Sharif Digital Repository

Dynamic hand gesture is an efficient approach used in Human Computer Interaction (HCI). The goal is to recognize and analyze the different hand gestures in a recorded video. There are some associated challenges such as video noises, illumination changes, rotation variance, hand occlusion which make the process more complicated.To do the research we used five different gestures out of the Sheffield hand gesture dataset which is collected from six persons under three different backgrounds and two illumination conditions. This procedure needs image processing in order to detect and segment the important parts involved in images such as hands and analyzing the changes and motions of them. We... 

Due to diversity in amputation possibilities, this thesis focuses on the specific case of ring finger amputation with some amount of stomp remaining. The goal is to design a robotic finger as a prosthetic, which its flexion and extension (position control) are instructed from an armband. The armband is equipped with 8 force sensors to detect volume variations in patient’s forearm. Its embedded microcontroller processes signals taken from these sensors, and using machine learning techniques (K-Nearest Regressor), decides on a specific angle for the finger. This angle value updates constantly, and using a flex sensor and a DC motor in finger, the desired flexion/extension is performed.... 

In this study, we create an evolution function that assesses prosthetic hands in terms of their ability to grasp various objects like a human hand. It is required to evaluate the reachable workspace of prosthetic hands and grasp ability to assess it completely. The first one can be done by using forward kinematics. The Volume of the Grasp Wrench space, one of the grasp qualities indexes, is used to measure the second one. Randomization and grasp taxonomy are used to generalize the grasp quality to indicate the prosthetic hand functionality. Afterward, the created evaluation function is used to specify the importance of each finger and DOF. The results show that the most significant finger is... 

The hand is an important part of the human body, the loss of all or part of it greatly reduces a person's ability to perform daily tasks. For people who have lost this significant organ, replacing it with an artificial limb that can meet some of their needs is essential. Today, all robotic prostheses use electromyographic (EMG) signals from the remaining muscles of the disabled limb as input signals. Classifying the EMG signal and converting it to a control signal faces serious challenges. Variation of signal properties over time, electrode slippage, muscle fatigue, changes in muscle contraction intensity, and changes in limb position and direction are some of these challenges. Therefore, a... 

The application of manipulators is becoming more and more popular in objects handling especially when it is desired to have access to remote areas in destructive or hazardous taskspaces. For this purpose, a hand-like mechanism must be designed to be used as an end-effector, which can grasp objects. In this paper a cable driven grasping mechanism has been presented. In the proposed mechanism each finger consists of three phalanxes which are actuated by a single motor. Also, locking and unlocking constraints are used in the mechanism in order to generate an anthropomorphic motion, in which, the order of reaching phalanxes to the object is sequential, in such a way that each phalanx starts... 

All humanare subject to a physiligical phenomenon known as tremor, which introduces unintended, relatively high frequency movments into various limbs. This involuntary movment is main reason of human disability in doing of precision tasks. Precision surgery like eye surgery is among them that surgeons must have very ittle tremor to enable them to oprate on the small anatomy of the eye. In this reaearch by emphasizing on reduction of muscle fatigue in precision surgery, weight balancing mechanism designed and analyzed. Fatigue is most important cause of tremor, thus we expected tremor amplitude reduce by reduction of muscle fatigue. Purpose mechanism is passive mechanism that balances the... 

The increasing use of the Internet as the main communications method, has increased the importance of user privacy and the security of their information. Different protocols and different methods have been proposed to provide security, but sometimes they are used to violate the network’s obligations. Increasing the users’ privacy and security, leads to the reduction of the network administrators power to control and manage the network, and this can create vulnerabilities which could be exploited by attackers to violate usage policies. Traffic analysis can be used by administrators to collect information from their network, without having to prohibit the use of security protocols. Different... 

in laparoscopic surgeries, act zone tissues are not directly palpable for the surgeon. Therefore, evaluating the mechanical behavior of the tissue and distinguishing healthiness or illness of that, are not achievable for the surgeon. In this treatise, the matter of discerning the soft and bulky tissues mechanical properties by a robotic arm during the laparoscopic surgery, is regarded. In first step, a tool like a two finger miniature hand was designed in which either of fingers have utilized a parallelogram mechanism for opening and closing. The dimensional design of the mechanism was undertake in away that the tool has the ability of going through a 10mm diameter path and grabbling and... 

The main idea in this project is investigation of multidimensional recording brain signal (ECoG) for estimation of 3D arm trajectory. First we introduce a general structure with variable blocks, in this structure we have many ways to estimate hand trajectory and obtain different result. By statistical test we find the best state of this structure and apply it on other dtae set trials. Electrocorticography (ECoG) has seen recent use in this regard because it offers a higher spatiotemporal resolution than non-invasive EEG and is less invasive than intracortical microelectrodes and have been shown to contain reliable information about the direction of arm Trajectory and movements. We using... 

The main goal of this thesis is the design and development of a rehabilitation device for helping patients “to improve blood circulation” & retain and recover their abilities if possible that were lost during the stroke or a accident like that (my research in karaj/iran shows that it is possible by just movement of the specific body part). The focus is on hand in this thesis because Injuries to the hand are common and can be very debilitating since our hands are our primary means for interacting with our world. For rehabilitation in case of human hand there are several practices that should be done for patients either in home or in a rehabilitation center, time and money that is supposed to... 

Sign Language Recognition using cameras is an alternative way of human communication with personal computers. These systems don’t need to use keyboard. They are used when touching keyboard is not possible or for what ever reason, when we don’t want to use keyboard. In this problem the person shows one of the alphabets with his hand and we capture and process that in real-time to recognize the letter. The problem of previous works in this area are the decreasing rate of detection in condition where the angle of sign and viewer changes. The purpose of our work is getting better result by using depth image from Kinect. We use Pugeault and Bowden dataset (that has fingerspelling sign in multiple... 

In this thesis, study of some kinds of dual band transmission lines and structures are investigated. Attention to 3 important kinds, CRLH, SCRLH and the equal phase line are introduced and the formulations of each one are derived and considered. Also the method of designing these lines are attached. These lines form a complete category that makes the ability of designing all kind of dual band line with arbitrary frequencies and result phases with arbitrary non-integer ratio less or more than 1. Also an important attention is paid for the designing these lines in the microstrip configuration. Various kinds of Dual band structures are proposed at the last part of the introducing each lines....