• Quantitative imaging for early detection of osteoarthritis

      Schetinin, Vitaly; University of Bedfordshire (University of Bedfordshire, 2020-07-09)
      The project supported by European Regional Development Fund is related to Quantitative Imaging for Early Detection of Osteoarthritis. The developed method has been tested on high resolution X-Ray images of knees at early stage when the pathological changes in patient's bones cannot be reliably quantified by using the standard radiologic tests. At early stage the pathology is latently developing and so being diagnosed later becomes untreatable. The proposed method has been developed in collaboration with Fusion Radiology (UK) and with Stavropol regional hospital (Russia). The Fusion Radiology (led by Mr Azizul Ambia) is a contractor of the NHS, providing radiology opinions for multiple UK hospitals. The regional hospital (the Deputy MD Anna Sadovaya) has verified the developed method on 160 patient cases. The new method has provided a statistically significant improvement of diagnostic accuracy on the anonymised patient records. The improvements were between 7% and 9%. The results achieved in the studies will allow radiologists to minimise false negative rate which is critically important for early diagnostics.
    • Battery-assisted electric vehicle charging: data driven performance analysis

      Ali, Junade; Dyo, Vladimir (2020-07-03)
      As the number of electric vehicles rapidly increases, their peak demand on the grid becomes one of the major challenges. A battery-assisted charging concept has emerged recently, which allows to accumulate energy during off-peak hours and in-between charging sessions to boost-charge the vehicle at a higher rate than available from the grid. While prior research focused on the design and implementation aspects of battery- assisted charging, its impact at large geographical scales remains largely unexplored. In this paper we analyse to which extent the battery-assisted charging can replace high-speed chargers using a dataset of over 3 million EV charging sessions in both domestic and public setting in the UK. We first develop a discrete-event EV charge model that takes into account battery capacity, grid supply capacity and power output among other parameters. We then run simulations to evaluate the battery-assisted charging performance in terms of delivered energy, charging time and parity with conventional high-speed chargers. The results indicate that in domestic settings battery-assisted charging provides 98% performance parity of high-speed chargers from a standard 3 kW grid connection with a single battery pack. For non-domestic settings, the battery-assisted chargers can provide 92% and 99% performance parity of high-speed chargers with 10 battery packs using 3kW and 7kW grid supply respectively.
    • Practical hash-based anonymity for MAC addresses

      Ali, Junade; Dyo, Vladimir (arXiv, 2020-06-18)
      Given that a MAC address can uniquely identify a person or a vehicle, continuous tracking over a large geographical scale has raised serious privacy concerns amongst governments and the general public. Prior work has demonstrated that simple hash-based approaches to anonymization can be easily inverted due to the small search space of MAC addresses. In particular, it is possible to represent the entire allocated MAC address space in 39 bits and that frequency-based attacks allow for 50% of MAC addresses to be enumerated in 31 bits. We present a practical approach to MAC address anonymization using both computationally expensive hash functions and truncating the resulting hashes to allow for k-anonymity. We provide an expression for computing the percentage of expected collisions, demonstrating that for digests of 24 bits it is possible to store up to 168,617 MAC addresses with the rate of collisions less than 1%. We experimentally demonstrate that a rate of collision of 1% or less can be achieved by storing data sets of 100 MAC addresses in 13 bits, 1,000 MAC addresses in 17 bits and 10, 000 MAC addresses in 20 bits.
    • Deep learning for biometric face recognition: experimental study on benchmark data sets

      Selitskaya, Natalya; Sielicki, S.; Jakaite, Livija; Schetinin, Vitaly; Evans, F.; Conrad, Marc; Sant, Paul (Springer International Publishing, 2020-06-09)
      There are still problems in applications of Machine Learning for face recognition. Such factors as lighting conditions, head rotations, emotions, and view angles affect the recognition accuracy. A large number of recognition subjects requires complex class boundaries. Deep Neural Networks have provided efficient solutions, although their implementations require massive computations for evaluation and minimisation of error functions. Gradient algorithms provide iterative minimisation of the error function. A maximal performance is achieved if parameters of gradient algorithms and neural network structures are properly set. The use of pairwise neural network structures often improves the performance because such structures require a small set of optimisation parameters. The experiments have been conducted on some face biometric benchmark data sets, and the main findings are presented in the form of a tutorial.
    • Survey on health care applications in 5G networks

