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Brigham Young University

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Articles 811 - 823 of 823

Full-Text Articles in Computer Sciences

Interactive Morphometrics From Three-Dimensional Surface Images, William A. Barrett, Shawn C. Becker May 1990

Interactive Morphometrics From Three-Dimensional Surface Images, William A. Barrett, Shawn C. Becker

Faculty Publications

Techniques have been developed for extracting three-dimensional (3D) measurements directly and interactively from 3D representations of surface anatomy. In order to obtain 3D measurements the anatomical surface is interrogated directly through the use of morphometric tools. Morphometric tools include points, 3D graphical "probes", and logical sectioning functions which interact with the surface through depth buffer compositing operations. Tools are interactively positioned on or through the surface to measure surface dimensions and partial volumes, or to define intersecting functions which allow surface anatomy to be visualized in the context of surrounding anatomy. Visualization is also enhanced because tools reveal much pertaining …

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Introductory Dataperfect® Instruction, Frances Jenson Larsen Apr 1990

Introductory Dataperfect® Instruction, Frances Jenson Larsen

Theses and Dissertations

The project should be used in a beginning computer class. These units contain projects from simple to complex. The first instructional unit uses a database that comes with the DataPerfect® program. The students build and manipulate a small database. Reports are prepared, and finally the students design an original database. These instructional units are intended to be used in a high school classroom with the DataPerfect® computer program. DataPerfect® is a copyrighted program marketed by WordPerfect Corporation of Orem, Utah.

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Interactive Measurement Of Three-Dimensional Cardiac Morphology, William A. Barrett, Shawn C. Becker Sep 1989

Interactive Measurement Of Three-Dimensional Cardiac Morphology, William A. Barrett, Shawn C. Becker

Faculty Publications

Techniques have been developed for extracting three-dimensional (3D) measurements directly and interactively from 3D representations of Cine CT images. In order to obtain 3D measurements the anatomical surface is interrogated directly through the use of a 3D graphical "probe" (line). The probe is interactively positioned and stretched between any visible surface points to allow direct capture of 3D (linear) distance. Distance measurements are updated in real time as the probe dynamically "penetrates" any intervening anatomy while providing valuable depth cuing for visual feedback and probe placement. Curvilinear distance is obtained by stretching the probe over multiple surface points. The probe …

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Probabilistic Segmentation Of Myocardial Tissue By Deterministic Relaxation, William A. Barrett, Shawn C. Becker, Jerome A. Broekhuijsen Sep 1989

Probabilistic Segmentation Of Myocardial Tissue By Deterministic Relaxation, William A. Barrett, Shawn C. Becker, Jerome A. Broekhuijsen

Faculty Publications

A recently-developed probabilistic model for automatically segmenting regions of interest in abdominal CT scans has been adapted to the challenging task of segmenting myocardial tissue in Cine CT scans. A system has been implemented on relatively low-cost hardware which performs such segmentations. Special techniques have been developed to improve consistency and accuracy. Early results of testing this new modality are encouraging and promising. Based on observations from experimentation, new directions for future work have been identified.

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A Relaxation Algorithm For Segmentation Of The Endocardial Surface From Cine Ct, William A. Barrett, Bryan S. Morse Sep 1989

A Relaxation Algorithm For Segmentation Of The Endocardial Surface From Cine Ct, William A. Barrett, Bryan S. Morse

Faculty Publications

A relaxation algorithm has been developed for automated segmentation of the endocardial surface from contrast Cine CT images. The image is contoured at an initial density threshold and a one-dimensional edge operator is applied orthogonally to each point of the contour. Output from the operator is used to generate a histogram, the mode of which identifies a new threshold. The image is contoured again at the new threshold and the process is repeated. Iteration continues with successive threshold estimates converging to a stable value in the region of the endocardial surface. Computer-determined thresholds compare favorably with manual segmentation while reducing …

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A Parallel-Processing Subsystem For Rapid 3-D Interpolation Of Ct Images, William A. Barrett, Stephen J. Allan, Scott R. Cannon Sep 1988

A Parallel-Processing Subsystem For Rapid 3-D Interpolation Of Ct Images, William A. Barrett, Stephen J. Allan, Scott R. Cannon

Faculty Publications

An inexpensive parallel-processing subsystem for the rapid interpolation of CT image planes is demonstrated with a variety of node topologies. The subsystem is based on a tree network of INMOS T414 Transputer processors and is hosted by an AT-based image workstation. The subsystem accepts a stack of eight arbitrarily-spaced 256 x 256 image planes from the host. Subsystem output to the host consists of a stack of 32 scaled and evenly-spaced image planes (256 x 256 x 32 with cubic voxels). Benchmark execution times ranged from 12.3 seconds for three nodes to 5.8 seconds for eight nodes.

