Consider the problem of using a vehicle to transport k objects one at a time between s stations on a circular track. Let the cost of the transportation be the rotal distance traveled by the vehicle on the track. An 0 (k + M(s, q)) time algorithm is presented to find a minimum cost transportation, where M (m, n) is the time to solve a minimum spanning tree problem on a graph with m edges and n v...

We describe an object oriented set of tools for carrying out integrated hierarchical pattern recognition in a tracking system composed of an arbitrary set of tracking devices. Two fundamental components are part of the method, a LayerSet object for pattern recognition operations and a TrackFilter object for manipulation of track candidates. The other major components in the package are: a manag...

As commercialisation and privatisation of railway systems reach the political agendas in a number of countries, including Australia, the separation of infrastructure from operating business dictates that track costs need to be shared on an equitable basis. There is also a world-wide trend towards increased pressures on rail track infrastructure through increases in axle loads and train speeds. ...

One of the most important factors influencing the track maintenance is the transitions between parts of the track with different vertical stiffness. The dynamic...

The vibrations produced by trains include two parts which are deterministic and random vibrations. Due to variation of dynamic loads and patterns of load-time, the random vibration of moving train is one of the most important issues in the field of railway engineering. One of the important sources in producing the train vibrations is rail roughness and irregularities. In this paper, responses o...

this paper deals with the threshold radius that warrants the use of single restraining rail for transit and railroads. different railways use different threshold radius from 91m to 365m to provide restraining rail. these threshold figures are probably experience driven choices. the need for restraining rail may be related to a so-called derailment alarm coefficient of 1.2 sustained over 2m leng...

A numerical tool is proposed to simultaneously assess various damage mechanisms that are driven by contact loading. The transfers loads the contact-patch level using three parameters: maximum pressure (pmax), creepage (c) and length (2a). local wear RCF predictions implemented based on existing models from literature. load input can originate vehicle–track simulations or manual of user. assessm...

The development of “slab track” was started by Japan in 1955 and the “Committee of slab track research” was established in 1971 for exclusive development of slab track. This makes Japan the country that has invested the most effort into slab tracks. On 5 January 2007, the THSR transferred from Japanese Shinkansen started its commercial operation. The stability and comfort of train operation hav...

Railway maintenance planners require a predictive model that can assess the railway track geometry degradation. The present paper uses a hierarchical Bayesian model as a tool to model the main two quality indicators related to railway track geometry degradation: the standard deviation of longitudinal level defects and the standard deviation of horizontal alignment defects. Hierarchical Bayesian...