26 research outputs found
Crossover in the nature of the metallic phases in the perovskite-type RNiO_3
We have measured the photoemission spectra of NdSmNiO,
where the metal-insulator transition and the N\'{e}el ordering occur at the
same temperature for and the metal-insulator transition
temperature () is higher than the N\'{e}el temperature for . For , the spectral intensity at the Fermi level is high in the
metallic phase above and gradually decreases with cooling in the
insulating phase below while for it shows a pseudogap-like
behavior above and further diminishes below . The results
clearly establish that there is a sharp change in the nature of the electronic
correlations in the middle () of the metallic phase of the
NiO system.Comment: 4 pages, 4 figure, submitted to Phys. Rev.
Quantum gates by coupled asymmetric quantum dots and controlled-NOT-gate operation
A quantum computer based on an asymmetric coupled dot system has been
proposed and shown to operate as the controlled-NOT-gate. The basic idea is (1)
the electron is localized in one of the asymmetric coupled dots. (2)The
electron transfer takes place from one dot to the other when the energy-levels
of the coupled dots are set close. (3)The Coulomb interaction between the
coupled dots mutually affects the energy levels of the other coupled dots. The
decoherence time of the quantum computation and the measurement time are
estimated. The proposed system can be realized by developing the technology of
the single-electron memory using Si nanocrystals and the direct combination of
the quantum circuit and the conventional circuit is possible.Comment: LaTeX, 7 pages, 5 figures, revised content, to appear in Phys. Rev.
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A semantic sensor web for environmental decision support applications
Sensing devices are increasingly being deployed to monitor the physical world around us. One class of application for which sensor data is pertinent is environmental decision support systems, e.g., flood emergency response. For these applications, the sensor readings need to be put in context by integrating them with other sources of data about the surrounding environment. Traditional systems for predicting and detecting floods rely on methods that need significant human resources. In this paper we describe a semantic sensor web architecture for integrating multiple heterogeneous datasets, including live and historic sensor data, databases, and map layers. The architecture provides mechanisms for discovering datasets, defining integrated views over them, continuously receiving data in real-time, and visualising on screen and interacting with the data. Our approach makes extensive use of web service standards for querying and accessing data, and semantic technologies to discover and integrate datasets. We demonstrate the use of our semantic sensor web architecture in the context of a flood response planning web application that uses data from sensor networks monitoring the sea-state around the coast of England
Cross-correlation redshift calibration without spectroscopic calibration samples in DES science verification data
Galaxy cross-correlations with high-fidelity redshift samples hold the potential to precisely calibrate systematic photometric redshift uncertainties arising from the unavailability of complete and representative training and validation samples of galaxies. However, application of this technique in the Dark Energy Survey (DES) is hampered by the relatively low number density, small area, and modest redshift overlap between photometric and spectroscopic samples. We propose instead using photometric catalogues with reliable photometric redshifts for photo-z calibration via cross-correlations. We verify the viability of our proposal using redMaPPer clusters from the Sloan Digital Sky Survey (SDSS) to successfully recover the redshift distribution of SDSS spectroscopic galaxies. We demonstrate how to combine photo-z with cross-correlation data to calibrate photometric redshift biases while marginalizing over possible clustering bias evolution in either the calibration or unknown photometric samples. We apply our method to DES Science Verification (DES SV) data in order to constrain the photometric redshift distribution of a galaxy sample selected for weak lensing studies, constraining the mean of the tomographic redshift distributions to a statistical uncertainty of z ā¼ Ā±0.01. We forecast that our proposal can, in principle, control photometric redshif
Sinonasal Involvement in Systemic Vasculitides and Cocaine-Induced Midline Destructive Lesions: Diagnostic Controversies
