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Faculty of Engineering and Information Sciences - Papers: Part A

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Full-Text Articles in Social and Behavioral Sciences

Interaction Prediction Between Groundwater And Quarry Extension Using Discrete Choice Models And Artificial Neural Networks, Johan Barthelemy, Timoteo Carletti, Louise Collier, Vincent Hallet, Marie Moriame, Annick Sartenear Jan 2016

Interaction Prediction Between Groundwater And Quarry Extension Using Discrete Choice Models And Artificial Neural Networks, Johan Barthelemy, Timoteo Carletti, Louise Collier, Vincent Hallet, Marie Moriame, Annick Sartenear

Faculty of Engineering and Information Sciences - Papers: Part A

Groundwater and rock are intensively exploited in the world. When a quarry is deepened the water table of the exploited geological formation might be reached. A dewatering system is therefore installed so that the quarry activities can continue, possibly impacting the nearby water catchments. In order to recommend an adequate feasibility study before deepening a quarry, we propose two interaction indices between extractive activity and groundwater resources based on hazard and vulnerability parameters used in the assessment of natural hazards. The levels of each index (low, medium, high, very high) correspond to the potential impact of the quarry on the ...


Action Recognition Based On Joint Trajectory Maps Using Convolutional Neural Networks, Pichao Wang, Zhaoyang Li, Yonghong Hou, Wanqing Li Jan 2016

Action Recognition Based On Joint Trajectory Maps Using Convolutional Neural Networks, Pichao Wang, Zhaoyang Li, Yonghong Hou, Wanqing Li

Faculty of Engineering and Information Sciences - Papers: Part A

Recently, Convolutional Neural Networks (ConvNets) have shown promising performances in many computer vision tasks, especially image-based recognition. How to effectively use ConvNets for video-based recognition is still an open problem. In this paper, we propose a compact, effective yet simple method to encode spatiotemporal information carried in 3D skeleton sequences into multiple 2D images, referred to as Joint Trajectory Maps (JTM), and ConvNets are adopted to exploit the discriminative features for realtime human action recognition. The proposed method has been evaluated on three public benchmarks, i.e., MSRC-12 Kinect gesture dataset (MSRC-12), G3D dataset and UTD multimodal human action dataset ...


A Novel Queue Management Policy For Delay-Tolerant Networks, Saeid Iranmanesh Jan 2016

A Novel Queue Management Policy For Delay-Tolerant Networks, Saeid Iranmanesh

Faculty of Engineering and Information Sciences - Papers: Part A

Delay-tolerant networks (DTNs) have attracted increasing attention from governments, academia and industries in recent years. They are designed to provide a communication channel that exploits the inherent mobility of trams, buses and cars. However, the resulting highly dynamic network suffers from frequent disconnections, thereby making node-to-node communications extremely challenging. Researchers have thus proposed many routing/forwarding strategies in order to achieve high delivery ratios and/or low latencies and/or low overheads. Their main idea is to have nodes store and carry information bundles until a forwarding opportunity arises. This, however, creates the following problems. Nodes may have short contacts ...


Mitigating Tap Changer Limit Cycles In Modern Electricity Networks Embedded With Local Generation Units, Dothinka Ranamuka Rallage, Ashish P. Agalgaonkar, Kashem M. Muttaqi, Md Jan E Alam Jan 2016

Mitigating Tap Changer Limit Cycles In Modern Electricity Networks Embedded With Local Generation Units, Dothinka Ranamuka Rallage, Ashish P. Agalgaonkar, Kashem M. Muttaqi, Md Jan E Alam

Faculty of Engineering and Information Sciences - Papers: Part A

Cascaded on-load tap changers (OLTCs) are widely used for coarse control of voltages in largely interconnected elec- tric power systems. There could be interactions between load dynamics and OLTC control under certain system operating conditions which may lead to the OLTC limit cycle phenomena, thereby resulting into long-term voltage oscillations in the system. In recent years, renewable and nonrenewable local generation (LG) units have been getting interconnected in modern power systems. The existence of OLTC limit cycles in the presence of LG has not been addressed in the literature in greater details. In this paper, the OLTC limit cycle phenomenon ...


