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Articles 170281 - 170310 of 198087

Full-Text Articles in Engineering

Management Information System For Iso 9000, Reem Mahmoud Abdel Motaal Jun 1999

Management Information System For Iso 9000, Reem Mahmoud Abdel Motaal

Archived Theses and Dissertations

No abstract provided.


Synthesis And Experimental Testing Of A Nonlinear Optimal Tracking Controller, Timothy Mclain, Randal W. Beard, Christopher A. Bailey Jun 1999

Synthesis And Experimental Testing Of A Nonlinear Optimal Tracking Controller, Timothy Mclain, Randal W. Beard, Christopher A. Bailey

Faculty Publications

This paper presents a novel approach for developing tracking controllers for nonlinear systems. The approach involves the numerical solution, by Galerkin approximation, of the time-varying Hamilton-Jacobi-Bellman (HJB) equation and results in a nonlinear controller approximating the optimal tracking control law for a specified desired trajectory and cost function. Experimental results are presented for a nonlinear pendulum system.


Evaluation Of Trimarc Procurement Procedures (Interim Report), Monica L. Osborne, Jerry G. Pigman Jun 1999

Evaluation Of Trimarc Procurement Procedures (Interim Report), Monica L. Osborne, Jerry G. Pigman

Kentucky Transportation Center Research Report

Innovative practices in construction contracting techniques have become more frequent and necessary in recent years. These practices benefit the transportation industry by experimenting with methods different from the traditional methods. This allows for growth and the adoption of procedures that provide higher quality and a better benefit to cost ratio.

An Advanced Traffic Management System (ATMS), referred to as TRIMARC (Traffic Response and Incident Management Assisting the River Cities), was installed in the Louisville, Kentucky and southern Indiana area. A system integrator approach was used for the installation, operation, and maintenance of this system. Special Experimental Project No. 14 (SEP-14) …


Evaluation Of Retesting In Kentucky's Driver License Process, Nikiforos Stamatiadis, Kenneth R. Agent, Jerry G. Pigman, Michael Ridgeway Jun 1999

Evaluation Of Retesting In Kentucky's Driver License Process, Nikiforos Stamatiadis, Kenneth R. Agent, Jerry G. Pigman, Michael Ridgeway

Kentucky Transportation Center Research Report

The objectives of this research were to first evaluate the existing practices regarding driver license renewal, driver retesting, and medical review board procedures and then identify and recommend methods that would improve these processes. The analysis of the Medical Review Board process indicated that, while it operates at an acceptable level in major urban areas, it is almost non-existent in most areas of the state. A brochure describing the process was developed for distribution to physicians. There is a universal agreement among researchers that vision has a significant role in driving performance and that visual abilities deteriorate with age. It …


Oxygen And Phosphorus Coordination Around Iron In Crystalline Ferric Ferrous Pyrophosphate And Iron-Phosphate Glasses With Uo₂ Or Na₂O, C. H. Booth, P. G. Allen, J. J. Bucher, N. M. Edelstein, D. K. Shuh, G. K. Marasinghe, Mevlüt Karabulut, C. S. Ray, D. E. Day Jun 1999

Oxygen And Phosphorus Coordination Around Iron In Crystalline Ferric Ferrous Pyrophosphate And Iron-Phosphate Glasses With Uo₂ Or Na₂O, C. H. Booth, P. G. Allen, J. J. Bucher, N. M. Edelstein, D. K. Shuh, G. K. Marasinghe, Mevlüt Karabulut, C. S. Ray, D. E. Day

Materials Science and Engineering Faculty Research & Creative Works

Fe K-edge x-ray absorption fine-structure (XAFS) measurements were performed on glass samples of (Fe3O4)0.3(P2O5)0.7 with various amounts of Na2O or UO2. Near-edge and extended-XAFS regions are studied and comparisons are made to several reference compounds. We find that iron in the base glass is ~25% divalent and that the Fe2+ coordination is predominantly octahedral, while Fe3+ sites are roughly split between tetrahedral and octahedral coordinations. Also, we measure roughly one FeñOñP link per iron. Substitution of Na2O or UO2 up to 15 mo1% primarily affects the first FeñO shell. The results are compared to data from the related material Fe3(P2O7)2.


