Planet RDF

It's triples all the way down

May 27

Leigh Dodds: Beyond Publishers and Consumers: Some Example Ecosystems

Yesterday I wrote a post suggesting that we should move

Posted at 14:37

AKSW Group - University of Leipzig: AKSW Colloquium, 30.05.2016, PARIS: Probabilistic Alignment of Relations, Instances, and Schema

Mohamed Sherif

In the incoming colloquium, Mohamed Ahmed Sherif will present the paper “PARIS: Probabilistic Alignment of Relations, Instances, and Schema” from Suchanek et al., published in the proceedings of VLDB 2012 [PDF].

Abstract

One of the main challenges that the Semantic Web faces is the integration of a growing number of independently designed ontologies. In this work, we present PARIS, an approach for the automatic alignment of ontologies. PARIS aligns not only instances, but also relations and classes. Alignments at the instance level cross-fertilize with alignments at the schema level. Thereby, our system provides a truly holistic solution to the problem of ontology alignment. The heart of the approach is probabilistic, i.e., we measure degrees of matchings based on probability estimates. This allows PARIS to run without any parameter tuning. We demonstrate the efficiency of the algorithm and its precision through extensive experiments. In particular, we obtain a precision of around 90% in experiments with some of the world’s largest ontologies.

This event is part of a series of events about Semantic Web technology. Please see http://wiki.aksw.org/Colloquium for further information about previous and future events. As always, Bachelor and Master students are able to get points for attendance and there is complimentary coffee and cake after the session.

Posted at 09:33

May 26

Leigh Dodds: Beyond publishers and consumers

In the open data community we tend to focus a lot on Publishers and Consumers.

Publishers have the data we want. We must lobby or convince them that publishing the data would be beneficial. And we need to educate them about licensing and how best to publish data. And we get frustrated when they don’t do those things

Consumers are doing the work to extract value from data. Publishers want to encourage Consumers to do things with their data. But are often

Posted at 16:47

Leigh Dodds: Beyond publishers and consumers

In the open data community we tend to focus a lot on Publishers and Consumers.

Publishers have the data we want. We must lobby or convince them that publishing the data would be beneficial. And we need to educate them about licensing and how best to publish data. And we get frustrated when they don’t do those things

Consumers are doing the work to extract value from data. Publishers want to encourage Consumers to do things with their data. But are often

Posted at 16:47

Leigh Dodds: Designing for the open digital commons

I wanted to share some thinking I’ve been doing around how to create products and services that embrace and support the digital commons. The digital commons is

Posted at 12:00

Leigh Dodds: Designing for the open digital commons

I wanted to share some thinking I’ve been doing around how to create products and services that embrace and support the digital commons. The digital commons is

Posted at 12:00

May 24

Ebiquity research group UMBC: Managing Cloud Storage Obliviously

Vaishali Narkhede, Karuna Pande Joshi, Tim Finin, Seung Geol Choi, Adam Aviv and Daniel S. Roche, Managing Cloud Storage Obliviously, International Conference on Cloud Computing, IEEE Computer Society, June 2016.

Consumers want to ensure that their enterprise data is stored securely and obliviously on the cloud, such that the data objects or their access patterns are not revealed to anyone, including the cloud provider, in the public cloud environment. We have created a detailed ontology describing the oblivious cloud storage models and role based access controls that should be in place to manage this risk. We have developed an algorithm to store cloud data using oblivious data structure defined in this paper. We have also implemented the ObliviCloudManager application that allows users to manage their cloud data by validating it before storing it in an oblivious data structure. Our application uses role-based access control model and collection based document management to store and retrieve data efficiently. Cloud consumers can use our system to define policies for storing data obliviously and manage storage on untrusted cloud platforms even if they are unfamiliar with the underlying technology and concepts of oblivious data structures.

Posted at 18:29

May 23

AKSW Group - University of Leipzig: AKSW Colloquium, 23.05.2016, Instance Matching and RDF Dataset Similarity

In the incoming colloquium, Mofeed Hassan will present the paper “Semi-supervised Instance Matching Using Boosted Classifiers” from Kejriwal et al., published in the proceedings of ESWC 2015 [PDF].

