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Large-scale fires have been increasingly reported in the news media. These events can cause a variety of irreversible damage, what encourages the search for effective solutions to prevent and fight fires. A promising solution is an automatic system based on computer vision capable of detecting fire in early stages, enabling rapid suppression to mitigate damage, minimizing combat and restoration costs. Currently, the most effective systems are typically based on convolutional neural networks (CNNs). However, these networks are computationally expensive and consume a large amount of memory, usually requiring graphics processing units to operate properly in emergency situations. Thus, we propose a CNN-based fire detector system suitable for low-power, resource-constrained devices. Our approach consists of training a deep detection network and then removing its less important convolutional filters in order to reduce its computational cost while trying to preserve its original performance. Through an investigation of different pruning techniques, our results show that we can reduce the computational cost by up to 83.60% and the memory consumption by up to 83.86% without degrading the system's performance. A case study was performed on a Raspberry Pi 4 where the results demonstrate the viability of implementing our proposed system on a low-end device. [ABSTRACT FROM AUTHOR]

Given a non-optimal Yagi-Uda antenna, this paper presents a technique to improve simultaneously and monotonically all its conflicting specifications. This is possible using the multiobjective optimization technique called Dominating Cone Line Search. Results for a 6 elements antenna, considering 3 conflicting specifications in 3 different frequencies, thus, a 9 objectives optimization problem, is presented. Index Terms--Multi-objective optimization and design, Yagi-Uda antenna.

The element-free Galerkin method (EFG) has specific characteristics that require the usage of techniques and data structures in order to provide efficient calculation. This paper address two problems concerning the EFG implementation. The point location problem, which must find in which subdomain the integration point is located, and the influence domain problem, which must find the nearest nodes to build an influence domain and construct the shape functions. This work proposes the use of new data structures and algorithms in order to solve these problems, speeding up the method and providing a fast and correct influence domain construction. Index Terms--Data structures, element-free Galerkin, kd-tree, meshless, trapezoidal map.

A novel design of a printed bowtie antenna without a ground plane and with size below a quarter wavelength for RFID readers is presented. Due to the lack of a ground plane, the designed antenna has omnidirectional characteristics and is insensitive to small permittivity deviations. For matching purposes without introducing gain distortion, a shorting strip connecting the radiating arms and four triangular shaped extensions of the radiating arms are added to the antenna design. Measurements show that operation in the 915 MHz band is met with a bandwidth of 13% (S11 < -10 dB) and gain around 2 dBi, while presenting an omnidirectional radiation pattern. Also, the proposed antenna design can be easily modified to operate at neighboring frequency bands. [ABSTRACT FROM AUTHOR]

ABSTRACT This article presents a systematic methodology to aid design a low-cost patch antenna for RFID readers. The geometric antenna parameters are found using multiobjective optimization for return loss minimization and gain maximization. To assess the use of low-cost FR-4 substrate the radiation efficiency has been investigated using software simulations. A prototype antenna was built and its parameters were measured in the anechoic chamber. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:905-908, 2016 [ABSTRACT FROM AUTHOR]

A new numerical discretization of the complex frequency shifted-perfectly matched layer (CFS-PML) is presented for truncation of open domains. This discretization is based on the theory of discrete differential forms applied to electromagnetism, which guarantees both the simplification of the algorithms and a more elegant formulation of expression. The curl Maxwell's equations are solved in time domain in terms of electric e magnetic fields. The Ampere-Maxwell law with, the constitutive relations included through the Hodge operator, is discretized in space by applying the Galerkin method. Conversely, the Faraday law is represented by topological relations via incidence matrix. The time domain discretization uses the leap-frog scheme with a recursive convolution inside PML region. Two examples are shown, the first one to validate the CFS-PML procedure and the second one to solve a typical ground penetrating radar scenario which include a lossy media. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:351-357, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27298 [ABSTRACT FROM AUTHOR]

This paper proposes a new reconfiguration heuristic in order to reduce the total power loss and the maximum current of electrical radial networks. It is based on the branch-and-bound strategy, which is an implicit enumeration method that uses a tree structure and bounds to organize the searching process. The search tree in this paper is constructed by subdividing the feasible set using the branch-exchange technique in the networks. The constraints and the Pareto dominance are responsible for pruning the search tree. The heuristic also returns a feasible switching plan for each solution. The algorithm was successfully applied to medium- and large-scale problems. [ABSTRACT FROM AUTHOR]

This letter introduces a novel method for fault location in alternate current transmission lines where neither the line parameters nor terminals synchronization is needed. As opposed to the previous works, it introduces a closed-form solution instead of iterative methods. The results are presented for simulated and real-world problems, indicating that the proposed algorithm attains good performance in the tested cases. [ABSTRACT FROM PUBLISHER]

This paper introduces a novel method for fault location in alternate current transmission lines relying on the voltage and current measurements in both line ends. The novelty of this method lies in the fact that there is no need for terminal synchronization and it can be applied to general untransposed transmission lines. The proposed formulation only applies a closed-form solution; thus, no iterative algorithm is required. Several simulated and real-world results are presented, and they show the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]