We provide a counterexample to Cover’s conjecture that the feedback capacity CFB of an additive Gaussian noise channel under power constraint P be no greater than the nonfeedback capacity C of the same channel under power constraint 2P , i.e., CFB(P ) C(2P ). Index Terms|Additive Gaussian noise channels, channel capacity, conjecture, counterexample, feedback.

Miriam H. Huntley1,∗, Arvind Murugan1,2,∗ and Michael P. Brenner Harvard John A. Paulson School of Engineering and Applied Sciences and the Kavli Institute for Bionano Science and Technology, Harvard University, Cambridge, Massachusetts 02138, USA 2 Physics and the James Franck Institute, University of Chicago, Chicago, IL 60637 and Department of Physics, Harvard University, 17 Oxford St. Cambr...

Arıkan’s polar coding, is by now a well studied technique that allows achieving the symmetric capacity of binary input memoryless channels with low complexity encoding and decoding, provided that the polar decoding architecture is used and the decoding metric is matched to the true channel. In this paper, we analyze communication rates that are achievable when the polar coding/decoding architec...

In this chapter we provide a brief introduction to multidimensional codes. In particular, we focus on product codes and other similar codes that use parity checks over multidimensional arrays. We present a brief introduction to product codes and their properties. We then focus on multidimensional codes based on single parity-check constituent codes. We provide two applications that illustrate t...

vi

Abstract—In this paper, the concept of composibility of the total channel capacity of the system of channels composed of two independent subsystems of channel is discussed. This system of channels is a function of entropies of the subsystems. Here, we show that the generalized entropies, the Tsalli’s entropy, the normalized Tsalli’s entropy and the Kapur’s entropy are compatible with the compos...

objective: the aim of this study was to evaluate and compare the cleaning ability and instrumentation time of manual and rotary methods used for preparation of primary anterior teeth. materials and methods: forty-four primary anterior teeth were used in this experimental study. access cavities were prepared and india ink was injected into the canals. the samples were divided into three groups a...

this study was designed to elucidate the effect of ascorbic acid on salivary total antioxidant capacity in smokers. in this single blind crossover clinical trial, the whole unstimulated saliva of 30 smokers, who were randomly divided into two groups, was collected. in the first phase after the saliva collection, one group of patients took 500 mg of vitamin c powder, for 3 weeks. then, saliva of...