782 research outputs found

    Allocating Air Traffic Flow Management Slots

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    In Europe, when an imbalance between demand and capacity is detected for air traffic network resources, Air Traffic Flow Management slots are allocated to flights on the basis of a First Planned First Served principle. We propose a market mechanism to allocate such slots in the case of a single constrained en-route sector or airport. We show that our mechanism provides a slot allocation which is economically preferable to the current one as it enables airlines to pay for delay reduction or receive compensations for delay increases. We also discuss the implementation of our mechanism through two alternative distributed approaches that spare airlines the disclosure of private information. Both these approaches have the additional advantage that they directly involve airlines in the decision making process. Two computational examples relying on real data illustrate our findings.Air Transportation, Market Mechanism Design, Air Traffic Flow Management slots, Collaborative Decision Making, SESAR.

    Development and Analysis of Self-Assembled Structures of Branched Colloidal Nanocrystals

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    Sviluppo ed Analisi di Strutture Autoassemblate di Nanocristalli Colloidali Ramificat

    A 2D Markerless Gait Analysis Methodology: Validation on Healthy Subjects

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    A 2D markerless technique is proposed to perform lower limb sagittal plane kinematic analysis using a single video camera. A subject-specific, multisegmental model of the lower limb was calibrated with the subject in an upright standing position. Ankle socks and underwear garments were used to track the feet and pelvis segments, whereas shank and thigh segments were tracked by means of reference points identified on the model. The method was validated against a marker based clinical gait model. The accuracy of the spatiotemporal parameters estimation was found suitable for clinical use (errors between 1% and 3% of the corresponding true values). Comparison analysis of the kinematics patterns obtained with the two systems revealed high correlation for all the joints (0.82<R2<0.99). Differences between the joint kinematics estimates ranged from 3.9 deg to 6.1 deg for the hip, from 2.7 deg to 4.4 deg for the knee, and from 3.0 deg to 4.7 deg for the ankle. The proposed technique allows a quantitative assessment of the lower limb motion in the sagittal plane, simplifying the experimental setup and reducing the cost with respect to traditional marker based gait analysis protocols

    Haz eso, haz aquello, mas yo estoy cayendo...: comprendiendo la enfermedad de Chron

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    This qualitative study was developed as an effort to understand the meaning and the impact of Chron's Disease on the carrier's life, opting for Life Oral History as the methodological reference and having as a base Hippocrates' monist philosophical school, for which the medical practice focuses on the sick person in his/her totality, taking into consideration his/her temperament and background. The therapeutics must reestablish the person's harmony with his/her environment and with himself/herself. It is an integrative, dynamic medicine that corresponds to the beginnings of psychosomatic medicine. The studies on Chron's Disease, through psychosomatic understanding, made possible to analyze the symptoms not as alien bodies to be eradicated, but as messengers of an appeal to be understood. Through them, the person's history can be recovered, which makes possible the development to more advanced levels of understanding if it is experienced and analyzed consciously.Buscando comprender el significado y el impacto de la Enfermedad de Chron en la vida de su portador, desarrollamos este estudio, de naturaleza cualitativa, optando por la Historia Oral de Vida como referencial metodológico, y teniendo como base filosófica la corriente monista, advenida de Hipócrates, donde la práctica médica tiene por objeto a la persona enferma en su totalidad, teniendo en cuenta su temperamento y su historia. La terapéutica debe restablecer la armonía de la persona con su ambiente y consigo misma y se trata de una medicina integradora y dinámica, que corresponde a los inicios de la medicina psicosomática. El Estudio de la enfermedad de Chron, por medio de la comprensión psicosomática, permitió que analizásemos los síntomas, no como cuerpos extraños a ser erradicados, mas como mensajeros de un apelo a ser comprendido. Por intermedio de ellos, puede ser rescatada la historia de un individuo que, si conscientemente vivida y analizada, permite el desarrollo hasta niveles más evolucionados de entendimiento.Buscando compreender o significado e o impacto da doença de Chron na vida de seu portador, desenvolvemos este estudo, de natureza qualitativa, optando pela História Oral de Vida como referencial metodológico, tendo como base filosófica a corrente monista, advinda de Hipócrates, em que a prática médica tem por objeto a pessoa doente em sua totalidade, levando em conta seu temperamento e a sua história. A terapêutica deve restabelecer a harmonia da pessoa com seu ambiente e consigo mesma , trata-se de uma medicina integradora e dinâmica, que corresponde aos primórdios da medicina psicossomática. O estudo da doença de Chron, por meio da compreensão psicossomática, permitiu que analisássemos os sintomas, não como corpos estranhos a serem erradicados, mas como mensageiros de um apelo a ser compreendido. Por intermédio deles, pode ser resgatada a história de um indivíduo que, se conscientemente vivida e analisada, permite o desenvolvimento até níveis mais evoluídos de entendimento.UNIFESPUSP Escola de Enfermagem Departamento de Enfermagem Médico-CirúrgicaUNIFESPSciEL

