Strategies for developing and delivering a parental physical activity intervention : answers to the what and how

Background Parents are at risk for physical inactivity; however, few studies have designed physical activity (PA) interventions specifically applied to individuals with young children. To ensure the effectiveness of interventions, it may be useful to first elicit the needs from the target population and incorporate salient strategies identified to the design and delivery of a resultant intervention. We aimed to explore strategies for what to include in and how to best deliver a program designed to increase parental PA. Methods Twelve parents (6 mothers, 6 fathers) of children younger than 5 years participated in focus group discussions exploring strategies for an intervention program designed to increase parental PA. Results A range of themes such as Focus on the Children and Flexible Life/Family Plans imbedded in strategies such as persuasion and information, problem-solving, skill building, and environmental approaches were identified. In addition, a range of strategies for how to best deliver a parental PA intervention evidenced in emerging themes such as Diverse and Brief and Individualized Approach was discussed. Conclusions Future research should continue to adopt a ground up, community-based approach to the development and implementation of interventions for this at-risk group to ensure sustained involvement in regular PA.

Governing young people’s drug use: Crime, harm and contemporary drug use practices

Since the nineteenth century, drug use has been variously understood as a problem of epidemiology, psychiatry, physiology, and criminality. Consequently drug research tends to be underpinned by assumptions of inevitable harm, and is often directed towards preventing drug use or solving problems. These constructions of the drug problem have generated a range of law enforcement responses, drug treatment technologies and rehabilitative programs that are intended to prevent drug related harm and resituate drug users in the realm of neo-liberal functional citizenship. This paper is based on empirical research of young people’s illicit drug use in Brisbane. The research rejects the idea of a pre-given drug problem, and seeks to understand how drugs have come to be defined as a problem. Using Michel Foucault’s conceptual framework of governmentality, the paper explores how the governance of illicit drugs, through law, public health and medicine, intersects with self-governance to shape young people’s drug use practices. It is argued that constructions of the drug problem shape what drug users believe about themselves and the ways in which they use drugs. From this perspective, drug use practices are ‘practices of the self’, formed through an interaction of the government of illicit drugs and the drug users own subjectivity.

Stiffness-damping matching method of an ECAS system based on LQG control

A novel method of matching stiffness and continuous variable damping of an ECAS (electronically controlled air suspension) based on LQG (linear quadratic Gaussian) control was proposed to simultaneously improve the road-friendliness and ride comfort of a two-axle school bus. Taking account of the suspension nonlinearities and target-height-dependent variation in suspension characteristics, a stiffness model of the ECAS mounted on the drive axle of the bus was developed based on thermodynamics and the key parameters were obtained through field tests. By determining the proper range of the target height for the ECAS of the fully-loaded bus based on the design requirements of vehicle body bounce frequency, the control algorithm of the target suspension height (i.e., stiffness) was derived according to driving speed and road roughness. Taking account of the nonlinearities of a continuous variable semi-active damper, the damping force was obtained through the subtraction of the air spring force from the optimum integrated suspension force, which was calculated based on LQG control. Finally, a GA (genetic algorithm)-based matching method between stepped variable damping and stiffness was employed as a benchmark to evaluate the effectiveness of the LQG-based matching method. Simulation results indicate that compared with the GA-based matching method, both dynamic tire force and vehicle body vertical acceleration responses are markedly reduced around the vehicle body bounce frequency employing the LQG-based matching method, with peak values of the dynamic tire force PSD (power spectral density) decreased by 73.6%, 60.8% and 71.9% in the three cases, and corresponding reduction are 71.3%, 59.4% and 68.2% for the vehicle body vertical acceleration. A strong robustness to variation of driving speed and road roughness is also observed for the LQG-based matching method.

Manifestations of preoperational reasoning on similar programming tasks

In this research paper, we study a simple programming problem that only requires knowledge of variables and assignment statements, and yet we found that some early novice programmers had difficulty solving the problem. We also present data from think aloud studies which demonstrate the nature of those difficulties. We interpret our data within a neo-Piagetian framework which describes cognitive developmental stages through which students pass as they learn to program. We describe in detail think aloud sessions with novices who reason at the neo-Piagetian preoperational level. Those students exhibit two problems. First, they focus on very small parts of the code and lose sight of the "big picture". Second, they are prone to focus on superficial aspects of the task that are not functionally central to the solution. It is not until the transition into the concrete operational stage that decentration of focus occurs, and they have the cognitive ability to reason about abstract quantities that are conserved, and are equipped to adapt skills to closely related tasks. Our results, and the neo-Piagetian framework on which they are based, suggest that changes are necessary in teaching practice to better support novices who have not reached the concrete operational stage.

