2,875 research outputs found
Variabilidad morfométrica en crustáceos de playas arenosas de la Isla Grande de Chiloé, sur de Chile
Indexación: Web of Science; Scielo.The macroinfauna of exposed sandy beaches along the Chilean coast is dominated by crustaceans, which show an across-shore zonation; the talitrid amphipod Orchestoidea tuberculata as the dominant taxon in the upper levels, the cirolanid isopod Excirolana hirsuticauda is dominant in the mid-intertidal, and the anomuran crab Emerita analoga is common in the low levels. This study analyses samples collected during the spring of 2001 and 7 morphological characters were measured on 30 adults of each species: body length, body height, body width, antennae and uropodal exopod lengths. The study sites were located near 42°S, an area where various beach types (i.e., reflective, intermediate and dissipative) occur along the northern coasts of the Chilean archipelagos. The morphometric variability of O. tuberculata, E. hirsuticauda and E. analoga was analyzed using cluster and principal component analysis. The results of this study showed that independently of beach type, individuals of O. tuberculata inhabiting proximal beaches showed greater similarity than individuals inhabiting beaches located distant from each other. Individuals of E. analoga inhabiting similar beach types showed greater similarity than individuals living in different beach types. These results are discussed in relation to across-shore zonation and the natural history of these species.La macroinfauna de playas arenosas expuestas en la costa chilena está dominada por crustáceos, los cuales muestran una zonación transversal; el anfípodo talítrido Orchestoidea tuberculata es el taxón dominante en los niveles superiores, el isópodo cirolánido Excirolana hirsuticauda lo es en la parte media del intermareal y el anomuro Emerita analoga es dominante en los niveles bajos. Este estudio examinó la variabilidad morfométrica de estas 3 especies de crustáceos en relación a los tipos morfodinámicos de playas. Las muestras fueron recolectadas durante la primavera de 2001 y se examinaron 7 caracteres morfológicos medidos en 30 adultos de cada especie: longitud del cuerpo, alto del cuerpo, ancho de cuerpo, longitud de las antenas y longitud de los urópodos. Los sitios de estudio se localizaron cerca de los 42°S, un área donde los diferentes tipos de playa (i.e., reflectivo, intermedio y disipativo) se producen a lo largo de las costas septentrionales de los archipiélagos chilenos. La variabilidad morfométrica de O. tuberculata, E. hirsuticauda y E. analoga se analizó mediante análisis de cluster y de componentes principales. Los resultados de este estudio mostraron que, independientemente del tipo de playa, los individuos de O. tuberculata que habitan playas próximas presentan una mayor similitud que con aquellas que habitan playas lejanas. Los individuos de E. analoga que habitan en el mismo tipo de playa mostraron una mayor similitud que con aquellas que habitan en diferentes tipos de playas. Estos resultados se discuten en relación con la zonificación a través del intermareal y la historia natural de estas especies.http://ref.scielo.org/rcysp
La notación musical vocal chilena contemporánea. El uso de nuevos sistemas gráficos en obras musicales vocales de los siglos XX y XXI: Una propuesta para su integración en la clase de lenguaje musical.
