Terahertz Communications and Sensing for 6G and Beyond: A Comprehensive View

The next-generation wireless technologies, commonly referred to as the sixth generation (6G), are envisioned to support extreme communications capacity and in particular disruption in the network sensing capabilities. The terahertz (THz) band is one potential enabler for those due to the enormous unused frequency bands and the high spatial resolution enabled by both short wavelengths and bandwidths. Different from earlier surveys, this paper presents a comprehensive treatment and technology survey on THz communications and sensing in terms of the advantages, applications, propagation characterization, channel modeling, measurement campaigns, antennas, transceiver devices, beamforming, networking, the integration of communications and sensing, and experimental testbeds. Starting from the motivation and use cases, we survey the development and historical perspective of THz communications and sensing with the anticipated 6G requirements. We explore the radio propagation, channel modeling, and measurements for THz band. The transceiver requirements, architectures, technological challenges, and approaches together with means to compensate for the high propagation losses by appropriate antenna and beamforming solutions. We survey also several system technologies required by or beneficial for THz systems. The synergistic design of sensing and communications is explored with depth. Practical trials, demonstrations, and experiments are also summarized. The paper gives a holistic view of the current state of the art and highlights the issues and challenges that are open for further research towards 6G.Comment: 55 pages, 10 figures, 8 tables, submitted to IEEE Communications Surveys & Tutorial

Patient Safety As An Interactional Achievement: Conversational Analysis In The Trauma Center Of An Inner City Hospital

In this dissertation, I apply the methodology of Conversational Analysis to highlight the informal communication of an emergency room work group with the objective of discovering recurrent patterns of interaction and the inherent relational work necessary to accomplish the safe medical care of patients in a Trauma Code on a level of safety comparative to that of ultra-safe systems as described in the literature of High Reliability Organizations. The significance of relational elements of interaction on emerging social order is highlighted in processes of attunement, or the diminishing of difference of status in the use of mitigated speech and the co-construction of narrative. The use of mitigated speech and narrative serve as conversational moves of consequence, by which participants seek cooperation, coordination, and collaborate in face-to-face interaction, in a mutually constructed course of action; that is, in providing safe medical care in a highly complex and high risk environment

Modelling of mmWave Propagation Channel for Off-body Communication Scenarios

Předkládaná disertační práce je zaměřena na \uv{Modelování propagačního kanálu pro off-body komunikaci v oblasti milimetrových vln}. Navzdory pokrokům v rámci bezdrátových sítí v přímé blízkosti člověka stále systémy 5. generace postrádají dostatečnou šířku pásma a dostatečně nízkou odezvu. To je způsobeno neefektivním využíváním rádiového spektra. Tento nedostatek je potřeba co nejdříve odstranit a právě z tohoto důvodu je hlavním cílem této práce navrhnout vylepšený model rádiového kanálů pro off-body komunikaci. Úkolem tohoto modelu je umožnit uživatelům efektivněji a přesněji simulovat propagaci signálu v rámci daného prostředí. Navržený model je dále optimalizován a ověřen vůči nejnovějším měřením, získaným z literatury. Nakonec je tento model implementován do simulačního nástroje NS-3, pomocí kterého je následně využit k simulaci množství scénářů. Hlavním výstupem této práce je ověřený model přenosového kanálu pro off-body komunikaci v rámci milimetrových vln, společně s jeho implementací do simulačního nástroje NS-3, díky čemuž je dostupný pro širokou veřejnost.This thesis addresses the \uv{Modeling of mmWave Propagation Channel for Off-body Communication Scenarios}. Despite the advancements in the body area wireless networks, the 5G systems are still struggling with not enough bandwidth and large latency due to inefficient utilization of radio spectrum. This issue calls for immediate action and therefore the main aim of this Ph.D. thesis is to propose a novel mmWave off-body channel, which will enable its users to more effectively simulate the signal propagation. The proposed model is further optimized and verified against state-of-the-art measurements from the literature. Finally, the developed model is implemented into the NS-3 simulator and utilized for plethora of simulation scenarios. The main output of this thesis is the verified developed model as well as the implementation inside the NS-3 simulator, which enables a wide society to use it.

Dynamics among overlapping memory representations in the hippocampus at long timescales

