List of Titles

A special magnetic coupler structure for three-coil wireless power transfer : analysis, design, and experimental verification

- Wang, Heshou, Cheng, Ka, Li, Xiaofei, Hu, Jiefeng

Authors: Wang, Heshou , Cheng, Ka , Li, Xiaofei , Hu, Jiefeng
Date: 2021
Type: Text , Journal article
Relation: IEEE Transactions on Magnetics Vol. 57, no. 11 (2021), p.
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Description: In this article, a special magnetic coupler for three-coil wireless power transfer (WPT) is proposed to eliminate the mutual inductance between the source coil and the receiver coil, which can significantly improve the design freedom. Specifically, unipolar Q coil, mixed QDD coil, and bipolar DD coil are designed for the source coil, the transmitter coil ( $\text{T}_{\mathrm {X}}$ ), and the receiver coil ( $\text{R}_{\mathrm {X}}$ ), respectively. By making use of unipolar coils and bipolar coils, this structure magnetically decouples the receiver coil from the source coil. Meanwhile, under different lateral misalignment conditions, this new coupler facilitates maintaining high efficiency. A laboratory prototype has been constructed to validate the proposed structure, demonstrating that the proposed structure can realize inherent characteristics, enhance misalignment tolerance, and energy transfer. The potential applications are EV systems, but this design can be generalizable to other three-coil systems. © 1965-2012 IEEE.

A unified model predictive voltage and current control for microgrids with distributed fuzzy cooperative secondary control

- Shan, Yinghao, Hu, Jiefeng, Chan, Ka, Islam, Syed

Authors: Shan, Yinghao , Hu, Jiefeng , Chan, Ka , Islam, Syed
Date: 2021
Type: Text , Journal article
Relation: IEEE Transactions on Industrial Informatics Vol. 17, no. 12 (DEC 2021), p. 8024-8034
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Description: A microgrid formed by a cluster of parallel distributed generation (DG) units is capable of operating in either islanded mode or grid-connected mode. Traditionally, by using model predictive control algorithms, these two operation modes can be achieved with two separate and different cost functions, which brings in control complexity and hence, compromises system reliability. In this article, a unified model predictive voltage and current control strategy is proposed for both islanded and grid-connected operations and their smooth transition. The cost function is kept unified with voltage and current taken into account without altering the control architecture. It can be used for high-quality voltage supply at the primary control level and for bidirectional power flow at the tertiary control level. In addition, by only using DGs' own and neighboring information, a distributed fuzzy cooperative algorithm is developed at the secondary layer to mitigate the voltage and frequency deviations inherent from the power droop. The fuzzy controller can optimize the secondary control coefficients for further voltage quality improvement. Comprehensive tests under various scenarios demonstrate the merits of the proposed control strategy over traditional methods.

Adaptive droop control using adaptive virtual impedance for microgrids with variable PV outputs and load demands

- Li, Zilin, Chan, Ka, Hu, Jiefeng, Guerrero, Josep

Authors: Li, Zilin , Chan, Ka , Hu, Jiefeng , Guerrero, Josep
Date: 2021
Type: Text , Journal article
Relation: IEEE Transactions on Industrial Electronics Vol. 68, no. 10 (2021), p. 9630-9640
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Description: In microgrids, intermittency of renewable energy sources (RES) and uncertain state-of-charge (SoC) of energy storage systems (ESS) can cause power deficiency to some distributed generation units (DGs). In this case, DGs with power deficiency may not meet the power demand, resulting in voltage collapse or frequency divergence. Unfortunately, this is seldom considered in inverter control design in existing literature. Thus, in-depth investigation into the microgrid performance under renewable energy resource fluctuations and appropriate control methods are urgently needed. In this article, an adaptive droop and adaptive virtual impedance control strategy is proposed. Unlike conventional droop control where the droop coefficients are fixed by assuming the DGs can always meet the load demand, the droop coefficients here are adjusted according to actual solar PV power output. In this way, proper power sharing among DGs can be achieved under renewable energy variation. Furthermore, the impact of varying DG capacities on system stability is mathematically investigated. An adaptive virtual impedance is then incorporated into the adaptive droop method to deal with the system instability caused by renewable energy variations. The proposed strategy is analyzed theoretically and validated in MATLAB/Simulink simulation and laboratory experiments. The results demonstrate the advantages of the proposed method over conventional approaches under various scenarios. © 1982-2012 IEEE.

