Understanding responses to environments for the Prisoner's Dilemma: A meta analysis, multidimensional optimisation and machine learning approach

This thesis investigates the behaviour that Iterated Prisoner’s Dilemma strategies should adopt as a response to different environments. The Iterated Prisoner’s Dilemma (IPD) is a particular topic of game theory that has attracted academic attention due to its applications in the understanding of the balance between cooperation and com petition in social and biological settings. This thesis uses a variety of mathematical and computational fields such as linear al gebra, research software engineering, data mining, network theory, natural language processing, data analysis, mathematical optimisation, resultant theory, markov mod elling, agent based simulation, heuristics and machine learning. The literature around the IPD has been exploring the performance of strategies in the game for years. The results of this thesis contribute to the discussion of successful performances using various novel approaches. Initially, this thesis evaluates the performance of 195 strategies in 45,600 computer tournaments. A large portion of the 195 strategies are drawn from the known and named strategies in the IPD literature, including many previous tournament winners. The 45,600 computer tournaments include tournament variations such as tournaments with noise, probabilistic match length, and both noise and probabilistic match length. This diversity of strategies and tournament types has resulted in the largest and most diverse collection of computer tournaments in the field. The impact of features on the performance of the 195 strategies is evaluated using modern machine learning and statistical techniques. The results reinforce the idea that there are properties associated with success, these are: be nice, be provocable and generous, be a little envious, be clever, and adapt to the environment. Secondly, this thesis explores well performed behaviour focused on a specific set of IPD strategies called memory-one, and specifically a subset of them that are considered extortionate. These strategies have gained much attention in the research field and have been acclaimed for their performance against single opponents. This thesis uses mathematical modelling to explore the best responses to a collection of memory-one strategies as a multidimensional non-linear optimisation problem, and the benefits of extortionate/manipulative behaviour. The results contribute to the discussion that behaving in an extortionate way is not the optimal play in the IPD, and provide evidence that memory-one strategies suffer from their limited memory in multi agent interactions and can be out performed by longer memory strategies. Following this, the thesis investigates best response strategies in the form of static sequences of moves. It introduces an evolutionary algorithm which can successfully identify best response sequences, and uses a list of 192 opponents to generate a large data set of best response sequences. This data set is then used to train a type of recurrent neural network called the long short-term memory network, which have not gained much attention in the literature. A number of long short-term memory networks are trained to predict the actions of the best response sequences. The trained networks are used to introduce a total of 24 new IPD strategies which were shown to successfully win standard tournaments. From this research the following conclusions are made: there is not a single best strategy in the IPD for varying environments, however, there are properties associated with the strategies’ success distinct to different environments. These properties reinforce and contradict well established results. They include being nice, opening with cooperation, being a little envious, being complex, adapting to the environment and using longer memory when possible

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

Nice Invincible Strategy for the Average-Payoff IPD

The Iterated Prisoner's Dilemma (IPD) is a well-known benchmark for studying the long term behaviours of rational agents. Many well-known strategies have been studied, from the simple tit-for-tat (TFT) to more involved ones like zero determinant and extortionate strategies studied recently by Press and Dyson. In this paper, we consider what we call invincible strategies. These are ones that will never lose against any other strategy in terms of average payoff in the limit. We provide a simple characterization of this class of strategies, and show that invincible strategies can also be nice. We discuss its relationship with some important strategies and generalize our results to some typical repeated 2x2 games. It's known that experimentally, nice strategies like the TFT and extortionate ones can act as catalysts for the evolution of cooperation. Our experiments show that this is also the case for some invincible strategies that are neither nice nor extortionate

Sanitizing Sociality: Owned Livelihoods, Embedded Economies and Social Wealth Among Delhi's Sanitation Workers

