66,465 research outputs found
On a hierarchical control strategy for multi-agent formation without reflection
This paper considers a formation shape control problem for point agents in a
two-dimensional ambient space, where the control is distributed, is based on
achieving desired distances between nominated agent pairs, and avoids the
possibility of reflection ambiguities. This has potential applications for
large-scale multi-agent systems having simple information exchange structure.
One solution to this type of problem, applicable to formations with just three
or four agents, was recently given by considering a potential function which
consists of both distance error and signed triangle area terms. However, it
seems to be challenging to apply it to formations with more than four agents.
This paper shows a hierarchical control strategy which can be applicable to any
number of agents based on the above type of potential function and a formation
shaping incorporating a grouping of equilateral triangles, so that all
controlled distances are in fact the same. A key analytical result and some
numerical results are shown to demonstrate the effectiveness of the proposed
method.Comment: Accepted by the 57th IEEE Conference on Decision and Contro
On global convergence of area-constrained formations of hierarchical multi-agent systems
This paper is concerned with a formation shaping problem for point agents in
a two-dimensional space, where control avoids the possibility of reflection
ambiguities. One solution for this type of problems was given first for three
or four agents by considering a potential function which consists of both the
distance error and the signed area terms. Then, by exploiting a hierarchical
control strategy with such potential functions, the method was extended to any
number of agents recently. However, a specific gain on the signed area term
must be employed there, and it does not guarantee the global convergence. To
overcome this issue, this paper provides a necessary and sufficient condition
for the global convergence, subject to the constraint that the desired
formation consists of isosceles triangles only. This clarifies the admissible
range of the gain on the signed area for this case. In addition, as for
formations consisting of arbitrary triangles, it is shown when high gain on the
signed area is admissible for global convergence.Comment: Accepted in the 59th IEEE Conference on Decision and Control (CDC
2020). arXiv admin note: text overlap with arXiv:1808.0031
“An ethnographic seduction”: how qualitative research and Agent-based models can benefit each other
We provide a general analytical framework for empirically informed agent-based simulations. This methodology provides present-day agent-based models with a sound and proper insight as to the behavior of social agents — an insight that statistical data often fall short of providing at least at a micro level and for hidden and sensitive populations. In the other direction, simulations can provide qualitative researchers in sociology, anthropology and other fields with valuable tools for: (a) testing the consistency and pushing the boundaries, of specific theoretical frameworks; (b) replicating and generalizing results; (c) providing a platform for cross-disciplinary validation of results
Embodied cognition and temporally extended agency
According to radical versions of embodied cognition, human cognition and agency should be explained without the ascription of representational mental states. According to a standard reply, accounts of embodied cognition can explain only instances of cognition and agency that are not “representation-hungry”. Two main types of such representation-hungry phenomena have been discussed: cognition about “the absent” and about “the abstract”. Proponents of representationalism have maintained that a satisfactory account of such phenomena requires the ascription of mental representations. Opponents have denied this. I will argue that there is another important representation-hungry phenomenon that has been overlooked in this debate: temporally extended planning agency. In particular, I will argue that it is very difficult to see how planning agency can be explained without the ascription of mental representations, even if we grant, for the sake of argument, that cognition about the absent and abstract can. We will see that this is a serious challenge for the radical as well as the more modest anti-representationalist versions of embodied cognition, and we will see that modest anti-representationalism is an unstable position
Macroporous materials: microfluidic fabrication, functionalization and applications
This article provides an up-to-date highly comprehensive overview (594 references) on the state of the art of the synthesis and design of macroporous materials using microfluidics and their applications in different fields
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A needs theory of governance
New-institutional economics hypothesizes imperfect rationality, self-seeking preferences, monetary-related needs, and opportunism as fundamental features of human behavior. Consistently, new-institutionalist models of governance highlight the efficiency and transaction costs minimizing features of control rights and governance. Differently, needs theory of governance, as here presented, hypothesizes imperfect rationality, multiple needs, and reciprocity, in which case opportunism is reduced to an exception to individual behavior. Consistently, it presents a theory that links production governance with the wellbeing of those partaking in production. Building on Maslow’s human psychology, the governance model suggested in this paper is aimed at evidencing the self-actualization potential of control rights, organizational structures and practices. The application of Maslow’s theory to the institutional structure of organizations suggests that the deepest organizational layers (control rights and governance) broadly correspond to the most basic needs in Maslow’s theory (survival, security and belonging), while the outer layers (managerial models and employment relations) correspond to the fulfillment of the highest needs (self-esteem and self-actualization). Cooperative firms are used as an illustration of governance solutions consistent with needs theory in human psychology
A new governance approach for multi-firm projects: lessons from Olkiluoto 3 and Flamanville 3 nuclear power plant projects
We analyze governance in two contemporary nuclear power plant projects: Olkiluoto 3 (Finland) and Flamanville 3 (France). We suggest that in the governance of large multi-firm projects, any of the prevalent governance approaches that rely on market, hierarchy, or hybrid forms, is not adequate as such. This paper opens up avenues towards a novel theory of governance in large projects by adopting a project network view with multiple networked firms within a single project, and by simultaneously going beyond organizational forms that cut across the traditional firm–market dichotomy. Our analysis suggests four changes in the prevailing perspective towards the governance of large projects. First, there should be a shift from viewing multi-firm projects as hierarchical contract organizations to viewing them as supply networks characterized by a complex and networked organizational structure. Second, there should be a shift in the emphasis of the predominant modes of governance, market and hierarchy towards novel governance approaches that emphasize network-level mechanisms such as self-regulation within the project. Third, there should be a shift from viewing projects as temporary endeavors to viewing projects as short-term events or episodes embedded in the long-term sphere of shared history and expected future activities among the involved actors. Fourth, there should be a shift from the prevailing narrow view of a hierarchical project management system towards an open system view of managing in complex and challenging institutional environments
Identification of Hessian matrix in distributed gradient-based multi-agent coordination control systems
Multi-agent coordination control usually involves a potential function that
encodes information of a global control task, while the control input for
individual agents is often designed by a gradient-based control law. The
property of Hessian matrix associated with a potential function plays an
important role in the stability analysis of equilibrium points in
gradient-based coordination control systems. Therefore, the identification of
Hessian matrix in gradient-based multi-agent coordination systems becomes a key
step in multi-agent equilibrium analysis. However, very often the
identification of Hessian matrix via the entry-wise calculation is a very
tedious task and can easily introduce calculation errors. In this paper we
present some general and fast approaches for the identification of Hessian
matrix based on matrix differentials and calculus rules, which can easily
derive a compact form of Hessian matrix for multi-agent coordination systems.
We also present several examples on Hessian identification for certain typical
potential functions involving edge-tension distance functions and
triangular-area functions, and illustrate their applications in the context of
distributed coordination and formation control
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