Determining the Delay Time of the Muscles Around the Knee Joint in Response to Rotational Perturbation From Support Surface

Introduction: Knee joint injuries usually occur in a short time, so analyzing the mechanism and process of this short time can be helpful to prevent similar injuries. This study aimed to determine and compare the reaction time of knee muscles and investigate the effect of knee position and perturbation direction on the reaction time of knee muscles in response to horizontal rotational perturbation applied to lower leg from support surface area. Materials and Methods: A total of 30 healthy women volunteers were received ±35 degrees of horizontal rotational perturbation and speed of 120 degrees per second from the sole while standing on the right leg in four conditions (external versus internal rotation of surface while the knee was in both extension and flexion position). Electromyography of knee muscles (vastus medialis and lateralis, medial and lateral hamstring and medial and lateral gastrocnemius) was measured to study the reaction time. Results: The reaction time of knee muscles during the perturbation was relatively long in this study (124 to 151 ms). It seems that muscles are recruited simultaneously in most conditions except in external rotation perturbation, with extension knee that the internal gastrocnemius muscle had significantly less delay time than the internal hamstring (P<0.05) and external quadriceps (P<0.05). The results show that most of these muscles do not react selectively and dependently on perturbation direction and knee position in response to horizontal rotational perturbation. Conclusion: In this study, little difference was seen in the reaction time of most knee muscles in all conditions. Thus in response to this type of perturbation, the knee muscles showed co-contraction.

DATA PROCESSING THROUGH AN ADDITIVE ROTATIONAL PERTURBATION TECHNIQUE IN A SECURED ENVIRONMENT OF PPRIVACY

As the usage of internet and web applications emerges faster, security and privacy of the data is the most challenging issue which we are facing, leading to the possibility of being easily damaged. Various conventional techniques are used for privacy preservation like condensation, randomization and tree structure etc., the limitations of the existing approaches are, they are not able to maintain proper balance between the data utility and privacy and it may have the problem with privacy violations. This paper presents an Additive Rotation Perturbation approach for Privacy Preserving Data Mining (PPDM). In this proposed work, various dataset from UCI Machine Learning Repository was collected and it is protected with a New Additive Rotational Perturbation Technique under Privacy Preserving Data Mining. Experimental result shows that the proposed algorithm’s strength is high for all the datasets and it is estimated using the DoV (Difference of Variance) method.

Posture Stabilization of Wheeled Mobile Robot Based on Passivity-Based Robust Switching Control with Model Uncertainty Compensation

Thisstudy presents apassivity-based robust switching control for the posture stabilization of wheeled mobile robots (WMRs) with model uncertainty. Essentially, this proposed strategy is switching between (1) passivity-based robust control to lead the robot to the neighborhood of local minima with a finite time and (2) another robust control to perturb the w-rotational motion of the WMR before the v-kinetic energy of the WMR become meaningless, thereby, eventually converging to the desired posture. Thus, combining two switching control laws ensures the global convergence of (x,y)-navigation of WMRs from any initial position to desired set. Especially, the inter-switching time is intentionallyselected before the WMR completely loses its mobility, which ensures a strict decrease in (x,y)-navigation potential energy and a better global convergence rate. In addition, this control architecture also includes model uncertainty compensation, often neglected in practice, and analytical study of rotational perturbation was also conducted. The Lyapunov technique and energetic passivity wereutilized to derive this control law. Simulation results are presented to illustrate the effectiveness of the proposed technique. It wasfound from the results that the WMR wasquickly converged to the desired posture even under the presence of model uncertainty.

High-resolution vibration–rotational spectra and rotational perturbation of the OO-stretching (ν6) band of CH2OO between 879.5 and 932.0 cm−1

We report the observation of a rotationally resolved ν6 band associated with the OO-stretching mode of the simplest Criegee intermediate, CH2OO, in the range of 879.5–932.0 cm−1 (11.37–10.73 μm) at an optical resolution of 0.0015 cm−1.

Reward feedback accelerates motor learning

Recent findings have demonstrated that reward feedback alone can drive motor learning. However, it is not yet clear whether reward feedback alone can lead to learning when a perturbation is introduced abruptly, or how a reward gradient can modulate learning. In this study, we provide reward feedback that decays continuously with increasing error. We asked whether it is possible to learn an abrupt visuomotor rotation by reward alone, and if the learning process could be modulated by combining reward and sensory feedback and/or by using different reward landscapes. We designed a novel visuomotor learning protocol during which subjects experienced an abruptly introduced rotational perturbation. Subjects received either visual feedback or reward feedback, or a combination of the two. Two different reward landscapes, where the reward decayed either linearly or cubically with distance from the target, were tested. Results demonstrate that it is possible to learn from reward feedback alone and that the combination of reward and sensory feedback accelerates learning. An analysis of the underlying mechanisms reveals that although reward feedback alone does not allow for sensorimotor remapping, it can nonetheless lead to broad generalization, highlighting a dissociation between remapping and generalization. Also, the combination of reward and sensory feedback accelerates learning without compromising sensorimotor remapping. These findings suggest that the use of reward feedback is a promising approach to either supplement or substitute sensory feedback in the development of improved neurorehabilitation techniques. More generally, they point to an important role played by reward in the motor learning process.

Rotational Pertubation of Masive Scalar Field Universes

In this course of presentation, we will consider the rotational perturbation of the Robertson-Walker universe will be examined in order to substantiate the possibility of the existence of Massive scalar field. We will study, the exact solutions for metric rotation Ω( r,t ) and the matter rotation w ( r,t ) under different conditions, and also study their nature and role from different angles.