Engineering Commons^™

A Finite Difference Soil-Structure Interaction Study Of A Section Of The Bonneville Navigation Lock Buttress Diaphragm Wall Utilizing Pressuremeter Test Results, Thomas C. Mccormack

Dissertations and Theses

The P-y curve, used in current practice as an efficient Iine-load vs. soil displacement model for input into the finite difference method of laterally loaded pile analysis, is extended in this study for use with cohesionless soils in diaphragm wall analysis on the Personal Computer with the BMCOL7 program. An analogous W-y curve is proposed, an elastic-plastic model with line-load limits developed from classical earth-pressure theories.

A new formula for predicting a horizontal wall modulus for cohesionless soils from the pressuremeter modulus is developed for use in predicting the displacements on the W-y curves. The resulting modulus values are shown …

Improving Crystallographic Macromolecular Images: The Real-Space Approach, A. D. Podjarny, T. N. Bhat, Martin Zwick

Systems Science Faculty Publications and Presentations

Macromolecular crystallographicy is a unique tool for imaging the structures of proteins and nucleic acids. Images are obtained from the Fourier transform of the diffraction pattern of the crystal by use of X-ray, neutron, and / or electron scattering. When X-ray and neutron scattering are used only diffraction amplitudes are experimentally measured, and phases have to be obtained. Multiple isomorphous replacement (MIR) has been the technique of choice for solving this phase problem in the determination of most macromolecular structures. Unfortunately, the method is extremely time consuming, especially when compared with the solution techniques available for small molecules; moreover, structure …

Threshold Characteristics Of Multimode Laser Oscillators, Mehdi Khoshnevissan

Dissertations and Theses

The threshold characteristics of multimode laser oscillators are considered in detail, and a new model is given for semiconductor diode lasers. Analytical expressions and numerical solutions are obtained for mode amplitudes, and over-all spectral characteristics of lasers operating above and below threshold. The theoretical results are i n agreement with experimental data. The band-ta-band absorption is included in the model and i t ' s effect is studied on the mixed broadening.

Hyperbolic Soil Parameters For Granular Soils Derived From Pressuremeter Tests For Finite Element Programs, Dieter Neumann

Dissertations and Theses

In the discipline of geotechnical Engineering the majority of finite element program users is familiar with the hyperbolic soil model. The input parameters are commonly obtained from a series of triaxial tests. For cohesionless soil ls however, today's sampling techniques fail to provide undisturbed soil specimen. Furthermore, routine triaxial tests can not be carried out on soils with grains exceeding 10 - 15 mm in size.

Numerical Solutions Of Continuous Wave Beam In Nonlinear Media, Jeffrey Huang

Dissertations and Theses

Deformation of a Gaussian beam is observed when it propagates through a plasma. Self-focusing of the beam may be observed when the intensity of the laser increases the index of refraction of plasma gas.

Due to the difficulties in solving the nonlinear partial differential equation in Maxwell's wave equation, a numerical technique has been developed in favor of the traditional analytical method. Result of numerical solution shows consistency with the analytical method. This further suggests the validity of the numerical technique employed.

A three dimensional graphics package was used to depict the numerical data obtained from the calculation. Plots from …

Parallel Approximate String Matching Applied To Occluded Object Recognition, David Smith

Dissertations and Theses

This thesis develops an algorithm for approximate string matching and applies it to the problem of partially occluded object recognition. The algorithm measures the similarity of differing strings by scanning for matching substrings between strings. The length and number of matching substrings determines the amount of similarity. A classification algorithm is developed using the approximate string matching algorithm for the identification and classification of objects. A previously developed method of shape description is used for object representation.

Elastic-Plastic Analysis Of Axisymmetrically Loaded Isotropic Circular And Annular Plates Undergoing Large Deflections, Aiman Raji Akileh

Dissertations and Theses

The concept of load analogy is used in the elastic and elastic-plastic analysis of isotropic circular and annular plates undergoing moderately large deflection. The effects of the nonlinear terms of lateral displacement and the plastic strains are considered as additional fictitious lateral loads, edge moments, and in-plane forces acting on the plate. The solution of an elastic or elastic-plastic Von Karman type plate is hence reduced to a set of two equivalent elastic plate problems with small displacements, namely, a plane problem in elasticity and a linear elastic plate bending problem. The method of finite element is employed to solve …

Metal Waveguide Modeling Of Tapered Quadratic Index Media, Lee W. Casperson, Bahram Zandi

Electrical and Computer Engineering Faculty Publications and Presentations

The basic electromagnetic properties of tapered graded index fibers are equivalent to the properties of a class of concave metallic waveguides. Although useful in their own right, such metal waveguides also provide a straightforward and inexpensive means for studying the characteristics of more complicated tapered media.

