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Full-Text Articles in Science and Technology Studies
Performance Of Ballast Influenced By Deformation And Degradation: Laboratory Testing And Numerical Modeling, Buddhima Indraratna, Ngoc Trung Ngo, Cholachat Rujikiatkamjorn
Performance Of Ballast Influenced By Deformation And Degradation: Laboratory Testing And Numerical Modeling, Buddhima Indraratna, Ngoc Trung Ngo, Cholachat Rujikiatkamjorn
Faculty of Engineering and Information Sciences - Papers: Part B
This paper presents a study on the deformation and degradation responses of railway ballast using large-scale laboratory testing and computational modeling approaches. A series of large-scale triaxial tests were carried out to investigate the ballast breakage responses under cyclic train loading subjected to varying frequencies, f=10-40 Hz. The role of recycled rubber energy-absorbing mats (REAMs) on reducing ballast breakage was also examined. Laboratory test results show that the ballast experiences significant degradation (breakage) and deformation, while the inclusion of REAMs can reduce the ballast breakage up to about 35%. Numerical modeling using the coupled discrete-continuum approach [coupled discrete-element method-finite-difference method …
Advancement Of Rail Ballast Testing Methodologies And Design Implications, Buddhima Indraratna, Ngoc Trung Ngo, Cholachat Rujikiatkamjorn, Fernanda Ferreira
Advancement Of Rail Ballast Testing Methodologies And Design Implications, Buddhima Indraratna, Ngoc Trung Ngo, Cholachat Rujikiatkamjorn, Fernanda Ferreira
Faculty of Engineering and Information Sciences - Papers: Part B
Given the limited capacity of available railway tracks in Australia to sustain increasingly faster and heavier trains, the development of innovative and sustainable ballasted tracks is essential for Australian transport infrastructure. Upon repeated train loading, ballast aggregates become degraded and fouled owing to the intrusion of external fines either from the subbase or surface, which decreases track drainage potentially leading to track instability. This paper reviews some advancements in testing methodologies and design implications of ballasted tracks stabilized with artificial inclusions, including geocomposites, energy absorbing rubber mats and end-of-life tires. Measured test data shows that the use of these waste …
Metamorphic Testing Of Navigation Software: A Pilot Study With Google Maps, Joshua Brown, Zhiquan Zhou, Yang-Wai Chow
Metamorphic Testing Of Navigation Software: A Pilot Study With Google Maps, Joshua Brown, Zhiquan Zhou, Yang-Wai Chow
Faculty of Engineering and Information Sciences - Papers: Part B
Millions of people use navigation software every day to commute and travel. In addition, many systems rely upon the correctness of navigation software to function, ranging from directions applications to self-driving machinery. Navigation software is difficult to test because it is hard or very expensive to evaluate its output. This difficulty is generally known as the oracle problem, a fundamental challenge in software testing. In this study, we propose a metamorphic testing strategy to alleviate the oracle problem in testing navigation software, and conduct a case study by testing the Google Maps mobile app, its web service API, and its …
Two Decades Of Advancement In Process Simulation Testing Of Ballast Strength, Deformation, And Degradation, Buddhima Indraratna, Ngoc Trung Ngo, Sanjay Nimbalkar, Cholachat Rujikiatkamjorn
Two Decades Of Advancement In Process Simulation Testing Of Ballast Strength, Deformation, And Degradation, Buddhima Indraratna, Ngoc Trung Ngo, Sanjay Nimbalkar, Cholachat Rujikiatkamjorn
Faculty of Engineering and Information Sciences - Papers: Part B
This paper describes salient features of a set of large-scale ballast testing equipment developed at the University of Wollongong, Australia, and how the test results and research outcomes have contributed to transforming tracks in the Australian heavy haul and commuter networks, particularly with regards to the strength, deformation, and degradation of ballast. Ideally, ballast assemblies should be tested in prototype scale under actual loading conditions. This is because a reduction in particle sizes for testing in smaller equipment can reduce the internal angle of friction (shearing resistance) of the granular assembly in a macro sense, and the angularity of the …
