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Journal articles on the topic 'Multiple Mobile Signal Sources'
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1
Sekiguchi, Kouhei, Yoshiaki Bando, Katsutoshi Itoyama, and Kazuyoshi Yoshii. "Layout Optimization of Cooperative Distributed Microphone Arrays Based on Estimation of Source Separation Performance." Journal of Robotics and Mechatronics 29, no. 1 (2017): 83–93. http://dx.doi.org/10.20965/jrm.2017.p0083.
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[abstFig src='/00290001/08.jpg' width='300' text='Optimizing robot positions for source separation' ] The active audition method presented here improves source separation performance by moving multiple mobile robots to optimal positions. One advantage of using multiple mobile robots that each has a microphone array is that each robot can work independently or as part of a big reconfigurable array. To determine optimal layout of the robots, we must be able to predict source separation performance from source position information because actual source signals are unknown and actual separation performance cannot be calculated. Our method thus simulates delay-and-sum beamforming from a possible layout to calculate gain theoretically, i.e., the expected ratio of a target sound source to other sound sources in the corresponding separated signal. Robots are moved into the layout with the highest average gain over target sources. Experimental results showed that our method improved the harmonic mean of signal-to-distortion ratios (SDRs) by 5.5 dB in simulation and by 3.5 dB in a real environment.
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Su, Kuo Lan, Bo Yi Li, and Jian Da Fong. "Development of the Escaping Programming System for Fire Environment." Applied Mechanics and Materials 300-301 (February 2013): 389–92. http://dx.doi.org/10.4028/www.scientific.net/amm.300-301.389.
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We present the path planning techniques of the fire escaping system using multiple mobile robots for intelligent building. The controller of the mobile robot is MCS-51 microchip, and acquires the detection signal from flame sensor through I/O pins, and receives the command from the supervised compute via wireless RF interface. The mobile robot transmits ID code, detection signal, location and orientation of the mobile robots to the supervised computer via wireless RF interface. We proposed A* searching algorithm to program escaping motion paths to guard peoples moving to the safety area using mobile robots, and develop user interface on the supervised computer for the fire escaping system. In the experimental results, the supervised computer locates the positions of fire sources by mobile robots, and programs the escaping paths on the user interface, and transmits the motion command to the mobile robots. The mobile robot guards peoples leaving the fire sources.
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Dang, Jian, Jiajun Gao, Zaichen Zhang, et al. "Performance of Optical Mobile Communications with User Mobility and Multiple Light Sources." Wireless Communications and Mobile Computing 2021 (September 13, 2021): 1–14. http://dx.doi.org/10.1155/2021/5573946.
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Optical mobile communication (OMC) is a recently proposed optical wireless communication concept aiming to provide very high-speed data rate optical wireless links for multiple and, in general, distributed mobile users. Previous work analyzed the rate performance of a two-user OMC system without user mobility. This paper extends the rate analysis to multiple users with mobility. The scenario of employing multiple light sources with possible user grouping is also considered. User mobility and multiple light sources lead to new challenges on the system design which are addressed for broadcast downlink communication in this work. Simulations show that user mobility decreases the rate, and the way of how to utilize multiple light sources has great impact on the performance. In particular, simultaneous power division usage of multiple light sources through user grouping and power allocation brings almost no gain as compared with the case of single light source. On the other hand, time division usage of multiple light sources is capable of compensating for the hardware deficiency and thus increasing the rate greatly. It is found that OMC is not only superior to the conventional scheme with nonadjustable channel gains but also outperforms free space optical scheme at high signal-to-noise ratio region.
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Annavajjala, Ramesh, Amine Maaref, and Jinyun Zhang. "Multiantenna Analog Network Coding for Multihop Wireless Networks." International Journal of Digital Multimedia Broadcasting 2010 (2010): 1–10. http://dx.doi.org/10.1155/2010/368562.
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This paper proposes a two-phase minimum mean-square-error bidirectional amplify-and forward (MMSE-BAF) relaying protocol to allow two sources exchange independent messages via a relay node equipped with multiple antennas. MMSE-BAF performs a joint linear MMSE filtering of the received signal after the multiple access phase before amplifying and forwarding the filtered signal using a single transmit antenna, possibly through a specific antenna selection procedure, during the broadcast phase. The proposed protocol extends upon the so-called analog network coding schemes in the literature in that it inherently exploits the multiple antennas at the relay station to reduce the noise enhancement typical of an AF protocol, and can also compensate for link imbalances between the relay and the sources and is agnostic to sources' modulation and coding schemes. We derive the instantaneous signal-to-noise ratio expressions for the received signal by the sources in the downlink and provide extensive link-level simulations for the MMSE-BAF protocol subject to both frequency flat and selective fading. Furthermore, we pinpoint the modifications to be incorporated into the IEEE 802.16e orthogonal-frequency-division multiple access (OFDMA) cellular standard (mobile WiMax) to enable support of multiantenna bidirectional communications and show that MMSE-BAF is a viable solution within that framework.
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Lehner, Andreas, and Alexander Steingaß. "Spatial Dynamic Wideband Modeling of the MIMO Satellite-to-Earth Channel." International Journal of Antennas and Propagation 2014 (2014): 1–20. http://dx.doi.org/10.1155/2014/102754.
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A novel MIMO (multiple input multiple output) satellite channel model that allows the generation of associated channel impulse response (CIR) time series depending on the movement profile of a land mobile terminal is presented in this paper. Based on high precise wideband measurements in L-band the model reproduces the correlated shadowing and multipath conditions in rich detail. The model includes time and space variant echo signals appearing and disappearing in dependence on the receive antenna position and movement, and the actual azimuths and elevations to the various signal sources. Attenuation and path delays relative to the hypothetical line of sight (LOS) ensure usability for ranging purposes. Parameters for car and pedestrian applications in urban and suburban environments are provided. The channel characteristics are determined independently of the transmitted signal. Therefore the usability, for example, for GPS and GALILEO, as well as wideband communication services from hovering platforms, is given.
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Liu, Jingrong, Zhongliang Deng, Enwen Hu, et al. "GNSS-5G Hybrid Positioning Based on Joint Estimation of Multiple Signals in a Highly Dependable Spatio-Temporal Network." Remote Sensing 15, no. 17 (2023): 4220. http://dx.doi.org/10.3390/rs15174220.
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The Global Navigation Satellite System (GNSS) has been widely used in every area of our daily life to provide accurate Positioning, Navigation, and Timing (PNT) services. However, due to the multipatch effect and an obstructed view of the satellite, GNSS receivers are susceptible to large-ranging errors, which are particularly prevalent in urban areas where precise positioning is indispensable. The deployment of the high-spatial-density Fifth-Generation (5G) network makes it possible to provide a broad area with high-precision positioning service. Obviously, it promoting the deep integration of the GNSS system and the 5G mobile communication network and establishing a Highly Dependable Spatio-temporal Network (HDSN) have become an inevitable trend. The existing algorithm for the fusion of multiple signals has difficulty settling problems such as the fast fluctuation of available signal sources and the poor stability of multi-scale multi-type signal estimation in GNSS-5G hybrid networks. Here, we propose a Square Root Unscented Stable Filter (SRUSF) for GNSS and 5G joint positioning with a compact coupled filter group architecture in a highly dependable spatio-temporal network. A stabilized coefficient is added to guarantee positive covariance of the estimation error. The possibility of divergence of filtering results due to the variation in signal sources and the incomplete agreement between the system model and the actual situation are reduced. The simulation results show that the proposed SRUSF method substantially enhances the positioning accuracy and reliability compared with the other five joint estimation methods for multiple signals. This work will enable the terminal of mass users to provide timing and positioning services with unprecedented accuracy and dependability under the GNSS and 5 G-based spatio-temporal network’s architecture.
