389 research outputs found

    Effect of Fines Content on the Cyclic Undrained Behavior of Sand

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    The influence of fines on the liquefaction potential of sandy soils has been studied by conducting isotropically consolidated stress controlled triaxial tests. Experimental results are compared with predictions using the theory developed by Nasser and Shokooh which is based on energy considerations. The theory determines the excess pore water pressure in terms of the number of cycles N, the dimensionless shear stress amplitude, and the initial and minimum values of the void ratio. The comparisons show good agreement between experimental data and model predictions for the pore water generation under cyclic loading for both loose and medium sands and medium silty soils

    Tetkik: Akan veri kümeleme algoritmalarını çalıştırma ve karşılaştırma

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    12th Turkish National Software Engineering Symposium, UYMS 2018; Istanbul; Turkey; 10 September 2018 through 12 September 2018Recently, clustering data streams have become an incredibly important research area for knowledge discovery as applications produce more and more unstoppable streaming data. In this paper we introduce clustering, streams and data streaming clustering algorithms, as well as discussions of the most important stream clustering algorithms, considering their structure. As an additional contribution of our work and differently from review and survey papers in stream clustering, we offer the practical part of the most known stream clustering algorithms, namely: (i) CluStream; (ii) DenStream; (iii) D-Stream; and (iv) ClusTree, showing their experimental results along with some performance metrics computation of for each, depending on MOA framework.Son zamanlarda, veri akışlarını kümelemek uygulamalar daha fazla durdurulamaz veri akışı üretirken bilgi keşfi için inanılmaz derecede önemli bir araştırma alanı haline gelmiştir.Bu makalede, kümeleme, akışlar ve veri akışlarını kümeleme algoritmalarını en önemli akım kümeleme algoritmalarının irdelenmesini yapılarını da göz önünde bulundurarak tanıtıyoruz. Çalışmamızın ek bir katkısı ve akış kümeleme alanında yapılmış tetkit ve gözden geçirme makalelerinden farklı olarak en bilinen akış kümeleme algoritmalarının Pratik kısmını, yani: (i) CluStream; (ii) DenStream; (iii) D-Stream; and (iv) ClusTree, MOA Java çerçevesine bağlı olarak, her biri için bazı performans metriklerinin hesaplanmasıyla birlikte deney sonuçlarını göstererek sunuyoruz

    Dating of Black Sea sediments from Romanian coast using natural 210Pb and fallout 137CS

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    The sediment samples collected near the shore from Romania were used for the determination of levels of natural 210Pb, 226Ra and fallout 137Cs radionuclides. The sediment samples were dried and ground to a fine powder. Airtight sealed samples were counted by gamma-spectrometer with 110 cm3 well-type HPGe detector for one week each. By using the isotopic analysis results, sediment accumulation rate was determined. A sedimentation rate of 0.20±0.01 cm·y-1 was determined using 210Pb method and 0.15±0.03 cm·y-1 using 137Cs isotope. Fallout peak from Chernobyl reactor accident, as well as the peaks due to nuclear tests, act as time markers

    Anthropogenic problems threatening major cities: Largest surface deformations observed in Hatay, Türkiye based on SBAS-InSAR

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    The surface deformation caused by tectonic activities and anthropogenic factors poses a great threat to cities worldwide. The investigation and monitoring of these deformations are crucial in order to create risk analysis for the future. The problem in this case is to investigate the surface deformations and their negative effects caused by groundwater use and to identify possible landslide areas. In this study, the surface deformations in Hatay province were analyzed using SBAS-InSAR. The results from these analyses were evaluated by field observations. Sentinel-1 descending (183 datasets) and ascending (147 datasets) track geometries were selected to determine the surface deformation and its temporal evolution. Both east-west and vertical surface deformations were calculated, and the surface deformation profiles, surface 3D models and time series were created. These time series were associated with monthly precipitation data. The deformation area was interpreted with regard to available well-log data and geological setting of the study area. As a result of the study, a surface deformation resembling a bowl like structure was observed in the industrial zone located in the city center of Hatay-Güzelburç. The deformation rates are approximately 22.3 cm/year in the form of subsidence, 3.6 cm/year in the form of eastern movement and 10.1 cm/year in the form of western movement. The deformation of this bowllike structure decelerated in the winter and accelerated in the summer due to excessive water use. The average monthly precipitation dataset supports these results. The stratigraphic data from water wells and the presence of limestone outside the eastern boundary of the deformation area show a thick clay layer in the eastern block of the bowl-shaped deformation structure. The difference between these two units, which causes a sharp anomaly at the eastern border of the deformation area, is interpreted as a probable normal fault. The second study area where surface deformations are observed is the landslide zone. The deformation was found to be 7.5 cm/year in a westward direction and 1.5 cm/year as subsidence

