Статті в журналах: "Ad hoc microphone arrays"

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Liaquat, Muhammad Usman, Hafiz Suliman Munawar, Amna Rahman, Zakria Qadir, Abbas Z. Kouzani, and M. A. Parvez Mahmud. "Sound Localization for Ad-Hoc Microphone Arrays." Energies 14, no. 12 (June 10, 2021): 3446. http://dx.doi.org/10.3390/en14123446.

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Sound localization is a field of signal processing that deals with identifying the origin of a detected sound signal. This involves determining the direction and distance of the source of the sound. Some useful applications of this phenomenon exists in speech enhancement, communication, radars and in the medical field as well. The experimental arrangement requires the use of microphone arrays which record the sound signal. Some methods involve using ad-hoc arrays of microphones because of their demonstrated advantages over other arrays. In this research project, the existing sound localization methods have been explored to analyze the advantages and disadvantages of each method. A novel sound localization routine has been formulated which uses both the direction of arrival (DOA) of the sound signal along with the location estimation in three-dimensional space to precisely locate a sound source. The experimental arrangement consists of four microphones and a single sound source. Previously, sound source has been localized using six or more microphones. The precision of sound localization has been demonstrated to increase with the use of more microphones. In this research, however, we minimized the use of microphones to reduce the complexity of the algorithm and the computation time as well. The method results in novelty in the field of sound source localization by using less resources and providing results that are at par with the more complex methods requiring more microphones and additional tools to locate the sound source. The average accuracy of the system is found to be 96.77% with an error factor of 3.8%.

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ONO, Nobutaka, LE TRUNG Kien, Shigeki MIYABE, and Shoji MAKINO. "Ad-hoc Microphone Array." IEICE ESS Fundamentals Review 7, no. 4 (2014): 336–47. http://dx.doi.org/10.1587/essfr.7.336.

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Himawan, I., I. McCowan, and S. Sridharan. "Clustered Blind Beamforming From Ad-Hoc Microphone Arrays." IEEE Transactions on Audio, Speech, and Language Processing 19, no. 4 (May 2011): 661–76. http://dx.doi.org/10.1109/tasl.2010.2055560.

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Hahmann, Manuel, Efren Fernandez-Grande, Henrry Gunawan, and Peter Gerstoft. "Sound source localization using multiple ad hoc distributed microphone arrays." JASA Express Letters 2, no. 7 (July 2022): 074801. http://dx.doi.org/10.1121/10.0011811.

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Sound source localization is crucial for communication and sound scene analysis. This study uses direction-of-arrival estimates of multiple ad hoc distributed microphone arrays to localize sound sources in a room. An affine mapping between the independent array estimates and the source coordinates is derived from a set of calibration points. Experiments show that the affine model is sufficient to locate a source and can be calibrated to physical dimensions. A projection of the local array estimates increases localization accuracy, particularly further away from the calibrated region. Localization tests in three dimensions compare the affine approach to a nonlinear neural network.

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Tavakoli, Vincent Mohammad, Jesper Rindom Jensen, Mads Graecboll Christensen, and Jacob Benesty. "A Framework for Speech Enhancement With Ad Hoc Microphone Arrays." IEEE/ACM Transactions on Audio, Speech, and Language Processing 24, no. 6 (June 2016): 1038–51. http://dx.doi.org/10.1109/taslp.2016.2537202.

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Liaquat, Muhammad Usman, Hafiz Suliman Munawar, Amna Rahman, Zakria Qadir, Abbas Z. Kouzani, and M. A. Parvez Mahmud. "Localization of Sound Sources: A Systematic Review." Energies 14, no. 13 (June 29, 2021): 3910. http://dx.doi.org/10.3390/en14133910.

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Sound localization is a vast field of research and advancement which is used in many useful applications to facilitate communication, radars, medical aid, and speech enhancement to but name a few. Many different methods are presented in recent times in this field to gain benefits. Various types of microphone arrays serve the purpose of sensing the incoming sound. This paper presents an overview of the importance of using sound localization in different applications along with the use and limitations of ad-hoc microphones over other microphones. In order to overcome these limitations certain approaches are also presented. Detailed explanation of some of the existing methods that are used for sound localization using microphone arrays in the recent literature is given. Existing methods are studied in a comparative fashion along with the factors that influence the choice of one method over the others. This review is done in order to form a basis for choosing the best fit method for our use.

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Bertrand, Alexander, Simon Doclo, Sharon Gannot, Nobutaka Ono, and Toon van Waterschoot. "Special issue on wireless acoustic sensor networks and ad hoc microphone arrays." Signal Processing 107 (February 2015): 1–3. http://dx.doi.org/10.1016/j.sigpro.2014.10.001.

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Taghizadeh, Mohammad J., Philip N. Garner, and Hervé Bourlard. "Enhanced diffuse field model for ad hoc microphone array calibration." Signal Processing 101 (August 2014): 242–55. http://dx.doi.org/10.1016/j.sigpro.2014.02.012.

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Taghizadeh, Mohammad J., Reza Parhizkar, Philip N. Garner, Hervé Bourlard, and Afsaneh Asaei. "Ad hoc microphone array calibration: Euclidean distance matrix completion algorithm and theoretical guarantees." Signal Processing 107 (February 2015): 123–40. http://dx.doi.org/10.1016/j.sigpro.2014.07.016.

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Pertila, Pasi, Matti S. Hamalainen, and Mikael Mieskolainen. "Passive Temporal Offset Estimation of Multichannel Recordings of an Ad-Hoc Microphone Array." IEEE Transactions on Audio, Speech, and Language Processing 21, no. 11 (November 2013): 2393–402. http://dx.doi.org/10.1109/taslp.2013.2286921.

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Woźniak, Szymon, and Konrad Kowalczyk. "Reverberation-Robust Self-Calibration and Synchronization of Distributed Microphone Arrays by Mitigating Heteroscedasticity and Outlier Occurrence in TDoA Measurements." Sensors 24, no. 1 (December 25, 2023): 114. http://dx.doi.org/10.3390/s24010114.

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The network of distributed microphone arrays is usually established in an ad hoc manner; hence, network parameters such as the mutual positioning and rotation of the arrays, positions of sources, and synchronization of their recording onset times are initially unknown. In this article, we consider the problem of passively jointly self-calibrating and synchronizing distributed arrays in reverberant rooms. We use a typical two-step approach where, initially, the relative geometry of the network is estimated using Direction of Arrival (DoA) measurements. Subsequently, the absolute scale and synchronization parameters are estimated using Time Difference of Arrival (TDoA) measurements. This article presents methods to improve the robustness and accuracy of estimation of the absolute geometric scaling and synchronization parameters in reverberant conditions, in which TDoA measurements do not follow a normal distribution; furthermore, outliers often occur. To remedy these issues, we propose a Weighted Least Squares (WLS) estimator and schema for weighting the TDoA measurements to increase the estimation accuracy from heteroscedastic TDoA measurements. In addition, we propose an iterative reweighing algorithm with a binary weight to detect and reject TDoA outliers, which exploits the residuals of the parametric model in the least absolute value minimization. A numerical evaluation shows significant improvements in the proposed method over the state of the art in terms of the relative scaling error and mean absolute value of the synchronization parameters.

