A Voice Service Development Kit for the Kasadaka platform

[This post is written by André Baart and describes his MSc thesis]

While the internet usage in the developing world is still low, the adoption of simple mobile phones is widespread. A way to offer the advantages of the internet to these populations is voice-based information systems. The KasaDaka voice-services platform is aimed at providing voice-services in the context of ICT for Development (ICT4D). The platform is based on a Raspberry Pi and a GSM modem, which enables affordable voice-service hosting, using the locally available GSM network. The platform takes into account the special requirements of the ICT4D context, such as limited internet connectivity and low literacy rates.

This research focuses on lowering the barrier to entry of voice-service development, by reducing the skill set needed to do so. A Voice Service Development Kit (VSDK) is developed that allows the development of voice-services by deploying and customizing provided building-blocks. These building blocks each represent a type of interaction that is often found in voice-services. (for example a menu, user voice input or the playback of a message) The researcher argues that the simplification of voice-service development is an essential step towards sustainable voice-services in the ICT4D context; As this increases the potential number of local voice-service developers, hremoving the dependency on foreign (and thus expensive) developers and engineers. This simplification should ideally be achieved by providing a graphical interface to voice-service development.

The VSDK was evaluated during the ICT4D course at the Vrije Universiteit Amsterdam, where students built applications for various ICT4D use-cases using the VSDK. Afterwards a survey was conducted, which provided insight on the students’ experiences with voice-service development and the VSDK. From the results of the evaluation is concluded that the building-block approach to voice-service development used in the VSDK, is successful for the development of simple voice-services. It allows newcomers to (voice-service) development, to quickly develop (simple) voice-services from a graphical interface, without requiring programming experience.

The VSDK combined with the existing KasaDaka platform provides a good solution to the hosting and development of voice-services in the ICT4D context.

More details can be found in the complete thesis.A slidedeck is included below. You can find the VSDK code on Andre’s Github: http://github.com/abaart/KasaDaka-VSDK

 

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Source: Victor de Boer

Posted in Staff Blogs, Victor de Boer

Machine-to-machine communication in rural conditions: Realizing KasadakaNet

[This post describes research by Fahad Ali and is based on his Msc. thesis]

Contextual constraints (lack of infrastructure, low-literacy etc.) play an important role in ICT for Development (ICT4D) projects. The Kasadaka project offers a technological platform for knowledge sharing applications in rural areas in Sub-Saharan Africa. However, lack of stable internet connections restrict exchange of data between distributed Kasadaka instances, which leads us to research alternative ways of machine-to-machine (m2m) communication.

Example of a KasadakaNet situation, with a wifi-donkey mounted on a bus, visiting a city and two remote villages, creating a so-called sneakernet

Fahad Ali’s research focuses on mobile elements and using wifi sneakernets for this m2m to enable information sharing between geographically distributed devices. He developed a Raspberry Pi-based device called the Wifi-donkey that can be mounted on a vehicle and facilitates information exchange with nearby devices, using the built-in wifi card of the rPi 3.The solution is based on Piratebox offline file-sharing and communications system built with free software and uses off-the-shelf Linux software components and configuration settings to allow it to discover and connect to nearby Kasadaka devices based using Wifi technologies.

Experimental setup: the wifi-donkey taped to an Amsterdam balcony to test range and bandwith.

We evaluated the solution by simulating a low resource setting and testing it by performing so-called “pass-bys” in an Amsterdam residential area. In these cases, SPARQL queries are exchanged between host and client devices and we measure amount of RDF triples transferred. This setup matches earlier case requirements as described in Onno Valkering’s work.Results show that the system works fairly reliably in the simulated setting. The machine-to-machine communication method can be used in various ICT4D projects that require some sort of data sharing functionality.

You can find out more about Fahad’s work through the following resources:

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DIVE+ collection enrichment paper wins best paper award at MTSR2017

Last week, I visited the 11th Metadata and Semantics Research Conference (MTSR2017) in Tallinn, Estonia. This conference brings together computer scientists. information scientists and people from the domain of digital libraries to discuss their work in metadata and semantics. The 2017 edition of the conference draws around 70 people which is a great size for a single-track conference with lively discussions. The paper included interesting tracks on Cultural Heritage and Library (meta)data as well as one on Digital Humanities.

