OUTLIERS DETECTION BY RANSAC ALGORITHM IN THE TRANSFORMATION OF 2D COORDINATE FRAMES

Over the years there have been a number of different computational methodsthat allow for the identification of outliers. Methods for robust estimation are knownin the set of M-estimates methods (derived from the method of MaximumLikelihood Estimation) or in the set of R-estimation methods (robust estimationbased on the application of some rank test). There are also algorithms that are notclassified in any of these groups but these methods are also resistant to gross errors,for example, in M-split estimation. Another proposal, which can be used to detectoutliers in the process of transformation of coordinates, where the coordinates ofsome points may be affected by gross errors, can be a method called RANSACalgorithm (Random Sample and Consensus). The authors present a study that wasperformed in the process of 2D transformation parameter estimation usingRANSAC algorithm to detect points that have coordinates with outliers. Thecalculations were performed in three scenarios on the real geodetic network.Selected coordinates were burdened with simulated values of errors to confirm theefficiency of the proposed method

Ethnobotanique de la Nation crie d'Eeyou Istchee et variation géographique des plantes médicinales antidiabétiques

Le diabète de type 2 affecte en moyenne 29% de la population adulte crie d’Eeyou Istchee (CEI). Afin d’identifier les plantes médicinales possédant un potentiel antidiabétique, des interviews ont été réalisés dans les communautés CEI de Wemindji et Oujé-Bougoumou. Utilisant une approche quantitative, les espèces mentionnées ont été classées et comparées à la pharmacopée des communautés avoisinantes. Seize et 25 plantes ont été mentionné à Wemindji et Oujé-Bougoumou, respectivement. Sept nouvelles espèces de plantes et une de champignon se sont ajoutées à la liste des espèces à potentiel antidiabétique, bien que la plupart de celles mentionnées pendant les interviews soit en communes à la pharmacopée CEI générale, démontrant ainsi leur importance culturelle. Des analyses phytochimiques sur deux de ces espèces, Rhododendron groenlandicum et Sarracenia purpurea, ont été réalisées à partir d’échantillons récoltés à différents endroits du territoire eeyouch. Bien qu’aucun patron n’ait été détecté dans la variation des composantes biologiquement actives chez S. purpurea, les composés phénoliques chez R. groenlandicum, particulièrement la (+)-catéchine, l’(-)-epicatéchine et la quercétine-3-galactoside, varient spatialement en fonction de paramètres d’insolation telles la radiation solaire ou la photopériode. Les échantillons de cette dernière espèce, testés in vitro dans le bioessai de l’adipogenèse des cellules adipocytes murines 3T3-L1, augmentent l’accumulation intracellulaire des triglycérides, leur conférant ainsi une activité diabétique semblable à la rosiglitazone. Cependant, cette activité était plus faible dans les échantillons à haute teneur en quercétine, cela pouvant ainsi avoir un impact sur la qualité d'un produit de santé naturel fabriqué à partir de cette espèce.Type 2 diabetes has reached epidemic proportions among Canada’s aboriginal populations and affects on average 29% of adult Cree of Eeyou Istchee (CEI). In collaboration with the Cree Board of Health and Social Services of James Bay and the CIHR team in Traditional Antidiabetic Aboriginal Medicines, interviews were held in the CEI communities of Wemindji and Oujé-Bougoumou to identify potential antidiabetic plants. Using a quantitative approach, species mentioned were ranked and compared to the pharmacopoeia of other participating communities. Sixteen and 25 plants were mentioned in Wemindji and Oujé-Bougoumou respectively. Seven new plant and one fungal species were added to the list of potential antidiabetic species, although most of those mentioned were common to the general CEI pharmacopoeia, thus supporting the cultural importance that they hold. Phytochemical analyses of two of these species, Rhododendron groenlandicum and Sarracenia purpurea, were made from accessions harvested throughout Eeyou Istchee. While no pattern was detected in the variation of S. purpurea’s biologically active compounds, phenolic compounds from R. groenlandicum, specifically (+)-catchin, (-)-epicatechin and quercetin-3-galactoside, varied spatially as a function of insolation parameters such as solar radiation or photoperiod. Samples from the latter, tested in vitro in the 3T3-L1 murine adipocytes adipogenesis bioassay, increased the intracellular accumulation of triglycerides, thus conferring it a glitazone-like antidiabetic activity. This activity, however, was weaker in accessions with high quercetin content, which could have an impact on the quality of a natural health product made from this species

Analysis of classification systems for the built environment: historical perspective, comprehensive review and discussion

