=Paper=
{{Paper
|id=Vol-1191/paper3
|storemode=property
|title=Sierra: Cooperative Request-Response for Resource Management in Disasters using Semantic Web Principles
|pdfUrl=https://ceur-ws.org/Vol-1191/paper3.pdf
|volume=Vol-1191
}}
==Sierra: Cooperative Request-Response for Resource Management in Disasters using Semantic Web Principles==
https://ceur-ws.org/Vol-1191/paper3.pdf
Sierra: Cooperative Request-Response for
Resource Management in Disasters using
Semantic Web Principles
Seyyed M. Shah, Christopher Brewster and Duncan Shaw
Aston University, Birmingham. B4 7ET
{s.m.a.shah|c.a.brewster}@aston.ac.uk
Abstract. Disasters cause widespread harm and disrupt the normal
functioning of society, and effective management requires the partici-
pation and cooperation of many actors. While advances in information
and networking technology have made transmission of data easier than
it ever has been before, communication and coordination of activities be-
tween actors remain exceptionally difficult. This paper employs semantic
web technology and Linked Data principles to create a network of inter-
communicating and inter-dependent on-line sites for managing resources.
Each site publishes available resources openly and a lightweight open-
data protocol is used to request and respond to requests for resources
between sites in the network.
1 Introduction
A disaster1 is defined by the UN as a “serious disruption of the functioning
of a community or a society involving widespread human, material, economic
or environmental losses and impacts, which exceeds the ability of the affected
community or society to cope using its own resources” [1]. Disaster and emer-
gency response is the most critical phase when emergency management agencies
attempt to provide services and assistance so as to save lives, reduce the im-
pacts on health, make sure that basic security and subsistence needs are met.
In attempting to achieve this, disaster response agencies face a number of chal-
lenges. A number of different resources need to be identified, including people,
physical resources, vehicles, etc. Agencies need to know their quantity, location
with respect to the disaster and the time when they are available. Time and
location are critical factors – resources provided too early, or too late or in the
wrong place can reduce the effectiveness of recovery [2]. As well as time and
location, collaboration is a critical factor. Usually any disaster of significant size
will involve efforts and resources from many different and diverse organisations
and individuals. Agencies need to know about these resources in detail so as to
deploy them appropriately. Effective management of these issues fundamentally
1
We use disaster and emergency interchangeably here although the UN defines an
emergency as a “threatening condition” significantly less serious than a disaster.
concerns the availability and access to information about the resources. A given
decision maker needs to know what, where, when and how for each and every
resource whether a human being helping out or a load of sandbags needed to
shore up a dyke in a flood.
This paper presents the prototype of a system built using semantic web
technologies and based on Linked Data principles which seeks to address the
information management challenges in disaster response. The paper is organised
as follows: In Section 2, challenges in creating software systems for emergency
response are discussed and set as evaluation criteria. Section 3 presents the co-
operative architecture for decentralised resource management in emergencies,
applying Linked Data principles for interoperability. A prototype implementa-
tion that demonstrates the the architecture is described in Section 4 along with
the ontologies created for the implementation. Section 5 presents a Case Study
that is used as an initial evaluation of the presented architecture.
2 Complexities of Software Tools and Resource
Management in Emergency
Turoff et al. [3] discuss developing practical emergency response systems and
present nine premises for preparedness, summarised here as follows:
– Regular Use: A system that is not used before a crisis will not be used during
the crisis.
– Information Focus: Responders only use a system if the information provided
is relevant to the emergency.
– Crisis Memory: Learning from previous crises is extremely important.
– Exceptions as Norms: Crises are unpredictable.
– Crisis Scope: Focus of problem solving shifts depending on the crises, each
problem requires a range of different resources.
– Role Transferability: Responder roles can interchange during an emergency.
– Information Validity: Providing timely information is critical to decision
making
– Open Information Exchange: Numerous responder organisations and indi-
viduals should exchange data freely.
– Unpredictable Coordination: Collaboration of responders and organisations
is not pre-determinable.
