Write Channel Model for Bit-Patterned Media Recording

We propose a new write channel model for bit-patterned media recording that reflects the data dependence of write synchronization errors. It is shown that this model accommodates both substitution-like errors and insertion-deletion errors whose statistics are determined by an underlying channel state process. We study information theoretic properties of the write channel model, including the capacity, symmetric information rate, Markov-1 rate and the zero-error capacity.Comment: 11 pages, 12 figures, journa

Excitations from Filled Landau Levels in Graphene

We consider graphene in a strong perpendicular magnetic field at zero temperature with an integral number of filled Landau levels and study the dispersion of single particle-hole excitations. We first analyze the two-body problem of a single Dirac electron and hole in a magnetic field interacting via Coulomb forces. We then turn to the many-body problem, where particle-hole symmetry and the existence of two valleys lead to a number of effects peculiar to graphene. We find that the coupling together of a large number of low-lying excitations leads to strong many-body corrections, which could be observed in inelastic light scattering or optical absorption. We also discuss in detail how the appearance of different branches in the exciton dispersion is sensitive to the number of filled spin and valley sublevels.Comment: 15 pages, 19 figure

Accurate implementation of leaping in space: The spatial partitioned-leaping algorithm

There is a great need for accurate and efficient computational approaches that can account for both the discrete and stochastic nature of chemical interactions as well as spatial inhomogeneities and diffusion. This is particularly true in biology and nanoscale materials science, where the common assumptions of deterministic dynamics and well-mixed reaction volumes often break down. In this article, we present a spatial version of the partitioned-leaping algorithm (PLA), a multiscale accelerated-stochastic simulation approach built upon the tau-leaping framework of Gillespie. We pay special attention to the details of the implementation, particularly as it pertains to the time step calculation procedure. We point out conceptual errors that have been made in this regard in prior implementations of spatial tau-leaping and illustrate the manifestation of these errors through practical examples. Finally, we discuss the fundamental difficulties associated with incorporating efficient exact-stochastic techniques, such as the next-subvolume method, into a spatial-leaping framework and suggest possible solutions.Comment: 15 pages, 9 figures, 2 table

Fisher Information in Weighted Distributions

Standard inference procedures assume a random sample from a population with density fμ(x) for estimating the parameter μ. However, there are many applications in which the available data are a biased sample instead. Fisher modeled biased sampling using a weight function w(x) ¸ 0, and constructed a weighted distribution with a density fμw(x) that is proportional to w(x)fμ(x). In this paper, we assume that fμ(x) belongs to an exponential family, and study the Fisher information about μ in observations obtained from some commonly arising weighted distributions: (i) the kth order statistic of a random sample of size m, (ii) observations from the stationary distribution of the residual lifetime of a renewal process, and (iii) truncated distributions. We give general conditions under which the weighted distribution has greater Fisher information than the original distribution, and specialize to the normal, gamma, and Weibull distributions. These conditions involve the distributions\u27 hazard rate and the reversed hazard rate functions

Transition from pediatric to adult care in emerging adults with type 1 diabetes: a blueprint for effective receivership

Abstract For adolescents and emerging adults, the transition from pediatrics to adult care is fraught with challenges both inside and outside the clinical arena, including assuming independent care for diabetes, working with new adult providers, and overcoming concomitant psychosocial issues, while maintaining work/school-life balance. Not surprisingly, glycemic control in emerging adults with type 1 diabetes is amongst the worst in all age groups. Thus, new and comprehensive strategies are needed by both pediatric and adult diabetes care teams to support young adults during the transition to adult care. In this review, we focus on challenges during the transition period and provide evidence-based recommendations for a receivership model to assist adult diabetes care teams in addressing these concerns. By coordinating efforts with pediatrics providers, identifying strengths and deficiencies in self-care, establishing rapport with young adult patients, directly addressing prevalent psychosocial concerns, and developing a team-based approach to keep patients engaged, adult care teams can prioritize support for the most vulnerable transition patients. Improved strategies to propel emerging adult patients through the transition period towards habits leading to optimal glycemic control could have a major long-term impact on preventing diabetes-related complications.https://deepblue.lib.umich.edu/bitstream/2027.42/148213/1/40842_2019_Article_78.pd

Military development and applications of simulation systems

Simulations used in training attempt to portray reality for the units or individuals participating in training. Some of the benefits of simulation training include; cost efficient training, training units in tasks that are too dangerous to perform otherwise, and training units in complex tasks in a repetitive fashion