42,881 research outputs found
The distributed particle detectors and data acquisition modules for Extensive Air Shower measurements at "HT-KZ" experiment
"HorizonT-Kazakhstan" (HT-KZ) is an extensive air shower new detector system of a new type
to be constructed at Nazarbayev University (NU), Astana, KZ. It is based on the idea of a
previous generation detector that is located at Tyan-Shan high-altitude Science Station of the
Physical Institute of Russian science academy at approximately 3340 meters above the sea level.
It will consist of 8 independent modules distributed on the roofs of NU with 1-2ns time
resolution. The purpose is to register Extensive Air Showers (EAS) coming from a wide range
of zenith angles. The measurements of the time characteristics of the EAS are to be taken
simultaneously at up to eight registration points separated by the distance up to one kilometer.
HT-KZ development is very important step in the EAS research area, especially, in the presence
of the last connected discoveries, such as multi-modal events This article presents the current
system development state, the R&D work of the system modules using the independent particle
detection modules. The distributed DAQ system and event synchronization system progress will
be discussed as wel
Design of object-oriented distributed simulation classes
Distributed simulation of aircraft engines as part of a computer aided design package is being developed by NASA Lewis Research Center for the aircraft industry. The project is called NPSS, an acronym for 'Numerical Propulsion Simulation System'. NPSS is a flexible object-oriented simulation of aircraft engines requiring high computing speed. It is desirable to run the simulation on a distributed computer system with multiple processors executing portions of the simulation in parallel. The purpose of this research was to investigate object-oriented structures such that individual objects could be distributed. The set of classes used in the simulation must be designed to facilitate parallel computation. Since the portions of the simulation carried out in parallel are not independent of one another, there is the need for communication among the parallel executing processors which in turn implies need for their synchronization. Communication and synchronization can lead to decreased throughput as parallel processors wait for data or synchronization signals from other processors. As a result of this research, the following have been accomplished. The design and implementation of a set of simulation classes which result in a distributed simulation control program have been completed. The design is based upon MIT 'Actor' model of a concurrent object and uses 'connectors' to structure dynamic connections between simulation components. Connectors may be dynamically created according to the distribution of objects among machines at execution time without any programming changes. Measurements of the basic performance have been carried out with the result that communication overhead of the distributed design is swamped by the computation time of modules unless modules have very short execution times per iteration or time step. An analytical performance model based upon queuing network theory has been designed and implemented. Its application to realistic configurations has not been carried out
Design of Object-Oriented Distributed Simulation Classes
Distributed simulation of aircraft engines as part of a computer aided design package being developed by NASA Lewis Research Center for the aircraft industry. The project is called NPSS, an acronym for "Numerical Propulsion Simulation System". NPSS is a flexible object-oriented simulation of aircraft engines requiring high computing speed. It is desirable to run the simulation on a distributed computer system with multiple processors executing portions of the simulation in parallel. The purpose of this research was to investigate object-oriented structures such that individual objects could be distributed. The set of classes used in the simulation must be designed to facilitate parallel computation. Since the portions of the simulation carried out in parallel are not independent of one another, there is the need for communication among the parallel executing processors which in turn implies need for their synchronization. Communication and synchronization can lead to decreased throughput as parallel processors wait for data or synchronization signals from other processors. As a result of this research, the following have been accomplished. The design and implementation of a set of simulation classes which result in a distributed simulation control program have been completed. The design is based upon MIT "Actor" model of a concurrent object and uses "connectors" to structure dynamic connections between simulation components. Connectors may be dynamically created according to the distribution of objects among machines at execution time without any programming changes. Measurements of the basic performance have been carried out with the result that communication overhead of the distributed design is swamped by the computation time of modules unless modules have very short execution times per iteration or time step. An analytical performance model based upon queuing network theory has been designed and implemented. Its application to realistic configurations has not been carried out
