Добірка наукової літератури з теми "Observations par drone"

The paper presents a generalized net (GN) model of the process of terrain observation with the help of unmanned aerial vehicles (UAVs) for the prevention and rapid detection of wildfires. Using a GN, the process of monitoring a zone (through a UAV, which is further called a reconnaissance drone) and the localization of forest fires is described. For a more indepth study of the terrain, the reconnaissance drone needs to coordinate with a second UAV, called a specialized drone, so that video and sensory information is provided to the supervising fire command operational center. The proposed GN model was developed to assist in the decision-making process related to the coordination of the operation of both UAVs under dynamically changing terrain circumstances, such as those related to preventing or quickly containing wildfires. It describes the stages (transitions), logical determinants (transition predicate matrices), and directions of information flow (token characteristics) within the process of localization of fires using the pair of reconnaissance and specialized drones.

Drone technology has been around the world more than a decade and the application has becomes more vital, especially, during the disaster event such as COVID-19 pandemic. However, some of the countries were not ready in implementating the technology due to various reasons. Thus, this study intended to identify the technological and legislative aspects of drone application for disaster response in cities environment and to propose strategic framework on optimization of drone capabilities in cities disaster response. The literature search has been conducted in order to explore the applicability of drone technology in disaster management and disaster response. Later, further investigations were carried out using the Participatory Action Research (PAR) approach. In the PAR method, the data were collected in two phases; 1) observation and discussions and 2) interview sessions. The observation and discussions were conducted to obtain the implementation process of using the drone during the disaster event by the rescue team via recorded video. To triangulate the information gathered from the discussion, a series of interview had been made. Where, six selected stakeholders from end-user, regulatory agency and supplier were interviewed. It is found that the implementation of drone technology framework in disaster consists of six perspectives, namely; actions, internal organization, external environment, needs specification and feasibility analysis. To make the framework works, stakeholders are required to function in a cohesive and collaborative manner as illustrated in the Harmonization Triangle. The strength of cohesion and collaboration has also opened up future study for a full scope disaster management cycle phases, known as response, recovery, mitigation and preparedness.

