202 research outputs found

    On the Complexity of Case-Based Planning

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    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

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    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

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

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    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

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

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    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

    Measurement and Modeling of Particle Radiation in Coal Flames

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    This work aims at developing a methodology that can provide information of in-flame particle radiation in industrial-scale flames. The method is based on a combination of experimental and modeling work. The experiments have been performed in the high-temperature zone of a 77 kWth swirling lignite flame. Spectral radiation, total radiative intensity, gas temperature, and gas composition were measured, and the radiative intensity in the furnace was modeled with an axisymmetric cylindrical radiation model using Mie theory for the particle properties and a statistical narrow-band model for the gas properties. The in-flame particle radiation was measured with a Fourier transform infrared (FTIR) spectrometer connected to a water-cooled probe via fiber optics. In the cross-section of the flame investigated, the particles were found to be the dominating source of radiation. Apart from giving information about particle radiation and temperature, the methodology can also provide estimates of the amount of soot radiation and the maximum contribution from soot radiation compared to the total particle radiation. In the center position in the flame, the maximum contribution from soot radiation was estimated to be less than 40% of the particle radiation. As a validation of the methodology, the modeled total radiative intensity was compared to the total intensity measured with a narrow angle radiometer and the agreement in the results was good, supporting the validity of the used approach

    Imigração e saĂșde: a (in)acessibilidade das mulheres imigrantes aos cuidados de saĂșde

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    A utilização dos serviços de saĂșde pelas populaçÔes imigrantes tem vindo a ser considerado um dos mais importantes indicadores da sua integração nas so- ciedades receptoras (Dias e col., 2009). No entanto, o conhecimento em torno da qualidade e da eficĂĄcia do acesso dos/as imigrantes aos cuidados de saĂșde, especialmente no que respeita Ă s mulheres imigran- tes, Ă© ainda escasso em Portugal (Fonseca e col., 2005). Embora os estudos nacionais tenham vindo, nas Ășltimas dĂ©cadas, a procurar traçar os diferentes perfis sociais das mulheres imigrantes em Portugal, sobretudo no que concerne Ă s suas relaçÔes fami- liares ou laborais (Wall e col., 2005), a investigação no domĂ­nio da saĂșde Ă© ainda parca e exclusora de uma anĂĄlise centrada no gĂ©nero ou interseccional. Neste texto apresenta-se uma reflexĂŁo sobre os de- terminantes que condicionam a (in)acessibilidade das mulheres imigrantes aos cuidados de saĂșde, enfatizando-se os fatores que poderĂŁo estar a agir no sentido contrĂĄrio Ă  sua integração neste setor

    Substance abuse and psychiatric co-morbidity as predictors of premature mortality in Swedish drug abusers a prospective longitudinal study 1970 - 2006

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    <p>Abstract</p> <p>Background</p> <p>Few longitudinal cohort studies have focused on the impact of substances abused and psychiatric disorders on premature mortality. The aim of the present study was to identify predictors of increased risk of drug related death and non drug related death in substance abusers of opiates, stimulants, cannabis, sedatives/hypnotics, hallucinogens and alcohol over several decades.</p> <p>Methods</p> <p>Follow-up study of a consecutive cohort of 561 substance abusers, admitted to a detoxification unit January 1970 to February 1978 in southern Sweden, and followed up in 2006. Demographic and clinical data, substance diagnoses and three groups of psychiatric diagnoses were identified at first admission. Causes of death were coded according to ICD-10 and classified as drug related deaths or non drug related deaths. To identify the incidence of some probable risk factors of drug related premature death, the data were subjected to a competing risks Cox regression analysis.</p> <p>Results</p> <p>Of 561 patients in the cohort, 11 individuals had either emigrated or could not be located, and 204/561 patients (36.4%) were deceased by 2006. The cumulative risk of drug related death increased more in the first 15 years and leveled out later on when non drug related causes of death had a similar incidence. In the final model, male gender, regular use of opiates or barbiturates at first admission, and neurosis were associated with an increased risk of drug related premature death, while cannabis use and psychosis were associated with a decreased risk. Neurosis, mainly depression and/or anxiety disorders, predicted drug related premature death while chronic psychosis and personality disorders did not. Chronic alcohol addiction was associated with increased risk of non drug related death.</p> <p>Conclusions</p> <p>The cohort of drug abusers had an increased risk of premature death to the age of 69. Drug related premature death was predicted by male gender, the use of opiates or barbiturates and depression and anxiety disorders at first admission. The predicted cumulative incidence of drug related death was significantly higher in opiate and barbiturate abusers over the observed period of 37 years, while stimulant abuse did not have any impact. Alcohol contributed to non drug related death.</p
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