Open Belgium 2021: The base API for open data linked Data Event Streams
Watch on YouTubeVideo summary
The Linked Data Event Stream (LDES) specification is introduced as a foundational API designed to modernize open data publishing by addressing critical issues such as "maintenance hell" and data replication problems inherent in managing numerous specific APIs. Unlike traditional feeds like RSS or Atom, LDES functions as an always-growing collection of immutable objects timestamped at creation, allowing users to access historical versions without altering the original truth. This architecture supports semantic pagination and fragmentation strategies based on geospatial, temporal, or prefix criteria, enabling efficient "just-in-time" data retrieval rather than requiring full dataset downloads. The proposed three-tier system consists of a core immutable feed as the master source, an optional middle tier of reusable indexes for specific needs like geospatial fragments, and a top tier of volatile querying interfaces that serve as fallbacks if they go offline.
Real-world implementations across Europe demonstrate the versatility of this approach, ranging from accelerating the publication of large Dutch key registers to interconnecting cultural heritage data in Ghent and resolving ambiguities in marine place names for the Flanders Marine Institute. In the Netherlands, LDES reduced the time to publish major registers from months to five weeks, while Belgium's "Collections of Ghent" project aims to create a unified time-series stream for museums and citizen contributions to track object movements over time. Furthermore, the Flemish government is actively converting authoritative datasets like the Building Registry and Address Registry into LDES using the OSLO semantic interoperability model, creating a sensor data platform that breaks down silos between diverse sources such as demographics and sensor readings. This evolution from older standards like OAI-PMH to JSON-LD driven hypermedia allows for loose coupling, version history retention, and lightweight cacheable fragments that significantly reduce server load compared to legacy resumption tokens.
To maximize the utility of these streams, tools like the LDES Client are being developed to harvest data from various providers, enabling third parties to build custom services such as dashboards, enrichment applications, and text search indexes. A notable use case involves the Dutch Digital Heritage Network's "Network of Terms," which utilizes a decentralized architecture where a fragmenter breaks RDF data into tiny, self-contained pieces served by lightweight servers, allowing for Google-like instant autocompletion without maintaining a centralized index. This ecosystem is designed to be resilient and collaborative, automatically incorporating new intermediate indexes while recovering just-in-time if others disappear, thereby making diverse datasets—from marine regions to digital twin models—queriable for the public. By aligning with the DCAT model and indicating compliance with specifications like 3CG, LDES facilitates seamless discovery and cross-border use cases, fostering a sustainable environment where open-source building blocks unlock new business models and data reuse opportunities.
Read the full video transcript
okay
um quickly sharing my screen
there we go thank you everyone for
uh joining this session on linked data
event streams and more specifically what
i think
is ought to be the base api for
open data sets
and this is really the base question
that i've been asking together with my
research team for the past time i i
think already eight years
and that's what's the best api to
publish an open data set and i'm not the
only one
who tries to find out
an answer or to find a question to find
an answer to that question
for example you have the the geospatial
uh people that started
with the wfs specification the web
feature service that is the geospatial
web querying
api you have the linked data people that
that started
the sparkle endpoints and and and a
query language that that can query over
over
uh graph data and you have many many
many other
specific apis that you can host over
your
data set but then of course from all
these great querying apis which one do
you
host well if you look for example at
flanders
uh then then there's you have the
address database they had they already
have
quite a couple of apis online
like the um they about have 17 on their
website and you can have a tool
wizard to help you pick the right api uh
that that you should start using to do
something with the address registry
but um if you want to look for a simple
autocompletion functionality that's not
included in the
in the set of apis so um so so that that
wouldn't work
and right now if you if you ask them how
much this costs
to keep online these 17 different very
specific apis
they would answer that costs a lot even
to maintain all these specific apis
that costs a lot so this this situation
where where
on top of a data set you keep creating
more and more
uh apis that you that you keep try to
keep uh
that you try to keep up with with the
recent trends
um that is uh
uh that is what i call a maintenance
hell because you
will uh just keep on creating legacy
apis that need to be
maintained a second fallback or like
the fallback approach to to that is uh
we will share a data dump
and then if you're interested you can
just create an auto completion api
yourself on top of that data set
and everyone is happy although with the
address registry what we noticed
is that for example um local governments
started
to create local changes to their own
copy of the
of the data set and they didn't go back
to the to the master data set
so in that sense we started creating
out of date hard to synchronize copies
of the
of the data sets that that are
maintained everywhere
by everyone and by nobody at the same
time
and this is what i call the replication
the
i think these are these are two really
big problems that we see when we try to
to to design the the best
api possible for for an open data set
and neither
of these two solutions is is is good
because
they both have uh have have problems so
how do you define
what your priorities should be when
trying to publish a new data set well
this is uh
then the idea that that we positioned is
that you should do
as uh as
as the the least amount of effort as as
possible and the least amount of effort
as
possible is when you keep working with
when you try to to get everyone to set
up their own uh querying api
but of course you need to be able to
make sure that everyone can sync with
the latest changes
on top of your master data so that you
really claim and advertise to everyone
i'm the master source of this data and
if there are updates in the in
happening in the real world you should
just come and fetch them from my
event stream and this is uh this is i
think
the the new uh the new next thing that
that we need to
convince everyone about is to make sure
that we do life cycle management across
our objects
uh that we do life cycle management for
or uh
for our data sets because that's and in
this way we're going to make sure that
this
completion api is always going to be
able to work on the last version
this geospatial interface as well this
linked data interface as well and so on
and so forth
but there's no specification yet for a
stream of linked data objects
and uh you may say well there's there's
of course news feeds like
like json feed or like atom rss
and so on but i like the ideas behind
behind these specifications but there
are no linked data specifications they
don't
allow any uh data sets to to be
uh to publish their latest objects
towards the outside world so we designed
one
over the last last two years we've been
designing this this interface
it's called the link data event stream
specification and we define a link data
event stream as an
always growing collection of never
changing objects
so never changing objects these are
objects that be that that live
that that live in a specific moment in
time for example
an air quality observation that an
observation that once was made and you
will never change that anymore in the
in the future because that was the truth
that that's at that point
um you could also see it as version
objects like a version of a specific uh
suite name or a version of a specific
address uh and and we'll make sure to uh
uh to make that object and if you want
to go back in time you will be able to
find
that object uh as it were
at that timestamp so
for uh for this interface we designed
one with the simplicity of atom and rss
also in mind and one page of
such event stream contains a data
description just like rss
it contains uh links to other pages
and it contains of course all the items
in that page
so so you can navigate through the
through the event stream
by just uh uh going uh following uh
links to the
thing if you want if you're a technical
person you want to go
dive deeper in this specification you
can find it at w3id.org
specification uh we're proud to uh
announce that
this is getting adopted by the cemec
program at the european commission
uh so this will really become a european
uh specification
for um for uh publishing linked data
so with link data event streams you can
just replicate
the data and that's interesting
but you cannot query the data then
you can you can only copy all the data
and if you would have a question
like um give me
uh all the air quality observations over
the past 10 years
you will just have to download all that
uh all that
all that data you will not be able to
immediately put in
uh put in uh give me an overview
of the of the of the yearly summaries
for example
of that of that time series or give me
all the exceptional
results over that period of time that's
also something that's not possible you
actually need to download it and you
need all to do all the processing
on uh your own machines that's also
interesting
why because the right effort is
happening or the right
investments are in are happening at the
right place
for example uh if i
uh i'm interested in a very specific uh
processing of a specific data set then
it's me who will have to invest in that
in that in that processing and i don't
think that should be the data publisher
that should
invest in my specific use of that of
that
data set but i do
think that we will be able to um
to grow towards a more efficient
ecosystem where we all work together
towards a more a better and more
efficient
uh data ecosystem where we share efforts
of indexing
data sets and this indexation this is
what i think can happen with
fragmentations let's look at
link data event streams how do we go
then in the end towards a specific
geospatial
interface i think that
you can uh first just geospatially
fragment that
that link data event stream you can
create styles
from that uh from that event stream so
that every
geospatial tile also has an event stream
in itself
and if then for example you need to
calculate the route from a to b
then you can just download the right
fragments of that
event stream just in time the data will
be uh will be less big to download it
will still be a considerable amount
amount of data to download but you will
be able to download it just in time to
answer your
uh query as well and this downloading
just in time
well this is also interesting because
that means that you can also do that on
a server
and if you do it on a server then you
can also expose again this querying
interface
so i think i see a three level
architecture that
that that for for for open data
