A new re-ranking method using enhanced pseudo-relevance feedback for content-based medical image retrieval

We propose a novel re-ranking method for content-based medical image retrieval based on the idea of pseudo-relevance feedback (PRF). Since the highest ranked images in original retrieval results are not always relevant, a naive PRF based re-ranking approach is not capable of producing a satisfactory result. We employ a two-step approach to address this issue. In step 1, a Pearson's correlation coefficient based similarity update method is used to re-rank the high ranked images. In step 2, after estimating a relevance probability for each of the highest ranked images, a fuzzy SVM ensemble based approach is adopted to re-rank the images. The experiments demonstrate that the proposed method outperforms two other re-ranking methods.

Probabilistic models over ordered partitions with applications in document ranking and collaborative filtering

Ranking is an important task for handling a large amount of content. Ideally, training data for supervised ranking would include a complete rank of documents (or other objects such as images or videos) for a particular query. However, this is only possible for small sets of documents. In practice, one often resorts to document rating, in that a subset of documents is assigned with a small number indicating the degree of relevance. This poses a general problem of modelling and learning rank data with ties. In this paper, we propose a probabilistic generative model, that models the process as permutations over partitions. This results in super-exponential combinatorial state space with unknown numbers of partitions and unknown ordering among them. We approach the problem from the discrete choice theory, where subsets are chosen in a stagewise manner, reducing the state space per each stage significantly. Further, we show that with suitable parameterisation, we can still learn the models in linear time. We evaluate the proposed models on two application areas: (i) document ranking with the data from the recently held Yahoo! challenge, and (ii) collaborative filtering with movie data. The results demonstrate that the models are competitive against well-known rivals.

The relevance of import competition to merger assessment in Australia

The Australian Competition and Consumer Commission has been criticised for failing to take due account of the impact import competition has on domestic firms when assessing whether or not a proposed merger will be likely to substantially lessen competition. This article reviews the approach taken by the ACCC to import competition in its merger assessments. Consideration is given to both the policy adopted by the ACCC and the statistical relevance that has, in fact, been placed on import competition in merger assessment. A conclusion is then drawn as to the appropriateness of the ACCC's current policy and practice.

Calcium chemistry of Blue Lake, Mt Gambier, Australia, and relevance to remarkable seasonal colour changes

Calcium speciation and other water quality variables in the Blue Lake, Mt Gambier, Australia, were monitored between August 1999 and August 2000 in order to test previously proposed mechanisms for the seasonal colour changes of this lake. The concentration of calcite was found to be highest in winter when the lake appears grey, and lowest in summer when the lake appears blue. A potential component of the colour change mechanism is therefore identified in which the lake is grey in winter because of non-selective scattering of light by calcite particles, and blue in summer because of the absence of absorbing or scattering impurities.

The relevance to international mergers of the ethical perspectives of participants

International mergers are becoming more widespread among medium-sized companies that for decades have held a prime position in their home country market, but who now feel threatened that they may not be of a significant size to continue to be viable in the international marketplace. The purpose of this paper is to examine the merger of one Australian company and one of its former competitors in the international marketplace from the perspective of the congruence between their espoused ethical cultures in business prior to the merger. A questionnaire comprising 46 questions was sent to the public relations manager of each organization prior to the merger. These managers were asked to fill in the questionnaire and to provide a copy of their code of ethics. The research found that organizations need to not only have a code of ethics, but also need to focus especially on the area of code augmentation to ensure that they communicate the ethos of their code to their employees.

A comprehensive formal ranking of the popularity of financial ratios in multivariate modeling of corporate collapse

This paper provides a fonnal ranking of the popularity of financial ratios in modeling corporate collapse. The analysis identified 48 financial ratios and ranked them according to their usefulness as portrayed in 53 studies that have utilized such ratios in modeling corporate collapse. The methodologies adopted in those studies are predominantly of the "multivariate" type. The 53 studies extend from 1966 to 2002, inclusive.

