Seminars
An Iterative Approach for the Process-level Composition of Web Services
Written by Annapaola Marconi ~ Thursday, 21 June 2007
I will present an iterative semi-automated development process for web service composition which dramatically reduces the effort for the composition task. The proposed approach automatically generates both the internal executable process (executable WS-BPEL) and its user interface (WSDL and abstract WS-BPEL). The composition process starts from composition requirements that can be easily specified through an intuitive graphical notation, and that can be incrementally refined on the basis of the results of the automated composition.
Transactions and Transaction Management in WS Compositions
Written by Michele Trainotti ~ Thursday, 14 June 2007
User-centric service composition
Written by Raman Kazhamiakin ~ Monday, 04 June 2007
During the everyday life the users operate various applications and services (e.g., agenda, traveling, entertainment) that potentially consume or block his resources (e.g., time/location). Currently, the user is left alone with the problem of maintaining consistency of these resources, often resulting in a conflict situation, which is difficult, if at all possible, to recover. The goal of the user centric service composition is to provide automated support for keeping the resources consistent, and to simplify the process of invocation and compensation of the resource-critical operations. In this talk we will consider in details the "trip-to-london" example, its features, and potential solutions.
Developing Web Service's Enabled Mobile Software: a Technology Overview
Written by Fabio Barbon ~ Monday, 28 May 2007
I'll present current technology offerings for developing "online" mobile applications. Then I'll give an overview of the issues specific to writing, debugging, installing and distributing software for mobile platforms. Finally I'll show a minimal example application running on a real device and interfacing to a real web service via gprs network.
Specification and automatic synthesis of Runtime monitors for Multi-threaded Java from Duration Calculus Specifications
Written by Paritosh Pandya ~ Friday, 23 March 2007
Interval Temporal Logics and Duration Calculi provide a rich and highly expressive notation for specifying complex requirements involving quantitative timing properties. Unfortunately, the logics are undecidable in generally and they do not admit good connections with Automata. In this talk we will present a new notation called QDDC-LOC for specifying requirements. This is based on the LIDL logic previously investigated. This notation can be efficiently converted into determinstic observers for property monintoring and verification. We have implemented the synthesis and integration of QDDC-LOC observers on several platforms including SAL, Uppaal and also Java. After introducing QDDC-LOC through some SAL examples, we will present the ongoing work on automatic synthesis of Runtime monitors for multi-threaded Java programs.
Automated Web Service Composition in Practice: the e-BookStore Case Study
Written by Annapaola Marconi ~ Friday, 2 March - Wednesday, 7 March 2007
We will discuss the feasibility and efficiency of our existing automated composition approach, from the specification of composition requirements to the generation of the new service, through its application on an industrial case study: the e-Bookstore composition scenario. The idea is to automatically synthesize a new WS-BPEL executable process that allows to order books and buy them via a secure credit card payment transaction. To achieve its task, the new service interacts with a set of existing complex services: the Amazon E-Commerce Services and an e-payment service offered by an Italian bank (Monte dei Paschi).
ASTRO: new challenges and perspectives for the EGov and Telco domains
Written by Marco Pistore ~ Friday, 16 February 2007
In the talk, I will illustrate two domains that are becomming more and more relevant for ASTRO: the E-Government and the Telco domains. We will discuss current and perspective projects in these areas, and the new problems and challenges that will arise, and possible approaches to solve those problems.
Specifying Data-Flow Requirements for the Automated Composition of Web Services
Written by Annapaola Marconi ~ Thursday, 27 April 2006
One of the fundamental ideas of Web Services and Service Oriented Architecture is the possibility to develop new applications by composing existing services that are available on the Web. Several approaches have been proposed to tackle the problem of Web Service Composition, but little effort has been devoted so far to the problem of modeling the requirements of the composition. However, it is clear that the possibility to express requirements specifying complex interactions patterns among the component services is an essential step to cope with a wide range of composition problems. I will present a new model which addresses one of the key aspects of composition requirements, namely the data flow among the component services. We develop graphical notations and a formal theory for the new model and we integrate it within an existing automated composition framework. Finally, I will show that the proposed approach can handle in an effective way realistic composition problems
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WS-CDL - choreography description language
Written by Raman Kazhamiakin ~ Thursday, 30 March 2006
The Web Services Choreography Description Language (WS-CDL) is an XML-based language that describes peer-to-peer collaborations of participants by defining, from a global viewpoint, their common and complementary observable behavior; where ordered message exchanges result in accomplishing a common business goal. In this presentation we discuss the language modelling capabilities and expresiveness, the possible relations with the research activities of the ASTRO project.
