An Agent-Based Algorithm exploiting Multiple Local Dissimilarities for Clusters Mining and Knowledge Discovery

We propose a multi-agent algorithm able to automatically discover relevant regularities in a given dataset, determining at the same time the set of configurations of the adopted parametric dissimilarity measure yielding compact and separated clusters. Each agent operates independently by performing a Markovian random walk on a suitable weighted graph representation of the input dataset. Such a weighted graph representation is induced by the specific parameter configuration of the dissimilarity measure adopted by the agent, which searches and takes decisions autonomously for one cluster at a time. Results show that the algorithm is able to discover parameter configurations that yield a consistent and interpretable collection of clusters. Moreover, we demonstrate that our algorithm shows comparable performances with other similar state-of-the-art algorithms when facing specific clustering problems

Specification and validation of the MODAM module manager

Electricity distribution networks are large complex systems that are continuously evolving. Agent-based models are a useful way of exploring possible future scenarios for these networks. This paper introduces MODAM, a software framework developed to support building large-scale agent-based models for electricity distribution network planning. This paper describes how models can be assembled in an automated manner at runtime, even though an agent may be composed of aspects that come together from separate components. The Module Manager, which weaves the components together in an automated manner, is described in this paper using formal specifications written in Z, and the specification is validated using the ZLive animation tool

Specification and validation of the MODAM module manager

Electricity distribution networks are large complex systems that are continuously evolving. Agent-based models are a useful way of exploring possible future scenarios for these networks. This paper introduces MODAM, a software framework developed to support building large-scale agent-based models for electricity distribution network planning. This paper describes how models can be assembled in an automated manner at runtime, even though an agent may be composed of aspects that come together from separate components. The Module Manager, which weaves the components together in an automated manner, is described in this paper using formal specifications written in Z, and the specification is validated using the ZLive animation tool

There is No Spoon: Reconsidering the Tax Compliance Puzzle

For over 40 years theorists have sought the effects of tax audits on voluntary compliance rates by studying individual taxpayer motivations. Yet no single theory has produced a taxpayer incentive model that both comports with experience and explains the effects of audits on compliance. This quandary is often termed the “tax compliance puzzle.” Consequently, some theorists have called for more capacious models that make room for the panoply of individual compliance motivations. This Article proposes that a more complex model is unnecessary. To the contrary, complex compliance and enforcement data can result from extremely simple behavioral rules of individual taxpayers and government examiners interacting over time. This Article describes an agent-based computational model that uses a single, simple rule of action for each taxpayer and examiner. The model produces three interesting effects supporting the conclusion that there may be no tax compliance puzzle to solve. First, the results comport with known U.S. compliance and audit rates. Second, the results suggest that while audit probability influences individual compliance decisions, it has negligible effects on system-level compliance patterns. Third, the results support the theory that the perceived strength of the tax authority correlates directly—but nonlinearly—with voluntary compliance rates. The model is not complete enough to determine conclusively that this last effect is due to perceived strength of the tax authority alone and might be due instead to factors such as social norms and other behaviorist theories

Formal specification and analysis of take-off procedure using VDM-SL

traffic management system is a complex adaptive and safety critical system which requires considerable attention for its modelling and verification. Currently Air traffic control (ATC) systems are heavily dependent upon human intervention at airport causing accidents and delays because of failure of communication. The purpose of this study is to develop, plan, manage and verify aircrafts movement procedures at the airport surface that prevent delays and collisions. The airport surface is decomposed into blocks and represented by the graph relation. The state space of the system is described by identifying all the possible components of the system. The ground and local controls monitor queues of the aircrafts moving from taxiway to take-off. It is insured that once an aircraft is inserted into a queue, it is eventually removed from it after the next queue has become available. The take-off procedure is provided using graph theory and Vienna Development Method Specification Language (VDM-SL) and analyzed using VDM-SL toolbox. Formal specification of graph-based model, taxiways, aircrafts, runways and controllers is provided in static part of the model. The state space analysis describing take-off algorithms is provided by defining optimal paths and possible operations in dynamic model expediting the departure procedure. The model is developed by a series of refinements following the stepwise development approach. The delays at airport surface require effective safety and guidance protocols to control air traffic at the airport. In static model, the safety criteria are described in terms of invariants over the data types carrying critical information. The safety is insured by defining pre/post conditions in description of operations for changing state space of the system. Although the proposed study is focussed more on the safety component, however, the efficiency is not ignored. Document type: Articl