Fundamentals of Inter-cell Overhead Signaling in Heterogeneous Cellular Networks

Heterogeneous base stations (e.g. picocells, microcells, femtocells and distributed antennas) will become increasingly essential for cellular network capacity and coverage. Up until now, little basic research has been done on the fundamentals of managing so much infrastructure -- much of it unplanned -- together with the carefully planned macro-cellular network. Inter-cell coordination is in principle an effective way of ensuring different infrastructure components behave in a way that increases, rather than decreases, the key quality of service (QoS) metrics. The success of such coordination depends heavily on how the overhead is shared, and the rate and delay of the overhead sharing. We develop a novel framework to quantify overhead signaling for inter-cell coordination, which is usually ignored in traditional 1-tier networks, and assumes even more importance in multi-tier heterogeneous cellular networks (HCNs). We derive the overhead quality contour for general K-tier HCNs -- the achievable set of overhead packet rate, size, delay and outage probability -- in closed-form expressions or computable integrals under general assumptions on overhead arrivals and different overhead signaling methods (backhaul and/or wireless). The overhead quality contour is further simplified for two widely used models of overhead arrivals: Poisson and deterministic arrival process. This framework can be used in the design and evaluation of any inter-cell coordination scheme. It also provides design insights on backhaul and wireless overhead channels to handle specific overhead signaling requirements.Comment: 21 pages, 9 figure

Open, Closed, and Shared Access Femtocells in the Downlink

A fundamental choice in femtocell deployments is the set of users which are allowed to access each femtocell. Closed access restricts the set to specifically registered users, while open access allows any mobile subscriber to use any femtocell. Which one is preferable depends strongly on the distance between the macrocell base station (MBS) and femtocell. The main results of the paper are lemmas which provide expressions for the SINR distribution for various zones within a cell as a function of this MBS-femto distance. The average sum throughput (or any other SINR-based metric) of home users and cellular users under open and closed access can be readily determined from these expressions. We show that unlike in the uplink, the interests of home and cellular users are in conflict, with home users preferring closed access and cellular users preferring open access. The conflict is most pronounced for femtocells near the cell edge, when there are many cellular users and fewer femtocells. To mitigate this conflict, we propose a middle way which we term shared access in which femtocells allocate an adjustable number of time-slots between home and cellular users such that a specified minimum rate for each can be achieved. The optimal such sharing fraction is derived. Analysis shows that shared access achieves at least the overall throughput of open access while also satisfying rate requirements, while closed access fails for cellular users and open access fails for the home user.Comment: 26 pages, 8 figures, Submitted to IEEE Transactions on Wireless Communication

Spatial and temporal variability of tropical storm and hurricane strikes in the Bahamas, and the Greater and Lesser Antilles

Coastal cities throughout the Caribbean Sea are evaluated to determine the geographical distributions of landfalling tropical storms and hurricanes. A strike model is used to measure tropical storm and hurricane force winds. Twenty-six specific locations in the Caribbean are studied over a time period of over one hundred years from 1901 until 2006. The Caribbean Sea geographically covers a small area of the world; however, this analysis demonstrates the wide variability of the frequency of tropical storms and hurricane strikes in this region. The southernmost portions of the Caribbean, for example Oranjestad, Aruba and Willemstad, Curacao, generally experience lower frequencies of strikes with a major hurricane return period of over 100 years in Oranjestad and Willemstad. Futhermore, Willemstad never experienced a major hurricane strike in the time period. Analyses of the northern parts of the Caribbean including Nassau, Bahamas, Nueva Gerona, Cuba, and Jamaica are locations that experience numerous instances of tropical storm and hurricane landfalls. Temporal variability is apparent and fluctuates greatly in different regions of the Caribbean Sea. Locations that experience higher frequencies of tropical storm strikes tend to have return periods of two to five years. Other areas with less frequent landfalls have return periods of up to fifteen years. For severe hurricanes, the range is from ten year return periods at Nassau, Bahamas to over 100 years at sites to the south in the study region. Specific events of landfalling tropical storms and hurricanes, or lack there of, are directly related to La Niña and El Niño events. The 1933 active hurricane season coincides with a significantly strong La Niña event. Less active hurricane seasons often take place during stronger El Niño years

