Algorithmic commonalities in the parallel environment

The ultimate aim of this project was to analyze procedures from substantially different application areas to discover what is either common or peculiar in the process of conversion to the Massively Parallel Processor (MPP). Three areas were identified: molecular dynamic simulation, production systems (rule systems), and various graphics and vision algorithms. To date, only selected graphics procedures have been investigated. They are the most readily available, and produce the most visible results. These include simple polygon patch rendering, raycasting against a constructive solid geometric model, and stochastic or fractal based textured surface algorithms. Only the simplest of conversion strategies, mapping a major loop to the array, has been investigated so far. It is not entirely satisfactory

The contour tree image encoding technique and file format

The process of contourization is presented which converts a raster image into a discrete set of plateaux or contours. These contours can be grouped into a hierarchical structure, defining total spatial inclusion, called a contour tree. A contour coder has been developed which fully describes these contours in a compact and efficient manner and is the basis for an image compression method. Simplification of the contour tree has been undertaken by merging contour tree nodes thus lowering the contour tree's entropy. This can be exploited by the contour coder to increase the image compression ratio. By applying general and simple rules derived from physiological experiments on the human vision system, lossy image compression can be achieved which minimises noticeable artifacts in the simplified image. The contour merging technique offers a complementary lossy compression system to the QDCT (Quantised Discrete Cosine Transform). The artifacts introduced by the two methods are very different; QDCT produces a general blurring and adds extra highlights in the form of overshoots, whereas contour merging sharpens edges, reduces highlights and introduces a degree of false contouring. A format based on the contourization technique which caters for most image types is defined, called the contour tree image format. Image operations directly on this compressed format have been studied which for certain manipulations can offer significant operational speed increases over using a standard raster image format. A couple of examples of operations specific to the contour tree format are presented showing some of the features of the new format.Science and Engineering Research Counci

A New polygon based algorithm for filling regions

[[abstract]]Region filling is a fundamental operation in computer graphics and image processing. There are broadly two classes of region filling: polygon based and pixel based. The conventional polygon based region filling algorithm typically uses data structures of records and fields. Using these data structures, the region filling process slows down because of the time-consuming operations of records and fields. This paper proposes a new polygon based region filling algorithm by using the proposed data structures of triples. This results in use of more efficient triple operations involving arrays and elements to fill a region. Using data structures of triples, the y-coordinate modification problem that occurs in the conventional algorithm simply disappears. In addition, contrary to the conventional approach, which uses troublesome geometrical considerations in deciding the even number of elements in each linked list, the proposed triple model uses a simple criterion to meet the even number requirement. Most important of all is the fact that the proposed criterion is independent of the polygon geometry. The experimental results strongly support superiority of the proposed algorithm. It is verified that the proposed algorithm is both theoretically and experimentally better than the conventional algorithm.[[notice]]補正完

A study of real-time computer graphic display technology for aeronautical applications

Hardware, algorithms and software for real-time raster graphics were designed and implemented

Knife Edge Scanning Microscope Brain Atlas Interface for Tracing and Analysis of Vasculature Data

The study of the neurovascular network in the brain is important to understand brain functions as well as causes of several brain dysfunctions. Many techniques have been applied to acquire neurovascular data. The Knife-Edge Scanning Microscope (KESM), developed by the Brain Network Lab at Texas A&M University, can generate whole-brain-scale data at submicrometer resolution. The specimen can be stained with different stains, and depending on the type of stain used, the KESM can image different types of microstructures in the brain. The India ink stain allows the neurovascular network in the brain to be imaged. In order to visualize and analyze such large datasets (~ 1.5 TB per brain), a lightweight, web-based mouse brain atlas called the Knife-Edge Scanning Microscope Brain Atlas (KESMBA) was developed in the lab. The atlas serves several whole mouse brain data sets including India ink. The multi-section overlay technique used in the atlas enables 3D visualization of the structural information in the data. To solve the challenging issue of tracing micro-vessels in the brain, in this thesis a semi-automated tracing and analysis method is developed and integrated into the KESM brain atlas. Using the KESMBA interface developed in this thesis, the user can look at the 3D structure of the vessels on the brain atlas and can guide the tracing algorithm. To analyze the vasculature network traced by the user, a data analysis component is also added. This new KESMBA interface is expected to help in quickly tracing and analyzing the vascular network of the brain with minimal manual effort. In order to visualize and analyze such large data sets (~ 1.5 TB per brain), a light-weight, web-based mouse brain atlas called the Knife-Edge Scanning Microscope Brain Atlas (KESMBA) was developed in the lab. The atlas serves several whole mouse brain data sets including India ink. The multi-section overlay technique used in the atlas enables 3D visualization of the structural information in the data. To solve the challenging issue of tracing micro-vessels in the brain, in this thesis a semi-automated tracing and analysis method is developed and integrated into the KESM brain atlas. Using the KESMBA interface developed in this thesis, the user can look at the 3D structure of the vessels on the brain atlas and can guide the tracing algorithm. In order to analyze the vasculature network traced by the user, a data analysis component is also added. This new KESMBA interface is expected to help in quickly tracing and analyzing the vascular network of the brain with minimal manual effort

Computer aids for the design of large scale integrated circuits.

The work described in this thesis is concerned with the development of CADIC (Computer Aided Design of Integrated Circuits), a suite of computer programs which allows the user to design integrated circuit layouts at the geometric level. Initially, a review of existing computer aids to integrated circuit design is carried out. Advantages and disadvantages of each computer aid is discused, and the approach taken by CADIC justified in the light of the review. The hardware associated with a design aid can greatly influence its performance and useability. For this reason, a critical review of available graphic terminals is also undertaken. The requirements, logistics, and operation of CADIC is then discussed in detail. CADIC provides a consise range of features to aid in the design and testing of integrated circuit layouts. The most important features are however CADIC's high efficiency in processing layout data, and the implementation of complete on-line design rule checking. Utilization of these features allows CADIC to substantially reduce the lengthy design turnaround time normally associated with manual design aids. Finally, the performance of CADIC is presented. Analysis of the results show that CADIC is very efficient at data processing, especially when small sections of the layout are considered. CADIC can also perform complete on-line design rule checking well within the time it takes the designer to start adding the next shape

Image Display and Manipulation System (IDAMS) program documentation, Appendixes A-D

The IDAMS Processor is a package of task routines and support software that performs convolution filtering, image expansion, fast Fourier transformation, and other operations on a digital image tape. A unique task control card for that program, together with any necessary parameter cards, selects each processing technique to be applied to the input image. A variable number of tasks can be selected for execution by including the proper task and parameter cards in the input deck. An executive maintains control of the run; it initiates execution of each task in turn and handles any necessary error processing

Simulation verification techniques study. Subsystem simulation validation techniques

Techniques for validation of software modules which simulate spacecraft onboard systems are discussed. An overview of the simulation software hierarchy for a shuttle mission simulator is provided. A set of guidelines for the identification of subsystem/module performance parameters and critical performance parameters are presented. Various sources of reference data to serve as standards of performance for simulation validation are identified. Environment, crew station, vehicle configuration, and vehicle dynamics simulation software are briefly discussed from the point of view of their interfaces with subsystem simulation modules. A detailed presentation of results in the area of vehicle subsystems simulation modules is included. A list of references, conclusions and recommendations are also given