3,273 research outputs found
Adapting LPGP to plan with deadlines
This paper describes two approaches that enable the AI Planner LPGP to reason about domains with exogenous events and goals with duration: the first investigates how such domains may be encoded using the planning domain definition language PDDL2.1 level 3, while the second involves directly modifying LPGP. Both approaches have been tested in a number of domains and conclusions are drawn about the relative merits of the two approaches
Improved NaI(Tl) and CsI(Tl)Detector Arrays for Environmental Airborne Gamma Spectrometry: Technical Progress Report
Investigation of Spatial and Temporal Aspects of Airborne Gamma Spectrometry: Preliminary Report on Phase II Survey of the Sellafield Vicinity, the Former RAF Carlisle site, the Albright & Wilson Plant, Workington Harbour and the Cumbrian Coastline, Conducted March 2000
Investigation of Spatial and Temporal Aspects of Airborne Gamma Spectrometry: Report on Phase III Survey of West Cumbria and Inner Solway, Conducted June 2000
Investigation of Spatial and Temporal Aspects of Airborne Gamma Spectrometry: Final Report
A study has been conducted which demonstrates the reproducibility of Airborne Gamma-ray Spectrometry (AGS)
and the effects of changes in survey parameters, particularly line spacing. This has involved analysis of new data collected from estuarine salt marsh and upland areas in West Cumbria and SW Scotland during three phases of field work, in which over 150000 spectra were recorded with a 16 litre NaI(Tl) detector. The shapes and inventories of radiometric features have been examined. It has been shown that features with dimensions that are large relative to the survey line spacing are very well reproduced with all line spacings, whereas smaller features show more variability. The AGS technique has been applied to measuring changes in the radiation environment over a range of time scales from a few days to several years using data collected during this and previous surveys of the area.
Changes due to sedimentation and erosion of salt marshes, and hydrological transportation of upland activity have
been observed
Investigation of Spatial and Temporal Aspects of Airborne Gamma Spectrometry: Report on Phase I Survey, Conducted April 1999
The Use of Classification in Automated Mathematical Concept Formation
Concept formation programs aim to produce a high yield of concepts which are considered interesting. One intelligent way to do this is to base a new concept on one or more concepts which are already known to be interesting. This requires a concrete notion of the `interestingness' of a particular concept. Restricting the concepts formed to mathematical definitions in finite group theory, we derive three measures of the importance of a concept. These measures are based on how much the concept improves a classification of finite groups. Introduction One approach to automatic mathematical concept formation is to perform a heuristic search through a space of sentences which define mathematical concepts. In the space, there will be some sentences which are rubbish, some which are plausible but not very exciting, and some which are important. In order to be able to do an effective search, reducing the number of rubbish sentences, and increasing the yield of important concepts, it is..
Intracellular events regulating cross-presentation
Cross-presentation plays a fundamental role in the induction of CD8-T cell immunity. However, although more than three decades have passed since its discovery, surprisingly little is known about the exact mechanisms involved. Here we give an overview of the components involved at different stages of this process. First, antigens must be internalized into the cross-presenting cell. The involvement of different receptors, method of antigen uptake, and nature of the antigen can influence intracellular trafficking and access to the cross-presentation pathway. Once antigens access the endocytic system, different requirements for endosomal/phagosomal processing arise, such as proteolysis and reduction of disulfide bonds. The majority of cross-presented peptides are generated by proteasomal degradation. Therefore, antigens must cross a membrane barrier in a manner analogous to the fate of misfolded proteins in the endoplasmic reticulum (ER) that are retrotranslocated into the cytosol for degradation. Indeed, some components of the ER-associated degradation machinery have been implicated in cross-presentation. Further complicating the matter, endosomal and phagosomal compartments have been suggested as alternative sites to the ER for loading of peptides on major histocompatibility complex class I molecules. Finally, the antigen presenting cells involved, particularly dendritic cell subsets and their state of maturation, influence the efficiency of cross-presentation
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