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proposes using techniques as described in the previous section to improve model performance, if <br />possible. Data-oriented approaches (e.g., aggregation) to increase performance will also be studied <br />in modeling tasks. <br />Network Performance <br />Currently, RTi is connected to the Internet by a 56Kbps line with CSU. CSU is connected to a high- <br />speed Internet backbone. The State is connected to the Internet by a 56Kbps line. <br />If the Briefing Room machine experiences delays in accessing the database at RTi, then it may be <br />necessary to place a copy of the CRDSS database at the State, either on the Briefing Room machine <br />or the database server at the State. This issue will again help to identify any limitations in CRDSS <br />and its use in a distributed environment (e.g., at division offices). Although some performance <br />degradation is expected because of the use of 56Kbps lines, it is hoped that this will not be an issue <br />that drives the design of the system. The costs associated with using T1 or faster lines is prohibitive <br />and is not an option at this time. <br />Performance for Multiple Users <br />It is anticipated that multiple users will access the CRDSS. The complete design of the scenario <br />database will be made in Year 2. Year 1 activities will concentrate on ensuring that multiple users <br />can make model runs in their own space (e.g., their home directories on workstations). <br />UNIX workstations using the X Window System allow more than one user to run programs on a <br />single machine. The graphical output from programs can be displayed on a machine other than the <br />machine on which the program is running. An example of where this situation would occur is when <br />one user is sitting in front of a workstation, and a second user is logged into the workstation from a <br />PC that has been installed with X Window System software. In this situation, the workstation is <br />providing all of the processing and disk resources for both users. <br />The performance of such a workstation will be greatly limited by the capabilities of the machine <br />(e.g., processor speed and disk access speed). By choosing a relatively inexpensive SGI Indy <br />machine for the Briefing Room, it is hoped that issues related to multiple user access are identified <br />early in the project before a large number of workstations are acquired. If the Briefing Room <br />workstation performs badly, then more powerful machines can be tested for use as CRDSS multi- <br />user machines. <br />It is also anticipated that the database server will experience a degradation in performance as more <br />users access the database. The issues discussed in previous database sections will be studied as more <br />users access the CRDSS database, and appropriate changes will be made to the database. <br />Performance of Output Devices <br />Output devices consist of printers and plotters. RTi is developing the CRDSS with the assumption <br />that output from non-GIS components will be printed on a PostScript printer (it is assumed that the <br />State will provide enough PostScript printers to satisfy users' printing needs). Some GIS displays <br />may be printable on a PostScript printer, but, because of map size, may require a plotter to provide <br />large media. <br />4 <br />A275 05.10.94 1.05-14 Malers, Brazil <br />