Dardanelles et Bosphore : Les détroits turcs aujourd’hui

Les Dardanelles et le Bosphore sont les «Détroits» par excellence. Couloirs maritimes étroits et sinueux situés de part et d’autre de la mer de Marmara, ils relient la mer Noire au bassin méditerranéen et ont constamment été, à ce titre, l’objet de conflits et de rivalités au cours de l’histoire. La période la plus récente y a vu une forte augmentation du trafic maritime, source de dangers et de risques écologiques qui ont poussé à la dissémination des installations portuaires stambouliotes. Les Dardanelles rurales contrastent en effet avec le Bosphore, axe médian d’une métropole de dix millions d’habitants, confronté à une urbanisation désordonnée et traversé par une circulation intra-urbaine intense. Ces détroits contribuent à l’orientation d’Istanbul vers le domaine pontique, aujourd’hui remise en question par une volonté d’ouverture de la Turquie vers la Méditerranée en tant que lien à l’Europe.Dardanelles and Bosphorus are probably the most emblematic straits in the world. These two narrow and winding waterways, together with the Sea of Marmora lying between them, link the Black Sea with the Mediterranean Basin, which have witnessed numerous conflicts throughout history. In recent years, they have experienced a sharp increase in maritime traffic, which is a threat to waterside residents and the natural environment. This has led to a gradual dispersion of Istanbul’s harbour plants and facilities. The rural environment of Dardanelles is in sharp contrast to the very densely urbanized Bosphorus, the hub of a metropolis with 10 million people, confronted with a chaotic urbanization process and intense intra-urban traffic. The Turkish Straits contribute to Istanbul’s vantage point in the region of the Black Sea, which is today challenged by Turkey’s new commitment to openness to the Mediterranean Basin as a venue for increasing trade with the European Union

Partial Sum Minimization of Singular Values in Robust PCA: Algorithm and Applications

Robust Principal Component Analysis (RPCA) via rank minimization is a powerful tool for recovering underlying low-rank structure of clean data corrupted with sparse noise/outliers. In many low-level vision problems, not only it is known that the underlying structure of clean data is low-rank, but the exact rank of clean data is also known. Yet, when applying conventional rank minimization for those problems, the objective function is formulated in a way that does not fully utilize a priori target rank information about the problems. This observation motivates us to investigate whether there is a better alternative solution when using rank minimization. In this paper, instead of minimizing the nuclear norm, we propose to minimize the partial sum of singular values, which implicitly encourages the target rank constraint. Our experimental analyses show that, when the number of samples is deficient, our approach leads to a higher success rate than conventional rank minimization, while the solutions obtained by the two approaches are almost identical when the number of samples is more than sufficient. We apply our approach to various low-level vision problems, e.g. high dynamic range imaging, motion edge detection, photometric stereo, image alignment and recovery, and show that our results outperform those obtained by the conventional nuclear norm rank minimization method.Comment: Accepted in Transactions on Pattern Analysis and Machine Intelligence (TPAMI). To appea

Questions de sens

Les comportements humains ayant un sens, il faudrait pour en rendre compte procéder à une opération d’interprétation, seul moyen de restituer (de « comprendre ») ce sens que l’« Autre » donne à ce qu’il fait. C’est un vieux philosophème toujours à l’œuvre en anthropologie, dans la mesure où elle se définit encore comme une « science des cultures ». En fait nous n’observons pas des comportements dont il faudrait en plus chercher le sens, nous sommes témoins d’actions dont éventuellement (en particulier lorsque nous nous déplaçons dans des situations non familières) nous ne savons pas donner une description correcte, auquel cas il nous faut apprendre à les décrire. Mais les actions ne sont pas des messages (ou des « textes ») que nous aurions à interpréter.Since human behaviours have meaning, an operation of interpretation would be required to understand them. This would be the only means of reestablishing (understanding) the meaning the “other” gives to that which he does. This old philosopheme is still operative in anthropology, to the extent that the discipline defines itself as a “science of cultures”. In fact we do not observe behaviours whose meaning we would further need to search for. We are witnesses of actions we finally do not know how to describe accurately (particularly when we move about in nonfamiliar situations). In that case we must learn to describe them. But actions are not messages (or texts) which we would have to interpret

