Comparative assessment of the vulnerability and resilience of 10 deltas : work document

Background information about: Nile delta (Egypt), Incomati delta (Mozambique), Ganges-Brahmaputra-Meghna (Bangladesh), Yangtze (China), Ciliwung (Indonesia), Mekong (Vietnam), Rhine-Meuse (The Netherlands), Danube (Romania), California Bay-Delta, Mississippi River Delta (USA

Multiangle observations of Arctic clouds from FIRE ACE: June 3, 1998, case study

In May and June 1998 the Airborne Multiangle Imaging Spectroradiometer (AirMISR) participated in the FIRE Arctic Cloud Experiment (ACE). AirMISR is an airborne instrument for obtaining multiangle imagery similar to that of the satellite-borne MISR instrument. This paper presents a detailed analysis of the data collected on June 3, 1998. In particular, AirMISR radiance measurements are compared with measurements made by two other instruments, the Cloud Absorption Radiometer (CAR) and the MODIS airborne simulator (MAS), as well as to plane-parallel radiative transfer simulations. It is found that the AirMISR radiance measurements and albedo estimates compare favorably both with the other instruments and with the radiative transfer simulations. In addition to radiance and albedo, the multiangle AirMISR data can be used to obtain estimates of cloud top height using stereoimaging techniques. Comparison of AirMISR retrieved cloud top height (using the complete MISR-based stereoimaging approach) shows excellent agreement with the measurements from the airborne Cloud Lidar System (CLS) and ground-based millimeterwave cloud radar

Intuitive human interactive with an arm robot for severely handicapped people - A one click approach.

International audienceAssistance to disabled people is still a domain in which a lot of progress needs to be done. The more severe the handicap is, more complex are the devices, implying increased efforts to simplify the interactions between man and these devices. In this document we propose a solution to reduce the interaction between a user and a robotic arm. The system is equipped with two cameras. One is fixed on the top of the wheelchair (eye-to-hand) and the other one is mounted on the end effector of the robotic arm (eye-in-hand). The two cameras cooperate to reduce the grasping task to one click. The method is generic, it does not require marks on the object, geometrical model or the database. It thus provides a tool applicable to any kind of graspable object. The paper first gives an overview of the existing grasping tools for disabled people and proposes a novel approach toward an intuitive human machine interaction

Intracerebral Implantation of Ionic Synthetic Hydrogels: Effect of Polar Substrata on Astrocytosis and Axons

In previous studies, hyperporous synthetic hydrogels of poly(glyceryl methacrylate) or p(GMA), containing bioadhesive substrates of collagen, were implanted into rat cerebral tissue in order to provide systems of oriented guidance channels for directing the growth of the scar and axons /28/. In the present study, ionic p(GMA)- collagen hydrogels containing polar chemical groups, either basic amino groups or acidic carboxyl groups, were evaluated for their tolerance and their effects on the brain scarring response and axonal reactivity after long-term implantation in the cerebral cortex. In all animals, the implants were well tolerated. Although both types of gels influenced the astroglial reaction near the bioimplant, hydrogels carrying carboxyl groups had the strongest influence on the elongation, the direction and the organization of astrocytic processes so that a glial matrix could form in regions of the gel. Extracellular material (e.g. reticulin) was also deposited into the gels carrying carboxyl groups. Although cortical nerve fibers .in the surrounding tissue showed a regenerative response, extending onto or into the matrices, this behavior seemed to depend more on the organization of the .astrocytic scar imposed by the gel than on the type of gel. We conclude that matrices carrying negatively charged groups influence favorably the astrocytosis and the deposition of connective tissue, and that this approach represents a new avenue in attempting to modulate the brain scar formation

Not all digital word of mouth is created equal: Understanding the respective impact of consumer reviews and microblogs on new product success

The expansion of the Internet and social media have triggered a differentiation of the word-of-mouth (WOM) concept, with consumer communication about brands and products now taking place in various settings and forms. Two important digital WOM types are microblogs and consumer reviews. To clarify their differential roles for product success, this study offers a theoretical framework of the influence of these two types of WOM, drawing from consumer information search theory and diffusion theory. The tests of the proposed framework use a longitudinal data set of video game sales and weekly information gathered from microblogs (i.e., over 13 million tweets from Twitter) and consumer reviews (i.e., more than 17,000 Amazon consumer reviews). Analyzing a system of equations provides evidence that the influence of microblogs and consumer reviews on new product success changes over time. Prior to launch, the volumes of microblogs and consumer reviews, together with advertising, represent primary sales drivers. After launch, the volume of microblogs is initially influential, then loses impact, whereas the impact of the volume of consumer reviews continues to grow. The valence of consumer reviews gains significance only near the end of the observation period, but the valence of microblogging is never influential

Active rough shape estimation of unknown objects

International audienceThis paper presents a method to determine the rough shape of an object. This is a step in the development of a One Click Grasping Tool, a grasping tool of everyday-life objects for an assistant robot dedicated to elderly or disabled. The goal is to determine the quadric that approximates at best the shape of an unknown object using multi-view measurements. Non-linear optimization techniques are considered to achieve this goal. Since multiple views are necessary, an active vision process is considered in order to minimize the uncertainty on the estimated parameters and determine the next best view. Finally, results that show the validity of the approach are presented

Vision-based grasping of unknown objects to improve disabled people autonomy.

International audienceThis paper presents our contribution to vision based robotic assistance for people with disabilities. The rehabilitative robotic arms currently available on the market are directly controlled by adaptive devices, which lead to increasing strain on the user's disability. To reduce the need for user's actions, we propose here several vision-based solutions to automatize the grasping of unknown objects. Neither appearance data bases nor object models are considered. All the needed information is computed on line. This paper focuses on the positioning of the camera and the gripper approach. For each of those two steps, two alternative solutions are provided. All the methods have been tested and validated on robotics cells. Some have already been integrated into our mobile robot SAM

Formations Near the Libration Points: Design Strategies Using Natural and Non-Natural Arcs

Space based observatory and interferometry missions, such as Terrestrial Planet Finder (TPF), Stellar Imager, and MAXIM, have sparked great interest in multi-spacecraft formation flight in the vicinity of the Sun-Earth/Moon (SEM) libration points. The initial phase of this research considered the formation keeping problem from the perspective of continuous control as applied to non-natural formations. In the present study, closer inspection of the flow, corresponding to the stable and center manifolds near the reference orbit, reveals some interesting natural relative motions as well as some discrete control strategies for deployment. A hybrid control strategy is also employed that combines both the natural formation dynamics with non-natural motions via input feedback linearization techniques