Hussein Zedan | De Montfort University (original) (raw)

Papers by Hussein Zedan

Abstract A Service oriented system emerges from composition of services. Dynamically composed rea... more Abstract A Service oriented system emerges from composition of services. Dynamically composed reactive Web services form a special class of service oriented system, where the delays associated with communication, unreliability and unavailability of services, and competition for resources from multiple service requesters are dominant concerns. As complexity of services increase, an abstract design language for the specification of services and interaction between them is desired.

Abstract Using the Internet to enhance e-learning has become a trend in modern higher education i... more Abstract Using the Internet to enhance e-learning has become a trend in modern higher education institutes. E-learning systems are increasingly becoming an important part of the strategy for delivering online and flexible e-learning. The main advantage of e-learning is the opportunity for students to interact electronically with each other and their teachers during forums, on discussion boards, by e-mail and in chat rooms.

ABSTRACT Wireless Mobile Ad hoc NETwork (WMANET) is a group of an independent wireless (Mobile/Se... more ABSTRACT Wireless Mobile Ad hoc NETwork (WMANET) is a group of an independent wireless (Mobile/Semi Mobile) nodes communicating on a peer-to-peer basis with no pre-established infrastructure. The unique characteristics of WMANET make such networks highly vulnerable to security attacks when compared with wired networks or infrastructure-based wireless networks.

Abstract Based on practical tool development and assessment, criteria are proposed for the assess... more Abstract Based on practical tool development and assessment, criteria are proposed for the assessment of software reengineering tools, covering both the tool features and methodology foundation. Keywords: software maintenance, re-engineering methodology, software tool, software assessment, assessment criteria.

Abstract This paper advocates that extracting formal specification semantically consistent to the... more Abstract This paper advocates that extracting formal specification semantically consistent to the original legacy system will facilitate further redesign and forward engineering greatly. The three parts of reengineering could be integrated on the basis of a wide spectrum language. The key approach to comprehension and the production of formal specification is a notion of abstraction. Transformation can help to change the original source code into alternative forms, but with the same semantics.

In this paper, Interval Temporal Logic (ITL) us used to specify and verify the event processor EP... more In this paper, Interval Temporal Logic (ITL) us used to specify and verify the event processor EP/3, which is a multi-threaded pipeline processor capable of executing parallel programs. We first give the high level specification of the EP/3 with emphasis on the interlock mechanism. The interlock mechanism is used in processor design especially for dealing with pipeline conflict problems. We prove that the specification satisfies certain safety and liveness properties.

A strong need for new approaches and new curricula in different disciplines in European education... more A strong need for new approaches and new curricula in different disciplines in European education area still exists. It is especially the case in the field of software engineering which has traditionally been underdeveloped in some areas. The curriculum presented in this paper is oriented towards undergraduate students of informatics and engineering. The proposed approach takes into account integration trends in European educational area and requirements of the labour market.

Abstract Web services are essentially black box components from a composer's or a mediator's pers... more Abstract Web services are essentially black box components from a composer's or a mediator's perspective. The behavioural description of any service can be asserted by the composer only through interface predicates exposed by the service provider Normally for proving properties of service compositions, pre/post conditions are found to be sufficient. However these properties are assertions only on the initial and final states of the service respectively.

Abstract Policies are increasingly used to govern the behaviour of complex distributed systems. M... more Abstract Policies are increasingly used to govern the behaviour of complex distributed systems. Most policy models that allow policy composition, to address the complexity of policies, are only concerned with structural composition. In this paper we argue that it is natural to compose policies also along the temporal axis, ie express policies that can dynamically change over time or on the occurrence of events.

Abstract Issues for designing adaptable hard real-time scheduler are discussed. A general approac... more Abstract Issues for designing adaptable hard real-time scheduler are discussed. A general approach that utilises milestones is given and illustrated using the Least Laxity Algorithm. The hard real-time tasks are guaranteed by means of an" alert" that is generated using the information provided by the milestones.

Abstract Technological development has become so manifest in all fields that it is now highly cru... more Abstract Technological development has become so manifest in all fields that it is now highly crucial to take it into consideration whenever possible. Such development has resulted in the tremendous amount of information that exists nowadays. Therefore, Service Oriented Architecture (SOA) has become an active area of research and development.

Process modelling is a vital issue for communicating with experts of the application domain. Depe... more Process modelling is a vital issue for communicating with experts of the application domain. Depending on the roles and responsibilities of the application domain experts involved, process models are discussed on different levels of abstraction. These may range from detailed regulation for process execution to the interrelation of basic core processes on a strategic level.

Abstract Policies provide a flexible and scalable approach to the management of distributed syste... more Abstract Policies provide a flexible and scalable approach to the management of distributed systems by separating the specification of security requirements and their enforcement Over the years the expressiveness of policy languages increased considerably making it possible to capture a variety of complex requirements that for example depend on the history of the system execution.

