Network interactions and performance of a multi-function IEC 61850 process bus

New substation technology, such as non-conventional instrument transformers,and a need to reduce design and construction costs, are driving the adoption of Ethernet based digital process bus networks for high voltage substations. Protection and control applications can share a process bus, making more efficient use of the network infrastructure. This paper classifies and defines performance requirements for the protocols used in a process bus on the basis of application. These include GOOSE, SNMP and IEC 61850-9-2 sampled values. A method, based on the Multiple Spanning Tree Protocol (MSTP) and virtual local area networks, is presented that separates management and monitoring traffic from the rest of the process bus. A quantitative investigation of the interaction between various protocols used in a process bus is described. These tests also validate the effectiveness of the MSTP based traffic segregation method. While this paper focusses on a substation automation network, the results are applicable to other real-time industrial networks that implement multiple protocols. High volume sampled value data and time-critical circuit breaker tripping commands do not interact on a full duplex switched Ethernet network, even under very high network load conditions. This enables an efficient digital network to replace a large number of conventional analog connections between control rooms and high voltage switchyards.

Interactions and consequences of inertia and switching costs

Purpose: Service research typically relates switching costs to customer loyalty, and portrays them as effective switching deterrents that engender harmful word-of-mouth (WOM). Rather than to customer loyalty, this paper aims to relate switching costs to consumer inertia, and show that while switching costs may result in customer retention, they can engender positive and negative WOM. This depends on whether the inertia stems from satisfaction or indifference. Design/methodology/approach: A mall-intercept survey investigated 518 customers' perceptions of their mobile phone service providers. Structural equation modelling fitted the data to the conceptual model. Findings: Switching costs deterred switching and engendered negative WOM, but only with low-inertia customers. With high-inertia customers, retention and WOM behaviours depended on whether the inertia stemmed from satisfaction or indifference. Satisfied customers with high switching costs tended to stay, gave more positive and less negative WOM. With indifferent customers, switching costs were unrelated to retention or WOM behaviours. Research limitations/implications: While they may be perceived negatively, switching costs can engender PWOM. Hence, research should not consider switching costs alone without considering the context that produces them. Practical implications: Service providers should segment their customers into low-inertia, high-inertia/satisfied and high-inertia/indifferent, and target each segment differently. By converting customers into the high-inertia/satisfied segment, service providers can make the best use of switching costs – not only in the traditional sense as a barrier to defection, but also as a way of generating positive WOM. Originality/value: This study is the first to consider the role of inertia with switching costs, positive WOM, and negative WOM. The findings suggest that past studies portraying switching costs as negative impediments that evoke only negative WOM might be misleading.

In vitro physical stimulation of tissue-engineered and native cartilage

Because of the limited availability of donor cartilage for resurfacing defects in articular surfaces, there is tremendous interest in the in vitro bioengineering of cartilage replacements for clinical applications. However, attaining mechanical properties in engineered cartilaginous constructs that approach those of native cartilage has not been previously achieved when constructs are cultured under free-swelling conditions. One approach toward stimulating the development of constructs that are mechanically more robust is to expose them to physical environments that are similar, in certain ways, to those encountered by native cartilage. This is a strategy motivated by observations in numerous short-term experiments that certain mechanical signals are potent stimulators of cartilage metabolism. On the other hand, excess mechanical loading can have a deleterious effect on cartilage. Culture conditions that include a physical stimulation component are made possible by the use of specialized bioreactors. This chapter addresses some of the issues involved in using bioreactors as integral components of cartilage tissue engineering and in studying the physical regulation of cartilage. We first consider the generation of cartilaginous constructs in vitro. Next we describe the rationale and design of bioreactors that can impart either mechanical deformation or fluid-induced mechanical signals.

