Engineering Commons^™

Performance Evaluation Of A Traffic Control Mechanism For Atm Networks, Andreas D. Bovopoulos

All Computer Science and Engineering Research

Future ATM networks will be required to support a plethora of services, transaction types and cell sequence behaviors with performance guarantees. Before this goal can be realized, however, some basically problems related to bandwidth allocation and traffic control in the ATM layer must be resolve. Such problems will in all likelihood defy solution as long as they studied in isolation without a unifying traffic characterization and traffic control framework. This work presented in this paper is part of an ongoing effort directed at the development of an integrated traffic characterization and control infrastructure for ATM networks. In this paper a …

Set-Valued Filtering And Smoothing, Wynn C. Stirling, Darryl Morrell

Faculty Publications

A theory of discrete-time optimal filtering and smoothing based on convex sets of probability distributions is presented. Rather than propagating a single conditional distribution as does conventional Bayesian estimation, a convex set of conditional distributions is evolved. For linear Gaussian systems, the convex set can be generated by a set of Gaussian distributions with equal covariance with means in a convex region of state space. The conventional point-valued Kalman filter is generated to a set-valued Kalman filter consisting of equations of evolution of a convex set of conditional means and a conditional covariance. The resulting estimator is an exact solution …

Convex Bayes Decision Theory, Wynn C. Stirling, Darryl Morrell

Faculty Publications

The basic concepts of Levi's epistemic utility theory and credal convexity are presented. Epistemic utility, in addition to penalizing error as is done with traditional Bayesian decision methodology, permits a unit of informational value to be distributed among the hypotheses of a decision problem. Convex Bayes decision theory retains the conditioning structure of probability-based inference, but addresses many of the objections to Bayesian inference through relaxation of the requirement for numerically definite probabilities. The result is a decision methodology that stresses avoiding errors and seeks decisions that are likely to be highly informative as well as true. By relaxing the …

The Synthesis Of Patterns Using A Series-Fed Array Of Annular Sector Radiating Line (Anserlin) Elements: Low-Profile, Circularly Polarized Radiators, James L. Drewniak, P. E. Mayes

Electrical and Computer Engineering Faculty Research & Creative Works

A series-fed, circularly polarized array of annular sector radiating-line elements that operates over a ground plane and has a low profile is presented. Pattern shaping can be achieved through control of the fraction of the incident power that is radiated by each element. This can be accomplished over a wide range by a simple adjustment in the geometry of each element. A synthesis technique is given, and experimental results are presented. The array is demonstrated to have a high return loss (good impedance match) and a low axial ratio

Hybrid Wafer Scale Microcircuit Integration -- [ 4989063 ], Edward S. Kolesar Jr.

AFIT Patents

A wafer scale integration arrangement wherein integrated circuit die of varying size, fabrication processes, and function are commonly mounted in the same host wafer using a filled epoxy material of special characteristics. The mounting epoxy material also serves as a substrate for the die interconnecting conductors in regions adjacent the mounted die. The described assembly also includes a newly available photosensitive polyimide material as a planarization and passivation covering for the die and host wafer and as a mounting surface for an interconnecting metal conductor array. Multiple levels of interconnection metal. Fabrication processes for the die to host wafer attachment …

Lrfd Cold-Formed Steel Design Manual, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Simplified Cost Models For Prefeasibility Mineral Evaluations. U.S. Bureau Of Mines Information Circular 9298, 35, Thomas W. Camm

Mining Engineering

In this U.S. Bureau of Mines report, mine and mill cost models are presented to make quick estimates of the cost to develop mineral deposits in the desert region of the Southwest United States. Regression analysis was used to generate capital and operating cost equations for each model in the form Y = AXB, where Y is the cost estimated and X is the assumed daily capacity in short tons. A and B are constants determined by the regression analysis. Each is broken down into 11 subcategories to facilitate escalation of costs for inflation and to increase their versatility in …

The Use Of Expert Systems In Demand Forecasting, Edward Sweeney

Books/Book chapters

No abstract provided.

