Engineering Commons^™

Decentralized Optimal Control With Application To Dynamic Routing In Computer Communication Networks, Ning Wang

Dissertations

This research considers the dynamic routing problem of computer communication networks in the framework of decentralized control theory. The routing dynamics are modeled in terms of a state equation with multiple controllers. Routing, or control of message flow, is formulated as an optimal control problem with multiple decision makers. Each decision maker may have access to different set of information and work cooperatively to optimize a common system performance index.

Necessary and sufficient conditions for optimality are derived for a system with a deterministic and a stochastic traffic patterns under a linear information structure and a quadratic performance index. The …

Lateral Coherence Of Aerosol-Scattered Laser Radiation, Donald D. Duncan, D. E. Larch

Electrical and Computer Engineering Faculty Publications and Presentations

To assess the probability of detection (by interferometric techniques) of illumination by a coherent source, we characterize the lateral coherence of the off-axis aerosol scattered radiation by applying the van Cittert-Zernike theorem. We find that, for 1.061-pm radiation at a target range of 1 km, the scattered radiation beyond 3.5 cm off axis does not display appreciable lateral coherence.

Modeling Of Purge Valve Closure, William W. Durgin, Benito Zannini

Office of the Provost Scholarship

In some nuclear reactor containment isolation applications, butterfly valves with pneumatic actuators are used to close pipelines in the event of containment pressure transients resulting from postulated accidents. A model is developed which predicts the closure time history of such valve/actuator systems under prescribed transients. Examples are presented which show the importance of the valve and actuator characteristics. It was found that actuation delays of sufficient magnitude could allow the dynamic torque to exceed the available actuator torque, thus preventing valve closure.

Estimating Particle Sizes, Concentrations, And Total Mass Of Ash In Volcanic Clouds Using Weather Radar, David M. Harris, William I. Rose

Department of Geological and Mining Engineering and Sciences Publications

Observations of the March 19, 1982 ash eruption of Mount St. Helens, made by the National Weather Service (NWS, Portland, Oregon) on 5-cm radar, were used to estimate the volume of the ash cloud (2000 ±500 km³), the concentration of ash (0.2–0.6 g m⁻³). and the total mass of ash erupted (3–10×10¹¹ g). The position of the cloud was also tracked by radar. Particle sizes in the ash cloud were estimated from settling velocities suggested by decreases in maximum ash cloud height with time as it moved away from the volcano. The March 19, 1982 …

Ground- And Excited-State Properties Of Solid Argon Under Pressure, Richard Alan Lesar

Richard Alan Lesar

A self-consistent perturbation model for calculating the ground- and excited-state electronic properties of molecular and rare-gas crystals is presented. A tight-binding approximation is used, in which the effects of the crystal potential, calculated with local-density functionals, are included as a perturbation on the molecules (or atoms). The molecular (atomic) wave functions are then computed from standard Hartree-Fock theory. For the case of solid argon under pressure, a decrease in atomic volume causes a gain in free energy, which is partially balanced by the energy required to compress the atom. Calculated exciton energies for Ar disagree by only 2.5% with experimental …

Pseudo-Brewster And Second-Brewster Angles Of An Absorbing Substrate Coated By A Transparent Thin Film, R. M.A. Azzam, T F. Thonn

Electrical Engineering Faculty Publications

The pseudo-Brewster angle of minimum reflectance for the p polarization, the corresponding angle for thes polarization, and the second-Brewster angle of minimum ratio of the p and s reflectances are all determined as functions of the thickness of a transparent film coating an absorbing substrate by numerical solution of the exact equations that govern such angles of the form Re(Z′/Z) = 0, where Z = R_p, R_s, or ρ represent the complex amplitude-reflection coefficients for the p and s polarizations and their ratio (ρ =R_p/R_s), …

Sun Position In Florida, Florida Solar Energy Center, Ross Mccluney

FSEC Energy Research Center®

Described herein is a procedure for determining the path of the sun through the Florida sky relative to a solar collector array, a window, a skylight or an entire building - information needed by architects, engineers and others for shading and orientation calculations involved in active and passive building design. It can be used for positioning exterior shading devices for maximum benefit. This information can also be used to pinpoint solar collector shading problems.

Open-Cycle Ocean Thermal Energy Conversion, Florida Solar Energy Center, Magdy Girgis

FSEC Energy Research Center®

In May 1983 the Florida Solar Energy Center(FSEC) received $ 328,000 from the federal Solar Energy Research Institute in Colorado to determine the feasibility of an Open-Cycle Ocean Thermal Energy Conversion (OTEC) concept. The objective of the project is to assess the economic and technological viability of the conceptual design of an Open Cycle OTEC power plant. FSEC and Create R&D Inc., Hanover, New Hampshire, bring together complementary skills and experience in resource assessment, component design, system engineering and project management. FSEC also will study possible sites for an OTEC plant in Florida as part of a complementary project funded …

Centers Of Polymer Research; Polymer Science In Northeastern Japan, Otto Vogl, T. Yamaguchi

Emeritus Faculty Author Gallery

No abstract provided.

