Authoring Software Research Articles

Dynamical investigation of railway vehicles on a curved track

The main objective of this article is an examination of railway vehicle dynamics during motion along a curved track. Two main aspects are presented in the paper. First, two different methods used while investigating multi-rigid body systems such as railway vehicles are discussed, i.e. the quasi-statical (or kineto-statical) and dynamical approaches. Second, two practical problems dealing with vehicle motion along a curved track are investigated. The problems under consideration refer to vibrations as well as stability, examined via finding obtained with the author's software as a result of numerical simulation. The work has both a practical and a cognitive character. The aim of the investigations is firstly to indicate the limitations of quasi-statical (and kineto-statical) methods and secondly to study the problems which cannot be treated by these methods. Two specific problems of the type investigated using a dynamical approach are the influence of track geometrical irregularities on the evaluation of vehicle ride properties and limit cycle occurrence during vehicle curve negotiation. Due to the renewed interest in the rapid passenger railway, the investigations take into consideration curves of large radii introduced along railway routes for increased velocities. Furthermore, it is shown under which conditions the obtained results may have an important practical application. This concerns the influence of vehicle suspension parameters as well as conditions of motion (speed, superelevation, curve radius, transition curve existence) on limit cycle occurrence. The limited value of conclusions dealing with vehicle ride properties obtained while using quasi-statical (kineto-statical) methods is proved through quantitative analysis. The problem of the influence of geometrical irregularities on wheel-rail pair wear is also pointed out.

On the Internet, software should be milked, not brewed

The explosion of the Web raises many difficult legal and economic issues. One of the most controversial is this: how can we protect the intellectual property embedded in the computer software that gets distributed over the Internet? The Web hypertext platform, particularly hypertext transfer protocol (HTTP) and Java, should encourage the quick and ubiquitous delivery of novel, ground breaking ideas for interacting with computers. Innovative user interface software, whether in the form of Java byte codes or Web browsers, should be protected by law. But this is very difficult. Software products and ideas are too easily duplicated or cloned, and software's authors are often compelled to expose the technical details of their products in order to disseminate them and create a market for their ideas and services, indirectly encouraging such cloning. The use of time stamping software to solve the Internet intellectual property problem is discussed.