In this demo, we present SEBDB, a novel blockchain database that integrates immutability and transparency properties of blockchain with modeling and query ability of relational database. In summary, SEBDB has the following advantages: First, it adopts the linked structure and full replication of data among multiple participants to guarantee immutability and transparency. Second, it introduces the relational model to blockchain without introducing extra overhead, based on which relational queries are supported. SEBDB supports SQL-like language as the general interface to support convenient application development, in which intrinsic operations are re-defined and re-implemented to suit for blockchain platform. Third, it supports rich verifiable queries based on the proposed authenticated index, thin clients can participate in the system regardless of limitations of storage, network, and computing resources. We demonstrate the usability and scalability of SEBDB using a donation system.

To determine the ordered weighted averaging (OWA) weights, the latent information function is developed to analyze the likelihood of occurrence for the preference value. The more likelihood a preference value is, the bigger the weight is, and vice versa. The proposed model is further extended to the situation where the preference value is an interval number by introducing a new method for interval number comparison. An example of energy technology evaluation is provided to demonstrate that the proposed approach is reasonable and simple.

Most existing distances between intuitionistic fuzzy sets are defined in linear plane representations in 2D or 3D space. Here, we define a new interpretation of intuitionistic fuzzy sets as a restricted spherical surface in 3D space. A new spherical distance for intuitionistic fuzzy sets is introduced. We prove that the spherical distance is different from those existing distances in that it is nonlinear with respect to the change of the corresponding fuzzy membership degrees. © 2009 Wiley Periodicals, Inc.