A Review Of Protection Systems For Distribution Networks Embedded With Renewable Generation, Joel Kennedy, Philip Ciufo, Ashish P. Agalgaonkar Jan 2016

A Review Of Protection Systems For Distribution Networks Embedded With Renewable Generation, Joel Kennedy, Philip Ciufo, Ashish P. Agalgaonkar

Faculty of Engineering and Information Sciences - Papers: Part A

The rapid growth of grid-connected embedded generation is changing the operational characteristics of power distribution networks. Amongst a range of issues being reported in the research, the effect of these changes on so-called 'traditional protection systems' has not gone without attention. Looking to the future, the possibility of microgrid systems and deliberate islanding of sections of the network will require highly flexible distribution management systems and a re-design of protection strategies. This paper explores the envisaged protection issues concerned with large penetrations of embedded generation in distribution networks extending into auto-reclosure and protection device coordination. A critical review of recently ...


A Multi-Agent Framework For Packet Routing In Wireless Sensor Networks, Dayong Ye, Minjie Zhang, Yun Yang Jan 2015

A Multi-Agent Framework For Packet Routing In Wireless Sensor Networks, Dayong Ye, Minjie Zhang, Yun Yang

Faculty of Engineering and Information Sciences - Papers: Part A

No abstract provided.


A Novel Mobility-Based Routing Protocol For Semi-Predictable Disruption Tolerant Networks, Saeid Iranmanesh, Kwan-Wu Chin Jan 2015

A Novel Mobility-Based Routing Protocol For Semi-Predictable Disruption Tolerant Networks, Saeid Iranmanesh, Kwan-Wu Chin

Faculty of Engineering and Information Sciences - Papers: Part A

This letter considers routing in delay tolerant networks whereby nodes have semi-predictable mobility patterns within a time period. We propose a mobility-based routing protocol (MBRP) where nodes construct a space-time graph dynamically. As the space-time graph may be incomplete, MBRP presents a heuristic that evaluates encountered nodes based on their recorded mobility patterns in order to disseminate a finite number of bundle replicas. Simulation results, over a service quality metric comprising of delivery, delay and overhead, show that MBRP achieves up to 105 % improvement as compared to four well-known routing protocols. Finally, MBRP is capable of achieving 50 % of the ...


On Using Wireless Power Transfer To Increase The Max Flow Of Rechargeable Wireless Sensor Networks, Tengjiao He, Kwan-Wu Chin, Sieteng Soh Jan 2015

On Using Wireless Power Transfer To Increase The Max Flow Of Rechargeable Wireless Sensor Networks, Tengjiao He, Kwan-Wu Chin, Sieteng Soh

Faculty of Engineering and Information Sciences - Papers: Part A

A key problem in Rechargeable Wireless Sensor Networks (WSNs) is determining the maximum amount of data that can be collected by a sink over a given time period. This maximum is constrained by link capacity and critically, by the available energy at each node. In this paper, we consider a novel approach to increase the maximum flow rate by exploiting recent advances in Wireless Power Transfer (WPT). Specifically, we deploy a finite number of WPT capable rovers next to bottleneck sensor nodes with the aim to increase the max flow rate of a WSN. We formulate a Mixed Integer Linear ...


Application Of Saturated Core Fault Current Limiters To Interconnected Distribution Networks, Sasareka Gunawardana Mudalige, Sarath Perera, Jeffrey W. Moscrop Jan 2015

Application Of Saturated Core Fault Current Limiters To Interconnected Distribution Networks, Sasareka Gunawardana Mudalige, Sarath Perera, Jeffrey W. Moscrop

Faculty of Engineering and Information Sciences - Papers: Part A

There is an increasing need for electricity utilities to limit fault levels in critical locations in power systems so that existing switchgear can continue to function as expected. This is particularly true in electrical distribution systems, where the increased penetration of renewable and decentralised generation is forcing the network to be highly interconnected in order to allow for higher integration capacity and reliable operation. Consequently, the short-circuit currents in distribution systems have increased significantly. In this background, application of fault current limiting devices is one of the solutions that is being considered by the Distribution Network Service Providers (DNSPs). A ...


