4,592 research outputs found
Iterative methods based on splittings for stochastic automata networks
Cataloged from PDF version of article.This paper presents iterative methods based on splittings (Jacobi, Gauss-Seidel, Successive Over Relaxation) and their block versions for Stochastic Automata Networks (SANs). These methods prove to be better than the power method that has been used to solve SANs until recently. With the help of three examples we show that the time it takes to solve a system modeled as a SAN is still substantial and it does not seem to be possible to solve systems with tens of millions of states on standard desktop workstations with the current state of technology. However, the SAN methodology enables one to solve much larger models than those could be solved by explicitly storing the global generator in the core of a target architecture especially if the generator is reasonably dense. (C) 1998 Elsevier Science B.V. All rights reserved
Travel Patterns and Expenditures of the Mature Market
Travel by persons over the age of 50 represents a key component of the leisure market. This paper examines participation in favorite activities, distance traveled, length of stay and expenditures for selected outdoor activities by this mature market based upon data from the Nationwide Recreation Survey. The paper then addresses some marketing implications suggested by these data for the development and marketing of leisure services
The Reliability and Reproducibility of Conventional, Digital and CT Created Cephalograms: A Comparative Study
poster abstractObjective: The purpose of this retrospective radiographic study was to determine the reliability and reproducibility of skeletal and dental measurements of lateral cephalograms created from computed tomography (CT) scan compared to the conventional and digital lateral cephalograms.
Method: Following reliability studies, CT records of 30 patients were obtained from the archives. The lateral cephalometric radiographs of these patients were initially manually traced. Then the same radiographs were scanned and traced using Dolphin Imaging software Version 11 (Dolphin Imaging, Chatsworth, CA, USA). Totally 16 (10 angular and 6 linear) measurements were performed. Cephalometric measurements performed on conventional, digital and CT created cephalograms were compared statistically using repeated measures analysis of variance. Statistical significance was set at p<0.05 level.
Result: The intrarater reliability test for each method showed high values r >.090 except for the mandibular length which had a correlation of 0.82 for the CT created cephalogram. Five measurements (N-A- Pog, N-S, ANS-PNS, Co-ANS and Co-Gn) were found to be significantly different between the CT created and conventional cephalograms and three measurements (SNB, ANB, and /1-MP) were found to be significantly different between the CT created and digital cephalograms.
Conclusion: The measurement differences between the conventional, digital and CT created cephalograms are statistically significant, but clinically acceptable
Insights into mantle-type volatiles contribution from dissolved gases in artesian waters of the Great Artesian Basin, Australia
The geochemical features of the volatiles dissolved in artesian thermal waters discharged over three basins (Millungera, Galilee and Cooper basin) of the Australian Great Artesian Basin (GAB) consistently indicate the presence of fluids from multiple gas sources located in the crust (e.g. sediments, oil reservoirs, granites) as well as minor but detectable contributions of mantle/magma-derived fluids. The gases extracted from 19 water samples and analyzed for their chemical and isotopic composition exhibit amounts of CO up to about 340mlSTP/L marked by a δC (Total Dissolved Carbon) ranging from -16.9 to +0.18‰ vs PDB, while CH concentrations vary from 4.4×10 to 4.9mlSTP/L. Helium contents were between 9 and >2800 times higher than equilibrium with Air Saturated Water (ASW), with a maximum value of 0.12mlSTP/L. Helium isotopic composition was in the 0.02-0.21 Ra range (Ra = air-normalized He/He ratio). The three investigated basins differ from each other in terms of both chemical composition and isotopic signatures of the dissolved gases whose origin is attributed to both mantle and crustal volatiles. Mantle He is present in the west-central and hottest part of the GAB despite no evidence of recent volcanism. We found that the partial pressure of helium, significantly higher in crustal fluids than in mantle-type volatiles, enhances the crustal He signature in the dissolved gases, thus masking the original mantle contribution. Neotectonic activity involving deep lithospheric structures and magma intrusions, highlighted by recent geophysical investigations, is considered to be the drivers of mantle/magmatic volatiles towards the surface. The results, although pertaining to artesian waters from a vast area of >542,000km, provide new constraints on volatile injection, and show that fluids' geochemistry can provide additional and independent information on the geo-tectonic settings of the Great Artesian Basin and its geothermal potential
Primary Molar Pulpotomies with Different Hemorrhage Control Agents and Base Materials: A Randomized Clinical Trial
Objective: To evaluate the clinical and radiographical success of primary molar pulpotomies which used 15.5% ferric sulfate (FS) or 1.25% sodium hypochlorite (NaOCl) for hemostasis and zinc oxide-eugenol (ZOE) and calcium hydroxide (CH) pastes as base materials.