The Mechanics Of Flycasting: The Flyline, Graig A. Spolek

Mechanical and Materials Engineering Faculty Publications and Presentations

In order to propel a fishing fly through the air toward the distant quarry, a rather massive line, to which the fly is attached, is cast. As the cast line rolls out, the fly actually accelerates horizontally and seems to defy physical law. The phenomenon is modeled simplistically to determine the magnitude of this effect. In the absence of air drag, the fly can accelerate to increase its velocity by an order of magnitude. Air friction dramatically decreases the effect, but some fly accelerationis still predicted. By tapering the flyline in various ways, the fly velocity history can be significantly …

Analysis And Prediction Of The Water Temperature Of The Mckenzie River, Oregon Using The Equilibrium Temperature Approach, R. Peder Hansen

Dissertations and Theses

A one dimensional, steady flow, unsteady temperature model is used to evaluate the effects of two U.S. Army Corps of Engineers (COE) dams and resulting reservoirs on hourly water temperatures of the mainstem McKenzie River from Delta Park (RM 62.1) to Leaburg Dam (RM 38.8). Both COE projects are on tributaries to the McKenzie River and at present have only bottom withdrawl capabilities.

Water temperatures were simulated using the equilibrium temperature approach with air temperature used to estimate equilibrium temperature and also using computed hourly equilibrium temperature. Results obtained using computed equilibrium temperatures were less satisfactory than results using air …

Propagation Of Optical Waves In Tapered Fibers And Metallic Wave Guides, Bahram Zandi

Dissertations and Theses

The equations tor the propagation of Electromagnetic and Optical waves in tapered fibers and metallic waveguides are derived. Solutions are derived for the displacement of the beam from the waveguide axis as a function of distance along the axis, and also tor the beam width as a function of distance. These equations are solved numerically for a variety of tapered guides. Experiments are conducted which verify the theoretical results.

Quadtree-Based Processing Of Digital Images, Ramin Naderi

Dissertations and Theses

Image representation plays an important role in image processing applications, which usually. contain a huge amount of data. An image is a two-dimensional array of points, and each point contains information (eg: color). A 1024 by 1024 pixel image occupies 1 mega byte of space in the main memory. In actual circumstances 2 to 3 mega bytes of space are needed to facilitate the various image processing tasks. Large amounts of secondary memory are also required to hold various data sets.

In this thesis, two different operations on the quadtree are presented.

There are, in general, two types of data …

Post-Buckled Performance Of Partially Restrained And Intermediately Supported Steel Angles, Perumal Radhakrishnan

Dissertations and Theses

The post-buckled performance of cross-braced single angles was experimentally determined. The results of this study will be used by the Bonneville Power Administration for the analysis of member performance in transmission towers.

Beam Propagation In Periodic Quadratic-Index Waveguides, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Several techniques are described for studying the propagation of off-axis polynomial Gaussian beams in media having straight axes and periodic z variations of the quadratic refraction and loss coefficients. For some periodic variations, exact analytical solutions of the paraxial equations are possible, and for sufficiently slow variations, WKB solutions can always be obtained. All results are expressed in conventional beam matrix form.

Forecasting For Local Water Management, Douglas Alan Putnam

Dissertations and Theses

Forecast models are investigated and developed for use in local water management to aid in determining short term water requirements and availability. The forecast models include precipitation occurrence and depth using a Markov chain model, temperature and solar radiation with a multivariate autoregressive model, and streamflow with autoregressive-moving average models. The precipitation, temperature, and solar radiation forecasts are used with a soil moisture model to determine water demands. A state space approach to the Muskingum-Cunge streamflow routing technique is developed. The forecast water demands and streamflow forecasts are used as inputs to this routing model. Forecast model errors and propagation …

Spontaneous Coherent Pulsations In Ring-Laser Oscillators: Stability Criteria, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The stability criteria implied by a simplified semiclassical laser model are considered in detail. It is found that two types of criteria must be distinguished. The first concerns the smallest pump rate for which infinitesimal perturbations of the steady-state solution will increase with time, and the second concerns the smallest pump rate for which large amplitude modulations will not damp away.

The Applicability Of Microcomputers To Local Water Management, Roderick Lee Allen

Dissertations and Theses

Historically, hydrologic models have been available only on mainframe computers and have therefore not been used by local water managers to support daily decisions. The development of the microcomputer presents an opportunity for that to change.

Mathematical models of soil moisture and river routing are selected, developed and tested for use on a microcomputer as an aid to local water management. The models are then integrated with an appropriate data base in a computer program written for a microcomputer. The result is a Decision Support System for local water managers.

In order to evaluate the feasibility of using the Decision …

Spontaneous Coherent Pulsations In Ring-Laser Oscillators, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Complex spontaneous-pulsation phenomena have been reported in xenon lasers operating at 3.51-μm wavelength, and a theoretical explanation for these effects has been given. However, the published models contain various simplifications and have so far yielded only qualitative agreement with xenon-laser experiments. Reported here is a more rigorous analytical model, which for the first time provides quantitative agreement with experimental observations. This model should also find direct application in interpreting or predicting the behavior of other spontaneously pulsing laser systems.

Microcomputer Mrp In Three Months: Photon Kinetics, Wayne W. Wakeland

Systems Science Faculty Publications and Presentations

Information about the company Photon Kinetics, a small, privately-held manufacturer of fiber optics test equipment, located in Beaverton, Oregon.