    Capacity Sharing within Virtual Centre

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    Airspace Architecture Study proposed the future Single European Airspace System, based on modern technologies that could divide the air traffic service provision from local infrastructure for data provision, enabling the decoupling of geographical location from the service provision. This decoupling would enable virtualisation where service providers could use data from the common data services, opening doors to different organisation of air traffic service provision, namely more advanced capacity sharing. Virtualisation concept is still under development and several recent studies evaluated some aspects of virtualisation in ATM, but did not yet address in detail the impacts of different Virtual Centre implementation scenarios. In this paper, we propose a linear optimisation model to evaluate the impact of virtualisation and capacity sharing in terms of delay reduction. We show that taking into account the current airspace design and air traffic management resources, even the air navigation service providers that accumulate the highest capacity-caused delays could decrease those in the range of 25-50% up to about 80% through internal collaboration. Furthermore, the decrease of over 50% of the total capacity- caused delays could be obtained if FABEC1 were to form a Virtual Centre, and the decrease of about 90% of the total European delay if the Single European Sky (SES) area would form a Virtual Centre. The analysed capacity sharing collaborations indicate the possibility of significant delay reductions, but would not be sufficient, on their own, to eliminate capacity-caused issues in Europe

    An integer programming formulation to allocate series of slots on an airport network

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    Several authors have introduced mathematical formulations for the airport slot allocation process, and the initial allocation in particular. They mostly replicate the current IATA process, performed on an airport-by- airport basis. However, airports are part of a network. The initial slot allocation should therefore be performed simultaneously at all airports, accounting for flight times to link departures and arrivals. [1] proposes an integer programming formulation to allocate a set of single-day slots on a network of airports. Extending that formulation, this paper additionally models the IATA rule stating that series rather than individual slots are to be allocated. A series of slots includes at least 5 slots at the same time and day-of-the-week, distributed regularly in a season. The objective of the allocation is to minimise airline costs due to the non-allocation of series of slots, their temporal displacement, and the deviation from the requested block or turnaround time for slots of coupled series. Preliminary experiments are based on a network of 152 European airports and consider about 300000 slot requests for seven Fridays of the 2017 summer season. Results quantify the increase of airline costs as a function of congestion. [1] Pellegrini P, Bolic T, Castelli L, Pesenti R, 2017. SOSTA: An effective model for the simultaneous optimisation of airport slot allocation. Transportation Research Part E: Logistics and Transportation Review 99:34-53

    Foot strike patterns in runners wearing floating heel, minimalist and conventional footwear

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    The purpose of this study was investigate the vertical loading rate and footstrike angles when running in floating heel shoes (a new concept called FBR (Faster and Better Runners) compared to conventional and minimalist shoes. Footstrike angle and force data were collected from 15 male recreational runners as they ran in three different footwear conditions, floating heel, conventional and minimalist shoes. Results revealed that running in floating heel shoes promotes a non-rearfoot strike and results in reduced vertical loafing rates compared to both conventional and minimalist footwear. These findings suggest that floating heel shoes may offer a new way of running with a nonrearfoot strike without the risk of impact related injuries

    FOOT STRIKE PATTERNS IN RUNNERS WEARING FLOATING HEEL, MINIMILIST AND CONVENTIONAL FOOTWEAR

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    The purpose of this study was investigate the vertical loading rate and footstrike angles when running in floating heel shoes (a new concept called FBR (Faster and Better Runners) compared to conventional and minimalist shoes. Footstrike angle and force data were collected from 15 male recreational runners as they ran in three different footwear conditions, floating heel, conventional and minimalist shoes. Results revealed that running in floating heel shoes promotes a non-rearfoot strike and results in reduced vertical loafing rates compared to both conventional and minimalist footwear. These findings suggest that floating heel shoes may offer a new way of running with a nonrearfoot strike without the risk of impact related injuries

    An unusual case of vertigo: the usefulness of nystagmus examination

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    Platelets in Non-alcoholic Fatty Liver Disease

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    Non alcoholic steatohepatitis (NASH) is the inflammatory reaction of the liver to excessive accumulation of lipids in the hepatocytes. NASH can progress to cirrhosis and hepatocellular carcinoma (HCC). Fatty liver is the hepatic manifestation of metabolic syndrome. A subclinical inflammatory state is present in patients with metabolic alterations like insulin resistance, type-2 diabetes, obesity, hyperlipidemia, and hypertension. Platelets participate in immune cells recruitment and cytokines-induced liver damage. It is hypothesized that lipid toxicity cause accumulation of platelets in the liver, platelet adhesion and activation, which primes the immunoinflammatory reaction and activation of stellate cells. Recent data suggest that antiplatelet drugs may interrupt this cascade and prevent/improve NASH. They may also improve some metabolic alterations. The pathophysiology of inflammatory liver disease and the implication of platelets are discussed in details
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