Towards a Unified Framework for Declarative Structured Communications

We present a unified framework for the declarative analysis of structured communications. By relying on a (timed) concurrent constraint programming language, we show that in addition to the usual operational techniques from process calculi, the analysis of structured communications can elegantly exploit logic-based reasoning techniques. We introduce a declarative interpretation of the language for structured communications proposed by Honda, Vasconcelos, and Kubo. Distinguishing features of our approach are: the possibility of including partial information (constraints) in the session model; the use of explicit time for reasoning about session duration and expiration; a tight correspondence with logic, which formally relates session execution and linear-time temporal logic formulas

Hypersimplicial subdivisions

Let π:Rn→Rd be any linear projection, let A be the image of the standard basis. Motivated by Postnikov’s study of postitive Grassmannians via plabic graphs and Galashin’s connection of plabic graphs to slices of zonotopal tilings of 3-dimensional cyclic zonotopes, we study the poset of subdivisions induced by the restriction of π to the k-th hypersimplex, for k=1,…,n−1 . We show that: For arbitrary A and for k≤d+1 , the corresponding fiber polytope F(k)(A) is normally isomorphic to the Minkowski sum of the secondary polytopes of all subsets of A of size max{d+2,n−k+1} . When A=Pn is the vertex set of an n-gon, we answer the Baues question in the positive: the inclusion of the poset of π -coherent subdivisions into the poset of all π -induced subdivisions is a homotopy equivalence. When A=C(d,n) is the vertex set of a cyclic d-polytope with d odd and any n≥d+3, there are non-lifting (and even more so, non-separated) π -induced subdivisions for k=2.The authors were supported by the Einstein Foundation Berlin under grant EVF-2015-230. Work of F. Santos is also supported by grants MTM2017-83750-P/AEI/10.13039/501100011033 and PID2019-106188GB-I00/AEI/10.13039/501100011033 of the Spanish State Research Agency

Diseño de sistema electrónico jerárquico mediante comandos para robot hexápodo

Ingeniero (a) ElectrónicoPregrad

Divergencia y convergencia regional en el Perú: 1978-1992

This is a paper on the Regional Convergence Hypothesis, applied to the Peruvian case during the 1978 – 1992 period. The research considers an important element, generally neglected by studies on economic growth: the spatial organization of the economy in regions. For that purpose, the empirical analysis has used spatial economic tools, applied to a panel model with fixed effects and SAR (1) errors. The findings show the absence of trends towards conditional convergence, which means that the Peruvian Departments as such lack steady growth paths in the medium term. The data also show that during the hyperinflation and structural adjustment periods, the less developed Departments presented slow down factors. Finally, the analysis shows that the public expenditure plays an important compensatory role of the decelerating and accelerating forces of growth, and that its impact is more favorable to growth when regions are considered, instead of the Departments. These results reinforce the idea that integration of the Departments into regions is necessary.

Estudio Dinámico del Sistema Araña-Tela de Araña en condiciones de Resonancia

Se ha estudiado el conjunto araña-tela de araña como un sistema dinámico, con la finalidad de obtener la respuesta de este sistema, cuando es sometido a condiciones de resonancia. La tela de araña es una estructura con una excelente combinación de resistencia, rigidez y tenacidad, óptima para transformar energía cinética en energía disipativa y así capturar a las presas. Sin embargo, hay condiciones ambientales externas que pueden llevar a esta estructura a condiciones de resonancia que podrían dañarla. De manera experimental se pudo comprobar que cuando ello ocurre, la araña es capaz de modificar la tensión de las sedas de la tela de araña, rigidizando la estructura para alejar al sistema de la zona de resonancia. La araña, mediante sus patas, censa la vibración en la tela de araña y actúa cuando las amplitudes aumentan significativamente y se mantienen por un largo periodo, cambiando así la tensión del sistema. Un modelo conceptual dinámico de un grado de libertad es una herramienta eficaz para replicar el comportamiento dinámico del conjunto araña-tela de araña en condiciones de resonanci