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Miyabe, Shigeki, Nobutaka Ono, and Shoji Makino. "Blind compensation of interchannel sampling frequency mismatch for ad hoc microphone array based on maximum likelihood estimation." Signal Processing 107 (February 2015): 185–96. http://dx.doi.org/10.1016/j.sigpro.2014.09.015.

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13

Wang, Lin, and Andrea Cavallaro. "Pseudo-Determined Blind Source Separation for Ad-hoc Microphone Networks." IEEE/ACM Transactions on Audio, Speech, and Language Processing 26, no. 5 (May 2018): 981–94. http://dx.doi.org/10.1109/taslp.2018.2803263.

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Sousa Júnior, W. M., and L. A. Silva. "Exploiting Heterogeneity in Ad Hoc networks with Antenna Arrays." Journal of Communication and Information Systems 19, no. 3 (December 30, 2004): 74–80. http://dx.doi.org/10.14209/jcis.2004.13.

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Reyna, Alberto, Jesús C. Garza, Luz I. Balderas, Jonathan Méndez, Marco A. Panduro, Gonzalo Maldonado, and Lourdes Y. García. "Virtual Antenna Arrays with Frequency Diversity for Radar Systems in Fifth-Generation Flying Ad Hoc Networks." Applied Sciences 14, no. 10 (May 16, 2024): 4219. http://dx.doi.org/10.3390/app14104219.

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This paper proposes the design of virtual antenna arrays with frequency diversity for radar systems in fifth-generation flying ad hoc networks. These virtual arrays permit us to detect targets from the sky with flying drones. Each array element is composed of a microstrip antenna mounted on quadcopter drones and is virtually connected with the other elements. The antennas are tuned to work at the lower fifth-generation frequency band of 3.5 GHz. The design process considers the optimization of frequency offsets and positions for each element to obtain a side lobe level reduction. This methodology is carried out by particle swarm optimization. Several design examples are presented with random frequency offsets and non-uniform positions. These designs are compared to uniform-spaced arrays excited with Hamming frequency offsets. The simulation results show that using random frequency offsets and non-uniform positions provides a minor side lobe level reduction. This research demonstrates the feasibility of using virtual arrays for radar systems in fifth-generation flying ad hoc networks.

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Wang, Lin, Tsz-Kin Hon, Joshua D. Reiss, and Andrea Cavallaro. "Self-Localization of Ad-Hoc Arrays Using Time Difference of Arrivals." IEEE Transactions on Signal Processing 64, no. 4 (February 2016): 1018–33. http://dx.doi.org/10.1109/tsp.2015.2498130.

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Pan, Yuxin, Walaa Hamouda, and Ahmed Elhakeem. "An efficient medium access control protocol for mobile ad hoc networks using antenna arrays." Canadian Journal of Electrical and Computer Engineering 32, no. 1 (2007): 19–25. http://dx.doi.org/10.1109/cjece.2007.364331.

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Scaglione, A., and Yao-Win Hong. "Opportunistic large arrays: cooperative transmission in wireless multihop ad hoc networks to reach far distances." IEEE Transactions on Signal Processing 51, no. 8 (August 2003): 2082–92. http://dx.doi.org/10.1109/tsp.2003.814519.

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Govindasamy, Siddhartan, Daniel Bliss, and David Staelin. "Spectral Efficiency in Single-Hop Ad-Hoc Wireless Networks with Interference Using Adaptive Antenna Arrays." IEEE Journal on Selected Areas in Communications 25, no. 7 (September 2007): 1358–69. http://dx.doi.org/10.1109/jsac.2007.070909.

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Magna, Gabriele, Manuela Stefanelli, Giuseppe Pomarico, Mario Luigi Naitana, Donato Monti, Corrado Di Natale, and Roberto Paolesse. "Chiral Recognition with Broad Selective Sensor Arrays." Chemosensors 10, no. 8 (August 4, 2022): 308. http://dx.doi.org/10.3390/chemosensors10080308.

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The detection and discrimination of chiral analytes has always been a topical theme in food and pharmaceutical industries and environmental monitoring, especially when dealing with chiral drugs and pesticides, whose enantiomeric nature assessment is of crucial importance. The typical approach matches novel chiral receptors designed ad hoc for the discrimination of a target enantiomer with emerging nanotechnologies. The massive synthetic efforts requested and the difficulty of analyzing complex matrices warrant the ever-growing exploitation of sensor array as an alternative route, using a limited number of chiral or both chiral and achiral sensors for the stereoselective identification and dosing of chiral compounds. This review aims to illustrate a little-explored winning strategy in chiral sensing based on sensor arrays. This strategy mimics the functioning of natural olfactory systems that perceive some couples of enantiomeric compounds as distinctive odors (i.e., using an array of a considerable number of broad selective receptors). Thus, fundamental concepts related to the working principle of sensor arrays and the role of data analysis techniques and models have been briefly presented. After the discussion of existing examples in the literature using arrays for discriminating enantiomers and, in some cases, determining the enantiomeric excess, the remaining challenges and future directions are outlined for researchers interested in chiral sensing applications.

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Boulos, Federico, Georg Frederik Riemschneider, and Stefano Caizzone. "3D Phased Array Enabling Extended Field of View in Mobile Satcom Applications." Electronics 13, no. 2 (January 10, 2024): 310. http://dx.doi.org/10.3390/electronics13020310.

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Satellite communication (satcom) is experiencing increased interest to cover the connectivity gaps of terrestrial networks. To ensure high performance and throughput for the user—and even more so in Communications-On-The-Move(COTM) systems, e.g., in aeronautics—steerable antennas such as phased arrays are required to adjust the beam so as to follow the satellite’s trajectory. The mutual movement of terminals and satellite in COTM systems calls for a broad Field of View (FoV) and, hence, poses a challenge to common planar systems. For improving the FoV, common solutions require ad hoc designs, such as multi-mode antennas, wide half-power-beamwidth antennas or metasurfaces. By contrast, 3D arrays are able to cover a wider angular region by the 3D allocation of the antennas. In this paper, the benefits and drawbacks of moving from 2D (planar) arrays to 3D phased arrays are investigated. Multiple geometrical configurations are analyzed, keeping in mind the size requirements of aeronautic terminals. The best configuration is, hence, an array capable of enhancing the FoV of the terminal. The proposed antenna architecture offers a good trade-off between design complexity and performance, and it could be further developed to become an aeronautic-grade terminal aperture.

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Davidsen, Richard E., Jørgen A. Jensen, and Stephen W. Smith. "Two-Dimensional Random Arrays for Real Time Volumetric Imaging." Ultrasonic Imaging 16, no. 3 (July 1994): 143–63. http://dx.doi.org/10.1177/016173469401600301.

