Semantic coordination through programmable Tuple spaces

Two of the main features of today complex software systems like pervasive computing systems and Internet-based applications are distribution and openness. Distribution revolves around three orthogonal dimensions: (i) distribution of control|systems are characterised by several independent computational entities and devices, each representing an autonomous and proactive locus of control; (ii) spatial distribution|entities and devices are physically distributed and connected in a global (such as the Internet) or local network; and (iii) temporal distribution|interacting system components come and go over time, and are not required to be available for interaction at the same time. Openness deals with the heterogeneity and dynamism of system components: complex computational systems are open to the integration of diverse components, heterogeneous in terms of architecture and technology, and are dynamic since they allow components to be updated, added, or removed while the system is running. The engineering of open and distributed computational systems mandates for the adoption of a software infrastructure whose underlying model and technology could provide the required level of uncoupling among system components. This is the main motivation behind current research trends in the area of coordination middleware to exploit tuple-based coordination models in the engineering of complex software systems, since they intrinsically provide coordinated components with communication uncoupling and further details in the references therein. An additional daunting challenge for tuple-based models comes from knowledge-intensive application scenarios, namely, scenarios where most of the activities are based on knowledge in some form|and where knowledge becomes the prominent means by which systems get coordinated. Handling knowledge in tuple-based systems induces problems in terms of syntax - e.g., two tuples containing the same data may not match due to differences in the tuple structure - and (mostly) of semantics|e.g., two tuples representing the same information may not match based on a dierent syntax adopted. Till now, the problem has been faced by exploiting tuple-based coordination within a middleware for knowledge intensive environments: e.g., experiments with tuple-based coordination within a Semantic Web middleware (surveys analogous approaches). However, they appear to be designed to tackle the design of coordination for specic application contexts like Semantic Web and Semantic Web Services, and they result in a rather involved extension of the tuple space model. The main goal of this thesis was to conceive a more general approach to semantic coordination. In particular, it was developed the model and technology of semantic tuple centres. It is adopted the tuple centre model as main coordination abstraction to manage system interactions. A tuple centre can be seen as a programmable tuple space, i.e. an extension of a Linda tuple space, where the behaviour of the tuple space can be programmed so as to react to interaction events. By encapsulating coordination laws within coordination media, tuple centres promote coordination uncoupling among coordinated components. Then, the tuple centre model was semantically enriched: a main design choice in this work was to try not to completely redesign the existing syntactic tuple space model, but rather provide a smooth extension that { although supporting semantic reasoning { keep the simplicity of tuple and tuple matching as easier as possible. By encapsulating the semantic representation of the domain of discourse within coordination media, semantic tuple centres promote semantic uncoupling among coordinated components. The main contributions of the thesis are: (i) the design of the semantic tuple centre model; (ii) the implementation and evaluation of the model based on an existent coordination infrastructure; (iii) a view of the application scenarios in which semantic tuple centres seem to be suitable as coordination media.

COBAMOS: Endnutzerprogrammierung auf Basis nachrichtenbasierter Komponentenvernetzung

Die Aufgabenstellung, welche dieser Dissertation zugrunde liegt, lässt sich kurz als die Untersuchung von komponentenbasierten Konzepten zum Einsatz in der Softwareentwicklung durch Endanwender beschreiben. In den letzten 20 bis 30 Jahren hat sich das technische Umfeld, in dem ein Großteil der Arbeitnehmer seine täglichen Aufgaben verrichtet, grundlegend verändert. Der Computer, früher in Form eines Großrechners ausschließlich die Domäne von Spezialisten, ist nun ein selbstverständlicher Bestandteil der täglichen Arbeit. Der Umgang mit Anwendungsprogrammen, die dem Nutzer erlauben in einem gewissen Rahmen neue, eigene Funktionalität zu definieren, ist in vielen Bereichen so selbstverständlich, dass viele dieser Tätigkeiten nicht bewusst als Programmieren wahrgenommen werden. Da diese Nutzer nicht notwendigerweise in der Entwicklung von Software ausgebildet sind, benötigen sie entsprechende Unterstützung bei diesen Tätigkeiten. Dies macht deutlich, welche praktische Relevanz die Untersuchungen in diesem Bereich haben. Zur Erstellung eines Programmiersystems für Endanwender wird zunächst ein flexibler Anwendungsrahmen entwickelt, welcher sich als Basis zur Erstellung solcher Systeme eignet. In Softwareprojekten sind sich ändernde Anforderungen und daraus resultierende Notwendigkeiten ein wichtiger Aspekt. Dies wird im Entwurf des Frameworks durch Konzepte zur Bereitstellung von wieder verwendbarer Funktionalität durch das Framework und Möglichkeiten zur Anpassung und Erweiterung der vorhandenen Funktionalität berücksichtigt. Hier ist zum einen der Einsatz einer serviceorientierten Architektur innerhalb der Anwendung und zum anderen eine komponentenorientierte Variante des Kommando-Musters zu nennen. Zum anderen wird ein Konzept zur Kapselung von Endnutzerprogrammiermodellen in Komponenten erarbeitet. Dieser Ansatz ermöglicht es, unterschiedliche Modelle als Grundlage der entworfenen Entwicklungsumgebung zu verwenden. Im weiteren Verlauf der Arbeit wird ein Programmiermodell entworfen und unter Verwendung des zuvor genannten Frameworks implementiert. Damit dieses zur Nutzung durch Endanwender geeignet ist, ist eine Anhebung der zur Beschreibung eines Softwaresystems verwendeten Abstraktionsebene notwendig. Dies wird durch die Verwendung von Komponenten und einem nachrichtenbasierten Kompositionsmechanismus erreicht. Die vorgenommene Realisierung ist dabei noch nicht auf konkrete Anwendungsfamilien bezogen, diese Anpassungen erfolgen in einem weiteren Schritt für zwei unterschiedliche Anwendungsbereiche.