PPT
Definizione e realizzazione di un modello architetturale per la gestione della transazionalità
Written by Edoardo Di Lorenzo ~ Thursday, 23 March 2006
A short introduction of WS, BPEL, transactions and the description of the work did in the thesis
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Integrating Web Service Discovery and Composition
Written by Piergiorgio Bertoli ~ Thursday, 16 March 2006
As part of the KWEB project, we are interested in providing an end-to-end approach to automatically discover and compose available semantic web services in order to fulfill a given user requirement. This requires integrating two high-level functionalities: service discovery and service composition. The integration is not trivial, as the two functionalities may give reciprocous feedback.
We describe and discuss a proposed architecture which exploits a two-layered form of web-service composition - first considering services as functional atoms, then dealing with their behavioral specification.
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UDDI Overview - part 2
Written by Gabriele Zacco ~ Thursday, 02 March 2006
UDDI is a project aiming at standardizing, on an XML base, the way in which businesses describe and publish their services, discover other businesses that offer desired services, and integrate each other. It implements the idea of a registry that much resembles that of the yellow pages. In this talk I will try to give an overview of the different aspect (such as the UDDI Specification and the UDDI Business Registry) involved in the integration of UDDI project into Service Oriented Applications.
PPT
Data Flow Modeling Language for WS Composition
Written by Annapaola Marconi ~ Thursday, 23 February 2006
The aim of the data flow modeling language is to allow the specification of complex requirements concerning data manipulation and exchange. In particular, data flow requirements specify how output messages (messages sent to component services) must be obtained from input messages (messages received from component services). This includes several important aspects: whether an input message can be used several times or just once, how several input messages must be combined to obtain an output message, whether all messages received must be processed and sent or not, etc.
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Monitoring instances and classes of Web-services
Written by Fabio Barbon ~ Tuesday, 14 February 2006
We support both "instance monitors" that deal with the execution of a single instance of a bpel process, as well as ``class monitors'' that report aggregated information about all the instances of a bpel process. We define a language for the specification of instance and class monitors. The language allows for specifying boolean, statistic, and time-related properties. We also show how we extended the automatic translator of all these kinds of monitors to Java programs.
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UDDI Overview - part 1
Written by Gabriele Zacco ~ Tuesday, 07 February 2006
UDDI is a project aiming at standardizing, on an XML base, the way in which businesses describe and publish their services, discover other businesses that offer desired services, and integrate each other. It implements the idea of a registry that much resembles that of the yellow pages. In this talk I will try to give an overview of the different aspect (such as the UDDI Specification and the UDDI Business Registry) involved in the integration of UDDI project into Service Oriented Applications.
PPT
Implementing transactionalilty in BPEL composition scenarios
Written by Michele Trainotti and Edoardo Di Lorenzo ~ Tuesday, 31 January 2006
Transactionallity is one of the most biggest issue in business process. Since we are using BPEL to compose business process, we are going to present a way to integrate transactionallity in BPEL. The presentation has two parts: in the first part we are going to take a look to the WS standards enabling transactions (WS-Transaction, BPT); in the second part we are going to take a close look to a proposed architecture to integrate a transaction protocol (BTP) in BPEL.
ODP
Exploration of a Framework for Co-Adaptive Processes
Written by Willem-Jan van den Heuvel ~ Tuesday, 24 January 2006
For future E-commerce systems that are engaged in many dynamic trading relationships, the ability to adapt themselves smoothly will increasingly become a critical characteristic.
In this talk, the basic semantic structure of contract-driven, collaborative processes will be explained. Then, a formal framework for self-adaptive systems will be introduced, arguing that self-adaptive systems should have explicit goals that should be captured in a goal-based architecture. Based on this framework, the notion of co-adaptation will be explained. In particular, four levels of co-adaptation will be presented, including an argumentation mechanism that can be used to enable co-adaptation at the higher levels.
Data Abstractions for the Verification of WS compositions
Written by Raman Kazhamiakin ~ Tuesday, 17 January 2006
The analysis of the WS composition behavior requires considering not only the control flow of the process, but also the corresponding data flow, since the latter makes a great impact on the correctness of the behavior. The problem is made much more difficult ny the necessity to manage arbitrary and infinite data domains, user-defined functions etc. We extend the traditional approaches based on the predicate abstractions and uninterrupted functions, and provide two models of abstractions that allow: 1) to manage the complexity by the abstraction parameterization and 2) to reason both on the universal properties (assertions) and existential properties (possibilities).
PPT
Specifying Requirements for Automated Composition of Web Services
Written by Annapaola Marconi ~ Tuesday, 10 January 2006
Automated Composition of Web Services aims at generating a new executable process that interacting with existing services published on the Web satisfies a given composition goal. Several approaches have been proposed to tackle this problem, but little effort has been devoted to the analysis of composition requirements. I will present a preliminary work on automated composition requirements, which aims at understanding what kind of requirements we need to specify when addressing an automated composition problem.