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Two-dimensional arrays are necessary for a variety of ultrasonic imaging techniques, including elevation focusing, 2-D phase aberration correction, and real time volumetric imaging. In order to reduce system cost and complexity, sparse 2-D arrays have been considered with element geometries selected ad hoc, by algorithm, or by random process. Two random sparse array geometries and a sparse array with a Mills cross receive pattern were simulated and compared to a fully sampled aperture with the same overall dimensions. The sparse arrays were designed to the constraints of the Duke University real time volumetric imaging system, which employs a wide transmit beam and receive mode parallel processing to increase image frame rate. Depth-of-field comparisons were made from simulated on-axis and off-axis beamplots at ranges from 30 to 160 mm for both coaxial and offset transmit and receive beams. A random array with Gaussian distribution of transmitters and uniform distribution of receivers was found to have better resolution and depth-of-field than both a Mills cross array and a random array with uniform distribution of both transmit and receive elements. The Gaussian random array was constructed and experimental system response measurements were made at several ranges. Comparisons of B-scan images of a tissue mimicking phantom show improvement in resolution and depth-of-field consistent with simulation results.

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Bushway, Paul J., Behrad Azimi, and Susanne Heynen-Genel. "Optimization and Application of Median Filter Corrections to Relieve Diverse Spatial Patterns in Microtiter Plate Data." Journal of Biomolecular Screening 16, no. 9 (September 6, 2011): 1068–80. http://dx.doi.org/10.1177/1087057111419028.

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The standard (STD) 5 × 5 hybrid median filter (HMF) was previously described as a nonparametric local backestimator of spatially arrayed microtiter plate (MTP) data. As such, the HMF is a useful tool for mitigating global and sporadic systematic error in MTP data arrays. Presented here is the first known HMF correction of a primary screen suffering from systematic error best described as gradient vectors. Application of the STD 5 × 5 HMF to the primary screen raw data reduced background signal deviation, thereby improving the assay dynamic range and hit confirmation rate. While this HMF can correct gradient vectors, it does not properly correct periodic patterns that may present in other screening campaigns. To address this issue, 1 × 7 median and a row/column 5 × 5 hybrid median filter kernels (1 × 7 MF and RC 5 × 5 HMF) were designed ad hoc, to better fit periodic error patterns. The correction data show periodic error in simulated MTP data arrays is reduced by these alternative filter designs and that multiple corrective filters can be combined in serial operations for progressive reduction of complex error patterns in a MTP data array.

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Mustaqim, Muhammad, Bilal A. Khawaja, Asghar A. Razzaqi, Syed Sajjad H. Zaidi, Syed A. Jawed, and Sameer H. Qazi. "Wideband and high gain antenna arrays for UAV-to-UAV and UAV-to-ground communication in flying ad-hoc networks (FANETs)." Microwave and Optical Technology Letters 60, no. 5 (April 8, 2018): 1164–70. http://dx.doi.org/10.1002/mop.31130.

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Liu, Enze, Sumanth Rao, Sam Havron, Grant Ho, Stefan Savage, Geoffrey M. Voelker, and Damon McCoy. "No Privacy Among Spies: Assessing the Functionality and Insecurity of Consumer Android Spyware Apps." Proceedings on Privacy Enhancing Technologies 2023, no. 1 (January 2023): 207–24. http://dx.doi.org/10.56553/popets-2023-0013.

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Consumer mobile spyware apps covertly monitor a user's activities (i.e., text messages, phone calls, e-mail, location, etc.) and transmit that information over the Internet to support remote surveillance. Unlike conceptually similar apps used for state espionage, so-called "stalkerware" apps are mass-marketed to consumers on a retail basis and expose a far broader range of victims to invasive monitoring. Today the market for such apps is large enough to support dozens of competitors, with individual vendors reportedly monitoring hundreds of thousands of phones. However, while the research community is well aware of the existence of such apps, our understanding of the mechanisms they use to operate remains ad hoc. In this work, we perform an in-depth technical analysis of 14 distinct leading mobile spyware apps targeting Android phones. We document the range of mechanisms used to monitor user activity of various kinds (e.g., photos, text messages, live microphone access) — primarily through the creative abuse of Android APIs. We also discover previously undocumented methods these apps use to hide from detection and to achieve persistence. Additionally, we document the measures taken by each app to protect the privacy of the sensitive data they collect, identifying a range of failings on the part of spyware vendors (including privacy-sensitive data sent in the clear or stored in the cloud with little or no protection).

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Kanan, Awos, Fayez Gebali, Atef Ibrahim, and Kin Fun Li. "Low-Complexity Scalable Architectures for Parallel Computation of Similarity Measures." Scientific Programming 2019 (May 26, 2019): 1–11. http://dx.doi.org/10.1155/2019/3185137.

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Processor array architectures have been employed, as an accelerator, to compute similarity distance found in a variety of data mining algorithms. However, most of the proposed architectures in the existing literature are designed in an ad hoc manner without taking into consideration the size and dimensionality of the datasets. Furthermore, data dependencies have not been analyzed, and often, only one design choice is considered for the scheduling and mapping of computational tasks. In this work, we present a systematic methodology to design scalable and area-efficient linear (1-D) processor arrays for the computation of similarity distance matrices. Six possible design options are obtained and analyzed in terms of area and time complexities. The obtained architectures provide us with the flexibility to choose the one that meets hardware constraints for a specific problem size. Comparisons with the previously reported architectures demonstrate that one of the proposed architectures achieves less area and area-delay product besides its scalability to high-dimensional data.

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Beni, Alessandra, Lapo Miccinesi, and Massimiliano Pieraccini. "Comparison between Compressive Sensing and Non-Uniform Array for a MIMO GBSAR with Elevation Resolution: Simulations and Experimental Tests." Electronics 12, no. 5 (February 23, 2023): 1100. http://dx.doi.org/10.3390/electronics12051100.

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Ground-based synthetic aperture radars (GBSAR) are popular instruments widely used for the monitoring of infrastructures. One of the main problems of ground-based interferometric radars is the elevation ambiguity. Multiple-input multiple-output (MIMO) arrays could solve this problem. This work proposes a study on possible MIMO configurations to achieve elevation resolution in ground-based radar measurements. Specifically, two array configurations are compared: a random sparse array suitable for the compressive sensing technique, and a non-uniform array. The two solutions are compared by means of simulations and experimental tests. An ad hoc system has been developed to jointly test the two configurations, and results obtained in a controlled and real urban scenario are shown. It is found that both systems are able to solve elevation ambiguity. The non-uniform array seems to achieve good performance in a general scenario, while the CS processing can outperform the other only after optimization, depending on the specific scenario and application.

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Castagnola, Elisa, Marco Marrani, Emma Maggiolini, Francesco Maita, Luca Pazzini, Davide Polese, Alessandro Pecora, et al. "Recording High Frequency Neural Signals Using Conformable and Low-Impedance ECoG Electrodes Arrays Coated with PEDOT-PSS-PEG." Advances in Science and Technology 102 (October 2016): 77–85. http://dx.doi.org/10.4028/www.scientific.net/ast.102.77.

