Leho Nigul

An Approach for Context-Aware Service Discovery and Recommendation

Given the large amount of existing services and the diversified needs nowadays, it is time-consuming for end-users to find appropriate services. To help end-users obtain their desired services, context-aware systems provide a promising way to automatically search and recommend services using a user’s context. However, existing context-aware techniques have limited support for dynamic adaption to newly added context types (e.g., location, time and activity). Due to the diversity of user’s environment, the available context types may change over time. It is challenging to anticipate a complete set of context types while we design a context aware system. In this paper, we propose a context modeling approach which can dynamically handle various context types and values. More specifically, we use ontologies to enhance the meaning of a user’s context values and automatically indentify the relations among different context values. Based on the relations among context values, we capture the potential services which the user might need. A case study is conducted to evaluate the effectiveness of our approach. The results show that our approach can use contexts to find users’ needs and recommend their desired services with high precision and recall.

An automatic approach for ontology-driven service composition

Current service composition techniques and tools are mainly designed for use by Service Oriented Architecture (SOA) professionals to solve business problems. This focus on SOA professionals creates challenges for the non-expert users, with limited SOA knowledge, who try to integrate SOA solutions into their online experience. To shelter non-expert users from the complexity of service composition, we propose an approach which automatically composes a service on the fly to meet the situational needs of a user. We present a tag-based service description schema which allows non-expert users to easily understand the description of services and add their own descriptions using descriptive tags. Instead of specifying the detailed steps for composing a service, a non-expert user would specify the goal of their desired activities using a set of keywords then our approach can automatically identify the relevant services to achieve the goal at run-time. A prototype is developed as a proof of concept. We conduct a case study to compare the performance of our approach in automatic service composition with a baseline approach which consists of the manual process of searching for services using keywords. The case study shows that our approach can achieve higher precision and recall than the baseline approach.

Ontology-driven service composition for end-users

Current service composition techniques and tools are mainly designed for use by Service-Oriented Architecture (SOA) professionals to solve business problems. Little attention has been paid to allowing end-users without sufficient service composition skills to compose services and integrate SOA solutions into their online experience to fulfill their daily activities. To shelter end-users from the complexity of service composition, we propose an approach which can compose services on the fly to meet the situational needs of end-users. We present a tag-based service description schema which allows non-IT professional users to easily understand the description of services and add their own descriptions using descriptive tags. Instead of requiring end-users to specify detailed steps for composition, the end-users only need to describe their goals using a few keywords. Our approach expands the meaning of a user’s goal using ontologies then derives a group of keywords to discover services in order to fulfill the goal. A prototype is developed as a proof of concept to show that our approach enables end-users to discover and compose services easily. We conduct a case study to evaluate the effectiveness of our approach that eases end-users to compose services without the knowledge of SOA technologies. The results of our case study show that our approach can effectively generate ad-hoc processes and discover services with relatively high precision and recall.

A framework for automatically supporting end-users in service composition

In Service Oriented Architecture (SOA), service composition integrates existing services to fulfill specific tasks using a set of standards and tools. However, current service composition techniques and tools are mainly designed for SOA professionals. It becomes challenging for end-users without sufficient service composition skills to compose services. In this paper, we propose a framework that supports end-users to dynamically compose and personalize services to meet their own context. Instead of requiring end-users to specify detailed steps in the composition, our framework only requires end-users to specify the goals of their desired activities using a few keywords to generate a task list. To organize the task list, we analyze the historical usage data and recover the control flows among the tasks in the task list. We also mine the task usage pattern from the historical usage data to recommend new services. A prototype is designed and developed as a proof of concept to demonstrate that our approach enables end-users to discover and compose services easily.

Incremental model synchronization in model driven development environments

Most modern model driven software development environments rely heavily on model transformations for generating various software design artifacts and eventually even source code. However, during development, maintenance and evolution activities, these software artifacts are subject to updates and refactoring operations. In such model driven development environments, these software artifacts need to be re-synchronized every time one of them is altered, so that they all remain consistent according to some specific rules, relations and domain constraints. Until now, the standard approach to model synchronization has been the re-application of all transformation rules, aiming thus for the complete re-generation of all artifacts in all models involved. This complete re-application is a safe yet computationally expensive way to ensure consistency among models. In this paper, we present a method for re-synchronizing software models in an incremental fashion by utilizing an indexing model. In this respect, using the proposed methodology, the time required for maintaining global model consistency is proportional to the size of the changes and not that of the models involved. The proposed approach has been applied for the incremental re-synchronization of large and complex models in the Eclipse Web Tools Platform (WTP). Results indicate that this solution can significantly reduce the time required to re-synchronize models in such comprehensive development environments as WTP.

Software maintainability benefits from annotation-driven code

Java annotations and their predecessors XDoclet annotations are well positioned to offer a substantial benefit for developing and maintaining software by combining relevant metadata together with the code that makes use of them. In this paper we share the insights that we gained by developing the J2EE Connector Tools suite, which is part of IBM Rational Application Developer. This tools suite is used to generate annotated Java code capable of connecting to Enterprise Information Systems through the Java EE Connector APIs. The generated code is annotation driven, and in the paper we show how the annotations in the generated code helped us to achieve a high degree of efficient code maintenance for the tools that generate the code as well as for the generated code itself.

The SOA programming model: challenges in a services oriented world

Over the past decade there has been a significant growth in the area of Service Oriented systems; in particular, systems that have been designed and built using the Service Oriented Architecture approach. The most popular and frequent implementation of SOA systems is based on Web Services, a technology that utilizes internet application layer protocols and standards for service description, service invocation and service composition. However, due to the plethora and diversity of types of services that are available as run time components and implemented in different languages, the middleware and the infrastructure required to make these components interoperable and deployable as services in different platforms grew in complexity. The technical skills required to design, build and test these systems become more difficult as the complexity and requirements of the systems increases and new deployment platforms become available.

Bridging the business-IT divide using BPM: challenges and opportunities

Building successful enterprise software requires an effective collaboration among Business and IT stakeholders. Business analysts capture requirements in business terms. Software engineers interpret these requirements and translate them into the domain of software technology. Yet the different backgrounds and skill sets of these two stakeholder groups naturally lead to the proverbial Business-IT divide. The two groups across the divide speak different languages, each with their own terms and semantics. It is not uncommon to see projects fail because of poorly understood and miscommunicated requirements across the Business-IT divide.

Improving development intelligence

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