Modelling and Analysis of Time-related Properties in Web Service Compositions
Written by Raman Kazhamiakin ~ Tuesday, 06 December 2005
In this paper we present an approach for modelling and analyzing time-related properties of Web service compositions defined as a set of BPEL4WS processes. We introduce a formalism, called Web Service Timed State Transition Systems (WSTTS), to capture the timed behavior of the composite web services. We also exploit an interval temporal logic called Quantified Discrete-time Duration Calculus (QDDC), to express complex timed assumptions and requirements on the system's behavior. Building on this formalization, we provide tools and techniques for model checking BPEL4WS compositions against time-related requirements. We perform a preliminary experimental evaluation of our approach and tools with the help of the e-Government case study.
PPT
Roman approach to an Automatic Composition of e-Services
Written by Andrew Gromyko ~ Tuesday, 29 November 2005
The framework of the Roman group (D. Berardi, D. Calvanese, G. De Giacomo, M. Lenzerini, M. Mecella) will be discussed. I will present their model and approach to distibuted system synthesis, an overview of the ESC tool. Finally, I'll remark on the applicability of IRST's planning framework and MBP to the same problem.
Knowledge level composition of web services: knowledge base updaes.
Written by Marco ~ Wednesday, 23 November 2005
In this talk we will discuss the current approach and other possible approaches for modeling knowledge base updates in the generation of the knowledge level state machine in knowledge level composition scenarios.
Knowledge Level Planning for Automated Web Service Composition
Written by Annapaola Marconi and Michele Trainotti ~ Wednesday, 16 November 2005
We will present an overview of the planning framework at the knowledge level, analyze in details its implementation and discuss some optimizations.
Knowledge Level Planning for Automated Web Service Composition
Written by Annapaola Marconi ~ Wednesday, 09 November 2005
Automated Composition of Web Services presents several challenges: on the one hand there is the need to deal with non-deterministic and partial observable domains, and with complex composition requirements, on the other hand there is the need to reason on the data exchanged by the services and thus to deal with complex data flow. We've tackled the first problem by defining a framework where web services are modeled with stateful, nondeterministic, and partially observable behaviors, and by applying planning as model checking techniques. The key aspect for extending this approach to deal with complex data flows is the definition of an appropriate model for providing a knowledge level description of the component services. I will present in details the proposed knowledge level model, show how it can be automatically obtained from the descriptions of the component services and describe the resulting planning framework at the knowledge level.
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A structured experimental analysis of web service composition
Written by Piergiorgio Bertoli ~ Wednesday, 02 November 2005
The performance of the various phases involved in composing a set of web services is greatly affected by a number of features of the problem:
- the number of involved services
- the size and structure of the component services (represented as number of states, depth, branching factor, etc.)
- the nature of the composition goal
Until now, no clear study has been performed to analyze the complexity of the various features over the various phases, which is necessary to evaluate the practical scalability of web service composition in real-life scenarios.
I will present the results of an ongoing analysis task in this direction, considering a variety of scalable composition problems involving differently structured services.
Web Service Composition: The Roman Model Revisited
Written by Marco Pistore ~ Wednesday, 26 October 2005
We will discuss the peer-to-peer architecture for a web service composition, focusing on how the synthesis, verification and monitoring techniques developed by ASTRO need to be adapted to be applied to this scenario.
Analysis of Communication Mechanisms in WS compositions. - second part
Written by Luca ~ Wednesday, 19 October 2005
I'm going to add to the theoretical presentation Raman did about our work on verification, an overview of the four communication models we consider, starting from the synchronous one up to the most general. Then I will explain how the algorithm for checking the adequacy of the model works.
PPT
Analysis of Communication Mechanisms in WS compositions
Written by Raman Kazhamiakin ~ Wednesday, 12 October 2005
One of the key aspects in the verification of WS composition is the communication model adopted for interactions representation. We discuss the analysis approach that allows 1) to reveal an adequate model that completely describes the given composition; 2) to check boundedness of the system; 3) to verify different important properties, e.g. non-looseness of messages, deadlock freeness, LTL properties.
PPT
KPLTL property monitor reduction - second part
Written by Fabio Barbon ~ Wednesday, 05 October 2005
Before describing the reduction algorithm, I'll introduce the WS monitoring problem in general for the newcomers. This shouldn't last more than 20 minutes. I'll describe how KPLTL property monitors are built and how the resulting fsm's are simplified. Before that I'll give an informal briefing on short-time goals for research activity on web service monitoring.
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KPLTL property monitor reduction
Written by Fabio Barbon ~ Wednesday, 21 September 2005
We'll describe how KPLTL property monitors are built and how the resulting fsm's are simplified. Before that We'll give an informal briefing on short-time goals for research activity on web service monitoring.
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An overview of the existing plan languages
Written by Dmitry Shaparau ~ Wednesday, 07 September 2005
Approaches to high-level planning task programming can roughly be classified into those making use of some form of deliberation and those which do not. These systems are embedded into system architectures ranging from reactive to deliberative. Reactive architectures are based on the set of rules which assigns the next action to the agent according to its perception of the world. Logic-based architectures try to obtain a goal-directed plan (sequence of actions) by using a symbolic description and a planner.
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