1,720,973 research outputs found
Optimising video summaries using unsupervised clustering
No full textRen, Kan Fernando, WAC Calic, Janko I-Lab, Centre for Communication System Research University o
Optimising video summaries using unsupervised clustering
No full textRen, Kan Fernando, WAC Calic, Janko I-Lab, Centre for Communication System Research University o
User aspects in synchronous visualisation of multiple photo streams.
Get PDFPhoto sharing is becoming a common way of maintaining
closeness and relationships with friends and family, and it can evoke pleasurable, enjoyable and exciting experiences. People have fun when sharing photos containing pleasant scenes or friends being caught doing something interesting. There has been a recent increase in studies that focus on the visualisation and sharing of photos using online services or sharing in the home environment using different digital technologies. Although previous studies have focussed on the important issues of photo sharing and visualisation, there is a dearth of research aimed at designing applications that enable people to share and visualise multiple photo streams that originate from multiple sources such as different people or capture devices. In addition, there is a lack of research that links new applications for photo sharing with user experience and the applications' value to the user.
This thesis, firstly, offers a new design for synchronous sharing and visualisation of multiple photo streams using temporal and social metadata. Moreover, different features, called transition modes, were added to the system to give a better experience within the system. The experience of photo sharing, however, does not exist without any connection to people or events; it is a social experience depending on people, places and time. Hence, an experimental study was conducted with twenty users, and the results demonstrate high user demand for concurrent presentation of multiple media streams as well as recommended transitions for extending its potential. In the second phase of this thesis, the temporal aspects of multiple photo streams such as manual transition, continuity detection and user desired time were designed and implemented. Following that, the results of the user study demonstrate good comprehension of the users' own and shared photo streams, and their temporal structure, even when presented at relatively high speeds. Users were easily able to contextualise events, recall specific photos and find them using the proposed interface. The final interface is built from the lessons that were learned from the first two phases of this study. In this version, the user was able to share their photos in real time and see them in an ambient display. Our final system for real-time photo sharing as an ambient display was tested in three different trials with three different user groups consisting of extended family, close friends and workplace colleagues. The results showed high user interest for extended family members and in the workplace environment
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
Non-reference depth map quality evaluation in immersive video applications.
Get PDFThree Dimensional Television (3DTV) and Free Viewpoint Television (FTV) are emerging multimedia applications, which promise to offer a new Quality of Experience (QoE) dimension. In order for such applications to offer an immersive experience for users a large number of viewpoints need to be transmitted, to a point where the high bandwidth utilisation becomes a major concern. One approach to this problem is the utilisation of the so called “depth maps” in Depth Image Based Rendering (DIBR) techniques, where different views, can be reconstructed (rendered) at the receiver side when required, with a fraction of the bandwidth. Therefore the quality and accuracy of the information present in depth maps and its ability to reconstruct the required views has become the subject of much greater scrutiny in multimedia research. Several challenges arise when assessing the quality of depth maps, such as the lack of a proper reference for comparing the available depth maps, especially when it comes to live High Definition (HD) content.
The first contribution of this thesis focuses on developing a novel subjective assessment approach, which addresses the presence of disocclusions in rendered views. The goal of this assessment approach is to enable the subjective evaluation of rendered views, to provide results that are more representative of the quality of the depth map utilised in the rendering process. The adopted approach performance has been evaluated through correlating the obtained subjective results with well-established objective metric measurements, such as PSNR, PSPNR, SSIM and VQM.
The second contribution of this thesis is concerned with establishing a test data set, which includes different colour sequences together with various depth estimation algorithms and different depth post processing techniques. State of the art depth estimation algorithms were examined such as RSGM, DERS and HRM, in order to obtain a wide range of depth map qualities. The depth map data set is utilised in the DIBR process to generate rendered views, which are in turn subjectively assessed utilising the approach developed in contribution one of this thesis. The assessment is carried out in both a 2D and 3D setup and statistical analysis is utilised to establish observations and conclusions over the depth map performance.
The third and final contribution of this thesis is related to a non-reference evaluation approach in assessing the quality of the depth maps utilised. This approach exploits the edges present in the available depth maps and compares that to the edges in the corresponding colour views. Edge pixels in depth maps are then classified into correct and error edge pixels. The obtained results are then correlated with the subjective results obtained in the second contribution. The result analysis of this non-reference model provides clear indications of depth map performance and its dependency on the associated colour sequence selection. The high correlation values with the subjective results were in the range of 75-81%. These correlation values are of more significance when compared to best performing quality metrics (e.g. VQM obtained correlation values of 59%) under the researched scenarios
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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