Раздел 4 Первое занятие

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Active information systems are database processing tools intend­ed⁴⁸ to represent and manipulate data description of large real-world systems that have a complex dynamic behaviour. It is apparent⁴⁹ that if the language of recipient and sender differs, the data of the mes­sage cannot be used.

In automated information systems the computers must receive and at the same time interpret and act on the data. In information systems, to be more explicit (точнее), the fields of computers and communications are merging⁵⁰.

Thus, the problem that hinders⁵¹ man-machine communication is language barrier. The computer system responds to commands only if they are given with total accuracy in a highly restricted artificial language. Without it an error message is the response.

Therefore, program optimisation is of crucial⁵² importance.

A certain language program often proves inefficient on another machine. A good deal of work is now being done on automated pro­gram optimisation. Machines with new architectures possessing highly parallel structures are now being designed and built. Parallel struc­tures including hundreds, even thousands, of processors are now be­ing designed and built. True, this software optimisation remains at the very early stage. What is needed? We need: (1) better algorithms;

2. better languages and operating systems; (3) better portability, so that software has a longer lifetime and can therefore sustain⁵³ more development; (4) better program optimisers.

Algorithms are especially important to take advantage of vector and microprocessor parallelism. Once we have designed algorithms, we must provide better languages to allow more efficient expression and execution⁵⁴ of these algorithms.

One does not wish to program all programs for all machines, es­pecially when it means reprogramming each program to get optimum performance. Other languages and programming paradigms should be portable (зд. используемые для всех видов компьютеров).

The potential for portable operating systems is obvious. But to achieve it requires much more progress in the areas of standards and optimisation.

True portability requires a high-level representation of algo­rithms, with no machine-dependent semantics.

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Микроэлектроника настоящее и будущее

Thus programming productivity becomes a more and more im­portant issue, which leads to the idea of sharing⁵⁵ programs across different hardware platforms to save time and cost on program de­velopment.

With the development of Internet and Wfeb computing (W-сеть), the sharing of programs across heterogeneous platforms, the estab­lishment of an unified⁵⁶ programming and computing environment⁵⁷ across the fundamentally heterogeneous World Wide Wfeb become critical issues, which lead to the booming (зд. появление) of brand⁵⁸ new programming languages such as Java. Another possible trend is the popularity of script⁵⁹ language on the Internet.

New programming languages that can support parallel and dis­tributed computing are in great demand. There are currently two approaches⁶⁰ to this special issue. One is to adapt⁶¹ currently avail­able popular programming languages, for example, С and Fortran, and equip them with special library. The results are parallel and dis­tributed programming languages like CC+ + , pC+ + , and HPF (High Performance Fortran). Another approach is to design con­ceptually new languages that exploit the fundamental principle of parallel and distributed computing. The results are programming languages like Linda.

Programming languages may be treated⁶² as useful vehicles⁶³ for gaining access to important distinctions⁶⁴ of computing.

Technological, economic and educational developments now al­low us to design information systems. Information systems model complex real-world events that have a complex dynamic behaviour⁶⁵. In automated information systems the computers must receive and at the same time interpret and act on the data. In information sys­tems, to be more explicit⁶⁶, the fields of computers and communica­tions are merging. The integration and coordination of the individu­al information systems and computers introduces new requirements, design parameters, and tradeoff⁶⁷.

These considerations⁶⁸ affect system issues ranging from the ar­chitecture of specific computers to the architecture of overall infor­mation systems.

The past couple of decades have seen tremendous progress in the technology of computing devices, both in terms of functionality