On the cost of fixed partial match queries in K-d trees

The final publication is available at Springer via http://dx.doi.org/10.1007/s00453-015-0097-4Partial match queries constitute the most basic type of associative queries in multidimensional data structures such as K-d trees or quadtrees. Given a query q=(q0,…,qK-1) where s of the coordinates are specified and K-s are left unspecified (qi=*), a partial match search returns the subset of data points x=(x0,…,xK-1) in the data structure that match the given query, that is, the data points such that xi=qi whenever qi¿*. There exists a wealth of results about the cost of partial match searches in many different multidimensional data structures, but most of these results deal with random queries. Only recently a few papers have begun to investigate the cost of partial match queries with a fixed query q. This paper represents a new contribution in this direction, giving a detailed asymptotic estimate of the expected cost Pn,q for a given fixed query q. From previous results on the cost of partial matches with a fixed query and the ones presented here, a deeper understanding is emerging, uncovering the following functional shape for Pn,q Pn,q=¿·(¿i:qi is specifiedqi(1-qi))a/2·na+l.o.t. (l.o.t. lower order terms, throughout this work) in many multidimensional data structures, which differ only in the exponent a and the constant ¿, both dependent on s and K, and, for some data structures, on the whole pattern of specified and unspecified coordinates in q as well. Although it is tempting to conjecture that this functional shape is “universal”, we have shown experimentally that it seems not to be true for a variant of K-d trees called squarish K-d trees.Peer ReviewedPostprint (author's final draft

Analytical solution to DGLAP integro-differential equation in a simple toy-model with a fixed gauge coupling

We consider a simple model for QCD dynamics in which DGLAP integro-differential equation may be solved analytically. This is a gauge model which possesses dominant evolution of gauge boson (gluon) distribution and in which the gauge coupling does not run. This may be ${\cal N} =4$ supersymmetric gauge theory with softly broken supersymmetry, other finite supersymmetric gauge theory with lower level of supersymmetry, or topological Chern-Simons field theories. We maintain only one term in the splitting function of unintegrated gluon distribution and solve DGLAP analytically for this simplified splitting function. The solution is found by use of the Cauchy integral formula. The solution restricts form of the unintegrated gluon distribution as function of transfer momentum and of Bjorken $x$. Then we consider an almost realistic splitting function of unintegrated gluon distribution as an input to DGLAP equation and solve it by the same method which we have developed to solve DGLAP equation for the toy-model. We study a result obtained for the realistic gluon distribution and find a singular Bessel-like behaviour in the vicinity of the point $x=0$ and a smooth behaviour in the vicinity of the point $x=1.$Comment: 25 page

A Review of Research on Shear Strength Decay in Members under Load Reversals

In the design of reinforced concrete earthquake-resisting frame members, it is critical that shear distress be limited in order to ensure acceptable deformation capacity and reduce damage. Accordingly, several ACI Building Code1 provisions for beams and columns of frames categorized as “special moment frames” are aimed at minimizing shear distress. Pertinent requirements include using a capacity design approach to calculate demand, neglecting any contribution of the concrete to nominal shear strength in beams, and limiting hoop spacing to one-fourth of the effective (beams) or overall (columns) member depth. These provisions are largely based on findings from early research aimed at understanding the behavior of frame members subjected to cycles of load reversals. The aim of this paper is to review relevant research on the behavior of frame members under earthquake-type demands, beginning with the first tests of flexural members subjected to fully reversed loads and ending with the 1983 ACI Building Code2, as it was the first ACI Code edition to incorporate several provisions aimed at minimizing shear strength decay. This paper describes the basis for pertinent ACI Building Code provisions (other code or design documents were not included in this review), emphasizes the importance of low shear stress demands, and highlights reinforcement detailing options that have been shown to improve member behavior. This review should therefore be of interest to students and structural engineers, particularly those learning or involved in earthquake-resistant design of reinforced concrete structures

Principales dispositivos tecnol?gicos que intervienen en el proceso de aprendizaje en los alumnos de grado d?cimo de la instituci?n educativa San Bernardo del municipio de Ibagu?