For reasons of space, we will not analyse these premises further, but we will
apply each premise to evaluate the work in this paper, and discuss how these
goals might be achieved in practice. Existing disaster and emergency response
systems used by emergency management agencies (EMAs), as our research has
found, tend to be stand alone systems. Thus the fire service are unable to com-
municate electronically with the police and the police cannot communicate with
the ambulance services etc. let alone with external third party data sources. Even
within a specific service, there can be minimal data sharing between different
offices and everything is communicated via faxes or emails.
This phenomenon of total lack of interoperability is also apparent in the
software tools that have been developed to support humanitarian emergency
response. In recent times, open-source online emergency response tools have
been made available [4], and these have become widely used by NGOs. One
of the most popular is Ushahidi [5] which allows crowd sourcing of information
about an emergency. Any organisation can deploy Ushahidi to collect information
from multiple “streams” for example, via text messages, email, twitter and web-
forms, so that help can be sent where needed. Each deployment of the tool
is completely independent of any other. This means that many organisations
can simultaneously deploy the tool. However, due to the centralised nature of
the tool, each organisation can only access information submitted to their own
site. Furthermore, separate systems that gather emergency information from the
public are not interoperable with Ushahidi. That is, the information collected
about the same emergency in Ushahidi and a separate legacy system is not
available to both sets of responders, even if there is overlap in the information
gathered. Similar comments can be made concerning Sahana Eden [6] another
popular humanitarian resource management tool.
This section has outlined some of the challenges for developing systems that
are used in emergencies. The premises are set as evaluation criteria tools used in
emergency that are centralised and not interoperable have been found. Follow-
ing the next section, a system is proposed for decentralised and interoperable
resource management in emergency scenarios, using semantic web technology.
2.1 Semantic Web Technologies
Semantic Web and Open Data technology builds on existing Web standards,
RDF and OWL are standards used to add meaning to published data. Semantic
technologies expect that data will be multi-authored and distributed, and cru-
cially, interlinked between separate data sets. Semantic technologies also allows
for creation and extension of formal ontologies, to provide a precise representa-
tions of aspects of the domain. Data from diverse systems can then be integrated
and the ontologies to serve as a common language for communication between
different organisations. Furthermore, separate systems using semantic standards
can be integrated to create new applications for existing data.
Semantic technologies are therefore particularly suited to use in disaster man-
agement. Emergency response is typically multi-organisation and distributed.
Using semantic technology has an important advantage- data from each organi-
sation about the same subject, in this case an emergency, is linked together. For-
mal ontologies provide a common language for communication- both human and
machine-based - about the emergency between diverse organisations. The graph-
like nature of RDF allows navigation around data points and automated logical
reasoning to improve the response. For example, the universal response database
described by Turoff et al. [3], could be encoded using RDF and published “open
data”. The next section describes a particular application of Semantic Web and
Open Data technologies towards improving disaster response.
Fig. 1. Network of sites with resource responses and requests
3 Sierra Architecture for Decentralised and Interoperable
Resource Management in Emergencies
In the light of the requirements identified in the previous section, we have devel-
oped a system based on the use of Semantic Technologies [7] and Linked Data
principles [8,9]. An approach based on Semantic Technologies enables a decen-
tralised and yet interoperable system design, a system which is both open to
further expansion and yet scalable for complex resource management.
The proposed system is made up of a network of machine-readable websites.
The purpose of each site is to hold information on resources, as well as act as an
interface to make requests and respond to requests from other sites. Each site
has a clearly defined remit e.g. the geographical area or organisation to which
the resources, requests and responses belong. The basic architecture of such a
network is shown in Figure 1.
Users of the site have access to the site (or sites) to which they are affiliated
and a user can belong to multiple sites. The site presents tools that allow a
user to view, modify and add data about resources concerning their particular
organisation or entity. The web site also allows users to respond to requests for
resources from any other site as well as make requests to other sites for resources
in the network. User can only manage resources and make responses and requests
from the sites to which they belong.
The users access the site via the Internet and a standard web browser. No
additional software is needed, as the sites must use web standards for the user
interface presentation. Using standards makes the sites accessible not only for a
variety of devices - mobile, desktop or dedicated app, but also to disabled users
via screen readers and magnification. A web based system is key in this scenario
because of the need for online collaboration in emergencies.
