Shape representation and coding of visual objets in multimedia applications — An overview

Emerging multimedia applications have created the need for new functionalities in digital communications. Whereas existing compression standards only deal with the audio-visual scene at a frame level, it is now necessary to handle individual objects separately, thus allowing scalable transmission as well as interactive scene recomposition by the receiver. The future MPEG-4 standard aims at providing compression tools addressing these functionalities. Unlike existing frame-based standards, the corresponding coding schemes need to encode shape information explicitly. This paper reviews existing solutions to the problem of shape representation and coding. Region and contour coding techniques are presented and their performance is discussed, considering coding efficiency and rate-distortion control capability, as well as flexibility to application requirements such as progressive transmission, low-delay coding, and error robustnes

Comment l'infirmier/ère peut-il/elle construire une relation interpersonnelle de qualité avec des personnes vivant un sentiment de dépendance ?: travail de Bachelor

Ce travail a été réalisé par deux étudiantes en soins infirmiers dans le cadre de leur travail de Bachelor. Cette thématique a pour but de relever différentes stratégies utiles à la construction d’une relation interpersonnelle de qualité soignant-soigné et plus particulièrement avec les personnes souffrant d’addictions. Les deux étudiantes ont pour cela recensé plusieurs articles de recherches sur le sujet en les mettant en lien avec la théorie infirmière de la relation interpersonnelle de Hildegard Peplau et la théorie de l’autodétermination de Deci et Ryan, mais également beaucoup d’éléments afin d’étayer leur recherche sur les lois, sur l’historique, et la politique cantonal et fédéral en rapport avec les addictions. Grâce aux différents articles qui décrivent ce que vivent les professionnels sur le terrain et aux appuis théoriques, elles ont pu démontrer que plusieurs éléments se rejoignent aussi bien pour les professionnels sur le terrain que pour les théoriciens. Les résultats relatifs à la question de recherche sont les différentes attitudes infirmières1 et modèles de soins à suivre afin d’avoir une relation de qualité avec les personnes vivant un sentiment de dépendance

Compatible relations on filters and stability of local topological properties under supremum and product

An abstract scheme using particular types of relations on filters leads to general unifying results on stability under supremum and product of local topological properties. We present applications for Frechetness, strong Frechetness, countable tightness and countable fan-tightness, some of which recover or refine classical results, some of which are new. The reader may find other applications as well.Comment: 28 page

Modèle de prévision et de gestion des crues:optimisation des opérations des aménagements hydroélectriques à accumulation pour la réduction des débits de crue

Floods are not only due to fatality. It is the responsibility of the human being to protect himself from heavy damages due to natural elements, and he sometimes has the chance to profit from a given situation to influence events. One of these possibilities is to manage floods by using existing dams and reservoirs, which can be efficiently operated to control the downstream discharges. Moreover, their retention capabilities may be enhanced by preventive gate or turbine operations, based on a flood forecast. The objectives of this research were to develop a new model for flood prediction and management for the Rhone river basin upstream from Lake of Geneva. Also, the underlaying objective was to create an operational discharge prediction and decision making tool, taking advantage of 72 hours ahead of the weather forecast provided by MeteoSwiss. A new hydrological model was developed, as well as another optimization tool for the preventive turbine and gate operations of large hydropower reservoirs. The new hydrological forecasting tool is based on a concept developed by the HYDRAM-EPFL. This concept allows the model to integrate tri-dimensional rainfall, temperature and evapo-transpiration fields and to simulate multiple hydrological processes. Indeed, the model is able to simulate glacier melt, snow pack constitution and melt, soil infiltration and runoff. The altimetric temperature gradient is considered by subdividing each basin into elevation bands, which allows segregating rainfalls and snowfalls. A new software called Routing System II was used and improved for modelling the catchment area. This object-oriented modelling tool permits the integration of flood routing in rivers as well as hydraulic structures such as river water intakes, reservoirs, turbines, gates and regulated systems. All these new products were used to build a flood prediction model, including the 10 major hydropower plants of the Rhone river basin upstream from Lake of Geneva. It has been calibrated and validated over a 60 months' period for an one hour time step continuous simulation. It also integrates all hydroelectricity production data of the existing hydropower plants. Its performance allows to correctly represent all hydrological cycles, as well as the observed floods, whose phases and intensities were perfectly simulated. Moreover, a new procedure for real-time data assimilation was developed in the model, in order to automatically adjust the initial conditions before starting a new hydrological forecast. The new optimization tool uses the hydrological forecast, especially the inflow forecasts in the reservoirs and the hydrographs at the numerous control points in the river network. This tool takes into account the mentioned data in order to provide an operational decision about any necessary preventive turbine or gate operations. It also allows the decision maker to obtain an indication on the cost of the decisions and of the non-decisions, as well as of the cost of an inappropriate decision due to an error in the flood forecast. This algorithm was validated against full simulation and against another optimization evolutionary algorithm called MOO , developed in the LENI-EPFL. It is able to provide a similar efficiency without excessive computation time, and to forward these results automatically into the simulation model for validation. The operational performance of the flood prediction and management model was evaluated by simulation of two major flood events occurred in the Rhone river basin in September 1993 and October 2000, as well as by a first operational use in September 2006. The obtained results indicated, that if the decisions relative to the operations of the 10 considered hydropower plants had been in accordance with the new decision tool, the decision would have been similar to a posteriori optimal solution. The application of the model to the Rhone River catchment area demonstrates the possibility to widely increase the protection effect due to the existing reservoirs. In fact, the observed reduction of the peak flow in the Rhone basin outlet was 12% in 1993 and 10% in 2000. By using the new model, the reduction would have reached 26% in 1993 and 21% in 2000. In this case, important damages could have been avoided near the riverside. This research project offers the possibility to highlight the potential of an increased flood routing into the existing accumulation reservoirs. It leads to a new theoretical optimization model, which can be used at a planification stage to evaluate the optimal flood routing influence of a multireservoir system. Finally, a new flood forecast and management model was developed for the Rhone River catchment area. This tool is in operation and its aim is now to optimize the existing flood protection potential. Thanks to its new performing forecast, data assimilation and optimization tools, the model is user-friendly and can be used in real-time. Although the system is now operational and convincing, it would be more profitable to explore the possibilities of dealing with uncertainty in the whole information path of the system. As a main goal, the system should be capable of providing the decision maker with an optimal decision and its associated objective risks

