Business Process Retrieval Based on Behavioral Semantics

This paper develops a framework for retrieving business processes considering search requirements based on behavioral semantics properties; it presents a framework called "BeMantics" for retrieving business processes based on structural, linguistics, and behavioral semantics properties. The relevance of the framework is evaluated retrieving business processes from a repository, and collecting a set of relevant business processes manually issued by human judges. The "BeMantics" framework scored high precision values (0.717) but low recall values (0.558), which implies that even when the framework avoided false negatives, it prone to false positives. The highest pre- cision value was scored in the linguistic criterion showing that using semantic inference in the tasks comparison allowed to reduce around 23.6 % the number of false positives. Using semantic inference to compare tasks of business processes can improve the precision; but if the ontologies are from narrow and specific domains, they limit the semantic expressiveness obtained with ontologies from more general domains. Regarding the perform- ance, it can be improved by using a filter phase which indexes business processes taking into account behavioral semantics propertie

A monitoring approach for runtime service discovery

Effective runtime service discovery requires identification of services based on different service characteristics such as structural, behavioural, quality, and contextual characteristics. However, current service registries guarantee services described in terms of structural and sometimes quality characteristics and, therefore, it is not always possible to assume that services in them will have all the characteristics required for effective service discovery. In this paper, we describe a monitor-based runtime service discovery framework called MoRSeD. The framework supports service discovery in both push and pull modes of query execution. The push mode of query execution is performed in parallel to the execution of a service-based system, in a proactive way. Both types of queries are specified in a query language called SerDiQueL that allows the representation of structural, behavioral, quality, and contextual conditions of services to be identified. The framework uses a monitor component to verify if behavioral and contextual conditions in the queries can be satisfied by services, based on translations of these conditions into properties represented in event calculus, and verification of the satisfiability of these properties against services. The monitor is also used to support identification that services participating in a service-based system are unavailable, and identification of changes in the behavioral and contextual characteristics of the services. A prototype implementation of the framework has been developed. The framework has been evaluated in terms of comparison of its performance when using and when not using the monitor component

A Framework for Collaborative Content Mashup with Pervasive Services

Kombineerides erinevaid teenuseid saavad mobiiltelefonid rahuldada paljusid tööstus ja ärivajadusi.Samas tuleb teenuste kombineerimise raames sisu õigesti tuvastamiseks ja tõlgendamiseks avastada ja töödelda suurt hulka andmeid. Kuna ainult ühe seadme kasu-tamine mingi ülesande lahendamiseks ei ole väga efektiivne on ühiste eesmärkide saa-vutamiseks soovitatav tööd mitme seadme vahel jagada. Pakume välja ja arendame üldraamistikku, mis toetab teenustele orienteeritud sisu segunemist ning laialt levinud teenuste loomise integreerimist, mis toimuks Business Process Execution Language (BPEL)-tuginevale kollaboratsioonile. Esitasime kollaboratsioonis seadmetele ressursi-säästliku teisaldamise plaani ja implementeerimise selle proof of concept'ina (kontseptsiooni tõestus). Hinnangu tulemused näitavad, et raamistik toetab kollaboratiivset ülesannete teisaldamise kava, mis vähendab mobiilsete seadete ressursside kasutamist.By composing pervasive services, mobile phones can support various industrial and commercial needs. However, the pervasive services composition involves discovering and processing a large amount of data in order to identify and interpret the content. Due to the limitation of the single device capability, it is advisable to collaborate with other devices via a wireless network to accomplish common goals. In this thesis, we propose and develop a generic framework that supports service-oriented content mashup and integrating pervasive services composition in the Business Process Execution Language (BPEL)-based collaboration. A resource-aware offloading scheme to collaborative devices has been proposed and implemented as a proof of concept. The evaluation results have shown that the framework supports collaborative task-offloading scheme that reduces the resource usage of mobile devices

Semantic-driven matchmaking of web services using case-based reasoning

With the rapid proliferation of Web services as the medium of choice to securely publish application services beyond the firewall, the importance of accurate, yet flexible matchmaking of similar services gains importance both for the human user and for dynamic composition engines. In this paper, we present a novel approach that utilizes the case based reasoning methodology for modelling dynamic Web service discovery and matchmaking. Our framework considers Web services execution experiences in the decision making process and is highly adaptable to the service requester constraints. The framework also utilises OWL semantic descriptions extensively for implementing both the components of the CBR engine and the matchmaking profile of the Web services

Flexible coordination techniques for dynamic cloud service collaboration

The provision of individual, but also composed services is central in cloud service provisioning. We describe a framework for the coordination of cloud services, based on a tuple‐space architecture which uses an ontology to describe the services. Current techniques for service collaboration offer limited scope for flexibility. They are based on statically describing and compositing services. With the open nature of the web and cloud services, the need for a more flexible, dynamic approach to service coordination becomes evident. In order to support open communities of service providers, there should be the option for these providers to offer and withdraw their services to/from the community. For this to be realised, there needs to be a degree of self‐organisation. Our techniques for coordination and service matching aim to achieve this through matching goal‐oriented service requests with providers that advertise their offerings dynamically. Scalability of the solution is a particular concern that will be evaluated in detail

