OSM Data Research Articles

Osmar: OpenStreetMap and R

OpenStreetMap provides freely accessible and editable geographic data. The osmar package smoothly integrates the OpenStreetMap project into the R ecosystem. The osmar package provides infrastructure to access OpenStreetMap data from different sources, to enable working with the OSM data in the familiar R idiom, and to convert the data into objects based on classes provided by existing R packages. This paper explains the package's concept and shows how to use it. As an application we present a simple navigation device.

OpenStreetMap: User-Generated Street Maps

The OpenStreetMap project is a knowledge collective that provides user-generated street maps. OSM follows the peer production model that created Wikipedia; its aim is to create a set of map data that's free to use, editable, and licensed under new copyright schemes. A considerable number of contributors edit the world map collaboratively using the OSM technical infrastructure, and a core group, estimated at approximately 40 volunteers, dedicate their time to creating and improving OSM's infrastructure, including maintaining the server, writing the core software that handles the transactions with the server, and creating cartographical outputs. There's also a growing community of software developers who develop software tools to make OSM data available for further use across different application domains, software platforms, and hardware devices. The OSM project's hub is the main OSM Web site.

Effects of the Three-Dimensionality of Ship Hull on the Wave Impact Pressure

A general expression for the impact pressure distribution on the flat bottom ship making slamming motion in waves is derived by matched asymptotic expansion on the bases of the shallow draft and the gravity free assumptions. 3-D flat plate formulation is utilized to have the solution in the outer region. For the solution in the inner region, its flow similarity to 2-D planing plate flow of which solution is known analytically is made use of. Both solutions are matched asymptotically to make them determinate and a composite solution valid in the entire region is obtained. The calculated results are compared with the experiments done by using free running model of a bulk carrier. Agreements between the experiments and the estimation based upon the OSM ship motion data are not satisfactory as expected. The cause of the discrepacy has been examined to find that it should be attributed to lack of the accuracy of the OSM estimation rather than the present pressure formula. It is shown that the situation can be improved considerably by using measured ship motion data instead of the OSM data.