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This paper presents a compact dual-band reconfigurable antenna. This antenna covers the Long-Term Evolution (LTE) bands 1.9 GHz, 2.4 GHz, and 3 GHz. The reconfigurability was achieved with two PIN-diodes which provided four switching states. Both frequency and radiation characteristics have consistent results. The antenna gain was evaluated at every switching state. Results from the simulation and measurements have good agreement. [ABSTRACT FROM AUTHOR]

Inequality of opportunity (IOp) in the four largest economies in Europe – France, Germany, Italy, and the United Kingdom – around 2015 accounts for a significant share of inequality of incomes, between 30 and 50 percent, depending on the inequality index and using a parametric approach. Mirroring the reduction of inequality of incomes over the last three decades, the long-term trend of IOp, the focus of this paper, has been declining for all countries but Italy. Declining trends are also observed for IOp estimated for age, gender, and birth cohorts sub-groups of the national populations. The closing of the gender gap accounts for a large share of the reduction of the IOp of the overall population. When decomposing age and birth cohort effects, the age effect of IOp exhibits an inverted U shape and, at the same age, IOp experienced by most recent cohorts is lower than preceding ones. To guide the interpretation of the observed declining trends, we use a theoretical framework describing the mechanisms through which changes in circumstances may be correlated to changes of inequality of opportunity. Three variables are considered by this framework: a) intergenerational persistence in educational attainment, b) return of education, and c) social origins. The first two variables are declining in all countries and are consistent with the reduction of IOp. However, 'higher' social origins seem to become increasingly more correlated with higher (labor) incomes and, in some countries (notably Italy), increasing relevance of this third variable slows down the overall reduction of IOp. Social origins, proxied by educated parents, remain significant even after controlling for parental resources (books at home when aged 14) or children' skills (numeracy and literacy). [ABSTRACT FROM AUTHOR]

The quality of signal at a particular location is essential to determine the performance of mobile system. The problem of poor network in Lagos, Nigeria needs to be addressed especially now that the attention is toward online learning and meetings. Existing empirical Path Loss (PL) models designed elsewhere are not appropriate for predicting the 4G Long-Term Evolution (LTE) signal in Nigeria. This research developed a modified Okumura-Hata model in 4G network. The Okumura-Hata model being the closest to the measured values was modified using the PL exponent. The modified model was enhanced by Gravitational Search Algorithm (GSA). The measured data, modified and existing models were simulated using MATLAB R2018a software. Root Mean Square (RMSE) was used to evaluate the performance modified and existing and models. The result showed that Enhanced GSA model outperformed the existing models. The study successfully developed a modified PL model for LTE in Lagos, Nigeria. Therefore, modified model will be a good model in network planning for voice and fast online data connection in 4G LTE network. [ABSTRACT FROM AUTHOR]

The Long Term Evolution (LTE) standard proposed by 3GPP aims to increase the availability of broadband services, with significant improvements to the LTE air interface employing various techniques. As a result, accurate channel estimation is critical for high transmission performance and system superiority. In this study, an LTE downlink system simulation program was developed to generate one frame of data on a single antenna port. The data consisted of randomly mapped bits, various modulation schemes, and coded symbols in a subframe as no transport channel was incorporated in this model. Each subframe was encoded with cell-specific reference signals, primary and secondary synchronization signals. To construct a frame, 10 subframes were generated independently. The frame was modulated using the LTE standard, passed through an Extended Vehicular A Model (EVA5) fading channel with additive white Gaussian noise (AWGN), and then demodulated. Finally, the received and equalized resource grid for all modulation types were displayed using minimum mean square error (MMSE) equalization with channel and noise estimates. The percentage root mean square error vector magnitude (RMS EVM) of the pre- and post-equalized signals were calculated. [ABSTRACT FROM AUTHOR]

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This paper analyzes the effect of the characteristics of 5G services on users' continuous intention to use, focusing on the technology acceptance model. With the start of the fourth industrial revolution in the 21st century, 5G is the best technology used in the Internet of Things, high-speed information and communication, artificial intelligence, big data, autonomous vehicles, virtual reality, augmented reality, robots, nanotechnology, and blockchain. The technical characteristics of 5G ultra-high-speed information communication are represented by ultra-high speed, ultra-high capacity, ultra-low delay, and ultra-high connectivity. 5G mobile communication technology is essential, and after the technology provided by 5G services is commercialized, it can play all its roles as a practical core new growth engine. 5G mobile communication (hereinafter referred to as 5G) is far superior to LTE, which is a 4G mobile communication, in terms of transmission speed, waiting time, and terminal capacity. 5G service is not just an axis of the process of developing mobile communication technology, but also the creation of innovative corporate value of technology. This is because higher network quality and innovation with 5G service technology will improve perceived usability, perceived ease of use, and perceived entertainment, which will ultimately have a positive impact on users' intention to use 5G services. Therefore, due to the lack of investment in information and communication bases, platforms, and applications, this paper can be used as the basis for establishing government policies. [ABSTRACT FROM AUTHOR]

Phenotypes are partly shaped by the environment, which can impact both short-term adaptation and long-term evolution. In dioecious species, the two sexes may exhibit different degrees of phenotypic plasticity and theoretical models indicate that such differences may confer an adaptive advantage when the population is subject to directional selection, either because of a systematically varying environment or a load of deleterious mutations. The effect stems from the fundamental asymmetry between the two sexes: female fertility is more limited than male fertility. Whether this asymmetry is sufficient for sexual dimorphism in phenotypic plasticity to evolve is, however, not obvious. Here, we show that even in conditions where it provides an adaptive advantage, dimorphic phenotypic plasticity may be evolutionarily unstable due to sexual selection. This is the case, in particular, for panmictic populations where mating partnerships are formed at random. However, we show that the effects of sexual selection can be counteracted when mating occurs within groups of related individuals. Under this condition, sexual dimorphism in phenotypic plasticity can not only evolve but offset the twofold cost of males. We demonstrate these points with a simple mathematical model through a combination of analytical and numerical results. [ABSTRACT FROM AUTHOR]

The long-term evolution of the Solar system is chaotic. In some cases, chaotic diffusion caused by an overlap of secular resonances can increase the eccentricity of planets when they enter into a linear secular resonance, driving the system to instability. Previous work has shown that including general relativistic contributions to the planets' precession frequency is crucial when modelling the Solar system. It reduces the probability that the Solar system destabilizes within 5 Gyr by a factor of 60. We run 1280 additional N -body simulations of the Solar system spanning 12.5 Gyr where we allow the general relativity (GR) precession rate to vary with time. We develop a simple, unified, Fokker–Planck advection–diffusion model that can reproduce the instability time of Mercury with, without, and with time-varying GR precession. We show that while ignoring GR precession does move Mercury's precession frequency closer to a resonance with Jupiter, this alone does not explain the increased instability rate. It is necessary that there is also a significant increase in the rate of diffusion. We find that the system responds smoothly to a change in the precession frequency: There is no critical GR precession frequency below which the Solar system becomes significantly more unstable. Our results show that the long-term evolution of the Solar system is well described with an advection–diffusion model. [ABSTRACT FROM AUTHOR]

