1,150 research outputs found

    A Biologically Inspired Approach for Robot Depth Estimation

    Get PDF
    Aimed at building autonomous service robots, reasoning, perception, and action should be properly integrated. In this paper, the depth cue has been analysed as an early stage given its importance for robotic tasks. So, from neuroscience findings, a hierarchical four-level dorsal architecture has been designed and implemented. Mainly, from a stereo image pair, a set of complex Gabor filters is applied for estimating an egocentric quantitative disparity map. This map leads to a quantitative depth scene representation that provides the raw input for a qualitative approach. So, the reasoning method infers the data required to make the right decision at any time. As it will be shown, the experimental results highlight the robust performance of the biologically inspired approach presented in this paper.This paper describes research done at UJI Robotic Intelligence Laboratory. Support for this laboratory was provided in part by Ministerio de EconomĂ­a y Competitividad (DPI2015-69041-R) and by Universitat Jaume I

    Connectionist models and figurative speech

    Get PDF
    This paper contains an introduction to connectionist models. Then we focus on the question of how novel figurative usages of descriptive adjectives may be interpreted in a structured connectionist model of conceptual combination. The suggestion is that inferences drawn from an adjective\u27s use in familiar contexts form the basis for all possible interpretations of the adjective in a novel context. The more plausible of the possibilities, it is speculated, are reinforced by some form of one-shot learning, rendering the interpretative process obsolete after only one (memorable) encounter with a novel figure of speech

    RoboCup@Home: Analysis and results of evolving competitions for domestic and service robots

    Get PDF
    Scientific competitions are becoming more common in many research areas of artificial intelligence and robotics, since they provide a shared testbed for comparing different solutions and enable the exchange of research results. Moreover, they are interesting for general audiences and industries. Currently, many major research areas in artificial intelligence and robotics are organizing multiple-year competitions that are typically associated with scientific conferences. One important aspect of such competitions is that they are organized for many years. This introduces a temporal evolution that is interesting to analyze. However, the problem of evaluating a competition over many years remains unaddressed. We believe that this issue is critical to properly fuel changes over the years and measure the results of these decisions. Therefore, this article focuses on the analysis and the results of evolving competitions. In this article, we present the RoboCup@Home competition, which is the largest worldwide competition for domestic service robots, and evaluate its progress over the past seven years. We show how the definition of a proper scoring system allows for desired functionalities to be related to tasks and how the resulting analysis fuels subsequent changes to achieve general and robust solutions implemented by the teams. Our results show not only the steadily increasing complexity of the tasks that RoboCup@Home robots can solve but also the increased performance for all of the functionalities addressed in the competition. We believe that the methodology used in RoboCup@Home for evaluating competition advances and for stimulating changes can be applied and extended to other robotic competitions as well as to multi-year research projects involving Artificial Intelligence and Robotics

    Linguistic probability theory

    Get PDF
    In recent years probabilistic knowledge-based systems such as Bayesian networks and influence diagrams have come to the fore as a means of representing and reasoning about complex real-world situations. Although some of the probabilities used in these models may be obtained statistically, where this is impossible or simply inconvenient, modellers rely on expert knowledge. Experts, however, typically find it difficult to specify exact probabilities and conventional representations cannot reflect any uncertainty they may have. In this way, the use of conventional point probabilities can damage the accuracy, robustness and interpretability of acquired models. With these concerns in mind, psychometric researchers have demonstrated that fuzzy numbers are good candidates for representing the inherent vagueness of probability estimates, and the fuzzy community has responded with two distinct theories of fuzzy probabilities.This thesis, however, identifies formal and presentational problems with these theories which render them unable to represent even very simple scenarios. This analysis leads to the development of a novel and intuitively appealing alternative - a theory of linguistic probabilities patterned after the standard Kolmogorov axioms of probability theory. Since fuzzy numbers lack algebraic inverses, the resulting theory is weaker than, but generalises its classical counterpart. Nevertheless, it is demonstrated that analogues for classical probabilistic concepts such as conditional probability and random variables can be constructed. In the classical theory, representation theorems mean that most of the time the distinction between mass/density distributions and probability measures can be ignored. Similar results are proven for linguistic probabiliities.From these results it is shown that directed acyclic graphs annotated with linguistic probabilities (under certain identified conditions) represent systems of linguistic random variables. It is then demonstrated these linguistic Bayesian networks can utilise adapted best-of-breed Bayesian network algorithms (junction tree based inference and Bayes' ball irrelevancy calculation). These algorithms are implemented in ARBOR, an interactive design, editing and querying tool for linguistic Bayesian networks.To explore the applications of these techniques, a realistic example drawn from the domain of forensic statistics is developed. In this domain the knowledge engineering problems cited above are especially pronounced and expert estimates are commonplace. Moreover, robust conclusions are of unusually critical importance. An analysis of the resulting linguistic Bayesian network for assessing evidential support in glass-transfer scenarios highlights the potential utility of the approach