Constraints meet concurrency

We investigate the benefits that emerge when the fields of constraint programming and concurrency meet. On one hand, constraints can be use in concurrency theory to increase the conciseness and the expressive power of concurrent languages from a pragmatic point of view. On the other hand, problems modeled by using constraints can be solved faster and more efficiently using a concurrent system. We explore both directions providing two separate lines of contribution. Firstly we study the expressive power of a concurrent language, namely Constraint Handling Rules, that supports constraints as a primitive construct. We show what features of this language make it Turing powerful. Then we propose a framework to solve constraint problems that is intended to be deployed on a concurrent system. For the development of this framework we used the concurrent language Jolie following the Service Oriented paradigm. Based on this experience, we also propose an extension to Service Oriented Languages to overcome some of their limitations and to improve the development of concurrent applications.

Smart cities, analysis of a strategic plan.

Abstract (English) Cities nowadays face complex challenges to meet objectives regarding socio-economic development and quality of life. The concept of "smart city" is a response to these challenges. Although common practices are being developed all over the world, different priorities are defined and different architectures are followed. In this master thesis I focuses on the applied architecture of Riverside's case study, through a progression model that underline the main steps that moves the city from a situation of crisis, to be appointed "Intelligent Community" of the 2012 by Intelligent Community Forum. I discuss the problem of integration among the physical, institutional and digital dimension of smart cities and the "bridges" that connect these three spatialities. Riverside's progression model takes as a reference a comprehensive framework made unifying the keys component of the three most quoted framework in this field: a technology-oriented vision (strongly promoted by IBM [Dirks et al. 2009]), an approach-oriented one [Schaffers et al. 2011] that is sponsored by many initiatives within the European Commission, and a purely service-oriented one [Giffinger et al. 2007][Toppeta, 2010].

Realisierung der IceCube MonteCarlo-Produktion im WLCG und Untersuchung von Auswirkungen meteorologischer Parameter auf die Erzeugung atmosphärischer Myonen

Das am Südpol gelegene Neutrinoteleskop IceCube detektiert hochenergetische Neutrinos über die schwache Wechselwirkung geladener und neutraler Ströme. Die Analyse basiert auf einem Vergleich mit Monte-Carlo-Simulationen, deren Produktion global koordiniert wird. In Mainz ist es erstmalig gelungen, Simulationen innerhalb der Architektur des Worldwide LHC Computing Grid (WLCG) zu realisieren, was die Möglichkeit eröffnet, Monte-Carlo-Berechnungen auch auf andere deutsche Rechnerfarmen (CEs) mit IceCube-Berechtigung zu verteilen. Atmosphärische Myonen werden mit einer Rate von über 1000 Ereignissen pro Sekunde aufgezeichnet. Eine korrekte Interpretation dieses dominanten Signals, welches um einen Faktor von 10^6 reduziert werden muss um das eigentliche Neutrinosignal zu extrahieren, ist deswegen von großer Bedeutung. Eigene Simulationen mit der Software-Umgebung CORSIKA wurden durchgeführt um die von Energie und Einfallswinkel abhängige Entstehungshöhe atmosphärischer Myonen zu bestimmen. IceCube Myonraten wurden mit Wetterdaten des European Centre for Medium-Range Weather Forcasts (ECMWF) verglichen und Korrelationen zwischen jahreszeitlichen sowie kurzzeitigen Schwankungen der Atmosphärentemperatur und Myonraten konnten nachgewiesen werden. Zudem wurde eine Suche nach periodischen Effekten in der Atmosphäre, verursacht durch z.B. meteorologische Schwerewellen, mit Hilfe einer Fourieranalyse anhand der IceCube-Daten durchgeführt. Bislang konnte kein signifikanter Nachweis zur Existenz von Schwerewellen am Südpol erbracht werden.

