Engineering Commons^™

Agent Jurisprudence, Michael N. Huhns, Munindar P. Singh

Faculty Publications

The agent metaphor comes packaged with a number of powerful abstractions. Some of these are psychological, such as beliefs, knowledge, and intentions-abstractions that were traditionally studied in AI. However, there are a number of other abstractions that the agent metaphor brings to the fore. Of these, one has been emphasizing the social abstractions. Close cousins of the social abstractions are the ethical and legal abstractions. These too are being recognized as increasingly important in developing agents that are not only sociable, but also well behaved.

Macros By Example In A Graphical Uims, Dan R. Olsen Jr., Jonathan Turner, Stephen Bart Wood, John R. Dance

Faculty Publications

A macro facility that allows end users to extend interactive graphical applications is presented as part of a user-interface management system (UIMS). Such macros are expressed by example; that is, the end user programs the macro in the application's generated user interface. Problems with macros-by-example in graphical applications are explored, and requirements to accommodate such a facility are defined for the UIMS dialogue model. Existing UIMS models are reviewed relative to these requirements, and the unique facilities of the MIKE (menu interaction kontrol environment) semantics-based model are presented. The implementation of the macro-by-example system is discussed, as well as the …

Evaluation Of Ch4/Nox Reduced Mechanisms Used For Modeling Lean Premixed Turbulent Combustion Of Natural Gas, Hemant P. Mallampalli, Thomas H. Fletcher, J Y. Chen

Faculty Publications

This study has identified useful reduced kinetic schemes that can be used in comprehensive multi-dimensional gas-turbine combustor models. Reduced mechanisms lessen computational cost and possess the capability to accurately predict the overall flame structure, including gas temperatures and key intermediate species such as CH₄, CO and NO_x. In this study, four-new global mechanisms with 5, 6, 7, and 9 steps based on the full GRI 2.11 mechanism, were developed and evaluated for their potential to model natural-gas chemistry (including NO_x chemistry) in gas turbine combustors. These new reduced mechanisms were optimized to model the high …

Modeling Soot Derived From Pulverized Coal, Alexander L. Brown, Thomas H. Fletcher

Faculty Publications

A semiempirical model has been developed for predicting coal-derived soot. The main feature of the model is a transport equation for soot mass fraction. Tar prediction options include either an empirical or a transport equation approach, which directly impacts the source term for soot formation. Also, the number of soot particles per unit mass of gas may be calculated using either a transport equation or an assumed average. Kinetics are based on Arrhenius rates taken from published measurements. Radiative properties are calculated as a function of averaged optical constants, predicted gas temperatures, predicted gas densities, and the soot mass fractions. …

Nitrogen Transformations In Coal During Pyrolysis, Simon R. Kelemen, Martin L. Gorbaty, P J. Kwiatek, Thomas H. Fletcher, Mathew Watt, Mark S. Solum, Ronald J. Pugmire

Faculty Publications

X-ray photoelectron spectroscopy (XPS) was used to identify and quantify the changes in organically bound nitrogen forms present in the tars and chars of coals after pyrolysis. For fresh coal, pyrrolic nitrogen is the most abundant form of organically bound nitrogen, followed by pyridinic, quaternary, and amino types. Some of the quaternary nitrogen species initially present in coal are lost upon mild pyrolysis, prior to hydrocarbon devolatilization. These quaternary species are attributed to pyridinic or basic nitrogen species associated with hydroxyl groups from carboxylic acids or phenols. A portion of the quaternary nitrogen species is lost at the very earliest …

Statistical Continuum Theory For Inelastic Behavior Of A Two-Phase Medium, Brent L. Adams, H. Garmestani, S. Lin

Faculty Publications

This work was supported in part (B.L. Adams) by the MRSEC Program of the National Science Foundation under Award no. DMR-9632556. Further support was provided by the Center for Materials Research and Technology (MARTECH at FSU) and Center for Nonlinear and Nonequilibrium Sciences (CENNAS at FAMU). A statistical contiuum mechanics formulation is presented to predict the inelastic behavior of a medium consisting of two isotropic phases. The phase distribution and morphology are represented by a two-point probability function. The isotropic behavior of the single phase medium is represented by a power law relationship between the strain rate and the resolved …

Nonlinear Optimal Control Of A Hydraulically Actuated Positioning System, Timothy Mclain, Randal W. Beard

Faculty Publications

In this paper, the nonlinear optimal control problem is formulated for the position control of an electrohydraulic servo system. The optimal control is given by the solution to the Hamilton-Jacobi-Bellman equation, which in this case cannot be solved explicitly. An alternative method, based upon successive Galerkin approximation, is used to obtain an approximate optimal solution. Preliminary simulation results, demonstrating the application of this approach to the position control of a hydraulically actuated device, are presented.