An efficient force-feedback hand exoskeleton for haptic applications

- Le, Duy, Nguyen, Linh

Authors: Le, Duy , Nguyen, Linh
Date: 2021
Type: Text , Journal article
Relation: International Journal of Intelligent Robotics and Applications Vol. 5, no. 3 (2021), p. 395-409
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Description: In this paper, a study on wearable exoskeleton devices which are capable of delivering sensation to the fingers while interacting with the virtual objects in virtual reality environment has been conducted. A force-controllable hand exoskeleton system is proposed, which is able to apply force feedback to the fingertip while allowing natural finger motions. The linkage structure was inspired by the skeletal structure of a human finger. Moreover, a series elastic actuator (SEA) mechanism, which consisted of a linear motor, a spring and a potentiometer, was presented as an actuating system. The force transmission through linkage has been investigated to ensure the force feedback ability at the fingertip. By using a PID controller, the proposed actuator module could generate the desired force in two different modes: free mode and interaction mode. The experimental results show that the proposed system could effectively deliver forces to the fingertips. © 2021, The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd.

Application of adaptive phase-field scaled boundary finite element method for functionally graded materials

- Pramod, Aladurthi, Hirshikesh, Natarajan, Sundararajan, Ooi, Ean Tat

Authors: Pramod, Aladurthi , Hirshikesh , Natarajan, Sundararajan , Ooi, Ean Tat
Date: 2021
Type: Text , Journal article
Relation: International Journal of Computational Methods Vol. 18, no. 3 (2021), p.
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Description: In this paper, an adaptive phase-field scaled boundary finite element method for fracture in functionally graded material (FGM) is presented. The model accounts for spatial variation in the material and fracture properties. The quadtree decomposition is adopted for refinement, and the refinement is based on an error indicator evaluated directly from the solutions of the scaled boundary finite element method. This combination makes it a suitable choice to study fracture using the phase field method, as it reduces the mesh burden. A few standard benchmark numerical examples are solved to demonstrate the improvement in computational efficiency in terms of the number of degrees of freedom. © 2021 World Scientific Publishing Company.

Bipolar radiofrequency ablation treatment of liver cancer employing monopolar needles : a comprehensive investigation on the efficacy of time-based switching

- Yap, Shelley, Ooi, Ean, Foo, Ji, Ooi, Ean Tat

Authors: Yap, Shelley , Ooi, Ean , Foo, Ji , Ooi, Ean Tat
Date: 2021
Type: Text , Journal article
Relation: Computers in Biology and Medicine Vol. 131, no. (2021), p.
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Description: Radiofrequency ablation (RFA) is a thermal ablative treatment method that is commonly used to treat liver cancer. However, the thermal coagulation zone generated using the conventional RFA system can only successfully treat tumours up to 3 cm in diameter. Switching bipolar RFA has been proposed as a way to increase the thermal coagulation zone. Presently, the understanding of the underlying thermal processes that takes place during switching bipolar RFA remains limited. Hence, the objective of this study is to provide a comprehensive understanding on the thermal ablative effects of time-based switching bipolar RFA on liver tissue. Five switch intervals, namely 50, 100, 150, 200 and 300 s were investigated using a two-compartment 3D finite element model. The study was performed using two pairs of RF electrodes in a four-probe configuration, where the electrodes were alternated based on their respective switch interval. The physics employed in the present study were verified against experimental data from the literature. Results obtained show that using a shorter switch interval can improve the homogeneity of temperature distribution within the tissue and increase the rate of temperature rise by delaying the occurrence of roll-off. The coagulation volume obtained was the largest using switch interval of 50 s, followed by 100, 150, 200 and 300 s. The present study demonstrated that the transient thermal response of switching bipolar RFA can be improved by using shorter switch intervals. © 2021 Elsevier Ltd

