A review of radio channel models for body centric communications

The human body is an extremely challenging environment for the operation of wireless communications systems, not least because of the complex antenna-body electromagnetic interaction effects which can occur. This is further compounded by the impact of movement and the propagation characteristics of the local environment which all have an effect upon body centric communications channels. As the successful design of body area networks (BANs) and other types of body centric system is inextricably linked to a thorough understanding of these factors, the aim of this paper is to conduct a survey of the current state of the art in relation to propagation and channel models primarily for BANs but also considering other types of body centric communications. We initially discuss some of the standardization efforts performed by the Institute of Electrical and Electronics Engineers 802.15.6 task group before focusing on the two most popular types of technologies currently being considered for BANs, namely narrowband and Ultrawideband (UWB) communications. For narrowband communications the applicability of a generic path loss model is contended, before presenting some of the scenario specific models which have proven successful. The impacts of human body shadowing and small-scale fading are also presented alongside some of the most recent research into the Doppler and time dependencies of BANs. For UWB BAN communications, we again consider the path loss as well as empirical tap delay line models developed from a number of extensive channel measurement campaigns conducted by research institutions around the world. Ongoing efforts within collaborative projects such as Committee on Science and Technology Action IC1004 are also described. Finally, recent years have also seen significant developments in other areas of body centric communications such as off-body and body-to-body communications. We highlight some of the newest relevant research in these areas as well as discussing some of the advanced topics which are currently being addressed in the field of body centric communications. Key Points Channel models for body centric comms ©2014. The Authors.

Children’s essentialist reasoning about language and race

Across four studies, we directly compared children’s essentialist reasoning about the stability of race and language throughout an individual’s lifespan. Monolingual English-speaking children were presented with a series of images of children who were either White or Black; each face was paired with a voice clip in either English or French. Participants were asked which of two adults each target child would grow up to be – one who was a ‘match’ to the target child in race but not language, and the other a ‘match’ in language but not race. Nine- to 10-year-old European American children chose the race-match, rather than the language-match. In contrast, 5–6-year-old European American children in both urban, racially diverse, and rural, racially homogeneous environments chose the language-match, even though this necessarily meant that the target child would transform racial categories. Although surprising in light of adult reasoning, these young children demonstrated an intuition about the relative stability of an individual’s language compared to her racial group membership. Yet, 5–6-year-old African American children, similar to the older European American children, chose the race-match, suggesting that membership in a racial minority group may highlight children’s reasoning about race as a stable category. Theoretical implications for our understanding of children’s categorization of human kinds are discussed.

Introducing Students to Pre-Nineteenth-Century Poetry in the Language Classroom

We as language instructors are tasked with preparing students to transition from language to literature courses. The shorter length of many poems makes them ideal for presentation in the language classroom, where the acquisition of communicative competence is the priority. Introductory and intermediate textbooks’ poetry offerings, however, are frequently drawn from a canon of poems by only a few nineteenth- and twentieth-century authors (Verlaine, Apollinaire, Prévert) and fail to expose students to broader aspects of French literature. This article offers strategies for presenting pre-nineteenth-century poetry to first- and second-year students of French using dizains from Scève’s Délie as examples.

Doing Focus Groups and Interviews with Recent Migrants to Northern Ireland: A Dynamic Interplay of Ethics, Language and Access

This case describes a qualitative social science research project that was conducted in 2009 and that examined the experiences of recent migrants to Northern Ireland. While background to the research and key findings are presented, the topic forms a backdrop to the case. The following aspects of the study are presented: the theoretical context; formulating the research question, design and methodology; key methodological issues; data collection and analysis; project dissemination; and research funding and reporting. The case pays particular attention to the needs and impact of different groups including the researcher, the funding body, the researcher’s employer and the researched. The significance of access, language and ethics to this study are examined. Finally, the way in which the research unfolded in an often-unpredictable way throughout the implementation process is highlighted in the narrative.

