DGNSS Cooperative Positioning in Mobile Smart Devices: A Proof of Concept

Global Navigation Satellite System (GNSS) constitutes the foremost provider for geo-localization in a growing number of consumer-grade applications and services supporting urban mobility. Therefore, low-cost and ultra-low-cost, embedded GNSS receivers have become ubiquitous in mobile devices such as smartphones and consumer electronics to a large extent. However, limited sky visibility and multipath scattering induced in urban areas hinder positioning and navigation capabilities, thus threatening the quality of position estimates. This work leverages the availability of raw GNSS measurements in ultralow-cost smartphone chipsets and the ubiquitous connectivity provided by modern, low-latency network infrastructures to enable a Cooperative Positioning (CP) framework. A Proof Of Concept is presented that aims at demonstrating the feasibility of a GNSS-only CP among networked smartphones embedding ultra-low-cost GNSS receivers. The test campaign presented in this study assessed the feasibility of a client-server approach over 4G/LTE network connectivity. Results demonstrated an overall service availability above 80%, and an average accuracy improvement over the 40% w.r.t. to the GNSS standalone solution

Multi-Modal Data Collection for Measuring Health, Behavior, and Living Environment of Large-Scale Participant Cohorts: Conceptual Framework and Findings from Deployments

As mobile technologies become ever more sensor-rich, portable, and ubiquitous, data captured by smart devices are lending rich insights into users' daily lives with unprecedented comprehensiveness, unobtrusiveness, and ecological validity. A number of human-subject studies have been conducted in the past decade to examine the use of mobile sensing to uncover individual behavioral patterns and health outcomes. While understanding health and behavior is the focus for most of these studies, we find that minimal attention has been placed on measuring personal environments, especially together with other human-centric data modalities. Moreover, the participant cohort size in most existing studies falls well below a few hundred, leaving questions open about the reliability of findings on the relations between mobile sensing signals and human outcomes. To address these limitations, we developed a home environment sensor kit for continuous indoor air quality tracking and deployed it in conjunction with established mobile sensing and experience sampling techniques in a cohort study of up to 1584 student participants per data type for 3 weeks at a major research university in the United States. In this paper, we begin by proposing a conceptual framework that systematically organizes human-centric data modalities by their temporal coverage and spatial freedom. Then we report our study design and procedure, technologies and methods deployed, descriptive statistics of the collected data, and results from our extensive exploratory analyses. Our novel data, conceptual development, and analytical findings provide important guidance for data collection and hypothesis generation in future human-centric sensing studies.This work was supported by Whole Communities—Whole Health, a research grand challenge at the University of Texas at Austin, and National Science Foundation Award SES-1758835.Office of the VP for Researc

History of English as punctuated equilibria? A meta-analysis of the rate of linguistic change in Middle English

In this paper, we explore the rate of language change in the history of English. Our main focus is on detecting periods of accelerated change in Middle English (1150–1500), but we also compare the Middle English data with the Early Modern period (1500–1700) in order to establish a longer diachrony for the pace at which English has changed over time. Our study is based on a meta-analysis of existing corpus research, which is made available through a new linguistic resource, the Language Change Database (LCD). By aggregating the rates of 44 individual changes, we provide a critical assessment of how well the theory of punctuated equilibria (Dixon 1997) fits with our results. More specifically, by comparing the rate of language change with major language-external events, such as the Norman Conquest and the Black Death, we provide the first corpus-based meta-analysis of whether these events, which had significant societal consequences, also had an impact on the rate of language change. Our results indicate that major changes in the rate of linguistic change in the late medieval period could indeed be connected to the social and cultural after-effects of the Norman Conquest. We also make a methodological contribution to the field of English historical linguistics: by re-using data from existing research, linguists can start to ask new, fundamental questions about the ways in which language change progresses.Peer reviewe

Joint Radar and Communication Design: Applications, State-of-the-Art, and the Road Ahead

Sharing of the frequency bands between radar and communication systems has attracted substantial attention, as it can avoid under-utilization of otherwise permanently allocated spectral resources, thus improving efficiency. Further, there is increasing demand for radar and communication systems that share the hardware platform as well as the frequency band, as this not only decongests the spectrum, but also benefits both sensing and signaling operations via the full cooperation between both functionalities. Nevertheless, the success of spectrum and hardware sharing between radar and communication systems critically depends on high-quality joint radar and communication designs. In the first part of this paper, we overview the research progress in the areas of radar-communication coexistence and dual-functional radar-communication (DFRC) systems, with particular emphasis on application scenarios and technical approaches. In the second part, we propose a novel transceiver architecture and frame structure for a DFRC base station (BS) operating in the millimeter wave (mmWave) band, using the hybrid analog-digital (HAD) beamforming technique. We assume that the BS is serving a multi-antenna user equipment (UE) over a mmWave channel, and at the same time it actively detects targets. The targets also play the role of scatterers for the communication signal. In that framework, we propose a novel scheme for joint target search and communication channel estimation, which relies on omni-directional pilot signals generated by the HAD structure. Given a fully-digital communication precoder and a desired radar transmit beampattern, we propose to design the analog and digital precoders under non-convex constant-modulus (CM) and power constraints, such that the BS can formulate narrow beams towards all the targets, while pre-equalizing the impact of the communication channel. Furthermore, we design a HAD receiver that can simultaneously process signals from the UE and echo waves from the targets. By tracking the angular variation of the targets, we show that it is possible to recover the target echoes and mitigate the resulting interference to the UE signals, even when the radar and communication signals share the same signal-to-noise ratio (SNR). The feasibility and efficiency of the proposed approaches in realizing DFRC are verified via numerical simulations. Finally, the paper concludes with an overview of the open problems in the research field of communication and radar spectrum sharing (CRSS)

