Strong converse rates for classical communication over thermal and additive noise bosonic channels

We prove that several known upper bounds on the classical capacity of thermal and additive noise bosonic channels are actually strong converse rates. Our results strengthen the interpretation of these upper bounds, in the sense that we now know that the probability of correctly decoding a classical message rapidly converges to zero in the limit of many channel uses if the communication rate exceeds these upper bounds. In order for these theorems to hold, we need to impose a maximum photon number constraint on the states input to the channel (the strong converse property need not hold if there is only a mean photon number constraint). Our first theorem demonstrates that Koenig and Smith's upper bound on the classical capacity of the thermal bosonic channel is a strong converse rate, and we prove this result by utilizing the structural decomposition of a thermal channel into a pure-loss channel followed by an amplifier channel. Our second theorem demonstrates that Giovannetti et al.'s upper bound on the classical capacity of a thermal bosonic channel corresponds to a strong converse rate, and we prove this result by relating success probability to rate, the effective dimension of the output space, and the purity of the channel as measured by the Renyi collision entropy. Finally, we use similar techniques to prove that similar previously known upper bounds on the classical capacity of an additive noise bosonic channel correspond to strong converse rates.Comment: Accepted for publication in Physical Review A; minor changes in the text and few reference

Discontinuity in the Environment, Firm Response and Dynamic Capabilities

This paper identifies and focuses on a specific type of environmental development called discontinuity. Discontinuities in the forms of rapid technological innovations, regulatory reforms, institutional overhauls, and socio-cultural developments are the source of opportunities and threats to the firm. Firm responds to these discontinuities in specific ways in sustaining its existence at different points of time. This paper conceptualizes discontinuity and identifies its natures; explores the possible types of responses by the firm, and their enablers. The capability of sensing, seizing and re-shaping are captured to establish the linkages in the framework of interrelations. It posits a set of propositions based on conceptual development and illustration of two cases.

Weld sequence optimization: the use of surrogate models for solving sequential combinatorial problems

The solution of combinatorial optimization problems usually involves the consideration of many possible design configurations. This often makes such approaches computationally expensive, especially when dealing with complex finite element models. Here a surrogate model is proposed that can be used to reduce substantially the computational expense of sequential combinatorial finite element problems. The model is illustrated by application to a weld path planning problem

EFFICIENCY ANALYSIS OF HOSPITALS IN THE GREAT PLAINS: AN URBAN-RURAL COMPARISON

This study examined the efficiency of a sample of hospitals in the Great Plains using a nonparametric approach. Technical efficiency was less than either allocative or scale efficiency. Urban hospitals are relatively more efficient than rural hospitals with respect to all efficiency measures. Private hospitals are more efficient than others.Health Economics and Policy,

Highly Scalable Algorithms for Robust String Barcoding

String barcoding is a recently introduced technique for genomic-based identification of microorganisms. In this paper we describe the engineering of highly scalable algorithms for robust string barcoding. Our methods enable distinguisher selection based on whole genomic sequences of hundreds of microorganisms of up to bacterial size on a well-equipped workstation, and can be easily parallelized to further extend the applicability range to thousands of bacterial size genomes. Experimental results on both randomly generated and NCBI genomic data show that whole-genome based selection results in a number of distinguishers nearly matching the information theoretic lower bounds for the problem