Improved Delay Estimates for a Queueing Model for Random Linear Coding for Unicast

Consider a lossy communication channel for unicast with zero-delay feedback. For this communication scenario, a simple retransmission scheme is optimum with respect to delay. An alternative approach is to use random linear coding in automatic repeat-request (ARQ) mode. We extend the work of Shrader and Ephremides, by deriving an expression for the delay of random linear coding over field of infinite size. Simulation results for various field sizes are also provided.Comment: 5 pages, 3 figures, accepted at the 2009 IEEE International Symposium on Information Theor

Re-conceptualising Approaches to Meeting the Health Needs of Homeless People

The experience of homelessness not only affects physical health, but can also constrain access to required health care. In a number of European countries, national strategies to tackle homelessness have sought to deliver integrated solutions across housing, health and other social policy areas. This article examines approaches to meeting the health care needs of homeless people in relation to such strategies, drawing upon recent research in Norway and Scotland. The article presents a comparative analysis of approaches to service provision in relation to welfare models and the concepts of universal and specialist provision. The analysis suggests a cross-national shift in the conceptualisation of appropriate responses to the health care needs of those who experience homelessness. The provision of some specialist health services, while reflecting a selective model of welfare, need not be solely interpreted as conflicting with a more universal model of ensuring access to mainstream services. Rather, the challenge is to recognise the need for a process approach which supports an effective transition from the (sometimes necessary) use of specialist services for this group, towards (the ideal of) full integration into mainstream health care

Eliminating Variables in Boolean Equation Systems

Systems of Boolean equations of low degree arise in a natural way when analyzing block ciphers. The cipher's round functions relate the secret key to auxiliary variables that are introduced by each successive round. In algebraic cryptanalysis, the attacker attempts to solve the resulting equation system in order to extract the secret key. In this paper we study algorithms for eliminating the auxiliary variables from these systems of Boolean equations. It is known that elimination of variables in general increases the degree of the equations involved. In order to contain computational complexity and storage complexity, we present two new algorithms for performing elimination while bounding the degree at $3$, which is the lowest possible for elimination. Further we show that the new algorithms are related to the well known \emph{XL} algorithm. We apply the algorithms to a downscaled version of the LowMC cipher and to a toy cipher based on the Prince cipher, and report on experimental results pertaining to these examples.Comment: 21 pages, 3 figures, Journal pape

Viewing Parmenides Through Appropriated Lenses – Two Aspects of Plutarch’s and Proclus’ Interpretations of Parmenides’ Poem

Filosofi mastergradsoppgaveMAHF-FILOFILO35

Barriers to health care access among undocumented migrant women in Norway.

The aim of this study was to explore undocumented migrant women’s subjective experiences of their health conditions and access to health care. The study is based on eight qualitative interviews with undocumented migrant women and eight qualitative interviews with health personnel at a health center for undocumented migrants in Oslo. The women were recruited by self-selection from patients at the health center. Both the women and the health professionals related the women’s health problems to their living conditions. Even though all of the women had extremely difficult living situations, their living conditions varied. Some lived in an apartment with a partner. Some had to move among the homes of various friends and had to be out all day while those friends were at work. The women with paid work had more structured daily lives than the others, with living situations that gave them some opportunities for rest and privacy. Domestic work in the black market for labor was associated with health problems due to the heavy and repetitive tasks performed while cleaning private homes. Limited rights to health care, fear of being reported, financial difficulties and poor language skills were mentioned as barriers to health care. These barriers lead to delay in seeking medical care and use of alternative health-seeking strategies. Factors that indirectly affected the health of the women included a lack of knowledge of both their rights and the available services in Norway. The pregnant women were unaware of their right to receive prenatal care.publishedVersio