Comparisons between impedance-based and time-based switching bipolar radiofrequency ablation for the treatment of liver cancer

- Yap, Shelley, Ooi, Ean, Foo, Ji, Ooi, Ean Tat

Authors: Yap, Shelley , Ooi, Ean , Foo, Ji , Ooi, Ean Tat
Date: 2021
Type: Text , Journal article
Relation: Computers in Biology and Medicine Vol. 134, no. (2021), p.
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Description: Switching bipolar radiofrequency ablation (bRFA) is a cancer treatment technique that activates multiple pairs of electrodes alternately based on a predefined criterion. Various criteria can be used to trigger the switch, such as time (ablation duration) and tissue impedance. In a recent study on time-based switching bRFA, it was determined that a shorter switch interval could produce better treatment outcome than when a longer switch interval was used, which reduces tissue charring and roll-off induced cooling. In this study, it was hypothesized that a more efficacious bRFA treatment can be attained by employing impedance-based switching. This is because ablation per pair can be maximized since there will be no interruption to RF energy delivery until roll-off occurs. This was investigated using a two-compartment 3D computational model. Results showed that impedance-based switching bRFA outperformed time-based switching when the switch interval of the latter is 100 s or higher. When compared to the time-based switching with switch interval of 50 s, the impedance-based model is inferior. It remains to be investigated whether the impedance-based protocol is better than the time-based protocol for a switch interval of 50 s due to the inverse relationship between ablation and treatment efficacies. It was suggested that the choice of impedance-based or time-based switching could ultimately be patient-dependent. © 2021 Elsevier Ltd

Development of the scaled boundary finite element method for crack propagation modeling of elastic solids subjected to coupled thermo-mechanical loads

- Iqbal, M. D., Birk, C., Ooi, Ean Tat, Gravenkamp, H.

Authors: Iqbal, M. D. , Birk, C. , Ooi, Ean Tat , Gravenkamp, H.
Date: 2021
Type: Text , Journal article
Relation: Computer Methods in Applied Mechanics and Engineering Vol. 387, no. (2021), p.
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Description: This study presents the development of the scaled boundary finite element method to model discrete crack propagation induced by thermal loads. The SBFEM excels in modeling stress singularities at sharp crack tips with high accuracy. Polygon meshes are used so that a robust local re-meshing algorithm can be utilized to propagate the crack. The scaled boundary finite element formulation for steady-state thermal stress analysis is presented. Following a scaled boundary finite element analysis of a given thermal problem, the effect of initial strains due to temperature is taken into account semi-analytically in a subsequent stress analysis. Several numerical examples are presented to validate the technique and illustrate its salient features. © 2021

Fuzzy logic and gradient descent-based optimal adaptive robust controller with inverted pendulum verification

- Hadipour Lakmesari, S., Mahmoodabadi, M., Ibrahim, Yousef

Authors: Hadipour Lakmesari, S. , Mahmoodabadi, M. , Ibrahim, Yousef
Date: 2021
Type: Text , Journal article
Relation: Chaos, Solitons and Fractals Vol. 151, no. (2021), p.
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Description: This paper develops an adaptive robust combination of feedback linearization (FL) and sliding mode controller (SMC) based on fuzzy rules and gradient descent laws. The new suggested control algorithm is tested to stabilize a fourth-order under-actuated nonlinear inverted pendulum system. More precisely, the reliable feedback linearization approach and the robust SMC controller are combined to design a stable control effort. In order to enhance the performance of the suggested controller, an adaptation technique as long as fuzzy rules are applied to update the control gains and the boundary layer parameter. Then, a novel evolutionary algorithm termed multi-objective ant lion optimizer (MOALO) is implemented to determine the control coefficients. The analysis and results conducted on the inverted pendulum system demonstrate the desired performance of the proposed control scheme by providing an optimal smooth control input, suitable tracking performance, and proper time responses. © 2021 Elsevier Ltd

Land-use changes concerning the riparian vegetation in Galela Lake, North Maluku, Indonesia

