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1.Special issue on computational intelligence for social media data mining and knowledge discovery

Author:Li, Y;Shyamasundar, RK;Wang, XH


2.Energy Dissipation During Impact of an Agglomerate Composed of Autoadhesive Elastic-Plastic Particles

Author:Liu, LF;Thornton, C;Shaw, SJ


Abstract:Discrete Element Method is used to simulate the impact of agglomerates consisting of autoadhesive, elastic-plastic primary particles. In order to explain the phenomenon that the elastic agglomerate fractures but the elastic-plastic agglomerate disintegrates adjacent to the impact site for the same impact velocity, we increase the impact velocity and lower the yield strength of the constituent particles of the agglomerate. We find that increasing the impact velocity can lead to the increased number of yielded contacts, and cause the elastic-plastic agglomerate to disintegrate faster. Mostly importantly, the energy dissipation process for the elastic-plastic agglomerate impact has been investigated together with the evolutions of the yielding contacts, and evolutions of velocity during impact.

3.Deformations of the standard model: SUq(3) flavor symmetry

Author:Gresnigt, NG


Abstract:The quantum group SUq(3) = Uq(su(3)) is taken as a baryon flavor symmetry and exceptionally accurate octet and decuplet baryons mass relations are obtained by accounting for the electromagnetic contribution to baryon masses (to zeroth order). The resulting charge specific q-deformed octet and decuplet baryon mass sum formulas are accurate to 0.02%% and 0.08%% respectively; a factor of 20 reduction in error compared to the standard Gell-Mann-Okubo mass formulas. An explicit formula for the Cabibbo angle, taken to be pi/14, in terms of the deformation parameter q and spin parity J(P) of the baryons is obtained.

4.Usable Authentication Mechanisms for Mobile Devices: An Exploration of 3D Graphical Passwords

Author:Yu, Z;Olade, I;Liang, HN;Fleming, C


Abstract:Current authentication systems in mobile devices such as smart phones have many shortcomings. Users tend to use simple textual passwords such as PINs, which are easily cracked by intruders. Meanwhile, graphical passwords suffer from shoulder surfing attack In this paper, a new authentication system using 3D graphical passwords, will be proposed and tested to offer more security for mobile devices. This authentication system allows users to interact with the 3D objects in a 3D virtual environment and these actions are tracked in the virtual environment and used to create unique passwords. Based on the previous studies of the 3D password scheme, this paper developed a simple testing program that enables users to create their own 3D password easily. At the end of the paper, some improvements of the program and this authentication system are discussed.

5.Identifying the influential spreaders in multilayer interactions of online social networks

Author:Al-Garadi, MA;Varathan, KD;Ravana, SD;Ahmed, E;Chang, V


Abstract:Online social networks (OSNs) portray a multi-layer of interactions through which users become a friend, information is propagated, ideas are shared, and interaction is constructed within an OSN. Identifying the most influential spreaders in a network is a significant step towards improving the use of existing resources to speed up the spread of information for application such as viral marketing or hindering the spread of information for application like virus blocking and rumor restraint. Users communications facilitated by OSNs could confront the temporal and spatial limitations of traditional communications in an exceptional way, thereby presenting new layers of social interactions, which coincides and collaborates with current interaction layers to redefine the multiplex OSN. In this paper, the effects of different topological network structure on influential spreaders identification are investigated. The results analysis concluded that improving the accuracy of influential spreaders identification in OSNs is not only by improving identification algorithms but also by developing a network topology that represents the information diffusion well. Moreover, in this paper a topological representation for an OSN is proposed which takes into accounts both multilayers interactions as well as overlaying links as weight. The measurement results are found to be more reliable when the identification algorithms are applied to proposed topological representation compared when these algorithms are applied to single layer representations.

