1,721,036 research outputs found
Experiments on robust indoor localization of mobile devices using interval arithmetic
Full text linkThe lack of techniques and tools to estimate the position of mobile devices with high accuracy and robustness is one of the major causes that limit the provision of advanced location-based services in indoor environments. An algorithm to enable mobile devices to estimate their positions in known indoor environments is discussed in this paper under the assumption that fixed network nodes are available at known locations. The discussed algorithm is designed to allow devices to estimate their positions by actively measuring the distances from visible fixed nodes. In order to reduce the errors introduced by the arrangement of the fixed nodes in the environment, the discussed algorithm transforms the localization problem into an optimization problem, which is then solved using interval arithmetic. Experimental results on the use of the discussed algorithm with distance estimates obtained using ultra-wide band are presented to assess the performance of the algorithm and to compare it with a reference alternative. Presented experimental results confirm that the discussed algorithm provides an increased level of robustness with respect to the considered reference alternative with no loss of accuracy
Simple and effective sign consistency using interval arithmetic
Full text linkPolynomial constraints over finite domains are expressed as equalities, inequalities, and disequalities of polynomials with integer coefficients whose variables take values from finite subsets of the integers. They are an interesting type of constraints that can be used to model many combinatorial problems over the integers. Sign consistency is a type of local consistency proposed specifically to support reasoning on polynomial constraints over finite domains. Sign consistency is parameterized in terms of a bounding function that is used to extract relevant information from a constraint when its variables are restricted to take values from a finite box. Known results from the literature on interval arithmetic can be readily used to propose a simple bounding function to support sign consistency. Preliminary experimental results show that the proposed bounding function is a promising candidate to effectively reason on polynomial constraints over finite domains
A bio-inspired approach to WiFi-based indoor localization
No full textIn this paper, the problem of indoor localization is investigated using a bio-inspired approach. The proposed approach relies on the use of WiFi networks, which nowadays can be considered a commodity available in all indoor environments. WiFi signals are used to obtain estimates of the distance between a smart device, whose position needs to be estimated, and the fixed access points of the network, which are assumed to be in known positions. Once a given number of range estimates from each available access point has been acquired, proper range averages are performed to feed the proposed localization algorithm. According to the proposed approach, localization is formulated in terms of an optimization problem, which is solved using an algorithm inspired from particle swarm optimization. Such an algorithm has been integrated in an add-on module of JADE, which is intended to execute on the smart device whose position needs to be estimated, and which was tested in relevant indoor scenarios. Experimental results in tested scenarios are shown in the last part of the paper in order to evaluate the performance of the proposed bio-inspired localization algorithm
Extending message handlers with pattern matching in the Jadescript programming language
No full textSoftware agents are characterized by sophisticated messaging capabilities that support distributed problem solving and that provide the basic ingredients for interoperability in open agent-based systems. Jadescript is an agent-oriented programming language that has been recently proposed to offer programmers the abstractions that characterize agents to concretely and effectively support the implementation of complex agent-based systems. As expected, the abstractions that Jadescript provides include native support for the advanced messaging capabilities that characterize agents. This paper describes a recent development of Jadescript that extends the language with a native support for pattern matching designed to simplify the reception of structured messages and to ease the management of complex conversations. The proposed support for pattern matching is intimately correlated with the type system of the language, and it can be used to effectively associate inbound messages with specific handlers. From the point of view of programmers, the proposed support for pattern matching allows clearly expressing the intended scope of message handlers, and it contributes to raise the level of abstraction of the language
Agent-based Computing for Enterprise Collaboration - Services and agents
No full textThe third "Agent-based Computing for Enterprise Collaboration" workshop at WETICE aimed at bringing together researcher in the field of collaboration supported by software agents. This paper briefly discusses the content of the papers as presented by the participating authors. Moreover, there is a summary of the main issues of the concluding panel discussions. © 2005 IEEE
A kinetic model of the dynamics of compromise in large multi-agent systems
Full text linkCompromise is one of the primary phenomena that govern the dynamics of the opinion in multi-agent systems. In this paper, compromise is isolated from other phenomena, and it is studied using a statistical framework designed to investigate collective properties of large multi-agent systems. The proposed framework is completed with the details needed to model compromise, and differential problems which describe the dynamics of the opinion under suitable hypotheses are presented. Long-time asymptotic solutions of obtained differential problems are discussed to confirm that compromise makes multi-agent systems tend to reach consensus. It is proved that compromise makes all agents tend to share the same opinion, and that the value of the asymptotic opinion can be expressed in terms of the characteristics of the multi-agent system and of the initial distribution of the opinion. Obtained analytic results are confirmed by independent simulations in an illustrative case
- …
