Cellular Automata Applications in Shortest Path Problem

Cellular Automata (CAs) are computational models that can capture the essential features of systems in which global behavior emerges from the collective effect of simple components, which interact locally. During the last decades, CAs have been extensively used for mimicking several natural processes and systems to find fine solutions in many complex hard to solve computer science and engineering problems. Among them, the shortest path problem is one of the most pronounced and highly studied problems that scientists have been trying to tackle by using a plethora of methodologies and even unconventional approaches. The proposed solutions are mainly justified by their ability to provide a correct solution in a better time complexity than the renowned Dijkstra's algorithm. Although there is a wide variety regarding the algorithmic complexity of the algorithms suggested, spanning from simplistic graph traversal algorithms to complex nature inspired and bio-mimicking algorithms, in this chapter we focus on the successful application of CAs to shortest path problem as found in various diverse disciplines like computer science, swarm robotics, computer networks, decision science and biomimicking of biological organisms' behaviour. In particular, an introduction on the first CA-based algorithm tackling the shortest path problem is provided in detail. After the short presentation of shortest path algorithms arriving from the relaxization of the CAs principles, the application of the CA-based shortest path definition on the coordinated motion of swarm robotics is also introduced. Moreover, the CA based application of shortest path finding in computer networks is presented in brief. Finally, a CA that models exactly the behavior of a biological organism, namely the Physarum's behavior, finding the minimum-length path between two points in a labyrinth is given.Comment: To appear in the book: Adamatzky, A (Ed.) Shortest path solvers. From software to wetware. Springer, 201

CLOTHO: a large-scale Internet of Things based crowd evacuation planning system for disaster management

In recent years, different kinds of natural hazards or man-made disasters happened that were diversified and difficult to control with heavy casualties. In this work, we focus on the rapid and systematic evacuation of large-scale densities of people after disasters to reduce loss in an effective manner. The optimal evacuation planning is a key challenge and becomes a hotspot of research and development. We design our system based on an Internet of Things (IoT) scenario that utilizes a mobile Cloud computing platform in order to develop the Crowd Lives Oriented Track and Help Optimizition system (CLOTHO). CLOTHO is an evacuation planning system for large-scale densities of people in disasters. It includes the mobile terminal (IoT side) for data collection and the Cloud backend system for storage and analytics. We build our solution upon a typical IoT/fog disaster management scenario and we propose an IoT application based on an evacuation planning algorithm that uses the Artificial Potential Field (APF), which is the core of CLOTHO. APF is conceptualized as an IoT service, and can determine the direction of evacuation automatically according to the gradient direction of the potential field, suitable for rapid evacuation of large population. People are usually in panic, which easily causes the chaos of evacuation and brings secondary disasters. Based on APF, we propose an evacuation planning algorithm names as Artificial Potential Field with Relationship Attraction (APF-RA). APF-RA guides the evacuees with relationship to move to the same shelter as much as possible, to calm evacuees and realize a more humanitarian evacuation. The experimental results show that CLOTHO (using APF and APF-RA) can effectively improve convergence rate, shorten the evacuation route length and evacuation time, and make the remaining capacity of the surrounding shelters well balanced

Common metrics for cellular automata models of complex systems

The creation and use of models is critical not only to the scientific process, but also to life in general. Selected features of a system are abstracted into a model that can then be used to gain knowledge of the workings of the observed system and even anticipate its future behaviour. A key feature of the modelling process is the identification of commonality. This allows previous experience of one model to be used in a new or unfamiliar situation. This recognition of commonality between models allows standards to be formed, especially in areas such as measurement. How everyday physical objects are measured is built on an ingrained acceptance of their underlying commonality. Complex systems, often with their layers of interwoven interactions, are harder to model and, therefore, to measure and predict. Indeed, the inability to compute and model a complex system, except at a localised and temporal level, can be seen as one of its defining attributes. The establishing of commonality between complex systems provides the opportunity to find common metrics. This work looks at two dimensional cellular automata, which are widely used as a simple modelling tool for a variety of systems. This has led to a very diverse range of systems using a common modelling environment based on a lattice of cells. This provides a possible common link between systems using cellular automata that could be exploited to find a common metric that provided information on a diverse range of systems. An enhancement of a categorisation of cellular automata model types used for biological studies is proposed and expanded to include other disciplines. The thesis outlines a new metric, the C-Value, created by the author. This metric, based on the connectedness of the active elements on the cellular automata grid, is then tested with three models built to represent three of the four categories of cellular automata model types. The results show that the new C-Value provides a good indicator of the gathering of active cells on a grid into a single, compact cluster and of indicating, when correlated with the mean density of active cells on the lattice, that their distribution is random. This provides a range to define the disordered and ordered state of a grid. The use of the C-Value in a localised context shows potential for identifying patterns of clusters on the grid

