Institute for Systems Research Technical Reports
Permanent URI for this collectionhttp://hdl.handle.net/1903/4376
This archive contains a collection of reports generated by the faculty and students of the Institute for Systems Research (ISR), a permanent, interdisciplinary research unit in the A. James Clark School of Engineering at the University of Maryland. ISR-based projects are conducted through partnerships with industry and government, bringing together faculty and students from multiple academic departments and colleges across the university.
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Item Next Generation Satellite Systems for Aeronautical Communications(2000) Ercetin, Ozgur; Ball, Michael O.; Tassiulas, Leandros; Tassiulas, Leandros; ISR; NEXTORThe US airspace is reaching its capacity with the current Air Traffic Control system and a number of flights that is constantly rising, and estimated to be over 54 million per year by 2002. The FAA has undertaken several projects to modernize the National Airspace System (NAS) to ensure the safety of the increasing number of flights. Of special importance is the modernization of the Air-Ground (A/G) Communications infrastructure, which is the heart of the air traffic control (ATC).The current plan in the modernization of the A/G communications is to migrate from analog voice only system to integrated digital voice and data system. The next generation satellite systems can be an alternative to the terrestrial A/G systems by their low propagation and transmission delays, global coverage, high capacity, and free flight suitable characteristics. In this paper, we give an overview of the current and the future ATC architectures, describe the systems and the communications issues in these systems, and develop a framework in which LEO/MEO next generation satellite systems can be integrated to the future ATC systems.
Item Integrated Product and Process Design Environment Tool for Manufacturing T/R Modules(1997) Karne, Ramesh K.; Lai, Hsing-Tsu; Dandekar, Swati V.; Baras, John S.; Ball, Michael O.; Bashyam, Sridhar; Trichur, Vinai S.; Karir, Manish; Kebede, Abraham; Williams, Jim; ISR; CSHCNWe present a decision making assistant tool for integrated product and process design environment for manufacturing applications. Specifically, we target microwave modules which use Electro-mechanical components and require optimal solutions to reduce cost, improve quality, and gain leverage in time to market the product. This tool will assist the product and process designer to improve their productivity and also enable to cooperate and coordinate their designs through a common design interface. We consider a multiobjective optimization model that determines components and processes for a given conceptual designs for microwave modules. This model outputs a set of solutions that are Pareto optimal with respect to cost, quality, and other metrics. In addition, we identify system integration issues for manufacturing applications, and propose an architecture which will serve as a building block to our continuing research in virtual manufacturing applications.Item Automated Network Fault Management(1997) Baras, John S.; Ball, Michael O.; Gupta, Sonjai K.; Viswanathan, P.; Shah, P.; ISR; CSHCNFuture military communication networks will have a mixture of backbone terrestrial, satellite and wireless terrestrial networks. The speeds of these networks vary and they are very heterogeneous. As networks become faster, it is not enough to do reactive fault management. Our approach combines proactive and reactive fault management . Proactive fault management is implemented by dynamic and adaptive routing. Reactive fault management is implemented by a combination of a neural network and an expert system. The system has been developed for the X.25 protocol. Several fault scenarios were modeled and included in the study: reduced switch capacity, increased packet generation rate of a certain application, disabled switch in the X.25 cloud, disabled links. We also modeled occurrence of alarms including severity of the problem, location of the event and a threshold. To detect and identify faults we use both numerical data associated with the performance objects (attributes) in the MIB as well as SNMP traps (alarms). Simulation experiments have been performed in order to understand the convergence of the algorithms, the training of the neural networks involved and the G2/NeurOn-Line software environment and MIB design.Item Hybrid Network Management(1996) Baras, John S.; Ball, Michael O.; Karne, Ramesh K.; Whitefield, David; Kelley, Stephen; Jang, Kap D.; Plaisant, Catherine; Roussopoulos, Nick; Stathatos, Kostas; Vakhutinsky, Andrrew; Valluri, Jaibharat; ISR; CSHCNWe describe our collaborative efforts towards the design and implementation of a next generation integrated network management system for hybrid network (INMS/HN). We describe the overall software architecture of the system at its current stage of development. This network management system if specifically designed to address issues relevant for complex heterogeneous networks consisting of seamlessly interoperable terrestrial and satellite networks. Network management systems are a key element for interoperability in such networks. We describe the integration of configuration management and performance management. The next step in this integration is fault management. In particular we describe the object model, issues of the Graphical User Interface (GUI), browsing tools and performance data graphical widget displays, management, information database (MIB) organization issues. Several components of the system are being commercialized by Hughes Networks Systems.- A revised version of this technical report has been published in
Proceedings of the AIAA: 16th International Communications Satellite Systems Conference and Exhibit, Part 1, pp. 490-500, Washington, D.C., February 25- 29, 1996.Item Integrated Network Management of Hybrid Networks(1996) Baras, John S.; Ball, Michael O.; Karne, Ramesh K.; Kelley, Stephen; Jang, Kap D.; Plaisant, C.; Roussopoulos, N.; Stathatos, K.; Vakhutinsky, A.; Valluri, J.; Whitefield, D.; ISR; CSHCNWe describe our collaborative efforts towards the design and implementation of a next generation integrated network management system for hybrid networks (INMS/HN). We describe the overall software architecture of the system at its current stage of development. This network management system is specifically designed to address issues relevant for complex heterogeneous networks consisting of seamlessly interoperable terrestrial and satellite networks. Network management systems are a key element for interoperability in such networks. We describe the integration of configuration management and performance management. The next step in this integration is fault management. In particular we describe the object model, issues of the Graphical User Interface (GUI), browsing tools and performance data graphical widget displays, management information database (MIB) organization issues. Several components of the system are being commercialized by Hughes Network Systems.- A revised version of this report has been published in
Proceedings of the 1st Conference of Commercial Development of Space, Part One, pp. 345-350, Albuquerque, New Mexico, January 7-11, 1996.Item On the Selection of Parts and Processes during Design of Printed Circuit Board Assemblies(1995) Ball, Michael O.; Baras, John S.; Bashyam, Sridhar; Karne, Ramesh K.; Trichur, Vinai S.; ISRWe consider a multiobjective optimization model that determines components and processes for given conceptual designs of printed circuit board assemblies. Specifically, out model outputs a set of solutions that are Pareto optimal with respect to a cost and a quality metric. The discussion here broadly outlines an integer programming based solution strategy, and represents in-progress work being carried out in collaboration with a manufacturing firm.