Methods: In 29 healthy children, 80 primary molars were randomly allocated to one of the study groups: Group 1: FS-ZOE, Group 2: FS-CH, Group 3: NaOCl-ZOE, and Group 4: NaOCl-CH. After hemostasis with the respective solutions, pulp stumps and floor of the pulp chambers were covered with either ZOE or CH pastes. All teeth were restored with stainless steel crowns. Follow-up examinations were carried out at 1, 3, 6, and 12 months.
Results: One tooth in Group 1 and two teeth in Group 4 were extracted because of pain and periapial pathosis at sixth month. After 12 months, clinical success rates of pulpotomies in Groups 1-4 were 95%, 100%, 100%, and 89.5%, respectively. The differences were not significant (P = 0.548). Radiographic success rates for Groups 1-4 were 80%, 88.9%, 78.9%, and 84.2%, respectively. No statistically significant difference was found (P = 0.968). Pain on percussion was the most observed clinical finding. However, internal root resorption was the most common radiological finding and it was observed significantly more in mandibular primary molars (P \u3c 0.05).
Conclusion: Both ZOE and CH can be preferred as base materials after hemostasis achieved by the use of 15.5% FS or 1.25% NaOCl in primary tooth pulpotomy
Geophysical anomalies and quartz deformation of the Warburton West structure, central Australia
This paper reports geophysical anomalies and intra-crystalline quartz lamellae in drill cores from the Warburton West Basin overlapping the border of South Australia and the Northern Territory. The pre-Upper Carboniferous ~450×300km-large Warburton Basin, north-eastern South Australia, is marked by distinct eastern and western magnetic, gravity and low-velocity seismic tomography anomalies. Quartz grains from arenite core samples contain intra-crystalline lamellae in carbonate-quartz veins and in clastic grains, similar to those reported earlier from arenites, volcanic rocks and granites from the Warburton East Basin. Universal Stage measurements of quartz lamellae in both sub-basins define Miller-Bravais indices of {10-12} and {10-13}. In-situ quartz lamellae occur only in pre-Late Carboniferous rocks whereas lamellae-bearing clastic quartz grains occur in both pre-Late Carboniferous and post-Late Carboniferous rocks - the latter likely redeposited from the pre-Late Carboniferous basement. Quartz lamellae in clastic quartz grains are mostly curved and bent either due to tectonic deformation or to re-deformation of impact-generated planar features during crustal rebound or/and post-impact tectonic deformation. Seismic tomography low-velocity anomalies in both Warburton West Basin and Warburton East Basin suggest fracturing of the crust to depths of more than 20km. Geophysical modelling of the Cooper Basin, which overlies the eastern Warburton East Basin, suggests existence of a body of high-density (~2.9-3.0gr/cm) and high magnetic susceptibility (SI~0.012-0.037) at a depth of ~6-10km at the centre of the anomalies. In the Warburton West Basin a large magnetic body of SI=0.030 is modelled below ~10km, with a large positive gravity anomaly offset to the north of the magnetic anomaly. In both the Warburton East and Warburton West the deep crustal fracturing suggested by the low velocity seismic tomography complicates interpretations of the gravity data. Universal Stage measurements of quartz lamellae suggest presence of both planar deformation features of shock metamorphic derivation and deformed planar lamella. The latter may be attributed either to re-deformation of impact-generated lamella, impact rebound deformation or/and post impact tectonic deformation. The magnetic anomalies in the Warburton East and West sub-basins are interpreted in terms of (1) presence of deep seated central mafic bodies; (2) deep crustal fracturing and (3) removal of Devonian and Carboniferous strata associated with rebound of a central uplift consequent on large asteroid impact. Further tests of the Warburton structures require deep crustal seismic transects
Data-driven malware detection for 6G networks: a survey from the perspective of continuous learning and explainability via visualisation
