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Author: bart

Using the Stardog Connection Pool in a Java Container

At Netage B.V. we are happy users of Stardog since version 4, as a Java shop we have plenty of options to connect and talk to the Stardog server which is great news. Our knowledge graph solutions are without exceptions based on a modular approach where various Java Web Archives (WAR) work together in a Java Container, in our case Tomee. All these applications need their own connection to the Stardog server, which leaves an interesting management challenge, how do you maintain the connection settings? Sharing connection settings When connecting to Stardog a set of connection parameters are required, at…

Knowledge Graph TechnologyOpen StandardsPragmatic AproachStardog

Reboot of “Using interface encapsulation to listen to linked data predicates”

Introduction 3 Years ago I wrote a blog post which was a submission to the ISWC 2014 Developers workshop. The idea has been implemented with the Enyo framework which at the time was still a viable ecosystem. The implementation has been used in production in various installations of our systems. Time has passed on and the EnyoJS framework is no longer supported, its successor was very much tied to react so would be very framework specific. In order to come up with a simple solution to the encapsulation problem I decided to reimplement the whole idea using WebComponents Design Principle…

Knowledge Graph Technologylinked dataTechnology

Central Version reporting of deployed artifacts with JEE

While building our RESC.Info solution stack we found ourselves with the challenge to query the build versions of the components installed. After searching the web and consulting various communities we found out there is no ‘standard’ way of solving this. What we actually wanted is a way to query the installed version of the various modules we deployed to the Java Container without any predefine knowledge which modules are actually installed. We did not want to rely on any platform/container specific solution to solve this. The approach taken Java comes standard with JMX, Java Management Extension, it would be preferable…

Technology

Using interface encapsulation to listen to linked data predicates

Introduction The article was a submission to ISWC 2014 Developer Workshop Linked data and its RDF model is known for its flexible schema less structure and integrated meta-data. Although this is great for expressiveness of the data, its is a nightmare for interface developers since all the modern interface paradigms are tree based. The standard way of interacting with data in these user interfaces is to use application logic to interact with interface elements which needs to query the data and decide which piece of information to put in which element. Trying to push free format RDF in a tree…

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Using IBM DB2 NoSQL Graph Store in Websphere Application Server Community Edition

This is the first of a series of blog posts about our experience with the IBM DB2 Express-C NoSQL Graph Store (hereafter DB2 RDF) in combination with IBM WebSphere Application Server Community Edition (hereafter WASCE). The DB2 RDF product allows the storage and manipulation of RDF data. The data can be stored in graphs, all according to W3C Recommendations. The DB2 RDF product uses the Apache Jena programming model to interact with the underlying store. In the very detailed documentation there is an outline of products and tools needed to get the basic DB2 RDF programming environment going. This series…

linked dataTechnology

Simple Application of Linked Data Principles for Firefighters

One way firefighters world wide assist themselves while navigating through towns and cities is recording ‘distinctive points’ (actually that is how we navigate through smoke as well.) So instead of a ‘turn left at the third traffic light’ we often record ‘turn left at ABC Pharmacy’. So where does linked data come into play? In the current economic situation shops come and go, so ‘ABC Pharmacy’ from the example might be long gone, leaving a driver clueless as where to turn left! What stays the same is the address, but then again navigating on addresses is not really trustworthy so…

linked data

The 99% of the time that public infrastructure does work

When I explain people about what I’m working on, better information for first responders, the conversation quite often drifts into the direction of infrastructure resilience. Telling that I intend to use open data sources, externally hosted API’s, public 3G and internet backbones amazes people. The amount of what-if scenario’s explained to me are endless. And yes, these concerns are very valid. If for example an airplane would crash in the middle of my service area there is more than a fair chance that all public communication networks will be overloaded. But how big is the chance of that actually happening?…

Random thoughts

The confusing shared visual representation

You just finished a novel from your favorite author, while reading you have build a visual image of the scenery described by the author. A bit later the filming by a well known Hollywood director makes it to a cinema nearby. A big fan as you are, you’ll be surely going out to see this movie! But after the opening scene you will find yourself confused and disappointed, the depiction created by the director doesn’t match yours at all. You wake up in the middle of the night during a holiday in a hotel, you have no idea where you…

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Afraid for Open Data

After visiting two Open Data related events in Amsterdam, Apps4nl and Open Innovation Festival, I found myself being afraid of what I had to conclude after these events. This might raise some eyebrows, coming from someone who claims to be a Linked Data enthusiast, and then blogging about being afraid for Open Data. The primary reason that got me started with Linked Data were the problems I saw with the lack of operational access to information. When I needed to explain this problem to the board of directors of the Fire Department Amsterdam I had to explain this in a…

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How it all started, answers to questions that weren’t asked.

About 3 years ago a group of fire fighters at a fire station in Amsterdam was confronted with a new navigation assistant in the fire truck. From a conceptual point of view the idea of having navigation assistance in a fire truck might be nice, but there are practical implications when using a system designed for normal traffic in an emergency vehicle , remember fire trucks are allowed to defy all the rules in traffic! Without elaborating on why it is not working as it should, the more abstract point is that it gives answers to questions we never asked. The…

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