Abstract

Instance matching concerns identifying pairs of instances that refer to the same underlying entity. Current state-of-the-art instance matchers use machine learning methods. Supervised learning systems achieve good performance by training on significant amounts of manually labeled samples. To alleviate the labeling effort, this paper presents a minimally supervised instance matching approach that is able to deliver competitive performance using only 2% training data and little parameter tuning. As a first step, the classifier is trained in an ensemble setting using boosting. Iterative semi-supervised learning is used to improve the performance of the boosted classifier even further, by re-training it on the most confident samples labeled in the current iteration. Empirical evaluations on a suite of six publicly available benchmarks show that the proposed system outcompetes optimization-based minimally supervised approaches in 1-7 iterations. The system’s average F-Measure is shown to be within 2.5% of that of recent supervised systems that require more training samples for effective performance.

After that, Michael Röder will present his paper “Detecting Similar Linked Datasets Using Topic Modelling” that has been accepted by the upcoming ESWC 2016 [PDF].

Abstract

The Web of data is growing continuously with respect to both the size and number of the datasets published. Porting a dataset to five-star Linked Data however requires the publisher of this dataset to link it with the already available linked datasets. Given the size and growth of the Linked Data Cloud, the current mostly manual approach used for detecting relevant datasets for linking is obsolete. We study the use of topic modelling for dataset search experimentally and present TAPIOCA, a linked dataset search engine that provides data publishers with similar existing datasets automatically. Our search engine uses a novel approach for determining the topical similarity of datasets. This approach relies on probabilistic topic modelling to determine related datasets by relying solely on the metadata of datasets. We evaluate our approach on a manually created gold standard and with a user study. Our evaluation shows that our algorithm outperforms a set of comparable baseline algorithms including standard search engines significantly by 6% F1-score. Moreover, we show that it can be used on a large real world dataset with a comparable performance.

About the AKSW Colloquium

This event is part of a series of events about Semantic Web technology. Please see http://wiki.aksw.org/Colloquium for further information about previous and future events. As always, Bachelor and Master students are able to get points for attendance and there is complimentary coffee and cake after the session.

Posted at 12:24

Ebiquity research group UMBC: Streamlining Management of Multiple Cloud Services

cloudhandshake

Aditi Gupta, Sudip Mittal, Karuna Pande Joshi, Claudia Pearce and Anupam Joshi, Streamlining Management of Multiple Cloud Services, IEEE International Conference on Cloud Computing, June 2016.

With the increase in the number of cloud services and service providers, manual analysis of Service Level Agreements (SLA), comparison between different service offerings and conformance regulation has become a difficult task for customers. Cloud SLAs are policy documents describing the legal agreement between cloud providers and customers. SLA specifies the commitment of availability, performance of services, penalties associated with violations and procedure for customers to receive compensations in case of service disruptions. The aim of our research is to develop technology solutions for automated cloud service management using Semantic Web and Text Mining techniques. In this paper we discuss in detail the challenges in automating cloud services management and present our preliminary work in extraction of knowledge from SLAs of different cloud services. We extracted two types of information from the SLA documents which can be useful for end users. First, the relationship between the service commitment and financial credit. We represented this information by enhancing the existing Cloud service ontology proposed by us in our previous research. Second, we extracted rules in the form of obligations and permissions from SLAs using modal and deontic logic formalizations. For our analysis, we considered six publicly available SLA documents from different cloud computing service providers.

Posted at 02:46

May 21

Dydra: Inferring Quicklisp System Descriptions

We presented, at the recent ELS 2016[0], the speculative results from using SPARQL to analyse implicit dependancy relations in the LISP ecosystem, as embodied in a recent Quicklisp[1] release.

Posted at 17:06

Leigh Dodds: First Impressions of Copenhagen’s City Data Exchange

Copenhagen have

Posted at 13:59

Leigh Dodds: First Impressions of Copenhagen’s City Data Exchange

Copenhagen have

Posted at 13:59

May 19

Leigh Dodds: Dungeons and Dragons and Data

I’ve run a number of presentations recently introducing teams at various organisations to the

Posted at 08:17

Leigh Dodds: Dungeons and Dragons and Data

I’ve run a number of presentations recently introducing teams at various organisations to the

Posted at 08:17

May 17

Bob DuCharme: Trying out Blazegraph

Especially inferencing.

Posted at 13:17

May 12

Leigh Dodds: Scoping the Bristol City Council data platform

Today I attended the

Posted at 19:05

Leigh Dodds: Scoping the Bristol City Council data platform

Today I attended the

Posted at 19:05

Frederick Giasson: New UMBEL 1.50 Ships With 20 Linked Ontologies

I am proud to announce the immediate release of UMBEL version 1.50. This is a major effort that took a year to release.

What is UMBEL?

Let’s start by explaining what is UMBEL for the ones that never encountered this project before. UMBEL stands for “Upper Mapping and Binding Exchange Layer“. It is a conceptual structure that is designed to help content interoperate between systems.

