• Web browser artefacts in private and portable modes: a forensic investigation

      Flowers, Cassandra; Mansour, Ali; al-Khateeb, Haider; Babraham Research Campus; University of Bedfordshire (Inderscience, 2016-04)
      Web browsers are essential tools for accessing the internet. Extra complexities are added to forensic investigations when recovering browsing artefacts as portable and private browsing are now common and available in popular web browsers. Browsers claim that whilst operating in private mode, no data is stored on the system. This paper investigates whether the claims of web browsers discretion are true by analysing the remnants of browsing left by the latest versions of Internet Explorer, Chrome, Firefox, and Opera when used in a private browsing session, as a portable browser, and when the former is running in private mode. Some of our key findings show how forensic analysis of the file system recovers evidence from IE while running in private mode whereas other browsers seem to maintain better user privacy. We analyse volatile memory and demonstrate how physical memory by means of dump files, hibernate and page files are the key areas where evidence from all browsers will still be recoverable despite their mode or location they run from.
    • Anonymity networks and the fragile cyber ecosystem

      Haughey, Hamish; Epiphaniou, Gregory; al-Khateeb, Haider; University of Northumbria; University of Bedfordshire (Elsevier, 2016-03)
      It is well known that government agencies have had the capability to eavesdrop on public switched telephone networks for many decades.1 However, with the growing use of the Internet and the increasing technical capabilities of agencies to conduct mass surveillance, an individual's right to privacy is of far greater concern in recent years. The ethical issues surrounding privacy, anonymity and mass-surveillance are complicated, with compelling arguments for and against, due in part to the fact that privacy and anonymity are desired by criminals and terrorists, not just individuals who care about their privacy.
    • How technology can mitigate and counteract cyber-stalking and online grooming

      al-Khateeb, Haider; Epiphaniou, Gregory; National Centre for Cyberstalking Research (Elsevier, 2016-01)
      With the virtual world becoming part of the social lives of adults and minors alike, new attack vectors emerged to increase the severity of human-related attacks to a level the community have not experience before. This article investigates and shares an outline on how technology could emerge further to counteract and mitigate the damage caused by online perpetrators. The review encourages approaching online harassment, stalking, bullying, grooming and their likes with an Incident Response methodology in mind. This includes a detection phase utilising automated methods to identify and classify such attacks, conduct digital forensic investigations to analyse the nature of the offence and reserve evidence, taking preventive measures as part of the reaction towards the problem such as filtering unwanted communications and finally looking at how we can rely on applicable computing to support and educate the victims.
    • Responsibility and non-repudiation in resource-constrained Internet of Things scenarios

      Oriwoh, Edewede; al-Khateeb, Haider; Conrad, Marc; University of Bedfordshire (International Conference on Computing and Technology Innovation (CTI 2015), 2016)
      The proliferation and popularity of smart autonomous systems necessitates the development of methods and models for ensuring the effective identification of their owners and controllers. The aim of this paper is to critically discuss the responsibility of Things and their impact on human affairs. This starts with an in-depth analysis of IoT Characteristics such as Autonomy, Ubiquity and Pervasiveness. We argue that Things governed by a controller should have an identifiable relationship between the two parties and that authentication and non-repudiation are essential characteristics in all IoT scenarios which require trustworthy communications. However, resources can be a problem, for instance, many Things are designed to perform in low-powered hardware. Hence, we also propose a protocol to demonstrate how we can achieve the authenticity of participating Things in a connectionless and resource-constrained environment.
    • The refocusing distance of a standard plenoptic photograph

      Hahne, Christopher; Aggoun, Amar; Velisavljević, Vladan; University of Bedfordshire (IEEE, 2015-06-12)
      In the past years, the plenoptic camera aroused an increasing interest in the field of computer vision. Its capability of capturing three-dimensional image data is achieved by an array of micro lenses placed in front of a traditional image sensor. The acquired light field data allows for the reconstruction of photographs focused at different depths. Given the plenoptic camera parameters, the metric distance of refocused objects may be retrieved with the aid of geometric ray tracing. Until now there was a lack of experimental results using real image data to prove this conceptual solution. With this paper, the very first experimental work is presented on the basis of a new ray tracing model approach, which considers more accurate micro image centre positions. To evaluate the developed method, the blur metric of objects in a refocused image stack is measured and compared with proposed predictions. The results suggest quite an accurate approximation for distant objects and deviations for objects closer to the camera device.
    • Threshold optimization for energy detection-based spectrum sensing over hyper-Rayleigh fading channels

