Social and Behavioral Sciences Commons^™

Development Of A Dynamic Model For A Hybrid Photovoltaic Thermal Collector - Solar Air Heater With Fins, Wenke Fan, Georgios Kokogiannakis, Zhenjun Ma, Paul Cooper

Faculty of Engineering and Information Sciences - Papers: Part A

A dynamic model for a hybrid Photovoltaic Thermal Collector-Solar Air Heater (PVT-SAH) with longitudinal fins was developed to enable assessment of the potential of the system to provide high temperature outlet air (60-90 °C) under dynamic boundary conditions. The model description includes the method for discretising the system into a number of control volumes, the energy balance equations for each control volume and the implementation of the numerical solution. Model validation has been successfully undertaken by using empirical verification of model predictions with an experimental facility and by comparing the model outputs with the reference data from the literature. The …

Dynamic Exergy Analysis For The Thermal Storage Optimization Of The Building Envelope, Valentina Bonetti, Georgios Kokogiannakis

Faculty of Engineering and Information Sciences - Papers: Part A

As a measure of energy "quality", exergy is meaningful for comparing the potential for thermal storage. Systems containing the same amount of energy could have considerably different capabilities in matching a demand profile, and exergy measures this difference. Exergy stored in the envelope of buildings is central in sustainability because the environment could be an unlimited source of energy if its interaction with the envelope is optimised for maintaining the indoor conditions within comfort ranges. Since the occurring phenomena are highly fluctuating, a dynamic exergy analysis is required; however, dynamic exergy modelling is complex and has not hitherto been implemented …

Microstructure And Micro-Texture Evolution During The Dynamic Recrystallisation Of A Ni-30fe-Nb-C Model Alloy, Parvez Mannan, Ahmed A. Saleh, Azdiar A. Gazder, Gilberto Casillas, Elena V. Pereloma

Faculty of Engineering and Information Sciences - Papers: Part A

The evolution of microstructure and micro-texture during discontinuous dynamic recrystallisation of an austenitic Ni-30Fe-Nb-C model alloy subjected to interrupted plane strain compression at strains (ε) of 0.23, 0.35, 0.68, 0.85 and 1.2 was investigated using electron backscattering diffraction and transmission electron microscopy. Throughout the strain range, the majority of dynamic recrystallisation events comprised nucleation in necklace-like arrangements located at and along grain boundaries via bulging. At ε ≥ 0.68, discrete nucleation events were also observed within grain interiors. Grain growth during dynamic recrystallisation is characteristic of strain induced boundary migration. The initial texture comprised Cube-RD ({013}〈100〉), Cube-ND ({001}〈310〉) and Cube …

Application Of Shock Mats In Rail Track Foundation Subjected To Dynamic Loads, Sinniah Navaratnarajah, Buddhima Indraratna, Sanjay Nimbalkar

Faculty of Engineering and Information Sciences - Papers: Part A

Rail track substructure (ballast, subballast and subgrade) is the most essential component of the railway system in view of track stability. The ballast is the largest component of the track substructure and it is the key load-bearing stratum packed with rock aggregates underneath and around the sleepers, thereby providing structural support against dynamic stresses caused by moving trains. However under large dynamic stresses exerted by heavy haul and high speed trains, the degradation of track substructure including ballast becomes significant. This in turn affects the track stability and creates frequent maintenance, thus increasing the life cycle cost of the rail …

Reproducing Personal Sound Zones Using A Hybrid Synthesis Of Dynamic And Parametric Loudspeakers, Jacob Donley, Christian H. Ritz, Bastiaan (Willem) Kleijn

Faculty of Engineering and Information Sciences - Papers: Part A

This paper proposes a hybrid approach to personal sound zones utilising multizone soundfield reproduction techniques and parametric loudspeakers. Crossover filters are designed, to switch between reproduction methods, through analytical analysis of aliasing artifacts in multizone reproductions. By realising the designed crossover filters, wideband acoustic contrast between zones is significantly improved. The trade-off between acoustic contrast and the bandwidth of the reproduced soundfield is investigated. Results show that by incorporating the proposed hybrid model the whole wideband bandwidth is spatial-aliasing free with a mean acoustic contrast consistently above 54.2dB, an improvement of up to 24.2dB from a non-hybrid approach, with as …

Simulink Model For Examining Dynamic Interactions Involving Electro-Mechanical Oscillations In Distribution Systems, Dothinka Ranamuka Rallage, Ashish P. Agalgaonkar, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

