17,880 research outputs found
Shocks in non-loaded bead chains with impurities
We numerically investigate the problem of the propagation of a shock in an
horizontal non-loaded granular chain with a bead interaction force exponent
varying from unity to large values. When is close to unity we observed
a cross-over between a nonlinearity-dominated regime and a solitonic one, the
latest being the final steady state of the propagating wave. In the case of
large values of the deformation field given by the numerical
simulations is completely different from the one obtained by analytical
calculation. In the following we studied the interaction of these shock waves
with a mass impurity placed in the bead chain. Two different physical pictures
emerge whether we consider a light or a heavy impurity mass. The scatter of the
shock wave with a light impurity yields damped oscillations of the impurity
which then behave as a solitary wave source. Differently an heavy impurity is
just shifted by the shock and the transmitted wave loses its solitonic
character being fragmented into waves of decreasing amplitudes.Comment: 9 pages, 18 figures, Accepted in European Physical Journal
PACKER: a switchbox router based on conflict elimination by local transformations
PACKER is an algorithm for switchbox routing, based on a novel approach. In an initial phase, the connectivity of each net is established without taking the other nets into account. In general, this gives rise to conflicts (short circuits). In the second stage, the conflicts are removed iteratively using connectivity-preserving local transformations. They reshape a net by displacing one of its segments without disconnecting it from the net. The transformations are applied in a asystematic way using a scan line technique. The results obtained by PACKER are very positive: it solves all well-known benchmark example
Neural network modeling of memory deterioration in Alzheimer's disease
The clinical course of Alzheimer's disease (AD) is generally characterized by progressive gradual deterioration, although large clinical variability exists. Motivated by the recent quantitative reports of synaptic changes in AD, we use a neural network model to investigate how the interplay between synaptic deletion and compensation determines the pattern of memory deterioration, a clinical hallmark of AD. Within the model we show that the deterioration of memory retrieval due to synaptic deletion can be much delayed by multiplying all the remaining synaptic weights by a common factor, which keeps the average input to each neuron at the same level. This parallels the experimental observation that the total synaptic area per unit volume (TSA) is initially preserved when synaptic deletion occurs. By using different dependencies of the compensatory factor on the amount of synaptic deletion one can define various compensation strategies, which can account for the observed variation in the severity and progression rate of AD
Nonlinear structural vibrations by the linear acceleration method
Numerical integration method for calculating dynamic response of nonlinear elastic structure
Framework for the Integration of Service and Technology Strategies
Organised by: Cranfield UniversityAfter sales service is a highly profitable business for manufacturers of technology-driven products. Due to
this fact competitors want to share in high profit margins. At the same time after sales business has to deal
with an increasing range of variants of products and technologies, shorter life cycles and changing
customer demands. In spite of these manifold challenges, often neither after sales departments are
involved in the early product development stage nor are customer demands and technical parameters
considered in the service development processes entirely. Therefore an integration of service and
technology strategies is necessary. This paper presents a framework for this integration that visualises the
complex interdependencies and interfaces between service as well as product and motor vehicle workshop
technologies.Mori Seiki – The Machine Tool Compan
Boolean pairs formed by the Δn0-sets
AbstractIt will be shown that for all numbers n and m with n > m ⩾ 1 the Boolean pairs (Δn0, Δm0) have undecidable elementary theories
Combining textual and visual information processing for interactive video retrieval: SCHEMA's participation in TRECVID 2004
In this paper, the two different applications based on the Schema Reference System that were developed by the SCHEMA NoE for participation to the search task of TRECVID 2004 are illustrated. The first application, named ”Schema-Text”, is an interactive retrieval application that employs only textual information while the second one, named ”Schema-XM”, is an extension of the former, employing algorithms and
methods for combining textual, visual and higher level information. Two runs for each application were submitted, I A 2 SCHEMA-Text 3, I A 2 SCHEMA-Text 4 for Schema-Text and I A 2 SCHEMA-XM 1, I A 2 SCHEMA-XM 2 for Schema-XM. The comparison of these two applications in terms of retrieval efficiency revealed that the combination of information from different data sources can provide higher efficiency for retrieval systems. Experimental testing additionally revealed that initially performing a text-based query and subsequently proceeding with visual similarity search using one of the returned relevant keyframes as an example image is a good scheme for combining visual and textual information
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