278,386 research outputs found
From Equivalence Principles to Cosmology: Cosmic Polarization Rotation, CMB Observation, Neutrino Number Asymmetry, Lorentz Invariance and CPT
In this paper, we review the approach leading to cosmic polarization rotation
observation and present the current status with an outlook. In the study of the
relations among equivalence principles, we found that long-range
pseudoscalar-photon interaction is allowed. Pseudoscalar-photon interaction
would induce a rotation of linear polarization of electromagnetic wave
propagating with cosmological/astrophysical distance. In 2002, DASI
successfully observed the polarization of the cosmological microwave background
radiation. In 2003, WMAP observed the correlation of polarization with
temperature anisotropy at more than 10 sigma in the cosmological microwave
background. From this high polarization-temperature correlation in WMAP
observation, we put a limit of 0.1 rad on the rotation of linear polarization
of cosmological microwave background (CMB) propagation. Pseudoscalar-photon
interaction is proportional to the gradient of the pseudoscalar field. From
phenomenological point of view, this gradient could be neutrino number
asymmetry current, other density current, or a constant vector. In these
situations, Lorentz invariance or CPT may or may not effectively be violated.
In this paper, we review and compile various results. Better accuracy in CMB
polarization observation is expected from PLANCK mission to be launched next
year. A dedicated CMB polarization observer in the future would probe this
fundamental issue more deeply.Comment: 9 pages, 2 figures, a few references with corresponding text change
added in this version, invited talk given in VIII Asia-Pacific International
Conference on Gravitation and Astophysics (ICGA8), August 29 - September 1,
2007, Nara Women's University, Japan, submitted to Progress of Theoretical
Physics Supplemen
The Relationship between Teachers\u27 Interaction Strategies and Student Oral Involvement
A lot of research has focused on exploring reasons for and solutions to Asian studentsâ reticence in speaking. It is found that their unwillingness to speak is affected not only by the students themselves but also by the situations they are placed in. However, there is still space to explore how teachers use interaction strategies to enhance studentsâ speaking involvement, especially in Vietnam. This paper examines the relationship between teacher interaction strategies and student oral involvement. The data were collected via audio-recording and class observation. Five experienced teachers and their respective classes at a center for foreign languages were invited to participate in the study. The data were analyzed qualitatively based on the three interaction strategies proposed by Lee and Ng (2010). The findings show that three types of interaction strategies were used by the teachers in the classroom and had a positive effect on student oral involvement. The extent to which students are involved orally in response to these strategies was discrepant. More importantly, there are others elements related to pedagogical factors such as lesson objectives, task type, activities used, classroom management and the proficiency level of the students which were also identified to impact a teacherâs interaction strategy decision making
âWhatâs it like to have ME?â The discursive construction of ME in computer-mediated communication and face-to-face interaction
ME/CFS (chronic fatigue syndrome) is a debilitating illness for which no cause or medical tests have been identified. Debates over its nature have generated interest from qualitative researchers. However, participants are difficult to recruit because of the nature of their condition. Therefore, this study explores the utility of the internet as a means of eliciting accounts. We analyse data from focus groups and the internet in order to ascertain the extent to which previous research findings apply to the internet domain. Interviews were conducted among 49 members of internet (38 chatline, 11 personal) and 7 members of two face-to-face support groups. Discourse analysis of descriptions and accounts of ME/CFS revealed similar devices and interactional concerns in both internet and face-to-face communication. Participants constructed their condition as serious, enigmatic and not psychological. These functioned to deflect problematic assumptions about ME/CFS and to manage their accountability for the illness and its effects
Introduction: The Fourth International Workshop on Epigenetic Robotics
