• Radio spectrum support for timely and reliable communication over vehicular ad-hoc networks (VANETs)

      Eze, Elias Chinedum; Zhang, Sijing; Liu, Enjie; Eze, Joy C. (SciTePress, 2017-04-24)
      This paper studied the required amount of radio spectral resource enough to support timely and reliable vehicular communication via vehicular ad-hoc networks (VANETs). The study focussed on both DSRC/WAVE and the European standard ITS-G5 that are based on recently approved IEEE 802.11p specification, which uses a simplified version of CSMA/CA as MAC protocol, and an STDMA MAC recently proposed by European Telecommunications Standards Institute (ETSI). The paper further carried out a feasibility analysis of radio spectrum requirement for timely and reliable vehicle-to-vehicle (V2V) communication. In the feasibility analysis, synchronized STDMA MAC is compared with the CSMA/CA MAC protocol, which 802.11p is based on. Message Reception Failure (MRF) probability is used as a performance metric to investigate and ascertain the minimum spectrum requirement for efficient, timely, and reliable V2V communication. Simulation results show that even at the same allocation of 10MHz channel bandwidth, STDMA MAC outperforms the CSMA/CA based MACs due to the fact that STDMA based MACs provide a structured shared medium access and prevent negative impact of unhealthy contention for shared channel access. The results further show that up to 40MHz channel bandwidth over 5.9GHz band would be required to guarantee optimal reliability of safety packets exchange in vehicular networks as opposed to 10MHz allocated in US.
    • A real-time monthly DR price system for the smart energy grid

      Mahmud, ASM Ashraf; Sant, Paul; Tariq, Faisal; Jazani, David; University of Bedfordshire; Queen Mary University of London (European Alliance for Innovation, 2017-08-03)
      The smart grid is the next generation bidirectional modern grid. Energy users' are keen on reducing their bill and energy suppliers are also keen on reducing their industrial cost. Our demand response model would benefit them both. We have tested our model with the UK based traditional price value using a real-time basis. Energy users significantly reduced their bill and energy suppliers reduced their industrial cost due to load shifting. The Price Control Unit (PCU) and Price Suggestions Unit (PSU) utilise and embedded algorithms to vary price based upon demand. Our model makes suggestions based on energy threshold and makes use of stochastic approximation methods to produce prices. Our results shows that bill and peak load reductions benefit both the energy provider and users. This model also addresses users' preferences, if users are non-responsive, they can still reduce their bills.
    • Real-time price savings through price suggestions for the smart grid demand response model

      Mahmud, ASM Ashraf; Sant, Paul; University of Bedfordshire (Institute of Electrical and Electronics Engineers Inc., 2017-06-15)
      The smart grid is the solution for the outdated current state of the power grid. An Energy Provider (EP) and Energy User (EU) are both looking to achieve savings. A Real-Time (RT) Demand Response (DR) pricing mechanism can reduce an EUs' bill and at the same time reduce the overall peak demand and Peak to Average Ratio (PAR) so that EP save their cost. In this paper, we will provide a model that uses a Price Suggestion Unit (pSU) and Price Control Unit (PCU) that provides Real-Time Price suggestions in the SG; we tested the model with a simultaneous perturbation stochastic approximation (SPSA) algorithm considering the threshold energy consumption with real data by using a stochastic iterative process. The EU has a choice to respond to the price suggestion. However, if they are non-responsive still they can still save on their bill in terms of taking advantage of the overall responses of other EUs.
    • Realization of periodic InAs QDs by in-situ four-beam laser-interference irradiation on the wetting layer

      Yang, Linyun; Yang, Xinning; Miao, Lili; Zhang, Wei; Huo, Dayun; Shi, Zhenwu; Peng, Changsi; Soochow University; Suzhou Institute of Nano-Tech and Nano-Bionics; Jiangsu Entry-Exit Inspection and Quarantine Bureau; et al. (SPIE, 2018-12-31)
      In this paper, during InAs/GaAs (001) quantum dot molecular beam epitaxy growth, four-beam pulsed laser-interference was used to in-situ irradiate on the wetting layer with an InAs coverage of 1.1 monolayer. Significant atomic layer removal and periodic nanostructures including nanoholes and nanoislands were obtained. These periodic nanostructures had a significant influence on quantum dot growth. Especially for the structure of nano-island, quantum dots preferentially nucleated at the edges of them. When the nano-island size becomes small enough, ordered quantum dot arrays are directly achieved on smooth GaAs surface with a follow-up InAs deposition accompanied by the disappearance of the nanoislands. This finding provides a potential technique leading to site-controlled and defect-free quantum dot fabrication.
    • RECMAC: reliable and efficient cooperative cross-layer MAC scheme for vehicular communication based on random network coding technique