1. Introduction The Hokkaido native horse (mainly bred in Hokkaido) is one of the eight native horse breeds endemic to Japan, and it has not been crossed with any foreign horse breeds. Their body heights are ≤ 140 cm. Among the Japanese native horses, native Hokkaido native horses are most used for horseback riding, trekking, and horse therapy. They are well-suited for beginners due to their small stature, comfortable yet fast gait [1]and mild-mannered temperament [2]. However only 1,083 Hokkaido native horses were registered in 2020 [3]. this is a very small number, and it indicates that this breed needs to be protected. Therefore, tools for proper breeding and management are necessary. Regular weight measurement is important for maintaining horse health [4]. However, horse weighing scales are expensive, and there is a concern that the restraints necessary during measurement may be stressful to the horses. In addition, it is usually impossible to measure the weight or assess physical condition at the breeding facilities. taking measurements requires significant time and labor (i.e., to transport a horse for measurement), and some breeders do not have the necessary equipment. Furthermore, if a horse is timid and dislikes contact with people or tools typical measurement techniques risk injury to both the horse and person. Therefore, if there is possibility to ascertain horse body weight without human contact, it would be useful for proper management of Hokkaido native horses. When considering no-contact methods for estimating the body weight of feral or young horses, using images that are captured from a distance would be ideal. To estimate horse weight, the formula weight (kg) = (heartgirth2 × body length) / (11,880 cm3), is commonly used [5]. Therefore, if the horse’s length can be measured without touching the horse, it could be useful to use in estimations of body weight. To take images for measuring body length, aerial images shot by drone were thought to be useful. Drones have improved in safety and functionality in recent years and are being used in various fields. Furthermore, the improved performance of drone cameras has made it possible to take high-resolution images. Labor can be kept to a minimum because images of many horses can be recorded at once, and there is no need to restrain them. Furthermore, it has been reported that drone flights at altitudes of 30 m or higher do not cause stress to horses [6]. There have been a few drone studies involving horses [6-10] however, no study has ever used a drone to monitor the physical condition of horses. Therefore, in our study, we used images recorded by a drone to measure the relative body length of Hokkaido native horses under grazing conditions and thereby monitor the growth of foals. 2. Material and Methods The experimental procedures in this study followed the Guide for the Care and Use of Agricultural Animals of Obihiro University (Obihiro, Hokkaido). All methods were carried out in accordance with the university regulations on the Management and Operation of Animal Experiments (accepted No. 19-119). The experiment was carried out at the Hokkaido native breeds production ranch in Mimura, Hokkaido, which contained one pasture (47 ha) and one paddock (0.5 ha). The group of Hokkaido native horses that we monitored was bred at the study site and consisted of one stallion, mares with foals, unpregnant mares, and geldings. The number of horses changed continuously as foals were born and horses were sold. However, the group size remained at approximately 70 individuals during the entire experimental period. Of these, 22 foals were born from December 2018 to September 2019 and their dams were selected. A Mavic 2 Pro drone (DJI, Nanshan, China) was used. This drone has obstacle avoidance and automatic airborne position-holding functions that use an ultrasonic sensor. The attached camera was supported by a three-axis gimbal and was set to face downward at a 90° angle. The camera lens had an automatic focus with a viewing angle of 77° (28 mm). The video was recorded in a 4K (60 fps) resolution and saved on a 32 GB micro-SD card (Panasonic, Japan). Drone flights were conducted during the day at an altitude between 30 m and 150 m in a location where the drone was visible, as required by law [11]. The drone was operated by a pilot located a sufficient distance away from the horse herd, horses could be observed to confirm the safety of both the horses and the pilot. The drone was operated manually by the same pilot for all flights. Video recording with the drone began before takeoff and stopped after landing. For each observation, the selected mares and foals were marked with blue or red spray paint on their backs. Flights took place over 14 days between May and October 2019, between 10:00 and 18:00 JST. Once the drone was recording and in flight, where a mare and foal pair was located, the altitude of the drone was adjusted so that both the mare and the foal could be seen directly from above with the camera facing straight down. This position was then held for a few seconds. This process was repeated for each pair, and finally the drone was landed at a safe place near the pilot. The foal’s body length was calculated relative to the body length of the mare, which was defined as one unit. This was because the exact distance between the foal and the drone could not be measured since the grazing land was rough terrain. According to the specifications of the drone, the displayed altitude is the altitude from the takeoff location, and it may differ from the actual altitude, for example, if the ground is inclined. Moreover, we could not record the absolute measurements of the body length, as it was not possible to capture the standard measure of length and the mare and foal pair in the same frame. First, one frame of each recording taken from directly above each foal and mare pair was extracted (one frame per pair, per flight). From the still image, the body length of the mare was measured in pixel units using an image processing software (Image J). Body length was measured from the point of the scapula (thoracic vertebrae 5) to the first caudal vertebra in a straight line along the vertebral column and defined as one mare length (Figure 1). The foal body length was measured as a proportion of this. The relationship between relative body length and age (in days) was analyzed using a bell curve option in Microsoft Excel (2016). Figure1: Sample aerial drone image of a mare and foal pair used to measure the growth rate of the foal. The dashed line illustrates how the mare’s body length was measured. Foal length is in mare equivalents; mare length was measured as 1 unit: point of scapula to first caudal vertebra. 3. Results and Discussion Image data from a total of 53 flights were obtained. From these flights, 886 body lengths were determined. One flight time was approximately 25 min, which varied due to the influence of the weather conditions on battery life. During one flight, approximately 20 mare-foal pairs were recorded. Although there was a maximum of 22 pairs available, identification challenges precluded the use of all pairs. For example, certain mares could not be identified due to the lack of paint marks as they had escaped during the spray paint marking, or foals of the same age, coat color, and sex could not be differentiated. A regression was obtained using a logarithmic function (Figure 2). The Equine Research Institute reports that body weight and body measurement increase rapidly from birth to weaning [12] and this corresponded to our results. Using the relationship of body measurements (body weight, height of withers, heart girth, cannon circumference) with age in days, significant logarithmic curves have been obtained [13]. In a previous study [13], body length was not reported, but body length measured by the drone and age in days (X) resulted in significant logarithmic curves being produced. In the current study, the following equation was constructed. Faculty Agriculture; Hokkaido University: 16: 11-17. Figure 2. Changes in the body length of native Hokkaido foals from 0 to 10 months of age as measured by aerial photographs taken by a drone. *Foal length is in mare equivalents; mare length was measured as 1 unit: point of scapula to first caudal vertebra. Y (proportion of mare length) = 0.0896 log(x) + 0.2490 (r2 = 0.54, p < 0.01). From these results, we concluded that it is possible to measure the relative body length of foals using a drone. Body length measurements using the drone varied more in this study than in a previous study [13]. The reasons for the variation are the mare's age and body size. The foal of an older, larger mare tends to have a higher birth weight and to grow faster. Alternatively, the milk yield of the mare can be affected by the amount of grass in the pasture. Because parturition timing was widely spread from December 2018 to September 2019, differences in grazing may have affected the development of the foals. However, this could not be clarified in the present study.? Based on the above, it can be said that further research is needed, but with progress in this type of research, drones can be applied to horse management. 4. Acknowledgement We wish to express our gratitude to Mr. Hiroyuki Kawahara, the manager of the ranch, for cooperating with our research. Helpful comments from many friends and colleagues have contributed significantly to the quality of this paper.

AbstractThe taxonomic and ecologic composition of Earth's biota has shifted dramatically through geologic time, with some clades going extinct while others diversified. Here, we derive a metric that quantifies the change in biotic composition due to extinction or origination and show that it equals the product of extinction/origination magnitude and selectivity (variation in magnitude among groups). We also define metrics that describe the extent to which a recovery (1) reinforced or reversed the effects of extinction on biotic composition and (2) changed composition in ways uncorrelated with the extinction. To demonstrate the approach, we analyzed an updated compilation of stratigraphic ranges of marine animal genera. We show that mass extinctions were not more selective than background intervals at the phylum level; rather, they tended to drive greater taxonomic change due to their higher magnitudes. Mass extinctions did not represent a separate class of events with respect to either strength of selectivity or effect. Similar observations apply to origination during recoveries from mass extinctions, and on average, extinction and origination were similarly selective and drove similar amounts of biotic change. Elevated origination during recoveries drove bursts of compositional change that varied considerably in effect. In some cases, origination partially reversed the effects of extinction, returning the biota toward the pre-extinction composition; in others, it reinforced the effects of the extinction, magnifying biotic change. Recoveries were as important as extinction events in shaping the marine biota, and their selectivity deserves systematic study alongside that of extinction.