- Soeprobowati, Tri, Jumari, Jumari, Saraswati, Tyas, Suhry, Hendro, Gell, Peter

Authors: Soeprobowati, Tri , Jumari, Jumari , Saraswati, Tyas , Suhry, Hendro , Gell, Peter
Date: 2021
Type: Text , Journal article
Relation: Ecological Engineering Vol. 170, no. (2021), p.
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Description: Galela Lake is the largest lake in the Halmahera Utara Regency, North Maluku Province, Indonesia, and is used for domestic water supply, irrigation, aquaculture, and tourism. However, its catchment has been cleared and developed for intensive agriculture. Therefore, there is a need to examine the land-use changes impacting the riparian vegetation of Galela Lake to establish a basis for the development of lake management plans. Research has been conducted at four research sites within the forest (Site I), farmland (Site II), a tourism area (Site III), and near the river inlet (Site IV). In each site, the riparian vegetation was surveyed from the lake banks to 500 m into the neighboring terrestrial habitat. Evidence for changes in the spatial distribution of land-use types in the vicinity of Galela Lake in 2002, 2015, and 2019 were obtained from Landsat images. Galela Lake (302.05 Ha) is exposed to various kinds of human use. During 2002–2019, barren land had been converted into build-up land, and much of the water body of the lake was converted into a riparian zone through the pressures of population growth. Ten of 89 plant species observed within the riparian vegetation around Galela Lake are included in The International Union for Conservation of Nature and Natural Resources (IUCN) Red List threatened species 2010. Coconut (Cocos nucifera), sugar palm (Arenga pinnata), fig (Ficus variegata), nutmeg (Myristica fragrans), and mango (Mangifera indica) were found to be the most important riparian trees. The second generation stands of riparian vegetation (pole and sapling strata) of several species exhibit potential as conservation plants for land and aquatic ecosystems, such as guest tree (Kleinhovia hospita), bamboo (Bambusa vulgaris), the figs (Ficus septica and F. variegata), and sugar palm (A. pinnata). © 2021 Elsevier B.V.

Model predictive control of microgrids – An overview

- Hu, Jiefeng, Shan, Yinghao, Guerrero, Josep, Ioinovici, Adrian, Chan, Ka, Rodriguez, Jose

Authors: Hu, Jiefeng , Shan, Yinghao , Guerrero, Josep , Ioinovici, Adrian , Chan, Ka , Rodriguez, Jose
Date: 2021
Type: Text , Journal article , Review
Relation: Renewable and Sustainable Energy Reviews Vol. 136, no. (2021), p.
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Description: The development of microgrids is an advantageous option for integrating rapidly growing renewable energies. However, the stochastic nature of renewable energies and variable power demand have created many challenges like unstable voltage/frequency and complicated power management and interaction with the utility grid. Recently, predictive control with its fast transient response and flexibility to accommodate different constraints has presented huge potentials in microgrid applications. This paper provides a comprehensive review of model predictive control (MPC) in individual and interconnected microgrids, including both converter-level and grid-level control strategies applied to three layers of the hierarchical control architecture. This survey shows that MPC is at the beginning of the application in microgrids and that it emerges as a competitive alternative to conventional methods in voltage regulation, frequency control, power flow management and economic operation optimization. Also, some of the most important trends in MPC development have been highlighted and discussed as future perspectives. © 2020 Elsevier Ltd
Description: This work was supported by School of Engineering, IT and Physical Sciences, Federation University Australia , under Project RGS20-5 .

Optical characterisation of alumina–mullite materials for solar particle receiver applications

- Chen, Jiangjing, Wheeler, Vincent, Liu, Boqing, Kumar, Apurv, Coventry, Joe, Lipiński, Wojciech

