65 research outputs found

    Mobile and web tools for participative learning

    Get PDF
    Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, para a obtenção do grau de Mestre em Engenharia InformáticaThe combination of different media formats has been a crucial aspect on teaching and learning processes. The recent developments of multimedia technologies over the Internet and using mobile devices can improve the communication between professors and students, and allow students to study anywhere and anytime, allowing each student progress at its own pace. The usage of these new platforms and the increase of multimedia sharing applied to educational environments allow a more participative learning, and make the study of interfaces a relevant aspect of existing multimedia learning systems. The work done in this dissertation explores interfaces and tools for participative learning,using multimedia educational systems over Internet broadband and mobile devices. In this work, aWeb-based learning system was developed, which enables to store, transmit, search and share the contents of courses captured in video and its extension to support Tablet PCs. The Web system, developed as part of the VideoStore project, explores video interfaces and video annotations, which encourage the participative work. The usage of Tablet PCs, through the mEmLearn project, has the aim to encourage the participative work, allowing the students to augment the course materials and to share them with other students or instructors

    Automated Podcasting System for Universities

    Get PDF
    This paper presents the results achieved at Graz University of Technology (TU Graz) in the field of automating the process of recording and publishing university lectures in a very new way. It outlines cornerstones of the development and integration of an automated recording system such as the lecture hall setup, the recording hardware and software architecture as well as the development of a text-based search for the final product by method of indexing video podcasts. Furthermore, the paper takes a look at didactical aspects, evaluations done in this context and future outlook

    Improving Searchability of Automatically Transcribed Lectures Through Dynamic Language Modelling

    Get PDF
    Recording university lectures through lecture capture systems is increasingly common. However, a single continuous audio recording is often unhelpful for users, who may wish to navigate quickly to a particular part of a lecture, or locate a specific lecture within a set of recordings. A transcript of the recording can enable faster navigation and searching. Automatic speech recognition (ASR) technologies may be used to create automated transcripts, to avoid the significant time and cost involved in manual transcription. Low accuracy of ASR-generated transcripts may however limit their usefulness. In particular, ASR systems optimized for general speech recognition may not recognize the many technical or discipline-specific words occurring in university lectures. To improve the usefulness of ASR transcripts for the purposes of information retrieval (search) and navigating within recordings, the lexicon and language model used by the ASR engine may be dynamically adapted for the topic of each lecture. A prototype is presented which uses the English Wikipedia as a semantically dense, large language corpus to generate a custom lexicon and language model for each lecture from a small set of keywords. Two strategies for extracting a topic-specific subset of Wikipedia articles are investigated: a naïve crawler which follows all article links from a set of seed articles produced by a Wikipedia search from the initial keywords, and a refinement which follows only links to articles sufficiently similar to the parent article. Pair-wise article similarity is computed from a pre-computed vector space model of Wikipedia article term scores generated using latent semantic indexing. The CMU Sphinx4 ASR engine is used to generate transcripts from thirteen recorded lectures from Open Yale Courses, using the English HUB4 language model as a reference and the two topic-specific language models generated for each lecture from Wikipedia

    Cyclic di-GMP mediates a histidine kinase/phosphatase switch by noncovalent domain cross-linking

    Get PDF
    Histidine kinases are key components of regulatory networks in bacteria. Although many of these enzymes are bifunctional, mediating both phosphorylation and dephosphorylation of downstream targets, the molecular details of this central regulatory switch are unclear. We showed recently that the universal second messenger cyclic di-guanosine monophosphate (c-di-GMP) drives Caulobacter crescentus cell cycle progression by forcing the cell cycle kinase CckA from its default kinase into phosphatase mode. We use a combination of structure determination, modeling, and functional analysis to demonstrate that c-di-GMP reciprocally regulates the two antagonistic CckA activities through noncovalent cross-linking of the catalytic domain with the dimerization histidine phosphotransfer (DHp) domain. We demonstrate that both c-di-GMP and ADP (adenosine diphosphate) promote phosphatase activity and propose that c-di-GMP stabilizes the ADP-bound quaternary structure, which allows the receiver domain to access the dimeric DHp stem for dephosphorylation. In silico analyses predict that c-di-GMP control is widespread among bacterial histidine kinases, arguing that it can replace or modulate canonical transmembrane signaling

    Cloud Computing in Nigeria: The Cloud Ecosystem Perspective

    Get PDF
    Information and Communications Technology (ICT) has gone through different phases of development, and the world is witnessing the emergence of a new technology paradigm called cloud computing. Cloud computing has pervasive access, its usage is simple and utilities are offered in pay-as-you-use. It therefore has the potential to open up ICT penetration in education, transaction, collaboration, information dissemination and in other areas of the life of a modern man. The cloud ecosystem describes the complex system of interdependent components that work together to enable cloud services provided to user. This paper presents a critical analysis of the benefits and challenges posed by the adoption and usage of cloud computing. Also presented is the relationship between important stakeholders in the cloud ecosystem. The paper further proposes methods of optimizing the benefits of cloud computing while reducing the challenges that might occur due to its adoption.http://dx.doi.org/10.4314/njt.v34i1.2

    Cyberinfrastructure for Airborne Sensor Webs

    Get PDF
    Since 2004 the NASA Airborne Science Program has been prototyping and using infrastructure that enables researchers to interact with each other and with their instruments via network communications. This infrastructure uses satellite links and an evolving suite of applications and services that leverage open-source software. The use of these tools has increased near-real-time situational awareness during field operations, resulting in productivity improvements and the collection of better data. This paper describes the high-level system architecture and major components, with example highlights from the use of the infrastructure. The paper concludes with a discussion of ongoing efforts to transition to operational status

