Image Encryption Algorithm Based on Substitution Principle and Shuffling Scheme

This research presents a method of image encryption that has been designed based on the algorithm of complete shuffling, transformation of substitution box, and predicated image crypto-system. This proposed algorithm presents extra confusion in the first phase because of including an S-box based on using substitution by AES algorithm in encryption and its inverse in Decryption. In the second phase, shifting and rotation were used based on secrete key in each channel depending on the result from the chaotic map, 2D logistic map and the output was processed and used for the encryption algorithm. It is known from earlier studies that simple encryption of images based on the scheme of shuffling is insecure in the face of chosen cipher text attacks. Later, an extended algorithm has been projected. This algorithm performs well against chosen cipher text attacks. In addition, the proposed approach was analyzed for NPCR, UACI (Unified Average Changing Intensity), and Entropy analysis for determining its strength.

TWO-POINT RESISTANCES IN SAILBOAT FRACTAL NETWORKS

The two-point resistance of fractal network has been studied extensively by mathematicians and physicists. In this paper, for a class of self-similar networks named sailboat networks, we obtain a recursive algorithm for computing resistance between any two nodes, using elimination principle, substitution principle and local sum rules on effective resistance.

Invasion implies substitution in ecological communities with class-structured populations

Long-term evolution of quantitative traits is classically and usefully described as the directional change in phenotype due to the recurrent fixation of new mutations. A formal justification for such continual evolution ultimately relies on the “invasion implies substitution”-principle. Here, whenever a mutant allele causing a small phenotypic change can successfully invade a population, the ancestral (or wild-type) allele will be replaced, whereby fostering gradual phenotypic change if the process is repeated. It has been argued that this principle holds in a broad range of situations, including spatially and demographically structured populations experiencing frequency and density dependent selection under demographic and environmental fluctuations. However, prior studies have not been able to account for all aspects of population structure, leaving unsettled the conditions under which the “invasion implies substitution”-principle really holds. In this paper, we start by laying out a program to explore and clarify the generality of the “invasion implies substitution”-principle. Particular focus is given on finding an explicit and functionally constant representation of the selection gradient on a quantitative trait. Using geometric singular perturbation methods, we then show that the “invasion implies substitution”-principle generalizes to well-mixed and scalar-valued polymorphic multispecies ecological communities that are structured into finitely many demographic (or physiological) classes. The selection gradient is shown to be constant over the evolutionary timescale and that it depends only on the resident phenotype, individual growth-rates, population steady states and reproductive values, all of which are calculated from the resident dynamics. Our work contributes to the theoretical foundations of evolutionary ecology.

Specificity of Interaction of Cooperative and Non-cooperative Tactics While Communicating in English as Lingua Franca

This article discusses the specificity of interaction of cooperative and non-cooperative tactics. Such interaction occurs during a person’s discursive adaptation while communicating in English as a lingua franca. Based on A. Cogo research, we differentiate between English as a lingua franca (ELF) and English as a native/first language (ENL). The above, in its turn, explains the fact that native English speakers will most likely adapt to interaction in ELF rather than impose ENL standards on non-ENL speakers. The following principles of tactic interaction have been singled out: a) unification and b) substitution. Tactic interaction based on the principle of unification presupposes using one tactic that ensures successful realization of the other. That is how the negative stereotyping tactic in conjunction with the intimacy achievement tactic ensures the successful realization of the latter. Another example of tactic interaction based on the principle of unification is the interaction of the intimacy achievement tactic with the one of intimacy achievement / manipulation. In case of the latter, politeness that is characteristic of the intimacy achievement tactic can be used with a non-obvious purpose. In case of tactic interaction based on the substitution principle, there is a transition of one tactic to the other, thus achieving the communicative goal. For example, manifestation of aggression can be changed by the tactic of intimacy achievement. In that case, a communicant’s aggressive behavior can be changed into the reconciliatory one, thus demonstrating readiness to achieve intimacy.

Steganography Using Substitution Principle

In this chapter, the author describes the various substitution-based image steganography techniques. Basically, there are four categories of substitution techniques: (1) least significant bit (LSB) substitution, (2) LSB array-based substitution, (3) group of bits substitution (GBS), and (4) adaptive LSB substitution. The LSB substitution-based techniques are very much insecure (detectable by RS analysis), so LSB array, GBS, and adaptive LSB substitution techniques are proposed in literature. If substitution principle is used in a steganography technique, then it must be evaluated by RS analysis.

Research on Opening and Closing Synchronization of Flexible Hatch on Space Shuttle

The space industry is developing rapidly, specifically with the development of the space shuttle. The position accuracy of the shuttle hatch is always a key problem when the space shuttle is in orbit. When hatch position accuracy meets the requirement of the central lock acquisition domain, the central lock can capture and lock, otherwise it will cause the hatch to not close properly. Aiming at this problem, this article solves it by using the basic theory of flexible body ADAMS. First, composite hatches are converted into an equivalent shell by using the equal stiffness substitution principle, deriving the neutral file (MNF) of the hatch by a classical module in ANSYS, and testing synchronization and accuracy of it under the condition of ideal rigidity and flexibility. Eventually, we obtain the curve of motion displacement at key points, then we can estimate whether the synchronization and accuracy of the hatch meets the requirements.