Biodegradation Of Thermoplastic And Hermosetting Polyesters From Z-Protected Glutamic Acid, R M. Tadros, Hossein Noureddini, Delmar C. Timm Jun 1999

Biodegradation Of Thermoplastic And Hermosetting Polyesters From Z-Protected Glutamic Acid, R M. Tadros, Hossein Noureddini, Delmar C. Timm

Papers in Biomolecular Engineering

In a previous article,1 the development and molecular characterization of three polyesters from N-carbobenzyloxy-L-glutamic acid (ZGluOH) were reported. The polymers were a linear, heterochain polyester (ZGluOH and ethylene glycol), a crosslinked heterochain polyester (ZGluOH and diglycidyl ether of 1,4-butanediol), and a crosslinked, heterochain aromatic polyester (ZGluOH and diglycidyl ether of bisphenol A). In this manuscript, results of biodegradation studies are reported. The three polymers hydrolyzed to low molecular weight oligomers similar to the monomers with lipase. When exposed to a mixed culture of micro-organisms, the first two resins degraded to biomass and respiratory gases. The crosslinked heterochain aromatic polyester resisted …


Revision Of The Rainfall Intensity Duration Curves For The Commonwealth Of Kentucky, Bernadette S. Dupont, David L. Allen Jun 1999

Revision Of The Rainfall Intensity Duration Curves For The Commonwealth Of Kentucky, Bernadette S. Dupont, David L. Allen

Kentucky Transportation Center Research Report

The purpose of this study was to revise and update the existing Rainfall Intensity- Duration-Frequency (IDF) Curves for the Commonwealth of Kentucky. The nine curves that currently govern Kentucky are based on data from First-Order Weather Stations in and around Kentucky. However, the new curves only utilize data from within the State. The data was gathered from both First Order and Co-operative Weather Stations. In accordance with Bulletin 71, the new curves reflect the climatological zones located within the state, thus producing only four IDF curves.


A Report On County Road Program Finance (Fiscal Year 1997-98), Patsy Anderson, Kris Koehler Jun 1999

A Report On County Road Program Finance (Fiscal Year 1997-98), Patsy Anderson, Kris Koehler

Kentucky Transportation Center Research Report

This report reflects the findings of a study of county road finance in Kentucky. Statistics contained in the report were derived from financial statements submitted by the counties to the Kentucky Department of Local Government.


A Needs Assessment And Technology Evaluation For Roadside Identification Of Commercial Vehicles, Jennifer R. Walton, Joseph D. Crabtree Jun 1999

A Needs Assessment And Technology Evaluation For Roadside Identification Of Commercial Vehicles, Jennifer R. Walton, Joseph D. Crabtree

Kentucky Transportation Center Research Report

Throughout North America, selected public agencies have been assigned the responsibility for monitoring commercial vehicle traffic to make sure the commercial vehicles operating on public roadways are in safe operating condition, have proper registration and operating authority, are within legal size and weight limits, and have paid all appropriate fees and taxes. To accomplish this goal, all 50 States have established roadside monitoring and enforcement programs.

With limited resources and increasingly heavy truck volumes, roadside enforcement officers must continually make decisions about which trucks to check and which to allow to proceed. This process of selecting some trucks for closer …


Artimis Telephone Travel Information Service: Current Use Patterns And User Satisfaction, Jill Clemons, Lisa Aultman-Hall, Sarah T. Bowling Jun 1999

Artimis Telephone Travel Information Service: Current Use Patterns And User Satisfaction, Jill Clemons, Lisa Aultman-Hall, Sarah T. Bowling

