Explore the vast range of titles available.

Fifth-generation (5G) networks offer high-speed data transmission with low latency, increased base station volume, improved quality of service (QoS), and massive multiple-input–multiple-output (M-MIMO) channels compared to 4G long-term evolution (LTE) networks. However, the COVID-19 pandemic has disrupted the achievement of mobility and handover (HO) in 5G networks due to significant changes in intelligent devices and high-definition (HD) multimedia applications. Consequently, the current cellular network faces challenges in propagating high-capacity data with improved speed, QoS, latency, and efficient HO and mobility management. This comprehensive survey paper specifically focuses on HO and mobility management issues within 5G heterogeneous networks (HetNets). The paper thoroughly examines the existing literature and investigates key performance indicators (KPIs) and solutions for HO and mobility-related challenges while considering applied standards. Additionally, it evaluates the performance of current models in addressing HO and mobility management issues, taking into account factors such as energy efficiency, reliability, latency, and scalability. Finally, this paper identifies significant challenges associated with HO and mobility management in existing research models and provides detailed evaluations of their solutions along with recommendations for future research.

This paper studies two new models for a telegraph process: Cox-based and elliptical telegraph processes. The paper deals with the stochastic motion of a particle on a straight line and on an ellipse with random positive velocity and two opposite directions of motion, which is governed by a telegraph–Cox switching process. A relevant result of our analysis on the straight line is obtaining a linear Volterra integral equation of the first kind for the characteristic function of the probability density function (PDF) of the particle position at a given time. We also generalize Kac’s condition for the telegraph process to the case of a telegraph–Cox switching process. We show some examples of random velocity where the distribution of the coordinate of a particle is expressed explicitly. In addition, we present some novel results related to the switched movement evolution of a particle according to a telegraph–Cox process on an ellipse. Numerical examples and applications are presented for a telegraph–Cox-based process (option pricing formulas) and elliptical telegraph process.

This work chronicles the rise of Western Union Telegraph from its origins in the helter-skelter ferment of antebellum capitalism to its apogee as the first corporation to monopolize an industry on a national scale. The battles that raged over Western Union's monopoly on nineteenth-century American telecommunications - in Congress, in courts, and in the press - illuminate the fierce tensions over the rising power of corporations after the Civil War and the reshaping of American political economy. The telegraph debate reveals that what we understand as the normative relationship between private capital and public interest is the product of a historical process that was neither inevitable nor uncontested. Western Union's monopoly was not the result of market logic or a managerial revolution, but the conscious creation of entrepreneurs protecting their investments. In the process, these entrepreneurs elevated economic liberalism above traditional republican principles of public interest and helped create a new corporate order.

A method of solving plane-strain boundary value problems for a reduced version of the double slip and rotation model is developed. It is assumed that the intrinsic spin vanishes. Elastic strains are neglected. The Mohr–Coulomb yield criterion is adopted. An analogy between the solutions for this model and classical rigid plastic solutions of pressure-independent plasticity is revealed. The method is based on introducing auxiliary variables that satisfy the equation of telegraphy in regions where both families of characteristics are curved. Therefore, Riemann's method can conveniently be applied to solving boundary value problems. The method is employed for analyzing the processes of plane-strain drawing and extrusion through a wedge-shaped die. Friction is neglected. The solution is given in terms of ordinary integrals. The effect of the angle of internal friction on processes’ parameters is revealed. The solution reduces to available solutions of pressure-independent plasticity if the angle of internal friction vanishes.

The year 2018 marks the 125th anniversary of the first of three published volumes on electromagnetic theory by the eminent Victorian electrical engineer, physicist and mathematician, Oliver Heaviside FRS. This commemorative issue of Philosophical Transactions of the Royal Society A celebrates the publication of this work by collecting papers on a broad spectrum across the field of electromagnetic theory, including innovative research papers interspersed between historical perspectives and relevant reviews. Heaviside was a remarkable man, an original thinker with brilliant mathematical powers and physical insight who made many significant contributions in his fields of interest, though he is remembered primarily for his 'step function', commonly used today in many branches of physics, mathematics and engineering. Here, we celebrate the man and his work by illustrating his major contributions and highlighting his great success in solving some of the great telegraphic engineering problems of the Victorian era, in part due to his development and detailed understanding of the governing electromagnetic theory. We celebrate his Electromagnetic theory: three volumes of insights, techniques and understanding from mathematical, physical and engineering perspectives-as dictated by J. C. Maxwell FRS, but interpreted, reformulated and expanded by Heaviside to advance the art and science of electrical engineering beyond all expectations. This article is part of the theme issue 'Celebrating 125 years of Oliver Heaviside's 'Electromagnetic Theory''.

In this work, the degradation of the random telegraph noise (RTN) and the threshold voltage (Vt) shift of an 8.3Mpixel stacked CMOS image sensor (CIS) under hot carrier injection (HCI) stress are investigated. We report for the first time the significant statistical differences between these two device aging phenomena. The Vt shift is relatively uniform among all the devices and gradually evolves over time. By contrast, the RTN degradation is evidently abrupt and random in nature and only happens to a small percentage of devices. The generation of new RTN traps by HCI during times of stress is demonstrated both statistically and on the individual device level. An improved method is developed to identify RTN devices with degenerate amplitude histograms.

This article explores a link between gutta-percha, the natural South-East Asian latex used nearly exclusively as an insulation for nineteenth-century British telegraph cables, and the development of electromagnetic field theory. Field theory emerged from the non-traditional methods of physicist Michael Faraday, who demonstrated that the energy in telegraph cables is located around, rather than within, the conducting wire. Eventually, the application of field theory in telegraphy required the knowledge and resources of Indigenous forest produce collectors, as well as contingent networks of Chinese and Malay traders linked into local and global supply chains. Telegraphic infrastructure, therefore, is not simply the cables and signalling systems developed by the British, but also the knowledge, resources, and cultures of South-East Asian Indigenous communities and lifeways that resisted the Western energy project ‘around’ the conducting wire. Britain’s global telegraphy enterprise relied on enormous quantities of gutta-percha, procured only by Indigenous collectors whose methods refused settler colonial agricultural practices like the plantation model. Based on the widespread demand for, and increasing shortage of, gutta-percha by the late nineteenth century, this article argues that Stoker’s Dracula characterizes the Count using language that overlaps with the ambient, uncategorizable energy of field theory, as well as non-Western practices crucial to the gutta-percha supply chain, like animal augury.

In this paper we present a systematic approach to sort out different types of random telegraph noises (RTN) in CMOS image sensors (CIS) by examining their dependencies on the transfer gate off-voltage, the reset gate off-voltage, the photodiode integration time, and the sense node charge retention time. Besides the well-known source follower RTN, we have identified the RTN caused by varying photodiode dark current, transfer-gate and reset-gate induced sense node leakage. These four types of RTN and the dark signal shot noises dominate the noise distribution tails of CIS and non-CIS chips under test, either with or without X-ray irradiation. The effect of correlated multiple sampling (CMS) on noise reduction is studied and a theoretical model is developed to account for the measurement results.

This paper exploits a unique historical experiment to estimate how information frictions distort international trade: the establishment of the transatlantic telegraph in 1866. I use newly collected data on cotton prices, trade, and information flows from historical newspapers and find that the average and volatility of the transatlantic price difference fell after the telegraph, while average trade flows increased and became more volatile. Using a trade model in which exporters use the latest news about a foreign market to forecast expected prices, I estimate the efficiency gains of the telegraph to be equivalent to 8 percent of export value.