A Survey of Positioning Systems Using Visible LED Lights

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.As Global Positioning System (GPS) cannot provide satisfying performance in indoor environments, indoor positioning technology, which utilizes indoor wireless signals instead of GPS signals, has grown rapidly in recent years. Meanwhile, visible light communication (VLC) using light devices such as light emitting diodes (LEDs) has been deemed to be a promising candidate in the heterogeneous wireless networks that may collaborate with radio frequencies (RF) wireless networks. In particular, light-fidelity has a great potential for deployment in future indoor environments because of its high throughput and security advantages. This paper provides a comprehensive study of a novel positioning technology based on visible white LED lights, which has attracted much attention from both academia and industry. The essential characteristics and principles of this system are deeply discussed, and relevant positioning algorithms and designs are classified and elaborated. This paper undertakes a thorough investigation into current LED-based indoor positioning systems and compares their performance through many aspects, such as test environment, accuracy, and cost. It presents indoor hybrid positioning systems among VLC and other systems (e.g., inertial sensors and RF systems). We also review and classify outdoor VLC positioning applications for the first time. Finally, this paper surveys major advances as well as open issues, challenges, and future research directions in VLC positioning systems.Peer reviewe

Persuasion prosody in prosecutor’s speech: Ukrainian and english

This paper presents the research of prosodic means conveying the persuasion modality in a prosecutor’s speech in court. The material under study consists of English and Ukrainian speeches of the prosecutors (the total duration time is 16 hours). The results of the experimental material examination demonstrate common and specific characteristics of prosody components (melody, loudness, tempo, timber and sentence stress) in English and Ukrainian. Pragmatics of prosody semantics and correlation between its parameters have been proved. It has been stated that in both English and Ukrainian an utterance becomes emphatic due to the prosodic means of persuasion in a prosecutor’s speech as follows:  1) changes of tempo; 2) changes of the pitch of a voice; 3) replacements of the rising tone with the falling one and vice versa; 4) usage of complex tones; 5) use of an interrupted ascending or descending scale; 6) change of sentence stress type; 7) division of a sense group into two or more parts. The above mentioned facts enable us to conclude that: while describing the first of these aspects of typological similarity of prosody in the compared languages, the parameters of the pitch component of intonation are most informative when differentiating attitudinal ones. The specificity of interaction between prosodic and grammar means when expressing persuasion in Ukrainian and English prosecutor’s speech is caused by a degree of distinction between the grammatical and vocabulary systems of the compared languages

Semantic Communications for Wireless Sensing: RIS-aided Encoding and Self-supervised Decoding

Semantic communications can reduce the resource consumption by transmitting task-related semantic information extracted from source messages. However, when the source messages are utilized for various tasks, e.g., wireless sensing data for localization and activities detection, semantic communication technique is difficult to be implemented because of the increased processing complexity. In this paper, we propose the inverse semantic communications as a new paradigm. Instead of extracting semantic information from messages, we aim to encode the task-related source messages into a hyper-source message for data transmission or storage. Following this paradigm, we design an inverse semantic-aware wireless sensing framework with three algorithms for data sampling, reconfigurable intelligent surface (RIS)-aided encoding, and self-supervised decoding, respectively. Specifically, on the one hand, we propose a novel RIS hardware design for encoding several signal spectrums into one MetaSpectrum. To select the task-related signal spectrums for achieving efficient encoding, a semantic hash sampling method is introduced. On the other hand, we propose a self-supervised learning method for decoding the MetaSpectrums to obtain the original signal spectrums. Using the sensing data collected from real-world, we show that our framework can reduce the data volume by 95% compared to that before encoding, without affecting the accomplishment of sensing tasks. Moreover, compared with the typically used uniform sampling scheme, the proposed semantic hash sampling scheme can achieve 67% lower mean squared error in recovering the sensing parameters. In addition, experiment results demonstrate that the amplitude response matrix of the RIS enables the encryption of the sensing data