    CrdS and CrdA Comprise a Two-Component System That Is Cooperatively Regulated by the Che3 Chemosensory System in Myxococcus xanthus

    Get PDF
    Myxococcus xanthus serves as a model organism for development and complex signal transduction. Regulation of developmental aggregation and sporulation is controlled, in part, by the Che3 chemosensory system. The Che3 pathway consists of homologs to two methyl-accepting chemotaxis proteins (MCPs), CheA, CheW, CheB, and CheR but not CheY. Instead, the output for Che3 is the NtrC homolog CrdA, which functions to regulate developmental gene expression. In this paper we have identified an additional kinase, CrdS, which directly regulates the phosphorylation state of CrdA. Both epistasis and in vitro phosphotransfer assays indicate that CrdS functions as part of the Che3 pathway and, in addition to CheA3, serves to regulate CrdA phosphorylation in M. xanthus. We provide kinetic data for CrdS autophosphorylation and demonstrate specificity for phosphotransfer from CrdS to CrdA. We further demonstrate that CheA3 destabilizes phosphorylated CrdA (CrdA~P), indicating that CheA3 likely acts as a phosphatase. Both CrdS and CheA3 control developmental progression by regulating the phosphorylation state of CrdA~P in the cell. These results support a model in which a classical two-component system and a chemosensory system act synergistically to control the activity of the response regulator CrdA

    Improving searchability of automatically transcribed lectures through dynamic language modelling

    Get PDF
    Recording university lectures through lecture capture systems is increasingly common. However, a single continuous audio recording is often unhelpful for users, who may wish to navigate quickly to a particular part of a lecture, or locate a specific lecture within a set of recordings. A transcript of the recording can enable faster navigation and searching. Automatic speech recognition (ASR) technologies may be used to create automated transcripts, to avoid the significant time and cost involved in manual transcription. Low accuracy of ASR-generated transcripts may however limit their usefulness. In particular, ASR systems optimized for general speech recognition may not recognize the many technical or discipline-specific words occurring in university lectures. To improve the usefulness of ASR transcripts for the purposes of information retrieval (search) and navigating within recordings, the lexicon and language model used by the ASR engine may be dynamically adapted for the topic of each lecture. A prototype is presented which uses the English Wikipedia as a semantically dense, large language corpus to generate a custom lexicon and language model for each lecture from a small set of keywords. Two strategies for extracting a topic-specific subset of Wikipedia articles are investigated: a naïve crawler which follows all article links from a set of seed articles produced by a Wikipedia search from the initial keywords, and a refinement which follows only links to articles sufficiently similar to the parent article. Pair-wise article similarity is computed from a pre-computed vector space model of Wikipedia article term scores generated using latent semantic indexing. The CMU Sphinx4 ASR engine is used to generate transcripts from thirteen recorded lectures from Open Yale Courses, using the English HUB4 language model as a reference and the two topic-specific language models generated for each lecture from Wikipedia. Three standard metrics – Perplexity, Word Error Rate and Word Correct Rate – are used to evaluate the extent to which the adapted language models improve the searchability of the resulting transcripts, and in particular improve the recognition of specialist words. Ranked Word Correct Rate is proposed as a new metric better aligned with the goals of improving transcript searchability and specialist word recognition. Analysis of recognition performance shows that the language models derived using the similarity-based Wikipedia crawler outperform models created using the naïve crawler, and that transcripts using similarity-based language models have better perplexity and Ranked Word Correct Rate scores than those created using the HUB4 language model, but worse Word Error Rates. It is concluded that English Wikipedia may successfully be used as a language resource for unsupervised topic adaptation of language models to improve recognition performance for better searchability of lecture recording transcripts, although possibly at the expense of other attributes such as readability

    Automation and robotics for the Space Exploration Initiative: Results from Project Outreach

    Get PDF
    A total of 52 submissions were received in the Automation and Robotics (A&R) area during Project Outreach. About half of the submissions (24) contained concepts that were judged to have high utility for the Space Exploration Initiative (SEI) and were analyzed further by the robotics panel. These 24 submissions are analyzed here. Three types of robots were proposed in the high scoring submissions: structured task robots (STRs), teleoperated robots (TORs), and surface exploration robots. Several advanced TOR control interface technologies were proposed in the submissions. Many A&R concepts or potential standards were presented or alluded to by the submitters, but few specific technologies or systems were suggested

    Holograms for seamless integration of remote students in the classroom

    Get PDF
    The new global scenario imposed by the SARS-CoV-2 virus has given rise to an atypical and problematic situation in multiple spheres. In very little time, the abrupt change from face-to-face to remote has not only required a rapid widespread use of digital technology, but also a change in methodology and communicative interactions. In the field of education, teachers have had to interact in new environments, with the combined use of face-to-face and non-face-to-face teaching being a major challenge. This paper presents the design and implementation of a cyber presence system for educational environments using Microsoft’s HoloLens 2 Mixed Reality (MR) headset. A software tool is developed that improves teaching scenarios through communication in mixed environments. The tool enables teachers to integrate the students in the classroom in a common space with remote students connected by videoconference. Our system is not limited to education, however, as it can also be deployed in any setting that requires remote communication, such as companies and governmental institutions.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was carried out under the framework of the grant PID2022-138453OB-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. Partial work carried out by Bessie Dominguez-Dager has been funded by the grant UAIND21-04C from University of Alicante
    corecore