363 research outputs found

    On the Complexity of Case-Based Planning

    Full text link
    We analyze the computational complexity of problems related to case-based planning: planning when a plan for a similar instance is known, and planning from a library of plans. We prove that planning from a single case has the same complexity than generative planning (i.e., planning "from scratch"); using an extended definition of cases, complexity is reduced if the domain stored in the case is similar to the one to search plans for. Planning from a library of cases is shown to have the same complexity. In both cases, the complexity of planning remains, in the worst case, PSPACE-complete

    Enhancement by postfiltering for speech and audio coding in ad-hoc sensor networks

    Full text link
    Enhancement algorithms for wireless acoustics sensor networks~(WASNs) are indispensable with the increasing availability and usage of connected devices with microphones. Conventional spatial filtering approaches for enhancement in WASNs approximate quantization noise with an additive Gaussian distribution, which limits performance due to the non-linear nature of quantization noise at lower bitrates. In this work, we propose a postfilter for enhancement based on Bayesian statistics to obtain a multidevice signal estimate, which explicitly models the quantization noise. Our experiments using PSNR, PESQ and MUSHRA scores demonstrate that the proposed postfilter can be used to enhance signal quality in ad-hoc sensor networks

    Refining complexity analyses in planning by exploiting the exponential time hypothesis

    Get PDF
    The use of computational complexity in planning, and in AI in general, has always been a disputed topic. A major problem with ordinary worst-case analyses is that they do not provide any quantitative information: they do not tell us much about the running time of concrete algorithms, nor do they tell us much about the running time of optimal algorithms. We address problems like this by presenting results based on the exponential time hypothesis (ETH), which is a widely accepted hypothesis concerning the time complexity of 3-SAT. By using this approach, we provide, for instance, almost matching upper and lower bounds onthe time complexity of propositional planning.Funding Agencies|National Graduate School in Computer Science (CUGS), Sweden; Swedish Research Council (VR) [621-2014-4086]</p

    Identification of T cell stimulatory epitopes from the 18 kDa protein of Mycobacterium leprae

    Get PDF
    We have used different mouse strains to examine in vivo and in vitro responses to the 18 kDa protein of Mycobacterium leprae, which appears to be strongly immunogenic in both mice and humans. B and T cell stimulatory epitopes recognised by different strains of mice have been mapped using overlapping peptides that span the entire 18 kDa protein. Previous work established that Immunization of mice with the 18 kDa protein results in specific antibody production to common B cell epitopes and immunization of mice with peptides containing these B cell epitopes resulted in the induction of specific IgG to only a limited subset of epitopes in each strain. Now we report that T cells purified from mice immunized with peptides that stimulate antibody production, proliferate in vitro when rechallenged. The proliferating T cells produce levels of IL-2 and IFN-Îł, that indicate antigen-specific T helper type 1 cells are present in significant numbers. Thus, a comparison of in vivo and in vitro data suggests that T cells bearing the phenotype associated with potentially protective cell-mediated responses can be primed in vivo by epitopes on small peptides. Since T cells from both strains of mice are capable of responding to the immunogenic synthetic peptides in vitro, but give different responses to the same peptides in vivo, factors other than epltope structure appear to influence T cell subset activation. This may have important implications for diseases such as leprosy where a polarized T cell response appears to develop and for the development of synthetic subunit vaccine

    An LP-Based Heuristic for Optimal Planning

    Full text link

    Information and feedback to improve occupational physicians’ reporting of occupational diseases: a randomised controlled trial

    Get PDF
    To assess the effectiveness of supplying occupational physicians (OPs) with targeted and stage-matched information or with feedback on reporting occupational diseases to the national registry in the Netherlands. In a randomized controlled design, 1076 OPs were divided into three groups based on previous reporting behaviour: precontemplators not considering reporting, contemplators considering reporting and actioners reporting occupational diseases. Precontemplators and contemplators were randomly assigned to receive stage-matched, stage-mismatched or general information. Actioners were randomly assigned to receive personalized or standardized feedback upon notification. Outcome measures were the number of OPs reporting and the number of reported occupational diseases in a 180-day period before and after the intervention. Precontemplators were significantly more male and self-employed compared to contemplators and actioners. There was no significant effect of stage-matched information versus stage-mismatched or general information on the percentage of reporting OPs and on the mean number of notifications in each group. Receiving any information affected reporting more in contemplators than in precontemplators. The mean number of notifications in actioners increased more after personalized feedback than after standardized feedback, but the difference was not significant. This study supports the concept that contemplators are more susceptible to receiving information but could not confirm an effect of stage-matching this information on reporting occupational diseases to the national registr

    Calculating Criticalities

    Get PDF
    We present a novel method for building style abstraction hierarchies in planning. The aim of this method is to minimize search by limiting backtracking both between abstraction levels and within an abstraction level. Previous approaches for building style abstractions have determined the criticality of operator preconditions by reasoning about plans directly. Here, we adopt a simpler and faster approach where we use numerical simulation of the planning process. We develop a simple but powerful theory to demonstrate the theoretical advantages of our approach. We use this theory to identify some simple properties lacking in previous approaches but possessed by our method. We demonstrate the empirical advantages of our approach by a set of four benchmark experiments using the system. We compare the quality of the abstraction hierarchies generated with those built by the and algorithms

    Building inclusive nations in the age of migration

    Get PDF
    This is an Accepted Manuscript of an article published by Taylor & Francis in Identities: Global Studies in Culture and Power on 06 Apr 2016, available online: http://dx.doi.org/10.1080/1070289X.2016.1148607Nation and diversity are often casted in oppositional terms. The present joint-intervention explores the limits and possibilities of what we call ‘inclusive nation’, i.e. a nation which embraces rather than expunging diversity. To reflect on this idea, the Loughborough University Nationalism Network (LUNN) organized a symposium, bringing together both academics and relevant stakeholders, to explore both theoretically and practically the feasibility of the inclusive nation. For reason of space, here we present only the theoretical views of academics. While Billig and Yuval-Davis highlight the inherent exclusive thrust of nationalism, Kaufmann and Hearn suggest two distinct ways to move away the traditional understanding of nationalism as a site of singularity, oppression and exclusion. A final rejoinder by Nyhagen pushes the debate further interrogating the boundaries of national belonging
    • 

    corecore