In this paper we consider an approach to developing complex database schemas. Apart from the theoretical model of the approach, we also developed a CASE tool named Integrated Information Systems*Case, R.6.2 (IIS*Case) that supports the practical application of the approach. In this paper the basis of our approach to the design and integration of database schemas and ways of using IIS*Case is outlined. The main features of a new version of IIS*Case, developed in Java, are described. IIS*Case is based on the concept of 'form type' and supports the conceptual modelling of a database schema, generating subschemas and integrating them into a relational database schema in 3NF. IIS*Case provides an intelligent support for complex and highly formalized design and programming tasks. Having an advanced knowledge of information systems and database design is not a compulsory prerequisite for using IIS*Case. IIS*Case is based on a methodology of gradual integration of independently designed subschemas into a database schema. The process of independent subschema design may lead to collisions in expressing real-world constraints. IIS*Case uses specialized algorithms for checking the consistency of constraints embedded in a database schema and its subschemas. This paper briefly outlines the application of the process of detecting collisions, and actions the designer may take to resolve them.The set of relation schemes of the application system Student Service is:• Student ({StudentId, Year}, {StudentId}, {}); and • Grade ({StudentId, CourseShortName, Date, Grade}, {StudentId+CourseShortName}, {}).The set of generated basic referential integrity constraints of the application system Student Service is:
Land administration systems are of great importance for a large number of stakeholders. One of the key problems related to land administration systems is the problem of the correctness of their state, meaning that data stored in land administration systems are not in concordance with the actual legal, spatial and topographic situation. The main causes of land administration systems' incorrect state are data collection and compilation, data processing, and data misuse. In this paper, we discuss the problems of data tampering, the long time needed for registering land administration system's transactions, and the possibility of double spending, which all can add incorrectness in a land administration system. Our research is based on the hypothesis that these problems may be addressed by means of distributed ledger technology, or to be more precise, by means of blockchain technology. The solution is presented in a form of a smart contract written in Solidity programing language that can cover even those more specific use cases in land administration systems such as sharing of ownership, transferring part of ownership, splitting or merging of real estate, and limiting the possibility of trading a real estate. The proposed smart contract represents an implementation of a programming interface that was created based on both ERC-20 and ERC-721 token standards, to satisfy the specific needs of land administration systems.INDEX TERMS Blockchain, Ethereum, land administration, real estate, smart contract.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.