ESD starts where STEM stops : integrating the social sciences into STEM

The Earth and its peoples are facing great challenges. As a species, humans are over-consuming the Earth’s resources and compromising the capacity of both natural and social systems to function in healthy and sustainable ways. Education at all levels and in all contexts, has a key role in helping societies move to more sustainable ways of living. Two areas in need of catch-up in relation to Education for Sustainable Development (ESD) are early childhood education and teacher education. Another area of challenge for ESD is the way it is currently oriented. To date, a great deal of emphasis has been placed on scientific and technological solutions to sustainability issues. This has led to an emphasis on STEM education as education’s main way of addressing sustainability. However, in this paper it is argued that sustainably is primarily a social issue that requires interdisciplinary education approaches. STEM approaches to ESD - emphasising knowledge construction and problem-solving - cannot, on their own, deal effectively with attitudes, values and actions towards more sustainable ways of living. In China and Australia, there are already policies, frameworks, guidelines and initiatives, such as Green Schools and Sustainable Schools that support such forms of ESD. STEM educators need to reach out to social scientists and social educators in order to more fully engage with activist and collaborative educational responses that equip learners with the knowledge, dispositions and capacities to ‘make a difference’.

Modelling as a vehicle for philosophical inquiry in the mathematics curriculum

Philosophical inquiry in the teaching and learning of mathematics has received continued, albeit limited, attention over many years (e.g., Daniel, 2000; English, 1994; Lafortune, Daniel, Fallascio, & Schleider, 2000; Kennedy, 2012a). The rich contributions these communities can offer school mathematics, however, have not received the deserved recognition, especially from the mathematics education community. This is a perplexing situation given the close relationship between the two disciplines and their shared values for empowering students to solve a range of challenging problems, often unanticipated, and often requiring broadened reasoning. In this article, I first present my understanding of philosophical inquiry as it pertains to the mathematics classroom, taking into consideration the significant work that has been undertaken on socio-political contexts in mathematics education (e.g., Skovsmose & Greer, 2012). I then consider one approach to advancing philosophical inquiry in the mathematics classroom, namely, through modelling activities that require interpretation, questioning, and multiple approaches to solution. The design of these problem activities, set within life-based contexts, provides an ideal vehicle for stimulating philosophical inquiry.

The power of percent

Which statistic would you use if you were writing the newspaper headline for the following media release: "Tassie’s death rate of deaths arising from transport-related injuries was 13 per 100,000 people, or 50% higher than the national average”? (Martain, 2007). The rate “13 per 100,000” sounds very small whereas “50% higher” sounds quite large. Most people are aware of the tendency to choose between reporting data as actual numbers or using percents in order to gain attention. Looking at examples like this one can help students develop a critical quantitative literacy viewpoint when dealing with “authentic contexts” (Australian Curriculum, Assessment and Reporting Authority [ACARA], 2013a, p. 37, 67). The importance of the distinction between reporting information in raw numbers or percents is not explicitly mentioned in the Australian Curriculum: Mathematics (ACARA, 2013b, p. 42). Although the document specifically mentions making “connections between equivalent fractions, decimals and percentages” [ACMNA131] in Year 6, there is no mention of the fundamental relationship between percent and the raw numbers represented in a part-whole fashion. Such understanding, however, is fundamental to the problem solving that is the focus of the curriculum in Years 6 to 9. The purpose of this article is to raise awareness of the opportunities to distinguish between the use of raw numbers and percents when comparisons are being made in contexts other than the media. It begins with the authors’ experiences in the classroom, which motivated a search in the literature, followed by a suggestion for a follow-up activity.

A comparative study of the semi-elastic and fully-elastic MapReduce models

MapReduce is a computation model for processing large data sets in parallel on large clusters of machines, in a reliable, fault-tolerant manner. A MapReduce computation is broken down into a number of map tasks and reduce tasks, which are performed by so called mappers and reducers, respectively. The placement of the mappers and reducers on the machines directly affects the performance and cost of the MapReduce computation in cloud computing. From the computational point of view, the mappers/reducers placement problem is a generation of the classical bin packing problem, which is NP-complete. Thus, in this paper we propose a new heuristic algorithm for the mappers/reducers placement problem in cloud computing and evaluate it by comparing with other several heuristics on solution quality and computation time by solving a set of test problems with various characteristics. The computational results show that our heuristic algorithm is much more efficient than the other heuristics and it can obtain a better solution in a reasonable time. Furthermore, we verify the effectiveness of our heuristic algorithm by comparing the mapper/reducer placement for a benchmark problem generated by our heuristic algorithm with a conventional mapper/reducer placement which puts a fixed number of mapper/reducer on each machine. The comparison results show that the computation using our mapper/reducer placement is much cheaper than the computation using the conventional placement while still satisfying the computation deadline.

Representations for evolutionary design modelling

This research looked at using the metaphor of biological evolution as a way of solving architectural design problems. Drawing from fields such as language grammars, algorithms and cellular biology, this thesis looked at ways of encoding design information for processing. The aim of this work is to help in the building of software that support the architectural design process and allow designers to examine more variations.

A novel hybrid evolutionary algorithm based on ACO and SA for distribution feeder reconfiguration with regard to DGs

This paper presents an efficient hybrid evolutionary optimization algorithm based on combining Ant Colony Optimization (ACO) and Simulated Annealing (SA), called ACO-SA, for distribution feeder reconfiguration (DFR) considering Distributed Generators (DGs). Due to private ownership of DGs, a cost based compensation method is used to encourage DGs in active and reactive power generation. The objective function is summation of electrical energy generated by DGs and substation bus (main bus) in the next day. The approach is tested on a real distribution feeder. The simulation results show that the proposed evolutionary optimization algorithm is robust and suitable for solving DFR problem.

