7,248 research outputs found
Image database system for glaucoma diagnosis support
Tato práce popisuje přehled standardních a pokročilých metod používaných k diagnose glaukomu v ranném stádiu. Na základě teoretických poznatků je implementován internetově orientovaný informační systém pro oční lékaře, který má tři hlavní cíle. Prvním cílem je možnost sdílení osobních dat konkrétního pacienta bez nutnosti posílat tato data internetem. Druhým cílem je vytvořit účet pacienta založený na kompletním očním vyšetření. Posledním cílem je aplikovat algoritmus pro registraci intenzitního a barevného fundus obrazu a na jeho základě vytvořit internetově orientovanou tři-dimenzionální vizualizaci optického disku. Tato práce je součásti DAAD spolupráce mezi Ústavem Biomedicínského Inženýrství, Vysokého Učení Technického v Brně, Oční klinikou v Erlangenu a Ústavem Informačních Technologií, Friedrich-Alexander University, Erlangen-Nurnberg.This master thesis describes a conception of standard and advanced eye examination methods used for glaucoma diagnosis in its early stage. According to the theoretical knowledge, a web based information system for ophthalmologists with three main aims is implemented. The first aim is the possibility to share medical data of a concrete patient without sending his personal data through the Internet. The second aim is to create a patient account based on a complete eye examination procedure. The last aim is to improve the HRT diagnostic method with an image registration algorithm for the fundus and intensity images and create an optic nerve head web based 3D visualization. This master thesis is a part of project based on DAAD co-operation between Department of Biomedical Engineering, Brno University of Technology, Eye Clinic in Erlangen and Department of Computer Science, Friedrich-Alexander University, Erlangen-Nurnberg.
How blockchain impacts cloud-based system performance: a case study for a groupware communication application
This paper examines the performance trade-off when implementing a blockchain architecture for a cloud-based groupware communication application. We measure the additional cloud-based resources and performance costs of the overhead required to implement a groupware collaboration system over a blockchain architecture. To evaluate our groupware application, we develop measuring instruments for testing scalability and performance of computer systems deployed as cloud computing applications. While some details of our groupware collaboration application have been published in earlier work, in this paper we reflect on a generalized measuring method for blockchain-enabled applications which may in turn lead to a general methodology for testing cloud-based system performance and scalability using blockchain. Response time and transaction throughput metrics are collected for the blockchain implementation against the non-blockchain implementation and some conclusions are drawn about the additional resources that a blockchain architecture for a groupware collaboration application impose
Low-rank Linear Fluid-structure Interaction Discretizations
Fluid-structure interaction models involve parameters that describe the solid
and the fluid behavior. In simulations, there often is a need to vary these
parameters to examine the behavior of a fluid-structure interaction model for
different solids and different fluids. For instance, a shipping company wants
to know how the material, a ship's hull is made of, interacts with fluids at
different Reynolds and Strouhal numbers before the building process takes
place. Also, the behavior of such models for solids with different properties
is considered before the prototype phase. A parameter-dependent linear
fluid-structure interaction discretization provides approximations for a bundle
of different parameters at one step. Such a discretization with respect to
different material parameters leads to a big block-diagonal system matrix that
is equivalent to a matrix equation as discussed in [KressnerTobler 2011]. The
unknown is then a matrix which can be approximated using a low-rank approach
that represents the iterate by a tensor. This paper discusses a low-rank GMRES
variant and a truncated variant of the Chebyshev iteration. Bounds for the
error resulting from the truncation operations are derived. Numerical
experiments show that such truncated methods applied to parameter-dependent
discretizations provide approximations with relative residual norms smaller
than within a twentieth of the time used by individual standard
approaches.Comment: 30 pages, 7 figure
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