Brief review on application of nonlinear dynamics in image encryption

Chaos-based cryptology has become one of the most common design techniques to design new encryption algorithms in the last two decades. However, many proposals have been observed to be weak against simple known attacks. However, security of proposals cannot be proved. An analysis roadmap is needed for the security analysis of new proposals. This study aims to address this shortcoming. Analysis and test results show that many chaos-based image encryption algorithms previously published in the nonlinear dynamics are actually not as secure as they are expressed although these algorithms do pass several statistical and randomness tests. A checklist has been proposed to solve these problems. The applications of the proposed checklist have been shown for different algorithms. The proposed checklist is thought to be a good starting point for researchers who are considering to work in chaos-based cryptography.     

Development of a new sensor material based on crystalline colloidal arrays embedded into polymer network

This study reports the development of a novel sensing material that reports on analyte concentrations via diffraction of visible light from polymerized crystalline colloidal arrays (PCCA). The PCCA contains periodic crystalline colloidal array (CCA) of spherical polystyrene colloids. This new method permanently locks the order of the CCA by embedding the CCA into a polymer network. These materials are mostly used in the development of novel materials which are basically called sensors for metal ions and all kinds of organic molecules. The polymer around the crystalline colloid can be functionalized with some recognition molecule, making these materials useful as optical sensors. We developed a sensor, utilizing crown ether, 2-aminomethyl-18-crown-6 (2A18C6) as the recognition agent, that detects K⁺ in the concentration range from 5 to 160 ppm.     

Energies and Landé factors for some excited levels in Lu I (<Emphasis Type="Italic">Z</Emphasis> = 71)

We have calculated relativistic energies and Landé factors for 5d6s ², 5d ²6s, 6s6p ², 6s ²7s, 5d ³, 5d6s7s, 6s ²6p, 5d6s6p, 5d ²6p and 6s ²7p excited levels outside the core [Xe]4f ¹⁴ in neutral lutetium (Lu I, Z = 71). These calculations are based on the multiconfiguration Hartree-Fock (MCHF) method, within the framework of the Breit-Pauli relativistic corrections. Moreover, the results obtained have been compared with other works.     

Interactive outranking approaches for multicriteria decision-making problems with imprecise information

PROMETHEE is a powerful method, which can solve many multiple criteria decision making (MCDM) problems. It involves sophisticated preference modelling techniques but requires too much a priori precise information about parameter values (such as criterion weights and thresholds). In this paper, we consider a MCDM problem where alternatives are evaluated on several conflicting criteria, and the criterion weights and/or thresholds are imprecise or unknown to the decision maker (DM). We build robust outranking relations among the alternatives in order to help the DM to rank the alternatives and select the best alternative. We propose interactive approaches based on PROMETHEE method. We develop a decision aid tool called INTOUR, which implements the developed approaches.     

An Alternative Approach to Elliptical Motion

Elliptical rotation is the motion of a point on an ellipse through some angle about a vector. The purpose of this paper is to examine the generation of elliptical rotations and to interpret the motion of a point on an ellipsoid using elliptic inner product and elliptic vector product. To generate an elliptical rotation matrix, first we define an elliptical ortogonal matrix and an elliptical skew symmetric matrix using the associated inner product. Then we use elliptic versions of the famous Rodrigues, Cayley, and Householder methods to construct an elliptical rotation matrix. Finally, we define elliptic quaternions and generate an elliptical rotation matrix using those quaternions. Each method is proven and is provided with several numerical examples.     

The impact of socio-technical communication styles on the diversity and innovation potential of global science collaboratories

Emerging cyber-infrastructure tools are enabling scientists to transparently co-develop, share, and communicate about real-time diverse forms of knowledge artifacts. In these environments, communication preferences of scientists are posited as an important factor affecting innovation capacity and robustness of social and knowledge network structures. Scientific knowledge creation in such communities is called global participatory science (GPS). Recently, using agent-based modeling and collective action theory as a basis, a complex adaptive social communication network model (CollectiveInnoSim) is implemented. This work leverages CollectiveInnoSim implementing communication preferences of scientists. Social network metrics and knowledge production patterns are used as proxy metrics to infer innovation potential of emergent knowledge and collaboration networks. The objective is to present the underlying communication dynamics of GPS in a form of computational model and delineate the impacts of various communication preferences of scientists on innovation potential of the collaboration network. Gained insight can ultimately help policy-makers to design GPS environments and promote innovation.     

Synthesis,structural, and spectral studies of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-bis- (5-methylsalicylidene)-2,2′-diamino-4-4′-di-(trifloromethyl)-diphenyl disulfide

A new disulfide compound N,N′-bis-(5-methylsalicylidene)-2,2′-diamino-4-4′-di-(trifloromethyl)-diphenyl disulfide (C₃₀H₂₂F₆N₂O₂S₂) was prepared and characterized by ¹H-NMR, IR, mass spectroscopy, and single-crystal X-ray diffraction. Spectroscopic assignments and the crystallographic results indicate the predominance of the phenol-imine tautomeric form. [For example, N=C double bonds 1.274(9)Å and 1.275(9)Å, two very close hydrogen peaks to the atomic positions of O atoms in difference Fourier map and two strong intramolecular hydrogen bonds (O–H\(\cdots\)N) with O\(\cdots\)N distances of 2.611(10) and 2. 613(8) Åstrongly indicate that this tautomeric form is preferred]. The strong effect of the para CF₃ groups in the molecular and crystallographic arrangement was attributed to the electronegativity of the CF₃ groups.     

On nadir points of multiobjective integer programming problems

In this study, we consider the nadir points of multiobjective integer programming problems. We introduce new properties that restrict the possible locations of the nondominated points necessary for computing the nadir points. Based on these properties, we reduce the search space and propose an exact algorithm for finding the nadir point of multiobjective integer programming problems. We present an illustrative example on a three objective knapsack problem. We conduct computational experiments and compare the performances of two recent algorithms and the proposed algorithm.     

Brieskorn manifolds as contact branched covers of spheres

We show that Brieskorn manifolds with their standard contact structures are contact branched coverings of spheres. This covering maps a contact open book decomposition of the Brieskorn manifold onto a Milnor open book of the sphere.      

A method to estimate turbulence intensity and transverse Taylor microscale in turbulent flows from spatially averaged hot-wire data

A new approach to evaluate turbulence intensity and transverse Taylor microscale in turbulent flows is presented. The method is based on a correction scheme that compensates for probe resolution effects and is applied by combining the response of two single hot-wire sensors with different wire lengths. Even though the technique, when compared to other correction schemes, requires two independent measurements, it provides, for the same data, an estimate of the spanwise Taylor microscale. The method is here applied to streamwise turbulence intensity distributions of turbulent boundary layer flows but it is applicable generally in any turbulent flow. The technique has been firstly validated against spatially averaged DNS data of a zero pressure-gradient turbulent boundary layer showing a good capacity to reconstruct the actual profiles and to predict a qualitatively correct and quantitatively agreeing transverse Taylor microscale over the entire height of the boundary layer. Finally, the proposed method has been applied to available higher Reynolds number data from recent boundary layer experiments where an estimation of the turbulence intensity and of the Taylor microscale has been performed.