In order to promote the engineering applications of carbon- and glass-fiber-reinforced epoxy hybrid rods, it is necessary to fully understand its long-term hygrothermal durability. In the present study, the water absorption behaviors of a hybrid rod in a water immersion environment are studied experimentally, the degradation rules of the mechanical properties are obtained, and establishing a life prediction model is attempted. The water absorption of the hybrid rod confirms to the classical Fick's diffusion model, and the water absorption concentration is determined by radial position, immersion temperature, and immersion time. In addition, the radial position of water molecules diffused into the rod is positively correlated with the diffusion concentration. The short-beam shear strength of the hybrid rod decreased significantly after 360 days of exposure; this is because water molecules interact with the polymer through hydrogen bonds to produce bound water during the immersion process, leading to resin matrix hydrolysis and plasticization, as well as interfacial debonding. In addition, the ingression of water molecules caused degradation in the viscoelastic behavior of the resin matrix in hybrid rods. The glass transition temperature of hybrid rods decreased by 17.4% after exposure at 80 °C for 360 days. The Arrhenius equation was used calculate the long-term life of short-beam shear strength in the actual service temperature based on the time–temperature equivalence theory. The stable strength retention for SBSS was found to be 69.38%, which is a useful durability design parameter for hybrid rods in civil engineering structures. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the long-term changes in the coastal stretch of the Lido barrier island, a 12 km sandy coast bordering the Lagoon of Venice, and to assess the impacts of human interventions in the system. Coastal modifications were examined in a GIS environment through the analysis of aerial photographs covering the period 1955–2019. To achieve our goal, the study area was divided into three cells (i.e., from north to south, A, B, and C), and the rates of shoreline change were calculated over five subsequent periods (i.e., 1955–1978, 1978–1987, 1987–1996, 1996–2006, and 2006–2019). The results mainly showed a positive trend in the long-term (cell A avg. 2.0 m/year; cell C avg. 1.2 m/year) and moderate erosion (cell A and C avg. 0.9 m/year) in the periods 1996–2006 and 2006–2019, probably due to an increase in the frequency of storm surges. However, major effects on beach erosion and progradation were produced by human interventions. In particular, positive impacts were derived from the shore-normal engineering structures intercepting longshore currents, whereas negative effects were from works functional to the realisation of the MoSE system at the Lido and Malamocco inlets, which reduced the amount of available sediment, thus contributing to the worsening conditions of cells A and C. In view of the expected sea-level rise, this area merits higher consideration for correct spatial planning in the framework of integrated coastal zone management. We suggest that a monitoring program of shoreline evolution must be set up to better manage its future development. [ABSTRACT FROM AUTHOR]

Gamma-ray binary systems, a subclass of high-mass X-ray binaries, show nonthermal emissions from radio to TeV. While efficient electron acceleration is considered to take place in them, the nature of the acceleration mechanism and the physical environments in these systems have been a long-standing question. In this work, we report on long-term recurrent patterns in the short-term variability of the soft X-ray emission of LS 5039, one of the brightest gamma-ray binary systems. The Neutron star Interior Composition Explorer (NICER) observed LS 5039 four times from 2018 to 2021. By comparing them with the previous Suzaku and NuSTAR long-exposure observations, we studied the long-term evolution of the orbital light curve in the soft X-ray band. Although the observations by NICER and Suzaku are separated by ∼14 yr, i.e., more than 103 orbits, the orbital light curves show remarkable consistency after calculating their running averages with a window width ≳70 ks. Furthermore, all of the light curves show short-term variability with a timescale of ∼10 ks. Since the column density did not vary when the flux changed abruptly, such a short-term variability seems to be an intrinsic feature of the X-ray emission. We propose that the short-term variability is caused by clumps (or inhomogeneities) of the companion star wind impacting the X-ray production site. The observed timescale matches well with the lifetime of the clumps interacting with the pulsar wind and the dynamical timescale of the relativistic intrabinary shock in the pulsar wind scenario. [ABSTRACT FROM AUTHOR]

Here we review present knowledge of the long-term behaviour of solar activity on a multi-millennial timescale, as reconstructed using the indirect proxy method. The concept of solar activity is discussed along with an overview of the dedicated indices used to quantify different aspects of variable solar activity, with special emphasis on sunspot numbers. Over long timescales, quantitative information about past solar activity is historically obtained using a method based on indirect proxies, such as cosmogenic isotopes 14 C and 10 Be in natural stratified archives (e.g., tree rings or ice cores). We give a historical overview of the development of the proxy-based method for past solar-activity reconstruction over millennia, as well as a description of the modern state of the art. Special attention is paid to the verification and cross-calibration of reconstructions. It is argued that the method of cosmogenic isotopes makes a solid basis for studies of solar variability in the past on a long timescale (centuries to millennia) during the Holocene (the past ∼ 12 millennia). A separate section is devoted to reconstructions of extremely rare solar eruptive events in the past, based on both cosmogenic-proxy data in terrestrial and lunar natural archives, as well as statistics of sun-like stars. Finally, the main features of the long-term evolution of solar magnetic activity, including the statistics of grand minima and maxima occurrence, are summarized and their possible implications, especially for solar/stellar dynamo theory, are discussed. [ABSTRACT FROM AUTHOR]

The genetic consequences of the subdivision of populations are regarded as significant to long‐term evolution, and research has shown that the scale and speed at which this is now occurring is critically reducing the adaptive potential of most species which inhabit human‐impacted landscapes. Here, we provide a rare and, to our knowledge, the first analysis of this process while it is happening and demonstrate a method of evaluating the effect of mitigation measures such as fauna crossings. We did this by using an extensive genetic data set collected from a koala population which was intensely monitored during the construction of linear transport infrastructure which resulted in the subdivision of their population. First, we found that both allelic richness and effective population size decreased through the process of population subdivision. Second, we predicted the extent to which genetic drift could impact genetic diversity over time and showed that after only 10 generations the resulting two subdivided populations could experience between 12% and 69% loss in genetic diversity. Lastly, using forward simulations we estimated that a minimum of eight koalas would need to disperse from each side of the subdivision per generation to maintain genetic connectivity close to zero but that 16 koalas would ensure that both genetic connectivity and diversity remained unchanged. These results have important consequences for the genetic management of species in human‐impacted landscapes by showing which genetic metrics are best to identify immediate loss in genetic diversity and how to evaluate the effectiveness of any mitigation measures. [ABSTRACT FROM AUTHOR]

The paper presents the long-term evolution and recent development of ultraviolet photodetectors. First, the general theory of ultraviolet (UV) photodetectors is briefly described. Then the different types of detectors are presented, starting with the older photoemission detectors through photomultipliers and image intensifiers. More attention is paid to silicon and different types of wide band gap semiconductor photodetectors such as AlGaN, SiC-based, and diamond detectors. Additionally, Ga2O3 is considered a promising material for solar-blind photodetectors due to its excellent electrical properties and a large bandgap energy. The last part of the paper deals with new UV photodetector concepts inspired by new device architectures based on low-dimensional solid materials. It is shown that the evolution of the architecture has shifted device performance toward higher sensitivity, higher frequency response, lower noise, and higher gain-bandwidth products. [ABSTRACT FROM AUTHOR]

