Search results for " Computer Science"
showing 10 items of 3983 documents
Gray codes and efficient exhaustive generation for several classes of restricted words
2015
We consider Gray codes and efficient exhaustive generating algorithms for the sets belonging to three major classes of restricted words, that are: (1) restricted growth sequences, (2) factor avoiding q-ary words, and (3) pattern avoiding permutations. For the first two classes, our Gray codes (and thus, our generating algorithms) are based on order relations obtained by specializing known order relations; namely Reflected Gray Code (RGC) order and its variations, and we call them Reflected Gray Code based orders. The Gray code and the generating algorithm for the third class are based on Steinhaus-Johnson-Trotter order, that is, order relation induced by Steinhaus-Johnson-Trotter Gray code …
Agricultural crop exposure and risk of childhood cancer: new findings from a case–control study in Spain
2016
Background Childhood cancer is the main cause of disease-related death in children in Spain. Although little is known about the etiology, environmental factors are potential explanations for a fraction of the cases. Previous studies have shown pesticides to be associated with childhood cancer. The difficulty of collecting personal environmental exposure data is an important limitation; this lack of information about pesticides motivates the development of new methods to subrogate this exposure. We developed a crop exposure index based on geographic information to study the relationship between exposure to different types of crops and risk of childhood tumors. Methods We conducted a populati…
Two genomes of highly polyphagous lepidopteran pests (Spodoptera frugiperda, Noctuidae) with different host-plant ranges
2017
International audience; Emergence of polyphagous herbivorous insects entails significant adaptation to recognize, detoxify and digest a variety of host-plants. Despite of its biological and practical importance - since insects eat 20% of crops - no exhaustive analysis of gene repertoires required for adaptations in generalist insect herbivores has previously been performed. The noctuid moth Spodoptera frugiperda ranks as one of the world’s worst agricultural pests. This insect is polyphagous while the majority of other lepidopteran herbivores are specialist. It consists of two morphologically indistinguishable strains (“C” and “R”) that have different host plant ranges. To describe the evol…
The TES-based cryogenic anticoincidence detector for IXO: First results from large area prototypes
2010
The technique which combines high resolution spectroscopy with imaging capability is a powerful tool to extract fundamental information in X-ray Astrophysics and Cosmology. TES (Transition Edge Sensors)-based microcalorimeters match at best the requirements for doing fine spectroscopy and imaging of both bright (high count rate) and faint (poor signal-to-noise ratio) sources. For this reason they are considered among the most promising detectors for the next high energy space missions and are being developed for use on the focal plane of the IXO (International X-ray Observatory) mission. In order to achieve the required signal-to-noise ratio for faint or diffuse sources it is necessary to r…
Baseline design of the thermal blocking filters for the X-IFU detector on board ATHENA
2014
ATHENA is an advanced X-ray observatory designed by a large European consortium to address the science theme "Hot and Energetic Universe" recently selected by ESA for L2 – the second Large-class mission within the Cosmic Vision science program (launch scheduled in 2028). One of the key instruments of the mission is the X-ray Integral Field Unit (X-IFU), an array of Transition Edge Sensor (TES) micro-calorimeters with high energy resolution (2.5 eV @ 6 keV) in the energy range 0.2÷12 keV, operating at the focal plane of a large effective area high angular resolution (5" HEW) grazing incidence X-ray telescope. The X-IFU operates at temperatures below 100 mK and thus requires a sophisticated c…
The focal plane assembly for the Athena X-ray Integral Field Unit instrument
2016
This paper summarizes a preliminary design concept for the focal plane assembly of the X-ray Integral Field Unit on the Athena spacecraft, an imaging microcalorimeter that will enable high spectral resolution imaging and point-source spectroscopy. The instrument's sensor array will be a ~ 3840-pixel transition edge sensor (TES) microcalorimeter array, with a frequency domain multiplexed SQUID readout system allowing this large-format sensor array to be operated within the thermal constraints of the instrument's cryogenic system. A second TES detector will be operated in close proximity to the sensor array to detect cosmic rays and secondary particles passing through the sensor array for off…
On real-time algorithms for the location search of discontinuous conductivities with one measurement
2008
We discuss, and compare, two simple methods that provide coordinates of a point in the vicinity of one inclusion within some object with homogeneous electrical properties. In the context of nondestructive testing such an inclusion may correspond to a material defect, whereas in medicine this may correspond to a lesion in the brain, to name only two possible applications. Both methods use only one pair of voltage/current measurements on the entire boundary of the object to determine a single pair of coordinates that is considered to be close to the center of the inclusion. The first method has been proposed previously by Kwon, Seo and Yoon; the second method, called here the effective dipole…
An improved immersed boundary method for curvilinear grids
2009
Abstract In the present paper we propose an extension of the direct-forcing immersed boundary technique, recently developed and employed by Verzicco and co-authors [Fadlun EA, Verzicco R, Orlandi P, Mohd-Yusof J. Combined immersed-boundary finite-difference methods for three-dimensional complex flow simulations. J Comput Phys 2000;161:35–60; Verzicco R, Fatica M, Iaccarino G, Moin P, Khalighi B. Large eddy simulation of a road vehicle with drag-reduction devices. AIAA J 2002;40(12):2447–55; Cristallo A, Verzicco R. Combined immersed boundary/large-eddy-simulations of incompressible three-dimensional complex flows. Flow Turbul Combust 2006;77(1–4):3–26.] and successively improved by Balaras …
Extending customer relationship management. From empowering firms to empowering customers
2013
Purpose – The focus of customer relationship management (CRM) literature has been predominantly on the firm perspective and on IT, not on customer or service orientation and value co-creation. This paper seeks to explore and analyse contemporary CRM frameworks and suggests future research directions. To achieve this, a thorough literature review on CRM is conducted focusing on recent advances within CRM. This provides a good basis for critically analysing the current status of both CRM theory and practice. Design/methodology/approach – The paper reviews CRM literature published 2003-2011. Based on the literature review, it introduces a conceptual framework of the changing role of customer d…
Semantic interoperability between BIM and GIS – review of existing standards and depiction of a novel approach
2019
International audience; When it comes to Big Data ecosystems, main technical challenges pertain to defining links between data, information and knowledge, thus reaching interoperability. Interoperability issues are addressed in the context of data curation related tasks. Interoperability is a major prerequisite for achieving data automation, validation, thus fighting counter-productiveness (notably through data incentivisation). The demand for interoperable, reusable and open data is more and more present, thus pushing forward the research for innovation data curation approaches. This article gives a high level description of our approach for bridging the interoperability gap among GIS (Geo…