The aim of this paper is to present an automatic, image-based system for catenary maintenance, a novel application of machine vision which has no equivalent today. This study focuses on the detection of droppers in catenary staves. The system takes benefit from the fact that dropper location inside catenary staves follows mounting rules, an information that is integrated into a top-down approac...

The architect Antonio Gaudi designed complex structures based on catenary systems. His beautiful forms were created by suspending pieces of string from hooks, deforming them with weights and other strings, then inverting the form to create the structural elements. Today’s architects are at a loss to reproduce these types of catenary forms when using even the most advanced design tools on the ma...

Contacts between pantograph and catenary are the most critical parts in the transmission of electrical energy for modern high-speed trains. Contact wire oscillations change combined force between pantograph and catenary, and the contact may even get lost. Therefore special pantographs and catenaries have been developed and further constructive changes are under development. A design criterion i...

Previous theoretical investigations of translating cables have been focused on the sagged cable equilibrium referred to here as the minimum cutenary. The minimum catenary is stable for finite translation speeds [ 1,2] and asymptotically approaches a buckling instability as the translation speed tends to infinity [2]. Experimental evidence presented in this paper validates this conclusion and th...

Human embryos aged six and one-half through 12 weeks were studied to determine the morphological changes in shape of the maxillary dental arch during this early developmental period. Age was determined by crown-rump lengths using the table of Patten ('53). When compared to a reference catenary curve, the embryonic dental arch exhibited several time-linked and directional changes in shape. First...

The catenary degree of an element s of a cancellative commutative monoid S is a nonnegative integer measuring the distance between the irreducible factorizations of s. The catenary degree of the monoid S, defined as the supremum over all catenary degrees occurring in S, has been heavily studied as an invariant of nonunique factorization. In this paper, we investigate the set C(S) of catenary de...

In the design process of a 2x25kV power supply, the location and sizing of autotransformers and the choice of the catenary type are usually two aspects very closely interrelated. As a result, the number of autotransformers can normally be reduced or augmented if the catenary is upgraded or downgraded respectively. In this paper, coupling equations between these two aspects are described in deta...

We construct an algorithmwhich computes the catenary and tame degree of a numerical semigroup. As an example we explicitly calculate the catenary and tame degree of numerical semigroups generated by arithmetical sequences in terms of their first element, the number of elements in the sequence and the difference between two consecutive elements of the sequence.

The pantograph current collector-catenary contact has been recognized as an established cause of permanent electromagnetic perturbation in a railway environment. In this paper the problems due to pantograph-catenary crawling are addressed. Introducing a suitable model for the radiating contacts, results in agreement with classical fields theory and with experimental measurements may be deduced....

This work presents a fully three-dimensional methodology for the computational analysis of the interaction between catenary and pantographs. The finite element method is used to support the modeling of the catenary while a multibody dynamics methodology is applied to support the pantograph modeling. The contact between the two subsystems is described using a penalty contact formulation. An high...