Attenuation And Propagation Of Voltage Unbalance In Radial Distribution Networks, Devinda Perera, Philip Ciufo, Lasantha G. Meegahapola, Sarath Perera Jan 2015

Attenuation And Propagation Of Voltage Unbalance In Radial Distribution Networks, Devinda Perera, Philip Ciufo, Lasantha G. Meegahapola, Sarath Perera

Faculty of Engineering and Information Sciences - Papers: Part A

Recently published International Electrotechnical Committee (IEC) technical reports IEC 61000-3-13 provides detailed methodologies for managing voltage unbalance (VU) in electric power systems. A key aspect in the VU emission allocation process is the estimation of VU propagation in different parts of the network. Although the VU propagation from upstream networks to downstream networks is adequately addressed, the attenuation of VU when propagating from downstream to upstream networks at the same voltage level has not been properly taken into account in the aforementioned methodologies. Furthermore, mains connected three-phase induction motors are known to attenuate VU, and there is no methodology currently ...


A Distributed Broadcast Algorithm For Duty-Cycled Networks With Physical Interference Model, Dianbo Zhao, Kwan-Wu Chin Jan 2015

A Distributed Broadcast Algorithm For Duty-Cycled Networks With Physical Interference Model, Dianbo Zhao, Kwan-Wu Chin

Faculty of Engineering and Information Sciences - Papers: Part A

Broadcast is a fundamental operation in multi-hop wireless networks. Given a source node with a message to broadcast, the objective is to propagate the message to all nodes in an interferencefree manner while incurring minimum latency. This problem, called Minimum-Latency Broadcast Scheduling (MLBS), has been studied extensively in wireless networks whereby nodes remain on all times and has been shown to be NP-hard. However, only a few studies have addressed this problem in the context of duty-cycled wireless networks, which unfortunately, remains NP-hard. In these networks, nodes do not wake up simultaneously, and hence, not all neighbors of a transmitting ...


A Refined General Summation Law For Vu Emission Assessment In Radial Networks, Jayatunga Vitharanage Upuli Priyadarshani Jayatunga, Sarath Perera, Philip Ciufo, Ashish P. Agalgaonkar Jan 2015

A Refined General Summation Law For Vu Emission Assessment In Radial Networks, Jayatunga Vitharanage Upuli Priyadarshani Jayatunga, Sarath Perera, Philip Ciufo, Ashish P. Agalgaonkar

Faculty of Engineering and Information Sciences - Papers: Part A

Voltage unbalance (VU) management of power systems requires the development of well researched engineering practices to maintain acceptable VU levels while utilising the total VU absorption capacity of the power system. In this regard, IEC/TR 61000-3-13:2008 prescribes a VU emission allocation methodology based on a stochastic approach which uses a general summation law in order to aggregate numerous sources of unbalance to take into account their random variations. On the other hand, recent deterministic studies on VU emission assessment at the post-connection stage of unbalanced installations present a complex VU factor based approach to determine constituent components of ...


A Secure Ipv6 Address Configuration Protocol For Vehicular Networks, Xiaonan Wang, Yi Mu, Guangjie Han, Deguang Le Jan 2014

A Secure Ipv6 Address Configuration Protocol For Vehicular Networks, Xiaonan Wang, Yi Mu, Guangjie Han, Deguang Le

Faculty of Engineering and Information Sciences - Papers: Part A

This paper proposes a secure address configuration protocol for IPv6-based vehicular networks. In this protocol, the network architecture is proposed. In this architecture, a vehicle obtains a unique address from a neighbor vehicle or an access point without DAD, and a leaving vehicle's address space can be automatically reclaimed for reassignment. Based on this architecture, the address configuration algorithm is presented. In this algorithm, an access point or a vehicle owns the unique address space and assigns a unique address to a neighbor vehicle without DAD, so the address configuration cost and delay are lowered. The identification of a ...


