By attaching anXDS Sigma 2 computer to Atlas via a shared disk, a multi-access facility has been developed without causing any interruption in the day to day running of the Atlas batch processing system. Jobs may be initiated on Atlas from a terminal and results from such jobs may be either returned to files or published on any of the normal Atlas peripherals.A statistics collecting package is included, which allows the gathering of information about any part of the system. Also, modifications can easily be made to the system to test the predictions of such a model. The model described here tries to relate response time to various system loads. In order to allow for the overlapping of disk and CPU time, we have queued the two activities in series.One of the useful side effects of constructing such I model is the focussing of attention on areas of the software which really do affect the response time. The paper outlines the development of this model, which is s t i l l in progress, highlighting some of the milestones and pitfalls encountered so far.KEY WORDS Multi-access Modelling Markov * This paper describes the work undertaken on an extension of a model first used by Scherr at MIT.
The Chilton multi‐access system has been running for about three years, and it is now possible in the light of experience to look back critically at the decisions taken during its definition. No system is entirely perfect and, by considering the highlights and shortcomings of this one (which may be described as being of the ‘support system’ type), similar designs in the future can benefit.
The purpose of this paper is to describe the implementation of a management training game on two different computers. A brief description of the game is included, giving an idea of what the game looks like to the players and the controller. The two implementations are, firstly, on an Atlas I computer, with a multi‐access system provided by an XDS Sigma 2 computer, and secondly on an ICL 1906A runing under the control of the GEORGE 4 operating system. Mention is made of some of the difficulties encountered in each case, and of the techniques employed to solve these problems.
In the final decade of the twentieth century, the Jet Propulsion Laboratory (JPL) was challenged to execute more missions "better, faster, and cheaper". Such a challenge would involve a search to operate missions at considerable cost reductions without compromising mission science return. One of the true success stories in cost-effective mission operations has been the development of a powerful and highly adaptable multi-mission sequencing system. JPL's Mission Management Office's (MMO's) Mission Planning and Sequencing Team (MPST) worked with core software developers to build and maintain this multi-mission sequencing system which capitalized on commonalities in mission sequencing and commanding. The MSPT, inaugurated in 1996, employed adaptable core mission software, tools, processes, procedures, scripting techniques, and interfaces to operate very different missions of varying mission complexity. Since its inauguration, the MPST has enabled the development and support for the sequencing and commanding of 10 different missions, as well as the coordination and operation of the Mars Relay network. These missions have included planetary orbital missions, planetary lander missions, a comet impact mission, an infrared astrophysics mission, solar wind and comet tail sample return missions, and other planetary and space physics missions. These missions have varied in cost and size from small Discovery class missions to a NASA flagship class "great observatory" mission. Mission spacecraft have included various bus architectures and have employed both deterministic and non-deterministic sequencing and operations. Yet by defining a set of adaptable, core capabilities, the MPST has successfully and economically serviced all of these missions.Similarly, project Mission Operations Systems are built upon core capabilities (ie. requirements, operational interfaces, software interface specifications, and core multi-mission software, processes and tools). These capabilities also share a considerable degree of commonality across all missions. By extending the philosophy of using adaptable, common core capabilities, we demonstrate that we can develop a core multi-mission Mission Operations System (MOS). We further demonstrate how these capabilities can support missions of varying complexity, spacecraft technology, and mission objectives. And finally, by providing a baseline to determine if an innovation has achieved its objective(s) and by providing a metric(s) to measure the innovation's enhancements, we argue that a multimission MOS would actually help enable the development of evolutionary and revolutionary capabilities. This paper describes the MPST Core sequencing and command capabilities. It discusses how these capabilities were adapted to very successfully operate missions of different objectives and complexity and what lessons were learned. It shows the considerable economic savings realized by its multi-missions approach. It then builds upon this approach to demonstrate how a complete multi-mission MOS could be develope...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.