Catapulting into STEM education : female students’ interactions within a middle school engineering project

Despite efforts to motivate students to engage in Science, technology, engineering and mathematics (STEM) education, women are still underrepresented in these areas in the workforce and higher education. Targeting females at high school or earlier may be a key towards engaging them in STEM. In this paper we report on the research question: How do middle school females interact for learning about engineering education? This ethnographic study, part of a three-year longitudinal research project, investigated Year 8 female students’ learning about engineering concepts associated with designing, constructing, testing, and evaluating a catapult. Through a series of lead-up lessons and the four lesson catapult challenge (total of 18 x 45-minute lessons over 9 weeks), data from two girls within a focus group showed that the students needed to: (1) receive clarification on engineering terms to facilitate more fluent discourse, (2) question and debate conceptual understandings without peers being judgemental, and (3) have multiple opportunities for engaging with materials towards designing, constructing and explaining key concepts learnt. Implications for teachers undertaking STEM education are evident, including outlining expectations for clarifying STEM terms, outlining to students about interacting non-judgementally, and providing multiple opportunities for interacting within engineering education.

Community wide interventions for increasing physical activity (protocol)

This is the protocol for a review and there is no abstract. The objectives are as follows: Primary research objective To determine the effects of community wide, multi-strategic interventions upon community levels of physical activity. Secondary research objectives 1. To explore whether any effects of the intervention are different within and between populations, and whether these differences form an equity gradient. 2. To describe other health (e.g. cardiovascular disease morbidity) and behavioural effects (e.g. diet) where appropriate outcomes are available. 3. To explore the influence of context in the design, delivery, and outcomes of the interventions. 4. To explore the relationship between the number of components, duration, and effects of the interventions. 5. To highlight implications for further research and research methods to improve knowledge of the interventions in relation to the primary research objective.

Front interactions in a three-component system

The three-component reaction-diffusion system introduced in [C. P. Schenk et al., Phys. Rev. Lett., 78 (1997), pp. 3781–3784] has become a paradigm model in pattern formation. It exhibits a rich variety of dynamics of fronts, pulses, and spots. The front and pulse interactions range in type from weak, in which the localized structures interact only through their exponentially small tails, to strong interactions, in which they annihilate or collide and in which all components are far from equilibrium in the domains between the localized structures. Intermediate to these two extremes sits the semistrong interaction regime, in which the activator component of the front is near equilibrium in the intervals between adjacent fronts but both inhibitor components are far from equilibrium there, and hence their concentration profiles drive the front evolution. In this paper, we focus on dynamically evolving N-front solutions in the semistrong regime. The primary result is use of a renormalization group method to rigorously derive the system of N coupled ODEs that governs the positions of the fronts. The operators associated with the linearization about the N-front solutions have N small eigenvalues, and the N-front solutions may be decomposed into a component in the space spanned by the associated eigenfunctions and a component projected onto the complement of this space. This decomposition is carried out iteratively at a sequence of times. The former projections yield the ODEs for the front positions, while the latter projections are associated with remainders that we show stay small in a suitable norm during each iteration of the renormalization group method. Our results also help extend the application of the renormalization group method from the weak interaction regime for which it was initially developed to the semistrong interaction regime. The second set of results that we present is a detailed analysis of this system of ODEs, providing a classification of the possible front interactions in the cases of $N=1,2,3,4$, as well as how front solutions interact with the stationary pulse solutions studied earlier in [A. Doelman, P. van Heijster, and T. J. Kaper, J. Dynam. Differential Equations, 21 (2009), pp. 73–115; P. van Heijster, A. Doelman, and T. J. Kaper, Phys. D, 237 (2008), pp. 3335–3368]. Moreover, we present some results on the general case of N-front interactions.

Physical activity in the lives of those living with lymphoedema following cancer treatment

Background Despite recent evidence demonstrating that exercise neither increases risk of nor exacerbates lymphoedema, lymphoedema prevention and management advice cautions against ‘repetitive use’ or ‘overuse’ of the affected arm. It is plausible that this advice creates a barrier to participation in exercise and, more generally, physical activity (any daily activity [PA]). This study explored the relationship between lymphoedema and PA among people following cancer treatment. Methods Social constructionist grounded theory guided study design, development of interview questions and the qualitative data analysis approach undertaken. Data were collected via focus groups and telephone interviews. Results Five focus groups (n=16 participants) and 13 telephone interviews were completed. Participants (women n=26, men n=3) were aged 39-80 years and were experiencing mild to severe lymphoedema following treatment for a variety of cancers. Participants varied in how they defined PA. Its perceived importance was mostly associated with the ability to partake in daily activities, with only some participants highlighting its importance for lymphoedema management or more general health benefits. Most participants’ PA decreased after diagnosis, a consequence of confusion around appropriate PA and fear that PA could worsen lymphoedema symptoms. Conclusions Lymphoedema guidelines need to be more clear and specific when discussing the role of PA and exercise in the prevention and management of lymphoedema. It may be more appropriate to discuss ways to optimize safety when engaging in specific tasks rather than to highlight the need for avoidance of participating in certain activities.