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Electrocorticography (ECoG) is receiving growing attention for both clinical and research applications thanks to its reduced invasiveness and ability of addressing large cortical areas. These benefits come with a main drawback, i.e. a limited frequency bandwidth. However, recent studies have shown that spiking activity from cortical neurons can be recorded when the ECoG grids present the following combined properties: (I) conformable substrate, (II) small neuron-sized electrodes with (III) low-impedance interfaces. We introduce here an ad-hoc designed ECoG device for investigating how electrode size, interface material composition and electrochemical properties affect the capability to record evoked and spontaneous neural signals from the rat somatosensory cortex and influence the ability to record high frequency neural signal components.Contact diameter reduction down to 8 μm was possible thanks to a specific coating of a (3,4-ethylenedioxytiophene)-poly (styrenesulfonate)-poly-(ethyleneglycol) (PEDOT-PSS-PEG) composite that drastically reduces impedance and increases electrical and ionic conductivities. In addition, the extreme thinness of the polyimide substrate (6 - 8 μm) and the presence of multiple perforations through the device ensure an effective contact with the brain surface and the free flow of cerebrospinal fluid. In-vivo validation was performed on rat somatosensory cortex.

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Huck-Iriart, Cristián, Lisandro Giovanetti, Paula Dos Santos Claro, Guinther Kellermann, Félix Requejo, and Aldo Craievich. "Formation dynamics of CoSi2thin nanoplates arrays studied by GISAXS in situ." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C742. http://dx.doi.org/10.1107/s2053273314092572.

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During the last decades an increasing demand for the development of new methods of preparation of nano-composite materials suited for technological applications has been observed [1]. The interest on these nanomaterials is related to the fact that many of their properties can be varied in a continuous way by changing size, shape and/or spatial ordering. Silicides of transition metals such as CoSi2 are of great interest because of the possibilities that they open to applications as a contact material for microelectronic devices [2]. A simple method for obtaining buried arrays of CoSi2 plates coherently embedded in a Si host lattice was described in a previous study [3]. Grazing-incidence small-angle X-ray "GISAXS" and transmission electron microscopy "TEM" results indicated that the nanoplates exhibit a hexagonal lateral shape and a remarkable uniform thickness. The lattice of each CoSi2 nanoplates was shown to be coherent with the host Si lattice, and parallel to one of the four planes belonging to the Si(111) crystallographic planes family. In this work we present a diffusion dynamics study of Co into Si single crystal lattice using in situ GISAXS setup designed ad-hoc. The Co atoms were initially embedded in a SiO2 thin film deposited on Si(001) substrates subjected to a isothermal treatment during 1 hour at several temperatures between 650-850 oC, The diffused Co react with Si atoms and form CoSi2 nanoplates. GISAXS intensity was modeled assuming that the total scattering intensity is the sum of the intensity produced by a set of spatially uncorrelated and spherical Co nanoparticles – embedded in the SiO2 layer - plus the intensity coming from the hexagonal nanoplates parallel to the different planes of the Si(111) family.

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Zamiri, Elyas, Alberto Sanchez, Marina Yushkova, Maria Sofia Martínez-García, and Angel de Castro. "Comparison of Different Design Alternatives for Hardware-in-the-Loop of Power Converters." Electronics 10, no. 8 (April 13, 2021): 926. http://dx.doi.org/10.3390/electronics10080926.

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This paper aims to compare different design alternatives of hardware-in-the-loop (HIL) for emulating power converters in Field Programmable Gate Arrays (FPGAs). It proposes various numerical formats (fixed and floating-point) and different approaches (pure VHSIC Hardware Description Language (VHDL), Intellectual Properties (IPs), automated MATLAB HDL code, and High-Level Synthesis (HLS)) to design power converters. Although the proposed models are simple power electronics HIL systems, the idea can be extended to any HIL system. This study compares the design effort of different coding methods and numerical formats considering possible synthesis tools (Precision and Vivado), and it comprises an analytical discussion in terms of area and speed. The different models are synthesized as ad-hoc modules in general-purpose FPGAs, but also using the NI myRIO device as an example of a commercial tool capable of implementing HIL models. The comparison confirms that the optimum design alternative must be chosen based on the application (complexity, frequency, etc.) and designers’ constraints, such as available area, coding expertise, and design effort.

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Grossi, Marco, Fabrizio Alfonsi, Marco Prandini, and Alessandro Gabrielli. "A Highly Configurable Packet Sniffer Based on Field-Programmable Gate Arrays for Network Security Applications." Electronics 12, no. 21 (October 25, 2023): 4412. http://dx.doi.org/10.3390/electronics12214412.

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Web applications and online business transactions have grown tremendously in recent years. As a result, cyberattacks have become a major threat to the digital services that are essential for our society. To minimize the risks of cyberattacks, many countermeasures are deployed on computing nodes and network devices. One such countermeasure is the firewall, which is designed with two main architectural approaches: software running on standard or embedded computers, or hardware specially designed for the purpose, such as (Application Specific Integrated Circuits) ASICs. Software-based firewalls offer high flexibility and can be easily ported to upgradable hardware, but they cannot handle high data rates. On the other hand, hardware-based firewalls can process data at very high speeds, but are expensive and difficult to update, resulting in a short lifespan. To address these issues, we explored the use of an (Field-Programmable Gate Array) FPGA architecture, which offers low latency and high-throughput characteristics along with easy upgradability, making it a more balanced alternative to other programmable systems, like (Graphics Processor Unit) GPUs or microcontrollers. In this paper, we presented a packet sniffer designed on the FPGA development board KC705 produced by Xilinx, which can analyze Ethernet frames, check the frame fields against a set of user-defined rules, and calculate statistics of the received Ethernet frames over time. The system has a data transfer rate of 1 Gbit/s (with preliminary results of increased data rates to 10 Gbit/s) and has been successfully tested with both ad hoc-generated Ethernet frames and real web traffic by connecting the packet sniffer to the internet.

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Verderio, Paolo, Stefano Bottelli, Chiara M. Ciniselli, Marco A. Pierotti, Susanna Zanutto, Manuela Gariboldi, and Sara Pizzamiglio. "Moving from Discovery to Validation in Circulating microRNA Research." International Journal of Biological Markers 30, no. 2 (April 2015): 258–61. http://dx.doi.org/10.5301/jbm.5000135.

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Background MicroRNAs (miRNAs), small noncoding RNAs, are involved in tumorigenesis and in the development of various cancers. Quantitative real-time polymerase chain reaction (qPCR) is the most commonly used tool to investigate miRNA expression, and qPCR low-density arrays are increasingly being used as an experimental technique for both the identification of potentially relevant miRNAs and their subsequent validation. Due to the reduced number of microRNAs to be validated, this phase is generally performed on ad hoc customized cards for which a technical robustness is assumed similar to that of the high-throughput cards used during the identification phase. Methods With the aim of investigating the degree of reproducibility between the 2 types of cards, we analyzed plasma-circulating miRNAs evaluated in 60 subjects enrolled in a colorectal cancer screening program. Results Our results showed a reproducibility between the 2 methods that was not fully satisfactory, with a concordance correlation coefficient equal to 0.69 (95% confidence interval, 0.12-0.92). Conclusions This report highlights the need to add a technical validation step to the high-throughput-based miRNA identification workflow, after their discovery and before the validation step in an independent series.

