Browsing by Author "Siewe, Francois"
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Item Metadata only 2PROM: A two-phase image retrieval optimization on dataspace using predictive modeling(IEEE, 2012) Fanzou Tchuissang, G. N.; Wang, N.; Kuicheu, N. C.; Siewe, Francois; Xu, D.Item Metadata only Access control mechanism for mobile ad hoc network of networks.(IEEE Computer Society, 2010-03) Al-Bayatti, Ali Hilal; Zedan, Hussein; Siewe, FrancoisItem Open Access An Adaptive Learning Ontological Framework Based on Learning Styles and Teaching Strategies(International Conference on Education and E-learning, 2017-09) Nafea, Shaimaa; Siewe, Francois; He, YingOntology are increasingly being used in a variety of applications, and particularly in adaptive e-learning. They have the potential to enable developers to create adaptive course content for specified domains. E-learning applications are thus able to use technology and educational content in order to generate content that matches the student's capabilities and knowledge. This personalises learning, rather than assuming that "one-size-fits-all" and providing all learners with the same content, which is what the majority of e-learning systems do. This study introduces a new approach that takes into account the fact that each learner has an individual learning style and needs. The approach enables to adapt the course content, teaching strategy and learning objects so that they correspond to each student’s learning styles. This is achieved with the use of artificial intelligent in the form of an ontology and rule-based reasoning. The proposed system takes some of the key design aspects such as extensibility, reusability, and maintainability into consideration in order to enhance performance of adaptive course content recommendation.Item Metadata only Advances in CAD simulation of textile yarns(Research Journal of Textile and Apparel, 2011-02-02) Grishanov, S. A.; Siewe, Francois; Cassidy, T.A project aimed at the 3D simulation of textile yarns from technical specifications was begun in 1993 and attracted support from both industry and research councils to enable the formation of a multi-national team of researchers to come together in the UK. Considerable progress has been made particularly in the simulation of knitting yarn and plain knit fabric. In recent times the team has tackled the problem of simulating mixture coloured yarns sometimes called melange. This has necessitated a more complicated model of yarn structure based on queuing theory which is outlined at the end of the paper. References are provided for readers who wish to learn more of the various theories and models that have been used throughout the course of this project.Item Open Access Agent-based Negotiation Approach for Feature Interactions in Smart Home Systems using Calculus of the Context-aware Ambient(Wiley, 2019-12-02) Alfakeeh, Ahmed S.; Al-Bayatti, Ali Hilal; Siewe, Francois; Baker, TharSmart Home Systems (SHSs) provide several services which are tailored to different residents’ preferences. As a result, SHSs are highly exposed to undesirable interactions, known as feature interactions (FIs). FIs might occur as a result of a conflict in services’ goals or a conflict with residents’ preferences. Previous studies have proposed solutions based on applying priorities, in which some services or preferable features are disabled in favour of other services. Alternatively, the agent-based negotiation approach (ABNA) utilises agents and applies negotiation, enabling services with contrary features to work simultaneously. ABNA avoids applying priority between services or house residents’ preferences whenever a space for a compromise exists. The mechanism of ABNA is based on the use of a hierarchy of features based on their contribution to the function of the service or on the importance of these features to house residents. To achieve a compromise between conflicting services, ABNA models services and residents by using agents, and implements a negotiation algorithm that allows services with conflicting features to work simultaneously. This paper presents a description of ABNA with a formal specification of ABNA in the Calculus of Context-aware Ambient (CCA). This enables the formal analysis of ABNA by using the execution environment of CCA.Item Open Access Analysing Petri Nets in a Calculus of Context-aware Ambients(IEEE, 2020-07-13) Siewe, Francois; Germanos, Vasileios; Zeng, W.This paper proposes an approach to analysing and verifying Petri nets using a Calculus of Context-aware Ambients (CCA). We propose an algorithm that transforms a Petri net into a CCA process. This demonstrates that any system that can be specified in Petri nets can also be specified