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Bukartas, Antanas, Jonas Wallin, Robert Finck, and Christopher Rääf. "Bayesian algorithm to estimate position and activity of an orphan gamma source utilizing multiple detectors in a mobile gamma spectrometry system." PLOS ONE 16, no. 1 (2021): e0245440. http://dx.doi.org/10.1371/journal.pone.0245440.
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To avoid harm to the public and the environment, lost ionizing radiation sources must be found and brought back under the regulatory control as soon as possible. Usually, mobile gamma spectrometry systems are used in such search missions. It is possible to estimate the position and activity of point gamma sources by performing Bayesian inference on the measurement data. The aim of this study was to theoretically investigate the improvements in the Bayesian estimations of the position and activity of a point gamma source due to introduction of data from multiple detectors with angular variations of efficiency. Three detector combinations were tested—a single 123% HPGe detector, single 4l NaI (Tl) detector and a 123% HPGe with 2x4l NaI (Tl) detector combination—with and without angular efficiency variations for each combination resulting in six different variants of the Bayesian algorithm. It was found that introduction of angular efficiency variations of the detectors did improve the accuracy of activity estimation slightly, while introduction of data from additional detectors lowered the signal-to-noise ratio threshold of the system significantly, increasing the stability and accuracy of the estimated source position and activity, for a given signal-to-noise ratio.
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Manacorda, Marco, and Andrea Tesei. "Liberation Technology: Mobile Phones and Political Mobilization in Africa." Econometrica 88, no. 2 (2020): 533–67. http://dx.doi.org/10.3982/ecta14392.
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Can digital information and communication technology foster mass political mobilization? We use a novel georeferenced data set for the entire African continent between 1998 and 2012 on the coverage of mobile phone signal together with georeferenced data from multiple sources on the occurrence of protests and on individual participation in protests to bring this argument to empirical scrutiny. We find that while mobile phones are instrumental to mass mobilization, this only happens during economic downturns, when reasons for grievance emerge and the cost of participation falls. The results are in line with insights from a network model with imperfect information and strategic complementarities in protest occurrence. Mobile phones make individuals more responsive to both changes in economic conditions—a mechanism that we ascribe to enhanced information—and to their neighbors' participation—a mechanism that we ascribe to enhanced coordination.
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Konikov, Alexander I. "Teaching advanced methods of signal processing and transmission at universities of civil engineering." Stroitel'stvo: nauka i obrazovanie [Construction: Science and Education] 11, no. 1 (2021): 63–72. http://dx.doi.org/10.22227/2305-5502.2021.1.5.
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Introduction. Development and widespread dissemination of information technologies, including the Internet, mobile communications, cloud computing, Big Data, the Internet of Things, digital twin, etc. are being proactively introduced into versatile production and business processes of the construction industry. Therefore, a graduate of a civil engineering university must master the fundamentals of the above-listed technologies and know how to use them in his/her practical activities. It’s particularly important for those specialities that deal with information technologies in civil engineering. However, a number of important areas of knowledge that serve as the basis for mobile communications, the Internet, and wireless technologies, are only taught at specialized universities and schools. Nevertheless, students of civil engineering universities need to understand the theoretical provisions and processes of information technologies. Materials and methods. Systematization, the benchmark method, theoretical generalization of data extracted from literary sources were applied. Results. The founding notions, needed to discuss digital technologies, encompass temporary signal notation, spectral characteristics, spectral bandwidth, time and frequency division, multiplexing, discrete sampling and quantization of a signal. It is impossible to successfully study and effectively use these advanced technologies without having understood these fundamental technologies. The author offers a simplified explanation of these notions and principal processes in terms of their application in the construction industry. Conclusions. The author addresses complicated issues of the theory of signals and their transmission over communication lines. He presents the three key ideas that serve as the basis for multiple advanced information technologies, including time and spectrum signal notation, time and frequency division, multiplexing, discrete sampling and quantization of a signal. The author’s ideas can be used to teach mobile technologies, the Internet, the Internet of Things, cloud and edge computing, digital twin, etc.
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Stancheva, Anushka. "EMC assassement criteria and interference protection for basic radio services in accordance with ITU-R recommendations." Yearbook Telecommunications 7 (August 12, 2021): 1–9. http://dx.doi.org/10.33919/ytelecomm.20.7.1.
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The effect of unwanted energy due to one or a combination of several desired and unwanted emissions upon reception in a radio communication system results in performance degradation, misinterpretation or loss of information. Multiple sources of interference may affect the receiver input: services of the same type or other operating in the same frequency band, services operating in adjacent frequency bands, sources generating continuous or short term interferences, fixed or mobile sources, etc. To prevent such interfering situations, a key element is the standardization of appropriate criteria for electromagnetic compatibility (EMC) and interference protection (IPC). The purpose of the studies and analyzes in this article is to systematize the criteria for electromagnetic compatibility for basic radio services based on the Publications of ITU-R. Criteria for four important areas of radio communications covering fixed, fixed satellite, broadcasting and mobile radio services are compared. Contributions are the categorization of the criteria according to the type of interfering signal and the results of the analyses, which show that the regulatory requirements and practical methods for interference protection and EMC for different radio services differ. Detailed criteria for predicting the probability of interference being standardized only for some radio services.
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Zacharias, Panagiotis P., Elpida G. Chatzineofytou, Sotirios T. Spantideas, and Christos N. Capsalis. "Distance scaling method for accurate prediction of slowly varying magnetic fields in satellite missions." Geoscientific Instrumentation, Methods and Data Systems 5, no. 2 (2016): 281–88. http://dx.doi.org/10.5194/gi-5-281-2016.
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Abstract. In the present work, the determination of the magnetic behavior of localized magnetic sources from near-field measurements is examined. The distance power law of the magnetic field fall-off is used in various cases to accurately predict the magnetic signature of an equipment under test (EUT) consisting of multiple alternating current (AC) magnetic sources. Therefore, parameters concerning the location of the observation points (magnetometers) are studied towards this scope. The results clearly show that these parameters are independent of the EUT's size and layout. Additionally, the techniques developed in the present study enable the placing of the magnetometers close to the EUT, thus achieving high signal-to-noise ratio (SNR). Finally, the proposed method is verified by real measurements, using a mobile phone as an EUT.
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Trujillo, José Antonio, Isabel de-la-Bandera, Jesús Burgueño, David Palacios, Eduardo Baena, and Raquel Barco. "Active Learning Methodology for Expert-Assisted Anomaly Detection in Mobile Communications." Sensors 23, no. 1 (2022): 126. http://dx.doi.org/10.3390/s23010126.
