Normative database of response surface method for human trunk extension in isometric mode.

Recent studies show that asymmetric movements are important Low Back Disorders risk factors. Measuring the trunk strength and identifying the coupling effects in different postures can provide an objective tool to assess one's task capacity. This paper estimates the maximum performance capacity for isometric trunk extension and accompanying torques. Thirty males performed maximum voluntary isometric extension in 33 trunk postures on Sharif Lumbar Isometric Strength Tester device. Corresponding moments and angular positions were collected. Second-order full response surface models (RSM) were exploited to formulate the relationship between strengths and three trunk angles. The results of correlation coefficient, percent of standard estimation error and lack of fit reflected the adequacy of models. In conclusion, the main torque was the extension, but at the same time lateral bending and rotation torques were observed. For predicting these three torques in a specific posture and injury prevention, the second order RSM is a useful tool. The presented models can be used in the fields of ergonomics, occupational biomechanics and sport.

Utilizing an Emotional Robot Capable of Lip-Syncing in Robot-Assisted Speech Therapy Sessions for Children with Language Disorders.

This study scrutinizes the impacts of utilizing a socially assistive robot, the RASA robot, during speech therapy sessions for children with language disorders. Two capabilities were developed for the robotic platform to enhance children-robot interactions during speech therapy interventions: facial expression communication (containing recognition and expression) and lip-syncing. Facial expression recognition was conducted by training several well-known CNN architectures on one of the most extensive facial expressions databases, the AffectNet database, and then modifying them using the transfer learning strategy performed on the CK+ dataset. The robot's lip-syncing capability was designed in two steps. The first step was concerned with designing precise schemes of the articulatory elements needed during the pronunciation of the Persian phonemes (i.e., consonants and vowels). The second step included developing an algorithm to pronounce words by disassembling them into their components (including consonants and vowels) and then morphing them into each other successively. To pursue the study's primary goal, two comparable groups of children with language disorders were considered, the intervention and control groups. The intervention group attended therapy sessions in which the robot acted as the therapist's assistant, while the control group only communicated with the human therapist. The study's first purpose was to compare the children's engagement while playing a mimic game with the affective robot and the therapist, conducted via video coding. The second objective was to assess the efficacy of the robot's presence in the speech therapy sessions alongside the therapist, accomplished by administering the Persian Test of Language Development, Persian TOLD. According to the first scenario, playing with the affective robot is more engaging than playing with the therapist. Furthermore, the statistical analysis of the study's results indicates that participating in robot-assisted speech therapy (RAST) sessions enhances children with language disorders' achievements in comparison with taking part in conventional speech therapy interventions.

Design, Manufacture, and Acceptance Evaluation of APO: A Lip-syncing Social Robot Developed for Lip-reading Training Programs.

Lack of educational facilities for the burgeoning world population, financial barriers, and the growing tendency in favor of inclusive education have all helped channel a general inclination toward using various educational assistive technologies, e.g., socially assistive robots. Employing social robots in diverse educational scenarios could enhance learners' achievements by motivating them and sustaining their level of engagement. This study is devoted to manufacturing and investigating the acceptance of a novel social robot named APO, designed to improve hearing-impaired individuals' lip-reading skills through an educational game. To accomplish the robot's objective, we proposed and implemented a lip-syncing system on the APO social robot. The proposed robot's potential with regard to its primary goals, tutoring and practicing lip-reading, was examined through two main experiments. The first experiment was dedicated to evaluating the clarity of the utterances articulated by the robot. The evaluation was quantified by comparing the robot's articulation of words with a video of a human teacher lip-syncing the same words. In this inspection, due to the adults' advanced skill in lip-reading compared to children, twenty-one adult participants were asked to identify the words lip-synced in the two scenarios (the articulation of the robot and the video recorded from the human teacher). Subsequently, the number of words that participants correctly recognized from the robot and the human teacher articulations was considered a metric to evaluate the caliber of the designed lip-syncing system. The outcome of this experiment revealed that no significant differences were observed between the participants' recognition of the robot and the human tutor's articulation of multisyllabic words. Following the validation of the proposed articulatory system, the acceptance of the robot by a group of hearing-impaired participants, eighteen adults and sixteen children, was scrutinized in the second experiment. The adults and the children were asked to fill in two standard questionnaires, UTAUT and SAM, respectively. Our findings revealed that the robot acquired higher scores than the lip-syncing video in most of the questionnaires' items, which could be interpreted as a greater intention of utilizing the APO robot as an assistive technology for lip-reading instruction among adults and children.

One-shot Learning from Demonstration Approach Toward a Reciprocal Sign Language-based HRI.