As in the previous editions, this workshop is trying to be a forum for multi-disciplinary research ranging from developmental psychology to neural sciences (in its widest sense) and robotics including computational studies. This is a two-fold aim of, on the one hand, understanding the brain through engineering embodied systems and, on the other hand, building artificial epigenetic systems. Epigenetic contains in its meaning the idea that we are interested in studying development through interaction with the environment. This idea entails the embodiment of the system, the situatedness in the environment, and of course a prolonged period of postnatal development when this interaction can actually take place. This is still a relatively new endeavor although the seeds of the developmental robotics community were already in the air since the nineties (Berthouze and Kuniyoshi, 1998; Metta et al., 1999; Brooks et al., 1999; Breazeal, 2000; Kozima and Zlatev, 2000). A few had the intuition â see Lungarella et al. (2003) for a comprehensive review â that, intelligence could not be possibly engineered simply by copying systems that are âready madeâ but rather that the development of the system fills a major role. This integration of disciplines raises the important issue of learning on the multiple scales of developmental time, that is, how to build systems that eventually can learn in any environment rather than program them for a specific environment. On the other hand, the hope is that robotics might become a new tool for brain science similarly to what simulation and modeling have become for the study of the motor system. Our community is still pretty much evolving and âunder constructionâ and for this reason, we tried to encourage submissions from the psychology community. Additionally, we invited four neuroscientists and no roboticists for the keynote lectures. We received a record number of submissions (more than 50), and given the overall size and duration of the workshop together with our desire to maintain a single-track format, we had to be more selective than ever in the review process (a 20% acceptance rate on full papers). This is, if not an index of quality, at least an index of the interest that gravitates around this still new discipline
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Technology - Empowering the Educational Researcher through Remote Observation
Observing students using computers often occurs through three methods: user-lab, on-site and remote data logging. Whilst each of these have their advantages with the new type of students such as elearners, an alternative method called web-conferencing remote observation is presented for observing students at a distance. This method collects both audio and video data of the observer through webcams and voice/video conversations. Students are able to interact with the software through application sharing facilities. Further, it allows both quantitative and qualitative data to be collected. This proof-of-concept method is presented here where it has been used in two previous studies using Windows Messenger and Netviewer. Although, video quality is not high the quality is sufficient for observational data
Reflecting in and on post-observation feedback in initial teacher training on certificate courses
This article examines evidence from two studies that concern the nature of post-observation feedback in certificate courses for teaching English to speakers of other languages. It uncovers the main characteristics of these meetings and asks whether there is evidence of reflection in these contexts. In considering reasons why making space for reflection is potentially difficult, the paper also examines the relationship and the role of assessment criteria and how these may impact on opportunities for reflection. The final part of the paper considers how a more reflective approach could be promoted in feedback conferences
The Lifecycle and Cascade of WeChat Social Messaging Groups
Social instant messaging services are emerging as a transformative form with
which people connect, communicate with friends in their daily life - they
catalyze the formation of social groups, and they bring people stronger sense
of community and connection. However, research community still knows little
about the formation and evolution of groups in the context of social messaging
- their lifecycles, the change in their underlying structures over time, and
the diffusion processes by which they develop new members. In this paper, we
analyze the daily usage logs from WeChat group messaging platform - the largest
standalone messaging communication service in China - with the goal of
understanding the processes by which social messaging groups come together,
grow new members, and evolve over time. Specifically, we discover a strong
dichotomy among groups in terms of their lifecycle, and develop a separability
model by taking into account a broad range of group-level features, showing
that long-term and short-term groups are inherently distinct. We also found
that the lifecycle of messaging groups is largely dependent on their social
roles and functions in users' daily social experiences and specific purposes.
Given the strong separability between the long-term and short-term groups, we
further address the problem concerning the early prediction of successful
communities. In addition to modeling the growth and evolution from group-level
perspective, we investigate the individual-level attributes of group members
and study the diffusion process by which groups gain new members. By
considering members' historical engagement behavior as well as the local social
network structure that they embedded in, we develop a membership cascade model
and demonstrate the effectiveness by achieving AUC of 95.31% in predicting
inviter, and an AUC of 98.66% in predicting invitee.Comment: 10 pages, 8 figures, to appear in proceedings of the 25th
International World Wide Web Conference (WWW 2016
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