Duarte Valladares, Cristián. 2013. La notación musical vocal chilena contemporánea. El uso de nuevos sistemas gráficos en obras musicales vocales de los siglos XX y XXI: Una propuesta para su integración en la clase de lenguaje musical. Memoria de titulo, Profesor Especializado en Teoría General de la Música (Profesor Guía: Cristián Guerra Rojas). 208 pp. Santiago: Departamento de Música y Sonología, Facultad de Artes, Universidad de Chile. En línea: hp://www.repositorio.uchile.cl/hand le/2250/11663
Design of a purchasing management system for a company in the shoe sector, maintenance and sale of footwear
El desarrollo de un sistema de gestión de compras permite a la organización el registro y control de los gastos generados, acción que toma importancia en cualquier empresa, más cuando no se dispone de un amplio flujo de capital para la ejecución de las compras de materiales e insumos. Su correcta administración es vital para el sostenimiento a través del tiempo, porque permiten el manejo de la información en tiempo real para la toma de decisiones de la compañía. Teniendo en cuenta la relevancia de este aspecto, se diseñó un sistema de gestión de compras para una empresa del sector zapatería, mantenimiento y venta de calzado, analizando factores internos y externos para su ejecución. Se desarrollaron tres etapas comprendidas por
diagnóstico, diseño y evaluación. Al finalizar este proceso se obtuvo una herramienta que permite consignar la información obtenida en el proceso de compras, facilitando la visualización y modificación de la misma en tiempo real, siento factor de soporte para la toma de decisiones de inversión de recurso de la compañía.The development of a purchasing management system allows the organization to record and control the expenses generated, an action that becomes important in any company, especially when there is not a large flow of money for the execution of purchases of materials and supplies. Its correct administration is important for sustainability over time, because it allows the management of information in real time for the company's decision-making. Taking into account the relevance of this aspect, a purchasing management system was designed for a company in the shoe industry, maintenance and sale of footwear, analyzing internal and external factors for its execution. Three stages were developed for its execution, diagnosis, design and evaluation. At the end of this process, a tool was obtained that allows the information obtained in the purchasing process to be recorded, facilitating its visualization and modification in real time, a support factor for the company's resource investment decision-making.Especializació
On reducing uncertainty on the Elliptical Plane modal identification method
The Elliptical Plane has been recently introduced as a modal identification method that uses an alternative plot of the receptance. The method uses the dissipated energy per cycle of vibration as a starting point. For lightly damped systems with conveniently spaced modes, it produces quite accurate results, especially when compared to the well-known method of the inverse. When represented in the Elliptical Plane, the shape of the receptance is elliptical near resonant frequencies. The modal damping factor can be determined from the angle of the ellipse’s major axis with the horizontal axis, whereas the real and imaginary parts of the modal constants can be determined from numerical curve-fitting (as in the method of the circle - Nyquist plot). However, the lack of points that can be used near the resonance (due to limitations in the frequency resolution, and effects from other modes near each resonance) and the fact that measurements are polluted by noise, bring uncertainty to the numerical curve-fitting. This paper aims at providing the first steps on the improvement of the quality of the modal identification of the receptance in the Elliptical Plane. The method and results are discussed with a multiple degree-of-freedom numerical example
Vertical positioning surveillance by magnetostrictive transducer
This work purpose is to create a positioning automated system of a tailstock to perform impact resistance tests on silicone mammary implants. This system is capable to measure and oversight the positioning through interrelation between three main components: programmable logic controller, human-machine interface and magnetostrictive transducer. Together, these components form an operational closed loop that ensures an appropriate positioning for the impact device. The paper describes how the closed loop works and also the algorithm implemented in the programmable logic controller which surveys the positioning. As a last topic, the paper presents the operator work on the machine’s operation in conjunction with human-machine interface. The results were satisfactory and in accordance with the limits determined on ABNT NBR ISO 14607 for this method of tests
Vertical distribution of the macroinfauna associated to bivalves in a sedimentary intertidal flat of southern Chile
Indexación: Web of Science; ScieloLa estructura comunitaria de la macroinfauna que habita en planicies intermareales, así como su distribución en la columna de sedimento, puede ser influida por una combinación de factores físicos y biológicos. El objetivo de este estudio fue determinar y comparar la distribución vertical y estructura comunitaria de la macroinfauna asociada a sedimentos con navajuelas (Tagelus dombeii) en la planicie intermareal de Pelluco, sur de Chile, durante febrero y septiembre de 2004. Se recolectaron muestras de sedimento y macroinfauna en sitios con y sin bivalvos, con un cilindro plástico dividido en 5 partes iguales. Durante ambos meses de muestreo, el número de especies, abundancia y biomasa total de la macroinfauna alcanzó, en casi todas las láminas sedimentarias, valores más altos en el sitio con T. dombeii. En ambos meses de muestreo, la composición faunística fue significativamente distinta entre sitios con y sin T. dombeii. Además, la similitud en la composición faunística entre láminas sedimentarias fue mayor en el sitio con T. dombeii durante ambos meses de muestreo. Estos resultados sugieren que el proceso de bioperturbación de