      Liu, Enjie; Effiok, Emmanuel; Hitchcock, Jonathan James; University of Bedfordshire (IEEE, 2020-04-13)
      In 2019, 5G was introduced and it is being gradually deployed all over the world. 5G introduces new concepts, such as network slicing to better support various applications with different performance requirements on data rate and latency; and edge and cloud computing that will be responsible for the leverage of computational requirements. This study aims to describe the functions and features of the key 5G technologies and conduct a survey on the latest development of driving technologies for 5G. This survey focuses on health care applications that would benefit from the advantages brought by 5G.
    • Fabrication and transfer printing of periodic Pt nanonetwork gratings

      Yu, Miao; Li, Li; Wu, Xiaomin; Song, Yingying; Liu, Jinyun; Wang, Zuobin; Changchun University of Science and Technology; University of Bedfordshire (AIP Publishing, 2020-03-13)
      Metal nanonetworks are applied in various applications, such as biomedicine, bionic materials, optical materials, and new energy materials. Here, periodic variable-sized Pt nanonetwork gratings (PtNGs) are fabricated on the surface of a Pt/Si substrate with single pulse two-beam direct laser interference lithography. The fabricated PtNGs are transferred onto the surface of a glass substrate with polymethyl methacrylate as the transfer mediator. Exposure with different film thicknesses, contrasts, and intensity distributions of the laser interference spot is analyzed, and the formation of nanopatterns is explained. Results show that with the change in the thicknesses of the Pt film, the exposed structures present Pt nanoparticles (PtNPs), Pt gratings, and PtNGs. The morphology and the feature size of the PtNGs are influenced by intensity distributions and the contrast of the laser interference spot significantly.
    • Design of a compact multiband circularly polarized antenna for global navigation satellite systems and 5G/B5G applications

      Falade, Oluyemi Peter; Ur-Rehman, Masood; Yang, Xiaodong; Safdar, Ghazanfar Ali; Parini, Clive G.; Chen, Xiaodong (Wiley, 2020-02-17)
      Design of a multiband circularly polarized antenna is proposed in this article. The antenna has a simple and compact form factor by employing single‐feed stacked patch structure. It exhibits good performance at the global navigation satellite system (GNSS) frequency bands of L1, L2, and L5 and cellular communications frequency band of 2.3 GHz. The antenna has a 3‐dB axial ratio bandwidth of 1.1%, 1.0%, 4.1%, and 1.5% at the four operating bands of L1 (1.575 GHz), L2 (1.227 GHz), L5 (1.176 GHz), and 2.3 GHz. The antenna also achieves a gain of more than 2.2 dBiC and efficiency of more than 70% at the four frequencies. A detailed parametric study is carried out to investigate the importance of different structural elements on the antenna performance. Results are verified through close agreement of simulations and experimental measurements of the fabricated prototype. Good impedance matching, axial ratio bandwidth, and radiation characteristics at the four operating bands along with small profile and mechanically stable structure make this antenna a good candidate for current and future GNSS devices, mobile terminals, and small satellites for 5G/Beyond 5G (5G/B5G) applications.
    • Evidence of power-law behavior in cognitive IoT applications

      Bebortta, Sujit; Senapati, Dilip; Rajput, Nikhil Kumar; Singh, Amit Kumar; Rathi, Vipin Kumar; Pandey, Hari Mohan; Jaiswal, Amit Kumar; Qian, Jia; Tiwari, Prayag; College of Engineering and Technology, Bhubaneshwar; et al. (Springer, 2020-02-03)
      The motivations induced due to the presence of scale-free characteristics of neural systems governed by the well-known power-law distribution of neuronal activities have led to its convergence with the Internet of things (IoT) framework. The IoT is one such framework, where the self-organization of the connected devices is a momentous aspect. The devices involved in these networks inherently relate to the collection of several consolidated devices like the sensory devices, consumer appliances, wearables, and other associated applications, which facilitate a ubiquitous connectivity among the devices. This is one of the most significant prerequisites of IoT systems as several interconnected devices need to be included in the convolution for the uninterrupted execution of the services. Thus, in order to understand the scalability and the heterogeneity of these interconnected devices, the exponent of power-law plays a significant role. In this paper, an analytical framework to illustrate the ubiquitous power-law behavior of the IoT devices is derived. An emphasis regarding the mathematical insights for the characterization of the dynamic behavior of these devices is conceptualized. The observations made in this direction are illustrated through simulation results. Further, the traits of the wireless sensor networks, in context with the contemporary scale-free architecture, are discussed.
    • Imaging quality assessment of different AFM working modes on living cancer cells

