• A band-suppression UWB suspended planar antenna incorporating a slotted spiral resonator

      See, Chan H.; Abd-Alhameed, Raed A.; Hraga, Hmeda I.; Excell, Peter S.; Jones, Steven M.R.; Noras, James M. (2013-09)
      A novel miniaturized planar inverted F-L antenna assembly is considered for UWB radio operations. The antenna design utilizes the electromagnetic coupling between an air dielectric planar inverted-F antenna (PIFA) and a parasitic planar inverted-L (PIL) element, with broadband feeding from a rectangular plate. To improve the functionality of the channel, a simple notch filter has been introduced through a local modification to the broadband feed plate, this takes the form of a simple slotted rectangular spiral resonator which is etched directly onto the plate. This allows the proposed antenna to maintain its full band UWB coverage, with the HYPERLAN/2 band centered at 5.35 GHz to be effectively rejected over the sub-band 5.15–5.725 GHz, without the need for substantial re-optimization of its principal structure parameters. The impedance bandwidth operates over the full UWB band, with VSWR better than 2, this performance is not degraded by the presence of the band rejection. The observed gains, radiation patterns, and group delay confirm that the antenna has appropriate characteristics for short range wireless applications.
    • A case study of financialization and EVA®

      Gleadle, P.; Cornelius, Nelarine (2008)
      This study contributes to the literature on shareholder value and financialization, which to date has produced few case studies at the individual firm level. We provide a grounded account of management control under financialization, focusing on the apparently dramatic turnaround in performance of one factory, located in the northeast of England (Midco). However, in contrast to some of the more prescriptive accounts of shareholder value implementation, we resist overly simplistic explanations that the turnaround was 'due to' EVA. Instead, we suggest that both the factory's prior experience of change, particularly TQM, plus the presence of economic insecurity facilitated the turnaround. We compare our findings with other relevant studies and suggest that EVA and financialized solutions do not constitute a panacea for struggling organizations. Specifically, a strategy prioritizing new product development may be incompatible with the type of practices introduced by Midco.
    • A comparative study of the effect of spray drying and hot-melt extrusion on the properties of amorphous solid dispersions containing felodipine

      Mahmah, O.; Tabbakh, R.; Kelly, Adrian L.; Paradkar, Anant R. (2014)
      OBJECTIVES: To compare the properties of solid dispersions of felodipine for oral bioavailability enhancement using two different polymers, polyvinylpyrrolidone (PVP) and hydroxypropyl methylcellulose acetate succinate (HPMCAS), by hot-melt extrusion (HME) and spray drying. METHODS: Felodipine solid dispersions were prepared by HME and spray drying techniques. PVP and HPMCAS were used as polymer matrices at different drug : polymer ratios (1 : 1, 1 : 2 and 1 : 3). Detailed characterization was performed using differential scanning calorimetry, powder X-ray diffractometry, scanning electron microscopy and in-vitro dissolution testing. Dissolution profiles were evaluated in the presence of sodium dodecyl sulphate. Stability of different solid dispersions was studied under accelerated conditions (40 degrees C/75% RH) over 8 weeks. KEY FINDINGS: Spray-dried formulations were found to release felodipine faster than melt extruded formulations for both polymer matrices. Solid dispersions containing HMPCAS exhibited higher drug release rates and better wettability than those produced with a PVP matrix. No significant differences in stability were observed except with HPMCAS at a 1 : 1 ratio, where crystallization was detected in spray-dried formulations. CONCLUSIONS: Solid dispersions of felodipine produced by spray drying exhibited more rapid drug release than corresponding melt extruded formulations, although in some cases improved stability was observed for melt extruded formulations.
    • A comparison between vector algorithm and CRSS algorithm for indoor localization

      Dama, Yousef A.S.; Abd-Alhameed, Raed A.; Hammad, H.; Zaid, R.; Excell, Peter S. (2014)
      In this paper a comparison between two indoor localization algorithms using received signal strength is utilized the vector algorithm and the Comparative Received Signal Strength algorithm. The comparison considered the effect of the radio map resolution, the number of access points, and the operating frequency on the accuracy of the localization process. The experiments were carried out using ray tracing software, measured values and MATLAB.
    • A Comparison of Co-Current and Counter-Current Modes of Operation in Urea Prilling Tower

