Search results for "detection"

Discovering single classes in remote sensing images with active learning

2012

When dealing with supervised target detection, the acquisition of labeled samples is one of the most critical phases: the samples must be yet representative of the class of interest, but must also be found among a vast majority of non-target examples. Moreover, the efficiency of the search is also an issue, since the samples labeled as background are not used by target detectors such as the support vector data description (SVDD). In this work we propose a competitive and effective approach to identify the most relevant training samples for one-class classification based on the use of an active learning strategy. The SVDD classifier is first trained with insufficient target examples. It is t…

A context-aware approach for long-term behavioural change detection and abnormality prediction in ambient assisted living

2015

This research aims to describe pattern recognition models for detecting behavioural and health-related changes in a patient who is monitored continuously in an assisted living environment. The early anticipation of anomalies can improve the rate of disease prevention. Here we present different learning techniques for predicting abnormalities and behavioural trends in various user contexts. In this paper we described a Hidden Markov Model based approach for detecting abnormalities in daily activities, a process of identifying irregularity in routine behaviours from statistical histories and an exponential smoothing technique to predict future changes in various vital signs. The outcomes of t…

A Hierarchical Detection and Response System to Enhance Security Against Lethal Cyber-Attacks in UAV Networks

2018

International audience; Unmanned aerial vehicles (UAVs) networks have not yet received considerable research attention. Specifically, security issues are a major concern because such networks, which carry vital information, are prone to various attacks. In this paper, we design and implement a novel intrusion detection and response scheme, which operates at the UAV and ground station levels, to detect malicious anomalies that threaten the network. In this scheme, a set of detection and response techniques are proposed to monitor the UAV behaviors and categorize them into the appropriate list (normal, abnormal, suspect, and malicious) according to the detected cyber-attack. We focus on the m…

2013

Distraction of goal-oriented performance by a sudden change in the auditory environment is an everyday life experience. Different types of changes can be distracting, including a sudden onset of a transient sound and a slight deviation of otherwise regular auditory background stimulation. With regard to deviance detection, it is assumed that slight changes in a continuous sequence of auditory stimuli are detected by a predictive coding mechanisms and it has been demonstrated that this mechanism is capable of distracting ongoing task performance. In contrast, it is open whether transient detection – which does not rely on predictive coding mechanisms – can trigger behavioral distraction, too…

Comparison between a guaiac and three immunochemical faecal occult blood tests in screening for colorectal cancer

2012

Abstract Background The aim of this study was to compare the performance of the guaiac-based faecal occult blood test (G-FOBT), with that of three immunochemical faecal occult blood tests (I-FOBT) which allow automatic interpretation. Patients and methods Under the French organised screening programme, 85,149 average-risk individuals aged 50–74 participating in the third screening round, performed both the G-FOBT (Hemoccult-II test) and one of the I-FOBTs: FOB-Gold, Magstream and OC-Sensor. Results Given the chosen threshold, the positivity ratio between the different I-FOBTs and the G-FOBT was 2.4 for FOB-Gold, 2.0 for Magstream and 2.2 for OC-Sensor (P = 0.17). The three I-FOBTs were supe…

Synthetic indicator of the impact of colorectal cancer screening programmes on incidence rates

2020

ObjectiveThe impact of a screening programme on colorectal cancer (CRC) incidence in its target population depends on several variables, including coverage with invitations, participation rate, positivity rate of the screening test, compliance with an invitation to second-level assessment and endoscopists’ sensitivity. We propose a synthetic indicator that may account for all the variables influencing the potential impact of a screening programme on CRC incidence.DesignWe defined the ‘rate of advanced adenoma on the target population’ (AA-TAP) as the rate of patients who received a diagnosis of advanced adenoma within a screening programme, divided by the programme target population. We com…

High definition colonoscopy combined with i-Scan is superior in the detection of colorectal neoplasias compared with standard video colonoscopy: a pr…

2010

Introduction Colonoscopy is the accepted gold standard for the detection of colorectal cancer. The aim of the current study was to prospectively compare high definition plus (HD+) colonoscopy with I-Scan functionality (electronic staining) vs. standard video colonoscopy. The primary endpoint was the detection of patients having colon cancer or at least one adenoma. Methods A total of 220 patients due to undergo screening colonoscopy, postpolypectomy surveillance or with a positive occult blood test were randomized in a 1 : 1 ratio to undergo HD+ colonoscopy in conjunction with I-Scan surface enhancement (90i series, Pentax, Tokyo, Japan) or standard video colonoscopy (EC-3870FZK, Pentax). D…

Faecal immunochemical tests: A valuable tool for colorectal cancer screening

2012

Colorectal cancer is a major health problem in industrialized ountries and fulfils the conditions required to justifymass screenng of the general population. Population-based controlled studies erformed in Europe have shown that guaiac faecal occult blood esting (G-FOBT) followed by colonoscopy to detect the cause of leeding can reduce colorectal cancer mortality [1]. Nearly all pubished studies evaluated the Hemoccult II (Beckman Coulter Inc., ea, USA) faecal occult blood test. Screening for colorectal caner using FOBT has, therefore, been included in the European Code gainst Cancer and has been endorsed by the European Commision [2]. Despite its high specificity, Hemoccult has been critic…

Intraprocedural bowel cleansing with the JetPrep cleansing system improves adenoma detection.

2014

AIM: To investigate the impact of JetPrep cleansing on adenoma detection rates. METHODS: In this prospective, randomized, crossover trial, patients were blindly randomized to an intervention arm or a control arm. In accordance with the risk profile for the development of colorectal carcinoma, the study participants were divided into high-risk and low-risk groups. Individuals with just one criterion (age > 70 years, adenoma in medical history, and first-degree relative with colorectal cancer) were regarded as high-risk patients. Bowel preparation was performed in a standardized manner one day before the procedure. Participants in the intervention arm underwent an initial colonoscopy with sta…

Evolving endoscopic strategies for detection and treatment of neoplastic lesions in inflammatory bowel disease

2013

The paradigm for neoplasia surveillance in IBD is rapidly evolving with advancements in endoscopic imaging technology. Modern technology has demonstrated a remarkably improved capacity to detect and characterize subtle neoplastic lesions. As such, practices of obtaining interval random biopsy specimens to identify “invisible”neoplasia and of recommending total proctocolectomy for treatment of early neoplastic lesions are gradually being phased out. Further research is required to confirm the safety and effectiveness of endoscopic resection of more advanced neoplastic lesions, including DALMs and lesions bearing HG-IEN. Moving forward, studies evaluating CRC risk profiles in IBD patients wou…