apis in the future that looks like this
at the core i see the link data event
stream it's the
it's the thing that if you don't do the
link data event stream then you're not
hosting
uh a proper open data set i believe if
you don't host
the base open data event stream
api then you're just cutting corners and
you're not giving your end users the
the flexibility they need on top of your
data
but on top of that link data event
stream what you should do what you must
do in fact
you can do optionally you can build some
reusable indexes yourself and this is
the second tier
you can fragment your link data event
stream by geospatial
areas or you can fragment it by um by
prefix saying that everything with the
letter a will be found in
in that in that part you can
also fragment it by time period you
could say well i'm going to to first
have
all my data from this year is in that
fragment while all the
others are in the order and you can have
many many
other different fragmentations that you
can uh think of
these are indexes that can be created by
you and yourself to stimulate the
ecosystem
of to reuse your data set but it can be
equally uh created by uh
third parties we will see in the in the
the next presentation we'll see some
interesting
use cases where third parties may
actually have good incentives to uh to
do exactly that
then uh on top of these reusable indexes
only then
i think that we will see querying
interfaces for which you
can if you really want to do developer
enablements as
a data owner you can for example host a
sparkle endpoint you can host a wfs
service a graphical
interface a cypher interface whatever
but i do
think that these things are um
are less stable if you if you do it as a
as a data data provider yourself
why because well they should always be a
last priority to keep online so if they
go offline
i think people should always be able to
fall back towards the reusable indexes
and even if these go offline that
they're able to fall back to the
linked data event stream at the core
good so this ecosystem then looks
something like this
this we will have multiple
fragmentations which you can see as
three structures on top of the event
stream and then
the for example the geospatial apis
these are going to download the right
fragments of the data when a specific
question comes in
but the specific apis will mostly be
hosted by the third parties themselves
we've all for these fragmentations we've
also built the tree specification
the tree specification is uh or the link
data event stream specification is built
upon
the tree specification uh but they the
3a specification allows you to
to fragment a collection of objects
and you can specify different
relations on top of your fragmentations
like you can have relations
concerning geospatial relations suffix
relation substring relations time
time based relations and so on and so
forth
that's it uh if this sounded somewhat
interesting know that my team is hiring
so this is my current team uh
i'm looking for more people so uh feel
free to send me an email
if you're interested in doing something
uh something with
the link data event streams that's going
to be the vision for the next
four years of research um
and uh that's it this was a very general
and
very abstract and very difficult uh
introduction
on link data event streams and three
three and everything that we are doing
uh in that realm but i want to make it
more concrete and that's why
i'm from from this moment on i'm going
to keep my mouth
shut and i have um
invited way more interesting people than
myself
i have invited people that actually do
things in the real world
um so yeah without spoiling
anything of their presentations i'm just
going to give the floor
to evan
okay thank you peter also thank you for
the invitation but it sounds a little
bit that we are doing stuff in the real
world and that you are doing nothing
real
important but i would say more the
opposite but anyway
let's see how i can get this working
share my screen
[Music]
okay
are you now seeing my screen
not yet but i suppose it's coming oh
well sorry i have to push another button
it's working now we don't see it yet
nope no okay
for um for everyone uh in in the in the
meantime yes now it's coming erin
oh something moving
uh and it stopped and airmen is gone
okay uh we'll wait a moment
it's crashing oh no you're uh you're
still
your sound is still here adam
yeah crawl is crashing okay i know he's
gone
uh okay just uh just to um
uh for the for the audience there will
be room after all the talks to ask
questions uh we we've foreseen quite
some time for for questions to specific
speakers so please write them down on a
piece of paper or write them down in the
chat
uh we'll get back to them uh after uh
after all the talks um
yeah and we'll try to moderate that
discussion
then hi aaron you're back
yeah a chrome crash
about technical problems but
now let's see if i can i will try to
share my
full screen right now and see if that's
improving
so it seems to take us some while
do you see my screen now yes no it works
where is yours okay great thanks sorry
for all the technical problems
um yeah so uh peter asked us to tell us
a little bit about what we are doing in
the netherlands
um so uh together with
walter uh uh we're going to to talk a
little bit about what we
what we did so far what our plans are
and
and motor will actually show a demo of
the link data event streams
proof concept that we are currently
working on um
so well my name is aaron fulmer i work
at the dutch cadastral and also at the
university of flint
and in the dutch cadastra
i'm leading the data science team and we
are trying to to bring link data
and knowledge graphs a step further in
our in our team
so at cadastral we have quite a
long-standing history
of of dealing with uh with link data
uh i think the the first data set the
key register
anderson buildings i think we published
already for more than five years that's
what we call
production linked data so it's really as
a production effort it's
available and you can use it
and we also have this approach used for
many other
data sets around however we found out
that
that maybe last year that's well
we had a lot of kind of problems
in this this this flow of dealing with
linked data especially we had a lot of
data sets standing in the queue to be
published
by by us sling data but
the team was not really capable of
handling all the data sets
because it simply took quite a while to
publish
data center's linked data we took
several months to to publish this kind
of key registers
so we thought and also the technology
was much more
further developed at that time when we
started five years ago we had to develop
a much of our own tools
but now a lot of improvements have been
made in the link data
tooling at least so last year we set
up a new approach can we make link data
more easily
more cost effective so that it doesn't
have to take months to publish a key
register of linked data but can we do it
within
maybe five or ten weeks but
it's much faster and and much simpler in
in tools and well we kind of succeeded
so now we publish
the new key registers with this new
approach
and in january
or february we released a buck 2.0 so
the key register
uh also building again but now a new
version
and now it takes us only five five weeks
to publish this kind of
uh large key registers so and also the
the key ranges of topography
uh large scale topography is also
published through this new
link data what you call registration
architecture so
you see that the links over here so how
does this
uh i won't go into details in this 10
minutes but
basically we get the data from a
postgres database
and then we have some very simple uh
tooling software components like the
enhancer and the microservice and
they will load in the end the triples
into the dbe triple store
and then we put a different views apis
on top of it most relevant for
our new approach is that we actually
kind of
divided the the linked data into two
parts so we have what we call the
registration view
this is the lower part uh sorry for the
dutch
by the way in this slide where we just
publish
a data set as is as linked data as
where the data model looks as much as
possible to the original data model
of the not linked data set
and then on top of it we put the
knowledge graph where we do
get a kind of object view on the data
where we integrate the data from the
different
data sets below but we also get a more
customer friendly
view on this data and
in line with the previous picture and on
top of this knowledge graph he put all
kinds of apis
on top of it for the different kind of
of users that we have
so this is now working quite okay so why
then
are we now moving on and also
participating in
this linked data event streams approve
concepts
well um we believe that it might be one
of the
the apis that we put on top of this
knowledge graph
infrastructure and also on the data set
um
we have to find out of course it's just
the first steps but
basically already it's it it um it also
fits with the with the ideas that we
have that link data should be much more
cost effective and much more
simplified in a way so there we have
already
a good connection i i think
with what we also have to find out okay
so then it might fit it might fit in the
tactical architecture but for what kind
of use cases
does it really make sense to use this
approach um so we have to find
find this out and finally we also find
it very interesting
uh i think we can work much more
together as
as belgium and the netherlands and to
learn from each other we are dealing
with the same kind of data same kind of
stuff so uh so we also see that a very
nice
start of collaboration between belgium
and
the netherlands on this topic
so um but what did we do already then on
this sling data event streams
and so that's the point in time that i
would like to hand over to
uh to water water can you show us what
we did so far
yeah thanks uh aaron and let me see
i'm going to share my screen if it's
okay you can
now see the triple store at
specifically you can see the two data
sets that we currently
expose through the ling data event
streams
so that is the the key registry large
scale topography
bgt on the left hand side you can also
see that these are fairly large data
sets so this is
the bgt logical topography key registry
is over 1.3 billion triples
and we also have the base registry of
addresses and buildings
or bach bag and that is 850 million
and slightly over 850 million triples so
these are relatively large
link data sets around 1 billion
slightly below slightly over 1 billion
and of course we want to expose them now
using
linked data event streams we did an
implementation of link data event
streams
which is currently here running on on
localhost so this is basically the
implementation
where i currently configured the bag
so the base registry of addresses and
buildings
and then i can search for different
times so we implemented the
time index and i can then when i change
the
the date i also get a different
different part of the of the key
registry back
so this is say the low level api i can
also because it's jason ld i can also
easily put it in our
triple store and then in the context of
a triple store it becomes a little bit
easier to process
of course what i just showed you was
really the raw json endpoint
and then you can also see a little bit
of the structure like how
the data is fragmented into different uh
different nodes that are part of the
same bigger collection
and specifically for our key registry
this is
one of the nodes that you can then