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Chen, Yu, Dongxiang Lu, and Guy Courbebaisse. "A Parallel Image Registration Algorithm Based on a Lattice Boltzmann Model." Information 11, no. 1 (December 19, 2019): 1. http://dx.doi.org/10.3390/info11010001.

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Image registration is a key pre-procedure for high level image processing. However, taking into consideration the complexity and accuracy of the algorithm, the image registration algorithm always has high time complexity. To speed up the registration algorithm, parallel computation is a relevant strategy. Parallelizing the algorithm by implementing Lattice Boltzmann method (LBM) seems a good candidate. In consequence, this paper proposes a novel parallel LBM based model (LB model) for image registration. The main idea of our method consists in simulating the convection diffusion equation through a LB model with an ad hoc collision term. By applying our method on computed tomography angiography images (CTA images), Magnet Resonance images (MR images), natural scene image and artificial images, our model proves to be faster than classical methods and achieves accurate registration. In the continuity of 2D image registration model, the LB model is extended to 3D volume registration providing excellent results in domain such as medical imaging. Our method can run on massively parallel architectures, ranging from embedded field programmable gate arrays (FPGAs) and digital signal processors (DSPs) up to graphics processing units (GPUs).

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Schinaia, Lorenzo, Andrea Scorza, Fabio Botta, Andrea Rossi, Roberto Maiozzi, Francesco Orsini, and Salvatore Andrea Sciuto. "A Novel, Low-Cost and Reliable Workbench for Optimal Voltage Distribution on Piezoelectric Array Actuators." Actuators 8, no. 1 (January 4, 2019): 6. http://dx.doi.org/10.3390/act8010006.

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The vibration control of structures is a valuable technique to increase their integrity and life-cycle. Among smart materials, the passive and active control systems based on piezoelectric elements have been studied in depth. Since the size and location of the piezo-elements on the structure are relevant matters for the damping efficiency, many works have focused on their placement optimization. Under certain circumstances, some structures may be excited by more vibration modes at the same time; hence, the signal conditioning system of the piezoelectric actuators must be capable of adjusting the driving signal in terms of voltage distribution, frequencies and associated amplitudes in order to maximize the damping efficiency. Moreover, in some applications, it could be useful to individually control each actuator therefore tailor-made power supply and signal generation systems are often necessary. This work suggests a low-cost and reliable workbench that overcomes the afore mentioned problems. The system consists of: (1) two arrays of 13 piezoceramic plates which have been glued on an aluminium beam, (2) ad hoc power supply equipment, and (3) mechanical relays arrays managed by a microcontroller for the individual handling of their operating modes. Furthermore, an Arduino board and an in-house software have been implemented in order to perform a task on each relay that is in turn wired to a single piezoelectric plate (PP). The performance of the developed system is evaluated in terms of noise and distortion of the testing signal measured at different points of the workbench. The results show that the proposed workbench may represent a good trade-off between affordability, accuracy and reliability and it can be used for several research purposes.

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Tambaro, Mattia, Elia Arturo Vallicelli, Gerardo Saggese, Antonio Strollo, Andrea Baschirotto, and Stefano Vassanelli. "Evaluation of In Vivo Spike Detection Algorithms for Implantable MTA Brain—Silicon Interfaces." Journal of Low Power Electronics and Applications 10, no. 3 (September 2, 2020): 26. http://dx.doi.org/10.3390/jlpea10030026.

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This work presents a comparison between different neural spike algorithms to find the optimum for in vivo implanted EOSFET (electrolyte–oxide-semiconductor field effect transistor) sensors. EOSFET arrays are planar sensors capable of sensing the electrical activity of nearby neuron populations in both in vitro cultures and in vivo experiments. They are characterized by a high cell-like resolution and low invasiveness compared to probes with passive electrodes, but exhibit a higher noise power that requires ad hoc spike detection algorithms to detect relevant biological activity. Algorithms for implanted devices require good detection accuracy performance and low power consumption due to the limited power budget of implanted devices. A figure of merit (FoM) based on accuracy and resource consumption is presented and used to compare different algorithms present in the literature, such as the smoothed nonlinear energy operator and correlation-based algorithms. A multi transistor array (MTA) sensor of 7 honeycomb pixels of a 30 μm2 area is simulated, generating a signal with Neurocube. This signal is then used to validate the algorithms’ performances. The results allow us to numerically determine which is the most efficient algorithm in the case of power constraint in implantable devices and to characterize its performance in terms of accuracy and resource usage.

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Feng, Liang, Veronica Pazzi, Emanuele Intrieri, Teresa Gracchi, and Giovanni Gigli. "Joint detection and classification of rockfalls in a microseismic monitoring network." Geophysical Journal International 222, no. 3 (June 12, 2020): 2108–20. http://dx.doi.org/10.1093/gji/ggaa287.

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SUMMARY A rockfall (RF) is a ubiquitous geohazard that is difficult to monitor or predict and poses a significant risk for people and transportation in several hilly and mountainous environments. The seismic signal generated by RF carries abundant physical and mechanical information. Thus, signals can be used by researchers to reconstruct the event location, onset time, volume and trajectory, and develop an efficient early warning system. Therefore, the precise automatic detection and classification of RF events are important objectives for scientists, especially in seismic monitoring arrays. An algorithm called DESTRO (DEtection and STorage of ROckfalls) aimed at combining seismic event automatic detection and classification was implemented ad hoc within the MATLAB environment. In event detection, the STA/LTA (short-time-average through long-time-average) method combined with other parameters, such as the minimum duration of an RF and the minimum interval time between two continuous seismic events is used. Furthermore, nine significant features based on the frequency, amplitude, seismic waveform, duration and multiple station attributes are newly proposed to classify seismic events in a RF environment. In particular, a three-step classification method is proposed for the discrimination of five different source types: RFs, earthquakes (EQs), tremors, multispike events (MSs) and subordinate MS events. Each component (vertical, east–west and north–south) at each station within the monitoring network is analysed, and a three-step classification is performed. At a given time, the event series detected from each component are integrated and reclassified component by component and station by station into a final event-type series as an output result. By this algorithm, a case study of the seven-month-long seismic monitoring of a former quarry in Central Italy was investigated by means of four triaxial velocimeters with continuous acquisition at a sampling rate of 200 Hz. During this monitoring period, a human-induced RF simulation was performed, releasing 95 blocks (in which 90 blocks validated) of different sizes from the benches of the quarry. Consequently, 64.9 per cent of EQs within 100 km were confirmed in a one-month monitoring period, 88 blocks in the RF simulation were classified correctly as RF events and 2 blocks were classified as MSs given their small energy. Finally, an ad hoc section of the algorithm was designed specifically for RF classification combined with EQ recognition. The algorithm could be applied in slope seismic monitoring to monitor the dynamic states of rock masses, as well as in slope instability forecasting and risk evaluation in EQ-prone areas.

