Multisensor systems and flood risk management. Application to the Danube Delta using radar and hyperspectral imagery

International audienceAt the beginning of the 21st century, flood risk still represents a major world threat ( 60% of natural disasters are initiated by storms ) and the climate warming might even accentuate this phenomenon in the future. In Europe, despite all the policies in place and the measures taken during the past decades, large floods have occurred almost every year. The news regularly confirms this reality and the serious threat posed by flood risks in Europe. This paper presents an application to the Danube Delta exploiting radar imagery ENVISAT/ASAR and hyperspectral imagery CHRIS/PROBA for mapping flooded and floodable areas during the events of spring 2006. The uses of multisensor systems, such as radar and hyperspectral imagers, contribute to a better comprehension of floods in this wetland, their impacts, and risk management and sustainable development in the delta. In the section Risk management, this paper approaches the methodological aspects related to the characterization of the flood hazard whereas in the section Forecasting we will focus on the knowledge and modeling of the Land cover. The method of kernels, particularly adapted to the highlighting of the special-temporal variations - Support Vector Machine - and the methods based on the principle of the vague logic ( object-oriented classifications ) will be implemented so as to obtain the information plan of the spatial data.En ce début de 21e siècle, le risque d'inondation constitue encore le risque majeur au monde ( avec les tempêtes, les inondations représentent 60% des catastrophes naturelles ) et le réchauffement climatique pourrait encore renforcer ce phénomène à l'avenir. En Europe, malgré toutes les politiques et les mesures prises, au cours des dernières décennies, de grandes inondations ont lieu quasiment chaque année. Les actualités confirment régulièrement la réalité et la prégnance du risque d'inondation en Europe. Cet article présente une application concernant le risque d'inondation durant les événements du printemps 2006 dans le delta du Danube en exploitant des images radar ENVISAT/ASAR et l'imagerie hyperspectrale CHRIS/PROBA en matière d'analyse et de cartographie des zones inondées et de la classe de l'inondable. L'utilisation couplée des techniques spatiales ( radar et hyperspectrale ) pourrait contribuer à une meilleure compréhension des phénomènes liés aux inondations dans le Delta du Danube, ainsi qu'à la gestion de ce risque dans le delta et à son développement durable. Dans la partie Gestion du risque, ce travail aborde des aspects méthodologiques liés à la caractérisation de l'aléa de l'inondation tandis que dans la partie Prévision, la connaissance et la modélisation de l'Occupation du sol seront abordés. Des méthodes des noyaux ( kernels ), adaptées en particulier à la mise en évidence des variations spatio-temporelles - Suport Vector Machine - ainsi que des méthodes basées sur le principe de la logique floue ( classifications orientées objet ) sont mis en place afin d'obtenir le plan d'information des données spatiales

Quel développement durable pour le delta du Danube ? Enquête à Pardina

International audienceRecenser et prendre en compte les spécificités locales, identifier collectivement les enjeux,emboîter les différentes échelles d'action, tels sont les principaux défis pour répondre auxenjeux du développement durable concernant le delta du Danube, en général, et la communede Pardina, en particulier. Le delta présente un intérêt environnemental, économique etsocial évident. Il présente une forte biodiversité, sa richesse biologique s'expliquant parl'importance des zones humides et la diversité des habitats d’oiseaux. Le statut actuel dudelta comme réserve de la Biosphère devrait permettre la reconstitution progressive de cesrichesses malmenées par les politiques passées centrées sur l'accroissement de la productivitédes biens agricoles. Mais le contexte économique actuel met la population locale en difficulté.Cette dernière est confrontée à l’isolement, au retard en matière de modernisation ou detransformation des infrastructures existantes, à un chômage en hausse et à un vieillissementgénéralisé. L’un des objectifs en termes de développement durable pour cette zone consisteà définir une stratégie globale capable de concilier respect de la biodiversité, prospéritééconomique et vie décente