Global Optimization Method For Robust Pricing Of Transportation Networks Under Uncertain Demand, Shuaian Wang, Lauren Gardner, S.Travis Waller Jan 2014

Global Optimization Method For Robust Pricing Of Transportation Networks Under Uncertain Demand, Shuaian Wang, Lauren Gardner, S.Travis Waller

Faculty of Engineering and Information Sciences - Papers: Part A

We extend the existing toll pricing studies with fixed demand to stochastic demand. A new and practical second-best pricing problem with uncertain demand is proposed and formulated as a stochastic mathematical program with equilibrium constraints. In view of the problem structure, we develop a tailored global optimization algorithm. This algorithm incorporates a sample average approximation scheme, a relaxation-strengthening method, and a linearization approach. The proposed global optimization algorithm is applied to three networks: a two-link network, a seven-eleven network and the Sioux-Falls network. The results demonstrate that using a single fixed estimation of future demand may overestimate the future system ...


Error Exponent Of Amplify And Forward Relay Networks In Presence Of I.I.D. Interferers, Bappi Barua, Farzad Safaei, Mehran Abolhasan Jan 2014

Error Exponent Of Amplify And Forward Relay Networks In Presence Of I.I.D. Interferers, Bappi Barua, Farzad Safaei, Mehran Abolhasan

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, we derive the random coding error exponent of amplify-and-forward (AF) relay networks in presence of arbitrary number of independent and identically distributed (i.i.d.) interferers both at the relay and the destination. Multiuser networks are common examples of interference limited networks. We derive the ergodic capacity of the network and present simulation results on the performance of the network where we compare the capacity and error exponent performance of interference limited networks with noise limited networks. Numerical results show that noise limited networks outperform interference limited networks even when only a very few interferers exist in ...


Optimal Adaptive Wireless Body Area Networks For High Speed In Health Services, Miftadi Sudjai, Le Chung Tran, Farzad Safaei, Son Lam Phung Jan 2014

Optimal Adaptive Wireless Body Area Networks For High Speed In Health Services, Miftadi Sudjai, Le Chung Tran, Farzad Safaei, Son Lam Phung

Faculty of Engineering and Information Sciences - Papers: Part A

Adaptive ultra-wideband wireless body area networks have been proposed as one of feasible mHealth platforms offering a high-speed, robust mobile health service. The error performance of such sytems outperforms non-adaptive systems by up to 4 dB. To further improve the error performance, the optimization of adaptive parameters is investigated in this paper. Simulation results show that the proposed optimal adaptive systems achieves a 2 dB gain with respect to bit error rate (BER). This improvement is equivalent to extra reduction of the power consumption up to 37% in these networks, thus increasing the longevity and reliability of mHealth services.


Characterisation Of Flicker Emission And Propagation In Distribution Networks With Bi-Directional Power Flows, D Perera, L Meegahapola, S Perera, P Ciufo Jan 2014

Characterisation Of Flicker Emission And Propagation In Distribution Networks With Bi-Directional Power Flows, D Perera, L Meegahapola, S Perera, P Ciufo

Faculty of Engineering and Information Sciences - Papers: Part A

With the increasing penetration levels of intermittent and fluctuating energy sources such as wind generating systems in the electricity grid, resulting voltage fluctuations and flicker can be expected to become an important power quality considerations. Due to significant bidirectional power flows resulting from large renewable power generation systems connected to downstream, voltage fluctuations may propagate from downstream to upstream. The work presented in this paper investigates and characterises flicker emission and propagation resulting from fluctuating generating sources connected to a distribution network. Mathematical models are developed for flicker emission under different generator control strategies and flicker propagation to upstream network ...