Research into the organisation of building project information began to bear fruit in the 1950s when the first classification system for the construction industry was introduced. Driven by the growing use of digital tools and technologies and by the first publication of ISO 12006-2 in 2001, this research topic has become incredibly popular in recent years. However, the absence of accurate historical traceability in the literature makes it difficult to understand the origin and evolution of the most prominent classification systems. The aim of this paper is to provide a comprehensive review of selected commonly used classification systems published in the last seven decades, delving into those developed in Sweden, the UK and the USA/Canada. Furthermore, the latest classification system launched by each of these countries (CoClass, Uniclass 2015 and OmniClass®, respectively) has been chosen to analyse, compare and discuss its strengths and weaknesses. The results of this research show that there is no consensus on the use of a common international classification system for the built environment. Although organisations worldwide are working diligently towards an internationally accepted standard classifier, the use of national classification systems still prevails. The main gaps to be bridged in this area are discussed in the paper and can be summarised as follows: (i) barriers are found to classify construction elements of residential buildings in a consistent, unambiguous and standardised manner, (ii) commonly used classification systems are designed so that the information required is acquired during the design and construction stages, and (iii) further work is needed to address the challenges of properly classifying construction elements at the operation and maintenance stage.Peer ReviewedObjectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats SosteniblesPostprint (published version

On the selection of significant variables in a model for the deteriorating process of facades

In previous works the authors of this paper have introduced a predictive system that uses survival analysis techniques for the study of time-to-failure in the facades of a building stock. The approach is population based, in order to obtain information on the evolution of the stock across time, and to help the manager in the decision making process on global maintenance strategies. For the decision making it is crutial to determine those covariates -like materials, morphology and characteristics of the facade, orientation or environmental conditions- that play a significative role in the progression of different failures. The proposed platform also incorporates an open source GIS plugin that includes survival and test moduli that allow the investigator to model the time until a lesion taking into account the variables collected during the inspection process. The aim of this paper is double: a) to shortly introduce the predictive system, as well as the inspection and the analysis methodologies and b) to introduce and illustrate the modeling strategy for the deteriorating process of an urban front. The illustration will be focused on the city of L’Hospitalet de Llobregat (Barcelona, Spain) in which more than 14,000 facades have been inspected and analyzed.Peer ReviewedPostprint (published version

Access to Indigenous and allopathic medicines: A systematic review of barriers and facilitators

Background: Globally, Indigenous peoples are the victims of social inequalities in health. Their state of health is much lower than the health of the general population. Colonialism, living conditions and access to care are the main determinants of observed health conditions. The scientific objective of this systematic literature review is to study the facilitators and barriers to access healthcare for both, traditional and allopathic medicines. Methods: An inclusive search of electronic databases (e.g ProQuest, Ovid, Medline, CINAHL PLUS, Cochrane Library, ApaPsyNet, PsyINFO and Sociological Abstracts databases) of the past 20 years was performed. We retained studies discussing (1) traditional medicine (TM) or allopathic medicine (AM) or both and occurring (2) within Indigenous population worldwide. We made no distinction between research carried out in rural as opposed to urban areas. Results: A total of 45 studies published between 1996 and 2016 met our inclusion criteria and this speaks to the high interest and contemporary pertinence of accessing both systems of healthcare for Indigenous populations worldwide. Our thematic analysis enabled us to group barriers and facilitators into five categories, namely related to personal, relational, cultural, structural and policy components. As far as barriers and facilitators are concerned, the category that encompasses the most themes is the structural category. Conclusions: Mutual respect, trust and understanding of each other’s modalities is essential to offer the best healthcare options from both AM and TM to Indigenous peoples and hence pave the way to reducing health inequities. Wellness and strength-based approaches must also be favoured

Access to Indigenous and allopathic medicines: A systematic review of barriers and facilitators

Background: Globally, Indigenous peoples are the victims of social inequalities in health. Their state of health is much lower than the health of the general population. Colonialism, living conditions and access to care are the main determinants of observed health conditions. The scientific objective of this systematic literature review is to study the facilitators and barriers to access healthcare for both, traditional and allopathic medicines. Methods: An inclusive search of electronic databases (e.g ProQuest, Ovid, Medline, CINAHL PLUS, Cochrane Library, ApaPsyNet, PsyINFO and Sociological Abstracts databases) of the past 20 years was performed. We retained studies discussing (1) traditional medicine (TM) or allopathic medicine (AM) or both and occurring (2) within Indigenous population worldwide. We made no distinction between research carried out in rural as opposed to urban areas. Results: A total of 45 studies published between 1996 and 2016 met our inclusion criteria and this speaks to the high interest and contemporary pertinence of accessing both systems of healthcare for Indigenous populations worldwide. Our thematic analysis enabled us to group barriers and facilitators into five categories, namely related to personal, relational, cultural, structural and policy components. As far as barriers and facilitators are concerned, the category that encompasses the most themes is the structural category. Conclusions: Mutual respect, trust and understanding of each other’s modalities is essential to offer the best healthcare options from both AM and TM to Indigenous peoples and hence pave the way to reducing health inequities. Wellness and strength-based approaches must also be favoured