Proactive and reactive runtime service discovery: a framework and its evaluation

The identification of services during the execution of service-based applications to replace services in them that are no longer available and/or fail to satisfy certain requirements is an important issue. In this paper we present a framework to support runtime service discovery. This framework can execute service discovery queries in pull and push mode. In pull mode, it executes queries when a need for finding a replacement service arises. In push mode, queries are subscribed to the framework to be executed proactively, and in parallel with the operation of the application, in order to identify adequate services that could be used if the need for replacing a service arises. Hence, the proactive (push) mode of query execution makes it more likely to avoid interruptions in the operation of service-based applications when a service in them needs to be replaced at runtime. In both modes of query execution, the identification of services relies on distance-based matching of structural, behavioural, quality, and contextual characteristics of services and applications. A prototype implementation of the framework has been developed and an evaluation was carried out to assess the performance of the framework. This evaluation has shown positive results, which are discussed in the paper

Dynamic architectural constraints monitoring and reconfiguration in service architectures

Service-oriented architecture is an architectural approach that can be applied for building autonomous service systems dynamically to satisfy on-demand business requests. During the execution of service compositions, architectural constraint violations relating to functional and non-fucntional system properties need to be handled intelligently and autonomously, possibly requiring architectural reconfigurations. We propose integrated architectural constraint violation handling to deal with architectural quality problems through dynamic reconfiguration. We concentrate on service replacement selection as a remedial strategy for a possible quality violation requiring architectural remedies

An intelligent framework for dynamic web services composition in the semantic web

As Web services are being increasingly adopted as the distributed computing technology of choice to securely publish application services beyond the firewall, the importance of composing them to create new, value-added service, is increasing. Thus far, the most successful practical approach to Web services composition, largely endorsed by the industry falls under the static composition category where the service selection and flow management are done a priori and manually. The second approach to web-services composition aspires to achieve more dynamic composition by semantically describing the process model of Web services and thus making it comprehensible to reasoning engines or software agents. The practical implementation of the dynamic composition approach is still in its infancy and many complex problems need to be resolved before it can be adopted outside the research communities. The investigation of automatic discovery and composition of Web services in this thesis resulted in the development of the eXtended Semantic Case Based Reasoner (XSCBR), which utilizes semantic web and AI methodology of Case Based Reasoning (CBR). Our framework uses OWL semantic descriptions extensively for implementing both the matchmaking profiles of the Web services and the components of the CBR engine. In this research, we have introduced the concept of runtime behaviour of services and consideration of that in Web services selection. The runtime behaviour of a service is a result of service execution and how the service will behave under different circumstances, which is difficult to presume prior to service execution. Moreover, we demonstrate that the accuracy of automatic matchmaking of Web services can be further improved by taking into account the adequacy of past matchmaking experiences for the requested task. Our XSCBR framework allows annotating such runtime experiences in terms of storing execution values of non-functional Web services parameters such as availability and response time into a case library. The XSCBR algorithm for matchmaking and discovery considers such stored Web services execution experiences to determine the adequacy of services for a particular task. We further extended our fundamental discovery and matchmaking algorithm to cater for web services composition. An intensive knowledge-based substitution approach was proposed to adapt the candidate service experiences to the requested solution before suggesting more complex and computationally taxing AI-based planning-based transformations. The inconsistency problem that occurs while adapting existing service composition solutions is addressed with a novel methodology based on Constraint Satisfaction Problem (CSP). From the outset, we adopted a pragmatic approach that focused on delivering an automated Web services discovery and composition solution with the minimum possible involvement of all composition participants: the service provider, the requestor and the service composer. The qualitative evaluation of the framework and the composition tools, together with the performance study of the XSCBR framework has verified that we were successful in achieving our goal

An approach to dynamic web service composition

Today, changeable requirements to modern web-oriented services demand their fast development and constant reengineering. This is realized via dynamic composition of services, allowing to estimate changes of both functional and nonfunctional service parameters. The last ones are considered using Web Services Agreement technique. Nevertheless, state-of-the-art SLA-aware methods are not able to consider all classes of non-functional parameters. They also don’t provide service run-time support and dynamic reconfiguration. The novel approach to dynamic Web Services Composition, extending SLA with QoS ontology, is described in the paper. It includes service selection agents that use the QoS ontology and WS-Agreements, allowing agents to choose the most appropriate service based on quality preferences exposed by service consumer. The proposed approach allows performing dynamic WS composition based on SLA, providing required values of QoS parameters, improving general QoS and decreasing service development and re-engineering time