      Wang, Guoliang; Sun, Baishun; Wu, Xiaomin; Zhang, Wenxiao; Qu, Yingmin; Song, Zhengxun; Wang, Zuobin; Li, Dayou; Changchun University of Science and Technology; University of Bedfordshire (IEEE, 2020-02-02)
      Since the invention of atomic force microscope (AFM) in 1986, its capabilities in biophysical research, such as living cell imaging, molecule imaging and recognition and drug treatment analysis, have been deeply investigated. Various types of working modes of atomic force microscopy have been employed for imaging and analyzing living cells. The physical properties of living cells can be directly illustrated by its good resolution images. In this paper, the applications of three AFM working modes including contact, tapping and quantitative imaging (QI) modes for the investigation of living lung cancer cells (A549) are presented. Meanwhile, the quality of images of the cells obtained by different working modes is compared through the image quality assessment (IQA) methods.
    • Direct imaging of IgE on the mica surface by tapping-mode atomic force microscopy

      Hu, Jing; Wang, Ying; Gao, Mingyan; Song, Zhengxun; Chen, Yujuan; Wang, Zuobin; Changchun University of Science and Technology; University of Bedfordshire (IEEE, 2020-02-02)
      Immunoglobulin E (IgE) antibody is essential in the functioning of the immune system, so the study of IgE has its practical and profound significance. Herein, the effect of protein concentration and adsorption time on IgE morphology of mica surface was investigated. For this purpose, atomic force microscopy (AFM) has been performed for monitoring protein morphology at different concentrations and adsorption times. In addition, the height and average roughness of IgE were also obtained. The changes of IgE molecule morphology including the shape, height and average roughness indicated that the interactions of protein-surface and protein-protein were varying with the protein concentration and adsorption time.
    • Establishing an optimized method for the separation of low and high abundance blood plasma proteins

      Yang, Henian; Wang, Guijie; Zhang, Tiantian; Beattie, John H.; Zhou, Shaobo; University of Bedfordshire; Bournemouth University; University of Aberdeen (PeerJ, 2020-02-01)
      The study tested the efficiency and reproducibility of a method for optimal separation of low and high abundant proteins in blood plasma. Firstly, three methods for the separation and concentration of eluted (E: low abundance), or bound (B: high abundance) proteins were investigated: TCA protein precipitation, the ReadyPrep™ 2-D cleanup Kit and Vivaspin Turbo 4, 5 kDa ultrafiltration units. Secondly, the efficiency and reproducibility of a Seppro column or a ProteoExtract Albumin/IgG column were assessed by quantification of E and B proteins. Thirdly, the efficiency of two elution buffers, containing either 25% or 10% glycerol for elution of the bound protein, was assessed by measuring the remaining eluted volume and the final protein concentration. Compared to the samples treated with TCA protein precipitation and the ReadyPrep™ 2-D cleanup Kit, the E and B proteins concentrated by the Vivaspin4, 5 kDa ultrafiltration unit were separated well in both 1-D and 2-D gels. The depletion efficiency of abundant protein in the Seppro column was reduced after 15 cycles of sample processing and regeneration and the average ratio of E/(B + E) × 100% was 37 ± 11(%) with a poor sample reproducibility as shown by a high coefficient of variation (CV = 30%). However, when the ProteoExtract Albumin/IgG column was used, the ratio of E/(B + E) × 100% was 43 ± 3.1% (n = 6) and its CV was 7.1%, showing good reproducibility. Furthermore, the elution buffer containing 10% (w/v) glycerol increased the rate of B protein elution from the ProteoExtract Albumin/IgG column, and an appropriate protein concentration (3.5 µg/µl) for a 2-D gel assay could also be obtained when it was concentrated with Vivaspin Turbo 4, 5 kDa ultrafiltration unit. In conclusion, the ProteoExtract Albumin/IgG column shows good reproducibility of preparation of low and high abundance blood plasma proteins when using the elution buffer containing 10% (w/v) glycerol. The optimized method of preparation of low/high abundance plasma proteins was when plasma was eluted through a ProteoExtract Albumin/IgG removal column, the column was further washed with elution buffer containing 10% glycerol. The first and second elution containing the low and high abundance plasma proteins, respectively, were further concentrated using Vivaspin® Turbo 4, 5 kDa ultrafiltration units for 1 or 2-D gel electrophoresis.
    • Linewidth study of pixelated aluminum nanowire gratings on polarization performance