Assessment of centre national d'Études spatiales real-time ionosphere maps in instantaneous precise real-time kinematic positioning over medium and long baselines

Precise real-time kinematic (RTK) Global Navigation Satellite System (GNSS) positioning requires fixing integer ambiguities after a short initialization time. Originally, it was assumed that it was only possible at a relatively short distance from a reference station (<10 km), because otherwise the atmospheric effects prevent effective ambiguity fixing. Nowadays, through the use of VRS, MAC, or FKP corrections, the distances to the closest reference station have been increased to around 35 km. However, the baselines resolved in real time are not as far as in the case of static positioning. Further extension of the baseline requires the use of an ionosphere-weighted model with ionospheric delay corrections available in real time. This solution is now possible thanks to the Radio Technical Commission for Maritime (RTCM) stream of SSR corrections from, for example, Centre National d’Études Spatiales (CNES), the first analysis center to provide it in the context of the International GNSS Service. Then, ionospheric delays are treated as pseudo-observations that have a priori values from the CLK RTCM stream. Additionally, satellite orbit and clock errors are properly considered using space-state representation (SSR) real-time radial, along-track, and cross-track corrections. The following paper presents the initial results of such RTK positioning. Measurements were performed in various field conditions reflecting realistic scenarios that could have been experienced by actual RTK users. We have shown that the assumed methodology was suitable for single-epoch RTK positioning with up to 82 km baseline in solar minimum (30 March 2019) mid and high latitude (Olsztyn, Poland) conditions. We also confirmed that it is possible to obtain a rover position at the level of a few centimeters of precision. Finally, the possibility of using other newer experimental IGS RT Global Ionospheric Maps (GIMs), from Chinese Academy of Sciences (CAS) and Universitat Politècnica de Catalunya (UPC) among CNES, is discussed in terms of their recent performance in the ionospheric delay domain.Peer ReviewedPostprint (published version

Ionospheric tomographic common clock model of undifferenced uncombined GNSS measurements

This is a post-peer-review, pre-copyedit version of an article published in Journal of geodesy. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00190-021-01568-8In this manuscript, we introduce the Ionospheric Tomographic Common Clock (ITCC) model of undifferenced uncombined GNSS measurements. It is intended for improving the Wide Area precise positioning in a consistent and simple way in the multi-GNSS context, and without the need of external precise real-time products. This is the case, in particular, of the satellite clocks, which are estimated at the Wide Area GNSS network Central Processing Facility (CPF) referred to the reference receiver one; and the precise realtime ionospheric corrections, simultaneously computed under a voxel-based tomographic model with satellite clocks and other geodetic unknowns, from the uncombined and undifferenced pseudoranges and carrier phase measurements at the CPF from the Wide Area GNSS network area. The model, without fixing the carrier phase ambiguities for the time being (just constraining them by the simultaneous solution of both ionospheric and geometric components of the uncombined GNSS model), has been successfully applied and assessed against previous precise positioning techniques. This has been done by emulating real-time conditions for Wide Area GPS users during 2018 in Poland.Peer ReviewedPostprint (published version

On the Security of Carrier Phase-based Ranging

Multicarrier phase-based ranging is fast emerging as a cost-optimized solution for a wide variety of proximity-based applications due to its low power requirement, low hardware complexity and compatibility with existing standards such as ZigBee and 6LoWPAN. Given potentially critical nature of the applications in which phase-based ranging can be deployed (e.g., access control, asset tracking), it is important to evaluate its security guarantees. Therefore, in this work, we investigate the security of multicarrier phase-based ranging systems and specifically focus on distance decreasing relay attacks that have proven detrimental to the security of proximity-based access control systems (e.g., vehicular passive keyless entry and start systems). We show that phase-based ranging, as well as its implementations, are vulnerable to a variety of distance reduction attacks. We describe different attack realizations and verify their feasibility by simulations and experiments on a commercial ranging system. Specifically, we successfully reduced the estimated range to less than 3 m even though the devices were more than 50 m apart. We discuss possible countermeasures against such attacks and illustrate their limitations, therefore demonstrating that phase-based ranging cannot be fully secured against distance decreasing attacks