Decentralized Target Tracking based on Multi-Robot Cooperative Triangulation

Target tracking with bearing-only sensors is a challenging problem when the target moves dynamically in complex scenarios. Besides the partial observability of such sensors, they have limited field of views, occlusions can occur, etc. In those cases, cooperative approaches with multiple tracking robots are interesting, but the different sources of uncertain information need to be considered appropriately in order to achieve better estimates. Even though there exist probabilistic filters that can estimate the position of a target dealing with incertainties, bearing-only measurements bring usually additional problems with initialization and data association. In this paper, we propose a multi-robot triangulation method with a dynamic baseline that can triangulate bearing-only measurements in a probabilistic manner to produce 3D observations. This method is combined with a decentralized stochastic filter and used to tackle those initialization and data association issues. The approach is validated with simulations and field experiments where a team of aerial and ground robots with cameras track a dynamic target.

Formation Control Driven by Cooperative Object Tracking

In this paper we introduce a formation control loop that maximizes the performance of the cooperative perception of a tracked target by a team of mobile robots, while maintaining the team in formation, with a dynamically adjustable geometry which is a function of the quality of the target perception by the team. In the formation control loop, the controller module is a distributed non-linear model predictive controller and the estimator module fuses local estimates of the target state, obtained by a particle filter at each robot. The two modules and their integration are described in detail, including a real-time database associated to a wireless communication protocol that facilitates the exchange of state data while reducing collisions among team members. Simulation and real robot results for indoor and outdoor teams of different robots are presented. The results highlight how our method successfully enables a team of homogeneous robots to minimize the total uncertainty of the tracked target cooperative estimate while complying with performance criteria such as keeping a pre-set distance between the teammates and the target, avoiding collisions with teammates and/or surrounding obstacles.

New perspectives on the history of brazilian agriculture.

One of the objectives of this book has been to highlight the importance of the history of agriculture in today's food production and consumption patterns, recovering parts of this history which are not easily found or which have been forgotten or neglected, but which have had a large impact on what we are today.

Revised definitions of invasive fungal disease from the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) Consensus Group.

BACKGROUND: Invasive fungal diseases are important causes of morbidity and mortality. Clarity and uniformity in defining these infections are important factors in improving the quality of clinical studies. A standard set of definitions strengthens the consistency and reproducibility of such studies. METHODS: After the introduction of the original European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) Consensus Group definitions, advances in diagnostic technology and the recognition of areas in need of improvement led to a revision of this document. The revision process started with a meeting of participants in 2003, to decide on the process and to draft the proposal. This was followed by several rounds of consultation until a final draft was approved in 2005. This was made available for 6 months to allow public comment, and then the manuscript was prepared and approved. RESULTS: The revised definitions retain the original classifications of "proven," "probable," and "possible" invasive fungal disease, but the definition of "probable" has been expanded, whereas the scope of the category "possible" has been diminished. The category of proven invasive fungal disease can apply to any patient, regardless of whether the patient is immunocompromised, whereas the probable and possible categories are proposed for immunocompromised patients only. CONCLUSIONS: These revised definitions of invasive fungal disease are intended to advance clinical and epidemiological research and may serve as a useful model for defining other infections in high-risk patients.

Statistique agricole annuelle / Ministère de l'agriculture, Direction de l'agriculture, Bureau des subsistances, des secours et de la statistique agricole

1889.

Statistique agricole annuelle / Ministère de l'agriculture, Direction de l'agriculture, Bureau des subsistances, des secours et de la statistique agricole

1886.

Statistique agricole annuelle / Ministère de l'agriculture, Direction de l'agriculture, Bureau des subsistances, des secours et de la statistique agricole

1906.

Statistique agricole annuelle / Ministère de l'agriculture, Direction de l'agriculture, Bureau des subsistances, des secours et de la statistique agricole

1887.

Statistique agricole annuelle / Ministère de l'agriculture, Direction de l'agriculture, Bureau des subsistances, des secours et de la statistique agricole

1888.

Statistique agricole annuelle / Ministère de l'agriculture, Direction de l'agriculture, Bureau des subsistances, des secours et de la statistique agricole

1891.

Statistique agricole annuelle / Ministère de l'agriculture, Direction de l'agriculture, Bureau des subsistances, des secours et de la statistique agricole

1885.

Berlin, la Wilhelmstrasse [ministère de l'agriculture de 1919 à 1945] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 58522

Mémoires de la Société des lettres, des sciences, des arts, de l'agriculture et de l'industrie de Saint-Dizier

1907 (T11)-1908.