Improved shear design rules for lipped channel beams with web openings

Cold-formed steel Lipped Channel Beams (LCB) with web openings are commonly used as floor joists and bearers in building structures. The shear behaviour of these beams is more complicated and their shear capacities 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 numerical study was undertaken to investigate the shear behaviour and strength of LCBs with web openings. Finite element models of simply supported LCBs under a mid-span load with aspect ratios of 1.0 and 1.5 were developed and validated by comparing their results with test results. They were then used in a detailed parametric study to investigate the effects of various influential parameters. Experimental and numerical results showed that the current design rules in cold-formed steel structures design codes are very conservative. Improved design equations were therefore proposed for the shear strength of LCBs with web openings based on both experimental and numerical results. This paper presents the details of finite element modelling of LCBs with web openings, validation of finite element models, and the development of improved shear design rules. The proposed shear design rules in this paper can be considered for inclusion in the future versions of cold-formed steel design codes.

Modelling users' contextual querying behaviour for web image searching

The rapid growth of visual information on Web has led to immense interest in multimedia information retrieval (MIR). While advancement in MIR systems has achieved some success in specific domains, particularly the content-based approaches, general Web users still struggle to find the images they want. Despite the success in content-based object recognition or concept extraction, the major problem in current Web image searching remains in the querying process. Since most online users only express their needs in semantic terms or objects, systems that utilize visual features (e.g., color or texture) to search images create a semantic gap which hinders general users from fully expressing their needs. In addition, query-by-example (QBE) retrieval imposes extra obstacles for exploratory search because users may not always have the representative image at hand or in mind when starting a search (i.e. the page zero problem). As a result, the majority of current online image search engines (e.g., Google, Yahoo, and Flickr) still primarily use textual queries to search. The problem with query-based retrieval systems is that they only capture users’ information need in terms of formal queries;; the implicit and abstract parts of users’ information needs are inevitably overlooked. Hence, users often struggle to formulate queries that best represent their needs, and some compromises have to be made. Studies of Web search logs suggest that multimedia searches are more difficult than textual Web searches, and Web image searching is the most difficult compared to video or audio searches. Hence, online users need to put in more effort when searching multimedia contents, especially for image searches. Most interactions in Web image searching occur during query reformulation. While log analysis provides intriguing views on how the majority of users search, their search needs or motivations are ultimately neglected. User studies on image searching have attempted to understand users’ search contexts in terms of users’ background (e.g., knowledge, profession, motivation for search and task types) and the search outcomes (e.g., use of retrieved images, search performance). However, these studies typically focused on particular domains with a selective group of professional users. General users’ Web image searching contexts and behaviors are little understood although they represent the majority of online image searching activities nowadays. We argue that only by understanding Web image users’ contexts can the current Web search engines further improve their usefulness and provide more efficient searches. In order to understand users’ search contexts, a user study was conducted based on university students’ Web image searching in News, Travel, and commercial Product domains. The three search domains were deliberately chosen to reflect image users’ interests in people, time, event, location, and objects. We investigated participants’ Web image searching behavior, with the focus on query reformulation and search strategies. Participants’ search contexts such as their search background, motivation for search, and search outcomes were gathered by questionnaires. The searching activity was recorded with participants’ think aloud data for analyzing significant search patterns. The relationships between participants’ search contexts and corresponding search strategies were discovered by Grounded Theory approach. Our key findings include the following aspects: - Effects of users' interactive intents on query reformulation patterns and search strategies - Effects of task domain on task specificity and task difficulty, as well as on some specific searching behaviors - Effects of searching experience on result expansion strategies A contextual image searching model was constructed based on these findings. The model helped us understand Web image searching from user perspective, and introduced a context-aware searching paradigm for current retrieval systems. A query recommendation tool was also developed to demonstrate how users’ query reformulation contexts can potentially contribute to more efficient searching.

