1,721,041 research outputs found
Trip phase recognition and transport mode classification through mobile sensing technologies
Full text linkAs urban populations grow and sustainability challenges increase, the ability to automatically detect transport modes and recognize trip phases using mobile sensor data has become critical for urban planning, public transport management, and environmental monitoring. This thesis presents a comprehensive approach to transport mode detection and trip phase recognition, utilizing GPS data from mobile devices. The core objective is to develop robust machine learning and deep learning models capable of classifying transportation modes such as walking, cycling, driving, and transit use (bus, metro, etc.) with high accuracy while simultaneously identifying trip phases, including access, egress, and waiting times.
By leveraging large-scale datasets such as the GeoLife and Sussex-Huawei Locomotion datasets, the study applies advanced data preprocessing techniques and designs multiple classification algorithms, including Random Forest and Convolutional Neural Networks (CNNs), to effectively distinguish between different transportation modes. A key contribution of this research is developing a novel framework for trip phase recognition, which segments journeys into distinct stages, enabling the automated calculation of critical transit metrics such as waiting time at public transport stops, access and egress times, and distance to and from transit stations.
The results of this study have wide-ranging implications, including optimizing public transportation systems, improving commuter experience, reducing carbon emissions by encouraging sustainable transportation choices, and providing policymakers and urban planners with actionable insights based on real-world mobility patterns. Furthermore, the thesis presents new key performance indicators (KPIs) to evaluate the accessibility level of public transit stations. This work advances transportation research and lays the groundwork for future developments in smart city initiatives and digital mobility services
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
A revision of the biginelli reaction under solid acid catalysis. Solvent-free synthesis of dihydropyrimidines over montmorillonite KSF
No full textThe reaction of aldehydes, β-dicarbonyl compounds and urea (Biginelli reaction) has been performed over solid acid catalysis, under solventless conditions or in water affording dihydropyrimidines in good yield and selectivity
Dehydration-hydration of α-alkynols over zeolite catalyst. Selective synthesis of conjugated enynes and α,β-unsaturated ketones
No full textα-Alkynols 1 are convened in high yield and selectivity into conjugated enynes 2 or α,β-unsaturated ketones 3 by treatment with acid zeolites. The exclusive production of compounds 2 or 3 depends on the nature of the starting material 1 and experimental conditions
Zeolite-Induced Heterodomino Reaction. Regioselective Synthesis of 2H-1-Benzopyrans from Phenols and α-Alkynols
No full textClay/water mixtures - A heterogeneous and ecologically efficient catalyst for the three-component stereoselective synthesis of tetrahydroquinolines
No full textThe three-component synthesis of tetrahydroquinolines 5 from aromatic amines 1, aromatic aldehydes 2 and cyclopentadiene (4) can be efficiently performed in water in the presence of the commercially available bentonite Bieliaca. The overall process involves the rapid initial production of the imines 3, which subsequently undergo aza-cycloaddition processes with clopentadiene, affording products in good yields and with excellent selectivities. The cycloaddition step is regiospecific and stereospecific, exclusively giving the endo product. It was possible to reuse the catalyst several rimes without lowering its efficiency. The process represents a clean, safe and environmentally friendly route for the production of a class of natural products displaying a wide range of biological activities
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