      Chatziantoniou, Eleftherios; Allen, Ben; Velisavljević, Vladan; University of Bedfordshire (IEEE, 2015-06)
    • A practical guide to coping with cyberstalking

      al-Khateeb, Haider; Alhaboby, Zhraa Azhr; Barnes, Jim; Brown, Antony; Brown, Raymond; Cobley, Phil; Gilbert, Jon; McNamara, Niamh; Short, Emma; Shukla, Mitul; et al. (Andrews UK Limited, 2015, 2015-04-19)
      To create fear, distress and to disrupt the daily activities of another person through cyberstalking is a crime, if you are currently affected by cyberstalking, it is crucial that you alert the police to your situation to keep yourself safe. This practical guide offers an outline of the area of cyberstalking and cyber abuse. Written in an approachable way, it describes the forms of intrusions that have been identified by research and through the accounts of victims. It considers the motivations of cyberstalkers and the enormous impact cyberstalking has on the lives of victims as well as the threats posed. The book provides advice and information about security for people currently experiencing cyberstalking and those who simply wish to take steps to further secure their online presence by taking preventative steps. The personal experience of living with threatening intrusions and recovery from the trauma of cyberstalking is explored.
    • View-popularity-driven joint source and channel coding of view and rate scalable multi-view video

      Chakareski, Jacob; Velisavljević, Vladan; Stankovic, Vladimir; University of Alabama; University of Bedfordshire; Strathclyde University (IEEE, 2015-04)
    • Introduction to the issue on visual signal processing for wireless networks

      Velisavljević, Vladan; Pesquet-Popescu, Beatrice; Vucetic, Branka; Reibman, Amy R.; Yang, Chenyang; University of Bedfordshire; ParisTech Telecom; University of Sydney; Purdue University; Beihang University (IEEE, 2015-02)
    • Performance analysis of energy detection over hyper-Rayleigh fading channels

      Chatziantoniou, Eleftherios; Allen, Ben; Velisavljević, Vladan; University of Bedfordshire (IET, 2015-01-01)
      This study investigates the performance of energy detection (ED)-based spectrum sensing over two-wave with diffused power (TWDP) fading channels, which have been found to provide accurate characterisation for a variety of fading conditions. A closed-form expression for the average detection probability of ED-based spectrum sensing over TWDP fading channels is derived. This expression is then used to describe the behaviour of ED-based spectrum sensing for a variety of channels that include Rayleigh, Rician and hyper-Rayleigh fading models. Such fading scenarios present a reliable behavioural model of machine-to-machine wireless nodes operating in confined structures such as in-vehicular environments.
    • Cluster-based polyrepresentation as science modelling approach for information retrieval

      Abbasi, Muhammad Kamran; Frommholz, Ingo (Springer Verlag, 2015)
      The increasing number of publications make searching and accessing the produced literature a challenging task. A recent development in bibliographic databases is to use advanced information retrieval techniques in combination with bibliographic means like citations. In this work we will present an approach that combines a cognitive information retrieval framework based on the principle of polyrepresentation with document clustering to enable the user to explore a collection more interactively than by just examining a ranked result list. Our approach uses information need representations as well as different document representations including citations. To evaluate our ideas we employ a simulated user strategy utilising a cluster ranking approach. We report on the possible effectiveness of our approach and on several strategies how users can achieve a higher search effectiveness through cluster browsing. Our results confirm that our proposed polyrepresentative cluster browsing strategy can in principle significantly improve the search effectiveness. However, further evaluations including a more refined user simulation are needed.
    • Joint source and channel coding of view and rate scalable multi-view video

