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- Decisions with multiple simultaneous goals and uncertain causal effectsPublication . Trigo, Paulo; Coelho, HelderA key aspect of decision-making in a disaster response scenario is the capability to evaluate multiple and simultaneously perceived goals. Current competing approaches to build decision-making agents are either mental-state based as BDI, or founded on decision-theoretic models as MDP. The BDI chooses heuristically among several goals and the MDP searches for a policy to achieve a specific goal. In this paper we develop a preferences model to decide among multiple simultaneous goals. We propose a pattern, which follows a decision-theoretic approach, to evaluate the expected causal effects of the observable and non-observable aspects that inform each decision. We focus on yes-or-no (i.e., pursue or ignore a goal) decisions and illustrate the proposal using the RoboCupRescue simulation environment.
- Parallel implementation of force algorithms for graph visualizationPublication . Zhansultan, Abenov; Sanzhar, Aubakirov; Trigo, PauloIn this paper we select some graph generate-and-render algorithms and evaluate their performance. The experimental results ground our proposal of a parallelized version of an algorithm (the Force Atlas 2) and the corresponding performance analysis. Our work resorts to graph visualization tools such as D3.js, jgraph, NetworkX, Gephi, and sigma.js. We analyze how to use those tools, their advantages and disadvantages and compare their performance. Since each of those tools use their own algorithms, we also conducted a comparative review of graph visualization algorithms. We reviewed algorithms such as FA (Force Atlas), FA2 (Force Atlas 2), FR (Fruchterman & Reingold), LinLog and Dijkstra (Dijkstra's algorithm). The different algorithms were experimentally compared on the same data. The experiments enabled to build a performance ranked perspective. The fastest algorithm was chosen, and experiments were carried out to optimize the rate of generation of graph coordinates by introducing parallel computations during the generation of graph coordinates. During the experiments, the best visualization algorithm for Force Atlas 2 graphs was identified and selected. This algorithm was parallelized, and we achieved a relevant speedup ratio around 26.7% and parallel efficiency around 30%.
- Agent inferencing meets the semantic webPublication . Trigo, Paulo; Coelho, HelderWe provide all agent; the capability to infer the relations (assertions) entailed by the rules that, describe the formal semantics of art RDFS knowledge-base. The proposed inferencing process formulates each semantic restriction as a rule implemented within a, SPARQL query statement. The process expands the original RDF graph into a fuller graph that. explicitly captures the rule's described semantics. The approach is currently being explored in order to support descriptions that follow the generic Semantic Web Rule Language. An experiment, using the Fire-Brigade domain, a small-scale knowledge-base, is adopted to illustrate the agent modeling method and the inferencing process.
- Multi-agent simulation of electricity markets economically-motivated decision-makingPublication . Trigo, Paulo; Sousa, Jorge A. M.; Marques, PauloThe key motivation for this research is the perception that within a near future the electricity market will be composed of individuals that may simultaneously undertake the roles of consumers, producers and traders of electricity. Those individuals are economically motivated “prosumer” (producer-consumer) agents that not only consume, but can also produce, store and trade electricity. Therefore, as the prosumer agents follow their economically motivated goals (e.g., aiming for profit) they will also experience different forms of power (e.g., market power) and their social relations (e.g., dependencies) will mutually influence their decisionmaking processes. This paper describes the most relevant aspects of a simulation tool that provides (human and virtual) prosumer agents na interactive and real-time game-like environment where they can explore (long-term and short-term) strategic behaviour and experience the effects of power and social influence in their decisionmaking processes. The work on the quantitative description of power and influence concepts, is described and details are provided throughout an illustrative example.