2,358 research outputs found

    Regional similarities in the distributions of well yield from crystalline rocks in Fennoscandia

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    Well yields from Precambrian and Palaeozoic bedrock in Norway, Sweden and Finland exhibit very similar and approximately log-normal distributions: all three data sets exhibit a median yield of 600–700 L hr-1, despite the differences in climate and lithology. This similarity is tentatively reflected on a larger geographical scale by a meta-analysis of the international data sets on crystalline rock aquifers from other recently glaciated areas (i.e., without a thick regolith of weathered rock). An heuristic treatment of the Fennoscandian data sets suggests that this median yield is consistent with the following bulk properties of shallow (to c. 70–80 m depth) crystalline bedrock: transmissivity of 0.56 ± 0.30 m2 d-1 (6.4 ± 3.4 x 10-6 m2 s-1) and hydraulic conductivity of around 1.1 (± 0.6) x 10-7 m s-1

    Mass-spectrometric study of the rhenium-oxygen system

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    Rhenium, having the second highest melting point among the metals, is used for refractory containers. Thermodynamic values for rhenium oxide is determined by mass spectrometry and X ray diffraction

    Learning from one example in machine vision by sharing probability densities

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.Includes bibliographical references (p. 125-130).Human beings exhibit rapid learning when presented with a small number of images of a new object. A person can identify an object under a wide variety of visual conditions after having seen only a single example of that object. This ability can be partly explained by the application of previously learned statistical knowledge to a new setting. This thesis presents an approach to acquiring knowledge in one setting and using it in another. Specifically, we develop probability densities over common image changes. Given a single image of a new object and a model of change learned from a different object, we form a model of the new object that can be used for synthesis, classification, and other visual tasks. We start by modeling spatial changes. We develop a framework for learning statistical knowledge of spatial transformations in one task and using that knowledge in a new task. By sharing a probability density over spatial transformations learned from a sample of handwritten letters, we develop a handwritten digit classifier that achieves 88.6% accuracy using only a single hand-picked training example from each class. The classification scheme includes a new algorithm, congealing, for the joint alignment of a set of images using an entropy minimization criterion. We investigate properties of this algorithm and compare it to other methods of addressing spatial variability in images. We illustrate its application to binary images, gray-scale images, and a set of 3-D neonatal magnetic resonance brain volumes.Next, we extend the method of change modeling from spatial transformations to color transformations. By measuring statistically common joint color changes of a scene in an office environment, and then applying standard statistical techniques such as principal components analysis, we develop a probabilistic model of color change. We show that these color changes, which we call color flows, can be shared effectively between certain types of scenes. That is, a probability density over color change developed by observing one scene can provide useful information about the variability of another scene. We demonstrate a variety of applications including image synthesis, image matching, and shadow detection.by Erik G. Miller.Ph.D

    Schistosoma mansoni Infection in Finchaa Sugar Estate: Public health Problem Assessment based on Clinical Records and Parasitological Surveys, Western Ethiopia

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    The survey of Schistosoma mansoni (S. mansoni) in Finchaa Sugar Estate, Western Ethiopia, was conducted to investigate the prevalence and health problems of schistosomiasis with some of the risk factors. The examination was undertaken based on the analysis of retrospective clinical data from the health center and a cross-sectional parasitological examinations using Kato-thick smear slides in April-June 2012/2013. Over the period 2008 to 2013 average prevalence among suspected patients at the health centre was 30.9%. Examination of double kato-thick smear slides from a random sample of 602 individuals from most schistosomiasis affected camp 7 revealed the prevalence of 37.5%. S. mansoni infection is become a year-round public health problem in Finchaa, Sugar Estate possibly due to permanent streams, water bodies and water contact behaviors and also reduced effectiveness of current control measures. Among the 7th camps, village A (camp 7) is the most schistosomiasis affected area (37.5%) followed by Kuyisa (25%). This is attributed to the presence of permanent stream (Fekerie stream) near camp 7. The present finding shows that the prevalence and intensity of schistosomiasis in the more affected camp 7 of Finchaa Sugar Estate was significantly higher among males than in females and its prevalence and intensity was found to be higher among study population within the age group of 11-20 years old. This study indicates that schistosomiasis is a major health problem in Finchaa Sugar Estate with moderate prevalence. The study results will provide an additional clinical and parasitological data on the current status of S. mansoni in Finchaa Sugar Estate and could serve as a guide in designing, developing and implementing intervention strategies to mitigate morbidity due to S. mansoni especially in highly risk groups under the Ethiopian health service system.Keywords: Egg per gram; Finchaa Sugar Estate; Kato-katz; Schistosomiasis; S. mansoni; Public healt

    An analysis of surface area estimates of binary volumes under three tilings

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    Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (leaves 77-79).by Erik G. Miller.M.S

    COMPASS: a 2.6m telescope for CMBR polarization studies

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    COMPASS (COsmic Microwave Polarization at Small Scale) is an experiment devoted to measuring the polarization of the CMBR. Its design and characteristics are presented
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