T. dombeii afecta la distribución vertical de la fauna asociada y que este efecto no sería dependiente de la época del año.The community structure of the macroinfauna inhabiting intertidal flats, as well as its distribution inside the sediment column, can be influenced by a combination of physical and biological factors. The objective of this study was to evaluate the vertical distribution and the community structure of the macroinfauna associated to sediments containing razor clams (Tagelus dombeii), during February and September, 2004 on the intertidal flat of Pelluco, Southern Chile. Sediment and macroinfauna samples were collected from sites with and without bivalves, using plastic cylinders divided into 5 equal parts. During both sampling months, the total number of species and the total abundance and biomass of the macroinfauna reached, in almost all sedimentary layers, higher values in the site with T. dombeii. In both sampling months, the faunistic composition was significantly different between sites with and without T. dombeii. In addition, the similarity in the faunistic composition between sedimentary layers was higher in the site with T. dombeii. The results of this study suggest that the bioturbation process of T. dombeii affects the vertical distribution of the associated macroinfauna and that this effect would not be dependent on the time year.http://ref.scielo.org/qqr38
Exploring the Synergies between Join Point Interfaces and Feature-Oriented Programming
Feature-oriented programming FOP, and aspect-oriented programming AOP have been used to develop modular software product lines SPL. Both approaches focus on modularizing classes behavior and crosscutting concerns CC. Therefore, the symbiosis of FOP and AOP would permit reaching pros and cons of both software development approaches. Concretely, FOP permits a modular refinement of classes collaboration for software product lines SPL -an adequate structural representation of heterogeneous CC, but FOP does not well represent homogeneous CC. On the other hand, traditional AOP structurally well modularizes homogeneous CC, but aspects are not adequate to represent collaboration of classes for software evolution. In addition, AOP solutions present implicit dependencies and strong coupling between classes and aspects. Since Join Point Interface JPI solves mentioned AOP issues, this paper present JPI Feature Modules to represent and modularize the structure of FOP and JPI SPL instances, i.e., classes and join point interfaces for a transparent implementation in a FOP and JPI context. This paper, highlights benefits of a FOP and JPI symbiosis for the modular software conception using a case study to exemplify its use
Calorimeters for Precision Timing Measurements in High Energy Physics
Current and future high energy physics particle colliders are capable to provide instantaneous luminosities of 1034 cm^(-2)s^(-1) and above. The high center of mass energy, the large number of simultaneous collision of beam particles in the experiments and the very high repetition rates of the collision events pose huge challenges. They result in extremely high particle fluxes, causing very high occupancies in the particle physics detectors operating at these machines. To reconstruct the physics events, the detectors have to make as much information as possible available on the final state particles. We discuss how timing information with a precision of around 10 ps and below can aid the reconstruction of the physics events under such challenging conditions. High energy photons play a crucial role in this context. About one third of the particle flux originating from high energy hadron collisions is detected as photons, stemming from the decays of neutral mesons. In addition, many key physics signatures under study are identified by high energy photons in the final state. They pose a particular challenge in that they can only be detected once they convert in the detector material. The particular challenge in measuring the time of arrival of a high energy photon lies in the stochastic component of the distance to the initial conversion and the size of the electromagnetic shower. They extend spatially over distances which propagation times of the initial photon and the subsequent electromagnetic shower which are large compared to the desired precision. We present studies and measurements from test beams and a cosmic muon test stand for calorimeter based timing measurements to explore the ultimate timing precision achievable for high energy photons of 10 GeV and above. We put particular focus on techniques to measure the timing with a precision of about 10 ps in association with the energy of the photon. For calorimeters utilizing scintillating materials and light guiding components, the propagation speed of the scintillation light in the calorimeter is important. We present studies and measurements of the propagation speed on a range of detector geometries. Finally, possible applications of precision timing in future high energy physics experiments are discussed
Automated Completion of Partial Configurations as a Diagnosis Task Using FastDiag to Improve Performance
The completion of partial configurations might represent an expensive computational task. Existing solutions, such as those which use modern constraint satisfaction solvers, perform a complete search, making them unsuitable on large-scale configurations. In this work, we propose an approach to define the completion of a partial configuration like a diagnosis task to solve it by applying the FastDiag algorithm, an efficient solution for preferred minimal diagnosis (updates) in the analyzed partial configuration. We evaluate our proposed method in the completion of partial configurations of random medium and large-size features models and the completion of partial configurations of a feature model of an adapted version of the Ubuntu Xenial OS. Our experimental analysis shows remarkable improvements in our solution regarding the use of classical CSP-based approaches for the same tasks.Ministerio de Ciencia, Innovación y Universidades RTI2018-101204-B-C22Agencia Estatal de Investigación TIN2017-90644-RED
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