The Added Mass, Basset, And Viscous Drag Coefficients In Nondilute Bubbly Liquids Undergoing Small-Amplitude Oscillatory Motion, Ashok S. Sangani, D. Z. Zhang, A. Prosperetti

Biomedical and Chemical Engineering - All Scholarship

The motion of bubbles dispersed in a liquid when a small-amplitude oscillatory motion is imposed on the mixture is examined in the limit of small frequency and viscosity. Under these conditions, for bubbles with a stress-free surface, the motion can be described in terms of added mass and viscous force coefficients. For bubbles contaminated with surface-active impurities, the introduction of a further coeflicient to parametrize the Basset force is necessary. These coefficients are calculated numerically for random configurations of bubbles by solving the appropriate multibubble interaction problem exactly using a method of multipole expansion. Results obtained by averaging over several …

Web Crippling Behavior Of Sections With Web Openings, Wei-Wen Yu, James E. Langan, Roger A. Laboube

CCFSS Library (1939 - present)

No abstract provided.

Pthomas: An Adaptive Information Retrieval System On The Connection Machine., Robert Oddy, Bhaskaran Balakrishnan

School of Information Studies - Faculty Scholarship

This paper reports the state of development of PThomas, a network based document retrieval system implemented on a massively parallel fine-grained computer, the Connection Machine. The program is written in C*, an enhancement of the C programming language which exploits the parallelism of the Connection Machine. The system is based on Oddy’s original Thomas program, which was highly parallel in concept, and makes use of the Connection Machine’s single instruction multiple data (SIMD) processing capabilities. After an introduction to systems like Thomas, and their relationship to spreading activation and neural network models, the current state of PThomas is described, including …

Cadmium Adsorption On Iron Oxides In The Presence Of Alkaline-Earth Elements, Christina Cowan, John M. Zachara, Charles T. Resch

United States Department of Energy: Publications

Cadmium sorption on Fe₂O₃ • H₂O(am) in the presence of alkaline-earth cations was investigated with emphasis on the Cd-Ca binary system. In binary-element sorption experiments with Ca, Mg, Sr, and Ba, competition was observed primarily in Cd-Ca binary mixtures, which were studied at three ionic strengths (0.5, 0.1, and 0.005 M). The extent of competition increased with increasing Ca concentration. In single-element experiments changes in ionic strength (between 0.005 and 0.5 M) did not influence Cd sorption but did affect Ca sorption, implying that a portion of the Ca surface complexes were outer sphere. The …

Impacts Of Duct Leakage On Infiltration Rates, Space Conditioning Energy Use, And Peak Electrical Demand In Florida Homes, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

Testing for duct leakage was done in 91 homes. Tracer gas tests found that infiltration rates were four times greater when the air handler was operating than when it was off. Return leaks were found to average 10.0% of air handler total flow. House airtightness, in 63 of these homes, determined by blower door testing, averaged 12.38 air changes per hour at 50 Pascals (ACH50). When the duct registers were sealed, ACH50 decreased to 10.93, indicating that 11.7% of the house leaks were in the duct system.

Duct repairs were made on 25 homes. Blower door tests found 12.30 air …

Tailwater Recovery Demonstration Program Study, Doug Welch, Tim O'Halloran, Stuart Styles

BioResource and Agricultural Engineering

No abstract provided.

The Calendar - January 1991, Nova University

The Calendar

No abstract provided.

The Calendar - February 1991, Nova University

The Calendar

No abstract provided.

Subsidence Resulting From Multiple-Seam Longwall Mining In The Western United States - A Characterization Study, United States Department Of The Interior, Bureau Of Mines

Mines and Mineral Resources

This report details the investigation of multiple-seam longwall subsidence conducted by the U.S. Bureau of Mines from 1978 to 1989. A field investigation monitored ground surface movements over four upper-seam longwall panels and six lower-seam panels. The characteristics of the subsidence occurring as a result of mining these panels are examined; in particular, the angle of draw, subsidence development, total magnitude and areal extent, and critical width are evaluated and discussed. Comparisons are also made between the characteristics of multiple-seam longwall subsidence and single-seam longwall subsidence that occurred at the same site.

