software

Because the software of the Planet Earth Simulator Project is rather complex see for the details the growing documentation on the PES Wiki-Pages (below). Here we will only give a short idea of the whole endeavour.

Let us start with the human person, which perceives its world and has some cognitive models (CModels) 'in its head' which represent its knowledge about the world. To communicate the  knowledge to another person one has to put the  ideas into words of some language. These words are associated with 'meaning', with 'content'. Using specialized languages with specialized technical terms we call this content logical models (LModels). Cognitive models can change, by learning or by forgetting, consciously and unconsciously. Logical models can only change if one changes these explicitly, voluntarily.

A logical model is realized by some language. The main kinds of language are spoken sounds, written letters  or written icons, diagrams. In the beginning will the Planet Earth simulator Project only provide textual and visual logical models (in the  next step we will provide spoken language interfaces for every spoken language worldwide as well as special languages for the impaired).  The textual and visual logical models can be created by textual or visual editors. The textual logical models are represented by the Formal Systems Language (FSL); the visual models by the Factor Connector Language (FCL)(meanwhile even more simplified....). With regard to the human person using these languages they possess an associated 'natural' meaning. But to process this natural meaning on computers one has to translate these natural meanings in states and state changes of a virtual machine, which can be realized by some computer. The whole set of virtual states (data) and changes of these states (operations) and the thereby induced processes constitute another kind of meaning, an artificial meaning, the semantics of the logical models.

The semantics of the formal systems language (FSL) can also be understood as a virtual machine (VM) or as  an abstract machine which reflects this semantics. To realize such a virtual machine as a real process one has to translate this virtual machine into a program which uses the system calls of a real operating system (OS). Such an operating system then manages some real hardware (HW).

The realization of the virtual machine can be done in many different ways. In the Planet Earth Simulator Project we have raised some requirements which should be fulfilled independent of the details of an implementation. Thus it is assumed that the virtual machine (i) is scalable, (ii) can be distributed, (iii) can automatically be converted into a parallel machine, (iv) can be bound to real time and (v) can be run as a safety critical system.

From these requirements one can deduce several 'stories'  how to implement such a system. One possible layout of the PES-project could be the following one (cfg. the following figure):

PES Overview

In this layout the  PES-project assumes basically two kinds of users: the knowledge programmer and the "normal" user.

The knowledge programmer encodes parts of his experience into an LModel. This is either a new model or a modification of an existing LModel.

The normal user selects an existing LModel for simulation. This is done with the aid of the SC (:= Simulation controller).

The Simulation controller communicates with the CM (:= Cluster Manager).

The Cluster Manager starts and stops simulation instances. He also transmits messages between the Simulation Controller and the Simulators.

There could be two kinds of simulators: the World-Simulators (SimWorld) which are simulating world processes and the CognitiveAgent-Simulators (SimCA) which are simulating cognitive agents which are living in the simulated worlds.

PES Overview with Real World

The SimWorld Simulators can be connected to real world through sensors and actuators. If this is the case then the SimCognitiveAGents can indirectly also communicate with the real world.

The task of the software group is to built up all these components in one functional platform. For this we are using latest technology on all levels.

For the LModels the PES-project is using it's own language called FSL (:= Formal Systems Language).

To see more details of the software have a look to the PES cvs-server and it's folders.

To read more, look to the planetearthsimulator-Wiki pages.