Algebraic symmetries of generic (m+1)(m+1) dimensional periodic Costas arrays

In this work we present two generators for the group of symmetries of the generic $(m+1)$ dimensional periodic Costas arrays over elementary abelian $(\mathbb{Z}_p)^m$ groups: one that is defined by multiplication on $m$ dimensions and the other by shear (addition) on $m$ dimensions. Through exhaustive search we observe that these two generators characterize the group of symmetries for the examples we were able to compute. Following the results, we conjecture that these generators characterize the group of symmetries of the generic $(m+1)$ dimensional periodic Costas arrays over elementary abelian $(\mathbb{Z}_p)^m$ groups

Rethinking the development of social policy in front of the millennium goals. changing programs and speeches as alternatives to the official message

This article focuses on Mexicans, socially perceived as poor, and the impact of social policy in force in the second decade of the 21st century, focused on improving the living conditions of the population, living in poverty and facing the national democratic process, which represents the alternative of change to the national conditions in Mexico. A country with social inequalities, where the lack of guaranteeing equal living conditions through institutional frameworks that guarantee opportunities and access to common satisfiers is evident. Therefore, in the midst of a democratization process, the State seeks to address the levels of precariousness. In the midst of the recognition of the basic needs to be met among those who are reviewing the renewed social policy of the 21st century, the need to strengthen the living conditions of the excluded is prioritized and in its consolidation process it would guarantee attention to poverty through institutional channels. This is the case of the social development law, which deals with a problem of productive order from a State vision. An analysis is carried out that seeks to identify the relationship between the effectiveness of current actions to combat the lack of attention to basic needs and the institutionalized discourse, which, according to the social research approach, strengthens the interest in conducting studies on social precariousness as a group characteristic; fueled by the political discourse, exalted by the government in turn of the poor first. In this case, it is the message that strengthens the need to analyze the way, in which poverty is measured based on the recognition of poverty lines, as an instrument that allows knowing the number of people in that condition, according to the levels of dissatisfaction of food needs and due to the low level of economic income (inability to consume a basic set of food goods) for rural and urban environments. Therefore, it seeks to measure the lack of food needs, without considering the causes of inability to generate minimum income levels to consume basic foods

Interactions between inflation, monetary and fiscal policy.

In Chapter 1 I develop a simple model, that builds upon some previous work on financial innovation processes, to account for the main stylized facts observed during extreme hyperinflations. The modeling device used here helps to reconcile some conflicting views on the causes, development and end of a hyperinflation without departing from the rational expectations assumption. Specifically, it is shown that the effectiveness of a future orthodox reform to preclude the occurrence of a hyperinflation, either speculative or fundamental, is an endogenous outcome which depends on a wide array of policy choices (fiscal and monetary) and structural features of the economy. In Chapter 2 I examine the postulates of the Fiscal Theory of the Price Level (FTPL) under an interest rate peg. I show that the usual definition of a non-Ricardian plan involves a non-credible government policy commitment, thus confuting the interpretation of the FTPL as a policy-based equilibrium selection device. Then I identify the set of necessary conditions for the implementation of non-Ricardian fiscal plans that result in a unique equilibrium. A critical necessary condition for the credibility of a fiscalist plan is that the equilibrium level of seigniorage must be non-positive. I argue that the fiscalist stock-analogy is only meaningful, precisely, when money enters into the government constraint as a destination of funds, rather than as a source. In Chapter 3, I extend Buiter's (2001, 2002) criticism (non-Ricardian plans are generally non-implementable whenever the monetary authority sets a non-contingent sequence of money supplies) to an infinite horizon economy. In particular, it is shown that a fiscalist deflation involves the violation of a household's optimality condition and that the notion of a fiscally-induced speculative hyperinflation cannot be rationalized invoking a symmetry between the problem of pricing a potentially fiat non-convertible asset (like money) and that of pricing the stock of a private firm as advocated by the FTPL