5G is inherently prone to security vulnerabilities. We witness that many today’s networks contain 5G security flaws due to their reliance on the existing 4G network core. A lack of security standards for 5G IoT devices means network breaches and malware threats might run uncontrolled. The future 6G network is predicted to be implemented with artificial intelligence- driven communication via machine learning, enhanced edge computing, post-quantum cryptography and so forth. With the activation of edge computing, the computing power available at supercomputing servers is to be integrated directly into the devices at the entry point of a network in a distributed manner (e.g., antennas, routers, IoT sensors, etc). This feature brings an equal quality of service everywhere including remote regions (a.k.a service everywhere) which will trigger an exponential growth of associated applications. In this intricate environment, malware attacks are becoming more challenging to detect. This paper thus reviews the theoretical and experimental data-driven malware detection literature, in the large-scale data-intensive field, relating to: (1) continuous learning, including new concepts in multi-domain to multi-target learning and the challenges associated with unseen/unknown data, imbalance data and data scarcity, and (2) new explainability via visualisation concepts with a multi-labelling approach which allows identifying malware by their recipes while improving the interpretability of its decision process
Tracking the timing of Neotethyan oceanic slab break-off: Geochronology and geochemistry of the quartz diorite porphyries, NE Turkey
The initiation of the break-off of the northern branch of the Neotethyan oceanic lithosphere is an important but poorly understood event in the geology of the Sakarya Zone (SZ) in northeastern Turkey. Although it is well-known that Latest Cretaceous intrusives (~70 Ma) and early Eocene adakitic magmatic rocks are present in the eastern SZ, the outcrops of the early Eocene non-adakitic rocks are very limited, and their tectono-magmatic evolution has not been studied. We describe a small outcrop of non-adakitic quartz diorite porphyry in the Kov area of the Gümüşhane region in northeastern Turkey. The genesis of these porphyries is significant in evaluating the syn- to post-collision-related magmatism. The LA-ICP-MS zircon U-Pb dating revealed that the Kov quartz diorite porphyries (KQDP) formed at ca. 50 Ma, coeval with adakitic rocks, and ~20 Myr later than the slab roll-back-related intrusive rocks. The KQDPs are calc-alkaline in composition and enriched in large ion lithophile elements (LILEs) and light rare earth elements (LREEs) and depleted in high field strength elements (HFSEs; e.g., Nb, Ta, Ti), with significant negative anomalies of Nb, Ta, and Ti but positive anomalies of Th, U, and Pb. Isotopic compositions of the samples show limited range of variation and slight enrichment of 87Sr/86Sr(t) (0.70489 to 0.70555), εNd(t) (−1.4 to −1.2) with TDM of 1.11 to 1.61 Ga. Pb isotopic ratios of the samples point to an enriched mantle source. They were likely crystallized from the melt that originated from an EM2-type spinel-facies subcontinental lithospheric mantle (SCLM), followed by the fractionation with insignificant crustal assimilation. The SCLM was metasomatically enriched, and the metasomatic agent was likely H2O-rich fluids rather than sediments released from subducting oceanic crust during the Late Cretaceous closure of the Neotethyan oceanic lithosphere. In conjunction with the geological background and previous data, we propose that the generation of the KQDPs resulted from a slab break-off event that caused ascending or infiltration of hot asthenosphere, triggering mantle melting. Such sporadic occurrences of the KQDPs, with coeval adakitic rocks in the SZ, are likely associated with the onset of extensional tectonics due to the earlier stage of slab break-off along the region during the early Eocene period.publishe
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