799 research outputs found
Adaptive multi-agent system for a washing machine production line
This paper describes the implementation of a multi-agent system in a real industrial washing machine production line aiming to integrate process and quality control, allowing the establishment of feedback control loops to support adaptation facing condition changes. For this purpose, the agent-based solution was implemented using the JADE framework, being the shared knowledge structured using a proper ontology, edited and validated in Protégé and posteriorly integrated in the multi-agent system. The solution was intensively tested using historical real production data and it is now being installed in the real production line. The preliminary results confirm the initial expectations in terms of improvement of process performance and product quality
Towards self-organized service-oriented multi-agent systems
The demand for large-scale systems running in complex and even chaotic environments requires the consideration of new paradigms and technologies that provide flexibility, robustness, agility and responsiveness. Multiagents systems is pointed out as a suitable approach to address this challenge by offering an alternative way to design control systems, based on the decentralization of control functions over distributed autonomous and cooperative entities. However, in spite of their enormous potential, they usually lack some aspects related to interoperability, optimization in decentralized structures and truly self-adaptation. This paper discusses a new perspective to engineer adaptive
complex systems considering a 3-layer framework integrating several complementary
paradigms and technologies. In a first step, it suggests the integration of multi-agent systems with service-oriented architectures to overcome the limitations of interoperability and smooth migration, followed by the use of technology
enablers, such as cloud computing and wireless sensor networks, to provide a ubiquitous and reconfigurable environment. Finally, the resulted service-oriented multi-agent system should be enhanced with biologically inspired techniques, namely self-organization, to reach a truly robust, agile and adaptive system
Multi-agent systems in industry: current trends & future challenges
This paper introduces the multi-agent systems paradigm and presents some industrial applications of this AI approach, namely in manufacturing, handling and logistics domains. The road-blockers for the current weak adoption of this technology in industry are also discussed, and finally the current trends and several future challenges are pointed out to increase the wider dissemination and acceptance of the multi-agent technology in industry
Artificial reefs: from ecological processes to fishing enhancement tools
info:eu-repo/semantics/publishedVersio
Survival estimates of bycatch individuals discarded from bivalve dredges
The fate of released bycatch is an issue of great interest for fisheries research and management. Survival experiments were carried out to assess the survival capacity of animals damaged and discarded during clam dredging operations. Three common bycatch species, two fish (Trachinus vipera; Dicologlossa cuneata) and one crab (Polybius henslowii), were collected during the sorting of catches from a commercial dredging boat. An arbitrary score scale was used to quantify the type and extent of damage to the organisms. Onboard, damaged individuals were placed in tanks containing seawater which were subsequently transferred to the laboratory. Survival experiments were conducted during the subsequent 48h. D. cuneata exhibited the lowest mortality after 48h (54%), followed by P. henslowii (65%) and T. vipera (81%). Despite the magnitude of the percentage mortalities determined, the average number of individuals estimated to die during a 15 minutes tow (standard commercial fishing time) was relatively small: 1.2, 3.24 and 11 for D. cuneata, T. vipera and P. henslowii, respectively. Nevertheless, when these figures are extrapolated to cover all the dredging fleet the impact of this practice on the populations of the species studied can be significant, particulary for D. cuneata
Daily or weekly? The role of treatment frequency in the effectiveness of grammar treatment for children with specific language impairment.
This study compared the effectiveness of a school-based treatment for expressive grammar in 5-year-olds with specific language impairment delivered in two different dose frequencies: eight sessions delivered daily over 8 consecutive school days or eight sessions delivered weekly over 8 consecutive weeks. Eighteen children received treatment daily and 13 children received treatment weekly. In both groups, treatment consisted of eight 1-hour sessions of small group activities in a classroom setting. Techniques included explicit instruction, focused stimulation, recasting, and imitation. Results were analysed at the group level and as a case series with each child as their own control in a single-subject design. The 8-weeks group showed significantly greater gain in test scores over the treatment period than in an equal time period prior to treatment, whereas the 8-days group did not (Cohen's d = 1.64 for 8-weeks group). Single-subject analyses indicated that 46% of children in the 8-week group and 17% of children in the 8-day group showed a significant treatment effect. It is concluded that expressive grammar treatment was most effective when dose frequency was weekly over 8 weeks rather than daily over 8 days for 5-year-old children with specific language impairment.13 page(s
Preasymptotic Convergence of Randomized Kaczmarz Method
Kaczmarz method is one popular iterative method for solving inverse problems,
especially in computed tomography. Recently, it was established that a
randomized version of the method enjoys an exponential convergence for
well-posed problems, and the convergence rate is determined by a variant of the
condition number. In this work, we analyze the preasymptotic convergence
behavior of the randomized Kaczmarz method, and show that the low-frequency
error (with respect to the right singular vectors) decays faster during first
iterations than the high-frequency error. Under the assumption that the inverse
solution is smooth (e.g., sourcewise representation), the result explains the
fast empirical convergence behavior, thereby shedding new insights into the
excellent performance of the randomized Kaczmarz method in practice. Further,
we propose a simple strategy to stabilize the asymptotic convergence of the
iteration by means of variance reduction. We provide extensive numerical
experiments to confirm the analysis and to elucidate the behavior of the
algorithms.Comment: 20 page
Cognition, emotion and action: persistent sources of parent–offspring paradoxes in the family business
Purpose: The purpose of the study is to explore inductively the unique paradoxical tensions central to family business (FB) and to analyze how FB's members face these tensions and their implications in the personal and professional realms. Design/methodology/approach: A multiple-case study with 11 parent–offspring dyads from Portuguese FBs was conducted putting the focus on the micro-level interactions. Findings: The slopes of roles and relationality in FBs produces three persistent sets of tensions around cognition, emotion and action. These tensions exist in a paradoxical state, containing potentiality for synergy or trade-off. Originality/value: Our study is the first to empirically demonstrate that paradoxical tensions between parent and offspring are interrelated, by emphasizing the uniqueness of FB as a paradoxical setting and offering insights to negotiating of these singular paradoxes.info:eu-repo/semantics/acceptedVersio
Relação do genótipo do gene GDF-9 (fator de crescimento e diferenciação ? 9) e o escore corporal para a prolificidade de matrizes da raça Santa Inês.
O objetivo deste trabalho foi avaliar a influência do escore corporal na prolificidade em matrizes Santa Inês genotipadas para o gene GDF-9
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