Kentucky Transportation Center Research Report

This report summarizes the results of a phone survey which evaluated the user satisfaction of the telephone traveler information service, ARTIMIS, in Cincinnati/Northern Kentucky. Information was also gathered on the users preference for a 3 versus 7 digit access number, use patterns, and user characteristics. The sample was obtained by intercepting calls to the service during Winter 1999. Users rated the service high. Common suggestions for improvements included longer hours of operation and coverage of more roads suggesting the service is valuable to its users. The travelers perceived that they benefited most by avoiding traffic problems, saving time, and reducing …


Grain Oriented Crystallization, Piezoelectric, And Pyroelectric Properties Of (Baxsr₂ - X)Tisi₂O₈ Glass Ceramics, Jianping Zhang, Burtrand I. Lee, Robert W. Schwartz, Zhenya Ding Jun 1999

Grain Oriented Crystallization, Piezoelectric, And Pyroelectric Properties Of (Baxsr₂ - X)Tisi₂O₈ Glass Ceramics, Jianping Zhang, Burtrand I. Lee, Robert W. Schwartz, Zhenya Ding

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Polar, nonferroelectric (BaxSr2 - x)TiSi2O8 glass ceramics with highly oriented crystallites were prepared by a gradient temperature heat treatment technique. The crystallization mechanism and microstructures of (BaxSr2 - x)TiSi2O8 glass ceramics were investigated by means of differential thermal analysis, x-ray diffraction and scanning electron microscopy, and the dielectric, piezoelectric and pyroelectric properties were investigated for various compositions. The results show that polar (BaxSr2 - x)TiSi2O8 glass ceramics have a low dielectric constant and a high hydrostatic figure of merit dh × gh = ~ 2500. This high hydrostatic figure of merit, along with other unique characteristics, such as no aging …


Moving Transportation Toward Sustainable Development: The Need For A Paradigm Shift, Bahador Ghahramani, Stephen A. Raper Jun 1999

Moving Transportation Toward Sustainable Development: The Need For A Paradigm Shift, Bahador Ghahramani, Stephen A. Raper

Engineering Management and Systems Engineering Faculty Research & Creative Works

Despite progress in controlling exhaust emissions, the increase of cars on the road will surpass progress in emission control technology. The automobile is currently responsible for 50% of world fossil fuel consumption, 15-20% of CO2 emissions worldwide and overwhelming particulate air pollution in many urban centers. Current efforts in emissions control have been focused on improving the efficiency of fuels and automobiles and their emissions. However, as a mode of transportation, the automobile is one of the most inefficient, both in environmental and economic costs. Even the most efficient cars developed today will still significantly contribute to the amount …


Dual Channel Matched Filtering And Space-Time Adaptive Processing, Scott D. Berger Jun 1999

Dual Channel Matched Filtering And Space-Time Adaptive Processing, Scott D. Berger

Theses and Dissertations

We propose a dual channel matched filtering system that addresses two key challenges in the practical implementation of a single channel matched filtering system: secondary data support and computational cost. We demonstrated that the dual channel system requires half the secondary data to achieve nearly the same signal-to-interference plus noise ratio (SINR) as an equivalent single channel system. The key to the dual channel system is the block diagonalization of the interference plus noise correlation matrix with a fixed transformation. We investigated the application of this dual channel concept to the problem of space-time adaptive processing (STAP), referring to the …


Flow Separation Prevention On A Turbine Blade In Cascade At Low Reynolds Number, James P. Lake Jun 1999

Flow Separation Prevention On A Turbine Blade In Cascade At Low Reynolds Number, James P. Lake

Theses and Dissertations

The problem of flow separation from a low pressure turbine blade was investigated. The operating conditions under which the separation occurred were documented through measurement of surface pressure coefficients, boundary layer velocity and turbulence profiles, total pressure loss coefficient and wake velocity momentum deficit. Three different means for reducing the losses associated with the flow separation were also investigated. A boundary layer trip, dimples, and V-grooves were studied as passive means requiring no additional energy to reduce the separation losses. The boundary layer trip was only successful for an inlet and axial chord Reynolds number of 50k with a reduction …


Adaptive Interference Cancelation Techniques For Multicarrier Modulated Systems, Matthijs A. Visser May 1999