      Eze, Elias Chinedum; Zhang, Sijing; Liu, Enjie; Nweso, Emmanuel N.; Eze, Joy C.; University of Bedfordshire; Ebonyi State University (Institute of Electrical and Electronics Engineers Inc., 2016-10-24)
      In an unreliable cluster-based, broadcast-oriented vehicular network setting, we investigate the transmission reliability and throughput performance of random network coding (RNC) as a function of the packet generate rate. Our proposed model consists of a source vehicle broadcasting packets to a set of receivers (i.e. one-to-many) over independent broadcast erasure channels. The source vehicle performs RNC on N packets and broadcasts the encoded message to a set of receivers. In each hop, several vehicles form a cluster and cooperatively transmit the encoded or re-encoded packet. The combination of RNC, cluster based, and cooperative communications enables RECMAC to optimally minimize data redundancy, which means less overhead, and improve reliability as opposed to existing coding-based solutions. Theoretic analyses and simulation results show that RECMAC scheme can achieve optimal performance in terms of transmission reliability and throughput.
    • Reduced early handover for energy saving in LTE networks

      Kanwal, Kapil; Safdar, Ghazanfar Ali; University of Bedfordshire (IEEE, 2015-12-17)
      Long-term evolution (LTE) facilitates users with high data rate at the cost of increased energy consumption. eNodeBs are main energy hungry elements in LTE networks. Since power consumption directly affects the operational expenditure, thus the provision of cost effective services with adequate quality of service (QoS) has become a major challenge. This letter exploits the phenomenon of handover and presents a novel hybrid idea of reduced early handover with bandwidth expansion to achieve improved energy saving in LTE networks. Through system level simulations, the effectiveness of the proposed scheme is demonstrated. It is shown that the proposed energy saving scheme achieves around 35% energy efficiency compared to benchmark and other state of the art while still maintaining acceptable level of radio link failure.
    • Refocusing distance of a standard plenoptic camera

      Hahne, Christopher; Aggoun, Amar; Velisavljević, Vladan; Fiebig, Susanne; Pesch, Matthias; University of Bedfordshire; ARRI Cine Technik (OSA - The Optical Society, 2016-09-08)
      Recent developments in computational photography enabled variation of the optical focus of a plenoptic camera after image exposure, also known as refocusing. Existing ray models in the field simplify the camera's complexity for the purpose of image and depth map enhancement, but fail to satisfyingly predict the distance to which a photograph is refocused. By treating a pair of light rays as a system of linear functions, it will be shown in this paper that its solution yields an intersection indicating the distance to a refocused object plane. Experimental work is conducted with different lenses and focus settings while comparing distance estimates with a stack of refocused photographs for which a blur metric has been devised. Quantitative assessments over a 24 m distance range suggest that predictions deviate by less than 0.35 % in comparison to an optical design software. The proposed refocusing estimator assists in predicting object distances just as in the prototyping stage of plenoptic cameras and will be an essential feature in applications demanding high precision in synthetic focus or where depth map recovery is done by analyzing a stack of refocused photographs.
    • Reinforcement learning-driven information seeking: a quantum probabilistic approach

      Jaiswal, Amit Kumar; Liu, Haiming; Frommholz, Ingo; University of Bedfordshire (CEUR-WS, 2020-07-30)
      Understanding an information forager’s actions during interaction is very important for the study of interactive information retrieval. Although information spread in an uncertain information space is substantially complex due to the high entanglement of users interacting with information objects (text, image, etc.). However, an information forager, in general, accompanies a piece of information (information diet) while searching (or foraging) alternative contents, typically subject to decisive uncertainty. Such types of uncertainty are analogous to measurements in quantum mechanics which follow the uncertainty principle. In this paper, we discuss information seeking as a reinforcement learning task. We then present a reinforcement learning-based framework to model the foragers exploration that treats the information forager as an agent to guide their behaviour. Also, our framework incorporates the inherent uncertainty of the foragers’ action using the mathematical formalism of quantum mechanics.
    • Relia-MAC: timely and reliable communication for safety critical applications of VANET

