Evaluation of the effect of ND:YVO4 laser parameters on internal micro-channel fabrication in polycarbonate

This paper presents the development of Artificial Neural Network (ANN) models for the prediction of laser machined internal micro-channels’ dimensions and production costs. In this work, a pulsed Nd:YVO4 laser was used for machining micro-channels in polycarbonate material. Six ANN multi-layered, feed-forward, back-propagation models are presented which were developed on three different training data sets. The analysed data was obtained from a 33 factorial design of experiments (DoE). The controlled parameters were laser power, P; pulse repetition frequency, PRF; and sample translation speed; U. Measured responses were the micro-channel width and the micro-machining operating cost per metre of produced microchannel. The responses were sufficiently predicted within the set micro-machining parameters limits. Three carefully selected statistical criteria were used for comparing the performance of the ANN predictive models. The comparison showed that model which had the largest amount of training data provided the highest degree of predictability. However, in cases where only a limited amount of ANN training data was available, then training data taken from a Face Centred Cubic (FCC) model design provided the highest level of predictability compared with the other examined training data set

An artificial neural network for dimensions and cost modelling of internal micro-channels fabricated in PMMA using Nd:YVO4 laser

For micro-channel fabrication using laser micro-machining processing, estimation techniques are normally utilised to develop an approach for the system behaviour evaluation. Design of Experiments (DOE) and the Artificial Neural Networks (ANN) are two methodologies that can be used as estimation techniques. These techniques help in finding a set of laser processing parameters that provides the required micro-channel dimensions and in finding the optimal solutions in terms reducing the product development time, power consumption and of least cost. In this work, an integrated methodology is presented in which the ANN training experiments were obtained by the statistical software DoE to improve the developed models in ANN. A 33 factorial design of experiments (DoE) was used to get the experimental set. Laser power, P; pulse repetition frequency, PRF; and sample translation speed, U were the ANN inputs. The channel width and the produced micro-channel operating cost per metre were the measured responses. Four Artificial Neural Networks (ANNs) models were developed to be applied to internal micro-channels machined in PMMA using a Nd:YVO4 laser. These models were varied in terms of the selection and the quantity of training data set and constructed using a multi-layered, feed-forward structure with a the back-propagation algorithm. The responses were adequately estimated by the ANN models within the set micro-machining parameters limits. Moreover the effect of changing the selection and the quantity of training data on the approximation capability of the developed ANN model was discussed

Implementation of video feedback to assist the learning of presentation skills

This paper describes the implementation of an online video resource for both postgraduate and undergraduate students with the aim to improve the learning of presentation skills. As part of the final year project in this last academic year, presentations were recorded at the start of the second semester. These were then made available to the students during week eight of the semester over the web via student specific portal pages. The student's marks and feedback from the lecture assessors on the presentations were also made available. The students were also recorded during their final presentations at the end of the semester. The changes in student grades were examined and compared to those over the previous six years when such feedback was not available. The resource was also designed to aid lecturers to view presentations they may have missed and enter marks for their allocated students

An analysis of final year student project performance in mechanical engineering

This paper describes a statistical analysis of the students' results in mechanical engineering Final Year Project (FYP) at undergraduate level eight. Project marks of the final year students obtained over the past six years (2002-2008) were recorded and analysed. A detailed and comprehensive assessment of the marks achieved was examined. This included assessment of the presentation, report and progress results. This study provided an interesting insight into the trends of assessors' marking and students' performance. A gradual statistically significant reduction in student marks over these six years was noted. Reduced student performance over the last 10 years in Leaving Certificate mathematics along with the general fall of in the numbers of engineering students are discussed as possible contributing factors. Care must also be taken to ensure that marking is consistent and standard such that it fully and fairly expresses student performance

Automated control of laser systems for micromachining

In this thesis, the effects of process parameters on the resulting feature morphology and dimensions within line length scales and micro-fluidic devices is presented. Positioning stages, laser systems, and autonomous control systems were developed and designed for the machining of micro-channels on glass sheet and inside polycarbonate and PMMA samples. The developed real time closed loop control system was set-up via reconfigurable I/O Field-Programmable Gate Array (FPGA). In-depth analyses of the positional performance of the developed Nd:YVO4, and Nd:YAG laser systems were carried out. The results of these analyses indicated that the developed 3D translation stage of the Nd:YVO4 laser system is better with accuracy and repeatability values less than 65 µm for all the three axes. In particular, CO2 (1.5 kW, 10.6 µm) and Nd:YVO4 (2.5 W, 1.064 µm) laser systems were investigated experimentally and through system models in order to better understand the effects of laser and motion parameters on the process control. Predictive models, that relate the laser machining parameters (laser power; P, pulse repetition frequency; PRF, and sample translation speed; U) to the geometry and cost of the produced micro-channels, were developed. Detailed designs of experiments (DoE) were conducted and results from developed predictive models based on Artificial Neural Network (ANN) and Response Surface Methodology (RSM) techniques were compared with the actual results. Statistical estimators were used to evaluate these models and compare their predictive and generalization ability. Results showed that although the ANN models provided the highest prediction accuracy, both RSM and ANN modelling techniques could be utilised as effective predictive tools for resultant laser micro-machined dimensions and selection of laser micromachining parameters

