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Research and Advances Jul 1 1987

Arabic word processing

Recently developed word processing software can correctly format the cursive, interacting letters of the Arabic script. Moreover, new layout procedures can automatically intermix right-to-left Arabic writing with left-to-right text in European or other languages.
Research and Advances Jul 1 1987

Adjacency detection using quadcodes

A method is presented for determining whether two given regions are adjacent, and for finding all the neighbors of different sizes for a given region. Regions are defined as elementary squares of any size. In a companion paper [2], we introduce the quadcode and discuss its use in representing geometric concepts in the coded image, such as location, distance, and adjacency. In this paper we give a further discussion of adjacency in terms of quadcodes. Gargantini [1] discussed adjacency detection using linear quadtrees. Her discussion was applied to pixels, and a procedure was given to find a pixel's southern neighbor only. This paper considers elementary squares of any size, and gives procedures for both aspects of the problem: for determining whether two given regions are adjacent, and for finding all the neighbors of different sizes for a given region.
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Research and Advances Jul 1 1987

The quadcode and its arithmetic

The quadcode is a hierarchical data structure for describing digital images. It has the following properties: (1) straightforward representation of dimension, size, and the relationship between an image and its subsets; (2) explicit description of geometric properties, such as location, distance, and adjacency; and (3) ease of conversion from and to raster representation. The quadcode has applications to computer graphics and image processing because of its ability to focus on selected subsets of the data and to allow utilization of multiple resolutions in different parts of the image. A related approach is the quadtree. Samet recently presented a thorough survey of the literature in that field [7]. Gargantini [2] and Abel and Smith [1] presented linear quadtrees and linear locational keys that are efficient labeling techniques for quadtrees. In those papers the geometric concepts of the image are discussed by using the tree as an interpretive medium, and the approaches and procedures are based on traversal of the nodes in the tree. In this paper we present the quadcode system, which is a direct description of the image, and discuss the geometric concepts in terms of the coded images themselves.
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Research and Advances Jul 1 1987

Word division in Spanish

Spanish is a language with very precise and regular orthographic rules. A syllabication algorithm strictly based on syntactic analysis, not requiring any semantic knowledge, is presented and further extended to include hyphenation. Algorithms are presented as pattern matching schemata, and efficient implementations are considered.
Research and Advances May 1 1987

A statistical technique for comparing heuristics: an example from capacity assignment strategies in computer network design

An analysis of variance (ANOVA) model is developed for determining the existence of significant differences among strategies employing heuristics. Use of the model is illustrated in an application involving capacity assignment for networks utilizing the dynamic hierarchy architecture, in which the apex node is reassigned in response to changing environments. The importance of the model lies in the structure provided to the evaluation of heuristics, a major need in the assessment of benefits of artificial-intelligence applications. A nested three-factor design with fixed and random effects provides a numerical example of the model.
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Research and Advances Apr 1 1987

Attributes of the performance of central processing units: a relative performance prediction model

Using readily available data on CPU characteristics—main memory size, cache memory size, number of channels, and machine cycle time—it is possible to predict relative CPU performance for a wide range of machines. Statistical analyses indicate that these characteristics explain virtually all the variance in relative performance.
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Research and Advances Apr 1 1987

Computing multi-colored polygonal masks in pipeline architecture and its application to automated visual inspection

New techniques for computing multicolored polygonal masks for image analysis and computer vision applications are presented. The procedures do not require random access of the image memory. They are based on efficient generation of coordinate-reference images (ramps) and other simple general purpose architectural features such as look-up tables. The techniques presented are, unlike their predecessors, highly parallel and can be efficiently implemented in existing pipeline image processors. In addition, we show an architecture in the form of functional building blocks that will enable us to compute polygonal and other masks much faster than commercially available pipeline systems. Extensive motivation and use of the new algorithms for digital visual inspection applications are given throughout.
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Research and Advances Feb 1 1987

COBOL on a PC: a new perspective on a language and its performance

A comparison of Cobol performance on the PC AT Enhanced versus an IBM 370 mainframe suggests that high-quality PC compiler implementations—combined with the new language features of the Cobol 85 Standard—are improving the PC environment for Cobol to the point where serious applications can now be developed and debugged on the PC, either to be run on the PC itself, or for eventual uploading to a mainframe.
Research and Advances Dec 1 1986

Data parallel algorithms

Parallel computers with tens of thousands of processors are typically programmed in a data parallel style, as opposed to the control parallel style used in multiprocessing. The success of data parallel algorithms—even on problems that at first glance seem inherently serial—suggests that this style of programming has much wider applicability than was previously thought.
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Research and Advances Nov 1 1986

Schematic pseudocode for program constructs and its computer automation by SCHEMACODE

To achieve program control flow representation that is relatively independent of any given programming language, schematic pseudocode (SPC) uses a perceptual notation system composed of schemata whose syntax rules are described by a grammar. Source code documentation is supported by operational comments, and translation into a target procedural language is fully automatic.

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