113,286 research outputs found

    Evaluation of Motion Velocity as a Feature for Sign Language Detection

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    Popular video sharing websites contain a large collection of videos in various sign languages. These websites have the potential of being a significant source of knowledge sharing and communication for the members of the deaf and hard-of-hearing community. However, prior studies have shown that traditional keyword-based search does not do a good job of discovering these videos. Dr. Frank Shipman and others have been working towards building a distributed digital library by indexing the sign language videos available online. This system employs an automatic detector, based on visual features extracted from the video, for filtering out non-sign language content. Features such as the amount and location of hand movements, symmetry of motion etc. have been experimented with for this purpose. Caio Monteiro and his team designed a classifier which uses face detection to identify the region-of-interest (ROI) in a frame, and foreground segmentation to estimate amount of hand motion within the region. It was later improved upon by Karappa et al. by dividing the ROI using polar coordinates and estimating motion in each division to form a composite feature set. This thesis work examines another visual feature associated with the signing activity i.e. speed of hand movements. Speed based features performed better compared to the foreground-based features for a complex dataset of SL and non-SL videos. The F1 score showed a jump from 0.73 to 0.78. However, for a second dataset consisting of videos with single signers and static backgrounds, the classification scores dipped. More consistent performance improvements were observed when features from the two feature sets were used in conjunction. F1 score of 0.76 was observed for the complex dataset. For the second dataset, the F1 score changed from 0.85 to 0.86. Another associated problem is identifying the sign language in a video. The impact of speed of motion on the problem of classifying American Sign Language versus British Sign Language was found to be minimal. We concluded that it is the location of motion which influences this problem more than either the speed or the amount of motion. Non-speed related analyses of sign language detection were also explored. Since the American Sign Language alphabet is one-handed, it was expected that videos with left-handed signing might be falsely identified as British Sign Language, which has a two-handed alphabet. We briefly studied this issue with respect to our corpus of ASL and BSL videos and discovered that our classifier design does not suffer from this issue. Apart from this, we explored speeding up the classification process by computing symmetry of motion in the ROI on selected keyframes as a single feature for classification. The resulting feature extraction was significantly faster but the precision and recall values depreciated to 59% and 62% respectively for a F1 score of .61

    Proceedings of the 15th Conference on Knowledge Organization WissOrg'17 of theGerman Chapter of the International Society for Knowledge Organization (ISKO),30th November - 1st December 2017, Freie Universität Berlin

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    Wissensorganisation is the name of a series of biennial conferences / workshops with a long tradition, organized by the German chapter of the International Society of Knowledge Organization (ISKO). The 15th conference in this series, held at Freie Universität Berlin, focused on knowledge organization for the digital humanities. Structuring, and interacting with, large data collections has become a major issue in the digital humanities. In these proceedings, various aspects of knowledge organization in the digital humanities are discussed, and the authors of the papers show how projects in the digital humanities deal with knowledge organization.Wissensorganisation ist der Name einer Konferenzreihe mit einer langjährigen Tradition, die von der Deutschen Sektion der International Society of Knowledge Organization (ISKO) organisiert wird. Die 15. Konferenz dieser Reihe, die an der Freien Universität Berlin stattfand, hatte ihren Schwerpunkt im Bereich Wissensorganisation und Digital Humanities. Die Strukturierung von und die Interaktion mit großen Datenmengen ist ein zentrales Thema in den Digital Humanities. In diesem Konferenzband werden verschiedene Aspekte der Wissensorganisation in den Digital Humanities diskutiert, und die Autoren der einzelnen Beiträge zeigen, wie die Digital Humanities mit Wissensorganisation umgehen

    Evaluation of Motion Velocity as a Feature for Sign Language Detection

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    Popular video sharing websites contain a large collection of videos in various sign languages. These websites have the potential of being a significant source of knowledge sharing and communication for the members of the deaf and hard-of-hearing community. However, prior studies have shown that traditional keyword-based search does not do a good job of discovering these videos. Dr. Frank Shipman and others have been working towards building a distributed digital library by indexing the sign language videos available online. This system employs an automatic detector, based on visual features extracted from the video, for filtering out non-sign language content. Features such as the amount and location of hand movements, symmetry of motion etc. have been experimented with for this purpose. Caio Monteiro and his team designed a classifier which uses face detection to identify the region-of-interest (ROI) in a frame, and foreground segmentation to estimate amount of hand motion within the region. It was later improved upon by Karappa et al. by dividing the ROI using polar coordinates and estimating motion in each division to form a composite feature set. This thesis work examines another visual feature associated with the signing activity i.e. speed of hand movements. Speed based features performed better compared to the foreground-based features for a complex dataset of SL and non-SL videos. The F1 score showed a jump from 0.73 to 0.78. However, for a second dataset consisting of videos with single signers and static backgrounds, the classification scores dipped. More consistent performance improvements were observed when features from the two feature sets were used in conjunction. F1 score of 0.76 was observed for the complex dataset. For the second dataset, the F1 score changed from 0.85 to 0.86. Another associated problem is identifying the sign language in a video. The impact of speed of motion on the problem of classifying American Sign Language versus British Sign Language was found to be minimal. We concluded that it is the location of motion which influences this problem more than either the speed or the amount of motion. Non-speed related analyses of sign language detection were also explored. Since the American Sign Language alphabet is one-handed, it was expected that videos with left-handed signing might be falsely identified as British Sign Language, which has a two-handed alphabet. We briefly studied this issue with respect to our corpus of ASL and BSL videos and discovered that our classifier design does not suffer from this issue. Apart from this, we explored speeding up the classification process by computing symmetry of motion in the ROI on selected keyframes as a single feature for classification. The resulting feature extraction was significantly faster but the precision and recall values depreciated to 59% and 62% respectively for a F1 score of .61

