1,720,952 research outputs found
Microscopic interaction behavior between individual pedestrians
No full textDue to growing mobility in densely populated urban areas, public pedestrian walkways are becoming more and more crowded. Since space in these densely occupied areas is highly valued, the use of every square meter must be evaluated carefully. Microscopic pedestrian simulation models can provide such evaluation. However, fundamental knowledge on individual pedestrian behavior underpinning these models is hardly available. This study focuses on the so-called interaction behavior between individual pedestrians. It comprises the identification of aspects that influence individual interaction behavior, their effects on pedestrian movement and how these effects can be described and predicted. Assessment criteria and pedestrian experiments In unhindered walking, personal walking capabilities determine the intended path in lateral and in longitudinal direction. Walking outside of this intended path in unhindered walking is defined as interaction movement. Also, the passing side and the extent of evasion from the mean intended path are investigated. The effects of the direction of approach (i.e. bidirectional, crossing and overtaking situations), individual gender and motion pace and small groups on these three assessment criteria are examined. Laboratory experiments have been performed to obtain data on individual pedestrian interaction behavior. In these experiments twelve participants are initially asked to walk a length of 20 meters unhindered by other pedestrians. Thereafter, two or three participants are asked to walk simultaneously, in such a way that interaction between them is provoked. This has resulted in 1586 trajectories of individual pedestrians. Analyses on unhindered walking and interaction movements The unhindered trajectories are used to derive boundaries for the intended path in unhindered walking, mean walking paths and mean walking speeds. In addition, a method is presented to analyze the swaying effect in unhindered walking. It has been shown in this study that the observed step lengths and step frequencies are inversely proportional to each other. It is found that individual pedestrians perform interaction movement in 88% of the interaction situations observed in this study. These movements can be interpreted as some gallantry towards other pedestrians. This finding justifies the detailed modeling of pedestrian interaction movements in microscopic simulation models. In the bidirectional situation pedestrians strongly prefer passing each other on the right hand side. In crossing situations, walking in a hurry increases the probability of passing in front of other pedestrians and meeting a small group of two pedestrians increases the probability of passing at the back of this group. The passing side and the direction of approach mainly determine the direction and the extent of evasion from the individual mean walking path and from the individual mean walking speed during interaction. Pedestrians seem to prefer larger lateral evasion in bidirectional situations and larger longitudinal evasion in crossing situations. Men laterally evade more than women and hurried pedestrians laterally evade more than normally walking pedestrians. It seems that hurried pedestrian are either granted ‘right of way’ or that they take the initiative themselves in an early stage of the interaction process. The extent of evasion is larger when small groups are encountered. Implications for pedestrian modeling and recommendations for further research The observations on pedestrians in individual interaction situations differ in a number of issues from observations on individual pedestrians in flows. This indicates that behavioral reactions of individual pedestrians to other individual pedestrians differ from behavioral reactions of individual pedestrians to pedestrian flows. Moreover, it follows from this study that the passing side determines the ensuing lateral and longitudinal evasion. A conceptual model for implementing this into pedestrian models is given in the attached figure. This model differs from other models since interaction movements are determined based on a decision on the passing side instead of the other way around. Furthermore, hurried pedestrians behave significantly different than normally walking pedestrians and this aspect should thus be modeled. Several aspects regarding individual pedestrian interaction need further research. Among these are the initiation moment of interaction movements and the effects of gender, body size and age on pedestrian interaction. These aspects can be investigated with the observations obtained in this study. The effects of multiple individual pedestrians on the individual interaction behavior (i.e. individual behavior within pedestrian flows) were not investigated in this study. To gain knowledge on these effects it is of interest to analyze whether behavioral reactions of individual pedestrians to other individual pedestrians significantly differ from behavioral reactions of individual pedestrians to pedestrian flows.Transport & PlanningCivil Engineering and Geoscience
Robustness quantification for navigation locks that are part of the primary flood defense: A study into the effect of increasing the reliability requirement of structural elements on the robustness of the structural system
No full textRobustness is a hard-to-grip concept within engineering. This master thesis uses a framework to quantify the level of robustness that has been proposed by the Joint Committee on Structural Safety to assess the influence of the reliability requirement of a structural element. The lock complex at Weurt (the Netherlands) has been used for a case study to calculate robustness indices for multiple values of the reliability requirement. In addition, the influence of redundant elements has been examined. Based on the results it can be concluded that increasing the reliability requirement of an individual element does not necessarily result in a higher level of robustness. In some cases a lower robustness index is found. Redundant elements, however, do increase the level of robustness.Civil Engineering and GeosciencesHydraulic EngineeringHydraulic structures and Flood ris
Synergy between quantum computing and semiconductor technology
No full textAs part of the National Agenda for Quantum Technology, QuTech (TU Delft and TNO) has agreed to make quantum technology accessible to society and industry via its full-stack prototype: Quantum Inspire. This system includes two different types of programmable quantum chips: circuits made from superconducting materials (transmons), and circuits made from silicon-based materials that localize and control single-electron spins (spin qubits). Silicon-based spin qubits are a natural match to the semiconductor manufacturing community, and several industrial fabrication facilities are already producing spin-qubit chips. Here, we discuss our latest results in spin-qubit technology and highlight where the semiconducting community has opportunities to drive the field forward. Specifically, developments in the following areas would enable fabrication of more powerful spin-qubit based quantum computing devices: circuit design rules implementing cryogenic device physics models, high-fidelity gate patterning of low resistance or superconducting metals, gate-oxide defect mitigation in relevant materials, silicon-germanium heterostructure optimization, and accurate magnetic field generation from on-chip micromagnets.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.BUS/TNO STAF
Quantum inspire - Qutech's platform for co-development and collaboration in quantum computing
No full textThe mission of QuTech is to bring quantum technology to industry and society by translating fundamental scientific research into applied research. To this end we are developing Quantum Inspire (QI), a full-stack quantum computer prototype for future co-development and collaborative R&D in quantum computing. A prerelease of this prototype system is already offering the public cloud-based access to QuTech technologies such as a programmable quantum computer simulator (with up to 31 qubits) and tutorials and user background knowledge on quantum information science (www.quantum-inspire.com). Access to a programmable CMOS-compatible Silicon spin qubit-based quantum processor will be provided in the next deployment phase. The first generation of QI's quantum processors consists of a double quantum dot hosted in an in-house grown SiGe/28Si/SiGe heterostructure, and defined with a single layer of Al gates. Here we give an overview of important aspects of the QI full-stack. We illustrate QI's modular system architecture and we will touch on parts of the manufacturing and electrical characterization of its first generation two spin qubit quantum processor unit. We close with a section on QI's qubit calibration framework. The definition of a single qubit Pauli X gate is chosen as concrete example of the matching of an experiment to a component of the circuit model for quantum computation.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.BUS/TNO STAFFQCD/Vandersypen LabQCD/Scappucci LabQN/Veldhorst LabQN/Vandersypen LabBUS/Quantum Delf
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
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