Search results for "Structured model"
showing 10 items of 14 documents
Definition of a Model-Based Detector of Curvilinear Regions
2007
This paper describes a new approach for detection of curvilinear regions. These features detection can be useful for any matching based algorithm such as stereoscopic vision. Our detector is based on curvilinear structure model, defined observing the real world. Then, we propose a multi-scale search algorithm of curvilinear regions and we report some preliminary results.
Aligning Relational Schema and OWL Ontologies with Hidden Markov Model
2016
The problem of bridging the gap between relational schema and ontologies is actively investigated in the Semantic Web and business communities. The main motivations are the OBDA scenario, where a domain ontology allows to hidden the technical details of the db to end-users; and the persistent storage of ontologies in db for facilitating search and retrieval keeping the benefits of DBMSs such as security and integrity. In these cases, the ABox is usually stored into a db, and the TBox is maintained in an ontology; for this reason, schema alignment is a more significant problem than the instance matching one. The use of manual mappings is hard and expensive, especially for large representatio…
Model independent assertions for integration of heterogeneous schemas
1992
Due to the proliferation of database applications, the integration of existing databases into a distributed or federated system is one of the major challenges in responding to enterprises' information requirements. Some proposed integration techniques aim at providing database administrators (DBAs) with a view definition language they can use to build the desired integrated schema. These techniques leave to the DBA the responsibility of appropriately restructuring schema elements from existing local schemas and of solving inter-schema conflicts. This paper investigates the assertion-based approach, in which the DBA's action is limited to pointing out corresponding elements in the schemas an…
Numerical solution of a spatio-temporal gender-structured model for hantavirus infection in rodents.
2017
In this article we describe the transmission dynamics of hantavirus in rodents using a spatio-temporal susceptible-exposed-infective-recovered (SEIR) compartmental model that distinguishes between male and female subpopulations [L.J.S. Allen, R.K. McCormack and C.B. Jonsson, Bull. Math. Biol. 68 (2006), 511--524]. Both subpopulations are assumed to differ in their movement with respect to local variations in the densities of their own and the opposite gender group. Three alternative models for the movement of the male individuals are examined. In some cases the movement is not only directed by the gradient of a density (as in the standard diffusive case), but also by a non-local convolution…
Globally Optimized Equilibrium Shapes of Zirconia-Supported Rh and Pt Nanoclusters: Insights into Site Assembly and Reactivity
2019
Metal–support interfaces form an active site for many important catalytic reactions. The modeling of these interfacial sites calls for approximations to set up a structure model, which in turn may ...
An average structure model of the intermediate phase between sodalite and cancrinite
2018
Abstract Powder samples of the intermediate phase between sodalite and cancrinite (INT) have been synthesized hydrothermally. The formation of the INT phase was proved by both PXRD and TGA analysis and its stoichiometric composition was found to be |Na6.95(1)(CO3)0.48(2) (H2O)6.18(6)|[AlSiO4]6. The comparison of the intensity ratios of PXRD data with a SCXRD measurement indicates the formation of a comparable phase with the typical strong stacking disorder. The hexagonal lattice parameters with a=1266.3(2) pm and c=1586(1) pm and the unit cell setting were determined by Pawley fits. The average lattice and the stacking disorder along c axis could be confirmed by the reconstruction of three-…
Heteroepitaxial growth of Co on W(110) investigated by scanning tunneling microscopy
2003
We investigated the growth of Co submonolayers on bcc W(110) by scanning tunneling microscopy. Due to the strong Co-W bonding, monolayers of Co grow in equilibrium pseudomorphically on W(110) until the monolayer is almost completed. When excess atoms are deposited atop the pseudomorphic monolayer, it transforms to a close-packed (cp) monolayer with misfit dislocation lines parallel to $[11\ifmmode\bar\else\textasciimacron\fi{}0]$ (Nishiyama-Wassermann orientation). The structure of the cp monolayer, as concluded from atomically resolved STM images, deviates from the rigid hard-sphere model of a cp (111) layer. Details of the structure are compared to a structure model previously proposed by…
Construct validity of the Moral Development Scale for Professionals (MDSP)
2011
Olle Söderhamn1,2, John Olav Bjørnestad1, Anne Skisland1, Christina Cliffordson21Faculty of Health and Sport Sciences, University of Agder, Grimstad and Kristiansand, Norway; 2Department of Nursing, Health and Culture, University West, Trollhättan, SwedenAbstract: The aim of this study was to investigate the construct validity of the Moral Development Scale for Professionals (MDSP) using structural equation modeling. The instrument is a 12-item self-report instrument, developed in the Scandinavian cultural context and based on Kohlberg’s theory. A hypothesized simplex structure model underlying the MDSP was tested through structural equation modeling. …
A critical size for emergence of nonbulk electronic and geometric structures in dodecanethiolate-protected Au clusters.
2014
We report on how the transition from the bulk structure to the cluster-specific structure occurs in n-dodecanethiolate-protected gold clusters, Au(n)(SC12)m. To elucidate this transition, we isolated a series of Au(n)(SC12)m in the n range from 38 to ∼520, containing five newly identified or newly isolated clusters, Au104(SC12)45, Au(∼226)(SC12)(∼76), Au(∼253)(SC12)(∼90), Au(∼356)(SC12)(∼112), and Au(∼520)(SC12)(∼130), using reverse-phase high-performance liquid chromatography. Low-temperature optical absorption spectroscopy, powder X-ray diffractometry, and density functional theory (DFT) calculations revealed that the Au cores of Au144(SC12)60 and smaller clusters have molecular-like elec…
Identifiability problem for recovering the mortality rate in an age-structured population dynamics model
2014
In this article is studied the identifiability of the age-dependent mortality rate of the Von Foerster–Mc Kendrick model, from the observation of a given age group of the population. In the case where there is no renewal for the population, translated by an additional homogeneous boundary condition to the Von Foerster equation, we give a necessary and sufficient condition on the initial density that ensures the mortality rate identifiability. In the inhomogeneous case, modelled by a non-local boundary condition, we make explicit a sufficient condition for the identifiability property, and give a condition for which the identifiability problem is ill-posed. We illustrate this latter case wit…