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3. Broad-band ISDN
3.1 Outline of Broad-band ISDN
The broad-band ISDN (B-ISDN) being standardized at CCITT can be understood through such keywords as the asynchronous transfer mode (ATM), the fibre-to-the-home (FTTH), and a multimedia network covering data up through a high-definition TV (HDTV).
As shown in figure 7, the transmitted data stream is divided into sequences of a small amount of data called a cell. Each cell has a 5 octets header and a 48 octets information field. At the transmission line, cells are packed without any gap, as shown in figure 7. Various identifiers in the header specify a cell and contain sufficient information to deliver a cell. When a high bitrate is necessary, more cells are captured. In other words, network customers can define the capacity of a channel at their own will. This is called a virtual channel. Customers can take as many virtual channels as desired in their subscribers' lines.
B-ISDN is widely believed to be the telecommunication infrastructure for the twenty-first century. On the basis of B-ISDN, NTT announced the twenty-first century telecommunication service vision, by the name Vl&P, an acronym for visual, intelligent, and personal communications services.
Figure 7 Asynchronous Transfer Mode (ATM)
Table 2 HDTV digital transmission
|Studio grade||624M b/s|
|Program distribution grade||100-150M b/s|
|High quality entertainment||40-50M b/s|
|Application specific||10-20M b/s|
3.2 Multimedia Service Example
3.2.1 Visual Telephone
Visual telephone is believed to be one of the major terminals for the twenty-first century. Its picture quality will be much better than the CIF-based picture in the NISDN environment.
Depending on the application of high-definition TV (HDTV), necessary bitrates will become versatile, as shown in table 2. FTTH in B-ISDN will make a wide range of HDTV applications easy.
3.2.3 Personal Multimedia Teleconferencing
A desktop workstation (WS) used in the office will become multimedia. Office workers will be able to do many kinds of work at their WSs. Teleconferencing is an example. In order that office workers with their own WSs will be able to participate in meetings from their desks, multipoint capability is essential. The need for participants in a meeting to see one another makes multi-motion-picture-windowing important. It may be desirable to distinguish who is speaking.
Figure 8 shows a typical screen image of such a multimedia teleconferencing system developed by NTT. From the WS, a participant can send text, scanned image, and telewriting information; his own voice and image; and stored video in colour. The system has audio-window capability. The voice of a person whose picture window is at the left comes from the left, and the voice at the right from the right. Another feature is private conversation capability. Any two persons can talk confidentially during the meeting; this private conversation voice comes from the extreme right.
Network-casting is a notion that can be positioned somewhere between broadcasting and conventional telecommunication. Broadcast media such as radio or TV are called mass media, by which information is distributed to many people, e.g. several thousands of people. Conventional telecommunication media such as telephone and facsimile can distribute information to only a small number of people, e.g. less than 30 people in a certain amount of time, and thus may be called "mini-media." In relation to these, network-casting might be called a midi-medium.
Figure 8 Typical picture in the personal multimedia teleconferencing
A baseball game in a local stadium may be network-cast to people in a big city through B-ISDN. In an ATM switch, an incoming cell could be duplicated to branch into two or more outgoing cells, as shown in the upper part of figure 8. Then information from the visual source could be distributed to many points. The other method is to branch by using local nodes, as shown in the lower part of figure 9. These two methods could be combined for the economical realization of network-casting.
Different from broadcasting, which is dependent on radio waves, network-casting goes through optical fibre cables, whose capacity is unlimited. TV programmes that are represented by terms such as personalized TV and interactive TV can be distributed through B-ISDN. This is one reason for characterizing network-casting as a midi-medium.
Figure 9 Network-casting through B-ISDN
4. Concluding remarks
The status of ISDN service and its applications have been described. Multimedia communication, initiated by ISDN, will be promoted by B-ISDN. In addition to this, B-ISDN will facilitate offering a new information service, which might be called network-casting.
The electronic library
2. Library automation and the electronic library
3. Other examples of the electronic library
4. The electronic library of the future
The paper reviews the progress already made with the aid of automation and networking towards the creation of "electronic libraries" and then briefly describes various technologies now in the research or development stage. These include intelligent gateways, electronic publications and filing systems, telepresence, and on-line hypermedia systems. Finally, attention is given to suggesting scenarios for the future of the electronic library.
