3,173 research outputs found
Evaluating the social acceptability of voice based smartwatch search
There has been a recent increase in the number of wearable (e.g. smartwatch, interactive glasses, etc.) devices available. Coupled with this there has been a surge in the number of searches that occur on mobile devices. Given these trends it is inevitable that search will become a part of wearable interaction. Given the form factor and display capabilities of wearables this will probably require a different type of search interaction to what is currently used in mobile search. This paper presents the results of a user study focusing on users’ perceptions of the use of smartwatches for search. We pay particular attention to social acceptability of different search scenarios, focussing on in-put method, device form and information need. Our findings indicate that audience and location heavily influence whether people will perform a voice based search. The results will help search system developers to support search on smartwatches
Terrestrial Laser Scanning to Detect Liana Impact on Forest Structure
Tropical forests are currently experiencing large-scale structural changes, including an increase in liana abundance and biomass. Higher liana abundance results in reduced tree growth and increased tree mortality, possibly playing an important role in the global carbon cycle. Despite the large amount of data currently available on lianas, there are not many quantitative studies on the influence of lianas on the vertical structure of the forest. We study the potential of terrestrial laser scanning (TLS) in detecting and quantifying changes in forest structure after liana cutting using a small scale removal experiment in two plots (removal plot and non-manipulated control plot) in a secondary forest in Panama. We assess the structural changes by comparing the vertical plant profiles and Canopy Height Models (CHMs) between pre-cut and post-cut scans in the removal plot. We show that TLS is able to detect the local structural changes in all the vertical strata of the plot caused by liana removal. Our study demonstrates the reproducibility of the TLS derived metrics for the same location confirming the applicability of TLS for continuous monitoring of liana removal plots to study the long-term impacts of lianas on forest structure. We therefore recommend to use TLS when implementing new large scale liana removal experiments, as the impact of lianas on forest structure will determine the aboveground competition for light between trees and lianas, which has important implications for the global carbon cycle
Laparoscopic sleeve gastrectomy using a synthetic bioabsorbable staple line reinforcement material: Post-operative complications and 6 year outcomes.
BACKGROUND: Gastric leak after laparoscopic sleeve gastrectomy (LSG) is a serious complication. Currently, the literature lacks long-term outcomes in LSG and leak rates after reinforcement of the staple line. The aims are two-fold: to present leak rates from using staple line reinforcement and six year outcomes of LSG in relation to resolution of obesity-related comorbidities and long-term weight loss. MATERIALS AND METHODS: This is a single-institution, retrospectively reviewed study of 204 patient case files. Data from all patients undergoing LSG between December 2007 and May 2013 was collected. RESULTS: The total complication rate was 6.9% (14/204), with no recorded staple line leaks. The mean postoperative Body Mass Index (BMI) at 1 year, 2 years, 3 years, 4 years, 5 years, and 6 years was 39.3 ± 8, 38.7 ± 8, 40.4 ± 9, 40.5 ± 10, 43.0 ± 10, and 42.4 ± 7, respectively. The mean % excess weight loss at 1 year, 3 years, and 6 years was 48.4 ± 19, 51.7 ± 28, and 41.0 ± 21, respectively. There were no significant differences between follow-ups at year 1 and 3 (p > 0.05), and between year 3 and 6 (p > 0.05) for the mean % excess weight loss. The resolution rates for all patients were 74%, 61%, 79%, and 90% for hypertension, hypercholesterolemia, diabetes mellitus type 2 and obstructive sleep apnea, respectively. CONCLUSION: The synthetic bioabsorbable reinforcement material shows no staple line leaks making it safe to use. LSG as a procedure had a high resolution of obesity-related comorbidities as well as sustainable long-term weight loss
Crowdsourcing EO datasets to improve cloud detection algorithms and land cover change
Involving citizens in science is gaining considerable traction of late. With positive examples
(e.g. Geo-Wiki, FotoQuest Austria), a number of projects are exploring the options to engage
the public in contributing to scientific research, often by asking participants to collect some
data or validate some results. The International Institute for Applied Systems Analysis
(IIASA), with extensive experience in crowdsourcing and gamification, has joined Sinergise,
Copernicus Masters 2016 winners, to engage the public in an initiative involving ESA’s
Sentinel-2 satellite imagery.
