A survey of PASCAL-XSC and a language reference supplement on dynamic and flexible arrays

Ein PASCAL-XSC-Ueberblick und eine Sprachbeschreibungs-Ergaenzung zu dynamischen und flexiblen Feldern ----------------------------------------------------------------- PASCAL-XSC ist eine universelle Programmiersprache, die ausserdem speziell die Implementierung von hochentwickelten numerischen Algorithmen unterstuetzt. Das PASCAL-XSC System hat den Vorteil der Portabilitaet auf verschiedenen Plattformen (Personal Computer, Workstations, Grossrechner und Supercomputer) durch einen portablen Compiler, der nach ANSI-C uebersetzt. Mittels der mathematischen Module von PASCAL-XSC koennen numerische Algorithmen, die hochgenaue und automatisch verifizierte Ergebnisse liefern, sehr leicht programmiert werden. PASCAL-XSC vereinfacht das Design von Programmmen in den Ingenieurwissenschaften und im wissenschaftlichen Rechnen durch modulare Programmstruktur, benutzerdefinierte Operatoren, Ueberladen von Funktionen, Prozeduren und Operatoren, Funktionen und Operatoren mit allgemeinem Ergebnistyp und dynamische Felder. Arithmetische Standard Module fuer zusaetzliche numerische Datentypen (inclusive Operatoren und Standardfunktions von hoher Genauigkeit) und die exakte Ausdrucksauswertungn stellen die wichtigsten numerischen Tools dar. In PASCAL--XSC geschriebene Programme sind leicht lesbar, da alle Operationen, auch die in hoeheren mathematischen Raeumen, als Operatoren realisiert sind und in der ueblichen mathematischen Notation verwendet werden konnen. In aktuellen Compiler-Versionen von PASCAL-XSC wurde das Konzept der dynamischen Felder betr?chtlich erweitert. Ein Benutzer kann nun dynamische Felder mehrfach und mit unterschiedlicher Groesse zur Laufzeit seines Programmes allokieren. Dar?berhinaus koennen dynamische Felder auch als Komponenten anderer PASCAL Strukturen wie Records und statische Felder vereinbart werden. A Survey of PASCAL-XSC and a Language Reference Supplement on Dynamic and Flexible Arrays ---------------------------------------------------------- PASCAL-XSC is a general purpose programming language which provides special support for the implementation of sophisticated numerical algorithms. The new PASCAL-XSC system has the advantage of being portable across many platforms and is available for personal computers, workstations, mainframes and supercomputers by means of a portable compiler which translates to ANSI-C language. By using the mathematical modules of PASCAL-XSC, numerical algorithms which deliver highly accurate and automatically verified results can be programmed easily. PASCAL-XSC simplifies the design of programs in engineering and scientific computation by modular program structure, user-defined operators, overloading of functions, procedures, and operators, functions and operators with arbitrary result type and dynamic arrays. Arithmetic standard modules for additional numerical data types including operators and standard functions of high accuracy and the exact evaluation of expressions provide the main numerical tools. Programs written in PASCAL-XSC are easily readable since all operations, even those in the higher mathematical spaces, have been realized as operators and can be used in conventional mathematical notation. In current compiler versions of PASCAL-XSC, the concept of dynamic arrays has been significantly extended. A user is now able to allocate a dynamic array variable several times and with different size during the execution of his or her program. Moreover, dynamic arrays may now be declared as components of other PASCAL structures such as records or static arrays

Evaluation of Functional Data Models for Database Design and Use

The problems of design, operation, and maintenance of databases using the three most popular database management systems (Hierarchical, CQDASYL/DBTG, and Relational) are well known. Users wishing to use these systems have to make conscious and often complex mappings between the real-world structures and the data structuring options (data models) provided by these systems. In addition, much of the semantics associated with the data either does not get expressed at all or gets embedded procedurally in application programs in an ad-hoc way. In recent years, a large number of data models (called semantic data models) have been proposed with the aim of simplifying database design and use. However, the lack of usable implementations of these proposals has so far inhibited the widespread use of these concepts. The present work reports on an effort to evaluate and extend one such semantic model by means of an implementation. It is based on the functional data model proposed earlier by Shipman[SHIP81). We call this 'Extended Functional Data Model' (EFDM). EFDM, like Shipman's proposals, is a marriage of three of the advanced modelling concepts found in both database and artificial intelligence research: the concept of entity to represent an object in the real world, the concept of type hierarchy among entity types, and the concept of derived data for modelling procedural knowledge. The functional notation of the model lends itself to high level data manipulation languages. The data selection in these languages is expressed simply as function application. Further, the functional approach makes it possible to incorporate general purpose computation facilities in the data languages without having to embed them in procedural languages. In addition to providing the usual database facilities, the implementation also provides a mechanism to specify multiple user views of the database

