Solenoid actuated Five-fingered robotic hand design: evaluating the capability of solenoid actuators in generating basic finger motions

<span lang="EN-GB">There are numerous robotic hand designs but the five-fingered robotic hand design is the most dexterous robotic hand design due to its similar appearance and motions with the human hands. The fingers' motions are commonly driven by geared motors or other types of emerging technologies. However, the motions are yet to be driven directly by solenoid actuators due to its limited stroke length and also general perceptions of its applications as an actuator. Nevertheless, solenoid actuators are known for their fast reaction time and strong holding force which are useful to generate fast motions and strong grasping actions. To realise this concept, previous research and developments had been done by the authors but the outcome was not convincing enough due to the absence of a working prototype. Therefore, this paper introduced a new solenoid actuated robotic hand design and its prototype. The prototype was then tested and evaluated in accordance to the operational concept where the findings showed that the solenoid actuators were capable of generating basic finger motions</span><span>.</span>

Expressing Personalities of Conversational Agents through Visual and Verbal Feedback

As the uses of conversational agents increase, the affective and social abilities of agents become important with their functional abilities. Agents that lack affective abilities could frustrate users during interaction. This study applied personality to implement the natural feedback of conversational agents referring to the concept of affective computing. Two types of feedback were used to express conversational agents’ personality: (1) visual feedback and (2) verbal cues. For visual feedback, participants (N = 45) watched visual feedback with different colors and motions. For verbal cues, participants (N = 60) heard different conditions of agents’ voices with different scripts. The results indicated that the motions of visual feedback were more significant than colors. Fast motions could express distinct and positive personalities. Different verbal cues were perceived as different personalities. The perceptions of personalities differed according to the vocal gender. This study provided design implications for personality expressions applicable to diverse interfaces.

Frame Rate Up-Conversion in Echocardiography Images, Using Manifold-Learning and Image Registration

ABSTRACTIn this paper, we propose a new temporal frame interpolation algorithm for frame rate up-conversion (FRUC) in echocardiography images. This algorithm employs a combination of dimension reduction techniques and image registration to increase frame rate.If the distance between two successive frames of a video be great, motion jerkiness will appear between them and visual quality of the video will decrease. Some parts of heart have a very high speed motion, and echocardiography videos, obtained by available systems can’t take enough number of frames to show them well. So, to achieve an echocardiography image set with a better visual quality, more frames are necessary between two frames at a great distance. Here, we use dimension reduction techniques to find out the number of suitable frames between two consecutive frames to show the fast motions better, but don’t take much time. We project images to a 3-dimentional space by this way. Greater difference between the frames, results greater distance between corresponding embedded points. Thus, the distance between the embedded points is a scale for the suitable number of frames, needed between two successive frames. These frames are produced with the registration techniques.On the other hand, heart doesn’t have a constant speed during a cycle, but echocardiography images are recorded with constant speed. So, frames at a greater distance show fast motions of the heart, and frames at a lower distance show slow motions of the heart. While, we put unequal number of frames between successive frames, and in this way remove temporal coordination of the image set. To solve this problem, we put efficient number of linear average of available frames, in places that the number of inserted frames in between available frames is less than maximum to obtain an equal number of frames between all successive frames.

Switched-Impedance Control of Surgical Robots in Teleoperated Beating-Heart Surgery

A novel switched-impedance control method is proposed and implemented for telerobotic beating-heart surgery. Differing from cardiopulmonary-bypass-based arrested-heart surgery, beating-heart surgery creates challenges for the human operator (surgeon) due to the heart’s fast motions and, in the case of a teleoperated surgical robot, the oscillatory haptic feedback to the operator. This paper designs two switched reference impedance models for the master and slave robots to achieve both motion compensation and nonoscillatory force feedback during slave–heart interaction. By changing the parameters of the impedance models, different performances for both robots are obtained: (a) when the slave robot does not make contact with the beating heart, the slave robot closely follows the motion of the master robot as in a regular teleoperation system, (b) when contact occurs, the slave robot automatically compensates for the fast motions of the beating heart while the human operator perceives the nonoscillatory component of the slave–heart interaction forces, creating the feeling of making contact with an idle heart for the human operator. The proposed method is validated through simulations and experiments.

Erdős–Rényi law of large numbers in the averaging setup

We extend the Erdős–Rényi law of large numbers to the averaging setup both in discrete and continuous time cases. We consider both stochastic processes and dynamical systems as fast motions whenever they are fast mixing and satisfy large deviations estimates. In the continuous time case we consider flows with large deviations estimates which allow a suspension representation and it turns out that fast mixing of corresponding base transformations suffices for our results.

Geostrophic Adjustment and Wave–Vortex (Non)Interaction

The fundamental process of geostrophic adjustment is treated by the method of multi-scale asymptotic expansions in Rossby number and fast-time averaging (which is explained), first in the barotropic one-layer case, and then in the baroclinic two-layer case. Together with the standard quasi-geostrophic regime of parameters, the frontal (or semi-) geostrophic regime is considered. Dynamical separation of slow and fast motions is demonstrated in both regimes. The former obey quasi-geostrophic or frontal-geostrophic equations, thus providing formal justification of the heuristic derivation of Chapter 5. Fast motions are inertia-gravity waves in quasi-geostrophic case, and inertial oscillations in the frontal-geostrophic case. Geostrophic adjustment is also considered in the presence of coastal, topographic, and equatorial wave-guides, and, again, separation of fast and slow motions is demonstrated, the latter now including long Kelvin waves in the first case, long topographic waves in the second case, and long Kelvin and Rossby waves in the third case.