See-and-avoid quadcopter using fuzzy control optimized by cross-entropy

In this work we present an optimized fuzzy visual servoing system for obstacle avoidance using an unmanned aerial vehicle. The cross-entropy theory is used to optimise the gains of our controllers. The optimization process was made using the ROS-Gazebo 3D simulation with purposeful extensions developed for our experiments. Visual servoing is achieved through an image processing front-end that uses the Camshift algorithm to detect and track objects in the scene. Experimental flight trials using a small quadrotor were performed to validate the parameters estimated from simulation. The integration of cross- entropy methods is a straightforward way to estimate optimal gains achieving excellent results when tested in real flights

Rendimiento deportivo, estilos de liderazgo y evitación experiencial en jóvenes futbolistas almerienses

Suplemento de artículos seleccionados con revisión del Congreso Andaluz de Psicología de la Actividad Física y el Deporte (13 : 2011 : Sevilla). Editores : José Carlos Caracuel ; Rocío Bohórquez.Multiple studies have shown the effectiveness of Acceptance and Commitment Therapy (ACT) in enhancing sport performance (SP) -canoeing, tennis, handball, chess, etc.- since experimental avoidance (EA) plays an important role therein. This study addresses the relationship between EA and the psychological variables linked to SP in young footballers (Club Deportivo Vera) and between EA and leadership coaching. This study is justified by the possibility of improving SP by ACT protocols aimed at the acceptance of private events and bodily states and focuses on their behaviour in implementing their values. The instruments used were the Acceptance and Action Questionnaire II (AAQ-II) -which measures the degree of EA- the Psychological Characteristics Related to Sport Performance Questionnaire (CPRD) and the Sport Leadership Scale (LSS). The results show that the relationships (-.457) were statistically significant (p < .01) for EA and the psychological characteristics associated with SP. Likewise, the players' preference for autocratic leadership behaviour negatively correlated to these variables. On the basis of these result, we propose implementing ACT protocols to enhance players' SP

Pyothorax in a cat managed by intrathoracic debridement and postoperative ventilatory support

<p/> <p>A domestic-longhair cat presented due to lethargy, dyspnoea and hypersalivation. Radiographic examination revealed a bilateral pleural effusion, which was diagnosed as pyothorax based on cytological examination. Ultrasonographic examination revealed extensive loculations within the thoracic cavity. Exploratory sternotomy, under general anaesthesia, allowed the removal of approximately 100 ml of purulent fluid and debridement of a partially walled-off abscess and necrotic material from the pleural cavity. Postoperative positive-pressure ventilation was required due to severe respiratory depression. Intensive postoperative care, including intensive continuous monitoring, thoracostomy tube drainage and lavage of the pleural cavity and oesophagostomy tube feeding, was performed. Complete resolution of clinical signs had occurred by 15 days postoperatively. Clinical or radiographic abnormalities were not detected at a follow-up examination one year after surgery.</p

Conformational Stability of Hepatitis C Virus NS3 Protease

AbstractThe hepatitis C virus NS3 protease is responsible for the processing of the nonstructural region of viral precursor polyprotein in infected hepatic cells. NS3 has been considered a target for drug discovery for a long time. NS3 is a zinc-dependent serine protease. However, the zinc ion is not involved in the catalytic mechanism, because it is bound far away from the active site. Thus, zinc is essential for the structural integrity of the protein and it is considered to have a structural role. The first thermodynamic study on the conformational equilibrium and stability of NS3 and the effect of zinc on such equilibrium is presented here. In agreement with a previous calorimetric study on the binding of zinc to NS3, the global unfolding heat capacity is dominated by the zinc dissociation step, suggesting that the binding of zinc induces a significant structural rearrangement of the protein. In addition, contrary to other homologous zinc-dependent proteases, the zinc-free NS3 protease is not completely unstructured. It is apparent that the conformational landscape of hepatitis C virus NS3 protease is fairly complex due to its intrinsic plasticity, and to the interactions with its different effectors (zinc and the accessory viral protein NS4A) and their modulation of the population of the different conformational states

Pre-composting of municipal solid wastes as enhancer of bio-hydrogen production through dark fermentation process

This study was focused on bio-hydrogen production from thermophilic dry anaerobic acidogenic co-digestion (55 °C and 20 % of total solids) of pre-composted mixtures of organic fraction of municipal solid waste (OFMSW) and food waste (FW). Three different mixture ratios of OFMSW:FW (80:20, 70:30 and 50:50) have been tested. The application of pre-composting improved the hydrolytic and acidogenic phases in the subsequent acidogenic co-digestion, reaching an increase in the bio-hydrogen production in the range of 45.4–46.7 %. In this sense, the best results were obtained for the pretreated mixture with the ratio 70:30, with 42.9 LH2/kg VSadded and 53.9 % of H2 in the biogas. Finally, the kinetic study has corroborated that pre-composting clearly enhances the kinetics of acidogenic fermentation of OFMSW and FW mixtures. In fact, the μmax and YP values for the pretreated mixtures have been increased by a 20 % and 33 % respectively

Computer Vision Based General Object Following for GPS-denied Multirotor Unmanned Vehicles