Two New Parallel Processors For Real Time Classification Of 3-D Moving Objects And Quad Tree Generation, Farjam Majd

Dissertations and Theses

Two related image processing problems are addressed in this thesis. First, the problem of identification of 3-D objects in real time is explored. An algorithm to solve this problem and a hardware system for parallel implementation of this algorithm are proposed. The classification scheme is based on the "Invariant Numerical Shape Modeling" (INSM) algorithm originally developed for 2-D pattern recognition such as alphanumeric characters. This algorithm is then extended to 3-D and is used for general 3-D object identification. The hardware system is an SIMD parallel processor, designed in bit slice fashion for expandability. It consists of a library of …

Transient Flow Inverse Study Calculation Of Unsaturated Permeability Of Wood, Farid Piroozmandi

Dissertations and Theses

One of the major processes in lumber industry is wood drying. This process consumes large amounts of energy and capital, and due to the length of time it takes, it acts as a governing factor in lumber production levels. Development of improvements in processes and equipment used in wood drying can be expedited through computer simulation of various drying procedures. These numerical simulations depend on the accuracy of numerical models representing wood transport properties, including functional dependency of liquid permeability through wood with respect to local saturation level. Data available in the literature mainly represent wood permeability properties at fully …

Solvable Hill Equation, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

A second-order linear differential equation with continuous periodic coefficients is solved exactly in terms of elementary functions. Equations of this type arise commonly in several areas of physics, and the solutions may find practical applications. As an illustration, the results are applied to the problem of an electron in a one-dimensional periodic potential.

Power Characteristics Of Single‐Mode Semiconductor Lasers, Jaroslava Z. Wilcox, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The basic aspects of power calculations for high‐gain semiconductor lasers are briefly reviewed, and a straightforward one‐dimensional model is described. The relative importance of spontaneous emission, distributed losses, band‐to‐band absorption, and high single‐pass gain are investigated in detail.

The Dynamics Of The Columbia River Estuarine Ecosystem: Volume I And Volume Ii, Creddp, Charles A. Simenstad, David A. Jay, C. David Mcintire, Willa Nehlsen, Christopher R. Sherwood, Lawrence F. Small

Civil and Environmental Engineering Faculty Publications and Presentations

Integrates results from the CREDDP studies into a comprehensive synthesis. Includes physical setting and processes; relationships between physical and biological processes and among functional groups of organisms; species, biomass and productivity per habitat type per region. Approximately 360 pages per volume.

Determination Of Systemic Blood Pressure Via Autospectral Analysis Of Oscillometric Data, Eugene Elie Warner

Dissertations and Theses

The currently accepted methods for measuring systemic blood pressure are either highly accurate but invasive in nature or clinically convenient but prone to observer-related errors. A new oscillometric method uses sensitive signal conditioning and sensing equipment with a non-invasive arm cuff to record arterial pulsations. The goal of this study is to establish more reliable criteria for the identification of systolic and diastolic pressures from oscillometric data.

Circulatory Processes In The Columbia River Estuary, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Covers tidal circulation, density distribution, vertical mixing, salt transport, and low-frequency flow processes, with contributions to estuarine circulation theory.

Propagation Of Airy-Hermite-Gaussian Waveguide Modes In Free Space, Lee W. Casperson, O. M. Stafsudd, Leroy V. Sutter, Jonathan Gary Grossman

Electrical and Computer Engineering Faculty Publications and Presentations

The cavity modes of metal strip waveguide lasers are most simply expressed in terms of Airy-Hermite-Gaussian functions. The free space propagation of the resulting beam modes has been examined, and both near- and far-field patterns have been calculated and measured. Phase plates may be useful for enhancing the far-field intensity.

Load Flow And Contingency Analysis In Power Systems, Kianfar Sorooshian

Dissertations and Theses

A load flow and contingency analysis program for secure design, planning and operation of power systems. Depending on the application either Newton-Raphson or Fast- Decoupled method is employed to solve the load flow. Fault analysis is done by Z bus method. Contingency analysis may be done following the load flow solution by Fast-Decoupled method. The program is also interfaced with a graphic system which displays a single line diagram of the system on the graphic screen along with relevant data and informs the operator of any change by flashing the faulted bus or the line outage.

State Space Approach To Flood Stage Estimation, Gregory Allen Jones

Dissertations and Theses

A flood routing and stage prediction model is developed using the techniques of State Space and Kalman filtering. The governing equation is the physically based hydrologic method of flood routing with the output being an optimal estimate of stage given known inputs of streamflow. These equations are developed in state space and the Kalman filter is employed to estimate the flow and river stage.

The model is applied to the Toutle and Cowlitz Rivers in the State of Washington, where the stage is affected by a shifting bed elevation. With the deterministic inputs at Mayfield Dam on the Cowlitz and …

A Numerical Solution For Three Dimensional Beam Columns In The Elastic Region, Hamid Reza Afghan

Dissertations and Theses

The three differential equations describing the behavior of the beam columns in three dimensions are derived and presented in finite difference form. A computer model is developed to solve the simultaneous equations in the elastic regions and predict the member behavior.

The computer program is checked by comparing the results obtained from the program with data from other investigators, and classical analytical techniques.