Learning Optimal Control of Synchronization in Networks of Coupled Oscillators using Genetic Programming-based Symbolic Regression

Networks of coupled dynamical systems provide a powerful way to model systems with enormously complex dynamics, such as the human brain. Control of synchronization in such networked systems has far reaching applications in many domains, including engineering and medicine. In this paper, we formulate the synchronization control in dynamical systems as an optimization problem and present a multi-objective genetic programming-based approach to infer optimal control functions that drive the system from a synchronized to a non-synchronized state and vice-versa. The genetic programming-based controller allows learning optimal control functions in an interpretable symbolic form. The effectiveness of the proposed approach is demonstrated in controlling synchronization in coupled oscillator systems linked in networks of increasing order complexity, ranging from a simple coupled oscillator system to a hierarchical network of coupled oscillators. The results show that the proposed method can learn highly-effective and interpretable control functions for such systems.Comment: Submitted to nonlinear dynamic

The State-of-the-Art Questionnaire on Applied Systems Analysis: A Report on the Responses

This publication is the second report by the Survey Project on the structure and content of a proposed Series of monographs and a Handbook to survey the state-of-the-art of applied systems analysis. In the first report (RR-76-16, Systems Analysis: An Outline for the State-of-the-Art Survey Publications, July 1976), we presented a revised outline and current guidelines for the Survey Project publication program; in the present document, the sequel. we discuss the response to a questionnaire -- distributed widely throughout the systems analyst community -- upon which our revised outline is based. This report should be of interest to the questionnaire respondents, and to a wider audience as well. in that it reflects what some 160 analysts and others associated with systems analysis think about systems analysis, what they consider to be vital and important in this area, and what they think to be peripheral or of minor relevance

Systems Analysis: An Outline for the State-of-the-Art Survey Publications

IIASA plans to organize, commission, and publish a Series of volumes and a Handbook to survey the international state-of-the-art of applied systems analysis. This report provides the Survey Project's explication of the concept of applied systems analysis; it describes in detail the proposed Series and Handbook, including purpose, audience, international character, level of presentation, authors, reviewers, and remuneration policies. An outline spanning the field of interest of applied systems analysis is designed to help prospective authors with the choice of topics. Guidelines are provided for the acceptability of volumes for the Series, and suggestions for prospective authors on the preparation of prospectuses (outlines) for Series monographs are included. These prospectuses are submitted to the Editorial Board and special liaison committees established in each of IIASA's National Member Organizations. A summary checklist of procedures for development of Series volumes is provided in the Appendix

Система очистки солнечных панелей в космосе

The authors have demonstrated efficient TEM(00)operation of the Nd:YVO4 rod laser, one-end-pumped by a one-fibre-coupled diode laser. A 11.6W linearly polarised laser output with an optical efficiency of 54 percent in TEM(00)mode has been achieved

Composability in quantum cryptography

In this article, we review several aspects of composability in the context of quantum cryptography. The first part is devoted to key distribution. We discuss the security criteria that a quantum key distribution protocol must fulfill to allow its safe use within a larger security application (e.g., for secure message transmission). To illustrate the practical use of composability, we show how to generate a continuous key stream by sequentially composing rounds of a quantum key distribution protocol. In a second part, we take a more general point of view, which is necessary for the study of cryptographic situations involving, for example, mutually distrustful parties. We explain the universal composability framework and state the composition theorem which guarantees that secure protocols can securely be composed to larger applicationsComment: 18 pages, 2 figure

Surficial geologic materials of Linn County, Iowa

https://ir.uiowa.edu/igs_ofm/1009/thumbnail.jp

Impact Ionization in ZnS

The impact ionization rate and its orientation dependence in k space is calculated for ZnS. The numerical results indicate a strong correlation to the band structure. The use of a q-dependent screening function for the Coulomb interaction between conduction and valence electrons is found to be essential. A simple fit formula is presented for easy calculation of the energy dependent transition rate.Comment: 9 pages LaTeX file, 3 EPS-figures (use psfig.sty), accepted for publication in PRB as brief Report (LaTeX source replaces raw-postscript file

Attacks on quantum key distribution protocols that employ non-ITS authentication

We demonstrate how adversaries with unbounded computing resources can break Quantum Key Distribution (QKD) protocols which employ a particular message authentication code suggested previously. This authentication code, featuring low key consumption, is not Information-Theoretically Secure (ITS) since for each message the eavesdropper has intercepted she is able to send a different message from a set of messages that she can calculate by finding collisions of a cryptographic hash function. However, when this authentication code was introduced it was shown to prevent straightforward Man-In-The-Middle (MITM) attacks against QKD protocols. In this paper, we prove that the set of messages that collide with any given message under this authentication code contains with high probability a message that has small Hamming distance to any other given message. Based on this fact we present extended MITM attacks against different versions of BB84 QKD protocols using the addressed authentication code; for three protocols we describe every single action taken by the adversary. For all protocols the adversary can obtain complete knowledge of the key, and for most protocols her success probability in doing so approaches unity. Since the attacks work against all authentication methods which allow to calculate colliding messages, the underlying building blocks of the presented attacks expose the potential pitfalls arising as a consequence of non-ITS authentication in QKD-postprocessing. We propose countermeasures, increasing the eavesdroppers demand for computational power, and also prove necessary and sufficient conditions for upgrading the discussed authentication code to the ITS level.Comment: 34 page

Tight Finite-Key Analysis for Quantum Cryptography

Despite enormous progress both in theoretical and experimental quantum cryptography, the security of most current implementations of quantum key distribution is still not established rigorously. One of the main problems is that the security of the final key is highly dependent on the number, M, of signals exchanged between the legitimate parties. While, in any practical implementation, M is limited by the available resources, existing security proofs are often only valid asymptotically for unrealistically large values of M. Here, we demonstrate that this gap between theory and practice can be overcome using a recently developed proof technique based on the uncertainty relation for smooth entropies. Specifically, we consider a family of Bennett-Brassard 1984 quantum key distribution protocols and show that security against general attacks can be guaranteed already for moderate values of M.Comment: 11 pages, 2 figure