Robotic Tcf And Rigid-Body Calibration Methods, Edward Red, Xuguang Wang

Faculty Publications

For off-line programming to work, systematic methods must be developed to account for non-ideal performance of the parts and devices in the manufacturing cell. Although much of the literature focuses on robot inaccuracy, this paper considers practical methods for the tool control frame (TCF) calibration and rigid-body compensation required to close the inverse kinematics loop for target driven tasks.

Extracting The Relative Grain Boundary Free Energy And Mobility Functions From The Geometry Of Microstructures, Brent L. Adams, D. Kinderlehrer, W. W. Mullins, Anthony D. Rollett, Shlomo Ta'asan

Faculty Publications

This work was supported primarily by the MRSEC Program of the National Science Foundation under Award Number DMR-9632556. This paper describes a method for extracting, from measurements of a polycrystal, the relative excess free energy and the relative mobility of the grain boundaries as functions of the crystallographic type (five degrees of freedom) and relevant thermodynamic variables. The method requires the simultaneous measurement of both the geometry and the crystallography of a large number of grain boundary intersections; the crystallographic information may be obtained from orientation imaging microscopy (OIM). For simplicity, the intersections will be assumed to be triple junctions …

Electrode Performance Test On Single Ceramic Fuel Cells Using As Electrolyte Sr‐ And Mg‐Doped Lagao3, Kevin Huang, Man Feng, John B. Goodenough, Christopher Milliken

Faculty Publications

The electrode performance of a single solid oxide fuel cell was evaluated using a 500 μm thick La_0.9Sr_0.1Ga_0.8Mg_0.2O_2.85 (LSGM) as the electrolyte membrane. Comparison of La_0.6Sr_0.4CoO_3-δ (LSCo) and La_0.9Sr_0.1MnO₃ (LSM) as cathodes showed LSCo gave an exchange current density two orders of magnitude higher than that of LSM. Comparison of CeO₂/Ni and LSGM/Ni as anodes showed a degradation of the latter with time, and studies of the anode‐electrolyte interface and the reactivity of NiO and LSGM suggest better anode …

A Novel Laboratory Course On Advanced Chemical Engineering Experiments, Jochen A. Lauterbach, S. White, X. Lui, G. M. Bodner, W. N. Delgass

Faculty Publications

The chemical engineering curriculum in the United States has trained generations of technical experts who have successfully optimized chemical processes and products once they entered the chemical industry. The U.S. chemical industry, however, has entered a critical stage in which it must be able to create new and differentiated value through technical innovations that arc essential for long-term survival. This innovation process will require new skills that go far beyond the traditional expertise for the optimization of tasks possessed by young chemical engineers. The innovators must be able to identify new opportunities, explore the boundaries of technology, evaluate critical issues, …

Focused Graduate Education: An Invisible But Real Competitive Edge, Roland D. Kankey, Jan P. Muczyk, Neal M. Ely

Faculty Publications

The future mission of the Air Force will be diverse and complex. Advanced technology will play an increasingly prominent role; a smaller force must accomplish more. To support this mission, our acquisition corps must be intellectually capable, well educated and trained. Focused graduate education will be essential to sustain this effort.

Azimuthal Modulation Of C-Band Scatterometer Over Southern Ocean Sea Ice, David G. Long, David S. Early

Faculty Publications

In a continuing evaluation of the ERS-1 C-band scatterometer as a tool for studying polar sea ice, the authors evaluate the azimuthal modulation characteristics of Antarctic sea ice. ERS-1 AMI scatterometer mode data sets from several study regions dispersed in the Antarctic seasonal sea ice pack are evaluated for azimuthal modulation. When appropriate, the incidence angle dependence is estimated and removed in a study region before determining whether azimuthal modulation is present in the data. Other comparisons are made using the fore and aft beam measurement difference. The results show that over the ice pack, azimuthal modulation is less than …

Local Refinement Of Three-Dimensional Finite Element Meshes, M. L. Staten, Norman L. Jones

Faculty Publications

Mesh refinement is an important tool for editing finite element meshes in order to increase the accuracy of the solution. Refinement is performed in an iterative procedure in which a solution is found, error estimates are calculated, and elements in regions of high error are refined. This process is repeated until the desired accuracy is obtained.

