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Computer

Issue 6 • Date June 1988

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Displaying Results 1 - 6 of 6
  • The Optical File Cabinet: a random-access file system for write-once optical disks

    Page(s): 11 - 22
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (902 KB)  

    The Optical File Cabinet (OFC) is patterned after a conventional office file cabinet where all versions of a stored item are retained, but the current version of each item is the easiest to find. The OFC retains the favorable aspects of write-once optical disks while preserving the existing relationship between the operating system and the file system. Alternate approaches to write-once storage and the characteristics of write-once optical disks are described. The salient features of the OFC are examined, namely, the file system tree, growing data structures, and the large memory requirement. The relationship between the OFC and the operating system is discussed. Also considered are reliability, the user-level software interface, long-term storage, simulating the OFC, and implementation of the OFC on a Tektronix 4404 engineering workstation.<> View full abstract»

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  • Stepwise refinement and verification in box-structured systems

    Page(s): 23 - 36
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1139 KB)  

    The author proposes that the formality of specifications and designs be developed together in box structures with many sponsor and user interfaces. Box structures of data abstractions allow the stepwise refinement and verification of hierarchical system designs from their specifications at formal and informal levels. He discusses the features and advantages of the approach. He used a navigation and weather buoy case study and gives a detailed, step-by-step application of the method.<> View full abstract»

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  • System and application software for the Armstrong multiprocessor

    Page(s): 38 - 52
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1378 KB)  

    The authors identify problems with present parallel processing systems, and present Armstrong, a hardware-software system that is designed to address some of the problems discussed. They briefly describe the Armstrong hardware and discuss, in depth, the operating system software, and performance of the system on a real application, namely, and computation of the 2-D discrete Fourier transform of an image.<> View full abstract»

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  • Traditional, semantic, and hypersemantic approaches to data modeling

    Page(s): 53 - 63
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (924 KB)  

    An overview is given of past present data-modeling trends, and future directions are identified. The three traditional and commonly used data models that gained wide acceptance in the late 1960s and early 1970s and are used extensively today, namely the relational, hierarchical, and network models, are reviewed. Semantic data models that attempt to enhance the representation of operational information by capturing more of the meaning about data values and relationships are described. Enhancements to semantic data models that characterize hypersemantic data models and emphasize capturing inferential relationships are discussed.<> View full abstract»

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  • Programming in VS Fortran on the IBM 3090 for maximum vector performance

    Page(s): 65 - 76
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1089 KB)  

    Programming techniques necessary for high performance on the 3090 Vector Facilities are illustrated, showing that VS Fortran programs can achieve near-maximum execution rates. Relevant features of the 3090 architecture are reviewed, stressing the need to make efficient use of a hierarchical storage system and take advantage of the compound vector instructions. The key programming techniques for managing the storage hierarchy are loop sectioning, loop distribution, and data compaction. Vector register, cache reuse, and virtual memory, storage format, and page reuse are shown to lead to efficient use of the vector registers, the high speed cache, and the virtual memory system, respectively. The multiply-and-add compound instruction is discussed.<> View full abstract»

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  • Mathematical-oriented programming

    Page(s): 89 - 95
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    Two products that transform mathematical expressions into useful results are reviewed. One is Math View Professional version 0.94, a self-contained mathematics application that is capable of performing a nearly encyclopedic range of mathematical, graphical, and statistical operations. The authors briefly summarize the program's features, touch on the manual supplied with the review copy, offer some details about the program, and suggest some future improvements. The other product reviewed is MathCAD 2.0 which allows free-form mathematical expressions to be entered in much the say way as text is entered into a word processor. These packages provide tools for the non-computer-oriented problem solver.<> View full abstract»

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Computer, the flagship publication of the IEEE Computer Society, publishes highly acclaimed peer-reviewed articles written for and by professionals representing the full spectrum of computing technology from hardware to software and from current research to new applications.

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Editor-in-Chief
Ron Vetter
University of North Carolina
Wilmington