Studying complex surface dynamical systems using helium-3 spin-echo spectroscopy

The aim of the present thesis is to extend the range of application of the helium-3 spin-echo (HeSE) technique to complex surface dynamical systems. A twofold approach is presented: the development of improved experimental equipment and the investigation of a series of prototypical aromatic adsorbate systems. Chapter 1 discusses the motivation for this work and compares HeSE with other techniques probing surface motion. Subsequently, an introduction to the HeSE method is given in Chapter 2, explaining the theoretical background and describing the main components of the Cambridge spectrometer as well as the principle data aquisition and interpretation methods. Chapters 3 and 4 describe the development and testing of two new pieces of equipment. MiniScat, a compact helium atom scattering apparatus, has been designed as a sample preparation facility to enable structural studies and increase the experimental throughput. A new supersonic helium beam source improves the resolution of the HeSE spectrometer by a factor of 5.5 and extends accessible timescales into the nanometre range. The dynamics of cyclopentadienyl (Cp) on Cu(111) are presented in Chapter 5. The ionically bound Cp is remarkably mobile, moving in single jumps between adjacent hollow sites over an energy barrier of 41 ± 1 meV. The data exhibit multicomponent lineshapes that allow the determination of the energy difference between fcc and hcp sites of 12.3±0.3 meV in a Bayesian method probing the probability space of all data combined. Molecular dynamics (MD) simulations provide a friction coecient of 2.5 ± 0.5 ps1. Chapter 6 shows that a physisorbed pyrrole hops between bridge sites on Cu(111). Strong lateral interactions alter the lineshapes from a predicted double exponential towards an apparent single exponential decay. First principles density functional theory calculations by Sacchi and Jenkins reveal that a large contribution to the experimentally determined apparent activation energy of 53 ± 4 meV arises from a site-dependence in the zero point energies, primarily of the vibrational C–H and N–H out-of-plane bending and ring torsion modes which are not directly involved in the di↵usion process. The surface dynamics of thiophene/Cu(111) are investigated in Chapter 7. Thiophene adsorbs on top sites and forms a covalent S–Cu bond. Two competing activated processes manifest themselves in a kink in the Arrhenius plot: jump di↵usion between adjacent top sites over a barrier of 59 ± 4 meV and rotation around the S–Cu anchor point over a barrier of 22±2 meV. In addition, vertical motion relative to the surface is observed. MD simulations of the di↵usive motion reveal an exceptionally high friction of 5 ± 2 ps1

Applications

Volume 3 describes how resource-aware machine learning methods and techniques are used to successfully solve real-world problems. The book provides numerous specific application examples: in health and medicine for risk modelling, diagnosis, and treatment selection for diseases in electronics, steel production and milling for quality control during manufacturing processes in traffic, logistics for smart cities and for mobile communications

Artificial Intelligence and Cognitive Computing

Artificial intelligence (AI) is a subject garnering increasing attention in both academia and the industry today. The understanding is that AI-enhanced methods and techniques create a variety of opportunities related to improving basic and advanced business functions, including production processes, logistics, financial management and others. As this collection demonstrates, AI-enhanced tools and methods tend to offer more precise results in the fields of engineering, financial accounting, tourism, air-pollution management and many more. The objective of this collection is to bring these topics together to offer the reader a useful primer on how AI-enhanced tools and applications can be of use in today’s world. In the context of the frequently fearful, skeptical and emotion-laden debates on AI and its value added, this volume promotes a positive perspective on AI and its impact on society. AI is a part of a broader ecosystem of sophisticated tools, techniques and technologies, and therefore, it is not immune to developments in that ecosystem. It is thus imperative that inter- and multidisciplinary research on AI and its ecosystem is encouraged. This collection contributes to that

Smart Metering Technology and Services

Global energy context has become more and more complex in the last decades; the raising prices of fuels together with economic crisis, new international environmental and energy policies that are forcing companies. Nowadays, as we approach the problem of global warming and climate changes, smart metering technology has an effective use and is crucial for reaching the 2020 energy efficiency and renewable energy targets as a future for smart grids. The environmental targets are modifying the shape of the electricity sectors in the next century. The smart technologies and demand side management are the key features of the future of the electricity sectors. The target challenges are coupling the innovative smart metering services with the smart meters technologies, and the consumers' behaviour should interact with new technologies and polices. The book looks for the future of the electricity demand and the challenges posed by climate changes by using the smart meters technologies and smart meters services. The book is written by leaders from academia and industry experts who are handling the smart meters technologies, infrastructure, protocols, economics, policies and regulations. It provides a promising aspect of the future of the electricity demand. This book is intended for academics and engineers who are working in universities, research institutes, utilities and industry sectors wishing to enhance their idea and get new information about the smart meters