Learning sound representations using trainable COPE feature extractors

Sound analysis research has mainly been focused on speech and music processing. The deployed methodologies are not suitable for analysis of sounds with varying background noise, in many cases with very low signal-to-noise ratio (SNR). In this paper, we present a method for the detection of patterns of interest in audio signals. We propose novel trainable feature extractors, which we call COPE (Combination of Peaks of Energy). The structure of a COPE feature extractor is determined using a single prototype sound pattern in an automatic configuration process, which is a type of representation learning. We construct a set of COPE feature extractors, configured on a number of training patterns. Then we take their responses to build feature vectors that we use in combination with a classifier to detect and classify patterns of interest in audio signals. We carried out experiments on four public data sets: MIVIA audio events, MIVIA road events, ESC-10 and TU Dortmund data sets. The results that we achieved (recognition rate equal to 91.71% on the MIVIA audio events, 94% on the MIVIA road events, 81.25% on the ESC-10 and 94.27% on the TU Dortmund) demonstrate the effectiveness of the proposed method and are higher than the ones obtained by other existing approaches. The COPE feature extractors have high robustness to variations of SNR. Real-time performance is achieved even when the value of a large number of features is computed.Comment: Accepted for publication in Pattern Recognitio

Design of a 3D photonic band gap cavity in a diamond-like inverse woodpile photonic crystal

We theoretically investigate the design of cavities in a three-dimensional (3D) inverse woodpile photonic crystal. This class of cubic diamond-like crystals has a very broad photonic band gap and consists of two perpendicular arrays of pores with a rectangular structure. The point defect that acts as a cavity is centred on the intersection of two intersecting perpendicular pores with a radius that differs from the ones in the bulk of the crystal. We have performed supercell bandstructure calculations with up to $5 \times 5 \times 5$ unit cells. We find that up to five isolated and dispersionless bands appear within the 3D photonic band gap. For each isolated band, the electric-field energy is localized in a volume centred on the point defect, hence the point defect acts as a 3D photonic band gap cavity. The mode volume of the cavities resonances is as small as 0.8 $\lambda^{3}$ (resonance wavelength cubed), indicating a strong confinement of the light. By varying the radius of the defect pores we found that only donor-like resonances appear for smaller defect radius, whereas no acceptor-like resonances appear for greater defect radius. From a 3D plot of the distribution of the electric-field energy density we conclude that peaks of energy found in sharp edges situated at the point defect, similar to how electrons collect at such features. This is different from what is observed for cavities in non-inverted woodpile structures. Since inverse woodpile crystals can be fabricated from silicon by CMOS-compatible means, we project that single cavities and even cavity arrays can be realized, for wavelength ranges compatible with telecommunication windows in the near infrared.Comment: 11 figure

Using Energy Peaks to Measure New Particle Masses

We discussed in arXiv:1209.0772 that the laboratory frame distribution of the energy of a massless particle from a two-body decay at a hadron collider has a peak whose location is identical to the value of this daughter's (fixed) energy in the rest frame of the corresponding mother particle. For that result to hold we assumed that the mother is unpolarized and has a generic boost distribution in the laboratory frame. In this work we discuss how this observation can be applied for determination of masses of new particles, without requiring a full reconstruction of their decay chains or information about the rest of the event. We focus on a two-step cascade decay of a massive particle that has one invisible particle in the final state: C -> Bb -> Aab, where C, B and A are new particles of which A is invisible and a, b are visible particles. Combining the measurements of the peaks of energy distributions of a and b with that of the edge in their invariant mass distribution, we demonstrate that it is in principle possible to determine separately all three masses of the new particles, in particular, without using any measurement of missing transverse momentum. Furthermore, we show how the use of the peaks in an inclusive energy distribution is generically less affected by combinatorial issues as compared to other mass measurement strategies. For some simplified, yet interesting, scenarios we find that these combinatorial issues are absent altogether. As an example of this general strategy, we study SUSY models where gluino decays to an invisible lightest neutralino via an on-shell bottom squark. Taking into account the dominant backgrounds, we show how the mass of the bottom squark, the gluino and (for some class of spectra) that of the neutralino can be determined using this technique.Comment: 42 pages, 11 figure

Variations of the Energy of Free Particles in the pp-Wave Spacetimes

We consider the action of exact plane gravitational waves, or pp-waves, on free particles. The analysis is carried out by investigating the variations of the geodesic trajectories of the particles, before and after the passage of the wave. The initial velocities of the particles are non-vanishing. We evaluate numerically the Kinetic energy per unit mass of the free particles, and obtain interesting, quasi-periodic behaviour of the variations of the Kinetic energy with respect to the width $\lambda$ of the gaussian that represents the wave. The variation of the energy of the free particle is expected to be exactly minus the variation of the energy of the gravitational field, and therefore provides an estimation of the local variation of the gravitational energy. The investigation is carried out in the context of short bursts of gravitational waves, and of waves described by normalised gaussians, that yield impulsive waves in a certain limit.Comment: 20 pages, 18 figures, further arguments supporting the localizability of the gravitational energy are presented, published in Univers

