The Bio-Inspired and Social Evolution of Node and Data
in a Multilayer Network
Marialisa Scatà
1
, Alessandro Di Stefano
1
, Evelina Giacchi
1
, Aurelio La Corte
1
and Pietro Liò
2
1
Department of Electrical, Electronics and Computer Science Engineering,
University of Catania, A. Doria 6 street, Catania, Italy
2
Computer Laboratory, Department of Computer Science, University of Cambridge,
15 JJ Thomson Avenue, Cambridge CB3 0FD, U.K.
Keywords: Bio-Inspired, ICT, Social Networks, Multilayer Networks, Data Mining, Comorbidity, Game Theory,
Decision Making, Health.
Abstract: Following a bio-inspired approach, applied to multilayer social networks, the idea is to build a novel
paradigm aimed to improve methodologies and analysis in the Information and Communication
Technologies. The social network and the multilayer structure allow to carry out an analysis of the complex
patterns, in terms of the dynamics involving the main entities, nodes and data. The nodes represent the basic
kernel from which generating ties, interactions, flow of information, influences and action strategies that
affect the communities. The data, gathered from multiple sources, after their integration, will become
complex objects, enclosing different kinds of information. The proposed approach introduces a level of
abstraction that originates from the evolution of nodes and data transformed in “social objects”. This new
paradigm consists of a multilayer social network, divided into three layers, generating an increasing
awareness, from “things” to “knowledge”, extracting as much “knowledge” as possible. This paradigm
allows to redesign the ICT in a bio-networks driven approach.
1 INTRODUCTION
The new ICT paradigm is expected to contribute to
the process of improvement in the realization of a
knowledge-based networking, characterized by
innovation, making the networks sustainable with
processes based on a strategic bio-inspired approach,
considering also the social, human and cognitive
aspects. The future network needs to meet some
requirements, such as ubiquity, mobility,
dynamicity, reliability. The ubiquitous nature leads
to a logical fusion and integration of different
aspects of real and online social network platforms.
The network nodes acquire a common representation
through identity features. These features, following a
bio-inspired approach, enclose genotypic and
phenotypic traits. In addition to these traits, it is
important to consider also context-aware
capabilities, self-organization, self-protection,
perception, decision-making processes and cognitive
behavior. Considering these features, the nodes
interact through social networks and they are able to
self-organize dynamically in communities and
groups, based on aggregation metrics. We think that
the node is an abstraction, an object which collects
bio-inspired features as well as human and social
capabilities. Similarly, data shared inside the
network are a complex object, like a box, which
travels across the network through interactions
between nodes. Data and nodes represent the objects
that trigger influence, interaction, contagion and
decision criteria. These two entities enclose many
different social aspects. In the future of ICT we will
expect to be able to obtain context-aware services,
which stem from a bio-inspired approach able to
drive methodologies for analyzing social complex
networks. We propose in this paper an evolutionary
perspective of nodes and data, an innovative
multilayer perspective. To solve the heterogeneity
issue of these entities, we propose a social object
oriented approach, following the bio-inspired
principles in a multilayer social network. The paper
is organized as follows: the second section is about
background; in the third section we will explain the
social object oriented evolution of networks and the
novel bio-multilayer network schema; in the fourth
41
Scatà M., Di Stefano A., Giacchi E., La Corte A. and Liò P..
The Bio-Inspired and Social Evolution of Node and Data in a Multilayer Network.
DOI: 10.5220/0005119600410046
In Proceedings of the 5th International Conference on Data Communication Networking (DCNET-2014), pages 41-46
ISBN: 978-989-758-042-0
Copyright
c
2014 SCITEPRESS (Science and Technology Publications, Lda.)
section, we will focus on future directions
challenges and strategies of this work and finally we
conclude with some considerations.
2 BACKGROUND
2.1 Social Networks Analysis
The social network analysis is an analytical tool
used to understand how highly connected systems
and entities, which form social links and networks,
operate (Aggarwal, 2011). It considers social
relationships in terms of network theory, with nodes,
representing the individual actors within the
network, and ties (referred also as edges, links, or
connections), which are the relationships between
the individuals. The resulting structures are complex
graphs connecting social contacts, and the graph
theory, from a structural point of view, is able to
describe these relationships using metrics, such as
betweenness, centrality, degree, closeness, clustering
coefficient, etc. The power of social network
analysis is that it produces a different view, where
the attributes of individuals are less important than
their relationships and ties with other actors within
the network. Furthermore, the behavioral dimension
means that the individual’s actions have to be
evaluated not in isolation, but considering the
connections with the other players, who can use
different strategies (Easley and Kleinberg, 2010).
