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1.
Sensors (Basel) ; 23(8)2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37112445

RESUMO

Wireless communication has become an integral part of modern vehicles. However, securing the information exchanged between interconnected terminals poses a significant challenge. Effective security solutions should be computationally inexpensive, ultra-reliable, and capable of operating in any wireless propagation environment. Physical layer secret key generation has emerged as a promising technique, which leverages the inherent randomness of wireless-channel responses in amplitude and phase to generate high-entropy symmetric shared keys. The sensitivity of the channel-phase responses to the distance between network terminals makes this technique a viable solution for secure vehicular communication, given the dynamic behavior of these terminals. However, the practical implementation of this technique in vehicular communication is hindered by fluctuations in the communication link between line-of-sight (LoS) and non-line-of-sight (NLoS) conditions. This study introduces a key-generation approach that uses a reconfigurable intelligent surface (RIS) to secure message exchange in vehicular communication. The RIS improves the performance of key extraction in scenarios with low signal-to-noise ratios (SNRs) and NLoS conditions. Additionally, it enhances the network's security against denial-of-service (DoS) attacks. In this context, we propose an efficient RIS configuration optimization technique that reinforces the signals received from legitimate users and weakens the signals from potential adversaries. The effectiveness of the proposed scheme is evaluated through practical implementation using a 1-bit RIS with 64×64 elements and software-defined radios operating within the 5G frequency band. The results demonstrate improved key-extraction performance and increased resistance to DoS attacks. The hardware implementation of the proposed approach further validated its effectiveness in enhancing key-extraction performance in terms of the key generation and mismatch rates, while reducing the effect of the DoS attacks on the network.

2.
Sensors (Basel) ; 22(23)2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36501741

RESUMO

A study of the behavior of NB-IoT wireless communication in an industrial indoor environment was conducted in this paper. With Wireless Insite software, a scenario in the industrial sector was simulated and modeled. Our research examined how this scenario or environment affected the communication parameters of NB-IoT's physical layer. In this context, throughput levels among terminals as well as between terminals and transceiver towers, the power received at signal destination points, signal-to-noise ratios (SNRs) in the environment, and distances between terminals and transceivers are considered. These simulated results are also compared with the calculated or theoretical values of these parameters. The results show the effect of the industrial setting on wireless communication. The differences between the theoretical and simulated values are also established.

3.
Sensors (Basel) ; 21(16)2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34450725

RESUMO

The Internet of Things (IoT) and its applications in industrial settings are set to bring in the fourth industrial revolution. The industrial environment consisting of high profile manufacturing plants and a variety of equipment is inherently characterized by high reflectiveness, causing significant multi-path components that affect the propagation of wireless communications-a challenge among others that needs to be resolved. This paper provides a detailed insight into Narrow-Band IoT (NB-IoT), Industrial IoT (IIoT), and Wireless Sensor Networks (WSN) within the context of indoor industrial environments. It presents the applications of NB-IoT for industrial settings, such as the challenges associated with these applications. Furthermore, future research directions were put forth in the areas of NB-IoT network management using self-organizing network (SON) technology, edge computing for scalability enhancement, security in NB-IoT generated data, and proposing a suitable propagation model for reliable wireless communications.


Assuntos
Internet das Coisas , Redes de Comunicação de Computadores , Indústrias , Tecnologia , Tecnologia sem Fio
4.
Front Big Data ; 4: 640868, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34240048

RESUMO

With the advancement of social media networks, there are lots of unlabeled reviews available online, therefore it is necessarily to develop automatic tools to classify these types of reviews. To utilize these reviews for user perception, there is a need for automated tools that can process online user data. In this paper, a sentiment analysis framework has been proposed to identify people's perception towards mobile networks. The proposed framework consists of three basic steps: preprocessing, feature selection, and applying different machine learning algorithms. The performance of the framework has taken into account different feature combinations. The simulation results show that the best performance is by integrating unigram, bigram, and trigram features.