UMBEL is a coherent general structure of 34 000 reference concepts which provides a scaffolding to link and interoperate other datasets and domain vocabularies. The conceptual structure is organized in a structure of 31 mostly disjoint SuperType.

UMBEL is written in OWL 2 and SKOS.

What are UMBEL’s Objectives?

UMBEL’s main goals are:

  • To create a scaffolding for defining knowledge graphs
  • To create a rich semantic to identify and help disambiguating entities
  • To help expend queries to semantic search engines
  • To help inter-linking ontologies to create a coherent ontological environment
  • To help structure and federate information silos

What is new in UMBEL version 1.50?

Many things changed in UMBEL 1.50: additional of new concepts, multiple structural fixes and improvements, etc. However there are 3 major changes that occurred in this release:

  1. Complete update and addition of linkages between UMBEL reference concepts and related classes existing in external ontologies
  2. Removal of all the named individuals from UMBEL. UMBEL is now only composed of classes reference concepts
  3. Reshaping of the SuperType upper structure by adding new ones and removing some of them

For the complete list of UMBEL changes, I would strongly suggest you to read Mike’s blog post about this UMBEL release.

UMBEL Mapping to External Ontologies

One interesting aspect of the UMBEL structure is to use the coherent structure to federate information silos. We can do that by linking ontologies and vocabularies, used to describe entities indexed in these silos, directly into UMBEL.

But what does that mean? Let’s take a look at a portion of the UMBEL structure related to actors, authors and their relations to humans:

actors-authors-humans

Now let’s assumes that we have two data sources:

  1. DBpedia from which we want to use its Journalist entities, and
  2. Musicbrainz from which we want to use its solo musical artist entities

The journalist entities of the DBpedia data source belong to the dbpedia:Journalist class of the DBpedia ontology. The Musicbrainz solo musical artists belong to the mo:SoloMusicArtist class of the Music Ontology. If you check each of these ontology, you won’t find any connections between these two classes. They appears to be living in two different [conceptual] worlds.

However, what happens if these two classes get connected to some UMBEL reference concepts? Let’s take a look:

dbpedia-mo-connections

What we did here is to connect the two classes to the UMBEL reference structure using the equivalent to property. What we are stating with these assertions is that these two classes are equivalent to these other classes in UMBEL. This seems harmless, but when we start thinking about that, something special is happening.

The special thing that is happening is that we can now query the different datasets (Musicbrains and DBpedia) on new ground. We can now query them such that if I request to get the list of all humans, then I can and I will get all soloist and all journalist. If the data store to get all authors, then I would get all DBpedia journalists and maybe authors of other datasets that may be linked to the UMBEL reference structure.

This is an illustration of how UMBEL can be used to federate information silos.

The good news is that the UMBEL reference structure is already linked to 20 ontologies used by different organizations to define their data sources:

  1. DBPedia Ontology – Links between the DBpedia Ontology classes and the UMBEL Reference Concepts. Half of them comes from the linkage between Proton and UMBEL, and half the others come from hand mapping
  2. Geonames – Geonames
  3. Opencyc – OpenCyc Ontology
  4. Schema.org – Schema.org ontology defines entities known by Google and other search engines
  5. Wikipedia – Links between the Wikipedia pages and the UMBEL Reference Concepts
  6. DOAP – DOAP(Description of a Project) is a vocabulary for project description.
  7. ORG – The ORG (Core Organization) Ontology is a vocabulary for describing organizational structures for a broad variety of types of organization
  8. OO – OO(Open Organizations) is a vocabulary providing supplementary terms for organizations that wish to publish open data about themselves
  9. TRANSIT – TRANSIT(Transit) is a vocabulary for describing transit systems and routes
  10. TIME – The TIME(Time Ontology) defines temporal entities
  11. BIBO – BIBO (Bibliographic Ontology)
  12. CC – CC (CreativeCommons Ontology)
  13. Event – Event Ontology
  14. FOAF – FOAF (Friend Of A Friend Ontology) used to describe people and organizations
  15. GEO – WSG84 Geographic Ontology
  16. MO – MO (Music Ontology)
  17. PO – PO (Programmes Ontology)
  18. RSS – RSS (Really Simple Syndication Ontology)
  19. SIOC – SIOC (Semantically-Interlinked Online Communities Ontology)
  20. FRBR – FRBR (Functional Requirements for Bibliographic Records)

According to Linked Open Vocabularies (LOV) service, the UMBEL reference structure, along with these 20 ontologies linkage would enable you to reach 504 datasets tracked by LOV.

