S. Sarin and I. Greif, "Computer-based real-time conferencing systems," in Computer-Supported Cooperative Work: A Book of Readings, pp. 397--420, Morgan-Kaufman, 1988.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....characteristics of tasks and interaction styles, such as user roles, usage quotas, and resource contention manifested in deteriorated quality of service. Sarin and Greif discussed floor control for text based real time conferencing and point out a potential efficacy gain by employing multicasting [30]. Schooler touches on floor control issues with regard to video and audio in surveying multimedia conferencing [31] ITU standardization efforts on multipoint multimedia conferencing [38] are more geared towards circuit switched networks and do not include multicast provisions. In contrast to ....

S. Sarin and I. Greif. Computer-based real-time conferencing systems. In ComputerSupported Cooperative Work: A Book of Readings, pg. 397--420. Morgan-Kaufman, 1988.

....ViewBoards are electronic, they provide shared views for multiple people in a group setting. If each person in a group has their own ViewBoard, each of the ViewBoards can have a shared image. As one person makes changes to the image on their ViewBoard, the image is updated on the other ViewBoards [5, 6, 8, 11]. Similarly, changes on the ViewBoard can also result in changes to the image on the walls or counters. The images on the walls and counters are projections of computer generated images. One of the simplest ways to accomplish this is to take the video output from a computer display adapter and ....

Sunil Sarin and Irene Greif. Computer-Based Real-Time Conferencing Systems. Computer, pages 33-45, Octiber 1985.

....support effective group decision making. Most recent work in the GDSS literature has accordingly focused on how to best guide the group decision making process. Special Purpose Systems: A number of special purpose systems have been developed for specific kinds of group decisions. Sarin and Greif [40], for example, have implemented two real time conference systems including an interactive meeting scheduling system as well as a shared bit map graphics system. Other systems of this kind include NLS [12] that supports collaborative authoring of structured documents and TOPES [37] for graphically ....

Sarin, G. Computer-Based Real-Time Conferencing Systems. IEEE Computer (October 1985).

....contents is being modified. Awareness objects identify the users locking document parts. 5. 3 Telepointer service Telepointers are shared graphical entities designed to be manipulated by one participant at a time in order to point or get attention to a specific area or item of the public space [18]. The basic problem concerning the telepointer implementation is the lost shared context and consequent ambiguity in same time different place settings, particularly with large scale networks. To preserve the notion of movement, multiple messages have to be broadcasted to replicas. However, large ....

S. Sarin and I. Greif. Computer-based realtime conferencing systems. IEEE Computer, 18(10), October 1985.

....to support awareness in cooperative work are presented. 2 Shared spaces Shared spaces are the most noticeable way to support multiuser interactions in a shared environment based on personal workstations with graphical displays, keyboard and pointing devices. Shared spaces are defined by [Sarin 85] as the parts of several users graphical displays in which everyone sees the same information and by [Kamel 93] as a shared, dynamically updated display with one or more control centers. This kind of functionality has been originally attributed to the NLS system dated from 1968 [Sarin ....

....by [Sarin 85] as the parts of several users graphical displays in which everyone sees the same information and by [Kamel 93] as a shared, dynamically updated display with one or more control centers. This kind of functionality has been originally attributed to the NLS system dated from 1968 [Sarin 85,Greenberg 90,Engelbart 88b,Engelbart 88a] The user interface design issues posed by shared spaces are significantly different from the ones posed by a single user environment. In particular, the interaction modes must address multiple users interactions, different paradigms for display ....

[Article contains additional citation context not shown here]

S. Sarin and I. Greif. Computer-based real-time conferencing systems. IEEE Computer, 18(10), October 1985.

....the amount of retransmitted data in case of a transmission error. The token mechanism allows several levels of concurrency control. For example, we describe below a concurrency control hierarchy derived based on the collaboration paradigms used in existing systems [SFB 87, AEHL88, CF89, SG85] 6 Floor Control Real time teleconferencing systems employ such a strict concurrency control. A single token enforces control over a multipoint connection. The token will be passed on from one speaker to another whenever the floor is transferred. To obtain control of the floor, a participant ....