5.
Sensors (Basel) ; 20(24)2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33348587

RESUMO

With the popularity of smart wearable systems, sensor signal processing poses more challenges to machine learning in embedded scenarios. For example, traditional machine-learning methods for data classification, especially in real time, are computationally intensive. The deployment of Artificial Intelligence algorithms on embedded hardware for fast data classification and accurate fall detection poses a huge challenge in achieving power-efficient embedded systems. Therefore, by exploiting the associative memory feature of Hopfield Neural Network, a hardware module has been designed to simulate the Neural Network algorithm which uses sensor data integration and data classification for recognizing the fall. By adopting the Hebbian learning method for training neural networks, weights of human activity features are obtained and implemented/embedded into the hardware design. Here, the neural network weight of fall activity is achieved through data preprocessing, and then the weight is mapped to the amplification factor setting in the hardware. The designs are checked with validation scenarios, and the experiment is completed with a Hopfield neural network in the analog module. Through simulations, the classification accuracy of the fall data reached 88.9% which compares well with some other results achieved by the software-based machine-learning algorithms, which verify the feasibility of our hardware design. The designed system performs the complex signal calculations of the hardware's feedback signal, replacing the software-based method. A straightforward circuit design is used to meet the weight setting from the Hopfield neural network, which is maximizing the reusability and flexibility of the circuit design.


Assuntos
Acidentes por Quedas , Inteligência Artificial , Redes Neurais de Computação , Algoritmos , Computadores , Humanos
6.
Sensors (Basel) ; 20(19)2020 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-33023039

RESUMO

COVID-19, caused by SARS-CoV-2, has resulted in a global pandemic recently. With no approved vaccination or treatment, governments around the world have issued guidance to their citizens to remain at home in efforts to control the spread of the disease. The goal of controlling the spread of the virus is to prevent strain on hospitals. In this paper, we focus on how non-invasive methods are being used to detect COVID-19 and assist healthcare workers in caring for COVID-19 patients. Early detection of COVID-19 can allow for early isolation to prevent further spread. This study outlines the advantages and disadvantages and a breakdown of the methods applied in the current state-of-the-art approaches. In addition, the paper highlights some future research directions, which need to be explored further to produce innovative technologies to control this pandemic.


Assuntos
Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Pulmão/diagnóstico por imagem , Pneumonia Viral/diagnóstico , COVID-19 , Teste para COVID-19 , Infecções por Coronavirus/diagnóstico por imagem , Infecções por Coronavirus/etiologia , Humanos , Pulmão/virologia , Pandemias , Pneumonia Viral/diagnóstico por imagem , Pneumonia Viral/etiologia , Termografia/métodos , Tomografia Computadorizada por Raios X , Ultrassonografia/métodos
7.
J Ayub Med Coll Abbottabad ; 15(3): 43-6, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14727340

RESUMO

BACKGROUND: The objective of this study was to compare sealing capabilities of different filling materials when used as retrograde filling materials following apiceotomy (to check their sealing abilities as retro filling). In this study apical seal obtained following reverse retrograde root filling with amalgam, was compared with those obtained with, Glassinomer (GIC) and Zinc oxide eugonal (ZnO2E) cement. METHODS: The root canals of 50 extracted single rooted upper anterior human teeth were used in this study. The root canals were instrumented and obturated with laterally condensed, gutta-percha and zinc oxide sealer. Each tooth was a pically resected at 90 degrees to its long axis and the root surface isolated with two coats of nail polish. Teeth were divided into 4 groups, the 1st group received amalgam retrograde filling, the 2nd and 3rd group was retro filled with GIC and ZnO2E cement respectively and the 4th control group received no retrograde root filling. All these teeth were suspended in 1% methylene blue dye at room temperature for 72 hours, the roots were sectioned and dye penetration measured by using (stereomicroscope) microscope. The sealing abilities of these materials were determined by their ability to inhibit dye penetration. RESULTS: The result of this study has shown that GIC is just as effective as amalgam but ZnO2E cement showed poor sealing abilities. CONCLUSION: GIC is just as effective as Amalgam as a retro-sealer and on some instance, better then it, but a long term in vivo study is required to prove it.


Assuntos
Amálgama Dentário , Cimentos de Ionômeros de Vidro , Materiais Restauradores do Canal Radicular , Cimento de Óxido de Zinco e Eugenol , Humanos , Técnicas In Vitro
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