Petros Kavassalis

Publications

• SMS interactive TV: the convergence of television and mobile networks

  P. Kavassalis, M. Batikas, H. Sabalis, T. Zamani, S. Eustathiou

  Information and Communication Technologies: From Theory to Applications, 2004. Proceedings. 2004 International Conference on; 05/2004

  The paper attempts to explore the precise way of convergence of television and mobile networks, surround the ongoing and future developments of SMS interactive television and craft an intellectual framework, based on the economics of technical change, which can contribute to provide answers to the f... [more] The paper attempts to explore the precise way of convergence of television and mobile networks, surround the ongoing and future developments of SMS interactive television and craft an intellectual framework, based on the economics of technical change, which can contribute to provide answers to the future potential of this emerging activity.
• 2.35

  Impact points

  What makes a Web site popular?

  Petros Kavassalis, Stelios Lelis, Mahmoud Rafea, Seif Haridi

  Communications of the ACM. 01/2004; 47:50-55.

  To ensure a constant increase in user interest, clicks, recommendations, loyalty, and market share, first understand the information flows and connection networks surrounding each Web site in cyberspace.... [more] To ensure a constant increase in user interest, clicks, recommendations, loyalty, and market share, first understand the information flows and connection networks surrounding each Web site in cyberspace.

  Download

• Application Architecture Of The Internet Simulation

  Mahmoud Rafea, Fredrik Holmgren, Konstantin Popov, Seif Haridi, Stelios Lelis, Petros Kavassalis, Jakka Sairamesh

  09/2002;

  In this paper, we present an Internet simulation application: WoM. The WoM simulation aims at showing agglomerations of users in few web sites and at studying the different factors that lead to such a macro-structure. The paper focuses on the architecture of the multi-agent simulation environment. I... [more] In this paper, we present an Internet simulation application: WoM. The WoM simulation aims at showing agglomerations of users in few web sites and at studying the different factors that lead to such a macro-structure. The paper focuses on the architecture of the multi-agent simulation environment. In this environment, a simulation application is constructed using four different components categories, namely: agent collections, a worker, a communication channels component, and a control component. An agent collection can be constructed from different kinds of Small World graph components. Small World graphs are used to represent the social network and web sites links. An agent collection scales to hundreds of thousands of agents. A worker component is configured from a set of behavior components to implement the behavior of agent collections. Simulation input/output is monitored through a communication channel component. The control component is responsible for configuration and initialization of the application components. The control component, also, invokes the worker at each simulation time step. For scalability, the environment architecture is designed to be suitable for distribution and parallelization.

• Regularities in the Formation and Evolution of

  Stelios Lelis, Petros Kavassalis, Jakka Sairamesh, Seif Haridi, Mahmoud Rafea

  09/2002;

  In the real world, cities exist because of external economies associated with the geographic concentration of firms within a city. Of course, such a geographic proximity with input providers and consumers, would at first reduce transportation costs. But why cities, information cities, i.e. large agg... [more] In the real world, cities exist because of external economies associated with the geographic concentration of firms within a city. Of course, such a geographic proximity with input providers and consumers, would at first reduce transportation costs. But why cities, information cities, i.e. large agglomerations of people and economic activity emerge in the virtual world? In the Internet, transportation costs are zero. Web sites can easily be reached from anybody and everywhere with no particular cost. In these conditions of equal access distance, one would rather expect a smooth web geography with a relatively even distribution of visitors per site. However, the web economy illustrates strong agglomeration trends with a very small number of web sites capturing a large segment of the web population and the most of virtual economic activity. This paper attempts to provide a sound basis for the dynamics of population concentration in the web under increasing returns.

• Information Cities Over The Internet;

  Jakka Sairamesh, Petros Kavassalis, Manolis Marazakis, Christos Nikolaou

  09/2002;

  In the coming years, we expect many kinds of medium and large-scale information sites to emerge over the Internet, which will represent or mimic small and large "physical" cities. They will provide local and global information and services to registered inhabitants. Just like physical citi... [more] In the coming years, we expect many kinds of medium and large-scale information sites to emerge over the Internet, which will represent or mimic small and large "physical" cities. They will provide local and global information and services to registered inhabitants. Just like physical cities, these "information cities" (iCities) will house "infohabitants" who will participate in activities such as navigating the city, performing commercial transactions, socializing, and collaborating. We are already witnessing the emergence of large-scale web portals providing local information about cities, access to local government services, community services and a place for businesses to advertise and attract consumers on-line. In this paper, we present a taxonomy of information cities

• Evolution and Dynamics of Information Cities: Models, Taxonomy and Architecture

