38 research outputs found
A Learning-Based Framework for Two-Dimensional Vehicle Maneuver Prediction over V2V Networks
Situational awareness in vehicular networks could be substantially improved
utilizing reliable trajectory prediction methods. More precise situational
awareness, in turn, results in notably better performance of critical safety
applications, such as Forward Collision Warning (FCW), as well as comfort
applications like Cooperative Adaptive Cruise Control (CACC). Therefore,
vehicle trajectory prediction problem needs to be deeply investigated in order
to come up with an end to end framework with enough precision required by the
safety applications' controllers. This problem has been tackled in the
literature using different methods. However, machine learning, which is a
promising and emerging field with remarkable potential for time series
prediction, has not been explored enough for this purpose. In this paper, a
two-layer neural network-based system is developed which predicts the future
values of vehicle parameters, such as velocity, acceleration, and yaw rate, in
the first layer and then predicts the two-dimensional, i.e. longitudinal and
lateral, trajectory points based on the first layer's outputs. The performance
of the proposed framework has been evaluated in realistic cut-in scenarios from
Safety Pilot Model Deployment (SPMD) dataset and the results show a noticeable
improvement in the prediction accuracy in comparison with the kinematics model
which is the dominant employed model by the automotive industry. Both ideal and
nonideal communication circumstances have been investigated for our system
evaluation. For non-ideal case, an estimation step is included in the framework
before the parameter prediction block to handle the drawbacks of packet drops
or sensor failures and reconstruct the time series of vehicle parameters at a
desirable frequency
A Learning-based Stochastic MPC Design for Cooperative Adaptive Cruise Control to Handle Interfering Vehicles
Vehicle to Vehicle (V2V) communication has a great potential to improve
reaction accuracy of different driver assistance systems in critical driving
situations. Cooperative Adaptive Cruise Control (CACC), which is an automated
application, provides drivers with extra benefits such as traffic throughput
maximization and collision avoidance. CACC systems must be designed in a way
that are sufficiently robust against all special maneuvers such as cutting-into
the CACC platoons by interfering vehicles or hard braking by leading cars. To
address this problem, a Neural- Network (NN)-based cut-in detection and
trajectory prediction scheme is proposed in the first part of this paper. Next,
a probabilistic framework is developed in which the cut-in probability is
calculated based on the output of the mentioned cut-in prediction block.
Finally, a specific Stochastic Model Predictive Controller (SMPC) is designed
which incorporates this cut-in probability to enhance its reaction against the
detected dangerous cut-in maneuver. The overall system is implemented and its
performance is evaluated using realistic driving scenarios from Safety Pilot
Model Deployment (SPMD).Comment: 10 pages, Submitted as a journal paper at T-I
Implementation and Evaluation of a Cooperative Vehicle-to-Pedestrian Safety Application
While the development of Vehicle-to-Vehicle (V2V) safety applications based
on Dedicated Short-Range Communications (DSRC) has been extensively undergoing
standardization for more than a decade, such applications are extremely missing
for Vulnerable Road Users (VRUs). Nonexistence of collaborative systems between
VRUs and vehicles was the main reason for this lack of attention. Recent
developments in Wi-Fi Direct and DSRC-enabled smartphones are changing this
perspective. Leveraging the existing V2V platforms, we propose a new framework
using a DSRC-enabled smartphone to extend safety benefits to VRUs. The
interoperability of applications between vehicles and portable DSRC enabled
devices is achieved through the SAE J2735 Personal Safety Message (PSM).
