Prediction bounds for higher order total variation regularized least squares

We establish adaptive results for trend filtering: least squares estimation with a penalty on the total variation of $(k-1)^{\rm th}$ order differences. Our approach is based on combining a general oracle inequality for the $\ell_1$-penalized least squares estimator with "interpolating vectors" to upper-bound the "effective sparsity". This allows one to show that the $\ell_1$-penalty on the $k^{\text{th}}$ order differences leads to an estimator that can adapt to the number of jumps in the $(k-1)^{\text{th}}$ order differences of the underlying signal or an approximation thereof. We show the result for $k \in \{1,2,3,4\}$ and indicate how it could be derived for general $k\in \mathbb{N}$.Comment: 28 page

On the total variation regularized estimator over a class of tree graphs

We generalize to tree graphs obtained by connecting path graphs an oracle result obtained for the Fused Lasso over the path graph. Moreover we show that it is possible to substitute in the oracle inequality the minimum of the distances between jumps by their harmonic mean. In doing so we prove a lower bound on the compatibility constant for the total variation penalty. Our analysis leverages insights obtained for the path graph with one branch to understand the case of more general tree graphs. As a side result, we get insights into the irrepresentable condition for such tree graphs.Comment: 42 page

Comparison of quantization of charge transport in periodic and open pumps

We compare the charges transported in two systems, a spatially periodic and an open quantum pump, both depending periodically and adiabatically on time. The charge transported in a cycle was computed by Thouless, respectively by Buttiker et al. in the two cases. We show that the results agree in the limit where the two physical situations become the same, i.e., that of a large open pump.Comment: 7 page

Marginalismo y relaciones interétnicas: blancos e indios en la frontera rioplatense en el siglo XIX.

Este trabajo constituye una aproximación al tema del marginalismo en la frontera rioplatense del actual territorio argentino durante la primera mitad del siglo XIX. En el contexto de las intensas relaciones interétnicas, de carácter múltiple y cambiante que se establecieron en tal contexto entre indígenas pampeanos y no indígenas --básicamente, pobladores rurales de la región bonaerense-- se hace un estudio de varios casos de blancos que vivían entre los indios, de manera voluntaria o forzada.This paper represents an approach to the subject of marginalization during the first half of the 19th century in the Río de la Plata borderland of what is now Argentinean territory. In the context of the close interethnic relationshisps with a multiple and changing nature, that were established between Pampa indigenous and non-indigenous groups --basically rural inhabitants of the Buenos Aires region-- different cases are analyzed in reference to white population that lived among the Indians, whether by own will or forced

Living in the Margins : Porous Borders and Movements of Population in the Late Colonial New Vizcaya

Este artículo estudia la conformación multiétnica de pueblos de indios y misiones en la frontera norte de Nueva España –específicamente, en la provincia de Nueva Vizcaya– y la circulación de población entre espacios sociales y geográficos controlados y no controlados por el Estado colonial. Esta frontera porosa y permeable fue el escenario de una dinámica social que cuestionaba los postulados de segregación y control que habían intentado imponer las autoridades desde los primeros tiempos de la colonización y que trataron de reforzar durante el siglo XVIII, en el contexto del programa de afianzamiento del poder imperial conocido como reformas borbónicas.This paper studies the formation of ethnic Indian villages and missions on the northern frontier of New Spain -specifically in the province of New Vizcaya- and the movement of population between social and geographical spaces controlled and not controlled by the colonial state. This porous and permeable border was the scene of a social dynamic that questioned the principles of segregation and control that had been proposed by the authorities since the early days of colonization and tried to strength during the eighteenth century, in the context of the program known as Bourbon reforms.Fil: Ortelli, Sara Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Instituto de Geografía, Historia y Ciencias Sociales. Universidad Nacional del Centro de la Pcia.de Bs.as.. Instituto de Geografía, Historia y Ciencias Sociales; Argentin

Minimum-cost numerical prediction system for wind power in Uruguay, with an assessment of the diurnal and seasonal cycles of its quality