Low-income and socially marginalized people around the world regularly engage in anti-competitive practices. Often illegal and always offensive to those with faith in free markets, these practices rarely help the poor in general. They are, however, often tied to violence against other marginalized people and the obstruction of efficient public services, which can, in many cases, exacerbate the problems of the poor even further. How should we interpret such anti-market behavior? In this dissertation, I address this question through a case study of Delhi’s Balmiki community, a caste that is traditionally associated with sanitation-related work in northern India. Members of this caste, who are frequently referred to as “sweepers” or safai karamcharis, make up the vast majority of Delhi’s sanitation workforce. I show that the social life of this community is deeply permeated by anti-market social practices. Sometimes invisible to the state and sometimes a direct challenge to its authority, these practices help the Balmikis secure a sense of security in an otherwise precarious socio-economic landscape. Most salient among these practices is what I call “proprietary livelihood:” a system in which people effectively own their jobs rather than sell their labor on a market. In the first three chapters of this dissertation, I show how both informal and formal sector sanitation workers own their livelihoods, how their practices are similar to older forms of social organization in India and elsewhere, how their owned livelihoods constitute embedded and transparently social forms of wealth, and also how they use proprietary livelihood to protect themselves from the otherwise prevailing condition of expropriated freedom – a fundamentally modern/capitalist condition in which people’s material sustenance is separated from other aspects of their social lives. In the fourth chapter, I show how the practices of proprietary livelihood are intertwined with the anti-market practices of other members of the Balmiki community, specifically, a leader of organized crime and his political associates. In Chapter 5, I show how the practices of proprietary livelihood come into direct conflict with the bourgeois desires of upper-middle class homeowners to have “neat and clean” neighborhoods. In that same chapter, I also show how homeowner associations act as agents of proletarianization by subjecting the informal sanitation workers to the disciplinary processes of wage labor – processes that simultaneously destroy the transparently social nature of the sanitation workers’ wealth. In the final chapter of this dissertation, I critically engage the language that mainstream economists would use to conceptualize proprietary livelihood and the other forms of transparently social wealth found among Delhi’s Balmiki community. Mainstream economists would categorize these practices as forms of “rent extraction” and “rent seeking,” and they would argue that they introduce inefficiencies into Delhi’s sanitation system. I point out that this view would indeed be consistent with their neo-classical framework, but I go on to argue that the concept of rent itself – in both its classical and neo-classical formulations – is used to designate and domesticate transparently social forms of work and wealth that would otherwise disturb the economists’ worldview in which rational actors seek utility. I pursue this line of inquiry as part of a broader belief that we anthropologists should engage the terms and concepts of neoclassical economists more directly than we have thus far, not because they are correct, but because their dominance in the public sphere reflects the real-world dominance of the commodity form. In the process of making these arguments, I suggest three lines of further inquiry for anthropologists: (1) that we explore the possible existence of proprietary livelihood and similar forms of transparently social wealth in other contexts; (2) that we should pay a little less attention to wages, capital and commodities and consider for a while the role of rent in the everyday lives of people around the world (how they pay it, avoid it, extract it, and seek it); (3) that we should frame our inquiries in light of the condition of expropriated freedom, a condition that now prevails in almost every corner of the world

The Evolution of Architectural Pedagogy in the Age of Information: Advancing technologies and their implementation in architectural pedagogies

abstract: The contemporary architectural pedagogy is far removed from its ancestry: the classical Beaux-Arts and polytechnic schools of the 19th century and the Bauhaus and Vkhutemas models of the modern period. Today, the "digital" has invaded the academy and shapes pedagogical practices, epistemologies, and ontologies within it, and this invasion is reflected in teaching practices, principles, and tools. Much of this digital integration goes unremarked and may not even be explicitly taught. In this qualitative research project, interviews with 18 leading architecture lecturers, professors, and deans from programs across the United States were conducted. These interviews focused on advanced practices of digital architecture, such as the use of digital tools, and how these practices are viewed. These interviews yielded a wealth of information about the uses (and abuses) of advanced digital technologies within the architectural academy, and the results were analyzed using the methods of phenomenology and grounded theory. Most schools use digital technologies to some extent, although this extent varies greatly. While some schools have abandoned hand-drawing and other hand-based craft almost entirely, others have retained traditional techniques and use digital technologies sparingly. Reasons for using digital design processes include industry pressure as well as the increased ability to solve problems and the speed with which they could be solved. Despite the prevalence of digital design, most programs did not teach related design software explicitly, if at all, instead requiring students (especially graduate students) to learn to use them outside the design studio. Some of the problems with digital design identified in the interviews include social problems such as alienation as well as issues like understanding scale and embodiment of skill.Dissertation/ThesisPh.D. Design 201

Producer co-operatives in market systems : a case study of the Scottish Daily News in the context of the political economy of the press

This work is a study of power and control in industry, and focusses upon the possibility of radical democratic innovations in control. In particular the problems of producer co-operatives in market systems are examined. Volume I presents a detailed analysis of the Scottish Daily News workers' Co-operative, and seeks to isolate the reasons for the abrupt failure of the enterprise. Volume II examines the political economy of the press, and the difficulties to be encountered by any attempt to launch a noncommercial newspaper committed to radical politics. Volume III presents a review of the historical development of producer co-operatives, case studies of the two other co-operatives launched with the assistance of Department of Industry funds in 1975, KME and Triumph Meriden, discusses contemporary co-operative theory, and considers the extent of current co-operative development