DNAgents: Genetically Engineered Intelligent Mobile Agents

Mobile agents are a useful paradigm for network coding providing many advantages and disadvantages. Unfortunately, widespread adoption of mobile agents has been hampered by the disadvantages, which could be said to outweigh the advantages. There is a variety of ongoing work to address these issues, and this is discussed. Ultimately, genetic algorithms are selected as the most interesting potential avenue. Genetic algorithms have many potential benefits for mobile agents. The primary benefit is the potential for agents to become even more adaptive to situational changes in the environment and/or emergent security risks. There are secondary benefits such as the natural obfuscation of functions inherent to genetic algorithms. Pitfalls also exist, namely the difficulty of defining a satisfactory fitness function and the variable execution time of mobile agents arising from the fact that it exists on a network. DNAgents 1.0, an original application of genetic algorithms to mobile agents is implemented and discussed, and serves to highlight these difficulties. Modifications of traditional genetic algorithms are also discussed. Ultimately, a combination of genetic algorithms and artificial life is considered to be the most appropriate approach to mobile agents. This allows the consideration of agents to be organisms, and the network to be their environment. Towards this end, a novel framework called DNAgents 2.0 is designed and implemented. This framework allows the continual evolution of agents in a network without having a seperate training and deployment phase. Parameters for this new framework were defined and explored. Lastly, an experiment similar to DNAgents 1.0 is performed for comparative purposes against DNAgents 1.0 and to prove the viability of this new framework

Engineering framework for service-oriented automation systems

Tese de doutoramento. Engenharia Informática. Universidade do Porto. Faculdade de Engenharia. 201

Evaluation in artificial intelligence: From task-oriented to ability-oriented measurement

The final publication is available at Springer via http://dx.doi.org/ 10.1007/s10462-016-9505-7.The evaluation of artificial intelligence systems and components is crucial for the progress of the discipline. In this paper we describe and critically assess the different ways AI systems are evaluated, and the role of components and techniques in these systems. We first focus on the traditional task-oriented evaluation approach. We identify three kinds of evaluation: human discrimination, problem benchmarks and peer confrontation. We describe some of the limitations of the many evaluation schemes and competitions in these three categories, and follow the progression of some of these tests. We then focus on a less customary (and challenging) ability-oriented evaluation approach, where a system is characterised by its (cognitive) abilities, rather than by the tasks it is designed to solve. We discuss several possibilities: the adaptation of cognitive tests used for humans and animals, the development of tests derived from algorithmic information theory or more integrated approaches under the perspective of universal psychometrics. We analyse some evaluation tests from AI that are better positioned for an ability-oriented evaluation and discuss how their problems and limitations can possibly be addressed with some of the tools and ideas that appear within the paper. Finally, we enumerate a series of lessons learnt and generic guidelines to be used when an AI evaluation scheme is under consideration.I thank the organisers of the AEPIA Summer School On Artificial Intelligence, held in September 2014, for giving me the opportunity to give a lecture on 'AI Evaluation'. This paper was born out of and evolved through that lecture. The information about many benchmarks and competitions discussed in this paper have been contrasted with information from and discussions with many people: M. Bedia, A. Cangelosi, C. Dimitrakakis, I. GarcIa-Varea, Katja Hofmann, W. Langdon, E. Messina, S. Mueller, M. Siebers and C. Soares. Figure 4 is courtesy of F. Martinez-Plumed. Finally, I thank the anonymous reviewers, whose comments have helped to significantly improve the balance and coverage of the paper. This work has been partially supported by the EU (FEDER) and the Spanish MINECO under Grants TIN 2013-45732-C4-1-P, TIN 2015-69175-C4-1-R and by Generalitat Valenciana PROMETEOII2015/013.José Hernández-Orallo (2016). Evaluation in artificial intelligence: From task-oriented to ability-oriented measurement. 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Towards Informed Exploration for Deep Reinforcement Learning

In this thesis, we discuss various techniques for improving exploration for deep reinforcement learning. We begin with a brief review of reinforcement learning (RL) and the fundamental v.s. exploitation trade-off. Then we review how deep RL has improved upon classical and summarize six categories of the latest exploration methods for deep RL, in the order increasing usage of prior information. We then explore representative works in three categories discuss their strengths and weaknesses. The first category, represented by Soft Q-learning, uses regularization to encourage exploration. The second category, represented by count-based via hashing, maps states to hash codes for counting and assigns higher exploration to less-encountered states. The third category utilizes hierarchy and is represented by modular architecture for RL agents to play StarCraft II. Finally, we conclude that exploration by prior knowledge is a promising research direction and suggest topics of potentially impact

