An evolutionary algorithm for online, resource constrained, multi-vehicle sensing mission planning

Mobile robotic platforms are an indispensable tool for various scientific and industrial applications. Robots are used to undertake missions whose execution is constrained by various factors, such as the allocated time or their remaining energy. Existing solutions for resource constrained multi-robot sensing mission planning provide optimal plans at a prohibitive computational complexity for online application [1],[2],[3]. A heuristic approach exists for an online, resource constrained sensing mission planning for a single vehicle [4]. This work proposes a Genetic Algorithm (GA) based heuristic for the Correlated Team Orienteering Problem (CTOP) that is used for planning sensing and monitoring missions for robotic teams that operate under resource constraints. The heuristic is compared against optimal Mixed Integer Quadratic Programming (MIQP) solutions. Results show that the quality of the heuristic solution is at the worst case equal to the 5% optimal solution. The heuristic solution proves to be at least 300 times more time efficient in the worst tested case. The GA heuristic execution required in the worst case less than a second making it suitable for online execution.Comment: 8 pages, 5 figures, accepted for publication in Robotics and Automation Letters (RA-L

Political Institutions and Greenhouse Gas Controls

Research and insights taken from the field of political economy suggest that institutions limit the extent to which efficient policies to reduce greenhouse gas emissions are likely to be adopted. High transaction costs among nations, as well as domestic constraints like voter xenophobia and distrust of markets in the U.S. and ineffective legal and economic institutions in China, discourage international agreement. The U.S. must focus upon limiting economic harm from adopting poorly designed policies and developing strategies for adaptation or technology-driven geoengineering. Most importantly, the lessons of political economy must become central to the study of climate policy, including a healthy exchange of views between political economists and climate modelers.

Finite domination and Novikov rings. Iterative approach

Suppose C is a bounded chain complex of finitely generated free modules over the Laurent polynomial ring L = R[x,1/x]. Then C is R-finitely dominated, ie, homotopy equivalent over R to a bounded chain complex of finitely generated projective R-modules, if and only if the two chain complexes C((x)) and C((1/x)) are acyclic, as has been proved by Ranicki. Here C((x)) is the tensor product over L of C with the Novikov ring R((x)) = R[[x]][1/x] (also known as the ring of formal Laurent series in x); similarly, C((1/x)) is the tensor product over L of C with the Novikov ring R((1/x)) = R[[1/x]][x]. In this paper, we prove a generalisation of this criterion which allows us to detect finite domination of bounded below chain complexes of projective modules over Laurent rings in several indeterminates.Comment: 15 pages; diagrams typeset with Paul Taylor's "diagrams" macro package. Version 2: clarified proof of main theorem, fixed minor typos; Version 3: expanded introduction, now 16 pages; Version 4: corrected mistake on functoriality of mapping tor

Jobs, Workers and Changes in Earnings Dispersion

The 'fractal' nature of the rise in earnings dispersion is one of its key features and remains a puzzle. In this paper, we offer a new perspective on the causes of changes in earnings dispersion, focusing on the role of labour reallocation. Once we drop the assumption that all firms pay a given worker the same, the allocation of workers to firms matters for the dispersion of earnings. This perspective highlights two new factors that can affect the dispersion of earnings: rates of job and worker reallocation, and the nature of the process allocating workers to jobs. We set out a framework capturing this idea and quantify the impact of reallocation on earnings dispersion, using a dataset that comprises almost the universe of workers and the universe of employers in Maryland. We show that these factors have potentially large effects in general on earnings dispersion. In the case of Maryland over the period 1985-1994, the changing allocation of workers to jobs played a significant role in explaining movements in the dispersion of earnings.Earnings inequality, labour reallocation, matched worker and firm panels

The Impact of Contaminated RR Lyrae/Globular Cluster Photometry on the Distance Scale

RR Lyrae variables and the stellar constituents of globular clusters are employed to establish the cosmic distance scale and age of the universe. However, photometry for RR Lyrae variables in the globular clusters M3, M15, M54, M92, NGC2419, and NGC6441 exhibit a dependence on the clustercentric distance. For example, variables and stars positioned near the crowded high-surface brightness cores of the clusters may suffer from photometric contamination, which invariably affects a suite of inferred parameters (e.g., distance, color excess, absolute magnitude, etc.). The impetus for this study is to mitigate the propagation of systematic uncertainties by increasing awareness of the pernicious impact of contaminated and radial-dependent photometry.Comment: To appear in ApJ

Going Forward: The Eurasian Economic Union, The European Union And The Others

This is the final version of the article. It first appeared from LSE IDEAS via http://www.lse.ac.uk/IDEAS/publications/reports/pdf/LSE-IDEAS-Avoiding-a-New-Cold-War.pdfThe consequences of NATO and EU enlargement have discouraged Eurasian political elites from using the EEU as a stepping-stone to the neo-liberal world economic system. Their economic and geopolitical interests have been infringed by Western policies as illustrated by the conflict in Ukraine. The EEU has reacted by turning inward and eastward and an alternative geo-political bloc is in formation. It is likely to form a nationally based administratively coordinated form of capitalism, which in turn might lead to greater international conflict. The West should practise democracy between states to secure international stability rather than promoting democracy within states. A more pluralistic multi-speed EU, with less ambitious goals and taking into account external interests, could become a complimentary partner to the EEU and enhance peace and well-being

The Problem of Too Many Statistical Tests: Subgroup Analyses in a Study Comparing the Effectiveness of Online and Live Lectures

The more statistical analyses performed in the analysis of research data, the more likely it is that one or more of the conclusions will be in error. Multiple statistical analyses can occur when the sample contains several subgroups and the researchers perform separate analyses for each subgroup. For example, separate analyses may be done for different ethnic groups, different levels of education, and/or for both genders. Media reports of research frequently omit information on the number of subgroup analyses performed thus leaving the reader with insufficient information to assess the validity of the conclusions. This article discusses the problems with a media report on research that was analyzed by conducting many subgroup analyses. The article concludes that the quantitatively literate reader should be skeptical of articles that report subgroup analyses without reporting the number of analyses that were done

Eurasian integration could offer a counterpoint to the EU and the United States, but only in close co-operation with states like India and China

Russia, Belarus and Kazakhstan have pursued integration with the aim of creating a Eurasian Union by 2015. David Lane writes on the economic and political background underpinning Eurasian integration and its potential to act as a counterpoint to the hegemony of the United States in the global system. He argues that while the economic weight of the three Eurasian Union states is fairly limited, pursuing close co-operation with ‘BRICS’ countries such as Brazil, India and China could offer the basis for a more pluralist and multi-polar world