Challenges in platform-independent UWB ranging and localization systems

The Ultra-Wideband (UWB) technology has grown in popularity to the point in which there are numerous UWB transceivers on the market that use different center frequencies, bandwidths, or hardware architectures. At the same time, efforts are made to reduce the ranging and localization errors of UWB systems. Until now, not much attention has been dedicated to the cross-platform compatibility of these methods. In this paper, we discuss for the first time the challenges in obtaining platform-independent UWB ranging and localization systems. We derive our observations from a measurement campaign conducted with UWB devices from three different developers. We evaluate the differences in the ranging errors and channel impulse responses of the devices and show how they can affect ranging mitigation methods customized for one device only. Finally, we discuss possible solutions towards platform-independent UWB localization systems.publishedVersionPeer reviewe

Self-Learning Detection and Mitigation of Non-Line-of-Sight Measurements in Ultra-Wideband Localization

Non-line-of-sight (NLOS) propagation is one of the main error sources in indoor localization, so a large body of work has been dedicated to identifying and mitigating NLOS errors. The most accurate NLOS detection methods often rely on large training data sets that are time-consuming to obtain and depend on the environment and hardware. We propose a method for detecting NLOS distance measurements without manually collected training data and knowledge of channel statistics. Instead, the algorithm generates LOS/NLOS labels for sets of distance measurements between fixed sensors and the mobile target based on distance residuals. The residual-based detection has 70-80% accuracy but has high complexity and cannot be used with high confidence on all measurements. Therefore, we use the predicted labels and the channel impulse responses of the measurements to train a classifier that achieves over 90% accuracy and can be used on all measurements, with low complexity. After we train the classifier during an initial phase that captures specifics of the devices and of the environment, we can skip the residual-based detection and use only the trained model to classify all measurements. We also propose an NLOS mitigation method that reduces, on average, the mean and standard deviation of the localization error by 2.2 and 5.8 times, respectively.Peer reviewe

Acceptable Margin of Error : Quantifying Location Privacy in BLE Localization

Location privacy poses a critical challenge as the use of mobile devices and location-based services becomes more and more widespread. Proximity-detection data can reveal sensitive information about individuals, making it essential to preserve their location data. One way to achieve privacy protection is by adding noise to ground-truth data, which can introduce uncertainty while still allowing moderate utility for proximity-detection services and Received Signal Strength (RSS)-based localization. However, it is important to carefully adjust the amount of noise added in order to balance the privacy and accuracy concerns. This paper expands our previous work on evaluating location privacy bounds based on measurement error and intentionally added noise. Our model builds upon existing work in differential privacy and introduces other techniques to estimate privacy bounds specific to proximity data. By using real-world measurement data, we measure the privacy-accuracy trade-off and suggest cases where additional noise could be added. Our framework can be utilized to inform privacy-preserving location-based applications and guide the selection of appropriate noise levels in order to achieve the desired privacy-accuracy balance.acceptedVersionPeer reviewe

On the High Fluctuations of Received Signal Strength Measurements with BLE Signals for Contact Tracing and Proximity Detection

This paper presents a measurement-based analysis of the Received Signal Strength (RSS) of Bluetooth Low Energy (BLE) signals, under Line-of-Sight (LOS) and Non-Line-of-Sight (NLOS) scenarios, performed in tandem at two universities in Tampere, Finland, and Bucharest, Romania. We adopted the same hardware and methodology for measurements in both places, and paid particular attention to the impact of RSS on various environmental factors, such as LOS and NLOS scenarios and interference in 2.4 GHz band. In addition, we considered the receiver orientation and the different frequencies of BLE advertising channels. We show that snapshot RSS measurements typically have high variability, not easily explainable by classical path-loss models. A snapshot recording is defined here as one continuous recording at fixed device locations in a static setup. Our observations also show that aggregated RSS data (i.e., considering several snapshot measurements together) is more informative from a statistical point of view and more in agreement with current theoretical path-loss models than snapshot measurements. However, in BLE applications such as contact tracing and proximity detection, the receivers typically have access only to snapshot measurements (e.g., taken over a short duration of 10–20 minutes or less), so the accuracy of contact-tracing and proximity detection can be highly affected by RSS instabilities. In addition to presenting the measurement-based BLE RSS analysis in a comprehensive and well-documented format, our paper also emphasizes open challenges when BLE RSS is used for contact tracing, ranging, and positioning applications.publishedVersionPeer reviewe

High-Accuracy Ranging and Localization with Ultra-Wideband Communications for Energy-Constrained Devices

