• A newly designed economizer to improve waste heat recovery: A case study in a pasteurized milk plant

      Niamsuwan, S.; Kittisupakorn, P.; Mujtaba, Iqbal M. (2013)
      An economizer is normally employed to perform heat recovery from hot exhaust gases to cold fluid. In this work, a newly designed economizer is devised to achieve high heat recovery in a pasteurized milk plant. In the economizer, the hot exhaust gas is divided into two channels flowing up on the left and right sides. After that, it is moving down passing over aligned banks of tubes, which water is flowing inside, in a triple passes fashion. Moreover, three dimensional (3D) models with heat transfer including fluid dynamic have been developed, validated by actual plant data and used to evaluate the performance of the economizer. Simulation results indicate that the newly designed economizer can recover the heat loss of 38% and can achieve the cost saving of 13%.
    • A non-invasive airborne wave monitor

      Nichols, Andrew; Tait, Simon J.; Horoshenkov, Kirill V.; Shepherd, Simon J. (2013)
      This work presents a new acoustical method for remote measurement of the surface characteristics of the dynamic air-water interface in turbulent free-surface flows. The technique uses the reflection of a monochromatic ultrasonic wave by the dynamically rough air-water interface to measure the water surface position. It is found that with careful selection of the acoustical components and their configuration, the phase of the reflected signal responds to the local fluctuations in the fluid interface at the point of specular acoustic reflection. In order for the method to be applicable, three criteria must be satisfied: (1) the dominant wavelength of the surface under investigation must be greater than the first Fresnel zone corresponding to the wavelength and component geometry of the acoustical system; (2) the mean magnitude of the instantaneous local surface gradient must not exceed 0.025; and (3) the root-mean-square wave height must be greater than 1% of the acoustic wavelength. Under these conditions the mean error of the system is within 5% (and usually within 1%) of the acoustic wavelength, and is generally within 10% of the wave amplitude for turbulence generated waves, and 3% of the amplitude for gravity waves. This error may be reduced by optimising the acoustic wavelength for the surface of interest. For turbulent depth limited flows, the surface waves fall well within the criteria, and the absolute errors are independent of wave height, so for larger wave heights, the relative error can be considerably lower. The technique provides a robust system for monitoring the dynamics of free surface flows, which is non-invasive, low cost, and low power. The method has been tested on laboratory flows but should be applicable to remote sensing of free surface properties on a local scale in field environments where invasive techniques are difficult to implement such as might be found in coastal, river and wastewater environments.
    • A novel multi-standard dual-wide band polygon SLSIR filter

      Tu, Yuxiang X.; Ali, Ammar H.; Elmegri, Fauzi; Abousitta, M.; Abd-Alhameed, Raed A.; Hussaini, Abubakar S.; Elfergani, Issa T.; Rodriguez, Jonathan; Atiah, A.S. (2015)
      A novel multi-standard dual-wide band filter with a compact size of only 8.8 mm by 16.8mm is designed and developed for transceiver devices. The proposed filter has a fundamental bandwidth of 1.6GHz with fractional bandwidth (FBW) of 29.7% centered at the 5.4GHz band, and second bandwidth of 300.0MHz with FBW of 3.6% centered at the 8.15GHz band. The basic dual-wide bandwidth is attributed to the interaction of the novel modified polygon pair and upper stub loaded stepped impedance resonator. Moreover, the added down stub loaded stepped impedance resonator (SLSIR) further enhances the pass band performance by widening the bandwidth and optimizing reflection coefficient performance considerably. To validate the proposed ideas, the multi-standard filter is designed and simulated by Ansoft HFSS software. The simulated results agree well with the theory predictions. The featured broad bandwidths over two frequency bands and the miniaturized size of the proposed filter make it very promising for applications in future multi-standard wireless communication.
    • A Novel Prototyping and Evaluation Framework for NoC-Based MPSoC

      Tatas, K.; Siozios, K.; Bartzas, A.; Kyriacou, Costas; Soudris, D. (2013)
      This paper presents a framework for high-level exploration, Register Transfer-Level (RTL) design and rapid prototyping of Network-on-Chip (NoC) architectures. From the high-level exploration, a selected NoC topology is derived, which is then implemented in RTL using an automated design flow. Furthermore, for verification purposes, appropriate self-checking testbenches for the verification of the RTL and architecture files for the semi-automatic implementation of the system in Xilinx EDK are also generated, significantly reducing design and verification time, and therefore Non-Recurring Engineering (NRE) cost. Simulation and FPGA implementation results are given for four case studies multimedia applications, proving the validity of the proposed approach.
    • A novel real-time methodology for the simultaneous dynamic optimization and optimal control of batch processes