Reliable real-time kinematic (RTK) is crucially important for emerging global navigation satellite systems (GNSSs) applications, such as drones and unmanned vehicles. The performance of conventional single baseline RTK (SBRTK) with one reference station degrades greatly in dense, urban environments, due to signal blockage and multipath error. The increasing use of multiple reference stations for kinematic positioning can improve RTK positioning accuracy and availability in urban areas. This paper proposes a new algorithm for multi-baseline RTK (MBRTK) positioning based on the equivalence principle. The advantages of the solution are to keep observation independent and increase the redundancy to estimate the unknown parameters. The equivalent double-differenced (DD) observation equations for multiple reference stations are firstly developed through the equivalent transform. A modified Kalman filter with parameter constraints is proposed, as well as a partial ambiguity resolution (PAR) strategy is developed to determine an ambiguity subset. Finally, the static and kinematic experiments are carried out to validate the proposed algorithm. The results demonstrate that, compared with single global positioning system (GPS) and Beidou navigation system (BDS) RTK positioning, the GPS/BDS positioning for MBRTK can enhance the positioning accuracy with improvement by approximately (45%, 35%, and 27%) and (12%, 6%, and 19%) in the North (N), East (E), and Up (U) components, as well as the availability with improvement by about 33% and 10%, respectively. Moreover, the MBRTK model with two and three reference receivers can significantly increase the redundancy and provide smaller ambiguity dilution of precision (ADOP) values. Compared with the scheme-one and scheme-two for SBRTK, the MBRTK with multiple reference receivers have a positioning accuracy improvement by about (9%, 0%, and 6%) and (9%, 16%, and 16%) in N, E, and U components, as well as the availability improvement by approximately 10%. Therefore, compared with the conventional SBRTK, the MBRTK can enhance the strength of the kinematic positioning model as well as improve the positioning accuracy and availability.

Mesoscale eddies play an important role in regulating biogeochemical cycles. However, the response of biogeochemical variables to cold and warm eddies has not been well elucidated, mainly due to most previous studies relying on remote sensing techniques and lacking in situ observations below the surface water. Here, we used hydrographic and biochemical data from one survey in the northwestern Pacific to document the vertical biogeochemical structure of one cold and two warm eddies. We first compared the changes of key variables in the eddy core relative to eddy outside, explained the role of key layers (the mixing depth, pycnocline, nutricline, euphotic) in causing these changes, and then analyzed the main environmental factors affecting chlorophyll a (Chla) and phytoplankton communities. Finally we focused on the response mechanisms of key biogeochemical variables to the cold and warm eddies. The results showed that biological variables (Chla, microphytoplankton, picophytoplankton), salinity, dissolved inorganic nitrogen (DIN), dissolved inorganic phosphate (DIP), and dissolved inorganic silicate (DSi) in the cold eddy core increased by 0.2–134%, while in the warm eddy core, they decreased by 0.2–70% relative to the eddy outside. The cold and warm eddies were able to force the deep chlorophyll maximum (DCM), which rose or fell with the pycnocline, nutricline and euphotic depth (Zeu) as a whole. Cold eddies with a raised thermocline could lead to about 20 m elevated DCM and enhanced phytoplankton biomass when the nutricline and thermocline were coincident. In contrast, warm eddies drove isopycnals downward, resulting in a 10–25 m drop in DCM and a decrease in nutrient and Chla concentrations at the center of the eddies. The significant difference in the vertical structure of the phytoplankton community between the center and the outside of the eddy might be explained by the direct influence of both nutrient concentrations and stoichiometry changes. The contribution of microphytoplankton to total biomass was much smaller than that of picophytoplankton in oligotrophic waters where the DIN:DIP and DSi:DIN ratios are significantly low. Compared to nutrients, photosynthetically active radiation (PAR) might not be the main factor controlling phytoplankton biomass and abundance attributed to Zeu being consistently deeper than the mixed depth (Zm), whereas it was likely to be the key limiting factor affecting the vertical distribution of the phytoplankton community.

This article provides an historical account of the U.S. military’s creation of and reliance upon Earth observation media to orient their ability to conduct first the Cold War and then the War on Terror. Two technological case studies are provided: 1) an account of the development of the Semi-Automated Ground Environment (SAGE) system developed to automate the surveillance necessary for anti-nuclear bomber defence; and 2) a brief history of drone development from the nineteenth century to the present war on terror. These observational media systems provide evidence of how Kittler’s two claims regarding media development merge in the teleology of the digital and the “war answer” in which warfare has come to be autonomously guided by computerized media.Cet article offre un compte-rendu historique de la création de médias d’observation de la planète par l’armée américaine et de la dépendance de celle-ci sur ces médias pendant la Guerre froide et, par la suite, la Guerre contre le terrorisme. Deux études de cas sur la technologie s’ensuivent : 1) la présentation du Système d’infrastructure semi-automatique au sol (SAGE), développé afin d’automatiser la surveillance requise pour se défendre contre des bombardiers munis d’armes nucléaires; et 2) une brève histoire du développement des drones à partir du dix-neuvième siècle jusqu’à la Guerre contre le terrorisme actuelle. Ces systèmes d’observation montrent comment les deux affirmations de Friedrich Kittler sur le développement des médias convergent vers une téléologie du numérique et une « réponse guerrière », où la guerre se fait désormais par ordinateur.

