Capacity of a Class of Deterministic Relay Channels

The capacity of a class of deterministic relay channels with the transmitter input X, the receiver output Y, the relay output Y_1 = f(X, Y), and a separate communication link from the relay to the receiver with capacity R_0, is shown to be C(R_0) = \max_{p(x)} \min \{I(X;Y)+R_0, I(X;Y, Y_1) \}. Thus every bit from the relay is worth exactly one bit to the receiver. Two alternative coding schemes are presented that achieve this capacity. The first scheme, ``hash-and-forward'', is based on a simple yet novel use of random binning on the space of relay outputs, while the second scheme uses the usual ``compress-and-forward''. In fact, these two schemes can be combined together to give a class of optimal coding schemes. As a corollary, this relay capacity result confirms a conjecture by Ahlswede and Han on the capacity of a channel with rate-limited state information at the decoder in the special case when the channel state is recoverable from the channel input and the output.Comment: 17 pages, submitted to IEEE Transactions on Information Theor

Increasing the Capacity of Primary Care Through Enabling Technology.

Primary care is the foundation of effective and high-quality health care. The role of primary care clinicians has expanded to encompass coordination of care across multiple providers and management of more patients with complex conditions. Enabling technology has the potential to expand the capacity for primary care clinicians to provide integrated, accessible care that channels expertise to the patient and brings specialty consultations into the primary care clinic. Furthermore, technology offers opportunities to engage patients in advancing their health through improved communication and enhanced self-management of chronic conditions. This paper describes enabling technologies in four domains (the body, the home, the community, and the primary care clinic) that can support the critical role primary care clinicians play in the health care system. It also identifies challenges to incorporating these technologies into primary care clinics, care processes, and workflow

Considerations for Future IGS Receivers

Future IGS receivers are considered against the backdrop of GNSS signal modernization and the IGS’s goal of further improving the accuracy of its products. The purpose of this paper is to provide IGS members with a guide to making decisions about GNSS receivers. Modernized GNSS signals are analyzed with a view toward IGS applications. A schedule for minimum IGS receiver requirements is proposed. Features of idealized conceptual receivers are discussed. The prospects for standard commercial receivers and for software-defined GNSS receivers are examined. Recommendations are given for how the IGS should proceed in order to maximally benefit from the transformation in GNSS that will occur over the next decade.Aerospace Engineering and Engineering Mechanic

Historical Costume Simulation

The aim of this study is to produce accurate reproductions of digital clothing from historical sources and to investigate the implications of developing it for online museum exhibits. In order to achieve this, the study is going through several stages. Firstly, the theoretical background of the main issues will be established through the review of various published papers on 3D apparel CAD, drape and digital curation. Next, using a 3D apparel CAD system, this study attempts the realistic visualization of the costumes based on the establishment of a valid simulation reference. This paper reports the pilot exercise carried out to scope the requirements for going forward

Intimate relations between electronic nematic, d-density wave and d-wave superconducting states

This paper consists of two important theoretical observations on the interplay between l = 2 condensates; d-density wave (ddw), electronic nematic and d-wave superconducting states. (1) There is SO(4) invariance at a transition between the nematic and d-wave superconducting states. The nematic and d-wave pairing operators can be rotated into each other by pseudospin SU(2) generators, which are s-wave pairing and electron density operators. The difference between the current work and the previous O(4) symmetry at a transition between the ddw and d-wave superconducting states (Nayak 2000 Phys. Rev. B 62 R6135) is presented. (2) The nematic and ddw operators transform into each other under a unitary transformation. Thus, when a Hamiltonian is invariant under such a transformation, the two states are exactly degenerate. The competition between the nematic and ddw states in the presence of a degeneracy breaking term is discussed.Comment: 4 pages, 1 figures, updated to the published versio

State Amplification

We consider the problem of transmitting data at rate R over a state dependent channel p(y|x,s) with the state information available at the sender and at the same time conveying the information about the channel state itself to the receiver. The amount of state information that can be learned at the receiver is captured by the mutual information I(S^n; Y^n) between the state sequence S^n and the channel output Y^n. The optimal tradeoff is characterized between the information transmission rate R and the state uncertainty reduction rate \Delta, when the state information is either causally or noncausally available at the sender. This result is closely related and in a sense dual to a recent study by Merhav and Shamai, which solves the problem of masking the state information from the receiver rather than conveying it.Comment: 9 pages, 4 figures, submitted to IEEE Trans. Inform. Theory, revise

Dark matter, the CMSSM and lattice QCD

Recent lattice measurements have given accurate estimates of the light and strange quark condensates in the proton. We use these new results to significantly improve the dark matter predictions in a set of benchmark models that represent different scenarios in the constrained minimal supersymmetric standard model (CMSSM). Because the predicted cross sections are at least an order of magnitude smaller than previously suggested, our results have significant consequences for dark matter searches.Comment: 4 pages, 4 figure