Multiple systemic diseases produce various clinical manifestations in the sinonasal area. They usually appear as difficult-to-diagnose disease processes with slow, atypical clinical courses. The aim of this study was to evaluate the sinonasal manifestations of systemic vasculitides, highlighting key points for diagnosis and differential diagnosis with other pathological entities, especially cocaine-induced midline destructive lesions (CIMDL). A retrospective study was performed of 10 patients treated in our hospital during the last 5 years with an initial diagnosis of systemic vasculitides with sinonasal involvement: eight patients with granulomatosis with polyangiitis (GPA; new nomenclature for Wegener granulomatosis) and two patients with Churg-Strauss syndrome (CSS). The study variables were clinical presentation, nasal endoscopy results, maxillofacial scan results, nasal biopsy results, erythrocyte sedimentation rate, and autoimmune antibody levels. The definitive diagnosis was GPA in six (60%) patients, CSS in two (20%) patients, and CIMDL in two (20%) patients. Nasal symptoms were similar in all patients, but nasal polyps were present in only one patient with CSS. Systemic manifestations were absent in patients with CIMDL. Likewise, peripheral eosinophilia was observed only in the two patients with CSS. Specific positive biopsy specimens were obtained in six patients (all six patients with GPA, one with CSS, and one with CIMDL). Antineutrophil cytoplasmic antibodies (ANCA) were positive in all patients with GPA (proteinase 3 antigen in five patients and myeloperoxidase in one patient), and perinuclear ANCA was positive in one patient with CIMDL; however, this patient showed an undefined pattern. Finally, the response to treatment was adequate in all patients excluding those with CIMDL. GPA and CIMDL syndromes pose a difficult differential diagnosis because they have common clinical, serological, and histological presentations. Negative histological results do not exclude the diagnosis of sinonasal vasculitides. The absence of systemic manifestations and the lack of response to treatment will lead to the confirmation of CIMDL syndrome in a cocaine user. Otolaryngologists play an important role in the early and differential diagnosis of these diseases
IPHAS extinction distances to planetary nebulae
Aims. The determination of reliable distances to planetary nebulae (PNe) is a major difficulty in the study of this class of objects in the Galaxy. The availability of new photometric surveys such as IPHAS (the INT/WFC photometric HĪ± survey of the northern Galactic plane) covering large portions of the sky provide an opportunity to apply the so-called extinction method to determine the distances of a large number of objects. Methods. The technique is applied to a sample of 137 PNe located between -5 and 5 degrees in Galactic latitude, and between 29.52 and 215.49 degrees in longitude. The characteristics of the distance-extinction method and the main sources of errors are carefully discussed. Results. The data on the extinction of the PNe available in the literature, complemented by new observations, allow us to determine extinction distances for 70 PNe. A comparison with statistical distance scales from different authors is presented. Ā© ESO, 2010. Ā© 2010 ESO.link_to_subscribed_fulltex
A semantic sensor web for environmental decision support applications
Sensing devices are increasingly being deployed to monitor the physical world around us. One class of application for which sensor data is pertinent is environmental decision support systems, e.g., flood emergency response. For these applications, the sensor readings need to be put in context by integrating them with other sources of data about the surrounding environment. Traditional systems for predicting and detecting floods rely on methods that need significant human resources. In this paper we describe a semantic sensor web architecture for integrating multiple heterogeneous datasets, including live and historic sensor data, databases, and map layers. The architecture provides mechanisms for discovering datasets, defining integrated views over them, continuously receiving data in real-time, and visualising on screen and interacting with the data. Our approach makes extensive use of web service standards for querying and accessing data, and semantic technologies to discover and integrate datasets. We demonstrate the use of our semantic sensor web architecture in the context of a flood response planning web application that uses data from sensor networks monitoring the sea-state around the coast of England. Ā© 2011 by the authors; licensee MDPI, Basel, Switzerland
A semantic sensor web for environmental decision support applications
Sensing devices are increasingly being deployed to monitor the physical world around us. One class of application for which sensor data is pertinent is environmental decision support systems, e.g., flood emergency response. For these applications, the sensor readings need to be put in context by integrating them with other sources of data about the surrounding environment. Traditional systems for predicting and detecting floods rely on methods that need significant human resources. In this paper we describe a semantic sensor web architecture for integrating multiple heterogeneous datasets, including live and historic sensor data, databases, and map layers. The architecture provides mechanisms for discovering datasets, defining integrated views over them, continuously receiving data in real-time, and visualising on screen and interacting with the data. Our approach makes extensive use of web service standards for querying and accessing data, and semantic technologies to discover and integrate datasets. We demonstrate the use of our semantic sensor web architecture in the context of a flood response planning web application that uses data from sensor networks monitoring the sea-state around the coast of England