Prompt and efficient provision of documents or information is the most important function of the library. Librarians have worked for a long time towards performing this function more effectively and satisfactorily in the service of users.
Recent developments in information technology, which could be defined as a sophisticated technology related to the production, transfer, processing, and presentation of information based on a combination of computer and telecommunications technologies, opened a new way for librarianship. Save for some small libraries, it is difficult now to find one not equipped with a computer. The computer has come to be used for almost all tasks carried out in the library: acquisition, cataloguing, searching, circulation - and even for reference services.
Concurrently with the development of computer technology, there have also been the development of communications technology and the construction of extensive communication networks. The library community has worked to exploit this technology as well, and, as a result, library networks, large and small, have been built in many parts of the world. At present, many libraries, having completed the first phase of computerization and networking, are trying to make the systems more intelligent and easier to access and to make use of extensive information resources distributed at many places. The libraries resulting from these efforts are sometimes called electronic libraries.
By the term "electronic library," however, different people mean different things. A glance at the articles published in The Electronic Library, a journal dedicated to this subject, will reveal that they deal with a variety of topics, including OPACs, CD-ROMs, library automation, library networks, on-line information services, and multimedia information retrieval.
It could, of course, be supposed that the editor of the journal accepts contributions relevant not only to the electronic library per se but also to other technological components that would form part of the libraries of the future. Nevertheless, one might also conclude that at present there is no generally accepted definition of the term "electronic library."
Besides the problem of the definition, another problem arises when discussing the subject; the distinction between the electronic library and certain other concepts is not clear.
One such concept is electronic publishing. Although this concept, too, is not entirely clear, it usually means processes that produce publications in the formats of the new media. Since a library that provides users with this sort of publications may call itself an electronic library, the concept overlaps the electronic library in many respects.
Another related concept is a sophisticated computer-based work environment that enables one to access distributed computers and information resources and to communicate with others. Since provision of required information to the user is a major task that librarians must perform, this has many points in common with the electronic library. At present, intensive efforts are also being made in the area of multimedia information systems.
The ambiguity of the term "electronic library" reflects the fact that so far there have been few systems that many people can agree to call electronic library. In fact, there have been a variety of approaches to the electronic library:
- library automation and networking
- electronic publishing
- computer networks
- hypermedia systems
- more intelligent systems
Actual systems usually adopt some combination of these approaches.
Keeping these points in mind, the author reviews the work carried out so far as well as ongoing projects relating to the electronic library and its technological components. In section 2, contributions made by libraries are discussed, including library automation and networking and Maggie's Place. The author then discusses, in section 3, several other services and projects as examples of the electronic library. Included here are intelligent gateways, collections of electronic publications, electronic filing systems, telepresence, electronic journals, and on-line hypermedia systems. In the final section, after discussing the future of the technology, problems of facilitating access to information in the age of electronic libraries are considered.
Since databases, communication networks, multimedia and hypermedia systems, intelligent front-ends, and human interfaces, which have something to do with the present subject, are to be dealt with in detail by other speakers, the treatment of these points in my paper will be kept to a necessary minimum.
2. Library automation and the electronic library
With the introduction of information technology, there have recently been considerable changes in library operations. Since some of these changes may lead to the realization of the electronic library, the development in this area must be reviewed.
2.1 Library Materials and Electronic Publishing
Libraries collect a variety of materials for preservation and use. They include not only traditional print-on-paper media like books, journals, newspapers, and maps, but also audiovisual materials like gramophone records, audiocassettes, and video cassettes. Now, much of the information and data that has been recorded on the traditional media has also become available in electronic form. Many libraries have begun to collect this type of material, that is, products of a process called electronic publishing.
As with "electronic library," there is no general definition of what constitutes electronic publishing; nevertheless, Feeney  has divided the latter into five categories:
(1) Broadcast services (non-interactive): teletext, cable services, direct broadcasting by satellite
(2) On-line services (interactive): on-line databases, videotex
(3) Stand-alone products: videodiscs, compact discs (CD), digital optical discs
(4) Electronic journals: integrated publication systems covering writing, editing, refereeing, publishing, and reading
(5) Bulletin boards: electronic mail, teleconferencing
As Feeney points out, these categories are not mutually exclusive. For example, videodiscs may be used to supplement an on-line service for graphics backup or CD-ROMs can be made accessible on-line via networks.
