Abstract. This paper presents the language and software environment LEADSTO that has been developed to model and simulate the dynamics of Multi-Agent Systems (MAS) in terms of both qualitative and quantitative concepts. The LEADSTO language is a declarative order-sorted temporal language, extended with quantitative means. Dynamics of MAS can be modelled by specifying the direct temporal dependencies between state properties in successive states. Based on the LEADSTO language, a software environment was developed that performs simulations of LEADSTO specifications, generates simulation traces for further analysis, and constructs visual representations of traces. The approach proved its value in a number of projects within different domains of MAS research. 1

Abstract. A new, formal, role-based, framework for modeling and analyzing both real world and artificial organizations is introduced. It exploits static and dynamic properties of the organizational model and includes the (frequently ignored) environment. The transition is described from a generic framework of an organization to its deployed model and to the actual agent allocation. For verification and validation purposes, a set of dedicated techniques is introduced. Moreover, where most models can handle only two or three layered organizational structures, our framework can handle any arbitrary number of organizational layers. Henceforth, real-world organizations can be modeled and analyzed, as illustrated by a case study, within the DEAL project line. 1

Abstract. Agent-based simulation methods are a relatively new way to address complex systems. Usually the idea is that the agents used are rather simple, and the complexity and adaptivity of such a system are modelled by the interaction between these agents. However, another way to exploit agent-based simulation methods is by use of agents that themselves also have certain forms of learning or adaptation. In order to simulate adaptive agents with abilities matching those of their real-world biological or societal counterparts, a natural approach is to incorporate certain adaptation mechanisms such as classical conditioning into agent models. Existing models for adaptation mechanisms are usually based on quantitative, numerical methods, and more in particular, differential equations. Since agent-based simulation is usually based on qualitative, logical languages, these quantitative models are often not directly appropriate as an input in the context of agent-based simulation. To deal with this problem, this paper puts forward an integrative approach to simulate and analyse the dynamics of a conditioning process of an adaptive agent, integrating quantitative, numerical and qualitative, logical aspects within one expressive temporal specification language. To obtain a simulation model, an executable sublanguage of this language is used to specify the agent’s adaptation

A BDI-based continuous-time modelling approach for intracellular dynamics is presented. It is shown how temporalised BDI-models make it possible to model intracellular biochemical processes as decision processes. By abstracting from some of the details of the biochemical pathways, the model achieves understanding in nearly intuitive terms, without losing veracity: classical intentional state properties such as Beliefs, Desires and Intentions, are founded in reality through precise biochemical relations. In an extensive example, the complex regulation of Escherichia coli vis-à-vis lactose, glucose and oxygen is simulated as a discrete-state, continuous-time temporal decision manager. Thus a bridge is introduced between two different scientific areas: the area of BDI-modelling and the area of intracellular dynamics.

Abstract. In this paper a modelling approach to the dynamics within a multi-agent organisation is presented. A declarative, executable specification language for dynamics within an organisation is proposed as a basis for simulation. Moreover, to be able to specify and analyse dynamic properties within an organisation, another declarative specification language is put forward, which is much more expressive than the executable language for simulations. Supporting tools have been implemented that consist of a software environment for simulation of organisation models and a software environment for analysis of dynamic properties against traces of dynamics within an organisation. 1

This paper demonstrates the use of Point Graphs (PG) and temporal logic for analyzing courses of action (COA) in a Timed Influence Net (TIN) that models a dynamic uncertain situation. The current practice in courses of action analysis looks at the impacts of actions on the likelihood of the desired effects over a period of time. The impact of time, however, is not studied explicitly. This paper presents an algorithm that generates a corresponding Point Graph for a Timed Influence Net. This graph-based knowledge representation and reasoning formalism is shown to help reveal temporal behavior of the modeled system. A temporal language is also shown to interact with the graphical representation. An analysis on the graph addresses user-defined ‘what-if’ scenarios for a better understanding of the temporal relationships between certain actions that may result in a desired effect at a particular time instant. 1.

Abstract. To enable the development of automated support for the dynamics of design processes, a challenge is to model and analyse such dynamics in a formal manner. This paper contributes a declarative, logical approach for specification of dynamic properties of design processes, supported by a formal temporal language which has a high expressivity. This language can be used to specify dynamic properties at the level of a design process as a whole, or of parts thereof. At the most detailed level, in an executable sublanguage also simulation models are specified in a declarative, logical manner, which allows to use these specifications in logical analysis as well. The approach is illustrated by an example component-based agent-system design process. 1.

Abstract. Recognizing that trust states are mental states, this paper presents a formal analysis of the dynamics of trust in terms of the functional roles and representation relations for trust states. This formal analysis is done both in a logical framework and in a mathematical framework based on integral and differential equations. Furthermore, the paper presents formal specifications of a number of relevant dynamic properties of trust. The specifications provided were used to perform automated formal analysis of empirical and simulated data from two case studies, one involving two experiments with humans, and one involving simulation experiments in the context of an economic game.

Abstract. An approach for handling the complex dynamics of a multi-agent system is based on distinguishing aggregation levels. The behaviour at a given aggregation level is specified by a set of dynamic properties at that level, expressed in some (temporal) language. Such behavioural specifications may be complex and difficult to analyse. To enable automated analysis of system specifications, a simpler format is required. To this end, a specification at a lower aggregation level can be created, describing basic steps in the processes of a system. This paper presents a method and tool to support the automated creation of such a specification, as a refinement of a given higher level specification. The generated specification has a simple format which can easily be used for analysis. This paper describes an approach for automated verification of logical consequences of specifications using model checking techniques.

In this paper, the question is addressed which patterns in world dynamics are an indication for a conceptualisation of a world’s process as an agent. Six criteria are discussed that provide an indication for the world to show a form agency, and allows for suitable agent-based conceptualisation. The criteria take the form of relationships between the occurrence of certain patterns in the world’s dynamics, and are expressed as second-order properties of world dynamics. They are formalised in a reified temporal predicate (meta-)logical language and their use is illustrated in a case study, supported by automated support in the form of simulation and verification. 1