Linking Spatially Explicit Parallel Continuous and
Discrete Models
Boleslaw K. Szymanski and Gilbert Chen (Rensselaer
Polytechnic Institute)
Abstract:
This paper advocates the use of mobile agents for
linking simulations running on different computers. A Mobile Component
approach is proposed to enhance reusability of existing simulations and to
improve efficiency of component based simulations of complex systems. A basic
unit of the mobile component simulation is a simulation server with a
communication interface to mobile agents. Each mobile agent links and
coordinates component's execution. We used this approach to implement a
combined Lyme disease simulation. It consists of a partial differential
equation based continuous simulation and parallel discrete event simulation
with explicit space representation. The performance of this implementation is
presented to demonstrate the feasibility of the Mobile Component approach. In
addition, a process-port model of simulation is discussed. Its implementation
allows efficient linkage of simulation servers, if they are programmed in a
simulation language supporting the process-port model. We finally show that
the performance of the Mobile Component approach could be significantly
improved by using compiler techniques to eliminate overhead of communication
among simulation servers.
An Agent-Based Framework for Linking Distributed
Simulations
Linda F. Wilson, Daniel Burroughs, Jeanne Sucharitaves,
and Anush Kumar (Dartmouth College)
Abstract:
Simulations often operate on static datasets and data
sources, but many simulations would benefit from access to dynamic data. This
paper describes our work developing a software agent-based framework for
dynamically linking distributed simulations and other remote data resources.
The framework allows independently-designed simulations to communicate
seemlessly with no a priori knowledge of the details of other simulations and
data sources. In this paper, we discuss our architecture and current
implementation developed using the D'Agents mobile agent system. To
demonstrate the feasibility of our system, we present a prototype for a
hypothetical search and rescue mission.
'Plug and Test' - Software Agents in Virtual
Environments
Adelinde M. Uhrmacher (University Rostock) and Bernd
G. Kullick (University Ulm)
Abstract:
James - a Java Based agent modeling environment for
simulation has been developed to support the compositional construction of
test beds for multi-agent systems and their execution in distributed
environments. The modeling formalism of James imposes only few constraints on
the modeling of agents and facilitates a ``plug and test'' with pieces of
agent code which has been demonstrated in earlier work. However, even entire
agents can be run in James as they are run in their run-time environment. The
integration of agents as a whole is based on model templates which serve as
the agents' interface and representative during the simulation run. The effort
which is put into defining model templates for selected agent systems obviates
the need for the single agent programmer to get acquainted with the underlying
modeling and simulation formalism. Instead the agent programmer can compose
the experimental frame and test the programmed agents as they are. The
approach is illustrated with agents of the mobile agent system Mole.
Domain-General Simulation and Planning with Physical
Schemas
Marc S. Atkin, David L. Westbrook, and Paul R. Cohen
(University of Massachusetts at Amherst)
Abstract:
Physical schemas are representations of simple
physically grounded relationships and interactions such as ``move,'' ``push,''
and ``contain.'' We believe they are the conceptual primitives an agent
employs to understand its environment. Physical schemas can be used at varying
levels of abstraction across a variety of domains. We have designed a
domain-general agent simulation and control testbed based on physical schemas.
If a domain can be described in physical terms as agents moving and applying
force, it can be simulated in this testbed. Furthermore, we show that physical
schemas can be viewed as the basis for abstract plans and a domain-general
planner, GRASP. Our simulation and planning system is currently being
evaluated in a continuous, dynamic, and adversarial domain based on the game
of Capture the Flag. The paper concludes with an example of how GRASP was
applied to the problem of Course of Action generation and evaluation.
Using Agent-Based Modeling to Capture Airpower
Strategic Effects
Richard K. Bullock (Air Force Studies and
Analyses Agency) and Gregory A. McIntyre and Raymond R. Hill (Air Force
Institute of Technology)
Abstract:
Airpower's strength lies in quickly striking the enemy
directly where they are vulnerable while being unhampered by geography and
surface forces. Airpower theory suggests the effects of these strikes
propagate throughout an opponent's military system yielding catastrophic
output or strategic effects. Despite this theory being a cornerstone of US Air
Force doctrine, current Air Force models do not seem to capture airpower's
inherent strength. Since these models are used to support budgetary decision
making, the US may not be funding the airpower capability it needs. This
effort focuses on developing an approach to capture strategic effects in
models. The approach establishes a basis for the effects in military theory as
well as the field of Complex Adaptive Systems. Using these concepts as a
foundation, a simulation model called the Hierarchical Interactive Theater
Model (HITM) is constructed and exercised. HITM output depicts a cascading
deterioration in force effectiveness and eventual total collapse resulting
from destruction of vital targets. This outcome is consistent with the
expected results of strikes against centers of gravity defined in Air Force
doctrine suggesting agent-based modeling is an effective way to simulate
strategic effects at the operational level of war.