      Yu, Miao; Song, Zhengxun; Dong, Litong; Li, Li; Cao, Liang; Li, Wenjun; Song, Yingying; Lei, Li; Wang, Zuobin; Changchun University of Science and Technology; et al. (Optical Society of America, 2020-02-01)
      Nowadays, nanowire gratings are widely used in various applications such as imaging sensors and high-resolution microscopes. Structure parameters are the main factors that affect the optical performance of the gratings. This work aims to present the influence of the linewidth of pixelated aluminum nanowire gratings with a fixed period on the transmittance and extinction ratio in the visible region. By controlling the exposure doses of electron beam lithography (EBL), different linewidths of pixelated aluminum nanowire gratings with a period of 170 nm were fabricated. The significant effects of linewidth difference on the polarization performance were verified by the simulations of finite-difference time-domain (FDTD) software. The simulations were divided into two parts: the discussion of the pure aluminum without considering oxidation and the discussion of the surface aluminum being oxidized into the aluminum oxide. An optical system was built to evaluate the performance of the fabricated structures. The results show that the trends of the measurement results are consistent with that of simulation. This work will give a guide to the fabrication and evaluation of the nanowire gratings.
    • Utilising information foraging theory for user interaction with image query auto-completion

      Jaiswal, Amit Kumar; Liu, Haiming; Frommholz, Ingo; University of Bedfordshire (Springer, 2020-01-20)
      Query Auto-completion (QAC) is a prominently used feature in search engines, where user interaction with such explicit feature is facilitated by the possible automatic suggestion of queries based on a prefix typed by the user. Existing QAC models have pursued a little on user interaction and cannot capture a user’s information need (IN) context. In this work, we devise a new task of QAC applied on an image for estimating patch (one of the key components of Information Foraging Theory) probabilities for query suggestion. Our work supports query completion by extending a user query prefix (one or two characters) to a complete query utilising a foraging-based probabilistic patch selection model. We present iBERT, to fine-tune the BERT (Bidirectional Encoder Representations from Transformers) model, which leverages combined textual-image queries for a solution to image QAC by computing probabilities of a large set of image patches. The reflected patch probabilities are used for selection while being agnostic to changing information need or contextual mechanisms. Experimental results show that query auto-completion using both natural language queries and images is more effective than using only language-level queries. Also, our fine-tuned iBERT model allows to efficiently rank patches in the image.
    • A disulfiram-loaded fibers scaffold fabricated via electrospinning method

      Xie, Chenchen; Ding, Ran; Wang, Xinyue; Yan, Jin; Wang, Ying; Zhang, Wenxiao; Qu, Yingmin; Wang, Zuobin; Changchun University of Science and Technology; University of Bedfordshire (IEEE, 2020-01-02)
      In this study, we developed a disulfiram-loaded fibers scaffold via the electrospinning method for enhancing the stability of disulfiram and facilitating the appropriate distribution in tumor tissues. The drug release profile of the disulfiram-loaded fibers scaffold was examined by high-performance liquid chromatography. The results showed that both the initial burst release and the subsequent sustainable release of the drug were suitable for cancer treatments. The results of an MTT assay, which tested the therapeutic efficacy of electrospun fibers in vitro, showed that the DSF-PVDF fibers exhibited their anticancer activity due to the incorporation of DSF. It indicates that DSF is successfully incorporated into the electrospun fibers and the resultant electrospun fibers are highly promising for cancer treatments.
    • Growth of nerve cells induced by diverse nanopillar arrays

      Liu, Mengnan; Dong, Litong; Yang, Xueying; Guo, Xuan; Wang, Xuan; Xie, Chenchen; Song, Zhengxun; Wang, Zuobin; Li, Dayou; Changchun University of Science and Technology; et al. (IEEE, 2020-01-02)
      The nanotopographies can induce the growth of nerve cells and the growth of their synapses. Studying the anisotropic structures for the guidance of neuronal synapses is beneficial to the in vitro repair of neurons and the development of regenerative medicine. Thus, studying how diverse nanopillar arrays affect the growth of nerve cells is essential. This paper employed the technology of laser interference lithography (LIL) to fabricate different nanopillar arrays with the same and different size gaps between the X and Y directions, and observe how the structures induce the growth of nerve cells and their synapses.
    • Tunable phantoms and their verification

