Multiple input devices are increasingly used in user interfaces to make human-computer communication more efficient and effective. Interface designers have not only to decide on which input modes should be supported, but also how to fuse them into a single representation format that can be processed by the underlying application system. Drawing appropriate decisions requires, however, a sufficient understanding of the properties of fusion itself. While others have informally characterized input fusion as a transformation between information types, the purpose of the paper is to explore fusion by means of formal process modelling. That is, fusion processes are defined in a formal framework which supports proof of the existence of necessary properties following directly from the process definitions. The presented approach can be applied to analyse and compare fusion processes in existing systems, as well as an aid for interface designers, who have to verify the behaviour of their systems.

PREMO is a major new ISO/IEC standard for graphics and multimedia, which addresses many of the concerns that have been expressed about existing graphics standards. In particular, it addresses the issues of configuration, extension, and interoperation of and between PREMO implementations. This paper gives an overview of PREMO and highlights its most significant features.

GKS has evolved from a long process of national /1,2,3,4/ and international /5,6/ discussion on standardization of graphical systems. One of the basic principles of the Graphical Kernel System GKS is the concept of workstations that are used to address a display terminal with several input devices. This is a basic conceptual difference to the GSPC core system /6/, which will be discussed in this paper.A workstation represents a collection of graphical devices that are operated in a coordinated fashion by an operator at a given site. The whole workstation is treated in GKS as one logical unit.GKS features two dimensional output to and input from single or multiple workstations. Besides basic line drawing primitives raster graphics primitives are supported. The coordinates are transformed in a two-stage transformation process where the first stage can be set for each primitive and the second can be set for each workstation. Furthermore the setting of a workstation specific pen and text table allows control of the appearance of all primitives on the corresponding workstation.A segment facility provides means for structuring a picture in subparts. Segments may be created and deleted, the segment attributes may be dynamically modified, and the segments may be transformed. They can be displayed simultaneously or alternatively on different workstations. A device independent segment storage serves for inserting segments into other segments.