• 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.
    • Learner experience in hybrid virtual worlds: interacting with pedagogical agents

      Christopoulos, Athanasios; Conrad, Marc; Shukla, Mitul; University of Bedfordshire (SciTePress, 2019-12-31)
      Studies related to the Virtual Learning approach are conducted almost exclusively in Distance Learning contexts and focus on the development of frameworks or taxonomies that classify the different ways of teaching and learning. Researchers may be dealing with the topic of interactivity but mainly focusing on the interactions that take place within the virtual world. However, in non-distance learning contexts, where students not only share the virtual but also the physical space, different types of interplay can be observed. In this paper, we classify these ‘hybrid’ interactions and further correlate them with the impact that the instructional design decisions have on motivation and engagement. In particular, a series of experiments were conducted in the context of different Hybrid Virtual Learning units, with Computer Science and Technology students participating in the study, whilst, the chosen instructional design approach included the employment of different Pedagogical Agents who aimed at increasing the incentives for interaction and therefore, engagement. The conclusions provide suggestions and guidelines to educators and instructional designers who wish to offer interactive and engaging learning activities to their students.
    • Empirical investigation of factors that impact e-government adoption in Nigeria

      Chukwu, Joshua; Conrad, Marc; Crosbie, Tess (IADIS Press, 2019-12-31)
      This paper is a review of the impact of data protection/privacy, website usability and culture on e-government adoption. Along with Hofstede's cultural dimensions and technology acceptance theory, the paper uses these two theories to analyse the highly anticipated era of electronic government, an aspect through which government communicates with agencies and business organisation through information communication technology. We examine the adoption process, its challenges and difficulties, especially in developing countries like Nigeria considering fundamental deficiencies in basic infrastructure, human capacity, political and cultural constraints. This paper can help Nigerian government policy and decision makers develop strategies to adopt e-government services and improve the further development of these services. The paper does not only provide empirical support to previous research, but it validates and improve the results of similar studies in the field.
    • 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.
    • Study of in situ laser modification of Ga-droplets

      Yang, Xinning; Yang, Linyun; Miao, Lili; Zhuang, Siyi; Shi, Zhenwu; Peng, Changsi; Soochow University; University of Bedfordshire (SPIE, 2019-12-31)
      In this paper, we report the study on the size regulation of Ga-droplets by in situ laser irradiation. Gallium (Ga) droplets are grown on GaAs (001) substrate by molecular beam epitaxy (MBE) and the in situ laser irradiation is carried out by using an ultraviolet pulsed laser. The results show that: The laser irradiation will cause the expansion of Ga-droplets and then the adjacent Ga-droplets can touch with each other and larger Ga-droplets can be formed by the fusion of two or more droplets. So the size of Ga-droplets can be re-modified by laser irradiation and such modification is positively correlated with the irradiation intensity. In other words, we can easily define the size of Ga-droplets by using different laser irradiation energy.
    • Nephroblastoma analysis in MRI images

      Kaba, Djibril; McFarlane, Nigel J.B.; Dong, Feng; Graf, Norbert; Ye, Xujiong; University of Bedfordshire; Saarland University Hospital; University of Lincoln (International Society for Stereology, 2019-12-31)
      The annotation of the tumour from medical scans is a crucial step in nephroblastoma treatment. Therefore, an accurate and reliable segmentation method is needed to facilitate the evaluation and the treatments of the tumour. The proposed method serves this purpose by performing the segmentation of nephroblastoma in MRI scans. The segmentation is performed by adapting and a 2D free hand drawing tool to select a region of interest in the scan slices. Results from 24 patients show a mean root-mean-square error of 0.0481 ± 0.0309, an average Dice coefficient of 0.9060 ± 0.0549 and an average accuracy of 99.59% ± 0.0039. Thus the proposed method demonstrated an effective agreement with manual annotations.
    • Editorial for the 8th bibliometric-enhanced information retrieval workshop at ECIR 2019

