Search results for "ALGORITHMS"
showing 10 items of 1716 documents
Implementations of a novel algorithm for colour constancy
1997
AbstractIn agreement with the principles of the relativistic model proposed by Creutzfeldtet al., with the photometric rule (lightness anchoring rule) and with the influence of simultaneous contrast in the appearance of a visual scene, we propose a first-stage mechanism yielding substantial colour constancy. We have defined a set of first-stage colour descriptors, and to test their utility, we have performed a simulation using a Machine Vision System (MVS). The statistical stability of the descriptors for Munsell samples under different illuminants is good.
Steiner systems and configurations of points
2020
AbstractThe aim of this paper is to make a connection between design theory and algebraic geometry/commutative algebra. In particular, given any Steiner SystemS(t, n, v) we associate two ideals, in a suitable polynomial ring, defining a Steiner configuration of points and its Complement. We focus on the latter, studying its homological invariants, such as Hilbert Function and Betti numbers. We also study symbolic and regular powers associated to the ideal defining a Complement of a Steiner configuration of points, finding its Waldschmidt constant, regularity, bounds on its resurgence and asymptotic resurgence. We also compute the parameters of linear codes associated to any Steiner configur…
How to validate similarity in linear transform models of event-related potentials between experimental conditions?
2014
Abstract Background It is well-known that data of event-related potentials (ERPs) conform to the linear transform model (LTM). For group-level ERP data processing using principal/independent component analysis (PCA/ICA), ERP data of different experimental conditions and different participants are often concatenated. It is theoretically assumed that different experimental conditions and different participants possess the same LTM. However, how to validate the assumption has been seldom reported in terms of signal processing methods. New method When ICA decomposition is globally optimized for ERP data of one stimulus, we gain the ratio between two coefficients mapping a source in brain to two…
Algorithms and Organizing
2022
Abstract Algorithms are a ubiquitous part of organizations as they enable, guide, and restrict organizing at the level of everyday interactions. This essay focuses on algorithms and organizing by reviewing the literature on algorithms in organizations, examining the viewpoint of relationality and relational agency on algorithms and organizing, exploring the properties of algorithms, and concluding what these mean from an organizational communication viewpoint. Algorithms need data to be collected. The data are always biased, and algorithms exclude everything that is not in their code. They define what is seen as important. Their operating principles are opaque, and they are political due to…
Visualization of Jacques Lacan’s Registers of the Psychoanalytic Field, and Discovery of Metaphor and of Metonymy. Analytical Case Study of Edgar All…
2017
International audience; We start with a description of Lacan’s work that we then take into our analytics methodology. In a first investigation, a Lacan-motivated template of the Poe story is fitted to the data. A segmentation of the storyline is used in order to map out the diachrony. Based on this, it will be shown how synchronous aspects, potentially related to Lacanian registers, can be sought. This demonstrates the effectiveness of an approach based on a model template of the storyline narrative. In a second and more comprehensive investigation, we develop an approach for revealing, that is, uncovering, Lacanian register relationships. Objectives of this work include the wide and genera…
Gamma activity and geochemical features of building materials: estimation of gamma dose rate and indoor radon levels in Sicily.
2001
A high-purity germanium detector has been used to measure the abundance of radium (Ra), thorium (Th) and potassium (K) in building materials used in Sicilian dwellings. The measurements were performed to evaluate which material was suitable for the construction of an enclosure, which would have a low background emission. The materials examined in this work showed concentrations of 226Ra, 232Th and 40K dramatically variable depending on the lithologies, particularly in the case of blocks, sands and aggregates commonly used in building materials in Sicily. The results are discussed and a criterion is indicated to reduce the radiation dose to humans. Since radon inlet is a major health problem…
qFIBS: A Novel Automated Technique for Quantitative Evaluation of Fibrosis, Inflammation, Ballooning, and Steatosis in Patients With Nonalcoholic Ste…
2020
[Background and Aims] Nonalcoholic steatohepatitis (NASH) is a common cause of chronic liver disease. Clinical trials use the NASH Clinical Research Network (CRN) system for semiquantitative histological assessment of disease severity. Interobserver variability may hamper histological assessment, and diagnostic consensus is not always achieved. We evaluate a second harmonic generation/two‐photon excitation fluorescence (SHG/TPEF) imaging‐based tool to provide an automated quantitative assessment of histological features pertinent to NASH.
Contrast ultrasound LI-RADS LR-5 identifies hepatocellular carcinoma in cirrhosis in a multicenter restropective study of 1,006 nodules
2018
Background & Aims The use of contrast enhanced ultrasound (CEUS) for the diagnosis of hepatocellular carcinoma (HCC) in cirrhosis was questioned because of the risk of a false positive diagnosis in cases of cholangiocarcinoma. The American College of Radiology has recently released a scheme (CEUS Liver Imaging Reporting and Data System [LI-RADS®]) to classify lesions at risk of HCC investigated by CEUS. The aim of the present study was to validate this LI-RADS scheme for the diagnosis of HCC. Methods A total of 1,006 nodules from 848 patients with chronic liver disease at risk of HCC were collected in five Italian centers and retrospectively analyzed. Nodules were classified as LR-5, (HCC) …
A New Sampling Method for Spleen Stiffness Measurement Based on Quantitative Acoustic Radiation Force Impulse Elastography for Noninvasive Assessment…
2014
In our study, we evaluated the feasibility of a new sampling method for splenic stiffness (SS) measurement by Quantitative Acoustic Radiation Force Impulse Elastography (Virtual Touch Tissue Quantification (VTTQ)).We measured SS in 54 patients with HCV-related cirrhosis of whom 28 with esophageal varices (EV), 27 with Chronic Hepatitis C (CHC) F1–F3, and 63 healthy controls. VTTQ-SS was significantly higher among cirrhotic patients with EV (3.37 m/s) in comparison with controls (2.19 m/s,P<0.001), CHC patients (2.37 m/s,P<0.001), and cirrhotic patients without EV (2.7 m/s,P<0.001). Moreover, VTTQ-SS was significantly higher among cirrhotic patients without EV in comparison with bot…
Is Transient Elastography Needed for Noninvasive Assessment of High-Risk Varices? The REAL Experience
2019
INTRODUCTION: The Baveno VI consensus guidelines and an expanded algorithm suggest that transient elastography (TE) and platelet (PLT) count can be used to identify patients with cirrhosis who can avoid esophagogastroduodenoscopy (EGD). The primary aims of this study were to assess the ability of a simple algorithm, which uses only laboratory parameters, to predict medium/large esophageal varices (EV) in patients with hepatitis C virus (HCV) and cirrhosis from the Rete Sicilia Selezione Terapia-HCV (RESIST-HCV) cohort and to compare the performance of the algorithm with Baveno VI and Expanded Baveno VI criteria. The secondary aim was to assess the role of TE in ruling out large EV. METHODS:…