Decentralised Control of Adaptive Sampling in Wireless Sensor Networks

The efficient allocation of the limited energy resources of a wireless sensor network in a way that maximises the information value of the data collected is a significant research challenge. Within this context, this paper concentrates on adaptive sampling as a means of focusing a sensor’s energy consumption on obtaining the most important data. Specifically, we develop a principled information metric based upon Fisher information and Gaussian process regression that allows the information content of a sensor’s observations to be expressed. We then use this metric to derive three novel decentralised control algorithms for information-based adaptive sampling which represent a trade-off in computational cost and optimality. These algorithms are evaluated in the context of a deployed sensor network in the domain of flood monitoring. The most computationally efficient of the three is shown to increase the value of information gathered by approximately 83%, 27%, and 8% per day compared to benchmarks that sample in a naive non-adaptive manner, in a uniform non-adaptive manner, and using a state-of-the-art adaptive sampling heuristic (USAC) correspondingly. Moreover, our algorithm collects information whose total value is approximately 75% of the optimal solution (which requires an exponential, and thus impractical, amount of time to compute)

Decentralised control of material or traffic flows in networks using phase-synchronisation

We present a self-organising, decentralised control method for material flows in networks. The concept applies to networks where time sharing mechanisms between conflicting flows in nodes are required and where a coordination of these local switches on a system-wide level can improve the performance. We show that, under certain assumptions, the control of nodes can be mapped to a network of phase-oscillators. By synchronising these oscillators, the desired global coordination is achieved. We illustrate the method in the example of traffic signal control for road networks. The proposed concept is flexible, adaptive, robust and decentralised. It can be transferred to other queuing networks such as production systems. Our control approach makes use of simple synchronisation principles found in various biological systems in order to obtain collective behaviour from local interactions

Self-organising agent communities for autonomic resource management

The autonomic computing paradigm addresses the operational challenges presented by increasingly complex software systems by proposing that they be composed of many autonomous components, each responsible for the run-time reconfiguration of its own dedicated hardware and software components. Consequently, regulation of the whole software system becomes an emergent property of local adaptation and learning carried out by these autonomous system elements. Designing appropriate local adaptation policies for the components of such systems remains a major challenge. This is particularly true where the system’s scale and dynamism compromise the efficiency of a central executive and/or prevent components from pooling information to achieve a shared, accurate evidence base for their negotiations and decisions.In this paper, we investigate how a self-regulatory system response may arise spontaneously from local interactions between autonomic system elements tasked with adaptively consuming/providing computational resources or services when the demand for such resources is continually changing. We demonstrate that system performance is not maximised when all system components are able to freely share information with one another. Rather, maximum efficiency is achieved when individual components have only limited knowledge of their peers. Under these conditions, the system self-organises into appropriate community structures. By maintaining information flow at the level of communities, the system is able to remain stable enough to efficiently satisfy service demand in resource-limited environments, and thus minimise any unnecessary reconfiguration whilst remaining sufficiently adaptive to be able to reconfigure when service demand changes

Spatial random multiple access with multiple departure

We introduce a new model of spatial random multiple access systems with a non-standard departure policy: all arriving messages are distributed uniformly on a finite sphere in the space, and when a successful transmission of a single message occurs, the transmitted message leaves the system together with all its neighbours within a ball of a given radius centred at the message's location. We consider three classes of protocols: centralised protocols and decentralised protocols with either ternary or binary feedback; and analyse their stability. Further, we discuss some asymptotic properties of stable protocols

The Role of Corporate HR Functions In Multinational Corporations: The Interplay Between Corporate, Regional/National And Plant Level

The HR literature has been abundant in providing typologies of the roles of HR professionals in their organisation. These typologies are largely related to the changing nature of HRM over time, and the context in which empirical work was carried out. In this paper we focus on the context of the increasing internationalisation of firms and how this has an effect upon modern-day typologies of HR roles. We explore these roles by focusing on the way in which HRM practices come about. Especially in a MNC setting of increasing internationalisation of firms the issues of coordination, shared learning and standardisation versus leeway for adapting to the local context (customisation) are prominent. These issues present themselves both at the corporate and regional level and at the national and local (plant) level. On all these levels HR practitioners are active and find themselves amidst the interplay of both (de-)centralisation and standardisation versus customisation processes. This paper thus explores the way in which HR practices come into being and how they are implemented and coordinated. These insights help us understand further the roles of international corporate HR functions that are being identified. Our data is based on 65 interviews, which were held (as part of larger study of HR-function excellence) with HR managers, line managers and senior executives of six multinational companies in eight countries from September to December 2004. This data reveals new classifications of processes by which HR activities are developed, implemented and coordinated, both in terms of who is involved and how these processes are carried out

The Role of Corporate HR Funcitons in MNCs: The Interplay Between Corporate, Regional/National and Plant Level

The HR literature has been abundant in providing typologies of the roles of HR professionals in their organisation. These typologies are largely related to the changing nature of HRM over time, and the context in which empirical work was carried out. In this paper we focus on the context of the increasing internationalisation of firms and how this has an effect upon modern-day typologies of HR roles. We explore these roles by focusing on the way in which HRM practices come about. Especially in a MNC setting of increasing internationalisation of firms the issues of coordination, shared learning and standardisation versus leeway for adapting to the local context (customisation) are prominent. These issues present themselves both at the corporate and regional level and at the national and local (plant) level. On all these levels HR practitioners are active and find themselves amidst the interplay of both (de-)centralisation and standardisation versus customisation processes. This paper thus explores the way in which HR practices come into being and how they are implemented and coordinated. These insights help us understand further the roles of international corporate HR functions that are being identified. Our data is based on 65 interviews, which were held (as part of larger study of HR-function excellence) with HR managers, line managers and senior executives of six multinational companies in eight countries from September to December 2004. This data reveals new classifications of processes by which HR activities are developed, implemented and coordinated, both in terms of who is involved and how these processes are carried out

Embodied Evolution in Collective Robotics: A Review

This paper provides an overview of evolutionary robotics techniques applied to on-line distributed evolution for robot collectives -- namely, embodied evolution. It provides a definition of embodied evolution as well as a thorough description of the underlying concepts and mechanisms. The paper also presents a comprehensive summary of research published in the field since its inception (1999-2017), providing various perspectives to identify the major trends. In particular, we identify a shift from considering embodied evolution as a parallel search method within small robot collectives (fewer than 10 robots) to embodied evolution as an on-line distributed learning method for designing collective behaviours in swarm-like collectives. The paper concludes with a discussion of applications and open questions, providing a milestone for past and an inspiration for future research.Comment: 23 pages, 1 figure, 1 tabl