retrieve
the nodes have relationships to other
nodes
and those relations are semantically
qualified so you can go for a less than
or equal to relation
but you can also go for a larger
greater than or equal to relation so the
pagination is basically
semantically meaningful which is one of
the key innovations i think of linked
data event streams
you can also take a look at the incoming
node
so the incoming node is then the the key
registry collection
uh which gives you in this case 10
members and so those are
for black sofia object places of
residency in the netherlands
and these are this is actually the
content that is
part of the of the key registry and so
in this case
we are looking at something that won't
see so this is a place of
of residency not like a store or not an
office space right
so this is really great it's now running
on on localhost as i already mentioned
it took us only one sprint to implement
and
our sprints in the cadastral data
science team are three weeks so in three
weeks we were able to
to implement it comfortably also
able to give some feedback on the on the
link data event stream specification
so i would say it's a very good
specification and it's very easy to
implement
in the next sprint so the next three
weeks we will
make this part of our standard way of
exposing the key registries
this means that in three weeks from now
it will no longer run
from localhost it will actually run from
the online triple store and it will be
one of the ways in which our key
registries will be disclosed
now one final point that i want to make
here is that
if you expose things over this amount of
triples
you don't need to use any memory you can
actually use
very low level means to expose the data
so it's also a very cost effective way
to publish such
very large key registries
that's the demonstration of what we did
how easy it was and i would actually say
everybody should do this this is a great
way to expose your data as ling data
evan did you have some closing words i
otherwise i'll give it back to
peter no i have no closing words so
this is it
this uh yeah this this uh
makes me very happy this is uh this is
the first uh
uh or one of the first uh of a few
uh first implementations of the linked
data event stream specification
i'm very happy to see that it's that
it's easy to implement for for data
publishers even if
even if it's the first time looking at
the spec um
so uh so yeah when when do you think
that that
the audience here will be able to to
download the entire bgt
and the entire bag so all the addresses
in
in the netherlands um for as a link data
event stream
would that be before before the end of
the month will that be before summer
can you already make some some
guesstimations
can i answer this to evan yeah okay yeah
so uh
next print so that means the sprint
actually starts today
at the the new sprint so it means three
weeks from now we will have the public
endpoints available
which means that you can basically go to
the to the data sets that were also
communicated in the chat and then if you
go to slash
feed so that will be our new standard
path to expose
link data event streams if the data
contains a time dimension
then it will have this slash feed path
like you have sparkle or slash graphql
you will also have
slash feed and of course you should be
able to walk through all of the data it
scales very well
even for these large key registries of
over a billion triples
yeah i would say april first and if you
don't make it
then you can always say it was an april
first full joke
that's a good one and we're always on
the safe side yeah definitely
but but happy to hear that it uh that
that this means that if i
if i add some buffer that certainly
before summer there will be an uh a new
uh uh new http
points where you will be able to uh
fetch all the data
uh and and make your own intermediary
indexes on top of them
um there's a small question by by
retimer
on in in the chat uh whether these ten
objects they were the only changes at
this point of
time or was this just subsetted and i
think this is just indeed
a page of uh so if you would follow then
if you would go to the next page you
will see more
objects and that may have changed at
that time
uh so you always need to uh download
more pages than just
the the last base page i think yeah
um good so uh let's move towards the
the presentation uh of uh yeah because
it's a bit weird to kick off
at open belgium with with the great
presentation
by people from the netherlands so let's
see let's show that
in belgium where we don't have to uh to
to be shy
and that we can also do great things in
in belgium itself
and uh immediately from from uh from the
most beautiful city in belgium as well
uh so yeah no i will probably get some
comments in the chat as well
but uh uh one of the most beautiful
cities in
in in in flowers and belgium of course
is ghent
and uh olivier uh you're uh you're doing
a great project there right
i thank you uh pizza first of all thank
you for having me uh peter
so i'm olivia vandenslaugh um i'm so
strategist
at design museum kent i previously
worked
at memo and before that that was still
packed so the
center for um for expertise for digital
and that digitalization of
cultural heritage and now i'm working on
a
big project called the collections of
ghent
maybe first of all i'm not a developer
i'm an art historian and curator
um in background so i'm not the
technical profile in the panel but
nonetheless i'm going to try to give
this presentation for you just try and
share my screen
i also have an error
[Music]
um
please elaborate on your error uh if
there's something we can help you with
yes let's try it if it's the screen
test permission for access at the screen
is not
given yeah it's your browser you should
normally uh
be able to to give access
so if uh hi uh boris from cloud68 here
olivier if you can go
to the top side of your browser where
the url for the page is
on the left side of the url next to the
flashing microphone
you should have an icon with i guess i
can describe it as
two squares on top of each other
yeah so you're going to want to click on
that and it should say
on the screen a pop-up will come up and
on the screen share it might say
temporarily blocked
is that the case no i don't see the
same icon so what browser do you
currently have
a chrome
working
uh perhaps you can upload it as a pdf
olivier
is that a a possibility
yes then you click on um
the plus actions in the left corner
and then you should get the option to
upload a pdf
park could sell it to pizza if you want
to um
can you open your shower screen because
there's video in it
yes that's uh that's possible so uh
where did you send it
or send it to brecht as well i already
have it soon
okay can you share it yeah
there we go olivia floor is yours yes
next slide please
so yeah okay i'm just gonna let the
video play
okay
it's a new sound is there no sound
so if youtube video you can share it
directly
uh by going to the plus icon and pasting
the link of the youtube video there but
when screen share
uh there is no sound coming from your
computer it's directly
right sure
okay
yes that's that's in brief a very
big project we're working on um right
now next slide
yes what the video isn't saying is here
um
so opening up the shark account and
we're doing so
um it's linked open very important uh
usable
data and connects to an uh interoperable
image
and asset and
but we're also making it open so it's
not just creating
so so um it's not us just creating cool
things
but we also want to make sure anyone use
it and
use it in their own way next slice
so opening up isn't enough um
we started the whole project uh with the
basic idea
that they're already um a lot of
cultural data sets out there but they're
um always connected to each other or
they're
isolated and if they're not published
already
they remain in these closed silos all
governed by each
um institution on their own all
following their own logics
they are not really interoperable um
from the start
um so next slides um so what we want to
do at
heart at the core of the we want to
first of all and
connect and filter
collections from four museums uh
so we have uh some um
industry museum uh design museum
we also want to add an archive to the
pool
that's somewhat new because they all
in themselves use a different standard
to describe their data so that data is
also registered
in a way which also makes it hard for
them
to connect or communicate unless we
try and translate it into one standard
but then we want to take it one step
further we also want to allow
history to be to be published in that
same
data set or in the same day stream and
so we're looking at how people can crowd
harvest our crowd sources
and their objects but they can also use
the same model to do so
and so everything becomes interoperable
and everything can be queried
without distinguishing whether it comes
from an established collection or from
a citizen of ghent i
want to also create new heritage
um so we're talking about data event
streams and um
i think the the big idea here is that
heritage isn't static
um so why should i be um
if you look at people are registering
today um in
museums they do so um static
so if something changes um let's say
where a piece is in the depot or it's on
this place somewhere or in an
action space um the previous data always
lost certain and it's very hard to
retrieve unless you start working with
backup
and so we were thinking about together
with
what if we would start thinking about
cultural heritage or to
try to approach them as being time
series
what if he would be able to um
have one single truth but having that
that allows
for a multitude exposed
change as well and maybe next slide
so we have we can publish cultural
heritage objects
by using um the caching headers or by
making sure they're all time stamped we
can done
so uh go back in time and that would
allow us
um to create new applications
with them we could uh track where this
was through the
time we could also track how a
description object
changes maybe because the creator on
working on it
um but also i mean try to do that with
um value um that has been used
by the registrar
next slide please but
of course it's not enough to be useful
um
for the people or for the questions
already working in cultural heritage
institutions
but would be interesting we can try and
figure out
what the domain of cultural heritage uh
could um so we're working with also cool
tools
which is a new um application file
that's
um by flanders and it's part
of a bigger set of standards
um and we're using that subscribe or to
form
our cultural heritage data too but we
also have to put things on top of it
which is called records in context
standards
because we're also working with archives
and also at this point in time
does not um ready allow for um
describing
archive and the third uh big
framework we're working with is triple f
which is the international
um imaginability and framework
next slide by doing this
and by publishing a data stream object
that has
both texts coming
stand a few but also making sure that um
all the
possible reproductions are um in there
and you can query them
in time we want to authenticate them
reuse
and we're starting several
organs or several let's streams
of funding um also in the project one of
them is a financial scheme
where we can um 200 000
to subsidize uh let's first let's have
startups
to reuse the data and make a new
application but we're also starting
a cultural data lab where we want to
explore together with
the cultural heritage professionals and
the end users
