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Biserni C.,Viale Risorgimento | Garai M.,Viale Risorgimento
Energy Reports | Year: 2015

Especially in the last decade, efforts have been made in developing the sustainable building assessment tools, which are usually performed based on fundamentals of the First Law of Thermodynamics. However, this approach does not provide a faithful thermodynamic evaluation of the overall energy conversion processes that occur in buildings, and a more robust approach should be followed. The relevance of Second Law analysis has been here highlighted: in addition to the calculation of energy balances, the concept of exergy is used to evaluate the quality of energy sources, resulting in a higher flexibility of strategies to optimize a building design. Reviews of the progress being made with the constructal law show that diverse phenomena can be considered manifestations of the tendency towards optimization captured by the constructal law. The studies based on First and Second Principle of Thermodynamics results to be affected by the extreme generality of the two laws, which is consequent of the fact that in thermodynamics the "any system" is a black box with no information about design, organization and evolution. In this context, an exploratory analysis on the potentiality of constructal theory, that can be considered a law of thermodynamics, has been finally outlined in order to assess the energy performance in building design. © 2015 The Authors. Published by Elsevier Ltd.

Valdiserri P.,Viale Risorgimento | Biserni C.,Viale Risorgimento | Tosi G.,Viale Risorgimento | Garai M.,Viale Risorgimento
Energy Procedia | Year: 2015

This paper describes an integrated passive design approach to reduce the heating demand for an existing tertiary building through an improved thermal envelope design and high efficiency windows. The numerical optimization has been performed dynamically by means of TRNSYS simulation tool. The model here treated is aimed at the determination of the thermal demand with reference to a tertiary building in Italy, which it is supposed to be located in two different climatic zones, i.e., Bologna and Rome. The final part of the paper deals with the investment costs analysis, applied to each retrofitting scenario: it has been demonstrated that the simple payback period results to be strongly affected by the climatic zone of the building location and by the national policies of fiscal incentives. © 2015 The Authors.

Loreti L.,Viale Risorgimento | Barbaresi L.,Viale Risorgimento | De Cesaris S.,Viale Risorgimento | Garai M.,Viale Risorgimento
Energy Procedia | Year: 2015

This work is the result of a field study about overall comfort aspects performed in a secondary-school building during the winter season. The campaign aimed at describing the conditions of the school both from an objective and a subjective point of view, thus a questionnaire was administered to pupils during ongoing lessons. The monitored attributes concerned typical indoor quality aspects: acoustical, thermal, indoor air and visual quality. Weak points emerged from the data analysis and possible solutions are illustrated, focusing in particular on the acoustic aspects. © 2015 The Authors.

Valdiserri P.,Viale Risorgimento | Biserni C.,Viale Risorgimento
Sustainable Cities and Society | Year: 2016

In recent years, the interest of the scientific community towards building energy performance has become more evident in order to meet the National and European Directives. In this context, retrofits that result in improved building energy performance are widely investigated. The paper presents a comparative analysis of two different and complementary strategies to enhance the energy performance of an existing tertiary building located in Bologna, Italy. The first retrofit action is to reduce the heat transfer by transmission (i.e. use of low-emissivity glass) and the second one is to decrease the ventilation losses (i.e. installation of a heat recovery system). Then a third case has been investigated: it contemplates simultaneously both the solutions of windows replacement and installing a ventilation recovery system. Potential energy savings were calculated by means of dynamic simulation assisted by Trnsys energy simulation tool. Finally, an evaluation of the simple payback time and the net present value was performed in order to investigate global cost assessment. The window replacement option in the analyzed building office proved to be absolutely unprofitable, even if it would appear as the first and simplest action to be performed. On the contrary, the installation of a total energy recovery system resulted in sensible reduction of energy consumption and at the same time generated good values of NPV with reference to all the three different analyzed variation of the cost of energy. © 2016 Elsevier Ltd

Guidorzi P.,Viale Risorgimento | Barbaresi L.,Viale Risorgimento | D'Orazio D.,Viale Risorgimento | Garai M.,Viale Risorgimento
Energy Procedia | Year: 2015

The measurement of impulse responses inside of a room or a theatre is a critical task in architectural acoustics. The impulse responses are usually measured using either Exponential Sine Sweep (ESS) or Maximum Length Sequence (MLS) signals. The theory behind MLS generation and use is well developed and does not involve computational problems. When a non-linear system is measured, the distortion appears in the deconvolved impulse response as a series of peaks distributed over time, in deterministic positions. In case of presence of noise during the measurement, the phase of any spurious noise, even an impulsive one, is randomly distributed over the entire length of the recovered impulse response. The ESS signal shows some advantages over MLS, such as a better signal to noise ratio (SNR) and a robust non-linearity rejection. Typically, in the same conditions, the ESS has a dynamic range of about 15 dB higher than MLS. Nonetheless, the generation of an ESS signal and the subsequent analysis of impulse responses involve some problems whose solutions are not yet common practice and short impulsive noises can contaminate the sampled data, causing bad effects on the deconvolved impulse response, in form of a frequency decreasing sweep. For the above mentioned reasons ESS is generally more suitable than MLS for use in architectural acoustics, but in some cases the use of MLS signal is still to be preferred. Differences and advantages between impulse response measurements obtained by means of MLS or ESS, are analyzed and discussed in this paper and an in-depth analysis of both measurement methods is presented. Some case studies of impulse response measurements performed inside historical Italian opera houses using both MLS and ESS, in non-ideal conditions (for example in presence of spurious noise), are presented and examined, highlighting differences, advantages and pitfalls of both measurement methods. © 2015 The Authors.