Gay men, Gaydar and the commodification of difference

Purpose – The purpose of this paper is to investigate information communications technologies (ICT)-mediated inclusion and exclusion in terms of sexuality through a study of a commercial social networking web site for gay men. Design/methodology/approach – The paper uses an approach based on technological inscription and the commodification of difference to study Gaydar, a commercial social networking site. Findings – Through the activities, events and interactions offered by Gaydar, the study identifies a series of contrasting identity constructions and market segmentations that are constructed through the cyclic commodification of difference. These are fuelled by a particular series of meanings attached to gay male sexualities which serve to keep gay men positioned as a niche market. Research limitations/implications – The research centres on the study of one, albeit widely used, web site with a very specific set of purposes. The study offers a model for future research on sexuality and ICTs. Originality/value – This study places sexuality centre stage in an ICT-mediated environment and provides insights into the contemporary phenomenon of social networking. As a sexualised object, Gaydar presents a semiosis of politicised messages that question heteronormativity while simultaneously contributing to the definition of an increasingly globalised, commercialised and monolithic form of gay male sexuality defined against ICT

Form prevailing over substance?

The decision of the Court of Appeal in Kellas-Sharpe v PSAL Ltd [2012] QCA 371 considered a not unusual provision in a loan agreement, being a provision whereby a lender agrees to accept a lower or concessional rate of interest in circumstances of prompt payment by the borrower. The loan agreement in question provided for the borrower to pay a standard rate of interest of 7.5% per month. However, if the borrower was not in default, the lender agreed to accept interest at a concessional rate of interest of 4% per month. The issue for determination by the Court of Appeal (McMurdo P, Gotterson JA and Fryberg J) was whether the clause was subject to the equitable jurisdiction to relieve against penalties, and, if so, if the interest rate provision should be treated as a penalty making the interest rate provision void. In mounting this argument, the borrower was seeking to overturn a long line of authority which has repeatedly upheld the semantic distinction between an increase in the rate of interest (which attracts the doctrine concerning penalties) and an incentive to the borrower by way of a reduction in the interest rate for prompt payment (which does not attract the doctrine)...

E-learning 2.0 experiences within higher education : theorising students' and teachers' experiences in Web 2.0 learning

This study explores and evaluates students’ and teachers’ experiences when using a range of Web 2.0 tools in Higher Education teaching and learning. It contributes to our understanding of how Web 2.0 learning communities are constructed, experienced and the nature of the participation therein. This research extends our knowledge and understanding of the Web 2.0 phenomena, and provides a framework that can assist with improving future Web 2.0 implementation.

The rise of government in Early Childhood Education and Care following the Child Care Act 1972 : the lasting legacy of the 1990s in setting the reform agenda for ECEC in Australia

Less than twenty years on from the proclamation of the Child Care Act 1972, and introduction of funding for not-for-profit child care centres, a series of market-driven public policies paved the way for the emergence of Australia’s current ECEC quasi-market. Seeking to respond to increasing demand for work-related child care in the 1990s, and to manage associated costs, a succession of Australian Governments turned to market theory and New Public Management (NPM) principles to inform ECEC policy. Reflecting on an era of high policy activity within ECEC, this paper examines a series of policy events and texts that set the course for the reform agenda that was to ensue in ECEC.

Sense-making across space and time : implications for the organization and findability of information

This paper presents the results from a study of information behaviors, with specific focus on information organisation-related behaviours conducted as part of a larger daily diary study with 34 participants. The findings indicate that organization of information in everyday life is a problematic area due to various factors. The self-evident one is the inter-subjectivity between the person who may have organized the information and the person looking for that same information (Berlin et. al., 1993). Increasingly though, we are not just looking for information within collections that have been designed by someone else, but within our own personal collections of information, which frequently include books, electronic files, photos, records, documents, desktops, web bookmarks, and portable devices. The passage of time between when we categorized or classified the information, and the time when we look for the same information, poses several problems of intra-subjectivity, or the difference between our own past and present perceptions of the same information. Information searching, and hence the retrieval of information from one's own collection of information in everyday life involved a spatial and temporal coordination with one's own past selves in a sort of cognitive and affective time travel, just as organizing information is a form of anticipatory coordination with one's future information needs. This has implications for finding information and also on personal information management.