Posted at 13:53

May 03

AKSW Group - University of Leipzig: AKSW Colloquium, 09.05.2016: Hebrew MMoOn inventory, federated SPARQL query processing

In this week’s colloquium Bettina Klimek will give a practice talk of the paper ‘Creating Linked Data Morphological Language Resources with MMoOn – The Hebrew Morpheme Inventory‘, which she will present at the LREC conference 2016, 23-28 May 2016, Slovenia, Portorož.

Abstract

The development of standard models for describing general lexical resources has led to the emergence of numerous lexical datasets of various languages in the Semantic Web. However, there are no models that describe the domain of morphology in a similar manner. As a result, there are hardly any language resources of morphemic data available in RDF to date. This paper presents the creation of the Hebrew Morpheme Inventory from a manually compiled tabular dataset comprising around 52.000 entries. It is an ongoing effort of representing the lexemes, word-forms and morphologigal patterns together with their underlying relations based on the newly created Multilingual Morpheme Ontology (MMoOn). It will be shown how segmented Hebrew language data can be granularly described in a Linked Data format, thus, serving as an exemplary case for creating morpheme inventories of any inflectional language with MMoOn. The resulting dataset is described a) according to the structure of the underlying data format, b) with respect to the Hebrew language characteristic of building word-forms directly from roots, c) by exemplifying how inflectional information is realized and d) with regard to its enrichment with external links to sense resources.

As a second talk, Muhammad Saleem will present his thesis titled “Efficient Source Selection For SPARQL Endpoint Federation” . This thesis addresses two key areas of federated SPARQL query processing: (1) efficient source selection, and (2) comprehensive SPARQL benchmarks to test and ranked federated SPARQL engines as well as triple stores.

About the AKSW Colloquium

This event is part of a series of events about Semantic Web technology. Please see http://wiki.aksw.org/Colloquium for further information about previous and future events. As always, Bachelor and Master students are able to get points for attendance and there is complimentary coffee and cake after the session. The colloquium will take place in room P701.

Posted at 11:57

Ebiquity research group UMBC: chmod 000 Freebase

rip freebase

He’s dead, Jim.

Google recently shut down the query interface to Freebase. All that is left of this innovative service is the ability to download a few final data dumps.

Freebase was launched nine years ago by Metaweb as an online source of structured data collected from Wikipedia and many other sources, including individual, user-submitted uploads and edits. Metaweb was acquired by Google in July  2010 and Freebase subsequently grew to have more than 2.4 billion facts about 44 million subjects. In December 2014, Google announced that it was closing Freebase and four months later it became read-only. Sometime this week the query interface was shut down.

I’ve enjoyed using Freebase in various projects in the past two years and found that it complemented DBpedia in many ways. Although its native semantics differed from that of RDF and OWL, it was close enough to allow all of Freebase to be exported as RDF.  Its schema was larger than DBpedia’s and the data tended to be a bit cleaner.

Google generously  decided to donate the data to the Wikidata project, which began migrating Freebase’s data to Wikidata in 2015.  The Freebase data also lives on as part of Google’s Knowledge Graph.  Google recently allowed very limited querying of its knowledge graph and my limited experimenting with it suggests that has Freebase data at its core.

Posted at 01:22

May 02

Dublin Core Metadata Initiative: DC-2016 Paper Submission Deadline Extended

2016-05-02, Upon request, DCMI is extending the submission deadline for papers, project reports, and posters for the DC-2016 Technical Program from 13 May to 27 May 2016. The Call for Participation can be found on the conference website at http://dcevents.dublincore.org/index.php/IntConf/dc-2016/schedConf/cfp.

Posted at 23:59

Dublin Core Metadata Initiative: Elsevier's Bradley Allen to deliver DC-2016 keynote

2016-05-02, Bradley P. Allen, Chief Architect at Elsevier, will deliver the keynote address at DC-2016 in Copenhagen, Denmark. Brad has been a serial entrepreneur who has built and led teams in the design, development, launch and operation of innovative Web businesses. He works at the nexus of information retrieval, linked data and machine learning technologies, and is two for three on successful startup exits. Brad leads the Architecture group within Elsevier's technology organization, focusing on aligning technology vision and roadmap with corporate strategy, helping core development teams build and evolve products and infrastructure, and guiding Elsevier Labs' collaborative research into the future of scientific and medical publishing. For more information about the conference, visit http://dcevents.dublincore.org/index.php/IntConf/dc-2016/schedConf/ and subscribe to receive notifications. Conference registration will open June 1.