However, considering the fact that VRU movement dynamics, response times, and
crash scenarios are fundamentally different from vehicles, a specific framework
should be designed for VRU safety applications to study their performance. In
this article, we first propose an end-to-end Vehicle-to-Pedestrian (V2P)
framework to provide situational awareness and hazard detection based on the
most common and injury-prone crash scenarios. The details of our VRU safety
module, including target classification and collision detection algorithms, are
explained next. Furthermore, we propose and evaluate a mitigating solution for
congestion and power consumption issues in such systems. Finally, the whole
system is implemented and analyzed for realistic crash scenarios
Machine Learning-Driven Structure Prediction for Iron Hydrides
We created a computational workflow to analyze the potential energy surface
(PES) of materials using machine-learned interatomic potentials in conjunction
with the minima hopping algorithm. We demonstrate this method by producing a
versatile machine-learned interatomic potential for iron hydride via a neural
network using an iterative training process to explore its energy landscape
under different pressures. To evaluate the accuracy and comprehend the
intricacies of the PES, we conducted comprehensive crystal structure
predictions using our neural network-based potential paired with the minima
hopping approach. The predictions spanned pressures ranging from ambient to 100
GPa. Our results reproduce the experimentally verified global minimum
structures such as \textit{dhcp}, \textit{hcp}, and \textit{fcc}, corroborating
previous findings. Furthermore, our in-depth exploration of the iron hydride
PES at different pressures has revealed complex alterations and stacking faults
in these phases, leading to the identification of several new low-enthalpy
structures. This investigation has not only confirmed the presence of regions
of established FeH configurations but has also highlighted the efficacy of
using data-driven, extensive structure prediction methods to uncover the
multifaceted PES of materials
STRATIGRAPHY OF THE LOWER OLIGOCENE NUMMULITIC LIMESTONES, NORTH OF SONQOR (NW IRAN)
The lower Oligocene hyaline and porcellaneous larger foraminifera of a carbonate platform setting, north of Sonqor, were studied for high-resolution biostratigraphy in the context of European standard zonation (Shallow Benthic Zones). According to the geological map of Kermanshah, these beds were previously ascribed to the Miocene. The identified larger foraminifera include Nummulites fichteli Michelotti, Nummulites vascus Joly & Leymerie, Operculina complanata (Defrance), Asterigerina rotula (Kaufmann), Planorbulina bronnimanni Bignot & Decrouez, Discogypsina discus (Goës), Gypsina mastelensis Bursch, Halkyardia maxima Cimerman, Stomatorbina concentrica (Parker & Jones), Praerhapydionina delicata Henson, Penarchaias glynnjonesi (Henson), Austrotrillina aff. paucialveolata Grimsdale, and Haddonia heissigi Hagn, associated with the coralline alga Subterraniphyllum thomasii Elliott. The foraminiferal association characterises the SBZ 21 Zone (early Rupelian)
Serological survey of human Toxoplasma gondii infection in northern and central regions of Iran
Introduction: Toxoplasma gondii is an important zoonotic protozoan parasite that can
infect man and animals. The pathogen can infect the fetus by congenital transmission
during pregnancy. The aim of this study was to investigate T. gondii infection in people
referred to health care centers in northern and central regions of Iran.
Materials and methods: Serum samples from 712 individuals in Mazandaran, Isfahan and
ChaharmahalvaBakhtiari provinces, Iran, were examined for the levels of anti-T. Gondii
IgG by ELISA. Prevalence of T. gondii infection in respect of gender and age was
analyzed.
Results: The overall anti-T. gondii IgG prevalence in the study population was 72.05%. In
Mazandaran, Isfahan and ChaharmahalvaBakhtiari provinces,in male population
respectively 87.6, 41.46 and 61.81% and in female population respectively 89.31, 47.61
and 64.44% were sero-positive with anti-T. gondii IgG. Sero-prevalance of anti-T.gondii
IgG in the females was higher than in the males in the northern and central regions of Iran.
Discussion and conclusion:The present study demonstrates high prevalence of
Toxoplasma infection in northern and central regions of Iran and a higher prevalence of T.
gondii infection was observed in females. Significant difference in infection rate between
individuals living in northern and central areas in Iran was found (p <0.05), which
indicated that T. gondii infection is dependent on living places. Deeper investigations for
the potential risk factors that threat the Iranian populations, especially female are
recommended