For interaction between sites, the network uses core principles of Linked
Data. Firstly, data about physical resources that can be stored and exchanged
between sites are encoded in RDF using an extensible ontology. This allows sites
to exchange information about physical resources using a common, standards-
based notation. Secondly, a lightweight semaphore protocol and closely related
ontology is used to describe requests and responses for the exchange of physical
resources. Each site runs a SPARQL endpoints so that remote sites can query
them for information on resources, requests and responses.
A key aim of the system is decentralisation of sites that cooperate in the
network. Each site and its resources are under the separate control of the or-
ganisation or group to which they belongs. As sites are web-based, sites can
be physically located in geographically-diverse data centres. Web sites can be
backed-up, mirrored and relocated as needed during an emergency.
Importantly, each site can be completely independently implemented, yet
still be interoperable with other sites in the network. That is, if the protocol
and standards are implemented correctly many different deployments can work
together in a network. Interoperability via standards allows legacy systems to
be integrated, for example the resource tracking systems used by some emer-
gency responders could be integrated into the system with the addition of a
compatibility layer.
4 Prototype Implementation
This section describes a light-weight proof of concept implementation based on
the Drupal open source Content Management System (CMS). Drupal has been
chosen because apart from being open source and extensible, it has a substan-
tial set of contributed modules implementing semantic technologies and markup.
Particularly important are the modules that allow for Drupal to become an open
linked data system: RDF Extension, SPARQL, SPARQL views and Restful Web
Services 2 . With the open data modules, content is manually mapped to a se-
lected ontology, presented in RDF and queried using a SPARQL endpoint, via
the ARC2 PHP library. Other contributed modules used included ones that en-
able geo-location: OpenLayers, geofield and geophp 3 . These modules collectively
allow resources to have a location and to visualised using familiar online mapping
interfaces such as Google maps or Open Street Map.
The prototype also customises Drupal by adding custom content types, so
instead of managing blog posts and web pages, relevant kinds of content are
managed. The content types added are Resource, Request and Response, along
with the fields to represent those types. An instance of each type can be created
to represent actual resources, responses and requests. Interactive forms to create,
view, edit and delete the content types have been created along with fine-grained
2
Available from http://drupal.org/project/rdfx
3
Modules available from http://drupal.org/project/modules
multi-user permissions for doing the same. Mappings between each content type
and the ontology have also been created, so that Resource, Request and Response
content are presented as open data.
Screen-shots of the prototype application are shown in figure 2. The main
navigation menu (a) accesses features such as searching for resources (b), creating
requests (c) and viewing responses (d) from the network of sites.
In order to ensure meaningful URLs, we have developed an additional module
for Drupal, entitled Pathauto for RDF 4 By default Drupal URLs are not mean-
ingful; so the URL for a blog post might be http://example.com/?q=node/1
or http://example.com/node/1. However, with the built-in URL rewriting fea-
ture and the Path Auto module, content URLs are made readable, such as
http://example.com/blog/example-title. The effect of this is URLs that can
be used as URIs for the items stored. However, as the Path Auto and RDF
modules are not fully compatible, the RDF document describing an item is
available at the meaningless URL, http://example.com/node/1.rdf even if the
web page is a Path Auto one. The Path Auto for RDF module automatically
creates an alias for the RDF document at the same location as the URI e.g.
http://example.com/blog/example-title.rdf.
4.1 A Decentralised Network
So far we have described a stand-alone online system for managing resources. In
principle, the system so-far is equivalent to the kinds of resource management
systems used by emergency management organisations. Next, we describe how
this is used as the basis for a decentralised network of co-operative sites using a
novel linked-data based mechanism. Two ontologies have been created: Protocol
for Request-Response (PRR) and an Ontology for Real Resources (ORR)5 , to
respectively describe requests and responses and the physical resources that can
be transferred in a network of sites. The Ontology for Real Resources (ORR) is
used to encode information about resources as RDF triples that are interchanged
between organisations to describe resources in a common conceptual framework.
In order to establish a network, two steps are required. Firstly, two or more
sites must exist, each openly publishing resources, requests and responses. The
sites can include displays for viewing openly published resources, requests and
responses from the network. In Drupal, the displays can be created using Views
created using the the SPARQL Views module, to show internally held data and
data from external SPARQL endpoints. Secondly, any two sites can form coop-
erative network by subscribing to one another; adding each other as SPARQL
data source. Subscription requires site-users to add external sites. This allows
sites to:
– View and search for resources under the remit of external sites
4
Available under the terms of the GPL from http://drupal.org/sandbox/shah/
1871288.
