Edge-preserving self-healing: Keeping network backbones densely connected

Healing algorithms play a crucial part in distributed peer-to-peer networks where failures occur continuously and frequently. Whereas there are approaches for robustness that rely largely on built-in redundancy, we adopt a responsive approach that is more akin to that of biological networks e.g. the brain. The general goal of self-healing distributed graphs is to maintain certain network properties while recovering from failure quickly and making bounded alterations locally. Several self-healing algorithms have been suggested in the recent literature [IPDPS'08, PODC'08, PODC'09, PODC'11]; they heal various network properties while fulfilling competing requirements such as having low degree increase while maintaining connectivity, expansion and low stretch of the network. In this work, we augment the previous algorithms by adding the notion of edge-preserving self-healing which requires the healing algorithm to not delete any edges originally present or adversarialy inserted. This reflects the cost of adding additional edges but more importantly it immediately follows that edge preservation helps maintain any subgraph induced property that is monotonic, in particular important properties such as graph and subgraph densities. Density is an important network property and in certain distributed networks, maintaining it preserves high connectivity among certain subgraphs and backbones. We introduce a general model of self-healing, and introduce xheal+, an edge-preserving version of xheal[PODC'11]. © 2012 IEEE.

Exposición Internacional 1910. Buenos Aires.: Didactic leisure and international recognition

International exhibitions were greatly responsible for the modernization of western society. The motive for these events was based on the possibility of enhancing the country’s international status abroad. The genesis of world exhibitions came from the conviction that humanity as a whole would improve the continual flow of new practical applications, the development of modern communication techniques and the social need for a medium that could acquaint the general public with changes in technology, economy and society .
Since the first national industrial exhibitions in Paris during the eighteenth century and especially starting from the first Great Exhibition in London’s Hyde Park in 1851 these international events spread steadily all over Europe and the United States, to reach Latin America in the beginnings of the twentieth century . The work of professionals such as Daniel Burnham, Werner Hegemann and Elbert Peets made the relation between exhibitions and urban transformation a much more connected one, setting a precedent for subsequent exhibitions.
In Buenos Aires, the celebration of the centennial of independence from Spain in 1910 had many meanings and repercussions. A series of factors allowed for a moment of change in the city. Official optimism, economical progress, inequality and social conflict made of this a suitable time for transformation. With the organization of the Exposición Internacional the government had, among others, one specific aim: to achieve a network of visual tools to set the feeling of belonging and provide an identity for the mixture of cultures that populated the city of Buenos Aires at the time. Another important objective of the government was to put Buenos Aires at the level of European cities.
Foreign professionals had a great influence in the conceptual and factual shaping of the exhibition and in the subsequent changes caused in the urban condition. The exhibition had an important role in the ways of thinking the city and in the leisure ideas it introduced. The exhibition, as a didactic tool, worked as a precedent for conceiving leisure spaces in the future. Urban and landscape planners such as Joseph Bouvard and Charles Thays were instrumental in great part of the design of the Exhibition, but it was not only the architects and designers who shaped the identity of the fair. Other visitors such as Jules Huret or Georges Clemenceau were responsible for giving the city an international image it did not previously have.
This paper will explore on the one hand the significance of the exhibition of 1910 for the shaping of the city and its image; and on the other hand, the role of foreign professionals and the reach these influences had.

Queer Spaces, Sexual Violence and the Desire for Safety

Queer politics and spaces have historically been associated with ideals of sexual liberation. They are conceptualised as spaces where sex, and its intersections with intimacy, friendship and love can be explored outside of normative frameworks which value monogamous reproductive heterosexuality at the expense of other non-normative sexual expressions. In recent years, however, autonomous queer spaces such as the global Queeruption gatherings and other queer community spaces in Australia have become increasingly concerned with the presence and danger of sexual violence in queer communities. Almost without exception, this danger has been responded to through the creation of ‘safe(r) spaces’ policies, generally consisting of a set of guidelines and proscribed behaviours which individuals must agree to in order to participate in or attend the event or space. The guidelines themselves tend to privilege of sexual politics of affirmative verbal consent, insisting that such consent should be sought prior to any physical or sexual contact, inferring that a failure to do so is ethically unacceptable within. This chapter reflects on the attempts to construct queer communities as ‘safer spaces,’ arguing that the concepts of consent and safety are inadequate to develop a queer response to sexual violence. Such a response, it argues, must be based on the openness to possibilities and refusal of sexual restrictions and regulations that have always been central elements of queer theory and politics.

