Short signature without random oracles and the SDH assumption in bilinear groups

We describe a short signature scheme that is strongly existentially unforgeable under an adaptive chosen message attack in the standard security model. Our construction works in groups equipped with an efficient bilinear map, or, more generally, an algorithm for the Decision Diffie-Hellman problem. The security of our scheme depends on a new intractability assumption we call Strong Diffie-Hellman (SDH), by analogy to the Strong RSA assumption with which it shares many properties. Signature generation in our system is fast and the resulting signatures are as short as DSA signatures for comparable security. We give a tight reduction proving that our scheme is secure in any group in which the SDH assumption holds, without relying on the random oracle model.

Unintended consequences : satellite policy and Indigenous television

This article examines two instances of media policy involving satellite transmission and Indigenous television: the introduction of the Viewer Access Satellite Television (VAST) platform in 2010 and the introduction of AUSSAT in the mid-1980s. The government’s failure to provide community and Indigenous broadcasters with an access regime at the time of AUSSAT resulted in Australia’s first and only Indigenous commercial television licensee, Imparja. Over a quarter of a century later, Imparja now forms part of the joint-venture company that runs VAST, a key component of Australia’s digital switchover planning. During the passage of the legislative amendments required to establish VAST, the issue of access resurfaced – this time in relation to Australia’s national and community Indigenous television channels. The article recounts the events leading up to the 2010 Bill, and examines the intended and unintended consequences of satellite policy in relation to Indigenous media, including equalisation and transparency of government funding programs.

Developing a framework for subcontractor appraisal using a balanced scorecard

Subcontractors contribute significantly to construction projects and their performance can seriously affect over-all project success. It is crucial, therefore, to appraise the performance of subcontractors to ensure they satisfy the client's expectations and project requirements. To increase the transparency and accuracy of subcontractor appraisal, the baseline and target performance levels should be set at the outset so that the appraisers and those being appraised realize exactly what standards are to be achieved. The balanced scorecard, being a powerful tool for performance appraisal, offers a potentially good approach for modeling the subcontractor appraisal process. In this paper, an approach to developing a balanced scorecard subcontractor appraisal model is proposed and demonstrated through a questionnaire survey administered in Hong Kong and from which the baseline and target performance levels for large-scale skilled subcontractors are identified. A case example is used to illustrate the operation of the model. Finally, a means by which the model may be validated is demonstrated through the use of field experts. The results demonstrate the feasibility of developing a balanced scorecard model that can help improve the transparency of subcontractor appraisal despite the baseline and target performance levels changing according to the project characteristics, subcontractor categories and size.

Non-formal techniques for early assessment of design ideas for services

Designing systems for multiple stakeholders requires frequent collaboration with multiple stakeholders from the start. In many cases at least some stakeholders lack a professional habit of formal modeling. We report observations from student design teams as well as two case studies, respectively of a prototype for supporting creative communication to design objects, and of stakeholder-involvement in early design. In all observations and case studies we found that non-formal techniques supported strong collaboration resulting in deep understanding of early design ideas, of their value and of the feasibility of solutions.

Business process model abstraction

In order to execute, study, or improve operating procedures, companies document them as business process models. Often, business process analysts capture every single exception handling or alternative task handling scenario within a model. Such a tendency results in large process specifications. The core process logic becomes hidden in numerous modeling constructs. To fulfill different tasks, companies develop several model variants of the same business process at different abstraction levels. Afterwards, maintenance of such model groups involves a lot of synchronization effort and is erroneous. We propose an abstraction technique that allows generalization of process models. Business process model abstraction assumes a detailed model of a process to be available and derives coarse-grained models from it. The task of abstraction is to tell significant model elements from insignificant ones and to reduce the latter. We propose to learn insignificant process elements from supplementary model information, e.g., task execution time or frequency of task occurrence. Finally, we discuss a mechanism for user control of the model abstraction level – an abstraction slider.