  J. Sairamesh, P. Kavassalis, S. Haridi

  06/2002;

  Similar to physical cities, which emerged over many years in the physical world, we envision many kinds of large-scale "information cities" (iCities) to emerge over the Internet in the coming years. Some of these iCities will mimic small and large "physical" cities. They will pro... [more] Similar to physical cities, which emerged over many years in the physical world, we envision many kinds of large-scale "information cities" (iCities) to emerge over the Internet in the coming years. Some of these iCities will mimic small and large "physical" cities. They will provide local and global information and various valueadded services to inhabitants. Just like physical cities, these information cities will house "infohabitants", who will participate in activities such as searching, transacting, socializing, and collaborating. In this paper, we present an overview of the information cities project, and then we present a taxonomy of information cities and some dynamic models. We also describe design requirements and an open architecture for building an information city based on Webservices.

• Regularities in the Formation and Evolution of Information Cities.

  Stelios Lelis, Petros Kavassalis, Jakka Sairamesh, Seif Haridi, Fredrik Holmgren, Mahmoud Rafea, Antonis Hatzistamatiou

  Digital Cities II, Computational and Sociological Approaches, Second Kyoto Workshop on Digital Cities, Kyoto, Japan, October 18-20, 2001, Revised Papers; 01/2001

• Open Layered Networks: The Growing Importance of Market Coordination

  Petros Kavassalis, Joseph P. Bailey, Thomas Y. Lee

  06/2000;

  (*) Based upon the Internet perspective, this paper will attempt to clarify and revise several ideas about the separation between infrastructure facilities and service offerings in digital communications networks. The key notions that we will focus on in this paper are: i) the bearer service as a te... [more] (*) Based upon the Internet perspective, this paper will attempt to clarify and revise several ideas about the separation between infrastructure facilities and service offerings in digital communications networks. The key notions that we will focus on in this paper are: i) the bearer service as a technology-independent interface which exports blind network functionality to applications development; ii) the organizational consequences associated with the emergence of a sustainable market of bearer service: a clear movement at the level of industrial structure from traditional hierarchies to more market coordination. (*) Note: The authors would like to thank the MIT Internet telephony Consortium for financial support. A previous version of this paper has been published in Bohlin and Levin (eds), 1998, Telecommunications Transformation, Technology, Strategy and Policy, IOS Press, Amsterdam, under the title: Sustaining a Vertically Disintegrated Network through a Bearer Servic...

• The Internet: A Paradigmatic Rupture in Cumulative Telecom Evolution.

  Petros Kavassalis, Richard Jay Solomon, Pierre-Jean Benghozi

  Industrial & Corporate Change. 02/1996; 5(4).

• Open Standards and Interoperability : New Learning Models for Electronic Communications

  Pierre-Jean Benghozi, Richard Jay Solomon, Petros Kavassalis

  Programme National Persée, Revue d'Économie Industrielle. 01/1996; 75(1):163-185.

  [fre] L'article analyse l'impact des nouveaux modèles de normalisation, tels ceux mis en œuvre dans Internet, sur l'évolution des réseaux traditionnels de télécommunication. Il montre d'abord comment Internet résulte d'une approche cognitive différente de la transmission de donné... [more] [fre] L'article analyse l'impact des nouveaux modèles de normalisation, tels ceux mis en œuvre dans Internet, sur l'évolution des réseaux traditionnels de télécommunication. Il montre d'abord comment Internet résulte d'une approche cognitive différente de la transmission de données; celle-ci conduit à une nouvelle architecture des réseaux, fondée sur la mise en œuvre de protocoles d'accès assurant l'interopérabilité entre environnements techniques variés. Cette perspective diffère de l'approche en vigueur jusque là dans les réseaux de télécommunications, qui s'appuie sur une homogénéité technique garantie par le contrôle des opérateurs et sur l'élaboration de standards évolutifs. Les deux trajectoires technologiques présentées coexistent cependant de façon dynamique : elles accompagnent la compétition industrielle sur le marché des télécoms et entraînent des trajectoires locales d'évolution différenciées. À partir des observations portées sur ce secteur, le texte s'interroge sur l'éventualité de voir deux «designs dominants» continuer à coexister dans le temps, ainsi que sur l'incidence que peut avoir l'interopérabilité sur les capacités d'apprentissage des industries de réseau. [eng] The paper investigates the impact of the new standardization model, exemplified by the Internet, in the evolution of the traditional telecommunications networks. First, it shows why the Internet, emerging from a different cognitive perception of the data-communication problem, led to a new network architecture. The latter is based on the establisment of protocol «gateways» facilitating interoperability between heterogeneous network environments -instead of the operator - controlled homogeneity of the telecom networks and an «adaptative» way for open standards-setting. These two technological trajectories dynamically coexist and compete for market-shares, yielding relatively different local trajectories of evolution. Observations ra

• Network Explanations to Web Economy's Patterns of Growth

  Stelios Lelis, Petros Kavassalis, Mahmoud Rafea, Seif Harid

  Society for Computational Economics, Modeling, Computing, and Mastering Complexity 2003.