Authors: Chen, Jiangjing , Wheeler, Vincent , Liu, Boqing , Kumar, Apurv , Coventry, Joe , Lipiński, Wojciech
Date: 2021
Type: Text , Journal article
Relation: Solar Energy Materials and Solar Cells Vol. 230, no. (2021), p.
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Description: Alumina–mullite particles are used in high-temperature solar thermal applications such as solar particle receivers. In this study, optical properties of alumina–mullite materials with variable content of alumina and mullite are determined in the spectral range of 0.193–1.69 μm. Variable angle spectroscopic ellipsometry is performed for alumina–mullite thin films, which are fabricated by magnetron sputtering. The thin films are characterised by scanning electron microscopy, atomic force microscopy, and energy dispersive spectroscopy methods. The B-spline model is employed to generate ellipsometric parameters to fit the measured data and to obtain the optical properties. The investigated materials of variable content of alumina and mullite have a similar refractive index in the considered spectral range. The absorptive index of the alumina–mullite materials in the spectral range of 0.193–0.4 μm is higher than in the range 0.4–1.69 μm. The absorptive index decreases with increasing content of alumina in the spectral range of 0.193–0.4 μm. The material composed of similar proportions of alumina and mullite yields the highest absorptive index in the spectral range of 0.4–1.1 μm. The optical properties determined for the alumina–mullite materials are applied to obtain the radiative properties of spherical homogeneous particles. Mie theory is used to calculate absorption and scattering efficiency factors, as well as the scattering phase function. In addition, the scattering phase functions are obtained using the Henyey–Greenstein approximation and the transport approximation. The Monte Carlo ray-tracing method is employed to study the radiative transfer in a model one-dimensional particle curtain containing polydisperse particles exposed to high-flux solar irradiation. It is found that the overall reflectance, absorptance and transmittance of the particles only weakly depend on the optical properties of the materials investigated. © 2021 Elsevier B.V. Corrigendum to “Optical characterisation of alumina–mullite materials for solar particle receiver applications” [Solar Energy Mater. Solar Cell. 230 (2021) 111170] (Solar Energy Materials and Solar Cells (2021) 230, (S0927024821002130), (10.1016/j.solmat.2021.111170)) Solar Energy Materials and Solar Cells, Volume 231, October 2021, Article number 111225. https://doi.org/10.1016/j.solmat.2021.111225
Description: Alumina–mullite particles are used in high-temperature solar thermal applications such as solar particle receivers. In this study, optical properties of alumina–mullite materials with variable content of alumina and mullite are determined in the spectral range of 0.193–1.69 μm. Variable angle spectroscopic ellipsometry is performed for alumina–mullite thin films, which are fabricated by magnetron sputtering. The thin films are characterised by scanning electron microscopy, atomic force microscopy, and energy dispersive spectroscopy methods. The B-spline model is employed to generate ellipsometric parameters to fit the measured data and to obtain the optical properties. The investigated materials of variable content of alumina and mullite have a similar refractive index in the considered spectral range. The absorptive index of the alumina–mullite materials in the spectral range of 0.193–0.4 μm is higher than in the range 0.4–1.69 μm. The absorptive index decreases with increasing content of alumina in the spectral range of 0.193–0.4 μm. The material composed of similar proportions of alumina and mullite yields the highest absorptive index in the spectral range of 0.4–1.1 μm. The optical properties determined for the alumina–mullite materials are applied to obtain the radiative properties of spherical homogeneous particles. Mie theory is used to calculate absorption and scattering efficiency factors, as well as the scattering phase function. In addition, the scattering phase functions are obtained using the Henyey–Greenstein approximation and the transport approximation. The Monte Carlo ray-tracing method is employed to study the radiative transfer in a model one-dimensional particle curtain containing polydisperse particles exposed to high-flux solar irradiation. It is found that the overall reflectance, absorptance and transmittance of the particles only weakly depend on the optical properties of the materials investigated. © 2021 Elsevier B.V. Corrigendum to “Optical characterisation of alumina–mullite materials for solar particle receiver applications” [Solar Energy Mater. Solar Cell. 230 (2021) 111170] (Solar Energy Materials and Solar Cells (2021) 230, (S0927024821002130), (10.1016/j.solmat.2021.111170)) Solar Energy Materials and Solar Cells, Volume 231, October 2021, Article number 111225

Privacy-aware data fusion and prediction with spatial-temporal context for smart city industrial environment

