Search results for " Opera"
showing 10 items of 3606 documents
On the Bishop-Phelps-Bollobás type theorems
2017
This dissertation is devoted to the study of the Bishop-Phelps-Bollobás property in different contexts. In Chapter 1 we give a historical resume and the motivation behind this property as the classics Bishop-Phelps and Bishop-Phelps-Bollobás theorems. We define the Bishop-Phelps-Bollobás property (BPBp) and we comment on some important current results. In Chapter 2 we study similar properties to the BPBp. First, we define the Bishop-Phelps-Bollobás point property (BPBpp). The BPBpp is stronger than the BPBp. We study it for bounded linear operators and then for bilinear mappings. After that, we study two more similar properties: properties 1 and 2. Property 2 is just the dual property of th…
Essential norm estimates for composition operators on BMOA
2013
Abstract We provide two function-theoretic estimates for the essential norm of a composition operator C φ acting on the space BMOA; one in terms of the n-th power φ n of the symbol φ and one which involves the Nevanlinna counting function. We also show that if the symbol φ is univalent, then the essential norm of C φ is comparable to its essential norm on the Bloch space.
Diagnostic efficacy of panoramic mandibular index to identify postmenopausal women with low bone mineral densities
2011
Objectives: The aim of the study was to compare and assess the accuracy of panoramic mandibular index (PMI) and antegonial index (AI) in the panoramic radiographs of postmenopausal women with normal and low skeletal bone mineral densities( BMD) diagnosed by using dual energy x-ray absorptiometry ( DXA). Study Design: In panoramic radiographs obtained from 40 post menopausal women( 20 normal and 20 osteoporo tic) aged between 50-75 who’s BMD has already been assessed by a DXA, the mean was calculated for PMI and AI index values measured in the right and left mandibles. The PMI and AI index values were evaluated using the student’s t test. The correlation between the observers for indices was…
Exacus: Efficient and Exact Algorithms for Curves and Surfaces
2005
We present the first release of the Exacus C++ libraries. We aim for systematic support of non-linear geometry in software libraries. Our goals are efficiency, correctness, completeness, clarity of the design, modularity, flexibility, and ease of use. We present the generic design and structure of the libraries, which currently compute arrangements of curves and curve segments of low algebraic degree, and boolean operations on polygons bounded by such segments.
Fundamental solutions for general anisotropic multi-field materials based on spherical harmonics expansions
2016
Abstract A unified method to evaluate the fundamental solutions for generally anisotropic multi-field materials is presented. Based on the relation between the Rayleigh expansion and the three-dimensional Fourier representation of a homogenous partial differential operator, the proposed technique allows to obtain the fundamental solutions and their derivatives up to the desired order as convergent series of spherical harmonics. For a given material, the coefficients of the series are computed only once, and the derivatives of the fundamental solutions are obtained without any term-by-term differentiation, making the proposed approach attractive for boundary integral formulations and efficie…
3D DCE-MRI Radiomic Analysis for Malignant Lesion Prediction in Breast Cancer Patients
2022
Rationale and Objectives: To develop and validate a radiomic model, with radiomic features extracted from breast Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) from a 1.5T scanner, for predicting the malignancy of masses with enhancement. Images were acquired using an 8-channel breast coil in the axial plane. The rationale behind this study is to show the feasibility of a radio-mics-powered model that could be integrated into the clinical practice by exploiting only standard-of-care DCE-MRI with the goal of reducing the required image pre-processing (ie, normalization and quantitative imaging map generation).Materials and Methods: 107 radiomic features were extracted from a …
Matrix isolation studies and DFT calculations on molecular alkali metal bromates
2009
DFT and MP2 calculations have been carried out on a series of molecular alkali metal bromates MBrO3 (M = Na, K, Rb, Cs), and the results compared with matrix isolation IR studies on the vaporisation of the solid salts. For M = Na, K or Rb, no ternary molecular species were detected in the low temperature matrix, but vaporisation of solid caesium bromate at 730 K resulted in the formation of molecular CsBrO3, which was identified as having a C3v structure involving tridentate coordination. Additionally, the DFT and MP2 calculations provide estimates of the molecular parameters for all four MBrO3 species, and for the related MXO3 species CsClO3 and CsIO3. The proven stability of MBrO3 molecul…
Offshore Assets in the Transition from ‘Traditional Business Practice’ to ‘Connected Business Eco-systems’
2020
In many industrial sectors we have already begun to see how new business ecosystems gradually emerge turning the traditional business practices upside down. Particularly within relatively conventional sectors, such as upstream oil and gas (O&G) and land-based process industry, we expect to see substantial changes in the years to come. In this paper, we elaborate on principal challenges related to major structural changes and core technology platforms for the oil industry identifying critical features and elaborating on emerging operational principles. This is based on a critical review of latest industry conditions and practices that are targeted towards the creation of new business models …
Information Systems Students’ Impressions on Learning Modeling Enterprise Architectures
2020
This Full Research Paper presents enterprise architecture (EA) modeling tools utilized in an educational context. EA is a well-known and a commonly used approach for organizational development aiming to improve the alignment of business operations and information technology. This high level design of information technology (IT) driven business operations lays the foundations on lower level technical activities such as the design and implementation of application programs and features, system boundary interfaces, database distribution and data pipes, and system recovery. Organizations’ architectures are made visible by creating EA artefacts, such as business process diagrams, data models and…
PDE triangular Bézier surfaces: Harmonic, biharmonic and isotropic surfaces
2011
We approach surface design by solving second-order and fourth-order Partial Differential Equations (PDEs). We present many methods for designing triangular Bézier PDE surfaces given different sets of prescribed control points and including the special cases of harmonic and biharmonic surfaces. Moreover, we introduce and study a second-order and a fourth-order symmetric operator to overcome the anisotropy drawback of the harmonic and biharmonic operators over triangular Bézier surfaces. © 2010 Elsevier B.V. All rights reserved.