Why 'down under' is a cut above: a comparison of rates of and reasons for caesarean section in England and Australia

Background Most studies examining determinants of rising rates of caesarean section have examined patterns in documented reasons for caesarean over time in a single location. Further insights could be gleaned from cross-cultural research that examines practice patterns in locations with disparate rates of caesarean section at a single time point. Methods We compared both rates of and main reason for pre-labour and intrapartum caesarean between England and Queensland, Australia, using data from retrospective cross-sectional surveys of women who had recently given birth in England (n = 5,250) and Queensland (n = 3,467). Results Women in Queensland were more likely to have had a caesarean birth (36.2%) than women in England (25.1% of births; OR = 1.44, 95% CI = 1.28-1.61), after adjustment for obstetric characteristics. Between-country differences were found for rates of pre-labour caesarean (21.2% vs. 12.2%) but not for intrapartum caesarean or assisted vaginal birth. Compared to women in England, women in Queensland with a history of caesarean were more likely to have had a pre-labour caesarean and more likely to have had an intrapartum caesarean, due only to a previous caesarean. Among women with no previous caesarean, Queensland women were more likely than women in England to have had a caesarean due to suspected disproportion and failure to progress in labour. Conclusions The higher rates of caesarean birth in Queensland are largely attributable to higher rates of caesarean for women with a previous caesarean, and for the main reason of having had a previous caesarean. Variation between countries may be accounted for by the absence of a single, comprehensive clinical guideline for caesarean section in Queensland. Keywords: Caesarean section; Childbirth; Pregnancy; Cross-cultural comparison; Vaginal birth after caesarean; Previous caesarean section; Patient-reported data; Quality improvement

The role of metacognition in the development of EFL learners’ listening skill

This study investigated the impact of metacognitive instruction on the listening skill, and metacognitive knowledge of a group of male students (N = 30) who were learning English as a Foreign Language (EFL) in Iran. The study participants spoke Persian as a first language and were high-intermediate EFL learners. The participants received a guided lesson plan in metacognition (planning, monitoring, and evaluation) through a pedagogical cycle approach over a semester (eight weeks). International English Language Testing System listening tests (practice) were used to track the participants’ listening performance. Participants also completed a Metacognitive Awareness Listening Questionnaire, which examined their use of metacognitive awareness when engaged in listening tasks. Results indicated that the students improved their listening skill after being taught about metacognition; however, no significant use of metacognitive awareness was reported. This study concludes with a discussion of some potential implications, and provides scope for future research.

Second-order elastic finite element analysis of structures using a single element per member

Finite element frame analysis programs targeted for design office application necessitate algorithms which can deliver reliable numerical convergence in a practical timeframe with comparable degrees of accuracy, and a highly desirable attribute is the use of a single element per member to reduce computational storage, as well as data preparation and the interpretation of the results. To this end, a higher-order finite element method including geometric non-linearity is addressed in the paper for the analysis of elastic frames for which a single element is used to model each member. The geometric non-linearity in the structure is handled using an updated Lagrangian formulation, which takes the effects of the large translations and rotations that occur at the joints into consideration by accumulating their nodal coordinates. Rigid body movements are eliminated from the local member load-displacement relationship for which the total secant stiffness is formulated for evaluating the large member deformations of an element. The influences of the axial force on the member stiffness and the changes in the member chord length are taken into account using a modified bowing function which is formulated in the total secant stiffness relationship, for which the coupling of the axial strain and flexural bowing is included.

Contemporary cultures of service delivery to families : implications for music therapy

Family-centred and early intervention and prevention programs are a strong focus of current policy objectives within Australia, and a significant area of practice within the music therapy community. Recent shifts in the culture of policy and practice increasingly reflect ecological understandings by focussing on integrated and place-based approaches to service delivery. Further, current funding opportunities are strongly concerned with the extent to which interventions are able to reach out to highly vulnerable families that typically do not engage with services easily. Music therapy holds unique promise within these cultural shifts and thus advocates must develop a solid understanding of the concepts and related language in order to confidently engage with both funding and service systems. This paper uses an integrative review to first define and summarise current knowledge in three key areas relevant to contemporary Australian policy and practice: hard-to-reach families, home visiting as assertive outreach, and integrated or place-based service delivery. Evidence for the effectiveness of music therapy in relation to these key themes is then presented. Finally, the paper discusses the implications for the future of music therapy within the current Australian early intervention and prevention policy context and makes recommendations for moving forward on both practice and research fronts. While there is growing evidence and theory to suggest that music therapy may be uniquely efficacious in this area, greater Australian Journal of Music Therapy Vol 25, 2014 149 advocacy, documentation, research and adjustment of practices and language will further cement the position of the industry.

Physical activity patterns of Singaporean adolescents

The purpose of this study was to document the level of physical activity and sedentary behavior in a representative sample of Singaporean adolescents. A random sample of 1,827 secondary school students from six secondary schools (929 boys, 898 girls, mean age 14.9 +/- 1.2 yr) completed the Three-Day Physical Activity Recall (3DPAR) self-report instrument. Approximately 63% of Singaporean high school students met current guidelines requiring 60 min of moderate to vigorous physical activity daily. Just over half (51.6%) met the guideline calling for regular vigorous physical activity. Across all grade levels, boys were consistently more active than girls. More than 70% of Singaporean high school students exceeded the recommended 2 hours per day of electronic media use. Collectively, these findings suggest that a significant proportion of Singaporean adolescents are not sufficiently active and are in need of programs to promote physical activity and decrease sedentary behavior.

