Rotational traction testing : How can we improve the current test device?
- Authors: Twomey, Dara , Connell, Monique , Petrass, Lauren
- Date: 2014
- Type: Text , Conference paper
- Relation: 2014 10th Conference of the International Sports Engineering Association, ISEA 2014; Sheffield, United Kingdom; 14th-17th July 2014; published in Procedia Engineering, Vol. 72, p. 919-924
- Full Text:
- Reviewed:
- Description: Rotational resistance is an important sports surface property in optimising both performance and safety for participants. Despite various attempts to create valid devices to measure the rotational traction, the Studded Boot Apparatus (SBA) originally developed in 1975 is still used in the synthetic turf standards of many governing bodies of sport. In addition to validity limitations, poor operator reliability of the SBA has been reported and it was postulated that the manual nature of the device contributed significantly to this result. Therefore, the aim of this paper is to present data on the automation of the SBA and to discuss the reliability and validity issues of the device. An automated version of the SBA was developed called the UB Turf Tester (UBTT) and data was collected by ten inexperienced operators using the original SBA and the UBTT. Testing was undertaken on a synthetic turf and each operator completed ten trials with each device. Despite a slightly greater peak traction value for the UBTT, there was no significant difference between the peak traction for the two devices, F 1,2 = 0.341, p = 0.57. Greater reliability was found between operators for the UB Turf Tester. Given that the SBA is still commonly used to comply with standards, achieving the highest level of intra- and inter-operator reliability is both desirable and invaluable. However, the research on the validity of the device also needs to continue. Interestingly, limitations of the device were identified when it was first developed but very few adaptations have been implemented since then. Undoubtedly, the interaction between the human and the surface is a complex phenomenon but the weight force, the level of penetration, the pattern, shape and position of the cleats and the possibility of measuring rotational stiffness rather than peak traction all require further discussion and investigation.
QoS support in event detection in WSN through optimal k-coverage
- Authors: Alam, Kh Mahmudul , Kamruzzaman, Joarder , Karmakar, Gour , Murhsed, Manzur , Azad, Arman
- Date: 2011
- Type: Text , Conference paper
- Relation: 11th International Conference on Computational Science, ICCS 2011; Singapore, Singapore; 1st-3rd June 2011; published in Procedia Computer Science Vol. 4, p. 499-507
- Full Text:
- Reviewed:
- Description: Wireless sensor networks promise to guarantee accurate, fault tolerant and timely detection of events in large scale sensor fields. To achieve this the notion of k-coverage is widely employed in WSNs where significant redundancy is introduced in deployment as an event is expected to be sensed by at least k sensors in the neighborhood. As sensor density increases significantly with k, it is imperative to find the optimal k for the underlying event detection system. In this work, we consider the detection probability, fault tolerance and latency as the Quality of Service (QoS) metrics of an event detection system employing k-coverage and present a probabilistic model to guarantee given QoS support with the minimum degree of coverage taking into account the noise related measurement error, communication interference and sensor fault probability. This work eventually resolves the problem of over or under deployment of sensors, increases scalability and provides a well defined mechanism to tune the degree of coverage according to performance needs.
Simplifying and improving ant-based clustering
- Authors: Tan, Swee , Ting, Kaiming , Teng, Shyh
- Date: 2011
- Type: Text , Conference paper
- Relation: 11th International Conference on Computational Science, ICCS 2011; Singapore, Singapore; 1st-3rd June 2011, published in Procedia Computer Science Vol. 4, p. 46-55
- Full Text:
- Reviewed:
- Description: Ant-based clustering (ABC) is a data clustering approach inspired from cemetery formation activities observed in real ant colonies. Building upon the premise of collective intelligence, such an approach uses multiple ant-like agents and a mixture of heuristics, in order to create systems that are capable of clustering real-world data. Many recently proposed ABC systems have shown competitive results, but these systems are geared towards adding new heuristics, resulting in increasingly complex systems that are harder to understand and improve. In contrast to this direction, we demonstrate that a state-of-the-art ABC system can be systematically evaluated and then simplified. The streamlined model, which we call SABC, differs fundamentally from traditional ABC systems as it does not use the ant-colony and several key components. Yet, our empirical study shows that SABC performs more effectively and effciently than the state-of-the-art ABC system.
