957 resultados para AIRCRAFT SEAT


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The objective of the present study is to propose a method to dynamically evaluate discomfort of a passenger seat by measuring the interface pressure between the occupant and the seat during the performance of the most common activities of a typical flight(1). This article reports the results of resting and reading studies performed in a simulator that represents the interior of a commercial aircraft.

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Mode of access: Internet.

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This paper proposes a mixed validation approach based on coloured Petri nets and 3D graphic simulation for the design of supervisory systems in manufacturing cells with multiple robots. The coloured Petri net is used to model the cell behaviour at a high level of abstraction. It models the activities of each cell component and its coordination by a supervisory system. The graphical simulation is used to analyse and validate the cell behaviour in a 3D environment, allowing the detection of collisions and the calculation of process times. The motivation for this work comes from the aeronautic industry. The automation of a fuselage assembly process requires the integration of robots with other cell components such as metrological or vision systems. In this cell, the robot trajectories are defined by the supervisory system and results from the coordination of the cell components. The paper presents the application of the approach for an aircraft assembly cell under integration in Brazil. This case study shows the feasibility of the approach and supports the discussion of its main advantages and limits. (C) 2011 Elsevier Ltd. All rights reserved.

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Social surveys have established dose-response relationships between aircraft noise and annoyance, with a number of psychological symptoms being positively related to annoyance. Evidence that exposure to aircraft noise is associated with higher psychiatric hospital admission rates is mixed. Some evidence exists of an association between aircraft noise exposure and use of psychotropic medications. People with a pre-existing psychological or psychiatric condition may be more susceptible to the effects of exposure to aircraft noise. Aircraft noise can produce effects on electroencephalogram sleep patterns and cause wakefulness and difficulty in sleeping. Attendances at general practitioners, self-reported health problems and use of medications, have been associated with exposure to aircraft noise, but some findings are inconsistent. Some association between aircraft noise exposure and elevated mean blood pressure has been observed in cross-sectional studies of schoolchildren, but with little confirmation from cohort studies. There is no convincing evidence to suggest that all-cause or cause-specific mortality is increased by exposure to aircraft noise. There is no strong evidence that aircraft noise has significant perinatal effects. Using the World Health Organization definition of health, which includes positive mental and social wellbeing, aircraft noise is responsible for considerable ill-health. However, population-based studies have not found strong evidence that people living near or under aircraft flight paths suffer higher rates of clinical morbidity or mortality as a consequence of exposure to aircraft noise. A dearth of high quality studies in this area precludes drawing substantive conclusions.

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Aerodynamic drag is known to be one of the factors contributing more to increased aircraft fuel consumption. The primary source of skin friction drag during flight is the boundary layer separation. This is the layer of air moving smoothly in the immediate vicinity of the aircraft. In this paper we discuss a cyber-physical system approach able of performing an efficient suppression of the turbulent flow by using a dense sensing deployment to detect the low pressure region and a similarly dense deployment of actuators to manage the turbulent flow. With this concept, only the actuators in the vicinity of a separation layer are activated, minimizing power consumption and also the induced drag.

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Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Estatística e Gestão de Informação.

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Currently, China has the biggest automobile industry in the world. China’s economic situation helped the automobile market, as the internal demand of passenger cars increased substantially in the last years. Chinese automobile industry’s astonishing expansion over the past years has attracted many foreign automobile groups. SEAT decided to enter the Chinese market, following its expansion strategy to enter new markets. The purpose of this study is to analyse and understand the strategic entry of SEAT in the Chinese market, hence the choice of an explanatory case study (Yin, 2003). This study extends this analysis by examining the chines automobile market, more specifically the demand, the market segmentation and the intensity of competition, reviewing the SEAT company history, their competitive positioning and resources. I conclude that, although the Chinese market has growing potential, SEAT has failed to achieve its initial objective. The company has not been able to create a brand awareness in the Chinese market, unlike other foreign brands that have managed to accomplish that. This occurred, mostly, because of the high prices in comparison to its competitors due to additional import cost, such as import duties, transportation and distribution.

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The growing need to patrol and survey large maritime and terrestrial areas increased the need to integrate external sensors on aircraft in order to accomplish those patrols at increasingly higher altitudes, longer range and not depending upon vehicle type. The main focus of this work is to elaborate a practical, simple, effective and efficient methodology for the aircraft modification procedure resulting from the integration of an Elec-tro-Optical/Infra-Red (EO/IR) turret through a support structure. The importance of the devel-opment of a good methodology relies on the correct management of project variables as time, available resources and project complexity. The key is to deliver a proper tool for a project de-sign team that will be used to create a solution that fulfils all technical, non-technical and certi-fication requirements present in this field of transportation. The created methodology is inde-pendent of two main inputs: sensor model and aircraft model definition, and therefore it is in-tended to deliver the results for different projects besides the one that was presented in this work as a case study. This particular case study presents the development of a structure support for FLIR STAR SAPHIRE III turret integration on the front lower fuselage bulkhead (radome) of the LOCKHEED MARTIN C-130 H. Development of the case study focuses on the study of local structural analysis through the use of Finite Element Method (FEM). Development of this Dissertation resulted in a cooperation between Faculty of Science and Technology - Universidade Nova de Lisboa and the company OGMA - Indústria Aeronáutica de Portugal