<p class="05IsiAbstrak">This article mainly explores Mandarin Oriental Singapore’s Commercial Text among New Students: A Commercial Material Developments. This study uses participatory action research (PAR). The result indicates that</p><p class="05IsiAbstrak">commercial texts in the classroom student had autonomy in making a decision on particular lexico-grammatical resources they need to learn more or discuss with their pair, small group, and whole class discussion. They learn not only by locally produced materials but also commercial materials. These commercial materials drove them drawing on observation and reflective data, as the students engaged in meaning-making activities, they analyzed a variety of texts they read and shared the outcome of the analysis with their peers. This meaning-making engagement allowed them to understand and interpret texts in new and varied ways (Hodgson-Drysdale, 2014) so that relationship between content and language was evident.</p>

AbstractRising sand temperatures resulting from climate warming may cause the ‘feminization’ of sea turtle populations, which have temperature-dependent sex determination. In July and October 2021, we conducted surveys using a drone (also referred to as an unmanned aerial vehicle or UAV) and shore-based observations to assess the operational sex ratio (OSR) (number of males and females in breeding condition) for green turtles (Chelonia mydas) in the southern Great Barrier Reef, Australia (23.44 °S, 151.92 °E). Using drone-imagery, the length:width (L:W) ratio of a turtle’s head was used to distinguish loggerhead turtles (Caretta caretta) from green turtles, and the L:W of the carapace was used to distinguish juveniles from adult-sized green turtles. The first breeding pair was observed in shore-based surveys on 14 September 2021 and the number of mating turtles then increased to a peak on 4 October, about 8 weeks before the peak in nesting. A total of 94 km of drone transects with associated video footage was analysed. In October, at the peak of the mating season, the ratio of adult turtles displaying breeding behaviours near the island was 0.51 female (95% CI ± 0.17), supporting previous conclusions that despite the female-biased (> 80%) hatchling sex ratio, this population likely has a fairly balanced OSR. These findings are likely explained by males breeding 2–3 times more frequently than females, which helps mitigate female-biased hatchling sex ratios. Assessing the OSR of populations with extreme female hatchling bias may help to inform whether intervention is needed to increase male hatchling production.

Depuis ces dernières décennies, peu de sujets de la géologie de l’ingénieur ont attiré autant l’attention de la communauté scientifique que ceux traitant des risques naturels et plus particulièrement des instabilités gravitaires de grandes ampleurs reconnues sous les termes de DSGSD (Deep Seated Gravitational Slope Deformation) et de DSL (Deep Seated Landslide). Basée sur un nombre limité de cas d’étude à l’échelle naturelle (couplage datation et surveillance récente), la dynamique temporelle à court terme reste l’un de leurs aspects les moins étudiés aujourd’hui. Nous avons choisi l’exemple du massif de la Cristallère, situé en haute Vallée d’Aspe dans les Pyrénées béarnaises, où le DSL de la Cristallère a été récemment identifié et analysé à partir de deux méthodes de datation.Dans la continuité de ce travail, notre première approche consiste à évaluer la dynamique temporelle à court terme des mouvements de ce versant à différentes échelles et à partir de différentes méthodes de positionnement par satellites (constellations GPS et GLONASS) : positionnement multistations RGP (Réseau Géodésique Permanent), statique géodésique avec pivot et statique rapide avec pivot. Nous insistons dans ce travail, compte tenu des résultats originaux obtenus, sur l’intérêt du différentiel GNSS (Global Navigation Satellite System) avec un pivot qui se doit d’être proche géographiquement des observations à mener afin d’assurer une précision suffisante (de l’ordre du cm).Les observations et l'exploitation des modèles numériques de terrain issues des relevés aériens à différentes échelles obtenus avec un drone du type « aile volante » constituent la deuxième approche de ce travail de recherche. Elles viennent compléter la cartographie du site et démontrer l’existence d’un DSGSD à partir d’une caractérisation géomorphométrique haute résolution et haute précision (de l’ordre du cm également) ; elles permettent d’affiner la délimitation du DSL de la Cristallère et de sa zone la plus active (Pène du Thès) et du DSL du Peilhou.À ces deux approches complémentaires (combinaison de données tridimensionnelles ponctuelles et surfaciques), s’ajoutent préalablement un relevé de terrain géologique etgéophysique (mesures structurales, tomographies de résistivités électriques et profils électromagnétiques Very Low Frequency) ainsi qu’une analyse des archives disponibles sur les ouvrages présents dans le versant instable, tels que la galerie drainante de la centrale hydroélectrique du Baralet et l’ancien tunnel ferroviaire du Peilhou.L’utilisation combinée de ces trois approches confirme que les mouvements profonds du massif de la Cristallère sont encore actifs avec un forçage sismique avéré : la prise de conscience du rôle que peut jouer le DSGSD est tout aussi fondamentale. Ainsi tous les ouvrages existants dans le massif, ou les projets d’aménagement ou de réhabilitation sur ce site doivent considérer l’existence d’une déstructuration, lente et progressive de l’ensemble du massif (DSGSD). Par ailleurs, la méthodologie développée dans ce travail se veut générale et peut être utilisée pour surveiller et suivre, à court et moyen terme, tous types de mouvement de terrain, et en particulier les glissements de terrain ou rocheux, profonds ou superficiels, lents ou rapides<br>For these last decades, few subjects of the geology of the engineer have drawn the attention of the scientific community as much as those dealing of the natural hazards and more particularly with large-scale gravitational instabilities known as DSGSD (Deep Seated Gravitational Slope Deformation) and DSL (Deep Seated Landslide). Based on few cases study on a natural scale (dating and recent monitoring), short term temporal dynamics remains one of their least studied aspects today. We made the choice of the Cristallère massif as an example. It is located in Upper Aspe Valley of the Pyrenees (Béarn region). The Cristallère DSL was recently identified and analyzed through two dating methods.On the basis of this work, our first approach consists in assessing short term temporal dynamics of these slopes movements on various scales and with various methods of satellites positioning (GPS and GLONASS constellations): multistation positioning RGP (Permanent Geodetic Network in France), statics geodetic with pivot and fast static with pivot. We insist in this work, given the original results obtained, on the interest of the differential GNSS (Global Navigation Satellite System) with a pivot which must be geographically close to the observations to be carried out in order to ensure sufficient accuracy (cm).Observations and exploitation of drone digital elevation models of the site from aerial surveys at different scales obtained with a “flying wing” are the second approach to this research work. They complete the mapping of the site and demonstrate the existence of a DSGSD based on a high resolution and high precision geomorphometric characterization (cm); they make it possible to refine the delimitation of the Cristallère DSL and its most active area (Pène du Thès) and the Peilhou DSL.In addition to these two complementary approaches, a geological and geophysical survey (structural geology measurements, electrical resistivity tomographies and electromagnetic profiles Very Low Frequency surveys) and an analysis of the available data on the structures present in the unstable slope, such as the large diameter underground water pipe for the hydroelectric plant of Baralet and the former railway tunnel of Peilhou. The combined use of these three approaches confirms that the deep movements of the Cristallère massif are still active with proven seismic forcing: awareness of the potential role taken by the DSGSD is then fundamental. Thus, all the existing structures in the massif or the projects on this site (new constructions or rehabilitation of old structures) have to consider the existence of a slow and gradual change of the entire massif (DSGSD). Moreover, the methodology developed in this work is intended to be general. It also makes possible to monitor and follow, in the short and medium term, all types of ground movement, in particular landslides or rockslides, deep or superficial, slow or fast