Abstract An agent-oriented middleware supporting context-aware mobile eLearning services provisio... more Abstract An agent-oriented middleware supporting context-aware mobile eLearning services provision is presented. The middleware architecture developed for a distributed InfoStation-based network established within a University campus is described in detail. A concept for the control and management of service sessions and communications scenarios is also presented.

The aim of this paper is to provide a unified mathematical framework for program slicing which pl... more The aim of this paper is to provide a unified mathematical framework for program slicing which places all slicing work, for sequential programs, on a sound theoretical foundation. The main advantage to a mathematical approach is that it is not tied to a particular representation. In fact the mathematics provides a sound basis for any particular representation. We use the WSL (Wide Spectrum Language) program transformation theory as our framework.

Abstract A development method for the construction of provably correct robot control systems toge... more Abstract A development method for the construction of provably correct robot control systems together with its supporting tool environment are described. The method consists of four stages and is centered around the notion of widespectrum formalism within which an abstract (logical) representation is intermixed freely with the concrete representation of the system under consideration. We begin with a formal abstract specification expressed in Interval Temporal Logic (ITL).

Abstract Developing a joint curriculum across different institutions is a unique and novel initia... more Abstract Developing a joint curriculum across different institutions is a unique and novel initiative to harmonize university education in Europe, sharing the efforts of curriculum development (hence reducing their cost), and to improve the quality of education. Our ongoing project covers seven partner institutions from five countries–four in the role of beneficiary partners and three have an advisory role.

Abstract Current ontological specifications for semantically describing properties of Web service... more Abstract Current ontological specifications for semantically describing properties of Web services are limited to their static interface description. Normally for proving properties of service compositions, mapping input/output parameters and specifying the pre/post conditions are found to be sufficient. However these properties are assertions only on the initial and final states of the service respectively. They do not help in specifying/verifying ongoing behaviour of an individual service or a composed system.

Abstract Grids are increasingly being used in applications, one of which is e-learning. As most o... more Abstract Grids are increasingly being used in applications, one of which is e-learning. As most of academic and business institutions and training centres around the world have adopted this technology in order to create, deliver and manage their learning materials through the Web, the subject has become the focus of investigate. Still, collaboration between these institutions and centres is limited. Existing technologies such as grid, Web services and agents are promising better results.

Abstract. The potential for multi-agent systems within military defence environments is already w... more Abstract. The potential for multi-agent systems within military defence environments is already well established within recent research projects. Such systems are being developed for the purposes of Command and Control, Data Fusion, Data Mining and many others. Two areas for which development is still needed is the applicability of mobile agents and a security framework to protect agents, data and hosts.

Abstract A Service oriented system emerges from composition of services. Dynamically composed rea... more Abstract A Service oriented system emerges from composition of services. Dynamically composed reactive Web services form a special class of service oriented system, where the delays associated with communication, unreliability and unavailability of services, and competition for resources from multiple service requesters are dominant concerns. As complexity of services increase, an abstract design language for the specification of services and interaction between them is desired.

Abstract Using the Internet to enhance e-learning has become a trend in modern higher education i... more Abstract Using the Internet to enhance e-learning has become a trend in modern higher education institutes. E-learning systems are increasingly becoming an important part of the strategy for delivering online and flexible e-learning. The main advantage of e-learning is the opportunity for students to interact electronically with each other and their teachers during forums, on discussion boards, by e-mail and in chat rooms.

ABSTRACT Wireless Mobile Ad hoc NETwork (WMANET) is a group of an independent wireless (Mobile/Se... more ABSTRACT Wireless Mobile Ad hoc NETwork (WMANET) is a group of an independent wireless (Mobile/Semi Mobile) nodes communicating on a peer-to-peer basis with no pre-established infrastructure. The unique characteristics of WMANET make such networks highly vulnerable to security attacks when compared with wired networks or infrastructure-based wireless networks.

Abstract Based on practical tool development and assessment, criteria are proposed for the assess... more Abstract Based on practical tool development and assessment, criteria are proposed for the assessment of software reengineering tools, covering both the tool features and methodology foundation. Keywords: software maintenance, re-engineering methodology, software tool, software assessment, assessment criteria.

Abstract This paper advocates that extracting formal specification semantically consistent to the... more Abstract This paper advocates that extracting formal specification semantically consistent to the original legacy system will facilitate further redesign and forward engineering greatly. The three parts of reengineering could be integrated on the basis of a wide spectrum language. The key approach to comprehension and the production of formal specification is a notion of abstraction. Transformation can help to change the original source code into alternative forms, but with the same semantics.

In this paper, Interval Temporal Logic (ITL) us used to specify and verify the event processor EP... more In this paper, Interval Temporal Logic (ITL) us used to specify and verify the event processor EP/3, which is a multi-threaded pipeline processor capable of executing parallel programs. We first give the high level specification of the EP/3 with emphasis on the interlock mechanism. The interlock mechanism is used in processor design especially for dealing with pipeline conflict problems. We prove that the specification satisfies certain safety and liveness properties.