Monogamy and ground-state entanglement in highly connected systems

We consider the ground-state entanglement in highly connected many-body systems consisting of harmonic oscillators and spin-1/2 systems. Varying their degree of connectivity, we investigate the interplay between the enhancement of entanglement, due to connections, and its frustration, due to monogamy constraints. Remarkably, we see that in many situations the degree of entanglement in a highly connected system is essentially of the same order as in a low connected one. We also identify instances in which the entanglement decreases as the degree of connectivity increases.

Public knowledge and perceptions of connected health

Rationale, aims and objectives: This study aims to examine the public's knowledge and perceptions of connected health (CH).

Methods: A structured questionnaire was administered by face-to-face interview to an opportunistic sample of 1003 members of the public in 11 shopping centres across Northern Ireland (NI). Topics included public knowledge of CH, opinions about who should provide CH and views about the use of computers in health care. Multivariable analyses were conducted to assess respondents' willingness to use CH in the future.

Results: Sixty-seven per cent of respondents were female, 31% were less than 30 years old and 22% were over 60 years. Most respondents had never heard of CH (92%). Following a standard definition, the majority felt CH was a good idea (≈90%) and that general practitioners were in the best position to provide CH; however, respondents were equivocal about reductions in health care professionals' workload and had some concerns about the ease of device use. Factors positively influencing willingness to use CH in the future included knowledge of someone who has a chronic disease, residence in NI since birth and less concern about the use of information technology (IT) in health care. Those over 60 years old or who felt threatened by the use of IT to store personal health information were less willing to use CH in the future.

Conclusion: Increased public awareness and education about CH is required to alleviate concerns and increase the acceptability of this type of care.

Hybrid address spaces: A methodology for implementing scalable high-level programming models on non-coherent many-core architectures

This paper introduces hybrid address spaces as a fundamental design methodology for implementing scalable runtime systems on many-core architectures without hardware support for cache coherence. We use hybrid address spaces for an implementation of MapReduce, a programming model for large-scale data processing, and the implementation of a remote memory access (RMA) model. Both implementations are available on the Intel SCC and are portable to similar architectures. We present the design and implementation of HyMR, a MapReduce runtime system whereby different stages and the synchronization operations between them alternate between a distributed memory address space and a shared memory address space, to improve performance and scalability. We compare HyMR to a reference implementation and we find that HyMR improves performance by a factor of 1.71× over a set of representative MapReduce benchmarks. We also compare HyMR with Phoenix++, a state-of-art implementation for systems with hardware-managed cache coherence in terms of scalability and sustained to peak data processing bandwidth, where HyMR demon- strates improvements of a factor of 3.1× and 3.2× respectively. We further evaluate our hybrid remote memory access (HyRMA) programming model and assess its performance to be superior of that of message passing.

Gender and Public Space in Divided Cities

The paper addresses two connected questions: firstly, in what ways might ‘public’ and ‘private’ spaces in cities be gendered; and secondly, what might this mean for the possibilities for complex forms of civility in a divided city such as Belfast? The specific focus on gendered dynamics of entitlement to inhabit urban space in this paper begins with some consideration of debates about the quality and experience of everyday life in cities, and the emergence of commonsense notions of ‘public’ and ‘private’ behaviour. Following this, key research concerned with the gendered dynamics of claimed collective, and particularly national, identities are outlined, in order to consider the significance of this literature for any study of the gender dynamics of life in a contested political context such as Belfast.