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We propose a framework for discrete scientific data compression based on the tensor-train (TT) decomposition. Our approach is tailored to handle unstructured output data from discrete element method (DEM) simulations, demonstrating its effectiveness in compressing both raw (e.g. particle position and velocity) and derived (e.g. stress and strain) datasets. We show that geometry-driven "tensorization" coupled with the TT decomposition (known as quantized TT) yields a hierarchical compression scheme, achieving high compression ratios for key variables in these DEM datasets.

We present a novel computational framework for simulating suspensions of rigid spherical Janus particles in Stokes flow. We show that long-range Janus particle interactions for a wide array of applications may be resolved using fast, spectrally accurate boundary integral methods tailored to polydisperse suspensions of spherical particles. These are incorporated into our rigid body Stokes platform. Our approach features the use of spherical harmonic expansions for spectrally accurate integral operator evaluation, complementarity-based collision resolution, and optimal O(n) scaling with the number of particles when accelerated via fast summation techniques. We demonstrate the flexibility of our platform through three key examples of Janus particle systems prominent in biomedical applications: amphiphilic, bipolar electric and phoretic particles. We formulate Janus particle interactions in boundary integral form and showcase characteristic self-assembly and complex collective behavior for each particle type.

People?s quality of life in specific places is affected by their territories? characteristics and local agents? actions and interactions, as well as their responses to external influences. Formal and informal institutions contribute to shape those actions, interactions and responses. Following North (1990) and Storper (1995), the economic performance of places is influenced by their particular institutional setting; and, therefore, by the way a particular society is organised. Hence, the political and social dimensions acquire special importance. Relating those ideas to the bottom-up approach towards development, and its positive effect on the development of Mexican municipalities found by Rodriguez-Pose and Palavicini-Corona (2013), it is relevant and interesting to analyse if, in the Mexican context, formal and informal institutions have facilitated or not economic development at the local level. As the basis of the development from below approach stems from its proximity to local characteristics and agents, the lowest level of government jurisdiction is the focus of analysis. Two municipalities located in a Mexican state with a long presence of institutions and resulting mechanisms closer to citizens were selected in order to further assess the role of institutions. The hypothesis tested is that the general formal institutional context in Mexico has a relevant propitious role in LED. In relation to the case studies, the hypothesis is that a more favourable effect in one of the studied municipalities than the other is due to differences in the functioning of their formal institutions and the particularities of their informal ones. It was found that the national and sub-national formal institutional setting has allowed and, at some degree, stimulated municipalities to plan and execute local economic development actions during the period of analysis (1990-2015). However, abiding to the law and enforcing it are the main aspects to be addressed in this Latin American country. As far as the case studies are concerned, significant differences in their informal institutions affected the presence of the LED approach and their development performance from 1990 to 2010. Finally, in light of the concrete findings, I present a set of proposals to both introduce some adjustments to the legal framework and make the best of current formal and informal institutions prevailing in Mexico, in general, and the studied municipalities, in particular.

An efficient direct solver for volume integral equations with O(N) complexity for a broad range of problems is presented. The solver relies on hierarchical compression of the discretized integral operator, and exploits that off-diagonal blocks of certain dense matrices have numerically low rank. Technically, the solver is inspired by previously developed direct solvers for integral equations based on "recursive skeletonization" and "Hierarchically Semi-Separable" (HSS) matrices, but it improves on the asymptotic complexity of existing solvers by incorporating an additional level of compression. The resulting solver has optimal O(N) complexity for all stages of the computation, as demonstrated by both theoretical analysis and numerical examples. The computational examples further display good practical performance in terms of both speed and memory usage. In particular, it is demonstrated that even problems involving 10^{7} unknowns can be solved to precision 10^{-10} using a simple Matlab implementation of the algorithm executed on a single core., Submitted to the SIAM Journal of Scientific Computing (May 14, 2013). 32 pages, 12 figures, 6 sections

Different levels of government, multilateral organisations such as the World Bank (WB), and a great number of non-governmental organisations around the globe state either explicitly or implicitly their intentions to improve the development of places. Their main goal is to help societies to achieve higher standards in economic, educational, health and social security aspects, among others. To do this, they put emphasis on particular issues and, as a consequence, many adjectives to the word development have become common in the public policy literature. Thereby, combined words like human development, economic development, sustainable development and social development are familiar among practitioners and experts working to improve the well-being of people in diverse parts of the world. In addition, since 1990 scholars and multilateral organisations such as the Organisation for Economic Cooperation and Development (OECD) have recommended a local (i.e. the lowest sub-national level) response to the development challenges and opportunities originated by the globalisation of the world economy. In this context, the impact of bottom-up strategies towards local economic development has not been sufficiently assessed for both developed and developing countries. This paper presents a first approximation towards assessing the impact of such strategies in Mexican municipalities by proposing a simple model linking them to measures of human and social well-being such as the components of the human development index (HDI) calculated since 1990 by the United Nations Development Programme.