Improving the moment capacities of hollow flange cold-formed Litesteel Beams using web stiffeners

The LiteSteel Beam (LSB) is a new hollow flange section developed in Australia with a unique geometry consisting of torsionally rigid rectangular hollow flanges and a relatively slender web. The LSB is subjected to a relatively new Lateral Distortional Buckling (LDB) mode when used as flexural members. Unlike the commonly observed lateral torsional buckling, lateral distortional buckling of LSBs is characterised by cross sectional change due to web distortion. Lateral distortional buckling causes significant moment capacity reduction for LSBs with intermediate spans. Therefore a detailed investigation was undertaken to determine the methods of reducing the effects of lateral distortional buckling in LSB flexural members. For this purpose the use of web stiffeners was investigated using finite element analyses of LSBs with different web stiffener spacing and sizes. It was found that the use of 5 mm steel plate stiffeners welded or screwed to the inner faces of the top and bottom flanges at third span points considerably reduced the lateral distortional buckling effects in LSBs. Suitable design rules were then developed to calculate the enhanced elastic lateral distortional buckling moments and the higher ultimate moment capacities of LSBs with the chosen web stiffener arrangement. This paper presents the details of this investigation and the results.

A model for enhancing assessment and teaching practice at the coalface : Insights from a Fellow-In-Residence engagement program

Australian universities are currently engaging with new governmental policies and regulations that require them to demonstrate enhanced quality and accountability in teaching and research. The development of national academic standards for learning outcomes in higher education is one such instance of this drive for excellence. These discipline-specific standards articulate the minimum, or Threshold Learning Outcomes, to be addressed by higher education institutions so that graduating students can demonstrate their achievement to their institutions, accreditation agencies, and industry recruiters. This impacts not only on the design of Engineering courses (with particular emphasis on pedagogy and assessment), but also on the preparation of academics to engage with these standards and implement them in their day-to-day teaching practice on a micro level. This imperative for enhanced quality and accountability in teaching is also significant at a meso level, for according to the Australian Bureau of Statistics, about 25 per cent of teachers in Australian universities are aged 55 and above and more than 54 per cent are aged 45 and above (ABS, 2006). A number of institutions have undertaken recruitment drives to regenerate and enrich their academic workforce by appointing capacity-building research professors and increasing the numbers of early- and mid-career academics. This nationally driven agenda for quality and accountability in teaching permeates also the micro level of engineering education, since the demand for enhanced academic standards and learning outcomes requires both a strong advocacy for a shift to an authentic, collaborative, outcomes-focused education and the mechanisms to support academics in transforming their professional thinking and practice. Outcomes-focused education means giving greater attention to the ways in which the curriculum design, pedagogy, assessment approaches and teaching activities can most effectively make a positive, verifiable difference to students’ learning. Such education is authentic when it is couched firmly in the realities of learning environments, student and academic staff characteristics, and trustworthy educational research. That education will be richer and more efficient when staff works collaboratively, contributing their knowledge, experience and skills to achieve learning outcomes based on agreed objectives. We know that the school or departmental levels of universities are the most effective loci of changes in approaches to teaching and learning practices in higher education (Knight & Trowler, 2000). Heads of Schools are being increasingly entrusted with more responsibilities - in addition to setting strategic directions and managing the operational and sometimes financial aspects of their school, they are also expected to lead the development and delivery of the teaching, research and other academic activities. Guiding and mentoring individuals and groups of academics is one critical aspect of the Head of School’s role. Yet they do not always have the resources or support to help them mentor staff, especially the more junior academics. In summary, the international trend in undergraduate engineering course accreditation towards the demonstration of attainment of graduate attributes poses new challenges in addressing academic staff development needs and the assessment of learning. This paper will give some insights into the conceptual design, implementation and empirical effectiveness to date, of a Fellow-In-Residence Engagement (FIRE) program. The program is proposed as a model for achieving better engagement of academics with contemporary issues and effectively enhancing their teaching and assessment practices. It will also report on the program’s collaborative approach to working with Heads of Schools to better support academics, especially early-career ones, by utilizing formal and informal mentoring. Further, the paper will discuss possible factors that may assist the achievement of the intended outcomes of such a model, and will examine its contributions to engendering an outcomes-focussed thinking in engineering education.

