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A Survey Of Single And Multi-Hop Link Schedulers For Mmwave Wireless Systems, Jian Song, Kwan-Wu Chin
A Survey Of Single And Multi-Hop Link Schedulers For Mmwave Wireless Systems, Jian Song, Kwan-Wu Chin
Faculty of Engineering and Information Sciences - Papers: Part A
Wireless communication at 60. GHz, aka mmWave, provides extremely high data rates, i.e., several Gb/s. Moreover, devices have a much shorter transmission range as compared to those operating in the 2.4 and 5. GHz bands. Indeed, links can be treated as pseudo-wires with minimal interference leakage. As a result, future 60. GHz systems will have very high spatial reuse. This, however, is at the expense of high propagation loss, which can be overcome using directional or smart antennas. Another promising solution is to employ relays to boost the signal of weak links. In particular, if relays are properly selected, they …
Dc-Link Fault Current Limiter-Based Fault Ride-Through Scheme For Inverter-Based Distributed Generation, Amin Jalilian, Mehrdad Tarafdar Hagh, Mehdi Abapour, Kashem M. Muttaqi
Dc-Link Fault Current Limiter-Based Fault Ride-Through Scheme For Inverter-Based Distributed Generation, Amin Jalilian, Mehrdad Tarafdar Hagh, Mehdi Abapour, Kashem M. Muttaqi
Faculty of Engineering and Information Sciences - Papers: Part A
Owing to increasing the penetration level of the inverter-based distributed generations (IBDGs) in power systems, their fault ride-through (FRT) capability has become one of the essential issues of new grid codes. This study proposes a novel DC-link fault current limiter (DLFCL)-based FRT scheme to improve the FRT capability in IBDG units. The DLFCL module has almost no effect on normal operation of IBDG. When a short-circuit fault occurs in power system, the DLFCL module effectively limits the inverter output current and protects its switching devices. The employed DLFCL does not need any control, measurement and gate driving system. Also, it …
Improving Low Voltage Ride-Through Using Super Capacitor At The Dc Link Of Doubly-Fed Induction Generator Based Wind Turbine, Ahmed M. Haidar, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi
Improving Low Voltage Ride-Through Using Super Capacitor At The Dc Link Of Doubly-Fed Induction Generator Based Wind Turbine, Ahmed M. Haidar, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a simple methodology to improve the low voltage ride-through (LVRT) capability of Doubly Fed Induction Generator (DFIG) based wind turbines in order to ride through higher voltage sags and durations. The proposed method is based on selection of an appropriate value for DC side super capacitor (SC) in such a way that it could help wind turbine for LVRT without any need to crowbar protection. The operation of SC based wind turbine in normal and fault conditions is simulated using MATLAB/SIMULINK. The simulation results show that the proposed method can be used effectively for LVRT improvement and …
Improving Fault Ride-Through Of Three Phase Voltage Source Inverter During Symmetrical Fault Using Dc Link Fault Current Limiter, Mehrdad Tarafdar Hagh, Amin Jalilian, Seyed Behzad Naderi, Michael Negnevitsky, Kashem M. Muttaqi
Improving Fault Ride-Through Of Three Phase Voltage Source Inverter During Symmetrical Fault Using Dc Link Fault Current Limiter, Mehrdad Tarafdar Hagh, Amin Jalilian, Seyed Behzad Naderi, Michael Negnevitsky, Kashem M. Muttaqi
Faculty of Engineering and Information Sciences - Papers: Part A
The majority of distributed generation (DG) units utilize three phase voltage source inverter (VSI) to exchange electric power with the utility grid. The VSI employs semiconductor devices (SDs) with limited current withstand capabilities which are very vulnerable during grid faults. However, to ensure a secure and reliable operation of power systems at high penetration level of the DGs, most of the new grid codes worldwide require that the VSIs must have fault ride-Through (FRT) capability. This paper presents a DC link fault current limiter (DLFCL) based VSI FRT scheme to improve its FRT capability. In the proposed scheme, the DLFCL …
A Novel Hybrid-Link-Based Container Routing Model, Shuaian Wang
A Novel Hybrid-Link-Based Container Routing Model, Shuaian Wang
Faculty of Engineering and Information Sciences - Papers: Part A
Container routing determines how to transport containers from their origins to their destinations in a liner shipping network. Container routing needs to be solved a number of times as a subproblem in tactical-level decision planning of liner shipping operations. Container routing is similar to the multi-commodity flow problem. This research proposes a novel hybrid-link-based model that nests the existing origin-link-based and destination-link-based models as special cases. Moreover, the hybrid-link-based model is at least as compact as the origin-to-destination-link-based, origin-link-based and destination-link-based models in the literature.