Much research has been done on mesh refinement. Research has been focused on two-dimensional meshes and three-dimensional tetrahedral meshes ([1] Ning et al. (1993) Finite Elements in Analysis and Design, 13, 299–318; [2] Rivara, M. (1991) …

Singular And Plural Non-Deterministic Parameters, Sigurd Meldal, M. A. Walicki

Faculty Publications

The article defines algebraic semantics of singular (call-time-choice) and plural (run-time-choice) nondeterministic parameter passing and presents a specification language in which operations with both kinds of parameters can be defined simultaneously. Sound and complete calculi for both semantics are introduced. We study the relations between the two semantics and point out that axioms for operations with plural arguments may be considered as axiom schemata for operations with singular arguments.

A Unified Green's Function Analysis Of Complicated Dfb Lasers, Jim D. Freeze, Michael A. Jensen, Richard H. Selfridge

Faculty Publications

An efficient full-wave analysis technique for one-dimensional optical domains, known as the recursive Green's function method (RGFM), is presented for evaluation of distributed feedback (DFB) laser cavities with arbitrary material profiles. The method first constructs the Green's function of an inhomogeneous domain and subsequently uses Green's theorem to determine the laser optical field, lasing wavelength, and threshold gain. The technique is applied to investigate the performance of three DFB laser structures: a chirped-grating configuration, a modulated stripe width design, and a reduced duty cycle complex-coupled device. These structures are evaluated in terms of their single-mode lasing behavior and the uniformity …

Effect Of Temperature On Wetting Angle, Guna S. Selvaduray, R. Brindos

Faculty Publications

No abstract provided.

Predicting The Viscosity Of Alkanes Using Nonequilibrium Molecular Dynamics: Evaluation Of Intermolecular Potential Models, Richard L. Rowley, William Allen

Faculty Publications

Nonequilibrium molecular dynamics (NEMD) viscosity simulations of branched and linear alkanes at liquid densities were performed using both united-atom (UA) and all-atom (AA) intermolecular potential models in order to study the relative efficacy of the models in predicting fluid viscosity. Both models were used in conjunction with fixed bond lengths and bond angles, but different torsional potentials were investigated. The commonly used Ryckaert—Bellemans intermolecular potential model, which accurately predicts viscosities for short straight-chain alkanes, produced values for branched and long-chain alkanes that were significantly below experimental values. Likewise, a more complex UA model that uses transferrable site potentials and is …

An Ontology Tool For Distributed Information Environments, Kuhanandha Mahalingam, Michael N. Huhns

Faculty Publications

This paper describes how ontologies can be used for query formulation and semantic reconciliation in large distributed information environments. It presents a tool, written in Java, that can be used to create and browse ontologies, and construct ontology-based queries. The tool incorporates several abstraction mechanisms that enable users to manage large ontologies, which are typical of large information environments. The tool is being applied to an information system for healthcare administrators, which spans hospitals, clinics, and governmental health departments.

Secondary Dark Rings Of Internal Conical Refraction, Karl F. Warnick, David V. Arnold

Faculty Publications

This paper treats the phenomenon of internal conical refraction, in which a narrow beam propagating along an optical axis of a biaxial anisotropic medium spreads into a hollow cone. An expression is obtained for the intensity distribution produced by conical refraction that predicts additional fringes concentric to the well known Poggendorf dark ring for certain propagation distances and beam widths.

On-Line Cartesian Trajectory Control Of Mechanisms Along Complex Curves, Edward Red, Zhaoxue Yang

Faculty Publications

New methods have been developed to control a mechanism's realtime Cartesian motion along spatially complex curves such as Non-Uniform Rational B-splines (NURBS). The methods dynamically map the critical trajectory parameters between parameter space, Cartesian space, and joint space. Trajectory models that relate Cartesian tool speeds and accelerations to joint speeds and accelerations have been generalized so that they can be applied to most classes of robots and CNC mechanisms.

Teaching Electromagnetic Field Theory Using Differential Forms, Karl F. Warnick, Richard H. Selfridge, David V. Arnold

Faculty Publications

The calculus of differential forms has significant advantages over traditional methods as a tool for teaching electromagnetic (EM) field theory. First, films clarify the relationship between field intensity and flux density, by providing distinct mathematical and graphical representations for the two types of fields. Second, Ampere's and Faraday's laws obtain graphical representations that are as intuitive as the representation of Gauss's law. Third, the vector Stokes theorem and the divergence theorem become special cases of a single relationship that is easier for the student to remember, apply, and visualize than their vector formulations. Fourth, computational simplifications result from the use …

Effects Of Monomer Structure Ontheir Organization And Polymerizationin A Smectic Liquid Crystal, C. Allan Guymon, Erik N. Hoggan, Noal A. Clark, Thomas P. Rieker, David M. Walba, Christopher N. Bowman