Contrairement aux carottes de glace polaires, les variations isotopiques dans les carottes de glace tibétaines compliquent l'interprétation des signaux de température. L'une des principales raisons est que dans les régions de mousson aux latitudes basses et moyennes, les isotopes de l'eau sont influencés par des processus convectifs et nuageux. Il est nécessaire de mieux comprendre le comportement des isotopes de l'eau et les contrôles dynamiques impliqués dans la transpiration et la convection de l'humidité. Des observations in situ à grande échelle et des profils verticaux des isotopes de la vapeur pendant la convection seraient utiles, mais ces données sont rares. Le but de cette thèse a été de documenter les variations horizontales, verticales et temporelles de la mousson d'Asie de l'Est. D’abord, afin de documenter les variations horizontales près de la surface et saisonnières de la composition isotopique stable de l’eau en Chine, nous avons effectué des observations in situ des isotopes de la vapeur d'eau sur une vaste région de la Chine (plus de 10 000 km) pendant les saisons de pré-mousson et de mousson, à l'aide d'un système de mesure des isotopes de la vapeur d'eau nouvellement conçu et installé sur un véhicule. Nous avons constaté que les variations spatiales de la vapeur δ18O sont principalement contrôlées par la distillation de Rayleigh le long des trajectoires des masses d'air pendant la saison de pré-mousson, et sont fortement influencées par différentes sources d'humidité, les processus de recyclage continental et la convection le long du transport de l'humidité pendant la saison de la mousson. Ces résultats donnent un aperçu de la distribution spatiale et de la variabilité saisonnière de la composition isotopique de l'eau en Asie de l'Est et de leurs facteurs de contrôle, et soulignent la nécessité d'interpréter les enregistrements proxy dans le contexte du système régional et des sources d'humidité. Ensuite, pour mieux comprendre les processus physiques qui contrôlent la distribution verticale des isotopes de la vapeur et sa variabilité intra-saisonnière et saisonnière, nous avons observé les profils verticaux des isotopes de la vapeur de l'atmosphère jusqu'à la haute troposphère (de la surface du sol à 3856 m jusqu'à 11000 m d'altitude) de juin à octobre dans le sud-est du plateau tibétain à l'aide d'un drone spécialement conçu à cet effet. Pour l’échantillonnage, nous avons utilisé des sacs d’air, mais avons rencontré des problèmes de perméabilité généralement associés à ces sacs. Pour corriger ces problèmes, nous avons développé un modèle de diffusion et en avons calibré les paramètres avec des expériences de laboratoire. Ceci nous a permis de documenter pour la première fois que la distribution verticale des isotopes de la vapeur d'eau atmosphérique pendant toute la période de la mousson jusqu'à la haute troposphère, avec une résolution verticale et une gamme d'altitudes sans précédent. Nous constatons que les profils verticaux de la composition isotopique de la vapeur d'eau reflètent une combinaison de processus à grande échelle, en particulier la convection profonde et le recyclage continental le long des trajectoires, et les processus convectifs locaux, en particulier le détrainement convectif et la sublimation des cristaux de glace. Les variations saisonnières et intra-saisonnières observées sont généralement cohérentes verticalement, en raison du fort mélange convectif vertical et du détrainement convectif local de la vapeur provenant des basses couches, et reflètent les variations de convection profonde le long des trajectoires<br>Unlike polar ice core records, the isotope variations in Tibetan ice cores challenge the interpretation of temperature signals. One of the main reasons is that in monsoon regions at low and middle latitudes, water isotopes are influenced by convective and cloud processes. A deeper understanding of water isotope behavior and the dynamical controls involved in moisture transpiration and convection is needed. Large-scale in-situ observations and vertical profiles of vapor isotopes during convection would be helpful. However, such data are rare. The aim of this thesis was to document horizontal, vertical, and temporal variations in the isotopic composition of water in East Asian monsoon region. First, to document the horizontal and seasonal variations of water isotopes near the surface across China, we made in-situ observations of near-surface vapor isotopes over a large region (over 10000 km) across China in both pre-monsoon and monsoon seasons, using a newly-designed vehicle-based vapor isotope monitoring system. We found that the observed spatial variations of vapor δ18O are mainly controlled by Rayleigh distillation along air mass trajectories during the pre-monsoon period, but are significantly influenced by different moisture sources, continental recycling processes, and convection along moisture transport during the monsoon period. These results provide an overview of the spatial distribution and seasonal variability of water isotopic composition in East Asia and their controlling factors and emphasize the need to interpret proxy records in the context of the regional system and moisture sources. Second, to better understand the physical processes that control the vertical distribution of vapor isotopes and its intra-seasonal and seasonal variability, we observed the vertical profiles of atmosphere vapor isotopes up to the upper troposphere (from the ground surface at 3856m up to 11000m a.s.l.) from June to October in the southeastern Tibetan Plateau using a specially-designed unmanned-aerial-vehicle (UAV) system. For the sampling, we chose to carry air bags on UAVs as a portable sampling device, but encountered the permeability problem commonly associated with these bags. To corrected for this problem, we developed a diffusion model with diffusion parameters calibrated through laboratory experiments. This allows us to document for the first time the vertical distribution of atmospheric water vapor isotopes across the entire monsoon period up to the upper troposphere, boasting an unprecedented vertical resolution and altitude range. We find that the vertical profiles of water vapor isotopic composition reflect a combination of large-scale processes, in particular deep convection and continental recycling along trajectories, and local convective processes, in particular convective detrainment, and sublimation of ice crystals. The observed seasonal and intra-seasonal variations are generally vertically coherent, due to the strong vertical convective mixing and local convective detrainment of vapor originating from the low levels, and are mainly due to deep convection along trajectories