Physical activity in three regional communities in Queensland

Objective. To describe physical activity participation in three Queensland regional communities. Design. Cross-sectional mail survey of randomly selected residents, stratified by age and sex. Setting. Esk, Mareeba and Mount Isa. Participants. 1219 (58% female) adults, with a mean age 46.7 (SD 14.7) years. Main outcome measures. Proportion of people inactive, meeting Australian activity guidelines (a minimum of 150 minutes/week and 5 sessions/week), and walking a dog daily; time spent walking and cycling for transport; location and type of recreational physical activities. Results. Overall, 18% of respondents were inactive, with the highest proportions among women (22.3%) and older adults in Mount Isa (24.3%). The proportion meeting activity guidelines was 47% with the lowest proportions among women in Mount Isa (40.4%). Although 63% reported owning a dog, only 22% reported walking a dog daily. Few people reported walking or cycling for transport. The most common types of activities were walking, home-based exercise, running/jogging, and swimming, and the most common location was at or near home. Conclusions. Physical activity levels were lower in these regional communities than the state average. The findings indicate a need for physical activity policy and intervention strategies targeting regional and rural areas. This could focus on women and older adults, dog walking, and physical activity opportunities in or near the home.

Pilot study of an individualised early post partum intervention to increase physical activity in women with previous gestational diabetes

Background: Whilst the benefits of physical activity in preventing progression from impaired glucose tolerance to overt diabetes in older adults are well recognised, it is not clear which strategies may prevent progression to overt diabetes in women with recent gestational diabetes. We sought to devise and pilot test a convenient, home based exercise program with telephone support, suited to the early post partum period. Twenty eight women with recent gestational diabetes were enrolled six weeks post partum into a 12 week randomised controlled trial of Usual Care ("UC" Controls (n= 13)) vs. Supported Care ("SC" individualised exercise program with regular telephone support (n= 15)). Findings: Baseline characteristics for the whole cohort at six weeks post partum (Mean ± SD) were Age 33 ± 4 years, Weight 80 ± 20 kg and Body Mass Index (BMI) 30.0 ± 9.7 kg / m2. The primary outcome, planned physical activity, increased by Median (Range) 60 (0-540) mins/wk in the SC group vs. 0 (0-580) mins/wk in the UC group (p = 0.234, Mann Whitney U test). The change in planned physical activity predominantly comprised planned walking. Body weight, BMI, waist circumference, % body fat (measured by bioimpedance), fasting glucose and insulin did not change significantly over time in either group. Conclusions: The intervention designed to increase physical activity in post partum women with previous gestational diabetes was feasible. However, no evidence to suggest that this type of program provides any measurable improvement in metabolic or biometric parameters over a three month post partum follow up was observed.

Social cognitive mediators of the effect of the MobileMums intervention on physical activity

Objective To explore whether improvements in physical activity following the MobileMums intervention were mediated by changes in Social Cognitive Theory (SCT) constructs targeted in the intervention (barrier self efficacy, goal setting skills, outcome expectancy, social support, and perceived environmental opportunity for exercise). This paper also examined if the mediating constructs differed between initial (baseline to 6 weeks) and overall (baseline to 13 weeks) changes in physical activity. Methods Secondary analysis of data from a randomized controlled trial involving 88 postnatal women (<12 months postpartum). Participants were randomized to receive either the 12-week MobileMums intervention or a minimal-contact control condition. Physical activity and proposed mediators were assessed by self-report at baseline, 6 weeks, and 13 weeks. Walking for Exercise frequency was assessed using the Australian Women's Activity Survey and frequency of moderate-to-vigorous physical activity (MVPA) was assessed using a single-item question. Results Initial improvements in goal-setting skills mediated the relationship between experimental condition and initial changes in MVPA, αβ (95% CI) = 0.23(0.01, 0.59), and Walking for Exercise, αβ (95% CI) = 0.34(0.06, 0.73). Initial improvements in barrier self efficacy mediated the relationship between experimental condition and initial change in MVPA, αβ (95% CI) = 0.36(0.12, 0.65), but not Walking for Exercise. None of the SCT outcomes significantly mediated the relationship between experimental condition and overall (baseline to 13 weeks) change in frequency of MVPA or Walking for Exercise. Conclusion Future interventions with postnatal women using SCT should target barrier self-efficacy and goal setting skills in order to increase physical activity. (PsycINFO Database Record (c) 2012 APA, all rights reserved)