and what we can do with that data
which will be in the next slides
so this have the the technical
architecture
we're using it i'm not gonna really um
go deep in
this but as you can see it has two major
components
it's coming from uplift the cms so it's
a collect management
system where they are registering all
the data
um text from an object and then we also
have all the images um that describe
the objects or productions and and we
are trying to
um put them all the same data stream
which we will then publish via
a triple store which for this and the
virtuoso and from there on people
using uh sparkle queries to query the
whole data set of all the entire
objects both originating from the
cultural heritage professional as
from the um citizen from ghent and
um try and encourage reuse from that
and we will also build an immersive
room that will feed also today
data event stream as a kind of
demonstrate of the
the technology we're using um so thank
you
my presentation
all right cool olivier so uh so there's
a big
project the cogant project that's uh
that's going to
uh to publish by summer as well
going to publish a lot of collections so
really the raw data the
the the core data of of the museum in
ghent
five museum i think are are going to be
uh published
as open data um there
this this open data will be linked data
thanks to oslo culture
so oslo is the open standard for linking
organizations in flanders
which is a data standardization
initiative
uh they set the standard for for uh
cultural heritage
and um and it will be used uh to
uh to to make sure that that that
everyone can
again uh create derived services and
create
derived indexes on top of this uh
these data sets and also within the
cogent project which is really a big
project with a lot of different partners
we're going to make sure that link data
event streams there
make sure that everyone always has the
last version of the of the
of the data and that they always have
all the flexibility they need to do
anything that they want with the data
and this is really important and i think
that's really the driver
um behind every linked data event stream
so um so thanks a lot uh olivier for for
that presentation
uh we're a little bit behind schedule a
little bit due to the
to the technical difficulties uh that
that we had i hope we will be spared
from technical difficulties
uh for the next presentations um the
next uh
speaker is brits loneville uh brit are
you there
yes i am super can you try to share your
screen
and and let's hope that it goes uh
more swift than uh okay
[Music]
are you looking for the buttons or do
you find the buttons yes
so uh good afternoon everyone
my name is brit londonville and i work
at
flanders marine institute also known as
and i'm part of the data center working
on the marine regions project
and so today i'm going to present to you
the marine region's gazetteer
let me first introduce you to our
wonderful team
so we have landscapers which is our team
leader
and myself we are the two geographers of
the team
then you have salvador and patricia
those are the two biologists of the team
and then finally there's bertrand from
it who is supporting us in every way he
can
with the i.t related stuff now what is
marine regions all about
uh let me try to explain it to you by
using a
a very recognizable case um
meet mora moro which is a deep sea
fish and this deepsea fish you can find
it
around archimedes sea mount in the
mediterranean sea
now let's say you went out on a dive and
you saw quite a lot of muramuro
and you want to talk about this to your
american colleague
so you call him up you say man i saw
muramuru around archimedes mount and he
starts laughing his ass off
he asks you whether you were on drugs
during this dive because
no way that muramuru can be found
around archimedes sea mount and you're
definitely mistaken
so what was your crucial um mistake here
well you did not go to marine
regions.org because if you would have
gone to marine regions
then you would have seen that there is
actually two archimedes sea mounts
um there's an archimedes man in the
mediterranean sea and there's an
archimedes sea mount in the north
pacific ocean
and so what is marine regions or how
does uh marine regions come into this
story
well we try to improve um access to
and clarity of marine geo-referenced
place types
names and areas and we do this by
giving each unique geo object a geo
object or an energy id
so in this way you can clearly see the
difference between archimedes cement a
and archimedes seamount b that's not the
only thing we do
we also provide you with the coordinates
of course a latitude longitude
a bounding box if that's available
even if there's a wms linked to this
data we can show this on a small map
um we're also going to give you a little
bit of contextual information uh
through the place type this will tell
you is this a c mount is it a sandbank
or you're looking at something
completely different
and of course we'll give it a name
and now two objects can have the same
name but of course
one object can also have multiple names
and multiple languages
and we will also store all of this
information our database
and of course we're also going to
provide you with the source where did we
get this information
um marine regions integrates a lot of
other authoritative gazetteers such as
the jepco gazetteer of undersea
feature names but we also have created
some data sets our own
um such as the maritime joe
or the maritime maritime boundaries
geodatabase
containing exclusive economic zones
territorial sea so we have
included all this information in the
marine
regions gazetteer as well and finally a
very important feature of our gazetteer
that i have not talked about yet is the
relations because we have a hierarchy in
our gazetteer
with parents and children so we're going
to link objects to their parents and
and this way you can easily go through
this hierarchy and
and learn about marine regions objects
now how can users access this data
nowadays so what is the current state uh
there are several ways to access this
data you can
just go to our website to the search
page
you can browse through the hierarchical
browser so through the parent children
relation
for most important data sets we also
have ogc web services wfs wms
or we have rest services on our website
and then
we also have a marine uh regions
r package so m regents um if you want to
check that out
so that's the current state um but as we
have heard already
from our from the people who were
presenting before me
we can do more for our users and our
users include among others
big uh geographic databases such as
worms or urobus
or using marine regions and so in order
to go one step
beyond what we have been doing so far um
we are currently
involved in a project with uh the team
of peter
with harem delva and also uh with
the vlis open science team of mark
porter
and so we try to open up this data even
more make it even less ambiguous
um by um yes opening this data up as
linked open data basically
this is a six month project we are
currently at the end of month number two
um and so um what we have done until now
is
trying to link all our data to
vocabularies to make sure that
um it's very clear what we are
describing in what way we are describing
and so that everybody
um and especially divers in the
mediterranean sea
can then clearly explain to their
colleagues where they found
their fish thank you very much for
having me
and i hope this was clear for everyone
thank you a lot brett for the for the uh
very swift uh
presentation and it's it's it's uh i
really like i already forgot the name of
the fish but i really like the
the the example you you give here i gave
the arabic
but i i feel it i have a hard time to to
identify with
the case that i would uh would be scuba
diving in in
in in a warm mediterranean
uh uh atmosphere somewhere yeah that
that's something for uh for poscoruna i
think uh
to to look forward to um uh i find it
really interesting these three
presentations there like like the first
presentation was about address
registries the the this
and topological uh topographical
help me out uh topographical right uh
uh uh registries uh the second one was
about uh
about cultural heritage which is
something completely different and now
the third presentation was again
about something completely different and
still they're just a collection of
objects that
can be uh be managed as a link data
event stream
and this becomes really interesting that
we can start build to build uh tools
that
just work uh across all these things at
uh
at the same time and speaking of a tool
that can uh work on top of these three
different things
and is generic in in in that sense well
that's something that
brett is now going to present brett
thanks peter
should be loading
can you see my screen
yes okay so
i am brecht from id lab gans
and i'm working on the link data event
steam clients
the lds client in short and
so what does this do
this is being made in the the core hand
project um
like if you already said you have a few
museum partners in gans that
are publishing data so these are like
the data providers
and what you want is to build services
on top of that
for example olivier wants to build a
dashboard to see
what's the statuses of the institutions
how many
data they have published and if their
mappings are correct etcetera
or another service or application is the
enrichment application
and you want to add a link in the
metadata
from the object metadata to the image
itself or to a presentation manifests
following the f specification that that
describes how the the image
should be displayed another application
would be a text search index and so that
users can easily find objects
by by typing in a search bar
and of course to do this you need to
harvest
data from these institutions to your
application
and to do this i'm creating the lds
client
which is simply a harvester of linked
data event streams
and so that you can copy the data into
your
database system
now you've maybe have been wondering
don't we have oie bmr a difficult name
to do that which stands for the open
archives initiative
a protocol for metadata harvesting so
it sounds exactly like that and indeed
it
does similar things you have a
data provider with metadata and a
repository
and on the other side you have a service
provider
which runs a client-side application
called
harvester also that performs certain
requests
over the web and receives an xml encoded
metadata about the things and to do this
it has specific request types
and for example a verb list records give
me the records
from after this time okay
we have this but uh what
do we need now like this yep martin
is invented in 2001 and
yeah link data didn't exist at that time
actually
so it really needs an update
to to be more um performance
um for example it returns it works on
xml
nowadays people don't work a lot in xbox
it still exists a lot but we have we
already have json now and we have linked
data more coming up
like json ld so we need to go a step
further there
also it uses hard-coded requests
and now with data event streams you have
a more
hyper media driven approach and you the
client needs to follow
relations to new documents to new nodes
and these relations can be used
spatially or
in time based so the client and the
server becomes more
loosely coupled and you can even use
indexes to publish the data
also or epm is focused on the retrieving
the latest version of an object
while with event streams you can
maintain
all the versions yourself
and choose how
[Music]
when you will drop older versions for