In Australian medium voltage (MV) distribution networks, the majority of embedded local generation (LG) uses synchronous machine based technology. LG units with a synchronous generator can easily be dispatched and controlled to provide or absorb reactive power and thereby locally supporting the system voltage and increasing the voltage stability margin. The fast response from a synchronous machine based LG unit exciter will ensure fast voltage recovery. This will significantly improve the transient voltage stability. Also, the synchronous machine based LG units can provide inertial support to the system. Furthermore, some of these LG technologies work as standby power supplies all …

Power Generation Analysis Of Powerwindow, A Linear Wind Generator, Using Computational Fluid Dynamic Simulations, Seyed A. Jafari, Farzad Safaei, Buyung Kosasih, K C. Kwok

Faculty of Engineering and Information Sciences - Papers: Part A

A new linear wind generator (LWG), named PowerWindow, is introduced. The modular and scalable LWG is capable of generating power in low wind velocity condition, and hence can be an effective and safe power generator in built environments. The aerodynamic mechanism of the LWG power generation is elucidated using computational fluid dynamic (CFD) simulations, and the results are validated against the experimental data obtained from the prototype wind tunnel tests. The simulations provide important insights into the flow field in and around LWG particularly over the front and rear blades and how each one contributes to the power generation. This …

Dynamic Wetting Of Cao-Al2o3-Sio2-Mgo Liquid Oxide On Mgal2o4 Spinel, Hamed Abdeyazdan, Neslihan Dogan, Muhammad Rhamdhani, Michael Chapman, Brian Monaghan

Faculty of Engineering and Information Sciences - Papers: Part A

Inclusion type and content in steel is critical in steelmaking, affecting both productivity through clogging, and downstream physical properties of the steel. They are normally removed from steel by reacting with a slag (liquid oxide) phase. For efficient inclusion removal, the inclusions must attach/bond with this liquid phase. The strength of the attachment can be in part characterized by the wettability of the liquid oxide on the inclusions. In this study, the dynamic wetting of liquid oxides of the CaO-Al2O3-SiO2-MgO system on a solid spinel (MgAl2O4) substrate with low porosity of 1.9 pct was measured at 1773 K (1500 °C) …

Effects Of Hydrogen On The Critical Conditions For Dynamic Recrystallization Of Titanium Alloy During Hot Deformation, Jingwei Zhao, Hua Ding, Zhengyi Jiang, Dongbin Wei, Kezhi Linghu

Faculty of Engineering and Information Sciences - Papers: Part A

Hot deformation tests were performed to study the flow behavior and microstructural evolution of a Ti600 titanium alloy with different hydrogen contents. The effects of hydrogen on the critical conditions for the initiation of dynamic recrystallization (DRX) were investigated. The DRX kinetics models of hydrogenated Ti600 alloy were developed, and the DRX volume fractions were quantified under different deformation conditions. The results indicate that the addition of proper hydrogen (no greater than 0.3 pct) benefits the decrease of both the critical stress and critical strain for the initiation of DRX. The critical stress and critical strain are dependent linearly on …

A Comprehensive Tool To Analyse Dynamic Log Files From An Elekta-Synergy Accelerator, Sankar Arumugam, Aitang Xing, Claire Pagulayan, Lois Holloway

Faculty of Engineering and Information Sciences - Papers: Part A

This study presents the development of a software tool 'Treat Check' to analyse the dynamic log files from an Elekta - Synergy accelerator. The software generates formatted output in the form of a plot presenting errors in various treatment delivery parameters such as gantry angle, Multi Leaf Collimator (MLC) leaf position, jaw position and Monitor Units (MU) for each of the control-points (CP) of the treatment beam. The plots are automatically saved in Portable Document Format (pdf). The software also has the functionality to introduce these treatment delivery errors into the original plan in the Pinnacle (Philips) treatment planning system …

Geometric Design Optimization For Dynamic Response Problem Of Continuous Reinforced Concrete Beams, Pezhman Sharafi, Muhammad Hadi, Lip H. Teh

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a computer-aided design method for conceptual geometric layout optimization of multispan RC beams for any type of dynamic responses. A key feature of the paper is the development of a new cost-optimization method for geometric layout problems that take both cost parameters and dynamic responses into account to achieve an optimum design along with acceptable dynamic performance of RC beams. This method takes advantage of employing a new optimization formulation that considerably simplifies the preliminary layout design computations. It focuses on minimizing the structural cost subject to constraints on eigenfrequencies, modal shapes, and the static and dynamic …

Dynamic Testing Of Tekseal High Yield Grout To Provide An Orepass Plug Designed For Impact, I V. S Mutton, Alexander Remennikov, D Pateman

