1,276 research outputs found
Quantum marking and quantum erasure for neutral kaons
Entangled K0 anti-K0 pairs are shown to be suitable to discuss extensions and
tests of Bohr's complementarity principle through the quantum marking and
quantum erasure techniques suggested by M. O. Scully and K. Druehl [Phys. Rev.
A 25, 2208 (1982)]. Strangeness oscillations play the role of the traditional
interference pattern linked to wave-like behaviour, whereas the distinct
propagation in free space of the K_S and K_L components mimics the two possible
interferometric paths taken by particle-like objects.Comment: 4 RevTeX page
Does Social Presence or the Potential for Interaction reduce Social Gaze in Online Social Scenarios? Introducing the "Live Lab" paradigm.
Research has shown that people’s gaze is biased away from faces in the real-world but
towards them when they are viewed onscreen. Non-equivalent stimulus conditions may have
represented a confound in this research however, as participants viewed onscreen stimuli as
pre-recordings where interaction was not possible, compared to real-world stimuli which
were viewed in real-time where interaction was possible. We assessed the independent
contributions of online social presence and ability for interaction on social gaze by
developing the “live lab” paradigm. Participants in three groups (N = 132) viewed a
confederate either as a) a live webcam stream where interaction was not possible (one-way),
b) a live webcam stream where an interaction was possible (two-way) or c) as a prerecording.
Potential for interaction, rather than online social presence, was the primary
influence on gaze behaviour: Participants in the pre-recorded and one-way conditions looked
more to the face than those in the two-way condition, particularly when the confederate made
“eye contact”. Fixation durations to the face were shorter when the scene was viewed live,
particularly during a bid for eye contact
Our findings support the dual function of gaze, but suggest that online social presence alone
is not sufficient to activate social norms of civil inattention. Implications for the
reinterpretation of previous research are discussed
A Delayed Choice Quantum Eraser
This paper reports a "delayed choice quantum eraser" experiment proposed by
Scully and Dr\"{u}hl in 1982. The experimental results demonstrated the
possibility of simultaneously observing both particle-like and wave-like
behavior of a quantum via quantum entanglement. The which-path or both-path
information of a quantum can be erased or marked by its entangled twin even
after the registration of the quantum.Comment: twocolumn, 4pages, submitted to PR
Seeing two faces together: preference formation in humans and rhesus macaques
Humans, great apes and old world monkeys show selective attention to faces depending on conspecificity, familiarity, and social status supporting the view that primates share similar face processing mechanisms. Although many studies have been done on face scanning strategy in monkeys and humans, the mechanisms influencing viewing preference have received little attention. To determine how face categories influence viewing preference in humans and rhesus macaques (Macaca mulatta), we performed two eye-tracking experiments using a visual preference task whereby pairs of faces from different species were presented simultaneously. The results indicated that viewing time was significantly influenced by the pairing of the face categories. Humans showed a strong bias towards an own-race face in an Asian–Caucasian condition. Rhesus macaques directed more attention towards non-human primate faces when they were paired with human faces, regardless of the species. When rhesus faces were paired with faces from Barbary macaques
(Macaca sylvanus) or chimpanzees (Pan troglodytes), the novel species’ faces attracted more attention. These results
indicate that monkeys’ viewing preferences, as assessed by a visual preference task, are modulated by several factors,
species and dominance being the most influential
Afshar's Experiment does not show a Violation of Complementarity
A recent experiment performed by S. Afshar [first reported by M. Chown, New
Scientist {\bf 183}, 30 (2004)] is analyzed. It was claimed that this
experiment could be interpreted as a demonstration of a violation of the
principle of complementarity in quantum mechanics. Instead, it is shown here
that it can be understood in terms of classical wave optics and the standard
interpretation of quantum mechanics. Its performance is quantified and it is
concluded that the experiment is suboptimal in the sense that it does not fully
exhaust the limits imposed by quantum mechanics.Comment: 6 pages, 6 figure
Observation of off-diagonal geometric phase in polarized neutron interferometer experiments
Off-diagonal geometric phases acquired in the evolution of a spin-1/2 system
have been investigated by means of a polarized neutron interferometer. Final
counts with and without polarization analysis enable us to observe
simultaneously the off-diagonal and diagonal geometric phases in two detectors.
We have quantitatively measured the off-diagonal geometric phase for noncyclic
evolutions, confirming the theoretical predictions. We discuss the significance
of our experiment in terms of geometric phases (both diagonal and off-diagonal)
and in terms of the quantum erasing phenomenon.Comment: pdf, 22 pages + 8 figures (included in the pdf). In print on Phys.
Rev.
Exploring the measurement of markedness and its relationship with other linguistic variables
Antonym pair members can be differentiated by each word's markedness-that distinction attributable to the presence or absence of features at morphological or semantic levels. Morphologically marked words incorporate their unmarked counterpart with additional morphs (e.g., "unlucky" vs. "lucky"); properties used to determine semantically marked words (e.g., "short" vs. "long") are less clearly defined. Despite extensive theoretical scrutiny, the lexical properties of markedness have received scant empirical study. The current paper employs an antonym sequencing approach to measure markedness: establishing markedness probabilities for individual words and evaluating their relationship with other lexical properties (e.g., length, frequency, valence). Regression analyses reveal that markedness probability is, as predicted, related to affixation and also strongly related to valence. Our results support the suggestion that antonym sequence is reflected in discourse, and further analysis demonstrates that markedness probabilities, derived from the antonym sequencing task, reflect the ordering of antonyms within natural language. In line with the Pollyanna Hypothesis, we argue that markedness is closely related to valence; language users demonstrate a tendency to present words evaluated positively ahead of those evaluated negatively if given the choice. Future research should consider the relationship of markedness and valence, and the influence of contextual information in determining which member of an antonym pair is marked or unmarked within discourse
Identifying predictors of attitudes towards local onshore wind development with reference to an English case study
The threats posed by climate change are placing governments under increasing pressure to meet electricity demand from low-carbon sources. In many countries, including the UK, legislation is in place to ensure the continued expansion of renewable energy capacity. Onshore wind turbines are expected to play a key role in achieving these aims. However, despite high levels of public support for onshore wind development in principle, specific projects often experience local opposition. Traditionally this difference in general and specific attitudes has been attributed to NIMBYism (not in my back yard), but evidence is increasingly calling this assumption into question. This study used multiple regression analysis to identify what factors might predict attitudes towards mooted wind development in Sheffield, England. We report on the attitudes of two groups; one group (target) living close to four sites earmarked for development and an unaffected comparison group (comparison). We found little evidence of NIMBYism amongst members of the target group; instead, differences between general and specific attitudes appeared attributable to uncertainty regarding the proposals. The results are discussed with respect to literature highlighting the importance of early, continued and responsive community involvement in combating local opposition and facilitating the deployment of onshore wind turbines. (C) 2009 Elsevier Ltd. All rights reserved
- …