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Aranda, Luis Alberto, Antonio Sánchez, Francisco Garcia-Herrero, Yubal Barrios, Roberto Sarmiento, and Juan Antonio Maestro. "Reliability Analysis of the SHyLoC CCSDS123 IP Core for Lossless Hyperspectral Image Compression Using COTS FPGAs." Electronics 9, no. 10 (October 14, 2020): 1681. http://dx.doi.org/10.3390/electronics9101681.

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Hyperspectral images can comprise hundreds of spectral bands, which means that they can represent a large volume of data difficult to manage with the available on-board resources. Lossless compression solutions are interesting for reducing the amount of information stored or transmitted while preserving it at the same time. The Hyperspectral Lossless Compressor for space applications (SHyLoC), which is part of the European Space Agency (ESA) IP core’s library, has been demonstrated to meet the requirements of space missions in terms of compression efficiency, low complexity and high throughput. Currently, there is a trend to use Commercial Off-The-Shelf (COTS) on-board electronic devices on small satellites. Moreover, commercial Field-Programmable Gate Arrays (FPGAs) have been used in a number of them. Hence, a reliability analysis is required to ensure the robustness of the applications to Single Event Upsets (SEUs) in the configuration memory. In this work, we present a reliability analysis of this hyperspectral image compression module as a first step towards the development of ad-hoc fault-tolerant protection techniques for the SHyLoC IP core. The reliability analysis is performed using a fault-injection-based experimental set-up in which a hardware implementation of the Consultative Committee for Space Data Systems (CCSDS) 123.0-B-1 lossless compression standard is tested against configuration memory errors in a Xilinx Zynq XC7Z020 System-on-Chip. The results obtained for unhardened and redundancy-based protected versions of the module are put into perspective in terms of area/power consumption and availability/protection coverage gained to provide insight into the development of more efficient knowledge-based protection schemes.

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Polderman, I. M., M. Haverkorn, T. R. Jaffe, and M. I. R. Alves. "Low-frequency measurements of synchrotron absorbing HII regions and modeling of observed synchrotron emissivity." Astronomy & Astrophysics 621 (January 2019): A127. http://dx.doi.org/10.1051/0004-6361/201834405.

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Context. Cosmic rays (CRs) and magnetic fields are dynamically important components in the Galaxy, and their energy densities are comparable to that of the turbulent interstellar gas. The interaction of CRs and Galactic magnetic fields (GMF) produces synchrotron radiation clearly visible in the radio regime. Detailed measurements of synchrotron radiation averaged over the line-of-sight (LOS), so-called synchrotron emissivities, can be used as a tracer of the CR density and GMF strength. Aims. Our aim is to model the synchrotron emissivity in the Milky Way using a three-dimensional dataset instead of LOS-integrated intensity maps on the sky. Methods. Using absorbed HII regions, we measured the synchrotron emissivity over a part of the LOS through the Galaxy, changing from a two-dimensional to a three-dimensional view. Performing these measurements on a large scale is one of the new applications of the window opened by current low-frequency arrays. Using various simple axisymmetric emissivity models and a number of GMF-based emissivity models, we were able to simulate the synchrotron emissivities and compare them to the observed values in the catalog. Results. We present a catalog of low-frequency absorption measurements of HII regions, their distances and electron temperatures, compiled from literature. These data show that the axisymmetric emissivity models are not complex enough, but the GMF-based emissivity models deliver a reasonable fit. These models suggest that the fit can be improved by either an enhanced synchrotron emissivity in the outer reaches of the Milky Way or an emissivity drop near the Galactic center. Conclusions. Current GMF models plus a constant CR density model cannot explain low-frequency absorption measurements, but the fits improved with slight (ad hoc) adaptations. It is clear that more detailed models are needed, but the current results are very promising.

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Bonesini, Maurizio, Roberto Bertoni, Andrea Abba, Francesco Caponio, Marco Prata, and Massimo Rossella. "Improving the Time Resolution of Large-Area LaBr3:Ce Detectors with SiPM Array Readout." Condensed Matter 8, no. 4 (November 17, 2023): 99. http://dx.doi.org/10.3390/condmat8040099.

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LaBr3:Ce crystals have good scintillation properties for X-ray spectroscopy. Initially, they were introduced for radiation imaging in medical physics with either a photomultiplier or SiPM readout, and they found extensive applications in homeland security and gamma-ray astronomy. We used 1″ round LaBr3:Ce crystals to realize compact detectors with the SiPM array readout. The aim was a good energy resolution and a fast time response to detect low-energy X-rays around 100 keV. A natural application was found inside the FAMU experiment, at RIKEN RAL. Its aim is a precise measurement of the proton Zemach radius with impinging muons, to contribute to the solution to the so-called “proton radius puzzle”. Signals to be detected are characteristic X-rays around 130 KeV. A limit for this type of detector, as compared to the ones with a photomultiplier readout, is its poorer timing characteristics due to the large capacity of the SiPM arrays used. In particular, long signal falltimes are a problem in experiments such as FAMU, where a “prompt” background component must be separated from a “delayed” one (after 600 ns) in the signal X-rays to be detected. Dedicated studies were pursued to improve the timing characteristics of the used detectors, starting from hybrid ganging of SiPM cells; then developing a suitable zero pole circuit with a parallel ganging, where an increased overvoltage for the SiPM array was used to compensate for the signal decrease; and finally designing ad hoc electronics to split the 1″ detector’s SiPM array into four quadrants, thus reducing the involved capacitances. The aim was to improve the detectors’ timing characteristics, especially falltime, while keeping a good FWHM energy resolution for low-energy X-ray detection.

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Gaifas, Lorenzo, Moritz A. Kirchner, Joanna Timmins, and Irina Gutsche. "Blik is an extensible 3D visualisation tool for the annotation and analysis of cryo-electron tomography data." PLOS Biology 22, no. 4 (April 30, 2024): e3002447. http://dx.doi.org/10.1371/journal.pbio.3002447.

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Powerful, workflow-agnostic and interactive visualisation is essential for the ad hoc, human-in-the-loop workflows typical of cryo-electron tomography (cryo-ET). While several tools exist for visualisation and annotation of cryo-ET data, they are often integrated as part of monolithic processing pipelines, or focused on a specific task and offering limited reusability and extensibility. With each software suite presenting its own pros and cons and tools tailored to address specific challenges, seamless integration between available pipelines is often a difficult task. As part of the effort to enable such flexibility and move the software ecosystem towards a more collaborative and modular approach, we developed blik, an open-source napari plugin for visualisation and annotation of cryo-ET data (source code: https://github.com/brisvag/blik). blik offers fast, interactive, and user-friendly 3D visualisation thanks to napari, and is built with extensibility and modularity at the core. Data is handled and exposed through well-established scientific Python libraries such as numpy arrays and pandas dataframes. Reusable components (such as data structures, file read/write, and annotation tools) are developed as independent Python libraries to encourage reuse and community contribution. By easily integrating with established image analysis tools—even outside of the cryo-ET world—blik provides a versatile platform for interacting with cryo-ET data. On top of core visualisation features—interactive and simultaneous visualisation of tomograms, particle picks, and segmentations—blik provides an interface for interactive tools such as manual, surface-based and filament-based particle picking, and image segmentation, as well as simple filtering tools. Additional self-contained napari plugins developed as part of this work also implement interactive plotting and selection based on particle features, and label interpolation for easier segmentation. Finally, we highlight the differences with existing software and showcase blik’s applicability in biological research.