Fifth Generation (5G) signals using the millimeter wave (mmWave) spectrums are highly vulnerable to blockage due to rapid variations in channel link quality. This can cause the devices or User Equipment (UE) to suffer from connection failure. In a dual connectivity (DC) network, the channel's intermittency issues were partially solved by maintaining the UE's connectivity to primary (LTE advanced stations) and secondary (5G mmWave stations) simultaneously. Even though the dual-connected network performs excellently in maintaining connectivity, its performance drops significantly due to the inefficient handover from one 5G mmWave station to another. The situation worsens when UE travels a long distance in a highly dense obstacle environment, which requires multiple ineffective handovers that eventually lead to performance degradation. This research aimed to propose an Adaptive TTT Handover (ATH) mechanism that deals with unpredictable 5G mmWave wireless channel behaviors that are highly intermittent. An adaptive algorithm was developed to automatically adjust the handover control parameters, such as Time-to-Trigger (TTT), based on the current state of channel condition measured by the Signal-to-Interference-Noise Ratio (SINR). The developed algorithm was tested under a 5G mmWave statistical channel model to represent a time-varying channel matrix that includes fading and the Doppler effect. The performance of the proposed handover mechanism was analyzed and evaluated in terms of handover probability, latency, and throughput by using the Network Simulator 3 tool. The comparative simulation result shows that the proposed adaptive handover mechanism performs excellently compared to conventional handovers and other enhancement techniques. [ABSTRACT FROM AUTHOR]

Narrowband Internet of Things (NB-IoT) has quickly become a leading technology in the deployment of IoT systems and services, owing to its appealing features in terms of coverage and energy efficiency, as well as compatibility with existing mobile networks. Increasingly, IoT services and applications require location information to be paired with data collected by devices; NB-IoT still lacks, however, reliable positioning methods. Time-based techniques inherited from long-term evolution (LTE) are not yet widely available in existing networks and are expected to perform poorly on NB-IoT signals due to their narrow bandwidth. This investigation proposes a set of strategies for NB-IoT positioning based on fingerprinting that use coverage and radio information from multiple cells. The proposed strategies were evaluated on two large-scale datasets made available under an open-source license that include experimental data from multiple NB-IoT operators in two large cities: Oslo, Norway, and Rome, Italy. Results showed that the proposed strategies, using a combination of coverage and radio information from multiple cells, outperform current state-of-the-art approaches based on single cell fingerprinting, with a minimum average positioning error of about 20 m when using data for a single operator that was consistent across the two datasets vs. about 70 m for the current state-of-the-art approaches. The combination of data from multiple operators and data smoothing further improved positioning accuracy, leading to a minimum average positioning error below 15 m in both urban environments. [ABSTRACT FROM AUTHOR]

Many stratovolcanoes are characterised by cycles of edifice growth interrupted by collapse events. The long-term record of the evolution of such magmatic systems is mainly preserved in the deposits of the volcanic apron surrounding the active cone. Taranaki Volcano in New Zealand provides an unusually detailed example of these processes due to excellent coastal ring-plain and young cone exposures. In this study, we investigate the magmatic system of this volcano through three consecutive growth phases by sampling a detailed, stratigraphically controlled selection of volcanic clasts from volcaniclastic mass-flow deposits in the medial ring-plain. The clasts from three growth phases (GP1, 65–55 ka; GP2, 55–40 ka; GP3, 40–34 ka) differ in bulk composition and form geochemically distinct trends on variation diagrams. These trends can be modelled by mainly dacitic melt mixing with gabbroic and ultramafic xenolith compositions representing the plutonic assemblages beneath the edifice. Within short-term growth cycles (104 years), the geochemical differences between lower and upper sequences of GP units indicate that closer to an edifice collapse, both whole-rock major and trace element compositions display more evolved and scattered trends compared to post-collapse stages. Considering the long-term magmatic evolution of Taranaki Volcano, it is apparent that the pre-collapse compositions are more evolved than bulk rock compositions of the growth phases, indicating active upper-crustal reservoir conditions in pre-collapse states. Furthermore, the volume losses caused by sector collapses prior to GP2 and GP3 could decrease the pressure in the upper-crustal reservoir. Overall, the data obtained from the mid-age Taranaki volcanic system elucidate the mid- to upper-crustal magmatic processes and reservoir conditions throughout growth cycles. Further, it demonstrates the top-down control of volcanic edifice load change on the magmatic plumbing system expressed by the evolvement of whole-rock compositions towards the end of a growth cycle. [ABSTRACT FROM AUTHOR]

Magnetic fields are observed in massive Ap/Bp stars and are presumably present in the radiative zone of solar-like stars. To date, there is no clear understanding of the dynamics of the magnetic field in stably stratified layers. A purely toroidal magnetic field configuration is known to be unstable, developing mainly non-axisymmetric modes. Rotation and a poloidal field component may lead to stabilization. Here we perform global MHD simulations with the EULAG-MHD code to explore the evolution of a toroidal magnetic field located in a layer whose Brunt-Väisälä frequency resembles the lower solar tachocline. Our numerical experiments allow us to explore the initial unstable phase as well as the long-term evolution of such field. During the first Alfven cycles, we observe the development of the Tayler instability with the prominent longitudinal wavenumber, m = 1. Rotation decreases the growth rate of the instability and eventually suppresses it. However, after a stable phase, energy surges lead to the development of higher-order modes even for fast rotation. These modes extract energy from the initial toroidal field. Nevertheless, our results show that sufficiently fast rotation leads to a lower saturation energy of the unstable modes, resulting in a magnetic topology with only a small fraction of poloidal field, which remains steady for several hundreds of Alfven traveltimes. The system then becomes turbulent and the field is prone to turbulent diffusion. The final toroidal–poloidal configuration of the magnetic field may represent an important aspect of the field generation and evolution in stably stratified layers. [ABSTRACT FROM AUTHOR]

Microwave heating of pure alumina is studied experimentally and numerically, in a 2.45 GHz single‐mode cavity, for different density levels. Even considering a constant incident power, the results show a complex evolution of the alumina temperature: first a two‐step increase, then a maximum, and finally a cooling stage. In addition, a density dependence of the heating efficiency is observed: a more efficient heating occurs for lower densities. Using the effective medium approximation (EMA) to derive the physical data as functions of density, the numerical simulations are in contradiction with the experiments, proving that the EMA approach is not able to correctly predict the imaginary part of the permittivity. Furthermore, the simulations do not accurately describe the first moments of the heating, nor the long‐term evolution of the temperature (cooling). We then explain the origin of this discrepancy: the need to adjust the movable stub on the one hand, and to account for heat exchange between the cavity and its surroundings on the other. [ABSTRACT FROM AUTHOR]

Deploying networks in unlicensed spectrum has been drawing significant attention, which serves to alleviate the increasing demands in licensed spectrum. However, the network coexistence in unlicensed channel may lead to throughput degradation and unfairness. An appropriate spectrum‐sharing mechanism is therefore of great significance. In this paper, we study the performance limit of two representative mechanisms used in the coexistence with WiFi, including Duty Cycle (DC) and Listen‐Before‐Talk (LBT). In particular, both the throughputs of the coexisting network and WiFi under two mechanisms are derived as explicit expressions of system parameters, based on which the maximum total throughput of the coexisting network and WiFi is characterized under throughput fairness and 3GPP fairness, respectively. A systematic comparison between the optimal throughput performance of DC and LBT is conducted. It is found that if the coexisting network with LBT occupies the channel for a large period each time it successfully accesses the channel, then the maximum total throughput in LBT would be close to that in DC under both throughput fairness and 3GPP fairness. The optimal settings for DC and LBT mechanisms to achieve maximum total throughput are obtained, respectively, which sheds important light on the design of fair and efficient spectrum‐sharing protocols. [ABSTRACT FROM AUTHOR]

