Showing 4 results for Prosthesis
Volume 11, Issue 1 (3-2020)
Abstract
Language learning is not just the learning of vocabulary and grammar. Idioms are the useful structures between language speakers, especially in spoken language. Maybe the mysterious nature of these structures makes the speakers to be interested in using them. It was said mysterious because they do not have combinational meaning. Idioms have their own context of use and it motivates speakers to use them because the proper use of idioms shows the high level of communication skill of a foreign language learner. But due to the special structure of idioms, it is so hard to learn them.
Besides, cartoon is a kind of image which is simple, attractive and borderless.
It seems that the interaction between idiom and cartoon results in revealing connotational meaning of idiom and in this way, cartoon develops the literal meaning of idiom.
There are various studies on the relationship between text and image in book illustration, teaching language and different sciences and they have confirmed the positive impact of image especially in the form of cartoon or caricature in learning but there is no research about the role of cartoon in learning English idioms to Persian native speakers from the semiotic point of view.
This paper aims to evaluate the effect of interaction between speech and cartoon and achieve the effective features of cartoons in revealing the covert meaning of idioms, in the process of English idioms teaching to Persian speakers from semiotic point of view.
In this paper, the main problem is how the cartoon, in relation to idioms, changes the space of sense-making from an unpredictable semiotic space to a creative one and how this interaction causes a creative semiotic space to develop the concept of idioms. To evaluate this paper`s hypotheses, we used visual semiotics approach and discourse analysis method. The statistical population of this research includes 60 English language learners in intermediate and advanced level including 30 girls and 30 boys from north and south of Tehran. The hypotheses of this study are that: firstly, cartoons can cause the semiotic development via the sign spaces interaction, inducing a new cognition and developing the scope of imagination. Secondly, speech and cartoon can cause creative usage of idioms via making referential space, using the discourse dimensions and developing the linguistic game in inter-semiotic space.
The results show that, cartoons with the appropriate functions of cognitive, sensory- perceptual, emotional and aesthetic dimensions of discourse in which there are maximal transdiscourse relationship with idioms and make an effective interpretation or metadiscourse, cause a creative process and transcend the denotational meaning of idioms to connotational one. So, they can be considered as prosthesis for idioms. As a result, the hypotheses of this research are confirmed.
Mohammad Gharini, Majid Mohammadi Moghaddam, Farzam Farahmand,
Volume 17, Issue 1 (3-2017)
Abstract
The purpose of this paper is to investigate the effect of viscoelastic ankle foot prosthesis on below-knee amputee gait cycle by using dynamic simulation of human walking. A two dimensional, seven segment model is developed to simulate normal and amputee entire gait cycle equipped with foot-ground contact model in order to simulate entire gait cycle in an integrated way. In the first step, optimization procedure was coupled with forward dynamic to simulate normal gait cycle. Next step was started by replacing ideal torque generator of ankle joint with passive elements that represents passive prosthetic ankle-foot, in order to simulate below-knee amputee gait cycle. The optimal coefficients of joints that were obtained from dynamic simulation of normal gait cycle were then used for amputee model’s intact joints. Three type of optimal passive ankle foot prosthesis were designed using forward dynamic optimization and the simulation results were employed to compare the performance of different prostheses. The results indicated that using viscoelastic ankle foot prosthesis decreases speed-normalized total work, cost function, dynamic effort and increases speed of the amputee model. Hence using viscoelastic ankle foot prosthesis can improve below-knee amputee walking pattern
Iman Azarbayejani, Nima Jamshidi, Ehsan Hajisadeghian,
Volume 17, Issue 5 (7-2017)
Abstract
One of the very important issues in designing hand prosthesis is to consider their cover or cortex. The purpose of this research is to design a cover to have a similar behavior, as much as possible, to the human natural skin, in power transmission and deformation pattern. A layer made of Lorica®, which has similar properties to natural skin, has been added to the conventional cover which composed of three layers. Using finite element analysis Software, ANSYS V.15, the new four-layered cover has been investigated on three dimensional model of the hand prosthetics with different thickness for the outer layer, and the pattern of deformation and internal stresses in the prosthesis are measured. Optimal thickness of the outermost layer is evaluated due to stress and strain distribution and their transformation to prosthesis metallic core. The relationship between the thickness of this layer and the distribution of stress and deformation of the cover is not linear and direct and the thickness of 1.5mm shows better results among the measured values in this section. In this study, the fourth layer was added to improve the frictional and elastic properties of formerly used prosthetic covers, and its effects on stress and strain distribution in the prosthesis was investigated. It is determined that due to lack of linear correlation between the thickness and stress distribution, the optimal thickness of each layer must be selected based on design limitation like the ability of embedding tactile sensors in future for the minimum thickness.
Sh. Jannati, S.m. Ayati, A. Yousefikoma,
Volume 20, Issue 6 (6-2020)
Abstract
The goal of this paper is to design an online control interface for knee prosthesis based on the electromyography (EMG) signals of active thigh muscles. According to the time dependent nature of electromyography signals, translating such signals into precise commands in practical applications is a challenge for scientists. First stage for designing an online control interface is to design and implement a test setup for examining the proposed online control interface. To serve this purpose, active knee prosthesis is designed and manufactured using an elastic actuator mechanism. In order to measure the EMG signals, active muscles were detected based on the fundamental of muscles anatomy. In the second stage, filtering and data segmentation were utilized for electromyography signals smoothing, decreasing noises and reducing signal dimensions. Furthermore, time-delay neural network was used in order to map time domain features of EMG signals onto kinematic variables of knee joint. The angle and angular velocity of knee joint were estimated with accuracy of 0.85 (R2) for two locomotion modes including non-weight bearing and ground level walking. To implement online estimation of angular position, time domain features and neural network with 50 hidden layer’s neurons and 2 seconds time delay were used. Finally, online angular position estimation of knee joint was implemented on the designed test setup and results confirm proper tracking of online control interface.