This work presents the results of a numerical forecast system of minimum cost for the electric power generated by wind farms in Uruguay. By keeping at minimum levels both the computational costs and the complexity of the empirical corrections of the numerical results, we obtain a benchmark for the forecast skill of more complex forecast systems, that is easily available during their calibration stages and operative functioning. The work also aims to explore the diurnal and seasonal cycle of the forecasts quality. It is found that this simple forecast system produces very good results, albeit the dependencies of the forecast skill and errors respect to the season of the year and the time of the day are distinguishable. It is also found that it is necessary to take into account the diurnal and the seasonal cycles during the calibration of the empirical corrections. The good results of this simple technique might had been possible due to the relative smooth topography of Uruguay.Este trabalho apresenta os resultados de um sistema de previsão numérica de custo mínimo para a energia elétrica gerada pelos parques eólicos operacionais no Uruguai. Ao manter em níveis mínimos, tanto os custos computacionais como a complexidade das correções empíricas dos resultados numéricos, obtemos uma referência para a habilidade de previsão de sistemas de previsão mais complexos, que é facilmente disponível durante os estágios de calibração e funcionamento operacional. O trabalho também visa explorar o ciclo diurno e sazonal da qualidade das previsões. Verifica-se que esse sistema de previsão simples produz resultados muito bons, embora as dependências da habilidade e erros de previsão em relação à estação do ano e à época de o dia é distinguível. Verifica-se também que é necessário levar em consideração os ciclos diurnos e sazonais durante a calibração das correções empíricas. Os bons resultados desta técnica simples poderiam ter sido possíveis devido à topografia relativamente suave do Uruguai

Equivalence of Topological and Scattering Approaches to Quantum Pumping

The Schrödinger equation with a potential periodically varying in time is used to model adiabatic quantum pumps. The systems considered may be either infinitely extended and gapped or finite and connected to gapless leads. Correspondingly, two descriptions of the transported charge, one relating to a Chern number and the other to a scattering matrix, have been available for some time. Here we generalize the first one and establish its equivalence to the secon

Entre desiertos y serranías. Población, espacio no controlado y fronteras permeables en el Septentrión novohispano tardocolonial

En aquest article s’analitza la circulació de població a la província de Nova Biscaia a finals de l’època colonial, entre els espais controlats i aquells que quedaven fora del control de les autoritats. Encara que se suposava que estaven formalment integrats en la societat colonial com a súbdits de la corona, la vida d’aquests homes i dones transcorria entre la seva incorporació com a habitants de pobles i missions, hisendes o reals de mina, i la seva dedicació a les diverses activitats productives com a treballadors agrícoles, miners o pastors, i el seu establiment per temporades o la seva fugida definitiva als deserts i les regions muntanyenques, on continuaven la seva existència vinculant-se sovint a activitats delictives com el robatori de bestiar. Aquests espais actuaven, així, com a fronteres a l’interior de la mateixa societat colonial i contribuïen a delimitar i definir identitats socials i formes de vida.This article discusses population flows in the province of Nueva Vizcaya in the late colonial era between controlled areas and those which were outside the control of the colonial authorities. Although they were supposed to be formally integrated into colonial society as subjects of the Crown, the lives of these frontier men and women were spent between their condition as citizens of towns, well-integrated members of missions and haciendas and mine workers, or as outlaws in deserts and mountains engaged in criminal activities such as cattle rustling. These lands constituted real borders within colonial society and contributed to defining social identities in the North American confines of the colonial Spanish Empire.En este artículo se analiza la circulación de población en la provincia de Nueva Vizcaya a fines de la época colonial, entre los espacios controlados y aquellos que quedaban fuera del control de las autoridades. Aunque se suponía que estaban formalmente integrados en la sociedad colonial como súbditos de la corona, la vida de estos hombres y mujeres transcurría entre su incorporación como habitantes de pueblos y misiones, haciendas o reales de mina, y su dedicación a las diversas actividades productivas como trabajadores agrícolas, mineros o pastores, y su establecimiento por temporadas o su huida definitiva a los desiertos y serranías, donde continuaban su existencia vinculándose con frecuencia a actividades delictivas como el robo de ganado. Estos espacios actuaban, así, como fronteras en el interior de la propia sociedad colonial y contribuían a delimitar y definir identidades sociales y modos de vida