Faculty of Engineering and Information Sciences - Papers: Part A

Significant wear in orepasses particularly in the brow and chute areas is proportional to the tonnage throughput with increased wear associated with running orepasses empty. During planned shutdowns it may be necessary to isolate maintenance crews from objects falling from orepasses. In the last 15 years grout orepass plugs that can later be easily removed have been poured above chute maintenance areas. These provide protection from high energy impact and isolating workers from the hazard. Construction and removal methods will be briefly explained. Since it is not feasible to investigate the problem of orepass plug impact response using full-scale experimental …

Effect Of Austenitising And Deformation Temperatures On Dynamic Recrystallisation In Nb-Ti Microalloyed Steel, Andrii G. Kostryzhev, Abdullah Al Shahrani, Chen Zhu, Simon P. Ringer, Elena V. Pereloma

Faculty of Engineering and Information Sciences - Papers: Part A

An investigation into influence of the austenitising temperature and the austenite deformation temperature on Nb precipitation and recrystallisation kinetics was carried out for a steel containing 0.081C-0.021Ti-0.064Nb (wt. %). The austenite grain structure was correlated to the dispersive properties of Nb atom clustering and precipitation. Irrespective of the austenitising temperature, deformation to 0.75 strain at 1075 °C produced a fully recrystallised microstructure. After deformation at 975 °C, only partial recrystallisation was observed in the samples austenitised at higher temperature, whereas samples austenitised at lower temperature were fully recrystallised. The influence of solute drag and particle pinning effects on the recrystallisation …

Dynamic Of Negative Ions In Potassium-D-Ribose Collisions, D Almeida, F Ferreira Da Silva, G Garcia, P Limao-Vieira

Faculty of Engineering and Information Sciences - Papers: Part A

We present negative ion formation from collisions of neutral potassium atoms with D-ribose (C5H10O5), the sugar unit in the DNA/RNA molecule. From the negative ion time-of-flight (TOF) mass spectra, OH− is the main fragment detected in the collision range 50–100 eV accounting on average for 50% of the total anion yield. Prominence is also given to the rich fragmentation pattern observed with special attention to O− (16 m/z) formation. These results are in sharp contrast to dissociative electron attachment experiments. The TOF mass spectra assignments show that these channels are also observed, albeit with a much lower relative intensity. Branching …

Rectifying Differences In Transport, Dynamic, And Quasi-Equilibrium Measurements Of Critical Current Density, I A. Golovchanskiy, A V. Pan, O V. Shcherbakova, S A. Fedoseev

Faculty of Engineering and Information Sciences - Papers: Part A

The dependence of the critical current density (J_c ) on electric field criteria (E _cr) is studied for high-quality YBCO (YBa₂Cu₃O₇) thin films over the entire applied magnetic field (B_a) range. The quantitative model describing the J_c(B_a) dependence is compared and explained for the critical current densities obtained by different measurement techniques. Transport current and quasi-equilibrium magnetization measurement data can successfully be fitted by the model with appropriate electric field criteria. The dependence of the irreversibility field on the E _cr criterion can be obtained within …

Constant-Size Dynamic K-Times Anonymous Authentication, Man Ho Au, Willy Susilo, Yi Mu, Sherman S. M Chow

Faculty of Engineering and Information Sciences - Papers: Part A

Dynamic k-times anonymous authentication (k-TAA) schemes allow members of a group to be authenticated anonymously by application providers for a bounded number of times, where application providers can independently and dynamically grant or revoke access right to members in their own group. In this paper, we construct a dynamic k-TAA scheme with space and time complexities of O(log(k)) and a variant, in which the authentication protocol only requires constant time and space complexities at the cost of O(k) -sized public key. We also describe some tradeoff issues between different system characteristics. We detail all the zero-knowledge proof-of-knowledge protocols involved and …

Dynamic Properties Of Sand-Tyre Chip Mixtures, M S. Mashiri, M. Neaz Sheikh, J S Vinod, Hing Ho Tsang

Faculty of Engineering and Information Sciences - Papers: Part A

The stockpiling of scrap tyres is a significant environmental hazard and has attracted ample research attention to explore viable solutions to recycling and reuse of scrap tyres. The authors have recently proposed a novel seismic isolation method using sand-tyre chips (STCh) mixture for protecting buildings and infrastructure. Although the static properties of STCh mixture have been extensively studied, the investigation on the dynamic properties of the mixture has been limited. The dynamic properties of STCh mixture are important to its application for seismic protection of infrastructure. This paper presents the dynamic properties (shear modulus and damping ratio) of STCh mixture …

The Dynamic Wetting Characteristics Of Ladle Slags On Spinel, Hamed Abdeyazdan, Neslihan Dogan, Muhammad Rhamdhani, Michael W. Chapman, Brian Monaghan

Faculty of Engineering and Information Sciences - Papers: Part A

Inclusion removal by slag is primarily achieved by optimizing process conditions that promote slag contact with the inclusion. For efficient inclusion removal the inclusions must adhere to the slag phase. The strength of the attachment can be characterised by the wettability of the slag on the inclusions.