On the last day I presented our paper “Enriching Media Collections for Event-based Exploration” [draft pdf], co-authored with the people in the CLARIAH and DIVE+ team working on data enrichment and APIs: Liliana Melgar, Oana Inel Carlos Martinez Ortiz, Lora Aroyo and Johan Oomen.  The slides for the presentation can be found here on slideshare. We were very happy to hear that our paper was presented the MTSR2017 Best Paper Award!

In the paper, we present a methodology to publish, represent, enrich, and link heritage collections so that they can be explored by domain expert users. We present four methods to derive events from media object descriptions. We also present a case study where four datasets with mixed media types are made accessible to scholars and describe the building blocks for event-based proto-narratives in the knowledge graph

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Source: Victor de Boer

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Trip Report: ISWC 2017

Last week, I conferenced! I attended the 16th International Semantic Web Conference (ISWC 2017) in Vienna at the beginning of the week and then headed up to FORCE 2017 in Berlin for the back half of the week. For the last several ISWC, I’ve been involved in the organizing committee, but this year I got to relax. It was a nice chance to just be an attendee and see what was up. This was made even nicer by the really tremendous job Axel, Jeff and their team did  in organizing both the logistics and program. The venues were really amazing and the wifi worked!

WU campus #iswc2017 #UrbanSketchers pic.twitter.com/LYeEgFlNy4

— Sean Bechhofer (@seanbechhofer) October 22, 2017

Amazing reception in the Vienna city hall for all #iswc2017 attendees. Enjoy the conference! pic.twitter.com/aQvZTxhNNj

— Javier Fernández (@ciutti) October 22, 2017

#iswc2017 posters and demo session in the @wu_vienna spaceship library pic.twitter.com/5Jbo6ulkrn

— Marieke van Erp (@merpeltje) October 23, 2017

Before getting into what I thought were the major themes of the conference, lets do some stats:

  • 624 participants
  • Papers
    • Research track: 197 submissions – 44 accepted – 23% acceptance rate
    • In-use: 27 submissions – 9  accepted – 33% acceptance rate
    • Resources: 73 submissions – 23 accepted – 31% acceptance rate
  • 46 posters & 61 demos
  • Over 1000 reviews were done excluding what was done for the workshop / demos / posters. Just a massive amount of work in helping work get better.

This year they expanded the number of best reviewers and I was happy to be one of them:

The best reviewers of @iswc2017 #iswc2017 – research, resources + in-use – really important work! pic.twitter.com/j30HApBqdJ

— Paul Groth (@pgroth) October 23, 2017

You can find all the papers online as preprints.

The three themes I took away from the conference were:

  1. Ecosystems for knowledge engineering
  2. Learn from everything
  3. More media

Ecosystems for knowledge engineering

This was a hard theme to find a title for but there were several talks about how to design and engineer the combination of social and technical processes to build knowledge graphs. Deborah McGuinness in her keynote talked about how it took a village to create effective knowledge driven systems. These systems are the combination of experts, knowledge specialists, systems that do ML, ontologies, and data sources. Summed up by the following slide:

#iswc2017 @dlmcguinness takeaway artifact: Semantic-enable Framework pic.twitter.com/7tVqt80fjA

— iswc2017 (@iswc2017) October 23, 2017

My best idea is that this would fall under the rubric of knowledge engineering. Something that has always been part of the semantic web community. What I saw though was the development of more extensive ideas and guidelines about how to create and put into practice not just human focused systems but entire social-techical ecosystems that leveraged all manner of components.

Some examples: Gil et al.’s paper on  creating a platform for high-quality ontology development and data annotation explicitly discusses the community organization along with the platform used to enable it. Knoblock et al’s paper on creating linked data for the American Art Collaborative discusses not only the technology for generating linked data from heterogenous sources but the need for a collaborative workflow facilitated by a shared space (Github) but also the need for tools used to do expert review.  In one of my favorite papers, Piscopo et al evaluated the the provenance of Wikidata statements and also developed machine learning models that could judge authoritativeness & relevance of potential source material. This could provide a helpful tool in allowing Wikidata editors to garden the statements automatically added by bots. As a last example, Jamie Taylor in his keynote discussed how at Google they have a Knowledge Graph Schema team that is there to support a developers in creating interlocking data structures. The team is focused on supporting and maintaining quality of the knowledge graph.

