22,886 research outputs found
An Agent-Based Simulation API for Speculative PDES Runtime Environments
Agent-Based Modeling and Simulation (ABMS) is an effective paradigm to model systems exhibiting complex interactions, also with the goal of studying the emergent behavior of these systems. While ABMS has been effectively used in many disciplines, many successful models are still run only sequentially. Relying on simple and easy-to-use languages such as NetLogo limits the possibility to benefit from more effective runtime paradigms, such as speculative Parallel Discrete Event Simulation (PDES). In this paper, we discuss a semantically-rich API allowing to implement Agent-Based Models in a simple and effective way. We also describe the critical points which should be taken into account to implement this API in a speculative PDES environment, to scale up simulations on distributed massively-parallel clusters. We present an experimental assessment showing how our proposal allows to implement complicated interactions with a reduced complexity, while delivering a non-negligible performance increase
Enabling collaboration in virtual reality navigators
In this paper we characterize a feature superset for Collaborative
Virtual Reality Environments (CVRE), and derive a component
framework to transform stand-alone VR navigators into full-fledged
multithreaded collaborative environments. The contributions of our
approach rely on a cost-effective and extensible technique for
loading software components into separate POSIX threads for
rendering, user interaction and network communications, and adding a
top layer for managing session collaboration. The framework recasts
a VR navigator under a distributed peer-to-peer topology for scene
and object sharing, using callback hooks for broadcasting remote
events and multicamera perspective sharing with avatar interaction.
We validate the framework by applying it to our own ALICE VR
Navigator. Experimental results show that our approach has good
performance in the collaborative inspection of complex models.Postprint (published version
MiniCPS: A toolkit for security research on CPS Networks
In recent years, tremendous effort has been spent to modernizing
communication infrastructure in Cyber-Physical Systems (CPS) such as Industrial
Control Systems (ICS) and related Supervisory Control and Data Acquisition
(SCADA) systems. While a great amount of research has been conducted on network
security of office and home networks, recently the security of CPS and related
systems has gained a lot of attention. Unfortunately, real-world CPS are often
not open to security researchers, and as a result very few reference systems
and topologies are available. In this work, we present MiniCPS, a CPS
simulation toolbox intended to alleviate this problem. The goal of MiniCPS is
to create an extensible, reproducible research environment targeted to
communications and physical-layer interactions in CPS. MiniCPS builds on
Mininet to provide lightweight real-time network emulation, and extends Mininet
with tools to simulate typical CPS components such as programmable logic
controllers, which use industrial protocols (Ethernet/IP, Modbus/TCP). In
addition, MiniCPS defines a simple API to enable physical-layer interaction
simulation. In this work, we demonstrate applications of MiniCPS in two example
scenarios, and show how MiniCPS can be used to develop attacks and defenses
that are directly applicable to real systems.Comment: 8 pages, 6 figures, 1 code listin
Process Algebras
Process Algebras are mathematically rigorous languages with well defined semantics that permit describing and verifying properties of concurrent communicating systems.
They can be seen as models of processes, regarded as agents that act and interact continuously with other similar agents and with their common environment. The agents may be real-world objects (even people), or they may be artifacts, embodied perhaps in computer hardware or software systems.
Many different approaches (operational, denotational, algebraic) are taken for describing the meaning of processes. However, the operational approach is the reference one. By relying on the so called Structural Operational Semantics (SOS), labelled transition systems are built and composed by using the different operators of the many different process algebras. Behavioral equivalences are used to abstract from unwanted details and identify those systems that react similarly to external
experiments
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Modular HLA RTI services: The GRIDS approach
The Generic Runtime Infrastructure for Distributed Simulation (GRIDS) has been developed to investigate modularity issues in distributed simulation. It could be argued that although the HLA RTI is a widespread solution to distributed simulation, it cannot include all possible services. This paper investigates an approach to extending the distributed simulation services available in the HLA RTI. One example of this is bridging support for HLA/DIS legacy integration. This paper therefore presents GRIDS, how GRIDS can be used to provide modular service support for the HLA RTI, and a case study on legacy integration to demonstrate our approach
Supporting Cyber-Physical Systems with Wireless Sensor Networks: An Outlook of Software and Services
Sensing, communication, computation and control technologies are the essential building blocks of a cyber-physical system (CPS). Wireless sensor networks (WSNs) are a way to support CPS as they provide fine-grained spatial-temporal sensing, communication and computation at a low premium of cost and power. In this article, we explore the fundamental concepts guiding the design and implementation of WSNs. We report the latest developments in WSN software and services for meeting existing requirements and newer demands; particularly in the areas of: operating system, simulator and emulator, programming abstraction, virtualization, IP-based communication and security, time and location, and network monitoring and management. We also reflect on the ongoing
efforts in providing dependable assurances for WSN-driven CPS. Finally, we report on its applicability with a case-study on smart buildings
Embodied Evolution in Collective Robotics: A Review
This paper provides an overview of evolutionary robotics techniques applied
to on-line distributed evolution for robot collectives -- namely, embodied
evolution. It provides a definition of embodied evolution as well as a thorough
description of the underlying concepts and mechanisms. The paper also presents
a comprehensive summary of research published in the field since its inception
(1999-2017), providing various perspectives to identify the major trends. In
particular, we identify a shift from considering embodied evolution as a
parallel search method within small robot collectives (fewer than 10 robots) to
embodied evolution as an on-line distributed learning method for designing
collective behaviours in swarm-like collectives. The paper concludes with a
discussion of applications and open questions, providing a milestone for past
and an inspiration for future research.Comment: 23 pages, 1 figure, 1 tabl
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