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Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 588
Vladimir Spurny ◽  
Petr Munster ◽  
Adrian Tomasov ◽  
Tomas Horvath ◽  
Edvin Skaljo

Optical fiber communications are essential for all types of long- and short-distance transmissions. The aim of this paper is to analyze the previously presented security risks and, based on measurements, provide the risk level evaluation. The major risk is the possibility of inserting a splitter into the optical distribution network and capturing a portion of the entire spectrum, i.e., all channels in the optical fiber. Another significant security risk is crosstalk on multiplexers in networks with wavelength division multiplexing. The paper covers the macrobend attenuation evaluation of fiber and back-reflection measurements. Based on the measurements, risks were evaluated for both point-to-point and point-to-multipoint networks and, lastly, the paper covers crosstalk measurements of an optomechanical switch. Finally, all individual risks are evaluated according to the severity, and a proposal for risk minimization is provided.

2022 ◽  
Jung Tae (Steve) Kim

A lot of communication are developed and advanced with different and heterogeneous communication techniques by integration of wireless and wire connection. Conventional technology is mainly focus on information technology based on computer techniques in the field of industry, manufacture and automation fields. It consists of individual skill and technique. As new technologies are developed and enhanced with conventional techniques, a lot of new application is emerged and merged with previous mechanism and skills. The representative application is internet of things services and applications. Internet of things is breakthrough technologies and one of the innovation industries which are called 4 generation industry revolution. Many different types of object and devices are embedded in sensor node. They are inter-connected with optimized open system interconnection protocol over internet, wireless and wire medium. Most of communication is fully inter-connected with conventional techniques at point to point and end to application in general. Most of information in internet of things is weak against attack. This may induce vulnerable features to unauthorized and outside attacker over internet protocol, Bluetooth, Wi-Fi, and so forth. As high and low efficient equipment are merged into heterogeneous infrastructure, IoT communication surroundings has become more complex, Due to limited resources in IoT such as small memory, low power and computing power, IoT devices are vulnerable and disclosed with security problems. In this chapter, we analyzed security challenges and threats based on smart home network under IoT service.

Electronics ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 175
Jinlei Chen ◽  
Sheng Wang ◽  
Carlos E. Ugalde-Loo ◽  
Wenlong Ming ◽  
Oluwole D. Adeuyi ◽  

Although the control of modular multi-level converters (MMCs) in high-voltage direct-current (HVDC) networks has become a mature subject these days, the potential for adverse interactions between different converter controls remains an under-researched challenge attracting the attention from both academia and industry. Even for point-to-point HVDC links (i.e., simple HVDC systems), converter control interactions may result in the shifting of system operating voltages, increased power losses, and unintended power imbalances at converter stations. To bridge this research gap, the risk of multiple cross-over of control characteristics of MMCs is assessed in this paper through mathematical analysis, computational simulation, and experimental validation. Specifically, the following point-to-point HVDC link configurations are examined: (1) one MMC station equipped with a current versus voltage droop control and the other station equipped with a constant power control; and (2) one MMC station equipped with a power versus voltage droop control and the other station equipped with a constant current control. Design guidelines for droop coefficients are provided to prevent adverse control interactions. A 60-kW MMC test-rig is used to experimentally verify the impact of multiple crossing of control characteristics of the DC system configurations, with results verified through software simulation in MATLAB/Simulink using an open access toolbox. Results show that in operating conditions of 650 V and 50 A (DC voltage and DC current), drifts of 7.7% in the DC voltage and of 10% in the DC current occur due to adverse control interactions under the current versus voltage droop and power control scheme. Similarly, drifts of 7.7% both in the DC voltage and power occur under the power versus voltage droop and current control scheme.

