Mechanical

Invariant quaternion radial harmonic Fourier moments for color image retrieval
Moments and moment invariants have become a powerful tool in image processing owing to their image description capability and invariance property. But, conventional methods are mainly introduced to deal with the binary or gray-scale images, and the only approaches for color image always have poor color image description capability. Based on radial harmonic Fourier moments (RHFMs) and quaternion...


Stretching of a polymer chain anchored to a surface: the massive field theory approach
Taking into account the well-known correspondence between the field theoretical φ 4 O ( n )-vector model in the limit n → 0 and the behaviour of long-flexible polymer chains, the investigation of stretching of an ideal and a real polymer chain with excluded volume interactions in a good solvent anchored to repulsive and inert surfaces is performed. The calculations of the average stretchin...
Symmetry-protected entangling boundary zero modes in crystalline topological insulators
Crystalline topological insulators owe their topological character to the protection that certain boundary states acquire because of certain point-group symmetries. We first show that a Hermitian operator obeying supersymmetric quantum mechanisms (SUSY QM) delivers the entanglement spectrum. We then show that such an entanglement spectrum that is compatible with a certain point-group symmetry o...


Excess entropy and central charge of the two-dimensional random-bond Potts model in the large-Q limit
We consider the random-bond Potts model in the large- Q limit and calculate the excess entropy, S Γ , of a contour, Γ , which is given by the mean number of Fortuin–Kasteleyn clusters which are crossed by Γ . In two dimensions, S Γ is proportional to the length of Γ , to which—at the critical point—there are universal logarithmic corrections due to corners. These are calculated by ap...
A two-dimensional generalized thermoelastic diffusion problem for a half-space
In this work, we consider the two-dimensional problem of a thermoelastic half-space with a permeating substance in contact with the bounding plane in the context of the theory of generalized thermoelastic diffusion with one relaxation time. The bounding surface of the half-space is taken to be traction free and subjected to a time-dependent thermal shock. Laplace and Fourier transform technique...


Dynamic features of planetary gear train with tooth errors
As one of the inherited displacement excitation sources which are related to the gear vibration and noise problems, gear transmission error always consists of two parts: gear tooth geometric error and tooth elastic deformation under transmitted load. The gear tooth geometric errors were directly employed as the displacement excitations in previous papers, which are not accurate. In this paper, ...
Investigation of Lamb waves attenuation in elastic-viscoelastic three-layer adhesive joints in low and high frequencies: Theoretical modeling
In this paper the attenuation of Lamb waves in three-layer joints, including two elastic plates bonded together by a viscoelastic adhesive layer, is investigated in high and low frequencies using global matrix method. Theoretical boundary value problem in three-layer adhesive joints with perfect bond and traction-free boundary conditions on their outer surfaces is solved to find a combination o...

Singular perturbation adaptive control and vibration suppression of free-flying flexible space manipulators
Singular perturbation adaptive control is designed for free-flying space manipulators with multiple flexible links and unknown physical parameters. The dynamical Lagrange equation was established based on assumed mode technique and linear momentum conservation theory. A singular perturbation model has been formulated and used for designing a reduced-order controller. This controller consisted o...
Flex-16: A large-displacement monolithic compliant rotational hinge
This paper introduces a large-displacement monolithic compliant rotational hinge, called the Flex-16. The Flex-16 achieves 90° of rotation and is aimed for application as a compliant deployment hinge. A nonlinear parametric finite element model was created to rapidly analyze a variety of designs identified during a configuration study. Prototypes were tested to verify the model and to validate...

The significance of the configuration space Lie group for the constraint satisfaction in numerical time integration of multibody systems
The dynamics simulation of multibody systems (MBS) using spatial velocities (non-holonomic velocities) requires time integration of the dynamics equations together with the kinematic reconstruction equations (relating time derivatives of configuration variables to rigid body velocities). The latter are specific to the geometry of the rigid body motion underlying a particular formulation, and th...
Steepest-Ascent Revisited: Unconstrained Missile Trajectory
A Steepest-Ascent numerical procedure for offline trajectory optimization of a surface-to-surface missile attacking a stationary target is presented. A detailed numerical solution, starting from building the mathematical formulation till generating an offline angle of attack control history, is illustrated. A novel approach for guessing a nominal control program is conducted. The formulation en...

K-dimensional protection structure (KDPS) for multi-link failure in data center optical networks
Currently, data center has become one of the most important application resources. Meanwhile, there is huge amount of data streams within a data center or among different data centers, which requires the transmission channel with high bandwidth and good reliability. Optical networks become the essential solution for the data center interconnection. Especially for intra data center networks, the...
Adjustable enhancement of higher order soliton effect pulse compression by using optimized active dispersion decreased nonlinear fiber loop mirror
In this paper, four common dispersion profiles have been investigated for obtaining as high as possible wings free compressed pulse in nonlinear fiber loop mirror. show that linear profile can be considered as the best choice. Also, as the importance for enhanced adjustability of higher order soliton effect pulse compression, we propose a new simple method, as active fiber loop. According to ou...
Normal mode splitting in hybrid BEC-optomechanical system
We consider an opto-mechanical cavity system consisting of Bose-Einstein condensate (BEC), trapped inside the optical cavity and driven by single mode laser field. The intracavity field acts as nonlinear spring which couples the condensate mode with moving end mirror of the cavity. We study the occurrence of normal mode splitting in the position spectra of the mechanical oscillator and condensa...
Periodical Oscillation Phenomena Observed in Salt-Water Oscillator Experiments under Small Gravity Conditions
We examined periodical oscillation phenomena that were observed during salt-water oscillator experiments under a small gravity condition. This condition was realized by situating a lower-density gadolinium chloride (GdCl 3) aqueous solution on a higher-density sodium chloride (NaCl) aqueous solution and applying a downward magnetic force. The GdCl 3 solution concentration was 0.15 mol/kg (densi...