example you will only
maintain one year of data and after that
people should have harvested already in
their archive
so you can set some retention policies
how long you will
maintain certain versions also with the
server
and who ie works with the resumption
token this means that
um um every client is like
like served separately with the token
and the server needs to process this
token and
then give them the next objects
well with event streams you have
cacheable fragments every document is
the same
and this means that it becomes very
lightweight for server
to host these so all these things are
our ideas that have been evolved in the
in the last 20 years and are now applied
in the ending data specification
the lds client is available on github
you can find link here
it's implemented with an actor-based
architecture
and it's a new architecture communicates
calls
that we've been developing in id lab
it's a query engine um focusing on query
over linked different link data sources
and you can find the installation or the
instructions here in the
actual init lds client package
and you can use it as a command line
interface or as a javascript
library so let's now take an example
for the cohen project we have published
data of design museum
camps in this link now i want to
retrieve
all the data what i can do is for
example given mime type i want to
retrieve it in jsonld this here is the
context i want to apply it on for
example it can be a translation
in english and on i want to only
harvest after this time after january
the first
this year want all the data from there
on
and then the url to your event stream
now to see this live in action i've run
it here
in my command line um with these
parameters
and now you see the the objects on the
event stream are like floating in
so i can process these in my system
and create my own services on top of it
so feel free to try it out
in your comment line i would say and if
you have questions
i would like to hear it afterwards
thanks
thank you very much indeed really nice
to see that the history from
oai pmh uh towards uh
uh towards link data event streams and
that we indeed do the same
have the same idea in mind but that with
that or
solution is is more tailored towards
http unlinked data and and really brings
it into the
the into 2021 instead of uh
the 2001 uh version of the of the specs
so uh so uh so really interesting work
um
uh just maybe a side note that that it
is
uh alpha version code we we're sharing
this code
now for the first time at the at a
conference
so uh uh please open a lot of issues
when you when you encounter
onto the issues with it i i pasted the
link in the in the chats towards the
the link data event stream client um
please forgive us if something goes
wrong
please open issues and we'll try to fix
them as soon as possible and give it
also a second chance if you're uh if
you're able to do that
um with openness comes also a little bit
uh of
of uh you cannot you cannot
publish as uh early enough but on the
other hand you only
lose you you only have one chance to
make a first impression
and these two things need to be balanced
well i try to balance them by
uh by adding that a side note here so i
like to release
early but then please forgive us if
there are still mistakes in it
um good uh the
next presentation is uh by uh shorts
who's again from the uh from the
northern
neighbors um shirts can you
hear us can you can yeah and there's my
website
okay perfect so uh uh
feel free to take control of the
presentation
yes this is going to be hard of course
the previous experiences
having the previous experiences in mind
yeah it appears to be an iq test or
something
by which i don't mean that okay no
i think there it is share
all right the famous question can you
see my screen
at this moment we cannot
ah wait okay it's loading now yeah now
we can get slow
all right in a few seconds
there it is yes there it is
perfect it's perfect my name is george
valk i'm
involved in the dutch digital heritage
network and i'm going to
talk about auto completion which is a
very specific
use case for using
or potentially using linked data event
streams so
this is not a talk on the perspective of
a data publisher
but more of a data consumer
first off the dutch digital heritage
network is a
partnership founded in 2015
um a partnership of dutch cultural
heritage institutions in the netherlands
of course and our aim is to develop a
system of national facilities and
services for improving the visibility
the usability and the sustainability of
digital
heritage and one of these national
facilities that we are working on is
called the network of terms and i'll
explain this
in a little bit but first off a little
bit about cultural
heritage this is a painting a
rather unknown painting i have yet
to meet the first person that knows who
painted this painting it's called the
drawbridge
in new amsterdam this is actually
painted
near the place where i was born which
explains my rather grim
nature probably and if i show the next
painting then you
you'll probably know who painted this
one
this one is called almond blossom
and the creator of this painting
of course is vincent fengo
um however there are there is a problem
uh two institutions in this
in this example own a painting of fengo
on the left-hand side and on the
right-hand side both
institutions use different terms
to refer to the same information in this
case they use different
notations to refer to vincent van gaal
for
for instance written as vivengo or
vincent fingo
this of course is a problem for
findability because
people know that vivingo and vincent van
gogh actually are the same person
but machines do not unless you tell them
so so
of course we can encourage institutions
to use the
same terms to refer to the same
information for example
vincent van gogh easy right
yes but then there's another problem the
problem of identity of course
vincent van gogh as we know him is the
this famous painter but there's also
another vincent van gogh
his nephew who has exactly exactly the
same name so how can you distinguish
between these two persons of course
link data officer solution we can use
identifiers uris to refer to this
one creator of these paintings
these uris stem from what we call
terminology
sources and here are a bunch of them
and terminology sources is basically an
umbrella term for
for fisauri classification systems
reference lists
authority files etc there are
national terminology sources but also
international terminology sources
you may probably know a couple of these
so we want to encourage cultural
heritage institutions to start using
terms from terminology sources
especially to start using uris to revert
to terms from terminology sources
in order to improve the findability of
their information
but then new problems arise of course
user applications such as collection
management systems
can connect to the systems of these
various terminology sources
but these systems use different api
endpoints for example a sparkle endpoint
or some custom web api
and these terminology sources use
different data models for exposing their
information
and this makes it rather hard for user
applications to connect to these sources
because they have to understand the
various api protocols and the various
data models of these various terminology
sources
and this hinders of course uh the
easiness with
uh which for connecting to these sources
though
we conceived a solution and this
solution is called
the network of terms this is an
application
that is basically a gateway between user
applications
such as collection management systems
and terminology sources
so user applications do not have to
connect to the
systems of terminology sources anymore
they can connect to the network of terms
or to the
api of the network of terms so a user
application can send a
search query to the network of terms the
network of terms
then repackages this query and sends it
in real time to one or more terminology
sources
in parallel then collects the results of
these
individual sources repackages them
into one result set and returns this to
the user application
and this one result set contains the
matching
terms um including of course the crucial
uri that a collection manager can then
store in his user application or in this
collection management
system
the network of terms offers a uniform
api so that
user applications do not have to know
the specific api protocols and data
models of the various
terminology sources the api is working
perfectly
but it's rather hard to show this
to collection managers or less technical
people so we also developed a so-called
demonstrator
a rather simple visual interface that
you can use for
filling out some kind of search query
for example vincent van gogh
selecting one or more terminology
sources and when you hit the search
button
then this demonstrator calls our own
api searches the sources and presents
the results
this is also working perfectly but
there's one problem one big problem
users do not want to fill out an entire
search query in this case
vincent van gogh users are lazy
collection managers are lazy so they
want to have
some kind of google-like experience that
if they start typing
then matching terms should pop up
instantly in this case vincent go
so how can we
add this feature this functionality to
our network
of terms in a way that makes sense that
fits into our
architecture we could of course put into
place some kind of autocompletion server
this server would then harvest data from
all the terminology sources
and stores this in some kind of index
then user applications would be able to
query this autocompletion server
this however doesn't really fit into our
our architecture because it's not a
decentralized
solution it's a centralized solution you
would have to
collect all the terms from all the
terminology sources into one
index it's not a really scalable
solution because in this
picture there are just three terminology
sources but there are a lot more
and this is uh ever growing
so our auto completion server would have
to grow
too and this is not a very lightweight
solution our current network of terms
implementation is lightweight because it
directly queries the sources um
but this autocompletion server would
force us to
maintain the data that we harvest and
re-harvest it periodic periodically
in order to keep the information current
luckily we stumbled upon something
called tree and of course this has been
explained
before and three offers a solution for
our
auto completion uh problem so we teamed
up with id lab
with peter and uh and harm delpha
and asked them to develop a prototype
for us
that demonstrates uh the auto completion
functionality
for us using the tree vocabulary
and what it basically looks like looks
like is that there is
a terminology source this terminology
source publishes
its terms its data as rdf
this is rather common so this is not
really new
this is something that most terminology
sources in our network already do
this data gives us the opportunity to
introduce a new component the so-called
fragmenter
this fragmenter grabs the data
and creates lots of tiny fragments
of the original data file of the
original rdf data file
and for auto completion this basically
means that a fragment
for instance in the case of vincent van
gogh consists of
the v of van gogh this v has a relation
with the a
v a n etcetera so you can build up
an entire tree of relationships between
characters of terms so in the end
all terms all the parts of terms
have their own fragments have their own
fragment and this fragment basically is
