An Abstract Formal Basis for Digital Crowds

Crowdsourcing, together with its related approaches, has become very popular in recent years. All crowdsourcing processes involve the participation of a digital crowd, a large number of people that access a single Internet platform or shared service. In this paper we explore the possibility of applying formal methods, typically used for the verification of software and hardware systems, in analysing the behaviour of a digital crowd. More precisely, we provide a formal description language for specifying digital crowds. We represent digital crowds in which the agents do not directly communicate with each other. We further show how this specification can provide the basis for sophisticated formal methods, in particular formal verification.Comment: 32 pages, 4 figure

A self-managing infrastructure for ad-hoc situation determination

Automatically determining the situation of an ad-hoc group of people and devices within a smart environment is a significant challenge in pervasive computing systems. Current approaches often rely on an environment expert to correlate the situations that occur with the available sensor data, while other machine learning based approaches require long training periods before the system can be used. This paper presents a novel approach to situation determination that attempts to overcome these issues by providing a reusable library of general situation specifications that can be easily extended to create new specific situations, and immediately deployed without the need of an environment expert. The architecture of an accompanying situation determination infrastructure is provided, which autonomously optimises and repairs itself in reaction to changes or failures in the environment

MAKE-OR-BUY THEORIES: WHERE DO WE STAND?

The aim of this paper is to discuss the state-of-the art and the directions for research on the make-orbuy problem. After thirty years of research efforts, we now have numerous contributions explaining different aspects of the nature and existence of the firm. The search for a unified theory, however, still remains, at a theoretical level, a challenge. The task is not easy, perhaps because the theory of the firm develops along two different strands, one analyzing the factors influencing the boundaries, and the other one relating to the internal structure; or because, even inside the same research strand, it is not really easy to grasp the similarities and differences between contributions that have followed one another in rapid succession over the last few years. This paper examines the theories concerning the make-or-buy problem, focusing on recent contributions that have tried to develop a unified framework and emphasizes the role of incomplete contracts as a common and significant trait of the theories discussed

Flocking Behaviour: Agent-Based Simulation and Hierarchical Leadership

We have studied how leaders emerge in a group as a consequence of interactions among its members. We propose that leaders can emerge as a consequence of a self-organized process based on local rules of dyadic interactions among individuals. Flocks are an example of self-organized behaviour in a group and properties similar to those observed in flocks might also explain some of the dynamics and organization of human groups. We developed an agent-based model that generated flocks in a virtual world and implemented it in a multi-agent simulation computer program that computed indices at each time step of the simulation to quantify the degree to which a group moved in a coordinated way (index of flocking behaviour) and the degree to which specific individuals led the group (index of hierarchical leadership). We ran several series of simulations in order to test our model and determine how these indices behaved under specific agent and world conditions. We identified the agent, world property, and model parameters that made stable, compact flocks emerge, and explored possible environmental properties that predicted the probability of becoming a leader.Flocking Behaviour; Hierarchical Leadership; Agent-Based Simulation; Social Dynamics

Modelling and Verification of Multiple UAV Mission Using SMV

Model checking has been used to verify the correctness of digital circuits, security protocols, communication protocols, as they can be modelled by means of finite state transition model. However, modelling the behaviour of hybrid systems like UAVs in a Kripke model is challenging. This work is aimed at capturing the behaviour of an UAV performing cooperative search mission into a Kripke model, so as to verify it against the temporal properties expressed in Computation Tree Logic (CTL). SMV model checker is used for the purpose of model checking

Proactive SLA negotiation for service based systems: Initial implementation and evaluation experience

This paper describes a framework that we have developed to integrate proactive SLA negotiation with dynamic service discovery to provide cohesive runtime support for both these activities. The proactive negotiation of SLAs as part of service discovery is necessary for reducing the extent of interruptions during the operation of a service based system when the need for replacing services in it arises. The developed framework discovers alternative candidate constituent services for a service client application, and negotiates/agrees but does not activate SLAs with these services until the need for using a service becomes necessary. A prototype tool has been implemented to realize the framework. This prototype is discussed in the paper along with the results of the initial evaluation of the framework

Coordination approaches and systems - part I : a strategic perspective

This is the first part of a two-part paper presenting a fundamental review and summary of research of design coordination and cooperation technologies. The theme of this review is aimed at the research conducted within the decision management aspect of design coordination. The focus is therefore on the strategies involved in making decisions and how these strategies are used to satisfy design requirements. The paper reviews research within collaborative and coordinated design, project and workflow management, and, task and organization models. The research reviewed has attempted to identify fundamental coordination mechanisms from different domains, however it is concluded that domain independent mechanisms need to be augmented with domain specific mechanisms to facilitate coordination. Part II is a review of design coordination from an operational perspective