Reflexivity, its meanings and relevance for social work: a critical review of the literature

The concept of "reflexivity" has become increasingly significant in social work literature in relation to social work education, theory and practice. However, our reading of the literature indicates that there is a lack of clarity about the concept in terms of who is being exhorted to be "reflexive," when and how. This article addresses these questions through a critical review of social work literature since the 1990s that discusses the concept of "reflexivity." Given that many authors seem to use the concepts of "reflexivity" and "(critical) reflection" interchangeably, we also apply this analysis to "reflection" and "critical reflection." This article raises important questions about how the concepts of "reflexivity," "critical reflection" and "reflectivity" are defined and the different consequences such definitions might have for social work education, theory and practice.

Grid-based method for ranking images with multiple objects

One of the content-based image retrieval techniques is the shape-based technique, which allows users to ask for objects similar in shape to a query object. Sajjanhar and Lu proposed a method for shape representation and similarity measure called the grid-based method [1]. They have shown that the method is effective for the retrieval of segmented objects based on shape. In this paper, we describe a system which uses the grid-based method for retrieval of images with multiple objects. We perform experiments on the prototype system to compare the performance of the grid-based method with the Fourier descriptors method [2]. Preliminary results have been presented.

Challenging librarians : the relevance of the doctorate in professional practice

We, as librarians, are adept at challenging academics, students and administrators about the crucial role of information literacy in higher education and lifelong learning. Consequently, the push for strategic partnerships with academics is frequently in the foreground of our thinking. Concomitantly, the push for academic status for librarians is raised occasionally, particularly as a pay and equity issue. Yet, our purposes may appear somewhat misguided or rhetorical when contrasted to the nominal prerequisites required for professional practice, especially when compared with those of academics. The issues of information literacy and knowledge production within a knowledge economy compound such debate. This paper argues that ‘credential creep’ is catching up with librarians in the university sector. In order to be regarded as integral to academic endeavour, those of us who ‘teach’ information literacy may need to match the qualifications normally required by academics. Consonant with this proposal is the Australian and New Zealand Information Literacy Framework: Principles, Standards and Practice (Bundy, 2004) of the Australian and New Zealand Institute for Information Literacy (ANZIIL) and the Council of Australian University Librarians (CAUL). The Framework mirrors many of the desired outcomes of a doctoral degree, a degree possessed by approximately one per cent of Australian librarians but, in comparison, by more than fi fty-four per cent of Australian academics. This paper challenges—not academics—but librarians, to embrace the notion of undertaking doctoral study to enhance our professional (or amateur) practice and our information literacy. The recommendation is derived in essence from my study on doctoral research and information literacy (Macauley, 2001). It also incorporates the current discourse on these issues and uses personal narrative to articulate the findings. It seeks also to explore those tensions and contradictions commensurate with practising what we preach.

The relevance of demographic variables in assessing student satisfaction: a study of international postgraduate students

Servicing an increasingly diverse international student community in the globally competitive education market is a challenge faced by Australian universities. Market forecasts indicate a seven-fold increase in the number of students seeking higher education overseas by 2025 (Bohm et al, 2002) and with the growing diversity and competitiveness of the industry, universities will need to focus on factors influencing student satisfaction to improve service quality where required.

This paper, using logistic regression, ANOVA, and MANOVA, investigates the influence of country, age and gender with regard to satisfaction among international postgraduate students from four Asian countries studying in universities in Victoria. The results indicate that there is an inverse relationship between age and satisfaction among postgraduate students while the gender of the students does not have an impact on satisfaction, and that significant differences are evident between the four countries investigated with respect to the levels of satisfaction.

