One-Way Versus Two-Way Videotex

One-way and two-way videotex are often claimed to be more or less competing services, particularly if dedicated channels are used for the broadcast variety. In this paper we will try to dispel this notion. We will try to demonstrate that not only are the two services somewhat complementary in nature but that videotex will increase its potential by choosing a balanced combination of the two services. We also study the likely market penetration of videotex based on the speed of penetration of other communications-oriented services in the past and draw some conclusions how they might influence the market penetration of videotex systems and services

Public-Key Cryptosystems, Telesoftware and Other Novel Applications of Videotex

Telephone-based videotex systems are slowly changing from systems based on numeric, menu-type access methods that permit only information retrieval and limited message sending to more sophisticated, multiuser, interactive, transactional systems. This is partly due to the concept of adding external computers to the videotex network and partly due to the emergence of more intelligent terminals. In this paper, some major application areas that have been made possible by these developments, but have not yet received the attention they merit, are discussed in some detail: teleplaying, telegambling, telesoftware, telecomputing, and public-key cryptosystems. We maintain, and try to demonstrate, that these areas will significantly influence the market penetration and social impact of videotex. A number of the applications discussed will be available in Austria's videotex trial by September 82, making Austria the first country to offer such services on a nationwide videotex system

Propagating chain-free normal forms for EOL systems

We establish two types of normal forms for EOL systems. We first show that each ε-free EOL language can be generated by a propagating EOL system in which each derivation tree is chain-free. By this we mean that it contains at least one path from the root to the grandfather of a leaf in which each node has more than one son. We use this result to prove that each ε-free EOL language can be generated by a propagating EOL system in which each production has a right side of length at most two and which does not contain nonterminal chainproductions, i.e., productions A → B for nonterminals A and B. As applications of our results we give a simple proof for the decidability of the finiteness problem for EOL systems and solve an open problem concerning completeness of EOL forms

Printing without Paper?

More and more information is being read from cathode ray tube (CRT) screens. Despite improvements in many areas--display technology, readability of character sets, usable amount of information on a frame, software for handling pages--a glaring fact remains: Reading and browsing through information is still more pleasant using a stack of sheets of paper than using a display screen and electronically stored information. Yet, the preparation of hard-copy pages for once-only (or never) reading seems expensive and wasteful. It is our contention that this need not be the case if new concepts, such as printing on demand, and a concept we shall call multi-time paper (M-paper, for short) are used

On Alphabetic Searching in Videotex Systems

Of the four major types of interactive videotex systems currently being tested (Telidon, Teletel, Captains and Prestel-like) only one (Teletel) permits the use of alphabetic keywords for searching. It is contended that alphabetic keyword searching should be incorporated into future videotex systems. Methods of alphabetic keyword searching in the absence of alphanumeric keyboards are then discussed. A novel technique which has recently been implemented on Prestel-like systems is proposed as an interim solution until genuine alphabetic searching becomes available

Inhouse Versus Public Videotex Systems

The aim of this report is to analyse the relation between inhouse and public videotex systems and show that these systems are and should not be independent of each other and that they can and should complement each other rather than compete

Four Essays on Telematics and Videotex

These essays analyze the technology and possible new services resulting from the creation and introduction of new information services offered by videotex systems. The bare existence of these services and of the uses that this novel technology offers is far from sufficient to guarantee success. One has to take into account all relevant relationships with other services, which creates a "selection environment" that finally determines the acceptance of the new technology. It is extremely difficult to predict the market penetration and rate of diffusion of videotex services, factors that would be of significance for decision and policy makers. The authors examine the penetration of other, associated technologies (such as radio and television) in different countries and cultures and relate them to economic and social factors. New information services will be an important component of future society; indeed, they already have several definite features, whereas those of the future society are not yet discernible. Dr. Sebestyen addresses this problem, which transcends the macroeconomic impact of information technology and is a subject for study in the social sciences. Policies cannot be designed successfully without taking due account of all economic and social impacts of new technology. This is the overall message of these essays, together with an illustration of which uncertainties and risks a researcher in this field has to face

Printing Without Paper?

More and more information is being read from cathode ray tube (CRT) screens. Despite improvements in many areas -- display technology, readability of character sets, usable amount of information on a frame, software for handling pages -- a glaring fact remains: reading and browsing through information is still more pleasant using a stack of sheets of paper than using a display screen and electronically stored information. Yet, the preparation of hard-copy pages for once-only (or never) reading seems expensive and wasteful. It is the authors' contention that this need not be the case if new concepts, such as printing on demand, and a concept we shall call multi-time paper (M-paper, for short) are used

Some Remarks on Energy and Resource Consumption of New Information Technologies

Current research into the application of information technologies is largely focused on technological and socio-psychological issues. This report offers some remarks on the consumption of energy and other resources by these technologies. It is concluded that while in principle, new methods of telecommunication and information technology require fewer materials and less energy than traditional ones, carelessly designed systems and applications could cause tremendous increases in such use. The design of a new technological system together with human attitudes toward changing modes of communication will be primarily responsible for its consumption of energy and materials

Videotex Message Service Systems

Electronic message services supported by interactive videotex-like systems are described, classified, and analyzed in terms of the specific characteristics of such systems. A comparison of videotex message systems with other similar media is undertaken and the introduction of such service on an experimental basis is suggested. Recommendations are made to integrate special features, such as gateway services and an integrated Electronic Directory System, into such systems