Pope John Paul II, the Assassination Attempt, and the Soviet Union

“The attempt to murder the pope remains one of the century’s great mysteries,” wrote Carl Bernstein and Marco Politti in their 1996 biography of Pope John Paul II. Indeed, the mystery has remained unsolved since the pope was shot and wounded on May 13, 1981. A recent investigation concluded that the Soviet government was the perpetrator, but the situation should be examined in a broader historical context. What actually happened on May 13, 1981? Was it the sole decision and action of Mehmet Ali Agca, who was expressing his opposition to “Western imperialist policies,” as he had written in a threatening letter to a newspaper in 1979? Or had “someone else commissioned him to carry it out,” as Pope John Paul II alleged in a memoir written in 2005? Before evaluating the question from an historical standpoint, it is necessary to provide some background in order to establish a potential motive for the Soviet Union to support such an assassination attempt. Was Karol Wojtyla (the Pope’s birth name) really “[their] enemy,” as a party directive warned in 1979? Only then can we evaluate the Soviet Union’s involvement, or whether there was a conspiracy behind the attempted assassination of John Paul II at all. Finally, we should step back and look at the significance of the assassination attempt and the impact of the pope on the Cold War and Soviet dominance of Eastern Europe

Innovations, incentives, and regulation: forces shaping the payments environment

The migration to more efficient payment mechanisms is affected by innovations, incentives, and regulation. While advances in technology have yielded numerous payment method alternatives, many have not been widely adopted. A recent Chicago Fed conference explored why certain payment innovations have been more successful than others.Payment systems

Reform for Midwest urban schools--conference summary

Education - Middle West - Chicago (Ill.)

Wavelet transform - artificial neural network receiver with adaptive equalisation for a diffuse indoor optical wireless OOK link

This paper presents an alternative approach for signal detection and equalization using the continuous wavelet transform (CWT) and the artificial neural network (ANN) in diffuse indoor optical wireless links (OWL). The wavelet analysis is used for signal preprocessing (feature extraction) and the ANN for signal detection. Traditional receiver architectures based on matched filter (MF) experience significant performance degradation in the presence of artificial light interference (ALI) and multipath induced intersymbol interference (ISI). The proposed receiver structure reduces the effect of ALI and ISI by selecting a particular scale of CWT that corresponds to the desired signal and classifying the signal into binary 1 and 0 based on an observation vector. By selecting particular scales corresponding to the signal, the effect of ALI is reduced. We show that there is little variation when using 30 and 5 neurons in the first layer, with one layer ANN model showing a consistently worse BER performance than other models, whilst the 15 neuron model show some behaviour anomalies from a BER of approximately 10-3. The simulation results show that the Wavelet-ANN architecture outperforms the traditional MF based receiver even with the filter is matched to the ISI affected pulse shape. The Wavelet-ANN receiver is also capable of providing a bit error rate (BER) performance comparable to the equalized forms of traditional receiver structure

Stationary States of NLS on Star Graphs

We consider a generalized nonlinear Schr\"odinger equation (NLS) with a power nonlinearity |\psi|^2\mu\psi, of focusing type, describing propagation on the ramified structure given by N edges connected at a vertex (a star graph). To model the interaction at the junction, it is there imposed a boundary condition analogous to the \delta potential of strength \alpha on the line, including as a special case (\alpha=0) the free propagation. We show that nonlinear stationary states describing solitons sitting at the vertex exist both for attractive (\alpha0, a potential barrier) interaction. In the case of sufficiently strong attractive interaction at the vertex and power nonlinearity \mu<2, including the standard cubic case, we characterize the ground state as minimizer of a constrained action and we discuss its orbital stability. Finally we show that in the free case, for even N only, the stationary states can be used to construct traveling waves on the graph.Comment: Revised version, 5 pages, 2 figure

Chaos-based communication scheme using proportional and proportional-integral observers

In this paper, we propose a new chaos-based communication scheme using the observers. The novelty lies in the masking procedure that is employed to hide the confidential information using the chaotic oscillator. We use a combination of the addition and inclusion methods to mask the information. The performance of two observers, the proportional observer (P-observer) and the proportional integral observer (PI-observer) is compared that are employed as receivers for the proposed communication scheme. We show that the P-observer is not suitable scheme since it imposes unpractical constraints on the messages to be transmitted. On the other hand, we show that the PI-observer is the better solution because it allows greater flexibility in choosing the gains of the observer and does not impose any unpractical restrictions on the message

The Waste Land of Law School Fiction

Reviews of: The Paper Chase by John Osborn; The Letter of the Law by Katherine Roome; The Socratic Method by Michael Levi

Source Coding When the Side Information May Be Delayed

For memoryless sources, delayed side information at the decoder does not improve the rate-distortion function. However, this is not the case for more general sources with memory, as demonstrated by a number of works focusing on the special case of (delayed) feedforward. In this paper, a setting is studied in which the encoder is potentially uncertain about the delay with which measurements of the side information are acquired at the decoder. Assuming a hidden Markov model for the sources, at first, a single-letter characterization is given for the set-up where the side information delay is arbitrary and known at the encoder, and the reconstruction at the destination is required to be (near) lossless. Then, with delay equal to zero or one source symbol, a single-letter characterization is given of the rate-distortion region for the case where side information may be delayed or not, unbeknownst to the encoder. The characterization is further extended to allow for additional information to be sent when the side information is not delayed. Finally, examples for binary and Gaussian sources are provided.Comment: revised July 201