Aerodynamics of ribbed bicycle racing helmets
- Authors: Alam, Firoz , Chowdhury, Harun , Wei, Hozhi , Mustary, Israt , Zimmer, Gary
- Date: 2014
- Type: Text , Conference paper
- Relation: 2014 Conference of the International Sports Engineering Association p. 691-696
- Full Text: false
- Reviewed:
- Description: In competitive cycling, aero-helmets have been used around since 1980 to reduce aerodynamic resistance. Considerable design effort has been made to improve the aerodynamic efficiency of racing bicycle helmets over the years. However, the demand for further improvement has forced helmet manufacturers and designers to introduce new designs progressively. Recently several helmet manufacturers (e.g., LG, Lazer and Giro) have introduced dimples on the outer shell of helmet mimicking the so called 'Golf-ball' dimple effects with a view to further reduce aerodynamic drag of the helmet. However, no independently verifiable research so far has been reported in the public domain about the aerodynamic performance of ribbed bicycle helmets compared to smooth surfaced helmets. Hence, the primary objective of this work was to undertake an experimental study on four smooth aero-helmets including two latest model ribbed aero-helmets to understand their aerodynamic performance and the effect of dimples on helmets. The investigation was undertaken in an wind tunnel environment over a range of wind speeds, pitch and yaw angles. The experimental data indicate no measurable advantage between the smooth and ribbed helmets under varied pitch angles and at zero yaw angle.
A technique for parallel share-frequent sensor pattern mining from wireless sensor networks
- Authors: Rashid, Md. Mamunur , Gondal, Iqbal , Kamruzzaman, Joarder
- Date: 2014
- Type: Text , Conference paper
- Relation: 14th Annual International Conference on Computational Science, ICCS 2014; Cairns, Australia; 10th-12th June 2014; published in Procedia Computer Science p. 124-133
- Full Text:
- Reviewed:
- Description: WSNs generate huge amount of data in the form of streams and mining useful knowledge from these streams is a challenging task. Existing works generate sensor association rules using occurrence frequency of patterns with binary frequency (either absent or present) or support of a pattern as a criterion. However, considering the binary frequency or support of a pattern may not be a sufficient indicator for finding meaningful patterns from WSN data because it only reflects the number of epochs in the sensor data which contain that pattern. The share measure of sensorsets could discover useful knowledge about numerical values associated with sensor in a sensor database. Therefore, in this paper, we propose a new type of behavioral pattern called share-frequent sensor patterns by considering the non-binary frequency values of sensors in epochs. To discover share-frequent sensor patterns from sensor dataset, we propose a novel parallel technique. In this technique, we develop a novel tree structure, called parallel share-frequent sensor pattern tree (PShrFSP-tree) that is constructed at each local node independently, by capturing the database contents to generate the candidate patterns using a pattern growth technique with a single scan and then merges the locally generated candidate patterns at the final stage to generate global share-frequent sensor patterns. Comprehensive experimental results show that our proposed model is very efficient for mining share-frequent patterns from WSN data in terms of time and scalability.
Dynamic operation of post-combustion CO2 capture in Australian coal-fired power plants
- Authors: Bui, Mai , Gunawan, Indra , Verheyen, Vincent , Meuleman, Erik , Feron, Paul
- Date: 2014
- Type: Text , Conference paper
- Relation: 12th International Conference on Greenhouse Gas Control Technologies, GHGT 2014 p. 1368-1375
- Full Text:
- Reviewed:
- Description: Flexible operation of post-combustion CO2 capture (PCC) plants can improve efficiency through coordinating the balance between consumer demands for electricity and CO2 emission reductions. This strategy however, will impose process disturbances and the immediate and long term impact is unclear. There is a justified need for the development of accurate dynamic PCC models, as well as practical experience in dynamic operation of PCC pilot plants. This paper presents CSIRO PCC pilot plant data from the 2012 and 2013 dynamic campaigns using MEA solvent. The step-change approach to dynamic plant operation was implemented and the use of density meters to instantaneously measure CO2 loading instantaneously was investigated.
Aerodynamic drag measurements of FIFA-approved footballs
- Authors: Alam, Firoz , Chowdhury, Harun , George, Steven , Mustary, Israt , Zimmer, Gary
- Date: 2014
- Type: Text , Conference paper
- Relation: 2014 Conference of the International Sports Engineering Association p. 703-708
- Full Text:
- Reviewed:
- Description: Increasing technological advancements and demand for performance compel the ball manufacturers to introduce new designs. Construction of spherical footballs has been significantly changed over the years since 1970 from 32-panel leather stitched ball to 8-panel synthetic thermally bonded modern football. Despite being most popular game in the world, no data is available on aerodynamic properties of recently FIFA approved balls such as Adidas Cafusa (thermally bonded 32-panel), Nike Maxim (32- panel stitched), Umbro Neo (14-panel stitched, and Mitre Ultimax (26-panel stitched) footballs. Hence, the primary objective of this study was to determine aerodynamic drag of these balls and compare the findings with other balls introduced in late 2000. The aerodynamic forces were measured experimentally for a range of wind speeds in wind tunnel environment and their nondimensional coefficients were determined and compared. Additionally, a field test was also carried out to understand the perception of professional footballers.