Conceptual models describe an application domain to further communication and understanding, and serve as the basis for subsequent software design and implementation. For a language to be used for conceptual modelling, the semantics of its constructs must be well-defined w.r.t. the application domain. The semantics of the association construct, central to object-oriented modelling languages, ar...

Polymorphic equality is a controversial language construct. While being convenient for the programmer, it has been argued that polymorphic equality (1) invites to violation of software engineering principles, (2) lays a serious burden on the language implementor, and (3) enforces a runtime overhead due to the necessity of tagging values at runtime. We show that neither (2) nor (3) are inherent ...

We propose a novel language construct called communicating transactions, obtained by dropping the isolation requirement from classical transactions, which can be used to model automatic error recovery in distributed systems. We extend CCS with this construct and give a simple semantics for the extended calculus, called TransCCS. We develop a behavioural theory which is sound and complete with r...

The purpose of this paper is to improve the modelization of the rotational mixing which occurs in stellar radiation zones, through the combined action of the thermally driven meridional circulation and of the turbulence generated by the shear of differential rotation. The turbulence is assumed to be anisotropic, due to the stratification, with stronger transport in the horizontal directions tha...

The splitting of the frequencies of p-modemultiplets enables information to be gained about the internal rotation of the sun. Such data have revealed a transition at the base of the convection zone from differential rotation similar to that observed at the surface to almost solid-body rotation in the radiative interior. This transition region, known as the tachocline, has been found to be relat...

Generalized Hoare logic (GHL) is a formal logical system for proving invariance properties of programs. It was first introduced by Lamport to reason about simple concurrent programs with shared variables. It was generalized by Lamport and Schneider who noticed that the inference rules for each language construct (enabling invariance properties of statements to be derived from invariance propert...

One of the important tasks of exception handling is to restore program state and invariants. Studies suggest that this is often done incorrectly. We introduce a new language construct that integrates automated memory recovery with exception handling. When an exception occurs, memory can be automatically restored to its previous state. We also provide a mechanism for applications to extend the a...

This document reports experiment and result of Fudan WIM group in Expert Search track in TREC 2006. Our research mainly focus on the measurement of expertise. Inspired by the human procedure of expert search, we construct 2 models, a language model and a social network model are compared. The association function of expert and document is modified. And email search techniques are employed in do...

Sequential programming and work-flow programming are two useful, but radically different, ways of describing computational processing. Of the two, it is sequential programming that we teach all programmers and support by programming languages, whether in procedural, objectoriented, or functional paradigms. We teach workflow as a secondary style of problem decomposition for use in special situat...

Ubiquitous environments may become a reality in a foreseeable future and research is aimed on making them more and more adapted and comfortable for users. Our work consists on applying reinforcement learning techniques in order to adapt services provided by a ubiquitous assistant to the user. The learning produces a context model, associating actions to perceived situations of the user. Associa...