Graphical Editor for Graphical User Interfaces for an "Internet of Things" System

The aim for the graphical editor described in this paper is to simplify the creation of Graphical User Interfaces (GUIs) for PalCom (an “Internet of Things”-solution). Ideally, the people who are to use the GUIs will be able to create them themselves. Most graphical editors focus on placing graphical components (buttons etc.), then assigning them a function. The graphical editor described in this paper aims to introduce the opposite work flow, i.e. identify functionality and then suggest graphical components to express this functionality in the Graphical User Interface (GUI) to be created

End-User Composition of Graphical User Interfaces for PalCom Systems

AbstractIn ubiquitous computing, end-user composition allows users to combine multiple single-purpose devices into new, interesting constellations. In PalCom – a ubiquitous middleware – this is achieved without the need to write program code. In this paper we present a solution that in the same way allows users to create Graphical User Interfaces (GUIs) for such systems without coding. The approach is to focus on presenting functionality in a GUI rather than attaching functionality to manually added components. We see this as an inverted way of working with GUI development. The solution was realized in the form of a graphical editor for a PalCom specific User Interface Description Language. The tool produces platform independent GUI descriptions that can be interpreted on any platform. When compared to another common tool, the presented editor exhibited roughly 10x shorter development times. The learning time for new users was also evaluated with positive outcome, and a scalability evaluation showed that the solution can be used to create professional grade GUIs

Efficient Income Taxation in Steady State

With the Pareto principle as the sole normative criterion, simple necessary conditions for efficient tax rates on labour and capital incomes are established in an overlapping-generations model. The individuals in the economy have differing earning abilities and their labour supply is elastic. The analysis focuses on inragenerational aspects and is restricted to linear taxation in steady states of a closed economy. Both "global" results on the range of efficient tax rates, and "local" counterparts are given, the latter in the form of upper bounds that depend on the (uncompensated) elasticities of aggregate labour supply and private savings. The Golden Rule is shown to apply in this context