A Cost-Effective Software Testing Strategy Employing Online Feedback Information, Zhiquan Zhou, Arnaldo Sinaga, Willy Susilo, Lei Zhao, Kai-Yuan Cai
A Cost-Effective Software Testing Strategy Employing Online Feedback Information, Zhiquan Zhou, Arnaldo Sinaga, Willy Susilo, Lei Zhao, Kai-Yuan Cai
Faculty of Engineering and Information Sciences - Papers: Part B
An online partitioning strategy is presented, in which test cases are selected based on feedback information collected during the testing process. The strategy differs from con- ventional approaches because the partitioning is performed online rather than off-line and because the partitioning is not based on program code or specifications. It can, therefore, be implemented in the absence of the source code or specification of the program under test. The cost-effectiveness of the proposed strategy has been empirically investigated with a set of subject programs, namely, SPACE, SED, GREP, and the Siemens Suite of Programs. The results demonstrate that the proposed …
Metamorphic Testing For Adobe Data Analytics Software, Darryl C. Jarman, Zhiquan Zhou, Tsong Yueh Chen
Metamorphic Testing For Adobe Data Analytics Software, Darryl C. Jarman, Zhiquan Zhou, Tsong Yueh Chen
Faculty of Engineering and Information Sciences - Papers: Part B
It is challenging to test data analytics software because a test oracle might not be available. This study reports our experience of applying metamorphic testing to Adobe's data analytics software that is used for anomaly detection in a set of time series data. We make use of geometric transformations to build metamorphic relations and generate simple time series data as the source test cases. The results of this study show that metamorphic testing is highly effective for both verification and validation purposes. An investigation of the issues detected during metamorphic testing revealed three bugs in the software under test.
Factor Analytic Mixed Models For The Provision Of Grower Information From National Crop Variety Testing Programs, Alison B. Smith, Aanandini Ganesalingam, Haydn Kuchel, Brian R. Cullis
Factor Analytic Mixed Models For The Provision Of Grower Information From National Crop Variety Testing Programs, Alison B. Smith, Aanandini Ganesalingam, Haydn Kuchel, Brian R. Cullis
Faculty of Engineering and Information Sciences - Papers: Part A
Crop variety testing programs are conducted in many countries world-wide. Within each program, data are combined across locations and seasons, and analysed in order to provide information to assist growers in choosing the best varieties for their conditions. Despite major advances in the statistical analysis of multi-environment trial data, such methodology has not been adopted within national variety testing programs. The most commonly used approach involves a variance component model that includes variety and environment main effects, and variety by environment ( VxE ) interaction effects. The variety predictions obtained from such an analysis, and subsequently reported to growers, are …
A Revisit Of Three Studies Related To Random Testing, Tsong Yueh Chen, Fei-Ching Kuo, Dave Towey, Zhiquan Zhou
A Revisit Of Three Studies Related To Random Testing, Tsong Yueh Chen, Fei-Ching Kuo, Dave Towey, Zhiquan Zhou
Faculty of Engineering and Information Sciences - Papers: Part A
© 2015 Science China Press and Springer-Verlag Berlin Heidelberg Software testing is an approach that ensures the quality of software through execution, with a goal being to reveal failures and other problems as quickly as possible. Test case selection is a fundamental issue in software testing, and has generated a large body of research, especially with regards to the effectiveness of random testing (RT), where test cases are randomly selected from the software’s input domain. In this paper, we revisit three of our previous studies. The first study investigated a sufficient condition for partition testing (PT) to outperform RT, and …