A strong need for new approaches and new curricula in different disciplines in European education... more A strong need for new approaches and new curricula in different disciplines in European education area still exists. It is especially the case in the field of software engineering which has traditionally been underdeveloped in some areas. The curriculum presented in this paper is oriented towards undergraduate students of informatics and engineering. The proposed approach takes into account integration trends in European educational area and requirements of the labour market.

Abstract Web services are essentially black box components from a composer's or a mediator's pers... more Abstract Web services are essentially black box components from a composer's or a mediator's perspective. The behavioural description of any service can be asserted by the composer only through interface predicates exposed by the service provider Normally for proving properties of service compositions, pre/post conditions are found to be sufficient. However these properties are assertions only on the initial and final states of the service respectively.

Abstract Policies are increasingly used to govern the behaviour of complex distributed systems. M... more Abstract Policies are increasingly used to govern the behaviour of complex distributed systems. Most policy models that allow policy composition, to address the complexity of policies, are only concerned with structural composition. In this paper we argue that it is natural to compose policies also along the temporal axis, ie express policies that can dynamically change over time or on the occurrence of events.

Abstract Issues for designing adaptable hard real-time scheduler are discussed. A general approac... more Abstract Issues for designing adaptable hard real-time scheduler are discussed. A general approach that utilises milestones is given and illustrated using the Least Laxity Algorithm. The hard real-time tasks are guaranteed by means of an" alert" that is generated using the information provided by the milestones.

Abstract Technological development has become so manifest in all fields that it is now highly cru... more Abstract Technological development has become so manifest in all fields that it is now highly crucial to take it into consideration whenever possible. Such development has resulted in the tremendous amount of information that exists nowadays. Therefore, Service Oriented Architecture (SOA) has become an active area of research and development.

Process modelling is a vital issue for communicating with experts of the application domain. Depe... more Process modelling is a vital issue for communicating with experts of the application domain. Depending on the roles and responsibilities of the application domain experts involved, process models are discussed on different levels of abstraction. These may range from detailed regulation for process execution to the interrelation of basic core processes on a strategic level.

Abstract Policies provide a flexible and scalable approach to the management of distributed syste... more Abstract Policies provide a flexible and scalable approach to the management of distributed systems by separating the specification of security requirements and their enforcement Over the years the expressiveness of policy languages increased considerably making it possible to capture a variety of complex requirements that for example depend on the history of the system execution.

Abstract An agent-oriented middleware supporting context-aware mobile eLearning services provisio... more Abstract An agent-oriented middleware supporting context-aware mobile eLearning services provision is presented. The middleware architecture developed for a distributed InfoStation-based network established within a University campus is described in detail. A concept for the control and management of service sessions and communications scenarios is also presented.

The aim of this paper is to provide a unified mathematical framework for program slicing which pl... more The aim of this paper is to provide a unified mathematical framework for program slicing which places all slicing work, for sequential programs, on a sound theoretical foundation. The main advantage to a mathematical approach is that it is not tied to a particular representation. In fact the mathematics provides a sound basis for any particular representation. We use the WSL (Wide Spectrum Language) program transformation theory as our framework.

Abstract A development method for the construction of provably correct robot control systems toge... more Abstract A development method for the construction of provably correct robot control systems together with its supporting tool environment are described. The method consists of four stages and is centered around the notion of widespectrum formalism within which an abstract (logical) representation is intermixed freely with the concrete representation of the system under consideration. We begin with a formal abstract specification expressed in Interval Temporal Logic (ITL).

Abstract Developing a joint curriculum across different institutions is a unique and novel initia... more Abstract Developing a joint curriculum across different institutions is a unique and novel initiative to harmonize university education in Europe, sharing the efforts of curriculum development (hence reducing their cost), and to improve the quality of education. Our ongoing project covers seven partner institutions from five countries–four in the role of beneficiary partners and three have an advisory role.

Abstract Current ontological specifications for semantically describing properties of Web service... more Abstract Current ontological specifications for semantically describing properties of Web services are limited to their static interface description. Normally for proving properties of service compositions, mapping input/output parameters and specifying the pre/post conditions are found to be sufficient. However these properties are assertions only on the initial and final states of the service respectively. They do not help in specifying/verifying ongoing behaviour of an individual service or a composed system.

Abstract Grids are increasingly being used in applications, one of which is e-learning. As most o... more Abstract Grids are increasingly being used in applications, one of which is e-learning. As most of academic and business institutions and training centres around the world have adopted this technology in order to create, deliver and manage their learning materials through the Web, the subject has become the focus of investigate. Still, collaboration between these institutions and centres is limited. Existing technologies such as grid, Web services and agents are promising better results.

Abstract. The potential for multi-agent systems within military defence environments is already w... more Abstract. The potential for multi-agent systems within military defence environments is already well established within recent research projects. Such systems are being developed for the purposes of Command and Control, Data Fusion, Data Mining and many others. Two areas for which development is still needed is the applicability of mobile agents and a security framework to protect agents, data and hosts.