A Theory of Cheap Control in Embodied Systems

We present a framework for designing cheap control architectures for embodied agents. Our derivation is guided by the classical problem of universal approximation, whereby we explore the possibility of exploiting the agent's embodiment for a new and more efficient universal approximation of behaviors generated by sensorimotor control. This embodied universal approximation is compared with the classical non-embodied universal approximation. To exemplify our approach, we present a detailed quantitative case study for policy models defined in terms of conditional restricted Boltzmann machines. In contrast to non-embodied universal approximation, which requires an exponential number of parameters, in the embodied setting we are able to generate all possible behaviors with a drastically smaller model, thus obtaining cheap universal approximation. We test and corroborate the theory experimentally with a six-legged walking machine. The experiments show that the sufficient controller complexity predicted by our theory is tight, which means that the theory has direct practical implications. Keywords: cheap design, embodiment, sensorimotor loop, universal approximation, conditional restricted Boltzmann machineComment: 27 pages, 10 figure

Genomic diversity of burkholderia pseudomalleiIsolates, Colombia

We report an analysis of the genomic diversity of isolates of Burkholderia pseudomallei, the cause of melioidosis, recovered in Colombia from routine surveillance during 2016–2017. B. pseudomallei appears genetically diverse, suggesting it is well established and has spread across the region

Deep Learning: A Philosophical Introduction

Deep learning is currently the most prominent and widely successful method in artificial intelligence. Despite having played an active role in earlier artificial intelligence and neural network research, philosophers have been largely silent on this technology so far. This is remarkable, given that deep learning neural networks have blown past predicted upper limits on artificial intelligence performance—recognizing complex objects in natural photographs, and defeating world champions in strategy games as complex as Go and chess—yet there remains no universally-accepted explanation as to why they work so well. This article provides an introduction to these networks, as well as an opinionated guidebook on the philosophical significance of their structure and achievements. It argues that deep learning neural networks differ importantly in their structure and mathematical properties from the shallower neural networks that were the subject of so much philosophical reflection in the 1980s and 1990s. The article then explores several different explanations for their success, and ends by proposing ten areas of research that would benefit from future engagement by philosophers of mind, epistemology, science, perception, law, and ethics

The political economy of progressive fiscal contracts in Africa and Latin America

Motivation How can poorer developing countries escape from the vicious circle in which, because the state is fragile, those countries cannot raise sufficient public revenue to be able to finance development, leading to the persistence of poverty and state fragility? We explore a new approach to this problem, which we call progressive fiscal contracts, in which government earmarks the proceeds of particular taxes to be spent on forms of expenditure which will have widespread benefits for lower income groups, such as health, education and social protection. Taxpayers are thus offered a contractual relationship with government (better‐targeted delivery of public services in return for tax payments) in place of a coercive one (simply being ordered to pay taxes, with nothing being offered in exchange). We seek to examine whether this kind of contractual approach offers a way forward for developing countries. Purpose Across five countries (Bolivia, Ecuador, Venezuela, Ghana and Zambia) between 2000 and 2015, we seek to find out whether tax yields have improved following the introduction of progressive fiscal contracts, whether conflict and poverty have declined, and whether there have been countervailing costs in terms of reduced efficiency. We also examine the experience of two countries (Brazil and Chile) where there is no formal ear‐marking but government has encouraged the public to think of particular taxes as being associated with particular forms of expenditure. Approach and methods We assess the impact of changes in tax yields, welfare indicators and conflict indicators by means of panel‐data regressions, tabular comparisons and, in Bolivia, qualitative interviews. Changes in efficiency are assessed through examination of changes in tax structure. Findings Across all of the countries surveyed, the introduction of progressive fiscal contracts has been associated with a reduction in headcount poverty between 2000 and 2015, and in Bolivia our qualitative evidence suggests that the relationship can be seen as a causal one. In three cases out of five (Ghana, Bolivia and Ecuador) tax yields have increased, and in two (Ecuador and Bolivia) there was a significant reduction in political violence. In the Latin American cases examined, but not the African ones, there was a shift from royalty‐based taxation to income‐based taxation of natural resources, suggesting the likelihood of an improvement in efficiency over the period in those countries only. In these cases, the stereotypical view that progressive fiscal contracts improve equity at the expense of efficiency is contradicted. Policy implications (or conclusions) ‘Progressive fiscal contracts’, which originated as a device for making tax payments more palatable by offering social benefits in return, show promise as an innovative strategy for boosting tax ratios, reducing political violence and reducing poverty, which deserves further exploration

Reviewing the use of resilience concepts in forest sciences

Purpose of the review Resilience is a key concept to deal with an uncertain future in forestry. In recent years, it has received increasing attention from both research and practice. However, a common understanding of what resilience means in a forestry context, and how to operationalise it is lacking. Here, we conducted a systematic review of the recent forest science literature on resilience in the forestry context, synthesising how resilience is defined and assessed. Recent findings Based on a detailed review of 255 studies, we analysed how the concepts of engineering resilience, ecological resilience, and social-ecological resilience are used in forest sciences. A clear majority of the studies applied the concept of engineering resilience, quantifying resilience as the recovery time after a disturbance. The two most used indicators for engineering resilience were basal area increment and vegetation cover, whereas ecological resilience studies frequently focus on vegetation cover and tree density. In contrast, important social-ecological resilience indicators used in the literature are socio-economic diversity and stock of natural resources. In the context of global change, we expected an increase in studies adopting the more holistic social-ecological resilience concept, but this was not the observed trend. Summary Our analysis points to the nestedness of these three resilience concepts, suggesting that they are complementary rather than contradictory. It also means that the variety of resilience approaches does not need to be an obstacle for operationalisation of the concept. We provide guidance for choosing the most suitable resilience concept and indicators based on the management, disturbance and application context