The Development Of A Concrete Interlocking Partition Walling Unit, Haldane L. Johnson

Graduate Student Work

This research aimed to develop a better method of erecting internal partition walls for the Jamaican housing industry. An interlocking concrete block wall unit was considered appropriate because it used local materials and required semi-skilled labor to erect.

A timber mold was made to manually produce the 4 x 4 x 8 inch block. The concrete mix used had a cement to aggregate ratio of 1:7.5 and a sand to gravel ratio of 1:2 and a water cement ratio of 0.753. The average compressive strength of the block determined after three days was 351.56 psi. This translates into an expected …

Content And Strategies For Teaching Computer-Aided Drafting, Kurt Henry Becker

Engineering Education Faculty Publications

No abstract provided.

Testing The Economic Order Quantity Model On Maintenance Inventory, Teresa J. K. Hall

Graduate Student Work

This pilot study seeks to determine the effect a non-traditional method of inventory control may have on industrial maintenance repair parts inventory. The application of mathematical models designed for production inventory to Maintenance, Repair and Operating (MRO) inventory has not been widely researched, although theorists and practitioners feel there is potential for some models. The Economic Order Quantity (EOQ) theory has proven to be effective in production inventory circles. This pilot study examined the effectiveness of the EOQ in terms of holding cost of the inventory and number of out-of-stock conditions versus the Weighted Moving Average method currently in use …

Osha Compliance By Small And Medium Business, Bill W. Trammell

Graduate Student Work

It is hypothesized that even though governmental rules, regulations, and policies along with ethical. social, and moral dictates within our communities now require, even demand, that businesses and industry provide their employees a healthful and safe working environment the opposite is often the case. There is a substantial number of employers, within the small to medium sized industrial manufacturers, whose chief executive officers: (1) fail to implement a safety program within their organization; (2) fail to provide more than token attention to employee safety and the intent of the OSHA regulations; (3) have no sincerity or intention to complying with …

Investigation Of Channel Degradation 1991 Update Missouri River Gavins Point Dam To Platte River Confluence

United States Army Corps of Engineers, Omaha District

1. PURPOSE. This report is the fifth in a series of updates to Volume IV, supporting Technical Report, Missouri River Degradation. Volume IV is a part of the August 1981 Review Report of the water and Related Land Resources Management study for Metropolitan Sioux city and Missouri River Iowa, Nebraska, and South Dakota. This report, along with future updates, will provide the information necessary for proper management of the Missouri River in reference to degradation.

2. SCOPE. This report incorporates water surface profile and hydrographic survey data from the 1989 and 1990 water years for the purpose of updating the …

Transformation Of 1-Aminonapththalene At The Surface Of Smectite Clays, Calvin C. Ainsworth, Bruce D. Mcveety, Steven C. Smith, John M. Zachara

United States Department of Energy: Publications

One-aminonaphthalene is sorbed onto the Na-saturated smectite clays, montmorillonite and hectorite, by cation exchange. In the presence of Fe³⁺ either in the clay structure or on the clay surface, sorption is followed by the formation of a blue-colored complex, with the continuous disappearance of aminonaphthalene from solution and the clay surface. The rate of aminonaphthalene disappearance decreases as pH increases. With time, four major products that appear to be structural isomers of N(4- aminonaphthyl)-1-naphthylamine are produced. A simplified model of this transformation is suggested to be the oxidation by Fe³⁺ of sorbed aminonaphthalene forming a radical cation-clay complex. …

Automating Tolerance Synthesis: A Framework And Tools, Stephen C.-Y. Lu, Robert G. Wilhelm

Department of Mechanical and Materials Engineering: Faculty Publications

This paper describes CASCADE-T—a new approach to tolerance synthesis that uses a complete representation of the conditional tolerance relations that exist between features of a part under design. Conditional tolerances are automatically determined from functional requirements and shape information. Tolerance primitives based on the virtual boundary requirements approach to tolerance representation are composed to form more complex tolerance relationships. Artificial intelligence techniques, including a constraint network, frame-based system, and dependency tracking are used to support flexible and detailed computation for tolerance analysis and synthesis.

