Linda F. Wilson

Experiments in load migration and dynamic load balancing in SPEEDES

It is well known that the performance of a parallel discrete-event simulation (PDES) depends on the allocation of the workload to processors. In particular, poor performance may be the result of an imbalance of the workload on the processors. In earlier work, we examined automated load balancing techniques that statically allocated the workload based on prior run-time data. However, a good initial distribution of the workload may result in a load imbalance if the characteristics of the simulation change over time. Furthermore, some of the processors may gain external workloads at some point in time. Thus, there is a need for dynamic load balancing methods that can adapt to changes in the simulation or the system. In this paper, we discuss our experiments in dynamic load (object) migration and load balancing using the SPEEDES simulation framework.

Agent-directed simulation: challenges to meet defense and civilian requirements

The aim of this panel session is to point out the importance of agent-directed simulation, as a scientific concept and technological possibility, to enhance the potential of simulation in both civilian and defense applications. The members of the panel (organized by Dr. Ören) are: Dr. Erol Gelenbe, Dr. S. K. Numrich, Dr. Adelinde Uhrmacher, and Dr. Linda Wilson. The position statements of the panel members are given separately. Ören bases his arguments on the NATO Modelling and Simulation Master Plan. He points out the need to proactively advance simulation science and technology to satisfy the requirements of the sophisticated defense applications. He stresses that, among other methodological advance possibilities, the three categories of agent-directed simulation have to be properly developed and/or tailored for defense applications. Gelenbes interests include goal-directed knowledge processing abilities of agents in hostile environments. Numrich stresses on the need for command and search agents in defense applications. Uhrmacher states challenges for the users and the simulationists on the need of agents for modelling and agents for testing. Wilson covers four key challenges to agent-directed simulation that are: security, standards in communication, computer resources, and system management and monitoring.

A Security Framework for the Agent-Based Environment for Linking Simulations (ABELS)

The Agent-Based Environment for Linking Simulations (ABELS) framework is designed to allow independent and physically distributed simulations and other data resources to form a “data cloud” for the exchange of information. In particular, it uses a distributed brokering system to facilitate dynamic linkings between independently designed, autonomous participants, without requiring the use of stringent standards to which participants must conform. This article discusses the various security threats that can arise in the ABELS architecture and presents the current design and implementation of a security framework for the system.