Search results for "Decision Trees"

Geo-Epidemiology of Age-Related Macular Degeneration: New Clues Into the Pathogenesis

2015

Abstract PURPOSE: To evaluate the demographic, geographic, and race-related variables that account for geographic variability in prevalence rates of age-related macular degeneration (AMD). DESIGN: Systematic review, meta-regression, and decision-tree analysis. METHODS: A systematic literature review of PubMed, Medline, Web of Science, and Embase databases identified population-based studies on the prevalence of AMD published before May 2014. Only population-based studies that took place in a spatially explicit geographic area that could be geolocalized, and used retinal photographs and standardized grading classifications, were included. Latitude and longitude data (geolocalization) and the…

Efficient Pruning LMI Conditions for Branch-and-Prune Rank and Chirality-Constrained Estimation of the Dual Absolute Quadric

2014

International audience; We present a new globally optimal algorithm for self- calibrating a moving camera with constant parameters. Our method aims at estimating the Dual Absolute Quadric (DAQ) under the rank-3 and, optionally, camera centers chirality constraints. We employ the Branch-and-Prune paradigm and explore the space of only 5 parameters. Pruning in our method relies on solving Linear Matrix Inequality (LMI) feasibility and Generalized Eigenvalue (GEV) problems that solely depend upon the entries of the DAQ. These LMI and GEV problems are used to rule out branches in the search tree in which a quadric not satisfy- ing the rank and chirality conditions on camera centers is guarantee…

Automated Extraction of Motivic Patterns and Application to the Analysis of Debussy’s Syrinx

2009

A methodology for automated extraction of repeated patterns in discrete time series data is presented, dedicated to the discovery of musical motives in symbolic music representations. The basic principle of the approach consists in a search for closed patterns in a multi-dimensional parametric space, comprising various features related to melodic and rhythmic aspects, which can be organized into note-based and interval-based descriptions. The pattern description is further reduced through a lossless pruning of the sequence description. This requires in particular a detailed estimation of the specificity relations between patterns. For instance, a pattern is more specific than its suffix, an…

Development of a nutritional HACCP plan.

2002

Predicting the environmental suitability for onchocerciasis in Africa as an aid to elimination planning

2021

Recent evidence suggests that, in some foci, elimination of onchocerciasis from Africa may be feasible with mass drug administration (MDA) of ivermectin. To achieve continental elimination of transmission, mapping surveys will need to be conducted across all implementation units (IUs) for which endemicity status is currently unknown. Using boosted regression tree models with optimised hyperparameter selection, we estimated environmental suitability for onchocerciasis at the 5 × 5-km resolution across Africa. In order to classify IUs that include locations that are environmentally suitable, we used receiver operating characteristic (ROC) analysis to identify an optimal threshold for suitabil…

Does an optimal therapeutic sequence exist in advanced non-small cell lung cancer?

2008

A growing percentage of patients affected by advanced non-small cell lung cancer who progressed after first-line chemotherapy still have a good performance status and require second-line treatment.An overview of the state of the art of second-line therapeutic options is presented.The scope of the review is to give an update on the therapeutic options currently available for the second-line treatment of patients with advanced non-small cell lung cancer.Among chemotherapeutic drugs docetaxel and pemetrexed have been approved for second-line treatment of advanced non-small cell lung cancer. Although the drugs are equiactive in terms of response rate and survival parameters the latter has a cle…

Comparing Boosting and Bagging for Decision Trees of Rankings

2021

AbstractDecision tree learning is among the most popular and most traditional families of machine learning algorithms. While these techniques excel in being quite intuitive and interpretable, they also suffer from instability: small perturbations in the training data may result in big changes in the predictions. The so-called ensemble methods combine the output of multiple trees, which makes the decision more reliable and stable. They have been primarily applied to numeric prediction problems and to classification tasks. In the last years, some attempts to extend the ensemble methods to ordinal data can be found in the literature, but no concrete methodology has been provided for preference…

Cost-Effectiveness Analysis: Stress Ulcer Bleeding Prophylaxis with Proton Pump Inhibitors, H2 Receptor Antagonists

2012

Abstract Objectives Proton pump inhibitors (PPIs) and H2-receptor antagonists (H2RAs) present varying pharmacological efficacy in preventing stress ulcer bleeding (SUB) in intensive care units. The literature also reports disparate rates of ventilator-assisted pneumonia (VAP) as side effects of these treatments. We compared the cost-effectiveness of these two prophylactic pharmacological options. Methods We constructed a decision tree with a 60-day time horizon for patients at high risk for developing SUB, receiving either PPIs or H2RAs. For each treatment strategy, patients could be in one of three states of health: SUB, VAP, or no complication. Contemporary, clinically relevant probabilit…

[Clinical guidelines for the management of gastrointestinal stromal tumors]

2006

Treatment of gastrointestinal stromal tumors (GIST) has been revolutioned by the recently discovered molecular mechanism responsible for the oncogenesis of this disease. In addition, due to the rapid progress at molecular and clinical level observed in the last few years, there is a need to review the current state of the art in order to delineate appropriate guidelines for the optimal management of these tumors. A panel of experts from several specialities, including medical oncology, surgery, pathology, molecular biology and imaging, were invited to participate in a meeting to present and discuss a number of pre-selected questions, and to achieve a consensus according to the categories of…

Cost-Effectiveness Analysis of Different Testing Strategies that Use Antibody Levels to Detect Chronic Hepatitis C in Blood Donors.

2016

Aim. We conducted a cost-effectiveness analysis of seven hepatitis C virus (HCV) testing strategies in blood donors. Methods. Three of the seven strategies were based on HCV diagnosis and reporting guidelines in Mexico and four were from previous and current recommendations outlined by the CDC. The strategies that were evaluated determine antibody levels according to the signal-to-cut-off (S/CO) ratio and use reflex Immunoblot (IMB) or HCV RNA tests to confirm true positive (TP) cases of chronic HCV infection. Costs were calculated from the perspective of the Mexican Institute of Social Security (IMSS). A decision tree model was developed to estimate the expected number of true positive cas…