    AN INVESTIGATION INTO AN EXPERT SYSTEM FOR TELECOMMUNICATION NETWORK DESIGN

    Get PDF
    Many telephone companies, especially in Eastern-Europe and the 'third world', are developing new telephone networks. In such situations the network design engineer needs computer based tools that not only supplement his own knowledge but also help him to cope with situations where not all the information necessary for the design is available. Often traditional network design tools are somewhat removed from the practical world for which they were developed. They often ignore the significant uncertain and statistical nature of the input data. They use data taken from a fixed point in time to solve a time variable problem, and the cost formulae tend to be on an average per line or port rather than the specific case. Indeed, data is often not available or just plainly unreliable. The engineer has to rely on rules of thumb honed over many years of experience in designing networks and be able to cope with missing data. The complexity of telecommunication networks and the rarity of specialists in this area often makes the network design process very difficult for a company. It is therefore an important area for the application of expert systems. Designs resulting from the use of expert systems will have a measure of uncertainty in their solution and adequate account must be made of the risk involved in implementing its design recommendations. The thesis reviews the status of expert systems as used for telecommunication network design. It further shows that such an expert system needs to reduce a large network problem into its component parts, use different modules to solve them and then combine these results to create a total solution. It shows how the various sub-division problems are integrated to solve the general network design problem. This thesis further presents details of such an expert system and the databases necessary for network design: three new algorithms are invented for traffic analysis, node locations and network design and these produce results that have close correlation with designs taken from BT Consultancy archives. It was initially supposed that an efficient combination of existing techniques for dealing with uncertainty within expert systems would suffice for the basis of the new system. It soon became apparent, however, that to allow for the differing attributes of facts, rules and data and the varying degrees of importance or rank within each area, a new and radically different method would be needed. Having investigated the existing uncertainty problem it is believed that a new more rational method has been found. The work has involved the invention of the 'Uncertainty Window' technique and its testing on various aspects of network design, including demand forecast, network dimensioning, node and link system sizing, etc. using a selection of networks that have been designed by BT Consultancy staff. From the results of the analysis, modifications to the technique have been incorporated with the aim of optimising the heuristics and procedures, so that the structure gives an accurate solution as early as possible. The essence of the process is one of associating the uncertainty windows with their relevant rules, data and facts, which results in providing the network designer with an insight into the uncertainties that have helped produce the overall system design: it indicates which sources of uncertainty and which assumptions are were critical for further investigation to improve upon the confidence of the overall design. The windowing technique works by virtue of its ability to retain the composition of the uncertainty and its associated values, assumption, etc. and allows for better solutions to be attained.BRITISH TELECOMMUNICATIONS PL

    Unsolicited Narratives: The Experiences of Afro-Caribbean Women as Mathematics Learners and as Mathematics Educators in U.S. Institutions of Higher Education

    Get PDF
    Afro-Caribbean immigrant women are part of the brilliant makeup of Black excellence in the United States. Nevertheless, the experiences of Afro-Caribbean women as mathematics learners and as mathematics educators in U.S. institutions of higher education have yet to gain interest among researchers. These experiences are too often absent in the literature or are more times than not buried within categories such as women, foreign-born, or “Other” (Alfred & Swaminathan, 2004; Lather, 1991). When the experiences of Afro-Caribbean women are the focus of research, that inquiry rarely extends into the discipline of mathematics (Beck, 2010; King Miller, 2013) and is nearly nonexistent in examining the experiences of mathematics educators. The aim of this qualitative study, therefore, was to examine the social and contextual experiences of Afro-Caribbean women as mathematics learners and as mathematics educators in U.S. institutions of higher education. The narrative research project (e.g., Polkinghorne, 1988) employed figured worlds (e.g. Holland, Lachicotte, Skinner, & Cain, 1998) and intersectionality (e.g. Collins & Bilge, 2016) as theoretical frameworks. Data collection included dialogical interviews (Kvale, 2007) and documentary data (Patton, 2002); data analysis included dialogic and categorical approaches (Charmaz, 2014; Goodall, 2000). A heuristic (Moustaskas, 1990) approach to the study included the researcher positioning herself as a guide representing the outcomes of the analysis. The analysis of the data showed that when Afro-Caribbean women enter the figured world of mathematics as learners, an actualization of their social positioning, based on practices witnessed, creates spaces for authoring their self-in-person now as mathematics educators. As the now actualized mathematics educator, Afro-Caribbean women become advocates in mentoring people who look and sound like them and use key moments to educate others about their Caribbean figured worlds. Afro-Caribbean women shared moments of how being Black, women, and immigrant in mathematics figured worlds brought both challenging and dismaying experiences as well as praiseworthy experiences. Nonetheless, as demonstrated by the participants’ narratives, having a strong sense of self, knowledge, and purpose is useful in making oppressive moments teaching and learning opportunities rather than sources of distress in their mathematics and academic figured worlds

    The experience of money and the domestic moral economy of a group of young adults in Khayelitsha and their transition to adulthood

    Get PDF
    This thesis is a qualitative study of patterns of earning, sharing and spending among a cohort of young South African men and women, aged 25 to 35, in Khayelitsha, a mainly poor, Black African residential area of Cape Town. As less skilled ‘youth,' they are rarely able to sustain regular employment and therefore remain intermittently dependent on household income and resident in or near their parents' homes; they may have children but are not married. This thesis interprets how their low wage irregular employment and spending patterns affect relationships of mutuality and the dynamics of redistribution in their households. The thesis then considers how these phenomena change with their transition to ‘adulthood,' which occurred in the context of the COVID19 pandemic. The young adults experience a state of ‘locked in' material and existential depletion while balancing their aspirations, reflected in urgent and often conspicuous consumption, with their obligations in a context of chronic economic stress. As older adults, they progress from an economically dependent status to a mainly precarious adult status in their household where the matrix of domestic obligations and entitlements overwhelm youthful, aspirational spending. The thesis advances our understanding of the lived experience of money of ‘township youth' – as young adults – and then, as they progress into adulthood, of adult decision-making, in their domestic domain. The thesis unpacks and explains this experience in relation to the notion of a ‘domestic moral economy' produced at the nexus of economic and social cultural factors. Here responses of young adults to labour market conditions and consumerism impact on and are in turn impacted by social relations in the household. These responses introduced and embedded in both domestic relations and their social lives among peers and friends, demonstrate the inseparability of external capitalist relation of production from historically instituted social relations in the wider South African moral economy
    • 

    corecore