2,328 research outputs found
Multiple path prediction for traffic scenes using LSTMs and mixture density models
This work presents an analysis of predicting multiple future paths of moving objects in traffic scenes by leveraging Long Short-Term Memory architectures (LSTMs) and Mixture Density Networks (MDNs) in a single-shot manner. Path prediction allows estimating the future positions of objects. This is useful in important applications such as security monitoring systems, Autonomous Driver Assistance Systems and assistive technologies. Normal approaches use observed positions (tracklets) of objects in video frames to predict their future paths as a sequence of position values. This can be treated as a time series. LSTMs have achieved good performance when dealing with time series. However, LSTMs have the limitation of only predicting a single path per tracklet. Path prediction is not a deterministic task and requires predicting with a level of uncertainty. Predicting multiple paths instead of a single one is therefore a more realistic manner of approaching this task. In this work, predicting a set of future paths with associated uncertainty was archived by combining LSTMs and MDNs. The evaluation was made on the KITTI and the CityFlow datasets on three type of objects, four prediction horizons and two different points of view (image coordinates and birds-eye vie
Dublin City University digital twin: test bed for IoT sensor data visualization
It is said that a picture is worth a thousand words, what would it worth a digital 3D model then. A digital 3D model that can be explored and manipulated by the user. Digital Twin is a digital 3D model reconstruction of a specific area populated with normal objects such as Buildings, houses, fields where data can be exchanged between the physical word and the digital version. A digital Model, once constructed, can be manipulated for several purposes and applications such as test bed and data visualization. In this work a digital twin of the Dublin City University is presented and how it can be used to deploy real time sensor information. The digital twins were created using drone imagery and Bentley Context Capture software. OpenCities Planner is used to deploy the models online and to link with the IoT sensors. The steps followed from collecting the drone imagery to the final deployment of the digital twin are presented as they are important points to take into consideration when using the presented methodology
Direct evidence of a zigzag spin chain structure in the honeycomb lattice: A neutron and x-ray diffraction investigation on single crystal
We have combined single crystal neutron and x-ray diffractions to investigate
the magnetic and crystal structures of the honeycomb lattice .
The system orders magnetically below K with Ir ions forming
zigzag spin chains within the layered honeycomb network with ordered moment of
/Ir site. Such a configuration sharply contrasts the
N{\'{e}}el or stripe states proposed in the Kitaev-Heisenberg model. The
structure refinement reveals that the Ir atoms form nearly ideal 2D honeycomb
lattice while the octahedra experience a trigonal distortion that
is critical to the ground state. The results of this study provide much-needed
experimental insights into the magnetic and crystal structure crucial to the
understanding of the exotic magnetic order and possible topological
characteristics in the 5-electron based honeycomb lattice.Comment: Revised version as that to appear in PR
Moving object path prediction in traffic scenes using contextual information
Abstract: Moving object path prediction in traffic scenes from the perspective of a moving vehicle can improve safety on the road, which is the aim of Advanced Driver Assistance Systems (ADAS). However, this task still remains a challenge. Work has been carried out on the use of x,y positional information of the moving objects only. However, besides positional information there is more information that surrounds a vehicle that can be leveraged in the prediction along with the x, y features. This is known as contextual information. In this work, a deep exploration of these features is carried out by evaluating different types of data, using different fusion strategies. The core architectures of this model are CNN and LSTM architectures. It is concluded that in the prediction task, not only are the features important, but the way they are fused in the developed architecture is also of importance
Automation of Construction Progress Monitoring by Integrating 3D Point Cloud Data with an IFC-Based BIM Model
Automated construction progress monitoring using as-planned building information modeling (BIM) and as-built point cloud data integration has substantial potential and could lead to the fast-tracking of construction work and identifying discrepancies. Laser scanning is becoming mainstream for conducting construction surveys due to the accuracy of the data obtained and the speed of the process; however, construction progress monitoring techniques are still limited because of the complexity of the methods, incompleteness of the scanned areas, or the obstructions by temporary objects in construction sites. The novel method proposed within this study enables the extracting of BIM data, calculating the plane equation of the faces, and performing a point-to-plane distance estimation, which successfully overcomes some limitations reported in previous studies, including automated object detection in an occluded environment. Six datasets consisting of point clouds collected by static and mobile laser scanning techniques including the corresponding BIM models were analyzed. In all the analyzed cases, the proposed method automatically detected whether the construction of an object was completed or not in the as-built point cloud compared to the provided as-planned BIM model
Low-temperature electrical transport and double exchange in La(Pb,Ca)MnO
The resistivity in the ferromagnetic state of flux-grown
La_{2/3}(Pb,Ca)_{1/3}MnO_3 single crystals, measured in magnetic fields up to 7
T, reveals a strong quadratic temperature dependence at and above 50 K. At
lower temperatures, this contribution drops precipitously leaving the
resistivity essentially temperature independent below 20 K. The Seebeck
coefficient also reflects a change of regime at the same temperature. We
attribute this behavior to a cut-off of single magnon scattering processes at
long wavelengths due to the polarized bands of a double-exchange ferromagnet.Comment: 10 pages, TeX, 4 figures. Revised version. Submitte
Visual processing speed in hemianopia patients secondary to acquired brain injury: a new assessment methodology
Producción CientíficaBackground: There is a clinical need to identify diagnostic parameters that objectively quantify and monitor the
effective visual ability of patients with homonymous visual field defects (HVFDs). Visual processing speed (VPS) is an
objective measure of visual ability. It is the reaction time (RT) needed to correctly search and/or reach for a visual
stimulus. VPS depends on six main brain processing systems: auditory-cognitive, attentional, working memory,
visuocognitive, visuomotor, and executive. We designed a new assessment methodology capable of activating
these six systems and measuring RTs to determine the VPS of patients with HVFDs.