Natural disasters and the responsibility to protect

The International Law Commission (ILC) study on the protection of persons in the event of disasters has been ongoing since 2006. During this period, there has been continuous debate in the literature and in consultations with States as to whether the study should explore the Responsibility to Protect (R2P) persons in the event of natural disasters. In this article, the rationale for this continuing argument is explored considering that the ILC has repeatedly stated since 2008 that the study’s topic – assistance in the event of natural disasters – has no legal relationship with the R2P principle. In the final section it is proposed that the real knowledge gap in the ILC discussion and study is the positive affirmation of the rights of those most affected by natural disasters – women.

Enhanced coloration efficiency for electrochromic devices based on anodized N2O5 / Electrodeposited MoO3 Binary Systems

There is a continuous quest for developing electrochromic (EC)transition metal oxides (TMOs) with increased coloration efficiency. As emerging TMOs, Nb2O5 films, even those of ordered anodized nanochannels, have failed to produce the required EC performance for practical applications. This is attributed to limitations presented by its relatively wide bandgap and low capacity for accommodating ions. To overcome such issues, MoO3 was electrodeposited onto Nb2O5 nanochannelled films as homogeneously conformal and stratified α-MoO3 coatings of different thickness. The EC performance of the resultant MoO3 coated Nb2O5 binary system was evaluated. The system exhibited a coloration efficiency of 149.0 cm2 C−1, exceeding that of any previous reports on MoO3 and Nb2O5 individually or their compounds. The enhancement was ascribed to a combination of the reduced effective bandgap of the binary system, the increased intercalation probability from the layered α-MoO3 coating, and a high surface-tovolume ratio, while the Nb2O5 nanochannelled templates provided stability and low impurity pathways for charge transfer to occur.

Cheating immune secret sharing

We consider secret sharing with binary shares. This model allows us to use the well developed theory of cryptographically strong boolean functions. We prove that for given secret sharing, the average cheating probability over all cheating and original vectors, i.e., ρ ¯= 1 n ⋅ 2 −n ∑ n c=1 ∑ α∈Vn ρ c,α , satisfies ρ ¯⩾ 1 2 , and the equality holds ⇔ ρc,α satisfies ρc,α = 1/2 for every cheating vector δc and every original vector α. In this case the secret sharing is said to be cheating immune. We further establish a relationship between cheating-immune secret sharing and cryptographic criteria of boolean functions. This enables us to construct cheating-immune secret sharing.

Teaching for quality learning at university

by J. Biggs and C. Tang, Maidenhead, England, Open University Press, 2007, 360 pp., £29.99, ISBN-13: 978-0-335-22126-4

Flexural–torsional buckling behaviour and design of cold-formed steel compression members at elevated temperatures

Current design rules for the member capacities of cold-formed steel columns are based on the same non-dimensional strength curve for both fixed and pinned-ended columns at ambient temperature. This research has investigated the accuracy of using current ambient temperature design rules in Australia/New Zealand (AS/NZS 4600), American (AISI S100) and European (Eurocode 3 Part 1.3) standards in determining the flexural–torsional buckling capacities of cold-formed steel columns at uniform elevated temperatures using appropriately reduced mechanical properties. It was found that these design rules accurately predicted the member capacities of pin ended lipped channel columns undergoing flexural torsional buckling at elevated temperatures. However, for fixed ended columns with warping fixity undergoing flexural–torsional buckling, the current design rules significantly underestimated the column capacities as they disregard the beneficial effect of warping fixity. This paper has therefore recommended the use of improved design rules developed for ambient temperature conditions to predict the axial compression capacities of fixed ended columns subject to flexural–torsional buckling at elevated temperatures within AS/NZS 4600 and AISI S100 design provisions. The accuracy of the proposed fire design rules was verified using finite element analysis and test results of cold-formed lipped channel columns at elevated temperatures except for low strength steel columns with intermediate slenderness whose behaviour was influenced by the increased nonlinearity in the stress–strain curves at elevated temperatures. Further research is required to include these effects within AS/NZS 4600 and AISI S100 design rules. However, Eurocode 3 Part 1.3 design rules can be used for this purpose by using suitable buckling curves as recommended in this paper.