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On the capabilities of pattern classification using a PID concept
No full textWe present a concept for increasing the reliability of distance-based pattern classification models, applied to time-variant processes. In fault detection, static pattern classification is often used to differentiate between normal sensor data indicating ordinary uncritical states for the monitored process and abnormal data, indicating states that need to be resolved by maintenance or even dangerous states, that require the process to be switched off. Depending on the process and its environment, it can be difficult to classify, properly, each state the process can be in by employing sensor data. Sensor hardware limitations may also cause uncertainty when gathering the data for different process states. Inspired by conventional linear control theory, we propose a Proportional-Integral-Derivative (PID) concept which allows the determination of a relevance factor for a current classification, by consulting previous data and expert knowledge. It is based on the assumption that features of sensor data have different alteration rates, when transitioning into different states. The PID concept can be applied to several classical distance-based pattern recognition approaches such as Kohonen's Learning Vector Quantization (LVQ) or the k-means algorithm and allows them to classify abnormal data more reliably. The performance of this PID concept is demonstrated with test data sets. Problems that might occur when applying the PID concept to real applications and their solution are pointed out
Challenging academic performance to excel: the 'BE' project (performing Beyond Expectations)
No full textThis paper attempts succinctly present and share our recent experience and reflections in planning and producing a digitally-rich Teacher Training (TT) Numeracy and Additional Learning needs recently validated course in a a Higher Education Institution in the UK
Applying the Widget Paradigm to Learning Design: Towards a New Level of User Adoption
No full textResearching the sharing of learning designs is a well-established domain within the technology-enhanced learning research community. However, until now tools supporting educational modelling languages such as IMS Learning Design have reached a wide adoption in today's school practice. Following a design science research methodology we report on the design, implementation, and evaluation of a novel tool referred to as "Composer". The Composer supports the design of learning activities and has been developed according to design principles such as (a) interoperability between design-time and run-time systems based on the W3C Widget Standard, (b) inclusion of artefact types beyond content such as tools, people and events, (c) a user-friendly authoring environment. A first evaluation of the proof-of-concept implementation suggests that the tool is easy-to-use and provides added value for teachers when it comes to reflecting about the design of learning activities
High sensitivity humidity sensors using flexible surface acoustic wave devices made on nanocrystalline ZnO/polyimide substrates
No full textFlexible ZnO/polyimide surface acoustic wave (SAW) based humidity sensors were fabricated and their performances were investigated. ZnO films deposited on polyimide substrates are (0002) oriented columnar nanocrystals with grain sizes of 50–60 nm. SAW devices with different wavelengths showed high transmission performance, and the sensors exhibited a good repeatability in response to the cyclic change in humidity from ∼5% relative humidity (RH) to ∼87% RH. The responses of the sensors to RH change increase with the increase in humidity. The sensitivity increases with the decrease in wavelength owing to the improved characteristics of the sensors with shorter wavelengths. A high sensitivity of 34.7 kHz/10% RH has been obtained from a SAW sensor with no surface treatment, demonstrating that the flexible SAW humidity sensors are very promising for applications in flexible sensors and microsystems
Developments of interfaces containing auxetic constituents
No full textAuxetic materials display a negative Poisson’s ratio. Such materials have a host of potential benefits that could be exploited such as high shear resistance, fracture toughness, and high indentation resistance amongst others. The inclusion of auxetic materials within positive Poisson’s ratio materials is investigated in an attempt to improve the effective mechanical properties. The project focuses on the modification of mechanical properties of an adhesive, or interface, system via the addition of either auxetic and/or conventional constituents. The objective is achieved via two main approaches: a multi-layer adhesive/film interface and auxetic particulate filled adhesives. Multi-layer film/adhesive interfaces are modelled for Constant Interface Thickness (CIT) and Constant Constituent Layer Thickness (CCLT) systems using Finite Element Modelling (FEM), analytical expressions from averaging techniques for the effective elastic properties of a composite (the Ramirez approach) and a modified (weighted) Rule of Mixtures approach developed by the author. High and low modulus adhesives relative to the films are considered. In the second approach, FEM of particulate filled systems is performed for high and low modulus auxetic fillers relative to the matrix. The results are compared to existing analytical theories such as the Self-Consistent Field theory, Hashin Shtrikman and the bounding techniques of elasticity. Auxetic materials are predicted by the models to give rise to improvements in the effective mechanical properties (Young’s modulus and shear modulus) of both the multi-layer film/adhesive and particulate filled composite interfaces. Experimental work in support of the model predictions includes 3 and 4 point bending tests of multi-layer film adhesive interfaces comprising polypropylene films and polyolefin adhesive, and tensile testing of auxetic silica particulate (high modulus filler) and short chopped auxetic polypropylene fibre (low modulus filler) filled epoxy matrix composites. The multi-layer film adhesive approach requires an understanding of the production of auxetic polypropylene films. A parametric study of the melt extrusion process for the production of auxetic and conventional films has, therefore, been undertaken and has included producing, for the first time, auxetic PP films at significantly higher processing temperatures than those previously established in the vicinity of the melt onset temperature
Impact of carpet waste fibre addition on swelling properties of compacted clays
No full textMunicipalities and recycling and environmental authorities are concerned about the growing amount of carpet waste produced by household, commercial and industrial sectors. It is reported that 500,000 tonnes of carpet waste fibre are plunged into landfills annually in the UK. In the United States of America, around 10 million tonnes of textile waste was generated in 2003. In geotechnical engineering, expansive clay soils are categorised as problematic soils due to their swelling behaviour upon increase in the moisture content. The problematic nature of such soils is intensified with the increase in the plasticity index. This paper presents results of a comprehensive investigation into utilisation of carpet waste fibres in order to improve the swelling characteristics of compacted cohesive soils. Therefore, two different clay soils with markedly different plasticity indices (i.e. 17.0 and 31.5%) were treated with two different types of carpet waste fibre. Waste fibres were added to prepare specimens with fibre content of 1, 3 and 5 % by dry weight of soil. Soil specimens with different dry unit weights and moisture contents were prepared so as to the swelling behaviour of fibre reinforced compacted clays is completely attained under various scenarios. The results indicated that the behaviour of the fibre reinforced soils seems highly dependent on the initial compaction state and secondary on the moisture content. It was found that the swelling pressure drops rapidly as the percentage of fibre increases in samples prepared at the maximum dry unit weight and optimum moisture content. Reducing the dry unit weight, while maintaining constant moisture content or increasing the moisture content at constant dry unit weight was found to reduce the swelling pressure
Composites and Nanocomposites
No full textParticularly since the Second World War, technological advancement in aerospace, automotive and marine industries has required materials with superior properties and functionalities for new applications, something which is hard to achieve using monolithic materials such as metal, glass, polymer, etc. This has prompted research and development of innovative materials and structures for the next generation of aero-vehicles, automotives, boats, ships, etc