2022 ◽  
Vol 12 (2) ◽  
pp. 542
Martín H. Cruz-Rosales ◽  
Marco Antonio Cruz-Chávez ◽  
Federico Alonso-Pecina ◽  
Jesus del C. Peralta-Abarca ◽  
Erika Yesenia Ávila-Melgar ◽  

This work presents a metaheuristic with distributed processing that finds solutions for an optimization model of the university course timetabling problem, where collective communication and point-to-point communication are applied, which are used to generate cooperation between processes. The metaheuristic performs the optimization process with simulated annealing within each solution that each process works. The highlight of this work is presented in the algorithmic design for optimizing the problem by applying cooperative processes. In each iteration of the proposed heuristics, collective communication allows the master process to identify the process with the best solution and point-to-point communication allows the best solution to be sent to the master process so that it can be distributed to all the processes in progress in order to direct the search toward a space of solutions which is close to the best solution found at the time. This search is performed by applying simulated annealing. On the other hand, the mathematical representation of an optimization model present in the literature of the university course timing problem is performed. The results obtained in this work show that the proposed metaheuristics improves the results of other metaheuristics for all test instances. Statistical analysis shows that the proposed metaheuristic presents a different behavior from the other metaheuristics with which it is compared.

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0260210
Shan Wang ◽  
Ruhan Liu ◽  
Chu-Ren Huang

Leech’s corpus-based comparison of English modal verbs from 1961 to 1992 showed the steep decline of all modal verbs together, which he ascribed to continuing changes towards a more equal and less authority-driven society. This study inspired many diachronic and synchronic studies, mostly on English modal verbs and largely assuming the correlation between the use of modal verbs and power relations. Yet, there are continuing debates on sampling design and the choices of corpora. In addition, this hypothesis has not been attested in any other language with comparable corpus size or examined with longitudinal studies. This study tracks the use of Chinese modal verbs from 1901 to 2009, covering the historical events of the New Culture Movement, the establishment of the PRC, the implementation of simplified characters and the completion and finalization of simplification of the Chinese writing system. We found that the usage of modal verbs did rise and fall during the last century, and for more complex reasons. We also demonstrated that our longitudinal end-to-end approach produces convincing analysis on English modal verbs that reconciles conflicting results in the literature adopting Leech’s point-to-point approach.

2022 ◽  
pp. 119-140
Tiziano Volpentesta ◽  
Mario Miozza ◽  
Abhijeet Satwekar

Biopharmaceutical companies and health authorities continuously exchange information to provide safe and effective therapeutics. The interactions between the two require transparency and extensive documentation exchange concerning the processes which extend from the development through the manufacturing phase. The current processes rely on paper documentation, notebooks, and point-to-point electronic data interchange (EDI) for the storage of data. Thereby, generating challenges of data integrity within the internal siloed structures and the traceability of the medicinal products in the pursuit to avoid counterfeiting. With Industry 4.0 and blockchain, the authors envisioned a reinvented workflow that helps to 1) manage data integrity with decentralized trust and 2) improve the track and trace capabilities. Hence, biopharmaceutical companies can manage data in a more trustable manner while maintaining security and privacy, further enabling the external ecosystem with track and trace to ensure complete transparency until the therapeutics reach patients.

2022 ◽  
Vol 2161 (1) ◽  
pp. 012046
R Pradeep ◽  
N R Sunitha

Abstract A smart city is a technologically advanced metropolitan region with several connected devices that collects data using various electronic technologies, voice activation methods, and sensors. The information obtained from the data is utilised to efficiently manage assets, resources, and services; in turn, the data is used to enhance operations throughout the city. Achieving security for smart cities is one of the major challenges as the number of connected devices increases the vulnerability also increases. The security of a smart city system depends on the reliability of the security protocols used by the security systems. To design and develop a highly secure system for a smart city the security protocols used must be highly reliable. To prove the reliability of a security protocol the validation technique is not desirable because of its several drawbacks, these drawbacks can be overcome using the formal verification technique which provides the mathematical proof for its correctness. In this work, The Challenge-Handshake Authentication Protocol Point-to-Point (CHAP PPP) which is more commonly used in PPP authentication of smart cities is formally verified using the well-known verification technique known as the model checking technique. The Scyther model checker is the tool used to build the abstract security protocol model.

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