Spam filtering based on preference ranking

When the average number of spam messages received is continually increasing exponentially, both the Internet service provider and the end user suffer. The lack of an efficient solution may threaten the usability of the email as a communication means. In this paper we present a filtering mechanism applying the idea of preference ranking. This filtering mechanism will distinguish spam emails from other email on the Internet. The preference ranking gives the similarity values for nominated emails and spam emails specified by users, so that the ISP/end users can deal with spam emails at filtering points. We designed three filtering points to classify nominated emails into spam email, unsure email and legitimate email. This filtering mechanism can be applied on both middleware and at the client-side. The experiments show that high precision, recall and TCR (total cost ratio) of spam emails can be predicted for the preference based filtering mechanisms.

A ranking list for information systems journals

There has been an increasing focus internationally on the quality and impact of research outputs in recent years. Several countries, including the United Kingdom and New Zealand have implemented schemes to base the funding of research on research quality. The Australian government is planning to implement a Research Quality Framework (RQF) in the next few years that will impact greatly on funding of research in Australian universities. A key issue for Australian researchers is how the quality and impact of research is defined and measured in their discipline areas. Although peer review is widely used to assess the quality of research outputs, it is expensive and labour intensive. Other surrogate quality measures are often used. This paper focuses on measuring the quality of research outputs in the information systems discipline. We argue that measures such as citation indexes are inappropriate for information systems and that the publication outlet is a more suitable indicator of quality. We present a ranking list of journals for the information systems discipline, and discuss the approach we have taken in developing the list. We discuss how the ranking list may be used in defining and measuring the quality of information systems research outputs, the limitations inherent in the approach and discuss lessons we have learned in developing the list.

The relevance of role models to older aged generation Y consumers

This study assesses the relevance of role models, specifically sports role models, and the related concepts of anti-heroes and gender to Generation Y consumers in the older age group of 18-29 year olds. A qualitative study, following a post-positivist inquiry paradigm was conducted. The specific research strategy used was grounded theory, utilising deductive thought processes coupled with the process of constant comparison. A series of semi-structured in-depth interviews were carried out. Results suggest that direct relevance to the subject under investigation is a key determinant of role model choice. Gender is also found to have significant effect, as is media, both in the creation of role models and anti-heroes.

Drug bioactivation, covalent binding to target proteins and toxicity relevance

A number of therapeutic drugs with different structures and mechanisms of action have been reported to undergo metabolic activation by Phase I or Phase II drug-metabolizing enzymes. The bioactivation gives rise to reactive metabolites/intermediates, which readily confer covalent binding to various target proteins by nucleophilic substitution and/or Schiff's base mechanism. These drugs include analgesics (e.g., acetaminophen), antibacterial agents (e.g., sulfonamides and macrolide antibiotics), anticancer drugs (e.g., irinotecan), antiepileptic drugs (e.g., carbamazepine), anti-HIV agents (e.g., ritonavir), antipsychotics (e.g., clozapine), cardiovascular drugs (e.g., procainamide and hydralazine), immunosupressants (e.g., cyclosporine A), inhalational anesthetics (e.g., halothane), nonsteroidal anti-inflammatory drugs (NSAIDSs) (e.g., diclofenac), and steroids and their receptor modulators (e.g., estrogens and tamoxifen). Some herbal and dietary constituents are also bioactivated to reactive metabolites capable of binding covalently and inactivating cytochrome P450s (CYPs). A number of important target proteins of drugs have been identified by mass spectrometric techniques and proteomic approaches. The covalent binding and formation of drug-protein adducts are generally considered to be related to drug toxicity, and selective protein covalent binding by drug metabolites may lead to selective organ toxicity. However, the mechanisms involved in the protein adduct-induced toxicity are largely undefined, although it has been suggested that drug-protein adducts may cause toxicity either through impairing physiological functions of the modified proteins or through immune-mediated mechanisms. In addition, mechanism-based inhibition of CYPs may result in toxic drug-drug interactions. The clinical consequences of drug bioactivation and covalent binding to proteins are unpredictable, depending on many factors that are associated with the administered drugs and patients. Further studies using proteomic and genomic approaches with high throughput capacity are needed to identify the protein targetsof reactive drug metabolites, and to elucidate the structure-activity relationships of drug's covalent binding to proteins and their clinical outcomes.