All these structural and behavioral aspects have to
cope with the network dynamics, so that connections
and behaviors between nodes change over the time,
increasing the complexity of the analysis. Since a
significantly larger amount of data is available for
the case of online social networks, these networks
have made much more robust, in terms of statistical
significance, the verification of some structural
properties, such as the small world phenomenon,
preferential attachment, and other structural
dynamics. The community detection is one of the
most well-known structural problems in the context
of social networks (Fortunato, 2009); it is closely
related to the problem of finding structurally related
groups in the network, called communities. In order
to understand the complex dynamics of social
networks, in this work we suggest to change the
perspective of analysis, and evolving the concepts of
“node” and “data”, the bio-inspired social object,
which includes the social perspective and the bio-
inspired approach. Considering a data-centric
perspective, the social network analysis helps to
transform a context-aware object in a data “social”
object, while in a node-centric perspective, by
analyzing communities and their evolution in social
networks, we can introduce cognitive features in the
nodes, obtaining a node “social” object.
2.2 Multilayer Networks
Almost all real and virtual systems are inherently
composed of multiple layers (or subsystems), which
contribute to the wholeness of their functionality but
can also be considered as systems in their own right.
Network science has been largely successful in
abstracting meaning from single-layer subsystems
(Newman et al., 2009) and it is only recently that
multilayer networks (Kivelä et al., 2010) have
become a popular paradigm for the modeling of
interrelated subsystems and entire systems. This is
largely due to the capability of multilayer models for
understanding the bigger entity more realistically. In
fact, most real world entities are connected each
other in more than one way, from transportation
systems to social relationships.
Figure 1: Bio-Inspired Multilayer Network for ICT. (See
Text).
Figure 2: Dynamic Complex Patterns of the Multilayer
Structure. (See Text).
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This multiplexity, or the complexity caused by the
existence of more than one link between entities, has
been observed across multiple fields. In social
networks for instance, different and not mutually
exclusive relationships can be considered between
the same two people (e.g. friends, relatives,
colleagues, etc). Although social relationships are
difficult to measure and such rich information about
all the ties are rarely available, modeling social ties
considering only one dimension does not capture the
realistic human social dynamics. Networks, where
occur multi-edges of different types between the
same nodes, are referred as multiplex networks, or
more generally multilayer networks, since each type
of edge can be abstracted to either an independent or
interdependent layer (Kivelä et al., 2010). The real
potential of multilayer networks, in terms of
applications and value, has not been exploited yet.
One of the goals of the present work is to build and
interpret a multilayer network model able to detect
and separate the different layers and dimensions of
analysis of a bio-inspired network-oriented ICT
model.
3 A MULTILAYER APPROACH
SOCIAL OBJECT ORIENTED
The proposed paradigm in this paper is the result of
a biologically-inspired approach applied to complex
social networks. Exploiting a multilayer architecture,
it consists of an evolution process that involves both
nodes and data. This approach starts from the
consideration that all techniques and models related
to information and communication have to be based
on what governs the network dynamics. These
processes in a social-based context are determined
from nodes and data. This requires an evolution of
these entities inside a multilayer network which
shows the patterns of the different relationships and
interactions among nodes and communities, through
the sharing of data. The main goal is to solve all the
issues related to heterogeneity, which can be an
obstacle to more complex and deep analysis of
networks. The network is characterized by a
multitude of nodes of different nature, and by a
multi-channel data collection. The aim is to obtain
an evolution of the networks considering bio-
inspired social objects. This evolution will become
useful to enable the ICT procedures to be in line
with the bio-inspired processes that rule the complex
social network. The future ICT will be driven from
these objects creating strategies and applications
with an innovative and dynamic approach. The Fig.1
illustrates a multilayer social network, divided in
three different layers. The three layers show the
same topology but actually it could be different
across layers. The first layer is the social layer,
characterized by interactions between nodes through
the sharing of data. In the second layer we introduce
the comorbidity perspective, which is a medical
concept referring to the co-existing of different
diseases in the same subject, it creates other different
relationships between nodes, that represent
patients/individuals who share the same diseases or
morbidities. In the third layer we consider the ICT in
terms of interventions which involves the single
entities and the system as a whole. In this
perspective, the multilayer organization enables us
to analyze the complex patterns of analysis. Starting
from a simple node which interacts with other nodes,
we can obtain an evolution and a growing
awareness. The Fig. 2 shows the dynamic patterns as
the result of the coupling effect of interdependent
layers. Only by studying the inter-layer interactions
between nodes, it is possible to detect the emergent
behaviors and focus on the key features related to
data and nodes, from which these patterns are
generated. One perturbation in one layer could drive
changes in the other layers through interactions. The
evolution process from node and data to “social
objects”, is indicated in Fig. 3. The “social objects”
pave the way to the higher level of awareness,
referred as “knowledge”, the abstraction of the
outcome of the flow of information and social
objects. The social objects merge together all the
different cognitive, social and human aspects and the
various contexts. The node, in the proposed
paradigm, becomes an abstract object which
contains any kind of presence and/or participation in
the social networks. This can encompass simple
network nodes, both hardware and software, IoT
sensors, human nodes, etc. The node’s presence is
defined as a set of bio-inspired features, such as
genotype and phenotype. The genotype is
represented by the immutable traits of that object.
