Search results for " retrieval."
showing 10 items of 1102 documents
Ranking of Brain Tumour Classifiers Using a Bayesian Approach
2009
This study presents a ranking for classifers using a Bayesian perspective. This ranking framework is able to evaluate the performance of the models to be compared when they are inferred from different sets of data. It also takes into account the performance obtained on samples not used during the training of the classifiers. Besides, this ranking assigns a prior to each model based on a measure of similarity of the training data to a test case. An evaluation consisting of ranking brain tumour classifiers is presented. These multilayer perceptron classifiers are trained with 1H magnetic resonance spectroscopy (MRS) signals following a multiproject multicenter evaluation approach. We demonstr…
User experience-based information retrieval from semistar data ontologies
2019
The time necessary for the doubling of medical knowledge is rapidly decreasing. In such circumstances, it is of utmost importance for the information retrieval process to be rapid, convenient and straightforward. However, it often lacks at least one of these properties. Several obstacles prohibit domain experts extracting knowledge from their databases without involving the third party in the form of IT professionals. The main limitation is usually the complexity of querying languages and tools. This paper proposes the approach of using a keywords-containing natural language for querying the database and exploiting the system that could automatically translate such queries to already existi…
Extraction of Medical Terms for Word Sense Disambiguation within Multilingual Framework
2016
All the languages belonging to the same language family have a certain number of the common characteristics called language pair phenomena, which can be found quite useful for processing them for multilingual purposes like translation across the cognate languages, building dictionaries, thesauri, transcript collections, or for multilingual text retrieval of digital documents. In addition, it is estimated that more than 30% of English vocabulary has been inherited from Latin, which has dominated medical terminology in particular. We use this fact by exploring word sense disambiguation (WSD) in multilingual environment. Specifically in the medical domain, language pair phenomena can be limite…
First evaluation of the simultaneous SMOS and ELBARA-II observations in the Mediterranean region
2012
Abstract The SMOS (Soil Moisture and Ocean Salinity) mission was launched on November 2, 2009. Over the land surfaces, simultaneous retrievals of surface soil moisture (SM) and vegetation characteristics made from the multi-angular and dual polarization SMOS observations are now available from Level-2 (L2) products delivered by the European Space Agency (ESA). Therefore, first analyses evaluating the SMOS observations in terms of Brightness Temperatures (TB) and L2 products (SM and vegetation optical depth TAU) can be carried out over several calibration/validation (cal/val) sites selected by ESA over all continents. This study is based on SMOS observations and in situ measurements carried …
Exploring the use of Unmanned Aerial Vehicles (UAVs) with the simplified ‘triangle’ technique for soil water content and evaporative fraction retriev…
2020
Participation of Dr. Petropoulos has been funded by the ENViSIoN-EO Marie Skłodowska-Curie grant (grant No 752094), part of the European Union’s Horizon 2020 research and innovation programme. Part of the present collaborative work was also materialised in the framework of a short Term Scientific Mission (STSM) of the HARMONIOUS Cost Action which financially supported Dr Petropoulos’ visit between 4 to 15 February 2020 to the Department of Engineering of the University of Palermo, Italy. Η συμμετοχή του Δρ. Πετρόπουλου χρηματοδοτήθηκε από το πρόγραμμα της Ευρωπαϊκής Ένωσης για Έρευνα και Καινοτομία «Oρίζοντας 2020», δράση Marie Sklodowska - Curie , έργο ENViSIoN-EO (αριθ. 752094). Επίσης μέ…
An empirical study of recommendations in OLAP reporting tool
2015
This paper presents the results of the experimental study that was performed in laboratory settings in the context of the OLAP reporting tool developed and put to operation at the University. The study was targeted to explore which of the modes for generating recommendations in the OLAP reporting tool has a deeper impact on users (i.e. produces more accurate recommendations). Each of the modes of the recommendation component â report structure, user activity, and semantic â employs a separate content-based method that takes advantage of OLAP schema metadata and aggregate functions. Gained data are assessed (i) quantitatively by means of the precision/recall and other metrics from the lo…
A Comparative Study of Land Surface Emissivity Retrieval from NOAA Data
2001
Abstract A comparative study has been carried out on the most recent algorithms for the estimation of land surface emissivity (ϵ) using Advanced Very High Resolution Radiometer (AVHRR) data. Three of the algorithms are based on the Temperature-Independent Spectral Indices (TISI) concept using atmospherically corrected channels 3, 4, and/or 5, namely: (1) TISI BL , (2) TS-RAM, and (3) Δ day. The fourth is a simplified method based on the estimation of ϵ using atmospherically corrected data in the visible and near-infrared channels, called Normalized Difference Vegetation Index (NDVI) Thresholds Method (NDVI THM ). This method integrates a wide spectral data set of bare soil reflectivity meas…
Incentive Schemes, Private Information and the Double-Edged Role of Competition for Agents
2013
This paper examines the effect of imperfect labor market competition on the efficiency of compensation schemes in a setting with moral hazard and risk-averse agents, who have private information on their productivity. Two vertically differentiated firms compete for agents by offering contracts with fixed and variable payments. The superior firm employs both agent types in equilibrium, but the competitive pressure exerted by the inferior firm has a strong impact on contract design: For high degrees of vertical differentiation, i.e. low competition, low-ability agents are under-incentivized and exert too little effort. For high degrees of competition, high-ability agents are over-incentivized…
Improved quantitative phase imaging in lensless microscopy by single-shot multi-wavelength illumination using a fast convergence algorithm.
2015
We report on a novel algorithm for high-resolution quantitative phase imaging in a new concept of lensless holographic microscope based on single-shot multi-wavelength illumination. This new microscope layout, reported by Noom et al. along the past year and named by us as MISHELF (initials incoming from Multi-Illumination Single-Holographic-Exposure Lensless Fresnel) microscopy, rises from the simultaneous illumination and recording of multiple diffraction patterns in the Fresnel domain. In combination with a novel and fast iterative phase retrieval algorithm, MISHELF microscopy is capable of high-resolution (micron range) phase-retrieved (twin image elimination) biological imaging of dynam…
Off-axis digital holographic microscopy: practical design parameters for operating at diffraction limit.
2014
The utilization of microscope objectives (MOs) in digital holographic microscopy (DHM) has associated effects that are not present in conventional optical microscopy. The remaining phase curvature, which can ruin the quantitative phase imaging, is the most evident and analyzed. As phase imaging is considered, this interest has made possible the development of different methods of overcoming its undesired consequences. Additionally to the effects in phase imaging, there exist a set of less obvious conditions that have to be accounted for as MOs are utilized in DHM to achieve diffraction-limit operation. These conditions have to be considered even in the case in which only amplitude or intens…