Using MapReduce Streaming for Distributed Life Simulation on the Cloud

Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp

A complex systems approach to education in Switzerland

The insights gained from the study of complex systems in biological, social, and engineered systems enables us not only to observe and understand, but also to actively design systems which will be capable of successfully coping with complex and dynamically changing situations. The methods and mindset required for this approach have been applied to educational systems with their diverse levels of scale and complexity. Based on the general case made by Yaneer Bar-Yam, this paper applies the complex systems approach to the educational system in Switzerland. It confirms that the complex systems approach is valid. Indeed, many recommendations made for the general case have already been implemented in the Swiss education system. To address existing problems and difficulties, further steps are recommended. This paper contributes to the further establishment complex systems approach by shedding light on an area which concerns us all, which is a frequent topic of discussion and dispute among politicians and the public, where billions of dollars have been spent without achieving the desired results, and where it is difficult to directly derive consequences from actions taken. The analysis of the education system's different levels, their complexity and scale will clarify how such a dynamic system should be approached, and how it can be guided towards the desired performance

Task Allocation in Foraging Robot Swarms:The Role of Information Sharing

Autonomous task allocation is a desirable feature of robot swarms that collect and deliver items in scenarios where congestion, caused by accumulated items or robots, can temporarily interfere with swarm behaviour. In such settings, self-regulation of workforce can prevent unnecessary energy consumption. We explore two types of self-regulation: non-social, where robots become idle upon experiencing congestion, and social, where robots broadcast information about congestion to their team mates in order to socially inhibit foraging. We show that while both types of self-regulation can lead to improved energy efficiency and increase the amount of resource collected, the speed with which information about congestion flows through a swarm affects the scalability of these algorithms

The social and spatial behaviour of caribou Rangifer tarandus

All animals are social at some point in their life. The causes and consequences of animal social behaviour are widely studied, but the integration of space use and spatial features of the landscape within our understanding of social behaviour is not widely studied. My thesis broadly addresses the role of spatial features of the landscape and individual-level space use traits as potential drivers of emergent social behaviour in caribou (Rangifer tarandus). First, I present a theoretical framework linking social and spatial behaviour within the context of evolutionary and behavioural ecology theory. Next, I assess the relationship between social behaviour and space use across scales, from fine-scale foraging and interactions to coarse-scale examination of how individuals and groups vary social behaviour through space and time. Overall, I found that caribou social behaviour is linked to space use and spatial behaviour in four important ways. First, I found that collective movement was an important predictor for patterns of habitat selection, where caribou tend to select foraging habitat (i.e. lichen) while alone, but to move collectively between foraging patches. Second, despite high home range overlap between caribou, and thus potential to associate, sub-groups of individuals had strong social preference for one another and formed distinct social communities. Third, based on a thirty year dataset of caribou group size, I found that group sizes varied spatially and temporally. In contrast to our expectation, groups decreased in size as a function of increasing population density, while groups tended to be larger in winter compared to summer, presumably as a result of seasonal access to foraging opportunities. Finally, I found that social network strength and habitat specialization were density-dependent, while more social individuals were habitat generalists. However, habitat specialization had a greater effect on fitness, where habitat specialists had higher fitness than habitat generalists, but only at high density. My thesis addresses questions about the relationship between social and spatial behaviour and provides a theoretical framework for future studies to address similar questions. Throughout my thesis I also argue for the integration of various diverse ecological fields, including socioecology, spatial ecology, movement ecology, and conservation biology

Spatial and Temporal Models of Jomon Settlement

The Jomon culture is a tradition of complex hunter-gatherers which rose in the Japanese archipelago at the end of the Pleistocene (ca. 13,000 cal BP) and lasted until the 3rd millennium cal BP. Recent studies increasingly suggest how this long cultural persistence was characterised by repeated episodes of change in settlement pattern, primarily manifested as cyclical transitions between nucleated and dispersed distributions. Although it has been suggested that these events correlate with population dynamics, shifts in subsistence strategies, and environmental change, to date there have been very few attempts to provide a quantitative analysis of spatio-temporal change in Jomon settlement and its possible causes. This thesis is an attempt to fill that lacuna by adopting a twin-track approach to the problem. First, two case studies from central Japan have been examined using a novel set of methods, which have been specifically designed to handle the intrinsic chronological uncertainty which characterises most prehistoric data. This facilitated the application of a probabilistic framework for quantitatively assessing the available information, making it possible to identify alternating phases of nucleated and dispersed pattern during a chronological interval between 7000 and 3300 cal BP. Second, computer simulation (by means of an agent-based model) has been used to carry out a formal inquiry into the possible underlying processes that might have triggered the observed changes in the settlement pattern. The aim of this simulation exercise was two-fold. First, it has been used as a theory-building tool, combining several models from behavioural ecology and cultural transmission theory in order to provide explicit expectations in relation to the presence and absence of environmental disturbances. Second, the outcome of the simulation has been used as a template for linking the observed patterns to possible underlying socio-ecological processes suggested by the agent-based model. This endeavour has shown how some of the largest changes in the empirically observed settlement patterns can be simulated as emerging from the internal dynamics of the system rather than necessarily being induced by external changes in the environment

Ecology and Conservation of Parrots in Their Native and Non-Native Ranges

This book focuses on parrots, which are among the most fascinating, attractive, and threatened birds, combining and synthesizing recent research on the biology, ecology, and conservation of both native and non-native parrot populations across the world