    Making Digital Artifacts on the Web Verifiable and Reliable

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    The current Web has no general mechanisms to make digital artifacts --- such as datasets, code, texts, and images --- verifiable and permanent. For digital artifacts that are supposed to be immutable, there is moreover no commonly accepted method to enforce this immutability. These shortcomings have a serious negative impact on the ability to reproduce the results of processes that rely on Web resources, which in turn heavily impacts areas such as science where reproducibility is important. To solve this problem, we propose trusty URIs containing cryptographic hash values. We show how trusty URIs can be used for the verification of digital artifacts, in a manner that is independent of the serialization format in the case of structured data files such as nanopublications. We demonstrate how the contents of these files become immutable, including dependencies to external digital artifacts and thereby extending the range of verifiability to the entire reference tree. Our approach sticks to the core principles of the Web, namely openness and decentralized architecture, and is fully compatible with existing standards and protocols. Evaluation of our reference implementations shows that these design goals are indeed accomplished by our approach, and that it remains practical even for very large files.Comment: Extended version of conference paper: arXiv:1401.577

    Developing information services for special library users by designing a low cost digital library : the experiment of NOC-Digital Library

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    This research originates from a belief that special libraries in developing countries need to modernise and implement their ICT infrastructure and articulate information policies that will facilitate the exploitation of information resources to the optimum to increase national productivity. Special libraries and information centres in developing countries in general and in the Arab world in particular should start building their local digital libraries, as the benefit of establishing such electronic services is considerably massive and well known for expansion of research activities and for delivering services that satisfy the needs of targeted users. The aim of this paper is to provide general guideline for design a low cost digital library providing services that are most frequently required by various categories of special library users in developing countries. This paper also aims at illustrating strategies and method approaches that can be adopted for building such projects. The paper intends to describe the phases and stages implemented for building a low cost digital library services for the NOC. It also aims at highlighting the barriers and obstacles facing Arabic content in the digitization stage

    Interactive context-aware user-driven metadata correction in digital libraries

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    Personal name variants are a common problem in digital libraries, reducing the precision of searches and complicating browsing-based interaction. The book-centric approach of name authority control has not scaled to match the growth and diversity of digital repositories. In this paper, we present a novel system for user-driven integration of name variants when interacting with web-based information-in particular digital library-systems. We approach these issues via a client-side JavaScript browser extension that can reorganize web content and also integrate remote data sources. Designed to be agnostic towards the web sites it is applied to, we illustrate the developed proof-of-concept system through worked examples using three different digital libraries. We discuss the extensibility of the approach in the context of other user-driven information systems and the growth of the Semantic Web

    Telematics programme (1991-1994). EUR 15402 EN

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    Stigmergy in Web 2.0: a model for site dynamics

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    Building Web 2.0 sites does not necessarily ensure the success of the site. We aim to better understand what improves the success of a site by drawing insight from biologically inspired design patterns. Web 2.0 sites provide a mechanism for human interaction enabling powerful intercommunication between massive volumes of users. Early Web 2.0 site providers that were previously dominant are being succeeded by newer sites providing innovative social interaction mechanisms. Understanding what site traits contribute to this success drives research into Web sites mechanics using models to describe the associated social networking behaviour. Some of these models attempt to show how the volume of users provides a self-organising and self-contextualisation of content. One model describing coordinated environments is called stigmergy, a term originally describing coordinated insect behavior. This paper explores how exploiting stigmergy can provide a valuable mechanism for identifying and analysing online user behavior specifically when considering that user freedom of choice is restricted by the provided web site functionality. This will aid our building better collaborative Web sites improving the collaborative processes

    Raising awareness of the accessibility challenges in mathematics MOOCs

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    MOOCs provide learning environments that make it easier for learners to study from anywhere, at their own pace and with open access to content. This has revolutionised the field of eLearning, but accessibility continues to be a problem, even more so if we include the complexity of the STEM disciplines which have their own specific characteristics. This work presents an analysis of the accessibility of several MOOC platforms which provide courses in mathematics. We attempt to visualise the main web accessibility problems and challenges that disabled learners could face in taking these types of courses, both in general and specifically in the context of the subject of mathematics
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