Asymmetric Stochastic User Equilibrium Problem With Elastic Demand And Link Capacity Constraints, Qiang Meng, Zhiyuan Liu, Shuaian Wang
Asymmetric Stochastic User Equilibrium Problem With Elastic Demand And Link Capacity Constraints, Qiang Meng, Zhiyuan Liu, Shuaian Wang
Faculty of Engineering and Information Sciences - Papers: Part A
This paper focuses on model development and algorithm design for the general stochastic user equilibrium (SUE) problem with elastic demand, asymmetric link travel time functions and link capacity constraints. It first defines the generalised SUE conditions using generalised link travel time. An equivalent variational inequality (VI) model for these generalised SUE conditions is then developed and it is rigorously proven to be monotone and uniform Lipschitzcontinuous. These two properties of the proposed VI model ensure the global convergence of the self-adaptive prediction–correction algorithm incorporating cost averaging method as a solution algorithm. Finally, a numerical example is utilised to assess the …
A Distributed Maximal Link Scheduler For Multi Tx/Rx Wireless Mesh Networks, He Wang, Kwan-Wu Chin, Raad Raad, Sieteng Soh
A Distributed Maximal Link Scheduler For Multi Tx/Rx Wireless Mesh Networks, He Wang, Kwan-Wu Chin, Raad Raad, Sieteng Soh
Faculty of Engineering and Information Sciences - Papers: Part A
Recently, researchers have developed Wireless Mesh Networks (WMNs) where each router is capable of performing multiple transmissions or receptions concurrently; aka Multi Tx-Rx (MTR) WMNs. Consequently, each node is able to transmit (Tx) or receive (Rx) to/from its neighbors simultaneously. A fundamental problem in such WMNs is to derive a transmission schedule with minimal superframe length to maximize network capacity and minimize end-to-end delays. Unfortunately, deriving a minimal superframe length is equivalent to solving the NP-complete, MAX-CUT problem. To this end, there are a number of centralized schedulers, but only but only one distributed scheduler, called JazzyMAC. Henceforth, in this …
Energy-Aware Two Link-Disjoint Paths Routing, Gongqi Lin, Sieteng Soh, Mihai Lazarescu, Kwan-Wu Chin
Energy-Aware Two Link-Disjoint Paths Routing, Gongqi Lin, Sieteng Soh, Mihai Lazarescu, Kwan-Wu Chin
Faculty of Engineering and Information Sciences - Papers: Part A
Network robustness and throughput can be improved by routing each source-to-terminal (s, t) demand via two link-disjoint paths (TLDP). However, the use of TLDP incurs higher energy cost. Henceforth, we address the problem of minimizing the energy usage of networks that use TLDP. Specifically, our problem is to maximally switch off redundant network links while maintaining at least 0zT100% of (s, t) TLDP in the network, for a given T, and limiting the maximum link utilization (MLU) to no greater than a configured threshold. To address this problem, we present a fast heuristic, called TLDP by Shortest Path First (TLDP-SPF), …
Power-Aware Routing In Networks With Delay And Link Utilization Constraints, Gongqi Lin, Sieteng Soh, Mihai Lazarescu, Kwan-Wu Chin
Power-Aware Routing In Networks With Delay And Link Utilization Constraints, Gongqi Lin, Sieteng Soh, Mihai Lazarescu, Kwan-Wu Chin
Faculty of Engineering and Information Sciences - Papers: Part A
Current network infrastructures are over-provisioned and thus exhibit poor power efficiency at low traffic load. In this paper, we consider networks comprising of bundled links, whereby each link has one or more physical cables that can be switched off independently. The problem at hand is then to switch off redundant cables during off peak periods, while retaining the QoS provided to existing traffic demands. Unfortunately, the problem to maximally shutdown redundant cables is an NP-complete problem. Henceforth, we design a fast heuristic, called Multiple Paths by Shortest Path First (MSPF), that aims to maximize the number of switched-off cables subject …
Data Driven Encoding Of Structures And Link Predictions In Large Xml Document Collections, M Hagenbuchner, A C. Tsoi, M Kc, Shujia Zhang
Data Driven Encoding Of Structures And Link Predictions In Large Xml Document Collections, M Hagenbuchner, A C. Tsoi, M Kc, Shujia Zhang
Faculty of Engineering and Information Sciences - Papers: Part A
In recent years there have been some significant research towards the ability of processing related data, particularly the relatedness among atomic elements in a structure with those in another structure. A number of approaches have been developed with various degrees of success. This chapter provides an overview of machine learning approaches for the encoding of related atomic elements in one structure with those in other structures. The chapter briefly reviews a number of unsupervised approaches for such data structures which can be used for solving generic classification, regression, and clustering problems. We will apply this approach to a particularly interesting …