La distribucion hipergeometrica como binomial de poisson

Resumen En este trabajo demostramos que toda distribución hipergeométricaH(N, X,n) puede ser descrita como suma de pruebas independientes con probabilidades de éxito distintas entre sí. Tal distribución recibe habitualmente el nombre de binomial de Poisson o binomial generalizada.      

An approximate method for solving gas-solid non-catalytic reactions

A simple treatment for obtaining the solution of single isothermal gas-solid non-catalytic reactions is presented. The model is formulated under a local volumetric approach and permits to incorporate non-linear chemical kinetics and the change in porous structure during conversion. The methodology developed in this work is based on the quantize method for decoupling the solid and gas equations and on perturbation and matching techniques for approximating the gas conservation equation. With this strategy, the calculation of gas concentration and solid conversion at any time and position are reduced to the solution of two coupled algebraic equations. The model compares favourably with the exact (numerical) solution for a variety of cases. This procedure provides an effective and general tool for obtaining the solution of gas-solid reactions with minor calculations.     

Multimodal Interface Technologies for UAV Ground Control Stations

This paper examines different technologies that can be applied in the design and development of a ground control station for Unmanned Aerial Vehicles (UAVs) equipped with multimodal interfaces. Multimodal technologies employ multiple sensory channels/modalities for information transmission as well as for system control. Examples of these technologies could be haptic feedback, head tracking, auditory information (3D audio), voice control, tactile displays, etc. The applicability and benefits of those technologies is analyzed for a task consisting in the acknowledgement of alerts in an UAV ground control station composed by three screens and managed by a single operator. For this purpose, several experiments were conducted with a group of individuals using different combinations of modal conditions (visual, aural and tactile).     

Unmanned Aerial Vehicle Localization Based on Monocular Vision and Online Mosaicking

This paper presents a new approach for vision-based UAV localization, using mosaics as environment representations. Inter-image motions are used to estimate the motion of the UAV. Online mosaicking is applied to reduce the impact of the accumulative errors in UAV position estimation. A new method to build an stochastic mosaic given the image-to-image homographies is detailed. The mosaic consists of a network of inter-image relations, and is used to create a consistent view of the environment of the UAV and hence, to detect the drift in position estimation by using the mosaic as a resource. The technique could be called simultaneous localization and mosaicking. This technique is specially suitable for monitoring and surveillance tasks in which the UAV will repeatedly cover the same area. The paper also shows experimental results with real UAVs where the benefits of the proposed method are evident.     

UAVs Integration in the SWIM Based Architecture for ATM

The System Wide Information Management (SWIM) approach has been conceived to overcome the capacity and flexibility limitations of the current ATM systems. On the other hand the commercial applications of Unmanned Aerial Vehicles (UAVs) require the integration of these vehicles in the ATM. From this perspective, the unavoidable modernization of the ATM is seen as an opportunity to integrate the UAVs with the rest of the air traffic. This paper is devoted to study the feasibility and impact of the aggregation of UAVs on the future ATM supported by a SWIM inspired architecture. Departing from the existing technical documents that describe the fundamentals of SWIM we have explored the compatibility with a potential UAVs integration and also explored how the UAVs could help to improve the future ATM system. We will use the weather application as an example in both cases.     

Noninvasive sizing of subcellular organelles with light scattering spectroscopy

A long-standing impediment for applications of optical techniques in cellular biology is the inability to characterize subcellular structures whose dimensions are much less than about 1 /spl mu/m. In this paper, we describe a method based on light scattering spectroscopy that can find the size distribution of subcellular organelles as small as 100 nm with an accuracy of 20 nm. We report experiments using aqueous suspensions of subcellular organelles enriched in mitochondria, zymogen granules, and microsomes. From the observed light scattering spectra, we extract size distributions that are in excellent agreement with the results of electron microscopy. Further studies are underway to extract the shapes of organelles in addition to their sizes.     

Gangliosides in Podocyte Biology and Disease

Gangliosides constitute a subgroup of glycosphingolipids characterized by the presence of sialic acid residues in their structure. As constituents of cellular membranes, in particular of raft microdomains, they exert multiple functions, some of them capital in cell homeostasis. Their presence in cells is tightly regulated by a balanced expression and function of the enzymes responsible for their biosynthesis, ganglioside synthases, and their degradation, glycosidases. The dysregulation of their abundance results in rare and common diseases. In this review, we make a point on the relevance of gangliosides and some of their metabolic precursors, such as ceramides, in the function of podocytes, the main cellular component of the glomerular filtration barrier, as well as their implications in podocytopathies. The results presented in this review suggest the pertinence of clinical lipidomic studies targeting these metabolites.     

The autonomous mobile robot AURORA for greenhouse operation

AURORA has been conceived in order to substitute hard and unhealthy human work inside greenhouses by means of an autonomous mobile robot outfitted with appropriate sensors and operation devices. Emphasis has been put in the development of a new robotic platform specifically designed for greenhouse tasks, governed by a control architecture that supports both autonomous navigation and shared human control     

Cooperation Between UAS and Wireless Sensor Networks for Efficient Data Collection in Large Environments

This paper describes a method for collection of data from Wireless Sensor Network (WSN) deployed in large environments using Unmanned Aerial Systems (UAS). Unlike existing approaches, in which the WSN and the UAS act as independent units, the main novelty of the proposed method is that UAS and WSN cooperate to increase the performance of the mission. The proposed method presents two main cooperative behaviors: (1) the results of the WSN operation are used to update the UAS flight plan and; (2) the UAS trajectory is considered in the operation of the WSN in order to improve the data collection performance. The proposed method outperforms non-cooperative UAS-based collection approaches and traditional ground multi-hop collection schemes. The method has been experimented in the airfield of Bellavista in Seville (Spain) in March 2011.     

A Ground Control Station for a Multi-UAV Surveillance System

This paper presents the ground control station developed for a platform composed by multiple unmanned aerial vehicles for surveillance missions. The software application is fully based on open source libraries and it has been designed as a robust and decentralized system. It allows the operator to dynamically allocate different tasks to the UAVs and to show their operational information in a 3D realistic environment in real time. The ground control station has been designed to assist the operator in the challenging task of managing a system with multiple UAVs, trying to reduce his workload. The multi-UAV surveillance system has been demonstrated in field experiments using two quadrotors equipped with visual cameras.