6.A comparative study of models for shear strength of reinforced concrete T-beams

Author:Liu, J;Gao, ZY


Abstract:Reinforced concrete T-beams are widely used in bridges where beams are cast integrally with deck sections to either side at the beam tops. Although it has been recognized by numerous experimental studies that flanges may have a significant contribution to the shear strength of reinforced concrete T-beams, they are neglected in most of the design codes. In this paper, the load paths to transfer shear force in T-beams are firstly investigated with the help of existing experimental tests. Compared with rectangular beams, an additional load path diverts the diagonal compression from the loading point and the end support, and it carries a portion of the shear force through the flange to the end support. In order to find a relatively reliable model to predict the shear strength of T-beams, a comparative study is carried out among five representative models selected from the literature by using a database with 233 reported T-beam tests. Parametric studies with individual test series are also performed for a detailed evaluation of the five models. It is found that a model proposed by Cladera et al. (i.e., Model [3] is one of the models producing the least scattered predictions. The average shear strength experimental-to-predicted ratio V-exp/V-pred is 1.06 with the coefficient of variation (COV) of 19.6%%. At the same time, it is shown that Model [3] exhibits uniform results across the entire range of experimental data without obvious bias. At the same time, Model [3] is one of the models requiring the least computational effort but with the largest range of applicability.

7.Minimize Reactive Power Losses of Dual Active Bridge Converters using Unified Dual Phase Shift Control

Author:Wen, HQ;Su, B


Abstract:This paper proposed an unified dual-phase-shift (UDPS) control for dual active bridge (DAB) converters in order to improve efficiency for a wide output power range. Different operating modes of UDPS are characterized with respect to the reactive current distribution. The proposed UDPS has the same output power capability with conventional phase-shift (CPS) method. Furthermore, its implementation is simple since only the change of the leading phase-shift direction is required for different operating power range. The proposed UDPS control can minimize both the inductor rms current and the circulating reactive current for various voltage conversion ratios and load conditions. The optimal phase-shift pairs for two bridges of DAB converter are derived with respect to the comprehensive reactive power loss model, including the reactive components delivered from the load and back to the source. Simulation and experimental results are illustrated and explained with details. The effectiveness of the proposed method is verified in terms of reactive power losses minimization and efficiency improvement.

8.Quantitative and rapid detection of microcystin-LR using time-resolved fluorescence immunochromatographic assay based on europium nanospheres

Author:Zhang, Y;Ding, XL;Guo, MM;Han, TT;Huang, ZJ;Shang, HT;Huang, B


Abstract:In the present study, a novel time-resolved fluorescence immunochromatographic assay was established for the rapid quantitative detection of microcystin-leucine arginine (MC-LR). In this method, the europium nanoshpere labelled with anti-MC-LR antibodies was used as the luminescent tracer, dissolved in the running buffer and then added with the sample solution on the pad. MC-LR-BSA and goat anti-mouse antibody were dispensed on the nitrocellulose membrane for the test and the control line, respectively. The optimal parameters were 0.05 g L-1 MC-LR-BSA, 1 : 100 colloidal europium-antibody conjugate, and 10 min reaction time. The linear working range for MC-LR was 0.1-5 mu g L-1 with an IC50 of 0.78 mu g L-1 and a sensitivity of 0.035 mu g L-1. The low cross-reactivity was observed with MC-YR and MC-LF. The assay accuracy was confirmed by the HPLC method with a correlation coefficient of 0.99. When the variable coefficients were 4.4%% and 5.4%%, the average recoveries of tap and lake water were 94.6%% and 102.8%%, respectively. The time-resolved fluorescence immunochromatographic assay provides a sensitive, simple, and speedy performance for MC-LR quantitative determination and has a potential use for water sample screening.

9.Exploring a curriculum app and a social communication app for EFL learning

Author:Zou, B;Li, H;Li, JY


Abstract:Mobile apps are broadly used by students in and after class to improve their language skills. This study aimed to investigate how a curriculum app and a social communication app can be integrated into English language teaching and learning and what sorts of tasks can be employed to enhance learners' EFL learning. A curriculum app was created by the researchers and integrated into English teaching and learning in and out of class. Meanwhile, a social communication app used on mobile phones was also established for communication between students and the teacher. Questionnaires and interviews were conducted so as to explore students' perceptions of these apps. The findings indicated that mobile learning can be adapted in EFL lessons and learners' self-study. The apps providing sources connected to lessons and opportunities for communication offered additional support to students to practice English in and after class. Participants provided positive comments on the two apps for mobile learning.