      Cabanac, Guillaume; Frommholz, Ingo; Mayr, Philipp (CEUR-WS, 2019-12-31)
      The Bibliometric-enhanced Information Retrieval workshop series (BIR) at ECIR tackles issues related to academic search, at the crossroads between Information Retrieval and Bibliometrics. BIR is a hot topic investigated by both academia (e.g., ArnetMiner, CiteSeerχ, DocEar) and the industry (e.g., Google Scholar, Microsoft Academic Search, Semantic Scholar). This editorial presents the 8th iteration of the one-day BIR workshop held at ECIR 2019 in Cologne, Germany.
    • Anti-degranulation response of herbal formula in RBL-2H3 cells

      Hu, Jing; Chen, Yujuan; Zhu, Jiajing; Gao, Mingyan; Li, Jiani; Song, Zhengxun; Xu, Hongmei; Wang, Zuobin; Changchun University of Science and Technology; University of Warwick; et al. (Elsevier, 2019-12-28)
      Allergic diseases not only bring serious economic burden to the patients, but also consume a lot of substantial resources of social medical systems. Thus, the prevention and treatment of allergic diseases are imperative. In this study, the anti-degranulation activity of herbal formula was evaluated using the rat basophil leukemia cells (RBL-2H3) as in vitro model. The morphological and biophysical properties of RBL-2H3 cells before and after treatment with herbal formula were also determined. Notably, the herbal formula exhibits clearly inhibited degranulation by RBL-2H3 cells in a concentration-dependent manner without cytotoxic effect. Therefore, this herbal formula can be used as an alternative and promising therapeutic agent to ameliorate allergic diseases.
    • Design of a smart system for rapid bacterial test

      Patil, Rajshree; Levin, Saurabh; Rajkumar, Samuel; Ajmal, Tahmina; Institute of Chemical Technology (ICT), Mumbai; Foundation for Environmental Monitoring, Bangalore; University of Bedfordshire (MDPI, 2019-12-19)
      In this article, we present our initial findings to support the design of an advanced field test to detect bacterial contamination in water samples. The system combines the use of image processing and neural networks to detect an early presence of bacterial activity. We present here a proof of concept with some tests results. Our initial findings are very promising and indicate detection of viable bacterial cells within a period of 2 h. To the authors' knowledge this is the first attempt to quantify viable bacterial cells in a water sample using cell splitting. We also present a detailed design of the complete system that uses the time lapse images from a microscope to complete the design of a neural network based smart system.
    • IEEE Access special section: advances in interference mitigation techniques for device-to-device communications

      Ur-Rehman, Masood; Gao, Yue; Chaudhry, Mohammad Asad Rehman; Safdar, Ghazanfar Ali; Xu, Yanli; University of Essex; Queen Mary University of London; University of Toronto; University of Bedfordshire; Shanghai Maritime University (IEEE, 2019-12-17)
    • Influence of magnetic field on morphological structures and physiological characteristics of bEnd.3 cells cultured on polypyrrole substrates

      Yang, Xue; Ma, Ke; Yang, Libo; Chen, Yujuan; Qu, Yingmin; Wang, Ying; Wang, Xinyue; Yang, Fan; Sun, Qi; Song, Zhengxun; et al. (Royal Society of Chemistry, 2019-12-11)
      This paper employs a spin-coated method to construct conductive polypyrrole (PPy) substrates which present superior properties for controlling the morphological structures and functions of bEnd.3 cells. The PPy substrates with a homogeneous particle size, uniform distribution and proper roughness show enhanced hydrophilic characteristics and improve cell adhesion to the substrates. The changes in the mechanical properties of cells and the responses to the designed substrates and magnetic field are also explored. Due to the synergistic effect between the magnetic field and the conductive PPy substrate, the cells cultured in such an environment exhibit applanate shapes with more branches and enhanced cell viability. In addition, the cells preferentially extend along the magnetic field direction. The mechanical characteristics of cells change significantly under varying magnetic intensity stimulations (5–16 mT). The satisfying effect on cells' morphology and outgrowth is acquired at the magnetic intensities of 9–10 mT and duration of 20 min, compared with other stimulated groups, while retaining cell viability. Moreover, the cells express higher adhesion up to 5.2 nN. The results suggest that the application of the PPy substrates and magnetic field is a promising candidate for the protection of neurovascular units and treatment of neurological diseases.
    • Patient empowerment for cancer patients through a novel ICT infrastructure