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Toffalori, Cristina, Michela Riba, Laura Zito, Matteo Barcella, Orietta Spinelli, Lara Crucitti, Nicoletta Cieri, et al. "Acute Myeloid Leukemia Relapses after Allogenenic HSCT Display a Distinctive Immune-Related Signature, with Frequent and Functionally Relevant Alterations in HLA Class II Antigen Presentation and T Cell Costimulation." Blood 124, no. 21 (December 6, 2014): 427. http://dx.doi.org/10.1182/blood.v124.21.427.427.

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Abstract INTRODUCTION: Allogeneic Hematopoietic Stem Cell Transplantation (allo-HSCT) represents an effective form of adoptive immunotherapy for Acute Myeloid Leukemia (AML), thanks to the antitumor effect mediated by donor immune cells infused as part of the graft. Unfortunately, post-transplantation relapses remain a frequent observation, warranting further investigation on AML immunobiology. Our group demonstrated that relapses after partially HLA-incompatible HSCT are frequently due to the outgrowth of immune-resistant mutant AML clones characterized by genomic loss the mismatched histocompatibility determinants targeted by alloreactive donor T cells, and have thus gained a selective advantage upon pressure from the transplanted immune system, in a process called “leukemia immunoediting” (Vago et al., N Engl J Med, 2009). In the present study, we took advantage of high-throughput technologies to profile post-transplantation AML relapses with no genomic loss of HLA, to identify novel targets of the leukemia immunoediting process. METHODS: Serial AML samples were collected and FACS-purified from 9 patients at diagnosis, relapse after sole chemotherapy and relapse after allo-HSCT, and employed for whole transcriptome profiling using Illumina HumanHT12 microarrays. Deregulated genes were identified by pair-wise LIMMA analysis, and unsupervised enrichment analysis was performed interrogating the Gene Ontology database. High-throughput results were confirmed in a validation cohort of 12 patients by ad hoc designed qPCR assays, immunophenotypic analyses and functional experiments. In particular, co-cultures were performed using as responders peripheral blood lymphocytes harvested from patients after allo-HSCT, and as stimulators and targets their respective AML blasts collected at diagnosis or at relapse: read-outs included antigen-specific T cell activation, cytotoxicity, and cytokine release. RESULTS: Amongst all the genes expressed by purified AML blasts, a 110-gene signature (p<0.1) was able to discriminate between AML collected at disease diagnosis and at relapse after allo-HSCT. Most of the transcripts deregulated at post-transplantation relapse were involved in immune-related processes, and in particular in T cell costimulation and in the antigen presentation machinery. Conversely, no significant enrichment in immune-related processes was documented when comparing diagnosis with relapses after sole chemotherapy. Alterations in costimulatory molecules were confirmed by immunophenotypic analyses in a validation cohort: AML blasts at both diagnosis and post-transplantation relapse expressed high levels of co-inhibitory molecules (PDL-1, B7-H3 and Vista) and low levels of costimulatory ligands (ICOS-L, TNFSF4). At relapse after allo-HSCT we documented a marked reduction in Vista surface expression on AML blasts, and very high levels of PD-1 on donor-derived T cells. Even more evident were the de novo changes observed in the antigen presentation machinery at post-transplantation relapse: selective loss of surface expression of all HLA class II molecules and downregulation of their master regulator CIITA were detected in 4 out of the 12 patients analyzed, occurring exclusively in patients transplanted from partially HLA-incompatible donors. In 2 of the 4 cases Class II expression was recovered upon culturing AML blasts in the presence of interferon-γ. SNP arrays documented no genomic alterations in Class II genes or their regulators, suggesting an epigenetic origin of the alteration. Importantly, loss of HLA Class II surface expression in AML blasts resulted in the complete abrogation of functional recognition and killing by donor-derived T cells, supporting the hypothesis that these changes might foster immune evasion and relapse. CONCLUSIONS: Our results demonstrate that the deregulation of immune-related processes, and in particular of molecules and pathways involved in T cell-mediated allo-recognition, are pervasive and distinctive features of AML relapses after allo-HSCT. Identification of patient-specific mechanisms of immune evasion might be translated into personalized therapeutic approaches, tailored to restore or circumvent inefficient antigen presentation and T cell costimulation. Disclosures Bonini: MolMed S.p.A.: Consultancy.

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Kindt, Stijn, Jenthe Thienpondt, Luca Becker, and Nilesh Madhu. "Robustness of ad hoc microphone clustering using speaker embeddings: evaluation under realistic and challenging scenarios." EURASIP Journal on Audio, Speech, and Music Processing 2023, no. 1 (October 31, 2023). http://dx.doi.org/10.1186/s13636-023-00310-w.

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AbstractSpeaker embeddings, from the ECAPA-TDNN speaker verification network, were recently introduced as features for the task of clustering microphones in ad hoc arrays. Our previous work demonstrated that, in comparison to signal-based Mod-MFCC features, using speaker embeddings yielded a more robust and logical clustering of the microphones around the sources of interest. This work aims to further establish speaker embeddings as a robust feature for ad hoc microphone clustering by addressing open and additional questions of practical interest, arising from our prior work. Specifically, whereas our initial work made use of simulated data based on shoe-box acoustics models, we now present a more thorough analysis in more realistic settings. Furthermore, we investigate additional important considerations such as the choice of the distance metric used in the fuzzy C-means clustering; the minimal time range across which data need to be aggregated to obtain robust clusters; and the performance of the features in increasingly more challenging situations, and with multiple speakers. We also contrast the results on the basis of several metrics for quantifying the quality of such ad hoc clusters. Results indicate that the speaker embeddings are robust to short inference times, and deliver logical and useful clusters, even when the sources are very close to each other.

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Gerstoft, Peter, Yihan Hu, Michael J. Bianco, Chaitanya Patil, Ardel Alegre, Yoav Freund, and Francois Grondin. "Audio scene monitoring using redundant ad-hoc microphone array networks." IEEE Internet of Things Journal, 2021, 1. http://dx.doi.org/10.1109/jiot.2021.3103523.

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Gburrek, Tobias, Joerg Schmalenstroeer, and Reinhold Haeb-Umbach. "Geometry calibration in wireless acoustic sensor networks utilizing DoA and distance information." EURASIP Journal on Audio, Speech, and Music Processing 2021, no. 1 (July 2, 2021). http://dx.doi.org/10.1186/s13636-021-00210-x.