Recovery and reuse of ammonium from wastewater treatment plants : an application for agriculture

In wastewater treatment plants based on anaerobic digestion, supernatant and outflows from sludge dewatering systems contain significantly high amount of ammonium. Generally, these waters are returned to the head of wastewater treatment plant (WWTP), thereby increasing the total nitrogen load of the influent flow. Ammonium from these waters can be recovered and commercially utilised using novel ion-exchange materials. Mackinnon et al. have described an approach for removal and recovery of ammonium from side stream centrate returns obtained from anaerobic digester of a typical WWTP. Most of the ammonium from side streams can potentially be removed, which significantly reduces overall inlet demand at a WWTP. However, the extent of reduction achieved depends on the level of ammonium and flow-rate in the side stream. The exchange efficiency of the ion-exchange material, MesoLite, used in the ammonium recovery process deteriorates with long-term use due to mechanical degradation and use of regenerant. To ensure that a sustainable process is utilised a range of potential applications for this “spent” MesoLite have been evaluated. The primary focus of evaluations has been use of ammonium-loaded MesoLite as a source of nitrogen and growth medium for plants. A MesoLite fertiliser has advantage over soluble fertilisers in that N is held on an insoluble matrix and is gradually released according to exchange equilibria. Many conventional N fertilisers are water-soluble and thus, instantly release all applied N into the soil solution. Loss of nutrient commonly occurs through volatilisation and/or leaching. On average, up to half of the N delivered by a typical soluble fertiliser can be lost through these processes. In this context, use of ammonium-loaded MesoLite as a fertiliser has been evaluated using standard greenhouse and field-based experiments for low fertility soils. Rye grass, a suitable test species for greenhouse trials, was grown in 1kg pots over a period of several weeks with regular irrigation. Nitrogen was applied at a range of rates using a chemical fertiliser as a control and using two MesoLite fertilisers. All other nutrients were applied in adequate amounts. All treatments were replicated three times. Plants were harvested after four weeks, and dry plant mass and N concentrations were determined. At all nitrogen application rates, ammonium-loaded MesoLite produced higher plant mass than plants fertilised by the chemical fertiliser. The lower fertiliser effectiveness of the chemical fertliser is attributed to possible loss of some N through volatilisation. The MesoLite fertilisers did not show any adverse effect on availability of macro and trace nutrients, as shown by lack of deficiency symptoms, dry matter yield and plant analyses. Nitrogen loaded on to MesoLite in the form of exchanged ammonium is readily available to plants while remaining protected from losses via leaching and volatilisation. Spent MesoLite appears to be a suitable and effective fertiliser for a wide range of soils, particularly sandy soils with poor nutrient holding capacity.

Link discovery for Chinese/English cross-language web information retrieval

Nowadays people heavily rely on the Internet for information and knowledge. Wikipedia is an online multilingual encyclopaedia that contains a very large number of detailed articles covering most written languages. It is often considered to be a treasury of human knowledge. It includes extensive hypertext links between documents of the same language for easy navigation. However, the pages in different languages are rarely cross-linked except for direct equivalent pages on the same subject in different languages. This could pose serious difficulties to users seeking information or knowledge from different lingual sources, or where there is no equivalent page in one language or another. In this thesis, a new information retrieval task—cross-lingual link discovery (CLLD) is proposed to tackle the problem of the lack of cross-lingual anchored links in a knowledge base such as Wikipedia. In contrast to traditional information retrieval tasks, cross language link discovery algorithms actively recommend a set of meaningful anchors in a source document and establish links to documents in an alternative language. In other words, cross-lingual link discovery is a way of automatically finding hypertext links between documents in different languages, which is particularly helpful for knowledge discovery in different language domains. This study is specifically focused on Chinese / English link discovery (C/ELD). Chinese / English link discovery is a special case of cross-lingual link discovery task. It involves tasks including natural language processing (NLP), cross-lingual information retrieval (CLIR) and cross-lingual link discovery. To justify the effectiveness of CLLD, a standard evaluation framework is also proposed. The evaluation framework includes topics, document collections, a gold standard dataset, evaluation metrics, and toolkits for run pooling, link assessment and system evaluation. With the evaluation framework, performance of CLLD approaches and systems can be quantified. This thesis contributes to the research on natural language processing and cross-lingual information retrieval in CLLD: 1) a new simple, but effective Chinese segmentation method, n-gram mutual information, is presented for determining the boundaries of Chinese text; 2) a voting mechanism of name entity translation is demonstrated for achieving a high precision of English / Chinese machine translation; 3) a link mining approach that mines the existing link structure for anchor probabilities achieves encouraging results in suggesting cross-lingual Chinese / English links in Wikipedia. This approach was examined in the experiments for better, automatic generation of cross-lingual links that were carried out as part of the study. The overall major contribution of this thesis is the provision of a standard evaluation framework for cross-lingual link discovery research. It is important in CLLD evaluation to have this framework which helps in benchmarking the performance of various CLLD systems and in identifying good CLLD realisation approaches. The evaluation methods and the evaluation framework described in this thesis have been utilised to quantify the system performance in the NTCIR-9 Crosslink task which is the first information retrieval track of this kind.