40 p. Recurso Electr?nicoEn este art?culo se presentan los resultados de una investigaci?n adelantada con estudiantes de d?cimo grado de la Instituci?n Educativa San Bernardo ubicada en la zona rural del municipio de Ibagu?. El objetivo era determinar si los dispositivos tecnol?gicos usados por alguno(as) estudiantes incid?an en su proceso de aprendizaje. El enfoque metodol?gico que se utiliz? fue de car?cter mixto; Desde una perspectiva cualitativa, se recurri? a la entrevista semiestructurada, observaciones a la poblaci?n seleccionada, y desde la cuantitativa, a la encuesta de tipo abierta; el muestreo es probabil?stico no intencional, con 20 estudiantes entre los 15 y 18 a?os. Tambi?n, participaron algunos docentes que orientan diferentes ?reas en este grado. En los resultados encontrados se evidencia que en la poblaci?n seleccionada la mayor?a de los estudiantes hacen uso de los dispositivos tecnol?gicos en horas de clase; Adem?s, el manejo que le hacen a estos equipos es de forma inapropiada en (Redes sociales, juegos, chat y llamadas) causando distracci?n en sus actividades acad?micas. La investigaci?n permiti? concluir que son m?ltiples los factores que inducen a los estudiantes a utilizar tales dispositivos en el aula de clase; entre ellos, el poco inter?s de los estudiante por los aprendizajes te?ricos, la escasa motivaci?n por parte del docente al momento de desarrollar sus clases dado que privilegia las clases magistrales, por su parte, los docentes expresan el precario inter?s de los estudiante por formarse acad?micamente.In this article shows the results of an advanced research with 10 grade high school from San Bernardo educational institution of Ibagu? (Instituci?n eductiva San Bernardo del municipio de Ibagu?). The main goal was to determine if technological devices used for some students would influence in their learning process. The methodological focus that was used is about mixed character; from a qualitative perspective, it is used to half-estructured interview, observations to the target population from this research, and since the cuantitative character one, to the open type survey; the sampling is probabilistic sampling is unintentional, with a population of 20 students between 15 and 18 years old. In other hand, some teachers have been population participant who lead different subjects in that grade of high school. In the found results it may show that in the chosen populace the majority of students make use of technological devices in time class; In addition, the usages which make to those devices is in an inappropriate way in social media, games, chat and calls causing distraction in their academic activities. Keywords: Technological devices, learning process, school performance

Field Tests of Two Prestressed Concrete Girder Bridges for Live Load Distribution and Moment Continuity

Two similar bridges constructed with a live load continuous connection were tested for live load distribution and joint continuity. Girder distribution factors (GDFs) were compared to AASHTO equivalent values. For positive moments on all girders as for negative moments on interior girders, results using AASHTO equivalent GDFs were found to be generally conservative. However, for negative moments on exterior girders, test results exceeded AASHTO values, with 2-lane results significantly so. GDF results were verified with a FEA model, which produced similar behavior to the field tests. With respect to joint continuity, it is estimated that a simple span would produce a maximum positive moment about 7% higher than the actual structure, while a completely continuous structure would produce a maximum positive moment about 16% lower than the actual structure. For negative moments, the actual structure experienced about 28% of that of a continuous structure. Shear reactions were also investigated. Recommendations are proposed for evaluating transverse distribution of live load as well as the longitudinal distribution of live load, accounting for the effect of joint continuity

PWM digital configurable para simples proyectos

This paper presents the software implementation of an adjustable PWM (Pulse Width Modulator) prototype, developed in Verilog code, which functions as a training tool at the undergraduate level, or for the development of small projects. At the schematic level, the prototype presents the main module called PWM which integrates three modules (frequency, useful cycle, and display), as a complement to carry out results under the conditions specified in the functional profile. The base module integrates combinational and sequential circuits, i.e. counters, comparators, flip flops, function generators, etc. The final results obtained by simulation show the expected behavior in terms of frequency setting, duty cycle, and display.Este artículo presenta la implementación, en cuanto a software, de un prototipo de PWM (Modulador por Ancho de Pulso) ajustable, desarrollado en código Verilog, que funcione como herramienta de formación en el ámbito de pregrado, o el desarrollo de pequeños proyectos. En cuanto a esquema, el prototipo presenta un módulo principal llamado PWM el cual integra tres módulos (frecuencia, ciclo útil y display), como complemento para llevar a cabo resultados bajo las condiciones especificadas en el perfil funcional. La base de los módulos integra circuitos combinacionales y secuenciales, es decir contadores, comparadores, Flip Flops, generadores de funciones, etc. Los resultados finales obtenidos por simulación muestran el comportamiento esperado en cuanto a ajuste de frecuencia, ciclo útil y visualización

Espacio público como rehabilitador del tejido social : parque Eupari en Valledupar, como alternativa al pos conflicto

El proyecto consta de las necesidades de adoptarnos hoy en día a nuevos ritmos en la comunidad y a sociedades, compuesta por pobladores existentes y a grupos de personas emigrantes que son aquellos rehabilitados provenientes e3l conflicto armado, requerimos de especialidades que atraigan al público y nos eduquen para convivir en comunidad.With the need to adap to new rhythms in the community and to societies, composed of existing sttlers and groups and of emigrants who are those rehabilitated from the arrived conflicto, we reguire spaces that attract the public and educate us to live togwthwe in community.Arquitecto (a)Pregrad

Enseñanza de la aritmética y la geometría en las escuelas de Cundinamarca durante la introducción de la pedagogía pestalozziana 1867-1894: un estudio exploratorio