- Qi, Lianyong, Hu, Chunhua, Zhang, Xuyun, Khosravi, Mohammad, Pang, Shaoning

Authors: Qi, Lianyong , Hu, Chunhua , Zhang, Xuyun , Khosravi, Mohammad , Pang, Shaoning
Date: 2021
Type: Text , Journal article
Relation: IEEE Transactions on Industrial Informatics Vol. 17, no. 6 (2021), p. 4159-4167
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Description: As one of the cyber-physical-social systems that plays a key role in people's daily activities, a smart city is producing a considerable amount of industrial data associated with transportation, healthcare, business, social activities, and so on. Effectively and efficiently fusing and mining such data from multiple sources can contribute much to the development and improvements of various smart city applications. However, the industrial data collected from the smart city are often sensitive and contain partial user privacy such as spatial-temporal context information. Therefore, it is becoming a necessity to secure user privacy hidden in the smart city data before these data are integrated together for further mining, analyses, and prediction. However, due to the inherent tradeoff between data privacy and data availability, it is often a challenging task to protect users' context privacy while guaranteeing accurate data analysis and prediction results after data fusion. Considering this challenge, a novel privacy-aware data fusion and prediction approach for the smart city industrial environment is put forward in this article, which is based on the classic locality-sensitive hashing technique. At last, our proposal is evaluated by a set of experiments based on a real-world dataset. Experimental results show better prediction performances of our approach compared to other competitive ones. © 2005-2012 IEEE. *Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Shaoning Pang” is provided in this record**

Tissue programmed hydrogels functionalized with GDNF improve human neural grafts in Parkinson's disease

- Hunt, Cameron, Penna, Vanessa, Gantner, Carlos, Moriarty, Niamh, Long, Benjamin

Authors: Hunt, Cameron , Penna, Vanessa , Gantner, Carlos , Moriarty, Niamh , Long, Benjamin
Date: 2021
Type: Text , Journal article
Relation: Advanced Functional Materials Vol. 31, no. 47 (2021), p.
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Description: The survival and synaptic integration of transplanted dopaminergic (DA) progenitors are essential for ameliorating motor symptoms in Parkinson's disease (PD). Human pluripotent stem cell (hPSC)-derived DA progenitors are, however, exposed to numerous stressors prior to, and during, implantation that result in poor survival. Additionally, hPSC-derived grafts show inferior plasticity compared to fetal tissue grafts. These observations suggest that a more conducive host environment may improve graft outcomes. Here, tissue-specific support to DA progenitor grafts is provided with a fully characterized self-assembling peptide hydrogel. This biomimetic hydrogel matrix is programmed to support DA progenitors by i) including a laminin epitope within the matrix; and ii) shear encapsulating glial cell line-derived neurotrophic factor (GDNF) to ensure its sustained delivery. The biocompatible hydrogel biased a 51% increase in A9 neuron specification—a subpopulation of DA neurons critical for motor function. The sustained delivery of GDNF induced a 2.7-fold increase in DA neurons and enhanced graft plasticity, resulting in significant improvements in motor deficits at 6 months. These findings highlight the therapeutic benefit of stepwise customization of tissue-specific hydrogels to improve the physical and trophic support of human PSC-derived neural transplants, resulting in improved standardization, predictability and functional efficacy of grafts for PD. © 2021 Wiley-VCH GmbH. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Benjamin Long” is provided in this record**

Trustworthiness of self-driving vehicles for intelligent transportation systems in industry applications

- Chowdhury, Abdullahi, Karmakar, Gour, Kamruzzaman, Joarder, Islam, Syed

Authors: Chowdhury, Abdullahi , Karmakar, Gour , Kamruzzaman, Joarder , Islam, Syed
Date: 2021
Type: Text , Journal article
Relation: IEEE Transactions on Industrial Informatics Vol. 17, no. 2 (2021), p. 961-970
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Description: To enhance industrial production and automation, rapid and faster transportation of raw materials and finished products to and from distributed factories, warehouses and outlets are essential. To reduce cost with increased efficiency, this will increasingly see the use of connected and self-driving commercial vehicles fitted with industrial grade sensors on roads, shared with normal and self-driving passenger vehicles. For its wide adoption, the trustworthiness of self-driving vehicles in the intelligent transportation system (ITS) is pivotal. In this article, we introduce a novel model to measure the overall trustworthiness of a self-driving vehicle considering on-Board unit (OBU) components, GPS data and safety messages. In calculating the trustworthiness of individual OBU components, CertainLogic and beta distribution function (BDF) are used. Those trust values are fused using both the dempster-Shafer Theory (DST) and a logical operator of CertainLogic. Results of our simulation show that our proposed method can effectively determine the trust of self-driving vehicles. © 2005-2012 IEEE.

