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Articles 1 - 8 of 8

Full-Text Articles in Engineering

Density Currents In Circular Wastewater Treatment Tanks, David M. Laliberte Jan 1990

Density Currents In Circular Wastewater Treatment Tanks, David M. Laliberte

Dissertations and Theses

Deviations from ideal flow and settling occur in circular wastewater treatment tanks because of tank geometry, flow conditions, and density currents caused by variations in suspended solids concentration and temperature distributions. Thermally induced density currents were investigated in this study. Under winter, low flow conditions, measurements were made of vertical and radial temperature distributions in the circular chlorination tank at Lake Oswego, Or., and in the circular primary and secondary clarifiers at Bend, Or. Thermistor arrays were used to collect the data which exhibited both vertically well-mixed and a two-layer flow regime. Inlet geometry and suspended solids in the secondary ...


An Effective Cube Comparison Method For Discrete Spectral Transformations Of Logic Functions, Ingo Schafer Jan 1990

An Effective Cube Comparison Method For Discrete Spectral Transformations Of Logic Functions, Ingo Schafer

Dissertations and Theses

Spectral methods have been used for many applications in digital logic design, digital signal processing and telecommunications. In digital logic design they are implemented for testing of logical networks, multiplexer-based logic synthesis, signal processing, image processing and pattern analysis. New developments of more efficient algorithms for spectral transformations (Rademacher-Walsh, Generalized Reed-Muller, Adding, Arithmetic, multiple-valued Walsh and multiple-valued Generalized Reed- Muller) their implementation and applications will be described.


Threaded Octree Structures For Fast Neighbor Voxel Processing In A Parallel Ray Tracer, B.R. Naveen Chandra Jan 1990

Threaded Octree Structures For Fast Neighbor Voxel Processing In A Parallel Ray Tracer, B.R. Naveen Chandra

Dissertations and Theses

In the field of Computer Graphics, Ray Tracing has so far been the the best algorithm for rendering of realistic three dimensional images created by mathematical models. Ray Tracing is also known for its very large computation times, where the computation depends on the picture resolution, the number of objects and the complexity of the scene.


Investigation Of Techniques For High Speed Cmos Arbitrary Waveform Generation, Albert Henry Nehl Jan 1990

Investigation Of Techniques For High Speed Cmos Arbitrary Waveform Generation, Albert Henry Nehl

Dissertations and Theses

Today a growing number of applications in design engineering, production and environmental testing, and system service require specific analog waveforms and digital patterns. Such requirements are neither satisfactorily nor easily met by the use of standard function or single purpose, custom generators.

Traditional methods of waveform generation suffer from undesirable complexity or mediocre performance and are otherwise limited. For the majority of arbitrary waveform generation applications, including medical engineering, modal analysis and electronic engineering, direct digital synthesis techniques are satisfactory. Direct digital synthesis, based generally on periodic retrieval of predetermined amplitude values, may be used to 2 generate such waveforms ...


Hypercard-Based Learning Environment For Diades, Ali A. Shamsapour Jan 1990

Hypercard-Based Learning Environment For Diades, Ali A. Shamsapour

Dissertations and Theses

This thesis is an attempt to create a HyperCard-based learning environment to teach DIADES and other related material. It is a departure from the classical Computer Aided Instruction methods towards a more flexible and user-controlled design. The goal was to set the foundation of a new CAI design which would closely resemble a Hyper- Text system. These systems are characterized as having interconnections between related concepts in the CAI environment.


Decomposition Of Measured Contours Into Geometric Features For Dimensional Inspection, Devaraj Rajkumar Jan 1990

Decomposition Of Measured Contours Into Geometric Features For Dimensional Inspection, Devaraj Rajkumar

Dissertations and Theses

Image processing systems used in Vision Assisted Dimensional Inspection usually output a set of boundary pixels representing the part edges. This boundary information must be divided into several subsets representing the various edges of the actual object, so that comparisons with the nominal part can be made.

The purpose of this project is to devise a method to divide the set of pixels obtained from the image processing system into subsets of pixels. Each of these subsets represent an edge in the contour of the actual object. This method must also detect transition points between the adjacent features. This project ...


Finite Element Analysis Of Thermal Stresses In Semiconductor Devices, Joachim Karl Wilhelm Duerr Jan 1990

Finite Element Analysis Of Thermal Stresses In Semiconductor Devices, Joachim Karl Wilhelm Duerr

Dissertations and Theses

The failure of integrated circuit due to Silicon fracture is one of the problems associated with the production of a semiconductor device. The thermal stresses, which result in die cracking, are for the most part induced during the cooling process after attaching the die with Gold-Silicon solder. Major factors for stress generation in material systems are commonly large temperature gradients and substantial difference in coefficients of thermal expansion.


The Object-Oriented Design Of A Hardware Description Language Analyser For The Diades Silicon Compiler System, Lian Yang Jan 1990

The Object-Oriented Design Of A Hardware Description Language Analyser For The Diades Silicon Compiler System, Lian Yang

Dissertations and Theses

This thesis is one of the first to introduce a systematic and general Source Language Analysis System (called SLA) for a high -level synthesis system.