The hippocampus plays a central role in episodic memory and spatial navigation. The activity of individual neurons and ensembles of cells encodes location within an environment, the spatial context, and non-spatial behavioral task demands, creating unique codes for these features. The hippocampus plays a role both during the initial encoding of memory representations, and also at extended intervals in tasks which require flexible retrieval or self-localization. While behavior and memory can be stable for long periods of time, many studies have shown that their neural basis is more dynamic than expected. In the studies presented here, I used single-photon calcium imaging in freely behaving mice to track hippocampal single-unit activity over many recording sessions to test how circuit instability interacts with ongoing behavioral demands. In the first study, I asked whether the representation of multiple task demands remained stable alongside an animal’s behavior. Previous work has indicated that hippocampal activity will change as an animal’s performance in a task improves. Additionally, drift, the inactivation and replacement of neuron membership within the active population, may affect neurons that code for different aspects of a task at different rates. I tested this hypothesis by recording hippocampal activity in an alternation task which animals performed stably for multiple weeks. I found that the population code separating each task dimension was highly stable in spite of cell turn over, but that the distribution of task dimensions encoded by single neurons changed as a function of time. This change in distribution of task dimensions encoded by single neurons was not driven by different levels of stability among the different coding populations, as indicated by previous reports, but instead was driven by changing rates with which newly active neurons encoded task dimensions. In the second study, I looked at how new learning affected a previously-encoded task representation. Mice performed two different tasks in a plus-shaped maze in the sequence A-B-A over a nine-day sequence. One group performed the entire sequence on a single maze, while another group performed the second rule on a second maze. This allowed me to test the hypothesis that new learning in a single environment would cause greater change in the hippocampal representation for that environment than can be accounted for alone by time between recordings. This hypothesis is confirmed by multiple measures of single unit activity, and in the population code. Together, these results demonstrate that the instability observed in long term patterns of neuronal activity does not impair behavior, and that it may have a role in the ongoing refinement of the organization of hippocampal memory representations

Protecting the image of a nation: Jim Crow propaganda

This project investigates how the United States Information Agency (USIA) functioned as a propaganda machine on behalf of the United States government at the dawn of the Cold War and the Civil Rights Movement. Drawing from literature on propaganda, public relations, and public diplomacy, this thesis connects 20th century American propaganda to its roots in public relations, communication studies, and psychology. The Civil Rights movement exposed the cultural inertia of white supremacy in America for the world to see while American foreign policy makers sought to crystallize a cultural hegemony fashioned after American political, cultural, and economic systems. Although the cultural and political systems in America were in a state of radical flux as the Cold War and the Civil Rights movements affected one another. Thus, as the voice of America abroad, USIA was pushed to negotiate the psychological and cultural tensions experienced in America for foreign audiences. Using a discursive constructivist methodology, this study explores how American Cold War propaganda was developed by USIA to tell America’s story abroad. By critically examining USIA’s actions between 1953-1965 this study explores how USIA framed the image of the American race relations at the nexus of the Cold War and the US Civil Rights Movement. By analyzing propaganda disseminated by USIA regarding civil rights, examining US national security reports, US State Department memos, and supporting national intelligence community documents this project aims to answer the following research questions: RQ 1: How did the USIA frame the American race relations throughout the Campaign for Truth?, RQ 2: How did USIA bolster US prestige/soft power from 1953-1963?. RQ 3: How did USIA use communication and public relations to effectively mask the ugliness of the Civil Rights Movement? American propaganda integrated new forms of mass media communications technology with a sophisticated variety of strategies and tactics to manipulate public opinion around the world. Blending traditional message broadcasting with interpersonal forms of advocacy (cultural exchanges) in imaginative campaigns which coopted the Civil Rights Movement to affirm America’s strength as a political, moral, and economic leader

Joke-making Jews /jokes making Jews: Essays on humor and identity in American Jewish fiction

Beginning from the premise that humor plays a prominent role in the construction of group and individual identities, as a social phenomenon and a simultaneously alienating and assimilating force, these essays explore and examine humor and its construction of American Jewish identity within the context of various works of American Jewish fiction. Though organized as chapters, the essays do not build upon one another progressively, nor do they center on a unified thesis; rather, each is written to stand alone; however, each approaches the general subject of humor and identity in American Jewish fiction, and as a collection it is intended that the whole equal more than the sum of its parts; Following the Introduction, chapter two examines Abraham Cahan\u27s Yekl and the relationship between humor and identity for the Jewish immigrant at the turn of the 20th century. Attention is also paid to the absences of humor, and how these are likewise capable of constructing identity; Chapter three raises questions regarding the ethics of humor, particularly when dealing with the Holocaust. It examines Saul Bellow\u27s The Bellarosa Connection under the guiding question of What is to be gained by reading this novella? ---with specific attention being given to the connective function of the novella\u27s humor; Bernard Malamud\u27s God\u27s Grace is examined in chapter four, which seeks to read the novel as a retelling of an old Jewish joke, in the form of the story of Abraham and Isaac; Malamud\u27s reversal of the story, and his use of absurdist humor, is read as an affirmation of humanism and Jewish identity; Chapter five examines the humor of Philip Roth and Woody Allen, as representatives of second-generation anxieties about Jewish identity in America; Then, chapters six and seven explore two possible responses to these anxieties. Chapter six looks at the works of the Coen brothers and asserts that Jewishness has been deliberately absented from their narratives; chapter seven looks at the works of Allegra Goodman and Nathan Englander and asserts that, in their fiction, a new, anxiety-free Jewish Self is being constructed, with humor playing a prominent role in this postassimilationism

Occupational Safety

Occupational safety is generally defined as the science of the anticipation, recognition, evaluation and control of hazards arising in or from the work place that could impair the health and well-being of workers, taking into account the possible impact on the surrounding communities and the general environment. This domain is necessarily vast, encompassing a large number of disciplines and numerous workplace and environmental hazards