Unidirectional ablation minimizes unwanted thermal damage and promotes better thermal ablation efficacy in time-based switching bipolar radiofrequency ablation

- Ooi, Ean H., Ooi, Ean Tat

Authors: Ooi, Ean H. , Ooi, Ean Tat
Date: 2021
Type: Text , Journal article
Relation: Computers in Biology and Medicine Vol. 137, no. (2021), p.
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Description: Switching bipolar radiofrequency ablation (bRFA) is a thermal treatment modality used for liver cancer treatment that is capable of producing larger, more confluent and more regular thermal coagulation. When implemented in the no-touch mode, switching bRFA can prevent tumour track seeding; a medical phenomenon defined by the deposition of cancer cells along the insertion track. Nevertheless, the no-touch mode was found to yield significant unwanted thermal damage as a result of the electrodes’ position outside the tumour. It is postulated that the unwanted thermal damage can be minimized if ablation can be directed such that it focuses only within the tumour domain. As it turns out, this can be achieved by partially insulating the active tip of the RF electrodes such that electric current flows in and out of the tissue only through the non-insulated section of the electrode. This concept is known as unidirectional ablation and has been shown to produce the desired effect in monopolar RFA. In this paper, computational models based on a well-established mathematical framework for modelling RFA was developed to investigate if unidirectional ablation can minimize unwanted thermal damage during time-based switching bRFA. From the numerical results, unidirectional ablation was shown to produce treatment efficacy of nearly 100%, while at the same time, minimizing the amount of unwanted thermal damage. Nevertheless, this effect was observed only when the switch interval of the time-based protocol was set to 50 s. An extended switch interval negated the benefits of unidirectional ablation. © 2021 Elsevier Ltd

A distributed and anonymous data collection framework based on multilevel edge computing architecture

- Usman, Muhammad, Jan, Mian, Jolfaei, Alireza, Xu, Min, He, Xiangjian, Chen, Jinjun

Authors: Usman, Muhammad , Jan, Mian , Jolfaei, Alireza , Xu, Min , He, Xiangjian , Chen, Jinjun
Date: 2020
Type: Text , Journal article
Relation: IEEE Transactions on Industrial Informatics Vol. 16, no. 9 (2020), p. 6114-6123
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Description: Industrial Internet of Things applications demand trustworthiness in terms of quality of service (QoS), security, and privacy, to support the smooth transmission of data. To address these challenges, in this article, we propose a distributed and anonymous data collection (DaaC) framework based on a multilevel edge computing architecture. This framework distributes captured data among multiple level-one edge devices (LOEDs) to improve the QoS and minimize packet drop and end-to-end delay. Mobile sinks are used to collect data from LOEDs and upload to cloud servers. Before data collection, the mobile sinks are registered with a level-two edge-device to protect the underlying network. The privacy of mobile sinks is preserved through group-based signed data collection requests. Experimental results show that our proposed framework improves QoS through distributed data transmission. It also helps in protecting the underlying network through a registration scheme and preserves the privacy of mobile sinks through group-based data collection requests. © 2005-2012 IEEE.