Sentinel-2 imagery offers high revisit times and sufficient resolution for land change
detection applications. Unfortunately, simple (but fast) algorithms often fail due to many
false-positives: changes in clouds are perceived as land changes. The ability to discriminate
of cloudy pixels is thus crucial for any automatic or semi-automatic solutions that detect land
change.
A plethora of algorithms to distinguish clouds in Sentinel-2 data are available. However,
there is a need for better data on where and when clouds occur to help improve these
algorithms. To overcome this current gap in the data, we are engaging the public in this task.
Using a number of tools, developed at IIASA, and Sentinel Hub services, which provide fast
access to the entire global archive of Sentinel-2 data, the aim is to obtain a large data
resource of curated cloud classifications. The resulting dataset will be published as open
data and made available through Geopedia platform.
The gamified process will start by asking users if there are clouds on a small image (e.g. 8x8
pixels at the highest Sentinel-2 resolution of 10 m/px), which will provide us with a screening
process to pinpoint cloudy areas, employing Picture Pile crowdsourcing game from IIASA.
The next step will involve a more detailed workflow, as users will get a slightly larger image
(e.g. 64x64 pixels) and will then be asked to delineate different types of clouds: opaque
clouds (nothing is seen through the clouds), thick clouds (where the surface is still
discernible through the clouds), and thin clouds (where the surface is unequivocally covered
by a cloud); the rest of the image will be implicitly cloud-free. The resulting data will be
made available through the Geopedia portal, both for exploring and downloading. This
paper will demonstrate this process and show some results from a crowdsourcing campaign.
The approach will also allow us to collect other datasets in a rapid and efficient manner. For
example, using a slightly modified configuration, a similar workflow could be used to obtain
a manually curated land cover classification data set, which could be used as training data
for machine learning algorithms
Account of the Flatfishes of the Mangalore Coast and Notes on their Fishery
12 specimens were studied for morphological and meristic characters. Most characters agreed with earlier descriptions. Dorsal and anal fins were tipped white unlike black as reported by Fischer and Bianchi (1984). Maximum length recorded was 540 mm
The rotation curves of dwarf galaxies: a problem for Cold Dark Matter?
We address the issue of accuracy in recovering density profiles from
observations of rotation curves of galaxies. We ``observe'' and analyze our
models in much the same way as observers do the real galaxies. We find that the
tilted ring model analysis produces an underestimate of the central rotational
velocity. In some cases the galaxy halo density profile seems to have a flat
core, while in reality it does not. We identify three effects, which explain
the systematic biases: (1) inclination (2), small bulge, and (3) bar. The
presence of even a small non-rotating bulge component reduces the rotation
velocity. In the case of a disk with a bar, the underestimate of the circular
velocity is larger due to a combination of non-circular motions and random
velocities. Signatures of bars can be difficult to detect in the surface
brightness profiles of the model galaxies. The variation of inclination angle
and isophote position angle with radius are more reliable indicators of bar
presence than the surface brightness profiles. The systematic biases in the
central ~ 1 kpc of galaxies are not large. Each effect separately gives
typically a few kms error, but the effects add up. In some cases the error in
circular velocity was a factor of two, but typically we get about 20 percent.
