Sharif Digital Repository

In recent years, social robots have used simple and complicated context-aware systems to provide better services for users. The navigation module is one of the most important modules in which a context-aware system can be used; Where a social robot can change the way it navigates with respect to the context that the users are experiencing in a manner that fits the cultural background of the users. This kind of navigation helps the robot to keep its users safe both psychologically and physically. In this research, we present a context-aware navigation method that changes its proxemics due to the group context the users are experiencing. This research consists of three main parts: first, a... 

Sign language is an essential means of communication for millions of people around the world and serves as their primary language. However, most communication tools and technologies are designed for spoken and written languages, which can create barriers and limitations for the deaf community. By creating a sign language recognition system, we can bridge this communication gap and enable people who use sign language as their primary mode of expression to communicate better with people and their surroundings. This sign language recognition system increases the quality of education, the quality of health services, improves public interactions and creates equal opportunities for the deaf... 

This thesis covers the design and realization steps of the upper-body of RASA, a social humanoid robot to be used as a Persian sign language (PSL) teaching assistant. In the design and fabrication processes, three main requirments is defined. First requirement is the robot's ability to perform PSL. The second one is for the robot to posess the characteristics required for a social robot interacting with targeted groups of people. And the third one is for the robot to be realized with minimum required cost. Further design guidelines are generated based on these three requirements. Analysing the structure of Persian sign language, the kinematic layout of the upper-body of the robot, regarding... 

This study investigated the effect of Robot Assisted Language Learning (RALL) on the vocabulary learning and retention as well as anxiety and attitude of Iranian English as Foreign Language (EFL) junior high school students in Tehran-Iran. After taking a vocabulary pretest, 46 beginner level female students at the age of 12, studying in their first year of junior-high participated in two groups of RALL (30 students) and non-RALL (16 students) in this study. The textbook used was the English book (Prospect-1) devised by the Iranian Ministry of Education for 7th graders, and the vocabulary taught and tested (pretest and posttest) were taken from this book. Moreover, the treatment given by a... 

The present case study investigates the effect of applying a humanoid robot as a teacher- assistant to teach a foreign language (English in this case) to Iranian children with autism. Two groups of three male high-functioning autistic students (6-10 years old) with little or no background in English participated in the current study. The humanoid robot NAO made by Aldebaran Robotics was used as a teacher assistant to teach English to the Robot Assisted Language Learning (RALL) group. The non-RALL group received the same lessons simply without the presence of the robot in teaching sessions. However, the non-RALL group also had the chance to interact with the robot through some robotic games... 

Although Robot Assisted Language Learning (RALL) has recently received attention as a tool for language learning, its role in pragmatic development has gone unnoticed. Hence, this study sought to explore the effect of RALL on pragmatic learning of greeting, thanking, and request speech acts by young Persian-speaking EFL learners. To this end, 38 preschool female and male kids (3-6 years old) were assigned to the RALL (19 students) and game-based (19 students) groups. The humanoid robot for the RALL group was used as an assistant to the teacher while for the game-based group the instruction was based on gaming methods such as command, mystery bag and pass the ball games. The instructional... 

Nowadays, one of the challenges in social robotics is to navigate the robot in social environments with moving elements such as humans. The purpose of this study is to navigate the Arash 2 social robot in a dynamic environment autonomously without encountering moving obstacles (humans). The Arash 2 robot was first simulated in the Gazebo simulator environment in this research. The simultaneous location and mapping (SLAM) technique was implemented on the robot using a lidar sensor to obtain an environment map. Then, using the deep reinforcement learning approach, the neural network developed in the simulation environment was trained and implemented on the robot in the real environment. The... 

The usage of robots as our friends has been proliferated these days. Knowing that they are going to be used in ordinary houses, we should develop methods and algorithms in order to provide a situation for end-users to program their own robots for their desired tasks. Learning from Demonstrations (LfD) can play a crucial role in this field. In this study, we had taught a non-verbal communication method (pointing) to a robot utilizing LfD. The learning method used was TP-GMM1. The rationale to use this method was that it models all the degrees of freedom together, and we thought it might be an essential parameter to make a movement more natural and understandable which could be two vital... 

Using learning from demonstration approaches is one of the ways to teach a robot how to perform different skills. In classic methods of learning from demonstration, the subject should wear some sensors and devices which is and expensive way. But, with the progresses that have been made in the context of computer vision, it is possible now to achieve to the same results with less cost. Learning from observation is the approach that would be used in this project to do that. By using this method, when robot watches a video, it tries to understand the behavior of the subject and behave in the same way.The purpose of the project is that the robot learns some social (interactive) skills through... 