Este trabajo se concentra en indagar a propósito de tres aspectos relacionados con las prácticas de enseñanza de las matemáticas en las escuelas del Estado de Cundinamarca entre 1868 y 1894. Dichos aspectos corresponden a: primero, las características sociales, históricas y pedagógicas que sirvieron como marco para la producción de esas prácticas de enseñanza; segundo, los contenidos temáticos y algunas estrategias y métodos de enseñanza que se registraron en materiales como manuales escolares, legislación educativa y artículos dirigidos a maestros; tercero, la relación entre algunas discusiones propias del período histórico revisado con discusiones actuales en torno a la matemática escolar, y de ser posible, al campo de la didáctica de las matemáticas. Como se indicó anteriormente, el trabajo partió de la revisión de documentos que se produjeron y circularon en el período histórico señalado. La exploración de dicha documentación se hizo teniendo en cuenta elementos del enfoque arqueológico-genealógico, en tanto este posibilita identificar los contenidos y sentidos concretos asignados a los discursos que circularon en el período y que hoy podrían contribuir a la reflexión sobre la enseñanza y la didáctica de las matemáticas

Análisis de la Política Pública de Defensa Jurídica del Estado en Colombia 2002-2014

En la segunda mitad de la década de los noventa, empieza a generar en nuestro país preocupación el comportamiento de la litigiosidad contra el Estado y su impacto en las finanzas; informes de los órganos de control y de organismos internacionales, advertían sobre la situación y llamaban la atención de las autoridades para la toma de medidas adecuadas para controlar dicha situación. Dichas advertencias dieron lugar a medidas de diversa índole, los gobiernos han definido mecanismos orientados a la contención de los litigios contra el Estado y a mejorar la defensa de la Nación en los procesos judiciales, desde el primer periodo del presidente Álvaro Uribe, el tema de la defensa jurídica del Estado se ha incorporado en los planes de desarrollo y se ha procurado la consecución de recursos para la financiación de las diferentes iniciativas. No obstante, los informes del propio gobierno, de los órganos de control, de la banca internacional, de centros de investigación y universidades, muestran reiteradamente, como la situación no cede. La presente investigación está orientada a evaluar las políticas públicas en materia de defensa jurídica, adoptadas e implementadas a partir del año 2002 y hasta el año 2014; con el fin de identificar las fortalezas y debilidades que afectaron las diferentes etapas de su ciclo vital, esto es, desde su formación, hasta los diferentes ajustes durante el periodo evaluado. El documento presenta en primer lugar la revisión de la información relevante que permite identificar el nivel de conocimiento alcanzado sobre el tema (estado del arte); renglón seguido, se analizan los elementos estructurales de dichas políticas en sus diferentes momentos, identificando: enfoques, instrumentos de política, actores, tipologías; posteriormente se aborda el análisis de cada una de las fases de su ciclo vital, finalmente, se cruza la información y se hacen las inferencias correspondientes, que permitan plantear las conclusiones correspondientes y formular las recomendaciones que se consideren pertinentes.In the latest nineties, consciousness about litigiousness against the government and its impact on public finances start increasing in our country; national and international control agencies reports, point out about this situation and ask for the authorities in charge to take the appropriate actions to control such situation. This warning gave rise to different kind of actions, governments has define contention mechanisms for claims against the state and to improve national defense in judicial proceedings, since the first period of Alvaro Uribe as a president, national defense in judicial proceedings has been added to the development plans and efforts have been made to secure the necessary to finance these initiatives. Even thought, government, control agencies, international banking, research institutes and universities reports, repeatedly show how the situation does not yield. This investigation is aimed to evaluate public policy on legal defense, adopted and implemented from 2002 until 2014, in order to identify the strengths and weaknesses that affected the different stages of its life cycle, taking into consideration all adjustments and updates during the evaluated period. This document presents at first a review of all relevant information that allows us to identify the level of knowledge reached on this particular subject (state of the art); next, the structural elements of these policies are analyzed in their different moments, identifying: Approaches, policy instruments, actors, typologies; later each phase of its life cycle is analyzed, finally, information is analyzed and the corresponding inferences are made, allowing us to develop the appropriate conclusions and set relevant recommendations

Los órganos históricos de la catedral de México

This article contains a summary description of historical organs from the Mexican Cathedral. It begins with a historical synthesis of the instruments and goes on to analyze their acoustical design and concludes with a brief reference to their current state. Without doubt, these instrument are the most important of their kind in the whole of the American Continent. It is common knowledge that they were restored thirty years ago by the Dutch company in Zaandam called Flentrop Orgelbouw. Now, three decades later, they are to be newly restored and we truly hope that successfully so, and that such extremely important instruments will thus consolidate their heritage.El presente artículo es una descripción sumaria de los órganos históricos de la catedral de México. Inicio con una síntesis histórica de los instrumentos, posteriormente hago un análisis de su composición fónica, y concluyo con una breve reseña de su estado actual. Sin lugar a dudas, estos instrumentos son los más importantes en su tipo en el continente americano. Como es bien sabido, estos fueron restaurados hace treinta años por la compañía Flentrop Orgelbouw de Zaandam, Holanda. Actualmente, a tres décadas, se proyecta una nueva restauración. Hacemos votos para que este proyecto se consolide en beneficio de la recuperación patrimonial de tan importantes instrumentos