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Due to the great complexity, heterogeneity, and variety of services, anomaly detection is becoming an increasingly important challenge in the operation of new generations of mobile communications. In many cases, the underlying relationships between the multiplicity of parameters and factors that can cause anomalous behavior are only determined by human expert knowledge. On the other hand, although automatic algorithms have a great capacity to process multiple sources of information, they are not always able to correctly signal such abnormalities. In this sense, this paper proposes the integration of both components in a framework based on Active Learning that enables enhanced performance in anomaly detection tasks. A series of tests have been conducted using an online anomaly detection algorithm comparing the proposed solution with a method based on the algorithm output alone. The obtained results demonstrate that a hybrid anomaly detection model that automates part of the process and includes the knowledge of an expert following the described methodology yields increased performance.
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McKee, Forrest, and David Noever. "NEAR ULTRASONIC ATTACK AND DEFENSIVE COUNTERMEASURES." International Journal of Network Security & Its Applications 15, no. 03 (2023): 01–21. http://dx.doi.org/10.5121/ijnsa.2023.15301.
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The practical implications of issuing inaudible voice commands. The research mapped each attack vector to a tactic or technique from the MITRE ATT&CK matrix, covering enterprise, mobile, and Industrial Control System (ICS) frameworks. The experiment involved generating and surveying fifty near-ultrasonic audios to assess the attacks' effectiveness. Unprocessed commands achieved a 100% success rate, while processed commands achieved an 86% acknowledgment rate and a 58% overall executed (successful) rate. The research systematically stimulated previously unaddressed attack surfaces, aiming for comprehensive detection and attack design. Each ATT&CK identifier was paired with a tested defensive method, providing attack and defense tactics. The research findings revealed that the attack method employed Single Upper Sideband Amplitude Modulation (SUSBAM) to generate near-ultrasonic audio from audible sources. By eliminating the lower sideband, the design achieved a 6 kHz minimum from 16-22 kHz while remaining inaudible after transformation. The research also investigated the one-to-many attack surface, exploring scenarios where a single device triggers multiple actions or devices. Furthermore, the study demonstrated the reversibility or demodulation of the inaudible signal, suggesting potential alerting methods and the possibility of embedding secret messages like audio steganography. A critical methodological advance included tapping into the postprocessed audio signal when the server demodulates the signal for comparison to both the audible and inaudible input signals to improve the actionable success rates.
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Zhao, Yumin, Yunyue Elita Li, Enhedelihai Nilot, and Gang Fang. "Urban Running Activity Detected Using a Seismic Sensor during COVID-19 Pandemic." Seismological Research Letters 93, no. 1 (2021): 181–92. http://dx.doi.org/10.1785/0220210147.
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Abstract Human foot traffic in urban environments provides essential information for city planners to manage the urban resources and urban residents to plan their activities. Compared to camera or mobile-based solutions, seismic sensors detect human footstep signals with fewer privacy concerns. However, seismic sensors often record signals generated from multiple sources, particularly in an urban outdoor environment. In this article, we monitor people’s running activities during COVID-19 pandemic with a seismic sensor in a park in Singapore. We compare the spectra of natural and urban events in the recorded seismic data. For each 3 s seismic data, we define hierarchical screening criteria to identify footsteps based on the spectrum of the signal and its envelope. We derive the cadence of each runner by detecting the primary frequency of the footstep signals. The resulting algorithm achieves higher accuracy and higher temporal resolution for weak and overlapping signals compared to existing methods. Runner statistics based on four-month long seismic data show that urban running activities have clear daily and weekly cycles. Lockdown measures to mitigate COVID-19 pandemic promoted running activities, particularly over the weekends. Cadence statistics show that morning runners have higher cadence on average.
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Thorson, Jacob, Ashley Collier-Oxandale, and Michael Hannigan. "Using A Low-Cost Sensor Array and Machine Learning Techniques to Detect Complex Pollutant Mixtures and Identify Likely Sources." Sensors 19, no. 17 (2019): 3723. http://dx.doi.org/10.3390/s19173723.
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An array of low-cost sensors was assembled and tested in a chamber environment wherein several pollutant mixtures were generated. The four classes of sources that were simulated were mobile emissions, biomass burning, natural gas emissions, and gasoline vapors. A two-step regression and classification method was developed and applied to the sensor data from this array. We first applied regression models to estimate the concentrations of several compounds and then classification models trained to use those estimates to identify the presence of each of those sources. The regression models that were used included forms of multiple linear regression, random forests, Gaussian process regression, and neural networks. The regression models with human-interpretable outputs were investigated to understand the utility of each sensor signal. The classification models that were trained included logistic regression, random forests, support vector machines, and neural networks. The best combination of models was determined by maximizing the F1 score on ten-fold cross-validation data. The highest F1 score, as calculated on testing data, was 0.72 and was produced by the combination of a multiple linear regression model utilizing the full array of sensors and a random forest classification model.
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Iohov, O., V. Maliuk, and Ye Kaplun. "ALGORITHM FOR DETERMINING THE BOUNDARIES OF THE ZONE OF INTERFERENCE OPERATION OF THE RADIO CHANNEL OF THE UHF / VHF RANGE COMMUNICATION IN THE CONDITIONS OF OPERATION OF THE RADIOSHENOPRIAD SOURCE SYSTEM AT DIFFERENT HEIGHTS." Collection of scientific works of the National Academyof the National Guard of Ukraine 1, no. 37 (2021): 38–51. http://dx.doi.org/10.33405/2409-7470/2021/1/37/237826.
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A method for determining the limits of the maximum size of the stable radio reception area in the UHF / VHF range for mobile radio communication under the conditions of the radio interference system is proposed. The radio is intended to use a directional antenna or screen. Increasing the size of the stable radio reception area is provided by the optimal orientation at each point of the antenna device in azimuth and angle using the model of the radio channel, which allows to calculate the signal / interference ratio taking into account the spatial location of radio interference sources and digital 3D antenna pattern. receiver. The problem of determining the boundaries of the zone of stable radio exchange of mobile radio means using directional antennas in the conditions of real interference is formulated in the form of the problem of finding a single isoline in a scalar field. To determine the coordinates of the points of the map belonging to the isoline, a modification of the wave algorithm is proposed, which is low complexity and unambiguous results. Examples of practical use of the proposed numerical method allow us to conclude that the results are inconsistent with the data obtained in the known works by the analytical method for a particular case. At the same time, the numerical approach used significantly expands the possibilities of calculations by taking into account the location of multiple sources of radio interference at different altitudes, as well as the optimal orientation of the digital 3D - pattern of the antenna device of the signal receiver. The effectiveness of the proposed method is confirmed by increasing the area of the noise-tolerant radio exchange zone by 2.8 times in relation to the option of using a mobile radio with a dipole antenna. For the case of optimal orientation of the directional antenna of the receiver by the azimuth angle, additional optimization by the angle of the place gives a gain of 1.5 times.
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Iohov, O., V. Maliuk, and Ye Kaplun. "ALGORITHM FOR DETERMINING THE BOUNDARIES OF THE ZONE OF INTERFERENCE OPERATION OF THE RADIO CHANNEL OF THE UHF / VHF RANGE COMMUNICATION IN THE CONDITIONS OF OPERATION OF THE RADIOSHENOPRIAD SOURCE SYSTEM AT DIFFERENT HEIGHTS." Collection of scientific works of the National Academyof the National Guard of Ukraine 1, no. 37 (2021): 38–51. http://dx.doi.org/10.33405/2409-7470/2021/1/37/237826.