  From its early days, the World Wide Web space has demonstrated strong agglomeration trends with a very small number of web sites capturing the larger part of the Internet population. At a first glance, agglomeration over the virtual space sounds as a paradox. Web sites are numerous and highly divers... [more] From its early days, the World Wide Web space has demonstrated strong agglomeration trends with a very small number of web sites capturing the larger part of the Internet population. At a first glance, agglomeration over the virtual space sounds as a paradox. Web sites are numerous and highly diversified and can be easily reached from everywhere and anybody, with no particular transportation or search cost. However, Internet users use only a small number of sites for searching for information and products, interacting with others and socialize, thus producing dense concentrations and locational patterns similar to those observed in the physical space where few cities and industrial clusters host the huge majority of population and the entire industrial activity. Is that depending on the attractiveness of the popular web sites or are there agglomeration economies providing incentives to users to be in a location which have been visited by other users or pointed-in by other sites? This paper provides a sound basis for the dynamics of population concentration in the Web and put forward an explanation to web sites' growth by developing an agent-based computational model, with behavioural and economic variables, where the aggregate outcome emerges from the interaction of individual decisions. The model reproduces the empirically observed power law distribution of Internet users across web sites, demonstrating that a plausible explanation of web agglomeration phenomena can lie on the assumption of increasing returns and the percolation-like diffusion of the information over the Internet.

• Open communication standards are making possible the virtual equivalent of real city life, enabling delivery of such essential services as 911 emergency calls, traffic and health alerts, and market and medical information in real or near real time. This article explores the underlying technology frameworks and open standards needed to build the foundations for these and other information cities. An information city is a large Internet-based site offering a range of online services, including access to socia

  Petros Kavassalis

• Open-layered networks: the growing importance of market coordination

  Petros Kavassalis, Joseph P. Bailey, Thomas Y. Lee

  Decision Support Systems.

  Based upon the Internet perspective, this paper will attempt to clarify and revise several ideas about the separation between infrastructure facilities and service offerings in digital communications networks. The key notions that we will focus on in this paper are: (i) the bearer service (BS) as a ... [more] Based upon the Internet perspective, this paper will attempt to clarify and revise several ideas about the separation between infrastructure facilities and service offerings in digital communications networks. The key notions that we will focus on in this paper are: (i) the bearer service (BS) as a technology-independent interface which exports blind network functionality to applications development; and (ii) the organizational consequences associated with the emergence of a sustainable market of BS: a clear movement at the level of industrial structure from traditional hierarchies to more market coordination.

• Sustaining a Vertically Disintegrated Network through a Bearer Service Market

  Petros Kavassalis, Thomas Y. Lee, Joseph P. Bailey

  Based upon the Internet perspective, this chapter will attempt to clarify and revise several ideas about the separation between infrastructure facilities and service offerings in digital communications networks. The key notions that we will focus on in this paper are: i) the bearer service as a tech... [more] Based upon the Internet perspective, this chapter will attempt to clarify and revise several ideas about the separation between infrastructure facilities and service offerings in digital communications networks. The key notions that we will focus on in this paper are: i) the bearer service as a technology-independent interface which exports blind network functionality to applications development; ii) the sustainability of an independent market for bearer service and the organizational consequences associated with such a market.

• Flexible Specialization Path of the Internet

  Petros Kavassalis, William Lehr

• Open Layered Networks: the Growing Importance of Market Coordination

  Petros Kavassalis, Tom Lee, Joseph P. Bailey

  Based upon the Internet perspective, this paper will attempt to clarify and revise several ideas about the separation between infrastructure facilities and service offerings in digital communications networks. The key notions that we will focus on in this paper are: i) the bearer service as a techno... [more] Based upon the Internet perspective, this paper will attempt to clarify and revise several ideas about the separation between infrastructure facilities and service offerings in digital communications networks. The key notions that we will focus on in this paper are: i) the bearer service as a technology-independent interface which exports blind network functionality to applications development; ii) the organizational consequences associated with the emergence of a sustainable market of bearer service: a clear movement at the level of industrial structure from traditional hierarchies to more market coordination.