      Chakareski, Jacob; Velisavljević, Vladan; Stankovic, Vladimir; University of Alabama; University of Bedfordshire; Strathclyde University (IEEE, 2014-10)
      We study multicast of multi-view content in the video plus depth format to heterogeneous clients. We design a joint source-channel coding scheme based on view and rate embedded source coding and rateless channel coding. It comprises an optimization framework for joint view selection and source-channel rate allocation, and includes a fast method for separate optimization of the source and channel coding components, at a negligible performance loss wrt the joint solution. We demonstrate performance gains over a state-of-the-art method based on H.264/SVC, in the case of two client classes.
    • A secure MAC protocol for Cognitive Radio Networks (SMCRN)

      Alhakami, Wajdi; Mansour, Ali; Safdar, Ghazanfar Ali; Albermany, Salah A.; University of Bedfordshire (IEEE, 2014-10)
      In addition to standard authentication and data confidentiality requirements, Cognitive Radio Networks (CRNs) face distinct security issues such as primary user emulation and spectrum management attacks. A compromise of these will result in a denial of service, eavesdropping, forgery, or replay attack. These attacks must be considered while designing a secure media access control (MAC) protocol for CR networks. This paper presents a novel secure CR MAC protocol: the presented protocol is analysed for these security measures using formal logic methods such as Burrows-Abadi-Needham (BAN) logic. It is shown that the proposed protocol functions effectively to provide strong authentication and detection against malicious users leading to subsequent secure communication.
    • Dynamic adjustment of weighting and safety factors in playout buffers for enhancing VoIP quality

      Syed, Tazeen Shabana; Epiphaniou, Gregory; Safdar, Ghazanfar Ali; University of Bedfordshire (IEEE, 2014-10)
      The quality of Voice over Internet Protocol (VoIP) calls is highly influenced by transmission impairments such as delay, packet loss and jitter, with jitter being manifested as one of the deleterious effects affecting its quality. A jitter buffer is usually employed at the receiver side to mitigate its effects by adapting its parameters in a trade-off between delay and packet loss. This paper proposes a novel de-jitter algorithm that adaptively changes the size of the playout buffer depending on the network states, in order to effectively handle the packet loss and delay, whereas E-model is used to quantify speech quality. Based on the statistics of the received packets, the adaptive playout buffer algorithm dynamically adjusts the weighting factor (α) and the safety factor (β) for regulating the delay and trade-off loss, thus maximizing the quality for VoIP.
    • Objects, worlds, and students: virtual interaction in education

      Christopoulos, Athanasios; Conrad, Marc; Shukla, Mitul; University of Bedfordshire (Education Research International, 2014-09-22)
      The main aim of this study is to form a complete taxonomy of the types of interactions that relate to the use of a virtual world for engaging learning experiences, when blended and hybrid learning methods are to be used. In order to investigate this topic more accurately and effectively, we distinguish four dimensions of interactions based on the context in which these occur, and the involved parts: in-world and in-class, user-to-user and user-to-world interactions. In order to conduct investigation into this topic and form a view of the interactions as clear as possible, we observed a cohort of 15 undergraduate Computer Science students while using an OpenSim-based institutionally hosted virtual world. Moreover, we ran a survey where 50 students were asked to indicate their opinion and feelings about their in-world experience. The results of our study highlight that educators and instructors need to plan their in-world learning activities very carefully and with a focus on interactions if engaging activities are what they want to offer their students. Additionally, it seems that student interactions with the content of the virtual world and the in-class student-to-student interactions, have stronger impact on students’ engagement when hybrid methods are used.
    • Experimental circular phased array for generating OAM radio beams

      Bai, Qiang; Tennant, Alan; Allen, Ben; University of Bedfordshire; University of Sheffield (IEEE, 2014-09)
      A circular phased array antenna that can generate orbital angular momentum (OAM) radio beams in the 10 GHz band is described. The antenna consists of eight inset-fed patch elements and a microstrip corporate feeding network. A full-wave electromagnetic simulator is used to aid the antenna design and theoretical simulations are confirmed by measurements
    • An empirical polarisation domain channel availability model for cognitive radio