Adaptive Interference Cancelation Techniques For Multicarrier Modulated Systems, Matthijs A. Visser

Dissertations

Current wireline systems and wireless broadcasting systems employ multicarrier modulation (MCM). This includes the high-rate digital subscriber line (HDSL), digital audio broadcasting system (DAB) and the digital terrestrial television broadcasting system (dTTb). Multicarrier modulation is also envisioned for high-speed indoor wireless local area networks (WLAN). Additionally, multicarrier code division multiple access (MC-CDMA), a hybrid of orthogonal frequency division multiplexing (OFDM) and CDMA, is proposed for the downlink (base-to-mobile) of a 3rd generation wireless system as part of the IMT-2000 standardization process.

The performance of an MC-CDMA system--similar to a direct sequence CDMA (DS-CDMA) system--is limited by the presence of multiple …


Chemical Reactions And Mass Transport In Emulsion Liquid Membrane, Huifang Fan May 1999

Chemical Reactions And Mass Transport In Emulsion Liquid Membrane, Huifang Fan

Dissertations

Emulsion liquid membrane (ELM) systems are an important technique for wastewater cleanup. For this purpose, emulsion globules are dispersed in wastewater (external phase), each emulsion globule consisting of many tiny aqueous droplets (internal phase) enclosed in oil (membrane phase). Hazardous chemicals in the wastewater are transported into the internal droplets by mass transfer mechanisms.

Since Li first invented an ELM system in the 1960s, much research effort has been devoted to experimentally finding the optimal conditions for ELM recovery of various chemicals. Such studies would have benefited greatly from the guidance of mathematical models, especially those that provide analytical predictions. …


Long Term Risks Associated With Brownfield Containments, Shailesh Shirish Chirputkar May 1999

Long Term Risks Associated With Brownfield Containments, Shailesh Shirish Chirputkar

Dissertations

The sites at which the development is hindered by real or perceived contamination are called as Brownfield sites. It is a common trend in industry to develop these types of sites with surface and peripheral containments. It might prove unwise to develop the sites in this manner from a long term perspective without considering the associated risk. Because of this, a model has been proposed for long term risk assessments of brownfield containments.

Objectives of this study were to develop a contaminant transport model for flow of contaminants towards the surface and peripheral containments inside the site, a model for …


Utilization Of Processed Fly Ash In Mortar, Walairat Bumrongjaroen May 1999

Utilization Of Processed Fly Ash In Mortar, Walairat Bumrongjaroen

Dissertations

Grinding process is introduced to provide fine particles of coal fly ash that enhances the strength gain of cement mortars. It is discovered that grinding can make all the studied fly ashes more suitable for concrete use at higher replacement value than previously anticipated even when the effect of high carbon content is considered.

In this study, new mechanisms for strength gain of fly ash mortars are proposed. They are dispersion and nucleation, which are results from the presence of fly ash in the cement mortar. These effects are shown to enhance the hydration of cement. The pozzolanic action of …


A Methodology For Solving The Network Toll Design Problem, Mei Chen May 1999

A Methodology For Solving The Network Toll Design Problem, Mei Chen

Dissertations

Congestion pricing has been regarded as an efficient method to reduce network-wide travel cost. In this dissertation, a methodology for toll design is developed to provide policy-makers with suggestions on both where to charge tolls and how much the tolls should be. As opposed to the traditional approach of marginal social cost pricing, this methodology is capable of dealing with the more realistic case, in which only a small number of links can be tolled. Furthermore, this methodology is expanded to accommodate multiple user groups.

The toll design problem can be formulated using both deterministic and stochastic route choice models. …


Physical And Geotechnical Characterization Of Water Treatment Plant Residuals, Swamy C. Basim May 1999

Physical And Geotechnical Characterization Of Water Treatment Plant Residuals, Swamy C. Basim

Dissertations

The study of Water Treatment Plant (WTP) residuals is of recent origin and very little information is available in literature regarding these residuals. These waste materials have high solids contents, even in the mechanically dewatered condition, making it difficult to handle. These, along with stringent environmental regulations have forced the water utilities to look for new disposal options for these residuals. For this purpose as well as for evaluating suitable options for the beneficial reuse of residuals, it is essential to characterize WTP residuals.

