2,618 research outputs found
Network-centric automated planning and execution
Web services provide interoperability to network hosts with different capabilities. Complex tasks can be performed by composing services, assuming sufficient service descriptions are provided. Researchers are just beginning to realize the importance of accounting for network properties during automated service composition. The work presented in this thesis considers dynamic, heterogeneous networks—one type of network-centric environment.The purpose of this research is to improve network-centric service composition. This is accomplished by converting the service composition problem to an automated planning under uncertainty problem and by reasoning about network properties at various stages of the planning process. This thesis presents a method of improving the agents’ ability to construct, execute, and monitor plans in network-centric environments.There are two main contributions of this thesis: 1) generating qualitatively-different plans and 2) creating network-aware agents. As part of the former contribution, this thesis presents a comparison of methods used to create classical planning domains for distributed service composition problems. The other part of this contribution is an algorithm for guiding a plan-space planner to create qualitatively-different plans based on domain-dependent and network-centric plan evaluations. The second contribution pertains to network-awareness, which agents exhibit by reacting to changes in network conditions. This thesis describes methods of incorporating network-awareness into agents that 1) create plans, 2) execute plans, and 3) monitor plan execution.Experiments to validate the aforementioned contributions are presented in the context of an Improvised Explosive Device (IED) detection scenario. Several locations are monitored for IEDs using a variety of techniques including manual searching and visual change detection, as well as a variety of resources including humans, robots, and unmanned aerial vehicles (UAVs). Empirical results indicate that incorporating network-awareness into agents in dynamic, heterogeneous networks improves the overall service composition performance and effectiveness.M.S., Computer Science -- Drexel University, 200
Impact Assessment of Hypothesized Cyberattacks on Interconnected Bulk Power Systems
The first-ever Ukraine cyberattack on power grid has proven its devastation
by hacking into their critical cyber assets. With administrative privileges
accessing substation networks/local control centers, one intelligent way of
coordinated cyberattacks is to execute a series of disruptive switching
executions on multiple substations using compromised supervisory control and
data acquisition (SCADA) systems. These actions can cause significant impacts
to an interconnected power grid. Unlike the previous power blackouts, such
high-impact initiating events can aggravate operating conditions, initiating
instability that may lead to system-wide cascading failure. A systemic
evaluation of "nightmare" scenarios is highly desirable for asset owners to
manage and prioritize the maintenance and investment in protecting their
cyberinfrastructure. This survey paper is a conceptual expansion of real-time
monitoring, anomaly detection, impact analyses, and mitigation (RAIM) framework
that emphasizes on the resulting impacts, both on steady-state and dynamic
aspects of power system stability. Hypothetically, we associate the
combinatorial analyses of steady state on substations/components outages and
dynamics of the sequential switching orders as part of the permutation. The
expanded framework includes (1) critical/noncritical combination verification,
(2) cascade confirmation, and (3) combination re-evaluation. This paper ends
with a discussion of the open issues for metrics and future design pertaining
the impact quantification of cyber-related contingencies
A Conceptual Model for Network Decision Support Systems
We introduce the concept of a network DSS (NWDSS)
consisting of fluid, heterogeneous nodes of human
and machine agents, connected by wireless
technology, which may enter and leave the network at
unpredictable times, yet must also cooperate in
decision-making activities. We describe
distinguishing properties of the NWDSS and propose
a 3-tier conceptual model comprised of digital
infrastructure, transactive memory systems and
emergent collaborative decision-making. We suggest
a decision loop of Sense-Analyze-Adapt-Memory
leveraging TMS as a starting point for addressing the
agile collaborative requirements of emergent
decision-making. Several examples of innovative
NWDSS services are presented from Naval
Postgraduate School field experiments
Grounding Object Relations in Language-Conditioned Robotic Manipulation with Semantic-Spatial Reasoning
Grounded understanding of natural language in physical scenes can greatly
benefit robots that follow human instructions. In object manipulation
scenarios, existing end-to-end models are proficient at understanding semantic
concepts, but typically cannot handle complex instructions involving spatial
relations among multiple objects. which require both reasoning object-level
spatial relations and learning precise pixel-level manipulation affordances. We
take an initial step to this challenge with a decoupled two-stage solution. In
the first stage, we propose an object-centric semantic-spatial reasoner to
select which objects are relevant for the language instructed task. The
segmentation of selected objects are then fused as additional input to the
affordance learning stage. Simply incorporating the inductive bias of relevant
objects to a vision-language affordance learning agent can effectively boost
its performance in a custom testbed designed for object manipulation with
spatial-related language instructions.Comment: AAAI 2023 RL Ready for Production Worksho
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