1,720,953 research outputs found
Design and evaluation of a simulation environment for evaluating departure scheduling algorithms
No full textTo meet traffic demand predictions, the global air traffic management (ATM) system needs to be changed. Several visions on future ATM operations exist. A commonality between the different visions is 4D Trajectory management. This function enables plan-based operation as opposed to the state-based approach of the present system. Plan-based operation enables the optimization of traffic flows by generating 4D trajectories. A part of the traffic flow generation process is scheduling. The research presented in this thesis focuses on these scheduling opportunities. In this research the scheduling opportunities for departure traffic at a runway are investigated. A study of the existing literature showed that the most common scheduling algorithms currently available can be divided into four categories: first come first served, brand-and-bound, greedy search and genetic algorithms. A simulation environment is designed for evaluation of the departure scheduling algorithms using various input parameters like traffic situation, airport map and algorithm. The four algorithm categories are evaluated on output aspects like delay and robustness of the schedule and are compared with the current method of traffic scheduling. The evaluation of the scheduling algorithms shows that the performance of the current method of scheduling departure traffic performs well in comparison with the tested algorithms. In case of no disturbances the genetic algorithm performs slightly better than the current method, but the other algorithms do not have a better performance. When disturbances are taken into account, a bigger performance increase can be obtained by using scheduling algorithms.Group of Microwave Technology and Systems for Radar (MTSR)TelecommunicationsElectrical Engineering, Mathematics and Computer Scienc
Creating a Simulation Environment to Analyze Benefits of Real-time Taxi Flow Optimization Using Actual Data
No full textTo make optimal use of the available runway and taxiway infrastructure and to prevent the workload of the controllers becoming a limitation, a route-planning function that generates routes automatically is needed. The uncertainty in the taxi process is an important disturbance in today’s surface operations. To allow for deconfliction in the planning domain, the routes need to include time information. The route-planning function will need to use time-margins to provide a certain level of robustness against disturbances. A determining factor in the selection of the size of the margins is the tradeoff between the (maximum) capacity that can theoretically be achieved in the absence of disturbances and the robustness against disturbances. A key challenge is the identification of the relation needed to specify time margins as a function of traffic density and disturbance statistics. An important uncertainty of the taxi processes is the taxi speed. This paper will describe a method to obtain and quantify taxi traffic flow performance and taxi speed distribution using real world data from Amsterdam airport. Furthermore the development of a simulation environment to evaluate the performance of various route-planning functions for selectable time-margins and disturbance statistics is described. In addition a method is described to extract surface traffic scenarios from real world data. The scenarios are used to verify the fidelity of the surface traffic simulation.Electrical Engineering, Mathematics and Computer Scienc
Online Laboratory Sessions for the Education of Electrical Machines and Drives
No full textThis paper presents a method to implement online laboratory sessions for education in Electrical Engineering on subjects related to electrical machines and drives. The assignments for the laboratory sessions consist of: the preparation homework, where students have to study relevant theories; the development of circuit simulations; and the participation on a practical session online. For the latter, the students have to implement remotely various models in a physical setup based on the results of their homework tasks. After taking the assignments, the students should be able to: set up circuit simulations of electrical machines and drives; to implement relevant control of motor drives in a physical setup; and finally, to interpret the differences between the simulation and experiment results. Detailed design of the physical setup, the assignments, the relevant Information and Communication Technology (ICT) facilities are presented and discussed in this paper. An example and the feedback of applying it in a master level course is presented. The experience gained so far shows that the proposed online laboratory sessions can be used as supplementary educational resource to existing online education platforms.Virtual/online event due to COVID-19 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.DC systems, Energy conversion & Storag
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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