Online video resources to enable & enhance experiential learning

This paper describes the implementation of an online video resource for undergraduate students with the aim to improve the experiential learning. As part of the final year project for the last two academic years, presentations were recorded at the start of the second semester of 2007-2008 academic year. These were then made available to the students during week eight of the semester over the web via student specific portal pages. The student's marks and feedback from the lecture assessors on the presentations were also made available online. The students were also recorded during their final presentations at the end of the semester. The changes in student grades were examined and compared to those over the previous five years when such feedback was not available. The resource was also designed to aid lecturers in order for them to view presentations they may have missed and enter marks for their allocated students

Analysis of international graduate programmes structures for engineering education

This article traces the evolution of graduate study in Engineering in Ireland over three decades. Very few studies have shown the different norms and structures of graduate programmes in Ireland. In this paper, a review of traditional and structured PhD in terms of credit requirements and co-ordination structures is presented. The authors summarise the characteristics of graduate programmes in different universities in Ireland and compare these to those obtained in some of the leading international universities. The implementation of graduate programmes in Ireland is relatively recent and the structure of these programmes is still under development in the different universities. Plans for enhancement of graduate programs and the development of new initiatives to support graduate student academic and professional development are very important for the success of these programmes. The growth in enrolment reflects a broad diversity in background of students which will require not only increased financial resources but an adequate and sound organisational structure in order to move forward

An investigation of ESOL provision for adult Syrian refugees in Ireland: voices of support providers

This chapter describes a research project entitled An investigation of language and intercultural support for Syrian refugees in Ireland which explored the language and intercultural needs and supports provided to Syrian refugees who are resettling in towns across Ireland under the Irish Refugee Protection Programme (IRPP). This chapter focuses on the findings in relation to the provision of ESOL courses for adult refugees in the programme delivered by the local Education and Training Boards (ETBs). Through consultation with support providers from educational, community and NGO sectors across a number of resettlement towns in Ireland, the researchers seek to evaluate existing services, identify needs, and inform the development of additional supports in relation to English language supports for Syrian refugees in Ireland. Findings suggest that there are important lessons to be learnt in relation to the duration, intensity, content and format of the ESOL provision provided to these students and highlight an urgent need for the development of clear guidelines and appropriate training for the support providers involved

Beyond ESOL provision: perspectives on language, intercultural and integration support for Syrian refugees in Ireland

This chapter is the second in this volume (the first being Chapter 5) to report on a research project investigating language and intercultural support for Syrian refugees who are being resettled in towns across Ireland under the Irish Refugee Protection Programme (IRPP). Based on the perspectives of ESOL providers, resettlement workers, representatives of NGOs and organizations involved in the IRPP, as well as community-based service providers and volunteers, it explores the language and intercultural supports available to Syrian refugees beyond the official provision of English language training. Its findings indicate the need for intercultural training for those working with refugees, appropriate responses to refugees’ diverse needs, and support for sustainable integration in host communities. Emerging linguistic and cultural challenges faced by Syrian refugees in relation to employment, education, and social inclusion are discussed; the findings of this research point to the need for clear policy on refugee resettlement in Ireland

Changing evaluation of a master programme module to improve students' overall achievements

One of the modules delivered since 2001 in the Mechanical Engineering taught Masters Programme at Dublin City University is entitled “Product Design, Development and Value Analysis”. The module is assessed by two continuous assessments, both worth 10% and by a final exam worth 80%. In 2005, the exam period of this module was increased from 120 minutes to 150 minutes. Additionally, the second continuous assessment assignment was change from a report assignment to a set of 20 Multiple Choice Questions (MCQ) covering the entire module content. This assessment was run in the final week of the module. The first assignment was and remains as a report assignment. These two modifications were introduced to give the students sufficient time to complete the exam paper, and to provide a more comprehensive evaluation by the students for themselves as to their extent of knowledge on the module content. Average results of continuous assessment, exam marks, and overall marks before and after the change were assessed from 2002 to 2015 and presented in this paper. The two above-mentioned changes brought 14.2% increase in the continuous assessment average results, and 15.7% increase in the final exam marks. Therefore the combined effect of the changes has resulted in a significant positive increase in the student overall achievement within this module. The data and reasons behind these changes are discussed