luis barbosa - Academia.edu (original) (raw)
Papers by luis barbosa
European Transactions on Telecommunications, 1991
Multimedia communications is the field referring to the representation, storage, retrieval and di... more Multimedia communications is the field referring to the representation, storage, retrieval and dissemination of machine-processable information expressed in multiple media, such as text, voice, graphics, image, audio and video. With the advent of high capaciry storage devices powerful and yet economical computer workstations and high-speed integrated services digital networks providing a variety of multimedia communications services are becoming not only technically but also economically feasible. Applications in medicine, education, travel, real-estate, banking, insurance, administration and publishing and advertising are emerging at a fast pace. These applications are characterized by large multimedia documents that have to be communicated within very short delays. Computer-controlled cooperative work, whereby a group of users can jointly view, create, edit and discuss multimedia documents is going to be characteristic of many transactions in the year 2000. In this paper, we review the activity in Multimedia Communications, Services and Applications.
Studia Logica, 2013
In Computer Science stepwise refinement of algebraic specifications is a well-known formal method... more In Computer Science stepwise refinement of algebraic specifications is a well-known formal methodology for rigorous program development. This paper illustrates how techniques from Algebraic Logic, in particular that of interpretation, understood as a multifunction that preserves and reflects logical consequence, capture a number of relevant transformations in the context of software design, reuse, and adaptation, difficult to deal with in classical approaches. Examples include data encapsulation and the decomposition of operations into atomic transactions. But if interpretations open such a new research avenue in program refinement, (conceptual) tools are needed to reason about them. In this line, the paper's main contribution is a study of the correspondence between logical interpretations and morphisms of a particular kind of coalgebras. This opens way to the use of coalgebraic constructions, such as simulation and bisimulation, in the study of interpretations between (abstract) logics.
European Transactions on Telecommunications, 1991
Multimedia communications is the field referring to the representation, storage, retrieval and di... more Multimedia communications is the field referring to the representation, storage, retrieval and dissemination of machine-processable information expressed in multiple media, such as text, voice, graphics, image, audio and video. With the advent of high capaciry storage devices powerful and yet economical computer workstations and high-speed integrated services digital networks providing a variety of multimedia communications services are becoming not only technically but also economically feasible. Applications in medicine, education, travel, real-estate, banking, insurance, administration and publishing and advertising are emerging at a fast pace. These applications are characterized by large multimedia documents that have to be communicated within very short delays. Computer-controlled cooperative work, whereby a group of users can jointly view, create, edit and discuss multimedia documents is going to be characteristic of many transactions in the year 2000. In this paper, we review the activity in Multimedia Communications, Services and Applications.
Studia Logica, 2013
In Computer Science stepwise refinement of algebraic specifications is a well-known formal method... more In Computer Science stepwise refinement of algebraic specifications is a well-known formal methodology for rigorous program development. This paper illustrates how techniques from Algebraic Logic, in particular that of interpretation, understood as a multifunction that preserves and reflects logical consequence, capture a number of relevant transformations in the context of software design, reuse, and adaptation, difficult to deal with in classical approaches. Examples include data encapsulation and the decomposition of operations into atomic transactions. But if interpretations open such a new research avenue in program refinement, (conceptual) tools are needed to reason about them. In this line, the paper's main contribution is a study of the correspondence between logical interpretations and morphisms of a particular kind of coalgebras. This opens way to the use of coalgebraic constructions, such as simulation and bisimulation, in the study of interpretations between (abstract) logics.