Forming Fine Particles, Dennis R. Alexander

Department of Electrical and Computer Engineering: Faculty Publications

To alter feedstock material, the material is exposed to laser radiation applied at a selected angle of incidence, intensity and wavelength related to the refractive index of the feedstock material. Fine uniform particles may be formed through vapor explosion and/or plasma formation and used by this method to coat surfaces, such as with paint or adhesive or to suply uniform small particles to a heat engine. Moreover, moving materials such as a column of liquid may be subjected to high internal pressure and temperature for creating physical and chemical changes.

What To Look For And Why When Buying A Telecommunications Switch

ACUTA: Other Publications

There are three characteristics of institutions of higher education that have a strong

impact on telecommunications:

. Campus Environment

. Multiple Service Populations

. Limited Budgets

Each characteristic translates into requirements for an effective telecommunication

system.

To Serve the Campus Environment

A campus is usually the first image associated with the word "college" or "university." Typically, institutions of higher education are housed in several buildings which may be fairly close together, or spread over some distance, perhaps reaching across a city or even a state.

To serve the campus user, a system must provide feature transparency, regardless of location. Small …

Subsoiling, Contouring, And Tillage Effects On Erosion And Runoff, Paul J. Jasa, Elbert C. Dickey

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A study to evaluate the effectiveness of subsoiling on reducing soil erosion and water runoff from continuous com production was conducted. A rotating boom rainfall simulator was used on replicated treatments having either preplant in-row subsoiling or postplant between-row subsoiling used in both tilled and untilled surface conditions. Tilled and untilled treatments without subsoiling were used as checks. These six treatments were used up-and-downhill and on the contour.

Subsoiling reduced the rate of water runoff but did not significantly reduce the soil erosion rate after equilibrium had been reached between water application and runoff rates. Surface condition and farming direction …

Knowledge-Based Support For Management Of Concurrent, Multidisciplinary Design, Raymond E. Levitt, Yan Jin, Clive L. Dym

All HMC Faculty Publications and Research

Artificial intelligence (AI) applications to design have tended to focus on modeling and automating aspects of single discipline design tasks. Relatively little attention has thus far been devoted to representing the kinds of design 'metaknowledge' needed to manage the important interface issues that arise in concurrent design, that is, multidisciplinary design decision-making. This paper provides a view of the process and management of concurrent design and evaluates the potential of two AI approaches—blackboard architectures and co-operative distributed problem-solving (CDPS)—to model and support the concurrent design of complex artifacts. A discussion of the process of multidisciplinary design highlights elements of both …

Acuta Enews January 1991, Vol. 20, No. 1

ACUTA Newsletters

In This Issue

ECCI founder honored

Pocket phone test at UGA

Giving pays off for Emory

Digitizing X-rays

Illicall lists rates

Party Line

Enhancing Soil Conservation Practice Adoption With Targeted Educational Programs, Elbert C. Dickey, David P. Shelton, Paul J. Jasa

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Two independent, but closely related, grant funded educational programs were developed and implemented to reduce soil erosion in selected areas of eastern Nebraska. Traditional extension programming methods as well as other more non-traditional approaches were used extensively to enhance soil conservation practice adoption. In one program, encompassing 220 000 ha (540,000 acre) of cropland, annual soil erosion was reduced by 2.3 million t (2.5 million ton) and annual fuel savings of 1.5 million L (390,000 gal) were achieved through a reduction in the number of tillage operations. In the second project, more than 93 000 m (305,000 ft) of terraces …