      Rossi, F.; Manenti, F.; Mujtaba, Iqbal M.; Bozzano, G. (2014)
      A novel threefold optimization algorithm is proposed to simultaneously solve the nonlinear model predictive control and dynamic real-time optimization for batch processes while optimizing the batch operation time. Object-oriented programming and parallel computing are exploited to make the algorithm effective to handle industrial cases. A well-known literature case is selected to validate the algorithm.
    • A Novel Verification Scheme for Fine-Grained Top-k Queries in Two-Tiered Sensor Networks

      Ma, X.; Song, H.; Wang, J.; Gao, J.; Min, Geyong (2014)
      A two-tiered architecture with resource-rich master nodes at the upper tier and resource-poor sensor nodes at the lower tier is expected to be adopted in large scale sensor networks. In a hostile environment, adversaries are more motivated to compromise the master nodes to break the authenticity and completeness of query results, whereas it is lack of light and secure query processing protocol in tiered sensor networks at present. In this paper, we study the problem of verifiable fine-grained top- queries in two-tiered sensor networks, and propose a novel verification scheme, which is named Verification Scheme for Fine-grained Top- Queries (VSFTQ). To make top- query results verifiable, VSFTQ establishes relationships among data items of each sensor node using their orders, which are encrypted together with the scores of the data items and the interested time epoch number using distinct symmetric keys kept by each sensor node and the network owner. Both theoretical analysis and simulation results show that VSFTQ can not only ensure high probability of detecting forged and/or incomplete query results, but also significantly decrease the amount of verification information when compared with existing schemes.
    • A printed wideband MIMO antenna for mobile and portable communication devices

      See, Chan H.; Elkhazmi, Elmahdi A.; Samarah, Khalid G.; Al Khambashi, Majid S.; Abd-Alhameed, Raed A.; McEwan, Neil J.; Excell, Peter S. (2015)
      A printed crescent-shaped monopole MIMO antenna is presented for handheld wireless communication devices. The mutual coupling between the two antenna elements can be minimised by implementing a I-shaped common radiator. Both the simulated and measured results agree that the antenna covers the operating frequency band from 1.6 to 2.8 GHz with the return loss and isolation better than 10 dB and 14 dB respectively. To further verifying the MIMO characteristic including far-field, gain, radiation efficiency, channel capacity loss and envelope correlation, the results confirm that the antenna can operate effectively in a rich multipath environment.
    • A Priority-Based Admission Control Scheme for Commercial Web Servers

      Nafea, Ibtehal T.; Younas, M.; Holton, Robert; Awan, Irfan U. (2014)
      This paper investigates into the performance and load management of web servers that are deployed in commercial websites. Such websites offer various services such as flight/hotel booking, online banking, stock trading, and product purchases among others. Customers are increasingly relying on these round-the-clock services which are easier and (generally) cheaper to order. However, such an increasing number of customers' requests makes a greater demand on the web servers. This leads to web servers' overload and the consequential provisioning of inadequate level of service. This paper addresses these issues and proposes an admission control scheme which is based on the class-based priority scheme that classifies customer's requests into different classes. The proposed scheme is formally specified using -calculus and is implemented as a Java-based prototype system. The prototype system is used to simulate the behaviour of commercial website servers and to evaluate their performance in terms of response time, throughput, arrival rate, and the percentage of dropped requests. Experimental results demonstrate that the proposed scheme significantly improves the performance of high priority requests but without causing adverse effects on low priority requests.
    • A quantitative measure of the security risk level of enterprise networks

      Munir, Rashid; Pagna Disso, Jules F.; Awan, Irfan U.; Mufti, Muhammad R. (2013)
      Along with the tremendous expansion of information technology and networking, the number of malicious attacks which cause disruption to business processes has concurrently increased. Despite such attacks, the aim for network administrators is to enable these systems to continue delivering the services they are intended for. Currently, many research efforts are directed towards securing network further whereas, little attention has been given to the quantification of network security which involves assessing the vulnerability of these systems to attacks. In this paper, a method is devised to quantify the security level of IT networks. This is achieved by electronically scanning the network using the vulnerability scanning tool (Nexpose) to identify the vulnerability level at each node classified according to the common vulnerability scoring system standards (critical, severe and moderate). Probabilistic approach is then applied to calculate an overall security risk level of sub networks and entire network. It is hoped that these metrics will be valuable for any network administrator to acquire an absolute risk assessment value of the network. The suggested methodology has been applied to a computer network of an existing UK organization with 16 nodes and a switch.
    • A real-time dynamic optimal guidance scheme using a general regression neural network