Winkler Model For Dynamic Response Of Composite Caisson-Piles Foundations: Lateral Response, Rui Zhong, Maosong Huang

Faculty of Engineering and Information Sciences - Papers: Part A

As the first part of a sequence focusing on the dynamic response of composite caisson-piles foundations (CCPFs1), this paper develops a simplified method for the lateral response of these foundations. A Winkler model for the lateral vibration of the CCPF is created by joining the two components, the caisson and the pile group, where the four-spring Winkler model is utilized for the caisson and axial-lateral coupled vibration equations are derived for the pile group. For determining the coefficients of the four-spring Winkler model for the caissons, embedded footing impedance is used and a modification on the rotational embedment factor is …

Efficient And Dynamic Key Management For Multiple Identities In Identity-Based Systems, Hua Guo, Chang Xu, Zhoujun Li, Yanqing Yao, Yi Mu

Faculty of Engineering and Information Sciences - Papers: Part A

The traditional identity-based cryptography requires a user, who holds multiple identities, to hold multiple private keys, where each private key is associated with an identity. Managing multiple private/public keys is a heavy burden to a user due to key management and storage. The recent advancement of identity-based cryptography allow a single private key to map multiple public keys (identities); therefore the private key management is simplified. Unfortunately, the existing schemes capturing this feature do not allow dynamic changes of identities and have a large data size proportional to the number of the associated identities. To overcome these problems, in this …

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 …

Multi-Factor Coupling System Characteristic Of The Dynamic Roll Gap In The High-Speed Rolling Mill During The Unsteady Lubrication Process, Qiaoyi Wang, Zhengyi Jiang, Jingwei Zhao, Min Fang

Faculty of Engineering and Information Sciences - Papers: Part A

In the present work, a multi-factor coupling dynamic model of a rolling mill system for a dynamic roll gap during an unsteady lubrication process was developed on the basis of the rolling theory, lubrication and the friction theory, and the mechanical vibration theory. The multi-factor coupling model of interfacial film binding was coupled with the rolling force model, dynamic roll gap interface friction model and work roll movement model. The corresponding distributions of friction and pressure at varying surface roughness and times were systematically analyzed during the unsteady mixed lubrication process. The effects of the main processing parameters on the …

Dynamic Fingerprint Based On Human Motion And Posture, Amir Hesami, Fazel Naghdy, David Stirling

Faculty of Engineering and Information Sciences - Papers: Part A

The feasibility of generating a Dynamic FingerPrint (DFP) for an individual is explored. DFP is a unique signature generated based on a combination of body part movements. The body movements are obtained using a sensor suit recording inertial signals that are subsequently modeled on a humanoid frame with 23 degrees of freedom (DOF). Measured signals include position, velocity, acceleration, orientation, angular velocity and angular acceleration. DTW (Dynamic Time Warping) is XVHG WR FODVVLI\ WKH LQGLYLGXDO¶V identity. The approach is described and the characteristics of the algorithms are presented. It is anticipated that these approaches will have applications in surveillance and …

Dynamic Impression Insole In Rheumatoid Foot With Metatarsal Pain, Bao-Chi Chang, Jia-Yi Wang, Biing-Shiun Huang, Hsiao-Yi Lin, Winson Lee

Faculty of Engineering and Information Sciences - Papers: Part A

Background

Custom molded insoles with metatarsal supports are used to redistribute excessive loading under the metatarsal heads in patients with metatarsalgia. However, these pressure reductions are usually insufficient for the rheumatoid foot with painful deformed metatarsal heads. We developed an effective insole made by sequential foam padding under successive walking impression.

