1,432 research outputs found
Multiclass segmentation based on generalized fuzzy Gibbs random fields
The model of Gibbs random fields is widely applied to Bayesian segmentation due to its best property of describing the spatial constraint information. However, the general segmentation methods, whose model is defined only on hard levels but not on fuzzy set, may come across a lot of difficulties, e.g., getting the unexpected results or even nothing, especially when the blurred or degraded images are considered. In this paper, two multiclass approaches, based on the model of piecewise fuzzy Gibbs random fields (PFGRF) and that of generalized fuzzy Gibbs random fields (GFGRF) respectively, are presented to address these difficulties. In our experiments, both magnetic resonance image and simulated image are implemented with the two approaches mentioned above and the classical 'hard' one. These three different results show that the approach of GFGRF is an efficient and unsupervised technique, which can automatically and optimally segment the images to be finer.published_or_final_versio
Band and scattering tuning for high performance thermoelectric Sn1-xMnxTe alloys
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Prediction of the functional class of metal-binding proteins from sequence derived physicochemical properties by support vector machine approach
Metal-binding proteins play important roles in structural stability, signaling, regulation, transport, immune response, metabolism control, and metal homeostasis. Because of their functional and sequence diversity, it is desirable to explore additional methods for predicting metal-binding proteins irrespective of sequence similarity. This work explores support vector machines (SVM) as such a method. SVM prediction systems were developed by using 53,333 metal-binding and 147,347 non-metal-binding proteins, and evaluated by an independent set of 31,448 metal-binding and 79,051 non-metal-binding proteins. The computed prediction accuracy is 86.3%, 81.6%, 83.5%, 94.0%, 81.2%, 85.4%, 77.6%, 90.4%, 90.9%, 74.9% and 78.1% for calcium-binding, cobalt-binding, copper-binding, iron-binding, magnesium-binding, manganese-binding, nickel-binding, potassium-binding, sodium-binding, zinc-binding, and all metal-binding proteins respectively. The accuracy for the non-member proteins of each class is 88.2%, 99.9%, 98.1%, 91.4%, 87.9%, 94.5%, 99.2%, 99.9%, 99.9%, 98.0%, and 88.0% respectively. Comparable accuracies were obtained by using a different SVM kernel function. Our method predicts 67% of the 87 metal-binding proteins non-homologous to any protein in the Swissprot database and 85.3% of the 333 proteins of known metal-binding domains as metal-binding. These suggest the usefulness of SVM for facilitating the prediction of metal-binding proteins. Our software can be accessed at the SVMProt server
Electrical Conductivity Studies on Individual Conjugated Polymer Nanowires: Two-Probe and Four-Probe Results
<p>Abstract</p> <p>Two- and four-probe electrical measurements on individual conjugated polymer nanowires with different diameters ranging from 20 to 190 nm have been performed to study their conductivity and nanocontact resistance. The two-probe results reveal that all the measured polymer nanowires with different diameters are semiconducting. However, the four-probe results show that the measured polymer nanowires with diameters of 190, 95–100, 35–40 and 20–25 nm are lying in the insulating, critical, metallic and insulting regimes of metal–insulator transition, respectively. The 35–40 nm nanowire displays a metal–insulator transition at around 35 K. In addition, it was found that the nanocontact resistance is in the magnitude of 10<sup>4</sup>Ω at room temperature, which is comparable to the intrinsic resistance of the nanowires. These results demonstrate that four-probe electrical measurement is necessary to explore the intrinsic electronic transport properties of isolated nanowires, especially in the case of metallic nanowires, because the metallic nature of the measured nanowires may be coved by the nanocontact resistance that cannot be excluded by a two-probe technique.</p
Financialisation of News in China in the Age of the Internet: The Case of Xinhuanet