in CCA. Besides, the system can be analysed and verified using the CCA verification tools. We illustrate the practicality of our approach using a case study of the dining cryptographers problem.Item Open Access Analysing Use Case Diagrams in a Calculus of Context-aware Ambients(Infonomics Society, 2016-03) Siewe, Francois; Al-alshuhai, Ahmed; Almutairi, Saad; Almutairi, AbdulgaderUse case diagrams are an excellent tool for capturing and analyzing the functional requirements of a system under development. Context-aware use case diagrams are an extension of use case diagrams to cater for both the functional requirements and the context-awareness requirements of context-aware and pervasive systems. They provide (graphical) notations for specifying, visualizing and documenting the intended behavior of a context-aware system at an early stage of the system development life-cycle. This paper proposes an approach to analyzing context-aware use case diagrams usind a Calculus of Context-aware Ambients (CCA). An algorithm is proposed that translates a context-aware use case diagram into a CCA process. This process can then be analyzed using the CCA tools such as the simulator ccaPL which enables the execution of CCA processes and the model-checker ccaSPIN that can check automatically whether a CCA process satisfies a desired property, e.g. deadlock freedom and reachability. The proposed approach is evaluated using a real-word example of a context-aware pedestrian collision avoidance system.Item Metadata only Analysis and run-time verification of dynamic security policies.(Springer, 2006) Janicke, Helge; Siewe, Francois; Jones, Kevin; Cau, A. (Antonio); Zedan, HusseinItem Metadata only An application of queuing theory to modelling of melange yarns. Part I: A queuing model of melange yarn structure.(SAGE, 2009-11-01) Siewe, Francois; Grishanov, S. A.; Cassidy, T.; Banyard, GeoffreyA queuing model of staple fiber yarn is presented that enables the modeling and a better understanding of fiber migration in a yarn. The model provides a fine yarn structure where the migrational behavior of fibers is associated with the behavior of customers traveling across an open network of queuing systems to get services. Based on this analogy, the underlying mathematical foundation of the queuing theory is used for the modeling of yarn structure and properties. The model uses yarn technical specifications including yarn linear density and twist level, fiber linear density and length distribution, together with specific parameters such as fiber packing density distribution and migration probabilities. The model can be used for modeling a wide range of structurally different yarns; examples include marl, mottle and melange yarns, yarns with different levels of hairiness, and yarns produced by various spinning systems. The model can be used for 3D simulation of yarns in computer-aided design systems for textile design and for the prediction of mechanical properties of yarns.Item Metadata only An application of queuing theory to modelling of melange yarns. Part II: A method of estimating the fibre migration probabilities and a yarn structure simulation algorithm.(Sage, 2011-01) Grishanov, Sergei; Siewe, Francois; Cassidy, T.A queuing model of staple yarn structure was presented in Part I of this work, where the migration behaviours of fibres were simulated by the movement of customers in a Markovian network of queuing systems. Part II of the series proposes (i) a multi-dimensional minimization method for estimating the migration probabilities of fibres based on the analysis of the distribution of number of fibres in yarn cross-sections; (ii) a yarn structure simulation algorithm which uses the migration probabilities of fibres, yarn technical specifications (e.g. linear density and twist) and colour composition to produce a realistic three-dimensional image of a melange yarn. The result is a high quality three-dimensional image of a melange yarn showing its fibrous structure as well as the formation of hairiness. Due to the generic nature of the model and the simulation algorithm, this approach can be applied to a wide range of yarns including ring-spun or open-end spun yarns of solid shade or produced from melange blends. Further improvements to the proposed model are discussed including the application of inhomogeneous Poisson process and the analysis of energy relationships which govern the migration behaviour of fibres.Item Metadata only Architecture of EHARP routing protocols in ad hoc wireless networks.(IEEE, 2009) Al Otaibi, Saud; Siewe, FrancoisItem Metadata only Architecture of stability routing protocols in ad hoc wireless networks.