Feature Selection Using Regularization in Approximate Linear Programs for Markov Decision Processes

Approximate dynamic programming has been used successfully in a large variety of domains, but it relies on a small set of provided approximation features to calculate solutions reliably. Large and rich sets of features can cause existing algorithms to overfit because of a limited number of samples. We address this shortcoming using $L_1$ regularization in approximate linear programming. Because the proposed method can automatically select the appropriate richness of features, its performance does not degrade with an increasing number of features. These results rely on new and stronger sampling bounds for regularized approximate linear programs. We also propose a computationally efficient homotopy method. The empirical evaluation of the approach shows that the proposed method performs well on simple MDPs and standard benchmark problems.Comment: Technical report corresponding to the ICML2010 submission of the same nam

Improving cardiac rehabilitation session attendance using the Self-Regulatory Model and motivational interviewing: A randomised controlled trial

Objective: This study aimed to investigate the effectiveness of a theory-based, one-session intervention in enhancing cardiac rehabilitation (CR) adherence among patients attending their first class. The intervention session was structured to elicit and change patients' illness perceptions, and to enhance motivation. Design: Randomised, controlled trial. Participants: Patients attending for their first Phase III CR class were recruited. Outcome Measures: The primary outcome measure was the number of rehabilitation exercise sessions attended, providing data on participant adherence to the programme. The Illness Perception Questionnaire-Revised was used as a secondary outcome measure. Sociodemographic data and information on coping style and mood were also collected. Results: Patients in the intervention group were found to attend significantly more CR classes than the control group (p<.05). Illness perceptions were not found to be different between groups at three-month follow up. Sociodemographic, medical and psychological variables were not found to be associated with CR adherence, although high levels of anxiety and depression were reported among participants. Conclusions: Rates of initial CR attendance and ongoing adherence were relatively high among all participants. Improved adherence among the intervention group suggests that brief psychological intervention sessions may be useful within a CR setting. However, the lack of change in illness perceptions following intervention suggests that more research is necessary in order to understand the present findings. Other recommendations for future research are also discussed

Ruled with a pen: Land, language, and the invention of Maine

As Europeans expanded across North America in the seventeenth and eighteenth centuries, they parceled their territorial acquisitions into a variety of administrative subdivisions. Naming and dividing the land became an integral part of the project of colonization; the conquest of territory involved the transformation of unknown places into clearly defined jurisdictions. This dissertation examines the invention of one jurisdiction, the state of Maine, viewing the evolution of its borders as a reflection of the growth of state power in the region. Seeing an inextricable link between social and territorial boundaries, it ties the development of the territory of Maine to the formation of an alliance between property owners and English governments. The alliance promoted a vision of territoriality in which the land was divided into clearly marked jurisdictions exclusively governed by particular towns, counties, and provinces. These jurisdictions, in turn, granted and protected clearly marked estates that were the exclusive property of individuals; property rights and state sovereignty reinforced one another. This English system of territoriality competed with other visions of the land attached to different social arrangements. to Native Wabanakis, the right to use the land flowed from membership in fictive kin groups that included both human beings and the spirits of surrounding animals and natural features. French colonial officials treated their possessions adjacent to the Gulf of Maine as a network of military, economic, and missionary outposts that upheld the authority of church and state in a peripheral region. English notions of territoriality gained precedence over others because the alliance between property owners and the state facilitated the large-scale mobilization of human and material resources in trade and warfare. Far from being unproblematic facts of the environment, Maine\u27s boundaries are the physical traces of a historical process in which English colonists acquired vast quantities of natural resources at the expense of their French and Indian rivals. to give legitimacy to these conquests, the colonists promoted a form of state sovereignty characteristic of English-speaking North America: the land, under this system of territoriality, was construed as a measurable object to be possessed and exchanged by individuals

Marketing a memory of the world: Magna Carta and the student as producer perspective

From Runnymede in 1215, to parliamentary struggles, across the seas to a fledgling America, then onwards in time to many parts of the globe where it encourages human rights and shapes legal systems, the Magna Carta has been enormously influential. As a consequence, the document has been placed on UNESCO’s Memory of the World register, a process designed to preserve highly significant documentary archive collections. Of the four remaining copies of the Magna Carta, one is owned by Lincoln Cathedral of the UK and is on display to the general visitor in Lincoln Castle. This case study provides a critical account of the marketing of this document, arguing that the experiential dimensions of the Magna Carta exhibition are poorly executed. Additionally, as presently constituted, it is postulated that the existing marketing strategy will fail to capitalise on the opportunities presented by the 800th anniversary of the Magna Carta’s signing in 2015 and the planned national celebrations. Evidence for these claims have been drawn mainly from an inquiry led research project conducted by a group of undergraduate marketers and two tutors at Lincoln University, demonstrating the clear value of the “student as producer” approach to learning and research in marketing

Marketing a memory of the world: Magna Carta and the experiential servicescape

Purpose The aim of this paper is to analyse visitor perceptions of the Lincoln Magna Carta exhibition in the context of an experiential servicescape perspective. Design/methodology/approach Data comes from a questionnaire carried out with visitors to the Magna Carta exhibition in Lincoln Castle, UK. The approach was framed by the student as producer perspective, that is about re-engineering the relationship between academics and undergraduate students. Findings Three main problems exist in terms of the servicescape. These are guidance signage, the small, dark inauspicious surroundings of the exhibition itself and the level of visitor interactivity present. Research limitations/implications This is only a small scale project of one Magna Carta exhibition. Research with more visitors would help to further validate the findings and conclusions of this paper and also assist in other representations of the document in other sites. Practical implications Suggestions are made for improvement to a number of experiential servicescape elements. These improved representations also need to be planned for adequately in the new staging of the document, when Lincoln Castle receives planned additional funds from the Heritage Lottery. Social implications This paper draws our attention to the fact that The Magna Carta is a shared part of a global cultural identity, where the marketing of the document represents a great privilege. Originality/value The experiential servicescape framework is used in an original way to critique aspects of the current exhibition and to propose new ideas for representing the Magna Carta. This paper is based on original data that makes a novel contribution to the debate regarding research and learning in higher education