Most libraries try to offer these services to users, if their budgets permit them to do so. At the same time, publishers publish their products more and more in the electronic form, and it is forecast that electronic publications will come to form a large percentage of publications, sometimes without their counterpart in printed form. When a large part of the collection of a library becomes available in the electronic form and thus accessible electronically, some might call it an electronic library. Examples of this type are shown in section 3.2.1.
2.2 Library Automation and Networking
Library operations consist of the following major processes carried out with the aim of making the collection and other sources of information available to users: selection and acquisition; cataloguing; classification; indexing; searching; locating and retrieving; and circulation.
During the past 25 years or so, the computerization of part or all of these processes has progressed in most libraries with varying degrees of integration .
During the 1970s, a number of so-called total integrated library systems became available on the market, and these have been introduced into many libraries. In addition to providing modules to deal with the processes mentioned above, these systems usually provide access to networks and bibliographic utilities.
Access to outside information resources, e.g., catalogue databases located in other libraries and on-line information services, and communication with other libraries via networks are essential components of today's integrated library systems.
Some people may ask for more; Epstein  listed the following features librarians asked to have included in integrated systems: circulation control; public access catalogue; MARC record capability; authority control; acquisitions handling; materials booking; reserve book room control; serials control; local reference files and community information accessible on-line; word-processing; information and referral files accessible on-line; electronic mail; COM catalogue production; remote terminal access; two-way cable television; teletext; payroll and check production; budget control; staff scheduling; personnel records; personnel work statistics; access to outside databases; access to any other automated library system; interface to bibliographic utilities; and high-use indexes.
These features reflect the time when many of the full-text databases and CDROM publications currently available were still in development and were less spoken about within the library community. Including these in an integrated library system of today would produce what might be called an electronic library system.
The development of library networks at the regional and national levels, based on computer and data communications technologies, took place concurrently with the automation of individual libraries . At the core of the network were MARC records and union catalogues. The bodies responsible for the administration of the networks also developed hardware and software packages to be installed by member libraries to help automate their housekeeping and networking.
Another development based on modern technology was local area networks (LANs). Through this technology, which enables units within a relatively small area to be interconnected, local area networks have been installed in many libraries, sometimes as part of extensive campus networks, with more efficient resource sharing in view. Examples include public libraries [14, 26], as well as academic and special libraries [1, 2, 33].
Library automation and networking have rarely gone beyond the provision of secondary information like that in bibliographic databases. Today, many libraries are using electronic mail or telefacsimile to transmit requests for interlibrary lending, but those using telefacsimile for interlibrary lending, i.e., document delivery, are fewer, although there are some reports from libraries that have made use of it on experimental or routine basis [15, 31, 37]
2.3 Maggie's Place
If a library acquires electronic publications that can be accessed on-line by any user in the community, provides access to on-line catalogues and commercial bibliographic databases as well as to the community information files prepared by the library, and makes arrangements with other libraries for resource sharing, many librarians would not hesitate to call this library an electronic library.
Probably the best known example of this type would be Maggie's Place, of the Pikes Peak Library District in Colorado, USA [9, 11].
Planned and implemented under the leadership of its Director, Kenneth Dowlin, the Pikes Peak Library drew attention from all over the world. The seven-point role of the library prescribed by Dowlin provides the following services: (1) access to complicated or seldom-used databases; (2) community conferencing and message centre programmes; (3) on-line access to information on library resources; (4) access to community data and community information locations for referrals; (5) access to resources in other libraries via networking; (6) access to high-demand information and materials via computer or videodisc; and (7) access to electronic resources for those who cannot afford home computers or terminals .
Almost all these objectives were reached in this library and many librarians saw it as a model for the electronic library. At present, connection is made to two library networks, the CARL system and the MARMOT network, and users can access resources in other libraries via the networks.
The community information files accessible in the library and from home are: (1) calendar file; (2) agency file; (3) club file; (4) local documents; (5) local authors; (6) courses; (7) senior housing; (8) day care; and (9) facts .