As the dewatered residuals are plastic, the researcher may be prompted to treat these materials as …


On Scheduling Input Queued Cell Switches, Shizhao Li May 1999

On Scheduling Input Queued Cell Switches, Shizhao Li

Dissertations

Output-queued switching, though is able to offer high throughput, guaranteed delay and fairness, lacks scalability owing to the speed up problem. Input-queued switching, on the other hand, is scalable, and is thus becoming an attractive alternative. This dissertation presents three approaches toward resolving the major problem encountered in input-queued switching that has prohibited the provision of quality of service guarantees.

First, we proposed a maximum size matching based algorithm, referred to as min-max fair input queueing (MFIQ), which minimizes the additional delay caused by back pressure, and at the same time provides fair service among competing sessions. Like any maximum …


On-Line State And Parameter Estimation In Nonlinear Systems, David A. Haessig May 1999

On-Line State And Parameter Estimation In Nonlinear Systems, David A. Haessig

Dissertations

On-line, simultaneous state and parameters estimation in deterministic, nonlinear dynamic systems of known structure is the problem considered. Available methods are few and fall short of user needs in that they are difficult to apply, their applicability is restricted to limited classes of systems, and for some, conditions guaranteeing their convergence don't exist.

The new methods developed herein are placed into two categories: those that involve the use of Riccati equations, and those that do not. Two of the new methods do not use Riccati equations, and each is considered to be a different extension of Friedland' s parameter observer …


Optimization Of Urban Traffic Control Strategies By A Network Design Model, Wu Sun May 1999

Optimization Of Urban Traffic Control Strategies By A Network Design Model, Wu Sun

Dissertations

The efficiency of congested urban transportation networks can be improved by implementing appropriate traffic control strategies, such as signal control timing, turning movement control; implementation of one-way traffic policies, lane distribution controls etc.. In this dissertation, the following strategies are addressed: 1) Intersection left turn addition/deletion, 2) Lane designation,. and 3) Signal optimization.

The analogy between the network design problem (NDP) and the optimization of traffic control strategies motivated the formulation of an urban transportation network design problem (UTNDP) to optimize traffic control strategies. An UTNDP is a typical bi-level programming program, where the lower level problem is a User …


Development Of Computer Model And Expert System For Pneumatic Fracturing Of Geologic Formations, Brian Michael Sielski May 1999

Development Of Computer Model And Expert System For Pneumatic Fracturing Of Geologic Formations, Brian Michael Sielski

Dissertations

The objective of this study was the development of a new computer program called PF-Model to analyze pneumatic fracturing of geologic formations. Pneumatic fracturing is an in situ remediation process that involves injecting high pressure gas into soil or rock matrices to enhance permeability, as well as to introduce liquid and solid amendments. PF-Model has two principal components: (1) Site Screening, which heuristically evaluates sites with regard to process applicability; and (2) System Design, which uses the numerical solution of a coupled algorithm to generate preliminary design parameters.

Designed as an expert system, the Site Screening component is a high …


Fdtd-Based Full Wave Co-Simulation Model For Hybrid Electromagnetic Systems, Tong Li May 1999

Fdtd-Based Full Wave Co-Simulation Model For Hybrid Electromagnetic Systems, Tong Li

Dissertations

In high-frequency ranges, the present electronic design automation software has limited capabilities to model electromagnetic (EM) systems where there are strong field effects influencing their characteristics. In this situation, a full-wave simulation tool is desired for the analysis and design of high-speed and non-linear EM systems. It is necessary to explore the interaction between the field and electronic components during a transient process when field effects are more significant. The finite-difference time-domain (FDTD) technique receives growing attention in the area of EM system analysis and simulation due to its simplicity, flexibility and robustness. It is a full-wave simulation method that …


Observers For Discrete-Time Nonlinear Systems, Walter D. Grossman May 1999

Observers For Discrete-Time Nonlinear Systems, Walter D. Grossman

Dissertations

Observer synthesis for discrete-time nonlinear systems with special applications to parameter estimation is analyzed. Two new types of observers are developed. The first new observer is an adaptation of the Friedland continuous-time parameter estimator to discrete-time systems. The second observer is an adaptation of the continuous-time Gauthier observer to discrete-time systems. By adapting these observers to discrete-time continuous-time parameter estimation problems which were formerly intractable become tractable.