    On the Behaviour of Phillips-Perron Tests in the Presence of Persistent Cycles

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    In this paper, we analyse the impact of persistent cycles on the well-known semi-parametric unit root tests of Phillips and Perron (1988, Biometrika, Vol. 75, pp. 335-346). It is shown, both analytically and through Monte Carlo simulations, that the presence of complex (near) unit roots can severely bias the size properties of these tests. Given the popularity of these tests with applied researchers and their routine presence in most econometric software packages, the results presented in this paper suggest that practitioners should treat the outcomes of these tests with some caution when applied to data which display a strong cyclical component

    DADA: Degree-Aware Algorithms for Network-Based Disease Gene Prioritization

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    <p>Abstract</p> <p>Background</p> <p>High-throughput molecular interaction data have been used effectively to prioritize candidate genes that are linked to a disease, based on the observation that the products of genes associated with similar diseases are likely to interact with each other heavily in a network of protein-protein interactions (PPIs). An important challenge for these applications, however, is the incomplete and noisy nature of PPI data. Information flow based methods alleviate these problems to a certain extent, by considering indirect interactions and multiplicity of paths.</p> <p>Results</p> <p>We demonstrate that existing methods are likely to favor highly connected genes, making prioritization sensitive to the skewed degree distribution of PPI networks, as well as ascertainment bias in available interaction and disease association data. Motivated by this observation, we propose several statistical adjustment methods to account for the degree distribution of known disease and candidate genes, using a PPI network with associated confidence scores for interactions. We show that the proposed methods can detect loosely connected disease genes that are missed by existing approaches, however, this improvement might come at the price of more false negatives for highly connected genes. Consequently, we develop a suite called D<smcaps>A</smcaps>D<smcaps>A</smcaps>, which includes different uniform prioritization methods that effectively integrate existing approaches with the proposed statistical adjustment strategies. Comprehensive experimental results on the Online Mendelian Inheritance in Man (OMIM) database show that D<smcaps>A</smcaps>D<smcaps>A</smcaps> outperforms existing methods in prioritizing candidate disease genes.</p> <p>Conclusions</p> <p>These results demonstrate the importance of employing accurate statistical models and associated adjustment methods in network-based disease gene prioritization, as well as other network-based functional inference applications. D<smcaps>A</smcaps>D<smcaps>A</smcaps> is implemented in Matlab and is freely available at <url>http://compbio.case.edu/dada/</url>.</p

    Identification and characterization of 3.8 min 134mI

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    The [gamma]-ray spectra of iodine fractions rapidly separated from the products of slow neutron fission of 235U were studied. A 3.8 +/- 0.2 min species was found and was identified as 134mI from observations of corresponding growth in the intensities of the prominent 847 and 884 keV [gamma]-rays of 53 min 134I. This isomer is analogous to the 2.9 h isomer 134mCs and decays by the sequence 134mI (J[pi] = 8-)(J[pi] = 5+)134I (J[pi] = 4+) by transitions of and 44.4 +/- 0.1 keV(), respectively. For a 316 keV cross-over [gamma]-ray an upper limit of 1 % was obtained, and is near the intensity predicted by M4 systematics. A low-intensity [gamma]-ray of 234.3 +/- 0.5 keV was found This [gamma]-ray is interpreted as evidence for [beta]-decay (2%) of the isomer, possibly to the 0.29 sec 7- isomeric level in 134Xe.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34159/1/0000445.pd

    Isolation and Biophysical Characterisation of Bioactive Polysaccharides from Cucurbita Moschata (Butternut Squash)

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    Cucurbits are plants that have been used frequently as functional foods. This study includes the extraction, isolation, and characterisation of the mesocarp polysaccharide of Cucurbita moschata. The polysaccharide component was purified by gel filtration into three fractions (NJBTF1, NJBTF2, and NJBTF3) of different molecular weights. Characterisation includes the hydrodynamic properties, identification of monosaccharide composition, and bioactivity. Sedimentation velocity also indicated the presence of small amounts of additional discrete higher molecular weight components even after fractionation. Sedimentation equilibrium revealed respective weight average molecular weights of 90, 31, and 19 kDa, with the higher fractions (NJBTF1 and NJBTF2) indicating a tendency to self-associate. Based on the limited amount of data (combinations of 3 sets of viscosity and sedimentation data corresponding to the 3 fractions), HYDFIT indicates an extended, semi-flexible coil conformation. Of all the fractions obtained, NJBTF1 showed the highest bioactivity. All fractions contained galacturonic acid and variable amounts of neutral sugars. To probe further, the extent of glycosidic linkages in NJBTF1 was estimated using gas chromatography–mass spectrometry (GCMS), yielding a high galacturonic acid content (for pectin polysaccharide) and the presence of fructans—the first evidence of fructans (levan) in the mesocarp. Our understanding of the size and structural flexibility together with the high bioactivity suggests that the polysaccharide obtained from C. moschata has the potential to be developed into a therapeutic agent
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