1,784 research outputs found
Controlling Steering Angle for Cooperative Self-driving Vehicles utilizing CNN and LSTM-based Deep Networks
A fundamental challenge in autonomous vehicles is adjusting the steering
angle at different road conditions. Recent state-of-the-art solutions
addressing this challenge include deep learning techniques as they provide
end-to-end solution to predict steering angles directly from the raw input
images with higher accuracy. Most of these works ignore the temporal
dependencies between the image frames. In this paper, we tackle the problem of
utilizing multiple sets of images shared between two autonomous vehicles to
improve the accuracy of controlling the steering angle by considering the
temporal dependencies between the image frames. This problem has not been
studied in the literature widely. We present and study a new deep architecture
to predict the steering angle automatically by using Long-Short-Term-Memory
(LSTM) in our deep architecture. Our deep architecture is an end-to-end network
that utilizes CNN, LSTM and fully connected (FC) layers and it uses both
present and futures images (shared by a vehicle ahead via Vehicle-to-Vehicle
(V2V) communication) as input to control the steering angle. Our model
demonstrates the lowest error when compared to the other existing approaches in
the literature.Comment: Accepted in IV 2019, 6 pages, 9 figure
Use of idebenone in Leberâs Hereditary Optic Neuropathy â a case presentation and mini review of Idebenone treatment endpoints
Double Inverse Stochastic Resonance with Dynamic Synapses
We investigate the behavior of a model neuron that receives a
biophysically-realistic noisy post-synaptic current based on uncorrelated
spiking activity from a large number of afferents. We show that, with static
synapses, such noise can give rise to inverse stochastic resonance (ISR) as a
function of the presynaptic firing rate. We compare this to the case with
dynamic synapses that feature short-term synaptic plasticity, and show that the
interval of presynaptic firing rate over which ISR exists can be extended or
diminished. We consider both short-term depression and facilitation.
Interestingly, we find that a double inverse stochastic resonance (DISR), with
two distinct wells centered at different presynaptic firing rates, can appear.Comment: 12 pages, 7 figure
Fate of the Universe, Age of the Universe, Dark Matter, and the Decaying Vacuum Energy
It is shown that in the cosmological models based on a vacuum energy decaying
as a^{-2}, where a is the scale factor of the universe, the fate of the
universe in regard to whether it will collapse in future or expand forever is
determined not by the curvature constant k but by an effective curvature
constant k_{eff}. It is argued that a closed universe with k=1 may expand
forever, in other words simulate the expansion dynamics of a flat or an open
universe because of the possibility that k_{eff}=0 or -1, respectively. Two
such models, in one of which the vacuum does not interact with matter and in
another of which it does, are studied. It is shown that the vacuum equation of
state p_{vac}= -\rho_{vac} may be realized in a decaying vacuum cosmology
provided the vacuum interacts wuth matter. The optical depths for gravitational
lensing as a function of the matter density and other parameters in the models
are calculated at a source redshift of 2. The age of the universe is discussed
and shown to be compatible with the new Hipparcos lower limit of 11Gyr. The
possibility that a time-varying vacuum energy may serve as dark matter is
suggested.Comment: AAS LaTex, 29 pages, published in the Astrophysical Journal, 520, 45,
199
Simulation of ecological impacts of the new outer-harbour development in Zeebrugge
The new outer-harbour in Zeebrugge is to be protected by jetties extending 1,750 m seaward, This development will alter the local distribution of tidal and residual currents. Such hydrodynamic changes will, in turn, affect the dispersion pattern of dissolved and particular matters in the vicinity of Zeebrugge. A mathematical model is presented, which simulates the dispersion - before and after outer harbour development - of dissolved organic matters, faecal bacteria and heavy metals, which are indicative of, respectively domestic, human, and industrial pollutions
Predicting room occupancy with a single passive infrared (PIR) sensor through behavior extraction
Passive infrared sensors have widespread use in many applications, including motion detectors for alarms, lighting systems and hand dryers. Combinations of multiple PIR sensors have also been used to count the number of humans passing through doorways. In this paper, we demonstrate the potential of the PIR sensor as a tool for occupancy estimation inside of a monitored environment. Our approach shows how flexible nonparametric machine learning algorithms extract useful information about the occupancy from a single PIR sensor. The approach allows us to understand and make use of the motion patterns generated by people within the monitored environment. The proposed counting system uses information about those patterns to provide an accurate estimate of room occupancy which can be updated every 30 seconds. The system was successfully tested on data from more than 50 real office meetings consisting of at most 14 room occupants
Simple facet joint repair with dynamic pedicular system: Technical note and case series
Purpose: Facet joints are important anatomical structures for the stability of spine. Surgical or degenerative damage to a facet joint may lead to spinal instability and causes clinical problems. This article explains the importance of facet joints, reviews facet replacement systems, and describes a simple and effective method for facet replacement after surgical removal of facet joints. Materials and Methods: Ten patients were operated with the diagnosis of unilateral nerve root compression secondary to facet degeneration. The hypertrophic facet joints were removed with microsurgical techniques and the roots were decompressed. Then, a unilateral artificial facet joint was created using two hinged screws and a dynamic rod. Results: The clinical outcome of all the patients was determined good or excellent at second and last follow-up (mean 13.3 months) controls using visual analog scale (VAS) and Oswestry Disability Index (ODI) scores. Radiological evaluations also demonstrated no implant-related complications. Conclusions: The authors suggest that, if removal of a facet joint is necessary to decompress the nerve roots, the joint can be replaced by a construct composed of two hinged screws connected by a dynamic rod. This simple system mimics the function of a normal facet joint and is an effective technique for unilateral facet joint replacement
Beta, Dipole and Noncommutative Deformations of M-theory Backgrounds with One or More Parameters
We construct new M-theory solutions starting from those that contain 5 U(1)
isometries. We do this by reducing along one of the 5-torus directions, then
T-dualizing via the action of an O(4,4) matrix and lifting back to
11-dimensions. The particular T-duality transformation is a sequence of O(2,2)
transformations embedded in O(4,4), where the action of each O(2,2) gives a
Lunin-Maldacena deformation in 10-dimensions. We find general formulas for the
metric and 4-form field of single and multiparameter deformed solutions, when
the 4-form of the initial 11-dimensional background has at most one leg along
the 5-torus. All the deformation terms in the new solutions are given in terms
of subdeterminants of a 5x5 matrix, which represents the metric on the 5-torus.