An Experimental Study Of Temperature Separation In Swirling Flow, Hiromoto Kuroda

Doctoral Dissertations

The objective of the present investigation is to substantiate the mechanism of acoustic streaming; this was carried out by conducting detailed internal surveys of a Ranque-Hilsch swirling flow test rig at the condition when the vortex whistle was attenuated or excited. This control of the vortex whistle was accomplished by two methods.

In the first method where the vortex whistle was attenuated by placing a restriction at the exhaust, a Rankine vortex was observed to form, accompanied by an almost uniform total temperature distribution in the radial direction except for a dip near the vortex core; when the vortex whistle …

Photodetachment As A Control Mechanism For Diffuse Discharge Switches, Gerhard Schaefer, P. F. Williams, Karl H. Schoenbach, John T. Moseley

P. F. (Paul Frazer) Williams Publications

Photodetachment is considered as a control mechanism for diffuse discharge switches. Experiments have been performed on photodetachment of ions in the flowing afterglow of a dc glow discharge in oxygen. Experiments with different laser wavelengths and the dependence of the optogalvanic signal on the laser energy flux indicate that 0^- is the dominant negative ion. For an energy flux of 35 mJ/cm², 50 percent of the 0^- ions can be photodetached.

Acuta Enews December 1983, Vol. 12, No. 12

ACUTA Newsletters

In This Issue

PRESIDENT'S MESSAGE

TRIVIA

BITS & PIECES

INNOVATIVE COMMUNICATIONS SYSTEM OUTS F.I.T. IN FRONT

A QUANTUM LEAP FOR COMMUNICATIONS

Polarizability And Quadrupole Moment Of A Hydrogen Molecule In A Spheroidal Box, Richard Alan Lesar, D. R. Herschbach

Richard Alan Lesar

The polarizability and quadrupole moment of a hydrogen molecule enclosed within an infinite-walled spheroidal box are calculated as functions of the hox size, for a range corresponding to nominal pressures up to lo5 kbar. A five-term James and Coolidge variational wave function is employed and the Kirkwood approximation is used for the polarizability. Comparison is made with similar calculations for the H2+ molecule-ion and the II atom, and also with recent density-functional calculations. The box model proves to greatly exaggerate the compression of the H2 bond with pressure but nonetheless yields a realistic correlation of vibrational frequency with internuclear distance. …

Centers Of Polymer Research; Polymer Science In Northeastern Japan, Otto Vogl, T. Yamaguchi

Otto Vogl

No abstract provided.

Laterally Unsupported Purlins Subjected To Uplift, Roger A. Laboube

CCFSS Library (1939 - present)

INTRODUCTION A research study, conducted at Cornell University, provided a theoretical method for evaluating the state of stress for both C- and Z- purlins subjected to wind uplift loading. According to the Cornell analytical method, a Z-purlin has more load carrying capability than a similar C-purlin. Although experimental verification was provided, questions were raised, within the Metal Building Industry, regarding the strength of the C-versus the Z-section. The purpose of the work discussed herein was to develop information regarding the behavior of C- and Z-sections having identical cross-section dimensions. A brief description of the test program, along with a comparison …

Testing Of Steel Roof Deck Construction, Wei-Wen Yu, Lan-Cheng Pan, S. H. Lin

CCFSS Library (1939 - present)

INTRODUCTION In recent years, insulated steel roof deck construction has been widely used in industrial and commercial buildings. The use of roof assembly consisting of 3-in. deep, 22-gage, steel deck is being considered by Rooftex, Inc. of Houston, Texas, for Class 1-60 and Class 1-90 assemblies. At the request of Rooftex, two types of tests were conducted at the University of Missouri-Rolla in July 1983. These tests, which consisted of physical tests of steel roof decks and uplift pressure tests of insulated steel roof deck construction, were conducted to obtain the"necessary data for the approval of the Factory Mutual Research …

Ads Formal Semantics, Takayuki Kimura

All Computer Science and Engineering Research

Abstract Database System (ADS) is a data model developed for an enduring medical information system where frequent changes in the conceptual schema are anticipated and multi-level abstraction is required. The mechanism of abstraction in ADS is based on the abstraction operator of the lamba calculus. The formal semantics of a subset of the ADS model is presented using the denotational specification method.