Methods: New software was designed for assessing subject visual stimulus search and reach times (S-RT and R-RT
respectively), measured in seconds. Thirty-two different everyday visual stimuli were divided in four complexity
groups that were presented along 8 radial visual field positions at three different eccentricities (10o, 20o, and 30o).
Thus, for each HVFD and control subject, 96 S- and R-RT measures related to VPS were registered. Three additional
variables were measured to gather objective data on the validity of the test: eye-hand coordination mistakes
(ehcM), eye-hand coordination accuracy (ehcA), and degrees of head movement (dHM, measured by a head-tracker
system). HVFD patients and healthy controls (30 each) matched by age and gender were included. Each subject
was assessed in a single visit. VPS measurements for HFVD patients and control subjects were compared for the
complete test, for each stimulus complexity group, and for each eccentricity.
Results: VPS was significantly slower (p < 0.0001) in the HVFD group for the complete test, each stimulus
complexity group, and each eccentricity. For the complete test, the VPS of the HVFD patients was 73.0% slower
than controls. They also had 335.6% more ehcMs, 41.3% worse ehcA, and 189.0% more dHMs than the controls.
Conclusions: Measurement of VPS by this new assessment methodology could be an effective tool for objectively
quantifying the visual ability of HVFD patients. Future research should evaluate the effectiveness of this novel
method for measuring the impact that any specific neurovisual rehabilitation program has for these patients
Anomalous ferromagnetic spin fluctuations in an antiferromagnetic insulator Pr_{1-x}Ca_{x}MnO_{3}
The high temperature paramagnetic state in an antiferromagnetic (AFM)
insulator Pr_{1-x}Ca_{x}MnO_{3} is characterized by the ferromagnetic (FM) spin
fluctuations with an anomalously small energy scale. The FM fluctuations show a
precipitous decrease of the intensity at the charge ordering temperature
T_{CO}, but persist below T_{CO}, and vanish at the AFM transition temperature
T_{N}. These results demonstrate the importance of the spin ordering for the
complete switching of the FM fluctuation in doped manganites.Comment: REVTeX, 5 pages, 4 figures, submitted to Phys. Rev.
Distributional and reproductive aspects of the bigeye thresher shark (Alopias superciliosus) in the Atlantic ocean
Captura asociada a la pesquería de palangre de superficie dirigida a pez espadaThe bigeye thresher shark, Alopias supercilious is sometimes caught as bycatch in
pelagic longline fisheries targeting tunas and swordfish in the Atlantic Ocean. As part
of an ongoing cooperative program for fisheries and biological data collection, fishery
observer data from various fishing nations and projects were compiled and analyzed.
Those data sets include information on geographic location of the observations, as well
as size, sex and in some cases maturity stage. A total of 4371 bigeye threshers were
recorded throughout the Atlantic Ocean between 1992 and 2013, with the sizes ranging
from 70 to 305 cm FL (fork length). Considerable variability was observed in the catchat-
size, with particular emphasis on the tropical region where the mean sizes tended to
be smaller than in the other regions. The expected distribution of juvenile and adult
specimens also showed considerable variability, and the sex-ratios varied between
regions and size classes. Maturity ogives were fitted to data from 642 specimens, with
the median sizes at maturity estimated at 208.6 cm FL (corresponding to 349.1 cm TL)
for females and 159.2 cm FL (corresponding to 269.8 cm TL) for males. In addition, a
segmented regression model (SRM) was used for males, and two breakpoints (Bk1:
122.5cm FL, Bk2: 173.3cm FL) estimated, identifying transitions between the three
different maturity stages for male sharks (immature, maturing and mature). Only a few
pregnant females were recorded, always with the presence of two embryos (one per
uterus), and were distributed predominantly in the tropical northeast Atlantic closer the
African continent, and in the southwest region, with those regions possibly serving as
nursery areas for this species. These reproductive parameters, and especially the
estimated median sizes at maturity and low fecundity, highlight the vulnerability of this
species, reinforcing that the bigeye thresher tends to mature at a larger size than the
other species of the Alopiidae family. The biological and distributional patterns
presented can help managers adopt more informed and efficient conservation measures
for this species.En prensa0,000
Smart DCU digital twin: towards smarter universities
Although both smart city and digital twin are ambiguous and contested terms, there exists a co-creative link between the two. Theoretically, digital twin seems to be a sustainable digital solution for smart cities to achieve ideal city vision by digitization of physical urban spaces. This study investigates and informs the role, benefits and challenges in developing and deploying digital twin solution for efficient decision-making in infrastructure planning and management. This technology is experimented in a 3D cyberspace of Dublin City University, which is also one of the testbeds under the broader Smart Dublin umbrella. It is an ongoing project and expects to develop effective use-cases for monitoring present situations, multi-stakeholder collaboration and action research towards a responsive and adaptive campus environment
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