      Aredla, Jyothi; Zhang, Sijing; Liu, Enjie; University of Bedfordshire (Institute of Electrical and Electronics Engineers Inc., 2019-11-11)
      A vehicular ad-hoc network (VANET) is a type of ad-hoc network that has gained high attention over the past few years and is extensively used in safety critical applications in case of emergency like road accidents. The proper working of VANET in these safety critical applications requires the need of VANET supporting timely and reliable delivery of the data to the receiver vehicles. However, supporting both timely and reliable delivery of the data messages to the receiver has become highly challenging in VANET because vehicle mobility, dynamic mobility pattern of the vehicles, dynamic network topology, and error-prone wireless communication channel. In this paper, this challenge is addressed by proposing Relia-MAC framework that adds timing properties to the novel Adaptive Byte-Hybrid Automatic Repeat request (AB-HARQ) method. The uniqueness of this paper lies in developing a single framework which when implemented in a vehicular ad-hoc network can assure both timely and reliable delivery of the data packets. Both analytic model and simulation studies are used in this paper to evaluate the effectiveness of proposed framework. The simulation studies have identified the effectiveness of Relia-MAC framework in recording higher ring throughput value and packet delivery ratio.
    • A reliability aware protocol for cooperative communication in cognitive radio networks

      Shah, Munam Ali; Zhang, Sijing; Yang, Hong-Ji (Chinese Academy of Sciences, 2016-06-29)
      One of the challenging tasks in cognitive radio (CR) networks is to agree on a common control channel to exchange control information. This paper presents a novel medium access control (MAC) protocol for CR network which efficiently and intelligently establishes a common control channel between CR nodes. The proposed protocol is the first CR MAC protocol which is hybrid in nature and lies between global common control channel (GCCC) and non-GCCC family of MAC protocols. The dynamic nature of the protocol makes the CR nodes converge on a newly found control channel quicker whenever the interference from a licensed user is sensed. The analytical results show that the dynamic, hybrid and adaptive nature of proposed protocol yields higher throughputs when compared with other CR MAC protocols.
    • Reliable and enhanced cooperative cross-layer medium access control scheme for vehicular communication

      Eze, Elias Chinedum; Zhang, Sijing; Liu, Enjie; Eze, Joy C.; Muhammad, Shehu Jabaka; University of Bedfordshire; Ebonyi State University; Federal College of Education (Technical) Gusau (IET, 2018-04-05)
      In an unreliable cluster-based, broadcast vehicular network setting, we investigate the transmission reliability and throughput performance of random network coding (RNC) as a function of the percentage of packet generation rate and transmit power to noise ratio. In the paper, a novel scheme called reliable and efficient cooperative cross-layer MAC (RECMAC) is proposed. The proposed scheme consists of a source vehicle broadcasting packets to a set of receivers (i.e. one-to-many) over independent broadcast erasure channels. The source vehicle performs RNC on N packets and broadcasts the encoded message to a set of receivers. In each hop, several vehicles form a cluster and cooperatively transmit the encoded or re-encoded packet. The combination of RNC, cluster based, and cooperative communications enables RECMAC to optimally minimize data redundancy, which means less overhead, and improve reliability as opposed to coding-based solutions. Theoretical analyses and simulation results show that under the same conditions RECMAC scheme can achieve improved performance in terms of transmission reliability and throughput.
    • Reliable communication framework for time-critical wireless industrial control networks

      Karimireddy, Thanmayee; Zhang, Sijing; University of Bedfordshire (IEEE Computer Society, 2017-07-27)
      Industrial control network is considered as a system of several interconnecting devices that can control and monitor the industrial environments. Most control networks are widely used in industries with high degree of automation where the need of real of hard real time data accuracy is highly critical for high yield and machine uptime. The control packets transmitted over these control networks consists of hard real time data that is characterized as time-critical. Considering the hard real-time data accuracy and time-criticality, this paper proposes a framework to support reliable and timely transmission of control packets over industrial control networks. This framework is built on two approaches: control panel method and adaptive HARQ method. The control panel method is based on wireless token passing approach called timed token protocol that is widely used for hard real time traffic. The adaptive HARQ is developed to guarantee delivery of control packets accurately before the deadline. A combination of mathematical analysis and simulation studies are used in this paper to show the effectiveness of the proposed framework in providing reliable communication of time-critical control data.
    • Resource scheduling for hybrid broadcasting and cellular networks

