Search results for " Detection"
showing 10 items of 1676 documents
Weather sensor fault detection in meteorological masts
2020
Wind power has become the world’s fastest growing renewable technology. The world-wide wind power installed capacity has exceeded 597 GW, and the new installations during the last three years was an average of 50 GW per year. A major issue with wind power system and with meteorological masts is the relatively high cost of operation and maintenance (OM). Wind turbines and sensor towers are hard-to-access structures, and they are often located in remote areas. That’s why continuous monitoring of wind turbine health using automated failure detection algorithms can improve turbine reliability and reduce maintenance costs by detecting failures before they reach a catastrophic stage and by elimin…
Ultraviolet reflection and predation risk in diurnal and nocturnal Lepidoptera
2004
According to our extensive data on Lepidoptera (883 species), UV wing patterns are almost three times more common in nocturnal than in diurnal Lepidoptera. This might be due to predation, because the primary diurnal predators, birds, utilize UV light in foraging and even prefer UV-reflecting prey. To test this hypothesis, we conducted a field experiment with tethered living moths whose wings were artificially manipulated to reflect (UV+, reflection at UV wavelength: 15%) or absorb (UV - ) UV light, keeping longer wavelengths identical. Thus, any difference found in survival rates would be the result of the difference in wing patterns in UV spectrum. Significantly more UV+ moths th…
Foto2Events: From Photos to Event Discovery and Linking in Online Social Networks
2014
International audience; — Online social networking has become the predominant activity in the digital world thanks to multimedia data (mainly photos) sharing (e.g., photos now represent 93% of the top posts on Facebook). Discovering events where users are involved using their own posts and those shared by their friends would be of great importance. In this paper, we address this issue by providing an original approach able to detect, enrich and also link user's events using photos shared within his online social networks. Using metadata, our approach provides a multi-dimensional gathering of similar photos using their temporal, geographical, and social facets. To validate our approach, we i…
High-Z Materials for X-ray Detection: Material Properties and Characterization Techniques
2023
This book will provide readers with a good overview of some of most recent advances in the field of High-Z materials. There will be a good mixture of general chapters in both technology and applications in opto-electronics, X-ray detection and emerging optoelectronics applications. The book will have an in-depth review of the research topics from world-leading specialists in the field.
Modelling and prediction of perceptual segmentation
2017
While listening to music, we somehow make sense of a multiplicity of auditory events; for example, in popular music we are often able to recognize whether the current section is a verse or a chorus, and to identify the boundaries between these segments. This organization occurs at multiple levels, since we can discern motifs, phrases, sections and other groupings. In this work, we understand segment boundaries as instants of significant change. Several studies on music perception and cognition have strived to understand what types of changes are associated with perceptual structure. However, effects of musical training, possible differences between real-time and non real-time segmentation, and…
Determination at low ppm levels of dithiocarbamate residues in foodstuff by vapour phase-liquid phase microextraction-infrared spectroscopy
2010
Abstract A methodology based on the vapour phase (VP) generation of carbon disulphide from non-volatile dithiocarbamate compounds has been developed for determination of pesticide residues in foodstuff at low ppm levels. The method involves a selective reaction combined with liquid phase microextraction (LPME) and transmission infrared measurements. The use of a home made transmission cell improved the detection limits (LOD) compared to the use of attenuated total reflectance measurements by a factor of approximately 80. Using the most appropriate experimental conditions for the CS2 generation and LPME preconcentration, the precision of the methodology, expressed as the relative standard de…
An Image Segmentation Algorithm based on Community Detection
2016
International audience; With the recent advances in complex networks, image segmentation becomes one of the most appropriate application areas. In this context, we propose in this paper a new perspective of image segmentation by applying two efficient community detection algorithms. By considering regions as communities, these methods can give an over-segmented image that has many small regions. So, the proposed algorithms are improved to automatically merge those neighboring regions agglomerative to achieve the highest modularity/stability. To produce sizable regions and detect homogeneous communities, we use the combination of a feature based on the Histogram of Oriented Gradients of the …
New Optimization and Security Approaches to Enhance the Smart Grid Performance and Reliability
2016
International audience; Nowadays, the Smart Grid (SG) is becoming smarter thanks to the integration of different information and communication technologies to enhance the reliability and efficiency of the power grid. However, several issues should be met to ensure high SG performance. Among these issues, we cite the problem of electric vehicles (EVs) integration into the SG to avoid electricity intermittence due to the important load that EVs can create. Another issue is the SG communication network security that can be attempted by malicious intruders in order to create damages and make the power grid instable. In this context, we propose at a first level a Bayesian game-theory model that …
Motorcyclists Safety System to avoid Rear End Collisions based on Acoustic Signatures
2017
International audience; In many Asian countries, motorcyclists have a higher fatality rate as compared to other vehicles. Among many other factors, rear end collisions are also contributing for these fatalities. Collision detection systems can be useful to minimize these accidents. However, the designing of efficient and cost effective collision detection system for motorcyclist is still a major challenge. In this paper, an acoustic information based, cost effective and efficient collision detection system is proposed for motorcycle applications. The proposed technique uses the Short time Fourier Transform (STFT) to extract the features from the audio signal and Principal component analysis…
Remote Photoplethysmography Based on Implicit Living Skin Tissue Segmentation
2016
International audience; Region of interest selection is an essential part for remote photoplethysmography (rPPG) algorithms. Most of the time, face detection provided by a supervised learning of physical appearance features coupled with skin detection is used for region of interest selection. However, both methods have several limitations and we propose to implicitly select living skin tissue via their particular pulsatility feature. The input video stream is decomposed into several temporal superpixels from which pulse signals are extracted. Pulsatility measure for each temporal superpixel is then used to merge pulse traces and estimate the photoplethysmogram signal. This allows to select …