We apply these results to several M-theory backgrounds of the type AdS_r x
X^{11-r}. By appropriate choices of the T-duality and reduction directions we
obtain analogues of beta, dipole and noncommutative deformations. We also
provide formulas for backgrounds with only 3 or 4 U(1) isometries and study a
case, for which our assumption for the 4-form field is violated.Comment: v2:minor corrections, v3:small improvements, v4:conclusions expanded,
to appear in Class. Quant. Gra
Perceptions de la variabilitĂ© climati que et stratĂ©gies dâadaptation dans le systĂšme oasien de GourĂ© (Sud-est Niger)
Les savoirs liĂ©s au temps et Ă lâespace, et lâidentification des stratĂ©gies paysannes pour affronter les problĂšmes climatiques sont indispensables pour toute comprĂ©hension des questions climatiques. Pour mieux apprĂ©cier les perceptions de la variabilitĂ© climatique et les stratĂ©gies dâadaptation utilisĂ©es, une enquĂȘte semi structurĂ© qui a concernĂ© 60 personnes repartie dans 4 villages du dĂ©partement de GourĂ©, situĂ© dans lâEst du Niger est conduite selon une approche qualitative et quantitative. Les effets de la variabilitĂ© climatique ressentis par les agriculteurs sont lâariditĂ© du climat, lâaugmentation de la tempĂ©rature et le caractĂšre alĂ©atoire des pluies. Les Ă©leveurs la perçoivent de façon indirecte Ă travers la rĂ©duction du fourrage et de la disponibilitĂ© dâeau. Ces effets ont poussĂ© ces populations Ă adopter des stratĂ©gies dâadaptation comme la recherche de nouvelles variĂ©tĂ©s Ă cycle court et supportant les poches de sĂ©cheresse, la pratique des techniques de fixation des dunes pour la restauration du couvert herbacĂ©, lâutilisation de la fumure organique, la modification des dates de semis, le stockage de fourrage, le dĂ©stockage des animaux pendant la soudure, les priĂšres collectives de demande de pluies. Elles sont toutefois insuffisantes du fait de la persistance des effets nĂ©gatifs de la variabilitĂ© climatiques au Niger.Mots clĂ©s: VariabilitĂ© climatique, perception, stratĂ©gies dâadaptation, GourĂ©, NigerEnglish Title: Farmers perception and adaptation strategies to climate change in the oasis system of Goure (Southeast Niger)English AbstractKnowledge related to the perception of time and space, and identification of farmersâ strategies for dealing with climate change is a perequisite for a good understanding of climate issues. Farmersâ climate variability perceptions and adaptation strategies was studied using a survey conducted with sixty (60) farmers in the department of GourĂ©, located in eastern Niger. Results showed that farmers directly experience changes in climate variability through temperature increase, frequent drought and erratic rainfall. By contrast, herders sense the effects of climate change indirectly through fodder reduction and scarce water availability. These effects have prompted farmers to adopt coping strategies such as the use of improved varieties, early and drought tolerant, sand dune stabilization and land reclamation, use of organic manure, changing of planting dates, storage of fodder, the destocking of animals during drought periods, collective prayers for rain. These strategies, however, appear to be insufficient for addressing the negative effects of climate change in this part of Niger.Keywords: climate variability, perception, strategies of adaptation, Goure, Nige
Supernovae Ia Constraints on a Time-Variable Cosmological "Constant"
The energy density of a scalar field with potential , , behaves like a time-variable cosmological
constant that could contribute significantly to the present energy density.
Predictions of this spatially-flat model are compared to recent Type Ia
supernovae apparent magnitude versus redshift data. A large region of model
parameter space is consistent with current observations. (These constraints are
based on the exact scalar field model equations of motion, not on the widely
used time-independent equation of state fluid approximation equations of
motion.) We examine the consequences of also incorporating constraints from
recent measurements of the Hubble parameter and the age of the universe in the
constant and time-variable cosmological constant models. We also study the
effect of using a non-informative prior for the density parameter.Comment: Accepted for publication in Ap
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