      Hossain, M. Alamgir; Madkour, A.A.M.; Dahal, Keshav P.; Zhang, L. (2013)
      This paper presents an investigation into the challenges in implementing a hard real-time optimal non-stationary system using general regression neural network (GRNN). This includes investigation into the dynamics of the problem domain, discretisation of the problem domain to reduce the computational complexity, parameters selection of the optimization algorithm, convergence guarantee for real-time solution and off-line optimization for real-time solution. In order to demonstrate these challenges, this investigation considers a real-time optimal missile guidance algorithm using GRNN to achieve an accurate interception of the maneuvering targets in three-dimension. Evolutionary Genetic Algorithms (GAs) are used to generate optimal guidance training data set for a large missile defense space to train the GRNN. The Navigation, Constant of the Proportional Navigation Guidance and the target position at launching are considered for optimization using GAs. This is achieved by minimizing the. miss distance and missile flight time. Finally, the merits of the proposed schemes for real-time accurate interception are presented and discussed through a set of experiments. (C) 2012 Elsevier Ltd. All rights reserved.
    • A realization of integrated satellite-terrestrial communication networks for aeronautical services via joint radio resource management

      Cheng, Yongqiang; Xu, Kai J.; Pillai, Anju; Pillai, Prashant; Hu, Yim Fun; Ali, Muhammad; Ahmed, Adeel (2013)
      Despite air travel has not grown as predicted, air travel is still expected to rise to just less than doubling the current figure by 2030. This creates an urging need to develop more efficient Air Traffic Management (ATM) solutions. Around the globe, research and development initiatives have been launched to modernize the air traffic control infrastructures. These modernized infrastructures will be built around continuous information gathering, sharing and transferring of data between aircraft and air navigation service providers and airports ground infrastructure, which will be difficult for current aeronautical communications systems to handle. As a result, new communication infrastructures are required to manage future aeronautical communication traffic demand. This paper proposes an integrated aeronautical communication architecture consisting of four radio access technologies for communications between aircrafts and ground Aeronautical Telecommunication Network (ATN). The design and implementation of a Joint Radio Resource Management (JRRM) framework to manage these radio resources are discussed. The design is verified by a proof-of-concept JRRM prototype which is developed for the management of radio resource between the Inmarsat Broadband Global Area Network (BGAN) and the Aeronautical Mobile Airport Communication System (AeroMACS).
    • A redundancy software design for joint radio resource management system in a satellite-terrestrial based aeronautical communication network

      Cheng, Yongqiang; Xu, Kai J.; Hu, Yim Fun (2013)
      This paper presents a Master/Slave redundancy mechanism for the airborne Integrated Modular Radio to improve the reliability of the joint radio resource management (JRRM) system. The proposed mechanism adopts keep-alive heart beat messages and real time information synchronization to ensure a smooth switchover in the event of a platform failure. To enhance the scalability and decoupling of the system, the proposed hot swap solution makes the JRRM switchover transparent to both the higher layers and the lower layers. The experiment results and the performance obtained from the test-bed has proved the validity of the solution.
    • A review of location based services: current developments and trends

      Abd-Alhameed, Raed A.; Anoh, Kelvin O.O.; Ahmad, I.; Migdadi, Hassan S.O.; Asif, Rameez; Jan, Naeem A.; Ghazaany, Tahereh S.; Zhu, Shaozhen (Sharon); Elmegri, Fauzi; Bin-Melha, Mohammed S.; et al. (2013)
    • A robotic telescope for science and education

      Baruch, John E.F. (2015-04-01)
      John Baruch surveys the work of the Bradford Robotic Telescope – a project rooted in innovation and education, full of potential for an exciting future.
    • A structured approach for function based decomposition of complex multi-disciplinary systems

      Campean, I. Felician; Henshall, Edwin; Yildirim, Unal; Uddin, Amad; Williams, Huw (2013)
      The aim of this paper is to introduce the Systems State Flow Diagram as a structured approach to high level solution-independent function based decomposition of a complex multi-disciplinary system. The approach is discussed in the context of existing function modelling frameworks and in relation to current practice in industry. A generic case study is used to introduce the approach and to highlight the salient features, followed by an illustration on its application to the analysis of an electric vehicle powertrain. Experience with the practical application of the approach with engineering teams is discussed.
    • A suitable server placement for peer-to-peer live streaming