2.4 User Satisfaction with the Current Automated Libraries
Library automation and networking have changed libraries drastically, and computers have become essential equipment for librarians. At the same time, electronic publications appear to an increasing extent, and libraries acquire and offer these publications even though most libraries still do this on an experimental basis. Many librarians might agree on the view that these developments are an inevitable step that should in due course lead to the full-fledged electronic library.
There is, however, a different view. With the advent of more sophisticated, user-friendly information systems, most of which are still in the development stage, people may come to prefer these systems to traditional libraries except for reference to old print-on-paper documents. This is the scenario that Lancaster envisaged in his book, Toward Paperless Information Systems , published in 1978.
This view, I suspect, may have come less from the predicted advancement of technology than from the demarcation that librarians had unconsciously set to their work. The points here are as follows:
(1) Library operations start from the point where publications have appeared. Publications are considered to be data, i.e., things that are given.
(2) The library is concerned primarily with printed documents. Although it has been dealing with non-book materials as well to some extent, this might reinforce the view that the so-called new media constitute simply additional non-book materials.
(3) Major efforts have been made in libraries towards automation for access to secondary information. The primary information has been out of the sphere where the information technology plays a major role except for interlibrary loans sometimes done by telefacsimile.
(4) The automation of a library has been directed to computerizing individual processes carried out in the library. The traditional work flow within libraries has usually been retained without much rethinking about the whole process of library operations, a rethinking that is required in an age when the traditional systems such as those for publication, distribution or dissemination, storage, and retrieval are changing.
(5) The advent of the new technology that is now in the research or development stage will probably change the whole structure of information dissemination. As Alan Blatecky, Vice-President, MCNC, USA, pointed out, "Although communications and computing technologies have been changing rapidly over the last 20 years, the changes we face over the next decade will be radical and will change the way we think and do business; in effect, it will change our culture itself" .
3. Other examples of the electronic library
The huge collections of full-text databases that some on-line bibliographic services such as Dialog, BRS, Data-star, and NACSIS provide together with bibliographic databases might be called electronic libraries. In fact, if full texts, including diagrams and photographs, of many more journals were put on the computer and made available on-line with an appropriate tool to assist in obtaining the articles most relevant to the user's inquiry, any information could be retrieved on the desktop within several seconds, which is one of the goals of the electronic library.
The present systems, however, have not yet reached this point due mainly to the restrictions of the technology posed at the time of implementation and that continue. The problems are line speed, access time, the volume of data that can be stored, file structure and software for information retrieval. For these reasons, full-text data are usually limited to the coded character data of texts and therefore at present, diagrams and photographs must be sent to users by mail (snail-mail), telefacsimile, or some other means.
Efforts now being made in this area, however, lead one to expect that this will not continue for long. There are many systems worthy of mention.
3.1 Intelligent Gateways
Although, at present, the databases provided by on-line information retrieval services are mainly those of bibliographic data, recently there has been a significant increase in the number of full-text databases offered by the major online service vendors. One possibility of realizing an electronic library is to develop an intelligent gateway, or a front-end, that enables users to search the hundreds of databases provided by a number of vendors located at different places in the world.
EasyNet is one of the commercially available software packages of this type [22, 24]. EasyNet allows the searcher to choose the most appropriate database. There are two options for this; that is, either the software or the searcher may select the database. EasyNet then translates automatically the user's search query into the command language used by the system on which the required database resides; dials the system; logs in; accesses the database; and initiates a search. The limitation of this software is that it usually provides the name of only one system as the most relevant to the user's requirements .
Another approach of this type is BioSYNTHESIS, which is under development at Georgetown University, USA, as part of the Integrated Academic Information Management System (IAIMS) project sponsored by the National Library of Medicine (NLM), USA.
BioSYNTHESIS is a two-phase project to develop an intelligent retrieval system. The prototype BioSYNTHESIS II menu includes the following items :
(1) Bibliographic databases
a. On-line catalog
c. ALERTS/CURRENT CONTENTS
d. Full text
(2) Information databases
e. Drug and poison info
f. Physician data query (PDQ)
(3) Diagnostic systems
i. Electronic news
j. Mail Box
k. External access
The IAIMS project started several years ago with the intention of making the information management systems of academic health sciences centres more intelligent and of connecting them to each other as well as to the National Library of Medicine.