Stroke significantly impacts the quality of life. However, the long-term cognitive evolution in stroke is poorly predictable at the individual level. There is an urgent need to better predict long-term symptoms based on acute clinical neuroimaging data. Previous works have demonstrated a strong relationship between the location of white matter disconnections and clinical symptoms. However, rendering the entire space of possible disconnection-deficit associations optimally surveyable will allow for a systematic association between brain disconnections and cognitive-behavioural measures at the individual level. Here we present the most comprehensive framework, a composite morphospace of white matter disconnections (disconnectome) to predict neuropsychological scores 1 year after stroke. Linking the latent disconnectome morphospace to neuropsychological outcomes yields biological insights that are available as the first comprehensive atlas of disconnectome-deficit relations across 86 scores—a Neuropsychological White Matter Atlas. Our novel predictive framework, the Disconnectome Symptoms Discoverer, achieved better predictivity performances than six other models, including functional disconnection, lesion topology and volume modelling. Out-of-sample prediction derived from this atlas presented a mean absolute error below 20% and allowed personalize neuropsychological predictions. Prediction on an external cohort achieved an R 2 = 0.201 for semantic fluency. In addition, training and testing were replicated on two external cohorts achieving an R 2 = 0.18 for visuospatial performance. This framework is available as an interactive web application (http://disconnectomestudio.bcblab.com) to provide the foundations for a new and practical approach to modelling cognition in stroke. We hope our atlas and web application will help to reduce the burden of cognitive deficits on patients, their families and wider society while also helping to tailor future personalized treatment programmes and discover new targets for treatments. We expect our framework's range of assessments and predictive power to increase even further through future crowdsourcing. [ABSTRACT FROM AUTHOR]

The white chalk cliffs on the south coast of England are one of the most iconic coastlines in the world. Rock coasts located in a weak lithology, such as chalk, are likely to be most vulnerable to climate-change-triggered accelerations in cliff retreat rates. In order to make future forecasts of cliff retreat rates as a response to climate change, we need to look beyond individual erosion events to quantify the long-term trends in cliff retreat rates. Exposure dating of shore platforms using cosmogenic radionuclide analysis and numerical modelling allows us to study past cliff retreat rates across the Late Holocene for these chalk coastlines. Here, we conduct a multi-objective optimisation of a coastal evolution model to both high-precision topographic data and 10Be concentrations at four chalk rock coast sites to reveal a link between cliff retreat rates and the rate of sea-level rise. Furthermore, our results strengthen evidence for a recent acceleration in cliff retreat rates at the chalk cliffs on the south coast of England. Our optimised model results suggest that the relatively rapid historical cliff retreat rates observed at these sites spanning the last 150 years last occurred between 5300 and 6800 years ago when the rate of relative sea-level rise was a factor of 5–9 times more rapid than during the recent observable record. However, results for these chalk sites also indicate that current process-based models of rock coast development are overlooking key processes that were not previously identified at sandstone rock coast sites. Interpretation of results suggest that beaches, cliff debris and heterogenous lithology play an important but poorly understood role in the long-term evolution of these chalk rock coast sites. Despite these limitations, our results reveal significant differences in intertidal weathering rates between sandstone and chalk rock coast sites, which helps to inform the long-standing debate of "wave versus weathering" as the primary control on shore platform development. At the sandstone sites, subaerial weathering has been negligible during the Holocene. In contrast, for the chalk sites, intertidal weathering plays an active role in the long-term development of the shore platform and cliff system. Overall, our results demonstrate how an abstract, process-based model, when optimised with a rigorous optimisation routine, can not only capture long-term trends in transient cliff retreat rates but also distinguish key erosion processes active in millennial-scale rock coast evolution at real-world sites with contrasting rock types. [ABSTRACT FROM AUTHOR]

Phytoplankton‐bacteria interactions represent the evolution of complex cross‐kingdom networks requiring niche specialization of diverse microbes. Unraveling this co‐evolutionary process has proven challenging because microbial partnerships are complex, and their assembly can be dynamic as well as scale‐ and taxon‐dependent. Here, we monitored long‐term experimental evolution of phytoplankton‐bacteria interactions by reintroducing the intact microbiome into an axenized dinoflagellate Alexandrium tamarense to better understand microbiome assembly dynamics and how microbiome composition could shift and stabilize over 15 months. We examined host functioning by growth rate, photosynthetic capability, cell size, and other physiological signatures and compared it to associated microbial communities determined by 16S rRNA gene sequences. Our results showed that microbiome reconstitution did not restore the intact microbiome, instead a distinct microbial community shift to Roseobacter clade was observed in the re‐established cultures. In‐depth comparisons of microbial interactions revealed no apparent coupling between host physiology and specific bacterial taxa, indicating that highly represented, abundant taxa might not be essential for host functioning. The emergence of highly divergent Roseobacter clade sequences suggests fine‐scale microbial dynamics driven by microdiversity could be potentially linked to host functioning. Collectively, our results indicate that functionally comparable microbiomes can be assembled from markedly different, highly diverse bacterial taxa in changing environments. [ABSTRACT FROM AUTHOR]

Continuous experimentation (CE) refers to a set of practices used by software companies to rapidly assess the usage, value, and performance of deployed software using data collected from customers and systems in the field using an experimental methodology. However, despite its increasing popularity in developing web‐facing applications, CE has not been studied in the development process of business‐to‐business (B2B) mission‐critical systems. By observing the CE practices of different teams, with a case study methodology inside Ericsson, we were able to identify the different practices and techniques used in B2B mission‐critical systems and a description and classification of the four possible types of experiments. We present and analyze each of the four types of experiments with examples in the context of the mission‐critical long‐term evolution (4G) product. These examples show the general experimentation process followed by the teams and the use of the different CE practices and techniques. Based on these examples and the empirical data, we derived the HURRIER process to deliver high‐quality solutions that the customers value. Finally, we discuss the challenges, opportunities, and lessons learned from applying CE and the HURRIER process in B2B mission‐critical systems. [ABSTRACT FROM AUTHOR]

Data transmission through a wireless network has faced various signal problems in the past decades. The orthogonal frequency division multiplexing (OFDM) technique is widely accepted in multiple data transfer patterns at various frequency bands. A recent wireless communication network uses OFDM in longterm evolution (LTE) and 5G, among others. The main problem faced by 5G wireless OFDM is distortion of transmission signals in the network. This transmission loss is called peak-to-average power ratio (PAPR). This wireless signal distortion can be reduced using various techniques. This study uses machine learning-based algorithm to solve the problem of PAPR in 5G wireless communication. Partial transmit sequence (PTS) helps in the fast transfer of data in wireless LTE. PTS is merged with deep belief neural network (DBNet) for the efficient processing of signals in wireless 5G networks. Result indicates that the proposed system outperforms other existing techniques. Therefore, PAPR reduction in OFDM by DBNet is optimized with the help of an evolutionary algorithm called particle swarm optimization. Hence, the specified design supports in improving the proposed PAPR reduction architecture. [ABSTRACT FROM AUTHOR]