Ultra-wideband (UWB) communications have gained popularity in recent years for being able to provide distance measurements and localization with high accuracy, which can enhance the capabilities of devices in the Internet of Things (IoT). Since energy efficiency is of utmost concern in such applications, in this work we evaluate the power and energy consumption, distance measurements, and localization performance of two types of UWB physical interfaces (PHYs), which use either a low-or high-rate pulse repetition (LRP and HRP, respectively). The evaluation is done through measurements acquired in identical conditions, which is crucial in order to have a fair comparison between the devices. We performed measurements in typical line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios. Our results suggest that the LRP interface allows a lower power and energy consumption than the HRP one. Both types of devices achieved ranging and localization errors within the same order of magnitude and their performance depended on the type of NLOS obstruction. We propose theoretical models for the distance errors obtained with LRP devices in these situations, which can be used to simulate realistic building deployments and we illustrate such an example. This paper, therefore, provides a comprehensive overview of the energy demands, ranging characteristics, and localization performance of state-of-the-art UWB devices.acceptedVersionPeer reviewe

High-Accuracy Ranging and Localization with Ultra-Wideband Communications for Energy-Constrained Devices

Ultra-wideband (UWB) communications have gained popularity in recent years for being able to provide distance measurements and localization with high accuracy, which can enhance the capabilities of devices in the Internet of Things (IoT). Since energy efficiency is of utmost concern in such applications, in this work we evaluate the power and energy consumption, distance measurements, and localization performance of two types of UWB physical interfaces (PHYs), which use either a low-or high-rate pulse repetition (LRP and HRP, respectively). The evaluation is done through measurements acquired in identical conditions, which is crucial in order to have a fair comparison between the devices. We performed measurements in typical line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios. Our results suggest that the LRP interface allows a lower power and energy consumption than the HRP one. Both types of devices achieved ranging and localization errors within the same order of magnitude and their performance depended on the type of NLOS obstruction. We propose theoretical models for the distance errors obtained with LRP devices in these situations, which can be used to simulate realistic building deployments and we illustrate such an example. This paper, therefore, provides a comprehensive overview of the energy demands, ranging characteristics, and localization performance of state-of-the-art UWB devices.acceptedVersionPeer reviewe

Enterobacteria in the hospital environment and their antimicrobial resistance

CHU Reunion, France, Vasile Goldis Western University of Arad, Romania, Arad County Clinical Hospital, Romania, Victor Babeş University of Medicine and Pharmacy, Timişoara, Romania, The 5th International Congress of the Society of Anesthesiology and Reanimatology of the Republic of Moldova, 16th Edition of the International Course of Guidelines and Protocols in Anesthesia, Intensive Care and Emergency Medicine, 28th Meeting of the European Society for Computing and Technology in Anesthesia and Intensive Care September 27-29, 2018, Chisinau, the Republic of MoldovaBackground: Enterobacteria can produce enzymes (ESBLs) to inactivate beta-lactamins and can also be resistant to carbapenems (CRE), as superbugs. Objective: To evaluate the superbacteria frequency in the last two years in Arad County Clinical Hospital. Material and methods: The multidrug criteria described in Clinical Microbiology and Infection Volume 18, Issue 3, 2011 were used. VITEK and E-test for ESBLs and diffusometric anti-biograms methods for CRE were used, interpreted according to EUCAST and CLSI. Results: Were identified 5093 isolates, 67.85% were Gram negative (n = 3456), 2905 were enterobacteria (57.03% of total, 84.05% of Gram negatives). ESBLs represent 19.53% (n = 995), 15.2% (n = 151) in Surgical wards, 14.94% (n = 149) on ICU and 12.8% (n = 127) in Internal Medicine departments; they were present in all 24 hospital wards, colonizing even ambulatory patients (n = 32; 3.2%). Superbugs were 117 of these, most of which were present on ICUs (n = 57; 48.7%), Neurology (n = 15; 12.8%), Surgery (n=15; 12.8%) and Palliative (n = 12; 10.3%). Most multidrug resistant organisms were Klebsiella pneumoniae (n = 58; 49.6%), Proteus spp (n = 28; 23.91%) and Providencia stuartti (n = 19; 16.2%). Conclusions: Enterobacteria with extended resistance to cephalosporins and carbapenems were identified in the last two years in this hospital, especially in the ICU, Surgical and Internal Medicine departments, colonizing ambulatory patients as well. They are in the WHO alert, along with other Gram negative species, as Acinetobacter baumannii and Pseudomonas aeruginosa

Leczenie akromegalii w Rumunii. Jak blisko jesteśmy uzyskania kontroli nad chorobą?