Posted at 23:59

Dublin Core Metadata Initiative: DCMI Webinar: Modeling and Publishing of Controlled Vocabularies for the UNESKOS Project [Presented in Spanish]

2016-05-02, DCMI/ASIS&T Webinar: This webinar with Juan Antonio Pastor Sánchez, University of Murcia, presents the modeling and publishing process of the vocabularies for the UNESKOS project by applying Semantic Web technologies. More specifically, the vocabularies represented are the UNESCO Thesaurus and the Nomenclature for fields of Science and Technology. Both vocabularies are published as RDF datasets with a structure that allows its query and reuse according to the principles of Linked Open Data. The webinar will demonstrate the application of ISO-25964 standard to represent the UNESCO thesaurus using SKOS and the ISO-THES ontology. Technological solutions used for the project will also be discussed. For more information about the webinar and to register, visit http://dublincore.org/resources/training/#2016sanchez.

Se presentan los procesos de modelado y publicación de los vocabularios del proyecto UNESKOS aplicando tecnologías de la Web Semántica. Más específicamente, los vocabularios representados son el Tesauro de la UNESCO y la Nomenclatura de Ciencia y Tecnología. Ambos vocabularios están publicados como conjuntos de datos RDF con una estructura para facilitar su consulta y reutilización según los principios Linked Open Data. También se muestra como se ha aplicado la norma ISO-25964 para representar el tesauro de la UNESCO utilizando conjuntamente SKOS y la ontología ISO-THES. Asímismo se analizarán las soluciones tecnológicas empleadas para el proceso de publicación y consulta de ambos vocabularios. Registro: http://dublincore.org/resources/training/#2016sanchez.

Posted at 23:59

May 01

Ebiquity research group UMBC: Representing and Reasoning with Temporal Properties/Relations in OWL/RDF

Representing and Reasoning with Temporal
Properties/Relations in OWL/RDF

Clare Grasso

10:30-11:30 Monday, 2 May 2016, ITE346

OWL ontologies offer the means for modeling real-world domains by representing their high-level concepts, properties and interrelationships. These concepts and their properties are connected by means of binary relations. However, this assumes that the model of the domain is either a set of static objects and relationships that do not change over time, or a snapshot of these objects at a particular point in time. In general, relationships between objects that change over time (dynamic properties) are not binary relations, since they involve a temporal interval in addition to the object and the subject. Representing and querying information evolving in time requires careful consideration of how to use OWL constructs to model dynamic relationships and how the semantics and reasoning capabilities within that architecture are affected.

Posted at 21:13

April 30

Leigh Dodds: 101100

Today I am 101100.

That’s

Posted at 08:10

Leigh Dodds: 101100

Today I am 101100.

That’s

Posted at 08:10

April 25

Leigh Dodds: Data marketplaces, we hardly knew ye

I’m on a panel at the ODI lunchtime lecture this week, where I’m hoping to help answer the question of “

Posted at 16:21

Leigh Dodds: Data marketplaces, we hardly knew ye

I’m on a panel at the ODI lunchtime lecture this week, where I’m hoping to help answer the question of “

Posted at 16:21

April 23

Bob DuCharme: Playing with a proximity beacon

Nine-dollar devices send URLs to your phone over Bluetooth.

Posted at 13:30

April 22

AKSW Group - University of Leipzig: AKSW Colloquium, 25.04.2016, DISPONTE, Workbench for Big Data Dev

In this colloquium, Frank Nietzsche will present his master thesis titled “Game Theory- distributed solving”

Game theory analyzes the behavior of individuals in complex situations. One popular game in Europe and North America with such a complex situation is Skat. For the analysis of the game, the counterfactual regret minimization algorithm (CFR algorithm) was applied. Unfortunately, there is no guarantee that the algorithm works in three-person games. In general, it is difficult to solve three-person games. In addition, the algorithm calculates only a epsilon-Nash equilibrium. But for Skat, the Perfect Bayesian equilibrium would be a better solution. In fact, the Perfect Bayesian equilibrium is a subset of the Nash equilibrium. This raises the question of whether a Perfect Bayesian equilibrium can be calculated using the CFR algorithm. The analysis of this problem will be the last part of the presentation.

The second talk of the colloquium,  Dr. Michael Martin will  announce the student thesis on the AKSW website.

 

About the AKSW Colloquium

This event is part of a series of events about Semantic Web technology. Please see http://wiki.aksw.org/Colloquium for further information about previous and future events. As always, Bachelor and Master students are able to get points for attendance and there is complimentary coffee and cake after the session.

Posted at 14:05

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