Experiences in using INCA-CH precipitation nowcasting for Urban Flood Nowcasting

Presentación realizada en la 3rd European Nowcasting Conference, celebrada en la sede central de AEMET en Madrid del 24 al 26 de abril de 2019

Strong water stratification provides a refuge for rainbow smelt larvae Osmerus mordax in a sub-arctic estuary (Lake Melville, Labrador)

Estuaries provide nurseries for early life stages of fish that rely on the interaction between fresh- and saltwater. The 250 km long Lake Melville spans 2100 km2 and is the largest estuary of Labrador (northeastern Canada). This sub-arctic fjard hosts freshwater, anadromous, and marine fishes on which depend marine mammals and seabirds, but also coastal communities. Yet, how different fish species and life stages use the estuary as a habitat, in particular the importance of the low salinity surface layer for the development of fish larvae, remains unknown. By pairing seasonal hydroacoustic surveys conducted in summers 2018–2019 and winters 2019–2020 with net sampling and environmental DNA (eDNA) analyses, we test the hypothesis that the strong water stratification prevailing in upper Lake Melville provides a nursery for early life stages of fish, where they are protected from their predators. Ichthyoplankton aggregated just above and at the pycnocline, in the low salinity surface layer down to 25 m. Most adult pelagic fish occupied the bottom waters below the sharp pycnocline, although some ventured in the low salinity surface layer. Ten species of adult fish were captured in gill and fyke nets and 53 species were detected with eDNA. Larvae of rainbow smelt (Osmerus mordax) were ubiquitous in the surface layer in July and August and represented 100% of the ichthyoplankton assemblage sampled during these months. No fish larvae were detected in winter (February). We conclude that the low salinity surface layer provides a refuge for rainbow smelt larvae, a key forage species in the estuary. This study provides baseline information from which to assess future changes in biodiversity and distribution of fish in the Lake Melville estuary. It further supports the use of eDNA as a complementary tool for monitoring fish diversity in sub-arctic estuaries

Bewirtschaftung alpiner Speicherkraftwerke unter Berücksichtigung klimatischer und wirtschaftlicher Veränderungen

Die Wasserkraft ist mit grossen Herausforderungen konfrontiert. Ein neuartiger integrativer Ansatz erlaubt die Modellierung von komplexen Wasserkraftanlagen zur Beurteilung der Auswirkungen auf deren Betrieb. Das Simulationsprogramme Routing System beinhaltet nebst einem hydrologischen Modell für alpine Einzugsgebiete auch ein Betriebsmodul für Speicherkraftwerke

Scalable transient gene expression in Chinese hamster ovary cells in instrumented and non-instrumented cultivation systems

Cell expansion, gene transfer and protein production were all executed with a single serum-free, animal protein-free commercial medium designed for suspension-adapted Chinese hamster ovary cells (CHO DG44). This is a most important process to consider for clinical production of recombinant proteins. The transfection with polyethylenimine (PEI) was shown here to be scalable using both stirred-tank bioreactors of 3- and 150-l and novel agitated cultivation vessels (50ml ventilated centrifuge tubes and 1-l square-shaped glass bottles) that lack any instrumentation. The transient transfections spanned a range of working volumes from 2ml to 80l. The maximum transient recombinant antibody yield was 22mg/l, the highest ever reported for a multiliter transfection in CHO. The transiently expressed protein had the same extent of glycosylation as the same antibody produced from a stably transfected recombinant CHO cell lin