Noise Figure Measurement of Differential Amplifiers Using non-Ideal Baluns

This paper analyzes the noise and gain measurement of microwave differential amplifiers using two passive baluns. A general model of the baluns is considered, including potential losses and phase/amplitude unbalances. This analysis allows de-embedding the actual gain and noise performance of the isolated amplifier by using single-ended measurements of the cascaded system and baluns. Finally, measured results from two amplifier prototypes are used to validate the theoretical principles.

Reconstrucción ideal de un artesonado de la iglesia de Sta. Mª de la Cuesta de Durón a partir de los elementos encontrados durante su restauración

El lamentable estado del templo hizo que Luis de Villanueva y Susana Mora redactaran un Proyecto de Restauración, cuya primera fase era la Restauración de cubiertas. Éstas se desmontaron cuidadosamente, apareciendo en la nave sur una viga cambiada de posición de labra supuestamente mudéjar, lo que hizo exagerar las precauciones. Pudimos así observar otra ménsula de madera labrada que servía de apoyo a elementos pétreos de la cabecera. En la nave lateral norte se encontraron durmientes, varios tirantes, y rebajes equidistantes, que podrían corresponder a estribos. En la nave central, formando parte de las quijeras, estaban integrados elementos con sencillas decoraciones azuladas, que podrían corresponder a restos de los citados estribos de la nave lateral. Las hipótesis se comprobaron, y con el apoyo de textos especializados, se formuló una propuesta de techumbre que podría acercarnos a las construcciones de esta zona del Señorío de Mendoza entre los siglos XV y XVI.

IDRA (IDeal Resource Allocation): Computing ideal speedups in parallel logic programming

We present a technique to estimate accurate speedups for parallel logic programs with relative independence from characteristics of a given implementation or underlying parallel hardware. The proposed technique is based on gathering accurate data describing one execution at run-time, which is fed to a simulator. Alternative schedulings are then simulated and estimates computed for the corresponding speedups. A tool implementing the aforementioned techniques is presented, and its predictions are compared to the performance of real systems, showing good correlation.

IDRA (IDeal Resource Allocation): A tool for computing ideal speedups

Performance studies of actual parallel systems usually tend to concéntrate on the effectiveness of a given implementation. This is often done in the absolute, without quantitave reference to the potential parallelism contained in the programs from the point of view of the execution paradigm. We feel that studying the parallelism inherent to the programs is interesting, as it gives information about the best possible behavior of any implementation and thus allows contrasting the results obtained. We propose a method for obtaining ideal speedups for programs through a combination of sequential or parallel execution and simulation, and the algorithms that allow implementing the method. Our approach is novel and, we argüe, more accurate than previously proposed methods, in that a crucial part of the data - the execution times of tasks - is obtained from actual executions, while speedup is computed by simulation. This allows obtaining speedup (and other) data under controlled and ideal assumptions regarding issues such as number of processor, scheduling algorithm and overheads, etc. The results obtained can be used for example to evalúate the ideal parallelism that a program contains for a given model of execution and to compare such "perfect" parallelism to that obtained by a given implementation of that model. We also present a tool, IDRA, which implements the proposed method, and results obtained with IDRA for benchmark programs, which are then compared with those obtained in actual executions on real parallel systems.

Ficciones urbanas vernáculas diseñadas según principios artísticos. Permanencia y poder simbólico del ideal urbano tradicional

The theoretical contributions of John Ruskin, the analysis and proposals in Camillo Sitte?s City Planning According to Artistic Principles or the urban environment defense by Gustavo Giovannoni involved important restrictions on the destruction of this heritage and on the progressive Haussmanization of many European cities. But this interest on the endangered traditional city also caused the birth of a wide range of urban proposals which aimed at recreating or reproducing an ideal model of it. Erected under different circumstances and with multiple purposes, they did not only define new urban developments, but also succeeded in the context of the mentioned international fairs and exhibitions, appearing a whole family of them in diverse countries.

Observação Arquitectónica de Sta Mª da Feira: Argumentos para um futuro Ideal e Real

Análisis arquitectónico de una ciudad pequeña en el norte de Portugal, a través del estudio de cuatro espacios delimitados. Se parte de una visión general y actual de la sociedad y cultura portuguesas, en aspectos tales como el envejecimiento de la población, el uso extendido del coche, u otros, así como de las particularidades del medio físico de la ciudad ? la presencia de zonas verdes sostenibles y no aprovechadas, la herencia agrícola local ? para, enseguida, contemplar las soluciones existentes para esos mismos problemas. Tras este análisis general, y teniendo presente las necesidades actuales de carácter sostenible, se llega a una síntesis de propuestas arquitectónicas especificas para los cuatro espacios urbanos elegidos.