      Rahmanian, Nejat; Homayoonfard, M. (2014)
      In this paper, a model for urea prilling tower with co-current flow of cooling air and urea prills (particles) is presented. The process is modelled by simultaneous solution of the differential equations for hydrodynamics, heat and mass transfer between the air and prills. The process variables such as temperature, absolute and relative humidity of air along the height of the tower were obtained from this model. Temperature and moisture distribution of urea prills and their radial and vertical velocities were also calculated. The results of the present model were compared with the counter-current operation model available in the literature. The simulation results show that heat transfer performance for co-current operation is significantly less than that of the counter-current scenario. This is more pronounced for small prills, i.e. 1.0 mm than that of the large prills. The advantage of the model is that it can be used to investigate influence of operating parameters on efficiency of the co-current process. This also helps us to set the process control strategies for design and quality control purposes of the process.
    • A comprehensive study for indoor localization techniques using received signal strength

      Obeidat, Huthaifa A.N.; Abd-Alhameed, Raed A.; Elkhazmi, Elmahdi A.; Asif, Rameez; Usman, Muhammad; See, Chan H.; Elmegri, Fauzi; Ghazaany, Tahereh S.; Zhu, Shaozhen (Sharon); Noras, James M.; et al. (2013)
    • A database for facial behavioural analysis

      Yap, M.H.; Ugail, Hassan; Zwiggelaar, R. (2013)
      There is substantial interest in detection of human behaviour that may reveal people with deliberate malicious intent, who are engaging in deceit. Technology exists that is able to detect changes in facial patterns of movement and thermal signatures on the face. However, there is data deficiency in the research community for further study. Therefore this project aims to overcome the data deficiency in psychology study and algorithms development. A within-subjects design experiment was conducted, using immigration as a scenario for investigate participants in control and experimental conditions. A random sample of 32 volunteers were recruited, their age group is within 18 - 33. The study design required participants to answer questions on two topics, one as themselves and one as a predefined character. Data regarding visible and thermal images of facial movement and behaviour were collected. A rich FACS-coded database with high quality thermal images was established. Finally, recommendations for development and subsequent implementation of the facial analysis technique were made.
    • A fast approach to unknown tag identification in large scale RFID systems

      Liu, X.; Li, K.; Shen, Y.; Min, Geyong; Xiao, B.; Qu, W.; Li, H. (2013)
      Radio Frequency Identification (RFID) technology has been widely applied in many scenarios such as inventory control, supply chain management due to its superior properties including fast identification and relatively long interrogating range over barcode systems. It is critical to efficiently identify the unknown tags because these tags can appear when new tagged objects are moved in or wrongly placed. The state-of-the-art Basic Unknown tag Identification Protocol-with Collision-Fresh slot paring (BUIP-CF) protocol can first deactivate all the known tags and then collect all the unknown tags. However, BUIP-CF protocol investigates an ALOHA-like technique and causes too many tag responses, which results in low efficiency. This paper proposes a Fast Unknown tag Identification (FUI) protocol which investigates an indicator vector to label the unknown tags with a given accuracy and removes the time-consuming tag responses in the deactivation phase. FUI also adopts the classical Enhanced Dynamic Framed Slotted ALOHA (EDFSA) protocol to collect the labeled unknown tags. We then investigate the optimal parameter settings to maximize the performance of the proposed FUI protocol. Extensive simulation experiments are conducted to evaluate the performance of the proposed FUI protocol and the experimental results show that it considerably outperforms the state-of-the-art protocol.
    • A framework for comparing heterogeneous objects: on the similarity measurements for fuzzy, numerical and categorical attributes

      Bashon, Yasmina M.; Neagu, Daniel; Ridley, Mick J. (2013-09)
      Real-world data collections are often heterogeneous (represented by a set of mixed attributes data types: numerical, categorical and fuzzy); since most available similarity measures can only be applied to one type of data, it becomes essential to construct an appropriate similarity measure for comparing such complex data. In this paper, a framework of new and unified similarity measures is proposed for comparing heterogeneous objects described by numerical, categorical and fuzzy attributes. Examples are used to illustrate, compare and discuss the applications and efficiency of the proposed approach to heterogeneous data comparison and clustering.
    • A fully reversible data transform technique enhancing data compression of SMILES data

      Scanlon, Shagufta A.; Ridley, Mick J. (2013)
      The requirement to efficiently store and process SMILES data used in Chemoinformatics creates a demand for efficient techniques to compress this data. General-purpose transforms and compressors are available to transform and compress this type of data to a certain extent, however, these techniques are not specific to SMILES data. We develop a transform specific to SMILES data that can be used alongside other general-purpose compressors as a preprocessor and post-processor to improve the compression of SMILES data. We test our transform with six other general-purpose compressors and also compare our results with another transform on our SMILES data corpus, we also compare our results with untransformed data.
    • A general perspective on software-hardware defined cognitive radio based on emergency ad-hoc network topology