How do older adults respond to Active Australia physical activity questions? Lessons from cognitive interviews

The aim of this study was to examine older adults’ understanding and interpretation of a validated questionnaire for physical activity surveillance, the Active Australia Survey (AAS). To address this aim, cognitive interviewing techniques were used during face-to-face semi-structured interviews with 44 adults aged 65-89 years. Qualitative data analysis revealed that participants were confused with questionnaire phrasing, misunderstood the scope of activities to include in answers, and misunderstood the time frame of activities to report. They also struggled to accurately estimate the frequency and duration of their activities. Our findings suggest that AAS questions may be interpreted differently by older adults than intended by survey developers. Findings also suggest that older adults use a range of methods for calculating PA frequency and duration. The issues revealed in this study may be useful for adapting AAS for use in older community-dwelling adults.

Solo life to Second Life : the design of physical and virtual learning spaces inspired by the drama classroom

This paper explores the design of virtual and physical learning spaces developed for students of drama and theatre studies. What can we learn from the traditional drama workshop that will inform the design of drama and theatre spaces created in technology-mediated learning environments? The authors examine four examples of spaces created for online, distance and on-campus students and discuss the relationship between the choice of technology, the learning and teaching methods, and the outcomes for student engagement. Combining insights from two previous action research projects, the discussion focuses on the physical space used for contemporary drama workshops, supplemented by Web 2.0 technologies; a modular online theatre studies course; the blogging space of students creating a group devised play; and the open and immersive world of Second Life, where students explore 3D simulations of historical theatre sites. The authors argue that the drama workshop can be used as inspiration for the design of successful online classrooms. This is achieved by focusing on students’ contributions to the learning as individuals and group members, the aesthetics and mise-en-scene of the learning space, and the role of mobile and networked technologies. Students in this environment increase their capacity to become co-creators of knowledge and to achieve creative outcomes. The drama workshop space in its physical and virtual forms is seen as a model for classrooms in other disciplines, where dynamic, creative and collaborative spaces are required.

Eat Cook Grow : Mixing Human-Computer Interactions with Human-Food Interactions

Food has been a major agenda in political, socio-cultural, and environmental domains throughout history. The significance of food has been particularly highlighted in recent years with the growing public awareness of the unfolding impacts of climate change, challenging our understanding, practice, and expectations of our relationship with food. Parallel to this development has been the rise of web applications such as blogs, wikis, video and photo sharing sites, and social networking systems that are arguably more open, collaborative, and personalisable. These so-called ‘Web 2.0’ technologies have contributed to a more participatory Internet experience than what had previously been possible. An increasing number of these social applications are now available on mobile technologies where they take advantage of device-specific features such as sensors, location and context awareness, further expanding potential for the culture of participation and creativity. This international volume assembles a diverse collection of book chapters that contribute towards exploring and better understanding the opportunities and challenges provided by tools, interfaces, methods, and practices of social and mobile technology to enable engagement with people and creativity in the domain of food in contemporary society. It brings together an international group of academics and practitioners from a diverse range of disciplines such as computing and engineering, social sciences, digital media and human-computer interaction to critically examine a range of applications of social and mobile technology, such as social networking, mobile interaction, wikis, twitter, blogging, mapping, shared displays and urban screens, and their impact to foster a better understanding and practice of environmentally, socio-culturally, economically, and health-wise sustainable food culture.