We argue that the Java type system is sound, by proving a subject reduction theorem. We deene a subset of Java, a language which is safe and which reeects the most essential features of Java, a term rewriting system for the operational semantics and a type inference system to describe compile time type checking. We prove that program execution preserves the types, up to the subclass/subinterfac...

In this paper we propose an extension of TTCN (Tree and Tabular Combined Notation) to real-time TTCN. The extension is de-ned on a syntactical and semantical level. Syntactically, we provide facilities to annotate TTCN statements with two time values, namely an earliest execution time (EET) and a latest execution time (LET). The informal interpretation of these time values is that a TTCN statem...

Research in collaborative editing tends to have been undertaken in isolation rather than as part of a general information or application infrastructure. Our goal is to develop a universal information platform that can support collaboration in a range of application domains. Since not all user groups have the same conventions and not all tasks have the same requirements, this implies that it sho...

Stochastic (Markovian) process algebra extend classical process algebra with probabilistic exponentially distributed time durations denoted by rates (the parameter of the exponential distribution). Defining a semantics for such an algebra, so to derive Continuous Time Markov Chains from system specifications, requires dealing with transitions labeled by rates. With respect to standard process a...

Motivated by many practical applications that have to compute in the presence of uncertainty, we propose a monadic probabilistic language based upon the mathematical notion of sampling function. Our language provides a unified representation scheme for probability distributions, enjoys rich expressiveness, and offers high versatility in encoding probability distributions. We also develop a nove...

We present a module calculus for studying a simple model of link-time compilation. The calculus is stratified into a term calculus, a core module calculus, and a linking calculus. At each level, we show that the calculus enjoys a computational soundness property: if two terms are equivalent in the calculus, then they have the same outcome in a smallstep operational semantics. This implies that ...

Estelle is one of the standardized Formal Description Techniques for the specii-cation of communication protocols and distributed systems. Unfortunately, Estelle is not capable to express real-time requirements or characteristics of services or protocols which is especially important in the context of distributed multimedia systems. In this paper, we introduce an extension to Estelle called Rea...

The effects and influences of various operational parameters on the efficiency of mixer-settlers are thoroughly studied in this paper. One of the most important factors in designing a mixer-settler is to obtain an optimum operational extraction and overall efficiency. These two factors are dependent on various parameters such as impeller shape, size and speed of impeller, baffle size, residence...

operating parameters and membrane characteristics strongly affect the performance of electrodialysis reversal systems. the most impactful factors are applied voltage, flow rate, temperature, initial feed composition, and ion exchange membrane characteristics; the ph of the feed also has an effect, although to a lesser extent. to determine more precisely how all of these factors impact performan...

different manufacturing enterprises use regularly scheduling algorithms in order to help meeting demands over time and reducing operational costs. nowadays, for a better useofresources and manufacturingin accordance withcustomer needs and given the level ofcompetitionbetweencompanies, employing asuitablescheduling programhasa double importance. conventional productionmethods are constantly subs...