Les agents robotiques mobiles ou aériens sont confrontés au besoin de planifier des actions avec information incomplètesur l'état du monde. Dans ce contexte, cette thèse propose un cadre de modélisation et de résolution de problèmes deplanification de perception et de mission pour un drone hélicoptère qui évolue dans un environnement incertain etpartiellement observé afin de détecter et de reconnaître des cibles. Nous avons fondé notre travail sur les ProcessusDécisionnels Markoviens Partiellement Observables (POMDP), car ils proposent un schéma d'optimisation général pour lestâches de perception et de décision à long terme. Une attention particulière est donnée à la modélisation des sortiesincertaines de l'algorithme de traitement d'image en tant que fonction d'observation. Une analyse critique de la mise enoeuvre en pratique du modèle POMDP et du critère d'optimisation associé est proposée. Afin de respecter les contraintes desécurité et de sûreté de nos robots aériens, nous proposons ensuite une approche pour tenir compte des propriétés defaisabilité d'actions dans des domaines partiellement observables : le modèle AC-POMDP, qui sépare l'informationconcernant la vérification des propriétés du modèle, de celle qui renseigne sur la nature des cibles. Enfin, nous proposonsun cadre d'optimisation et d'exécution en parallèle de politiques POMDP en temps contraint. Ce cadre est basé sur uneoptimisation anticipée et probabilisée des états d'exécution futurs du système. Nous avons embarqué ce cadrealgorithmique sur les hélicoptères autonomes de l'Onera, et l'avons testé en vol et en environnement réel sur une missionde détection et reconnaissance de cibles<br>Mobile and aerial robots are faced to the need of planning actions with incomplete information about the state of theworld. In this context, this thesis proposes a modeling and resolution framework for perception and mission planningproblems where an autonomous helicopter must detect and recognize targets in an uncertain and partially observableenvironment. We founded our work on Partially Observable Markov Decision Processes (POMDPs), because it proposes ageneral optimization framework for perception and decision tasks under long-term horizon. A special attention is given tothe outputs of the image processing algorithm in order to model its uncertain behavior as a probabilistic observationfunction. A critical study on the POMDP model and its optimization criterion is also conducted. In order to respect safetyconstraints of aerial robots, we then propose an approach to properly handle action feasibility constraints in partiallyobservable domains: the AC-POMDP model, which distinguishes between the verification of environmental properties andthe information about targets' nature. Furthermore, we propose a framework to optimize and execute POMDP policies inparallel under time constraints. This framework is based on anticipated and probabilistic optimization of future executionstates of the system. Finally, we embedded this algorithmic framework on-board Onera's autonomous helicopters, andperformed real flight experiments for multi-target detection and recognition missions