An Approach For Online Assessment Of Rooftop Solar Pv Impacts On Low-Voltage Distribution Networks, Md Jan-E- Alam, Kashem Muttaqi, Darmawan Sutanto Jan 2014

An Approach For Online Assessment Of Rooftop Solar Pv Impacts On Low-Voltage Distribution Networks, Md Jan-E- Alam, Kashem Muttaqi, Darmawan Sutanto

Faculty of Engineering and Information Sciences - Papers: Part A

Assumption-based offline analysis tools may not be able to provide sufficient and accurate information for the corrective decision making to mitigate solar photovoltaic (PV) impacts in the future distribution grids. This is mainly due to the increasing penetration level of intermittent power generation resources and also the fluctuating behavior of consumer demand. Online assessment tools can assist to manage PV impacts and aid to mitigate those on a real-time basis. This paper proposes an approach for online assessment of rooftop PV impacts on low-voltage (LV) networks using real-time network data. A variable-width sliding window will be used to provide the ...


Improvements On An Authentication Scheme For Vehicular Sensor Networks, Joseph K. Liu, Tsz Hon Yuen, Man Ho Au, Willy Susilo Jan 2014

Improvements On An Authentication Scheme For Vehicular Sensor Networks, Joseph K. Liu, Tsz Hon Yuen, Man Ho Au, Willy Susilo

Faculty of Engineering and Information Sciences - Papers: Part A

In a recent paper, Shim (2012) presented a very interesting authentication scheme for vehicular sensor networks. Shim claimed that the scheme is secure against the highest adopted level of attack, namely the chosen-message attack (CID-CMA). Nevertheless, we find that the proof in Shim's paper does not actually prove that the scheme is secure in this level. Instead, it can only ensure that the scheme is secure in a strictly weaker level of attack, the adaptive chosen-identity and no-message attack (CID-NMA). In this paper, first we show that there exist some security risks in vehicular networks if a scheme, which ...


Voltage Unbalance Emission Allocation Using Constrained Bus Voltage Method In Radial Distribution Networks, Devinda Perera, Philip Ciufo, Sarath Perera, Lasantha Meegahapola Jan 2014

Voltage Unbalance Emission Allocation Using Constrained Bus Voltage Method In Radial Distribution Networks, Devinda Perera, Philip Ciufo, Sarath Perera, Lasantha Meegahapola

Faculty of Engineering and Information Sciences - Papers: Part A

The International Electrotechnical Committee Technical Report IEC 61000-3-13 is focused on the coordination of voltage unbalance (VU) in power systems by prescribing a methodology to determine individual VU emission allocation limits to installations. This paper provides an alternative VU emission allocation process to that of the IEC Technical Report, which is based on the concept of constrained bus voltage (CBV) method. The proposed methodology can be used in relation to radial distribution networks with symmetrical distribution lines. Several application examples of the proposed methodology are presented. It is shown that the proposed methodology is superior in comparison to the VU ...


An Algebraic Approach For Determination Of Dg Parameters To Support Voltage Profiles In Radial Distribution Networks, Kashem M. Muttaqi, An D. T Le, Michael Negnevitsky, Gerard Ledwich Jan 2014

An Algebraic Approach For Determination Of Dg Parameters To Support Voltage Profiles In Radial Distribution Networks, Kashem M. Muttaqi, An D. T Le, Michael Negnevitsky, Gerard Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

Rapidly increasing electricity demands and capacity shortage of transmission and distribution facilities are the main driving forces for the growth of Distributed Generation (DG) integration in power grids. One of the reasons for choosing a DG is its ability to support voltage in a distribution system. Selection of effective DG characteristics and DG parameters is a significant concern of distribution system planners to obtain maximum potential benefits from the DG unit. This paper addresses the issue of improving the network voltage profile in distribution systems by installing a DG of the most suitable size, at a suitable location. An analytical ...


Novel Algorithms For Complete Targets Coverage In Energy Harvesting Wireless Sensor Networks, Changlin Yang, Kwan-Wu Chin Jan 2014

Novel Algorithms For Complete Targets Coverage In Energy Harvesting Wireless Sensor Networks, Changlin Yang, Kwan-Wu Chin

Faculty of Engineering and Information Sciences - Papers: Part A

This paper addresses the problem of maximizing the network lifetime of rechargeable Wireless Sensor Networks (WSNs) whilst ensuring all targets are monitored continuously by at least one sensor node. The objective is to determine a group of sensor nodes, and their wake-up schedule such that within a time interval, one subset of nodes are active whilst others enter the sleep state to conserve energy as well as recharge their battery. We propose a Linear Programming (LP) based solution to determine the activation schedule of sensor nodes whilst affording them recharging opportunities and at the same time ensures complete target coverage ...