      Yuan, X.Q.; Yin, H.; Min, Geyong; Liu, X.; Hui, W.; Zhu, G.X. (2013)
      With the rapid growth of the scale, complexity, and heterogeneity of Peer-to-Peer (P2P) systems, it has become a great challenge to deal with the peer's network-oblivious traffic and self-organization problems. A potential solution is to deploy servers in appropriate locations. However, due to the unique features and requirements of P2P systems, the traditional placement models cannot yield the desirable service performance. To fill this gap, we propose an efficient server placement model for P2P live streaming systems. Compared to the existing solutions, this model takes the Internet Service Provider (ISP) friendly problem into account and can reduce the cross-network traffic among ISPs. Specifically, we introduce the peers' contribution into the proposed model, which makes it more suitable for P2P live streaming systems. Moreover, we deploy servers based on the theoretical solution subject to practical data and apply them to practical live streaming applications. The experimental results show that this new model can reduce the amount of cross-network traffic and improve the system efficiency, has a better adaptability to Internet environment, and is more suitable for P2P systems than the traditional placement models.
    • A survey of architectures and scenarios in satellite-based wireless sensor networks: system design aspects

      Celandroni, N.; Ferro, E.; Gotta, A.; Oligeri, G.; Roseti, C.; Luglio, M.; Bisio, I.; Cello, M.; Davoli, F.; Panagopoulos, A.D.; et al. (2013-01)
      This paper is not a survey related to generic wireless sensor networks (WSNs), which have been largely treated in a number of survey papers addressing more focused issues; rather, it specifically addresses architectural aspects related to WSNs in some way connected with a satellite link, a topic that presents challenging interworking aspects. The main objective is to provide an overview of the potential role of a satellite segment in future WSNs. In this perspective, requirements of the most meaningful WSN applications have been drawn and matched to characteristics of various satellite/space systems in order to identify suitable integrated configurations. Copyright (c) 2012 John Wiley & Sons, Ltd.
    • A systems approach to the development and use of FMEA in complex automotive applications

      Henshall, Edwin; Campean, I. Felician; Rutter, B. (2014)
      The effective deployment of FMEAs within complex automotive applications faces a number of challenges, including the complexity of the system being analysed, the need to develop a series of coherently linked FMEAs at different levels within the systems hierarchy and across intrinsically interlinked engineering disciplines, and the need for coherent linkage between critical design characteristics cascaded through the systems levels with their counterparts in manufacturing. The approach presented in this paper to address these challenges is based on a structured Failure Mode Avoidance (FMA) framework which promotes the development of FMEAs within an integrated Systems Engineering approach. The effectiveness of the framework is illustrated through a case study, centred on the development of a diesel exhaust aftertreatment system. This case study demonstrates that the structured FMA framework for function analysis supports an effective decomposition of complex interdisciplinary systems facilitating the DFMEA deployment through a series of containable, structured DFMEAs developed at successive system levels, with clear vertical integration of functional requirements and critical parameters cascade. The paper also discusses the way in which the approach supports deployment across engineering disciplines and domains, ensuring the integrity of information flow between the design and manufacturing activities.
    • A unified practical approach to modulation classification in cognitive radio using likelihood-based techniques

      Salam, A.O.A.; Sheriff, Ray E.; Al-Araji, S.R.; Mezher, K.; Nasir, Q. (2015)
      he automatic classification of digital modulated signals has been subject to extensive studies over the last decade, with numerous scholarly articles and research studies published. This paper provides an insightful guidance and discussion on the most practical approaches of automatic modulation classification (AMC) in cognitive radio (CR) using likelihood based (LB) statistical tests. It also suggests a novel idea of storing the known constellation sets on the receiver side using a look-up table (LUT) to detect the transmitted replica. Relevant performance measures with simulated comparisons in flat fading additive white Gaussian noise (AWGN) channels are examined. Namely, the average likelihood ratio test (ALRT), generalized LRT (GLRT) and hybrid LRT (HLRT) are particularly illustrated using linearly phase-modulated signals such as M-ary phase shift keying (MPSK) and quadrature amplitude modulation (MQAM). When the unknown signal constellation is estimated using the maximum likelihood (ML) method, results indicate that the HLRT performs well and near optimal in most situations without extra computational burden.
    • A verified and optimized Stream X-Machine testing method, with application to cloud service certification

      Simons, A.J.H.; Lefticaru, Raluca (Wiley, 2020-05)
      The Stream X-Machine (SXM) testing method provides strong and repeatable guarantees of functional correctness, up to a specification. These qualities make the method attractive for software certification, especially in the domain of brokered cloud services, where arbitrage seeks to substitute functionally equivalent services from alternative providers. However, practical obstacles include: the difficulty in providing a correct specification, the translation of abstract paths into feasible concrete tests, and the large size of generated test suites. We describe a novel SXM verification and testing method, which automatically checks specifications for completeness and determinism, prior to generating complete test suites with full grounding information. Three optimisation steps achieve up to a ten-fold reduction in the size of the test suite, removing infeasible and redundant tests. The method is backed by a set of tools to validate and verify the SXM specification, generate technology-agnostic test suites and ground these in SOAP, REST or rich-client service implementations. The method was initially validated using seven specifications, three cloud platforms and five grounding strategies.