Behavioural variation of acellular slime moulds

Protists are represented in every biome and have a diverse range of ecosystem roles.However, protists are severely under-represented in the scientific literature with fewstudies on how their diversity or behaviour affects ecosystem functioning. One group ofprotists, the acellular slime moulds, have been extensively studied for the behaviouralabilities of the model species Physarum polycephalum. Although the decision-making andproblem-solving abilities of P. polycephalum are well known, it is unclear whether thebehaviour of P. polycephalum is representative of acellular slime mould species andwhether their behaviour varies within individuals or strains. I investigated variations inacellular slime moulds at the species, strain and individual level and found a wide range ofvariability. Age affected two strains of P. polycephalum in a non-linear pattern and Iobserved age-related fluctuations in behaviour, physiology and cellular measures (Chapter1). I found a non-linear relationship between age and decision-making, as well as distinctdifferences in decision-making between strains (Chapter 2). I found variation in foragingbehaviour between three species of acellular slime moulds and each species also showed behavioural variation depending on the foraging environment as well as variations ininteractions between species (Chapter 3). I was able to observe facilitation betweenspecies where foraging success improved in the presence of other acellular slime mouldspecies (Chapter 3). The diversity of behaviour and physiology found within individualsand strains of P. polycephalum demonstrates the importance of including information onstrains and age in future behavioural investigations. In addition, variation in behaviourbetween species demonstrates the diversity of behaviour within this group of protists andhighlights the need for further research to understand how the behaviour of these protistsaffect species diversity and ecosystem functioning

Unconventional Computing and Music: An Investigation into Harnessing Physarum polycephalum

This thesis presents an investigation into developing musical systems with an Unconventional Computing substrate. Computer musicians have found it difficult to access the field of Unconventional Computing, which is likely due to its resource-intensive and complex nature. However, ongoing research is establishing the myxomycete Physarum polycephalum as a universally-accessible and versatile biological computing substrate. As such, the organism is a potential gateway for computer musicians to begin experimenting with aspects of Unconventional Computing. Physarum polycephalum, in its vegetative plasmodium form, is an amorphous unicellular organism that can respond with natural parallelism to the environmental conditions that surround it. This thesis explores the challenges and opportunities related to developing musical systems with Physarum polycephalum. As this area of inquiry is in its infancy, the research took inspiration from a common approach in Unconventional Computing: a journey of exploration and discovery. This journey consisted of a selection of waypoints that provided direction while allowing the research to explore applications of Physarum polycephalum in order to establish how it may be useful in Computer Music. These waypoints guided the research from adapting established prototypes for musical application to developing purpose-made musical demonstrators for use outside of the laboratory. Thus, the thesis reports on a series of Computer Music systems that explore one or more features of Physarum polycephalum's behaviour and physiology. First, the text presents an approach to algorithmic composition that exploits the organism's ability to form and reconfigure graph-like structures. Next, the thesis reports on systems that harness the plasmodium's electrical potential oscillations for sound synthesis and compositional tools. Finally, the thesis presents musical devices that encompass living plasmodium as electrical components. Where applicable, the thesis includes artefacts from demonstrations of these systems, some of which were developed in collaboration with a composer. The findings from this journey demonstrate that Physarum polycephalum is an appropriate substrate for computer musicians wanting to explore Unconventional Computing approaches creatively. Although Physarum polycephalum is relatively robust as a biological substrate, several obstacles arose during this project. This research addressed such obstacles by reviewing and selecting approaches that maintained the organism's accessibility to computer musicians. As a result, the work suggests methods for developing systems with the organism that are practical for the average music technologist and also beneficial to the wider group of scientists investigating Physarum polycephalum for other purposes.Plymouth University HumPA Studentshi

