Abstract: A method for determining paths from a first vertex and a second vertex in an acyclic directed graph comprises determining a plurality of paths from one or more root vertices in the graph to one or more leaf vertices in the graph, storing each of the plurality of paths as a respective array in a computer database, each respective array comprising a respective root, a respective leaf, and up to a plurality of intermediate vertices, and determining whether the first vertex and the second vertex are both represented in one or more of the arrays.

Abstract: A system for the storage, management and analysis of electronic health records (“EHRs”) is provided. The system comprises an EHR analysis system in communication with one the EHR systems of one or more healthcare provider enterprises via a network, such as the internet. The EHR analysis system receives and stores in a database EHR data and information identifying the format the data is stored in, and is capable of transmitting the data in the same or different format. The system also includes an authoring platform for building and publicizing applications to analyze stored EHR data, allow end users to run the applications on the stored data and present the results of the applications to the end users.

Abstract: A semantic database platform may include an interface through which a user may provide data in a form selected by the user and a database that stores the data in the form selected by the user. The data may be organized into events, each of which includes one or more facts, each of which facts may include a value and an indication vocabulary of which the value is a member. The user may select the vocabulary. The database may store the data in the form in which it is presented by the user.