696 research outputs found
Robustness of Reliability Predictions for a Series System of Identical Components
Robustness of reliability predictions for series systems with identical components, assuming exponential failure distributio
GEOS-3 ocean current investigation using radar altimeter profiling
Both quasi-stationary and dynamic departures from the marine geoid were successfully detected using altitude measurements from the GEOS-3 radar altimeter. The quasi-stationary departures are observed either as elevation changes in single pass profiles across the Gulf Stream or at the crowding of contour lines at the western and northern areas of topographic maps generated using altimeter data spanning one month or longer. Dynamic features such as current meandering and spawned eddies can be monitored by comparing monthly mean maps. Comparison of altimeter inferred eddies with IR detected thermal rings indicates agreement of the two techniques. Estimates of current velocity are made using derived slope estimates in conjunction with the geostrophic equation
Evaluating two different dose frequencies and cumulative intervention intensities to improve past tense production for early school-aged children with developmental language disorder
Aims: This study compared two dose frequency conditions of an explicit intervention with 50 trials per session designed to improve past tense marking in early school-aged children with developmental language disorder (DLD). The influence of allomorphs on intervention effects was also examined. Methods: Data from previously conducted intervention studies were combined and analysed. Participants included nine children (mean age = 6;5 years) who received 20–30-min intervention sessions provided twice per week for 10 weeks (1000 trials; 400–600 min) and 20 children (mean age = 6;6) who received 20–30-min intervention sessions provided once per week for 10 weeks (500 trials; 200–300 min). Repeated measures included criterion-referenced probes for production of untrained past tense verbs collected throughout baseline, intervention, and maintenance phases. The rate of progress in each phase was analysed using logistic regression. The proportion of participants who produced past tense allomorphs correctly at pre-intervention, post-intervention, and maintenance testing points was analysed. Results: Logistic regression showed a stable baseline, highly significant progress during the intervention phase, and a marginally significant shallow decline during the maintenance phase. Those in the twice per week group showed a greater rate of progress during the intervention phase leading to significantly higher scores in the maintenance period when compared with the once per week group. The allomorphic category of past tense verbs did not appear to influence outcomes. Conclusions: Participants receiving intervention twice per week appeared to demonstrate a greater rate of progress with intervention than those receiving it once per week, although once per week was also effective. However, these results should be interpreted with caution. Limitations to study design indicate that a larger randomised controlled trial is required. All past tense allomorphs improve to a similar degree when treated with this intervention. What this paper adds: What is already known on the subject Understanding the parameters of dosage and intensity are important for clinical practice. Research evaluating the efficacy and/or effectiveness of interventions delivered in different dose/intensity conditions is scarce. There appears to be different interpretations of what constitutes dosage and intensity in published research. What this paper adds to existing knowledge This study retrospectively compared dosage and intensity conditions of intervention provided twice per week to intervention provided once per week. Both dose frequencies could be delivered in clinical settings. Results from this study were analysed by grouping data from multiple testing points, rather than comparing pre-post results. This approach demonstrated the variability of individual performance that would otherwise be lost with conventional methods of analysis. This study demonstrated that all past tense allomorphs improve to a similar degree when treated with this intervention. What are the potential or actual clinical implications of this work? Parameters of dosage and intensity are still not clearly defined well enough for translation to clinical practice. In consideration of current research, this intervention may be more effective if delivered twice per week. If clinicians are treating past tense, all allomorphs should be considered as priorities for intervention targets
Reflecting on the Physics of Notations applied to a visualisation case study
This paper presents a critical reflection upon the concept of 'physics of notations' proposed by Moody. This is based upon the post hoc application of the concept in the analysis of a visualisation tool developed for a common place mathematics tool. Although this is not the intended design and development approach presumed or preferred by the physics of notations, there are benefits to analysing an extant visualisation. In particular, our analysis benefits from the visualisation having been developed and refined employing graphic design professionals and extensive formative user feedback. Hence the rationale for specific visualisation features is to some extent traceable. This reflective analysis shines a light on features of both the visualisation and domain visualised, illustrating that it could have been analysed more thoroughly at design time. However the same analysis raises a variety of interesting questions about the viability of scoping practical visualisation design in the framework proposed by the physics of notations
Summary of Skylab S-193 altimeter altitude results
The SKYLAB S-193 altimeter altitude results are presented in a concise format for further use and analysis by the scientific community. The altimeter mission and instrumentation is described along with the altimeter processing techniques and values of parameters used for processing. The determination of reference orbits is discussed, and the tracking systems utilized are tabulated. Techniques for determining satellite pointing are presented and a tabulation of pointing for each data mission included. The geographical location, the ocean bottom topography, the altimeter-determined ocean surface topography, and the altimeter automatic gain control history is presented. Some typical applications of this data are suggested
The spatial distribution of the photostability of thionine in zeolite L nanochannels investigated by Photobleaching Lifetime Imaging Microscopy
Dye photobleaching is a photochemical reaction that can be investigated locally using fluorescence microscopy techniques. In this study, a user-friendly computational tool to assist photobleaching experiments called Photobleaching Lifetime Imaging Microscopy (PbLIM) is presented. With this tool it is possible to recover the photobleaching kinetics spatially, where a photobleaching lifetime is generated for each pixel of the image. Our model was applied to the photobleaching process of thionine encapsulated into the one-dimensional nano-channels of Zeolite L (ZL), from where we gained insight into the molecular oxygen distribution inside the ZL channels, as well as the detailed photobleaching of the confined thionine. © The Royal Society of Chemistry and Owner Societies 2016
Entanglement for all quantum states
It is shown that a state that is factorizable in the Hilbert space
corresponding to some choice of degrees of freedom, becomes entangled for a
different choice of degrees of freedom. Therefore, entanglement is not a
special case but is ubiquitous in quantum systems. Simple examples are
calculated and a general proof is provided. The physical relevance of the
change of tensor product structure is mentioned.Comment: 9 page
Gb/s visible light communications with colloidal quantum dot color converters
This paper reports the utilization of colloidal semiconductor
quantum dots as color converters for Gb/s visible light
communications. We briefly review the design and properties of
colloidal quantum dots and discuss them in the context of fast
color conversion of InGaN light sources, in particular in view of
the effects of self-absorption. This is followed by a description of
a CQD/polymer composite format of color converters. We show
samples of such color-converting composite emitting at green, yellow/orange
and red wavelengths, and combine these with a blueemitting
microsize LED to form hybrid sources for wireless visible
light communication links. In this way data rates up to 1 Gb/s over
distances of a few tens of centimeters have been demonstrated. Finally,
we broaden the discussion by considering the possibility for
wavelength division multiplexing as well as the use of alternative
colloidal semiconductor nanocrystals
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