Long-chain bases, phosphatidic acid, MAPKs, and reactive oxygen species as nodal signal transducers in stress responses in Arabidopsis

Due to their sessile condition, plants have developed sensitive, fast and successful ways to contend to environmental changes. These mechanisms operate as informational wires conforming extensive and intricate networks that are connected in several points. The responses are designed as pathways orchestrated by molecules that are transducers of protein and non-protein nature. Their chemical nature imposes selective features such as specificity, formation rate and generation site to the informational routes. Enzymes such as mitogen-activated protein kinases (MAPK) and non-protein, smaller molecules, such as long chain bases, phosphatidic acid and reactive oxygen species are recurrent transducers in the pleiotropic responses to biotic and abiotic stresses in plants. In this review, we considered these four components as nodal points of converging signaling pathways that start from very different stimuli and evoke very different responses. These pleiotropic effects may be explained by the possibility that every one of these four mediators can be expressed from different sources, cellular location, temporality or magnitude. Here, we review recent advances in our understanding of the interplay of these four specific signaling components in Arabidopsis cells, with an emphasis on drought, cold and pathogen stresses

Framework to estimate the benefit-cost ratio of pavement skid improvements at the network level

Research has proven that low values of pavement skid increase crash risk. Minimum skid thresholds have been established in order to screen projects for further testing and improvements. Skid resistance values are used in addition to crash data, pavement condition data, and roadway features to select and prioritize skid improvement projects. Furthermore, skid resistance performance models have been developed in order to capture the skid deterioration over time. However, the aforementioned studies did not quantify the economic impact of skid improvements over a time period for a network. This thesis fills this information gap, by providing a framework that quantifies the Benefit-Cost Ratio (BCR) of skid resistance improvements at the network level. A skid deterioration model is developed using the Markov Chain process, in order to account for the base case scenario when no treatment is applied. Benefits are quantified as the reduction of expected crashes compared to the base case scenario, using the concept of Crash Rate Ratio (CRR). Costs are quantified as the costs of pavement resurface treatments that improve skid. A sample of highway sections that comprise 564 lane-miles in Texas is evaluated to demonstrate the applicability of the proposed methodology. As a result, a Benefit-Cost Ratio curve was generated for different minimum skid thresholds.Civil, Architectural, and Environmental Engineerin

Aproximación variacional de vórtices solitónicos asimétricos en medios no lineales no locales

El objetivo principal del presente trabajo ha sido modelar estructuras en forma de vórtice solitónico que surgen de la ecuación no lineal de Schrödinger en dos dimensiones, así que se ha utilizado una aproximación variacional [Anderson, 1983a] para determinar la dinámica del sistema y el método Split Step de Fourier [Weideman and Herbst, 1986] para simular la propagación. Las cantidades dinámicas que se determinaron fueron la potencia, el momento lineal, el momento angular y el Hamiltoniano, considerando dos casos: un caso local Kerr y un caso no local general. El caso Kerr se trabajó analíticamente mientras que para el caso no local se implementó la aproximación variacional desarrollada con el método de Newton-Rapson multivariante [Duque et al., 2018]. La función de prueba propuesta ha sido un vórtice solitónico asimétrico, en el cual nos interesamos en encontrar los parámetros óptimos de amplitud y ancho del haz. La propagación de los resultados obtenidos, al igual que el método variacional, se realizaron numéricamente con el software de cálculo MATLAB. Para la propagación se utilizó el método Split Step de Fourier, obteniendo resultados conocidos para comparar con trabajos de otros autores y nuestro caso de estudio particular. Se presentan los resultados de 10 propagaciones diferentes, con variaciones de los valores de constante de propagación, carga topológica, asimetría y grado de no localidad. Hemos encontrado, mediante la aproximación variacional, que el vórtice asimétrico propuesto, descrito por el parámetro de asimetría, puede tener un comportamiento de haz auto atrapado bajo cierta combinación de parámetros de no localidad y grado de asimetría. Además, estas estructuras generadas presentan mayor estabilidad en su propagación a mayor grado de no localidad