Network operators are attempting many innovations and changes in 5G using self-organizing networks (SON). The SON operates on the measurement reports (MR), which are obtained from user equipment (UE) and secured against malware and userspace programs. However, the synchronization signal block that the UE relies on to measure the wireless environment configured by a base station is not authenticated. As a result, the UE will likely gauge the wrong wireless environment configured by a false base station (FBS) and transmit the corresponding MR to the serving base station, which poisons the data used for 5G SONs. Therefore, the serving base stations must verify the authenticity of the MR. The 3GPP has advocated numerous solutions for this issue, including the use of public key certificates, identity-based keys, and group keys. Although the solution leveraging group keys have better efficiency and practicality than the other two, they are vulnerable to security threats caused by key leaks via insiders or malicious UE. In this paper, we analyze these security issues and propose an improved group key protocol that uses a new network function, called a broadcast message authentication network function (BMANF), which validates broadcasted messages on behalf of the UE. The protocol operates in two phases: initial and verification. During the initial phase, the 5G core network distributes a shared secret key to the BMANF and UE, allowing the latter to request an authentication ticket from the former. During the verification phase, the UE requests the BMANF to validate the broadcasted messages received from base stations using the ticket and its corresponding shared key. For evaluation, we formally verified the proposed protocol, which was then compared with alternative methods in terms of computing cost. As a result, the proposed protocol fulfills the security requirements and shows a lower overhead than the alternatives. [ABSTRACT FROM AUTHOR]

In the previous work of Yue et al. (2022), the ionospheric evolution during the Holocene (9455 BC to 2015 AD) was comprehensively and carefully investigated for the first time using the Global Coupled Ionosphere-Thermosphere-Electrodynamics Model developed at the Institute of Geology and Geophysics, Chinese Academy of Sciences (GCITEM-IGGCAS), driven by realistic geomagnetic fields, CO2 levels, and solar activity derived from ancient media records and modern measurements. In this study, we further quantify the effects of the three drivers on thermospheric neutral density and temperature variations during the Holocene. We find that the oscillations of solar activity contribute more than 80 % of the thermospheric variability, while either CO2 or the geomagnetic field contributes less than 10 %. The effect of CO2 on the global mean neutral density and temperature is comparable to that of the geomagnetic field throughout the Holocene but is more significant after 1800 AD. In addition, thermospheric density and temperature show approximately linear variations with the dipole moment of the geomagnetic field, CO2 , and F10.7, with only the linear growth rate associated with the geomagnetic field varying significantly in universal time and latitude. The increasing dipole moment and CO2 cool and contract the thermosphere, while solar activity has the opposite effect. The higher the altitude, the greater the influence of the three factors on the thermosphere. Different factors produce different seasonal variations in thermosphere changes. Furthermore, we predict that a 400 ppm increase in CO2 will result in a 50 %–70 % and 84–114 K reduction in global mean neutral density and temperature, respectively, which should directly affect the orbit and lifetime of spacecraft and space debris. [ABSTRACT FROM AUTHOR]

With the anticipated growth of the internet of things (IoT) market, many low-power wide-area (LPWA) technologies have been introduced to connect a wide range of IoT devices with varying performance requirements. The narrowband internet of things (NB-IoT) is a 3rd generation partnership project (3GPP) standardized LPWA technology that meets most IoT service requirements. In this paper, the design and implementation of the physical uplink transmitting chain as well as the physical downlink receiving chain of the NB-IoT user equipment (UE) are presented. Both chains' main blocks are designed to follow the 3GPP NB-IoT LTE standard Release 14 (Rel-14). The whole design is experimentally implemented on the Virtex 7 (VC 709) Connectivity kit, and all performance metrics are reported. Moreover, an NB-IoT base station is implemented and integrated with the two prototyped UEs to set-up an NB-IoT system, which is employed to send data from one UE to another UE through the NB-IoT base station using two FPGAs (one to implement the sending UE and the other one to implement the receiving UE) and three universal software radio peripherals (USRPs) B200 (one to implement the RF front-end of the transmitting UE FPGA, one to implement the base station RF front-end, and one to implement the RF front-end of the receiving UE FPGA). Experimental results show that the implemented NB-IoT system is working successfully, as the two NB-IoT UEs communicate together successfully through the NB-IoT base station and exchange the data properly. [ABSTRACT FROM AUTHOR]

Anomaly detection (AD) is a solution for cellular operators to overcome the difficulty of quality control over the proliferation of cellular phone usage. The telecommunications network monitoring system with anomaly detection enables immediate discovery of problems before they become more complex. Monitoring activities produce logs, which are then analyzed according to the interest, often with the help of statistics and visualizations. Relying on humans for analysis is increasingly difficult due to the immense amount of logs in modern telecommunication networks. This work extends the monitoring to automated anomaly detection by using various ELK modules to form an intelligent monitoring system. A testbed based on OpenAirInterface (OAI) and USRP B210 radiohead is used, which includes the functionalities of HSS, MME, SGW, PGW, eNB, and UE. The proposed system has an average accuracy of 91.5%. This is supported by an average value of the proportion of normal conditions that are correctly predicted at 99.31%. On the other hand, the system can still maintain the functionality of the cellular telecommunications network with an excellent predicate on service quality. [ABSTRACT FROM AUTHOR]

Current and future cellular networks are expected to deliver increased data performance to meet increasingly exponential customer needs. Because of the heterogeneity of future devices and technologies available today, high quality and efficient communication is the challenge for LTE networks. The licensed bandwidth of LTE is used according to standard rules. The unlicensed bandwidth to handle network traffic must expand its bandwidth and increase the data rates. The 5 GHz unlicensed band is most effective and suitable. However, this 5 GHz band has Wi-Fi and frequency coordination of both LTE and Wi-Fi networks during sharing of spectrum. Here the spectrum is shared among the LTE and WiFi network and access 5 GHz unlicensed band. In particular, it affects Wi-Fi performance through downlink transmission of LTE. In this research article, an experimental findings and analysis in 5 GHz frequency spectrum, presented that LTE affects the performance of the Wireless Fidelity network and that to achieve optimal coexistence, a true frequency difference must be maintained. [ABSTRACT FROM AUTHOR]

The ever-increasing demand for high data rates and high connection densities in the vehicle communication network, along with the widespread adoption of radio access over the Third Generation Partnership Project (3GPP) standard, has been a major driver for the research on cellular vehicle-to-everything (C-V2X) communication. Nevertheless, Wi-Fi and other wireless communication technology work on the 5.9 GHz unlicensed band has also undergone booming proliferation over the years. C-V2X users dedicated band on the 5.9 GHz spectrum may thus suffer from both co-channel and adjacent channel interference, which cannot be negligible, especially in urban scenarios. To this end, 3GPP has standardized relay technology in New Radio (NR) V2X sidelink to extend the transmission range under interference. In this paper, through a link-level and system-level simulation study, we evaluate the sidelink performance in relaying scenarios under different interference. Motivated by the recent success of deep learning, a novel neural network is further introduced as a unified benchmark for interference mitigation evaluation. Numerical results show that there exist challenges in the real-time optimization of transmission scheme selection and power allocation in relay-assisted cases. The simulation also reveals that the interference incurred by NR on unlicensed spectrum (NR-U) signals and other sidelink signals is intractable to be suppressed, which may bring potential challenges in future works. [ABSTRACT FROM AUTHOR]

