Dynamics of Innovation in an “Open Source” Collaboration Environment: Lurking, Laboring and Launching FLOSS Projects on SourceForge

A systems analysis perspective is adopted to examine the critical properties of the Free/Libre/Open Source Software (FLOSS) mode of innovation, as reflected on the SourceForge platform (SF.net). This approach re-scales March’s (1991) framework and applies it to characterize the “innovation system” of a “distributed organization” of interacting agents in a virtual collaboration environment. The innovation system of the virtual collaboration environment is an emergent property of two “coupled” processes: one involves interactions among agents searching for information to use in designing novel software products, and the other involves the mobilization of individual capabilities for application in the software development projects. Micro-dynamics of this system are studied empirically by constructing transition probability matrices representing movements of 222,835 SF.net users among 7 different activity states. Estimated probabilities are found to form first-order Markov chains describing ergodic processes. This makes it possible to computate the equilibrium distribution of agents among the states, thereby suppressing transient effects and revealing persisting patterns of project-joining and project-launching.innovation systems, collaborative development environments, industrial districts, exploration and exploitation dynamics, open source software, FLOSS, SourceForge, project-joining, project-founding, Markov chain analysis.

Proceedings of Mathsport international 2017 conference

Proceedings of MathSport International 2017 Conference, held in the Botanical Garden of the University of Padua, June 26-28, 2017. MathSport International organizes biennial conferences dedicated to all topics where mathematics and sport meet. Topics include: performance measures, optimization of sports performance, statistics and probability models, mathematical and physical models in sports, competitive strategies, statistics and probability match outcome models, optimal tournament design and scheduling, decision support systems, analysis of rules and adjudication, econometrics in sport, analysis of sporting technologies, financial valuation in sport, e-sports (gaming), betting and sports

Concept of a Robust & Training-free Probabilistic System for Real-time Intention Analysis in Teams

Die Arbeit beschäftigt sich mit der Analyse von Teamintentionen in Smart Environments (SE). Die fundamentale Aussage der Arbeit ist, dass die Entwicklung und Integration expliziter Modelle von Nutzeraufgaben einen wichtigen Beitrag zur Entwicklung mobiler und ubiquitärer Softwaresysteme liefern können. Die Arbeit sammelt Beschreibungen von menschlichem Verhalten sowohl in Gruppensituationen als auch Problemlösungssituationen. Sie untersucht, wie SE-Projekte die Aktivitäten eines Nutzers modellieren, und liefert ein Teamintentionsmodell zur Ableitung und Auswahl geplanten Teamaktivitäten mittels der Beobachtung mehrerer Nutzer durch verrauschte und heterogene Sensoren. Dazu wird ein auf hierarchischen dynamischen Bayes’schen Netzen basierender Ansatz gewählt

The Impact of Teams in Multiagent Systems

Across many domains, the ability to work in teams can magnify a group's abilities beyond the capabilities of any individual. While the science of teamwork is typically studied in organizational psychology (OP) and areas of biology, understanding how multiple agents can work together is an important topic in artificial intelligence (AI) and multiagent systems (MAS). Teams in AI have taken many forms, including ad hoc teamwork [Stone et al., 2010], hierarchical structures of rule-based agents [Tambe, 1997], and teams of multiagent reinforcement learning (MARL) agents [Baker et al., 2020]. Despite significant evidence in the natural world about the impact of family structure on child development and health [Lee et al., 2015; Umberson et al., 2020], the impact of team structure on the policies that individual learning agents develop is not often explicitly studied. In this thesis, we hypothesize that teams can provide significant advantages in guiding the development of policies for individual agents that learn from experience. We focus on mixed-motive domains, where long-term global welfare is maximized through global cooperation. We present a model of multiagent teams with individual learning agents inspired by OP and early work using teams in AI, and introduce credo, a model that defines how agents optimize their behavior for the goals of various groups they belong to: themselves (a group of one), any teams they belong to, and the entire system. We find that teams help agents develop cooperative policies with agents in other teams despite game-theoretic incentives to defect in various settings that are robust to some amount of selfishness. While previous work assumed that a fully cooperative population (all agents share rewards) obtain the best possible performance in mixed-motive domains [Yang et al., 2020; Gemp et al., 2020], we show that there exist multiple configurations of team structures and credo parameters that achieve about 33% more reward than the fully cooperative system. Agents in these scenarios learn more effective joint policies while maintaining high reward equality. Inspired by these results, we derive theoretical underpinnings that characterize settings where teammates may be beneficial, or not beneficial, for learning. We also propose a preliminary credo-regulating agent architecture to autonomously discover favorable learning conditions in challenging settings

