Estimation and compensation of clipping noise in OFDMA systems

We propose an efficient and low-complexity scheme for estimating and compensating clipping noise in OFDMA systems. Conventional clipping noise estimation schemes, which need all demodulated data symbols, may become infeasible in OFDMA systems where a specific user may only know his own modulation scheme. The proposed scheme first uses equalized output to identify a limited number of candidate clips, and then exploits the information on known subcarriers to reconstruct clipped signal. Simulation results show that the proposed scheme can significantly improve the system performance.

Under great pressure, a diamond is being formed: The SBS over time

This article observes a paradox in the recent history of the Special Broadcasting Service. It is argued that, in contrast to the Australian Broadcasting Corporation, the role and general direction of SBS were not extensively debated as part of the ‘culture wars’ that occurred during the years of the Howard government. While that made SBS a less fraught space during that period, it may now be a factor in the comparative lack of support being given by the Rudd Labor government to SBS in comparison with the ABC, as some of the ‘special’ status of SBS has been blunted by its drift towards more mainstream programming and a mixed economy of commercial advertising, as well as government funding.

Framing Culture : Criticism and Policy in Australia

How is contemporary culture 'framed' - understood, promoted, dissected and defended - in the new approaches being employed in university education today? How do these approaches compare with those seen in the public policy process? What are the implications of these differences for future directions in theory, education, activism and policy? Framing Culture looks at cultural and media studies, which are rapidly growing fields through which students are introduced to contemporary cultural industries such as television, film and video. It compares these approaches with those used to frame public policy and finds a striking lack of correspondence between them. Issues such as Australian content on commercial television and in advertising, new technologies and new media, and violence in the media all highlight the gap between contemporary cultural theories and the way culture and communications are debated in public policy. The reasons for this gap must be investigated before closer relations can be established. Framing Culture brings together cultural studies and policy studies in a lively and innovative way. It suggests avenues for cultural activism that have been neglected in cultural theory and practice, and it will provoke debates which are long overdue.

Mining Negative Relevance Feedback for Information Filtering

It is a big challenge to clearly identify the boundary between positive and negative streams. Several attempts have used negative feedback to solve this challenge; however, there are two issues for using negative relevance feedback to improve the effectiveness of information filtering. The first one is how to select constructive negative samples in order to reduce the space of negative documents. The second issue is how to decide noisy extracted features that should be updated based on the selected negative samples. This paper proposes a pattern mining based approach to select some offenders from the negative documents, where an offender can be used to reduce the side effects of noisy features. It also classifies extracted features (i.e., terms) into three categories: positive specific terms, general terms, and negative specific terms. In this way, multiple revising strategies can be used to update extracted features. An iterative learning algorithm is also proposed to implement this approach on RCV1, and substantial experiments show that the proposed approach achieves encouraging performance.

The use of the Index for Inclusion in a regional educational learning community

This project utilised the materials of the Index for Inclusion (Booth & Ainscow, 2002) to enhance the development of a learning community of educators in Education Queensland in 2009. The values, dimensions and indicators of the Index for Inclusion, were incorporated into the professional development package, On the Same Page (Education Queensland, 2008), to enhance its wider purpose to improve inclusive education practices explicit within the P-12 Curriculum Framework (Education Queensland, 2008). The incorporation of the values, dimensions and indicators of the Index enabled deeper reflection by participants about their expectations of students and their resulting teaching practices. The subsequent development of action plans assisted participants to develop “a curriculum for all” (Education Queensland, 2008, p. 9). Deeper reflection, action planning and ‘distance travelled’ in understanding of inclusive education were apparent in the comments by participants and their evaluation of the professional development package.

Authentic assessment of work integrated learning

The paper examines how poster presentations can be used to authentically assess student learning during internships. While poster presentations are commonly used for assessment in the sciences, they are an innovative approach to assessment in the humanities. It is argued that posters are one way that universities can overcome the substantial challenges of assessing work integrated learning. The paper evaluates the use of poster presentations for assessment in two internship units at the Queensland University of Technology (QUT)]. The first is a unit in the Faculty of Business where students majoring in advertising, marketing and public relations are placed in a variety of organisations. The second unit is a law unit where students complete placements in government legal offices. The two units adopt different approaches to the poster assessment; the unit in the Faculty of Business is non-graded and the poster assessment task requires students to reflect on their learning during the internship. The law unit is graded and requires students to present on a research topic that relates to their internship. In both units the posters were presented during a poster showcase which was attended by students, workplace supervisors and members of faculty. The paper evaluates the benefits of poster presentations for students, workplace supervisors and faculty and concludes that posters can effectively and authentically assess various learning outcomes in internships in different disciplines.

Hell-vetica

Helvetica (connotes Swiss typeface) has been used the most widely from street signs to government campaign posters since 1957. Helvetica represents a great leap forward for modernity: clean, sans-serif, optimistic. However in history, there was a movement against Helvetica among American artists and designers since David Carson and Paula Scher indicted Helvetica as the cause of Vietnam war. Paradoxically, we celebrated its 50th birthday in 2007. Helvetica’s message it this: “you are going to get to your destination on time; your plan will not crash; your money is safe in our vault; we will not break the package; the paperwork has been filled in; everything is going to be OK” (Finlo Rohrer, Helvetica At 50, BBC News Magazine 9 May 2007). The artwork, Hell-vetica describes its characteristic of double agent for modernism and postmodernism in this contemporary era by combination of a stylised graphical form of a heart shape in red and a typographical manipulation - Hell-vetica.

Inducing shades of meaning by matrix methods : a first step towards thematic analysis of opinion

This article explores two matrix methods to induce the ``shades of meaning" (SoM) of a word. A matrix representation of a word is computed from a corpus of traces based on the given word. Non-negative Matrix Factorisation (NMF) and Singular Value Decomposition (SVD) compute a set of vectors corresponding to a potential shade of meaning. The two methods were evaluated based on loss of conditional entropy with respect to two sets of manually tagged data. One set reflects concepts generally appearing in text, and the second set comprises words used for investigations into word sense disambiguation. Results show that for NMF consistently outperforms SVD for inducing both SoM of general concepts as well as word senses. The problem of inducing the shades of meaning of a word is more subtle than that of word sense induction and hence relevant to thematic analysis of opinion where nuances of opinion can arise.

Augmenting web service discovery by cognitive semantics and abduction

We argue that web service discovery technology should help the user navigate a complex problem space by providing suggestions for services which they may not be able to formulate themselves as (s)he lacks the epistemic resources to do so. Free text documents in service environments provide an untapped source of information for augmenting the epistemic state of the user and hence their ability to search effectively for services. A quantitative approach to semantic knowledge representation is adopted in the form of semantic space models computed from these free text documents. Knowledge of the user’s agenda is promoted by associational inferences computed from the semantic space. The inferences are suggestive and aim to promote human abductive reasoning to guide the user from fuzzy search goals into a better understanding of the problem space surrounding the given agenda. Experimental results are discussed based on a complex and realistic planning activity.

Spoken term detection using fast phonetic decoding

While spoken term detection (STD) systems based on word indices provide good accuracy, there are several practical applications where it is infeasible or too costly to employ an LVCSR engine. An STD system is presented, which is designed to incorporate a fast phonetic decoding front-end and be robust to decoding errors whilst still allowing for rapid search speeds. This goal is achieved through mono-phone open-loop decoding coupled with fast hierarchical phone lattice search. Results demonstrate that an STD system that is designed with the constraint of a fast and simple phonetic decoding front-end requires a compromise to be made between search speed and search accuracy.