Distributed Smart Camera (DSC) networks are power constrained real-time distributed embedded systems that perform computer vision using multiple cameras. Providing data aggregation techniques that is criti-cal for running complex image processing algorithms on DSCs is a challenging task due to complexity of video and image data. Providing highly desirable SQL APIs for sophisticated query processing in DSC networks is also challenging for similar reasons. Research on DSCs to date have not addressed the above two problems. In this thesis, we develop a novel SOA based middleware framework on a DSC network that uses Distributed OSGi to expose DSC network services as web services. We also develop a novel web service composition scheme that aid in data aggregation and a SQL query interface for DSC net-works that allow sophisticated query processing. We validate our service orchestration concept for data aggregation by providing query primitive for face detection in smart camera network.

The Web turns out to be a collection of services that interoperate through the Internet. As the number of services increase, it is getting more and more diffucult for users to find, filter and integrate these services depending on their requirements. Automatic techniques are being developed to fulfill these tasks. The first step toward automatic composition is the discovery of services needed. UDDI which is one of the accepted web standards, provides a registry of web services. However representation capabilities of UDDI are insufficient to search for services on the basis of what they provide. Semantic web initiatives like OWL and OWL-S are promising for locating exact services based on their capabilities. In this thesis, a new semantic service discovery mechanism is implemented based on OWL-S service profiles. The service profiles of an advertisement and a request are matched based on OWL ontologies describing them. In contrast to previous work on the subject, the ontologies of the advertisement and the request are not assumed to be same. In case they are different, schema matching algorithms are applied. Schema matching algorithms find the mappings between the given schema models. A hybrid combination of semantic, syntactic and structural schema matching algorithms are applied to match ontologies

Web service composition is an inevitable aspect of web services technology, which solves complex problems by combining available basic services and ordering them to best suit the problem requirements. Automatic composition gives us flexibility of selecting best candidate services at composition time, this would require the user to define the resource allocation constraints for selecting and composing candidate web services. Resource allocation constraints define restrictions on how to allocate resources, and scheduling under resource allocation constraints to provide proper resource allocation to tasks. In this work, web service composition system named as CWSF (Composite Web Service Framework) constructed for users to define a workflow system in which a rich set of constraints can be defined on web services. On the contrary many technologies and studies, CWSF provides a user-friendly environment for modeling web service composition system. The output of the framework is the scheduling of web service composition in which how and when web services are executed are defined. With this work, a language, CWSL is defined to describe workflow, resource allocation constraints, selection and discovery rules of web services and associated semantic information. An important property of CWSF system is converting web service composition problem into a constraint satisfaction problem to find the best solution that meet the all criteria defined by user. Furthermore, CWSF has ability to display other possible solutions to provides users flexibility. This study also includes semantic matching and mapping facilities for service discovery.

In Web service composition, service discovery and combining suitable services through determination of interoperability among different services are important operations. Utilizing semantics improves the quality and facilitates automation of these operations. There are several previous approaches for semantic service discovery and service matching. In this work, we exploit and extend these semantic approaches in order to make Web service composition process more facilitated, less error prone and more automated. This work includes a service discovery and service interoperability checking technique which extends the previous semantic matching approaches. In addition to this, as a guidance system for the user, a new semantic domain model is proposed that captures semantic relations between concepts in various ontologies.

In today&#039 / s world, composite web services are widely used in service oriented computing, web mashups and B2B Applications etc. Most of these services are composed manually. However, the complexity of manually composing web services increase exponentially with the increase in the number of available web services, the need for dynamically created/updated/discovered services and the necessity for higher amount of data bindings and type mappings in longer compositions. Therefore, current highly manual web service composition techniques are far from being the answer to web service composition problem. Automatic web service composition methods are recent research efforts to tackle the issues with manual techniques. Broadly, these methods fall into two groups: (i) workflow based methods and (ii) methods using AI planning. This thesis investigates the application of AI planning techniques to the web service composition problem and in particular, it proposes the use of the abductive event calculus in this domain. Web service compositions are defined as templates using OWL-S (&quot / OWL for Services&quot / ). These generic composition definitions are converted to Prolog language as axioms for the abductive event calculus planner and solutions found by the planner constitute the specific result plans for the generic composition plan. In this thesis it is shown that abductive planning capabilities of the event calculus can be used to generate the web service composition plans that realize the generic procedure.