Salti S.,Viale Risorgimento | Di Stefano L.,Viale Risorgimento
Image and Vision Computing | Year: 2013

Recursive Bayesian Estimation (RBE) is a widespread solution for visual tracking as well as for applications in other domains where a hidden state is estimated recursively from noisy measurements. From a practical point of view, deployment of RBE filters is limited by the assumption of complete knowledge on the process and measurement statistics. These missing tokens of information lead to an approximate or even uninformed assignment of filter parameters. Unfortunately, the use of the wrong transition or measurement model may lead to large estimation errors or to divergence, even when the otherwise optimal filter is deployed. In this paper on-line learning of the transition model via Support Vector Regression is proposed. The specialization of this general framework for linear/Gaussian filters, which we dub Support Vector Kalman (SVK), is then introduced and shown to outperform a standard, non adaptive Kalman filter as well as a widespread solution to cope with unknown transition models such as the Interacting Multiple Models (IMM) filter. © 2012 Elsevier B.V. All rights reserved.

Tombari F.,Viale Risorgimento | Salti S.,Viale Risorgimento | Di Stefano L.,Viale Risorgimento
International Journal of Computer Vision | Year: 2013

In the past few years detection of repeatable and distinctive keypoints on 3D surfaces has been the focus of intense research activity, due on the one hand to the increasing diffusion of low-cost 3D sensors, on the other to the growing importance of applications such as 3D shape retrieval and 3D object recognition. This work aims at contributing to the maturity of this field by a thorough evaluation of several recent 3D keypoint detectors. A categorization of existing methods in two classes, that allows for highlighting their common traits, is proposed, so as to abstract all algorithms to two general structures. Moreover, a comprehensive experimental evaluation is carried out in terms of repeatability, distinctiveness and computational efficiency, based on a vast data corpus characterized by nuisances such as noise, clutter, occlusions and viewpoint changes. © 2012 Springer Science+Business Media, LLC.

Delpivo C.,Viale Risorgimento | Micheletti G.,Viale Risorgimento | Boga C.,Viale Risorgimento
Synthesis (Germany) | Year: 2013

Quinoxaline and dihydropyrazine derivatives were obtained in high yields by simple addition of 1,2-diamines and 1,2-dicarbonyl compounds in water. In some cases, the products spontaneously precipitated from the reaction mixture, making it possible to recover and reuse the mother liquor for further condensations. The very mild reaction conditions, the high yields of the products, and the absence of any catalyst make this methodology an efficient and green route to quinoxalines and dihydropyrazines. © Georg Thieme Verlag Stuttgart New York.

Poggi M.,Viale Risorgimento | Mattoccia S.,Viale Risorgimento
Proceedings - IEEE Symposium on Computers and Communications | Year: 2016

In this paper we propose an effective and wearable mobility aid for people suffering of visual impairments purely based on 3D computer vision and machine learning techniques. By wearing our device the users can perceive, guided by audio messages and tactile feedback, crucial information concerned with the surrounding environment and hence avoid obstacles along the path. Our proposal can work in synergy with the white cane and allows for very effective and real-time obstacle detection on an embedded computer, by processing the point-cloud provided by a custom RGBD sensor, based on passive stereo vision. Moreover, our system, leveraging on deep-learning techniques, enables to semantically categorize the detected obstacles in order to increase the awareness of the explored environment. It can optionally work in synergy with a smartphone, wirelessly connected to the the proposed mobility aid, exploiting its audio capability and standard GPS-based navigation tools such as Google Maps. The overall system can operate in real-time for hours using a small battery, making it suitable for everyday life. Experimental results confirmed that our proposal has excellent obstacle detection performance and has a promising semantic categorization capability. © 2016 IEEE.

Biserni C.,Viale Risorgimento | Garai M.,Viale Risorgimento
International Journal of Heat and Technology | Year: 2016

Building energy assessment is usually performed based on fundamentals of the First Law of Thermodynamics, which is mainly concerned on quantitative energy aspects. However, this approach does not provide a faithful thermodynamic evaluation of the overall energy conversion processes that occur in buildings, and a more robust approach should be followed. This paper presents an exploratory work to study the relevance of Second Law analysis: in addition to the calculation of energy balances, the concept of exergy is used to evaluate the quality of energy sources, resulting in a higher flexibility of strategies to optimize a building design. In this context, a digression on the potentiality of constructal theory, that can be considered a law of thermodynamics, has been outlined.

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