Data Quality of Digital Process Data: A Generalized Framework and Simulation/Post-Hoc Identification Strategy

Digital process data are becoming increasingly important for social science research, but their quality has been gravely neglected so far. In this article, we adopt a process perspective and argue that data extracted from socio-technical systems are, in principle, subject to the same error-inducing mechanisms as traditional forms of social science data, namely biases that arise before their acquisition (observational design), during their acquisition (data generation), and after their acquisition (data processing). As the lack of access and insight into the actual processes of data production renders key traditional mechanisms of quality assurance largely impossible, it is essential to identify data quality problems in the data available—that is, to focus on the possibilities post-hoc quality assessment offers to us. We advance a post-hoc strategy of data quality assurance, integrating simulation and explorative identification techniques. As a use case, we illustrate this approach with the example of bot activity and the effects this phenomenon can have on digital process data. First, we employ agent-based modelling to simulate datasets containing these data problems. Subsequently, we demonstrate the possibilities and challenges of post-hoc control by mobilizing geometric data analysis, an exemplary technique for identifying data quality issues.Digitale Prozessdaten werden für die sozialwissenschaftliche Forschung immer wichtiger, doch ihre Qualität wurde in der Diskussion bisher stark vernachlässigt. In diesem Beitrag nehmen wir eine Prozessperspektive ein und argumentieren, dass Daten, die aus soziotechnischen Systemen extrahiert werden, im Prinzip denselben fehlerverursachenden Mechanismen unterliegen wie traditionelle Formen sozialwissenschaftlicher Daten, nämlich Verzerrungen, die vor ihrer Erfassung (Beobachtungsdesign), während ihrer Erfassung (Datengenerierung) und nach ihrer Erfassung (Datenverarbeitung) entstehen. Da der fehlende Zugang und Einblick in die eigentlichen Prozesse der Datenproduktion wichtige Mechanismen der traditionellen Qualitätssicherung weitgehend unmöglich machen, ist es unerlässlich, Datenqualitätsprobleme in den zur Verfügung stehenden Daten zu identifizieren – das heißt, sich auf die Möglichkeiten zu konzentrieren, die uns die post-hoc Qualitätsprüfung bietet. Wir entwickeln eine Post-hoc-Strategie der Datenqualitätssicherung, die Simulation und explorative Identifizierungstechniken integriert. Als Anwendungsfall illustrieren wir diesen Ansatz am Beispiel von Bot-Aktivitäten und den Auswirkungen, die dieses Phänomen auf digitale Prozessdaten haben kann. Dazu setzen wir zunächst eine agentenbasierte Modellierung ein, um Datensätze mit derartigen Datenproblemen zu simulieren. Anschließend demonstrieren wir die Möglichkeiten und Herausforderungen der Post-hoc-Kontrolle, indem wir die geometrische Datenanalyse einsetzen, eine exemplarische Technik zur Identifizierung von Datenqualitätsproblemen

The role of reward signal in deep reinforcement learning

The goal of the thesis is to study the role of the reward signal in deep reinforcement learning. The reward signal is a scalar quantity received by the agent, and it has a big impact on both the training process of a reinforcement learning algorithm and its resulting behaviour. Firstly, we study the behaviour of an agent that is learning with different reward signals in the same environment with the same learning algorithm. We introduce and measure agents’ happiness as a relation between agents’ actual reward obtained from the environment, as compared to the possible maximum and minimum rewards in a given setting. The experiments show that the rewards intended to result in a given behaviour during training do not result in the same behaviour when agents interact with each other. Secondly, we use these observations to investigate the role of the reward signal further. Namely, we explore the space of all possible reward signals in a given environment through an evolutionary algorithm. Through experiments, we demonstrate that it is possible to learn complex behaviours of winning, losing, and cooperating through reward signal evolution. Some of the solutions found by the algorithm are surprising, in the sense that they would probably not have been chosen by a person trying to hand-code a given behaviour through a specific reward signal. The results presented in the thesis indicate that the role of the reward signal in reinforcement learning is likely bigger than indicated by its current coverage in the literature and is worth investigating in greater detail. Not only can it lead to programmes with less overfitting, but it can also improve our understanding of what reinforcement learning algorithms are really learning. This in turn will give us more robust, explainable, and overall safer systems