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El objetivo principal de este trabajo es proponer un modelo de organización y de funcionamiento de un laboratorio de Unmanned Aircraft Systems para Gestión Aeronáutica de la UAB, a partir de la fijación de unos objetivos a corto, medio y largo plazo, e identificando un modelo de toma de decisión de cambios en la estrategia de desarrollo del laboratorio que permita la adaptación a las posibles evoluciones del entorno

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Deterioration in portland cement concrete (PCC) pavements can occur due to distresses caused by a combination of traffic loads and weather conditions. Hot mix asphalt (HMA) overlay is the most commonly used rehabilitation technique for such deteriorated PCC pavements. However, the performance of these HMA overlaid pavements is hindered due to the occurrence of reflective cracking, resulting in significant reduction of pavement serviceability. Various fractured slab techniques, including rubblization, crack and seat, and break and seat are used to minimize reflective cracking by reducing the slab action. However, the design of structural overlay thickness for cracked and seated and rubblized pavements is difficult as the resulting structure is neither a “true” rigid pavement nor a “true” flexible pavement. Existing design methodologies use the empirical procedures based on the AASHO Road Test conducted in 1961. But, the AASHO Road Test did not employ any fractured slab technique, and there are numerous limitations associated with extrapolating its results to HMA overlay thickness design for fractured PCC pavements. The main objective of this project is to develop a mechanistic-empirical (ME) design approach for the HMA overlay thickness design for fractured PCC pavements. In this design procedure, failure criteria such as the tensile strain at the bottom of HMA layer and the vertical compressive strain on the surface of subgrade are used to consider HMA fatigue and subgrade rutting, respectively. The developed ME design system is also implemented in a Visual Basic computer program. A partial validation of the design method with reference to an instrumented trial project (IA-141, Polk County) in Iowa is provided in this report. Tensile strain values at the bottom of the HMA layer collected from the FWD testing at this project site are in agreement with the results obtained from the developed computer program.

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La crisi econòmica global és, sens dubte, el principal motiu de preocupació de la societat. Les dificultats que estant patint empreses i treballadors queden plasmades enl'evolució catastròfica de certes variables macroeconòmiques tals com els índex de(de)creixement del PIB, la taxa d'atur, el dèficit públic o la inversió privada.En aquest context, els grans sectors de l'economia són els que reben major atenciómediàtica i popular.Els problemes en el sistema financer han estat els grans protagonistes d'aquesta crisi, doncs en són l'origen i s'espera que siguin part important en la recuperació.En el context espanyol, el sector immobiliari ha endurit encara més la crisi, deixant a centenars de milers de treballadors a l'atur i donant símptomes de ser un sector que mai podrà recuperar la dimensió de la que havia gaudit els últims anys. Dins d'un entorn econòmic recessiu, el sector automobilístic mundial ha estat colpejat molt durament, en especial a Espanya.A les notícies de caigudes en les matriculacions, s'han succeït retallades de la producció, EROs temporals, reduccions de plantillla.... i l'adjudicació de l'Audi Q3 a la fàbrica que Seat té a Martorell, i que salvarà milers de llocs de treball.Hem volgut doncs, analitzar la crisi de l'automòbil a Espanya, centrant-nos en Seat i el Grup Volkswagen, i tractar de manera profunda el cas de l'Audi Q3.Estudiarem la importància de que el Q3 es fabriqui aquí, els motius pels quals Seat haestat l'elegida, el seguiment que la premsa n'ha fet i l'impacte econòmic i social querepresenta. Finalment, esperem conèixer què necessita el nostre país per aconseguir que el sector automobilístic segueixi sent important en el futur, i s'eviti que poc a poc es vagi deslocalitzant.

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Background and aim of the study: Bicuspid aortic valve is the most common congenital heart malformation, and a high percentage of patients with this condition will develop complications over time. It is rare that pilots undergo aortic valve surgery, and the confirmation of flight-licensing requirements after aortic valve replacement (AVR) is a challenge for the patient's cardiac surgeon and, particularly, for the Aeromedical Examiner (AME). Only AMEs are able to determine the flight status of pilots. Furthermore, in military and in civil aviation (e.g., Red Bull Air Race), the high G-load environment experienced by pilots is an exceptional physiological parameter, which must be considered postoperatively. Methods: A review was conducted of the aeronautical, surgical and medical literature, and of European pilot-licensing regulations. Case studies are also reported for two Swiss Air Force pilots. Results: According to European legislation, pilots can return to flight duty from the sixth postoperative month, with the following limitations: that an aortic bioprosthesis presents no restrictions in cardiac function, requires no cardioactive medications, yet requires a flight operation with co-pilot, the avoidance of accelerations over +3 Gz and, in military aviation, restricts the pilot to non-ejection-seat aircraft. The patient follow up must include both echocardiographic and rhythm assessments every six months. Mechanical prostheses cannot be certified because the required anticoagulation therapy is a disqualifying condition for pilot licensing. Conclusion: Pilot licensing after aortic valve surgery is possible, but with restrictions. The +Gz exposition is of concern in both military and civilian aviation (aerobatics). The choice of bioprosthesis type and size is determinant. Pericardial and stentless valves seem to show better flow characteristics under high-output conditions. Repetitive cardiological controls are mandatory for the early assessment of structural valve disease and rhythm disturbances. A pre-emptive timing is recommended when reoperation is indicated, without waiting for clinical manifestations of structural valve disease.

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Iowa has two seat belt laws, which have been amended several times since the original law took eff ect July 1, 1986. The most recent changes, effective July 1, 2010, were made during the 2010 legislative session by Senate File 2381.