Rolling Horizon Coevolutionary planning for two-player video games

This paper describes a new algorithm for decision making in two-player real-time video games. As with Monte Carlo Tree Search, the algorithm can be used without heuristics and has been developed for use in general video game AI. The approach is to extend recent work on rolling horizon evolutionary planning, which has been shown to work well for single-player games, to two (or in principle many) player games. To select an action the algorithm co-evolves two (or in the general case N) populations, one for each player, where each individual is a sequence of actions for the respective player. The fitness of each individual is evaluated by playing it against a selection of action-sequences from the opposing population. When choosing an action to take in the game, the first action is chosen from the fittest member of the population for that player. The new algorithm is compared with a number of general video game AI algorithms on a two-player space battle game, with promising results

Automatic Game Parameter Tuning using General Video Game Agents

Automatic Game Design is a subfield of Game Artificial Intelligence that aims to study the usage of AI algorithms for assisting in game design tasks. This dissertation presents a research work in this field, focusing on applying an evolutionary algorithm to video game parameterization. The task we are interested in is player experience. N-Tuple Bandit Evolutionary Algorithm (NTBEA) is an evolutionary algorithm that was recently proposed and successfully applied in game parameterization in a simple domain, which is the first experiment included in this project. To further investigating its ability in evolving game parameters, We applied NTBEA to evolve parameter sets for three General Video Game AI (GVGAI) games, because GVGAI has variety supplies of video games in different types and the framework has already been prepared for parameterization. 9 positive increasing functions were picked as target functions as representations of the player expected score trends. Our initial assumption was that the evolved games should provide the game environments that allow players to obtain score in the same trend as one of these functions. The experiment results confirm this for some functions, and prove that the NTBEA is very much capable of evolving GVGAI games to satisfy this task

Independent Learning Approaches: Overcoming Multi-Agent Learning Pathologies In Team-Games

Deep Neural Networks enable Reinforcement Learning (RL) agents to learn behaviour policies directly from high-dimensional observations. As a result, the field of Deep Reinforcement Learning (DRL) has seen a great number of successes. Recently the sub-field of Multi-Agent DRL (MADRL) has received an increased amount of attention. However, considerations are required when using RL in Multi-Agent Systems. For instance Independent Learners (ILs) lack the convergence guarantees of many single-agent RL approaches, even in domains that do not require a MADRL approach. Furthermore, ILs must often overcome a number of learning pathologies to converge upon an optimal joint-policy. Numerous IL approaches have been proposed to facilitate cooperation, including hysteretic Q-learning (Matignon et al., 2007) and leniency (Panait et al., 2006). Recently LMRL2, a variation of leniency, proved robust towards a number of pathologies in low-dimensional domains, including miscoordination, relative overgeneralization, stochasticity, the alter-exploration problem and the moving target problem (Wei and Luke, 2016). In contrast, the majority of work on ILs in MADRL focuses on an amplified moving target problem, caused by neural networks being trained with potentially obsolete samples drawn from experience replay memories. In this thesis we combine advances from research on ILs with DRL algorithms. However, first we evaluate the robustness of tabular approaches along each of the above pathology dimensions. Upon identifying a number of weaknesses that prevent LMRL2 from consistently converging upon optimal joint-policies we propose a new version of leniency, Distributed-Lenient Q-learning (DLQ). We find DLQ delivers state of the art performances in strategic-form and Markov games from Multi-Agent Reinforcement Learning literature. We subsequently scale leniency to MADRL, introducing Lenient (Double) Deep Q-Network (LDDQN). We empirically evaluate LDDQN with extensions of the Cooperative Multi-Agent Object Transportation Problem (Bucsoniu et al., 2010), finding that LDDQN outperforms hysteretic deep Q-learners in domains with multiple dropzones yielding stochastic rewards. Finally, to evaluate deep ILs along each pathology dimension we introduce a new MADRL environment: the Apprentice Firemen Game (AFG). We find lenient and hysteretic approaches fail to consistently learn near optimal joint-policies in the AFG. To address these pathologies we introduce Negative Update Intervals-DDQN (NUI-DDQN), a MADRL algorithm which discards episodes yielding cumulative rewards outside the range of expanding intervals. NUI-DDQN consistently gravitates towards optimal joint-policies in deterministic and stochastic reward settings of the AFG, overcoming the outlined pathologies

PLATFORM-DRIVEN CROWDSOURCED MANUFACTURING FOR MANUFACTURING AS A SERVICE

Platform-driven crowdsourced manufacturing is an emerging manufacturing paradigm to instantiate the adoption of the open business model in the context of achieving Manufacturing-as-a-Service (MaaS). It has attracted attention from both industries and academia as a powerful way of searching for manufacturing solutions extensively in a smart manufacturing era. In this regard, this work examines the origination and evolution of the open business model and highlights the trends towards platform-driven crowdsourced manufacturing as a solution for MaaS. Platform-driven crowdsourced manufacturing has a full function of value capturing, creation, and delivery approach, which is fulfilled by the cooperation among manufacturers, open innovators, and platforms. The platform-driven crowdsourced manufacturing workflow is proposed to organize these three decision agents by specifying the domains and interactions, following a functional, behavioral, and structural mapping model. A MaaS reference model is proposed to outline the critical functions and inter-relationships. A series of quantitative, qualitative, and computational solutions are developed for fulfilling the outlined functions. The case studies demonstrate the proposed methodologies and can pace the way towards a service-oriented product fulfillment process. This dissertation initially proposes a manufacturing theory and decision models by integrating manufacturer crowds through a cyber platform. This dissertation reveals the elementary conceptual framework based on stakeholder analysis, including dichotomy analysis of industrial applicability, decision agent identification, workflow, and holistic framework of platform-driven crowdsourced manufacturing. Three stakeholders require three essential service fields, and their cooperation requires an information service system as a kernel. These essential functions include contracting evaluation services for open innovators, manufacturers' task execution services, and platforms' management services. This research tackles these research challenges to provide a technology implementation roadmap and transition guidebook for industries towards crowdsourcing.Ph.D

Structural market changes and strategic adaptation along the value chain:theoretical perspectives and empirical evidence

Strukturelle Veränderungen der Wettbewerbslandschaft, insbesondere die Deregulierung von Märkten und der rasante technologische Fortschritt, nehmen Einfluss auf die optimale Gestaltung von Wertschöpfungsprozessen. Zwei wesentliche Trends sind beobachtbar: die zunehmende Desintegration von Produktionsprozessen und die Neuinterpretation der Rolle des Kunden im Wertschöpfungsprozess. Im Rahmen von drei empirischen und einer konzeptionellen Analyse werden wesentliche Implikationen für die erfolgreiche Gestaltung von Wertschöpfungsprozessen abgeleitet und erwartete Erfolgswirkungen struktureller Veränderungen entlang der Wertschöpfungskette kritisch reflektiert