Full textAbstract:
A method for determining the limits of the maximum size of the stable radio reception area in the UHF / VHF range for mobile radio communication under the conditions of the radio interference system is proposed. The radio is intended to use a directional antenna or screen. Increasing the size of the stable radio reception area is provided by the optimal orientation at each point of the antenna device in azimuth and angle using the model of the radio channel, which allows to calculate the signal / interference ratio taking into account the spatial location of radio interference sources and digital 3D antenna pattern. receiver. The problem of determining the boundaries of the zone of stable radio exchange of mobile radio means using directional antennas in the conditions of real interference is formulated in the form of the problem of finding a single isoline in a scalar field. To determine the coordinates of the points of the map belonging to the isoline, a modification of the wave algorithm is proposed, which is low complexity and unambiguous results. Examples of practical use of the proposed numerical method allow us to conclude that the results are inconsistent with the data obtained in the known works by the analytical method for a particular case. At the same time, the numerical approach used significantly expands the possibilities of calculations by taking into account the location of multiple sources of radio interference at different altitudes, as well as the optimal orientation of the digital 3D - pattern of the antenna device of the signal receiver. The effectiveness of the proposed method is confirmed by increasing the area of the noise-tolerant radio exchange zone by 2.8 times in relation to the option of using a mobile radio with a dipole antenna. For the case of optimal orientation of the directional antenna of the receiver by the azimuth angle, additional optimization by the angle of the place gives a gain of 1.5 times.
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Shusterman, Alexis A., Jinsol Kim, Kaitlyn J. Lieschke, Catherine Newman, Paul J. Wooldridge, and Ronald C. Cohen. "Observing local CO<sub>2</sub> sources using low-cost, near-surface urban monitors." Atmospheric Chemistry and Physics 18, no. 18 (2018): 13773–85. http://dx.doi.org/10.5194/acp-18-13773-2018.
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Abstract. Urban carbon dioxide comprises the largest fraction of anthropogenic greenhouse gas emissions, but quantifying urban emissions at subnational scales is highly challenging, as numerous emission sources reside in close proximity within each topographically intricate urban dome. In attempting to better understand each individual source's contribution to the overall emission budget, there exists a large gap between activity-based emission inventories and observational constraints on integrated, regional emission estimates. Here we leverage urban CO2 observations from the BErkeley Atmospheric CO2 Observation Network (BEACO2N) to enhance, rather than average across or cancel out, our sensitivity to these hyperlocal emission sources. We utilize a method for isolating the local component of a CO2 signal that accentuates the observed intra-urban heterogeneity and thereby increases sensitivity to mobile emissions from specific highway segments. We demonstrate a multiple-linear-regression analysis technique that accounts for boundary layer and wind effects and allows for the detection of changes in traffic emissions on scale with anticipated changes in vehicle fuel economy – an unprecedented level of sensitivity for low-cost sensor technologies. The ability to represent trends of policy-relevant magnitudes with a low-cost sensor network has important implications for future applications of this approach, whether as a supplement to existing, sparse reference networks or as a substitute in areas where fewer resources are available.
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Proctor, Philippe, Christof Teuscher, Adam Hecht, and Marek Osiński. "Proximal Policy Optimization for Radiation Source Search." Journal of Nuclear Engineering 2, no. 4 (2021): 368–97. http://dx.doi.org/10.3390/jne2040029.
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Rapid search and localization for nuclear sources can be an important aspect in preventing human harm from illicit material in dirty bombs or from contamination. In the case of a single mobile radiation detector, there are numerous challenges to overcome such as weak source intensity, multiple sources, background radiation, and the presence of obstructions, i.e., a non-convex environment. In this work, we investigate the sequential decision making capability of deep reinforcement learning in the nuclear source search context. A novel neural network architecture (RAD-A2C) based on the advantage actor critic (A2C) framework and a particle filter gated recurrent unit for localization is proposed. Performance is studied in a randomized 20×20 m convex and non-convex simulation environment across a range of signal-to-noise ratio (SNR)s for a single detector and single source. RAD-A2C performance is compared to both an information-driven controller that uses a bootstrap particle filter and to a gradient search (GS) algorithm. We find that the RAD-A2C has comparable performance to the information-driven controller across SNR in a convex environment. The RAD-A2C far outperforms the GS algorithm in the non-convex environment with greater than 95% median completion rate for up to seven obstructions.
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Yi, Difei, Jun Li, Chengpei Tang, Ziqi Lin, Yu Han, and Rui Qiu. "Task Offloading in Wireless Powered Mobile Crowd Sensing: A Matching-Based Approach." Electronics 11, no. 15 (2022): 2377. http://dx.doi.org/10.3390/electronics11152377.
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Mobile crowd sensing (MCS) is a new sensing paradigm that leverages participatory sensing data from mobile devices for accomplishing large-scale sensing tasks. Incentivizing device owners to contribute high-quality sensing data is a prerequisite for the success of MCS services. In this paper, we first propose a pre-contracting incentive mechanism that involves the participation of not only the device owners located in close proximity to Point of Interests (PoIs) but also the device owners that are going to pass through those locations. Furthermore, the quality of sensing data is guaranteed through the use of redundancy. In particular, sensing data from multiple device owners is processed and compared at an edge side (i.e., base station) so as to detect the measurement error at the proximity of data sources. Simulation results confirm that the proposed incentive mechanism is efficient in terms of improving the total utility.
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Signorini, Gianni, Claudio Siviero, Igor Simone Stievano, and Stefano Grivet-Talocia. "Enhanced Mpilog macromodels for Signal and Power Integrity Simulations." International Symposium on Microelectronics 2015, no. 1 (2015): 000306–11. http://dx.doi.org/10.4071/isom-2015-wa61.
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Due to increasingly stringent low-cost and small form-factor design constraints, Signal and Power Integrity analyses (SI&PI) have gained a paramount importance in the definition and optimization of mobile platforms. Operating margins are dramatically reduced in order to meet all the required design targets and constraints (extensive re-use, time-to-market, etc.). In this scenario, transistor-level simulations for platform-level analyses are inefficient and often, impractical. I/O-buffer models become essential and their accuracy is crucial for the reliability of SI&PI studies. As data-rates increase, signaling swing reduces and power-supply voltage noise becomes inevitable, state-of-the-art legacy models are limited for SI&PI co-simulations. This work summarizes the recent enhancements of “Mpilog”-class macromodels for high-speed I/O-buffers. Mpilog macromodels reproduce voltage and currents at I/O and (multiple) supply ports as weighted combinations of pull-up/pull-down static and dynamic components. The static parts are extracted via nested DC sweeps simulations and reproduced by tensor representations obtained via high-order singular value decomposition (SVD) processes. The dynamic components are described by linear state-space models identified from device's transient responses to suitable stimuli. For transmitters, the weighting functions match the output-port transitions and the dynamic supply-current profiles, capturing also the dependency of switching delays upon supply-voltage fluctuations; this is a key feature that enables Mpilog macromodels to precisely reproduce simultaneous-switching-noise (SSN) effects in complex system-level SI&PI simulations. The macromodels can be readily synthesized as SPICE netlists (including resistors, capacitors and controlled-sources) or Verilog-A codes; this allows their use in any SPICE-type electrical solver. Several examples of realistic SI&PI simulations for single-ended and differential interfaces are presented. Transistor-level simulations are compared with the corresponding ones based on Mpilog-macromodels: the resulting accuracy and the speed-up factors are extensively discussed. Comparisons with state-of-the-art legacy models (IBIS) are also discussed.
