Taha Osman

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

Semantic-Driven Matchmaking and Composition of Web Services Using Case-Based Reasoning

BPEL has emerged as the industrial standard language for modelling behavioral aspects of web services. To support business partners in dynamically and flexibly binding their services together, different BPEL processes need to be efficiently matched. This paper identifies and defines various types of structural matching for BPEL processes. The matching definitions are based on heuristics: they take behavioral interaction aspects of the compared services into account, but abstract from irrelevant syntactical differences. Since the definitions are structural, they can be efficiently computed, and thus are useful to support dynamic and flexible binding of services. The approach is illustrated with an example from an existing business scenario.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, and investigate the use of case adaptation for service composition. Our framework considers Web services execution experiences in the decision making process and is highly adaptable to the service requester constraints. The framework also utilizes OWL semantic descriptions extensively for implementing both the components of the CBR engine and the matchmaking profile of the Web services.

A pragmatic approach to semantic repositories benchmarking

The aim of this paper is to benchmark various semantic repositories in order to evaluate their deployment in a commercial image retrieval and browsing application. We adopt a two-phase approach for evaluating the target semantic repositories: analytical parameters such as query language and reasoning support are used to select the pool of the target repositories, and practical parameters such as load and query response times are used to select the best match to application requirements. In addition to utilising a widely accepted benchmark for OWL repositories (UOBM), we also use a real-life dataset from the target application, which provides us with the opportunity of consolidating our findings. A distinctive advantage of this benchmarking study is that the essential requirements for the target system such as the semantic expressivity and data scalability are clearly defined, which allows us to claim contribution to the benchmarking methodology for this class of applications.

An Integrative Semantic Framework for Image Annotation and Retrieval

Most public image retrieval engines utilise free-text search mechanisms, which often return inaccurate matches as they in principle rely on statistical analysis of query keyword recurrence in the image annotation or surrounding text. In this paper we present a semantically-enabled image annotation and retrieval engine that relies on methodically structured ontologies for image annotation, thus allowing for more intelligent reasoning about the image content and subsequently obtaining a more accurate set of results and a richer set of alternatives matchmaking the original query. Our semantic retrieval technology is designed to satisfy the requirements of the commercial image collections market in terms of both accuracy and efficiency of the retrieval process. We also present our efforts in further improving the recall of our retrieval technology by deploying an efficient query expansion technique.

FADI: a fault tolerant environment for open distributed computing

FADI (FAult tolerant DIstributed environment) is a complete programming environment for the reliable execution of distributed application programs. FADI encompasses all aspects of modern fault-tolerant distributed computing. The built-in user-transparent error detection mechanism covers processor node crashes and hardware transient failures. The mechanism also integrates user-assisted error checks into the system failure model. The nucleus non-blocking checkpointing mechanism combined with a novel selective message logging technique delivers an efficient, low-overhead backup and recovery mechanism for distributed processes. FADI also provides a means of remote automatic process allocation on distributed system nodes.

Semantic annotation and retrieval of image collections

In order to maximise the benefit of the colossal repository of digital images available both publicly and in private collections, intelligent matchmaking tools are required. Unfortunately, most image search engines rely on free-text search that often returns inaccurate sets of results based on the recurrence of the search keywords in the text accompanying the images. In this paper we present a semantically-enabled image annotation and retrieval engine that relies on methodically structured ontologies for image annotation, thus allowing for more intelligent reasoning about the image content and subsequently obtaining a more accurate set of results and a richer set of alternatives matchmaking the original query.

Knowledge-Intensive Semantic Web Services Composition

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, and investigate the use of case adaptation for service composition. Our framework considers Web services execution experiences in the decision making process and is highly adaptable to the service requester constraints. The framework takes knowledge-intensive approach and utilizes OWL semantic descriptions extensively for implementing both the components of the CBR engine and the matchmaking profile of the Web services.

Attribute-Based Authorization for Grid Computing

the development of adequate security solutions and in particular of authorization techniques for grid computing systems is a challenging task. Traditional security trends tried to overcome this problem by using a low-level access control policy which maps a user’s identity to a local account. This approach is not scalable and is hard to manage in a distributed environment. Current trends started adopting approaches that pass attributes for authorization instead of passing user’s credentials. The problem still hasn’t been solved completely primarily because it uses PKI (Public Key Infrastructure) user certificate for authorization, and the main problem with this approach is the inflexibility of the PKI infrastructure when it comes to open distributed systems (Grid). Additionally implementations of attribute-based authorization have largely adopted the XML based SAML (Security Assertion Markup Language) and XACML (eXtensible Access Control Markup Language) standards for authentication and authorization. The author investigates an approach that uses XACML for Authorizations and utilizes a proxy for the attribute authorityto allow for the distribution of attribute requests to numerous attribute authorities to whom the user is subscribed.

Utilising semantic technologies for intelligent indexing and retrieval of digital images

The proliferation of digital media has led to a huge interest in classifying and indexing media objects for generic search and usage. In particular, we are witnessing a colossal growth in digital image repositories that are difficult to navigate using free-text search mechanisms, which often return inaccurate matches as they in principle rely on statistical analysis of query keyword recurrence in the image annotation or surrounding text. In this paper we present a semantically-enabled image annotation and retrieval engine that is designed to satisfy the requirements of the commercial image collections market in terms of both accuracy and efficiency of the retrieval process. Our search engine relies on methodically structured ontologies for image annotation, thus allowing for more intelligent reasoning about the image content and subsequently obtaining a more accurate set of results and a richer set of alternatives matchmaking the original query. We also show how our well-analysed and designed domain ontology contributes to the implicit expansion of user queries as well as the exploitation of lexical databases for explicit semantic-based query expansion.

A review of communication and Java technologies in the ATTAIN project

We present a review of the applications of wireless Java technology in the advanced traffic and travel information (ATTAIN) system. Currently the ATTAIN system uses SMS (small message service) text and HTTP (hyper text transfer protocol program to communicate between mobile telephone users and the server.