Duas décadas antes da publicação do “Relatório Brundtland”, a sustentabilidade ambiental já recorria a imagens de Observação da Terra (OT), recolhidas por satélites artificiais, úteis para meteorologia, monitorizar a poluição, desertificação, e alterações climáticas. África deu os primeiros passos no Espaço nos anos 70. Os países africanos investiram já mais de 300M de dólares em satélites de OT, e alguns constroem os seus próprios CubeSat. Ao contrário da Europa, nunca se materializou uma Agência Espacial que unisse esforços dos países africanos. Muitos stakeholders de ambiente africanos usam dados espaciais, e era importante perceber porque não fruiu ainda uma iniciativa espacial multinacional, e como poderia semelhante cooperação servir a sustentabilidade ambiental naquela região. A metodologia seguida aliou a pesquisa bibliográfica a um inquérito feito a entidades africanas dos setores de Espaço e de ambiente. Na primeira fase analisaram-se as 24 iniciativas espaciais africanas. Foram classificadas segundo uma escala proposta pelo autor, que dá primazia ao conhecimento, sobre a industrialização e orçamento. Concluiu-se que a África do Sul, a Argélia, a Nigéria, e Egito são os maiores casos de sucesso. Sendo evidente que as aplicações de OT têm impacto positivo na sustentabilidade ambiental, em África e noutras regiões do globo, foi realizado um inquérito (segunda fase) que obteve 95 respostas. Os inquiridos conhecem iniciativas espaciais, sobretudo não africanas, valorizam o Espaço como resposta aos desafios da sustentabilidade ambiental, e creem ser prioritário o conhecimento versus tecnologia. A casuística dos insucessos de iniciativas multinacionais africanas, torna irrealista esse tipo cooperação em Espaço, e impossível de emular o modelo da Agência Espacial Europeia. Propõe-se então, o roadmap para ajudar atores africanos a melhor guiar os seus esforços espaciais para sustentabilidade ambiental. O roadmap abrange boas práticas para iniciativas espaciais nacionais e multinacionais africanas, e o desenvolvimento local de aplicações de OT. São enfatizadas as potencialidades dos drones e das tendências “New Space”. Considera-se que os atores de Espaço africanos poderão alcançar mais sucesso investindo na educação e em políticas de dados abertas para a produção de informação pertinente aos stakeholders do ambiente.<br>Already two decades before the “Brundtland” Report” was published, environmental sustainability was being served by Earth Observation (EO) images, collected by man-made satellites, and useful for meteorology, monitoring pollution, desertification and climate change. Africa took its first step into space in the 1970s. Over 700M USD have been since invested in EO satellites by African Nations, some building CubeSats on their own. Unlike in Europe, a Space Agency that would have joined African Nations’ forces never materialized. However, many environmental stakeholders in Africa use space data, and it is important to grasp why a multinational space initiative has not come into fruition, and how such cooperation could serve environmental sustainability in the region. The methodology followed combined bibliographic research and a survey made with African entities from the space and environment sectors. In the first phase, the 24 African space initiatives were analysed. This classification was made with a scale proposed by the author, which over emphasizes know-how over industrialisation and budget. Algeria, Nigeria, Egypt and South Africa were graded as the most successful. Evidence showing that EO applications can leave a positive impact on environmental sustainability in Africa and other regions in the world, a survey (undertaken in the second phase) gathered 95 responses, covering 34 of the 54 African nations. The responders were found to be knowledgeable about space initiatives, especially non-African, value space as a response to environmental sustainability challenges, and believe know-how should be a priority over technology. The underlying reasons why multinational initiatives have not succeeded in Africa, makes such type of cooperation unrealistic in space, and impossible to emulate the European Space Agency model. A roadmap is then devised to help African actors guide their space efforts towards environmental sustainability. This roadmap covers best practices for national and multinational African space initiatives, and the development of OT applications. The potential offered by drones and New Space trends are emphasized. It is considered that African space actors can achieve more success by investing in education and open data policies in order to produce information pertinent to environment stakeholders.

The minuet is the Baroque dance “par excellence,” first danced in Louis XIV’s court. One of its intrinsic characteristics is the deliberate contradiction between the movements and the music. Phrase lengths can also vary, thus creating even more intricate ambiguities between music and steps. Choreographic descriptions are given. As to tempo, the sources are by no means unanimous. Minuets in French court dances typically come in pairs, a tradition Bach generally follows: although no dynamic instructions are offered, the two Bach minuets examined here have clear stylistic differences. Minuet I has almost no slurs for the first eighteen bars; Montéclair’s bowings for the minuet are examined and used as an initial blueprint for this example. By contrast, the first half of Minuet II centers around a musette-like drone and is more legato in character. The Observations section provides detailed musical and technical advice, and source-derived quotations.

Abstract The Student’s Research Companion focuses on an often-overlooked part of the academic experience. This chapter briefly illustrates the observations, convictions, and conclusions that drove us to curate mindsets and notions useful to those who engage their next research journey.