The motivation of this research is to show that visual based object tracking and following is reliable using a cheap GPS-denied multirotor platform such as the AR Drone 2.0. Our architecture allows the user to specify an object in the image that the robot has to follow from an approximate constant distance. At the current stage of our development, in the event of image tracking loss the system starts to hover and waits for the image tracking recovery or second detection, which requires the usage of odometry measurements for self stabilization. During the following task, our software utilizes the forward-facing camera images and part of the IMU data to calculate the references for the four on-board low-level control loops. To obtain a stronger wind disturbance rejection and an improved navigation performance, a yaw heading reference based on the IMU data is internally kept and updated by our control algorithm. We validate the architecture using an AR Drone 2.0 and the OpenTLD tracker in outdoor suburban areas. The experimental tests have shown robustness against wind perturbations, target occlusion and illumination changes, and the system's capability to track a great variety of objects present on suburban areas, for instance: walking or running people, windows, AC machines, static and moving cars and plants

New criteria to determine the destabilization of the acidogenic anaerobic co-digestion of organic fraction of municipal solid waste (OFMSW) with mixed sludge (MS)

Effect of hydraulic retention time (HRT) on bio-hydrogen production from co-digestion of organic fraction of municipal solid waste (OFMSW) and mixed sludge (MS) in dry thermophilic conditions (55 °C and 20% total solids) was investigated. A decreasing sequence of six HRTs, from 2.9 to 0.8-days, was performed to evaluate the stability of the system and the influence of HRT on the organic matter solubilization, the daily hydrogen production (HP) and the specific hydrogen production (SHP). Best results were obtained operating at 1.2-days HRT: HP of 3.67 L H2/Lreactor/day, SHP of 33.8 mL H2/gVSadded and hydrogen percentage in biogas of 52.4%. However, HRTs lower than 1.2-days induce failure in the system due to an unbalance of the hydrolytic phase. This fact was corroborated through the evaluation of two indirect parameters, “non-solubilized carbon” (NSC) and “acidogenic substrate as carbon” (ASC), and the relationships of NSC/TOC and ASC/TOC

Evolución histórica de los vehículos aéreos no tripulados hasta la actualidad

The origin and development of unmanned aviation has been almost matched that of manned aviation, starting both from an almost common point. As in conventional manned aviation, military applications, have been the motor of technological development and the potential applications of these types of systems throughout much of the twentieth century and early twenty-first century. Finally it has been in relatively recent times that these systems are experiencing an impressive boom due to the discovery of the wide variety of commercial and civil operations that are able to perform very effectively. This paper attempts to summarize the historical evolution that these systems have suffered and in the end, to present a quick analysis of the major civil / commercial applications, trying to provide an overview of the main types of systems, their classification and general configuration.Peer Reviewe

Toward Visual Autonomous Ship Board Landing of a VTOL UAV

In this paper we tackle the problem of landing a helicopter autonomously on a ship deck, using as the main sensor, an on-board colour camera. To create a test-bed, we first adequately simulate the movement of a ship landing platform on the Sea, for different Sea States, for different ships, randomly and realistically enough. We use a commercial parallel robot to get this movement. Once we had this, we developed an accurate and robust computer vision system to measure the pose of the helipad with respect to the on-board camera. To deal with the noise and the possible fails of the computer vision, a state estimator was created. With all of this, we are now able to develop and test a controller that closes the loop and finish the autonomous landing task

Ubiquitous Sensor Networks in IMS: an Ambient Intelligence Telco Platform

Ubiquitous Sensor Network (USN) concept describes the integration of heterogeneous and geographically dispersed Wireless Sensor and Actuator Networks (WS&AN) into rich information infrastructures for accurate representation and access to different dynamic user’s physical contexts. This relatively new concept envisions future Sensor-Based Services leading to market disruptive innovations in a broad range of application domains, mainly personal (lifestyle assistants), community (professional users) and industrial domains. The support for this broad range of innovative Ambient Intelligence services urgently demands a standardized access to different WS&AN, and Telco Operators have an opportunity to lead this technological challenge as they evolve towards future Next-Generation Networks. Telefónica Research and Development is a leading innovation company that provides communication services for businesses and consumers. Networks and Service Platforms is a major Telefónica I+D innovation area where new Service Architectures and Platforms concepts are essential for the development of services with a high differentiation value. This contribution describes Telefónica I+D activities directed to the design of an Ambient Intelligence Platform integrating USN concepts over NGN architectures. In our view IP Multimedia Subsystem (IMS) concepts can enable and promote a first generation of Sensor-Based Services where multimedia interactive sessions are enriched with contextual information from WS&ANs. To this end three major design criteria are addressed at three different levels. At the application layer, OMA Service Environment and OGC Sensor Web Enablement are combined to define a specific USN Service Enabler. At the communication, management and control level WS&AN Gateways are defined for integrating WS&ANs infrastructures into all-IP IMS environments. While at the lower level, data and meta-data exchanges with different WS&ANs entities are homogeneously represented using OGC® SensorML standard. Finally this paper concludes by discussing some preliminary business opportunities we foresee for the proposed Platform