The improved grasshopper optimization algorithm and its applications

Grasshopper optimization algorithm (GOA) proposed in 2017 mimics the behavior of grasshopper swarms in nature for solving optimization problems. In the basic GOA, the influence of the gravity force on the updated position of every grasshopper is not considered, which possibly causes GOA to have the slower convergence speed. Based on this, the improved GOA (IGOA) is obtained by the two updated ways of the position of every grasshopper in this paper. One is that the gravity force is introduced into the updated position of every grasshopper in the basic GOA. And the other is that the velocity is introduced into the updated position of every grasshopper and the new position are obtained from the sum of the current position and the velocity. Then every grasshopper adopts its suitable way of the updated position on the basis of the probability. Finally, IGOA is firstly performed on the 23 classical benchmark functions and then is combined with BP neural network to establish the predicted model IGOA-BPNN by optimizing the parameters of BP neural network for predicting the closing prices of the Shanghai Stock Exchange Index and the air quality index (AQI) of Taiyuan, Shanxi Province. The experimental results show that IGOA is superior to the compared algorithms in term of the average values and the predicted model IGOA-BPNN has the minimal predicted errors. Therefore, the proposed IGOA is an effective and efficient algorithm for optimization.

Analytical Investigation into Effects of Capillary Force on Condensate Film Flowing over Horizontal Semicircular Tube in Porous Medium

A theoretical investigation is performed into the problem of laminar filmwise condensation flow over a horizontal semicircular tube embedded in a porous medium and subject to capillary forces. The effects of the capillary force and gravity force on the condensation heat transfer performance are analyzed using an energy balance approach method. For analytical convenience, several dimensionless parameters are introduced, including the Jakob number Ja, Rayleigh number Ra, and capillary force parameter Boc. The resulting dimensionless governing equation is solved using the numerical shooting method to determine the effect of capillary forces on the condensate thickness. A capillary suction velocity can be obtained mathematically in the calculation process and indicates whether the gravity force is greater than the capillary force. It is shown that if the capillary force is greater than the condensate gravity force, the liquid condensate will be sucked into the two-phase zone. Under this condition, the condensate film thickness reduces and the heat transfer performance is correspondingly improved. Without considering the capillary force effects, the mean Nusselt number is also obtained in the present study as N u ¯ | V 2 ∗ = 0 = 2 R a D a / J a 1 / 2 ∫ 0 π 1 + cos θ 1 / 2 d θ .

Gravity Attraction as a Result of Resonant Interaction between Standing Quantum Recurrences

It has been shown theoretically that a gravity force can be formed between two phonon generators through resonant interacting between their phonon wave functions-standing recurrences in the medium of the physical vacuum. Following the theoretical model, an experimental gravity generator was developed based on a massive ferromagnetic toroid core with a coil.

Mass of prominences experiencing failed eruptions

A number of solar filaments/prominences demonstrate failed eruptions, when a filament at first suddenly starts to ascend and then decelerates and stops at some greater height in the corona. The mechanism of the termination of eruptions is not clear yet. One of the confining forces able to stop the eruption is the gravity force. Using a simple model of a partial current-carrying torus loop anchored to the photosphere and photospheric magnetic field measurements as the boundary condition for the potential magnetic field extrapolation into the corona, we estimated masses of 15 eruptive filaments. The values of the filament mass show rather wide distribution in the range of $4\times10^{15}$ – $270\times10^{16}$ g. Masses of the most of filaments, laying in the middle of the range, are in accordance with estimations made earlier on the basis of spectroscopic and white-light observations.

A possible way of unification of the gravity (Newton) and electric (Coulomb) forces by using a hydrodynamic analogy

Although the gravity is the most important force acting on the Universe scale, on small scales the electrical interaction prevails. Indeed, the Coulomb force between two charged particles is very high as compared to the gravity force between the masses carrying electric charges. Therefore, a solution would be to connect the two forces by extending the hydrodynamic analogy successfully introduced in the author’s previous works. These papers provide a model for gravity, an important conclusion being the dependence of the gravity coefficient in Newton formula on the age of the Universe. Unlike mass-energy, the total electric charge in the Universe is null. Therefore, we must consider limited regions of the Universe (example: atoms, nuclei) to express Coulomb's strong forces. In the following we take into consideration that any electric charge (electrons, protons, quarks etc.) is carried by a mass. Unlike the gravity force which is modeled by hydrodynamic sources on a global scale, Coulomb’s force is modeled by an equivalent vortex mass on a local scale.