659 research outputs found
Relaxation in the glass-former acetyl salicylic acid studied by deuteron magnetic resonance and dielectric spectroscopy
Supercooled liquid and glassy acetyl salicylic acid was studied using
dielectric spectroscopy and deuteron relaxometry in a wide temperature range.
The supercooled liquid is characterized by major deviations from thermally
activated behavior. In the glass the secondary relaxation exhibits the typical
features of a Johari-Goldstein process. Via measurements of spin-lattice
relaxation times the selectively deuterated methyl group was used as a
sensitive probe of its local environments. There is a large difference in the
mean activation energy in the glass with respect to that in crystalline acetyl
salicylic acid. This can be understood by taking into account the broad energy
barrier distribution in the glass.Comment: 8 pages, 3 figures, Submitted to Phys. Rev.
Evaluating Lifeworld as an emancipatory methodology
Disability research is conducted within a highly politicised âhotbedâ of competing paradigms and principles. New researchers, who want to work within the social model, are soon faced with complex and challenging methodological and philosophical dilemmas. The social model advocates research agendas that are focused on the emancipation and empowerment of disabled people but, in reality, these are rarely achieved. To be successful researchers need to engage with innovative and creative methodologies and to share their experiences of these within environments that welcome challenge and debate. This paper focuses on Lifeworld and assesses its value as a tool for emancipatory research. Using examples from a study with parents, whose children were in the process of being labelled as having autism, the paper illustrates how the principles that âunderpinâ the methodology offered a supportive framework for a novice researcher
A novel infrared video surveillance system using deep learning based techniques
This is the author accepted manuscript. The final version is available from Springer via the DOI in this record.This paper presents a new, practical infrared video based surveillance
system, consisting of a resolution-enhanced, automatic target detection/recognition
(ATD/R) system that is widely applicable in civilian and military applications. To
deal with the issue of small numbers of pixel on target in the developed ATD/R
system, as are encountered in long range imagery, a super-resolution method is
employed to increase target signature resolution and optimise the baseline quality
of inputs for object recognition. To tackle the challenge of detecting extremely
low-resolution targets, we train a sophisticated and powerful convolutional neural
network (CNN) based faster-RCNN using long wave infrared imagery datasets
that were prepared and marked in-house. The system was tested under different
weather conditions, using two datasets featuring target types comprising pedestrians
and 6 different types of ground vehicles. The developed ATD/R system can
detect extremely low-resolution targets with superior performance by effectively
addressing the low small number of pixels on target, encountered in long range applications.
A comparison with traditional methods confirms this superiority both
qualitatively and quantitativelyThis work was funded by Thales UK, the Centre of Excellence for
Sensor and Imaging System (CENSIS), and the Scottish Funding Council under the project
âAALART. Thales-Challenge Low-pixel Automatic Target Detection and Recognition (ATD/ATR)â,
ref. CAF-0036. Thanks are also given to the Digital Health and Care Institute (DHI, project
Smartcough-MacMasters), which partially supported Mr. Monge-Alvarezâs contribution, and
to the Royal Society of Edinburgh and National Science Foundation of China for the funding
associated to the project âFlood Detection and Monitoring using Hyperspectral Remote Sensing
from Unmanned Aerial Vehiclesâ, which partially covered Dr. Casaseca-de-la-Higueraâs,
Dr. Luoâs, and Prof. Wangâs contribution. Dr. Casaseca-de-la-Higuera would also like to acknowledge
the Royal Society of Edinburgh for the funding associated to project âHIVEâ
Engrained experienceâa comparison of microclimate perception schemata and microclimate measurements in Dutch urban squares
Acceptance of public spaces is often guided by perceptual schemata. Such schemata also seem to play a role in thermal comfort and microclimate experience. For climate-responsive design with a focus on thermal comfort it is important to acquire knowledge about these schemata. For this purpose, perceived and ârealâ microclimate situations were compared for three Dutch urban squares. People were asked about their long-term microclimate perceptions, which resulted in âcognitive microclimate mapsâ. These were compared with mapped microclimate data from measurements representing the common microclimate when people stay outdoors. The comparison revealed some unexpected low matches; people clearly overestimated the influence of the wind. Therefore, a second assumption was developed: that it is the more salient wind situations that become engrained in peopleâs memory. A comparison using measurement data from windy days shows better matches. This suggests that these more salient situations play a role in the microclimate schemata that people develop about urban places. The consequences from this study for urban design are twofold. Firstly, urban design should address not only the ârealâ problems, but, more prominently, the âperceivedâ problems. Secondly, microclimate simulations addressing thermal comfort issues in urban spaces should focus on these perceived, salient situations
The Image of the City Out of the Underlying Scaling of City Artifacts or Locations
Two fundamental issues surrounding research on the image of the city
respectively focus on the city's external and internal representations. The
external representation in the context of this paper refers to the city itself,
external to human minds, while the internal representation concerns how the
city is represented in human minds internally. This paper deals with the first
issue, i.e., what trait the city has that make it imageable? We develop an
argument that the image of the city arises from the underlying scaling of city
artifacts or locations. This scaling refers to the fact that, in an imageable
city (a city that can easily be imaged in human minds), small city artifacts
are far more common than large ones; or alternatively low dense locations are
far more common than high dense locations. The sizes of city artifacts in a
rank-size plot exhibit a heavy tailed distribution consisting of the head,
which is composed of a minority of unique artifacts (vital and very important),
and the tail, which is composed of redundant other artifacts (trivial and less
important). Eventually, those extremely unique and vital artifacts in the top
head, i.e., what Lynch called city elements, make up the image of the city. We
argue that the ever-increasing amount of geographic information on cities, in
particular obtained from social media such as Flickr and Twitter, can turn
research on the image of the city, or cognitive mapping in general, into a
quantitative manner. The scaling property might be formulated as a law of
geography.
Keywords: Scaling of geographic space, face of the city, cognitive maps,
power law, and heavy tailed distributions.Comment: 13 pages, 9 figures, 2 table
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