      Chatziantoniou, Eleftherios; Allen, Ben; Velisavljević, Vladan; University of Bedfordshire (IEEE, 2014-09)
      In dynamic spectrum access networks, cognitive radio terminals monitor their spectral environment in order to detect and opportunistically access unoccupied frequency channels. The overall performance of such networks depends on the spectrum occupancy or availability patterns. Accurate knowledge on the channel availability enables optimum performance of such networks in terms of spectrum and energy efficiency. This work proposes a novel probabilistic channel availability model that can describe the channel availability in different polarizations for mobile cognitive radio terminals that are likely to change their orientation during their operation. A Gaussian approximation is used to model the empirical occupancy data that was obtained through a measurement campaign in the cellular frequency bands within a realistic operational scenario.
    • Dynamic user equipment-based hysteresis-adjusting algorithm in LTE femtocell networks

      Xiao, Zhu; Zhang, Xu; Maple, Carsten; Allen, Ben; Liu, Enjie; Mahato, Shyam Babu; University of Bedfordshire; Southeast University, Nanjing; Hunan University, Chang sha; University of Warwick (IEEE, 2014-09)
      In long-term evolution (LTE) femtocell networks, hysteresis is one of the main parameters which affects the performance of handover with a number of unnecessary handovers, including ping-pong, early, late and incorrect handovers. In this study, the authors propose a hybrid algorithm that aims to obtain the optimised unique hysteresis for an individual mobile user moving at various speeds during the inbound handover process. This algorithm is proposed for two-tier scenarios with macro and femto. The centralised function in this study evaluates the overall handover performance indicator. Then, the handover aggregate performance indicator (HAPI) is used to determine an optimal configuration. Based on the received reference signal-to-interference-plus-noise ratio, the distributed function residing on the user equipment (UE) is able to obtain an optimal unique hysteresis for the individual UE. Theoretical analysis with three indication boundaries is provided to evaluate the proposed algorithm. A system-level simulation is presented, and the proposed algorithm outperformed the existing approaches in terms of handover failure, call-drop and redundancy handover ratios and also achieved better overall system performance.
    • Protein data modelling for concurrent sequential patterns

      Lu, Jing; Keech, Malcolm; Wang, Cuiqing; University of Bedfordshire (DEXA, 2014-09)
      Protein sequences from the same family typically share common patterns which imply their structural function and biological relationship. The challenge of identifying protein motifs is often addressed through mining frequent itemsets and sequential patterns, where post-processing is a useful technique. Earlier work has shown that Concurrent Sequential Patterns mining can be applied in bioinformatics, e.g. to detect frequently occurring concurrent protein sub-sequences. This paper presents a companion approach to data modelling and visualisation, applying it to real-world protein datasets from the PROSITE and NCBI databases. The results show the potential for graph-based modelling in representing the integration of higher level patterns common to all or nearly all of the protein sequences.
    • K-order surrounding roadmaps path planner for robot path planning

      Li, Yueqiao; Li, Dayou; Maple, Carsten; Yue, Yong; Oyekan, John O. (Springer, 2014-09)
      Probabilistic roadmaps are commonly used in robot path planning. Most sampling-based path planners often produce poor-quality roadmaps as they focus on improving the speed of constructing roadmaps without paying much attention to the quality. Poor-quality roadmaps can cause problems such as poor-quality paths, time-consuming path searching and failures in the searching. This paper presents a K-order surrounding roadmap (KSR) path planner which constructs a roadmap in an incremental manner. The planner creates a tree while answering a query, selects the part of the tree according to quality measures and adds the part to an existing roadmap which is obtained in the same way when answering the previous queries. The KSR path planner is able to construct high-quality roadmaps in terms of good coverage, high connectivity, provision of alternative paths and small size. Comparison between the KSR path planner and Reconfigurable Random Forest (RRF), an existing incremental path planner, as well as traditional probabilistic roadmap (PRM) path planner shows that the roadmaps constructed using the KSR path planner have higher quality that those that are built by the other planners.