      Song, Panjin; Xiong, Jian; Gui, Lin; Qiu, Meikang; Zhang, Yue; Shanghai Jiao Tong University; Pace University; University of Bedfordshire (IEEE Computer Society, 2015-08-06)
      This paper proposes a novel Resource Scheduling (RS) method by using Hybrid Broadcasting and Cellular Networks (HBCN). In this approach, the hot or common information is assigned with higher priority levels and is preferentially scheduled. The Equivalent Throughput (ET) and fairness are redefined and discussed. Simulations show the ETs of the networks are improved by using the proposed algorithms, the hotter the information, the more efficient the network. Moreover, the simulations also show the more cells in the coverage of the terrestrial broadcasting network, the more efficient of the HBCN.
    • Response of bEnd.3 cells to growing behavior on the graphene oxide film with 2-D grating structure by two-beam laser interference

      Yan, Jin; Cao, Liang; Wang, Lu; Xie, Chengcheng; Liu, Yan; Song, Zhengxun; Xu, Hongmei; Weng, Zhankun; Wang, Zuobin; Li, Li (Springer Science and Business Media Deutschland GmbH, 2021-02-22)
      Graphene (G) and its derivatives are important nanomaterials with potential medical applications for biosensors and implanting biomaterials. The hydrophobicity and surface microstructures of substrates have great influences on the biological and physical properties of the surface-bound cells. In this work, we used the two-beam laser interference (TBLI) technique to prepare a two-dimensional (2-D) grating structure on the surface of graphene oxide (GO) film. We investigated the effect of GO and the GO film with the 2-D grating structure substrates on the growth behavior of rat brain microvascular endothelial (bEnd.3) cells. The results demonstrated that the cell spreading area and the number of surface-bound cells were closely related to the hydrophobicity of the substrate and the presence of oxygen-containing functional groups (OCGs). Due to the interaction of laser and GO, the GO in the interference area was transformed into reduced graphene oxide (RGO). The grating-structured GO film significantly affected the direction of cell spreading and morphology. It has a good application prospect as a scaffold in tissue engineering, and promising applications in the fields that require highly directional growth of cells, such as nerve injury repair, tendon repair and regeneration.
    • Response of MG63 osteoblast cells to surface modification of Ti-6Al-4V implant alloy by laser interference lithography

      Liu, Qi; Li, Wenjun; Cao, Liang; Wang, Jiajia; Qu, Yingmin; Wang, Xinyue; Qiu, Rongxian; Di, Xu; Wang, Zuobin; Liang, Bojian; et al. (Elsevier, 2017-07-14)
      The response of human osteoblast-like osteosarcoma cells (MG63) to surface modification of Ti-6Al-4V implant alloy was investigated by Laser Interference Lithography (LIL). In this work, laser interference lithography was employed to fabricate the microstructures of grooves, dots and dimples onto the surfaces of Ti-6Al-4V samples. Two and three beam LIL systems were developed to carry out the experiments. The laser treatment resulted in the increases of the roughness and the contact angle of water on the implant alloy surfaces. The proliferation of osteoblasts was analyzed by MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay for the time periods of 4 hours, 2 days, 3 days, and 6 days. The MTT test results demonstrated that the laser treatment surfaces had a positive impact on the proliferation of osteoblast cells after 24 hours. The alloy surface morphology and the morphological changes of MG63 cells cultured on the laser textured Ti-6Al-4V surface were observed by Scanning Electron Microscope (SEM). The SEM results indicated that the osteoblast cells were aligned on grooved surfaces and they were prolonged with the structures. Enzymatic detachment results showed that the 20 µm grooved structures provided the better cell adhesion to the textured Ti-6Al-4V surfaces.
    • Review of mobile applications for optimizing the follow-up care of patients with diabetes