....speaker may hold the token during the first phase, whereas the token may be replicated and distributed to the questioners during the second phase. Replicated tokens will be destroyed at the end of the second phase. Discussion Groups Some environments such as real time conferencing systems [CF89, SG85] envisage a session breaking up into smaller discussion groups and thus holding multiple, concurrent conversations. In such a system, initially only a single token would be created and passed on from one speaker to another to achieve strict floor based control. However, the token can be ....

S. Sarin and I. Greif. Computer-based Real-Time Conferencing Systems. IEEE Computer, 18(10):33--49, October 1985.

....However, its widespread acceptance for this purpose is not supported by the evidence of research. Application sharing systems allow participants to share an ordinary single user application (e.g. a word processor or spreadsheet) The applications runs on one workstation. A controller (Sarin Greif, 1985) interacts with the program as one user and sends the screen image to every participant s workstation. The controller provides each participant with a telepointer (mouse pointer) so they can point into the shared space. The users access to the shared data is controlled through a floor control ....

Sarin, S. & Greif, I. (1985). 'Computer-based Real-Time Conferencing Systems.' IEEE Computer, 18(10), pp. 33-45.

....is worsened by the inadequacies of the current window systems for application sharing. Even though these issues are well known [16] they remain ignored in the latest graphics toolkits, such as Java GUI toolkits. Sharing collaboration transparent applications received great interest in the 1980s [2,9,13,15,16,22]. It was then predicted to be the dominant technology for synchronous collaborative work in the near future [13] However, in the recent years researchers have mostly turned to collaboration aware applications. Despite the great benefits of sharing collaboration transparent applications, the need ....

S. Sarin and I. Greif. Computer-based real-time conferencing systems. IEEE Computer, 18(10):33-45, October 1985.

....rollback and to reduce the amount of retransmitted data in case of a transmission error. We use the token mechanism to allow several levels of concurrency control. The following control hierarchy is derived based on schemes proposed in the literature [SFB 87, AEHL88, FKLC88, EGR89, CF89, SG85, Lan86, Lan90, Swi88, Str87] Floor Control As described earlier, real time teleconferencing systems employ such a strict concurrency control. A single token enforces such control over a multipoint connection. The token will be passed on from one speaker to another whenever the floor is ....

....speaker may hold the token during the first phase, whereas the token may be replicated and distributed to the questioners during the second phase. Replicated tokens will be destroyed at the end of the second phase. Discussion Groups Some environments such as real time conferencing systems [CF89, SG85] envisage a session breaking up into smaller discussion groups and thus holding multiple, concurrent conversations. In such a system, initially only a single token would be created and passed on from one speaker to another to achieve strict floor based control. However, the token can be ....

Sunil Sarin and Irene Greif. Computer-based Real-Time Conferencing Systems. IEEE Computer, 18(10):33--49, October 1985.

....Stefik suggested roving locks for the Xerox CoLab system [74] to serve alternating floor requests, where auditory signals and manual negotiation between parties indicate floor passing. The idea of automated floor control was proposed for the scheduling and calendaring systems RTCal and MPCal [31, 67]. Lantz V Conf system [41] first realized a floor control unit to interface with a conference agent mediating I O between shared applications. MMConf by Crowley et al. 9] features a centralized architecture where a token based scheme regulates usage of telepointers between replicated ....

Sarin S, Greif I (1988) Computer based real-time conferencing systems. In Computer Supported Cooperative Work: A Book of Readings, 397-420. Morgan-Kaufman

....those streams converging on it. This has a matching demultiplexer at the other end of the connection, from which streams diverge to their respective destinations as shown in Figure 3.3. This scheme is similar to the use of a central controller to serialise updates to a shared workspace [Sarin85] and to combine individual voice streams for conferencing [Ades87] In these cases, the amount of communication can also be reduced by eliminating the need for a direct link between each participant. Source Source Sink Sink Multiplexer Demultiplexer Figure 3.3: Centralised Approach. ....