      Kondylakis, Haridimos; Bucur, Anca; Crico, Chiara; Dong, Feng; Graf, Norbert; Hoffman, Stefan; Koumakis, Lefteris; Manenti, Alice; Marias, Kostas; Mazzocco, Ketti; et al. (Academic Press Inc., 2019-12-06)
      As a result of recent advances in cancer research and “precision medicine” approaches, i.e. the idea of treating each patient with the right drug at the right time, more and more cancer patients are being cured, or might have to cope with a life with cancer. For many people, cancer survival today means living with a complex and chronic condition. Surviving and living with or beyond cancer requires the long-term management of the disease, leading to a significant need for active rehabilitation of the patients. In this paper, we present a novel methodology employed in the iManageCancer project for cancer patient empowerment in which personal health systems, serious games, psychoemotional monitoring and other novel decision-support tools are combined into an integrated patient empowerment platform. We present in detail the ICT infrastructure developed and our evaluation with the involvement of cancer patients on two sites, a large-scale pilot for adults and a small-scale test for children. The evaluation showed mixed evidences on the improvement of patient empowerment, while ability to cope with cancer, including improvement in mood and resilience to cancer, increased for the participants of the adults′ pilot.
    • Atomic force acoustic microscopy reveals the influence of substrate stiffness and topography on cell behavior

      Liu, Yan; Li, Li; Chen, Xing; Wang, Ying; Liu, Mengnan; Yan, Jin; Cao, Liang; Wang, Lu; Wang, Zuobin; Changchun University of Science and Technology; et al. (Beilstein-Institut, 2019-11-26)
      The stiffness and the topography of the substrate at the cell-substrate interface are two key properties influencing cell behavior. In this paper, atomic force acoustic microscopy (AFAM) is used to investigate the influence of substrate stiffness and substrate topography on the responses of L929 fibroblasts. This combined nondestructive technique is able to characterize materials at high lateral resolution. To produce substrates of tunable stiffness and topography, we imprint nanostripe patterns on undeveloped and developed SU-8 photoresist films using electron-beam lithography (EBL). Elastic deformations of the substrate surfaces and the cells are revealed by AFAM. Our results show that AFAM is capable of imaging surface elastic deformations. By immunofluorescence experiments, we find that the L929 cells significantly elongate on the patterned stiffness substrate, whereas the elasticity of the pattern has only little effect on the spreading of the L929 cells. The influence of the topography pattern on the cell alignment and morphology is even more pronounced leading to an arrangement of the cells along the nanostripe pattern. Our method is useful for the quantitative characterization of cell-substrate interactions and provides guidance for the tissue regeneration therapy in biomedicine.
    • Study of SU-8 photoresist cross-linking process by atomic force acoustic microscopy

      Zhao, Yujing; Liu, Yan; Wang, Zuobin; Wang, Lu; Li, Li; Hou, F.; Song, Zhengxun; Weng, Zhankun; (Wiley, 2019-11-26)
      In this paper, a method is presented to detect the different phases of epoxy cross-linking process and the subsurface structures of SU-8 thin films by atomic force acoustic microscopy (AFAM). The AFAM imaging of SU-8 thin films was investigated under different exposure and bake conditions. Optimized conditions were obtained for the cross-linking of SU-8 thin film at the exposure does of eight laser pulses with the laser fluence 10 mJ cm-2 per pulse and the post exposure bake (PEB) time at 90 s. The subsurface structures of undeveloped SU-8 thin films were visible in the AFAM images. This method provides an effective and low-cost way for the determination of different phases of epoxy cross-linking process in nanostructured compounds, for the non-destructive testing of subsurface defects, and for the evaluation of the quality of patterned structures.
    • Point controlled energy efficient medium access in WLANs for low latency communications