Over-Voltage Mitigation Within Distribution Networks With A High Renewable Distributed Generation Penetration, Joel Kennedy, Philip Ciufo, Ashish Agalgaonkar Jan 2014

Over-Voltage Mitigation Within Distribution Networks With A High Renewable Distributed Generation Penetration, Joel Kennedy, Philip Ciufo, Ashish Agalgaonkar

Faculty of Engineering and Information Sciences - Papers: Part A

The rapid growth of grid-connected distributed generation has increased the likelihood of over-voltage occurrences in distribution networks. In recent times, much research has taken place in order to develop a control strategy to mitigate the voltage rise problem. However, most of the published strategies require re-tuning when additional resources are connected, or have a strong dependence on network parameters, such as fault level. This paper proposes a novel over-voltage mitigation scheme that has many advantages not observed in literature. Firstly, the control scheme can integrate with an existing feeder in a plug-and-play fashion. No prior analysis is necessary to configure ...


A Structure Optimization Algorithm Of Neural Networks For Large-Scale Data Sets, Jie Yang, Jun Ma, Matthew J. Berryman, Pascal Perez Jan 2014

A Structure Optimization Algorithm Of Neural Networks For Large-Scale Data Sets, Jie Yang, Jun Ma, Matthew J. Berryman, Pascal Perez

Faculty of Engineering and Information Sciences - Papers: Part A

Over the past several decades, neural networks have evolved into powerful computation systems, which are able to learn complex nonlinear input-output relationship from data. However, the structure optimization problem of neural network is a big challenge for processing huge-volumed, diversified and uncertain data. This paper focuses on this problem and introduces a network pruning algorithm based on sparse representation, termed SRP. The proposed approach starts with a large network, then selects important hidden neurons from the original structure using a forward selection criterion that minimizes the residual output error. Furthermore, the presented algorithm has no constraints on the network type ...


On Improving Capacity And Delay In Multi Tx/Rx Wireless Mesh Networks With Weighted Links, Hung-Yi Loo, Sieteng Soh, Kwan-Wu Chin Jan 2013

On Improving Capacity And Delay In Multi Tx/Rx Wireless Mesh Networks With Weighted Links, Hung-Yi Loo, Sieteng Soh, Kwan-Wu Chin

Faculty of Engineering and Information Sciences - Papers: Part A

This paper considers the problem of deriving a link schedule for Time Division Multiple Access (TDMA)-based concurrent transmit/receive Wireless Mesh Networks (WMNs) that results in low end-to-end delays as well as high network capacity. We first propose a MAX-CUT heuristic approach, called Algo-2, that maximizes link activations in each slot of a super-frame. Algo-2 is shown to produce better network capacity as compared to existing heuristic approaches and significantly improves the super-frame length of an existing MAX-CUT approach that enforces 2-phase transmit-receive restriction - a node that transmits (receives) in slot i ≥ 1 is to become a receiver (transmitter ...


Efficiency And Equity Of Speed Limits In Transportation Networks, Shuaian Wang Jan 2013

Efficiency And Equity Of Speed Limits In Transportation Networks, Shuaian Wang

Faculty of Engineering and Information Sciences - Papers: Part A

This paper examines the impact of speed limits on network efficiency, in terms of total travel time of all road users, and equity among road users from different origin-destination (OD) pairs, in terms of the change of travel time after imposing a speed limit scheme. We find that after imposing a speed limit scheme, the total travel time of all road users may decrease or increase; road users of some OD pairs may experience longer travel time, while other OD pairs may have shorter travel time. In view of the importance of speed limits on network efficiency and equity, we ...