Supporting group mobility in mission-critical wireless networks for SIP-based applications

Diplomityössä tarkastellaan viiveherkkien SIP-sovellusten verkkoalueiden välistä ryhmäliikkuvuutta langattomissa, IEEE 802.11x -pohjaisissa IPv4/IPv6 verkkoympäristöissä. Nykyaikaisissa kriisinhallintatehtävissä reaaliaikaisen viestinnän merkitys on viime vuosina vahvasti korostunut. Tähän tarkoitukseen käytetyt viestintäjärjestelmät ovat olleet tavallisesti erittäin kalliita. Langattomien teknologioiden nopea kehitys on kuitenkin suunnannut mielenkiinnon edullisiin, kaupallisiin siviilipuolen valmisratkaisuihin. Pitkät yhteydensiirtoviiveet ovat tärkeä ongelma reaaliaikaliikenteen yhteydensiirron kannalta. VoIP-pohjaisen puheliikenteen on todettu kestävän enimmillään suuruusluokkaa 100 ms olevia viiveaikoja palvelunlaadun ratkaisevasti kärsimättä. Linkkitason yhteydensiirron ohella duplikaattiosoitteiden tarkistuksella DHCP-osoitteenhaun aikana ja SIP-yhteyden uudelleenmuodostuksella on saumattoman yhteydensiirron kannalta olennainen merkitys. Ryhmäliikkuvuus on saanut osakseen paljon huomiota ad hoc -verkkojen tutkimuksessa. Työssä tutkitaan mandollisesti saavutettavia hyötyjä, joita ryhmäliikkuvuusmalli pystyisi perinteiseen yhteydensiirtotapaan nähden tuomaan hierarkkisissa infrastruktuurisissa SIP-verkoissa. Sovellustason liikkuvuutta ja signaloinnin tehokkuutta tarkastellaan kaistankäytön ja tietoturvallisuuden näkökulmasta. Kokeellisessa osiossa pyritään mallintamaan ryhmäyhteydensiirtoja yksinkertaisessa, simuloidussa ympäristössä. Päätelmien tueksi yhteydensiirtojen suorituskykyä arvioidaan lisäksi numeerisella analyysilla.This thesis studies the provision of group mobility during inter-domain hand-offs for delay-sensitive SIP applications over wireless IPv4/IPv6 network environment, based on the IEEE 802.11x platform. In contemporary disaster relief operations, the role of real-time communications has been strongly escalating over the recent years. The communication systems used for these ends have been conventionally very expensive. The rapid evolution of wireless technologies has brought the focus of interest to the affordable Common-Off-the-Shelf civilian applications. Long latencies during hand-offs for real-time traffic are a very important problem. As the studies have pointed out, the VoIP-based voice traffic can withstand maximum approximate disruption times of 100 ms, without too high degradation in the quality of service. Along with the link-layer hand-off, the duplicate address detection procedure during DHCP address acquisition and the SIP connection re-establishment both have a major impact on the hand-off latency. The group mobility has gained high attention in the research of ad-hoc networks. The work studies the benefits that this scheme could possibly bring over the conventional hand-offs in hierarchical infrastructured SIP networks. Different approaches to application-level mobility and the signaling efficiency are examined from the viewpoint of bandwidth usage and network security. In the experimental part, group hand-offs are modeled in a simple, simulated environment. In addition, a numerical analysis is used to assess the hand-off performance to support the made conclusions

Radio Communications

In the last decades the restless evolution of information and communication technologies (ICT) brought to a deep transformation of our habits. The growth of the Internet and the advances in hardware and software implementations modified our way to communicate and to share information. In this book, an overview of the major issues faced today by researchers in the field of radio communications is given through 35 high quality chapters written by specialists working in universities and research centers all over the world. Various aspects will be deeply discussed: channel modeling, beamforming, multiple antennas, cooperative networks, opportunistic scheduling, advanced admission control, handover management, systems performance assessment, routing issues in mobility conditions, localization, web security. Advanced techniques for the radio resource management will be discussed both in single and multiple radio technologies; either in infrastructure, mesh or ad hoc networks