just an rdf file a very small rdf file
that an
rdf file nonetheless then
there's some fragments server because
all these tiny fragments
in itself do not do anything you need a
server to make these fragments
accessible a fragment server so
uh interestingly uh the data uh the
the the source data must be provided by
the source
if you cannot do this and then you're
not a really good data publisher
right um you can of course
uh provide some kind of rdf dump however
uh and this is of course the interesting
interesting part
you could also offer your data as some
kind of linked data event stream so that
becomes a continuous stream
which would then fit into into a
pipeline
where as soon as updates arrive from a
terminology source for instance
a new term has been added
the fragmenter could recreate
or create a fragment of the new term and
then make it accessible for the
fragments
server to serve it to whoever is
interested in these fragments
the other components the fragmenter and
the fragment server however
can either be provided by the
terminology source if the source has the
resources for
maintaining this kind of infrastructure
or a service provider can do this and
this fits rather well into the
picture that peter painted at the
beginning
this is the tier approach there's
something that you must do yourself as
data publisher
and there are things that you can do but
also things that
other people or other parties can can do
for you this
uh that this is all good but
there's still no auto completion
functionality right we have a bunch of
fragments
and a fragment server but that's it so
there's we
we need more than this so the fragment
server the fragment server are
very very simple servers they just serve
plain rdf files to
offer this autocompletion functionality
we need an autocompletion client and
this is
a smart client it knows how to request
fragments from one or more fragment
servers
it knows how to interpret the data
inside these fragments
and it knows something about
autocompletion for instance
about ordering the results ordering the
terms in some kind of
a fashion that makes sense for
autocompletion
um interestingly uh uh
tapping into what breth already
mentioned this auto completion client
too has been developed using the
communica framework
um so our auto completion client is not
it's just a simple client it's
it's basically a small a query engine
that understands the vocabulary that we
use
for making autocompletion work
at the end there's of course a user
application or as peter mentioned
in his talk an awesome application this
is the part where the user interface
resides this is where end users for
instance
collection managers of cultural heritage
institutions
work and this is where they fill out
their search query where the
autocompletion
functionality starts to kick in and the
user application
operates the autocompletion client which
then queries
the fragments server or servers and
there we have it autocompletion
functionality but what does it look like
in practice
we also asked idealab to not only
develop a prototype for the fragments
fragmenter and the fragment server but
also a demonstrator
official interface in order to show the
results so that actually works
and this is it you can go to this uri
and try some
some terms yourself that this
demonstrator currently
searches for sources for quite different
sources for instance the cultural
heritage resource and the
second world war a world war ii
thesaurus
so this is my query f-i-r
and it's uh it results in terms like
fur first fires firewalls
etc uh is there something special about
this demonstrator
no this is this is exactly the
functionality
that you would expect of an
autocompletion function
right a search bar and autocompleted
results
um so from an end user's perspective
this is precisely what we want
uh however underneath it all there's
this fragmenter
there are these fragments there's the
three specifications there's
a link data event stream hopefully
eventually in place
for making this work and this fits
perfectly into our architecture of
having this
decentralized approach with linked data
as the core
method for publishing and using data
so what's next this is a prototype
so we need to test it thoroughly for
instance
we want to measure performance
especially user perceived performance is
it
good enough for users to use
and another perspective is what is the
exact quality of the autocomplete
terms so we need to look at the contents
of the
of the terms that are found if this is
all successful then we would like to
bring it into
production uh we don't know yet when but
probably
uh uh thinking of air evan here on april
the first we have to
wait wait and see um that's it
thank you very very much uh if you would
like to know more about this
autocompletion functionality please uh
please contact us tech at network
thank you
awesome thanks thanks so
um we've now seen
three data sets being presented an
address registry
um to the the cultural heritage data set
the marine regions gazetteer
we've seen two clients being presented
one
just taking a copy of the entire uh link
data event stream and
uh the second client was autocompletion
across
uh across a fragmentation i've put all
the links that you that you need
to to recreate that for your own data
sets i put them all in the chat so the
all the tools that we create as should
be at an open belgium event of course
are
open source and all the data sets are
open data so please
uh try to get your hands dirty we're i'm
an academic so so i'm afraid that
sometimes
uh what i say is a little bit too early
for for for market adoption sometimes
but it's
i promise you that's pretty close to
markets and options so so if you want to
be
one step ahead start playing with uh
with these
uh these tools the next presentation
is again another
data sets use case so now we've mainly
talked about
base registries or or
data sets that really need to be reused
as they are the reference for for for
many other data sets
uh but i think uh olivier also already
mentions ah well time
series we we should men we should try to
to also find an overlap with time series
i think that this is exactly what uh
mchills from imac is going to uh to hint
towards right
flip uh you're on mute
that's another one for the bingo yeah
see if i can pass
[Music]
iq tests
let me know if you see something it is
loading so
uh i think yes you passed the iq test
congruently great
floor is yours
so yes my name is philippe mchills and
yeah i'm i'm working for
emac but we're working together
on digital twins also with uh with
flanders with uh
information agency in flanders and
um yeah i wanted to explain in this
presentation
how we see linked data events
streams supporting digital twins
so for those of you who don't really
know what digital twins are
they're basically decision support
systems for city planners and policy
makers that's how
we look at them so um it's more than
just uh yeah defensive visualizations
that you typically see
in these demos of course the idea is
that we are trying to
understand the dynamics of cities by
merging data streams
and by applying models to those data
streams
for performing simulations good example
is if we want to
implement circulation plans in cities
then we want to
maybe um simulate the effects
of several different circulation plans
see what the effects are and then choose
the ones the one that fits
best our criteria the thing with
with digital twins and these
computational models that are running
behind it is that they're quite
data-hungry machines
what we want to do basically is
correlate and process data from from
different sources and
of different nature so peter was hinting
towards it
it can be sensor data for a large part
of course sensor data is very important
for us but also it can also be other
data
for instance um i will show a case where
where
demographic data can can play a role as
well um and you want to correlate all of
this so you will need something else
as well so what's the concept of
what we are doing in the duvet project
which is a european digital twin project
the idea there is that we try to
see data sources models and
visualizations
as components that can be fitted
generically to a central data block
that's that's the concept that we are
trying to look at and now of course
it's all very nice but if you want to
connect these data sources and and
they're all in different
uh formats and they're all they don't
have uh
clear semantics or they're not the
semantics are not well defined
that's uh easily going to bring us into
problems it's gonna be an integration
nightmare and it's going to be very
costly to
adapt these data sources to make sure
that they work with our models
and and what we want to do is to connect
any data source with any model so it's a
bit difficult then
so uh yeah back to the fancy demos the
fancy demos of digital twins is what you
see it's the iceberg at the top
uh but below that is a whole lot of
things going on and a big part of that
is actually
getting data to be interoperable
to break the silos that are typically
found in these data sources
to address the issues of data quality
and do things like data analyzation
so that's um our biggest problem and we
kind of figured that out uh one day
we had a very good id and we naively
tried to solve the uh issue of figuring
out what is the quality of life
in a certain part of the city so street
by street we wanted to
assess the quality of life in the city
and we had kind of an equation that
would take into account
different aspects of the city so this
could be
are there shops nearby is there public
transportation in your neighborhoods how
busy is the street you are living in
are there parks etc etc so very very
diverse
data sources and um
yeah most of these data sources were
available somehow in some form but
usually they were not really um
yeah semantically well defined so they
were not published as openly in data
so and we quickly found out that it was
way too hard to try and
manually hook up every part of every
data sets
to each other so it was almost
impossible
and this was really typical for a lot of
use cases that we tried to implement
using digital twins
so um with duets we have the
we have the the intent to create a
digital twin
platform for flanders um so
the idea is then okay where is the data
in flanders and
um there's quite a lot of data um so
there's the authentic
authentic data sources and we which are
being
hosted by by the flanders information
agency
but there's also tons of other data
sources
spread across so many different
organizations they're countless
but most of these data sets
unfortunately
are not published so they're not
accessible
but even if they are accessible they're
not always interoperable
so that's the that's the main issue we
face um
and one by one on boarding just does not
scale it's too expensive
um so um we were kind of
yeah disillusioned you could say
uh because um yeah
how how do we go about this i mean
there's there's lots and lots of data
but it's
it's really way too hard to just
onboard it and use it in digital twins
so um we saw earlier today that and this
is really giving us hope
uh are giving me hope and i was really
enthusiastic to see this
um that's that it's actually very easy
to implement the
link data event stream standards and so
um i think
link data event streams can help in many
ways
um first of all they can
remove obstacles that we are typically
facing when we try to publish open data
and we have seen that it's very easy to
implement
and it's also a strategy where we can
separate publication from the actual