A Simulation Test-Bed to Evaluate Multi-Agent Control
of Manufacturing Systems
Robert W. Brennan and William O
(University of Calgary)
Abstract:
Current research in the area of manufacturing planning
and control has moved away from traditional centralized solutions towards
distributed architectures that range from hierarchical to heterarchical.
Between these two extremes of the control architecture spectrum lies the
holonic manufacturing systems paradigm, where partial dynamic hierarchies of
agents cooperate to meet global system objectives in the face of disturbances.
This paper describes a simulation test bed for the evaluation of a distributed
multi-agent control architecture for holonic manufacturing systems that
integrates discrete-event simulation software into its design to allow the
control architecture to be evaluated with a variety of emulated manufacturing
systems.
Agent-Directed Simulation - Challenges to Meet Defense
and Civilian Requirements
Tuncer I. Ören (Information Technologies
Research Institute), S. K. Numrich (U.S. Naval Research Laboratory), Adelinde
M. Uhrmacher (University of Rostock), Linda F. Wilson (Dartmouth College) and
Erol Gelenbe (University of Central Florida)
Abstract:
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. Gelenbe's
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.
Multi-Agent Enabled Modeling and Simulation Towards
Collaborative Inventory Management in Supply Chain
Yonghui Fu and
Rajesh Piplani (Nanyang Technological University), Robert de Souza
(Viewlocity) and Jingru Wu (National University of Singapore)
Abstract:
This paper is framed to address the preliminary
approaches towards process-oriented collaborative inventory management in
supply chain taking advantage of multi-agent technology in terms of modeling
and simulation. Initially, a SCM Support Model is proposed as a foundation to
combine the supply chain processes with the multi-agent system. In succession,
a simple PC assembling case is investigated and simulated mainly to validate
the SCM Support Model. As a result, the combination has the potential to make
possible a real strategic competitive advantage for the entire supply chain
and will enable new forms of business, namely, collaborative inventory
management. Accordingly, a theoretical framework of collaborative inventory
management is highlighted to refine and extend the SCM Support Model with the
purpose to synchronize decisions as well as actions.
Agent-Based Simulation of Dynamic Online
Auctions
Hideyuki Mizuta (IBM Research) and Ken Steiglitz
(Princeton University)
Abstract:
The need to understand dynamic behavior in auctions is
increasing with the popularization of online auctions. Applications include
designing auction mechanisms, bidding strategies, and server systems. We
describe simulations of a typical online auction, where the duration is fixed,
and the second-highest price is continuously posted and determines the
winner's payment. We modeled agents of exactly two types, idealizations and
simplifications of those observed in practice: early bidders, who can bid any
time during the auction period, and snipers, who wait till the last moments to
bid. This allows us to study the interactions of the two types of bidders
during the course of auctions, and the effects of the two strategies on the
probability of winning, the final price, and the formation of price consensus
in iterated auctions. Results show that 1) early bidders can win with a lower
price on average than snipers, but much less often; 2) the late bidding
strategy of snipers is effective; and 3) in iterated auctions, adjustment
feedback of motivational parameters can lead to effective price consensus with
small fluctuations.
Use of Discrete Event Simulation to Validate an Agent
Based Scheduling Engine
Shubhabrata Biswas and Sara Merchawi
(DELMIA Corporation)
Abstract:
This paper discusses the use of simulation in a new
context. Most often QUEST is viewed as a standalone simulation tool to analyze
and understand shop floor behavior. It has rarely been used in conjunction
with other proprietary software. This paper attempts to demonstrate how QUEST
is being used in conjunction with an Agent Based Scheduling Software
(henceforth referred to as Scheduler) developed using JAVA. The Scheduler is a
multi-threaded application using software agents. It can run in a distributed
manner over a LAN. This paper deals with the Agent Based Architecture of the
Scheduler as well as the important role of Simulation in validating the
Scheduler.