Waveform Design for 5G and Beyond

5G is envisioned to improve major key performance indicators (KPIs), such as peak data rate, spectral efficiency, power consumption, complexity, connection density, latency, and mobility. This chapter aims to provide a complete picture of the ongoing 5G waveform discussions and overviews the major candidates. It provides a brief description of the waveform and reveals the 5G use cases and waveform design requirements. The chapter presents the main features of cyclic prefix-orthogonal frequency-division multiplexing (CP-OFDM) that is deployed in 4G LTE systems. CP-OFDM is the baseline of the 5G waveform discussions since the performance of a new waveform is usually compared with it. The chapter examines the essential characteristics of the major waveform candidates along with the related advantages and disadvantages. It summarizes and compares the key features of different waveforms.Comment: 22 pages, 21 figures, 2 tables; accepted version (The URL for the final version: https://onlinelibrary.wiley.com/doi/abs/10.1002/9781119333142.ch2

Discovering Class-Specific Pixels for Weakly-Supervised Semantic Segmentation

We propose an approach to discover class-specific pixels for the weakly-supervised semantic segmentation task. We show that properly combining saliency and attention maps allows us to obtain reliable cues capable of significantly boosting the performance. First, we propose a simple yet powerful hierarchical approach to discover the class-agnostic salient regions, obtained using a salient object detector, which otherwise would be ignored. Second, we use fully convolutional attention maps to reliably localize the class-specific regions in a given image. We combine these two cues to discover class-specific pixels which are then used as an approximate ground truth for training a CNN. While solving the weakly supervised semantic segmentation task, we ensure that the image-level classification task is also solved in order to enforce the CNN to assign at least one pixel to each object present in the image. Experimentally, on the PASCAL VOC12 val and test sets, we obtain the mIoU of 60.8% and 61.9%, achieving the performance gains of 5.1% and 5.2% compared to the published state-of-the-art results. The code is made publicly available

Payoff-Based Dynamics for Multiplayer Weakly Acyclic Games

We consider repeated multiplayer games in which players repeatedly and simultaneously choose strategies from a finite set of available strategies according to some strategy adjustment process. We focus on the specific class of weakly acyclic games, which is particularly relevant for multiagent cooperative control problems. A strategy adjustment process determines how players select their strategies at any stage as a function of the information gathered over previous stages. Of particular interest are “payoff-based” processes in which, at any stage, players know only their own actions and (noise corrupted) payoffs from previous stages. In particular, players do not know the actions taken by other players and do not know the structural form of payoff functions. We introduce three different payoff-based processes for increasingly general scenarios and prove that, after a sufficiently large number of stages, player actions constitute a Nash equilibrium at any stage with arbitrarily high probability. We also show how to modify player utility functions through tolls and incentives in so-called congestion games, a special class of weakly acyclic games, to guarantee that a centralized objective can be realized as a Nash equilibrium. We illustrate the methods with a simulation of distributed routing over a network

The technical and economic efficiency analyses of performance of brown trout (Salmo trutta fario l., 1758) fed by the commercial diets enriched with different levels of linolenic acid (lna; 18:3 n-3)

This study was designed to determine the technical and economic efficiency levels of the commercial basal feeds enriched with 10%, 5% and 0% rates of LNA (LNA10, LNA5 and LNA0) on the growth performance of brown trout by analyzing the marginal factor cost (MFC) and the marginal revenue of physical product (MRPP). A total of 300 brown trout with an initial individual weight of 4±0.05 g were randomly divided in 12 cages (25 fingerlings in each cage), and kept under 24L:0D (light/dark) photoperiod condition for 9 weeks treated by LNA10, LNA5 and LNA0. The results of the study showed that LNA0 and LNA10 of the effective feed sources, respectively on the growth performance of brown trout were more suitable to produce as the homogeneous products for the consumers and differentiated those for the drug industry in view of the economic and technical efficiencies

