Search results for "Artifact"
showing 10 items of 193 documents
Unsupervised Eye Blink Artifact Identification in Electroencephalogram
2018
International audience; The most prominent type of artifact contaminating electroencephalogram (EEG) signals is the eye blink (EB) artifact. Hence, EB artifact detection is one of the most crucial pre-processing step in EEG signal processing before this artifact can be removed. In this work, an approach that identifies EB artifacts without human supervision and automated varying threshold setting is proposed and evaluated. The algorithm functions on the basis of correlation between two EEG electrodes, Fp1 and Fp2, followed by EB artifact threshold determination utilizing the amplitude displacement from the mean. The proposed approach is validated and evaluated in terms of accuracy and error…
Morphology-based measurement of activation time in human atrial fibrillation
2003
The measurement of the activation time is crucial to allow the correct automatic analysis and classification of intracardiac electrograms recorded in the human atria during atrial fibrillation (AF). This study proposes a method which accounts for the morphology of bipolar signals. After ventricular artifact removal and activation wave recognition, the fiducial point of the activation wave was set at its local barycentre (LB). The method was tested on a set of 30 AF bipolar recordings of increasing complexity class; its performance was compared with that of the traditional methods of maximum peak (MP) or maximum slope (MS) estimation, taking the manual measurements performed by an expert car…
An offline/real-time artifact rejection strategy to improve the classification of multi-channel evoked potentials
2008
The primary goal of this paper is to improve the classification of multi-channel evoked potentials (EPs) by introducing a temporal domain artifact detection strategy and using this strategy to (a) evaluate how the performance of classifiers is affected by artifacts and (b) show how the performance can be improved by detecting and rejecting artifacts in offline and real-time classification experiments. Using a pattern recognition approach, an artifact is defined in this study as any signal that may lead to inaccurate classifier parameter estimation and inaccurate testing. The temporal domain artifact detection tests include: a within-channel standard deviation (STD) test that can detect sign…
Raw material variability as archaeological tools: Preliminary results from a geochemical study of the basalt vessel workshop at Iron Age Tel Hazor, I…
2016
The discovery of a basalt vessel workshop at Tel Hazor, one of the most important Iron Age sites in the Near East, marks a turning point in our understanding of stone artifact production and distribution during the1st millennium BCE. It offers a rare opportunity to characterize ancient raw material sources, production sites, and study production, trade and distribution systems. The basalt vessel workshop, the only one of its kind in the Levant, produced large quantities of bowl preforms and production waste. To better understand the production and distribution systems behind this specialized production center, in 2011 we initiated a focused geochemical project that concentrated on the produ…
The Application of the Essential Oils of Thymus vulgaris L. and Crithmum maritimum L. as Biocidal on Two Tholu Bommalu Indian Leather Puppets
2021
The chemical profile of the Thymus vulgaris (Lamiaceae) essential oil (EO) was investigated in order to evaluate its biological properties against microorganisms affecting two Tholu Bommalu, typical Indian leather puppets stored at the International Puppets Museum “Antonio Pasqualino” of Palermo, Italy. A GC–MS analysis, using both polar and apolar columns, was used to determine the chemical composition of the essential oil. The aim of this study was to evaluate the antimicrobial effectiveness of the Thymus vulgaris and Crithmum maritimum essential oils in vapor phase to disinfect heritage leather puppets. Pieces of leather artifacts that were affected by different bacterial colonies were e…
Potential pitfalls in fetal neurosonography
2005
Objective To present anatomic variants of the fetal brain and artifacts related to scanning techniques that could be misinterpreted as abnormalities on prenatal neurosonographic studies. Methods The findings were derived from fetal neurosonographic studies performed routinely from 16 to 36 weeks' gestation during the last 3 years, supervised by a sonologist specialized in neonatal cranial sonography. Results The pitfalls were divided into three groups: brain parenchyma, ventricular system and choroid plexus. We provide images of these pseudolesions and clues to their differentiation from true brain pathology. Conclusions Knowledge of misleading images seen on fetal neurosonographic studies …
Stones, Bones, and Hillfort: Radiocarbon Dating of Ķivutkalns Bronze-Working Center
2013
The Bronze Age site of ķivutkalns with its massive amount of archaeological artifacts and human remains is considered the largest bronze-working center in Latvia. The site is a unique combination of cemetery and hillfort believed to be built on top of each other. This work presents new radiocarbon dates on human and animal bone collagen that somewhat challenge this interpretation. Based on analyses using a Bayesian modeling framework, the present data suggest overlapping calendar year distributions for the contexts within the 1st millennium BC. The carbon and nitrogen isotopic ratios indicate mainly terrestrial dietary habits of studied individuals and nuclear family remains buried in one o…
Specification of Business Components
2003
Component-based software development is a potential reuse paradigm for the future. While the required technologies for a component-style system development are widely available, for instance Sun's Enterprise Java Beans, a problem inhibits the breakthrough of the component paradigm in business applacation domains: compared to traditional engineering disciplines there is a lack of standardized methods to describe business components. Such a description has to address several aspects: What services are offered and requested by a business component? How can these services be used? Are there any interdependencies between the services of a set of business components? What quality characteristics …
Information Systems and Business Strategy
2003
The main purpose of this chapter is to deep into the importance attached to the Information Systems for the proper formulation of the corporate strategy. After introducing the basis of the strategic planning tradition model, which suggests the subordination of the Information Systems (IS) to the Business Strategy, we propose a new model that views the IS as an strategic instrument suited for the strategy formulation stage, rather than operational tools for the strategy control phase. Success in the application of this model we call “Concurrent Business/IS Strategic Planning Model” will closely depend on the consistency, coherence and soundness of the IS, both internal and external. In order…
Business Process Reference Models: Survey and Classification
2006
Within the Information Systems field, reference models are well-known for many years. The aim of this paper is to survey and to describe reference models for business processes. Our analysis of 30 process reference models is based on a framework consisting of criteria such as application domain, used process modeling languages, model's size, known evaluations and applications of process reference models. Furthermore, we identify model domains, which have been dealt with, describe similarities and differences between the available process reference models, and point to open research questions.