Investigation Of X70 Line Pipe Steel Fracture During Single Edge-Notched Tensile Testing Using Acoustic Emission Monitoring, Turbadrakh Chuluunbat, Cheng Lu, Andrii Kostryzhev, A Kiet Tieu
Investigation Of X70 Line Pipe Steel Fracture During Single Edge-Notched Tensile Testing Using Acoustic Emission Monitoring, Turbadrakh Chuluunbat, Cheng Lu, Andrii Kostryzhev, A Kiet Tieu
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents an investigation of the fracture behavior of X70 pipeline steel using the acoustic emission (AE) monitoring technique. The AE monitoring technique is widely used in mechanical and materials research for detection of plastic deformation, fracture initiation and crack growth. However, quantitative dependences of the AE parameters (such as signal amplitude and frequency) on the fracture parameters of X70 pipeline steel (such as ductile and brittle fracture initiation and propagation) have not been studied in depth and are therefore not completely understood. In this paper, we report an investigation of the effect of loading conditions on the fracture …
Influence Of Loading Conditions During Tensile Testing On Acoustic Emission, Turbadrakh Chuluunbat, Cheng Lu, Andrii Kostryzhev, A Kiet Tieu
Influence Of Loading Conditions During Tensile Testing On Acoustic Emission, Turbadrakh Chuluunbat, Cheng Lu, Andrii Kostryzhev, A Kiet Tieu
Faculty of Engineering and Information Sciences - Papers: Part A
The Acoustic Emission (AE) monitoring technique is widely used in mechanical and material research for detection of plastic deformation, fracture initiation and crack growth. However, the influence of AE features (such as signal amplitude, frequency, rise time and duration) on the fracture parameters (such as brittle or ductile mode of propagation and fracture propagation speed) is not completely understood. In this paper, the effect of loading conditions on fracture behavior was studied using AE monitoring during tensile testing of an aluminum alloy specimen. The fracture development was observed using a high speed video camera and was analyzed using the finite …
Behavior Of Fresh And Fouled Railway Ballast Subjected To Direct Shear Testing: Discrete Element Simulation, B Indraratna, N T Ngo, C Rujikiatkamjorn, J S. Vinod
Behavior Of Fresh And Fouled Railway Ballast Subjected To Direct Shear Testing: Discrete Element Simulation, B Indraratna, N T Ngo, C Rujikiatkamjorn, J S. Vinod
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents the three-dimensional discrete element method (DEM) that was used to study the shear behaviour of fresh and coal fouled ballast in direct shear testing. The volumetric changes and stress-strain behaviour of fresh and fouled ballast were simulated and compared with the experimental results. 'Clump logic' in Particle Flow Code (PFC3D) incorporated in a MATLAB Code was used to simulate irregular shaped particles in which groups of ten to twenty spherical balls were clumped together in appropriate sizes to simulate ballast particles. Fouled ballast with various Void Contaminant Index (VCI), ranging from 20%VCI to 70%VCI, were modelled by …
Molecular Weight Distribution Of Network Strands In Double Network Hydrogels Estimated By Mechanical Testing, Hai Xin, Hugh Ralph Brown, Geoffrey M. Spinks
Molecular Weight Distribution Of Network Strands In Double Network Hydrogels Estimated By Mechanical Testing, Hai Xin, Hugh Ralph Brown, Geoffrey M. Spinks
Faculty of Engineering and Information Sciences - Papers: Part A
The remarkably high toughness of double network (DN) hydrogels is related to the energy dissipation that occurs due to the scission of network strands in the most tightly crosslinked of its two interpenetrating networks. The loading curve during tensile testing of DN hydrogels usually takes a complex shape and sometimes shows yielding. Wang and Hong recently proposed a model [1] based on the successive scission of the shortest remaining elastically active strands during tensile loading that predicts the shape of the loading curve of one DN hydrogel reasonably well. In the present study, the model was modified slightly and applied …
Behaviour Of Clay-Fouled Ballast Under Drained Triaxial Testing, Buddhima Indraratna, Nayoma C. Tennakoon, Sanjay Shrawan Nimbalkar, Cholachat Rujikiatkamjorn
