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Autonomous Abstraction Of Policies Based On Policy Homomorphism

Autonomous Abstraction Of Policies Based On Policy Homomorphism Rajendran, Srividhya A life long learning agent performing in a complex and dynamic environment needs the ability to learn increasingly complex tasks over time. These agents over their lifetime have to learn new tasks, adapt the policies of already learned tasks and extract and reuse the knowledge gained to learn new, more complex tasks. To do this, they need methods that allow them to autonomously extract knowledge from the already learned policy instances and reuse the knowledge gained to learn related tasks in novel environments.This dissertation presents a novel approach that enables an agent to autonomously abstract reusable skills and concepts using policy instances of a similar task type and use the resulting abstractions to learn related tasks in novel situations. To achieve this, this work formalizes a novel idea of policy homomorphism that allows autonomous extraction of general policies for task types . Each extracted general policy is here an abstract policy that is homomorphic to the set of specific policy instances of the corresponding task type that it is derived from and is made up of abstract states that identify situations in which the given policy is applicable and abstract actions that identify actions that need to be performed in those situations. Once extracted, the generalized policies are reused in new contexts to address related tasks by adding them as higher level actions that the agent can choose to perform. To facilitate the autonomous abstraction of a policy of a given task type from a set of policies, the agent has to identify and categorize policies for various tasks into different task types . To achieve this the policy generalization approach presented here employs a utility-based criterion that enables the agent to autonomously categorize and generalize a set of situation-specific policies of different task types into a set of general policies containing one general policy for each identified task type using the policy homomorphism framework. To demonstrate the working of this policy generalization method we show the abstraction of a general policy for a specific task type using two sets of policies of different task types in a grid world domain and further show how the abstracted general policies can be used to learn related tasks in novel grid world environments. Further, to demonstrate the working of the utility based criterion to identify task types and autonomously abstract general policies for the identified task types we show the abstraction of general polices using the utility criterion from a set of situation-specific policies of different task types in a grid world domain.

Examining The Effects Of Early Life Stress From Maternal Separation On Measures Of Pain And Anxiety

Examining The Effects Of Early Life Stress From Maternal Separation On Measures Of Pain And Anxiety Uhelski, Megan Lynne Animal models of stress-induced conditions have provided important insight into the physiological mechanisms of many chronic disorders. Models of early life stress involve procedures designed to induce prenatal or postnatal stress upon pups, which produces adult rats with enhanced stress responses and behavioral similarities to animal models of schizophrenia, anxiety, and depression. Since little research has focused on the effect of maternal separation on adult pain processing, the purpose of the current study is to examine both sensory and affective pain measures in adult rats following repeated maternal separation in infancy, a common model of early life stress. Eighty-six male pups were utilized following either early maternal separation (EMS) or early handling (EH). Although sensory thresholds remained unaltered for adult EMS rats, their emotional response to nociceptive stimuli intensified under certain conditions. In addition, EMS rats demonstrated more hyperactivity and anxiety-like behavior in the elevated plus maze. This indicates that early life stress leads to exaggerated emotional responses to novel or nociceptive stimuli in adulthood. Further research could determine whether or not this pattern holds true for different pain models, or if post-weaning enrichment could reverse the effects of maternal separation on pain processing.

An "absent Presence": An Internal History Of Insular Jewish Communities Prior To Expulsion In 1290

An "absent Presence": An Internal History Of Insular Jewish Communities Prior To Expulsion In 1290 Bennett, Jason Holder This thesis, based on a study based on the legal and popular documents regarding Jews and Judaism in thirteenth-century England, argues that the Expulsion of the Insular Jews in 1290 was not just a financial decision as has been argued in the past by other historians. Most historians focus on one or two aspects of the Insular experience or Expulsion, with fiscal reasons always in the forefront. This work covers and analyzes excerpts from various poems, chronicles, and martyrologies from popular literature and art to show the feelings and beliefs of the populace on Jews and Judaism in that time and place, an unprecedented use of available sources. The study makes use of methodologies such as economic analysis, oral tradition, and others in a synthetic schema that might otherwise be ignored in a more traditional survey of Insular Judaic history. Insular Judaic history is itself a branch seldom studied, with these or any methods.

Performance Evaluation In Reverse Logistics With Data Envelopment Analysis

Performance Evaluation In Reverse Logistics With Data Envelopment Analysis Tonanont, Ake Good reverse logistics design can save cost, increase revenues, and gain competitive edges over the rivals. Design of the optimized reverse supply chain model is a very important task to help enterprises save cost and gain benefits from their supply chains. In this study, reverse logistics is considered as a part of the Closed Loop Supply Chain (CLSC). CLSC combines forward and reverse flow together in the supply chain. Each component in a forward and reverse supply chain results in the efficiency of CLSC. Therefore, considering forward and reverse supply chain together as a CLSC will result in more benefits in improving efficiency of the supply chain than considering it separately. Since most data in the reverse supply chain are very difficult to obtain and many companies do not want to provide their reverse supply chain data due to business reasons, the data is secretly kept. Due to these reasons, there is a need to create a simulation model of CLSC to get reasonable data that can be used in this study.This research proposes a methodology to design a good reverse supply chain by using the specified parameters. The statistical experiments with Data Envelopment Analysis (DEA) were applied to obtain an optimized model. This model is used to evaluate efficiency of the reverse logistics model and also provides the opportunity to improve efficiency by varying the significant parameters. Two case studies of carpet recycling were provided as the examples to show how to apply this methodology.