Efficient topography optimization of a washing machine cabinet to reduce radiated noise during the dehydration process

Journal of Mechanical Science and Technology - In modern society, the use of washing machines has increased owing to increased interest in personal hygiene. Over the years, the performance of...     

A novel reversible data hiding scheme with two-dimensional histogram shifting mechanism

Multimedia Tools and Applications - In this paper, we propose a novel reversible data hiding technique based on two-dimensional histogram shifting for quantized discrete cosine transformation...     

Iterative Self-Interference Mitigation in Full-Duplex Wireless Communications

Wireless Personal Communications - This paper considers a full-duplex wireless communication system in which detection of the desired signal is hindered not only by the self-interference (SI), but...     

Inhomogeneous softening during annealing of ultrafine-grained silver processed by HPT

The softening in ultrafine-grained silver processed by high-pressure torsion (HPT) was studied during annealing using differential scanning calorimetry (DSC). Two separate exothermic peaks were observed in the DSC thermogram of the HPT-processed sample. It is shown that the first and the second peaks are related to the recrystallization of the middle volume and the surface regions of the HPT-processed disk, respectively. Therefore, a very inhomogeneous sandwich-like microstructure develops during annealing with a soft interior and hard surface layers. The lower thermal stability of the middle region appears to be related to the stronger twinning activity since the twinned volumes can act as nuclei for recrystallized grains. The higher twin-fault probability in the interior is attributed to the larger strain due to the outflow of material between the anvils of the HPT facility during quasi-constrained processing.     

Interface control for resolved CFD-DEM with capillary interactions

In this work, a resolved CFD–DEM coupling model for the simulation of gas-liquid-solid flows is developed: the interface capturing method based on the colour function is employed for fluids (i.e. a gas and liquid) whilst Discrete Element Method (DEM) is used for particles. The Volume Penalisation (VP) method is adopted to consider the hydrodynamic interactions between fluids and particles along with the Immersed Free Surface (IFS) method, which artificially extends the gas-liquid interface into the interior of the particle to account for the wettability. The unique point of the proposed model is that the thickness of the gas-liquid interface can be controlled by using both interface compression and diffuse interface techniques simultaneously. From the simulation results, it is presented that the accurate evaluation of the surface tension force as well as the capillary force can be achieved by appropriately controlling the interface thickness. Moreover, the major two methods in the literature to calculate the capillary force are compared in this work. The validity of the proposed model is presented for both static and dynamic cases. The behaviour of two colliding particles with a dynamic liquid bridge is then simulated to demonstrate the applicability of the proposed model to a complex three-phase system.     

A Series-elastic Robot for Back-pain Rehabilitation

This paper addresses the robot-assisted rehabilitation of back pain, an epidemic health problem affecting a large portion of the population. The design is composed of two springs in series connected to an end-effector via a pair of antagonistic cables. The spring and cable arrangement forms an elastic coupling from the actuator to the output shaft. An input-output torque model of the series-elastic mechanism is established and studied numerically. The study also illustrates the variation of the mechanism’s effective stiffness by changing the springs’ position. In addition, we built a prototype of the robotic mechanism and design experiments with a robotic manipulator to experimentally investigate its dynamic characteristics. The experimental results confirm the predicted elasticity between the input motion and the output torque at the end-effector. We also observe an agreement between the data generated by the torque model and data collected from the experiments. An experiment with a full-scale robot and a human subject is carried out to investigate the human-robot interaction and the mechanism behavior.

     

Transverse vibration control of axially moving web systems by regulation of axial tension

International Journal of Control, Automation and Systems - In this paper, an active control scheme to suppress the transverse vibrations of an axially moving web system by regulating its transport...