Evaluation of a cloud infrastructure for the CMS distributed data analysis in the top quark sector at the LHC

Nella fisica delle particelle, onde poter effettuare analisi dati, è necessario disporre di una grande capacità di calcolo e di storage. LHC Computing Grid è una infrastruttura di calcolo su scala globale e al tempo stesso un insieme di servizi, sviluppati da una grande comunità di fisici e informatici, distribuita in centri di calcolo sparsi in tutto il mondo. Questa infrastruttura ha dimostrato il suo valore per quanto riguarda l'analisi dei dati raccolti durante il Run-1 di LHC, svolgendo un ruolo fondamentale nella scoperta del bosone di Higgs. Oggi il Cloud computing sta emergendo come un nuovo paradigma di calcolo per accedere a grandi quantità di risorse condivise da numerose comunità scientifiche. Date le specifiche tecniche necessarie per il Run-2 (e successivi) di LHC, la comunità scientifica è interessata a contribuire allo sviluppo di tecnologie Cloud e verificare se queste possano fornire un approccio complementare, oppure anche costituire una valida alternativa, alle soluzioni tecnologiche esistenti. Lo scopo di questa tesi è di testare un'infrastruttura Cloud e confrontare le sue prestazioni alla LHC Computing Grid. Il Capitolo 1 contiene un resoconto generale del Modello Standard. Nel Capitolo 2 si descrive l'acceleratore LHC e gli esperimenti che operano a tale acceleratore, con particolare attenzione all’esperimento CMS. Nel Capitolo 3 viene trattato il Computing nella fisica delle alte energie e vengono esaminati i paradigmi Grid e Cloud. Il Capitolo 4, ultimo del presente elaborato, riporta i risultati del mio lavoro inerente l'analisi comparata delle prestazioni di Grid e Cloud.

Performance studies of the CMS distributed analysis system in the associated Higgs boson production with top quarks

L'obiettivo di questa tesi è studiare la fattibilità dello studio della produzione associata ttH del bosone di Higgs con due quark top nell'esperimento CMS, e valutare le funzionalità e le caratteristiche della prossima generazione di toolkit per l'analisi distribuita a CMS (CRAB versione 3) per effettuare tale analisi. Nel settore della fisica del quark top, la produzione ttH è particolarmente interessante, soprattutto perchè rappresenta l'unica opportunità di studiare direttamente il vertice t-H senza dover fare assunzioni riguardanti possibili contributi dalla fisica oltre il Modello Standard. La preparazione per questa analisi è cruciale in questo momento, prima dell'inizio del Run-2 dell'LHC nel 2015. Per essere preparati a tale studio, le implicazioni tecniche di effettuare un'analisi completa in un ambito di calcolo distribuito come la Grid non dovrebbero essere sottovalutate. Per questo motivo, vengono presentati e discussi un'analisi dello stesso strumento CRAB3 (disponibile adesso in versione di pre-produzione) e un confronto diretto di prestazioni con CRAB2. Saranno raccolti e documentati inoltre suggerimenti e consigli per un team di analisi che sarà eventualmente coinvolto in questo studio. Nel Capitolo 1 è introdotta la fisica delle alte energie a LHC nell'esperimento CMS. Il Capitolo 2 discute il modello di calcolo di CMS e il sistema di analisi distribuita della Grid. Nel Capitolo 3 viene brevemente presentata la fisica del quark top e del bosone di Higgs. Il Capitolo 4 è dedicato alla preparazione dell'analisi dal punto di vista degli strumenti della Grid (CRAB3 vs CRAB2). Nel capitolo 5 è presentato e discusso uno studio di fattibilità per un'analisi del canale ttH in termini di efficienza di selezione.

