2,000 research outputs found

    A biomimetic algorithm for the improved detection of microarray features,

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    One the major difficulties of microarray technology relate to the processing of large and - importantly - error-loaded images of the dots on the chip surface. Whatever the source of these errors, those obtained in the first stage of data acquisition - segmentation - are passed down to the subsequent processes, with deleterious results. As it has been demonstrated recently that biological systems have evolved algorithms that are mathematically efficient, this contribution attempts to test an algorithm that mimics a bacterial-"patented" algorithm for the search of available space and nutrients to find, "zero-in" and eventually delimitate the features existent on the microarray surface

    'Extremotaxis': Computing with a bacterial-inspired algorithm

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    We present a general-purpose optimization algorithm inspired by “run-and-tumble”, the biased random walk chemotactic swimming strategy used by the bacterium Escherichia coli to locate regions of high nutrient concentration The method uses particles (corresponding to bacteria) that swim through the variable space (corresponding to the attractant concentration profile). By constantly performing temporal comparisons, the particles drift towards the minimum or maximum of the function of interest. We illustrate the use of our method with four examples. We also present a discrete version of the algorithm. The new algorithm is expected to be useful in combinatorial optimization problems involving many variables, where the functional landscape is apparently stochastic and has local minima, but preserves some derivative structure at intermediate scales

    Protozoa grazing evaluation : a novel way to assess wastewater treatment performance?

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    African migrant traders’ experiences in Johannesburg inner city : towards the migrant calculated risk and adaptation framework

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    Abstract: Globally, migrants face numerous socio-economic and institutional impediments that hinder their participation in the labour market of host cities and/or countries. This motivates them to join the informal economic sector to make a living. Applying the concept of tactical cosmopolitanism to understand the social and economic agency of African migrants, this article reports on an explorative analysis of the experiences of informal African migrant street traders (African migrant traders) operating in Johannesburg inner city, Gauteng, South Africa. The study revealed that African migrant traders left their countries of origin to secure better opportunities and to escape hostile conditions in their home countries. Despite the host city turning out to be more hostile and xenophobic, making life and finding formal employment opportunities more challenging, the thought of the more difficult life conditions in their home countries has led them to trading on the streets..

    Evolutionary Behavior Tree Approaches for Navigating Platform Games

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    Computer games are highly dynamic environments, where players are faced with a multitude of potentially unseen scenarios. In this article, AI controllers are applied to the Mario AI Benchmark platform, by using the Grammatical Evolution system to evolve Behavior Tree structures. These controllers are either evolved to both deal with navigation and reactiveness to elements of the game, or used in conjunction with a dynamic A* approach. The results obtained highlight the applicability of Behavior Trees as representations for evolutionary computation, and their flexibility for incorporation of diverse algorithms to deal with specific aspects of bot control in game environments

    VAL - Vehicular adaptation layer, for NDN

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    High mobility and intermittent connectivity of nodes are the main characteristics of Vehicular Ad-Hoc Networks (VANETs). These two aspects cause problems in traditional IP networking. Named Data Networking (NDN) is presented as one of the most promising paradigms for the future Internet. NDN is a data-centric architecture. It relies on data names instead of the host's location to make forwarding decisions. In NDN, any node can be a candidate for supplying the desired content. This feature makes the NDN architecture appealing for VANET scenarios (V-NDN). This paper presents a strategy for applying NDN to VANETs with support for geographical-based forwarding. For this purpose, an additional layer called Vehicular Adaptation Layer (VAL), is proposed to illustrate how this can be performed without altering the NDN primitives and core structure. VAL provides: 1) a mechanism to bind NDN data names to the producers' and consumers' geographic areas; 2) a discovery mechanism to find producers' areas and 3) the capability of implementing, in a plug-and-play manner, geo-forwarding algorithms capable of guiding Interests towards data producers and Data packets towards data consumers.- (undefined

    Interactive technologies in stroke recovery : uncovering challenges and opportunities through physiotherapist’s perspective

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    Abstract in proceedings of the Fourth International Congress of CiiEM: Health, Well-Being and Ageing in the 21st Century, held at Egas Moniz’ University Campus in Monte de Caparica, Almada, from 3–5 June 2019.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/publishedVersio

    Protozoa grazing evaluation : a novel way to assess wastewater treatment performance?

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