Simulation validation remains a central and growing challenge, especially when models are large-scale and complex. To advance rigorous simulation validation, we have developed a component-based modeling environment called Scalable Entity Structure Modeler (SESM), which is based on the multi-aspect, multiresolution component-based modeling paradigm. Using a multi-view graphical modeling interfac...

The subject of this paper is the description of a process-centered software development environment called MERLIN which monitors and guides teams of software developers and managers in producing software objects. Software objects (or objects for short) include all sorts of documents like the requirements analysis, design, code, user manuals, contracts etc. For each user, MERLIN automatically di...

Over the past few years OMG CORBA implementations have matured. Consequently, organizations are now developing sophisticated distributed applications based on OMG standards. Many of these applications may be characterized as being multi-language implementations, running as multiple interdependent processes within a multi-vendor hardware and software environment. While ORB vendors address the de...

To make effective use of distributed systems acting together to form a virtual enterprise, global coordinated operations must be possible. Such operations may be mere queries or complex update operations. In this paper, we describe an existing system at the University of Florida which not only models a Virtual Enterprise using a common object-oriented semantic association model, but acts as a t...

We describe a learning environment for high school biology called BGuILE that engages students in scientific investigations in which they can explore interesting problems in evolution and ecology. The environment supports productive inquiry by two interrelated means. First, the system structures students’ investigations, encouraging them to compare competing hypotheses, articulate predictions, ...

We describe a mechanism based on distributed Event-Condition-Action (ECA) rules that supports data coordination in a multidatabase setting. The proposed mechanism includes an ECA rule language and a rule execution engine that transforms rules when they are first posted, and then coordinates their execution. Like traditional ECA rules, our ECA rule language has three parts: an event language, a ...

Many sophisticated environments allow creating and managing of scientific workflows, whereas the workflow itself is provided as a service. Scientific Grids handle large amounts of data and share resources, but the implementation of service-based applications that use scientific infrastructures remains a challenging task, due to the heterogeneity of Grid middleware and different programming mode...

Since 1996 the Communication Studies programme at Roskilde University (Denmark) has been offered as distance education. During the four years, we have improved our means to achieve a functioning CSCL pedagogy, developing from initially a somewhat naïve translation of face-to-face and group organized PBL to an online context, into a now rather reflected CSCL learning concept, with intensive faci...

Simulation exercises are particularly popular for training in emergency situations. Exercises can vary in their degree of realism, complexity and level of stress, but they all try to reproduce a scenario of a real emergency so that each participant simulates the actions carried out for the role they should play. They not only support effective and situated learning, but they can also serve to i...

In the development of information systems, object-oriented speciication (e.g. Troll 4]) is useful for conceptually modeling of the universe of discourse. Viewing an information system as a collection of communicating objects is close to the intuitive perception of such systems on a conceptual level. Nowadays complex information systems (e.g. knowledge bases) have to be exible to accommodate for...