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Cobos, Maximo, Fabio Antonacci, Anastasios Alexandridis, Athanasios Mouchtaris, and Bowon Lee. "A Survey of Sound Source Localization Methods in Wireless Acoustic Sensor Networks." Wireless Communications and Mobile Computing 2017 (2017): 1–24. http://dx.doi.org/10.1155/2017/3956282.
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Wireless acoustic sensor networks (WASNs) are formed by a distributed group of acoustic-sensing devices featuring audio playing and recording capabilities. Current mobile computing platforms offer great possibilities for the design of audio-related applications involving acoustic-sensing nodes. In this context, acoustic source localization is one of the application domains that have attracted the most attention of the research community along the last decades. In general terms, the localization of acoustic sources can be achieved by studying energy and temporal and/or directional features from the incoming sound at different microphones and using a suitable model that relates those features with the spatial location of the source (or sources) of interest. This paper reviews common approaches for source localization in WASNs that are focused on different types of acoustic features, namely, the energy of the incoming signals, their time of arrival (TOA) or time difference of arrival (TDOA), the direction of arrival (DOA), and the steered response power (SRP) resulting from combining multiple microphone signals. Additionally, we discuss methods not only aimed at localizing acoustic sources but also designed to locate the nodes themselves in the network. Finally, we discuss current challenges and frontiers in this field.
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Agrawal, Pranav, Stan Fong, Dirk Friesen, and Sriram Narasimhan. "Maximum likelihood estimation for leak localization in water distribution networks using in-pipe acoustic sensing." Journal of the Acoustical Society of America 153, no. 3_supplement (2023): A300. http://dx.doi.org/10.1121/10.0018930.
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With drinking water resources rapidly depleting with time, water conservation efforts have received special emphasis, especially in arid regions like California. One of the major sources of unused water expenditure is inconspicuous leaks in underground water distribution networks (WDN), making it highly essential to quickly detect and localize them. The leak detection and localization problem has been widely studied for a straight pipeline system, however, estimating the leak location in a pipe network remains largely unexplored. In this study, we measure the acoustic pressure signals inside a pipe network at multiple locations using state-of-the-art hydrophone-enabled devices. To localize the leaks in pipe networks, we propose maximum likelihood estimation, which has previously shown high efficacy in localizing mobile devices in a cellular network. In this approach, the cross-correlation of the filtered signals from different sensor pairs yields multiple time delays corresponding to multiple acoustic paths traversed by the leak noise in the pipe network, which is more difficult to solve compared to a straight pipe system. The leak location is then identified by maximizing a conditional probability distribution function of the distance between the sensor and the leak location.
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Brunello, Andrea, Andrea Dalla Torre, Paolo Gallo, Donatella Gubiani, Angelo Montanari, and Nicola Saccomanno. "Crowdsourced Reconstruction of Cellular Networks to Serve Outdoor Positioning: Modeling, Validation and Analysis." Sensors 23, no. 1 (2022): 352. http://dx.doi.org/10.3390/s23010352.
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Positioning via outdoor fingerprinting, which exploits the radio signals emitted by cellular towers, is fundamental in many applications. In most cases, the localization performance is affected by the availability of information about the emitters, such as their coverage. While several projects aim at collecting cellular network data via crowdsourcing observations, none focuses on information about the structure of the networks, which is paramount to correctly model their topology. The difficulty of such a modeling is exacerbated by the inherent differences among cellular technologies, the strong spatio-temporal nature of positioning, and the continuously evolving configuration of the networks. In this paper, we first show how to synthesize a detailed conceptual schema of cellular networks on the basis of the signal fingerprints collected by devices. We turned it into a logical one, and we exploited that to build a relational spatio-temporal database capable of supporting a crowdsourced collection of data. Next, we populated the database with heterogeneous cellular observations originating from multiple sources. In addition, we illustrate how the developed system allows us to properly deal with the evolution of the network configuration, e.g., by detecting cell renaming phenomena and by making it possible to correct inconsistent measurements coming from mobile devices, fostering positioning tasks. Finally, we provide a wide range of basic, spatial, and temporal analyses about the arrangement of the cellular network and its evolution over time, demonstrating how the developed system can be used to reconstruct and maintain a deep knowledge of the cellular network, possibly starting from crowdsourced information only.
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Ivakin, Anatoliy N., John E. Joseph, and D. Benjamin Reeder. "Midfrequency sound transmission from mobile sources in a deep Arctic ocean at short and medium ranges: Time-domain modeling and data analysis." Journal of the Acoustical Society of America 151, no. 4 (2022): A190. http://dx.doi.org/10.1121/10.0011061.
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Midfrequency (2300–3000 Hz) LFM sweeps (3 s-long, one per minute) and CW 57 s-long signals at multiple frequencies (950, 1050, 1150, 2800, 2900, and 3000 Hz) were transmitted by two mobile sources EMATTs moving at three knots in circular patterns under ice in the Beaufort Sea on March 12, 2016. Acoustic pressure time series were recorded on five vertically and horizontally separated receivers Acousonde, which provided different combinations of source-receiver ranges (0.3–10 km) and depths (45–183 m). A time-domain model of propagation and reverberation is suggested that accounts for refraction in water column and scattering from ocean boundaries (bottom and ice). Effects of spatial variations of the environment, particularly the two shallow ducts, at 0–75 m and 75–250 m water depths, as well as bottom and ice roughness, are demonstrated. Preliminary results of the model-data comparisons are presented. Possibilities for remote sensing of the arctic environment are discussed. [Work supported by ONR.]
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McKee, Forrest, and David Noever. "Nuance: Near Ultrasound Attack on Networked Communication Environments." International Journal on Cybernetics & Informatics 12, no. 3 (2023): 89–107. http://dx.doi.org/10.5121/ijci.2023.120307.
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This study investigates a primary inaudible attack vector on Amazon Alexa voice services using near ultrasound trojans and focuses on characterizing the attack surface and examining the practical implications of issuing inaudible voice commands. The research maps each attack vector to a tactic or technique from the MITRE ATT&CK matrix, covering enterprise, mobile, and Industrial Control System (ICS) frameworks. The experiment involved generating and surveying fifty near-ultrasonic audios to assess the attacks' effectiveness, with unprocessed commands having a 100% success rate and processed ones achieving a 58% overall success rate. This systematic approach stimulates previously unaddressed attack surfaces, ensuring comprehensive detection and attack design while pairing each ATT&CK Identifier with a tested defensive method, providing attack and defense tactics for prompt-response options. The main findings reveal that the attack method employs Single Upper Sideband Amplitude Modulation (SUSBAM) to generate near-ultrasonic audio from audible sources, transforming spoken commands into a frequency range beyond human-adult hearing. By eliminating the lower sideband, the design achieves a 6 kHz minimum from 16-22 kHz while remaining inaudible after transformation. The research investigates the one-to-many attack surface where a single device simultaneously triggers multiple actions or devices. Additionally, the study demonstrates the reversibility or demodulation of the inaudible signal, suggesting potential alerting methods and the possibility of embedding secret messages like audio steganography.
