1,720,973 research outputs found
Dynamic identification of industrial robots from low-sampled data
No full textThis paper proposes a fast and on-site method for the dynamic identification of industrial robots from low-sampled position and torque data. Owing to the basic architecture of the employed controller, only trapezoidal-velocity trajectories can be enforced for identification purposes. Differently from previous literature, where this kind of trajectories were performed with limited joint velocities and range of motions, the procedure proposed hereafter is characterized by fast movements performed on wide angular ranges. Furthermore, in order to identify the influence of friction without deriving complex friction models, a novel method is outlined that decouples frictional torques from gravitational, centrifugal and inertial ones. Finally, although multiple experiments of different kinds have been performed, inertial parameters are determined in one singular step, thus avoiding possible error increase due to sequential identification algorithms
Minority Game: A Logic-Based Approach in TuCSoN
No full textMinority Game is receiving an increasing interest because it models emergent properties of complex systems including rational entities, such as for instance the evolution of financial markets. As such, Minority Game provides for a simple yet stimulating scenario for system simulation.
In this paper, we aim at presenting a logic approach to the Minority Game whose goal is to overcome the well-known limits of the equation model in the verification of the system behaviour. We realise the social system simulation using a novel MAS metamodel based on agents and artifacts, where the agent rationality is obtained using a BDI architecture.
To this end, we adopt the TuCSoN infrastructure for agent coordination, and its logic-based tuple centre abstractions as artifact representatives. By implementing Minority Game over TuCSoN, we show some of the benefits of the artifact model in terms of flexibility and controllability of the simulation.
A number of parameters can affect the behaviour of Minority Game simulation: such parameters are explicitly represented in the coordination artifact, so that they can be tuned up during the simulation. In particular, experiments are shown where memory size and number of wrong moves are adopted as the tuning parameters
An engineering method for the power flow assessment in servo-actuated automated machinery: Mechatronic modeling and experimental evaluation
No full textIn this paper, an engineering method for the power flow assessment of a position-controlled servo-mechanism is outlined. The considered system is composed of a permanent magnet synchronous motor coupled to a standard power converter, and directly connected to a slider crank mechanism. After the accurate description of a consistent power flow model, a sequential identification technique is discussed, which allows to determine the dynamic parameters of linkage, electric motor and electronic driver by means of non-invasive experimental measures. The proposed model allows to accurately predict the major sources of power loss within the system
Simulating Minority Game with TuCSoN
No full textMinority Game is receiving an increasing interest because it models emergent properties of complex systems including rational entities, such as for instance the evolution of financial markets. As such, Minority Game provides for a simple yet stimulating scenario for system simulation.
In this paper, we aim at showing new perspectives in agent-based simulation by adopting a novel MAS meta-model based on agents and artifacts, and by applying it to Minority Game simulation. To this end, we adopt the TuCSoN infrastructure for agent coordination, and its logic-based tuple centre abstractions as artifact representatives. By implementing Minority Game over TuCSoN, we show some of the benefits of the artifact model in terms of flexibility and controllability of the simulation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Argumentation and Artifacts for Negotiation Support
No full textNegotiation is a central process in an agent society where autonomous agents have to cooperate in order to resolve conflicting interests and yet compete to divide limited resources. A direct dialogical exchange of information between agents usually leads to competitive forms of negotiation where the most powerful agents win. Alternatively, an intelligent mediated interaction may better achieve the goal of reaching a common agreement and supporting cooperative negotiation. In both cases argumentation is the reference framework to rationally manage conflicting knowledge or objectives, a framework which provides the fundamental abstraction “argument” to exchange pieces of information. In this paper we present a novel conceptual framework for negotiation dialogues using argumentation between autonomous software agents which enables their dialogues to be automated. The framework, called SANA (Supporting Artifacts for Negotiation with Argumentation), incorporates intelligent components able to assist the agent participants to reach agreement by inferring mutuallyacceptable proposals. The framework also permits agents to engage in negotiation dialogues with each other, generating and exchanging proposed deals and arguments for and against these proposals. Acceptability of proposals is then assessed in terms of an agreed argumentation framework semantics. We present the architecture of our framework, along with the syntax, and outline denotational semantics of an associated agent interaction protocol, called SANAP
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