The phenotype is a combination of observable
features, behavioral manifestations of genotype, and
the result of interactions between genes,
environment, and random factors. The multitude of
heterogeneous nodes, with capabilities of self-
organization, through mechanisms of aggregation
and clustering techniques, becomes an organized
structure of communities and groups. Enabling
context-awareness and cognitive capabilities, the
nodes become smart, able to decide their strategies
inside and outside the communities. Adding abilities
TheBio-InspiredandSocialEvolutionofNodeandDatainaMultilayerNetwork
43
Figure 2 3: Evolution of Node and Data. The evolution, involving data and nodes, is a process which starts from
disaggregated and heterogeneous things, and gets the social objects and finally, the knowledge for the ICT.
extracted from complex social networks analysis, in
terms of emerging behaviors, we will obtain the
abstraction, which is the social object node. The
data, the other entity of the network, are any kind of
collected information, useful to network analysis.
The data could consist of statistical data, data
gathered from sensors, social data, derived from
online and real social network platforms. Collecting
data may be relatively easy, but the complexity
arises in combining and integrating datasets from
multiple sources and different contexts, in order to
extract the real knowledge about networks. This is
the reason why, as we will explain in the next
section, we need a complex mining, able to fuse and
integrate in a unique structure these heterogeneous
data, collected from different sources and of
different nature. Furthermore, we have to integrate
data considering the different contexts and
environmental conditions in which these data are
generated, considering who created them and for
what purpose, so we have to consider a context-
aware data mining, related to how attributes should
be interpreted according to the different contexts.
4 FUTURE STRATEGIES AND
APPLICATIONS
4.1 Knowledge Mining for Health
Public Health and Clinical Interventions
Management is one of the future targets of the ICT
and networking. The aim is to improve the
efficiency of some processes related with this
context, optimizing methodologies and procedures,
providing technological support systems. Social
network phenomena appear to be relevant in the
health context, in particular in the biological and
behavioral traits linked to diseases. Some diseases
appear to spread through social ties (Christakis and
Fowler, 2007), so the importance of considering the
structure of social ties and the social contagion
process for a better understanding of the subtle and
deep processes underlying these social phenomena.
These issues imply an increasingly better evaluation
of the methodologies of analysis of the social
networks. In fact, a future changing in relationships
can affect the extraction techniques in the node
behaviors, relating them to the diseases that arise
and, subsequently, evaluate the relationships
between them, and the co-occurrence in the same
individual, that will be defined and treated in the
next section. Therefore, this complex analysis
involves multiple levels of awareness, from the
nature of nodes, in terms of behavior and biological
traits (genotype and phenotype), to their behavior
when organized in communities. In this scenario,
nodes and data become the entities to focus on,
looking for both the extraction of behavioral rules
and the data mining processes. The level of
abstraction proposed in this paper allows to treat the
network entities as social objects and then, the use of
appropriate techniques for the collection, integration
and analysis of data, would make possible the
realization of a higher level of mining (Scatà, Di
Stefano and La Corte, 2014). The weights assigned
to these interactions and the social dynamics, such as
the social contagion related to diseases in this
scenario, could be crucial for extracting more
knowledge related to the probability that some
individuals, for example the ones who are more at
risk than others, are going to contract certain
diseases. This deeper analysis would be unthinkable
using the traditional methods. The diagnostics is
driven by a complex system of analysis that gathers
and integrates the traits that characterize the nodes
and data.
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4.2 Comorbidity and Social Behaviors
Comorbidity means the co-occurrence of one or
more different diseases in the same patient.
Comorbidity represents an extremely complex field
of research, and the complexity arises because of the
complex relationships between conditions, disorders
or diseases, all related to a single individual/patient.
These conditions are often independent each other,
in fact there could be no pathological association
among them, but sometimes the relation is very
strong and it is due to direct or indirect causal
relationships and the shared risk factors among
diseases (Tong et al., 2007), more than a chance
alone. The complexity is also due to the uncertainty
that depends on the number of associated
morbidities (Capobianco E. and Liò P., 2013).
