Machinima interventions: innovative approaches to immersive virtual world curriculum integration

The educational value of Immersive Virtual Worlds (IVWs) seems to be in their social immersive qualities and as an accessible simulation technology. In contrast to these synchronous applications this paper discusses the use of educational machinima developed in IVW virtual film sets. It also introduces the concept of media intervention, proposing that digital media works best when simply developed for deployment within a blended curriculum to inform learning activity, and where the media are specifically designed to set challenges, seed ideas, or illustrate problems. Machinima, digital films created in IVWs, or digital games offer a rich mechanism for delivering such interventions. Scenes are storyboarded, constructed, shot and edited using techniques similar to professional film production, drawing upon a cast of virtual world avatars controlled through a human–computer interface, rather than showing real‐life actors. The approach enables academics or students to make films using screen capture software and desktop editing tools. In student‐generated production models the learning value may be found in the production process itself. This paper discusses six case studies and several themes from research on ideas for educational machinima including: access to production; creativity in teaching and learning; media intervention methodology; production models; reusability; visualisation and simulation

Stabilization over power-constrained parallel Gaussian channels

This technical note is concerned with state-feedback stabilization of multi-input systems over parallel Gaussian channels subject to a total power constraint. Both continuous-time and discrete-time systems are treated under the framework of H2 control, and necessary/sufficient conditions for stabilizability are established in terms of inequalities involving unstable plant poles, transmitted power, and noise variances. These results are further used to clarify the relationship between channel capacity and stabilizability. Compared to single-input systems, a range of technical issues arise. In particular, in the multi-input case, the optimal controller has a separation structure, and the lower bound on channel capacity for some discrete-time systems is unachievable by linear time-invariant (LTI) encoders/decoder

Replicability of data collected for empirical estimation of relative pollen productivity

The effects of repeated survey and fieldwork timing on data derived from a recently proposed standard field methodology for empirical estimation of relative pollen productivity (RPP) have been tested. Seasonal variations in vegetation and associated pollen assemblages were studied in three contrasting cultural habitat types; semi-natural ancient woodlands, lowland heaths, and unimproved, traditionally managed hay meadows. Results show that in woodlands and heathlands the standard method generates vegetation data with a reasonable degree of similarity throughout the field season, though in some instances additional recording of woodland canopy cover should be undertaken, and differences were greater for woodland understorey taxa than for arboreal taxa. Large differences in vegetation cover were observed over the field season in the grassland community, and matching the phenological timing of surveys within and between studies is clearly important if RPP estimates from these sites are to be comparable. Pollen assemblages from closely co-located moss polsters collected on different visits are shown to be variable in all communities, to a greater degree than can be explained by the sampling error associated with pollen counting, and further study of moss polsters as pollen traps is recommended

Integral control of port-Hamiltonian systems: non-passive outputs without coordinate transformation

In this paper we present a method for the addition of integral action to non-passive outputs of a class of port-Hamiltonian systems. The proposed integral controller is a dynamic extension, constructed from the open loop system, such that the closed loop preserves the port-Hamiltonian form. It is shown that the controller is able to reject the effects of both matched and unmatched disturbances, preserving the regulation of the non-passive outputs. Previous solutions to this problem have relied on a change of coordinates whereas the presented solution is developed using the original state vector and, therefore, retains its physical interpretation. In addition, the resulting closed loop dynamics have a natural interpretation as a Control by Interconnection scheme.Comment: 8 pages, 2 figure

Large-signal stability conditions for semi-quasi-Z-source inverters: switched and averaged models

The recently introduced semi-quasi-Z-source in- verter can be interpreted as a DC-DC converter whose input- output voltage gain may take any value between minus infinity and 1 depending on the applied duty cycle. In order to generate a sinusoidal voltage waveform at the output of this converter, a time-varying duty cycle needs to be applied. Application of a time-varying duty cycle that produces large-signal behavior requires careful consideration of stability issues. This paper provides stability results for both the large-signal averaged and the switched models of the semi-quasi-Z-source inverter operating in continuous conduction mode. We show that if the load is linear and purely resistive then the boundedness and ultimate boundedness of the state trajectories is guaranteed provided some reasonable operation conditions are ensured. These conditions amount to keeping the duty cycle away from the extreme values 0 or 1 (averaged and switched models), and limiting the maximum PWM switching period (switched model). The results obtained can be used to give theoretical justification to the inverter operation strategy recently proposed by Cao et al. in [1].Comment: Submitted to the IEEE Conf. on Decision and Control, Florence, Italy, 201

The Musical Significance of Pop

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A qualitative exploration of social motivational influences in determining the physical activity of 30–60 year old adults

Introduction: Adults over 60–65 years old are a group considered vulnerable to the risks of sedentary lifestyle causing decreased quality of life and poor health. Australian government figures estimate the number of over 65s will reach 8.1 million by 2056, and 11.2 million by 2101. One key opportunity to prevent sedentary lifestyles in older adults is to understand and promote motivation towards physical activity in middle-aged adults. This study qualitatively examined the motivationally relevant behaviours (‘motivational atmosphere’) of key social agents towards physical activity and sedentary lifestyles in adults between 30 and 60 years of age. Methodology: Twenty participants (32–60 years old) of varying activity levels were recruited from local workplaces and a GP referral scheme. Participants took part in semi-structured interviews to examine which social agents affected their motivation towards PA and how/why. A critical rationalist philosophy was deployed in the gathering and analysis of data. Results: Using inductive content analysis, 307 raw themes were coded into 38 categories and five higher dimensions, labelled: (1) providing information and impetus; (2) supporting progress and competence; (3) affiliation and belongingness; (4) logistical considerations; and (5) emotional support. Spouses, close family, work colleagues, GPs and the media were perceived to be highly influential social agents, with many others listed (e.g., personal trainers, local government). Whilst spouses, family and work colleagues influenced motivation through ‘leading-by-example’, ‘reminding/persuading’ and ‘support/encouragement’, GPs and the media were more likely to exert an influence by offering advice, guidance and recommendations, or in some cases ‘sounding-the-alarm-bell’. The consistency of messages from these different agents (media, health professionals, friends/family) was also noted as a key determinant of attitudes and actions. Whilst health was often central to participants’ responses, social interactions and friendships were also key reasons people gave for becoming or staying active (and for being sedentary). Further, there was preliminary evidence that the sources and types of influence changed as a function of current activity level. Conclusion: The results facilitate future interventions by suggesting specific behavioural recommendations in relation to known social agents, as well as guiding theoretical development/ refinement. The findings suggest that interventions should encompass psychological and social as-well-as health considerations, and that health professionals must understand the ‘motivational atmosphere’ of each client. Finally, the findings suggest that future research and modelling should adopt methodologies that better address the complexity inherent in the social determination of motivation