A hybrid evolutionary algorithm based on ACO and SA for distribution feeder reconfiguration

This paper deals with an efficient hybrid evolutionary optimization algorithm in accordance with combining the ant colony optimization (ACO) and the simulated annealing (SA), so called ACO-SA. The distribution feeder reconfiguration (DFR) is known as one of the most important control schemes in the distribution networks, which can be affected by distributed generations (DGs) for the multi-objective DFR. In such a case, DGs is used to minimize the real power loss, the deviation of nodes voltage and the number of switching operations. The approach is carried out on a real distribution feeder, where the simulation results show that the proposed evolutionary optimization algorithm is robust and suitable for solving the DFR problem.

Leadership in problem-oriented policing

Purpose – The purpose of this paper is to explore the role of leadership in problem-oriented policing (POP). Design/methodology/approach – This paper uses interrupted time series models to isolate the impact on crime trends of a transformational leader's efforts to spearhead the implementation of a program of POP, called the problem solving model (PSM), in a southern state in Australia. Findings – This paper finds that the PSM led directly to an impact on overall crime, with a significant reduction in crimes per 100,000 persons per year after the introduction of the PSM. The majority of the overall crime drop attributable to implementation of POP was driven by reductions in property crime. It was noted that the leadership influence of the PSM was not effective in reducing all types of crime. Crimes against the person where not affected by the introduction of the PSM and public nuisance crimes largely followed the forecasted, upward trajectory. Practical implications – The driver behind the PSM was Commissioner Hyde and the success of the PSM is largely attributable to his strong commitment to transformational leadership and a top-down approach to implementation. These qualities encapsulate the original ideas behind POP that Goldstein (1979, 2003), back in 1979, highlighted as critical for the success of future POP programs. Social implications – Reducing crime is an important part of creating safe communities and improving quality of life for all citizens. This research shows that successful implementation of the PSM within South Australia under the strong leadership of Commissioner Hyde was a major factor in reducing property crime and overall crime rates. Originality/value – This paper is valuable because it demonstrates the link between strong leadership in policing, the commissioner's vision for POP and how his vision then translated into widespread adoption of POP. The study empirically shows that the statewide adoption of POP led to significant reductions in crime, particularly property crime.

Optimal distributed generation placement in radial distribution systems

Distributed generation (DG) resources are commonly used in the electric systems to obtain minimum line losses, as one of the benefits of DG, in radial distribution systems. Studies have shown the importance of appropriate selection of location and size of DGs. This paper proposes an analytical method for solving optimal distributed generation placement (ODGP) problem to minimize line losses in radial distribution systems using loss sensitivity factor (LSF) based on bus-injection to branch-current (BIBC) matrix. The proposed method is formulated and tested on 12 and 34 bus radial distribution systems. The classical grid search algorithm based on successive load flows is employed to validate the results. The main advantages of the proposed method as compared with the other conventional methods are the robustness and no need to calculate and invert large admittance or Jacobian matrices. Therefore, the simulation time and the amount of computer memory, required for processing data especially for the large systems, decreases.

Lattice-based completely non-malleable public-key encryption in the standard model

An encryption scheme is non-malleable if giving an encryption of a message to an adversary does not increase its chances of producing an encryption of a related message (under a given public key). Fischlin introduced a stronger notion, known as complete non-malleability, which requires attackers to have negligible advantage, even if they are allowed to transform the public key under which the related message is encrypted. Ventre and Visconti later proposed a comparison-based definition of this security notion, which is more in line with the well-studied definitions proposed by Bellare et al. The authors also provide additional feasibility results by proposing two constructions of completely non-malleable schemes, one in the common reference string model using non-interactive zero-knowledge proofs, and another using interactive encryption schemes. Therefore, the only previously known completely non-malleable (and non-interactive) scheme in the standard model, is quite inefficient as it relies on generic NIZK approach. They left the existence of efficient schemes in the common reference string model as an open problem. Recently, two efficient public-key encryption schemes have been proposed by Libert and Yung, and Barbosa and Farshim, both of them are based on pairing identity-based encryption. At ACISP 2011, Sepahi et al. proposed a method to achieve completely non-malleable encryption in the public-key setting using lattices but there is no security proof for the proposed scheme. In this paper we review the mentioned scheme and provide its security proof in the standard model. Our study shows that Sepahi’s scheme will remain secure even for post-quantum world since there are currently no known quantum algorithms for solving lattice problems that perform significantly better than the best known classical (i.e., non-quantum) algorithms.

On the hardness of the sum of K mins problem

The sum of k mins protocol was proposed by Hopper and Blum as a protocol for secure human identification. The goal of the protocol is to let an unaided human securely authenticate to a remote server. The main ingredient of the protocol is the sum of k mins problem. The difficulty of solving this problem determines the security of the protocol. In this paper, we show that the sum of k mins problem is NP-Complete and W[1]-Hard. This latter notion relates to fixed parameter intractability. We also discuss the use of the sum of k mins protocol in resource-constrained devices.