The result is the false inference that the density profile of the halo flattens
in the central parts. Our observations of real galaxies show that for a large
fraction of galaxies the velocity of gas rotation (as measured by emission
lines) is very close to the rotation of stellar component (as measured by
absorption lines). This implies that the systematic effects discussed in this
paper are also applicable both for the stars and emission-line gas.Comment: ApJ, in press, 30 pages, Latex, 21 .eps figure
Design of an Implantable Device for Ocular Drug Delivery
Ocular diseases, such as, glaucoma, age-related macular degeneration (AMD), diabetic retinopathy, and retinitis pigmentosa require drug management in order to prevent blindness and affecting million of adults in USA and worldwide. There is an increasing need to develop devices for drug delivery to address ocular diseases. This study focuses on the design, simulation, and development of an implantable ocular drug delivery device consisting of micro-/nanochannels embedded between top and bottom covers with a drug reservoir made from polydimethylsiloxane (PDMS) which is silicon-based organic and biodegradable polymer. Several simulations were carried out with six different micro-channel configurations in order to see the feasibility for ocular drug delivery applications. Based on the results obtained, channel design of osmotic I and osmotic II satisfied the diffusion rates required for ocular drug delivery. Finally, a prototype illustrating the three components of the drug delivery design is presented. In the future, the device will be tested for its functionality and diffusion characteristics
Heterogeneity in pre-monsoon aerosol types over the Arabian Sea deduced from ship-borne measurements of spectral AODs
Ship-borne sunphotometer measurements obtained in the Arabian Sea (AS) in the pre-monsoon season (18 April–10 May 2006) during a cruise campaign (ICARB) have been used to retrieve the Aerosol Optical Depth (AOD; &tau;) and the Ångström wavelength exponent (α). The continents surrounding the AS produce natural and anthropogenic aerosols that have distinctive influences on α and its spectral distribution. The α values were estimated by means of the least-squares method over the spectral bands 340–1020 nm and 340–870 nm. The spectral distribution of AOD in logarithmic co-ordinates could be fit using a 2nd order polynomial with higher accuracy in the wavelength band 340–1020 nm than in the 340–870 nm band. A polynomial fit analytically parameterizes the observed wavelength dependencies of AOD with least errors in spectral variation of α and yields accurate estimates of the coefficients (<i>a</i><sub>1</sub> and <i>a</i><sub>2</sub>). The coarse-mode (positive curvature in the ln&tau;<sub>&lambda;</sub> vs. ln&lambda;) aerosols are mainly depicted in the Northern part of the AS closely associated with the nearby arid areas while fine-mode aerosols are mainly observed over the far and coastal AS regions. In the study period the mean AOD at 500 nm is 0.25&plusmn;0.11 and the α<sub>340-1020</sub> is 0.90&plusmn;0.19. The α<sub>340-870</sub> exhibits similar values (0.92&plusmn;0.18), while significant differences revealed for the constant terms of the polynomial fit (<i>a</i><sub>1</sub> and <i>a</i><sub>2</sub>) proportionally to the wavelength band used for their determination. Observed day-to-day variability in the aerosol load and optical properties are direct consequence of the local winds and air-mass trajectories along with the position of the ship
Churn, Baby, Churn: Strategic Dynamics Among Dominant and Fringe Firms in a Segmented Industry
This paper integrates and extends the literatures on industry evolution and dominant firms to develop a dynamic theory of dominant and fringe competitive interaction in a segmented industry. It argues that a dominant firm, seeing contraction of growth in its current segment(s), enters new segments in which it can exploit its technological strengths, but that are sufficiently distant to avoid cannibalization. The dominant firm acts as a low-cost Stackelberg leader, driving down prices and triggering a sales takeoff in the new segment. We identify a “churn” effect associated with dominant firm entry: fringe firms that precede the dominant firm into the segment tend to exit the segment, while new fringe firms enter, causing a net increase in the number of firms in the segment. As the segment matures and sales decline in the segment, the process repeats itself. We examine the predictions of the theory with a study of price, quantity, entry, and exit across 24 product classes in the desktop laser printer industry from 1984 to 1996. Using descriptive statistics, hazard rate models, and panel data methods, we find empirical support for the theoretical predictions
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