996 resultados para Cognitive agent
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The cure characteristics and mechanical properties of short nylon fiber- styrene /whole tyre reclaim (SBR/WTR) composites with and without an interfacial bonding agent based on 4,4 diphenyl methane diisocyanate and polyethylene glycol (MDI/PEG) have been studied. An 80:40 blend of SBR/ WTR reinforced with 20 phr of short nylon fiber has been selected and the MDI/ PEG ratio has been changed from 0.67:1 to 2:1. The minimum and maximum torques increased with isocyanate concentration. The scorch time and cure time showed an initial reduction. The cure rate showed an initial improvement. Tensile strength, tear strength and abrasion resistance increased with MDI/PEG ratio, these values were higher in longitudinal direction. Resilience and compression set increased with isocyanate concentration.
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The thesis describes the development and evaluation of epoxy resin as interfacial bonding agent for short Nylon-6 fiber elastomer composites. Epoxy resin is well known for its adhesive property. The potential use of it as interfacial bonding agent in short fiber composite is not explored yet. Three rubbers viz., acrylonitrile butadiene rubber (NBR), Neoprene rubber (CR) and styrene butadiene rubber (SBR) were selected and different fiber loading were tried. The resin concentration was optimized for each fiber loading with respect to cure characteristics and mechanical properties. Rheological characteristics and thermal degradation of the composites containing different fiber loading and different resin concentrations were studied in detail to find the effect of epoxy resin bonding system. The mechanical properties were studied in detail. The short Nylon -6 fiber improved most of the mechanical properties of all the three rubbers. Tensile strength showed a dip at 10 phr fiber loading in the case of CR while it was continuously increased with fiber loading in the case of NBR and SBR. All the composites showed anisotropy in mechanical properties. The epoxy resin is an effective bonding agent for short Nylon -6 fiber reinforced NBR and CR composites. Epoxy resin improved tensile strength, abrasion resistance and modulus of these composites. SEM studies confirmed the improved bonding of fiber and matrix in the presence of epoxy bonding agent. Epoxy resin was not effective as bonding agent in the case of short Nylon fiber- SBR composite. From the rheological studies of the composites with and without bonding agent it was observed that all the composite exhibited pseudoplasticity, which decreased with temperature. At higher shear rates all the mixes showed plug flow. SEM pictures showed that maximum orientation of fibers occured at a shear rate, just before the onset of plug flow. The presence of fiber reduced the temperature sensitivity of the flow at a given shear rate. Die swell was reduced in the presence of fiber. Shear viscosity of the composite was increased in the presence of resin. Die swell was increased in the presence of epoxy resin for composites at all shear rates. The thermal degradation of NBR and SBR composites with and without bonding agent followed single step degradation pattern. Thermal stability of the composites was improved in the presence of bonding agent. The degradation of virgin elastomer and the composites followed first order kinetics.
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This thesis entitled Physicochemical and molecular characterization of bacteriophages ΦSP-1and ΦSP-3, specific for pathogenic Salmonella and evaluation of their potential as biocontrol agent . Salmonella were screened using standard methodologies from various environmental samples including chicken caecum. Salmonella strains, which were previously isolated and stocked in the lab, were also included in this study as host, for screening Salmonella specific lytic phages. The Salmonella strain in this study designated as S49 which helped in phage propagation by acting as host bacteria was identified as Salmonella enterica subsp. enterica by 16S rRNA gene analysis and serotyping . A total of three Salmonella specific phage named as ΦSP-1, ΦSP-2 and ΦSP-3 were isolated from chicken intestine samples via an enrichment protocol employing the double agar overlay method. ΦSP-1 and ΦSP-3 showing consistent lytic nature were selected for further study and were purified by repeated plating after picking of single isolated plaques from the lawns of Salmonella S49 plates. Both the phages produced small, clear plaques indicating their lytic nature. ΦSP-1 and ΦSP-3 were concentrated employing PEG-NaCl precipitation method before further characterization. The focus of present study was to isolate, characterize and verify the efficacy of lytic bacteriophages against the robust pathogen Salmonella, capable of surviving under various hostile conditions. Two phages, ΦSP-1 and ΦSP-3, belonging to two families, Podovoridae and Siphoviridae were isolated.