10.Application of Hough Transform Feature Extraction to Reduce Angular Vibration in Images Captured from Moving Objects

Author:Afolabi, D;Man, KL;Liang, HN;Zhang, N;Lim, EG;Wan, KY


Abstract:This paper details an ongoing research aimed at developing computational approach to reducing/eliminating vibration and light glare in images captured by digital cameras especially when the scene contains moving objects or the camera is mounted on a moving vehicle / flying drone. The algorithms developed are focused at real-time image acquisition where the enhanced/corrected images are need almost immediately after they are captured. The results show that these methods of reducing the stated problems are effective and it can be further developed for various applications.

11.On the theoretical distribution of the wind farm power when there is a correlation between wind speed and wind turbine availability

Author:Kan, C;Devrim, Y;Eryilmaz, S


Abstract:It is important to elicit information about the potential power output of a wind turbine and a wind farm consisting of specified number of wind turbines before installation of the turbines. Such information can be used to estimate the potential power output of the wind farm which will be built in a specific region. The output power of a wind turbine is affected by two factors: wind speed and turbine availability. As shown in the literature, the correlation between wind speed and wind turbine availability has an impact on the output of a wind farm. Thus, the probability distribution of the power produced by the farm depending on the wind speed distribution and turbine availability can be effectively used for planning and risk management. In this paper, the theoretical distribution of the wind farm power is derived by considering the dependence between turbine availability and the wind speed. The theoretical results are illustrated for real wind turbine reliability and wind speed data.

12.2,2-Dicyanovinyl-end-capped oligothiophenes as electron acceptor in solution processed bulk-heterojunction organic solar cells

Author:Wu, J;Ma, Y;Wu, N;Lin, Y;Lin, J;Wang, L;Ma, CQ


Abstract:Three 2,2-dicyanovinyl (DCV) end-capped A-pi-D-pi-A type oligothiophenes (DCV-OTs) containing dithieno[3,2-b: 2',3'-d] silole (DTSi), cyclopenta[1,2-b: 3,4-b'] dithiophene (DTCP) or dithieno[3,2-b: 2',3'-d] pyrrole (DTPy) unit as the central donor part, mono-thiophene as the pi-conjugation bridge were synthesized. The absorption spectroscopies, cyclic voltammetry of these compounds were characterized. Results showed that all these compounds have intensive absorption band over 500-680 nm with a LUMO energy level around -3.80 eV, which is slightly higher than that of [6,6] phenyl-C-61-butyric acid methyl ester (PC61BM, E-LUMO = -4.01 eV), but lower than that of poly(3-hexylthiophene) (P3HT, ELUMO = -2.91 eV). Solution processed bulk heterojunction "all-thiophene'' solar cells using P3HT as electron donor and the above mentioned oligothiophenes as electron acceptor were fabricated and tested. The highest power conversion efficiency (PCE) of 1.31%% was achieved for DTSi-cored compound DTSi(THDCV) 2, whereas PTB7: DTSi(THDCV) 2 based device showed slightly higher PCE of 1.56%%. Electron mobilities of these three compounds were measured to be around 10 (5) cm(2) V (1) s (1) by space charge limited current method, which is much lower than that of PC61BM, and was considered as one of the reason for the low photovoltaic performance. (C) 2015 Elsevier B.V. All rights reserved.

13.Impact of Parasitic Elements on RF Performance of Nanometre-Scale MOSFET Structures

Author:Lam, S


Abstract:A recently reported nanometre-scaled MOSFET structure with regrown source and drain is examined. The parasitic circuit elements are identified and quantitatively determined to estimate their impact on the transistor's RF performance. Due to the relatively large lateral parasitic capacitances from the gate electrode to the regrown source and drain regions, the current gain cut-off frequency f(T) of such a transistor is optimistically estimated to be 184 GHz which is not impressive for nanoelectronic devices with an effective gate length of 30 nm. However, with the significantly reduced parasitic series resistances due to the regrown source and drain structures together with the use of the metal gate, the maximum frequency of oscillation f(max) can attain to 820 GHz. This brings about an implication that device structure optimization to reduce the parasitic resistances has a dominant beneficial effect on the RF performance over the negative impact caused by the increased parasitic capacitances.


