221,845 research outputs found
Evolutionary games on multilayer networks: A colloquium
Networks form the backbone of many complex systems, ranging from the Internet
to human societies. Accordingly, not only is the range of our interactions
limited and thus best described and modeled by networks, it is also a fact that
the networks that are an integral part of such models are often interdependent
or even interconnected. Networks of networks or multilayer networks are
therefore a more apt description of social systems. This colloquium is devoted
to evolutionary games on multilayer networks, and in particular to the
evolution of cooperation as one of the main pillars of modern human societies.
We first give an overview of the most significant conceptual differences
between single-layer and multilayer networks, and we provide basic definitions
and a classification of the most commonly used terms. Subsequently, we review
fascinating and counterintuitive evolutionary outcomes that emerge due to
different types of interdependencies between otherwise independent populations.
The focus is on coupling through the utilities of players, through the flow of
information, as well as through the popularity of different strategies on
different network layers. The colloquium highlights the importance of pattern
formation and collective behavior for the promotion of cooperation under
adverse conditions, as well as the synergies between network science and
evolutionary game theory.Comment: 14 two-column pages, 8 figures; accepted for publication in European
Physical Journal
Evaluation of an Internet Document Delivery Service
An Internet-based Document Delivery Service (DDS) has been developed within the framework of the CNR ( the Italian Research National Council) Project BiblioMIME, in order to take advantage of new Internet technologies and promote cooperation among CNR and Italian university libraries. Adopting such technologies changes the traditional organisation of DDS and may drastically reduce costs and delivery times.
An information system managing DDS requests and monitoring the temporal evolution of the service has been implemented, running on the local-area network of a test-site library. It aims to track number and types of documents requested and received, user distribution, delivery times and types (surface mail, fax, Internet), to automate repetitive manual procedures and to deal with the various accounting methods used by other libraries. Transmission of documents is carried out by means of an e-mail/Web gateway system supporting document exchange via Internet, which assists receiving libraries in retrieving requested documents.
This paper describes the architecture and main design features of the e-mail/Web gateway server (the BiblioMime server). This approach permits librarians to continue using e-mail service to send large documents, while resolving problems that users may encounter when downloading large size files with e-mail agents. The library operator sends the document as an attachment to the destination address; on fly the e-mail server extracts and saves the attachments in a web-server disk file and substitutes them with a new message part that includes an URL pointing to the saved document. The receiver can download these large objects by means of a user-friendly browser.
We further discuss the data gathered during the triennium 1998-2000; this consists of about 5,000 DDS transactions per annum with 300 other Italian scientific and bio-medical libraries and commercial document suppliers. Use of the instruments described above allowed us to evaluate the performance of service âbeforeâ and âafterâ the use of Internet Document Delivery and to extract some critical data regarding DDS. Those include:
a) libraries with which we have greater numbers of exchanges and their turnaround times;
b) extraordinary reduction in costs and delivery times;
c) the most frequently requested serial titles (allowing cost-effective decisions on new subscriptions);
d) impact on DDS of library participation in consortia which allow user access to greater numbers of online serials
Cooperation techniques between LTE in unlicensed spectrum and Wi-Fi towards fair spectral efficiency
On the road towards 5G, a proliferation of Heterogeneous Networks (HetNets) is expected. Sensor networks are of great importance in this new wireless era, as they allow interaction with the environment. Additionally, the establishment of the Internet of Things (IoT) has incredibly increased the number of interconnected devices and consequently the already massive wirelessly transmitted traffic. The exponential growth of wireless traffic is pushing the wireless community to investigate solutions that maximally exploit the available spectrum. Recently, 3rd Generation Partnership Project (3GPP) announced standards that permit the operation of Long Term Evolution (LTE) in the unlicensed spectrum in addition to the exclusive use of the licensed spectrum owned by a mobile operator. Alternatively, leading wireless technology developers examine standalone LTE operation in the unlicensed spectrum without any involvement of a mobile operator. In this article, we present a classification of different techniques that can be applied on co-located LTE and Wi-Fi networks. Up to today, Wi-Fi is the most widely-used wireless technology in the unlicensed spectrum. A review of the current state of the art further reveals the lack of cooperation schemes among co-located networks that can lead to more optimal usage of the available spectrum. This article fills this gap in the literature by conceptually describing different classes of cooperation between LTE and Wi-Fi. For each class, we provide a detailed presentation of possible cooperation techniques that can provide spectral efficiency in a fair manner
Metric clusters in evolutionary games on scale-free networks
The evolution of cooperation in social dilemmas in structured populations has
been studied extensively in recent years. Whereas many theoretical studies have
found that a heterogeneous network of contacts favors cooperation, the impact
of spatial effects in scale-free networks is still not well understood. In
addition to being heterogeneous, real contact networks exhibit a high mean
local clustering coefficient, which implies the existence of an underlying
metric space. Here, we show that evolutionary dynamics in scale-free networks
self-organize into spatial patterns in the underlying metric space. The
resulting metric clusters of cooperators are able to survive in social dilemmas
as their spatial organization shields them from surrounding defectors, similar
to spatial selection in Euclidean space. We show that under certain conditions
these metric clusters are more efficient than the most connected nodes at
sustaining cooperation and that heterogeneity does not always favor--but can
even hinder--cooperation in social dilemmas. Our findings provide a new
perspective to understand the emergence of cooperation in evolutionary games in
