The conceptual schema of Ethereum

There is an abundant literature on Ethereum, but as far as we know what is missing is its explicit conceptual schema. We present here the conceptual schema of Ethereum in UML. The schema should be useful to those that want to understand Ethereum. We also show that the schema is necessary for developing the schema of Ethereum–based DApps. We present a few population constraints, and show that they suffice for the specification at the conceptual level of what is understood by immutability of a blockchain. We also show that the well–known reification construct and an initial constraint suffice to specify at the conceptual level that the Ethereum blockchain stores the full state history.Peer ReviewedPreprin

Generic Data Manipulation in a Mixed Global/Local Conceptual Model

Modern content management systems allow end-user schema creation, which can result in schema heterogeneity within a system. Building functionality to create and modify data must keep pace with this heterogeneity, but the cost of constant development is high. In this paper, we present a novel approach that extends our previous integration system that uses domain structures—global schema fragments—and local type and integration operators by introducing new local record operators and global insert and update operators. We present two widgets that use the new operators: (i) a generic clone widget that allows users to selectively clone records shown in a global widget while creating new local records; (ii) a generic clone exploration widget that allows users to browse the CloneOf relationships and reason about how different cloned records and structures have evolved. We demonstrate our system with a running example of the clone and exploration widgets in a robotics educational repository

Social navigation support for groups in a community-based educational portal

This work seeks to enhance a user's experience in a digital library using group-based social navigation. Ensemble is a portal focusing on computing education as part of the US National Science Digital Library providing access to a large amount of learning materials and resources for education in Science, Technology, Engineering and Mathematics. With so many resources and so many contributing groups, we are seeking an effective way to guide users to find the right resource(s) by using group-based social navigation. This poster demonstrates how group-based social navigation can be used to extend digital library portals and how it can be used to guide portal users to valuable resources. © 2013 Springer-Verlag