Matched-Filter Detection of Mode-Locked Laser Signals

The passive Fabry-Perot cavity is shown to be a good practical approach to the match-filter optimization for the sensitive detection of mode-locked laser signals. Doppler measurements of relative motion over a wide range of velocities are possible simply by measuring the cavity length for a peak output

Air Conditioning Systems with Dual Ducts: Innovative Approaches for the Design of the Transport Network of the Air

We present two methods for sizing the network for the transport of the air, from the air handling unit to the terminal units, for a dual duct system, where air flows in the “cold” duct at a temperature less than the ambient temperature, while air flows in the “hot” duct at a temperature higher than the ambient temperature. The methods, compared to the traditional design criteria, lead to a reduction of channel size and, therefore, of overall network size and cost as well. The first method requires the “cold” channel to transport air at a temperature value slightly lower (1 ÷ 2°C) than the minimum inlet temperature (variable with time) required by the zones. The second requires the “hot” channel to transport air at a temperature value slightly higher (1 ÷ 2°C) than the maximum inlet temperature (variable with time) required by the zones. The methods have been applied to some reference networks. The saving of side surface of the networks varies between 14 and 27% with respect to the traditional approach; the constraint on the maximum speed of the air through the ducts is always respected, while this does not always occur with traditional criteria

Gesture Recognition by Using Depth Data: Comparison of Different Methodologies

In this chapter, the problem of gesture recognition in the context of human computer interaction is considered. Several classifiers based on different approaches such as neural network (NN), support vector machine (SVM), hidden Markov model (HMM), deep neural network (DNN), and dynamic time warping (DTW) are used to build the gesture models. The performance of each methodology is evaluated considering different users performing the gestures. This performance analysis is required as the users perform gestures in a personalized way and with different velocity. So the problems concerning the different lengths of the gesture in terms of number of frames, the variability in its representation, and the generalization ability of the classifiers have been analyzed

Towards Italian Opera Houses: A Review of Acoustic Design in Pre-Sabine Scholars

The foundation of architectural acoustics as an independent science is generally referred to Sabine’s early studies and their application. Nevertheless, since the 16th Century, a great number of authors wrote essays and treatises on the design of acoustic spaces, with a growing attention to the newborn typology of the Opera house, whose evolution is strongly connected to the cultural background of the Italian peninsula. With roots in the Renaissance rediscovery of Vitruvius’s treatise and his acoustic theory, 16th- to 19th-Century Italian authors tackled several issues concerning the construction of theatres—among them, architectural and structural features, the choice of the materials, the social meanings of performances. Thanks to this literature, the consolidation of this body of knowledge led to a standardisation of the forms of the Italian Opera house throughout the 19th Century. Therefore, the scope of this review paper is to focus on the treatises, essays and publications regarding theatre design, written by pre-Sabinian Italian scholars. The analysis of such literature aims at highlighting the consistencies in some 19th-Century minor Italian Opera houses, in order to understand to what extent this scientific and experimental background was part of the building tradition during the golden age of the Italian Oper

Lithic raw materials availability in the northeastern coast of magellan strait (chile): An exploratory approach

Se caracteriza la disponibilidad de materias primas líticas en la costa nororiental del estrecho de Magallanes (Magallanes, Chile) a partir de la información obtenida en nueve muestreos de roca realizados entre bahía Posesión y bahía Laredo siguiendo la metodología propuesta por Franco y Borrero (1999) para el muestreo de fuentes secundarias de aprovisionamiento lítico. Se describe la abundancia, riqueza, calidad para la talla y tamaño de las rocas disponibles en los depósitos costeros. La determinación microscópica de cortes delgados de roca permitió la identificación petrográfica de distintos tipos, especialmente entre las rocas de grano fino oscuras, los cuales corresponden a variedades diferentes a aquellas más frecuentes en el campo volcánico Pali Aike. Los nuevos datos se discuten en el marco de la información glaciológica y arqueológica disponible para el área y en una escala mayor, en comparación con los resultados previos obtenidos en el campo volcánico Pali Aike.Lithic raw materials availability in the northeastern coast of the strait of Magellan (Magellan, Chile) is characterized by means of nine rock samples collected between Posesión and Laredo bays following Franco and Borrero’s (1999) sampling methodology. Abundance, richness, flintknapping quality and size of rocks in coastal deposits are described. Thin section microscopic determinations allowed us to identify several types of lithic raw materials, especially of fine-grained dark rocks, which are different to those usually present in the Pali Aike volcanic field. These new data are discussed in relationship with the glaciological and archaeological information available for the area, and in a greater scale in comparison to previous results obtained from the Pali Aike volcanic field.Fil: Charlin, Judith Emilce. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; ArgentinaFil: D’Orazio, Massimo. Università degli Studi di Pisa; Itali

