659 research outputs found
The Greedy Dirichlet Process Filter - An Online Clustering Multi-Target Tracker
Reliable collision avoidance is one of the main requirements for autonomous
driving. Hence, it is important to correctly estimate the states of an unknown
number of static and dynamic objects in real-time. Here, data association is a
major challenge for every multi-target tracker. We propose a novel multi-target
tracker called Greedy Dirichlet Process Filter (GDPF) based on the
non-parametric Bayesian model called Dirichlet Processes and the fast posterior
computation algorithm Sequential Updating and Greedy Search (SUGS). By adding a
temporal dependence we get a real-time capable tracking framework without the
need of a previous clustering or data association step. Real-world tests show
that GDPF outperforms other multi-target tracker in terms of accuracy and
stability
A multistate model for early decision making in oncology
The development of oncology drugs progresses through multiple phases, where
after each phase a decision is made about whether to move a molecule forward.
Early phase efficacy decisions are often made on the basis of single arm
studies based on RECIST tumor response as endpoint. This decision rules are
implicitly assuming some form of surrogacy between tumor response and long-term
endpoints like progression-free survival (PFS) or overall survival (OS). The
surrogacy is most often assessed as weak, but sufficient to allow a rapid
decision making as early phase studies lack the survival follow up and number
of patients to properly assess PFS or OS. With the emergence of therapies with
new mechanisms of action, for which the link between RECIST tumor response and
long-term endpoints is either not accessible yet because not enough data is
available to perform a meta-regression, or the link is weaker than with
classical chemotherapies, tumor response based rules may not be optimal. In
this paper, we explore the use of a multistate model for decision making based
on single-arm early phase trials. The multistate model allows to account for
more information than the simple RECIST response status, namely, the time to
get to response, the duration of response, the PFS time and time to death. We
propose to base the decision on efficacy on the OS hazard ratio (HR), predicted
from a multistate model based on early phase data with limited survival
follow-up, combined with historical control data. Using three case studies and
simulations, we illustrate the feasibility of the estimation of the OS HR using
a multistate model based on limited data from early phase studies. We argue
that, in the presence of limited follow up and small sample size, and on
assumptions within the multistate model, the OS prediction is acceptable and
may lead to better decisions for continuing the development of a drug
Digitalization in Thermodynamics
Digitalization is about data and how they are used. This has always been a key topic in applied thermodynamics. In the present work, the influence of the current wave of digitalization on thermodynamics is analyzed. Thermodynamic modeling and simulation is changing as large amounts of data of different nature and quality become easily available. The power and complexity of thermodynamic models and simulation techniques is rapidly increasing, and new routes become viable to link them to the data. Machine learning opens new perspectives, when it is suitably combined with classical thermodynamic theory. Illustrated by examples, different aspects of digitalization in thermodynamics are discussed: strengths and weaknesses as well as opportunities and threats
Kinematic analysis of handwriting movements in patients with Alzheimer's disease, mild cognitive impairment, depression and healthy subjects
A variety of studies have demonstrated that motor disorders, parkinsonism and extrapyramidal motor symptoms (EPMS) are common in patients with Alzheimer's disease (AD). Several studies have reported an association of EPMS with severity, progression and poor prognosis of AD. The majority of these studies used clinical assessments for the rating of EPMS. In this study, kinematic handwriting analysis was used to quantify differences in fine hand motor function in patients with probable AD and mild cognitive impairment (MCl, as an assumed initial stage of AD) compared to depressed patients and healthy controls. Both patients with MCl and patients with probable AD exhibited loss of fine motor performance. Movements of AD patients were significantly less regular than those of healthy controls. Copyright (C) 2003 S. Karger AG, Basel
Fast 3D Extended Target Tracking using NURBS Surfaces
This paper proposes fast and novel methods to jointly estimate the target's
unknown 3D shape and dynamics. Measurements are noisy and sparsely distributed
3D points from a light detection and ranging (LiDAR) sensor. The methods
utilize non-uniform rational B-splines (NURBS) surfaces to approximate the
target's shape. One method estimates Cartesian scaling parameters of a NURBS
surface, whereas the second method estimates the corresponding NURBS weights,
too. Major advantages are the capability of estimating a fully 3D shape as well
as the fast processing time. Real-world evaluations with a static and dynamic
vehicle show promising results compared to state-of-the-art 3D extended target
tracking algorithms.Comment: In Proceedings of IEEE Intelligent Transportation Systems Conference
(ITSC), 201
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