Analysis and testing of internal combustion engine driven linear alternator

Introduction. Internal combustion engine technology has been considered for the alternator system in the last two decades. Especially when considering fuel diversity, reliability, portability, power density, research studies are increasing day by day. In this respect, interest has been focused on linear generator studies. Purpose. The goal of the research is to investigate the performance of a linear generator and its application to generate electrical energy from an internal combustion engine to solve the range problem of small electric powered vehicles. The generator, unlike a traditional generator, consists of a linear generator with a crank mechanism driven by an internal combustion engine. Originality. The configuration of the linear generator with internal combustion engine crank has not previously been reported. Methods. The numerical solution of the generator was carried out by the finite element method in the Ansys Maxwell software in a cylindrical coordinate system. The effect of stroke length and frequency on voltage and output power was investigated by monitoring an external electrical load. A prototype linear generator has been designed and produced considering the sizing dimensions. The configuration can be used in power-hungry applications and increase the range of small electric vehicles. Results. The results from simulation and practice are largely in agreement. Practical value. A practical mechanical system was built comprising a linear generator connected to a 2.2 kW internal combustion engine via a crank connecting rod for analysis.Вступ. Останні два десятиліття розглядалася техніка двигуна внутрішнього згоряння для системи генератора змінного струму. Особливо з урахуванням різноманітності видів палива, надійності, портативності, питомої потужності кількість досліджень зростає з кожним днем. У зв’язку з цим інтерес був зосереджений на дослідженнях лінійних генераторів. Мета. Метою дослідження є аналіз продуктивності лінійного генератора та його застосування для вироблення електроенергії від двигуна внутрішнього згоряння для вирішення проблеми запасу ходу малих електромобілів. Генератор, на відміну від традиційного, складається з лінійного генератора з кривошипно-шатунним механізмом, що рухається двигуном внутрішнього згоряння. Оригінальність. Про конфігурацію лінійного генератора з кривошипом двигуна внутрішнього згоряння раніше не повідомлялося. Методи. Чисельне рішення генератора проводилося методом скінченних елементів у програмі Ansys Maxwell в циліндричної системі координат. Вплив довжини та частоти ходу на напругу та вихідну потужність досліджували шляхом моніторингу зовнішнього електричного навантаження. З урахуванням габаритних розмірів розроблено та виготовлено прототип лінійного генератора. Конфігурація може використовуватися в енергоємних застосуваннях і збільшувати запас ходу невеликих електромобілів. Результати. Результати моделювання та з практики переважно збігаються. Практична цінність. Для аналізу було побудовано практичну механічну систему, що складається з лінійного генератора, з’єднаного з двигуном внутрішнього згоряння потужністю 2,2 кВт через шатун кривошипу

Neurofilament light chain as neuronal injury marker - What is needed to facilitate implementation in clinical laboratory practice?

Neurobiomarkers have attracted significant attention over the last ten years. One promising biomarker is the neurofilament light chain protein (NfL). Since the introduction of ultrasensitive assays, NfL has been developed into a widely used axonal damage marker of relevance to the diagnosis, prognostication, follow-up, and treatment monitoring of a range of neurological disorders, including multiple sclerosis, amyotrophic lateral sclerosis, and Alzheimer's disease. The marker is increasingly used clinically, as well as in clinical trials. Even if we have validated precise, sensitive, and specific assays for NfL quantification in both cerebrospinal fluid and blood, there are analytical, as well as pre- and post-analytical aspects of the total NfL testing process, including biomarker interpretation, to consider. Although the biomarker is already in use in specialised clinical laboratory settings, a more general use requires some further work. In this review, we provide brief basic information and opinions on NfL as a biomarker of axonal injury in neurological diseases and pinpoint additional work needed to facilitate biomarker implementation in clinical practice

Forward tunneling current in Pt/p-InGaN and Pt/n-InGaN Schottky barriers in a wide temperature range

Cataloged from PDF version of article.The current-transport mechanisms of the Pt contacts on p-InGaN and n-InGaN were investigated in a wide temperature range (80-360 K) and in the forward bias regime. It was found that the ideality factor (n) values and Schottky barrier heights (SBHs), as determined by thermionic emission (TE), were a strong function of temperature and Phi(b0) show the unusual behavior of increasing linearly with an increase in temperature from 80 to 360 K for both Schottky contacts. The tunneling saturation (J(TU)(0)) and tunneling parameters (E-0) were calculated for both Schottky contacts. We observed a weak temperature dependence of the saturation current and a fairly small dependence on the temperature of the tunneling parameters in this temperature range. The results indicate that the dominant mechanism of the charge transport across the Pt/p-InGaN and Pt/n-InGaN Schottky contacts are electron tunneling to deep levels in the vicinity of mixed/screw dislocations in the temperature range of 80-360 K. (c) 2012 Elsevier B.V. All rights reserved

Probing the loss origins of ultra-smooth Si3N4\mathrm{Si_3N_4} integrated photonic waveguides

On-chip optical waveguides with low propagation losses and precisely engineered group velocity dispersion (GVD) are important to nonlinear photonic devices such as soliton microcombs. Yet, despite intensive research efforts, nonlinear integrated photonic platforms still feature propagation losses orders of magnitude higher than in standard optical fiber. The tight confinement and high index contrast of integrated waveguides make them highly susceptible to fabrication induced surface roughness. Therefore, microresonators with ultra-high Q factors are, to date, only attainable in polished bulk crystalline, or chemically etched silica based devices, that pose however challenges for full photonic integration. Here, we demonstrate the fabrication of silicon nitride ($\mathrm{Si_3N_4}$) waveguides with unprecedentedly smooth sidewalls and tight confinement with record low propagation losses. This is achieved by combining the photonic Damascene process with a novel reflow process, which reduces etching roughness, while sufficiently preserving dimensional accuracy. This leads to previously unattainable \emph{mean} microresonator Q factors larger than $5\times10^6$ for tightly confining waveguides with anomalous dispersion. Via systematic process step variation and two independent characterization techniques we differentiate the scattering and absorption loss contributions, and reveal metal impurity related absorption to be an important loss origin. Although such impurities are known to limit optical fibers, this is the first time they are identified, and play a tangible role, in absorption of integrated microresonators. Taken together, our work provides new insights in the origins of propagation losses in $\mathrm{Si_3N_4}$ waveguides and provides the technological basis for integrated nonlinear photonics in the ultra-high Q regime