(IEEE, 2009) Al Otaibi, Saud; Siewe, FrancoisItem Open Access Building CPU stubs to optimize CPU bound systems: An application of dynamic performance stubs.(2011) Trapp, Peter; Meyer, Markus; Facchi, Christian; Janicke, Helge; Siewe, FrancoisDynamic performance stubs provide a framework for the simulation of the performance behavior of software modules and functions. Hence, they can be used as an exten- sion to software performance engineering methodologies. The methodology of dynamic performance stubs can be used for a gain oriented performance improvement. It is also possible to identify “hidden” bottlenecks and to prioritize optimization possibilities. Nowadays, the processing power of CPUs is mainly increased by adding more cores to the architecture. To have benefits from this, new software is mostly designed for parallel processing, especially, in large software projects. As software performance optimizations can be difficult in these environments, new methodologies have to be defined. This paper evaluates a possibility to simulate the functional behavior of software algorithms by the use of the simulated software functionality. These can be used by the dynamic performance stub framework, e.g., to build a CPU stub, to replace the algorithm. Thus, it describes a methodology as well as an implementation and evaluates both in an industrial case study. Moreover, it presents an extension to the CPU stubs by applying these stubs to simulate multi-threaded applications. The extension is evaluated by a case study as well. We show show that the functionality of software algorithms can be replaced by software simulation functions. This stubbing approach can be used to create dynamic performance stubs, such as CPU stubs. Additionally, we show that the concept of CPU stubs can be applied to multi-threaded applications.Item Metadata only Building semantic relationships incrementally in dataspace.(IEEE, 2009) Kuicheu, Nathalie Cindy; Wang, N.; Fanzou, N. T. G.; Xu, De; Siewe, FrancoisRecently, the notion of Dataspace has been introduced as a virtual space where many data sources are managed regardless of their structures and locations; this, with the aim to return best efforts answers to user's queries. In fact, a dataspace is a set of participants which are data sources connected to the dataspace and a set of relationships between those participants. A data source, a participant, could be a file, a relational database, XML repository, web pages and so on. However, no formal definitions about relationships which could be built among the data sources have been proposed. Therefore, one of the challenges occurring in this new abstraction of data management is to incrementally build meaningful relationships between sources. In this paper, we introduce SEM-HDM, a SEMantics-based Heterogeneous Data Management which aims at constructing semantic relationships between heterogeneous sources of data based on a defined syntax and semantics. In fact, SEM-HDM first constructs a Semantic dictionary and then a reasoning dictionary which is improved incrementally by analyzing user's activities on a given dataspace. We show on an example of three heterogeneous sources of data how SEM-HDM builds his semantic and reasoning dictionary.Item Open Access CA-UCON: A Context-Aware Usage Control Model(Proceedings of CASEMANS 2011, ACM Press, 2011-09-21) Al-Mutairi, A.; Siewe, FrancoisUsage CONtrol (UCON) model is the latest major enhance- ment of the traditional access control models which enables mutability of subject and object attributes, and continuity of control on usage of resources. In UCON, access permission decision is based on three factors: authorisations, obliga- tions and conditions. While authorisations and obligations are requirements that must be ful lled by the subject and the object, conditions are subject and object independent requirements that must be satis ed by the environment. As a consequence, access permission may be revoked (and the access stopped) as a result of changes in the environment regardless of whether the authorisations and obligations re- quirements are met. This constitutes a major shortcoming of the UCON model in pervasive computing systems which constantly strive to adapt to environmental changes so as to minimise disruptions to the user. To overcome this limita- tion, this paper proposes a Context-Aware Usage CONtrol (CA-UCON) model which extends the traditional UCON model to enable adaptation to environmental changes in the aim of preserving continuity of access. When the authori- sations and obligations requirements are met by the subject and the object, and the conditions requirements fail due to changes in the environment or the system context, CA- UCON model triggers speci c actions to adapt to the new situation. Besides the data protection, CA-UCON model so enhances the quality of services, striving to keep explicit interactions with the user at a minimum.Item Metadata only CA-UCON: A context-aware usage control model.