Fast Central Catadioptric Line Extraction

International audienceLines are particularly important features for different tasks such as calibration, structure from motion, 3D reconstruction in computer vision. However, line detection in catadioptric images is not trivial because the projection of a 3D line is a conic eventually degenerated. If the sensor is calibrated, it has been already demonstrated that each conic can be described by two parameters. In this way, some methods based on the adaptation of conventional line detection methods have been proposed. However, most of these methods suffer from the same disadvantages than in the perspective case (computing time, accuracy, robustness, ...). In this paper, we then propose a new method for line detection in central catadioptric image comparable to the polygonal approximation approach. With this method, only two points of a chain allows to extract with a very high accuracy a catadioptric line. Moreover , this algorithm is particularly fast and is applicable in realtime. We also present experimental results with some quantitative and qualitative evaluations in order to show the quality of the results and the perspectives of this method

Le roi sans visage

Ce texte de Jean Bazin se situe au croisement de ses premiers travaux sur l’Afrique occidentale et de leurs développements plus récents sur le savoir anthropologique. Lorsqu’il entreprit ses enquêtes dans les années 1960-1970, la question de la royauté occupa une place centrale dans sa réflexion. C’est à partir d’un cas qu’il l’aborda, celui de Segu, une ville située sur le cours moyen du Niger qui avait été, à partir du début du xviiie siècle, la capitale d’un très puissant royaume. Pour Jea..

Logiques du politique

Jean Bazin, directeur d’études Explication anthropologique et explication historique (avec Alban Bensa, directeur d’études) Dans ce séminaire nous avons entrepris depuis plusieurs années de soumettre à une investigation critique le savoir ethnologique, l’envisageant à la fois dans son appareil théorique - les grandes notions (en particulier celle de culture) et les catégories par lesquelles il constitue et organise son objet - et dans ses conditions pratiques et ses manières de faire (comment..

Proteome data to explore the impact of pBClin15 on Bacillus cereus ATCC 14579

AbstractThis data article reports changes in the cellular and exoproteome of B. cereus cured from pBClin15.Time-course changes of proteins were assessed by high-throughput nanoLC-MS/MS. We report all the peptides and proteins identified and quantified in B. cereus with and without pBClin15. Proteins were classified into functional groups using the information available in the KEGG classification and we reported their abundance in term of normalized spectral abundance factor. The repertoire of experimentally confirmed proteins of B. cereus presented here is the largest ever reported, and provides new insights into the interplay between pBClin15 and its host B. cereus ATCC 14579. The data reported here is related to a published shotgun proteomics analysis regarding the role of pBClin15, “Deciphering the interactions between the Bacillus cereus linear plasmid, pBClin15, and its host by high-throughput comparative proteomics” Madeira et al. [1]. All the associated mass spectrometry data have been deposited in the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org) via the PRIDE partner repository (http://www.ebi.ac.uk/pride/), with the dataset identifier PRIDE: PXD001568, PRIDE: PXD002788 and PRIDE: PXD002789

Dynamic Programming and Skyline Extraction in Catadioptric Infrared Images

International audienceUnmanned Aerial Vehicles (UAV) are the subject of an increasing interest in many applications and a key requirement for autonomous navigation is the attitude/position stabilization of the vehicle. Some previous works have suggested using catadioptric vision, instead of traditional perspective cameras, in order to gather much more information from the environment and therefore improve the robustness of the UAV attitude/position estimation. This paper belongs to a series of recent publications of our research group concerning catadioptric vision for UAVs. Currently, we focus on the extraction of skyline in catadioptric images since it provides important information about the attitude/position of the UAV. For example, the DEM-based methods can match the extracted skyline with a Digital Elevation Map (DEM) by process of registration, which permits to estimate the attitude and the position of the camera. Like any standard cameras, catadioptric systems cannot work in low luminosity situations because they are based on visible light. To overcome this important limitation, in this paper, we propose using a catadioptric infrared camera and extending one of our methods of skyline detection towards catadioptric infrared images. The task of extracting the best skyline in images is usually converted in an energy minimization problem that can be solved by dynamic programming. The major contribution of this paper is the extension of dynamic programming for catadioptric images using an adapted neighborhood and an appropriate scanning direction. Finally, we present some experimental results to demonstrate the validity of our approach