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AbstractDue to the ad hoc nature of wireless acoustic sensor networks, the position of the sensor nodes is typically unknown. This contribution proposes a technique to estimate the position and orientation of the sensor nodes from the recorded speech signals. The method assumes that a node comprises a microphone array with synchronously sampled microphones rather than a single microphone, but does not require the sampling clocks of the nodes to be synchronized. From the observed audio signals, the distances between the acoustic sources and arrays, as well as the directions of arrival, are estimated. They serve as input to a non-linear least squares problem, from which both the sensor nodes’ positions and orientations, as well as the source positions, are alternatingly estimated in an iterative process. Given one set of unknowns, i.e., either the source positions or the sensor nodes’ geometry, the other set of unknowns can be computed in closed-form. The proposed approach is computationally efficient and the first one, which employs both distance and directional information for geometry calibration in a common cost function. Since both distance and direction of arrival measurements suffer from outliers, e.g., caused by strong reflections of the sound waves on the surfaces of the room, we introduce measures to deemphasize or remove unreliable measurements. Additionally, we discuss modifications of our previously proposed deep neural network-based acoustic distance estimator, to account not only for omnidirectional sources but also for directional sources. Simulation results show good positioning accuracy and compare very favorably with alternative approaches from the literature.

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Raponi, Simone, Gabriele Oligeri, and Isra Mohamed Ali. "Sound of guns: digital forensics of gun audio samples meets artificial intelligence." Multimedia Tools and Applications, April 6, 2022. http://dx.doi.org/10.1007/s11042-022-12612-w.

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AbstractClassifying a weapon based on its muzzle blast is a challenging task that has significant applications in various security and military fields. Most of the existing works rely on ad-hoc deployment of spatially diverse microphone sensors to capture multiple replicas of the same gunshot, which enables accurate detection and identification of the acoustic source. However, carefully controlled setups are difficult to obtain in scenarios such as crime scene forensics, making the aforementioned techniques inapplicable and impractical. We introduce a novel technique that requires zero knowledge about the recording setup and is completely agnostic to the relative positions of both the microphone and shooter. Our solution can identify the category, caliber, and model of the gun, reaching over 90% accuracy on a dataset composed of 3655 samples that are extracted from YouTube videos. Our results demonstrate the effectiveness and efficiency of applying Convolutional Neural Network (CNN) in gunshot classification eliminating the need for an ad-hoc setup while significantly improving the classification performance.

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Kindt, Stijn, Jenthe Thienpondt, Luca Becker, and Nilesh Madhu. "Correction: Robustness of ad hoc microphone clustering using speaker embeddings: evaluation under realistic and challenging scenarios." EURASIP Journal on Audio, Speech, and Music Processing 2024, no. 1 (January 15, 2024). http://dx.doi.org/10.1186/s13636-023-00319-1.

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Perevalov, Eugene, Danny Safi, Lang Lin, and Rick S. Blum. "Spatial Multiplexing Gains for Realistic Sized Ad Hoc Networks with Directional Antenna Arrays." EURASIP Journal on Wireless Communications and Networking 2007, no. 1 (October 22, 2007). http://dx.doi.org/10.1155/2007/98490.

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Brofiga, Martina, Fabio Poggio, Francesca Callegari, Mariateresa Tedesco, and Paolo Massobrio. "Modularity and neuronal heterogeneity: Two properties that influence in vitro neuropharmacological experiments." Frontiers in Cellular Neuroscience 17 (March 20, 2023). http://dx.doi.org/10.3389/fncel.2023.1147381.

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IntroductionThe goal of this work is to prove the relevance of the experimental model (in vitro neuronal networks in this study) when drug-delivery testing is performed.MethodsWe used dissociated cortical and hippocampal neurons coupled to Micro-Electrode Arrays (MEAs) arranged in different configurations characterized by modularity (i.e., the presence of interconnected sub-networks) and heterogeneity (i.e., the co-existence of neurons coming from brain districts). We delivered increasing concentrations of bicuculline (BIC), a neuromodulator acting on the GABAergic system, and we extracted the IC50 values (i.e., the effective concentration yielding a reduction in the response by 50%) of the mean firing rate for each configuration.ResultsWe found significant lower values of the IC50 computed for modular cortical-hippocampal ensembles than isolated cortical or hippocampal ones.DiscussionAlthough tested with a specific neuromodulator, this work aims at proving the relevance of ad hoc experimental models to perform neuropharmacological experiments to avoid errors of overestimation/underestimation leading to biased information in the characterization of the effects of a drug on neuronal networks.

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Yi, Haibo. "Parallel Finite Field Algorithms for Communications and Sensor Networks." ACM Transactions on Sensor Networks, April 17, 2023. http://dx.doi.org/10.1145/3572774.

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Sensor network integrates sensor technology, embedded computing technology, modern network and wireless communication technology, distributed information processing technology, etc. It can monitor, perceive and collect the information of various environments or monitoring objects in real time through various integrated micro sensors, and process the information through the embedded system. The perceived information is transmitted to the user terminal by multi-hop relay through the random ad-hoc wireless communication network. The coding of communications and sensor networks affects the efficiency of communication. The main coding technology is based on finite field. Among operations in finite fields, divisions are time-consuming operations since they are generally computed via inversions and multiplications. We present techniques to exploit extend binary trees for fast divisions in finite fields. We implement the finite field algorithm on Field Programmable Logic Arrays (FPGAs) in a parallel way. The implementation result from FPGAs shows that the parallel finite field algorithm can speed up the process of coding of communications and sensor networks.

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Munger, T., and S. Desa. "A Statistical Design of Experiments Approach to Machine Learning Model Selection in Engineering Applications." Journal of Computing and Information Science in Engineering 21, no. 1 (August 17, 2020). http://dx.doi.org/10.1115/1.4047915.

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Abstract An important but insufficiently addressed issue for machine learning in engineering applications is the task of model selection for new problems. Existing approaches to model selection generally focus on optimizing the learning algorithm and associated hyperparameters. However, in real-world engineering applications, the parameters that are external to the learning algorithm, such as feature engineering, can also have a significant impact on the performance of the model. These external parameters do not fit into most existing approaches for model selection and are therefore often studied ad hoc or not at all. In this article, we develop a statistical design of experiment (DOEs) approach to model selection based on the use of the Taguchi method. The key idea is that we use orthogonal arrays to plan a set of build-and-test experiments to study the external parameters in combination with the learning algorithm. The use of orthogonal arrays maximizes the information learned from each experiment and, therefore, enables the experimental space to be explored extremely efficiently in comparison with grid or random search methods. We demonstrated the application of the statistical DOE approach to a real-world model selection problem involving predicting service request escalation. Statistical DOE significantly reduced the number of experiments necessary to fully explore the external parameters for this problem and was able to successfully optimize the model with respect to the objective function of minimizing total cost in addition to the standard evaluation metrics such as accuracy, f-measure, and g-mean.

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