13,268 research outputs found
Dual arm master controller development
The advanced servomanipulator (ASM) slave was designed with an anthropomorphic stance gear/torque tube power drives, and modular construction. These features resulted in increased inertia, friction, and backlash relative to tape driven manipulators. Studies were performed which addressed to human factor design and performance tradeoffs associated with the corresponding master controller best suited for the ASM. The results of these studies, as well as the conceptual design of the dual arm master controller, are presented
A simplified instrument for recording and indicating frequency and intensity of icing conditions encountered in flight
Mapping the dynamic interactions between vortex species in highly anisotropic superconductors
Here we use highly sensitive magnetisation measurements performed using a
Hall probe sensor on single crystals of highly anisotropic high temperature
superconductors to study the dynamic interactions
between the two species of vortices that exist in such superconductors. We
observe a remarkable and clearly delineated high temperature regime that
mirrors the underlying vortex phase diagram. Our results map out the parameter
space over which these dynamic interaction processes can be used to create
vortex ratchets, pumps and other fluxonic devices.Comment: 7 pages, 3 figures, to be published in Supercond. Sci. Techno
Stochastic fictitious play with continuous action sets
Continuous action space games are ubiquitous in economics. However, whilst learning dynamics in normal form games with finite action sets are now well studied, it is not until recently that their continuous action space counterparts have been examined. We extend stochastic fictitious play to the continuous action space framework. In normal form games with finite action sets the limiting behaviour of a discrete time learning process is often studied using its continuous time counterpart via stochastic approximation. In this paper we study stochastic fictitious play in games with continuous action spaces using the same method. This requires the asymptotic pseudo-trajectory approach to stochastic approximation to be extended to Banach spaces. In particular the limiting behaviour of stochastic fictitious play is studied using the associated smooth best response dynamics on the space of finite signed measures. Using this approach, stochastic fictitious play is shown to converge to an equilibrium point in two-player zero-sum games and a stochastic fictitious play-like process is shown to converge to an equilibrium in negative definite single population games
Assessing the Effectiveness of a Computer Simulation in Introductory Undergraduate Environments
We present studies documenting the effectiveness of using a computer simulation, specifically the Circuit Construction Kit (CCK) developed as part of the Physics Education Technology Project (PhET) [1, 2], in two environments: an interactive college lecture and an inquiry-based laboratory. In the first study conducted in lecture, we compared students viewing CCK to viewing a traditional demonstration during Peer Instruction [3]. Students viewing CCK had a 47% larger relative gain (11% absolute gain) on measures of conceptual understanding compared to traditional demonstrations. These results led us to study the impact of the simulation's explicit representation for visualizing current flow in a laboratory environment, where we removed this feature for a subset of students. Students using CCK with or without the explicit visualization of current performed similarly to each other on common exam questions. Although the majority of students in both groups favored the use of CCK over real circuit equipment, the students who used CCK without the explicit current model favored the simulation more than the other grou
Development of quantum perspectives in modern physics
Introductory undergraduate courses in classical physics stress a perspective
that can be characterized as realist; from this perspective, all physical
properties of a classical system can be simultaneously specified and thus
determined at all future times. Such a perspective can be problematic for
introductory quantum physics students, who must develop new perspectives in
order to properly interpret what it means to have knowledge of quantum systems.
We document this evolution in student thinking in part through pre- and
post-instruction evaluations using the Colorado Learning Attitudes about
Science Survey. We further characterize variations in student epistemic and
ontological commitments by examining responses to two essay questions, coupled
with responses to supplemental quantum attitude statements. We find that, after
instruction in modern physics, many students are still exhibiting a realist
perspective in contexts where a quantum-mechanical perspective is needed. We
further find that this effect can be significantly influenced by instruction,
where we observe variations for courses with differing learning goals. We also
note that students generally do not employ either a realist or a quantum
perspective in a consistent manner.Comment: 18 pages, plus references; 3 figures; 9 tables. PACS: 01.40.Fk,
03.65._
Learning to facilitate arts-in-health programmes: a case study of musicians facilitating creative interventions for mothers with symptoms of postnatal depression
There is growing research documenting the effects of arts-in-health interventions on diverse participant groups. However, the impact of interventions on facilitators remains largely lacking. Drawing on a case study project, this article reports on a qualitative study to understand the practices, challenges, enablers and impacts for musicians of facilitating creative interventions for women with symptoms of postnatal depression. Thematic analysis revealed that the musicians used specific practices to successfully facilitate their activities, relying on a balance of forward-planning with the need to retain flexibility and provide women with autonomy and opportunities for social bonding. Key challenges included coping with the emotional impact of the project as well as facilitating different types of creative activities, while a strong sense of team and the structure of the interventions supported delivery. Finally, the project enabled the development of both generic and context-specific creative facilitation skills, and also contributed to the facilitators’ wellbeing. The logistical, educational and support implications for other practitioners seeking to establish such interventions are considered within the context of arts-in-health and musicians’ education
How group singing facilitates recovery from the symptoms of postnatal depression: a comparative qualitative study
Background: Previous research has demonstrated that making music can enhance positive emotions as well as support positive psychological functioning. However, studies tend to be limited by lack of comparison with other psychosocial interventions. This study builds on a three-arm randomised controlled trial (RCT) that demonstrated that group singing for mothers and babies, but not group creative play, can lead to faster recovery from moderate-severe symptoms of postnatal depression than usual care. The aim was to elucidate the mechanisms of the group singing intervention in order to account for its recovery properties.
Methods: Qualitative research was conducted with 54 mothers who had experienced symptoms of postnatal depression. Mothers completed a 10-week programme of either group singing or group creative play as part of the wider RCT study. Data were collected via a series of 10 semi-structured focus groups conducted at the end of each 10-week programme. These were designed to elicit subjective and constructed experiences of the singing and play interventions and were analysed inductively for emergent themes.
Results: Five distinctive features of the group singing emerged: (i) providing an authentic, social and multicultural creative experience, (ii) ability to calm babies; (iii) providing immersive ‘me time’ for mothers; (iv) facilitating a sense of achievement and identity; (v) enhancing mother-infant bond.
Conclusions: Community group singing interventions may reduce symptoms of postnatal depression through facilitating a functional emotional response rooted in the needs of new motherhood. These features are of relevance to others seeking to implement creative interventions for maternal mental health.
Trial registration: NCT02526407. Registered 18 August 2015
Correlating Student Beliefs With Student Learning Using The Colorado Learning Attitudes about Science Survey
A number of instruments have been designed to probe the variety of attitudes, beliefs, expectations, and epistemological frames taught in our introductory physics courses. Using a newly developed instrument -- the Colorado Learning Attitudes about Science Survey (CLASS)[1] -- we examine the relationship between students' beliefs about physics and other educational outcomes, such as conceptual learning and student retention. We report results from surveys of over 750 students in a variety of courses, including several courses modified to promote favorable beliefs about physics. We find positive correlations between particular student beliefs and conceptual learning gains, and between student retention and favorable beliefs in select categories. We also note the influence of teaching practices on student beliefs
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