Palaeoclimate Change

Level 3 (BSc) module with lectures and practical

The choreography of the classroom: performance and embodiment in teaching

The body is central to all human interaction and is literally the instrument through which teachers communicate. The topic of embodiment has increasingly been addressed in the literature on Education and more broadly in the Social Sciences, however there are few accounts of what embodiment looks like in actual teaching; how it enhances communication of the curriculum, and shapes teachers’ relationships with the students. Using a multiple case study methodology, I examine the embodied teaching styles of two university professors to investigate the intrinsic complexities that arise in the practice of teaching. The literature on corporality often characterizes the body as a text to be "read" by scholars prioritizing a static approach to embodiment focused on issues of identity. Little has been offered on the physical dimension of embodiment focusing on the sensory experience of being a moving feeling human being. This study offers new perspectives on the performance of teaching through a choreographic framework that emphasizes the role of the body in performance, as well as adding new insights into the relationship between the design of a course, and how it is orchestrated in the live performance space of the classroom. Three distinctive yet interrelated themes emerged during this study: the embodied, the structural, and the relational. Each theme contributed to create the implicit curriculum of the class, and offers distinctive insights into the tacit dimension of communication that is both ubiquitous and difficult to articulate. The first set of findings relates to the ways teachers embody and communicate the curriculum, examining the common gestures, movement patterns, pacing, and energetic dynamics used to animate their lectures. To honor embodied ways of interacting and communicating, it was essential to develop a method that could analyze movement data. Skills and techniques to study movement from dance were used to explore the everyday movements of teachers and bring to the forefront the specific ways each communicated concepts with the body. Attention to the embodied highlighted the qualitative and sensory dimension of teaching. For instance, I was attuned to how each teacher reacted to the attitude and energy level of the students and adjusted their tone of voice, pace of the class, or entire lesson plan to engage students in learning. The second set of findings investigates the relationship between the structural design of a course and how teachers orchestrate the planned curriculum within the classroom. A choreographic frame broadens the scope of the study to examine the aesthetic dimensions of the classroom. For instance, how each teacher chooses to vary the pace, energy, and focus of the class to communicate concepts and ideas to the students, as well interweave multiple streams of information through their embodied communication, the content of the lectures, power point and visual illustrations, etc. In this chapter, the role of the teacher as a designer of the educational experience is explored in relation to how they make the curriculum come alive in the performative space of the classroom. The third set of findings draws explores the relational aspects of teaching and examines how each teacher conceptualized and enacted caring in the classroom. This section investigate the ever-present challenge teachers face; how to build a relationship of trust and understanding with students, while concurrently offering challenges that will encourage them to grow and flourish. This study address issues integral to teacher education including the relationship between the planned curriculum and the way it is implemented in the classroom, as well as the relational dynamic developed between teachers and students. The performing arts provide a framework for understanding artistry in teaching highlighting the convergence of the performative, the creative design and orchestration of curriculum, and the relational aspects of teaching to make vivid the rich sensory world of the tacit dimension and how it creates the ambience for learning

Landscapes of Play: An exploration and illumination of children’s unsupervised play close to home and a researcher’s journey to becoming posthuman.

Title: Landscapes of Play: An exploration and illumination of children’s unsupervised play close to home and a researcher’s journey to becoming posthuman. Author: Mandy Jo Andrews This thesis explores children’s play experiences and engagements out of doors close to home. Adopting a Deleuzian informed posthumanism the researcher’s journey towards immanence prompts re-thinking about play, childhood-nature entanglements, and play-space-place-player generation. Children’s unsupervised play outside of organised settings such as school or adventure playgrounds is less researched than that of organised settings. This thesis puts to work Deleuze’s process philosophy and Barad’s agential realism, together with Haraway’s biology informed multispecies manifesto, Bennett’s focus on vibrant agential matter and the literature of Virginia Woolf, to experiment with and illuminate some molar and molecular play adventures, constraints, escapes, intra-actions and entanglements experienced by and with small groups of children aged between 3 and 12 in their ‘playing-out’ in 6 housing areas in South West England. Each location chosen had access to a range of man-made and natural, mineral and biological play opportunities, cues, affordances and potentiality. The research questions initially focused on where children choose to play, what they do in the favoured play places, and how they materially experience play spaces and places. As the human focus was decentred during the study it became post-qualitative research of assemblages, haecceities and entanglements of the becoming players illuminating the molecular richness of the play events. The questions progressed from where does this happen and how does it feel, to how does this work, and what does this do? A range of new methods were introduced into the research doings, including clay plaques prompted by the materiality of play spaces and collage ‘merzboards’3, sound and visual recording, and thinking with the agents and acts of playing and diffractively through other writings. Putting to work these intra-actions prompts a re-turning to re-thinking of a children’s play engagement model, ‘the play cycle’ and together with a new conceptualisation of topoludic4 agency in landscapes for play acknowledges it as a creative and vital process. Further new knowledge emerged from this entanglement with landscapes of play and players as it offers an illumination and exemplification of some children’s outdoor play as intra-active, interpellating events, a consideration of ‘topoludic’ potentialities of the contextual landscapes, and play as a vital ‘wobble’ a challenge to the expected, that sets new lines of flight running, offering new intensities and events. Finally, it offers insight into the tensions experienced between traditional academic expectation and researcher ‘becoming posthuman’ over the period of research, as I let go of the constraints of the academy to explore in immanence and fluid creativity

2016 Ariadne Forecast: For European Social Change and Human Rights Funders

The Ariadne Forecast is a community created resource. Ariadne is a flexible network of more than 550 funders in 25 countries. Ariadne participants and other friends of the network, were asked six questions about trends in their field for 2016. More than 140 funders, including, for the first time, members of the Assifero and ACRI networks in Italy, and Admical in France, submitted written answers. In Belgium, France, The Netherlands, Hungary and the UK, 20 grant-makers of differing seniority and interests were interviewed at greater length. In January and early February, we held forecast meetings for funders in Brussels, Paris, London and The Hague to discuss and add to the findings. At each of those meetings 2 senior meteorologists, who have deep experience of the sector, were invited to assess the trends uncovered so far and add their judgment. These meetings and the discussion at them were private, but the final forecast is publicly available for all, as a reflection on the sector.From this input the Ariadne team has distilled an overall forecast, looking at trends globally, as well as at European and national levels. This year we are delighted to add France and Italy to the UK and The Netherlands in the country analyses