management of the data which i think
makes it much more feasible to to
achieve
the requirements are fairly limited
they're well written
and they're easy to implement what's
also helping
is that it's a more robust approach to
to building
time series around sensor data
typically today the approach of keeping
time series of
on sensor data is to to subscribe to the
sensor event stream
um but the problem there is that yeah
you need to specify what kind of data
you want to historically keep
and with link data event streams if we
just onboard everything as link data
event streams not only the sensor data
but also the context that we have a
robust way of
keeping everything the history of
everything which is essential in digital
twins
and make sure that we can time travel
not only in the values of the sensors
but
also in the context of the sensors
and also the context of the digital twin
itself because if
you are doing evidence-based policies
and you want to validate the results of
a simulation you want to be able to go
back in time not only in terms of the
results
but also in terms of the surrounding
conditions
if uh if you're doing experiments of uh
an implement circulation plan in a city
but you don't have this the the
situation of the actual streets
of that time at the time you were
running the simulation
then you cannot recreate the experiments
and the results are not
worth much um
so another good thing is that we can
have these
reusable building blocks where we can do
things like reconciliation which is
essential and we want to be able
to link elements of the of one data
stream
to elements in another one so being able
to
have a uniform system of referring to to
records
and also linking to other sources is
essential to us
and also of course having the
possibility to create derived data
streams
where we can have where we can subscribe
onto the raw data stream
apply calibration models do aggregations
apply anonymization with all our
essential tools for us
in building digital tweets
and a good example of such a building
block is address match
which is actually an existing service of
the of the flemish
government where they based on
addresses and and the way they are
entered into a system try to resolve
that to
an actual address record which is very
similar to the demo
we just we just happened to see for uh
when we were looking for vincent trango
in all of its possible writings
and what we want to achieve basically is
to not just have data sources
but eventually to have all linked data
sources
and if all of these data sources can be
published as link data event streams
then
that's going to speed us up considerably
so i'm very hopeful
and also very thankful for everyone that
is doing that
thank you
thank you very much philippe it's it's
one one thing i particularly um
liked in your presentation is the fact
that you said like ah but it's really
important in order
even even if you want to prove something
later on uh
towards your government if you if you
got a certain certificate uh
saying ah because of uh uh because of
that street
and and uh and this um uh
just thinking and this artwork that is
that at that moment was
at the museum uh and that's why you get
a certificate that you actually visited
that
that that artwork and that and that
street as well just trying to combine
different data sets here
that then still you also want to rewind
your data set or you want to go back in
time and make sure that
you can still uh still prove that that
certificate
is correct or or it was correct at
that time so that's indeed uh another
it's called it's called the
data traveling capabilities uh traveling
uh
data time traveling capabilities i'm
sorry um and and it's considered
essential in
also in big data processing by the way
so yeah and certainly if you have
digital twins where you have then
forecasting models and then based on 100
data sets then
you do a certain forecasting then if
later someone comes to you and say ah
but why did you do that in hindsight
look look what happened we could have
predicted this then you can say ah
could we okay let's let's go back and
let's uh
that's also that's also the nice uh very
nice aspect on elders i think because it
includes
archiving um or archiving specifications
so you can be specific about what your
intent is in terms of
retention of data in that kind of stuff
it's really important
yeah okay great so
let's move to the last presentation and
then
there's some room for uh questions uh i
hope
it's a uh analysis are you are you with
us
we had some technical difficulties at
the uh in the beginning i hope we will
we were able to resolve this by now
i hope um hi i'm alright
we can hear you that's already a good
thing yeah i had some difficulties
but that's solved right now
um i should be able
to share my camera and share my screen
so no webcam for me but i'm on the
laptop of my daughter so i think we
blocked that
earlier
try to cheer my screen
otherwise peter maybe you can share your
screen and
we can switch to that then
yes
um
i'll give it one more try
now i of course need to be able to open
a powerpoint presentation called
um
yeah i'm on a computer that's not my
problem
actually if you want i can show the
presentation
uh okay yes that would hurt that would
help me yes
okay
okay i also have it ready astrid do you
want me to do it instead
okay i'll just uh just try to do it uh
it was
it was loading it said ah okay
i think i now share my screen yeah yeah
okay okay
perfect yeah thank you so i will just uh
shout when we switch
uh perfect yes thank you so much for
this collaboration
uh so thank you peter and all the
colleagues uh
to have us here and as um informative
london and now digital
uh digital flandering so maybe digital
flanders is the new name
um what i really want to share with you
today is the
experience we the experiences we had
and the capacity capacity building we
did at digital vlandryn
so i won't go into technical details but
i'll give you
a short uh tour around in our learning
curve about the
linked data event streams and then you
will also see the link with
the digital twin project and um the
items philip already mentioned
in his uh in his slide so you can
move on to the next slide please
yes so maybe um i just wanted to
um to post this because digital of
london
is just uh the new name um very recently
of uh
information agency for the international
community
so it's actually the same uh company
with
some more i.t uh departments now
involved and it's now called the guitar
plan
but we're actually the same people um
okay next thank you
so within the digital of london we have
um
different programs and who are um
working on the the digitization of the
flemish government and its stakeholders
uh and within the heat of london we also
have a
program where i'm working for and that's
the program authoritative data sources
of detail of land
and uh within this program we have uh
some experiences about linked data event
streams and insights
and that's what i really would like to
share with you today so we have
one aspect on the smart data trick
and then link data event streams for the
building registry and the address
registry um
a really short thing about oslo
and the linked data event streams for
the large
scale reference database also called
hereby
or basisguard flandren for the dutch
speaking people
so first of all i want to zoom out a
little bit
um from open data to smart open data
so um we started a track i think one
year and a half ago
um about smart data and to zoom
a little bit out on how we can uh open
up our scope and
um with an open mind and open innovative
thoughts
how we can manage all the data
and the data streams that are coming
ahead of us so we have now
uh certainly in the smart city landscape
but also
in governments and the evidence-based
policy
track everybody's going into that data
becomes still more and more a foundation
for designing the society
and the future of the citizens and and
policy makers of tomorrow
that's also the link to what philip just
told
and we have multiple data sources we
have the
slow moving data as we know it and
that's the data
from the like for example the base
registries and the
authoritative data sources and we also
have
more new data streams like the
fast moving data from sensors or
real-time updates we need from different
data sources
and those uh those things are very
challenging
those huge amounts of data how can we
cross those data on the different
domains how can we link
all those data with their context how
can we make data more reusable
in that context and how do we deal with
scalability and once only principle and
all that kind of
um challenges can you skip
yes so that's why we what we call them
the smart data trajectory and we really
want to focus on
the findability accessibility
interoperability reusability and the
ease of use of
data and for that um linked data
is for us key so what we understand in
smart data is actually that it can make
the connections
between the different data sets and if
you then consider a smart
region a smart city or something like
that
you need to be able to connect the
objects in the field
like a road a building an address
with potential fast-moving data sources
like sensors
and the smoother the link is going the
more information you can distract from
it
and this can help or enable to provide
solutions in the field of mobility
healthcare
environment so that's the zoom out i
wanted to make
and to have all this the qualitative
data alternative data sources are really
fundamental
to have it on to have these data
available to link all this to
okay and so in our learning curve
step one is um we started
last summer a prototyping phase on
linked data event streams and linked
data fragments
um and then you can yes
and to make the story complete it was
together with the team of imac
id lab but also some
enthusiastic students from open summer
of code and of course our information
flanders information agency or
informative land
we started a prototype uh on linked data
event streams and if you now
click uh a street thank you all right
it's uh i'm i'm showing it
yeah but uh but i also wanted to make
make uh make clear to the to the
the community at open knowledge belgium
that we also did it at open summer of
code so so uh so we also
so so the foundations of link data event
streams really also come from within
within open knowledge belgium itself
okay so um prototyping with link data
event streams for fast and slow moving
data so what the
the the first hurt we
hurdle we wanted to take was of course
um how can
we uh manage uh sensor data so fast
moving data
and um are we able to to publish it in a
in a sustainable way and
what's the the knowledge we need for
that um and how do we relate it with the
slow moving data sets and so
there was um a kind of capacity
capacity building needed um
and then we started with with the
prototype with the team of peter on link
data event streams
it also gave us um some really
interesting insights on the
architectural part
um you will see it later on in the
presentation it really is the blueprint
for
something big we're doing today and it
also gives a
really valuable insights on scalability
load
the possibilities on the query side so
for reusers etc
um next slide
so what we um at least what i uh
found really uh valuable and and learned
from the prototype was that we could
publish
um a fast-moving data set and a
slow-moving data set so sensor
data on which we were very um
or yeah quite immature
and also our base registry the address
registry as link data event stream so