Expected components of the system, which are still in the research stage, are a context selector and an information analyser, which will enhance the system's capability by making it more intelligent and thus allow even the novice user to exploit the system's full capacity with great ease.
3.2 Collections of Electronic Publications:
Networked and Not Networked
3.2.1 Optical Disc Installations
CD-ROMs and other optical disc publications have been increasing in number. Although the major part of this category is bibliographic or composed of other reference data, the number of full-text databases is expected to increase rapidly. Since more and more publishers are introducing electronic processing, it is easier to produce publications in electronic form in spite of the fact that the present practice is to have print-on-paper publications.
A factor contributing to the predicted growing share of electronic publications is standardization. Adoption by publishers and printers of standards such as those related to the Standard Generalized Markup Language (SGML), which, while intended to serve for print-on-paper publications as well, will encourage the introduction of electronic processing in the whole publication process and will certainly change the nature of publications. A decision on the medium of publications (i.e. in one or more forms) can be made even at the last stage.
When a variety of electronic publications is available at one place, it becomes a kind of electronic library. From a technical point of view, remote access to a centralized collection of data via a star network is not a big problem, except for matters related to data security.
Thus, several libraries have installed a number of optical disc publications for public use either by asking the user to come to a designated room to operate one of the computers specified for each disc , or by allowing the user to access them on-line .
3.2.2 Electronic Document Delivery
Ambitious efforts have been made in the publishing community, sometimes in cooperation with other bodies like libraries, with different objectives in mind, to create huge collections of publications in electronic form and deliver the contents to users at remote sites. Examples include Adonis using CD-ROMs, APOLLO by satellite transmission, and HERMES by means of teletex .
The Knowledge Warehouse is a project that has been conceived and carried out by Publishers Databases Ltd. United Kingdom, with the support of the British Library and the Department of Trade and Industry. The project aimed to construct a national archive of the electronic form of knowledge works by establishing the methods for preserving the electronic version of works [5, 36].
3.3 Electronic Filing Systems
The electronic filing system refers to a mass storage system that uses optical discs as storage media. There are two types of optical discs: erasable and WORM (write once, read many). At present, many systems are available on the market and users can choose the most appropriate ones according to their requirements for storage capacity or other characteristics. The storage capacity of one model reaches a level of 1,000 Gbytes. The system usually stores, instead of coded characters, digitized images of documents, which require more storage capacity. Many firms make use of the system for storing technical reports, patent information, transactions information, scientific data, and so on.
If the contents of books and journals are stored on a system and the user is able to search any part of a book or any article in a journal, the system becomes a kind of electronic library.
ELNET, the electronic library network, is a full-text database of articles compiled from 37 newspapers and 120 magazines published in Japan. It is considered to be a kind of computerized clipping service. The system allows online searching by keywords and free text terms, and if searchers find relevant articles, they can, by using a simple command, order copies of the original documents stored on digital optical discs, which are then transmitted by facsimile in a matter of seconds . As of 1 April 1992, the system contained 2 million articles.
The storage consists of nine jukebox-type optical disc drives, on each of which up to 25 discs can be mounted. The optical discs are of the WORM type and can store, in theory, on average 20,000 articles per disc - in practice, slightly less than this figure. At present, 40 to 50 per cent of the total storage capacity has been filled by 2 million articles. Two thousand articles per day, or 600,000 articles per year, are added to the system.
The database has digitized images of articles and thus includes photographs and diagrams as well as characters. The resolution of the digitized images is 400 dpi, a quality equivalent to the G4 facsimile. For the moment, not all articles are included in the database. Articles written and signed by outside contributors are sometimes omitted because the copyright usually belongs to them.
Terms such as telepresence, virtual proximity, artificial reality, and virtual reality, though their connotations differ slightly, especially between the first and the second pairs, usually refer to an artificially created environment where people can imagine handling a real object that does not exist in immediate proximity to them, or where people at different locations can sense and talk to each other as if they were participating in a meeting held in one room.
If one could, while sitting at one's desk, visit any library in the world, pass through the entrance to the main hall, walk down the corridors, enter a room, select any book from the shelves, browse in one book after another, or read one from cover to cover as desired, and print any page of which a copy is wanted - all of this simply by mouse-clicking on the icons on the screen and thus have access to huge amounts of data or information regardless of its location, the system would be a realization of telepresence.
