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An evaluation framework for stereo-based driver assistance
This is the post-print version of the Article - Copyright @ 2012 Springer VerlagThe accuracy of stereo algorithms or optical flow methods is commonly assessed by comparing the results against the Middlebury
database. However, equivalent data for automotive or robotics applications
rarely exist as they are difficult to obtain. As our main contribution, we introduce an evaluation framework tailored for stereo-based driver assistance able to deliver excellent performance measures while
circumventing manual label effort. Within this framework one can combine several ways of ground-truthing, different comparison metrics, and use large image databases.
Using our framework we show examples on several types of ground truthing techniques: implicit ground truthing (e.g. sequence recorded without a crash occurred), robotic vehicles with high precision sensors, and to a small extent, manual labeling. To show the effectiveness of our evaluation framework we compare three different stereo algorithms on
pixel and object level. In more detail we evaluate an intermediate representation
called the Stixel World. Besides evaluating the accuracy of the Stixels, we investigate the completeness (equivalent to the detection rate) of the StixelWorld vs. the number of phantom Stixels. Among many findings, using this framework enables us to reduce the number of phantom Stixels by a factor of three compared to the base parametrization. This base parametrization has already been optimized by test driving vehicles for distances exceeding 10000 km
Towards designing robust coupled networks
Natural and technological interdependent systems have been shown to be highly
vulnerable due to cascading failures and an abrupt collapse of global
connectivity under initial failure. Mitigating the risk by partial
disconnection endangers their functionality. Here we propose a systematic
strategy of selecting a minimum number of autonomous nodes that guarantee a
smooth transition in robustness. Our method which is based on betweenness is
tested on various examples including the famous 2003 electrical blackout of
Italy. We show that, with this strategy, the necessary number of autonomous
nodes can be reduced by a factor of five compared to a random choice. We also
find that the transition to abrupt collapse follows tricritical scaling
characterized by a set of exponents which is independent on the protection
strategy
A Comparison of Consistent Discretizations for Elliptic Problems on Polyhedral Grids
In this work, we review a set of consistent discretizations for second-order elliptic equations, and compare and contrast them with respect to accuracy, monotonicity, and factors affecting their computational cost (degrees of freedom, sparsity, and condition numbers). Our comparisons include the linear and nonlinear TPFA method, multipoint flux-approximation (MPFA-O), mimetic methods, and virtual element methods. We focus on incompressible flow and study the effects of deformed cell geometries and anisotropic permeability.acceptedVersio
Innovator resilience potential: A process perspective of individual resilience as influenced by innovation project termination
Innovation projects fail at an astonishing rate. Yet, the negative effects of innovation project failures on the team members of these projects have been largely neglected in research streams that deal with innovation project failures. After such setbacks, it is vital to maintain or even strengthen project members’ innovative capabilities for subsequent innovation projects. For this, the concept of resilience, i.e. project members’ potential to positively adjust (or even grow) after a setback such as an innovation project failure, is fundamental. We develop the second-order construct of innovator resilience potential, which consists of six components – self-efficacy, outcome expectancy, optimism, hope, self-esteem, and risk propensity – that are important for project members’ potential of innovative functioning in innovation projects subsequent to a failure. We illustrate our theoretical findings by means of a qualitative study of a terminated large-scale innovation project, and derive implications for research and management
Endometrial Cancer Presenting as Acute Urinary Retention: a Case Report and Review of the Literature
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Endometrial Cancer Presenting as Acute Urinary Retention : a Case Report and Review of The Literature
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Oxygen Isotope Effect Resulting from Polaron-induced Superconductivity in Cuprates
The planar oxygen isotope effect coefficient measured as a function of hole
doping in the Pr- and La-doped YBa2Cu3O7 (YBCO) and the Ni-doped
La1.85Sr0.15CuO4 (LSCO) superconductors quantitatively and qualitatively
follows the form originally proposed by Kresin and Wolf, which was derived for
polarons perpendicular to the superconducting planes. Interestingly, the
inverse oxygen isotope effect coefficient at the pseudogap temperature also
follows the same formula. These findings allow the conclusion that the
superconductivity in YBCO and LSCO results from polarons or rather bipolarons
in the CuO2 plane. The original formula, proposed for the perpendicular
direction only, is obviously more generally valid and accounts for the
superconductivity in the CuO2 planes.Comment: Dedicated to Alex M\"uller on the occasion of his 90th birthda
Evolution of Assortative Mating in a Population Expressing Dominance
In this article, we study the influence of dominance on the evolution of
assortative mating. We perform a population-genetic analysis of a two-locus
two-allele model. We consider a quantitative trait that is under a mixture
of frequency-independent stabilizing selection and density- and frequency-dependent
selection caused by intraspecific competition for a continuum of resources.
The trait is determined by a single (ecological) locus and expresses intermediate
dominance. The second (modifier) locus determines the degree of assortative
mating, which is expressed in females only. Assortative mating is based on
similarities in the quantitative trait (‘magic trait’ model).
Analytical conditions for the invasion of assortment modifiers are derived
in the limit of weak selection and weak assortment. For the full model, extensive
numerical iterations are performed to study the global dynamics. This allows
us to gain a better understanding of the interaction of the different selective
forces. Remarkably, depending on the size of modifier effects, dominance can
have different effects on the evolution of assortment. We show that dominance
hinders the evolution of assortment if modifier effects are small, but promotes
it if modifier effects are large. These findings differ from those in previous
work based on adaptive dynamics
Multitemperature mapping of dust structures throughout the Galactic Plane using the PPMAP tool with Herschel Hi-GAL data
We describe new Hi-GAL based maps of the entire Galactic Plane, obtained using continuum data in the wavelength range 70–500 μm. These maps are derived with the PPMAP procedure, and therefore represent a significant improvement over those obtained with standard analysis techniques. Specifically they have greatly improved resolution (12 arcsec) and, in addition to more accurate integrated column densities and mean dust temperatures, they give temperature-differential column densities, i.e., separate column density maps in twelve distinct dust temperature intervals, along with the corresponding uncertainty maps. The complete set of maps is available online. We briefly describe PPMAP and present some illustrative examples of the results. These include (a) multi-temperature maps of the Galactic H II region W5-E, (b) the temperature decomposition of molecular cloud column-density probability distribution functions, and (c) the global variation of mean dust temperature as a function of Galactocentric distance. Amongst our findings are: (i) a strong localised temperature gradient in W5-E in a direction orthogonal to that towards the ionising star, suggesting an alternative heating source and providing possible guidance for models of the formation of the bubble complex, and (ii) the overall radial profile of dust temperature in the Galaxy shows a monotonic decrease, broadly consistent both with models of the interstellar radiation field and with previous estimates at lower resolution. However, we also find a central temperature plateau within ∼6 kpc of the Galactic centre, outside of which is a pronounced steepening of the radial profile. This behaviour may reflect the greater proportion of molecular (as opposed to atomic) gas in the central region of the Galaxy
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