      Zhang, Qing; Ur-Rehman, Masood; Yang, Xiaodong (American Scientific Publishers, 2020-01-01)
      Digital phantoms are very important for body area networks and other biomedical applications. However, it is important to note that most existing phantoms are static, including 3D scanned and voxel models. Recent research has revealed that tunable phantoms are still very necessary for body area networks since various postures should be considered. In this paper, parameterized digital phantoms are generated from 2D images. The train of thought and results presented in the paper are worth reference for phantom researchers.
    • Information foraging for enhancing implicit feedback in content-based image recommendation

      Jaiswal, Amit Kumar; Liu, Haiming; Frommholz, Ingo; University of Bedfordshire (ACM, 2019-12-31)
      User implicit feedback plays an important role in recommender systems. However, finding implicit features is a tedious task. This paper aims to identify users' preferences through implicit behavioural signals for image recommendation based on the Information Scent Model of Information Foraging Theory. In the first part, we hypothesise that the users' perception is improved with visual cues in the images as behavioural signals that provide users' information scent during information seeking. We designed a content-based image recommendation system to explore which image attributes (i.e., visual cues or bookmarks) help users find their desired image. We found that users prefer recommendations predicated by visual cues and therefore consider the visual cues as good information scent for their information seeking. In the second part, we investigated if visual cues in the images together with the images itself can be better perceived by the users than each of them on its own. We evaluated the information scent artifacts in image recommendation on the Pinterest image collection and the WikiArt dataset. We find our proposed image recommendation system supports the implicit signals through Information Foraging explanation of the information scent model.
    • Displacement error analysis of 6-DoF virtual reality

      Aksu, Ridvan; Chakareski, Jacob; Velisavljevic, Vladan; University of Alabama; University of Bedfordshire (ACM, 2019-12-31)
      Virtual view synthesis is a critical step in enabling Six-Degrees of Freedom (DoF) immersion experiences in Virtual Reality (VR). It comprises synthesis of virtual viewpoints for a user navigating the immersion environment, based on a small subset of captured viewpoints featuring texture and depth maps. We investigate the extreme values of the displacement error in view synthesis caused by depth map quantization, for a given 6DoF VR video dataset, particularly based on the camera settings, scene properties, and the depth map quantization error. We establish a linear relationship between the displacement error and the quantization error, scaled by the sine of the angle between the location of the object and the virtual view in the 3D scene, formed at the reference camera location. In the majority of cases the horizontal and vertical displacement errors induced at a pixel location of a reconstructed 360° viewpoint comprising the immersion environment are respectively proportional to 3/5 and 1/5 of the respective quantization error. Also, the distance between the reference view and the synthesized view severely increases the displacement error. Following these observations: displacement error values can be predicted for given pixel coordinates and quantization error, and this can serve as a first step towards modeling the relationship between the encoding rate of reference views and the quality of synthesized views.
    • Study of in situ laser modification of InAs/GaAs quantum dots

      Miao, Lili; Yang, Linyun; Yang, Xinning; Zhuang, Siyi; Shi, Zhenwu; Peng, Changsi; Soochow University; University of Bedfordshire (SPIE, 2019-12-31)
      We have investigated the modification of self-assembled InAs/GaAs quantum dots (QDs) by in situ pulsed laser irradiation. The QDs were fabricated by molecular beam epitaxy (MBE) in Stranski-Krastanov mode at 480℃ and then at the same temperature the pulsed laser was in situ introduced to modify the QDs with different energy. The dependence of morphology evolution on irradiation energy was carefully studied by AFM testing. The results show that laser excitation can enable both desorption and diffusion of In atoms which may induce strong modification on the InAs QDs. For irradiation of a moderate energy, the 3D dot-like InAs QD will transform into 2D oval-shaped island; Once the irradiation energy is high enough, the InAs QDs will be completely removed off from the surface. The involved mechanism is also discussed. Herein, we have proposed a new approach of fabricating QDs which is high-efficient, pollution-free, oxidation-free and defect-resistant and it is believed in the near future, it may find wide applications in both the fundamental physics research and emerging device manufacture.