Faculty Publications

Photopolymerizable diacrylate monomers dissolved in fluid-layer smectic A and smectic C liquid crystal (LC) hosts exhibited significant spatial segregation and orientation that depend strongly on monomer structure. Small, flexible monomers such as 1,6-hexanediol diacrylate (HDDA) oriented parallel to the smectic layers and intercalated, whereas rod-shaped mesogen-like monomers such as 1,4-di-(4-(6-acryloyloxyhexyloxy)benzoyloxy)-2-methylbenzene (C6M) oriented normal to the smectic layers and collected within them. Such spatial segregation caused by the smectic layering dramatically enhanced photopolymerization rates; for HDDA, termination rates were reduced, whereas for C6M, both the termination and propagation rates were increased. These polymerization precursor structures suggest novel materials-design paradigms for gel …

Analytical Models For Vehicle/Gap Distribution On Automated Highway Systems, Jacob Tsao, Randolph W. Hall, Indrajit Chatterjee

Faculty Publications

Highway congestion has in recent years become a pervasive problem for urban and suburban areas alike. The concept of Automated Highway Systems is based on the belief that integration of sensing, communication, and control technologies into vehicles and highways can lead to a large improvement in capacity and safety without requiring a significant amount of additional highway right-of-way. A fundamental determinant of Automated Highway Systems capacity is the vehicle-following rule, the rule that governs the behavior of vehicles traveling along a common lane (e.g., the spacing between any two longitudinally adjacent vehicles). Vehicle following affects the longitudinal capacity (achievable flow …

Multilevel Block Coded Modulation With Unequal Error Protection, Robert H. Morelos-Zaragoza, Marc P. C. Fossorier, Shu Lin, Hideki Imai

Faculty Publications

Multilevel block coded modulation (BCM) schemes with unequal error protection (UEP) are investigated. These schemes are based on unconventional set partitions that greatly reduce the error coefficients associated with multi-stage decoding of conventional BCM, at the expense of smaller intra-set distances.

Concatenated Multilevel Coded Modulation Schemes For Digital Satellite Broadcasting, Robert H. Morelos-Zaragoza, Hideki Imai

Faculty Publications

The error performance of bandwith-efficient concatenated multilevel coded modulation (MCM) schemes for digital satellite broadcasting is analyzed. Nonstandard partitioning, multistage decoding, and outer Reed-Solomon (RS) codes are employed to provided unequal error protection capabilities.

Chemical Stability Study Of Bace0.9Nd0.1O3−Α High Temperature Proton-Conducting Ceramic, Fanglin Chen, O. Toft Sorensen, Guangyao Meng, Dingkum Peng

Faculty Publications

BaCe_0.9Nd_0.1O_3−a (BCN) ceramic is known to be an excellent high-temperature proton conductor and is a candidate electrolyte for use in solid oxide fuel cells, hydrogen or steam sensors and steam electrolysers. In this work, the chemical stability of BCN was investigated systematically by combining XRD and DTA–TG techniques to study its processing compatibility and its feasibility in potential applications. It was found that above 1200 °C, BCN reacted with alumina or zirconia, leading to the loss of barium and an excess of cerium. In cold water, both sintered BCN disks and powder samples had very …

Ellipsometric And Raman Spectroscopic Study Of Thermally Formed Films On Titanium, E. Hristova, Lj. Arsov, Branko N. Popov, Ralph E. White

Faculty Publications

Thermal films on titanium surfaces were formed by heating titanium samples in air at atmospheric pressure. The optical constants, thickness, and structure of the formed films at various temperatures and times of heating were investigated by ellipsometry and Raman spectroscopy. The complex index of refraction and the thickness of generated films were determined by comparing the experimental loci and obtained by ellipsometric measurements with theoretical computed vs. curves. It was found that the thickness in homogeneity and porosity of formed films increase with increasing temperature and the duration of the thermal treatment. Beyond a certain critical temperature, the appearance of …

The Effects Of Organic Compounds On Inhibition Of Hydrogen Permeation Through A Mild Steel Membrane, H. A. Duarte, D. M. See, Branko N. Popov, Ralph E. White

Faculty Publications

The effectiveness of 5-(4-pyridyl)-2,7-nonadiene, and 1 phenyl-2-propyn-ol (PP) on inhibition of the hydrogen evolution reaction on a 1010 steel membrane and on the degree of hydrogen ingress into the membrane was determined. Hydrogen evolution rates and permeation currents were monitored as a function of time at different applied potentials. In the presence of 0.5 g/liter PP in the electrolyte, the hydrogen discharge and permeation current density were inhibited by 98 and95%, respectively.

The Agent Test, Michael N. Huhns, Munindar P. Singh

Faculty Publications

The authors consider agents on the World Wide Web, including information retrieval agents. They propose a test for agenthood, involving communication in multi-agent systems.