      Abdul Salam, Ahmed O; Al-Araji, S.R.; Nasir, Q.; Mezher, K.; Sheriff, Ray E. (2014)
      This paper presents a different perspective on the collective concept of software-hardware defined radio (SHDR) in cognitive radio (CR) networks. The SHDR is proposed considering the multiple hardware functionalities conceived by software defined radio, which generally reflects on the adaptable recognition of network services and operational conditions. An ad-hoc network scheme is envisaged as an alternative to a conventional cellular network to accommodate for emergency situations. The connection to such emergency backup network could be established on CR engines built in normal or dedicated smart phone handsets.
    • A kernel P systems survey

      Gheorghe, Marian; Ipate, F. (2014)
      In this short paper one overviews the two years development of kernel P systems (kP systems for short), a basic class of P systems combining features of different variants of such systems. The definition of kP systems is given, some examples illustrate various features of the model and the most significant results are presented.
    • A Low-Profile Ultra-Wideband Modified Planar Inverted-F Antenna

      See, Chan H.; Hraga, Hmeda I.; Abd-Alhameed, Raed A.; McEwan, Neil J.; Noras, James M.; Excell, Peter S. (2013)
      A miniaturized modified planar inverted-F antenna (PIFA) is presented and experimentally studied. This antenna consists of a planar rectangular monopole top-loaded with a rectangular patch attached to two rectangular plates, one shorted to the ground and the other suspended, both placed at the optimum distance on each side of the planar monopole. The fabricated antenna prototype had a measured impedance bandwidth of 125%, covering 3 to 13GHz for reflection coefficient better than -10 dB. The radiator size was 20 x 10 x 7.5 mm(3), making it electrically small over most of the band and suitable for incorporation in mobile devices. The radiation patterns and gains of this antenna have been cross-validated numerically and experimentally and confirm that this antenna has adequate characteristics for short range ultra-wideband wireless applications.
    • A manufacturing failure mode avoidance framework for aerospace manufacturing

      Goodland, J.; Campean, I. Felician; Caunce, A.; Victory, J.L.; Jupp, M.L. (2013)
      Enhancement in productivity and cost effectiveness of high value manufacturing requires a process based management strategy. This paper introduces a Manufacturing Failure Mode Avoidance (MFMA) framework based on 4 high level process steps and underpinned by a sequence of engineering and process analysis tools to support a structured function-based decomposition of complex manufacturing processes and a continuous flow of information towards the development of robust control plans. The approach draws from experience in the automotive industry, where Failure Mode Avoidance (FMA) has been strategically adopted to achieve a step change in the effectiveness of business and engineering processes associated with the product creation processes. The paper presents a case study of the deployment of the MFMA framework to an aircraft manufacturing process followed by a broader discussion of the strength of the approach and its generic applicability to complex high value manufacturing engineering.
    • A miniaturised monopole wideband antenna with reconfigurable band rejection for WLAN/WiMAX

      Elfergani, Issa T.; Hussaini, Abubakar S.; See, Chan H.; Rodriguez, Jonathan; Abd-Alhameed, Raed A.; Marques, P. (2015)
      This paper proposes a tuneable band-rejected miniaturised monopole antenna. The band-notching was achieved by printing an inner chorded crescent shape over the surface of the substrate. By placing a small varactor between the inner and outer arches, the centre frequency of each notch can be individually shifted downwards. The design of the proposed structure has a controllable rejection in the range from 2.38 to 3.87 GHz maintaining a wideband performance from 1.5 to 5 GHz based on VSWR ≤ 2. The antenna prototype was fabricated and tested. Simulated and measured results are performed and analysed. With a compact size, the proposed monopole antenna may well work as an internal antenna in a portable device.
    • A multi-service cluster-based decentralized group key management scheme for high mobility users

