Search results for "Distributed System"

Robust Network Agreement on Logical Information

2011

Abstract Logical consensus is an approach to distributed decision making which is based on the availability of a network of agents with incomplete system knowledge. The method requires the construction of a Boolean map which defines a dynamic system allowing the entire network to consent on a unique, global decision. Previous work by the authors proved the method to be viable for applications such as intrusion detection within a structured environment, when the agent's communication topology is known in advance. The current work aims at providing a fully distributed protocol, requiring no a priori knowledge of each agent's communication neighbors. The protocol allows the construction of a r…

Mutual entity authentication for LTE

2011

In this paper we outline the Authentication and Key Agreement protocol (EPS-AKA) found in Long-Term Evolution (LTE) systems. This architecture is the 3GPP version of a 4G access security architecture. The LTE security architecture is a mature evolved architecture, with both strengths and weaknesses. In this paper we propose an amendment to the EPS-AKA protocol to make it a full mutual (online) entity authentication protocol. We also analyze the proposal, highlighting both the improvements and the drawbacks of the new AKA protocol.

The Quest for available bandwidth measurement techniques for large-scale distributed systems

2009

In recent years the research community has developed many techniques to estimate the end-to-end available bandwidth of an Internet path. This important metric can be potentially exploited to optimize the performance of several distributed systems and, even, to improve the effectiveness of the congestion control mechanism of TCP. Thus, it has been suggested that some existing estimation techniques could be used for this purpose. However, existing tools were not designed for large-scale deployments and were mostly validated in controlled settings, considering only one measurement running at a time. In this paper, we argue that current tools, while offering good estimates when used alone, migh…

Remote programming of network robots within the UJI Industrial Robotics Telelaboratory: FPGA vision and SNRP network protocol

2009

This paper presents the UJI Industrial Robotics Telelaboratory, which lets Ph.D. and Master’s degree students perform robotics and computer vision tele-experiments. By using this system, students are able to program experiments remotely via the Web, in order to combine the use of a field-programmable gate array (FPGA) to provide real-time vision processing, a conveyor belt, and a Motoman industrial manipulator. This paper introduces the novel SNRP protocol (i.e., Simple Network Robot Protocol), which permits the integration of network robots and sensors within an e-learning platform in a simple and reliable manner. As long as the students are able to interact remotely with a real robotic sc…

A CAN Fieldbus Based Architecture for Distributed Control Systems Implementation

2003

Abstract The application of distributed systems theory to the implementation of industrial control systems is one of the best options to develop simple, scalable and physically distributed control systems. Following this line, our group has proposed a new architecture based on Rule Nets (RN) as an HLP over CAN fieldbus for the implementation of Distributed Systems. This architecture has been applied to several control applications, obtaining excellent results. The most outstanding feature of the architecture was its simplicity in the control systems design, without any efficiency loss. New capabilities have been added to improve its features and develop new analysis tools, in order to incre…

The Max-Product Algorithm Viewed as Linear Data-Fusion: A Distributed Detection Scenario

2019

In this paper, we disclose the statistical behavior of the max-product algorithm configured to solve a maximum a posteriori (MAP) estimation problem in a network of distributed agents. Specifically, we first build a distributed hypothesis test conducted by a max-product iteration over a binary-valued pairwise Markov random field and show that the decision variables obtained are linear combinations of the local log-likelihood ratios observed in the network. Then, we use these linear combinations to formulate the system performance in terms of the false-alarm and detection probabilities. Our findings indicate that, in the hypothesis test concerned, the optimal performance of the max-product a…

Distributed Systems for Fusion of Visual Information

1997

Distributed image retrieval on DAISY

2006

The paper describes an application of image retrieval based on DAISY architecture (distributed architecture for intelligent system). The creation of pictorial indexes may require a number of hours depending on the size of the pictorial data base. The problem can become more complex in the case of distributed database systems. In both cases a distributed architecture can be the natural and more efficient solution. DAISY architecture is based on the concept of co-operating behavioral agents supervised by a central engagement module. Preliminary experiments, to evaluate the performance of the system, have been performed on a astronomical database and coral image

A distributed genetic algorithm for restoration of vertical line scratches

2008

This paper reports a distributed algorithm for the restoration of still frames corrupted by vertical line scratches. The restoration is here approached as an optimisation problem, and is solved using an ad-hoc Genetic Algorithm. The distributed algorithm is designed following a pipeline logical structure. The front end is a network of standard workstations with heterogeneous operating systems. The quality of image is appreciable and the computational time is quite low with respect the sequential version.

Identification of Distributed Systems with Logical Interaction Structure

2012

This paper focuses on the structure identification problem for a class of networked systems, where the interaction among components or agents is described through logical maps. In particular, agents are heterogeneous cooperating systems, i.e. they may have different individual dynamics and different interaction rules depending on input events. While we assume that the individual agents' dynamics are known, each agent has partial knowledge of the logical map encoding the interaction of another agent with its neighbors. Based on the so-called algebraic normal form for binary functions, we present a technique by which the network structure described by a logical function can be dynamically est…