Methods

Seventeen consecutive rheumatoid arthritic outpatients with metatarsal pain participated in this repeated measures study of 7-mm flat Ethylene Vinyl Acetate, custom molded and dynamic impression insoles. Peak plantar pressure, pressure-time integral, contact area and mean force were measured by a Pedar-X mobile system. Pain levels were assessed using …

Dynamic Change Impact Analysis For Maintaining And Evolving Agent Systems, Hoa Khanh Dam, Aditya Ghose

Faculty of Engineering and Information Sciences - Papers: Part A

In contrast to an increasing number of agent-based applica- tions in various domains, there has been very little work on maintenance and evolution of agent systems. This paper ad- dresses this gap with a focus on change impact analysis, i.e. estimating the potential eects of changes before they are made as an agent system evolves. We propose a technique for performing impact analysis in an agent system using dy- namic information about agent behaviour. Our approach builds a representation of an agent's behaviour by analyzing its execution traces which consist of goals and plans, and uses this representation to estimate …

Dynamic Characteristics Of A Hybrid Microgrid With Inverter And Non- Inverter Interfaced Renewable Energy Sources: A Case Study, A V. Jayawardena, L G. Meegahapola, S Perera, D A. Robinson

Faculty of Engineering and Information Sciences - Papers: Part A

Microgrids are becoming important constituents of electric power distribution networks. Microgrids are typically comprised of both inverter interfaced (e.g. double-fed induction generator (DFIG), solar-photovoltaic (PV) system) and non-inverter interfaced (e.g. synchronous generator) renewable energy generators (REGs), hence their dynamic characteristics are significantly different from the conventional grids comprised of centralised synchronous generators. Different inherent characteristics of REGs, power dispatch levels, relative REG capacities, and external grid characteristics are some of the important features of significant interest in relation to microgrid dynamic behaviour. For this study a microgrid model was developed in DIgSILENT Power Factory based on the IEEE-13 bus system …

Feasibility Of Passivhaus Standards And Alternative Passive Design On Climatic Zones Of Chile - Determination Of Energy Requirements With Dynamic Simulation, Javier Carrasco Eade, Georgios Kokogiannakis

Faculty of Engineering and Information Sciences - Papers: Part A

The current building envelope standards from Article 4.1.10 of the “General Law of Urban Planning and Construction” The current building envelope standards from Article 4.1.10 of the “General Law of Urban Planning and Construction” in Chile are applied on a typical residential building for the climate of Concepción (36° Latitude South, 73° Longitude West) and a detailed energy simulation program is used to assess the energy performance of this building. The simulation results of the Chilean standards are then compared with simulation results of PassivHaus standards upon the same building layout and with simulation results from the same typical building …

Team Situation Awareness Measure Using Semantic Utility Functions For Supporting Dynamic Decision-Making, Jun Ma, Jie Lu, Guangquan Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

Team decision-making is a remarkable feature in a complex dynamic decision environment, which can be supported by team situation awareness. In this paper, a team situation awareness measure (TSAM) method using a semantic utility function is proposed. The semantic utility function is used to clarify the semantics of qualitative information expressed in linguistic terms. The individual and team situation awareness are treated as linguistic possibility distributions on the potential decisions in a dynamic decision environment. In the TSAM method, team situation awareness is generated through reasoning and aggregating individual situation awareness based on a multi-level hierarchy mental model of the …

Dynamic Response Analysis Of The Rotating Blade Of Horizontal Axis Wind Turbine, Xiong Liu, Xianmin Zhang, Gangqiang Li, Yan Chen, Zhiquan Ye

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a dynamic response analysis of the blade of horizontal axis wind turbines using finite element method. The blade is treated as a cantilever and modeled with two-node beam element. The blade element-momentum theory is applied to calculate the aerodynamic loads. Dynamic inflow and dynamic stall are taken into account to reflect the transient aerodynamics. The centrifugal stiffening is introduced to consider the restoring effects of centrifugal force. An aerodynamic damping model is presented for calculating the overall damping ratio instantaneously during time-domain simulation. The structural dynamic equation is solved using Newmark method and the overall dynamic response …

Adoption Of Dynamic Simulation For Energy Performance Rating Tool For Korean Residential Buildings: Edem-Samsung, Saeeta Ghauri, Cameron Johnstone, Jaemin Kim, Georgios Kokogiannakis, Paul Tuohy, Kyung-Hun Woo

Faculty of Engineering and Information Sciences - Papers: Part A

Currently, there is a high emphasis on reducing the energy consumption and carbon emissions of buildings worldwide. Korea is facing an emerging issue of energy savings in buildings in perspective of new green economic policy. In this context, various policy measures including the energy efficiency ratings for buildings are being implemented for domestic and non-domestic buildings. In practice, design teams tend to prefer easy to use assessment tools to optimise energy performance and carbon ratings while they are concerned about calculation accuracy and the accurate representation of the dynamics involved associated with the characteristics of Korean residential buildings. This paper …