Korean ubiquitous-eco-city : a smart-sustainable urban form or a branding hoax?

The buzzwords of zero-carbon, low-carbon, carbon-neutral, smart-eco and ubiquitous-eco have become common brands for the sustainable eco-cities of the 21st century. This paper focuses on one of these city types ‘ubiquitous-eco-city’ (u-eco-city). The principal premise of a u-eco-city is to provide a high quality of life and place to residents, workers and visitors with low-to-no negative impacts on the natural environment by using state-of-the-art technologies in the planning, development and management stages. The paper aims to put this premise into a test and address whether u-eco-city is a dazzling smart and sustainable urban form that constitutes an ideal 21st century city model or just a branding hoax. This paper explores recent developments and trends in the ubiquitous technologies, infrastructures, services and management systems, and their utilisation and implications for the development of u-eco-cities. The paper places Korean u-eco-city initiatives under microscope, and critically discusses their prospects in forming a smart and sustainable urban form and become an ideal city model.

A closed-form approximation for pricing temperature-based weather derivatives

This paper develops analytical distributions of temperature indices on which temperature derivatives are written. If the deviations of daily temperatures from their expected values are modelled as an Ornstein-Uhlenbeck process with timevarying variance, then the distributions of the temperature index on which the derivative is written is the sum of truncated, correlated Gaussian deviates. The key result of this paper is to provide an analytical approximation to the distribution of this sum, thus allowing the accurate computation of payoffs without the need for any simulation. A data set comprising average daily temperature spanning over a hundred years for four Australian cities is used to demonstrate the efficacy of this approach for estimating the payoffs to temperature derivatives. It is demonstrated that expected payoffs computed directly from historical records are a particularly poor approach to the problem when there are trends in underlying average daily temperature. It is shown that the proposed analytical approach is superior to historical pricing.

Retrieval of health advice on the web: AEHRC at ShARe/CLEF eHealth Evaluation Lab Task 3

This paper details the participation of the Australian e- Health Research Centre (AEHRC) in the ShARe/CLEF 2013 eHealth Evaluation Lab { Task 3. This task aims to evaluate the use of information retrieval (IR) systems to aid consumers (e.g. patients and their relatives) in seeking health advice on the Web. Our submissions to the ShARe/CLEF challenge are based on language models generated from the web corpus provided by the organisers. Our baseline system is a standard Dirichlet smoothed language model. We enhance the baseline by identifying and correcting spelling mistakes in queries, as well as expanding acronyms using AEHRC's Medtex medical text analysis platform. We then consider the readability and the authoritativeness of web pages to further enhance the quality of the document ranking. Measures of readability are integrated in the language models used for retrieval via prior probabilities. Prior probabilities are also used to encode authoritativeness information derived from a list of top-100 consumer health websites. Empirical results show that correcting spelling mistakes and expanding acronyms found in queries signi cantly improves the e ectiveness of the language model baseline. Readability priors seem to increase retrieval e ectiveness for graded relevance at early ranks (nDCG@5, but not precision), but no improvements are found at later ranks and when considering binary relevance. The authoritativeness prior does not appear to provide retrieval gains over the baseline: this is likely to be because of the small overlap between websites in the corpus and those in the top-100 consumer-health websites we acquired.