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Jung, Soyi, Won Joon Yun, Joongheon Kim, and Jae-Hyun Kim. "Coordinated Multi-Agent Deep Reinforcement Learning for Energy-Aware UAV-Based Big-Data Platforms." Electronics 10, no. 5 (2021): 543. http://dx.doi.org/10.3390/electronics10050543.
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This paper proposes a novel coordinated multi-agent deep reinforcement learning (MADRL) algorithm for energy sharing among multiple unmanned aerial vehicles (UAVs) in order to conduct big-data processing in a distributed manner. For realizing UAV-assisted aerial surveillance or flexible mobile cellular services, robust wireless charging mechanisms are essential for delivering energy sources from charging towers (i.e., charging infrastructure) to their associated UAVs for seamless operations of autonomous UAVs in the sky. In order to actively and intelligently manage the energy resources in charging towers, a MADRL-based coordinated energy management system is desired and proposed for energy resource sharing among charging towers. When the required energy for charging UAVs is not enough in charging towers, the energy purchase from utility company (i.e., energy source provider in local energy market) is desired, which takes high costs. Therefore, the main objective of our proposed coordinated MADRL-based energy sharing learning algorithm is minimizing energy purchase from external utility companies to minimize system-operational costs. Finally, our performance evaluation results verify that the proposed coordinated MADRL-based algorithm achieves desired performance improvements.
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Seng, Jasmine Kah Phooi, Kenneth Li-minn Ang, Eno Peter, and Anthony Mmonyi. "Artificial Intelligence (AI) and Machine Learning for Multimedia and Edge Information Processing." Electronics 11, no. 14 (2022): 2239. http://dx.doi.org/10.3390/electronics11142239.
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The advancements and progress in artificial intelligence (AI) and machine learning, and the numerous availabilities of mobile devices and Internet technologies together with the growing focus on multimedia data sources and information processing have led to the emergence of new paradigms for multimedia and edge AI information processing, particularly for urban and smart city environments. Compared to cloud information processing approaches where the data are collected and sent to a centralized server for information processing, the edge information processing paradigm distributes the tasks to multiple devices which are close to the data source. Edge information processing techniques and approaches are well suited to match current technologies for Internet of Things (IoT) and autonomous systems, although there are many challenges which remain to be addressed. The motivation of this paper was to survey these new paradigms for multimedia and edge information processing from several technological perspectives including: (1) multimedia analytics on the edge empowered by AI; (2) multimedia streaming on the intelligent edge; (3) multimedia edge caching and AI; (4) multimedia services for edge AI; and (5) hardware and devices for multimedia on edge intelligence. The review covers a wide spectrum of enabling technologies for AI and machine learning for multimedia and edge information processing.
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Didion, Elise M., Megan Doyle, and Joshua B. Benoit. "Bacterial Communities of Lab and Field Northern House Mosquitoes (Diptera: Culicidae) Throughout Diapause." Journal of Medical Entomology 59, no. 2 (2021): 648–58. http://dx.doi.org/10.1093/jme/tjab184.
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Abstract Diapause is a hormonally driven response which is triggered by environmental cues that signal impending adverse conditions and prompts metabolic, developmental, and behavioral changes to allow survival until the return of favorable conditions. Microbial symbionts have been shown to influence the metabolism, development, and behavior of their host organisms, all of which are common diapause-associated characteristics. Surveys of bacterial components in relation to diapause have been examined in few systems, of which the species are usually inactive during dormancy, such as eggs or pupae. This is specifically intriguing as adult female diapause in Culex pipiens (Diptera: Culicidae) can last between 4 and 7 mo and females remain mobile within their hibernacula. Furthermore, it is unknown how microbiota changes associated with prolonged dormancy are different between the lab and field for insect systems. This study aims to characterize how the microbiota of C. pipiens changes throughout diapause under both field and lab settings when provided identical food and water resources. Based on these studies, C. pipiens microbiota shifts as diapause progresses and there are considerable differences between field and lab individuals even when provided the same carbohydrate and water sources. Specific bacterial communities have more association with different periods of diapause, field and lab rearing conditions, and nutritional reserve levels. These studies highlight that diapausing mosquito microbiota studies ideally should occur in field mesocosms and at multiple locations, to increase applicability to wild C. pipiens as prolonged exposure to artificial rearing conditions could impact metrics related to diapause-microbiome interactions. Additionally, these findings suggest that it would be worthwhile to establish if the microbiota shift during diapause impacts host physiology and whether this shift is critical to diapause success.
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Lim, Say Ying, David Taniar, and Bala Srinivasan. "Mobile Information Processing Involving Multiple Non-collaborative Sources." International Journal of Business Data Communications and Networking 3, no. 2 (2007): 72–93. http://dx.doi.org/10.4018/jbdcn.2007040105.
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Ross, Montgomery F. "Automatic level control of multiple audio signal sources." Journal of the Acoustical Society of America 96, no. 5 (1994): 3207. http://dx.doi.org/10.1121/1.411209.
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Luaces, Miguel R., Jesús A. Fisteus, Luis Sánchez-Fernández, et al. "Accessible Routes Integrating Data from Multiple Sources." ISPRS International Journal of Geo-Information 10, no. 1 (2020): 7. http://dx.doi.org/10.3390/ijgi10010007.
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Providing citizens with the ability to move around in an accessible way is a requirement for all cities today. However, modeling city infrastructures so that accessible routes can be computed is a challenge because it involves collecting information from multiple, large-scale and heterogeneous data sources. In this paper, we propose and validate the architecture of an information system that creates an accessibility data model for cities by ingesting data from different types of sources and provides an application that can be used by people with different abilities to compute accessible routes. The article describes the processes that allow building a network of pedestrian infrastructures from the OpenStreetMap information (i.e., sidewalks and pedestrian crossings), improving the network with information extracted obtained from mobile-sensed LiDAR data (i.e., ramps, steps, and pedestrian crossings), detecting obstacles using volunteered information collected from the hardware sensors of the mobile devices of the citizens (i.e., ramps and steps), and detecting accessibility problems with software sensors in social networks (i.e., Twitter). The information system is validated through its application in a case study in the city of Vigo (Spain).
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Zhao, Zanshan, Weiguang Xing, and Weiming Gan. "Multiple ultra-wideband signal sources exploiting XPM in SFRL." Optoelectronics Letters 18, no. 2 (2022): 77–84. http://dx.doi.org/10.1007/s11801-022-1098-6.
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Fabrikov, A. V. "Array signal processing for localization of multiple radiation sources." Measurement Techniques 40, no. 5 (1997): 405–12. http://dx.doi.org/10.1007/bf02504209.