Lattice Boltzmann Modelling of Fluid Flow through Porous Media. A Comparison between Pore-Structure and Representative Elementary Volume Methods

In this study, we present a novel comparison between pore-structure (PS) and representative elementary volume (REV) methods for modelling fluid flow through porous media using a second-order lattice Boltzmann method (LBM). We employ the LBM to demonstrate the importance of the configuration of square obstacles in the PS method and compare the PS and the REV methods. This research provides new insights into fluid flow through porous media as a novel study. The behaviour of fluid flow through porous media has important applications in various engineering structures. The aim of this study is to compare two methods for simulating porous media: the PS method, which resolves the details of the solid matrix, and the REV method, which treats the porous medium as a continuum. Our research methodology involves using different arrangements of square obstacles in a channel including in-line, staggered and random for the PS method and a porosity factor and permeability value for the REV method. We found that the porosity and obstacle arrangement have significant effects on the pressure drop, permeability and flow patterns in the porous region. While the REV method cannot simulate the details of fluid flow through pore structures compared to the PS method, it is able to provide a better understanding of the flow field details around obstacles (Tortuosity). This study has important applications in improving our understanding of transport phenomena in porous media. Our results can be useful for designing and optimizing various engineering systems involving porous media

Analysis of second harmonic generation in photonic-crystal-assisted waveguides

We study second harmonic generation in a planar dielectric waveguide having a low-index, polymer core layer, bounded by two multilayer stacks. This geometry allows exceptionally strong confinement of the light at the fundamental wavelength inside the core region with virtually zero net propagation losses for distances that exceed several centimeters, provided material and scattering losses are neglected. A phase-matched configuration of the waveguide is reported in which the pump signal is the lowest-order mode of the waveguide, and the generated second harmonic signal corresponds to the third propagation mode of the waveguide. Using a polymer waveguide core, having chi(2)=100 pm/V, we predict a conversion efficiency of approximately 90% after a propagation distance of 2 mm, using peak pump intensities inside the core of the waveguide of 1.35 GW/cm^2. If the waveguide core contains polymer layers with different glass transition temperatures, the layers can be poled independently to maximize the overlap integral, and similar pump depletions may be achieved over a distance of approximately 500 microns.Comment: 20 pages, 7 figures, 330k

Heat pumps in existing heating and hot water systems: an evaluation of primary energy savings and reduction of CO2 produced

In a previous work we recorded a significant contribution to urban air pollution attributable to heating systems powered by fuel. Thus, we propose the replacement of existing boilers for heating and domestic hot water (DHW) production systems with high temperature air-to-water heat pumps as an intervention to improve urban air quality and energy use. We analyze replacement scenarios within the entire residential building stock of two Italian cities, Milan and Salerno, belonging to different climate zones and with their own thermophysical characteristics. For each of them, the consequences of the replacement intervention in terms of primary energy savings and lower CO2 production are evaluated. The results show a reduction of primary energy consumption by 34% in Milan and 43% in Salerno, and of CO2 production by 30% in Milan and 39% in Salerno

Performance Assessment of Different Roof Integrated Photovoltaic Modules under Mediterranean Climate

AbstractMany countries, for aesthetic purposes, offer economic advantages (tax deductions, incentives, etc..) for the installation of building integrated photovoltaic modules (BIPV), with water-tightness capability and adequate mechanical resistance in order to substitute tile covering or part of it. Nevertheless, poor or absent ventilation under BIPV panels could cause them to overheat and reduce their efficiency.It is well established that the presence of an air gap between a photovoltaic (PV) module and roof covering facilitates ventilation cooling under the device and consequently reduces cell temperature and improves its performance.In this study, we investigated the thermal performance of PV modules installed in a real scale experimental building over a traditional clay tile pitched roof in Italy for almost one year (from August 2009 to June 2010). One PV module was rack-mounted over the roof covering with a 0.2 m air gap; the others were fully integrated and installed at the same level of the roof covering (one with an air gap of 0.04 m, the other mounted directly in contact with the insulation). Temperature and heat flux measurements for each panel, and environmental parameters were recorded.Experimental results demonstrate that even though the rack-mounted PV module constantly maintains cell temperature below that of the other full-building integrated modules, due to the presence of a higher air gap, the difference in the energy produced by the PV modules estimated for the entire monitoring period is less than 4%