      Mapoka, Trust T.; AlSabbagh, Haider M.; Dama, Yousef A.S.; Shepherd, Simon J.; Abd-Alhameed, Raed A.; Bin-Melha, Mohammed S.; Anoh, Kelvin O.O. (2015)
      Previous cluster based group key management schemes for wireless mobile multicast communication lack efficiency in rekeying the group key if high mobility users concurrently subscribe to multiple multicast services that co-exist in the same network. This paper proposes an efficient multi-service group key management scheme suitable for high mobility users which perform frequent handoffs while participating seamlessly in multiple multicast services. The users are expected to drop subscriptions after multiple cluster visits hence inducing huge key management overhead due to rekeying the previously visited cluster keys. However we adopt our already proposed SMGKM system with completely decentralised authentication and key management functions to address demands for high mobility environment with same level of security and less overhead. Through comparisons with existing schemes and simulations, SMGKM shows resource economy in terms of rekeying communication overhead in high mobility environment with multi-leaves.
    • A new approach for implementing QO-STBC over OFDM

      Dama, Yousef A.S.; Migdadi, Hassan S.O.; Shuaieb, Wafa S.A.; Elkhazmi, Elmahdi A.; Abdulmula, E.A.; Abd-Alhameed, Raed A.; Hammoudeh, W.; Masri, A. (2015)
      A new approach for implementing QO-STBC and DHSTBC over OFDM for four, eight and sixteen transmitter antennas is presented, which eliminates interference from the detection matrix and improves performance by increasing the diversity order on the transmitter side. The proposed code promotes diversity gain in comparison with the STBC scheme, and also reduces Inter Symbol Interference.
    • A new approach to designing firewall based on multidimensional matrix

      Cheng, Y.Z.; Wang, W.P.; Min, Geyong; Wang, J.X. (2015-08-25)
      Firewalls are crucial elements to enhance network security by examining the field value of every packet and decide whether to accept or discard the packet according to the firewall policy. However, the design of firewall policies, especially for enterprise networks, is complex and error-prone. This paper aims to propose an effective firewall design method to ensure the consistency, compactness and completeness of firewall rules. Specifically, we develop a new designing model, namely firewall design matrix, and the corresponding construction algorithm for mapping firewall rules to firewall design matrix. A firewall generation algorithm is proposed to generate the target firewall rules that are equivalent to the original ones while maintaining the completeness. Theoretical proof and extensive experiments on both real-world and synthetic firewalls are conducted to evaluate the performance of the proposed method. The results demonstrate that it can achieve a high compression ratio efficiently while maintaining the firewall rules conflict-free. Copyright (c) 2013 John Wiley & Sons, Ltd.
    • A new link lifetime estimation method for greedy and contention-based routing in mobile ad hoc networks

      Noureddine, H.; Ni, Q.; Min, Geyong; Al-Raweshidy, H. (2014)
      Greedy and contention-based forwarding schemes were proposed for mobile ad hoc networks (MANETs) to perform data routing hop-by-hop, without prior discovery of the end-to-end route to the destination. Accordingly, the neighboring node that satisfies specific criteria is selected as the next forwarder of the packet. Both schemes require the nodes participating in the selection process to be within the area that confronts the location of the destination. Therefore, the lifetime of links for such schemes is not only dependent on the transmission range, but also on the location parameters (position, speed and direction) of the sending node and the neighboring node as well as the destination. In this paper, we propose a new link lifetime prediction method for greedy and contention-based routing which can also be utilized as a new stability metric. The evaluation of the proposed method is conducted by the use of stability-based greedy routing algorithm, which selects the next hop node having the highest link stability.
    • A new process chain for producing bulk metallic glass replication masters with micro- and nano-scale features

      Vella, P.C.; Dimov, S.S.; Brousseau, E.; Whiteside, Benjamin R. (2015)
      A novel process chain for serial production of polymer-based devices incorporating both micro- and nano-scale features is proposed. The process chain is enabled by the use of Zr-based bulk metallic glasses (BMG) to achieve the necessary level of compatibility and complementarity between its component technologies. It integrates two different technologies, namely laser ablation and focused ion beam (FIB) milling for micro-structuring and sub-micron patterning, respectively, thus to fabricate inserts incorporating different length scale functional features. Two alternative laser sources, namely nano-second (NS) and pico-second (PS) lasers, were considered as potential candidates for the first step in this master-making process chain. The capabilities of the component technologies together with some issues associated with their integration were studied. To validate the replication performance of the produced masters, a Zr-based BMG insert was used to produce a small batch of micro-fluidic devices by micro-injection moulding. Furthermore, an experimental study was also carried out to determine whether it would be possible by NS laser ablation to structure the Zr-based BMG workpieces with a high surface integrity whilst retaining the BMG's non-crystalline morphology. Collectively, it was demonstrated that the proposed process chain could be a viable fabrication route for mass production of polymer devices incorporating different length scale features.