5
These ontologies form part of a wider effort in the Disaster 2.0 project to survey and
fill the gaps in ontologies for disaster and emergency response cf. [10]
(a) Resources Mapped (b) Searching Resources
(c) Making a Request (d) Gathering Responses
Fig. 2. Prototype user interface screen-shots
– Publish requests for resources from an external site
– View the responses for requests made to an external site
– View requests made for the resources under the remit of the local site
– Publish responses to requests for local-site resources
In effect creating an interoperable network of distributed independent sites
for resource management in an emergency. The following sections describes the
linked data based protocol and the ontology for describing resources.
4.2 PRR: Protocol for Request Response
The Protocol for Request Response ontology consists of three classes and ten
properties, shown in figure 3. The two main classes are prr:Request and prr:Response,
which extend from the abstract prr:BaseClass for the common properties pro-
vided. Sites publish instances of either Request or Response for a given Resource
to enact the protocol.
Given two sites (e.g bham, aston) that hold a register of resources and the
sites subscribe to each other, the protocol is as follows. The bham site makes a
Fig. 3. Class diagram: Protocol for Request Response
request for a widget from aston, by creating and publishing an instance of the
prr:Request class. The prr:Request slots are filled as shown in Table 1.
Slot Value
Request Name Widget Request
Comment With our thanks
Item http://aston/widget
Item Site http://aston/
Requesting Site http://bham/
Start Date [desired date & time]
Stop Date [desired date & time]
Table 1. A request by bham for a widget from aston with URI http://bham/request/
widget-request, this request is encoded as triples and published on the bham site.
The request is published as open data and accessible via the bham SPARQL
endpoint. As the aston site subscribes to the bham endpoint, the request appears
on the aston site. The aston site can either accept or reject the request for
the widget by creating an instance of the prr:Response class that references
the original prr:Request from bham. The bham site will see the response as it
subscribes to the aston site.
The request is published as linked data and accessible via the aston SPARQL
endpoint. As the bham site subscribes to the aston endpoint and the response
contains the URI of the original request, the bham site can determine if the orig-
inal request was accepted. In the case the request is not accepted, the comment
slot can help the requester re-submit an acceptable request. The protocol steps
in this scenario are outlined in the sequence diagram shown in Figure 4.
6
Where there are similar requests made by other sites for the same need, they are
linked in this slot.
Slot Value
Response Name Widget Response
Comment Not a problem
Request URI http://aston/request/widget-request
Status “accepted”
Also Fulfils Requests Requests fulfilled by this response 6
Table 2. A response by aston to the request for a widget from bham with URI http:
//aston/response/widget-request this request is encoded as triples and published
on the aston site.
Fig. 4. Sequence diagram: overview of Protocol for Request Response
5 Evaluation via Case Study
We evaluated the system by means of a conceptual evaluation based on emer-
gency management organisations. Various emergency services, local and national
government are the responders. Requests can include items such as sand bags,
sand, water pumps, and pontoons.
In this type of emergency a great amount of co-operation and co-ordination
is needed between the emergency responders. Each emergency service needs to
respond to the needs of the affected population with available resources. An
important issue with such response is interoperability. As noted above, tradi-
tionally each organisation is only aware of their own resources, and the only
way they are aware of resources of what exists elsewhere is through informal
networks, telephone calls etc. Each emergency service typlically uses a separate
system for managing resources, as the needs and response of each service nat-
urally differ. Software systems which are designed as stand alone and without
interoperability cause problems when responders require resources from outside
organisations. Responders must find and contact the relevant person to request
resources, and making manual requests for resources can take valuable time away
from response.
With the proposed system in place, each emergency service runs a separate
instance, for example, the fire service controls the site ‘FireServices’ and the lo-
cal council controls the ‘LocalCouncil’ site. The sites publish data openly via the
mechanism set out in this paper but are normally used for managing resources
within the organisations. The two sites subscribe to each other and form a net-
work of independent but cooperative sites for resource management. This fulfils
several of the evaluation criteria. Firstly the systems allow for ‘open information
exchange’, publishing requests with the principles of linked open data. The sites
are obviously decentralised and interoperable using a direct open data protocol
based on RDF and SPARQL. The independent systems are also expected to be
in regular use for day-to-day resource management.