Author:Fischer, T;De Biswas, K;Ham, JJ;Naka, R;Huang, WX


15.Clinical Validity and Reliability of the Malay Language Translations of Gastroesophageal Reflux Disease Questionnaire and Quality of Life in Reflux and Dyspepsia Questionnaire in a Primary Care Setting

Author:Vadivelu, S;Ma, ZF;Ong, EW;Hassan, N;Hassan, NFHN;Aziz, SHSA;Kueh, YC;Lee, YY


Abstract:Background: Gastroesophageal Reflux Disease Questionnaire (GERDQ) and Quality of Life in Reflux and Dyspepsia Questionnaire (QOLRAD) are reliable tools for evaluation of GERD. Aim: We aimed to test validity and reliability of Malay language translations of GERDQ and QOLRAD in a primary care setting. Methods: The questionnaires were first translated into the Malay language (GERDQ-M and QOLRAD-M). Patients from primary care clinics with suspected GERD were recruited to complete GERDQ-M, QOLRAD-M, and Malay-translated 36-item short-form health survey (SF-36 or SF36-M), and underwent endoscopy and 24-h pH-impedance test. Results: A total of 104 (mean age 47.1 years, women 51.9%%) participants were enrolled. The sensitivity and specificity for GERDQ-M cut-off score >= 8 were 90.2 and 77.4%%, respectively. Based on this cut-off score, 54.7%% had a high probability of GERD diagnosis. GERD-M score >= 8 vs. <8 was associated with erosive esophagitis (p < 0.001), hiatus hernia (p = 0.03), greater DeMeester score (p = 0.001), and Zerbib scores for acid refluxes (p < 0.001) but not non-acid refluxes (p = 0.1). Mean total scores of QOLRAD-M and SF-36-M were correlated (r = 0.74, p < 0.001). GERDQ-M = 8, erosive esophagitis, and DeMeester >= 14.72 were associated with impaired QOLRAD-M in all domains (all p < 0.02) but this was not seen with SF-36. Conclusions: GERDQ-M and QOLRAD-M are valid and reliable tools applicable in a primary care setting. (C) 2018 S. Karger AG, Basel

16.Experimental and Numerical Study on Impact of Double Layer Vegetation in Open Channel Flows

Author:Rahimi, HR;Tang, X;Singh, P


Abstract:This paper studies the effects of different types and configurations of double layer vegetation on the flow of open channels. The vegetation is simulated through cylindrical dowels with a diameter of 6.35 mm and heights of 10 and 20 cm, which represent short and tall dowels, respectively. Profiles for instantaneous velocities were obtained by acoustic Doppler velocimetry (ADV) at different locations around vegetation with multiple staggered and linear formations. The experiment covers a wide range of sparse to dense vegetation configurations. Furthermore, different flow depths were selected to simulate fully submerged cases for short vegetation and to capture the inflection of velocity over the mixing region between short and tall dowels. The results reveal that the velocity profile is mostly uniform at the depth of short vegetation in different configurations with various densities. The velocity starts to increase in the region near the top edge of short vegetation, followed by a significant increase through the height of tall vegetation to the free surface. Generally, the flow velocity behind the vegetation layer is significantly smaller than that in free regions adjacent to short and tall vegetation. The overall idea of the present study was to simulate the same sets of vegetation configurations using a K-epsilon model with mesh sensitivity analysis to capture inflections over the short vegetation region. The experimental investigations with a numerical study were explored for double layer vegetation, which was corroborated and found to have good agreement for different vegetation configurations. (C) 2019 American Society of Civil Engineers.