Introduction: In Romania, no nationwide data for acromegaly treatment and control rate are available. Our objective was to assess the acromegaly control rate in a tertiary referral centre, which covers an important part of Romanian territory and population of patients with acromegaly. Materials and methods: We reviewed the records of all 164 patients (49 males and 115 females; median age 55 [47, 63.5] years) with newly or previously diagnosed acromegaly, who have been assessed at least once in our tertiary referral centre between January 1, 2012 and March 31, 2016. This sample represents 13.6% of the total expected 1200 Romanian patients with acromegaly and covers 82.9% of the counties in Romania. Control of acromegaly was defined as a random serum growth hormone (GH) < 1 ng/mL and an age-normalised serum insulin-like growth factor-I (IGF-I) value. The GH and IGF-I values used for calculation of the control rate were those at the last evaluation. The same assays for GH and IGF-I measurement were used in all patients. Results: There were 147 treated and 17 untreated patients. Of the 147 patients assessed after therapy, 137 (93.2%) had pituitary surgery, 116 (78.9%) were on medical treatment at the last evaluation, and 67 (45.5%) had radiotherapy. Seventy-one (48.3%) had a random GH < 1 ng/mL, 54 (36.7%) had a normalised, age-adjusted IGF-I, and 42 (28.6%) had both normal random serum GH and IGF-I. Conclusions: In Romania, acromegaly benefits from the whole spectrum of therapeutic interventions. However, the control rate remains disappointing.Wstęp: W Rumunii nie są dostępne ogólnokrajowe dane dotyczące leczenia akromegalii ani wskaźnika kontroli choroby. Badanie przeprowadzono w celu oceny wskaźnika kontroli akromegalii w ośrodku referencyjnym trzeciego stopnia, który obejmuje opieką zdrowotną znaczną część obszaru Rumunii i populacji pacjentów z akromegalią. Materiał i metody: Autorzy dokonali przeglądu danych medycznych wszystkich 164 chorych [49 mężczyzn i 115 kobiet; mediana wieku 55 lat (47; 63,5)] z noworozpoznaną lub wcześniej zdiagnozowaną akromegalią, których przynajmniej jednokrotnie zbadano w ośrodku referencyjnym trzeciego stopnia (miejsce pracy autorów) w okresie od 1 stycznia 2012 roku do 31 marca 2016 roku. Ta próba stanowiła 13,6% całej rumuńskiej populacji chorych na akromegalię szacowaną na 1200 osób i reprezentowała 82,9% okręgów administracyjnych w Rumunii. Kontrolę akromegalii definiowano jako stężenie przygodne hormonu wzrostu (growth hormone, GH) w surowicy wynoszące poniżej 1 ng/ml oraz normalizacja odpowiednio do wieku stężenia insulinopodobnego czynnika wzrostu 1 (insulin-like growth factor-1, IGF-1) w surowicy. Do obliczenia wskaźnika kontroli choroby stosowano wartości GH i IGF-1 z ostatnich pomiarów. U wszystkich pacjentów używano tych samych testów do pomiarów GH i IGF-1. Wyniki: Badanie obejmowało 147 chorych poddanych leczeniu i 17 chorych nieleczonych. Spośród 147 chorych ocenianych po terapii, u 137 (93,2%) zastosowano leczenie chirurgiczne, 116 (78,9%) w momencie ostatniej wizyty kontrolnej stosowało leczenie farmakologiczne, a 67 (45,5%) poddano radioterapii. U 71 chorych (48,3%) przygodne stężenie GH w surowicy wynosiło poniżej 1 ng/ml, u 54 (36,7%) uzyskano normalizację stężenia IGF-1 skorygowanego względem wieku, a u 42 chorych (28,6%) uzyskano normalizację obu parametrów — GH i IGF-1. Wnioski: W Rumunii u chorych na akromegalię stosuje się szerokie spektrum interwencji terapeutycznych, jednak wskaźnik kontroli choroby nadal pozostaje niezadawalający