461 research outputs found
A note on stress-driven anisotropic diffusion and its role in active deformable media
We propose a new model to describe diffusion processes within active
deformable media. Our general theoretical framework is based on physical and
mathematical considerations, and it suggests to use diffusion tensors directly
coupled to mechanical stress. A proof-of-concept experiment and the proposed
generalised reaction-diffusion-mechanics model reveal that initially isotropic
and homogeneous diffusion tensors turn into inhomogeneous and anisotropic
quantities due to the intrinsic structure of the nonlinear coupling. We study
the physical properties leading to these effects, and investigate mathematical
conditions for its occurrence. Together, the experiment, the model, and the
numerical results obtained using a mixed-primal finite element method, clearly
support relevant consequences of stress-assisted diffusion into anisotropy
patterns, drifting, and conduction velocity of the resulting excitation waves.
Our findings also indicate the applicability of this novel approach in the
description of mechano-electrical feedback in actively deforming bio-materials
such as the heart
The impact on innovation off-shoring on organizational adaptability
We analyze the effects of captive off-shoring of innovation activities on the firms’
ability to adapt their organizational processes and structures. Starting from
complexity theory, we use three consecutive waves of the German part of the
Community Innovation Survey to test our hypotheses. We find an inverted u-shape
of innovation off-shoring on the effectiveness of organizational adaptability,
implying an optimal threshold value of innovation off-shoring. This value is 11%
for share of off-shored R&D, 15% for downstream innovation activities such as
local market adaptation, and 34% for design activities. We also analyze several
contingency variables. In particular we show that the costs of innovation off-shoring
in terms of reduced organizational adaptability are exacerbated by a strong focus on
R&D and a strong embeddedness in on-shore networks. Smaller firms find it easier to
deal with the management complexity induced by geographical dispersion of
innovation activities because of their greater flexibility
Zur Entwicklung der Gewalt in Deutschland : Schwerpunkte: Jugendliche und Flüchtlinge als Täter und Opfer
Unter Mitarbeit von Prof. Dr. Thomas Mößle, Laura Beckmann und Eberhard Mecklenbur
An Efficient Similarity Digests Database Lookup -- a Logarithmic Divide and Conquer Approach
Investigating seized devices within digital forensics represents a challenging task due to the increasing amount of data. Common procedures utilize automated file identification, which reduces the amount of data an investigator has to examine manually. In the past years the research field of approximate matching arises to detect similar data. However, if n denotes the number of similarity digests in a database, then the lookup for a single similarity digest is of complexity of O(n). This paper presents a concept to extend existing approximate matching algorithms, which reduces the lookup complexity from O(n) to O(log(n)). Our proposed approach is based on the well-known divide and conquer paradigm and builds a Bloom filter-based tree data structure in order to enable an efficient lookup of similarity digests. Further, it is demonstrated that the presented technique is highly scalable operating a trade-off between storage requirements and computational efficiency. We perform a theoretical assessment based on recently published results and reasonable magnitudes of input data, and show that the complexity reduction achieved by the proposed technique yields a 220-fold acceleration of look-up costs
An Efficient Similarity Digests Database Lookup – A Logarithmic Divide & Conquer Approach
Investigating seized devices within digital forensics represents a challenging task due to the increasing amount of data. Common procedures utilize automated file identification, which reduces the amount of data an investigator has to examine manually. In the past years the research field of approximate matching arises to detect similar data. However, if n denotes the number of similarity digests in a database, then the lookup for a single similarity digest is of complexity of O(n). This paper presents a concept to extend existing approximate matching algorithms, which reduces the lookup complexity from O(n) to O(log(n)). Our proposed approach is based on the well-known divide and conquer paradigm and builds a Bloom filter-based tree data structure in order to enable an efficient lookup of similarity digests. Further, it is demonstrated that the presented technique is highly scalable operating a trade-off between storage requirements and computational efficiency. We perform a theoretical assessment based on recently published results and reasonable magnitudes of input data, and show that the complexity reduction achieved by the proposed technique yields a 2 20-fold acceleration of look-up costs
Auf der Suche nach dem Narrativ. Fritz Breithaupt erkundet das narrative Gehirn und ĂĽbersieht eine Leerstelle
Rezension zu: Fritz Breithaupt: Das narrative Gehirn. Was unsere Neuronen erzählen. Berlin: Suhrkamp 2022. 368 S. EUR 28,-. ISBN 978-3-518-58778-
Auf der Suche nach dem Narrativ. Fritz Breithaupt erkundet das narrative Gehirn und ĂĽbersieht eine Leerstelle
Review of: Fritz Breithaupt: Das narrative Gehirn. Was unsere Neuronen erzählen. Berlin: Suhrkamp 2022. 368 S. EUR 28,-. ISBN 978-3-518-58778-
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