Engineering

Publication Search Results

Now showing 1 - 10 of 980
  • (1995) Helmore, Phillip
    Conference Paper
    Many methods for predicting the resistance of various types of marine craft are now available in the literature. Some methods are more reliable than others, and knowing which are the best can be important. At UNSW we have begun a long-term program of implementing the various methods for student use, and evaluating them by comparisons with available data. The prediction methods cover displacement, pre-planing and planing hulls, and catamarans. This paper looks at some of the methods which have been programmed and some which have not, their limitations, and some experiences of the use of those which have been programmed. The opportunity is also taken to correct typographical errata in some of the original papers which otherwise limits the use of the methods.

  • (2009) Forbes, Gareth Llewellyn; Randall, Robert Bond
    Conference Paper
    The non-intrusive measurement of the condition of blades within a gas turbine would be a significant aid in the maintenance and continued operation of these engines. Online condition monitoring of the blade health by non-contact measurement methods is the ambition of most techniques. The current dominant method uses proximity probes to measure blade arrival time for subsequent monitoring. It has recently been proposed however, that measurement of the turbine casing vibration response could provide a means of blade condition monitoring, and even give the prospect of providing an estimation of the blade modal parameters. The casing vibration is believed to be excited pre-dominantly by (i) the moving pressure waveform around each blade throughout its motion and (ii) the moments applied by the stationary stator blades. Any changes to the pressure profile around the rotating blades, due to their vibration, will in turn affect these two dominant excitation forces, such that there will be some correlation between the casing response and blade vibrations. Previous work has introduced an analytical model of a gas turbine casing, and simulated pressure signal, associated with the rotating blades. The effect of individual rotor blade vibrations has been developed in order to understand the complex relationship between these excitation forces. A simplified turbine test rig has been constructed. Various aspects of the previous analytical modelling are presented, and then investigated and verified using results from the experimental program with this simplified test rig.

  • (2002) Magin, Douglas; Helmore, Phillip
    Conference Paper
    Despite numerous studies on the reliability of peer marking of oral presentation skills, no empirical studies to date have addressed the validity issue of whether students use a different 'perspective' from teachers in making an overall assessment. This paper analyses peer and teacher assessment data from thesis presentations made by students enrolled in a fourth year subject 'Communications for Professional Engineers'. The study uses a novel application of the 'index of association' statistic to determine the extent to which the variance of marks by teachers and by peers for the overall quality of the presentations can be attributed to factors other than errors associated with unreliable measures. Results indicate that students had applied criteria which were quite different from those used by teachers. The discussion describes methodologies which can be employed to determine which skill criteria are most influential in the determination of a global mark for oral presentations, and outlines plans to identify the ways in which students and staff differ in the criteria they apply.

  • (1995) Mubaraki, Brian; Bandyopadhyay, Srikanta; Fowle, R; Mathew, Philip; Heath, P
    Journal Article

  • (2008) Wakefield, Claire; Meiser, Bettina; Gaff, C; Barratt, Anthony; Patel, Minoo; Suthers, G; Lobb, Elizabeth; Ramsay, J; Mann, G
    Journal Article
    Purpose: Despite the established importance of the role of family history in prostate cancer, relatively little research encompasses the psychosocial issues relevant to unaffected men with a family history of prostate cancer. To determine the completeness and quality of available literature on the issues faced by men with a high risk of prostate cancer, we conducted a multidisciplinary review of the literature to provide some guidance on the information that clinicians might provide to men who are concerned about family history. Materials and Methods: A structured literature search was conducted by a multidisciplinary team of clinicians and researchers who reviewed the medical and psychosocial literature, and identified 21 relevant studies. Results: Research suggests that many high risk patients are concerned about the risk of prostate cancer, and some may significantly overestimate that risk. Several studies have shown high screening rates among high risk patients and high levels of interest in genetic testing for prostate cancer risk should it become available, yet many men also report a desire for more information about their personal risk and risk management options. Conclusions: Given the lack of clear data on the efficacy of prostate cancer screening among high risk patients, clinicians could consider providing men who are concerned about family history with information on their personal risk, help them to clarify the potential benefits, limitations and harms of prostate cancer screening in their situation, and then support their choice regarding the management of prostate cancer risk.

  • (2008) Caresta, Mauro; Kessissoglou, Nicole
    Conference Paper
    A model to describe the low frequency dynamic and acoustic responses of a submarine hull subject to an eccentric harmonic propeller shaft excitation is presented. The submarine is modelled as a fluid-loaded, ring stiffened cylindri-cal shell with internal bulkheads and conical end caps. The stiffeners are introduced using a smeared approach. A harmonic axial force is introduced by the propeller and is transmitted to the hull through the shaft. It results in excita-tion of the accordion modes only if the force is symmetrically distributed to the structure. Otherwise the excitation can be modelled as the sum of a distributed load and a moment applied to the edge of the hull. This leads to excitation of the higher order circumferential modes that can result in high noise signature. Structural and acoustic responses are presented in terms of deformation shapes and directivity patterns for the radiated sound pressure. Results for the case of purely axisymmetric excitation and the case in which an eccentricity is introduced are compared.

  • (2001) Magin, Douglas; Helmore, Phillip
    Conference Paper
    Recent reviews on assessment in higher education have emphasised the importance of written formative assessment as part of the process of assessing oral presentation skills, and have identified the need for case studies to investigate the content and character of feedback which students receive. The paper analyses the written feedback provided by teachers who acted as assessors for conference presentations made by engineering students enrolled in a fourth year subject at The University of New South Wales. The study employs content analysis to describe the extent, content, and character of these comments, and to identify which performance skills staff focus on in providing such feedback.

  • (2001) Helmore, Phillip
    Journal Article
    The March 2001 issue of MARENSA’s newsletter, Seaspace, carried the following report: ‘It is understood that HMAS Brisbane and HMAS Anzac competed recently in a sharp sprint over a three-mile course. Anzac had hoped that a quick engagement of gas turbine power would get them first to the finish line, but Brisbane’s 35-year-old boilers and steam turbines responded promptly to full throttle and the old girl showed she still had an unequalled turn of speed. It has been reported that she reached 32 knots on one minute from a standing start.’ Having no experience with the acceleration of naval vessels, reaching 32 knots in one minute from a standing start sounded very quick to me. With interest aroused, I pulled out my copy of Lackenby’s (1952) paper and did the following calculations to check whether the claim was reasonable:

  • (1998) Helmore, Phillip
    Journal Article
    A recent publication says that the primary spelling of the word for the depth of water required to float a ship is draught, with draft as the secondary spelling. A survey of thirty practising naval architects was made to check the claim, and found that a large majority of Australian-educated naval architects spell it draft. The overall results are interesting and are given here.

  • (2003) Magin, Douglas; Helmore, Phillip; Barber, Tracie J
    Conference Paper
    A number of studies have questioned the criterion validity of peer assessed oral presentations. Claims have been made that students are likely to employ a different perspective from teachers when assessing overall presentation quality, even when both are guided by a common checklist of relevant skill components.To date, no empirical investigations have been undertaken to determine how students differ from staff in the criteria they apply. this paper analyses peer and teacher assessment data from thesis presentations made by engineering students in a fourth year communications subject. The data consists of peer and teacher ratings on eight skill components listed on a checklist (used for feedback only), together with a global mark for the presentation (the summative assessment).The scores on the eight items were then subject to multiple regression analysis using the global mark as the criterion. Substantial differences were found between the two multiple regression equations. Discussion focuses on how these differences affect the validity of peer assessments, and the level of agreement between teacher and student assessment.