56 research outputs found
Multi-Object Tracking with Interacting Vehicles and Road Map Information
In many applications, tracking of multiple objects is crucial for a
perception of the current environment. Most of the present multi-object
tracking algorithms assume that objects move independently regarding other
dynamic objects as well as the static environment. Since in many traffic
situations objects interact with each other and in addition there are
restrictions due to drivable areas, the assumption of an independent object
motion is not fulfilled. This paper proposes an approach adapting a
multi-object tracking system to model interaction between vehicles, and the
current road geometry. Therefore, the prediction step of a Labeled
Multi-Bernoulli filter is extended to facilitate modeling interaction between
objects using the Intelligent Driver Model. Furthermore, to consider road map
information, an approximation of a highly precise road map is used. The results
show that in scenarios where the assumption of a standard motion model is
violated, the tracking system adapted with the proposed method achieves higher
accuracy and robustness in its track estimations
Environment Perception Framework Fusing Multi-Object Tracking, Dynamic Occupancy Grid Maps and Digital Maps
Autonomously driving vehicles require a complete and robust perception of the
local environment. A main challenge is to perceive any other road users, where
multi-object tracking or occupancy grid maps are commonly used. The presented
approach combines both methods to compensate false positives and receive a
complementary environment perception. Therefore, an environment perception
framework is introduced that defines a common representation, extracts objects
from a dynamic occupancy grid map and fuses them with tracks of a Labeled
Multi-Bernoulli filter. Finally, a confidence value is developed, that
validates object estimates using different constraints regarding physical
possibilities, method specific characteristics and contextual information from
a digital map. Experimental results with real world data highlight the
robustness and significance of the presented fusing approach, utilizing the
confidence value in rural and urban scenarios
One-sample log-rank tests with consideration of reference curve sampling variability
The one-sample log-rank test is the method of choice for single-arm Phase II
trials with time-to-event endpoint. It allows to compare the survival of the
patients to a reference survival curve that typically represents the expected
survival under standard of care. The classical one-sample log-rank test,
however, assumes that the reference survival curve is deterministic. This
ignores that the reference curve is commonly estimated from historic data and
thus prone to statistical error. Ignoring sampling variability of the reference
curve results in type I error rate inflation. For that reason, a new one-sample
log-rank test is proposed that explicitly accounts for the statistical error
made in the process of estimating the reference survival curve. The test
statistic and its distributional properties are derived using martingale
techniques in the large sample limit. In particular, a sample size formula is
provided. Small sample properties regarding type I and type II error rate
control are studied by simulation. A case study is conducted to study the
influence of several design parameters of a single-armed trial on the inflation
of the type I error rate when reference curve sampling variability is ignored.Comment: 24 pages, 2 pictures, 1 supplementary fil
Liquid‐Liquid Equilibrium and Interfacial Properties of the System Water + Hexylacetate + 1‐Hexanol
Experimental and theoretical investigations of the phase diagram and the interfacial tension are presented. The theoretical framework was able to predict the phase behavior and the interfacial tension with a high accuracy, where only binary experimental data enter the model parameter. The theory permits the calculation of the concentration profiles across the interface. The profiles show that 1-hexanol will be enriched, which was expected. In same circumstances a competition between hexylacetate and 1-hexanol was figured out leading to slight minima in the profile of 1-hexanol
On Minc's sheltered middle path
This paper shows that a construction, which was introduced by Piotr Minc in
connection with a problem that came from Helly type theorems and that allows to
replace three PL-arcs with a "sheltered middle path", can in the case of
general (non-PL) paths result in the topologist's sine curve.Comment: 18 pages, 3 figure
Hadron Spectroscopy with Dynamical Chirally Improved Fermions
We simulate two dynamical, mass degenerate light quarks on 16^3x32 lattices
with a spatial extent of 2.4 fm using the Chirally Improved Dirac operator. The
simulation method, the implementation of the action and signals of
equilibration are discussed in detail. Based on the eigenvalues of the Dirac
operator we discuss some qualitative features of our approach. Results for
ground state masses of pseudoscalar and vector mesons as well as for the
nucleon and delta baryons are presented.Comment: 26 pages, 17 figures, 10 table
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