Multilevel Models (MLM) have pioneered the analysis of hierarchical data, with two or more levels. Agent-Based Models (ABM) are also used to analyse social phenomena in which there are two or more levels involved. This paper addresses the integration between MLM and ABM. To provide a basis of comparison, we focus on differential school effectiveness analysis, where MLM has been well studied, us...

Many automated system analysis techniques (e.g., model checking, model-based testing) rely on first obtaining a model of the system under analysis. System modeling is often done manually, which is often considered as a hindrance to adopt model-based system analysis and development techniques. To overcome this problem, researchers have proposed to automatically “learn” models based on sample sys...

It is of great biological interest to understand the molecular origins of chemotactic behavior of E. coli by developing population-level models based on the underlying signaling pathway dynamics. We derive macroscopic models for E.coli chemotaxis that match quantitatively with the agent-based model (SPECS) for all ranges of the spacial gradient, in particular when the chemical gradient is large...

Given their simple nature, the success of keyword based retrieval systems is astonishing. Although these methods seemingly only process words (and their word counts), they rely on and credit most of their success to the keyword’s implicit semantics. In fact each keyword is a representation of a thought, or concept. Recent developments in NLP make it possible to use bigger syntactical units (lik...

We present an empirical study of user activity in online BBC discussion forums, measured by the number of posts written by individual debaters and the average sentiment of these posts. Nearly 2.5 million posts from over 18 thousand users were investigated. Scale-free distributions were observed for activity in individual discussion threads as well as for overall activity. The number of unique u...

Consider a decentralized agent-based approach for service location, where agents provide and consume services, and also cooperate with each other by giving referrals to other agents. That is, the agents form a referral network. Based on feedback from their users, the agents judge the quality of the services provided by others. Further, based on the judgments of service quality, the agents also ...

Simulating fine-grained agent-based models requires extensive computational resources. In this article, we present an approach that reduces the number of agents by adaptively abstracting groups of spatial agents into meta-agents that subsume individual behaviours and physical forms. Particularly, groups of agents that have been clustering together for a sufficiently long period of time are dete...

A foreclosed property can have a negative impact on the prices of other properties within its neighborhood and these reduced property prices can lead to further foreclosures within the neighborhood; this is known as the foreclosure contagion effect. This effect has been demonstrated, within the real estate literature, to occur. Traditionally, real estate research have used statistical regressio...

A general -observation-basedqualitative framework to extract agent-based pedestrian behavior is presented. To extract qualitative rules from data we use tools, from Formal Concept Analysis, for implicational reasoning.