devices have significant impacts on EMI problems in VLSI design and operation. In this paper, a simple transmission line model was implemented as an initial step to represent the EMI mechanisms associated with an IC package. Numerical modeling results were compared with near field scanning measurements and show that the magnetic field deduced from the measurements agrees well with the numerical predictions.

Estimating Dc Power Bus Noise, Jingkun Mao, Bruce Archambeault, James L. Drewniak, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

Simultaneous switching noise (SSN) resulting from IC devices can result in significant power bus noise, as well as radiation problems. An approach for estimating the power bus noise spectrum is presented in this paper. The power bus noise caused by digital circuits injecting high-frequency noise onto the DC buses feeding digital devices is calculated. The transient current drawn by an IC device is modeled using the load current and the shoot-through current through the power dissipation capacitance. Modeling and experimental results for several digital chips are shown. The modeling agrees well with the experimental results.