Tasmanian devils have spawned two transmissible cancer lineages, named devil facial tumor 1 (DFT1) and devil facial tumor 2 (DFT2). We investigated the genetic diversity and evolution of these clones by analyzing 78 DFT1 and 41 DFT2 genomes relative to a newly assembled, chromosome-level reference. Time-resolved phylogenetic trees reveal that DFT1 first emerged in 1986 (1982 to 1989) and DFT2 in 2011 (2009 to 2012). Subclone analysis documents transmission of heterogeneous cell populations. DFT2 has faster mutation rates than DFT1 across all variant classes, including substitutions, indels, rearrangements, transposable element insertions, and copy number alterations, and we identify a hypermutated DFT1 lineage with defective DNA mismatch repair. Several loci show plausible evidence of positive selection in DFT1 or DFT2, including loss of chromosome Y and inactivation of MGA, but none are common to both cancers. This study reveals the parallel long-term evolution of two transmissible cancers inhabiting a common niche in Tasmanian devils. [ABSTRACT FROM AUTHOR]

In contrast to long-term relationships, far less is known about the temporal evolution of transient relationships, although these constitute a substantial fraction of people's communication networks. Previous literature suggests that ratings of relationship emotional intensity decay gradually until the relationship ends. Using mobile phone data from three countries (US, UK, and Italy), we demonstrate that the volume of communication between ego and its transient alters does not display such a systematic decay, instead showing a lack of any dominant trends. This means that the communication volume of egos to groups of similar transient alters is stable. We show that alters with longer lifetimes in ego's network receive more calls, with the lifetime of the relationship being predictable from call volume within the first few weeks of first contact. This is observed across all three countries, which include samples of egos at different life stages. The relation between early call volume and lifetime is consistent with the suggestion that individuals initially engage with a new alter so as to evaluate their potential as a tie in terms of homophily. [ABSTRACT FROM AUTHOR]

With the continuous promotion of China's electricity market reform, the introduction of competition in the power generation market provides a new research direction for the generation expansion planning (GEP) problem, which is of great significance in the promotion of the optimization of the power energy structure. In the context of marketization, the electricity price expectation during the planning period is a key factor of GEP for independent power generation groups. There is some literature showing that the electricity price expectation in the planning period can be estimated according to certain laws of market supply and demand, while it seems to us that a future Pay as Bid (PAB) mechanism is better to determine the electricity price expectation. In this paper, to explore the impact of these two different electricity price formation mechanisms on the evolution of the generation market, a multi-agent framework is first established to describe the interaction process among the generation market agents; then, a GEP model for independent power generation groups is developed in the market competition environment, and four representative scenarios are finally designed for detailed comparative studies. Based on these case studies, the conclusion can be summarized as: (1) the PAB bidding mechanism has a lower electricity price and higher market installed capacity almost all the time during the whole planning period for all four scenarios; (2) it is more important that PAB can reduce the impact of parameter uncertainty in the laws of market supply and demand, which can obtain more reliable and reasonable results regarding the long-term evolution of the generation market. [ABSTRACT FROM AUTHOR]

Under complex geostress caused by long-term geological evolution, approximately parallel bedding structures are normally created in rocks due to sedimentation or metamorphism. This type of rock is known as transversely isotropic rock (TIR). Due to the existence of bedding planes, the mechanical properties of TIR are quite different from those of relatively homogeneous rocks. The purpose of this review is to discuss the research progress into the mechanical properties and failure characteristics of TIR and to explore the influence of the bedding structure on the rockburst characteristics of the surrounding rocks. First, the P-wave velocity characteristics of the TIR is summarized, followed by the mechanical properties (e.g., the uniaxial compressive strength, the triaxial compressive strength, and tensile strength) and the related failure characteristics of the TIR. The strength criteria of the TIR under triaxial compression are also summarized in this section. Second, the research progress of the rockburst tests on the TIR is reviewed. Finally, six prospects for the study of the transversely isotropic rock are presented: (1) measuring the Brazilian tensile strength of the TIR; (2) establishing the strength criteria for the TIR; (3) revealing the influence mechanism of the mineral particles between the bedding planes on rock failure from the microscopic point of view; (4) investigating the mechanical properties of the TIR in complex environments; (5) experimentally investigating the rockburst of the TIR under the stress path of "the three-dimensional high stress + internal unloading + dynamic disturbance"; and (6) studying the influence of the bedding angle, thickness, and number on the rockburst proneness of the TIR. Finally, some conclusions are summarized. [ABSTRACT FROM AUTHOR]

Summary: Fifth‐generation (5G) networks deal with high‐frequency data rates, ultra‐low latency, more reliability, massive network capacity, more availability, and a more uniform user experience. To validate the high‐frequency rates, 5G networks engage beam searching operation. By adopting a beam searching state between the short and long sleep, one can reduce the system's delay. The energy consumption of user equipment (UE) in 5G networks is much higher than in the 4G networks. To reduce the energy consumption and increase the energy saving in UE, Long‐Term Evolution (LTE)‐5G networks adopt the discontinuous reception (DRX) scheme with a fixed number of short sleep. LTE‐DRX without beam search operation (i.e., beam alignment) cannot work in 5G networks. Hence, keeping this scenario in mind, we have modeled a new modified directional discontinuous reception (MD‐DRX) mechanism for LTE‐5G networks. The MD‐DRX mechanism captures the behavior of a beam searching, an inactive, an active, a long sleep, an ON, and a short sleep states. The short sleep state consists of a maximum M short sleep. To get the optimal energy saving and energy consumption (i.e., energy efficiency) from the MD‐DRX mechanism, it is required to check the system's throughput. The trade‐off between energy saving/energy consumption and throughput will provide the system's optimal energy saving and optimal energy consumption. In this paper, we have obtained the system's optimal energy saving and throughput by optimizing the maximum short sleep and short sleep duration. To get the energy efficiency for LTE‐5G networks, the trade‐off between average energy consumption/energy saving and throughput is shown. [ABSTRACT FROM AUTHOR]

SMC X-1 is a high-mass X-ray binary showing superorbital modulation with an unstable period. Previous monitoring shows three excursion events in 1996–1998, 2005–2007, and 2014–2016. The superorbital period drifts from ≳60 to ≲40 d and then evolves back during an excursion. Here, we report a new excursion event of SMC X-1 in 2020–2021, indicating that the superorbital modulation has an unpredictable, chaotic nature. We trace the spin-period evolution and find that the spin-up rate accelerated 1 yr before the onset of this new excursion, which suggests a possible inside-out process connecting the spin-up acceleration and the superorbital excursion. This results in a deviation of the spin-period residual, similar to the behaviour of the first excursion in 1996–1998. In further analysis of the pulse profile evolution, we find that the pulsed fraction shows a long-term evolution and may be connected to the superorbital excursion. These discoveries deepen the mystery of SMC X-1 because they cannot be solely interpreted by the warped-disc model. Upcoming pointed observations and theoretical studies may improve our understanding of the detailed accretion mechanisms taking place. [ABSTRACT FROM AUTHOR]