An efficient forward propagation of multiple random fields using a stochastic Galerkin scaled boundary finite element method

- Mathew, Tittu, Pramod, A. L. N., Ooi, Ean Tat, Natarajan, Sundararajan

Authors: Mathew, Tittu , Pramod, A. L. N. , Ooi, Ean Tat , Natarajan, Sundararajan
Date: 2020
Type: Text , Journal article
Relation: Computer Methods in Applied Mechanics and Engineering Vol. 367, no. (2020), p.
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Description: This paper serves to extend the existing literature on the Stochastic Galerkin Scaled Boundary Finite Element Method (SGSBFEM) in two ways. The first part of this work deals with the formulation of multiple non-correlated Gaussian random fields using the conventional Karhunen–Loéve expansion technique and its forward propagation through the Spectral Stochastic Scaled Boundary Finite Element setting using the polynomial surface fit method in terms of the scaled boundary coordinates. The advantages in adopting such a forward propagation technique in capturing the statistical moments of Quantities of Interest (QoI) across the domain, are highlighted using carefully chosen linear elastic problems having large to least correlated random fields as inputs. The second contribution is the extension of the proposed forward Uncertainty Quantification (UQ) to take into account multiple independent random fields, followed by Polynomial Chaos Expansion (PCE) based sensitivity analysis. Both the computational efficiency and the accuracy of the proposed framework under different input random field correlation settings are elaborated upon by comparing their results against that obtained using the current existing SGSBFEM in the literature. Moreover, the stochastic results are validated for all the numerical examples using the Monte Carlo method. © 2020 Elsevier B.V.

Application of scaled boundary finite element method for delamination analysis of composite laminates using cohesive zone modelling

- Garg, Nikhil, Prusty, Gangadhara, Ooi, Ean Tat, Song, Chongmin, Pearce, Garth, Phillips, Andrew

Authors: Garg, Nikhil , Prusty, Gangadhara , Ooi, Ean Tat , Song, Chongmin , Pearce, Garth , Phillips, Andrew
Date: 2020
Type: Text , Journal article
Relation: Composite Structures Vol. 253, no. (2020), p. 1-10
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Description: In this paper, the scaled boundary finite element method (SBFEM) is evaluated for two-dimensional delamination analysis of composite laminates. The delamination phenomenon was studied using cohesive zone modelling (CZM). A bi-linear (triangular) traction-separation law was used to describe the interface behaviour, which was modelled using zero-thickness interface elements. Local arc-length solution technique was used to solve the non-linearity due to the interface behaviour. In this research, pure Mode I and Mode II as well as mixed mode delamination studies have been conducted using the SBFEM formulation. A variety of numerical experiments were performed. Good agreement was observed between the SBFEM simulation and the available numerical and experimental results in the open literature. A comparison between the SBFEM and other traditional methods shows that the presented formulation can solve the same physical problem with a reduction in the computational cost by more than half. The study highlights the advantages of SBFEM over other methods for modelling delamination in composite laminates using CZM.
Description: This project is conducted within the ARC Training Centre for Automated Manufacture of Advanced Composites (IC160100040), supported by the Commonwealth of Australia under the Australian Research Council's Industrial Transformation Research Program.

Electric vehicle participated electricity market model considering flexible ramping product provisions

- Zhang, Xian, Hu, Jiefeng, Wang, Huaizhi, Wang, Guibin, Chan, Ka, Qiu, Jing

Authors: Zhang, Xian , Hu, Jiefeng , Wang, Huaizhi , Wang, Guibin , Chan, Ka , Qiu, Jing
Date: 2020
Type: Text , Journal article
Relation: IEEE Transactions on Industry Applications Vol. 56, no. 5 (2020), p. 5868-5879
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Description: This article studies electric vehicle (EV) potential to participate in the energy market and provide flexible ramping products (FRPs). EV traffic flows are predicted by the deep belief network, and the availability of flexible EVs is estimated based on the predicted EV traffic flows. Then, a novel market mechanism in distribution system is proposed to encourage the dispatchable EV demand to react to economic signals and provide ramping services. The designed market model is based on locational marginal pricing of energy and marginal pricing of FRPs. System ramping capacity constraints and EV operation constraints are incorporated in the proposed model to achieve the balance between the system social cost minimization and the EV traveling convenience. Moreover, typical uncertainties are considered by the scenario-based approach. Finally, simulations are conducted to verify the effectiveness of the established model and demonstrate the contributions of EVs to the system reliability and flexibility. © 1972-2012 IEEE.
Description: ITIAC: Funding details: JCYJ20170817100412438, 2019-AAAE-1307, JCYJ20190808141019317

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