This paper addresses the lack of proper Learning from Demonstration (LfD) architectures for Sign Language-based Human-Robot Interactions to make them more extensible. The paper proposes and implements a Learning from Demonstration structure for teaching new Iranian Sign Language signs to a teacher assistant social robot, RASA. This LfD architecture utilizes one-shot learning techniques and Convolutional Neural Network to learn to recognize and imitate a sign after seeing its demonstration (using a data glove) just once. Despite using a small, low diversity data set (~ 500 signs in 16 categories), the recognition module reached a promising 4-way accuracy of 70% on the test data and showed good potential for increasing the extensibility of sign vocabulary in sign language-based human-robot interactions. The expansibility and promising results of the one-shot Learning from Demonstration technique in this study are the main achievements of conducting such machine learning algorithms in social Human-Robot Interaction.

Directional control of surface rolling molecules exploiting non-uniform heat-induced substrates.

Molecular machines, such as nanocars, have shown promising potential for various tasks, including manipulation at the nanoscale. In this paper, we examined the influence of temperature gradients on nanocar and nanotruck motion as well as C60 - as their wheel - on a flat gold surface under various conditions. We also compared the accuracy and computational cost of two different approaches for generating the temperature gradient. The results show that severe vibrations and frequent impacts of gold atoms at high temperatures increase the average distance of C60 from the substrate, reducing its binding energy. Moreover, the temperature field drives C60 to move along the temperature variation; still, the diffusive motion of C60 remained unchanged in the direction perpendicular to the temperature gradient. Increasing the magnitude of the temperature gradient speeds up its motion parallel to the gradient, while raising the average temperature of the substrate increases the diffusion coefficient in all directions. The temperature field influences the nanocar motion in the same manner as C60. However, the nanocars have a substantially shorter motion range compared to C60. The relatively larger, heavier, and more flexible chassis of the nanocar makes it more sluggish than the nanotruck. In general, the motion of large and heavy surface rolling molecules is less affected by the temperature field compared to small and light molecules. The results of the study show that concentrated heat sources can be employed to push surface rolling molecules or break down their large clusters. We can exploit a temperature field as a driving force to push nanocars in a desired direction on prebuilt pathways.

Social Robotics, Education, and Religion in the Islamic World: An Iranian Perspective.

The social impact of robotics applied to domains such as education, religion, nursing, and therapy across the world depends on the level of technology as well as the culture in which it is used. By studying how robots are used in Iran, a technologically-savvy country with a long history and a rich culture, we explore their possible impact on interrelated areas of religious and ethical features in education in an Islamic society. To accomplish this task, a preliminary exploratory study was conducted using two social robots as teaching assistants in Islamic religion classes for 42 elementary students. More than 90% of the participants in the study absolutely preferred the robot-assisted religion class over one taught by a human. Building on the results from the students' viewpoints and exam scores, the acceptability and potential of using social robots in the education of Islamic religious concepts in Iran are further discussed in this paper.

Arash: A social robot buddy to support children with cancer in a hospital environment.

This article presents the thorough design procedure, specifications, and performance of a mobile social robot friend Arash for educational and therapeutic involvement of children with cancer based on their interests and needs. Our research focuses on employing Arash in a pediatric hospital environment to entertain, assist, and educate children with cancer who suffer from physical pain caused by both the disease and its treatment process. Since cancer treatment causes emotional distress, which can reduce the efficiency of medications, using social robots to interact with children with cancer in a hospital environment could decrease this distress, thereby improving the effectiveness of their treatment. Arash is a 15 degree-of-freedom low-cost humanoid mobile robot buddy, carefully designed with appropriate measures and developed to interact with children ages 5-12 years old. The robot has five physical subsystems: the head, arms, torso, waist, and mobile-platform. The robot's final appearance is a significant novel concept; since it was selected based on a survey taken from 50 children with chronic diseases at three pediatric hospitals in Tehran, Iran. Founded on these measures and desires, Arash was designed, built, improved, and enhanced to operate successfully in pediatric cancer hospitals. Two experiments were devised to evaluate the children's level of acceptance and involvement with the robot, assess their feelings about it, and measure how much the robot was similar to the favored conceptual sketch. Both experiments were conducted in the form of storytelling and appearance/performance evaluations. The obtained results confirm high engagement and interest of pediatric cancer patients with the constructed robot.

Directing the diffusive motion of fullerene-based nanocars using nonplanar gold surfaces.

