1,878 research outputs found
Hub operations delay recovery based on cost optimisation - Dynamic cost indexing and waiting for passengers strategies
In this paper, two strategies for airlines’ operations at a hub are combined and analysed: dynamic cost indexing, to recover delay, and waiting for connecting passengers at the hub. Agent Based Modelling techniques have been used to model the airlines’ operations considering detailed passenger’s itineraries, an extended arrival manager operation with slot negotiation, and delay and uncertainty at different phases of the flights. Results show that, when optimising the total cost, there is a trade-off between connecting and non-connecting passengers with respect to the gate to gate trip time. Waiting for passengers arises as an interesting technique when minimising airline operating costs
Vista D5.1 - Initial Assessment Report
This deliverable presents Vista’s model and its calibration. The features of each of the model layers (strategic, pre-tactical and tactical) are described along with their calibration. A total of 58 scenarios with four foreground factors are modelled. The results of the layers are produced independently to present the capabilities of the system. These initial results are described and the next steps identified
Vista D5.2 - Final Assessment Report
Vista examines the effects of conflicting market forces on European performance in ATM, through the evaluation of impact metrics on four key stakeholders, and the environment. Vista models the current, 2035 and 2050 timeframes based on various factors and their potential evolution. Vista’s model covers the three temporal phases of ATM (strategic, pre-tactical and tactical), and represents a typical (busy) day of operations. The model is able to estimate the impact of factors on the different phases independently, allowing us to capture how indicators change under different scenarios and execution phases. This deliverable presents the final results obtained from the model, together with a detailed description of the various parts of the model, the analysis performed to prepare the data, and the model calibration
CASSIOPEIA II D3.2 - Final technical report
The FlightPath 2050 presents Europe’s Vision for Aviation for the future. In what refers to air traffic management, this vision includes concrete goals for the punctuality of flights and capacity of the air traffic management system. Additionally, the document adds a concrete goal in what refers to passenger mobility, stating that 90% of the passengers should be able to travel door-to-door in Europe within 4 hours.
Passenger mobility is obviously the ultimate goal of the air transport system, which mission is to transport passengers and freight, not airplanes. However, punctuality is currently mostly measured as aircraft operations performance. Moreover, most air traffic management technology improvements are targeting aircraft punctuality and not passenger punctuality. Passenger punctuality depends critically on passenger connectivity, as a missed connection impacts very negatively in passenger mobility performance.
Increasing the predictability of air transport operations has limits. Not only meteorological conditions can affect the punctuality but also countless operational hazards impact the air traffic management system. Making the system adaptable to changes in the operational conditions, capable of re-configuring itself to accommodate to a new scenario seems a better approach than trying to make the system robust, which ultimately could be too expensive or impossible.
Studying how different mechanisms improve the adaptability of the system is a complex problem. On one hand, it is a challenge to design a procedure that provides adaptability without impacting other performance metrics of the system. On the other hand, complex mechanisms usually require dedicated simulation frameworks, capable of modelling realistically a large number of parameters as well as providing a performance framework capable of evaluating in detail (e.g. beyond simple statistical properties) how the system adapts to the new conditions and how those mechanisms target a performance goal.
The CASSIOPEIA DCI-4HD2D project extension studied how changing the trajectory of each aircraft to either minimise fuel consumption or to minimise time to destination can be used as a adaptability mechanism, to work together with other ATM improvements, to address passenger connectivity.
Understanding how this mechanism, known as Dynamic Cost Indexing (DCI), increases the adaptability of the system, required the analysis, design and implementation of a complex software system as a collection of interacting, autonomous agents.
This document reports on the cases of study selected and the analysis of the outcome of the simulations performed, assessing how DCI contributes to passenger connectivity and, ultimately, to passenger mobility improvement
Aircraft systems architecting: a functional-logical domain perspective
Presented is a novel framework for early systems architecture design. The framework defines data structures and algorithms that enable the systems architect to operate interactively and simultaneously in both the functional and logical domains. A prototype software tool, called AirCADia Architect, was implemented, which allowed the framework to be evaluated by practicing aircraft systems architects. The evaluation confirmed that, on the whole, the approach enables the architects to effectively express their creative ideas when synthesizing new architectures while still retaining control over the process
Building a Holistic ATM Model for Future KPI Trade-Offs
We present the model developed within the Vista project, studying the future evolution of trade-offs between Key Performance Indicators. The model has a very broad scope and aims to simulate the changes that business and regulatory forces have at a strategic, pre-tactical and tactical level. The relevant factors that will affect the air transportation system are presented, as well as the scenarios to be simulated. The overall architecture of the model is described and a more detailed presentation of the economic component of the model is given. Some preliminary results of this part of the model illustrate its main mechanisms and capabilities
Autohydrolysis extraction of bioactive compounds from pineapple waste
The aim of this research was to evaluate the influence of temperature, time and
mass/volume ratio on the release of sugars and polyphenols using an autohydrolysis procedure
from pineapple waste and determine its antioxidant activity. A Box-Bhenken design was used with
three factors (time, temperature and mass/volume ratio) at three levels. All treatments were
performed in triplicate. For autohydrolysis treatments, an oil bath was used [1]. After extraction
process, liquid phases or hydrolysates were analyzed for glucose and fructose concentration by
high performance liquid chromatography (HPLC) [2]. The Folin-Ciocalteu assay was used to
measure total polyphenols of hydrolysates [3] and HPLC to identify these molecules [4]. Free
radical scavenging activity (DPPH assay) and radical cation decolorization assay (ABTS) were
assayed [5].
Figure 1, shows the antioxidant activity obtained from experimental matrix Box-Bhenken design
from autohydrolysis treatments of pineapple waste. It was observed most treatments have higher
activity than control, this is due to the abundance of bioactive compounds present in the
hydrolysates.
Conclusion: Autohydrolysis process is a good alternative for an effective extraction (using water
as only reaction medium) of value-added compounds that can be used for alcoholic drinks
enriched with natural antioxidants. In addition, this technology is an environmentally friendly
extraction alternative in compared with traditional chemical process
Oxygen-Induced Dimerization of Alkyl-Manganese(II) 2,6-Bisiminopyridine Complexes: Selective Synthesis of a New Ditopic NNN-Pincer Ligand
The outcome of the reaction of manganese(II) dialkyls with 2,6-bisiminopyridine (BIP) ligands is dramatically altered by the presence of very small amounts of oxygen (< 0.5 mol %), leading to binuclear species. These arise from the dimerization of the initial product, a Mn(II) 4-alkyl-2,6-bisiminodihydropyridinate alkyl complex. Cleavage of the binuclear Mn products with methanol affords the free dimeric bases, which can be regarded as a special type of ditopic NNN pincer ligand with an unusual tricyclic framework. The coordinative ability of the new ligands has been probed with the syntheses of Zn and Pd organometallic derivativesMinisterio de Economía e Innovación TQ2015- 68978-
Behind the Eastern-Western European convergence path: The role of geography and trade liberalization
This paper proposes a 2-block 3-region economic geography model that can account for the most salient stylized facts experienced by Eastern European transition economies during the period 1990-2005. In contrast to the existing literature, which has favored technological explanations, trade liberalization is the only driving force. The model correctly predicts that in the first half of the period, trade liberalization led to divergence in GDP per capita, both between the West and the East and within the East. Consistent with the data, in the second half of the period, this process was reversed and convergence became the dominant force. © 2013 Springer-Verlag Berlin Heidelberg
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