(ACM, 2011) Almutairi, Abdulgader; Siewe, FrancoisItem Metadata only The Calculus of context-aware ambients.(Elsevier, 2010-02-25) Siewe, Francois; Zedan, Hussein; Cau, A. (Antonio)We present the Calculus of Context-aware Ambients (CCA in short) for the modelling and verification of mobile systems that are context-aware. This process calculus is built upon the calculus of mobile ambients and introduces new constructs to enable ambients and processes to be aware of the environment in which they are being executed. This results in a powerful calculus where both mobility and context-awareness are first-class citizens. We present the syntax and a formal semantics of the calculus. We propose a new theory of equivalence of processes which allows the identification of systems that have the same context-aware behaviours. We prove that CCA encodes the π-calculus which is known to be a universal model of computation. Finally, we illustrate the pragmatics of the calculus through many examples and a real-world case study of a context-aware hospital bed.Item Open Access A case study of image retrieval on lung cancer chest x-ray pictures.(IEEE, 2008) Gile Narcisse Fanzou, T.; Ning, W.; Cindy, N.; Siewe, Francois; Xudong, L.; De, X.This paper presents a case study of an image retrieval system based on a notion of similarity between images in a multimedia database and where a user request can be an image file or a keyword. The CBIR (Content Based Image Retrieval) system, the current System of Search for Information (SSI) --e.g. PEIR, MIRC, MIR, IRMA, and Pathopic-- and the Current Search Engines (CSE) --e.g. Google, Yahoo and Alta Vista-- make image search possible only when the query is a keyword. This type of search is limited because keywords are not expressive enough to describe all important characteristics of an image. For example, an exact match request cannot be formulated in such systems and in SSI system, users should know natural language (e.g. English, French or German) used. We used XIRS (an XML Image Retrieval System) to set up a similarity distance between images, then to compare the request image with those in a database. An experimentation of XIRS on lung cancer diagnosis is presented. The statistics show that our system is more efficient than leading CBIR systems such as ERIC7, PEIR, PathoPic and CSE.Item Open Access CCA: a calculus of context-aware ambients.(IEEE, 2009) Siewe, Francois; Cau, A. (Antonio); Zedan, HusseinWe present a process calculus, CCA, for the modelling and verification of mobile systems that are context-aware. This process calculus is built upon the calculus of mobile ambients and introduces new constructs to enable ambients and processes to be aware of the environment in which they are being executed. This results in a powerful calculus where mobility and context-awareness are first-class citizens. We present the syntax and a formal semantics of the calculus. We show that CCA can encode the -calculus, and illustrate the pragmatics of the calculus through a case study of a context-aware hospital bed.Item Open Access A Comparison Study between RCCAR and Conventional Prediction Techniques for Resolving Context Conflicts in Pervasive Context-Aware Systems(International Arab Conference on Information Technology (ACIT'2016), 2016-10) Al-Shargabi, Asma Abdulghani Qassem; Siewe, Francois; Zahary, Ammar ThabitIn Pervasive computing environment, context-aware systems face many challenges to keep high quality performance. One-challenge faces context-aware systems is conflicted values come from different sensors because of different reasons. These conflicts affect the quality of context and as a result the quality of service as a whole. This paper is extension to our previous work, which is published in [15]. In our previous work, we presented an approach for resolving context conflicts in context-aware systems. This approach is could RCCAR (Resolving Context Conflicts Using Association Rules). RCCAR is implemented and verified well in [15], this paper conducts further experiments to explore the performance of RCCAR in comparison with the traditional prediction methods. The basic prediction methods that have been tested include simple moving average, weighted moving average, single exponential smoothing, double exponential smoothing, and ARMA. Experiments is conducted using Weka 3.7.7 and Excel; the results show better achievements for RCCAR against the conventional prediction methods. More researches are recommended to eliminate the cost of RCCAR.