In addition to the two newly developed observers, two observers already described in the literature are analyzed and deficiencies with respect to noise rejection are demonstrated. improved versions of these observers are proposed …


Study Of Reactive Media For Chromium Removal From Groundwater By Permeable Barriers, Hemant S. Desai May 1999

Study Of Reactive Media For Chromium Removal From Groundwater By Permeable Barriers, Hemant S. Desai

Theses

The purpose of the study was to select reduction media for application in permeable barriers for removing chromate ions from groundwater emanating from chromium refining sites in New Jersey. The high pH condition of groundwater in such sites is expected to pose limitations on the use of metallic iron (Fe0) as the sole reductive medium.

Reasonable reduction kinetics was achieved using iron at pH < 9.2. Several pH lowering media were investigated and were found to have either very slow or very fast dissolution kinetics, which rendered them impractical for use in passive permeable barriers. Two other media, namely: pyrite and siderite minerals have shown promising results, but fell short of achieving the required performance. Detailed investigation of interfacial processes in a batch reactor have shown that the addition of a small amount of a neutral salt can significantly improve chromate reduction kinetics, even at high pH conditions around 10.9.

The formation of passivating layers, which can slowdown the reaction significantly, was found to be important at high pH conditions. It is recommended that an injection system be used with the reactive barrier to …


Development Of Icejet Machining Technology, Dimitri V. Shishkin May 1999

Development Of Icejet Machining Technology, Dimitri V. Shishkin

Theses

This work was concerned with the application of ice powder for material processing. Material cutting and surface cleaning were also studied. As a result, innovative cleaning and etching technology was pioneered. The corresponding technology was designed and demonstrated.

The study involved investigation of water freezing, crushing of generated ice, ice transportation, formation of ice water and ice air streams and, finally, use of this stream for material cutting and cleaning. The theoretical work included investigation of the phase change in water and ice formation, effect of ice temperature on particles behavior and entrainment of ice particles by the water stream. …


Multi-Lifecycle Assessment Design Tools And Software Development, Ji Jin May 1999

Multi-Lifecycle Assessment Design Tools And Software Development, Ji Jin

Theses

This thesis introduces the concept of Multi-lifecycles and a Multi-lifecycle assessment (MLCA) methodology for evaluating the energy consumption and environmental emissions of a product. MLCA quantifies materials, energy, and environmental burdens associated with end-of-life options, as well as obtains the value of returning parts and materials back to use, through demanufacturing, reengineering and remanufacturing.

A Multi-lifecycle Assessment software is developed as a tool to implement MLCA methodologies. By this software, one can practice a full life-cycle analysis on a product, or compare the environmental impacts of different products. Detailed designs on MLCA software including the databases, user interfaces, and algorithm …


In Situ Enhancement Of Well Recovery By Pneumatic Media Injection, Michael Thomas Galbraith May 1999

In Situ Enhancement Of Well Recovery By Pneumatic Media Injection, Michael Thomas Galbraith

Theses

The objective of this thesis was to develop a new process for enhancing recovery wells at hazardous waste sites. The process, known as an extended radius well (ERW), involves injection of ceramic beads directly into groundwater plumes to create drainage paths for liquid contaminants. This is a variant of Pneumatic Fracturing, which is a patented in situ remediation process developed to increase permeability of soil and rock formations by injection of high pressure gas.

The research study comprised laboratory investigations, engineering scale tests, and a field pilot demonstration. The laboratory investigations examined the properties of several candidate media to determine …