An ensemble method for predicting subnuclear localizations from primary protein structures

Background Predicting protein subnuclear localization is a challenging problem. Some previous works based on non-sequence information including Gene Ontology annotations and kernel fusion have respective limitations. The aim of this work is twofold: one is to propose a novel individual feature extraction method; another is to develop an ensemble method to improve prediction performance using comprehensive information represented in the form of high dimensional feature vector obtained by 11 feature extraction methods. Methodology/Principal Findings A novel two-stage multiclass support vector machine is proposed to predict protein subnuclear localizations. It only considers those feature extraction methods based on amino acid classifications and physicochemical properties. In order to speed up our system, an automatic search method for the kernel parameter is used. The prediction performance of our method is evaluated on four datasets: Lei dataset, multi-localization dataset, SNL9 dataset and a new independent dataset. The overall accuracy of prediction for 6 localizations on Lei dataset is 75.2% and that for 9 localizations on SNL9 dataset is 72.1% in the leave-one-out cross validation, 71.7% for the multi-localization dataset and 69.8% for the new independent dataset, respectively. Comparisons with those existing methods show that our method performs better for both single-localization and multi-localization proteins and achieves more balanced sensitivities and specificities on large-size and small-size subcellular localizations. The overall accuracy improvements are 4.0% and 4.7% for single-localization proteins and 6.5% for multi-localization proteins. The reliability and stability of our classification model are further confirmed by permutation analysis. Conclusions It can be concluded that our method is effective and valuable for predicting protein subnuclear localizations. A web server has been designed to implement the proposed method. It is freely available at http://bioinformatics.awowshop.com/snlpr​ed_page.php.

Website designers : how do they experience information literacy?

This paper presents the findings from the first phase of a larger study into the information literacy of website designers. Using a phenomenographic approach, it maps the variation in experiencing the phenomenon of information literacy from the viewpoint of website designers. The current result reveals important insights into the lived experience of this group of professionals. Analysis of data has identified five different ways in which website designers experience information literacy: problem-solving, using best practices, using a knowledge base, building a successful website, and being part of a learning community of practice. As there is presently relatively little research in the area of workplace information literacy, this study provides important additional insights into our understanding of information literacy in the workplace, especially in the specific context of website design. Such understandings are of value to library and information professionals working with web professionals either within or beyond libraries. These understandings may also enable information professionals to take a more proactive role in the industry of website design. Finally, the obtained knowledge will contribute to the education of both website-design science and library and information science (LIS) students.

Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 ◦C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value.

Social media and Web 2.0 : teacher-librarians, risk and inequity

This paper reports research into teacher-­‐librarians’ perceptions of using social media and Web 2.0 in teaching and learning. A pilot study was conducted with teacher-­‐librarians in five government schools and five private schools in southeast Queensland. The findings revealed that there was a strong digital divide between government schools and private schools, with government schools suffering severe restrictions on the use of social media and Web 2.0, leading to an unsophisticated use of these technologies. It is argued that internet ‘over-­‐ blocking’ may lead to government school students not being empowered to manage risks in an open internet environment. Furthermore, their use of information for academic and recreational learning may be compromised. This has implications particularly for low socioeconomic students, leading to further inequity in the process and outcomes of Australian education.