      Safdar, Ghazanfar Ali; Ur-Rehman, Masood; University of Bedfordshire; University of Essex (IEEE, 2019-11-18)
      Wireless networks are going through huge development due to growth in demand and supply of new wireless terminals having multiple features. Their application areas range from communication to infotainment and medical to gaming. Inclusion of large number of features make availability of sufficient power for long operational hours a key challenge in these devices. Hence, limited battery life of wireless terminals makes energy efficiency an important issue in wireless networks. Medium access control (MAC) protocols play an essential role in this context. In fact, MAC protocols can have a significant impact on energy consumption since both transmission and reception activities are very costly in terms of energy. A centralised polling based MAC avoids collisions and can guarantee a higher energy efficiency with respect to pure carrier sense multiple access (CSMA). Pointer controlled slot allocation and resynchronisation (PCSAR) protocol implements power conscious scheduling techniques to enable terminals enter prolonged sleep state, thereby improving the overall energy consumption of the network. This paper investigates the performance of PCSAR and compares it with the IEEE 802.11 standard infrastructure power save mode (PSM). Results demonstrate that PCSAR outperforms the standard mode in a composite rate WLAN scenario. Moreover, use of TDM based circuit switching makes PCSAR more reliable. These features make it a potentially good candidate for energy efficient reliable low latency communication for current (4G/LTE) and future (5G and beyond) applications.
    • What does the pedagogical agent say?

      Christopoulos, Athanasios; Conrad, Marc; Shukla, Mitul; University of Bedfordshire (Institute of Electrical and Electronics Engineers Inc., 2019-11-14)
      The successful employment of Virtual Reality Environments in distance education contexts led to the development of various frameworks and taxonomies related to the Virtual-Learning approach. However, when it comes to Blended or 'Hybrid' Virtual Learning (HVL) scenarios, where the learners are concurrently co-present both in the physical and in the virtual environment, the lines are hard to be drawn as this has been a relatively unexplored area. Considering the aforementioned change in the setup of the educational context, different implications, challenges and outcomes are expected to be observed. Motivated by this shortcoming, we conducted a series of experiments with Computer Science and Technology students and investigated the impact of interactions on learners' motivation to engage with the 3D virtual world and the educational activities by extension. In this paper, we discuss students' preconceptions towards the inclusion of 3D Virtual Learning Environments in the context of their studies and further elicit their thoughts related to the impact of the 'hybrid' interactions. In addition, we investigate the educational value of different Non-Player Characters (Pedagogical Agents) and their impact on the attractiveness of the virtual world and the educational tasks. The concluding remarks provide guidance to educators and instructional designers who work in such setups or consider to employ Pedagogical Agents. To this end, employing Pedagogical Agents requires careful consideration as they need to be meaningful and fully incorporated in the learner's task. Another take-away message concerns the elements that foster a situated learning experience as they are associated with immersive experiences.
    • 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.
    • Single-cell patterning technology for biological applications

      Wang, Zihui; Lang, Baihe; Qu, Yingmin; Li, Li; Song, Zhengxun; Wang, Zuobin; ; Changchun University of Science and Technology; University of Bedfordshire (AIP Publishing, 2019-11-11)
      Single-cell patterning technology has revealed significant contributions of single cells to conduct basic and applied biological studies in vitro such as the understanding of basic cell functions, neuronal network formation, and drug screening. Unlike traditional population-based cell patterning approaches, single-cell patterning is an effective technology of fully understanding cell heterogeneity by precisely controlling the positions of individual cells. Therefore, much attention is currently being paid to this technology, leading to the development of various micro-nanofabrication methodologies that have been applied to locate cells at the single-cell level. In recent years, various methods have been continuously improved and innovated on the basis of existing ones, overcoming the deficiencies and promoting the progress in biomedicine. In particular, microfluidics with the advantages of high throughput, small sample volume, and the ability to combine with other technologies has a wide range of applications in single-cell analysis. Here, we present an overview of the recent advances in single-cell patterning technology, with a special focus on current physical and physicochemical methods including stencil patterning, trap- and droplet-based microfluidics, and chemical modification on surfaces via photolithography, microcontact printing, and scanning probe lithography. Meanwhile, the methods applied to biological studies and the development trends of single-cell patterning technology in biological applications are also described.