The Effects Of Certain Impurities And Their Interactions On Zinc Electrowinning, Donald R. Fosnacht, Thomas J. O'Keefe

Materials Science and Engineering Faculty Research & Creative Works

The effects of germanium, antimony, arsenic, cobalt, glue, and free acid concentration were studied on both commercial and synthetic electrolytes. The effects of a single factor and the combined effects of multiple factors were elucidated. The temperature, zinc concentration, and current density were varied for some of the tests. It was found that the acid content was the most critical factor when impurity levels were at normal plant solution concentrations. The ranges where the effect of the impurity became apparent were: greater than 20 ppb (parts per billion) for antimony; 40 ppb for germanium; 120 ppb for arsenic; and 7 …

Stochastic Estimation Applied To The Land Speed Of Sound Record Attempt By A Rocket Car, David A. Reinholz

Theses and Dissertations

Optimal linear smoothing theory is applied to the data from the Speed of Sound record attempt of a three-wheeled rocket car on 17 December 1979. A forward-backward estimation method is used which employs a seven state forward-running extended Kalman filter and a Meditch-form backward recursive 'fixed-interval' smoothing algorithm. Data for this analysis is supplied by a longitudinal accelerometer mounted on the vehicle and tracking radar measurements of range, azimuth, and elevation. States of interest include two components of vehicle position and velocity, accelerometer time-correlated error, and radar range and azimuth bias errors. Two iterations of the forward-backward smoothing algorithm provide …

Solar Air Heaters For On-Farm Crop Drying: Case Studies, Alvin Ray Womac

Masters Theses

Three types of suspended plate solar air heaters were installed on farms in Tennessee to supply heat for grain and crop drying. A wrap-around solar air heater was constructed on a row crop farm in West Tennessee and used to dry 210 m³ (6000 bu) of corn during Fall 1982 and 105 m³ (3000 bu) of wheat during Spring 1983. Three portable solar air heaters were installed on a row crop farm in Middle Tennessee and used to dry 800 m³ (23000 bu) of soybeans and 120 m³ (3500 bu) of corn during Fall 1982. A …

H & V News

Building Services Engineering

No abstract provided.

Two-Dimensional Computer Modeling Of Joints And Fractures In Continua, Royd R. Nelson

Theses and Dissertations

This thesis presents a numerical formulation which incorporates the effects of joints, cracks, and fractures into a mathematical mode used to in an existing finite element code. Two separate crack definitions were incorporated, one involving a discrete crack model, and the other a continuum approach defining a new material with regularly spaced joints. Several examples are also presented demonstrating the use of this capability.

Method And Apparatus For Making Aligned Flake Composite Wood Material Including Integral Baffles, Gordan P. Krueger, Anders E. Lund, Roy D. Adams

Michigan Tech Patents

A method and apparatus for forming a loosely felted mat of elongated wood flakes mixed with a binder, the mat including a longitudinal axis and the wood flakes being aligned in mutually parallel relation and parallel to the longitudinal axis of the mat. The wood flakes are held in alignment in the mat by a plurality of closely spaced thin planar baffles, the baffles being comprised of a material which can form an integral part of the mat.

Augmentation Of Free Surface Heat And Mass Transfer Due To Electrostatic Fields, Alan F. Smelewicz, Mark P. Majcher, James B. Nystrom, William W. Durgin

Office of the Provost Scholarship

Experiments were conducted to measure heat transfer rates and mass transfer rates from a water surface in the presence of electrostatic fields of various strengths generated between the water surface and a wire grid above the surface.

Heat transfer rates were determined by the temperature decay after heating the test and control basins. Mass transfer rates were determined by measuring the water loss while holding the basins at fixed temperatures.

It was found that very little increase in transfer coefficients took place for voltages below an onset voltage which depended on atmospheric conditions and test geometry. The heat transfer coefficient …

Centers Of Polymer Research; Polymer Science In Hokkaido, Japan, Otto Vogl, J. Sohma

Emeritus Faculty Author Gallery

No abstract provided.

Effect Of Refrigerant Charge And Condenser Temperature On The Operating Characteristics Of A Vapor-Compression Air Conditioning System, Ezzat Fikri Assaad

Archived Theses and Dissertations

No abstract provided.

Centers Of Polymer Research; Polymer Science In Hokkaido, Japan, Otto Vogl, J. Sohma

Otto Vogl

No abstract provided.

Photovoltaics: A Question And Answer Primer, Florida Solar Energy Center, Ingrid Melody

FSEC Energy Research Center®

Of all the solar energy technologies, photovoltaics (PV) show the greatest promise for worldwide acceptance and application. Their universal appeal lies in the fact that they generate electricity from the sun. Working photovoltaics have no moving parts, are relatively simple in design, need very little maintenance and are environmentally benign. They simply and silently produce electricity whenever they are exposed to light.

Limiting Efficiencies For Multiple Energy-Gap Quantum Devices, Cheng-Hsiao Wu, Richard M. Williams

Electrical and Computer Engineering Faculty Research & Creative Works

We have used a thermodynamic model to calculate theoretical limiting efficiencies for simple and multiple gap solar cells. The limiting efficiency is 26% for a simple solar cell of hydrogenated amorphous silicon, operating at one Sun sensitivity. For a multiple gap cell made from hydrogenated amorphous silicon, together with a second cell, made from a material with lower band gap, it is 38%. The optimum band gap for the second material is 1.0 eV.

H & V News

Building Services Engineering

No abstract provided.