Comparative Analysis Of Dynamic Line Rating Models And Feasibility To Minimise Energy Losses In Wind Rich Power Networks, Mathew Simms, Lasantha Meegahapola Jan 2013

Comparative Analysis Of Dynamic Line Rating Models And Feasibility To Minimise Energy Losses In Wind Rich Power Networks, Mathew Simms, Lasantha Meegahapola

Faculty of Engineering and Information Sciences - Papers: Part A

Wind power generation has indicated an exponential increase during last two decades and existing transmission network infrastructure is increasingly becoming inadequate to transmit remotely generated wind power to load centres in the network. The dynamic line rating (DLR) is one of the viable solutions to improve the transmission line ampacity during high wind penetration without investing on an additional transmission network. The main objective of this study is to identify the basic differences between two main line rating standards, since transmission network service providers (TNSPs) heavily depend on these two standards when developing their line rating models. Therefore, a parameter ...


Large Networks Of Vertical Multi-Layer Graphenes With Morphology-Tunable Magnetoresistance, Zengji Yue, Igor Levchenko, Shailesh Kumar, Donghan Seo, Xiaolin Wang, S X. Dou, Kostya Ken Ostrikov Jan 2013

Large Networks Of Vertical Multi-Layer Graphenes With Morphology-Tunable Magnetoresistance, Zengji Yue, Igor Levchenko, Shailesh Kumar, Donghan Seo, Xiaolin Wang, S X. Dou, Kostya Ken Ostrikov

Faculty of Engineering and Information Sciences - Papers: Part A

We report on the comparative study of magnetotransport properties of large-area vertical few-layer graphene networks with different morphologies, measured in a strong (up to 10 T) magnetic field over a wide temperature range. The petal-like and tree-like graphene networks grown by a plasma enhanced CVD process on a thin (500 nm) silicon oxide layer supported by a silicon wafer demonstrate a significant difference in the resistance-magnetic field dependencies at temperatures ranging from 2 to 200 K. This behaviour is explained in terms of the effect of electron scattering at ultra-long reactive edges and ultra-dense boundaries of the graphene nanowalls. Our ...


A Three-Phase Power Flow Approach For Integrated 3-Wire Mv And 4-Wire Multigrounded Lv Networks With Rooftop Solar Pv, Md J E Alam, K M. Muttaqi, Darmawan Sutanto Jan 2013

A Three-Phase Power Flow Approach For Integrated 3-Wire Mv And 4-Wire Multigrounded Lv Networks With Rooftop Solar Pv, Md J E Alam, K M. Muttaqi, Darmawan Sutanto

Faculty of Engineering and Information Sciences - Papers: Part A

With increasing level of rooftop solar photovoltaic (PV) penetration into low voltage (LV) distribution networks, analysis with realistic network models is necessary for adequate capturing of network behavior. Traditional three-phase 3-wire power flow approach lacks the capability of exact analysis of 4-wire multigrounded LV networks due to the approximation of merging the neutral wire admittance into the phase wire admittances. Such an approximation may not be desirable when neutral wire and grounding effects need to be assessed, especially in the presence of single-phase solar power injection that may cause a significant level of network unbalance. This paper proposes a three-phase ...


Approximation Algorithm For Data Broadcasting In Duty Cycled Multi-Hop Wireless Networks, Dianbo Zhao, Kwan-Wu Chin Jan 2013

Approximation Algorithm For Data Broadcasting In Duty Cycled Multi-Hop Wireless Networks, Dianbo Zhao, Kwan-Wu Chin

Faculty of Engineering and Information Sciences - Papers: Part A

Broadcast is a fundamental operation in wireless networks. To this end, many past studies have studied the NP-hard, broadcast problem for always-on multi-hop networks. However, in wireless sensor networks, nodes are powered by batteries, meaning, they have finite energy. Consequently, nodes are required to have a low duty cycle, whereby they switch between active and sleep state periodically. This means that a transmission from a node may not reach all of its neighbors simultaneously. Consequently, any developed broadcast protocols must consider collisions and the wake-up times of neighboring nodes. Henceforth, this paper studies the minimum latency broadcast scheduling problem in ...