Songoku is a prototype system of this type with an emphasis on the browsing process . The name Songoku, or Sunhour in Chinese, is that of a fictitious character in the form of a monkey which, in a novel, followed a famous Chinese priest, Xuanzang, who actually did travel to India in the seventh century to acquire texts of the Buddhist scripture.
In addition to providing almost all the functions listed
Songoku the computer may also read texts to the user by means of a speech- generation subsystem. Additional functions that the developers plan to include are:
- to allow the user to browse among the book shelves in search of desired books;
- to create new book shelves filled with books related to the topic that the user commands;
- to see the view of the town where the library is located;
- to allow users to participate in the production of electronic books;
- to develop an electronic management system to protect the copyright; and - to have a synchronized presentation of texts, music, speech, still images, and moving pictures. Some of these remain to be realized.
3.5 Electronic Journals
By the term "electronic journals" is meant here a networked computer system that enables people in the research community, whose roles entitle them to access to materials in process, to write, submit, edit, referee, or modify the contributions made to a journal, and to read them when "published." From the technical point of view, there are no big differences between conferencing, messaging, and on-line publishing. Two systems are well known: EIES and BLEND.
EIES (Electronic Information Exchange System) is an electronic journal system developed at the New Jersey Institute of Technology, United States . The system had the following "publications": a newsletter called Chimo; a public conference or unrefereed journal called Paper Fair; an unrefereed publication called Poetry Corner; an electronic journal entitled Mental Workload; and an inquiry-answer system called Legitech (from this a "brief" is compiled afterwards for each inquiry). The system also included other functions such as messaging, conferencing, and directory services.
BLEND (Birmingham and Loughborough Electronic Network Development) is another electronic journal system developed by two universities in the United Kingdom . The system was designed to include the following publications and messaging facilities: refereed papers; comments and discussion; annotated abstracts or annotated bibliography; LINC News; Bulletin; cooperative writing of papers; poster papers; enquiry-answer system between experts; and "Readers Only." At the implementation stage, special efforts have been made to develop userfriendly interfaces. The project is well documented.
3.6 On-line Hypermedia Systems
A hypertext system is a computer system that handles textual data and allows the author to link textual chunks. The system also provides the facilities for the user to manipulate these chunks and to create new links from one chunk to another chunk, to bibliographic data, or to notes added by the user. Yankelovich and others point out remarkable features of the hypertext system as follows:
using a computer-based hypertext system, students and researchers can quickly follow trails of footnotes and related materials without losing their original context; thus, they are not obliged to search through library stacks to look up referenced books and articles. Explicit connections-links - allow readers to travel from one document to another, effectively automating the process of following references in an encyclopedia. 
Hypermedia is an extension of hypertext that incorporates, in addition to texts, other forms of presentation such as diagrams, still images, sound, and moving pictures.
If, as claimed, a user could obtain information regardless of its medium by using this sort of system, then it might be unnecessary to have the books, journals, bibliographic databases, or other information sources that are, at present, provided separately by various agents.
Vannevar Bush's "memex" is considered by many specialists as a prototype of the hypermedia system - although he proposed using dry microphotography for storage of his "mechanized private file and library," which he named "memex" . The essential feature of the memex is "associative indexing," a process of "tying two items together."
Current research efforts are focused on the implementation of Bush's idea on the computer and in a network environment.
There are a number of hypermedia systems on the market, and many more are in the research and development stage. Examples are: Analyst (Xerox Special Information Systems); Andrew (Carnegie-Mellon University); Guide (Owl International); Intermedia (Brown University); Telesophy (Bellcore); Xanadu (Autodesk); and so on. Here I shall refer to only one of these, Intermedia.
Intermedia is a hypermedia system that works in a multi-user, network environment . The system was developed at the Institute for Research in Information and Scholarship, Brown University. It contains five applications: a text editor, a graphics editor, a scanned image viewer, a three-dimensional object viewer, and a time-line editor. A significant feature of the system is a "web," which is a set of links that have been grouped together under a single name. Intermedia is used at the English and biology departments of Brown University and at the Johns Hopkins medical school to create electronic course materials that provide students with new exploratory environments for their fields .
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