Personalising Crime and Crime-fighting in Factual Television:an Analysis of Social Actors and Transitivity in Language and Images

This article addresses the lack of work on media and crime in Critical Discourse Analysis (CDA), using an example of a factual television crime report. The existing research in media studies and criminology points to the way that the media misrepresents crime by distorting public understandings and backgrounding structural issues, such as poverty, which are related to crime thereby legitimising a criminal justice system that serves the interests of the powerful in society. Using social actor and transitivity analysis, this article shows how multimodal CDA can make an important contribution as it reveals the more subtle linguistic strategies and visual representations by which this process is accomplished, showing how each plays a part in the recontextualisation of social practice. This programme backgrounds which crimes are committed but foregrounds mental states and the neutrality of policing.

Ecopoetics: The Language of Nature, The Nature of Language by Scott Knickerbocker (review)

Review of Ecopoetics: The Language of Nature, The Nature of Language by Scott Knickerbocker Boston: University of Massachusetts Press, 2012. Pp. x + 203.
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Patient safety and communication: A new assessment for doctors trained in countries where language differs from that of the host country: Results of a pilot using a domain-based assessment

Objective

Global migration of healthcare workers places responsibility on employers to comply with legal employment rights whilst ensuring patient safety remains the central goal. We describe the pilot of a communication assessment designed for doctors who trained and communicated with patients and colleagues in a different language from that of the host country. It is unique in assessing clinical communication without assessing knowledge.

A 14-station OSCE was developed using a domain-based marking scheme, covering professional communication and English language skills (speaking, listening, reading and writing) in routine, acute and emotionally challenging contexts, with patients, carers and healthcare teams. Candidates (n = 43), non-UK trained volunteers applying to the UK Foundation Programme, were provided with relevant station information prior to the exam.

The criteria for passing the test included achieving the pass score and passing 10 or more of the 14 stations. Of the 43 candidates, nine failed on the station criteria. Two failed the pass score and also the station criteria. The Cronbach's alpha coefficient was 0.866.

This pilot tested ‘proof of concept’ of a new domain-based communication assessment for non-UK trained doctors.

The test would enable employers and regulators to verify communication competence and safety in clinical contexts, independent of clinical knowledge, for doctors who trained in a language different from that of the host country.

ZIL: An Energy-Efficient Indoor Localization System Using ZigBee Radio to Detect WiFi Fingerprints

In existing WiFi-based localization methods, smart mobile devices consume quite a lot of power as WiFi interfaces need to be used for frequent AP scanning during the localization process. In this work, we design an energy-efficient indoor localization system called ZigBee assisted indoor localization (ZIL) based on WiFi fingerprints via ZigBee interference signatures. ZIL uses ZigBee interfaces to collect mixed WiFi signals, which include non-periodic WiFi data and periodic beacon signals. However, WiFi APs cannot be identified from these WiFi signals by ZigBee interfaces directly. To address this issue, we propose a method for detecting WiFi APs to form WiFi fingerprints from the signals collected by ZigBee interfaces. We propose a novel fingerprint matching algorithm to align a pair of fingerprints effectively. To improve the localization accuracy, we design the K-nearest neighbor (KNN) method with three different weighted distances and find that the KNN algorithm with the Manhattan distance performs best. Experiments show that ZIL can achieve the localization accuracy of 87%, which is competitive compared to state-of-the-art WiFi fingerprint-based approaches, and save energy by 68% on average compared to the approach based on WiFi interface.

On the Security of Cognitive Radio Networks

Cognitive radio has emerged as an essential recipe for future high-capacity high-coverage multi-tier hierarchical networks. Securing data transmission in these networks is of utmost importance. In this paper, we consider the cognitive wiretap channel and propose multiple antennas to secure the transmission at the physical layer, where the eavesdropper overhears the transmission from the secondary transmitter to the secondary receiver. The secondary receiver and the eavesdropper are equipped with multiple antennas, and passive eavesdropping is considered where the channel state information of the eavesdropper’s channel is not available at the secondary transmitter. We present new closedform expressions for the exact and asymptotic secrecy outage probability. Our results reveal the impact of the primary network on the secondary network in the presence of a multi-antenna wiretap channel.