Decision Support Systems: Issues and Challenges; Proceedings of an International Task Force Meeting, June 23-25, 1980

This book reports on a three-day meeting on Decision Support Systems held at IIASA. IIASA's interest in sponsoring the meeting was spurred by several factors. First, the term DSS clearly is used in a wide range of contexts; we hoped to develop a deeper understanding of the term and the new field to which it refers. Second, we felt that ongoing work in the DSS field would be enhanced by interaction between professionals who had been working on such systems and people from fields that function as "resource disciplines" for DSS. Finally we wished to bring professionals from several nations together, from the east as well as the west, to share experiences and to assess the viability of the DSS concept in different cultures. The broad objectives set for this meeting were realized in a number of ways. Virtually all the participants testified that they had gained a deeper understanding of DSS, the role it can play in asssisting managers in organizations, and the need for further development in key areas

A transputer based parallel database system.

A sophisticated database application generation environment known as DB4GL has been developed at Sheffield City Polytechnic. A unique feature of DB4GL is the object-oriented application model used to specify and generate database applications. Although DB4GL has many advanced and powerful features, such as a self-describing data dictionary and extensive integrity rule processing facilities; the system has not been designed for high performance in either the generation tools or the generated database applications. The Parallel-DB4GL (P-DB4GL) project represents an attempt to improve the performance of the generated database applications, by constructing a new concurrent implementation of DB4GL for execution on transputer-based parallel hardware. This thesis describes the DB4GL system as developed to the commencement of the P-DB4GL project. A prototype P-DB4GL system has been implemented that demonstrates how significant performance gains can be obtained from a concurrent implementation on transputer-based parallel hardware. Based on the successful results of this prototype system, designs for a fully functional multiprocessor P-DB4GL system are proposed. The details of this prototype and the fully functional designs are presented in this thesis. The thesis also provides an evaluation of the P-DB4GL project as a whole, and concludes with some suggestions for further research in the areas of parallel databases and object-oriented system implementation

Extracting Functionally Equivalent Object-Oriented Designs from Legacy Imperative Code

This research defines a methodology for automatically extracting functionally equivalent object-oriented designs from legacy imperative programs. The Parameter-Based Object Identification (PBOI) methodology is based on fundamental ideas that relate programs written in imperative languages such as C or COBOL to objects and classes written in object-oriented languages such as Ada 95 or C ++. Transformations have been developed that formalize the PBOI methodology and a formal proof is provided showing the extracted object-oriented design is functionally equivalent to the legacy imperative system. To focus the task of re-engineering, generic models of imperative programming languages and object-oriented programming languages have been developed. The formal transformations convert imperative subprograms represented in the Generic Imperative Model (GIM) into classes and objects represented in the Generic Object-Oriented Design Model (GOM). A taxonomy of imperative subprograms has also been developed which classifies all imperative subprograms into one of six categories. A proof-of-concept prototype has been developed and a 3000-line FORTRAN-77 system has been converted to an object-oriented design as a feasibility demonstration

The Sudbury Neutrino Observatory

The Sudbury Neutrino Observatory is a second generation water Cherenkov detector designed to determine whether the currently observed solar neutrino deficit is a result of neutrino oscillations. The detector is unique in its use of D2O as a detection medium, permitting it to make a solar model-independent test of the neutrino oscillation hypothesis by comparison of the charged- and neutral-current interaction rates. In this paper the physical properties, construction, and preliminary operation of the Sudbury Neutrino Observatory are described. Data and predicted operating parameters are provided whenever possible.Comment: 58 pages, 12 figures, submitted to Nucl. Inst. Meth. Uses elsart and epsf style files. For additional information about SNO see http://www.sno.phy.queensu.ca . This version has some new reference