Unpacking ‘lessons learned’ : investigating failures and considering alternative solutions

One of the most common ways to share project knowledge is to capture the positive and negative aspects of projects in the form of lessons learned (LL). If effectively used, this process can assist project managers in reusing project knowledge and preventing future projects from repeating mistakes. Nevertheless, the process of capturing, storing, reviewing and reusing LL often remains suboptimal. Despite the potential for rich knowledge capture, lessons are often documented as simple, line-item statements devoid of context. Findings from an empirical investigation across four cases revealed a range of reasons related to the perceived quality, process and visibility of LL that lead to their limited use and application. Drawn from the cross-case analysis, this paper investigates an integrated approach to LL involving the use of a collaborative Web-based tool, which is easily accessible, intelligible and user-friendly, allowing more effective sharing of project knowledge and overcoming existing problems with LL.

The adoption of Web 2.0 within enterprises : employees' perspectives

This project explores employees’ adoption of Web 2.0 within organisations. It shows that the adoption of Web 2.0 is a challenging and dynamic process that changes over time. The adoption is, also, influenced by a number of interrelated issues including: People Traits, Social Influence, Trust, Technological Attributes, Relevance of Web 2.0, Web 2.0 Maturity, Organisational Support, and Organisational Practice.

Application of kaolin amorphous derivative as a nitrogen carrier

Sandy soils have low nutrient holding capacity and high water conductivity. Consequently, nutrients applied as highly soluble chemical fertilisers are prone to leaching, particularly in heavily irrigated environments such as horticultural soils and golf courses. Amorphous derivatives of kaolin with high cation exchange capacity may be loaded with desired nutrients and applied as controlledrelease fertilisers. Kaolin is an abundant mineral, which can be converted to a meso-porous amorphous derivative (KAD) using facile chemical processes. KAD is currently being used to sequester ammonium from digester effluent in sewage treatment plants in a commercial environment. This material is also known in Australia by the trade name MesoLite. The ammonium-saturated form of KAD may be applied to soils as a nitrogen fertiliser. Up to 7% N can be loaded onto KAD by contacting it with high-ammonia concentration wastewater from sewerage treatment plants. This poster paper demonstrates plant uptake of nitrogen from KAD and compares its efficiency as a fertiliser with NH4SO4. Rye grass was grown in 1kg pots in a glass-house. Nitrogen was applied at a range of rates using NH4SO4 and two KAD materials carrying 7% and 3% nitrogen, respectively. All other nutrients were applied in adequate amounts. All treatments were replicated three times. Plants were harvested after four weeks. Dry mass and N concentrations were determined by standard methods. At all N application rates, ammonium-loaded KAD produced significantly higher plant mass than for NH4SO4. The lower fertiliser effectiveness of NH4SO4 is attributed to possible loss of some N through volatilisation. Of the two KAD types, the material with lower CEC value supported slightly higher plant yields. The KAD materials did not show any adverse effect on availability of trace elements, as evidenced by lack of deficiency symptoms and plant analyses. Clearly, nitrogen loaded on to KAD in the form of ammonium is likely to be protected from leaching, but is still available to plants. These data suggest that KAD-based fertilisers may be suitable substitutes for water soluble N, K and other cation fertilisers for leaching soils.

Director competencies for effective enterprise technology governance

In relation to enterprise technology governance (ETG), opinions differ between there being no need for board of director involvement to there being an urgent need for such involvement. This research highlights the need for boards to provide ETG oversight of technology-related strategy, investment and risk, and to be competent in doing so. We identify a large gap between board’s awareness of the importance of ETG, their taking action and the competency requirements for effective ETG. Further, while there is considerable research and literature about operational IT governance frameworks and operational IT competencies, there is no known research into the specific competencies boards of directors need to effectively govern enterprise technology. This research focuses on and develops a board-level ETG competency set using a mixed methods approach within a recognised competency development framework. Further development is tracked using a rigour scale to demonstrate a medium to high level of competency validity for the derived set. This research contributes to practice by providing the first known industry validated ETG competency set situated within new and emerging technology. It contributes to the body of knowledge in the modification and application of competency development and competency validation frameworks not previously applied to the role of board director.