A self-isolated multiple-input-multiple-output (MIMO) antenna in a compact shared ground structure is proposed for 5G systems. The proposed MIMO antenna consists of customized M-pattern, closely coupled members. It benefits to attain good isolation of the targeted bandwidth transversely without additional de-coupling structures. It is discovered that the arm of M-pattern antenna members can cancel out the coupling on the system and achieve sound isolation among antenna members. A relevant matching circuit model is discussed to show how the suggested theory works in principle. The mixed couplings among antenna members neutralize by modifying the antenna shape with the help of electric and magnetic coupling and surface currents. The proposed self-isolated 2-member MIMO antenna demonstrates sound isolation superior to 15 dB transversely in the frequency bands dedicated to 5G NR: n48/n78 and long-term evolution (LTE) band 42/43/48/52 (3.2–3.98 GHz). Moreover, the proposed 2-member design structure has a scalability advantage. It is extended into an 8-members structure, where a pair of antennas located at each side of the frame offers orthogonality. The proposed 8-members M-pattern MIMO is validated using fabricated and simulated measurements. The investigational results show that the 8-members MIMO (M-shaped) system is effective in higher order MIMO antenna design and offers more than 20 dB isolation transversely in the frequency band 5G NR n48 and LTE band 42/43/52(3.29–3.66 GHz). [ABSTRACT FROM AUTHOR]

Microplastic (MP) pollution is one of the greatest threats to marine ecosystems. Cold seeps are characterized by methane‐rich fluid seepage fueling one of the richest ecosystems on the seafloor, and there are approximately more than 900 cold seeps globally. While the long‐term evolution of MPs in cold seeps remains unclear. Here, how MPs have been deposited in the Haima cold seep since the invention of plastics is demonstrated. It is found that the burial rates of MPs in the non‐seepage areas significantly increased since the massive global use of plastics in the 1930s, nevertheless, the burial rates and abundance of MPs in the methane seepage areas are much lower than the non‐seepage area of the cold seep, suggesting the degradation potential of MPs in cold seeps. More MP‐degrading microorganism populations and functional genes are discovered in methane seepage areas to support this discovery. It is further investigated that the upwelling fluid seepage facilitated the fragmentation and degradation behaviors of MPs. Risk assessment indicated that long‐term transport and transformation of MPs in the deeper sediments can reduce the potential environmental and ecological risks. The findings illuminated the need to determine fundamental strategies for sustainable marine plastic pollution mitigation in the natural deep‐sea environments. [ABSTRACT FROM AUTHOR]

Small-signal model of the MOSFET is an equivalent circuit of its electric components, which defines the electrical characteristics of a MOSFET. The non-quasi-static (NQS) model is one of the most accurate small-signal models used for designing analog/RF circuits. Electronic circuits designed for advanced high-frequency analog/RF applications like (Long-Term Evolution) LTE and (Internet-of-Things) IoT applications, the proper selection of MOSFET is essential. The MOSFETs with lower static power dissipation and high linearity are best suitable for low-power high-frequency analog/digital circuit applications. In this paper, a cylindrical silicon-on-insulator (SOI) Schottky Barrier (SB) MOSFET is investigated, and analog/RF parameters such as transconductance (gm), intrinsic-voltage gain (AV), ION/IOFF ratio, cutoff-frequency (fT), maximum oscillation frequency (fmax), transconductance-generation factor (TGF), gain-frequency product (GFP), transconductance-frequency product (TFP), gain-bandwidth product (GBWP) and gain-transconductance frequency product (GTFP) are extracted. Also, the NQS small-signal model parameters of SOI-SB MOSFET are extracted for the analog circuit application for the frequency range up to 500 GHz. The analog/RF parameters and NQS small-signal parameters of cylindrical SOI-SB MOSFET are compared with cylindrical SB-MOSFET and cylindrical dielectric-pocket (DP) SB-MOSFET. [ABSTRACT FROM AUTHOR]

This paper addresses what Akhil Gupta calls the 'temporality of infrastructure' or 'infrastructure as an open-ended process' by examining changes in the spatiotemporal configuration of a telecommunications network in Papua New Guinea (PNG). It describes the arrival of Digicel Group Ltd, a privately owned foreign company, in response to the PNG government's 2005 decision to allow competition in the market for mobile communications, and it charts the ensuing rapid uptake of mobile phones by users who previously had no access to telecommunications services. It demonstrates how between the years 2007 and 2017, different forms and degrees of connectivity were produced through shifts in network infrastructure: from 2G to 4G LTE technologies; from basic handsets to smartphones; and from the sale of prepaid vouchers ('flex cards') by airtime resellers to purchases of airtime online and at ATMs by mobile users. These shifts widened a digital divide between urban and rural areas that deferred if not denied the promise of national coevalness regardless of where one resides. That is, not only infrastructural time but also 'infrastructural citizenship', to use Charlotte Lemanski's term, came to be imagined, represented, and lived as a function of one's location in a network of uneven connections. [ABSTRACT FROM AUTHOR]

Bottom currents are key processes that contribute to the shaping of submarine slopes, with the redistribution of sediments in contourite systems. Despite numerous recent studies on contourite systems, the complexity and diversity of these sedimentary systems are still not fully understood and often underestimated. Their understanding requires comprehensive works integrating all scales from seismic architecture to microfacies. This paper focuses on a contouritic ridge located between 2000 m and 2500 m water depth on the Mozambique margin. Bathymetry, seismic data and piston cores collected during the PAMELA‐MOZ3 cruise allow a multi‐scale study from large depositional geometries to sedimentary facies. At the seismic scale, the contouritic ridge shows three stages of evolution with: (i) initiation and development of the drift/moat system; (ii) an intermediate stage with successive incisions and aggradations; and (iii) moat infill and drift erosion during the Plio‐Quaternary. Plio‐Quaternary deposits are composed of hemipelagic, turbiditic and contouritic facies filling the moat. Coarse‐grained contouritic facies, dominated by planktonic foraminifera, are identified on the western flank of the ridge between the moat infill and the erosional area at the top of the ridge. They consist of condensed deposits, with sedimentation rate about 0.3 cm/ka, indicating a strong and stable bottom current that winnows away the fine‐grained component. This facies could be present more generally in an intermediate position between erosion and depositional areas in contourite systems. At present, the contourite system is located at the transition depth between North Atlantic Deep Water and Antarctic Intermediate Water. Trajectories of bottom currents are complex and interact with sporadic turbidity currents and anti‐clockwise eddies that participate in reshaping the sea floor morphology. Although Plio‐Quaternary depositional geometries indicate the end of drift/moat development, the moat filling and drift erosion are also related to bottom currents and constitute atypical contouritic sedimentation. [ABSTRACT FROM AUTHOR]

