High assurance security is extremely diicult to acheive in distributed computer systems due to their inherent non-determinism and heterogeneity. The practical application of formal methods is the key to high assurance security in open, distributed environments. This paper presents a methodology that applies formal methods within a dual framework to achieve secure interoperation of heterogeneous...

To answer the question “Which clustering function should one use?” for a given task, we consider an axiomatic approach to the theory of Clustering, with special focus on uniqueness theorems characterizing popular clustering functions. We argue that such theorems can be used to decide exactly when a particular clustering function should be used or avoided. We discuss abstract properties of clust...

A semigroup S is called locally finite (respectively, periodic) if each finitely generated (respectively, each monogenic) subsemigroup in S is finite. A semigroup variety is locally finite (respectively, periodic) if so are all its members. Clearly, every locally finite variety is periodic but the converse is not true. The issues related to determining extra properties that distinguish locally ...

High assurance security is extremely di cult to acheive in distributed computer systems due to their inherent non-determinism and heterogeneity. The practical application of formal methods is the key to high assurance security in open, distributed environments. This paper presents a methodology that applies formal methods within a dual framework to achieve secure interoperation of heterogeneous...

A data schema is a set of constructs that emulate relations between domain instances. Schema evolution is changes in the data schema and a system of data consistency support for such modifications. Axiomatic model regulates modifications and maintains data consistency by ensuring that the data schema always satisfies a set of axioms. This paper is an extension to previous work, which has define...