159,908 research outputs found
Black Holes and Vacuum Cleaners: Using Metaphor, Relevance, and Inquiry in Labels for Space Images
This study extended research on the development of explanatory labels for
astronomical images for the non-expert lay public. The research questions
addressed how labels with leading questions/metaphors and relevance to everyday
life affect comprehension of the intended message for deep space images, the
desire to learn more, and the aesthetic appreciation of images. Participants
were a convenience sample of 1,921 respondents solicited from a variety of
websites and through social media who completed an online survey that used four
high-resolution images as stimuli: Sagittarius A*, Solar Flare, Cassiopeia A,
and the Pinwheel Galaxy (M101). Participants were randomly assigned initially
to 1 of 3 label conditions: the standard label originally written for the
image, a label with a leading question containing a metaphor related to the
information for the image, or a label that contained a fact about the image
relevant to everyday life. Participants were randomly assigned to 1 image and
compared all labels for that image. Open-ended items at various points asked
participants to pose questions to a hypothetical astronomer. Main findings were
that the relevance condition was significantly more likely to increase wanting
to learn more; the original label was most likely to increase overall
appreciation; and, smart phone users were more likely to want to learn more and
report increased levels of appreciation. Results are discussed in terms of the
need to examine individual viewer characteristics and goals in creating
different labels for different audiences.Comment: 50 pages, 7 tables, 2 figures, accepted by the journal "Psychology of
Aesthetics, Creativity, and the Arts
Laboratory studies of atomic collision processes of importance in planetary atmospheres
Progress in the following research supported under NSG 7386 is reported: (1) measurement of differential cross sections for atomic and molecular collisions relevant to analysis and modeling of data from Pioneer 11, Pioneer 12, Voyager 1, and Voyager 2; (2) analysis of measured differential cross section results to provide scattering data in forms that are easy to apply to atmospheric modeling work; (3) analysis of the data to give basic information on the molecular potentials involved in the scattering process; and (4) development and initial use of apparatus to study dissociative processes in neutral molecules
Water vapor diffusion membranes
The program is reported, which was designed to define the membrane technology of the vapor diffusion water recovery process and to test this technology using commercially available or experimental membranes. One membrane was selected, on the basis of the defined technology, and was subjected to a 30-day demonstration trial
Laboratory studies of atomic collision processes of importance in planetary atmospheres
A series of differential cross sections for angular scattering and charge transfer was measured. These studies employ position-sensitive detectors (PSD's) to collect collision products scattered over a wide range of angles; and the research program includes investigation of differential cross sections for total angular scattering, charge transfer, stripping, and other collisions. All of these processes can be studied with the same basic apparatus, but minor modifications in the equipment details and in the data acquisition programs and techniques are required for each individual experiment
Uncertainty in Soft Temporal Constraint Problems:A General Framework and Controllability Algorithms forThe Fuzzy Case
In real-life temporal scenarios, uncertainty and preferences are often
essential and coexisting aspects. We present a formalism where quantitative
temporal constraints with both preferences and uncertainty can be defined. We
show how three classical notions of controllability (that is, strong, weak, and
dynamic), which have been developed for uncertain temporal problems, can be
generalized to handle preferences as well. After defining this general
framework, we focus on problems where preferences follow the fuzzy approach,
and with properties that assure tractability. For such problems, we propose
algorithms to check the presence of the controllability properties. In
particular, we show that in such a setting dealing simultaneously with
preferences and uncertainty does not increase the complexity of controllability
testing. We also develop a dynamic execution algorithm, of polynomial
complexity, that produces temporal plans under uncertainty that are optimal
with respect to fuzzy preferences
A correlation of optical, radio, and interplanetary records of solar events Final report
Correlation of optical, radio, and interplanetary records of solar event
Balancing antagonistic time and resource utilization constraints in over-subscribed scheduling problems
In this paper, we report work aimed at applying concepts of constraint-based problem structuring and multi-perspective scheduling to an over-subscribed scheduling problem. Previous research has demonstrated the utility of these concepts as a means for effectively balancing conflicting objectives in constraint-relaxable scheduling problems, and our goal here is to provide evidence of their similar potential in the context of HST observation scheduling. To this end, we define and experimentally assess the performance of two time-bounded heuristic scheduling strategies in balancing the tradeoff between resource setup time minimization and satisfaction of absolute time constraints. The first strategy considered is motivated by dispatch-based manufacturing scheduling research, and employs a problem decomposition that concentrates local search on minimizing resource idle time due to setup activities. The second is motivated by research in opportunistic scheduling and advocates a problem decomposition that focuses attention on the goal activities that have the tightest temporal constraints. Analysis of experimental results gives evidence of differential superiority on the part of each strategy in different problem solving circumstances. A composite strategy based on recognition of characteristics of the current problem solving state is then defined and tested to illustrate the potential benefits of constraint-based problem structuring and multi-perspective scheduling in over-subscribe scheduling problems
T Tauri variability in the context of the beat-frequency model
We examine the implications of a beat frequency modulated model of T Tauri
accretion. In particular we show that measurements of the variability of
accretion generated lines can be used in conjunction with existing photometry
to obtain a measurement of the underlying photospheric and disc flux. This
provides an independent way of checking spectral energy distribution modelling.
In addition, we show how spectroscopy of T Tauri stars can reveal the
inclination angle between the magnetic axis and the plane of the disc.Comment: uuencoded compressed postscript. The preprint is also available at
http://www.ast.cam.ac.uk/preprint/PrePrint.htm
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