realistic structured populations
Features, operation principle and limits of SPI and I2C communication protocols for smart objects: a novel SPI-based hybrid protocol especially suitable for IoT applications
The Internet of Things (IoT) is an expression, sometimes abused by companies given the absence of an unambiguous meaning, that indicates the upcoming evolution of Internet as it has been known so far. In fact, all objects will have network capabilities which will be exploited to overcome, in certain situations, human intervention. Thanks to the direct cooperation of new class of devices, aware of their operating scenario and interconnected in subnetworks, our life style will be strongly enhanced and simplified. IoT, however, is not yet the âEl Doradoâ of technology, capable of revolutionizing everyday life: some aspects and open issues have to be carefully
analyzed. The huge complexity of this new technology forces companies to select a specific research field: for this reason, they focus only on some features that an IoT device should have to guarantee fulfillment of requirements. In this context, this research work concerns an analysis of features, operation principle and limits of SPI and I2C communication protocols followed by the proposal of
a new hybrid protocol suited for embedded systems, named FlexSPI, thought as an evolution of the classic SPI. Thanks to a robust software architecture, it is able to provide many features that can be used by smart objects to enhance their capabilities. In this way, sensors and actuators or, more in general, subsystems, can quickly exchange data and efficiently react to malfunctioning; moreover,
number of devices on bus can be safely increased even while smart object is performing operations
Why is IPv6 Deployment Important for the Internet Evolution?, Journal of Telecommunications and Information Technology, 2011, nr 2
Replacing the IPv4 protocol with IPv6 on the Internet is currently one of the aims of the European Union policy. The main reason for this replacement is the effeteness of the addresses pool in the IPv4 protocol, which can cause serious complications in the evolution of the Internet and its adaptation in new areas, e.g., in next generation mobile telephony or the so called Internet of Things. Simultaneously, the addressing capabilities of the IPv6 protocol are practically unlimited and its new functionalities increase the attractiveness of its usage. The article discusses the problems connected with the IPv6 deployment on the Internet. Especially, the rules for realization of the IPv6 deployment and rules for cooperation of IPv4 with IPv6 (including cooperation tests) in network infrastructure and in applications are presented. Moreover, the European projectsâ results and the activityâs directions of the national project Future Internet Engineering are discussed
ICANNâNow and Then: ICANNâs Reform and Its Problems
This paper sheds some light upon the major problem arising from the current normative infrastructure of the DNS and provides a possible solution to the current physical problem of the DNS. The paper\u27s main focus is the single-entity control of the A Root. The paper uses as a starting point the Blueprint prepared by the Committee on ICANN Evolution and Reform and raises the question: Has this reform done anything to resolve the single-entity control of the A Root? The paper argues that the reform has done nothing to solve the problem because the international privatization of the DNS merely substitutes the administration of the DNS function without making changes to the normative infrastructure of the DNS. In light of the above, the paper argues that there is a need to declare independence from a one-entity controlled DNS. The suggested approach is to share authority over the root by acknowledging that countries that are accountable to their populations are the authorities for their own ccTLDs. Once technical and political independence has been achieved, the technical and, to some degree, political management of the DNS should be exercised through an international body. In order to initiate a discussion for a truly international body this paper offers nine principles that a new international ccTLD cooperation organization should observe when working on its own creation
Collective navigation of complex networks: Participatory greedy routing
Many networks are used to transfer information or goods, in other words, they
are navigated. The larger the network, the more difficult it is to navigate
efficiently. Indeed, information routing in the Internet faces serious
scalability problems due to its rapid growth, recently accelerated by the rise
of the Internet of Things. Large networks like the Internet can be navigated
efficiently if nodes, or agents, actively forward information based on hidden
maps underlying these systems. However, in reality most agents will deny to
forward messages, which has a cost, and navigation is impossible. Can we design
appropriate incentives that lead to participation and global navigability?
Here, we present an evolutionary game where agents share the value generated by
successful delivery of information or goods. We show that global navigability
can emerge, but its complete breakdown is possible as well. Furthermore, we
show that the system tends to self-organize into local clusters of agents who
participate in the navigation. This organizational principle can be exploited
to favor the emergence of global navigability in the system.Comment: Supplementary Information and Videos:
https://koljakleineberg.wordpress.com/2016/11/14/collective-navigation-of-complex-networks-participatory-greedy-routing
Research on the Sustainability of the Enterprise Business Ecosystem from the Perspective of Boundary:The China Case
In the context of the Internet, the business environment shows great uncertainty. This kind of uncertainty has not only changed the original competitive boundary of enterprise completely, but also the competition rules of enterprise. The cooperation of enterprises with suppliers, producers, sellers, customers, other organizations and stakeholders is getting closer and closer. The competition among enterprises is no longer the competition between individual enterprises, but based on the co-evolution under the business ecosystem. Therefore, how to create a good business ecosystem and sustainable development is the main problem faced by enterprises. This paper conducts an exploratory case study on the sustainability of the business ecosystem of enterprises from the perspective of boundary, to provide a new theoretical basis for the sustainable development of enterprises. This study investigates the specific impact of various system elements on the sustainable development of enterprises, summarizes the theoretical model, and finally provides feasible suggestions on promoting the sustainable development of the business ecosystem from the perspective of boundary
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