In an emergency, such as a flood scenario, FireServices responders can use the
system to request resources from the Council site and vice-versa. For example,
if residents are being evacuated, the LocalCouncil site can send a request to the
FireServices site for rafts by publishing the request openly. This eliminates the
need for the council to find and contact the correct person, instead the user
has ‘Information Focus’ on getting the resources needed for the evacuation task,
using familiar tools. ‘Crisis Memory’ is also built into the systems, as previous
requests and responses are available from each organisation in the network.
The proposed systems cannot make crises more predictable, so it does not
directly address the issues ‘exceptions as norms’ or ‘crisis scope’ mentioned above
in Section 2. However, because of the flexibility of the system, any site can request
from any other, allowing for ‘Unpredicted Coordination’. So for example, a local
builders’ merchant can set up a site to join the network and respond to requests
to provide sand bags for the affected population. Finally, roles are transferable
in the systems at both macro and micro levels; responders can also become
requesters and individual users can be granted more privileges to respond to
and make requests. Because the system uses open data, it is possible for all
organisations involved to have the most up-to-date information about resources
available, for greatest “information validity”.
This initial demonstrative evaluation has shown how the proposed system
fulfils the aim set out in this paper and the criteria of [3]. In order to perform
a complete evaluation, an emergency practice exercise is planned with the In-
termunicipality Civil Protection Center7 in the Province of Pisa and Livorno,
Italy.
6 Related Work
Several works from the literature are related to the current proposed system for
cooperative resource management in emergency. The protocol used for commu-
nication between sites forms a Semantic Web Service [11], however in this work,
7
http://valdicecina.salaoperativaprociv.org/
the focus is on physical resource exchange and so a minimal protocol is created
as a very-lightweight semantic web service. Furthermore, the current tool uses
geo-location information and semantic web in a similar vein to stSPARQL [12]
and the closely related geoSPARQL [13]. In the current work, simple latitude and
longitude pairs are used to represent resource locations. Further development is
required for the integration of geoSPARQL or stSPARQL like features.
More closely related to the prototype presented here are Ushahidi [5] and
Sahana Eden [6] tools. As previously noted, these tools are centralised with single
installations and not-interoperable with other installations of the same tool. [14]
describe a system for presenting existing data for emergencies as Semantic Web
Services, this system is also centralised and external. Sahana Eden publishes
data openly via a RESTful API [15], however no applications have been found
to exploit this data. In the current prototype, cooperation and interoperability
between sites using the same software is a key feature.
Another area of related work are the ontologies for managing disasters: Man-
agement of a Crisis Vocabulary (MOAC) [16] and Humanitarian eXchange Lan-
guage (HXL) [17]. MOAC terms originated from the Ushahidi platform and use
during the Haiti crisis, HXL is inspired by MOAC. The aim for both ontologies
is to present and exchange information about disasters, attempting to cover the
entire disaster. In contrast, the ontologies presented here focuses on a specific
aspect of disaster- resource exchange. Furthermore, MOAC and HXL are based
on observations of crises and have not been integrated into a tool that publishes
data, whereas the ORR and PRR ontologies are developed for inter-site coop-
eration and interoperability the prototype tool and to achieve the goals from
[3].
7 Conclusion
This paper has presented an ontology and protocol for resource management
in emergency response. A network of sites is created by mutual subscription to
SPARQL endpoints, where available resources are published openly. Any site
in the network can also use the open data based protocol to publish requests
for particular resources. The site to which the resource belongs can respond
via the protocol. The proposal consists of a distributed network of cooperative
but independent organisations that can publish and exchange resources, without
centralised control. The proposed protocol is also designed to interoperate with
existing an legacy systems.
Acknowledgement
This research has been supported by the Disaster 2.0 project (http://www.disaster20.
eu) funded by the ‘Prevention, preparedness and consequence management of terror-
ism and other security-related risks’ programme, European Commission – Directorate-
Home Affairs (HOME/2010/CIPS/AG/002).
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