A big discussion area was the idea coming out of the US for a project / initiative around an Open Knowledge Network introduced by Guha. Again, I’ll put this under the notion of how to create these massive social-technical knowledge systems.

I think more work needs to be done in this space not only with respect to the dynamics of these ecosystems as Michael Lauruhn and I discussed in a recent paper but also from a reuse perspective as Pascal Hitzler has been talking about with ontology design patterns.

Learn from everything

The second theme for me was learning from everything. Essentially, this is the use of the combination of structured knowledge and unstructured data within machine learning scenarios to achieve better results. A good example of this was presented by Achim Rettinger on using cross modal embeddings to improve semantic similarity and type prediction tasks:

Nice presentation by Achim Rettinger about a cross modal approach combining knowledge, visual and textual features #iswc2017 pic.twitter.com/Q6k74A6yUD

— Jörn Hees (@joernhees) October 25, 2017

Likewise, Nada Lavrač discussed in her keynote how to different approaches for semantic data mining, which also leverages different sources of information for learning. In particular, what was interesting is the use of network analysis to create a smaller knowledge network to learn from.

Nada Lavrač #keynote on the power of flattening Structured Data for #datamining and a few takeaway notes for #iswc2017 pic.twitter.com/Py6IfWaqBv

— iswc2017 (@iswc2017) October 24, 2017

A couple of other examples include:

It’s worth calling out the winner of the renewed  Semantic Web Challenge from IBM, which used deep learning in combination with sources such as dbpedia, geonames and background assumptions for relation learning.

2017-10-23 20.44.14.jpg

Socrates – Winner SWC

(As an aside, I think it’s pretty cool that the challenge was won by IBM on data provided by Thomson Reuters with an award from Elsevier. Open innovation at its best.)

For a more broad take on the complementarity between deep learning and the semantic web, Dan Brickley’s paper is a fun read. Indeed, as we start to potentially address common sense knowledge we will have to take more opportunity to learn from everywhere.

Future of knowledge graph according to Jamie Taylor #iswc2017 keynote: Linking entities to actions, commonsense (but important!) knowledge https://t.co/2xjWqNIRZX

— Yolanda Gil (@yolandagil) October 25, 2017

More media

Finally, I think we saw an increase in the number of works dealing with different forms of media. I really enjoyed the talk on Improving Visual Relationship Detection using Semantic Modeling of Scene Descriptions given by Stephan Brier. Where they used a background knowledge base to improve relation prediction between portions of images:

tresp.png

There was entire session focused on multimodal linked data including talks on audio ( MIDI LOD cloud, the Internet Music Archive as linked data) and images IMGPedia content analyzed linked data descriptions of Wikimedia commons.  You can even mash-up music with the SPARQL-DJ.

Conclusion

DBPedia won the 10 year award paper. 10 years later semantic technologies and in particular the notion of a knowledge graph are mainstream (e.g. Thomson Reuters has a 100 billion node knowledge graph). While we may still be focused too much on the available knowledge graphs  for our research work, it seems to me that the community is branching out to begin to answer a range new questions (how to build knowledge ecosystems?, where does learning fit?, …) about the intersection of semantics and the web.

Random Notes:

Filed under: academia, linked data, trip report Tagged: #iswc2017, #linkeddata, machine learning, semantic tech, semantic web
Source: Think Links

Posted in Paul Groth, Staff Blogs

Dancing and Semantics

This post describes the MSc theses of Ana-Liza Tjon-a-Pauw and Josien Jansen. 

As a semantic web researcher, it is hard to sometimes not see ontologies and triples in aspects of my private life. In this case, through my contacts with dancers and choreographers, I have since a long time been interested in exploring knowledge representation for dance. After a few failed attempts to get a research project funded, I decided to let enthusiastic MSc. students have a go to continue with this exploration. This year, two Information Sciences students, Josien Jansen and Ana-Liza Tjon-a-Pauw, were willing to take up this challenge, with great success. With their background as dancers they did not only have the necessary background knowledge at but also access to dancers who could act as study and test subjects.