Verifying service continuity in a satellite reconfiguration procedure: application to a satellite
The paper discusses the use of the TURTLE UML profile to model and verify service continuity during dynamic reconfiguration of embedded software, and space-based telecommunication software in particular. TURTLE extends UML class diagrams with composition operators, and activity diagrams with temporal operators. Translating TURTLE to the formal description technique RT-LOTOS gives the profile a formal semantics and makes it possible to reuse verification techniques implemented by the RTL, the RT-LOTOS toolkit developed at LAAS-CNRS. The paper proposes a modeling and formal validation methodology based on TURTLE and RTL, and discusses its application to a payload software application in charge of an embedded packet switch. The paper demonstrates the benefits of using TURTLE to prove service continuity for dynamic reconfiguration of embedded software
Synchronizing a modular robot colony for cooperative tasks based on intrainter robot communications
The implementation of robotic cooperative tasks such as pushing an object toward a desired destination or manipulating an object using mobile robots or robotic arms requires motion coordination between the robot colony. When a robot is built by the union of several robots, such as modular robot systems, it is critical to have the complete coordination of each robot configuration within the colony and also overall robot coordination of the colony. The paper presents a demonstration of parallel motion for modular robot configurations through the combination of two types of communications, i.e., Inter-robot and Intra-robot communications. The two types of communications are described and implemented in a real modular robot system. Experiments are executed to show the performance of the robot colony synchronizatio
Modules program structures and the structuring of operating systems
In this paper some views are presented on the way in which complex systems, such as Operating Systems and the programs to be interfaced with them can be constructed, and how such systems may become heavily library oriented. Although such systems have a dynamic nature, all interfacing within and among modules can be checked statically. It will be shown that the concepts presented are equally valid for single user systems, multi-programming systems and even distributed systems. The ideas have been spurred by the implementation of a modular version of Pascal and a supporting Operating System, currently nearing completion at Twente University of Technology, The Netherlands
Mobile Online Gaming via Resource Sharing
Mobile gaming presents a number of main issues which remain open. These are
concerned mainly with connectivity, computational capacities, memory and
battery constraints. In this paper, we discuss the design of a fully
distributed approach for the support of mobile Multiplayer Online Games (MOGs).
In mobile environments, several features might be exploited to enable resource
sharing among multiple devices / game consoles owned by different mobile users.
We show the advantages of trading computing / networking facilities among
mobile players. This operation mode opens a wide number of interesting sharing
scenarios, thus promoting the deployment of novel mobile online games. In
particular, once mobile nodes make their resource available for the community,
it becomes possible to distribute the software modules that compose the game
engine. This allows to distribute the workload for the game advancement
management. We claim that resource sharing is in unison with the idea of ludic
activity that is behind MOGs. Hence, such schemes can be profitably employed in
these contexts.Comment: Proceedings of 3nd ICST/CREATE-NET Workshop on DIstributed SImulation
and Online gaming (DISIO 2012). In conjunction with SIMUTools 2012.
Desenzano, Italy, March 2012. ISBN: 978-1-936968-47-
From modular to centralized organization of synchronization in functional areas of the cat cerebral cortex
Recent studies have pointed out the importance of transient synchronization
between widely distributed neural assemblies to understand conscious
perception. These neural assemblies form intricate networks of neurons and
synapses whose detailed map for mammals is still unknown and far from our
experimental capabilities. Only in a few cases, for example the C. elegans, we
know the complete mapping of the neuronal tissue or its mesoscopic level of
description provided by cortical areas. Here we study the process of transient
and global synchronization using a simple model of phase-coupled oscillators
assigned to cortical areas in the cerebral cat cortex. Our results highlight
the impact of the topological connectivity in the developing of
synchronization, revealing a transition in the synchronization organization
that goes from a modular decentralized coherence to a centralized synchronized
regime controlled by a few cortical areas forming a Rich-Club connectivity
pattern.Comment: 24 pages, 8 figures. Final version published in PLoS On
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