Power system applications of fiber optics

Power system applications of optical systems, primarily using fiber optics, are reviewed. The first section reviews fibers as components of communication systems. The second section deals with fiber sensors for power systems, reviewing the many ways light sources and fibers can be combined to make measurements. Methods of measuring electric field gradient are discussed. Optical data processing is the subject of the third section, which begins by reviewing some widely different examples and concludes by outlining some potential applications in power systems: fault location in transformers, optical switching for light fired thyristors and fault detection based on the inherent symmetry of most power apparatus. The fourth and final section is concerned with using optical fibers to transmit power to electric equipment in a high voltage situation, potentially replacing expensive high voltage low power transformers. JPL has designed small photodiodes specifically for this purpose, and fabricated and tested several samples. This work is described

The Media as Participants in the International Legal Process

We know what we know about current international events through the media. The media (with their instantaneous transmission of images and sound across great distances) inform us of everything from the train bombings in Madrid and London, to human rights abuses in Darfur, to the fall of Saddam Hussein’s Iraq. Yet the media do not simply communicate raw information; they selectively filter, define and give shape to the events that they cover — in terms of what is happening, whether it is appropriate, and how relevant international actors should and do respond. The media thus are the nerves of the international system, and, as mass communicators, they perform critical functions in the international legal process. The media’s effects on societies and individuals have been studied from a gamut of academic and political angles. In international legal scholarship, however, the media tend to be discussed briefly or in certain limited contexts, such as the use of the media to disseminate propaganda or the regulation and control of the media. There has not been any comprehensive study on the media’s functions in the international legal process. The lack of scholarship in this regard is likely attributable, at least in part, to the facts that the media are unconventional participants, and that they oftentimes operate “behind the scenes” — as messengers for other actors and at deep levels of the public subconscious. If anything, however, these characteristics increase, rather than decrease, the media’s influence. This Article examines that influence. In Part I of this Article, I put in context the question of the media’s influence in the international legal process. That process is characterized by significant communicative gaps that the media help fill. In Part II, I analyze the media’s functions at every stage of the international legal process — from the prescription of international law, to its codification, invocation, application and even termination. In Part III, I address systemic factors that impede media performance, demonstrating that, although the media perform important legal functions, they do not perform those functions perfectly. In Part IV, I consider efforts to minimize these imperfections. I conclude that the media will continue to operate imperfectly but as unique and specialized participants in the international legal process. The goal, then, is to recognize both the media’s functions and their limits so that we, as international scholars and practitioners, can work within that process to achieve desirable legal and policy outcomes

Sensing Aided Reconfigurable Intelligent Surfaces for 3GPP 5G Transparent Operation

Can reconfigurable intelligent surfaces (RISs) operate in a standalone mode that is completely transparent to the 3GPP 5G initial access process? Realizing that may greatly simplify the deployment and operation of these surfaces and reduce the infrastructure control overhead. This paper investigates the feasibility of building standalone/transparent RIS systems and shows that one key challenge lies in determining the user equipment (UE)-side RIS beam reflection direction. To address this challenge, we propose to equip the RISs with multi-modal sensing capabilities (e.g., using wireless and visual sensors) that enable them to develop some perception of the surrounding environment and the mobile users. Based on that, we develop a machine learning framework that leverages the wireless and visual sensors at the RIS to select the optimal beams between the base station (BS) and users and enable 5G standalone/transparent RIS operation. Using a high-fidelity synthetic dataset with co-existing wireless and visual data, we extensively evaluate the performance of the proposed framework. Experimental results demonstrate that the proposed approach can accurately predict the BS and UE-side candidate beams, and that the standalone RIS beam selection solution is capable of realizing near-optimal achievable rates with significantly reduced beam training overhead.Comment: The RIS dataset and script files will be available soon. arXiv admin note: text overlap with arXiv:2211.0756