Following the definition provided by the US
National Library of Medicine, comorbidity is
considered to be a secondary diagnosis, detected
simultaneously or one after another in the same
patient. Comorbidity is associated with multiple
different symptoms, decreased length and quality of
life and increased healthcare management (Islam M.
et al., 2014). The study of comorbidity relationships
between diseases could be exploited to build a
model for predicting the diseases an individual may
develop in the future, so the idea would be to
prevent or at least inhibit the future occurrence. The
analysis of comorbidity has to consider different
dimensions morbidities (Capobianco E. and Liò P.,
2013): the clinical dimension, related to diagnosis
and treatment; the therapeutic dimension, which
seeks to restore the steady state but can add
complexity based on the reaction to drugs or
interventions; the genetic dimension, which looks
for the molecular causes, the levels of gene
expression, susceptibility and risk factors; the omics
dimension, which highlights the common causes
behind comorbidity and it consists also of a
functional analysis based on gene sets. It is
necessary to consider the computational aspects, as
inferential approaches may help to identify the
direction of causality, for example, using evidence
synthesis. In the future work, we want to add another
dimension, the social one, in fact we will evaluate
how social behaviors can influence the evolution of
patients in terms of comorbidity. One of the ideas
underlying this paper, in terms of comorbidity, is to
highlight also the psycho-cognitive aspects of the
individual (node) that will influence his behavior
against illness, empowering patients in the
healthcare decision process (Gorini A. and
Pravettoni G., 2011). The way to conduct this social
interaction analysis could be using theoretical and
analytical tools, such as decision-making and game-
theoretic approach, that we will introduce in the next
subsection.
4.3 Decision-Making and
Game-Theoretic Strategies
The decision's criteria depend both on individual
knowledge and social context, intrinsically linked
and dependent each other. Thanks to its individual
knowledge, the node, acquiring awareness of the
context and the environment to which it belongs, is
able to analyze the information received by its
neighbors, evaluating their actual behaviors and
predicting the future ones. The node, once
established its objective, compares all the
alternatives using its set of decision's criteria, among
them it is also possible to establish a hierarchy,
giving a different weight to each single criterion and
creating a scale of preferences. Then, the node can
choose the best alternative trying to improve its
individual utility and also the one of the community.
The evaluation could be conducted also using simple
heuristics (Bagnoli, Guazzini and Liò, 2007).
Another future challenge in the multilayer structure
is to model interactions between nodes in a
comorbidity scenario. Game theory and the game-
theoretic approach could represent an analytical tool
that helps us in studying these interactions,
considering for instance a multi-player game, where
each player is an individual/patient who has
simultaneously multiple co-occurrent diseases or
morbidities which are in competition each other. The
competition depends on the fact that the selection of
a treatment or procedure could influence another
morbidity because of the side-effects of drugs.
Figure 4: Future directions of social-object oriented
paradigm.
In this competing scenario, at each time step the
patient has to choose his strategy, considering
simultaneously different decision parameters, related
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45
not only to himself but also to his community, as
explained before, so there is no a strategy that is
absolutely better than the other ones.
5 CONCLUSIONS
The evolution process, that involves nodes and data,
enables us to give a new definition, which tries, first
of all, to solve the issue related to the management
of heterogeneous data and different nodes. In Fig. 4
we show the future directions of social-object
oriented paradigm. The social multilayer network
allowed us to analyze the complex dynamic patterns
involving these entities, shedding light on the
different types of interactions at various layers. The
multiplex structure, consisting of three layers, the
social layer, the comorbidity layer and the ICT layer,
allows to consider, respectively, the social
interactions and the social contagion between nodes
through the sharing of data, the comorbidity
relations between diseases, and the ICT
interventions as a result of the analysis of the
complex patterns involving entities, the context and
the system as a whole. The multilayer social network
paradigm describes the evolution of data and nodes,
considering an increasing level of awareness, from
things to knowledge between social objects nodes
through the social objects data. This evolution
process leads to a bio-inspired network-driven ICT,
redesigning the ICT communication paradigm.
Future works will be focused on a complex analysis
which accounts for the different aspects and data to
get a knowledge-based mining, supported by
datasets collected related to this context. The topic,
which we are going to develop, is linked to health
and also other applications and we will focus on
studying and modeling the decision-making
processes using a game-theoretic approach, in order
to analyze from this new social perspective the issue
of comorbidity and the influence of social behaviors.
ACKNOWLEDGEMENTS
This work was supported by "Programma
Operativo Nazionale “Ricerca & Competitività
2007-2013” within the project "PON04a2_C –
Smart Health”.
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