Technological advancements, barging economics quest for swift communication. The growing demand for data rate and network coverage has pursued telecommunication companies to expand and upgrade their network for maximum coverage and agile speed. The Long Term Evolution (LTE) networks are based on a homogenous configuration comprised of Macrocells. However, during peak hours these macro base stations respond to few numbers of clients whereas many of the user's requests remain unresponded since these stations lack adequate capacity to tolerate the load of increased traffic on the network. To avoid congestion homogeneous networks are turned into heterogeneous networks by augmenting macro base stations with Low Power Nodes (LPN) using femto, pico, and microcells. We propose a new call handling algorithm in which cells are deployed in a hierarchical manner where the priority of originating calls is given to femtocell. The proposed algorithm was implemented for a realistic scenario in a teaching institution and the performance was assessed and compared for 4 scenarios using 3 user cases. Results show that there is a significant improvement in the number of connections established and throughput for both indoor and outdoor users when we increase LPN for a certain critical area. During peak hours, in the fading environment, there is only a 50% connectivity ratio in presence of a single macrocell for 200 users. After applying our algorithm, the connectivity boosts up to 80% which is further increased by deploying more LPNs. Over a well-organized network, the proposed scheme attested to be more efficient than those formerly used, subsequently contributing satisfying outcomes for the end-users. [ABSTRACT FROM AUTHOR]

The European Telecommunications Standards Institute ("ETSI") is responsible for developing and promulgating modern cellular standards such as LTE and 5G. These mainstream cellular standards are expanding throughout the economy, particularly with the adoption and growth of new cellular standards for the "Internet of Things" ("IOT'), whereby diverse new industries such as energy, medical, automotive, appliances, warehousing, and many others increasingly adopt and incorporate cellular functionality to wirelessly connect their products to global communications systems. Many of the technologies used in those standards are patented by ETSI members, who collectively agree on which technologies to include in a standard (e.g., their own) and which to exclude (e.g., those patented by others). More than thirty years ago, government competition agencies warned ETSI that this collective exclusion of competing technologies by way of standardization would raise competition law issues and risk antitrust enforcement against ETSI and its members. ETSI had a responsibility to prevent its members from using the standardization process, and their patents included in the standards they develop, to entrench their own business interests while excluding competitors. Pragmatically, ETSI drafted, and ultimately adopted, a policy whereby members would commit to license their patents that were accepted into a standard-known as standard-essential patents ("SEPs")-on fair, reasonable, and nondiscriminatory ("FRAND") terms. Companies, lawyers, government representatives, competition law experts, lobbyists, ambassadors, and scholars have been arguing over the meaning of FRAND and its requirements ever since. Billions of dollars in annual patent licensing royalties are at stake. Rather than addressing ETSI's FRAND policy from the more common perspective-arguinga bout what FRAND should mean or which policy approaches are best-in this Article, the authors take a fresh approach focusing on a historical review and analysis of what the drafters of the ETSI FRAND policy intended and believed it did mean at the time they wrote and approved it. Because many historical ETSI records are maintained as confidential to ETSI members-which perhaps has contributed to the relative dearth of prior scholarship relating to historical ETSI processes-this Article results from an extensive review of publicly available materials from the period when the ETSI Intellectual Property Rights ("IPR") Policy was developed and enacted and reports on the contemporaneous accounts of those involved. The authors then apply these historical documents and accounts to assess key issues in today's policy and legal disputes. The results show that many of the issues spawning debates about interpretation of the ETSI policy were expressly addressed by the ETSI drafters at the time that the ETSI IPR Policy was created and approved, and that significant historical evidence is available regarding the expressly intended meaning and application of the ETSI IPR Policy. [ABSTRACT FROM AUTHOR]

This article proposes a four-port multiple input multiple output (MIMO) ultra-wideband (UWB) antenna that operates across 3 to 13 GHz. Four identical fractal patches are placed orthogonally to each other. The uniqueness of the proposed design is that it does not need to incorporate any dedicated/specific design/component to realize notches within the UWB range. The elimination of notches, enhancement of bandwidth, and improvement of isolation have been achieved by integrating a resistance-loaded stub with the ground plane. The isolation between the elements was measured to be below -20 dB across the entire operating band. The fabricated prototype exhibits better diversity parameters like envelop correlation coefficient (ECC) < 0.003, diversity gain (DG) > 9.99, channel capacity loss (CCL) < 0.4 bps/Hz, and mean effective gain (MEG) < 2 dB. The proposed MIMO antenna shows omnidirectional radiation patterns with a peak gain of 5.4 dBi and radiation efficiency > 66% with required compactness having interelement (edge to edge) distance of 5.4 mm. After application of decoupling method radiation efficiency varies from 66% to 82% with gain ranging between 1.8 and 5.54 dBi. The diverse performance of the fabricated MIMO proves it to be a good candidate for UBW imaging, LTE applications, and S, C, and X band applications. [ABSTRACT FROM AUTHOR]

This study used rainfall and annual landslide data for the 2003–2017 period in Taiwan to determine the long-term evolution of landslides and conducted a spatiotemporal analysis of landslides at the subwatershed scale. The historically severe landslide induced by Typhoon Morakot in 2009 was mainly distributed in the central mountainous region and southern Taiwan. The Mann–Kendall trend test revealed that in 2003–2017, 13.2% of subwatersheds in Taiwan exhibited an upward trend of landslide evolution. Local outlier analysis results revealed that the landslide high–high cluster was concentrated in the central mountainous region and southern Taiwan. Moreover, the spatiotemporal analysis indicated 24.2% of subwatersheds in Taiwan in 2003–2017 as spatiotemporal landslide hot spots. The main patterns of spatiotemporal landslide hot spots in 2003–2017 were consecutive, intensifying, persistent, oscillating, and sporadic hot spots. The recovery rate in the first two years after the extreme rainfall-induced landslide event in Taiwan was 22.2%, and that in the third to eighth years was 31.6%. The recovery rate after extreme rainfall-induced landslides in Taiwan was higher than that after major earthquake-induced landslides in the world, and the new landslides were easily induced in the area of rivers and large landslide cases after Typhoon Morakot in 2009. [ABSTRACT FROM AUTHOR]

SARS-CoV-2 evolves rapidly in part because of its high mutation rate. Here, we examine whether this mutational process itself has changed during viral evolution. To do this, we quantify the relative rates of different types of single-nucleotide mutations at 4-fold degenerate sites in the viral genome across millions of human SARS-CoV-2 sequences. We find clear shifts in the relative rates of several types of mutations during SARS-CoV-2 evolution. The most striking trend is a roughly 2-fold decrease in the relative rate of G→T mutations in Omicron versus early clades, as was recently noted by Ruis et al. (2022. Mutational spectra distinguish SARS-CoV-2 replication niches. bioRxiv, doi:10.1101/2022.09.27.509649). There is also a decrease in the relative rate of C→T mutations in Delta, and other subtle changes in the mutation spectrum along the phylogeny. We speculate that these changes in the mutation spectrum could arise from viral mutations that affect genome replication, packaging, and antagonization of host innate-immune factors, although environmental factors could also play a role. Interestingly, the mutation spectrum of Omicron is more similar than that of earlier SARS-CoV-2 clades to the spectrum that shaped the long-term evolution of sarbecoviruses. Overall, our work shows that the mutation process is itself a dynamic variable during SARS-CoV-2 evolution and suggests that human SARS-CoV-2 may be trending toward a mutation spectrum more similar to that of other animal sarbecoviruses. [ABSTRACT FROM AUTHOR]