A Type Inference Algorithm for Secure Ambients

We consider a type discipline for the Ambient Calculus that associates ambients with security levels and constrains them to be traversed by or opened in ambients of higher security clearance only. We present a bottom-up algorithm that, given an untyped process $P$, computes a minimal set of constraints on security levels such that all actions during runs of $P$ are performed without violating the security level priorities. Such an algorithm appears to be a prerequisite to use type systems to ensure security properties in the web scenario

Space-Aware Ambients and Processes

Resource control has attracted increasing interest in foundational research on distributed systems. This paper focuses on space control and develops an analysis of space usage in the context of an ambient-like calculus with bounded capacities and weighed processes, where migration and activation require space. A type system complements the dynamics of the calculus by providing static guarantees that the intended capacity bounds are preserved throughout the computation

Composing Communicating Systems, Synchronously

Communicating systems are nowadays part of everyday life, yet programming and analysing them is difficult. One of the many reasons for this difficulty is their size, hence compositional approaches are a need. We discuss how to ensure relevant communication properties such as deadlock freedom in a compositional way. The idea is that communicating systems can be composed by taking two of their participants and transforming them into coupled forwarders connecting the two systems. It has been shown that, for asynchronous communications, if the participants are \u201ccompatible\u201d then composition satisfies relevant communication properties provided that the single systems satisfy them. We show that such a result changes considerably for synchronous communications. We also discuss a different form of composition, where a unique forwarder is used

Choreography automata

Automata models are well-established in many areas of computer science and are supported by a wealth of theoretical results including a wide range of algorithms and techniques to specify and analyse systems. We introduce choreography automata for the choreographic modelling of communicating systems. The projection of a choreography automaton yields a system of communicating finite-state machines. We consider both the standard asynchronous semantics of communicating systems and a synchronous variant of it. For both, the projections of well-formed automata are proved to be live as well as lock- and deadlock-free

On Composing Communicating Systems

Communication is an essential element of modern software, yet programming and analysing communicating systems are difficult tasks. A reason for this difficulty is the lack of compositional mechanisms that preserve relevant communication properties. This problem has been recently addressed for the well-known model of communicating systems, that is sets of components consisting of finite-state machines capable of exchanging messages. The main idea of this approach is to take two systems, select a participant from each of them, and derive from those participants a pair of coupled gateways connecting the two systems. More precisely, a message directed to one of the gateways is forwarded to the gateway in the other system, which sends it to the other system. It has been shown that, under some suitable compatibility conditions between gateways, this composition mechanism preserves deadlock freedom for asynchronous as well as symmetric synchronous communications (where sender and receiver play the same part in determining which message to exchange). This paper considers the case of asymmetric synchronous communications where senders decide independently which message should be exchanged. We show here that preservation of lock freedom requires sequentiality of gateways, while this is not needed for preservation of either deadlock freedom or strong lock freedom

Polymorphic intersection type assignment for rewrite systems with abstraction and -rul

We define two type assignment systems for first-order rewriting extended with application, -abstraction, and -reduction, using a combination of intersection types and second-order polymorphic types. The first system is the general one, for which we prove subject reduction, and strong normalisation of typeable terms. The second is a decidable subsystem of the first, by restricting to rank 2 (intersection and quantified) types. For this system we define, using an extended notion of unification, a notion of principal typing which is more general than ML’s principal type property, since also the types for the free variables of terms are inferre

Review about comorbidities of behavioural disorders in children and adolescents: The focus on attention-deficit/hyperactivity disorder

Disruptive behavior disorders (DBD) present high comorbidity rate mainly for opposite-defiant disorders that are frequent among children, adolescents and adults affected by with attention deficit and hyperactivity disorder (ADHD), probably as result of common temperamental risk factors such as attention, distraction, impulsivity. ADHD tend to manifest in about 50% of individuals diagnosed as disruptive behavioral disorders

Behavioural disorders in children and adolescents: A conceptual review about the therapeutic alliance with family and school

Aim: In disruptive behavioral disorders, given the wide range of symptomatic manifestations and the complexity of the sociofamiliar contexts in which they develop, it is now proven that more visible and more stable results can be achieved over time through multimodal and multidimensional interventions. These are accomplished through the integration of psychotherapeutic interventions for the child and parents, counseling interventions for all the various practitioners who come into contact with the child in school, sports, and social settings, through the possibility of organizing multiple settings in patient can be followed by several health professionals such as child and adolescent neuropsychiatrist, neuropsychomotricist, occupation therapist, psychologist