and it was quite a similar way
we didn't have to do anything exotic it
could fit for both
types of data sets and um
some really interesting insights on the
linked data fragments
where you can have your query module
and um question it question efficiently
uh through different data sources that
was really um
uh interesting for me and then the
second
um step um was actually uh the
opportunity
we had to um step into the samick
projects with
uh peter his team um to make um
a few of our authoritative data sources
into linked data event streams and you
can see them
already up front in the above
so we have the building registry address
registry
large scale reference database and it's
all based of course on the
semantic interoperability model of oslo
so it's really a quick overview
um for the building registry and address
registry
we already work with event streams
but um in this um
semi pilot uh we move oh
okay thank you linked data event streams
so um the ongoing work right now
uh i'm not going to step into detail is
that actually
uh the link data event stream is uh
it's ready to be published and it's now
in a test phase
uh as a projection on top of the raw
uh data set what's that what is the link
pointing to
ah well that was ah that should be an
error
the that's that's not a link uh yeah
it's the yeah okay it's the flemish uri
standards okay but i will put a link to
the to the pull request
that white prepared yeah in the chat
maybe a copy paste
stuff okay and key in this um
in this realization of link data event
streams is
for us um with our colleagues of uh oslo
open standards for linked organizations
is the semantic
uh interoperability model and so the
vocabularies and the application
profiles and i
the url is also on the on the web page
uh it's key to achieve a link data event
stream
uh for our data sources and you can
switch to the next one
and the standards being used for the
realization of this one
are addressing register and i'm sorry
for that but it's in
in dutch and herbau in register so
um also available on that of london.be
move to the next pizzer okay
and then we have the large scale
reference database also called uh
here b or basisguard flandren
which is a large-scale topographic map
containing
um lots of information about uh
buildings parcels roads
uh whatsoever and uh today
uh this is available as a vfs and is
also
um dumpable as a
by download downloading your data set
and there
uh our colleague is still working on and
then you can move to the next slide
this is um in the face where um
we need to run now an oslo
standardization
project to make it fit and then
we can move on with link data event
stream implementation
so that's quite brief about this one
and then um step three it's um
even um it's always a little bit bigger
um and step three is actually that the
link data event streams
and the concept about it is really at
the core
of our new architecture that we are now
going to
um further uh
uh how do you say it proposed to the
policy makers in uh
belgium in our relative project so
roland
is it's a really big thing
in in flanders and um so we are now
preparing um
how do you call it an english a nota for
the flemish government
in which we present our architecture uh
and all our um tools telling
all our goals for this reliance project
um and really in the core of this we
also
use link data event streams in our
technical solution
so this is actually a zoom out of the
release project we are now working on
sensor data platform and what you see
here is
actually um four silos or four
um key components of this uh
trajectory um and why are we doing this
that's maybe the first question to
answer
uh analysts you're muted all of a sudden
can you unmute
ah and uh she's gone yes no i'm like
okay great it was done automatically
but uh as i was saying because i'm
really enthusiastic about the
uh project and the sensor data platform
we are going to
uh page there is that um we really want
to
uh enable data publishing
and data reuse uh for a more
um and brighter and
bigger uh data flow of all kinds of data
and specifically sensor data and what we
do
so we re what we try to do is uh
bridging
um the gap for the data suppliers and
the data sources
and also sensor data sources to unlock
them from there
maybe silo they are in and uh by all
by um moving it into the architecture we
are
proposing here with
open source building blocks we want to
enable this data
to flow and to be uh much more easier to
reuse
by uh other partners by new business
models
that kind of thing so the lancer
block you see in the middle consists of
all kinds of
open source components we sometimes also
call it a publication street
of components with in the core link data
event streams with which
all those data suppliers can more easily
maybe publish as linked data their data
and unlock it from
or the domain or the supplier or the
location
where they uh originated from and
that's the first part and then um but
that's maybe not this
relevant here in this um meeting
we really focus on standards for all
this um
we want to have an ecosystem that works
with it and a governance on it
and so this is just um an image of our
functional architecture
in a more detailed way but
what i really wanted to show you was
that link data event streams is really
in the core of our solution it is a
draft
but um i think it's a beautiful way
forward to
unlock the data thank you
thank you very much uh annalise um
i would like to ask all speakers that
that
that have spoken to to share their
webcam
again with uh so that so that we can be
visible again to the
to the audience
and um yeah well i i think the
the really nice thing about about your
presentation analysis is is that
is to to show that that this was really
the the beginning of linkedin event
streams in in
last summer uh during during summer of
code but that had evolved and that we
got more and more people on board
uh while doing that and that now it's
really at the core of
of what we want to do uh regarding data
management at the
the the flemish government um
which of course will will translate into
into multiple tools generic tooling that
that that will be uh created but uh
not to be underestimated is that you
also said that there are going to be two
link data event streams
that we're going to start with one the
address registry in flanders
and to do the the here be in front of
flanders the grb the
reference which is the which is exactly
the bgt in the netherlands
and the address registry or the address
and building registry in the netherlands
is also going to be
to do and also the address registry in
flanders
so this will cater for some really
interesting cross
across member state use cases um
and and i'm really looking forward to to
seeing how like
two completely different backends with
the same data but with different
slightly different data models because
the netherlands has their own data
models and and
flanders have their own data models that
we can can still then
later on align them and make sure that
we can seamingless
uh seamlessly uh uh query over the the
two data sets in parallel at least that
if we can give a demo like that that
would be great and if then at the same
time
we can for free give a demo where we can
also query
over marine regions gazetteer over the
the five
collections in from the museum in ghent
over
uh digital twin models over uh
uh what else did we talk about i i
almost already forgot
um but um all these different data sets
i think they will
they will become queriable to the masses
this way
and we will have an automatic ecosystem
when when people
set up a new intermediate index it will
be added to the ecosystem if they put it
put it
put it down it will also okay they
disappeared but
still the the ecosystem will be able to
recover by just uh
fetching android data just in time
we have about two minutes left for uh
questions luckily i don't see too many
questions
popping up in the chat but if there
would be
any questions it is no or never and i
will only take
one question which was not according to
us to plan but still i think we had an
interesting
session any questions in the chat
three two one
ah i see shirts typing shorts feel free
to immediately uh
take the take the floor ah thanks peter
yeah i have
one question um uh how do you publish
your
data set information if you use linked
data event streams
for instance how does this ld
s fit into the d-cad model
uh aravind told something about slash
feed for publishing your event streams
but how can we discover your event
streams
uh yes this is also part of the of the
3cg
specifications so you can also just go
to the specification
and read about dcat compatibility where
that's mentioned but indeed i i do see
that
that these collections are going to be
added as distributions of data sets so
uh that the the dcat model is is a is a
catalog uh the data sets and
distribution
i think the data set is like the address
registry and then the the defeat is your
specific distribution of how to retrieve
the
uh the data set but but also adding the
the metadata about the specific
collection and
the views that are created on on top of
that you will be able to have even
richer
uh metadata in which you can use your
dcat catalog to say like
oh i just want all the uh collections or
all the distributions
that for example have a use the property
social result time
and for me social result time that would
indicate that i have a time series so
can you can uh can can use that in the
tree specification just as
uh geraldine also posted in the in in
the chat we also indeed
uh uh points to dc terms conforms to to
indicate that you
uh confirm that you conform to the the
three specifications so that in that way
you can also
immediately find all the data sets that
that use this way of
publishing their data okay thank you
good and this was immediately a question
for me so so so thank you very much it's
six o'clock
my uh my kids is screaming downstairs
for for my
attention so i will also not take more
of your
uh time this way but
uh i want to wrap up by saying that
the presentations uh please dear
speakers
send them to me if i don't already have
them i will make sure that they're uh
posted online so that it can be used by
uh the uh by the audience to uh
to to to read up on it and to click the
links in in in
your uh presentations um the video
itself will also be shared on the open
belgium
uh website if you uh in the audience
want to
uh start get your hands dirty with link
data event streams
ping me or go to the github repository
or send us
send us an email or just immediately go
to the specs get your hands dirty we
will be more than happy to
to help you out if you bump uh against
uh
against anything and last but not least
i would like to um but not made
penultimate uh uh but not but not least
i will thank my speakers brett brits
analyst philippe olivier erwin
voter who already left and ensures thank
you very much for being part of this
uh thanks for for making uh making link
data event streams credible because
because thanks to your implementations
and thanks to your
uh projects using it in the real world
it is becoming a reality
not because there's some vague
specification uh about it
um so thank you very much and for your
enthusiastic uh presentations
and last but not least i would like to
thank of course the people from cloud86
who have been uh great at providing us
with uh
support uh when when things didn't
always technically work out
so with these final words um thank you
everyone
and uh see you uh see you online
in in your next question about leak data
event strips
bye
okay okay
you