A million people die every year as a result of war and terrorism. According to these statistics, armed conflict will cost another 20 million lives in the coming two decades. Is there anything we can do to stop that from happening? The origin of war is one of the oldest questions of humanity. Every major religion sets rules that limit armed conflicts. Yet war seems to be a destructive power that is present throughout history. Is it within our power to prevent war and terrorism? British meteorologist Lewis Fry Richardson was one of the first to apply statistical analysis to warfare. Richardson was a Quaker whose beliefs prevented him from serving in combat, so he drove an ambulance during World War I instead. It was then that he first began to collect data on the death toll attributable to armed conflict. Richardson went on to study military confrontations from 1820 to 1945, ranging from minor local skirmishes to all-out world wars. As we might expect, he found that the deadlier the conflict, the less frequent its occurrence. What was not expected, however, was his observation that the frequency of wars follows a similar kind of scaling law as earthquakes and avalanches. There are roughly fifteen conflicts each century costing more than a million lives. Those with a death toll above 100,000 occur 100 times, those with 10,000 or more deaths 800 times, and so on. A tenfold increase in lethality thus corresponds with an eightfold decline in frequency. This came as a great surprise because it suggests that wars don’t occur randomly. The fixed proportion of smaller and bigger conflicts shows that they are interrelated and that there is a common set of forces driving a dispute toward war. This is a profoundly worrying conclusion for historians, who customarily ascribe each new outbreak of violence to a set of unique contingencies. Yet this is only part of the story. Scaling law statistics suggest that there is something universal shared by all wars—something that may be inherent to human society.

The progressive upgrading of heavy-duty gas turbines, aimed at increased performance, can ultimately introduce more onerous operating conditions, to the point that original design limits can be approached. An increased gas turbine pressure ratio together with compression and expansion line adjustments can directly affect the rotor axial thrust. Other than the individual forces acting on the rotor, a key component to be taken into account is the fluid film thrust bearing, which should assure safe and reliable operation during the worst case operating conditions. Typically, such bearings are designed with large safety margins, yet it is possible that the new and more challenging conditions require a bearing capability upgrade, especially when field retrofit needs pose additional constraints. A succession of performance upgrades have been carried out on Ansaldo Energia’s AE94.2 E-Class GT. An accurate understanding of the thrust-related phenomena proved necessary and drove improvements in the thrust bearing design along with hardware adjustments to lower the rotor thrust. This paper addresses calculations and experimental arrangements for the rotor axial thrust evaluation on the aforementioned GT and considers both the matters related to the secondary air system for the thrust generation and the mechanical/functional matters for the bearing upgrade. It is shown that issues such as uneven load sharing across the thrust bearing, or the variability of rotor thrust from engine to engine within the fleet, strongly affect the maximum thrust assessment and thus the requirements used in the process of selecting a suitable bearing. A predictive calculation method is described considering the main thrust contributions. Field experimental setups and main observations are reported. Measurements have been carried out using thermocouples and load cells placed on many of the thrust bearing pads. Moreover, the engine cavities carrying the highest and/or the most uncertain thrust share have been instrumented and characterized by pressure sensors. The development of an upgraded thrust bearing is finally depicted through the main issues addressed, such as improved thrust pad lining material, increased load sharing efficiency and enlarged thrust bearing active surface area. Waukesha Bearings test results on the upgraded lining material, a high-tin aluminium alloy are reported as well. A multidisciplinary approach is presented as necessary to manage the crucial challenge of improving the thrust balancing system, especially in the case of a formerly designed engine which receives a powerful upgrade.

Visual navigation is a cornerstone of many modern navigation systems, from computer mice sensors through cars, guided missiles, spacecraft proximity operations and landers. Since 2017 the Students’ Space Association at Warsaw University of Technology has been developing the FOK rocket - a guidance, navigation and control research and development platform. The rocket is aerodynamically controlled using canards and is capable of reaching an apogee of about 1700 metres, a speed of Mach 0.6. It is fully reusable thanks to a parachute recovery system. Currently, the team is developing a vision-based navigation system composed of visible-light and infrared seekers. The goal of the mission is to guide the rocket towards ground-based visible or infrared markers. As part of the project, the team works on software-in-the-loop testing of developed GNC algorithms. The tests are conducted within the SKA RFS software - an in-house developed tool for simulating a variety of sounding rockets. It is a 6DOF flight simulation tool able to simulate multi-staged rockets, equipped with multiple engines, multiple parachutes, and aerodynamic control systems. It also allows conducting simulations of a stream from the rocket-mounted camera. As the next iteration of the FOK project aims to use an infrared camera, the team faced the challenge of simulating infrared camera images within the RFS software to test the developed vision navigation algorithms. This paper will present techniques for generating artificial infrared images for visual navigation simulation. Artificial images will be generated based on source images taken in the visible-light spectrum. Two methods for artificial image generation will be investigated: the first using a simple correlation between the visible and infrared images and the second utilising neural networks. The correlation method compares a set of reference infrared and visible-light spectrum images of the same scene to determine a correlation between red, green and blue channels and an infrared channel. Several correlation functions are used: simple linear correlation between single visible and infrared pixel intensities and linear correlations of pixel grids of various sizes. The correlation functions will be determined using the least square method. The neural network method will use a generative adversarial network (GAN) to generate artificial infrared images based on provided visible spectrum images. The same set of source materials will be used for training as in the correlation method. Two sets of training images are considered: images acquired using an integrated infrared-visible spectrum camera mounted on an unmanned aerial vehicle (UAV) and additionally images from Earth observation satellites (namely the data from the European Copernicus system). Images from the integrated infrared-visible camera will be acquired over relevant scenes - fields, forests, heath - landscapes usually encountered during the prospective flight of the FOK rocket. The paper will conclude with a detailed comparison of the developed methods both in terms of quantitative metrics describing the similarity of artificially generated images and original infrared images, speed of execution and required memory, as well as in terms of subjective perception of the generated images. Examples of generated artificial imagery will be presented based on simulated FOK rocket flights as well as recording from relevant drone flight.