1,720,952 research outputs found
Improving the last mile in a public transport trip with automated vehicles using an agent based simulation model: A Delft case study
No full textThe last mile in a public transport trip appears to be one of the main deterrents in public transport to be competitive with other modes of transport. The reason for this bad performance of the last mile can be related to the slow and inflexible character of the last mile. Where PRT systems aspire to deliver an on demand, direct service to a passenger, they are bound to fixed separated infrastructure and would therefore face high investment costs for the application of PRT systems on the last mile. As automated vehicles can make use of any kind of road that is available the investment costs are considerably lower. The system presented in this thesis is a last mile transportation service operated by automated vehicles on existing infrastructure. Multiple operational strategies have been simulated using an agent based simulation model in AnyLogic. This simulation model has been applied on the case study Delft Zuid - Technological Innovation campus. For this case study a travel demand survey has been conducted, from which the results serve as one of the main inputs of the simulation model. The outcomes of the simulations indicate that relocating empty vehicles, intermediate charging have a positive effect on the performance of the system on the last mile without compromising any other system performance parameter. Pre-booking of vehicles (via a smartphone app) showed to be very beneficial with regard to the average waiting time for a passenger. However, as vehicles are locked for a longer period the system capacity decreases. The speed of the vehicles appeared one of the main determinants for the energy use of the vehicles and therefore the available system capacity. Speed variations have shown large reductions in the average travel time for a passenger.Transport & PlanningCivil Engineering and Geoscience
Exploring the use of automated vehicles as last mile connection of train trips through an agent-based simulation model: An application to Delft, Netherlands
No full textThe last mile in a public transport trip is known to bring a large disutility for passengers, because the conventional transport modes for this stage of the trip can, in many cases, be rather slow, inflexible and not provide a seamless experience to passengers. Fully automated vehicles (AVs), that is, those which do not need a driver, could act as a first mile/last mile connection to mass public transport modes. In this paper, we study a system that we call Automated Last-Mile Transport (ALMT), which consists of a fleet of small, fully automated, electric vehicles to improve the last mile performance of a trip done in a train. An agent-based simulation model was proposed for the ALMT whereby a dispatching algorithm distributes travel requests amongst the available vehicles using a FIFO sequence and selects a vehicle based on a set of specified control conditions (e.g. travel time to reach a requesting passenger). The model was applied to the case-study of the connection between the train station Delft Zuid and the Technological Innovation Campus (Delft, The Netherlands) in order to test the methodology and understand the performance of the system in function of several operational parameters and demand scenarios. The most important conclusion from the baseline scenario was that the ALMT system was only able to compete with the walking mode and that additional measures were needed to increase the performance of the ALMT system in order to be competitive with cycling. Relocating empty vehicles or allowing pre-booking of vehicles led to a significant reduction in average waiting time, whilst allowing passengers to drive at a higher speed led to a large reduction in average travel time, whilst simultaneously reducing system capacity as energy use is increased
Het verbeteren van de last-mile in een OV reis met automatische voertuigen: Een Delftse case studie en stated preference onderzoek gecombineerd
No full textDe last-mile in een openbaar vervoer (OV)reis is een van de meest hinderlijke gedeelten van een reis perOV,hierdoor is het OV veelal niet in staat om te kunnen concurreren met de auto. De oorzaak kan deels worden gevonden in het gebrek aan flexibiliteit en de lage snelheden die de veelal conventionele vervoersmiddelen op de last-mile kenmerken.Recente technologische ontwikkelingen makeninnovatieve vraaggestuurde vervoersconceptenmet zelfrijdende voertuigen mogelijk. Deze zijn onafhankelijk van vaste infrastructuur en zouden ideaalop de last-mile ingezetkunnen worden, om zo het diffusepatroon en lage vervoersvolume efficiënt tebedienen. Om de vervoerwaarde en de prestatie van een vraaggestuurd vervoersysteem met zelfrijdende voertuigen op de last-mile te bepalen is alscase:Station Delft-Zuid –TU Delft gekozen.Bij een vervoerwaarde studie metdergelijke innovatieve techniek wordt verwachtdat psychologische factoren, naast depuur instrumentele aspecten, expliciet een rol spelen in de vervoerwijzekeuzevan reizigers. Het meenemen van deze preferenties is daarom van belang, teneindede vervoerwaarde niet substantieel te over-of onderschatten. In dit paper zijnde uitkomsten van twee onderzoeken gecombineerd, een instrumenteel onderzoek (simulatiemodel + enquête) naar de vervoerwaarde van een systeem van zelfrijdende voertuigen en een stated preference (SP)-experiment om de invloed van diversepsychologische factoren op de vervoerwaarde te bepalen.De resultaten laten zien dat er een aanzienlijke vervoerwaarde bestaat voor zelfrijdende voertuigen op de last-mile, te weten57% van de steekproefpopulatie.Methetsimulatiemodel zijn diverse ITS maatregelengesimuleerd, deze maatregelen omvatten wijzigingen in de netwerkstructuur, voertuiggedragen het reizigersgedrag.De prestatie van het last-mile systeem, bleekveelalpositiefbeïnvloedt te worden door bovenstaande maatregelen.Effecten werden gemeten in een vergroting van de systeemcapaciteit, een reductie van de gemiddelde wachttijd ofwel van de gemiddelde reistijd. Het parallel toepassen van deze maatregelen realiseerteen aantrekkelijkere concurrentiepositie ten opzichte van de conventionele vervoerswijzen. De meest kenmerkende maatregel,het strategisch plaatsen van voertuigen,op locaties voorafgaand aan het ontstaan van vervoersvraag laat een reductie in de gemiddelde wachttijd van 40% zien.Uit het SP-experimentblijkt dat de attitudes ‘duurzaamheid’ en ‘vertrouwen’ de twee belangrijkste aspectenzijn in de vervoerwijzekeuze, terwijl de in-voertuigtijd niet minder negatief wordt ervaren dan in een door de reiziger gereden carsharing systeem. Dit suggereert dat de gebruikelijk genoemde voordelen van zelfrijdende voertuigenwellicht nog niet worden ervaren door de reiziger vanvandaag, en illustreert het belang om hier aandacht aan te schenken voor een succesvolle implementatievan zelfrijdende voertuigen
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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