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Kim, Chang-Young, Dezhen Song, Yiliang Xu, Jingang Yi, and Xinyu Wu. "Cooperative Search of Multiple Unknown Transient Radio Sources Using Multiple Paired Mobile Robots." IEEE Transactions on Robotics 30, no. 5 (2014): 1161–73. http://dx.doi.org/10.1109/tro.2014.2333097.
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Chang, Chung-Liang, and Bo-Han Wu. "A Dynamic Cooperative Scheme with Multiple Antennas for Indoor Mobile Robot Localization." Abstract and Applied Analysis 2013 (2013): 1–14. http://dx.doi.org/10.1155/2013/972371.
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This paper proposes a spatial cooperative diversity and decision-making technique to enhance signal detection and indoor mobile robot positioning performance of a global positioning satellite system (GNSS) receiver. Though the adaptive antenna array technique in early research could effectively promote antijamming freedom, overcome time-varying system, and mitigate narrowband and wideband interferences, factors such as the decrease of signal magnitude caused by obstacles (especially in the indoor environment), multipath, and blanking effect caused by the change in antenna direction with the motion of mobile robot can degrade the detection and interference mitigation performance of GNSS receivers. This paper aims to develop a dynamic cooperative scheme to proceed with the switch, selection, combination, and optimization among antennas. In addition, a signal processing experimental platform is also established to receive actually indoor GNSS signals for verification. The proposed scheme is capable of effectively promoting the postcorrelation signal-to-noise ratio (SNR) capability of a GNSS receiver under the indoor environment.
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Bashar, Dr Abul. "Artificial Intelligence Based LTE MIMO Antenna for 5th Generation Mobile Networks." September 2020 2, no. 3 (2020): 155–62. http://dx.doi.org/10.36548/jaicn.2020.3.002.
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Artificial intelligence based long term evolution multi in multi output antenna supporting the fifth generation mobile networks is put forth in the paper. The mechanism laid out in paper is devised using the monopole-antenna integrated with the switchable pattern. The long term evolution based multiple input and multiple output antenna is equipped with four antennas and capable of providing a four concurrent data streams quadrupling the theoretical maximum speed of data transfer allowing the base station to convey four diverse signals through four diverse transmit antennas for a single user equipment. The utilization of the long term evolution multiple input multiple output is capable of utilizing the multi-trial broadcasting to offer betterments in the signal performance as well as throughput and spectral efficiency when used along the fifth generation mobile networks. So the paper proposes the artificial intelligence based long term evolution multiple input multiple output four transmit antenna with four diverse signal transmission capacity that is operating in the frequency of 3.501 Gigahertz frequency. The laid out design is evaluated using the Multi-input Multi output signal analyzer to acquire the capacity of the passive conveyance of the various antennas with the diverse combination of patterns. The outcomes observed enables the artificial intelligence antenna to identify the choicest antenna to be integrated in the diverse environments for improving the throughput, signal performance and the data conveyance speed.
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Zhang, Ao, Fang Liu, and Fan Rang Kong. "Doppler Distortion Removal Method for Multiple Acoustic Sources." Applied Mechanics and Materials 373-375 (August 2013): 874–79. http://dx.doi.org/10.4028/www.scientific.net/amm.373-375.874.
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In wayside fault diagnosis of train bearings, the phenomenon of Doppler distortion in the acoustic signal of moving acoustic source acquired with a microphone leads to the difficulty for signal analysis. In this paper, a new method based on Dopplerlet transform and re-sampling is proposed to eliminate the Doppler distortion of multiple acoustic sources which provide a reference for wayside fault diagnosis of train bearings. Firstly, search the parameters space to find the primary functionsDopplerlet atoms. According to the Morse acoustic theory, the instantaneous frequency of the Dopplerlet atom which we choose to remove Doppler distortion of the corresponding acoustic source can be acquired. Then, the re-sampling sequence can be established in time domain. Through the resample, the Doppler distortion can be removed. In the end of this paper, an experiment with practical acoustic signals is carried out, and the results verified the effectiveness of this method.
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Prijono, Wahyu Adi. "PERFORMANSI JARINGAN CODE DIVISION MULTIPLE ACCESS (CDMA) MENGGUNAKAN MOBILE PHONE JAMMER." SISTEM Jurnal Ilmu Ilmu Teknik 16, no. 1 (2020): 42–51. http://dx.doi.org/10.37303/sistem.v16i1.191.
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The use of communication tools in some places can be disturb to many people, for example in place of worship and a meeting room. It can be prevented by using a device called a mobile phone jammer. Use of Mobile Phone Jammer can jamming the mobile station signals (CDMA and GSM) both uplink and downlink with the workings of the mobile phone jammer issuing signal with a frequency that is similar to the mobile station, however the power emitted is greater. The research will be discussed on the placement of the mobile phone jammer in the room. With two is the parameter is repeater and without repeater. In primary data capture method does is method of spectrum analyzer and method of walktest. On walktest software used is tems investigation 8.0.3 for retrieval of data with the parameter of quality a signal ( Ec / Io , FFER , RSSI , TxPo , and TxGa ) and MapInfo as logfile processing results of TEMS Investigation which can show the maximum range where the mobile station can be jamming. Based on measurements with the method of spectrum analyzer, power mobile phone jammer has power – 74,6 dB and by using mathematical calculations obtained range 43 m. On measurement method using walktest, the first parameter is the chosen location without repeaters the maximum range the jammer by 17 metres and with power jammer effective registration -62.9 dB. Whereas, in the location parameter contained repeater the maximum range jammer obtained is 10 meters and power jammer effective 60,2 dB.
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Yang, Tao, and Leon O. Chua. "Chaotic Digital Code-Division Multiple Access (CDMA) Communication Systems." International Journal of Bifurcation and Chaos 07, no. 12 (1997): 2789–805. http://dx.doi.org/10.1142/s0218127497001886.
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In this paper, the structure, principle and framework of chaotic digital code-division multiple access ((CD)2 MA) communication systems are presented. Unlike the existing CDMA systems, (CD)2MA systems use continuous pseudo-random time series to spread the spectrum of message signal and the spread signal is then directly sent through a channel to the receiver. In this sense, the carrier used in (CD)2MA is a continuous pseudo-random signal instead of a single tone as used in CDMA. We give the statistical properties of the noise-like carriers. In a (CD)2MA system, every mobile station has the same structure and parameters, only different initial conditions are assigned to different mobile stations. Instead of synchronizing two binary pseudo-random sequences as in CDMA systems, we use an impulsive control scheme to synchronize two chaotic systems in (CD)2MA. The simulation results show that the channel capacity of (CD)2MA is twice as large than that of CDMA.
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Zeng, Riya, Biqing Zhong, Weihang Liu, Sihui Liu, Qiang Guo, and Yiting Kang. "A Heterogeneous Ensemble Approach for Terrain Classification with Tracked Mobile Robots." Journal of Physics: Conference Series 2478, no. 10 (2023): 102001. http://dx.doi.org/10.1088/1742-6596/2478/10/102001.
