Dice, entropy, and likelihood

We show that a famous die experiment used by E. T. Jaynes as intuitive justification of the need for maximum entropy (ME) estimation admits, in fact, of solutions by classical, Bayesian estimation. The Bayesian answers are the maximum probable (m.a.p.) and posterior mean solutions to the problem. These depart radically from the ME solution, and are also much more probable answers.     

Comment on "Evaluation of transient response"

It is suggested that Thomson's recursive formulas are more general than originally indicated. These formulas have also been derived by Kaufman, but for a more general case and using a different approach.     

Comment on "Variable frequency crystal oscillators"

In a practical variable frequency crystal oscillator the difference between the operating and series resonant frequencies is always smaller than fp- fs. This limitation can be overcome by a negative capacitance realized using a NIC which does not seriously degrade overall stability.     

对“存储采样前馈序列”的评述

评述了文献[1]所构造的所谓“存储采样前馈序列”。     

Comment on "Cheating prevention in visual cryptography"

Visual cryptography (VC), proposed by Naor and Shamir, has numerous applications, including visual authentication and identification, steganography, and image encryption. In 2006, Horng showed that cheating is possible in VC, where some participants can deceive the remaining participants by forged transparencies. Since then, designing cheating-prevention visual secret-sharing (CPVSS) schemes has been studied by many researchers. In this paper, we cryptanalyze the Hu-Tzeng CPVSS scheme and show that it is not cheating immune. We also outline an improvement that helps to overcome the problem.     

Comment on "Fast square-and-multiply exponentiation for RSA"

Recently Hui and Lam announced that they had developed a new technique for improving the performance of RSA computation based on the square-and-multiply exponentiation [see ibid., vol. 30, no. 17, p. 1396-7, 1994]. In fact, their proposed algorithm is a well-known approach to exponentiation termed the m-ary method which essentially is a modification of the standard square-and-multiply algorithm     

Cross entropy, dissimilarity measures, and characterizations of quadratic entropy

A unified approach is given for constructing cross entropy and dissimilarity measures between probability distributions, based on a given entropy function or a diversity measure. Special properties of quadratic entropy introduced by Rao [7] are described. In particular it is shown that the square root of the Jensen difference (dissimilarity measure) arising out of a quadratic entropy provides a metric on a probability space. Several characterizations of quadratic entropy are obtained.     

Comment on "Joint Phase and Timing Acquisition in Data Transmission"

In the above paper several strategies for joint phase and timing recovery have been investigated. Here we point out that some results from the paper about the mean-square error method for one-dimensional modulation are faulty.     

Comment on "From the summation-by-parts algorithm to Pi"

Comments on the paper by Mosig (IEEE Antennas and Propagation Magazine, vol.47, p.38-40, 2005 December). The paper by Mosig discussed acceleration of convergence of series. Without commenting on either the validity or efficiency of his method, the present author would like to draw attention to an existing method, published long ago by D. Shanks (1955). Briefly stated, this method takes a sequence and defines partial sums, which is described in this paper.     

Comment on "On the presentation of Maxwell's theory"

It is shown by an example that the relations defining mechanical actions on charges and currents moving with respect to an inertial observer do not coincide, if referred to the latter, with the relations referred to an observer moving with charges and currents, even when velocities are nonrelativistic.     

Comment on "An interpretation of the magnetron problem"

The characteristic features of the smooth bore cylindrical magnetron are discussed. It is pointed out that these features, contrary to recently expressed views, have their origin in cooperative space charge wave interactions rather than in electron-electron scattering in the electron cloud.