The questions of the two projects was therefore: 1) How can we model and represent dance in a sensible manner so that computers can make sense of choreographs and 2) How can we communicate those choreographies to the dancers?

Screenshot of the mobile choreography assistant prototype

Josien’s thesis addressed this first question. Investigating to what extent choreographers can be supported by semi-automatic analysis of choreographies through the generation of new creative choreography elements. She conducted an online questionnaire among 54 choreographers. The results show that a significant subgroup is willing to use an automatic choreography assistant in their creative process. She further identified requirements for such an assistant, including the semantic levels at which should operate and communicate with the end-users. The requirements are used for a design of a choreography assistant “Dancepiration”, which we implemented as a mobile application. The tool allows choreographers to enter (parts of) a choreography and uses multiple strategies for generating creative variations in three dance styles. Josien  evaluated the tool in a user study where we test a) random variations and b) variations based on semantic distance in a dance ontology. The results show that this latter variant is better received by participants. We furthermore identify many differences between the varying dance styles to what extent the assistant supports creativity.

Four participants during the 2nd user experiment. From left to right this shows variations presented through textual, 2D animation, 3D animation, and auditory instructions.

In her thesis, Ana-Liza dove deeper into the human-computer interaction side of the story. Where Josien had classical ballet and modern dance as background and focus, Ana-Liza looked at Dancehall and Hip-Hop dance styles. For her project, Ana-Liza developed four prototypes that could communicate pieces of computer-generated choreography to dancers through Textual Descriptions, 2-D Animations, 3-D Animations, and Audio Descriptions. Each of these presentation methods has its own advantages and disadvantages, so Ana-Liza made an extensive user survey with seven domain experts (dancers). Despite the relatively small group of users, there was a clear preference for the 3-D animations. Based on the results, Ana-Liza also designed an interactive choreography assistant (IDCAT).

The combined theses formed the basis of a scientific article on dance representation and communication that was accepted for publication in the renowned ACE entertainment conference, co-authored by us and co-supervisor Frank Nack.

You can find more information here:

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ABC-Kb Network Insitute project kickoff

The ABC-Kb team, clockwise from top-left: Dana Hakman, Cerise Muller, Victor de Boer, Petra BosVU’s Network Institute has a yearly Academy Assistant programme where small interdisciplinary research projects are funded. Within these projects, Master students from different disciplines are given the opportunity to work on these projects under supervision of VU staff members. As in previous years, this year, I also participate as a supervisor in one of these projects, in collaboration with Petra Bos from the Applied Linguistics department. And after having found two enthusiastic students: Dana Hakman from Information Science and Cerise Muller from Applied Linguistics, the project has just started.

Our project “ABC-Kb: A Knowledge base supporting the Assessment of language impairment in Bilingual Children” is aimed at supporting language therapists by (re-)structuring information about language development for bilingual children. Speech language therapists and clinical linguists face the challenge of diagnosing children as young as possible, also when their home language is not Dutch. Their achievements on standard (Dutch) language tests will not be reliable indicators for a language impairment. If diagnosticians had access to information on the language development in the Home Language of these children, this would be tremendously helpful in the diagnostic process.

This project aims to develop a knowledge base (KB) collecting relevant information on the specificities of 60 different home languages (normal and atypical language development), and on contrastive analyses of any of these languages with Dutch. To this end, we leverage an existing wiki: meertaligheidentaalstoornissenvu.wikispaces.com

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DIVE+ in Europeana Insight

This months’ edition of Europeana Insight features articles from this year’s LODLAM Challenge finalists, which include the winner: DIVE+. The online article “DIVE+: EXPLORING INTEGRATED LINKED MEDIA” discusses the DIVE+ User studies, data enrichment, exploratory interface and impact on the cultural heritage domain.

