21,114 research outputs found
Our Troubled Health Care System: Why Is It So Hard to Fix? Nineteenth Annual Herbert Lourie Memorial Lecture on Health Policy.
This brief draws heavily on Judith Feder, 2004, "Crowd-Out and the Politics of Health Reform," The Journal of Law, Medicine, and Ethids 32(3): 461-464. We all know that affordable health care is now back on the political agenda, and it's about time! Because all of us--families, businesses, and governments--are struggling with the ever-increasing costs of care. Every year about a million people are added to the rolls of the uninsured. In 2006, it was even more, over 2 million. The number of people without health insurance coverage has reached more than 47 million. People *with* insurance are seeing their benefits dwindle and their health care costs consume their wabes. Even people with health insurance find themselves unable to pay their medical bills and going without needed care. The bottom line is that, increasingly, our health insurance system fails to protect us when we get sick.health insurance, uninsurance, cost of medical care
On the calculation of the minimax-converse of the channel coding problem
A minimax-converse has been suggested for the general channel coding problem
by Polyanskiy etal. This converse comes in two flavors. The first flavor is
generally used for the analysis of the coding problem with non-vanishing error
probability and provides an upper bound on the rate given the error
probability. The second flavor fixes the rate and provides a lower bound on the
error probability. Both converses are given as a min-max optimization problem
of an appropriate binary hypothesis testing problem. The properties of the
first converse were studies by Polyanskiy and a saddle point was proved. In
this paper we study the properties of the second form and prove that it also
admits a saddle point. Moreover, an algorithm for the computation of the saddle
point, and hence the bound, is developed. In the DMC case, the algorithm runs
in a polynomial time.Comment: Extended version of a submission to ISIT 201
Optimal Feedback Communication via Posterior Matching
In this paper we introduce a fundamental principle for optimal communication
over general memoryless channels in the presence of noiseless feedback, termed
posterior matching. Using this principle, we devise a (simple, sequential)
generic feedback transmission scheme suitable for a large class of memoryless
channels and input distributions, achieving any rate below the corresponding
mutual information. This provides a unified framework for optimal feedback
communication in which the Horstein scheme (BSC) and the Schalkwijk-Kailath
scheme (AWGN channel) are special cases. Thus, as a corollary, we prove that
the Horstein scheme indeed attains the BSC capacity, settling a longstanding
conjecture. We further provide closed form expressions for the error
probability of the scheme over a range of rates, and derive the achievable
rates in a mismatch setting where the scheme is designed according to the wrong
channel model. Several illustrative examples of the posterior matching scheme
for specific channels are given, and the corresponding error probability
expressions are evaluated. The proof techniques employed utilize novel
relations between information rates and contraction properties of iterated
function systems.Comment: IEEE Transactions on Information Theor
Recommended from our members
Pay Equity Legislation
[Excerpt] The issue of pay equity has attracted substantial attention in recent Congresses. A number of measures, including bills that would provide additional remedies, mandate “equal pay for equivalent jobs,” or require studies on pay inequity, have been introduced in each of the last several congressional sessions. In the 111th Congress, similar legislation has been introduced, including the Paycheck Fairness Act (H.R. 12/S. 182/S. 3772), the Fair Pay Act (H.R. 2151/S. 904), and the Title VII Fairness Act (S. 166). In addition, on January 29, 2009, President Obama signed the Lilly Ledbetter Fair Pay Act of 2009 (H.R. 11/S. 181). This legislation supersedes the 2007 Supreme Court decision in Ledbetter v. Goodyear Tire & Rubber Co., Inc., by amending Title VII to clarify that the time limit for suing employers for pay discrimination begins each time they issue a paycheck. Although the House of Representatives passed both the Ledbetter legislation and the Paycheck Fairness Act as a combined package, the Senate did not combine the two bills and has not yet taken up the latter for a vote. Recently, however, Senator Reid reintroduced the Paycheck Fairness Act as S. 3772, and the bill has been placed on the Senate calendar
An Achievable Rate for the MIMO Individual Channel
We consider the problem of communicating over a multiple-input
multiple-output (MIMO) real valued channel for which no mathematical model is
specified, and achievable rates are given as a function of the channel input
and output sequences known a-posteriori. This paper extends previous results
regarding individual channels by presenting a rate function for the MIMO
individual channel, and showing its achievability in a fixed transmission rate
communication scenario.Comment: to be presented at ITW201
Relativistic effects on LEED intensities from Au(111)
Comparison of relativistically and nonrelativistically calculated intensity versus energy profiles in low energy electron diffraction (LEED) from the (111) surface of Au (Z = 79) reveals that relativistic corrections are quite significant. They can however, be obtained in very good approximation by quasirelativistic calculations, in which spin-averaged relativistic phase shifts are used as input for the nonrelativistic multiple scattering formalism. Further, relativistic effects on intensities are found to be comparable to differences arising from different approximations to the exchange part of the ion core potential
- …
