21,997 research outputs found
An introduction to interactive sonification
The research field of sonification, a subset of the topic of auditory display, has developed rapidly in recent decades. It brings together interests from the areas of data mining, exploratory data analysis, human–computer interfaces, and computer music. Sonification presents information by using sound (particularly nonspeech), so that the user of an auditory display obtains a deeper understanding of the data or processes under investigation by listening
Theories of Technological Progress and the British Textile Industry from Kay to Cartwright
Editada en la Fundación Empresa PúblicaLa industria textil británica continúa en el centro del debate sobre la revolución industrial. Las innovaciones técnicas en el período produjeron una aceleración extraordinaria del crecimiento del output y una considerable reducción de los precios de los tejidos. En este trabajo presentamos un estudio de la comunidad de los inventores responsables de la transformación tecnológica, lo que nos permite alcanzar una serie de conclusiones nuevas sobre el ritmo y dirección de la actividad innovadora durante la revolución industrialThe cotton textile industry remains central to all accounts of the first industrial revolution. Innovations in this period precipitated an extraordinary acceleration in the growth of output and a steep decline in the cost of producing all varieties of cloth. In this paper we outline an explanation through an analysis of the community of inventors responsible for the technological transformation, which enables us to offer some generalizations of the pace and pattern of the inventive activity in this period.Publicad
(63)Cu NQR Evidence for Spatial Variation of Hole Concentration in La(2-x)Sr(x)CuO(4)
We report experimental evidence for the spatial variation of hole
concentration x_(hole) in the high Tc superconductor La(2-x)Sr(x)CuO(4) (0.04
<= x <= 0.16) by using (63)Cu NQR for (63)Cu isotope enriched samples. We
demonstrate that the extent of the spatial variation of the local hole
concentration D(x)_(hole) is reflected on (63)1/T1 and deduce the temperature
dependence. D(x)_(hole) increases below 500 - 600K, and reaches values as large
as D(x)_(hole)/x ~ 0.5 below ~ 150K. We estimate the length scale of the
spatial variation in x_(hole) to be R_(hole) >~ 3nm from analysis of the NQR
spectrum.Comment: Accepted for publication in Physical Review Letter
Multilayered folding with voids
In the deformation of layered materials such as geological strata, or stacks
of paper, mechanical properties compete with the geometry of layering. Smooth,
rounded corners lead to voids between the layers, while close packing of the
layers results in geometrically-induced curvature singularities. When voids are
penalized by external pressure, the system is forced to trade off these
competing effects, leading to sometimes striking periodic patterns.
In this paper we construct a simple model of geometrically nonlinear
multi-layered structures under axial loading and pressure confinement, with
non-interpenetration conditions separating the layers. Energy minimizers are
characterized as solutions of a set of fourth-order nonlinear differential
equations with contact-force Lagrange multipliers, or equivalently of a
fourth-order free-boundary problem. We numerically investigate the solutions of
this free boundary problem, and compare them with the periodic solutions
observed experimentally
Effects of horizontal vibration on hopper flows of granular materials
The current experiments investigate the discharge of glass spheres in a planar wedge-shaped hopper (45 degree sidewalls) that is vibrated hoizontally. When the hopper is discharged without vibration, the discharge occurs as a funnel flow, with the material exiting the central region of the hopper and stagnant material along the sides. With horizontal vibration, the discharge rate increases with the velocity of vibration as compared with the discharge rate without vibration. For a certain range of acceleration parameters (20-30 Hz and accelerations greater than about 1 g), the discharge of the material occurs in an inverted-funnel pattern, with the material along the sides exiting first, followed by the material in the core; the free surface shows a peak at the center of the hopper with the free surface particles avalanching from the center toward the sides. During the deceleration phase of a vibration cycle, particles all along the trailing or low-pressure wall separate from the surface and fall under gravity for a short period before reconnecting the hopper. For lower frequencies (5 and 10 Hz), the free surface remains horizontal and the material appears to discharge uniformly from the hopper
Effects of Horizontal Vibration on Hopper Flows of Granular Material
This study experimentally examines the flow of glass spheres in a wedge-shaped hopper that is vibrated hoizontally. When the hopper is discharged without vibration, discharge occurs as a funnel flow, with the material exiting the central region of the hopper and stagnant material along the sides. With vibration, the discharge of the material occurs in reverse, with the material along the sides exiting first, followed by the material in the central region. These patterns are observed with flow visualization and high-speed photography. The study also includes measurements of the discharge rate, which increases with the amplitude of the velocity of vibration
Appraisals of previous maths experiences play an important role in maths anxiety
Maths anxiety affects many people, from young children through to older adults. Whilst there has been debate concerning the developmental trajectory of maths anxiety and negative maths attitudes, little attention has been given to the role of appraisals of previous maths experiences. We surveyed 308 adults (mean age = 27.56 years, SD = 11.25) and assessed self-reported measures of maths anxiety, mathematical resilience, maths attitudes, and appraisal of previous maths experiences. As hypothesised, all variables were found to be interrelated. Maths anxiety was significantly negatively related to appraisal of previous maths experiences, mathematical resilience and maths attitudes. Moreover, appraisal of previous maths experiences was shown to mediate the relations between i) maths anxiety and maths attitudes, and ii) mathematical resilience and maths attitudes. The findings demonstrate the importance of considering current appraisals of previous maths experiences and are consistent with an interpretation account of maths anxiety. This may help inform cognitive based interventions that focus on one’s interpretation of past events to support current and future maths learning and engagement
Glimmers: Resolving the Privacy/Trust Quagmire
Many successful services rely on trustworthy contributions from users. To
establish that trust, such services often require access to privacy-sensitive
information from users, thus creating a conflict between privacy and trust.
Although it is likely impractical to expect both absolute privacy and
trustworthiness at the same time, we argue that the current state of things,
where individual privacy is usually sacrificed at the altar of trustworthy
services, can be improved with a pragmatic , which allows
services to validate user contributions in a trustworthy way without forfeiting
user privacy. We describe how trustworthy hardware such as Intel's SGX can be
used client-side -- in contrast to much recent work exploring SGX in cloud
services -- to realize the Glimmer architecture, and demonstrate how this
realization is able to resolve the tension between privacy and trust in a
variety of cases
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