SquashFS is a Linux compress filesystem. Hixosfs is a filesystem used to improve file content search by using metadata informations. In this paper we propose to use Hixosfs idea in SquashFS context by creating a new filesystem HSFS. HSFS is a compress Linux filesystem to store metadata within inodes. We test our idea with DICOM file used to store medical images.

We provide a mathematical model that supports the formal description of visual interfaces’ behaviour. The formalism is based on type-inference notation, in which each variable is defined in the domain of the interface basic widgets, and each transition from a given state of the interface to the following one is represented by the application of an inference rule. When a sequence of actions is made by the user, the behaviour of the corresponding interface is totally defined by the set of inference rules. This formalism allows the designer to formally verify the properties of the interface.

We provide a resource-free characterization of register machines that computes their output within polynomial time O(n^k), by defining our version of predicative recursion and a related recursive programming language. Then, by means of some restriction on composition of programs, we define a programming language that characterize the register machines with a polynomial bound imposed over time and space complexity, simultaneously. A simple syntactical analysis allows us to evaluate the complexity of a program written in these languages.

In this paper we propose a solution to improve the search among compress data. A Linux filesystem has been implemented by combining the advantages of squashfs (compression) and hixosfs (for research). We test our idea with DICOM file used to store medical images.

We define a version of predicative recursion, a related programming language, and a hierarchy of classes of programs that represents a resource-free characterization of register machines computing their output within polynomial time O(n^k), for each finite k. Then, we introduce an operator of diagonalization, that allows us to extend the previous hierarchy and to capture the register machines with computing time bounded by an exponential limit O(n^n^k ). Finally, by means of a restriction on composition of programs, we characterize the register machines with a polynomial bound imposed over time and space complexity, simultaneously.

We investigate the relationship between template metaprogramming and computational complexity, showing how C++ templates characterize the class of polynomialtime computable function, by means of template recursion and specialization. Hence, standard C++ compilers can be used to certify polytime-bounded programs.