      Ersotelos, Nikolaos; Margioris, Andrew N.; Zhang, Xu; Dong, Feng; University of Bedfordshire; University of Crete (Hellenic Endocrine Society/Springer, 2018-10-13)
      Several smartphone applications aim at facilitating communication between patients and healthcare providers. In this review, we evaluate and compare the most promising applications in the field of diabetes mellitus (DM) and obesity. Most applications monitor body weight, fasting or postprandial blood glucose, glycosylated hemoglobin (Hgb) A1c (HgbA1c), and units and types of insulin used. Nine clinically tested applications and two Web platforms were grouped into three categories that were evaluated and compared. Group 1 included seven applications focusing mainly on monitoring DM, fitness and weight, blood glucose levels, and HbA1c. Group 2 included two applications that focus on insulin dosage calculators and glucose self-monitoring tests. Group 3 included two web-platforms that interact with patients via SMS (short message service) messaging. A common feature of the applications examined was the limited number of clinical parameters tested, the small number of subjects taking part in the evaluation, and the fact that the controls were not randomized. Furthermore, the interfaces of the applications varied and were not standardized. Finally, another common characteristic across applications was the lack of standardization of the interface and the overall structure due to language barriers, the devices usually having been designed around a specific language. Lastly, most applications lacked a critical mass of evaluators and were thus not worthy of being considered of serious clinical relevance. The current smartphone applications for DM are characterized by a limited number of participants, a small number of parameters, and a lack of standardization. BACKGROUND METHODS RESULTS CONCLUSIONS
    • The road ahead for body-centric wireless communication and networks

      Ur-Rehman, Masood; Abbasi, Qammer Hussain; Alomainy, Akram; University of Bedfordshire; Texas A & M University at Qatar; University of Engineering and Technology, Pakistan; Queen Mary University of London (Institution of Engineering and Technology, 2015-02-26)
      Wireless interaction of the human user with the computing devices has seen a profound growth in the past decade. Wearable technology has successfully moved past the adoption stage and now stands at the brink of massive diversification with an explosion in popularity and applicability. The estimated market value of the wearable technology is expected to hit $32 billion mark by 2020 [1, 2]. It would cause the global wearable devices market it to grow from 20 million device shipments in 2015 to 187.2 million units annually by 2020 [3].
    • RSSI indoor localization through a Bayesian strategy

      Zhou, Fu; Lin, Kaixian; Ren, Aifeng; Cao, Dongjian; Zhang, Zhiya; Ur-Rehman, Masood; Yang, Xiaodong; Alomainy, Akram; Xidian University; University of Bedfordshire; et al. (IEEE, 2017-10-02)
      A method to locate the position of the user in an indoor environment employing Bayesian theory is presented in this paper. A detailed analysis of the positional accuracy is carried out evaluating effects of two major degradation factors namely the measurement and calculation errors. The proposed technique makes use of the Gaussian distribution of random data in indoor Zigbee propagation model based on received signal strength indicator (RSSI) and the triangular positioning algorithm, maximum likelihood estimation (MLE) and Bayesian theory. It identifies the user's location calculating the maximum probability point. The proposed method offers high accuracy levels with a mean error of 0.1363m as compared to the mean error values of 1.4059m and 0.4291m for the triangular localization and triangular localization with MLE methods, respectively.
    • A scalable and license free 5G Internet of radio light architecture for services in homes businesses

      Cosmas, John; Meunier, Ben; Ali, Kareem; Jawad, Nawar; Salih, Mukhald; Meng, Hong-Ying; Ganley, Martin; Gbadamosi, James; Savov, Atanas; Hadad, Zion; et al. (IEEE Computer Society, 2018-08-16)
      In this paper we present a 5G Internet Radio-Light (IoRL) architecture for homes that can be readily deployed because it utilizes unlicensed visible light and millimeter wave part of the spectrum, which does not require Mobile Network Operator (MNO) permission to deploy and which is used to provide inhabitants of houses with accurate location, interaction, access to Internet and Cloud based services such as high resolution video on a Tablet PC. The paper describes the home use cases and the IoRL architecture.
    • Scalable DB+IR technology: processing Probabilistic Datalog with HySpirit

      Frommholz, Ingo; Roelleke, Thomas; University of Bedfordshire; Queen Mary, University of London (Springer Verlag, 2016-01-26)
      Probabilistic Datalog (PDatalog, proposed in 1995) is a probabilistic variant of Datalog and a nice conceptual idea to model Information Retrieval in a logical, rule-based programming paradigm. Making PDatalog work in real-world applications requires more than probabilistic facts and rules, and the semantics associated with the evaluation of the programs. We report in this paper some of the key features of the HySpirit system required to scale the execution of PDatalog programs. Firstly, there is the requirement to express probability estimation in PDatalog. Secondly, fuzzy-like predicates are required to model vague predicates (e.g. vague match of attributes such as age or price). Thirdly, to handle large data sets there are scalability issues to be addressed, and therefore, HySpirit provides probabilistic relational indexes and parallel and distributed processing. The main contribution of this paper is a consolidated view on the methods of the HySpirit system to make PDatalog applicable in real-scale applications that involve a wide range of requirements typical for data (information) management and analysis.