The paper was co-authored by Victor de Boer, Oana Inel, Lora Aroyo, Chiel van den Akker, Susane Legene, Carlos Martinez, Werner Helmich, Berber Hagendoorn, Sabrina Sauer, Jaap Blom, Liliana Melgar and Johan Oomen

Screenshot of the Europeana Insight article

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Source: Victor de Boer

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SEMANTiCS2017

This year, I was conference chair of the SEMANTiCS conference, which was held 11-14 Sept in Amsterdam. The conference was in my view a great success, with over 310 visitors across the four days, 24 parallel sessions including academic and industry talks, six keynotes, three awards, many workshops and lots of cups of coffee. I will be posting more looks back soon, but below is a storify item giving an idea of all the cool stuff that happened in the past week.

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Source: Victor de Boer

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Event Extraction From Radio News Bulletins For Linked Data

[This post is based on the BSc. Thesis of Kim van Putten (Computer Science, VU Amsterdam)]

As part of the Bachelor’s degree Computer Science at the VU Amsterdam, Kim van Putten conducted her bachelor thesis in the context of the DIVE+ project .

The DIVE+ demonstrator is an event-centric linked data browser which aims to provide exploratory search within a heterogeneous collection of historical media objects. In order to structure and link the media objects in the dataset, the events need to be identified first. Due to the size of the data collection manually identifying events in infeasible and a more automatic approach is required. The main goal of the bachelor project was to find a more effective way to extract events from the data to improve linkage within the DIVE+ system.

The thesis focused on event extraction from radio news bulletins of which the text content were extracted using optical character recognition (OCR). Data preprocessing was performed to remove errors from the OCR’ed data. A Named Entity Recognition (NER) tool was used to extract named events and a pattern-based approach combined with NER and part-of-speech tagging tools was adopted to find unnamed events in the data. Errors in the data caused by the OCR were found to cause poor performance of the NER tools, even after data cleaning.

The results show that the proposed methodology improved upon the old event extraction method. The newly extracted events improved the searchability of the media objects in the DIVE+ system, however, they did not improve the linkage between objects in the linked data structure. Furthermore,
the pattern-based method of event extraction was found to be too coarse-grained and only allowed for the extraction of one event per object. To achieve a finer granularity of event extraction, future research is necessary to find a way to identify what the relationships between Named Entities and verbs are and which Named Entities and verbs describe an event.

The full thesis is available for download here and the presentation here. Following, we show a poster that summrizes the main findings and the presentation of the thesis.

Poster - Event Extraction for Radio New Bulletins

Posted in DIVE+

Discovering the underlying structure of controversial issues with topic modeling

[This post is by Tibor Vermeij about his Master project]

For the Master project of the Information Sciences programme at the Vrije Universiteit, Tibor Vermeij investigated a solution to discover the structure of controversial issues on the web. The project was done in collaboration with the Controcurator project.

Detecting controversy computationally has been getting more and more attention. Because there is a lot of data available digitally, controversy detection methods that make use of machine learning and natural language processing techniques have become more common. However, a lot of studies try to detect the controversy of articles, blog post or tweets individually. The relation between controversial entities on the web is not often explored.

To explore the structure of controversial issues a combination of topic modeling and hierarchical clustering was used. With topic modeling, the content discussed in a set of Guardian articles was discovered. The resulting topics were used as input for a Hierarchical agglomerative clustering algorithm to find the relations between articles.

The clusters were evaluated with a user study. A Questionnaire was sent out that tested the performance of the pipeline in three categories: The similarity of articles within a cluster, the cohesion of the clusters and the hierarchy and the relation between controversy of single articles compared to the controversy of their corresponding clusters.

The questionnaire showed promising results. The approach can be used to get an indication of the general content of the articles. Articles within the same cluster were more similar compared to articles of different clusters, which means that the chosen clustering method resulted in coherent topics in the controversial clusters that were retrieved. Opinions on controversy itself showed a high amount of variance between participants, re-enforcing the subjectiveness of human controversy estimation. While the deviation between the individual assessments was quite high, averaged rater scores were comparable to calculated scores which suggest a correlation between the controversy of articles within the same cluster.

The full thesis can be found here https://drive.google.com/file/d/0B6qAc8tgJOHUWVo4UURqWkZ1UDg/view?usp=sharing.

The presentation can be found here https://drive.google.com/open?id=14ELkY_9UxppL62uxLg5cAMk8yYKqmHKFQtbAznT3HX0.

Posted in Masters Projects