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Dynamic Display And Quantitative Analysis Of Three-Dimensional Left Ventricular Pathology, William A. Barrett, Jayaram K. Udupa Sep 1988

Dynamic Display And Quantitative Analysis Of Three-Dimensional Left Ventricular Pathology, William A. Barrett, Jayaram K. Udupa

Faculty Publications

Techniques have been developed for automated extraction and dynamic interactive display of three-dimensional (3D) left ventricular (LV) surface anatomy from Cine CT images using a PC-based image display architecture. Images of both endocardial and myocardial surface anatomy are generated from multiple views at multiple time instances to demonstrate various LV pathologies including apical akinesis, apical and posterior aneurysms, LV Failure, IHSS, and a left atrial myxoma. Surface generation requires interpolation between scans, surface tracking, and rendering. Generation of 60 views corresponding to a single time instance requires approximately 15 minutes. LV dimensions are measured between two or more surface points …

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Digital Neural Networks, Tony R. Martinez Jan 1988

Digital Neural Networks, Tony R. Martinez

Faculty Publications

Demands for applications requiring massive parallelism in symbolic environments have given rebirth to research in models labeled as neural networks. These models are made up of many simple nodes which are highly interconnected such that computation takes place as data flows amongst the nodes of the network. To present, most models have proposed nodes based on simple analog functions, where inputs are multiplied by weights and summed, the total then optionally being transformed by an arbitrary function at the node. Learning in these systems is accomplished by adjusting the weights on the input lines. This paper discusses the use of …

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Can Programmers Reuse Software?, Scott N. Woodfield, David W. Embley, Del T. Scott Jul 1987

Can Programmers Reuse Software?, Scott N. Woodfield, David W. Embley, Del T. Scott

Faculty Publications

An experiment asked programmers untrained in reuse to evaluate component reusability. They did poorly. Are reusability's promises hollow? Or are there some answers?

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Algebraic Geometry For Computer-Aided Geometric Design, Thomas W. Sederberg, Ronald N. Goldman Jun 1986

Algebraic Geometry For Computer-Aided Geometric Design, Thomas W. Sederberg, Ronald N. Goldman

Faculty Publications

Classical algebraic geometry has been virtually ignored in computer-aided geometric design. However, because it deals strictly with algorithms, it is really more suited to this field than is modern algebraic geometry, which introduces abstractions far removed from the algorithmic nature of computer-aided design. This tutorial examines resultants, curve implicitization, curve inversion, and curve intersection. Discussion follows a series of examples simple enough for those with only a modest algebra background to follow.

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A Generalized Information Structure To Be Used In A Human-Factors Knowledge Base, Bruce J. Wachlin Nov 1985

A Generalized Information Structure To Be Used In A Human-Factors Knowledge Base, Bruce J. Wachlin

Theses and Dissertations

The purpose of this thesis is to design a generalized information structure that can be used in a human-factors knowledge base. The information structure will take into account the human factors requirements and the hardware characteristics of the system. In this thesis the design and implementation of several prototype systems of a generalized information structure to be used in a human-factors knowledge base are presented.

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Computing As A Part Of A P.H.D Students Education: A Position Paper, Andrew D. Bailey, Rayman D. Meservy Jan 1983

Computing As A Part Of A P.H.D Students Education: A Position Paper, Andrew D. Bailey, Rayman D. Meservy

Faculty Publications

The skills and abilities associated with computer literacy are becoming required tools for accounting Ph.D. students. Not only are new doctoral students entering Ph.D. programs with better skills, they are also applying these skills more on a day to day basis. This paper presents a brief discussion of a number of issues associated with computer use and computer literacy in general. The paper also presents several aspects of the Ph.D. program at the University of Minnesota and how computers are affecting the program.

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A Hidden-Line Algorithm For Hyperspace, Robert P. Burton, David R. Smith Feb 1982

A Hidden-Line Algorithm For Hyperspace, Robert P. Burton, David R. Smith

Faculty Publications

An object-space hidden-line algorithm for higher-dimensional scenes has been designed and implemented. Scenes consist of convex hulls of any dimension, each of which is compared against the edges of all convex hulls not eliminated by a hyperdimensional clipper, a depth test after sorting and a minimax text. Hidden and visible elements are determined in accordance with the dimensionality of the selected viewing hyperspace. When shape alone is the attribute of interest, hidden-line elimination need be performed only in that hyperspace. The algorithm is of value in the production of shadows of hyperdimensional models, including but not limited to four-dimensional space-time …

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