This paper discusses the recent development of Xinhuanet.com, a news website launched by Xinhua News Agency, one of China’s key central state-owned news organisations. Xinhuanet Co. Ltd., the business entity running the website, went public in October 2016 in Shanghai. This has marked the first step in the state news agency’s financialisation. Two main questions are addressed. First, what were the main driving forces behind Xinhuanet’s transformation from a governmental cultural organisation to a publicly traded enterprise, the majority shareholder of which remains Xinhua? Second, how to understand the nature of this transformation in relation to Xinhua’s wider marketisation process and that of the Chinese media sector as a whole? The paper argues that Xinhua’s financialisation via Xinhuanet is best understood as part of a state-administrated initiative in accord with Xinhua’s own business ambitions. The financialisation of news by state players such as Xinhuanet does not alter the underlying ownership structure of Chinese news media, which remain ultimately state-controlled
Phylogeny of the Infraorder Pentatomomorpha Based on Fossil and Extant Morphology, with Description of a New Fossil Family from China
<div><h3>Background</h3><p>An extinct new family of Pentatomomorpha, Venicoridae Yao, Ren & Cai <b>fam. nov.</b>, with 2 new genera and 2 new species (<em>Venicoris solaris</em> Yao, Ren & Rider <b>gen. & sp. nov.</b> and <em>Clavaticoris zhengi</em> Yao, Ren & Cai <b>gen. & sp. nov.</b>) are described from the Early Cretaceous Yixian Formation in Northeast China.</p> <h3>Methodology/Principal Findings</h3><p>A cladistic analysis based on a combination of fossil and extant morphological characters clarified the phylogenetic status of the new family and has allowed the reconstruction of intersuperfamily and interfamily relationships within the Infraorder Pentatomomorpha. The fossil record and diversity of Pentatomomorpha during the Mesozoic is discussed.</p> <h3>Conclusions/Significance</h3><p>Pentatomomorpha is a monophyletic group; Aradoidea and the Trichophora are sister groups; these fossils belong to new family, treated as the sister group of remainder of Trichophora; Pentatomoidea is a monophyletic group; Piesmatidae should be separated as a superfamily, Piesmatoidea. Origin time of Pentatomomorpha should be tracked back to the Middle or Early Triassic.</p> </div
Novel silicon nanotubes
Novel silicon nanotubes with inner-diameter of 60-80 nm was prepared using; hydrogen-added dechlorination of SiCl4 followed by chemical vapor deposition (CVD) on a NixMgyO catalyst. The TEM observation showed that the suitable reaction temperature is 973 K for the formation of silicon nanotubes. Most of silicon nanotubes have one open end and some have two closed ends. The shape of nanoscale silicon, however, isa micro-crystal type at 873 K, a rod or needle type at 993 K and an onion-type at 1023 K, respectively
Evidence for Anthropogenic Surface Loading as Trigger Mechanism of the 2008 Wenchuan Earthquake
Two and a half years prior to China's M7.9 Wenchuan earthquake of May 2008,
at least 300 million metric tons of water accumulated with additional seasonal
water level changes in the Minjiang River Valley at the eastern margin of the
Longmen Shan. This article shows that static surface loading in the Zipingpu
water reservoir induced Coulomb failure stresses on the nearby Beichuan thrust
fault system at <17km depth. Triggering stresses exceeded levels of daily lunar
and solar tides and perturbed a fault area measuring 416+/-96km^2. These stress
perturbations, in turn, likely advanced the clock of the mainshock and directed
the initial rupture propagation upward towards the reservoir on the
"Coulomb-like" Beichuan fault with rate-and-state dependent frictional
behavior. Static triggering perturbations produced up to 60 years (0.6%) of
equivalent tectonic loading, and show strong correlations to the coseismic
slip. Moreover, correlations between clock advancement and coseismic slip,
observed during the mainshock beneath the reservoir, are strongest for a longer
seismic cycle (10kyr) of M>7 earthquakes. Finally, the daily event rate of the
micro-seismicity (M>0.5) correlates well with the static stress perturbations,
indicating destabilization.Comment: 22 pages, 4 figures, 3 table
Solar wind speed theory and the nonextensivity of solar corona
The solar corona is a complex system, with nonisothermal plasma and being in
the self-gravitating field of the Sun. So the corona plasma is not only a
nonequilibrium system but also a nonextensive one. We estimate the parameter of
describing the degree of nonextensivity of the corona plasma and study the
generalization of the solar wind speed theory in the framework of nonextensive
statistical mechanics. It is found that, when use Chapman's corona model (1957)
as the radial distribution of the temperature in the corona, the nonextensivity
reduces the gas pressure outward and thus leads a significant deceleration
effect on the radial speed of the solar wind.Comment: 12 pages,1 figure, 1 table, 21 references; UN/ESA/NASA Workshop on
Basic Space Science and the International Heliophysical Year 2007, National
Astronomical Observatory of Japan, 18-22 June, 2007, Tokyo, Japa
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