Autism is a neurodevelopmental disorder for which there is no definitive cure and it is increasing every year for people with this disorder. In the last decade, the use of virtual environment to improve the skills of people on the autism spectrum has increased. In this research, a semi-intelligent algorithm was designed for a virtual reality game that could provide a more appropriate step to the user according to the user's responses. Our focus is on designing games to strengthen the child in terms of shared attention and eye contact. In other words, we seek to create a virtual environment with the ability to intelligently adapt to interact with our user and turn it into a suitable coaching... 

Nowadays, by increasing the applications of robots in military, industry and also home usages, researchers are looking for the most efficient algorithms to control the robots. As Prof. Zadeh presented the fuzzy systems in 1965 as a proper probabilistic logic, fuzzy control has been developed and now is one of the most applicable procedures in new aspects of controlling because of its less required computational capacity and more proper stability. Although the human like and quadruped robots are more applicable because of their coincidence with more difficult conditions compared to the wheeled robots, more complicated methods should be implemented to control them.The main subject of this... 

Employing social robots in interactions with children for educational and healthcare objectives could enhance the efficiency of interventions and boost the children’s cognitive and affective outcomes by increasing engagement and providing motivation. This dissertation investigates three main subtopics to determine the efficacy of utilizing social robots in speech therapy sessions in interactions with children suffering from speech and language disorders. We hypothesize that interacting with social robots acting as therapists’ assistants in speech therapy interventions contributes to the formation of language-based communications and improves the individuals’ language skills. The first... 

In this thesis, Model reference adaptive control in fractional order systems was discussed. Various types of this problem can be introduced based on fractional order dynamics in system equations, reference model equations or adaptation laws, which some of them play more important role in real-world applications, also some of them have more complexity in governing mathematical equations and in stability analysis. Fractional order dynamics were recently used in many real-world applications like model reference control, Chaos synchronization and Chaos control, so studying adaptive control in this fields, could be important. Nowadays, Model reference adaptive control was used in many industrial... 

Social robots are a group of robots designed and built to interact with humans, so the ability to interact emotionally in these robots, especially in interaction with people with hearing and speech disorders, is essential because these people do not have an emotional state sound. Therefore, in this research, an emotional interaction system based on recognizing the user's emotional state from his facial state using deep learning algorithms as well as performing an appropriate emotional response on the robot's face has been designed and implemented on an expressive social robot. In order to design the emotional state recognition system, first, the best model was found on the large AffectNet... 

No-one likes being confined to a hospital bed. Children particularly can feel lonely, bored or frightened in these conditions. Hours feel like days, and they may not be able to fully comprehend why they are there. Among kids hospitalized because of distinct diseases, children with cancer have incomparable status and needs. They experience physical and mental problems caused by cancer and medications. Cancer treatment may cause distress which can lessen the effectiveness of the treatment. Utilizing social robots to interact with children in clinical environments has been verified to both diminish their distress level and enhance the effectiveness of the treatment process. To improve the... 

The purpose of this research is the design and fabrication of a mobile social robot for children with cancer. This robot is named Arash. Interaction with the robot can improve children's education, as well as their mental condition. Design and development of Arash robot project have been carried out in a number of M.Sc. projects. In the present study, it is specifically focused on three areas of activity:
1. Design and fabrication of the robot head (and the overall appearance of the robot)
2. Design and development of human-robot interactions
3. Social and educational interactions/interventions of the robot with children
In this study, with the cooperation of child... 

Electron states of diamond vacancy under stress were studied theoretically. The generalized Hubbard model is used to calculate the electrons energy levels. The results shows that the degeneracy of some levels (T, with triple space degeneracy) reduced to levels with lower degeneracy (E, with double space degeneracy and A, without degeneracy). Besides this spiting of degeneracy the energy of all states changed and therefore the transition energy between these states changed too. Jahn-Teller effect was observed  

In this thesis, first the fundamental theory of stochastic fractional systems has been introduced and the basic of this theorem in control system consisting the controllability and stability has been introduced. It is shown that these basics are playing enormous role in define and understanding such system. Also, Linear Quadratic Regulators has been introduced and appropriate steps to define such controller in the systems. Simulation results shows the effectiveness of the proposed method. On the other hand, the problem of filtering and estimation has been presented with two different method. The first method is to use the idea of optimality and Kalman filter as optimal filter and the second...