Shear strengths of lipped channel beams with stiffened web openings using numerical studies

This paper presents the details of numerical studies on the shear behaviour and strength of lipped channel beams (LCBs) with stiffened web openings. Over the last couple of decades, cold-formed steel beams have been used extensively in residential, industrial and commercial buildings as primary load bearing structural components. Their shear strengths are considerably reduced when web openings are included for the purpose of locating building services. Our research has shown that shear strengths of LCBs were reduced by up to 70% due to the inclusion of web openings. Hence there is a need to improve the shear strengths of LCBs with web openings. A cost effective way to improve the detrimental effects of a large web opening is to attach appropriate stiffeners around the web openings in order to restore the original shear strength and stiffness of LCBs. Hence numerical studies were undertaken to investigate the shear strengths of LCBs with stiffened web openings. In this research, finite element models of LCBs with stiffened web openings in shear were developed to simulate the shear behaviour and strength of LCBs. Various stiffening methods using plate and LCB stud stiffeners attached to LCBs using screw-fastening were attempted. The developed models were then validated by comparing their results with experimental results and used in parametric studies. Both finite element analysis and experimental results showed that the stiffening arrangements recommended by past re-search for cold-formed steel channel beams are not adequate to restore the shear strengths of LCBs with web openings. Therefore new stiffener arrangements were proposed for LCBs with web openings based on experimental and finite element analysis results. This paper presents the details of finite element models and analyses used in this research and the results including the recommended stiffener arrangements.

Towards tacit knowledge sharing over social web tools

Purpose - Researchers debate whether tacit knowledge sharing through Information Technology (IT) is actually possible. However, with the advent of social web tools, it has been argued that most shortcomings of tacit knowledge sharing are likely to disappear. This paper has two purposes: firstly, to demonstrate the existing debates in the literature regarding tacit knowledge sharing using IT, and secondly, to identify key research gaps that lay the foundations for future research into tacit knowledge sharing using social web. Design/methodology/approach - This paper reviews current literature on IT-mediated tacit knowledge sharing and opens a discussion on tacit knowledge sharing through the use of social web. Findings - First, the existing schools of thoughts in regards to IT ability for tacit knowledge sharing are introduced. Next, difficulties of sharing tacit knowledge through the use of IT are discussed. Then, potentials and pitfalls of social web tools are presented. Finally, the paper concludes that whilst there are significant theoretical arguments supporting that the social web facilitates tacit knowledge sharing there is a lack of empirical evidence to support these arguments and further work is required. Research limitations/implications - The limitations of the review includes: covering only papers that were published in English, issues of access to full texts of some resources, possibility of missing some resources due to search strings used or limited coverage of databases searched. Originality/value - The paper contributes to the fast growing literature on the intersection of KM and IT particularly by focusing on tacit knowledge sharing in social media space. The paper highlights the need for further studies in this area by discussing the current situation in the literature and disclosing the emerging questions and gaps for future studies.

Using Wikipedia to improve web service discovery

Building and maintaining software are not easy tasks. However, thanks to advances in web technologies, a new paradigm is emerging in software development. The Service Oriented Architecture (SOA) is a relatively new approach that helps bridge the gap between business and IT and also helps systems remain exible. However, there are still several challenges with SOA. As the number of available services grows, developers are faced with the problem of discovering the services they need. Public service repositories such as Programmable Web provide only limited search capabilities. Several mechanisms have been proposed to improve web service discovery by using semantics. However, most of these require manually tagging the services with concepts in an ontology. Adding semantic annotations is a non-trivial process that requires a certain skill-set from the annotator and also the availability of domain ontologies that include the concepts related to the topics of the service. These issues have prevented these mechanisms becoming widespread. This thesis focuses on two main problems. First, to avoid the overhead of manually adding semantics to web services, several automatic methods to include semantics in the discovery process are explored. Although experimentation with some of these strategies has been conducted in the past, the results reported in the literature are mixed. Second, Wikipedia is explored as a general-purpose ontology. The benefit of using it as an ontology is assessed by comparing these semantics-based methods to classic term-based information retrieval approaches. The contribution of this research is significant because, to the best of our knowledge, a comprehensive analysis of the impact of using Wikipedia as a source of semantics in web service discovery does not exist. The main output of this research is a web service discovery engine that implements these methods and a comprehensive analysis of the benefits and trade-offs of these semantics-based discovery approaches.