Composizione dinamica di funzioni di rete virtuali in ambienti cloud

Questo documento si interroga sulle nuove possibilità offerte agli operatori del mondo delle Reti di Telecomunicazioni dai paradigmi di Network Functions Virtualization, Cloud Computing e Software Defined Networking: questi sono nuovi approcci che permettono la creazione di reti dinamiche e altamente programmabili, senza disdegnare troppo il lato prestazionale. L'intento finale è valutare se con un approccio di questo genere si possano implementare dinamicamente delle concatenazioni di servizi di rete e se le prestazioni finali rispecchiano ciò che viene teorizzato dai suddetti paradigmi. Tutto ciò viene valutato per cercare una soluzione efficace al problema dell'ossificazione di Internet: infatti le applicazioni di rete, dette middle-boxes, comportano costi elevati, situazioni di dipendenza dal vendor e staticità delle reti stesse, portando all'impossibilità per i providers di sviluppare nuovi servizi. Il caso di studio si basa proprio su una rete che implementa questi nuovi paradigmi: si farà infatti riferimento a due diverse topologie, una relativa al Livello L2 del modello OSI (cioè lo strato di collegamento) e una al Livello L3 (strato di rete). Le misure effettuate infine mostrano come le potenzialità teorizzate siano decisamente interessanti e innovative, aprendo un ventaglio di infinite possibilità per il futuro sviluppo di questo settore.

Integration of a simulation platform for electrical mobility within the arrowhead interoperability framework

This dissertation document deals with the development of a project, over a span of more than two years, carried out within the scope of the Arrowhead Framework and which bears my personal contribution in several sections. The final part of the project took place during a visiting period at the university of Luleå. The Arrowhead Project is an European project, belonging to the ARTEMIS association, which aims to foster new technologies and unify the access to them into an unique framework. Such technologies include the Internet of Things phe- nomenon, Smart Houses, Electrical Mobility and renewable energy production. An application is considered compliant with such framework when it respects the Service Oriented Architecture paradigm and it is able to interact with a set of defined components called Arrowhead Core Services. My personal contribution to this project is given by the development of several user-friendly API, published in the project's main repository, and the integration of a legacy system within the Arrowhead Framework. The implementation of this legacy system was initiated by me in 2012 and, after many improvements carried out by several developers in UniBO, it has been again significantly modified this year in order to achieve compatibility. The system consists of a simulation of an urban scenario where a certain amount of electrical vehicles are traveling along their specified routes. The vehicles are con-suming their battery and, thus, need to recharge at the charging stations. The electrical vehicles need to use a reservation mechanism to be able to recharge and avoid waiting lines, due to the long recharge process. The integration with the above mentioned framework consists in the publication of the services that the system provides to the end users through the instantiation of several Arrowhead Service Producers, together with a demo Arrowhead- compliant client application able to consume such services.

Progettazione di un applicativo di supporto al monitoraggio di team situati

Lo scopo della tesi e quello di giungere alla realizzazione di un prototipo, che si basi su tecnologie specifiche quali GPS, Android e Bluetooth, per l'infrastruttura di un sistema che può essere visto come l'unione di tre macro parti distinte, centrale di controllo, dispositivo mobile e pulsossimetro. Concentrandosi in particolare sugli ultimi due componenti citati e realizzando un sistema di comunicazione che si basa su un Web Service ispirato al modello REST, si giungerà, attraverso un attento processo logico dettato dai canoni dell'ingegneria del software, al prototipo finale. Il prototipo che sarà realizzato rappresenterà oltre che un primo sistema funzionante e operativo, un punto di partenza per estensioni future, con lo scopo di perfezionare le funzionalità già esistenti o di fornirne di aggiuntive.

Applicazione Jolie - Servizio Prenotazioni

Introduzione sulla service-oriented architecture, i microservices, il linguaggio Jolie e descrizione della progettazione ed implementazione di un'applicazione Jolie service-oriented per la prenotazione di spazi (Booking Service).

Exploiting OSGi capabilities from MHP applications

In this paper we introduce a cooperative environment between the Interactive Digital TV (IDTV) and home networking with the aim of allowing the interaction between interactive TV applications and the controllers of the in-home appliances in a natural way. More specifically, our proposal consists of merging MHP (Multimedia Home Platform), one of the main standard frameworks for IDTV, with OSGi (Open Service Gateway Initiative), the most widely used open platform to set up Residential Gateways. To overcome the radically different nature of these specifications the function-oriented MHP middleware and the service-oriented OSGi framework , we define a new kind of application, coined as XbundLET. Although this software bridge is suitable to enable the interaction between MHP and OSGi applications in both directions, we concretely focus on exposing our implementation experience in only one direction: from MHP to the OSGi world.