Behaviour Of Clay-Fouled Ballast Under Drained Triaxial Testing, Buddhima Indraratna, Nayoma C. Tennakoon, Sanjay Shrawan Nimbalkar, Cholachat Rujikiatkamjorn
Faculty of Engineering and Information Sciences - Papers: Part A
Contamination or fouling of rail ballast with external fines, including slurried and pumped subgrade material (e.g. clay and silt), is one of the primary reasons for track deterioration. Fouling causes differential settlement of the track, and also decreases the load-bearing capacity, owing to the reduction in the friction angle of the granular assembly. In certain circumstances, fouled ballast needs to be cleaned or replaced to maintain the desired track stiffness, load-bearing capacity and track alignment, all of which influence safety. This paper presents and discusses the results of a series of large-scale triaxial tests conducted on latite basalt, a rail …
Dynamic Testing Of Tekseal High Yield Grout To Provide An Orepass Plug Designed For Impact, I V. S Mutton, Alexander Remennikov, D Pateman
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 …
Design And Experimental Testing Of An Adaptive Magneto-Rheological Elastomer Base Isolator, Yancheng Li, Jianchun Li, Weihua Li
Design And Experimental Testing Of An Adaptive Magneto-Rheological Elastomer Base Isolator, Yancheng Li, Jianchun Li, Weihua Li
Faculty of Engineering and Information Sciences - Papers: Part A
Magnetorheological elastomer (MRE) is known for its field-sensitive shear modulus and damping property when it is exposed to a magnetic field. It has a great potential for the development of vibration reduction devices. Many research, mostly in mechanical engineering, have been focused on different kinds of vibration absorbers and vibration isolators, however few research addresses its potential in base isolation system in civil engineering application. The objective of this paper is to pilot the design and experimental testing of a novel device, an adaptive MRE base isolator, for the development of smart base isolation system. A large-scale design of the …
Different Modes Of Dust Testing For Bulk Solids, Ian Frew, Peter W. Wypych, Leong Mar
Different Modes Of Dust Testing For Bulk Solids, Ian Frew, Peter W. Wypych, Leong Mar
Faculty of Engineering and Information Sciences - Papers: Part A
The loss of dust from the mining, processing, storage, handling, transportation and loading of bulk materials is creating an increasing number of problems for industry and the community. This includes loss of valuable material and export income, increasing workplace dust emissions (e.g. from mine sites, loading, receival, ports, bulk berths) and decreasing ambient air quality and human health, especially for nearby communities. It is virtually impossible to estimate the total cost of these problems to industry and the community. An initial key step in addressing dust problems is to quantify the dustiness or dustability of bulk materials. This paper examines …
Acoustic Emission Monitoring Of Split Formation During Charpy Impact Testing Of High Strength Steel, Andrii Kostryzhev, R B. Punch, Claire L. Davis, Martin Strangwood
Acoustic Emission Monitoring Of Split Formation During Charpy Impact Testing Of High Strength Steel, Andrii Kostryzhev, R B. Punch, Claire L. Davis, Martin Strangwood
Faculty of Engineering and Information Sciences - Papers: Part A
Acoustic emission (AE) monitoring has been used to detect split formation during room temperature low blow Charpy impact testing of high strength thick strip steels. The AE signal analysis identified separate signals originating from hammer impact, plastic deformation (verified using Charpy impact testing on mild steel with no splits) and split initiation/growth. The presence of splits was confirmed by sectioning and fractography, and the splits were brittle in nature. A possible correlation between the AE signal features and fracture mode is presented.
Pilot-Scale Testing Of Diatomaceous Earth Filtration For Removal Of Cryptosporidium Oocysts, Jerry E. Ongerth, Primrose E. Hutton
Pilot-Scale Testing Of Diatomaceous Earth Filtration For Removal Of Cryptosporidium Oocysts, Jerry E. Ongerth, Primrose E. Hutton
Faculty of Engineering and Information Sciences - Papers: Part A
No abstract provided.