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Abstract Terrain classification plays a vital role in the autonomous driving of tracked mobile robots. This article proposes a heterogeneous ensemble method to enhance the classification performance with weak classifiers. Combined with principal component analysis (PCA) and ReiefF, a feature selection approach aims to find an effective feature set. Based on the proposed method, the framework has been developed to simplify the signal process in feature extraction. Extreme Learning Machine (ELM) is utilized as the individual classifier for three kinds of signal sources. With the learning process experience, ensemble weights have been generated to support the whole ensemble flow, which is closely correlated with terrain categories, classifiers and signal sources. Due to the structure of tracked mobile robots, the application maneuvers are extended to the front and rear drive modes, while the steady-state turning and straight-line maneuvers. The results demonstrate that the proposed method can significantly enhance the performance of terrain classification.
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Wilson, N. D., and S. S. Rappaport. "Cellular mobile packet radio using multiple-channel CSMA." IEE Proceedings F Communications, Radar and Signal Processing 132, no. 6 (1985): 517. http://dx.doi.org/10.1049/ip-f-1.1985.0098.
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Loutfi, Amy, Silvia Coradeschi, Achim J. Lilienthal, and Javier Gonzalez. "Gas distribution mapping of multiple odour sources using a mobile robot." Robotica 27, no. 2 (2009): 311–19. http://dx.doi.org/10.1017/s0263574708004694.
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SUMMARYMobile olfactory robots can be used in a number of relevant application areas where a better understanding of a gas distribution is needed, such as environmental monitoring and safety and security related fields. In this paper, we present a method to integrate the classification of odours together with gas distribution mapping. The resulting odour map is then correlated with the spatial information collected from a laser range scanner to form a combined map. Experiments are performed using a mobile robot in large and unmodified indoor and outdoor environments. Multiple odour sources are used and are identified using only transient information from the gas sensor response. The resulting multi-level map can be used as a representation of the collected odour data.
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Xue, Yu, and Zhiqiang John Zhai. "Inverse identification of multiple outdoor pollutant sources with a mobile sensor." Building Simulation 10, no. 2 (2016): 255–63. http://dx.doi.org/10.1007/s12273-016-0322-3.
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Schwarz, Stefan, and Stefan Pratschner. "Multiple Antenna Systems in Mobile 6G: Directional Channels and Robust Signal Processing." IEEE Communications Magazine 61, no. 4 (2023): 64–70. http://dx.doi.org/10.1109/mcom.001.2200258.
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Ko, B., and S. Lee. "Noise source localization by applying multiple signal classification with wavelet transformation." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 221, no. 1 (2007): 11–21. http://dx.doi.org/10.1243/0954406jmes311.
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In an inverse acoustic problem with nearfield sources, it is important to separate multiple acoustic sources and to measure the position of each target. This paper proposes a new algorithm by applying multiple signal classification (MUSIC) to the outputs of discrete wavelet transformation with subband selection based on the entropy threshold. Some numerical experiments show that the proposed method can estimate the more precise positions than a conventional MUSIC algorithm under moderately correlated signal and relatively low signal-to-noise ratio case.
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Salvati, Daniele, and Sergio Canazza. "Incident Signal Power Comparison for Localization of Concurrent Multiple Acoustic Sources." Scientific World Journal 2014 (2014): 1–13. http://dx.doi.org/10.1155/2014/582397.
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In this paper, a method to solve the localization of concurrent multiple acoustic sources in large open spaces is presented. The problem of the multisource localization in far-field conditions is to correctly associate the direction of arrival (DOA) estimated by a network array system to the same source. The use of systems implementing a Bayesian filter is a traditional approach to address the problem of localization in multisource acoustic scenario. However, in a real noisy open space the acoustic sources are often discontinuous with numerous short-duration events and thus the filtering methods may have difficulty to track the multiple sources. Incident signal power comparison (ISPC) is proposed to compute DOAs association. ISPC is based on identifying the incident signal power (ISP) of the sources on a microphone array using beamforming methods and comparing the ISP between different arrays using spectral distance (SD) measurement techniques. This method solves the ambiguities, due to the presence of simultaneous sources, by identifying sounds through a minimization of an error criterion on SD measures of DOA combinations. The experimental results were conducted in an outdoor real noisy environment and the ISPC performance is reported using different beamforming techniques and SD functions.
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GORGADZE, SVETLANA F., and ANASTASIA V. ERMAKOVA. "EFFICIENCY OF MULTIPLE ACCESS OPTIONS FOR 5G AND 6G CELLULAR NETWORKS." H&ES Research 14, no. 2 (2022): 19–26. http://dx.doi.org/10.36724/2409-5419-2022-14-2-19-26.
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Introduction: IMT2020 (5G) networks can significantly improve the performance of previous generation mobile communication systems in terms of improving broadband multiple access (eMBB – enhanced Mobile Broadband) and providing ultra-reliable low-latency communication (ULLRC – Ultra Low Latency Rellable Communication). The purpose of the work is to review and comparative analysis of multiple access technologies for promising mobile communication networks, which are based on OFDM. Result: The general principles of signal generation and processing when using variants of signals with OFDM using various methods of digital filtering of subcarrier frequencies are considered. For those OFDM options where a cyclic prefix may not be used (FBMC, UFMC), the possibility of increasing the information transfer rate is controversial, since the impulse responses of filters, for example, with FBMC, significantly exceed the duration of information signals, which increases intersymbol interference. Practical significance: The analysis of the general principles for constructing devices for generating and processing physical layer signals for OFDM variants with various methods of additional digital filtering of subcarrier frequencies shows that in all cases there is a significant complication of digital algorithms for generating and processing signals with a practical absence or in some cases a small gain (not more than (0.5&0.8) dB in relation to signal/noise) by the magnitude of the error per information bit. Based on the results of computer simulation, it is shown that OFDM technology and its variants do not allow obtaining breakthrough solutions in the field of physical layer signal characteristics for 5G and 6G networks, and alternative options for building group signal structures should be considered.
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Karis, Demetrios, and Bonnie L. Zeigler. "Evaluation of Mobile Telecommunication Systems." Proceedings of the Human Factors Society Annual Meeting 33, no. 4 (1989): 205–9. http://dx.doi.org/10.1177/154193128903300401.
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Mobile telephony exhibits transmission characteristics and user-interface features distinct from traditional telephony. To study these differences in systems designed for use in commercial airplanes, trains, and automobiles, we used a variety of techniques, including both laboratory and field observations. We found that mobile telephony, viewed from the user's perspective, is quite different from traditional telephone service. In the present paper, we review the assessment techniques that we employed, and consider their strengths and weaknesses for characterizing the performance of mobile telecommunication systems. Our results indicate that there are five major sources of potential user-interface problems in mobile telephony: (1) use of credit cards; (2) system delays; (3) lack of coordination among multiple sources of feedback; (4) the mechanism for completing multiple calls without credit-card reentry; (5) voice dialing. Because solving the problems we have identified does not require new or overly expensive technology, solutions are fairly straightforward to implement during the early design period. However, once units have been manufactured and installed, it can be both very difficult and very expensive to recover from the problems we have identified.
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Muñoz-Rodríguez, D., and K. W. Cattermole. "Multiple criteria for hand-off in cellular mobile radio." IEE Proceedings F Communications, Radar and Signal Processing 134, no. 1 (1987): 85. http://dx.doi.org/10.1049/ip-f-1.1987.0015.
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