Estudio comparativo del diseño de mezclas de concreto convencional utilizando diferentes aditivos acelerantes de resistencia; con agregados de las canteras Tres Tomas y La Victoria de la región de Lambayeque

El concreto con aditivo acelerante de resistencia es un concreto que obtiene tempranas resistencias a diferencia de un concreto convencional, una de las propiedades más valiosa y la que le da versatilidades es la acelerada resistencia a la compresión La presente investigación trata de buscar una metodología para comparar y obtener dosificaciones de mezclas con aditivos acelerantes de resistencia, tanto en concretos curados y sin curar; con asentamiento de rango 3”- 4” usando cemento portland tipo ICO y MS y aditivo acelerante de resistencia SIKA RAPID 1 y CHEMA ESTRUCT, para lo cual se empezó con el diseño de un concreto patrón, el cual sirvió de base principal para la obtención del concreto con acelerantes de resistencia. Asimismo, se expone las propiedades de los diferentes materiales usados en la investigación, para lo cual los agregados (fino y grueso) fueron ensayados para conocer sus propiedades, mientras que las propiedades del cemento, aditivo acelerante de resistencia SIKA RAPID 1 y CHEMA ESTRUCT, fueron proveídas por los fabricantes. Para el concreto patrón, los porcentajes de arena y piedra para el agregado global se hallaron haciendo diferentes ensayos en proporciones y ensayos a la resistencia a la compresión a los 3, 7 y 28 días, con una relación agua/cemento de 0.65. Las dosificaciones de los aditivos se utilizaron en base a las especificaciones técnicas de las marcas de los aditivos acelerantes de resistencia SIKA RAPID 1 y CHEMA ESTRUCT, para los cuales se fueron adicionando aditivo en diferentes dosificaciones según el aditivo a utilizar, 0.50 %, 1.75% y 3.00% (respecto al peso del cemento) para SIKA RAPID 1; y 0.78%, 1.17% y 1.55% (respecto al peso del cemento) para CHEMA ESTRUCT respectivamente (respecto al peso del cemento). El diseño del concreto con acelerante de resistencia de mejores resistencias tempranas fue el concreto con aditivo SIKA RAPID 1, en la dosificación superior, añadiendo 3.00% (respecto al peso del cemento), un concreto curado utilizando cemento MS obteniendo una resistencia a la compresión de f’c = 312 kg/cm2 en 28 días.Tesi

Gestión administrativa y su influencia en los servicios de saneamiento del distrito de Virú

El presente trabajo de investigación tuvo como objetivo determinar de qué manera la gestión administrativa influye en los servicios de saneamiento del distrito de Virú. La investigación es de tipo explicativa, con diseño no experimental y se utilizó la metodología de carácter cuantitativo. La población estuvo conformada por 52,407 habitantes del distrito de Virú. Para hallar la cantidad de la muestra de estudio se aplicó los instrumentos a 384 colaboradores, elegidos mediante el muestreo no probabilístico por conveniencia e interés del estudio. La técnica de recolección de datos fue la encuesta, y se elaboraron dos instrumentos de recolección de datos los cuales fueron: el cuestionario de gestión administrativa y el cuestionario de servicio de saneamiento. Los resultados obtenidos en la investigación han determinado que existe una relación altamente significativa directa entre ambas variables; ya que se ha obtenido un resultado por mitades de 0.896 de la primera variable y un 0.892 de la segunda variable el cual indica un alto nivel de confiabilidad. Las conclusiones se interpretan en términos aplicados en la prueba de hipótesis contrastando que existe un alto grado de aceptabilidad de cada hipótesis planteada, coincidiendo así también con estudios anteriores y fundamentos teóricos.Tesi