In recent years, web services have become an emerging technology for communication and integration between applications in many areas such as business to business (B2B) or business to commerce (B2C). In this growing technology, it is hard to compose web services manually because of the increasing number and compexity of web services. Therefore, automation of this composition process has gained a considerable amount of popularity. Automated web service composition can be achieved either by generating the composition plan dynamically using given inputs and outputs, or by locating the correct services if an abstract process model is given. This thesis investigates the former method which is dynamicly generating the composition by using the abductive lanning capabilities of the Event Calculus. Event calculus axioms in Prolog language, are generated using the available OWL-S web service descriptions in the service repository, values given to selected inputs from ontologies used by those semantic web services and desired output types selected again from the ontologies. Abductive Theorem Prover which is the AI planner used in this thesis, generates composition plans and execution results according to the generated event calculus axioms. In this thesis, it is shown that abductive event calculus can be used for generating web services composition plans automatically, and returning the results of the generated plans by executing the necessary web services.

In this thesis, some novel ideas are presented for solving automated web service composition problem. Some possible real world problems such as partial observability of environment, nondeterministic effects of web services, service execution failures are solved through some mechanisms. In addition to automated web service composition, automated web service invocation task is handled in this thesis by using reflection mechanism. The proposed approach is based on AI planning. Web service composition problem is translated to AI planning problem and a novel AI planner namely &ldquo / Simplanner&rdquo / that is designed for working in highly dynamic environments under time constraints is adapted to the proposed system. World altering service calls are done by conforming to the WS-Coordination and WS-Business Activity web service transaction specifications in order to physically repair failure situations and prevent undesired side effects of aborted web service composition efforts.

In this thesis, a web service composition and execution framework is presented for semantically annotated web services. A monolithic approach to automated web service composition and execution problem is chosen, which provides some benefits by separating the composition and execution phases. An AI planning method using a logical formalism called Event Calculus is chosen for the composition phase. This formalism allows one to generate a narrative of actions and temporal orderings using abductive planning techniques given a goal. Functional properties of services, namely input/output/precondition/effects(IOPE) are taken into consideration in the composition phase and non-functional properties, namely quality of service (QoS) parameters are used in selecting the most appropriate solution to be executed. The repository of OWL-S semanticWeb services are translated to Event Calculus axioms and the resulting plans found by the Abductive Event Calculus Planner are converted to graphs. These graphs can be sorted according to a score calculated using the defined quality of service parameters of the atomic services in the composition to determine the optimal solution. The selected graph is converted to an OWL-S file which is executed consequently.

In this thesis, some enhancements to an existing automatic web service composition and execution system are described which provide a practical significance to the existing framework with scalability, i.e. the ability to operate on large service sets in reasonable time. In addition, the service storage mechanism utilized in the enhanced system presents an effective method to maintain large service sets. The described enhanced system provides scalability by implementing a pre-processing phase that extracts service chains and problem initial and goal state dependencies from service descriptions. The service storage mechanism is used to store this extracted information and descriptions of available services. The extracted information is used in a forward chaining algorithm which selects the potentially useful services for a given composition problem and eliminates the irrelevant ones according to the given problem initial and goal states. Only the selected services are used during the AI planning and execution phases which generate the composition and execute the services respectively.

Composition of web services is one of the flexible and easiest approaches for creating composite services that fulfill complex tasks. Together with providing convenience in creation of new software applications, service composition has various challenges. One of them is the satisfaction of user-defined Quality of Service (QoS) requirements while selecting services for a composition. Load balancing issue is another challenge as uncontrolled workload may lead to violation of service providers&rsquo / QoS declarations. This thesis work proposes a QoS aware method for optimum service composition while taking into account load balancing. M/M/C queuing model is utilized for the individual services to determine sojourn time distribution for possible compositions. Percentile of the execution time, price and availability are considered as QoS parameters. Proposed algorithm selects the optimum composition according to QoS constraints and utility provided by the services. The performance of the method is evaluated by custom simulation software and is compared to two other methods, random selection and average execution timebased optimal service selection.