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The goal of this work is to develop an Open Agent Architecture for Multilingual information retrieval from Relational Database. The query for information retrieval can be given in plain Hindi or Malayalam; two prominent regional languages of India. The system supports distributed processing of user requests through collaborating agents. Natural language processing techniques are used for meaning extraction from the plain query and information is given back to the user in his/ her native language. The system architecture is designed in a structured way so that it can be adapted to other regional languages of India
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Routine activity theory introduced by Cohen& Felson in 1979 states that criminal acts are caused due to the presenceof criminals, vic-timsand the absence of guardians in time and place. As the number of collision of these elements in place and time increases, criminal acts will also increase even if the number of criminals or civilians remains the same within the vicinity of a city. Street robbery is a typical example of routine ac-tivity theory and the occurrence of which can be predicted using routine activity theory. Agent-based models allow simulation of diversity among individuals. Therefore agent based simulation of street robbery can be used to visualize how chronological aspects of human activity influence the incidence of street robbery.The conceptual model identifies three classes of people-criminals, civilians and police with certain activity areas for each. Police exist only as agents of formal guardianship. Criminals with a tendency for crime will be in the search for their victims. Civilians without criminal tendencycan be either victims or guardians. In addition to criminal tendency, each civilian in the model has a unique set of characteristicslike wealth, employment status, ability for guardianship etc. These agents are subjected to random walk through a street environment guided by a Q –learning module and the possible outcomes are analyzed
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Agent based simulation is a widely developing area in artificial intelligence.The simulation studies are extensively used in different areas of disaster management. This work deals with the study of an agent based evacuation simulation which is being done to handle the various evacuation behaviors.Various emergent behaviors of agents are addressed here. Dynamic grouping behaviors of agents are studied. Collision detection and obstacle avoidances are also incorporated in this approach.Evacuation is studied with single exits and multiple exits and efficiency is measured in terms of evacuation rate, collision rate etc.Net logo is the tool used which helps in the efficient modeling of scenarios in evacuation
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Many examples for emergent behaviors may be observed in self-organizing physical and biological systems which prove to be robust, stable, and adaptable. Such behaviors are often based on very simple mechanisms and rules, but artificially creating them is a challenging task which does not comply with traditional software engineering. In this article, we propose a hybrid approach by combining strategies from Genetic Programming and agent software engineering, and demonstrate that this approach effectively yields an emergent design for given problems.
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In many real world contexts individuals find themselves in situations where they have to decide between options of behaviour that serve a collective purpose or behaviours which satisfy one’s private interests, ignoring the collective. In some cases the underlying social dilemma (Dawes, 1980) is solved and we observe collective action (Olson, 1965). In others social mobilisation is unsuccessful. The central topic of social dilemma research is the identification and understanding of mechanisms which yield to the observed cooperation and therefore resolve the social dilemma. It is the purpose of this thesis to contribute this research field for the case of public good dilemmas. To do so, existing work that is relevant to this problem domain is reviewed and a set of mandatory requirements is derived which guide theory and method development of the thesis. In particular, the thesis focusses on dynamic processes of social mobilisation which can foster or inhibit collective action. The basic understanding is that success or failure of the required process of social mobilisation is determined by heterogeneous individual preferences of the members of a providing group, the social structure in which the acting individuals are contained, and the embedding of the individuals in economic, political, biophysical, or other external contexts. To account for these aspects and for the involved dynamics the methodical approach of the thesis is computer simulation, in particular agent-based modelling and simulation of social systems. Particularly conductive are agent models which ground the simulation of human behaviour in suitable psychological theories of action. The thesis develops the action theory HAPPenInGS (Heterogeneous Agents Providing Public Goods) and demonstrates its embedding into different agent-based simulations. The thesis substantiates the particular added value of the methodical approach: Starting out from a theory of individual behaviour, in simulations the emergence of collective patterns of behaviour becomes observable. In addition, the underlying collective dynamics may be scrutinised and assessed by scenario analysis. The results of such experiments reveal insights on processes of social mobilisation which go beyond classical empirical approaches and yield policy recommendations on promising intervention measures in particular.
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Previous research has considered entrepreneurship as a way out of poverty and as a chance to foster economic growth. Moreover, specifically start-ups headed by women have played an important role in the economic development and it has been argued that gender-related issues, amongst others, play a significant role for the performance of a country or region. Against this background, this qualitative study explores desires, reluctances and constraints toward entrepreneurial activities of a comparably homogenous group of potential (poor) entrepreneurs in an emerging economy—cleaning ladies in Istanbul. We focus on this particular context as still rather little is known on reasons why women do not start a business (in Turkey). We believe exploring the reasons why certain individuals choose not to become entrepreneurs is at least as telling as investigating why they do so. We draw upon the social dimensions of entrepreneurship by Shapero and Sokol (1982) alongside Institutional Theory and posit that normative and cognitive forces may shape individual decisions on entrepreneurship. We identified two basic clusters of women and discuss possible hindrance factors undermining entrepreneurial desires and limitations for entrepreneurship as well as possible avenues for policy makers (and MNCs) to foster entrepreneurship in the given community.
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Estudi sobre el tractament biològic amb Pantoea agglomerans EPS125 per tal d'evitar la podridura de la fruita
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