A Necessary Constraint on the Use of Extended Harmonic Analysis for Tide Predictions

When American and British tide researchers, in an effort to improve tide predictions for large-range shallow-water tides, greatly expanded the number of tide constituents (extended harmonic analysis), they chose the added frequencies by selecting peaks of energy greatly exceeding the continuum (noise level) in a high-resolution Fourier analysis of tide residuals (observed minus predicted). Unfortunately, some tide agencies are now routinely analyzing for a greatly expanded number of constituents without checking as to whether the amplitudes of these added constituents are significantly larger than the continuum. They do this believing that more is necessarily better; actually, in some cases, a future prediction may be worse unless this check is done routinely

Energy Wars - Chrome vs. Firefox Which browser is more energy efficient?

This paper presents a preliminary study on the energy consump- tion of two popular web browsers. In order to properly measure the energy consumption of both environments, we simulate the usage of various applications, which the goal to mimic typical user interactions and usage. Our preliminary results show interesting findings based on ob- servation, such as what type of interactions generate high peaks of energy consumption, and which browser is overall the most efficient. Our goal with this preliminary study is to show to users how very different the efficiency of web browsers can be, and may serve with advances in this area of study.FCT -Fundação para a Ciência e a Tecnologia (UIDB/50014/2020

Identification of energy saving potential in steam boiler through an ISO 50001 standard

The energy performance of steam boilers, such as the efficiency and the evaporation ratio can decrease along time because of the poor combustion, heat transfer fouling, poor operation, and low maintenance rate. The energy indicators assessment allows to observe the abnormal operational deviations to implement corrective action, so it is necessary to find out the level of efficiency in real time to evaluate the thermal performance, which is an obligatory requirement to implement the energy management program in the industry. As a contribution in the area of energy efficiency in steam boilers, the results of an applied research are presented, where the behavior of steam production and gas consumption as input variables were considered to apply the methodology and obtain the energy saving results on a boiler from 125.000lb/h steam capacity. The consumption and energy production control charts, the base and goal line, and base 100 indicators were calculated to facilitate the energy monitoring of the steam boiler for a period six month. Letting the application of the methodology to recognize saving opportunities starting from the analysis of variables that impact the energy consumption affected by different ways energy consumption of the company. The study showed a linear base with the form EB = 0.0595x + 0.988, with a linear correlation equal to R2 = 0.973 and a goal line EG = 0.0586x + 1.3814, with a linear correlation of R² = 0.97, which means statistical validity in the data collection. Additionally, the base 100 index was calculated to identify satisfactory the peaks of energy efficiency, showing efficiency and inefficiency in the process. The study shows that data reflected below the efficiency rate (100) are considered peaks of energy inefficiency, which means energy saving opportunities for operational control, maintenance management, production planning, besides the typical ones due to technological changes

Energy peaks: a high energy physics outlook

Energy distributions of decay products carry information on the kinematics of the decay in ways that are at the same time straightforward and quite hidden. I will review these properties and discuss their early historical applications as well as more recent ones in the context of i) methods for the measurement of masses of new physics particle with semi-invisible decays, ii) the characterization of Dark Matter particles produced at colliders, iii) precision mass measurements of Standard Model particles, in particular of the top quark. Finally I will give an outlook of further developments and applications of energy peaks method for high energy physics at colliders and beyond.Comment: Review written for MPLA; typos corrected, references adde

Interaction Properties of the Periodic and Step-like Solutions of the Double-Sine-Gordon Equation

The periodic and step-like solutions of the double-Sine-Gordon equation are investigated, with different initial conditions and for various values of the potential parameter $\epsilon$. We plot energy and force diagrams, as functions of the inter-soliton distance for such solutions. This allows us to consider our system as an interacting many-body system in 1+1 dimension. We therefore plot state diagrams (pressure vs. average density) for step-like as well as periodic solutions. Step-like solutions are shown to behave similarly to their counterparts in the Sine-Gordon system. However, periodic solutions show a fundamentally different behavior as the parameter $\epsilon$ is increased. We show that two distinct phases of periodic solutions exist which exhibit manifestly different behavior. Response functions for these phases are shown to behave differently, joining at an apparent phase transition point.Comment: 17pages, 15 figure