S. Sarin and I. Grief. Computer-Based Real-Time Conferencing Systems. IEEE Computer, pages 33--45, October 1985. (p 37)

....that the application is busy and that the user must wait. c) Help cursor, showing information about the icon under the cursor Figure 1. Conventional uses of cursors to show semantic information and only a few point systems used them over the years, e.g. multiple telepointers in Mblink [13], and the single active cursor in shared window systems [3] It wasn t until 1987 that telepointers (and indeed groupware in general) were revisited with any seriousness. CoLab was a computer supported meeting room with a variety of electronic meeting tools [14,15] It included a shared virtual ....

Sarin S. and Greif I. (1985). Computer-based real-time conferencing systems. IEEE Computer, 18(10), pp. 33-45. Reprinted in [7].

....and selection policy. The flows consistency model assures that most update operation can be executed immediately because they cannot generate conflicting updates. Reversible Execution This is another recent proposal for concurrency control in groupware systems. With reversible execution [Sari85], operations are executed immediately but information is kept so that they may be reversed later if necessary. Many optimistic concurrency control mechanisms fall into this category [Bern87] A global time ordering is defined for the operations (this may be provided by a central sequencer or by ....

Sarin, Sunil; Greif, Irene. "Computer-Based Real-Time Conferencing Systems." IEEE Computer, Vol. 18, No. 10, Oct/85.

No context found.

S. Sarin and I. Greif, "Computer-based real-time conferencing systems," in Computer-Supported Cooperative Work: A Book of Readings, pp. 397--420, Morgan-Kaufman, 1988.

No context found.

S. Sarin and I. Greif. Computer-based real-time conferencing systems. In ComputerSupported Cooperative Work: A Book of Readings, pg. 397--420. Morgan-Kaufman, 1988.

No context found.

S. Sarin. Computer-based real-time conferencing systems. IEEE Computer, 7(10):33--45, Oct. 1985.

No context found.

S.Sarin, I.Greif, Computer-based Real-time Conferencing System, IEEE Computer, 18(10), Oct. 1985, pp.33-45.

No context found.

Sarin, S., & Greif, I., Shared-data conferencing, (1985), Computer-based real-time conferencing systems, IEEE Computer, 18(10), pp. 33-45.

No context found.

Sunil Sarin and Irene Greif, Computer-Based Real-Time Conferencing Systems, in Computer Supported Cooperative Work: A Book of Readings, Irene Greiff (ed), Morgan Kaufmann, 1988, pp397-421.

No context found.

Sunil Sarin and Irene Greif, Computer-Based Real-Time Conferencing Systems, in Computer Supported Cooperative Work: A Book of Readings, Irene Greiff (ed), Morgan Kaufmann, 1988, pp397-421.

No context found.

Sunil Sarin and Irene Greif, Computer-Based Real-Time Conferencing Systems, in Computer Supported Cooperative Work: A Book of Readings, Irene Greiff (ed), Morgan Kaufmann, 1988, pp397-421.

No context found.

S. Sarin and I. Greif, `Computer-based real-time conferencing systems', IEEE Computer, 18, (10), 33-- 45 (1985).

No context found.

Sarin, S. & Greif, I. (1985). Computer-Based Real-Time Conferencing Systems. Computer, 33-45.

No context found.

S. Sarin and I. Greif. "Computer-Based Real-Time Conferencing Systems." IEEE Computer Magazine, October 1985, Vol. 18, No. 10, pp. 33-49.

No context found.

S. Sarin and I. Greif. Computer based real-time conferencing systems. In Computer Supported Cooperative Work: A Book of Readings, pages 397--420. Morgan-Kaufman, 1988.

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