Search results for "Graphics"
showing 10 items of 1223 documents
Modeling crowd dynamics through coarse-grained data analysis
2018
International audience; Understanding and predicting the collective behaviour of crowds is essential to improve the efficiency of pedestrian flows in urban areas and minimize the risks of accidents at mass events. We advocate for the development of crowd traffic management systems, whereby observations of crowds can be coupled to fast and reliable models to produce rapid predictions of the crowd movement and eventually help crowd managers choose between tailored optimization strategies. Here, we propose a Bi-directional Macroscopic (BM) model as the core of such a system. Its key input is the fundamental diagram for bi-directional flows, i.e. the relation between the pedestrian fluxes and d…
Acquisition, filtering and toll data processing system for obtaining origin-destination matrix and travel times on highways
2012
This paper presents an acquisition, filtering and real-time toll data processing system that provides a base for resolution and generation of studies and models of behavior on highways. Crossing points estimation, speed calculation, study traffic flow, travel time estimation and stopping points can also be provided. The complexity of processing with supplied data volume makes indispensable a less relevant information filtering. This filtering can be done through indicators such as speed or nullity of fields and a performance improvement job in database level using views, materializations, partitioning and parallelism. A web application called MODA has been developed. This application make e…
Controlling false match rates in record linkage using extreme value theory
2011
AbstractCleansing data from synonyms and homonyms is a relevant task in fields where high quality of data is crucial, for example in disease registries and medical research networks. Record linkage provides methods for minimizing synonym and homonym errors thereby improving data quality. We focus our attention to the case of homonym errors (in the following denoted as ‘false matches’), in which records belonging to different entities are wrongly classified as equal. Synonym errors (‘false non-matches’) occur when a single entity maps to multiple records in the linkage result. They are not considered in this study because in our application domain they are not as crucial as false matches. Fa…
geomIO: An Open‐Source MATLAB Toolbox to Create the Initial Configuration of 2‐D/3‐D Thermo‐Mechanical Simulations From 2‐D Vector Drawings
2019
Creating the initial geometry and temperature configuration of 3D numerical simulations is a challenging task. Professional tools are expensive. They often have a steep learning curve and do mostly not interface with the numerical simulation software used by the geodynamics and tectonics academic community. There, we developed geomIO (geometry Input/Output), a MATLAB toolbox to create the initial configuration of geological models regarding model geometry and temperature structure. geomIO allows users to create a geo-referenced 3D volume by drawing multiple 2D cross-sections in a standard vector graphics editor. The volume is then used to assign material properties and set up initial temper…
Additional file 3 of Exploring why global health needs are unmet by research efforts: the potential influences of geography, industry and publication…
2020
Additional file 3. Correspondence Table ICD-10 – MeSH.
Unified computing facility design based on open source software
2012
The article describes e-infrastructure development in Latvia and migration to national Cloud as regional partner facility (RPF) in European Union (EU). In Latvia many public and private Computing Clouds is in operation and problem is how to integrate these resources as one RPF and how to design one unified computing facility that is used for many different applications. The authors offer their solution at Cloud software as a Service and Hardware as a Service level which is based on usage of open source packaged bundles.
Exudate-based diabetic macular edema detection in fundus images using publicly available datasets
2010
International audience; Diabetic macular edema (DME) is a common vision threatening complication of diabetic retinopathy. In a large scale screening environment DME can be assessed by detecting exudates (a type of bright lesions) in fundus images. In this work, we introduce a new methodology for diagnosis of DME using a novel set of features based on colour, wavelet decomposition and automatic lesion segmentation. These features are employed to train a classifier able to automatically diagnose DME through the presence of exudation. We present a new publicly available dataset with ground-truth data containing 169 patients from various ethnic groups and levels of DME. This and other two publi…
3D grafikas atveidošana reālā laikā ar Vulkan API
2017
Maģistra darba mērķis veikt pētījumu par dažādām 3D grafikas atveidošanas iespējām uz mūsdienu datoriem, fokusējoties uz Vulkan programmsaskarni (turpmāk API), apskatot tās stiprās un vājas puses kā arī atšķirības no alternatīvām. Līdz šim tirgu ir dominējušas 2 API, lai izmantotu videokartes grafisko procesoru (turpmāk GPU) grafikas atveidošanai – OpenGL un DirectX. Tā kā mūsdienās 3D grafikas detalizācija un sarežģītība ir augoša, ir nepieciešami jauni risinājumi, kas precīzāk atbilst mūsdienu datoru arhitektūrai un ierīču daudzveidībai, kā arī dotu izstrādātājiem lielāku kontroli pār visiem notiekošajiem aprēķinu procesiem. Darba ietvaros ir izstrādāti divi 3D grafikas dzinēji. Vienā ir …
Optical calibration of a multispectral imaging system based on interference filters
2005
We present a new approach to optically calibrate a multispectral imaging system based on interference filters. Such a system typically suffers from some blurring of its channel images. Because the effectiveness of spectrum reconstruction depends heavily on the quality of the acquired channel images, and because this blurring negatively affects them, a method for deblurring and denoising them is required. The blur is modeled as a uniform intensity distribution within a circular disk. It allows us to characterize, quantitatively, the degradation for each channel image. In terms of global reduction of the blur, it consists of the choice of the best channel for the focus adjustment according to…
An automated image analysis methodology for classifying megakaryocytes in chronic myeloproliferative disorders
2008
This work describes an automatic method for discrimination in microphotographs between normal and pathological human megakaryocytes and between two kinds of disorders of these cells. A segmentation procedure has been developed, mainly based on mathematical morphology and wavelet transform, to isolate the cells. The features of each megakaryocyte (e.g. area, perimeter and tortuosity of the cell and its nucleus, and shape complexity via elliptic Fourier transform) are used by a regression tree procedure applied twice: the first time to find the set of normal megakaryocytes and the second to distinguish between the pathologies. The output of our classifier has been compared to the interpretati…