2,414 research outputs found
Adaptive observers for nonlinearly parameterized systems subjected to parametric constraints
We consider the problem of adaptive observer design in the settings when the
system is allowed to be nonlinear in the parameters, and furthermore they are
to satisfy additional feasibility constraints. A solution to the problem is
proposed that is based on the idea of universal observers and non-uniform
small-gain theorem. The procedure is illustrated with an example.Comment: 19th IFAC World Congress on Automatic Control, 10869-10874, South
Africa, Cape Town, 24th-29th August, 201
Communication-Optimal Distributed Dynamic Graph Clustering
We consider the problem of clustering graph nodes over large-scale dynamic
graphs, such as citation networks, images and web networks, when graph updates
such as node/edge insertions/deletions are observed distributively. We propose
communication-efficient algorithms for two well-established communication
models namely the message passing and the blackboard models. Given a graph with
nodes that is observed at remote sites over time , the two
proposed algorithms have communication costs and
( hides a polylogarithmic factor), almost matching
their lower bounds, and , respectively, in the
message passing and the blackboard models. More importantly, we prove that at
each time point in our algorithms generate clustering quality nearly as
good as that of centralizing all updates up to that time and then applying a
standard centralized clustering algorithm. We conducted extensive experiments
on both synthetic and real-life datasets which confirmed the communication
efficiency of our approach over baseline algorithms while achieving comparable
clustering results.Comment: Accepted and to appear in AAAI'1
An MLSA-based online scheme for the rapid identification of Stenotrophomonas isolates
An online scheme to assign Stenotrophomonas isolates to genomic groups was developed using the multilocus sequence analysis (MLSA), which is based on the DNA sequencing of selected fragments of the housekeeping genes ATP synthase alpha subunit (atpA), the recombination repair protein (recA), the RNA polymerase alpha subunit (rpoA) and the excision repair beta subunit (uvrB). This MLSA-based scheme was validated using eight of the 10 Stenotrophomonas species that have been previously described. The environmental and nosocomial Stenotrophomonas strains were characterised using MLSA, 16S rRNA sequencing and DNA-DNA hybridisation (DDH) analyses. Strains of the same species were found to have greater than 95% concatenated sequence similarity and specific strains formed cohesive readily recognisable phylogenetic groups. Therefore, MLSA appeared to be an effective alternative methodology to amplified fragment length polymorphism fingerprint and DDH techniques. Strains of Stenotrophomonas can be readily assigned through the open database resource that was developed in the current study (www.steno.lncc.br/)
A global measurement approach versus a country-specific measurement approach â Do they draw the same picture of child poverty? The case of Vietnam
Child poverty can be measured using approaches that aim to make cross-country comparisons on a regional or global scale or to capture a countryâs specific poverty context. The first can be referred to as a global approach and the second as a country-specific approach. These underlying rationales for the design and use of a child poverty approach have great implications for their theoretical and conceptual frameworks. This paper investigates whether the conceptual differences between the global and country-specific approaches also draw a different empirical picture of child poverty when applied to a specific country. Vietnam is used as a case study for the application of both approaches and analysis of results. The methodology used identifies children at two different levels of poverty, namely severe deprivation and absolute poverty. Findings suggest that the country-specific approach is more inclusive than the global approach, identifying a larger percentage of children as poor and capturing the large majority of those children identified under the global approach. Poverty figures of both approaches further convey a varying picture of child poverty when considering the different dimensions of vulnerability. The demographic composition of the poverty groups by either one or both of the approaches does not display significant differences.child poverty, multidimensional poverty, Vietnam
From Affect Theoretical Foundations to Computational Models of Intelligent Affective Agents
[EN] The links between emotions and rationality have been extensively studied and discussed. Several computational approaches have also been proposed to model these links. However, is it possible to build generic computational approaches and languages so that they can be "adapted " when a specific affective phenomenon is being modeled? Would these approaches be sufficiently and properly grounded? In this work, we want to provide the means for the development of these generic approaches and languages by making a horizontal analysis inspired by philosophical and psychological theories of the main affective phenomena that are traditionally studied. Unfortunately, not all the affective theories can be adapted to be used in computational models; therefore, it is necessary to perform an analysis of the most suitable theories. In this analysis, we identify and classify the main processes and concepts which can be used in a generic affective computational model, and we propose a theoretical framework that includes all these processes and concepts that a model of an affective agent with practical reasoning could use. Our generic theoretical framework supports incremental research whereby future proposals can improve previous ones. This framework also supports the evaluation of the coverage of current computational approaches according to the processes that are modeled and according to the integration of practical reasoning and affect-related issues. This framework is being used in the development of the GenIA(3) architecture.This work is partially supported by the Spanish Government projects PID2020-113416RB-I00, GVA-CEICE project PROMETEO/2018/002, and TAILOR, a project funded by EU Horizon 2020 research and innovation programme under GA No 952215.Alfonso, B.; Taverner-Aparicio, JJ.; Vivancos, E.; Botti, V. (2021). From Affect Theoretical Foundations to Computational Models of Intelligent Affective Agents. Applied Sciences. 11(22):1-29. https://doi.org/10.3390/app112210874S129112
Can filesharers be triggered by economic incentives? Results of an experiment
Illegal filesharing on the internet leads to considerable financial losses for artists and copyright owners as well as producers and sellers of music. Thus far, measures to contain this phenomenon have been rather restrictive. However, there are still a considerable number of illegal systems, and users are able to decide quite freely between legal and illegal downloads because the latter are still difficult to sanction. Recent economic approaches account for the improved bargaining position of users. They are based on the idea of revenue-splitting between professional sellers and peers. In order to test such an innovative business model, the study reported in this article carried out an experiment with 100 undergraduate students, forming five small peer-to-peer networks.The networks were confronted with different economic conditions.The results indicate that even experienced filesharers hold favourable attitudes towards revenue-splitting.They seem to be willing to adjust their behaviour to different economic conditions
Feature paper in environmental chemistry and technology
Attention to the environment and its problems has undergone unprecedented growth in recent years [...]
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