1,721,058 research outputs found
The University of Southampton Optics and Photonics Society
No full textThe Optics and Photonics Society (OPSoc) consists of postgraduate students from multiple departments within the University of Southampton, all with a common interest: light. It combines the university’s OSA and SPIE student chapters into a society that benefits all members. Most students are members of both the OSA and SPIE. OPSoc seeks to enhance the student experience by providing opportunities for professional development and networking through events falling under three main arms, namely, academic, social, and outreach. Special activities are also organized occasionally
Characterisation of hollow-core photonic bandgap fibres and other multimode fibres for optical communications
No full textProgress in multimode fibre technology has opened diverse opportunities in science and technology, one of which is pushing data capacities beyond the fundamental limits of conventional single-mode fibre, so as to avert network gridlock precipitated by exponentially growing global traffic demands. Hollow-core photonic bandgap fibres (HC-PBGFs), where light propagates in air rather than glass, have been considered as a potential candidate for high-capacity telecommunications applications, while offering superior performance over solid-core fibres in terms of low loss, low latency, and ultralow nonlinearity.This thesis presents research conducted as part of the efforts of the EU FP7 project MODE-GAP to pioneer developments in HC-PBGF and related space-division multiplexing technologies. This work is involved with the characterisation of primarily HC-PBGFs and also solid-core multimode fibres, recently and respectively fabricated through the facilities of the Optoelectronics Research Centre and other project partners. A time-of-flight method is applied to make extensive measurements on these fibres to study their modal properties, including mode coupling and differential modal delay, in order to assess their capabilities for single-mode as well as mode-division multiplexed data transmission. In support of the fibre design process, this work has aided the full characterisation of the first ever fabricated 37-cell HC-PBGFs and enabled subsequent mode-division multiplexing trials at a record capacity of 73.7 Tbit/s. Characterisation of multi-kilometre record-length HC-PBGFs is also performed, and has supported the demonstration of these fibres in metro network environments.To further understand the modal processes and facilitate fibre improvement, a simulation environment is constructed based on a power coupling propagation model. This has enhanced interpretations of experimental time-of-flight data, as well as validated a proposed theory relating mode coupling and loss in HC-PBGFs.Finally, an experimental technique is introduced to inspect longitudinal defects in solid- and hollow-core fibres, by applying time-of-flight principles
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
N20EMv2 dataset for automatic music transcription from multimodal singing
No full text<p>N20EMv2 dataset for multimodal automatic music transcription from multimodal singing, presented in our TOMM 2024 paper, Automatic Lyric Transcription and Automatic Music Transcription from Multimodal Singing. This dataset contains recordings of two modalities: audio and video. </p>
<p>Our paper is available at: https://dl.acm.org/doi/10.1145/3651310.</p>
<p>Code is available at: https://github.com/guxm2021/SVT_SpeechBrain</p>
<p>Please cite our work as:</p>
<pre>@article{gu2024automatic,
title={Automatic Lyric Transcription and Automatic Music Transcription from Multimodal Singing},
author={Gu, Xiangming and Ou, Longshen and Zeng, Wei and Zhang, Jianan and Wong, Nicholas and Wang, Ye},
journal={ACM Transactions on Multimedia Computing, Communications and Applications},
publisher={ACM New York, NY},
year={2024}
}</pre>
Modular and extensible lesson on optical fibre communication for youths
No full textOptical fibre communication enables the global internet, but few youths ever learn about how it works, even at a basic level, until tertiary education. While some middle school curricula might include simple geometrical optics concepts like reflection and refraction, they often lack contextual linkage to worldwide telecommunications. Through our studies, we have found that students are more engaged in the learning process when the material directly relates to real life. To address this gap, and moreover to tackle the issue of the STEM skills shortage, we have designed a self-contained lesson to introduce youths to this topic. It is modularised into three parts, beginning with using light to communicate Morse code, and then covering advanced themes such as multiplexing and fibre guidance based on total internal reflection. The modules can be taught sequentially or individually depending on educational level. They emphasise a more phenomenological than theoretical approach and include hands-on activities using easily obtainable materials. We outline the lesson and pedagogical guidelines for classroom settings, as well as evaluate actual classes run. This lesson can be flexibly implemented in formal classes or through educational outreach programmes
Dataset for Modular and extensible lesson on optical fibre communication for youths
No full textThis dataset supports the publication: Nicholas H. L. Wong et al (2019). Modular and extensible lesson on optical fibre communication for youths. Physics Education</span
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
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