Search results for " Sampling"
showing 10 items of 375 documents
Clinically-Driven Virtual Patient Cohorts Generation: An Application to Aorta
2021
The combination of machine learning methods together with computational modeling and simulation of the cardiovascular system brings the possibility of obtaining very valuable information about new therapies or clinical devices through in-silico experiments. However, the application of machine learning methods demands access to large cohorts of patients. As an alternative to medical data acquisition and processing, which often requires some degree of manual intervention, the generation of virtual cohorts made of synthetic patients can be automated. However, the generation of a synthetic sample can still be computationally demanding to guarantee that it is clinically meaningful and that it re…
Efficient anomaly detection on sampled data streams with contaminated phase I data
2020
International audience; Control chart algorithms aim to monitor a process over time. This process consists of two phases. Phase I, also called the learning phase, estimates the normal process parameters, then in Phase II, anomalies are detected. However, the learning phase itself can contain contaminated data such as outliers. If left undetected, they can jeopardize the accuracy of the whole chart by affecting the computed parameters, which leads to faulty classifications and defective data analysis results. This problem becomes more severe when the analysis is done on a sample of the data rather than the whole data. To avoid such a situation, Phase I quality must be guaranteed. The purpose…
Portability in analytical chemistry: a green and democratic way for sustainability
2019
International audience; Recent advances in portability of analytical equipment have been considered to enlighten the advantages offered by portable instrumentation on greening the analytical methods. Their use drastically reduces sampling, sample stockage, and transport, thus avoiding environmental side effects and risks, also improving decision-making. The fact that portable instrumentation is, in general, less expensive than bench instruments and apparatuses makes also available the analytical tools for extended sectors of the population, thus making accessible the advantages derived from analytical methods. The role of sensor technology and portable miniaturized systems has been consider…
Cooperative compressive power spectrum estimation in wireless fading channels
2017
This paper considers multiple wireless sensors that cooperatively estimate the power spectrum of the signals received from several sources. We extend our previous work on cooperative compressive power spectrum estimation to accommodate the scenario where the statistics of the fading channels experienced by different sensors are different. The signals received from the sources are assumed to be time-domain wide-sense stationary processes. Multiple sensors are organized into several groups, where each group estimates a different subset of lags of the temporal correlation. A fusion centre (FC) combines these estimates to obtain the power spectrum. As each sensor group computes correlation esti…
Force probe simulations using a hybrid scheme with virtual sites.
2017
Hybrid simulations, in which a part of the system is treated with atomistic resolution and the remainder is represented on a coarse-grained level, allow for fast sampling while using the accuracy of atomistic force fields. We apply a hybrid scheme to study the mechanical unfolding and refolding of a molecular complex using force probe molecular dynamics (FPMD) simulations. The degrees of freedom of the solvent molecules are treated in a coarse-grained manner while atomistic resolution is retained for the solute. The coupling between the solvent and the solute is provided using virtual sites. We test two different common coarse-graining procedures, the iterative Boltzmann inversion method an…
Circulating cell-free DNA: an up-coming molecular marker in exercise physiology.
2012
The phenomenon of circulating cell-free DNA (cfDNA) concentrations is of importance for many biomedical disciplines including the field of exercise physiology. Increases of cfDNA due to exercise are described to be a potential hallmark for the overtraining syndrome and might be related to, or trigger adaptations of, immune function induced by strenuous exercise. At the same time, exercise provides a practicable model for studying the phenomenon of cfDNA that is described to be of pathophysiological relevance for different topics in clinical medicine like autoimmune diseases and cancer. In this review, we are summarizing the current knowledge of exercise-based acute and chronic alterations i…
Consumers' perceptions of mobile banking continuous usage in Finland and South Africa
2015
This study examines continuous usage behaviour related to mobile banking (m-banking) among consumers living in Finland (FI) and South Africa (ZA). The study investigates three post-adoption behavioural consequences - namely, trust, satisfaction and word of mouth. Using purposeful sampling techniques, we found that trust plays a significant role in promoting continuous usage of m-banking. In general, the respondents reported high levels of trust in m-banking technology and were satisfied with the m-banking application and services. In addition, convenience, user friendliness and speed emerged as the main sub-topics related to satisfaction. In most cases, the convenience of using m-banking do…
Attention Check Items and Instructions in Online Surveys: Boon or Bane for Data Quality?
2019
In this paper, we examine rates of careless responding and reactions to detection methods (i.e., attention check items and instructions) in an experimental setting based on two different samples. First, we use a quota sample (with monetary incentive), a central data source for internet-based surveys in sociological and political research. Second, we include a voluntary opt-in panel (without monetary incentive) well suited for conducting survey experiments (e.g., factorial surveys). Respondents’ reactions to the detection items are analyzed by objective, nonreactive indicators (i.e., break-off, item non-response, and measurement quality), and two self-report scales. Our reaction analyses rev…
Toward fast and accurate emergency cases detection in BSNs
2020
International audience; In body sensor networks (BSNs), medical sensors capture physiological data from the human body and send them to the coordinator who act as a gateway to health care. The main aim of BSNs is to save peoples' lives. Therefore, fast and correct detection of emergencies while maintaining low-energy consumption of sensors is essential requirement of BSNs. In this study, the authors propose a new adaptive data sampling approach, where the sampling ratio is adapted based on the sensed data variation. The idea is to use the modified version of the cumulative sum (CUSUM) algorithm (modified CUSUM) that they previously proposed for wireless sensor networks to monitor the data v…
Preliminary Results on the Use of Leather Chrome Shavings for Air Passive Sampling
2012
A new passive sampler based on low-density polyethylene (LDPE) layflat tube filled with chrome shavings from tannery waste residues was evaluated to determine volatile organic compounds (VOCs) in indoor and outdoor areas. VOCs were directly determined by head space-gas chromatography-mass spectrometry (HS-GC-MS) without any pretreatment of the sampler and avoiding the use of solvents. Limit of detection values ranging from 20 to 75 ng sampler−1and good repeatability values were obtained for VOCs under study with relative standard deviation values from 2.8 to 9.6% except for carbon disulfide for which it was 22.5%. The effect of the amount of chrome shavings per sampler was studied and resul…