A new method for guiding the motion of fullerene and fullerene-based nanocars is introduced in this paper. The effects of non-flat substrates on the motion of C60, a nanocar and a nanotruck are investigated at different conditions and temperatures. Their behavior is studied using two different approaches: analyzing the variation in potential energy and conducting all-atom classical molecular dynamics simulations. This paper proposes that the use of a stepped substrate will make their motion more predictable and controllable. The results of the simulations show that C60 stays on the top side of the step and cannot jump over the step at temperatures of 400 K and lower. However, at temperatures of 500 K and higher, C60 has sufficient energy to travel to the down side of the step. C60 attaches to the edge and moves just alongside of the edge when it is on the down side of the step. The edge also restricts the motion of C60 alongside the edge and reduces its range of motion. By considering the motion of C60, the general behavior of the nanocar and nanotruck is predictable. The nanocar stays on the top side of the step at temperatures of 400 K and less; at 500 K and higher temperatures, its wheels jump off the edge, and its range of motion is restricted. The relatively rigid chassis of the nanotruck does not allow the free individual motion of the wheels. As a result, the entire nanotruck stays on the top side of the step, even at 600 K. A pathway with the desired route can be fabricated for the motion of C60 and nanocars using the method presented in this paper. This represents a step towards the directional motion of C60 and nanocars.

Influence of the tip mass on the tip-sample interactions in TM-AFM.

This paper focuses on the influences of the tip mass ratio (the ratio of the tip mass to the cantilever mass), on the excitation of higher oscillation eigenmodes and also on the tip-sample interaction forces in tapping mode atomic force microscopy (TM-AFM). A precise model for the cantilever dynamics capable of accurate simulations is essential for the investigation of the tip mass effects on the interaction forces. In the present work, the finite element method (FEM) is used for modeling the AFM cantilever to consider the oscillations of higher eigenmodes oscillations. In addition, molecular dynamics (MD) is used to calculate precise data for the tip-sample force as a function of tip vertical position with respect to the sample. The results demonstrate that in the presence of nonlinear tip-sample interaction forces, the tip mass ratio plays a significant role in the excitations of higher eigenmodes and also in the normal force applied on the surface. Furthermore, it has been shown that the difference between responses of the FEM and point-mass models in different system operational conditions is highly affected by the tip mass ratio.

Effects of higher oscillation modes on TM-AFM measurements.

The finite element method and molecular dynamics simulations are used for modeling the AFM microcantilever dynamics and the tip-sample interaction forces, respectively. Molecular dynamics simulations are conducted to calculate the tip-sample force data as a function of tip height at different lateral positions of the tip with respect to the sample. The results demonstrate that in the presence of nonlinear interaction forces, higher eigenmodes of the microcantilever are excited and play a significant role in the tip and sample elastic deformations. Using comparisons between the results of FEM and lumped models, how some aspects of the system behavior can be hidden when the point-mass model is used is illustrated.

Robust adaptive backstepping control of uncertain Lorenz system.

In this paper, a novel robust adaptive control method is proposed for controlling the Lorenz chaotic attractor. A new backstepping controller for the Lorenz system based on the Lyapunov stability theorem is proposed to overcome the singularity problem that appeared in using the typical backstepping control method. By exploiting the property of the system, the resulting controller is shown to be singularity free and the closed loop system is globally stable. Due to unavailability of system states measurement in practice, the controller is selected such that only one system state is needed. To overcome the problem of parameter uncertainty, an additional term to Lyapunov function is added and an identification scheme is adopted to have a negative definite Lyapunov function derivative. The simulation results demonstrate the effectiveness of the proposed controllers and approaches.

A rigid body spring model to investigate the lateral shift - restraining force behavior of the patella.

Patellar lateral stability was studied using a 2D transverse plane model with deformable articular surfaces. Quadriceps muscles and patellar tendon were considered as strings with predefined forces and lateral and medial retinaculum as tensile springs. Deformation behavior of articular cartilage was modeled by a set of compression springs perpendicular to articular surfaces, based on rigid body spring model method (RBSM). Patellar lateral stability was investigated using restraining force method (the external force required to cause up to 10 mm lateral displacement on patella). The results were in good agreement with experimental reports for normal joint, vastus lateralis and vastus medialis relieved. Small changes in the femoral trochlear groove geometry provided significant variation in patellar stability. Simulation of different surgical treatments showed that the tibial tubercle medialization is the most effective procedure for patellar subluxation and dislocation disorders.

Surface modeling of complicated geometries with incomplete erroneous data points-an extension to B-spline approach.

Based on the analogy between the B-spline curve modeling and the force-deflection behavior of a beam subjected to lateral point loads, an extension to the B-spline surface modeling method was introduced. The proposed method has strong extrapolating capability and can develop accurate surface models over an incomplete net of data points without affecting the original data. Extrapolation of the incomplete part of the data net is conducted simultaneously with interpolation of the existing part, with no need to recalculation. Approximation or data smoothing is a natural extension of the method, however, the smoothing intensity can be controlled continuously without reducing the number of spline intervals. The performance of the method was evaluated on some known analytical surfaces and produced more accurate results in comparison with the regular B-spline approach. The results indicate that the proposed method can also filter erroneous data points and reconstruct the original surface successfully.