17.Key management and key distribution for secure group communication in mobile and cloud network

Author:Vijayakumar, P;Chang, V;Deborah, LJ;Kshatriya, BSR


Abstract:With the computing systems becoming more and more pervasive and ubiquitous due to the invention of cloud computing and mobile phone based applications, secure data transmission is the pressing need for a real time perspective of the technologies. Examples of the need for secure key management and distribution environments include secure transmission of health related SMS, telecare medicine provisioning for critical applications such as heart disorders, secure agriculture monitoring, data transmission in surveillance scenarios, secure military networks, etc. In the context of key exchange for secure group communication, the computational complexities need to be addressed in particular due to the advent of resource constrained mobile phones, sensors and other embedded devices. This special issue introduces some of the novel approaches for enabling secure group communication in the contexts related to cloud and mobile computing. (C) 2018 Published by Elsevier B.V.

18.Dual algorithm for truncated fractional variation based image denoising

Author:Liang, HX;Zhang, JL


Abstract:Fractional-order derivative is attracting more and more attention of researchers in image processing because of its better property in restoring more texture than the total variation. To improve the performance of fractional-order variation model in image restoration, a truncated fractional-order variation model was proposed in Chan and Liang [Truncated fractional-order variation model for image restoration, J. Oper. Res. Soc. China]. In this paper, we propose a dual approach to solve this truncated fractional-order variation model on noise removal. The proposed algorithm is based on the dual approach proposed by Chambolle [An algorithm for total variation minimisation and applications, J. Math Imaging Vis. 20 (2004), pp. 89-97]. Conversely, the Chambolle's dual approach can be treated as a special case of the proposed algorithm with fractional order . The work of this paper modifies the result in Zhang et al. [Adaptive fractional-order multi-scale method for image denoising, J. Math. Imaging Vis. 43(1) (2012), pp. 39-49. Springer Netherlands 0924-9907, Computer Science, pp. 1-11, 2011], where the convergence is not analysed. Based on the truncation, the convergence of the proposed dual method can be analysed and the convergence criteria can be provided. In addition, the accuracy of the reconstruction is improved after the truncation is taken.

19.The dual effects of home country institutions on the internationalization of private firms in emerging markets Evidence from China

Author:Li, FR;Ding, D


Abstract:Purpose - This study aims to examine the dual effects of home country institutional forces (i.e. institutional support and institutional constraints) on the internationalization of private firms in emerging markets. By doing so, this study aims to examine the applicability of the two seemingly paradoxical views (i.e. the governmental promotion view and the institutional escapism view) in explaining private firms' internationalization. Further, this study investigates how the effect of the home country institutional environment on firms' internationalization is contingent upon firm characteristics. Design/methodology/approach - A sample of Chinese private firms is used to examine the effect of home country institutions on internationalization. Findings - Empirical findings suggest that both institutional support and institutional constraints promote the internationalization of private firms in emerging markets. Moreover, it is found that firm resources strengthen the effect of government support on internationalization. It is also found that firms' business ties strengthen the effect of institutional constraint on internationalization, whereas firms' political ties weaken the effect of institutional constraints on internationalization. Originality/value - By adopting an integrated and comprehensive investigation of the dual effects of home country institutional environment in emerging markets on internationalization, this study provides evidence to the applicability of the two competing views (i.e. the governmental promotion view and the institutional escapism view) in relation to home country institutional effects on internationalization. In addition, this study examines how institutional effects vary across firms with different resources and social ties, thus extends understandings of the boundary conditions of the two institutional effects.

20.Dopamine Surface Modification of Trititanate Nanotubes: Proposed In-Situ Structure Models.

Author:Liu, Ruochen; Fu, Xuejian; Wang, Congyi; Dawson, Graham

Source:Chemistry (Weinheim an der Bergstrasse, Germany),2016,Vol.22

Abstract:Two models for self-assembled dopamine on the surface of trititanate nanotubes are proposed: individual monomer units linked by π-π stacking of the aromatic regions and mono-attached units interacting through hydrogen bonds. This was investigated with solid state NMR spectroscopy studies and powder X-ray diffraction.
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