Contemporaneous correlations within individuals in an automated web-based walking program (Walk@Work) over a six week period (three phases) of time

Introduction: Participants may respond to phases of a workplace walking program at different rates. This study evaluated the factors that contribute to the number of steps through phases of the program. The intervention was automated through a web-based program designed to increase workday walking. Methods: The study reviewed independent variable influences throughout phases I–III. A convenience sample of university workers (n=56; 43.6±1.7 years; BMI 27.44±.2.15 kg/m2; 48 female) were recruited at worksites in Australia. These workers were given a pedometer (Yamax SW 200) and access to the website program. For analyses, step counts entered by workers into the website were downloaded and mean workday steps were compared using a seemingly unrelated regression. This model was employed to capture the contemporaneous correlation within individuals in the study across observed time periods. Results: The model predicts that the 36 subjects with complete information took an average 7460 steps in the baseline two week period. After phase I, statistically significance increases in steps (from baseline) were explained by age, working status (full or part time), occupation (academic or professional), and self reported public transport (PT) use (marginally significant). Full time workers walked more than part time workers by about 440 steps, professionals walked about 300 steps more than academics, and PT users walked about 400 steps more than non-PT users. The ability to differentiate steps after two weeks among participants suggests a differential affect of the program after only two weeks. On average participants increased steps from week two to four by about 525 steps, but regular auto users had nearly 750 steps less than non-auto users at week four. The effect of age was diminished in the 4th week of observation and accounted for 34 steps per year of age. In phase III, discriminating between participants became more difficult, with only age effects differentiating their increase over baseline. The marginal effect of age by phase III compared to phase I, increased from 36 to 50, suggesting a 14 step per year increase from the 2nd to 6th week. Discussion: The findings suggest that participants responded to the program at different rates, with uniformity of effect achieved by the 6th week. Participants increased steps, however a tapering off occurred over time. Age played the most consistent role in predicting steps over the program. PT use was associated with increased step counts, while Auto use was associated with decreased step counts.

Stigmergy within web modelling languages : positive feedback mechanisms

Stigmergy is a biological term originally used when discussing insect or swarm behaviour, and describes a model supporting environment-based communication separating artefacts from agents. This phenomenon is demonstrated in the behavior of ants and their food foraging supported by pheromone trails, or similarly termites and their termite nest building process. What is interesting with this mechanism is that highly organized societies are formed without an apparent central management function. We see design features in Web sites that mimic stigmergic mechanisms as part of the User Interface and we have created generalizations of these patterns. Software development and Web site development techniques have evolved significantly over the past 20 years. Recent progress in this area proposes languages to model web applications to facilitate the nuances specific to these developments. These modeling languages provide a suitable framework for building reusable components encapsulating our design patterns of stigmergy. We hypothesize that incorporating stigmergy as a separate feature of a site’s primary function will ultimately lead to enhanced user coordination.

Experimental studies of the shear behaviour and strength of lipped channel beams with web openings

Cold-formed steel members are increasingly used as primary structural elements in the building industries around the world due to the availability of thin and high strength steels and advanced cold-forming technologies. Cold-formed lipped channel beams (LCB) are commonly used as flexural members such as floor joists and bearers. However, their shear capacities are determined based on conservative design rules. Current practice in flooring systems is to include openings in the web element of floor joists or bearers so that building services can be located within them. Shear behaviour of LCBs with web openings is more complicated while their shear strengths are considerably reduced by the presence of web openings. However, limited research has been undertaken on the shear behaviour and strength of LCBs with web openings. Hence a detailed experimental study involving 40 shear tests was undertaken to investigate the shear behaviour and strength of LCBs with web openings. Simply supported test specimens of LCBs with aspect ratios of 1.0 and 1.5 were loaded at midspan until failure. This paper presents the details of this experimental study and the results of their shear capacities and behavioural characteristics. Experimental results showed that the current design rules in cold-formed steel structures design codes are very conservative for the shear design of LCBs with web openings. Improved design equations have been proposed for the shear strength of LCBs with web openings based on the experimental results from this study.