The Architecture of Soft Machines

This thesis speculates about the possibility of softening architecture through machines. In deviating from traditional mechanical conceptions of machines based on autonomous, functional and purely operational notions, the thesis proposes to conceive of machines as corporeal media in co-constituting relationships with human bodies. As machines become corporeal (robots) and human bodies take on qualities of machines (cyborgs) the thesis investigates their relations to architecture through readings of William S. Burroughs’ proto-cyborgian novel The Soft Machine (1961) and Georges Teyssot’s essay ‘Hybrid Architecture: An Environment for the Prosthetic Body’ (2005) arguing for a revision of architecture’s anthropocentric mandate in favour of technologically co-constituting body ideas. The conceptual shift in man-machine relations is also demonstrated by discussion of two installations shown at the Venice Biennale, Daniel Libeskind’s mechanical Three Lessons in Architecture (1985) and Philip Beesely’s responsive Hylozoic Ground (2010). As the purely mechanical model has been superseded by a model that incorporates digital sensing and embedded actuation, as well as soft and compliant materiality, the promise of softer, more sensitive and corporeal conceptions of technology shines onto architecture. Following Nicholas Negroponte’s ambition for a ‘humanism through machines,’ stated in his groundbreaking work, Soft Architecture Machines (1975), and inspired by recent developments in the emerging field of soft robotics, I have developed a series of practical design experiments, ranging from soft mechanical hybrids to soft machines made entirely from silicone and actuated by embedded pneumatics, to speculate about architectural environments capable of interacting with humans. In a radical departure from traditional mechanical conceptions based on modalities of assembly, the design of these types of soft machines is derived from soft organisms such as molluscs (octopi, snails, jellyfish) in order to infuse them with notions of flexibility, compliance, sensitivity, passive dynamics and spatial variability. Challenging architecture’s alliance with notions of permanence and monumentality, the thesis finally formulates a critique of static typologisation of space with walls, floors, columns or windows. In proposing an embodied architecture the thesis concludes by speculating about architecture as a capacitated, sensitive and sensual body informed by reciprocal conditioning of constituent systems, materials, morphologies and behaviours

Cellular automaton model of crowd evacuation inspired by slime mould

In all the living organisms, the self-preservation behaviour is almost universal. Even the most simple of living organisms, like slime mould, is typically under intense selective pressure to evolve a response to ensure their evolution and safety in the best possible way. On the other hand, evacuation of a place can be easily characterized as one of the most stressful situations for the individuals taking part on it. Taking inspiration from the slime mould behaviour, we are introducing a computational bio-inspired model crowd evacuation model. Cellular Automata (CA) were selected as a fully parallel advanced computation tool able to mimic the Physarum’s behaviour. In particular, the proposed CA model takes into account while mimicking the Physarum foraging process, the food diffusion, the organism’s growth, the creation of tubes for each organism, the selection of optimum tube for each human in correspondence to the crowd evacuation under study and finally, the movement of all humans at each time step towards near exit. To test the model’s efficiency and robustness, several simulation scenarios were proposed both in virtual and real-life indoor environments (namely, the first floor of office building B of the Department of Electrical and Computer Engineering of Democritus University of Thrace). The proposed model is further evaluated in a purely quantitative way by comparing the simulation results with the corresponding ones from the bibliography taken by real data. The examined fundamental diagrams of velocity–density and flow–density are found in full agreement with many of the already published corresponding results proving the adequacy, the fitness and the resulting dynamics of the model. Finally, several real Physarum experiments were conducted in an archetype of the aforementioned real-life environment proving at last that the proposed model succeeded in reproducing sufficiently the Physarum’s recorded behaviour derived from observation of the aforementioned biological laboratory experiments

Computer-generated Circulation Diagrams

The way in which computers are used is important in the theory, philosophy and practice of architecture. Architects are already using computers to construct complex three dimensional geometric models of their buildings and are beginning to analyse these models using environmental and structural software, a development which raises new questions about the role of architects and engineers. This dissertation puts forward the hypothesis that architects will at times need to be actively involved in computer programming by writing or modifying software. The hypothesis is based on the assumption that the form of a building and its spatial configuration are influenced by the nature of the design process itself. If architects are to have a complete and subtle control over design and to identify their own personal aesthetic language, they must also have control over the design process including the way computer software tools are developed and used. The hypothesis is tested using the example of a ferry terminal, a building type whose function is largely dominated by passenger circulation. Even thought passengers have a very straightforward aim to reach their final destination, the rules governing the way passengers move around the building are complex and a single computer program will not be able to cover all possible aspects of such behaviour. Thus, architects must have the freedom to formulate different rules and study the effects they have on their design. This particularly applies in non-emergency situations when each individual moves inside the building according to different needs and desires. A program was written which runs in real time so that the architect can see the effect of changing the parameters that control the process. The program can be used as evaluation mechanism to study the performance of postulated design or it can be use as creative mechanism where the design may emerge out of the process in the same way that animals create paths in the woods. Either way, the general aim is to optimize the design according to criteria over which the architect, again, must have complete control.EThOS - Electronic Theses Online ServiceGBUnited Kingdo