Showing 7 results for Ppo
Mr Saeed Mollahoseini Paghale, Mr Milad Fallahzade, Dr Mohammadreza Amirseyfadini,
Volume 0, Issue 0 (11-2019)
Abstract
Introduction and objectives: In the past decades, the control of hand tremors in neurological disorders such as Parkinson's has attracted a lot of attention. The theories of closed-loop deep brain stimulation method are increasing significantly. The purpose of this article is to provide an automatic closed-loop method for the rehabilitation of Parkinson's patients with hand tremor symptoms using machine learning.
Materials and methods: In this article, a mathematical model including muscle model, basal ganglia, cerebral cortex and supplementary motor area is used to simulate tremor. Also, to control hand tremors, a non-integer proportional-derivative-integral controller (non-integer PID) has been used, as well as using the smart Proximal Policy Optimization (PPO) algorithm as a subset of reinforcement learning to adjust the coefficients.
Findings: In addition to reducing hand tremors and automatic learning for use in different levels of the disease, which has given acceptable results compared to other control methods, among the advantages of the Prihadi method is the practical implementation of this method in the real world due to the simplicity of the controller. And also the easy implementation of the intelligent algorithm is due to the automatic adjustment of the coefficients of artificial intelligence networks.
Conclusion: In addition to optimizing output symptoms such as hand tremors compared to other controllers, the proposed intelligent system can also be used for all levels of the disease due to its adaptability, causing a significant reduction in the side effects caused by continuous brain stimulation in the brain stimulation method. It opens in the form of a ring.
Mr Mohammad Ali Naseri Rouhani, Dr Mohammad Taghi Amiri Khorasani, Dr Mohammad Reza Amir Seifaldini,
Volume 14, Issue 11 (4-2016)
Abstract
Objective: The aim of this study was to investigate the effect of non- stability surface of support leg on the instep kicking kinematics in soccer players. Materials and Methods: 30 male soccer players participated in this study. After the measurement of static and dynamic balance tests by the Biodex System, 20 players were selected who were at a desired level of the balance. Data were recorded using the three- dimensional motion analysis system with 6 optoelectronic cameras (200 HZ). The kinematic parameters in three critical moments of kicking (Forward swing of hip, Contact to ball, Follow through) were compared by using repeated measures of variance and independent t- test (0/05). Results: The results showed that the values of maximum angular velocity and displacement of hip and velocity of ball at the kicking over stability surface was significantly higher from the kicking over non- stability surface. Conclusion: These results indicate that the kicking over non- stability surface causes the lower of kinematic parameters in the more of the kicking skill phases and the movement prime velocity of ball
Mr Mostafa Haj Lotfalian, Dr Mahdi Kargarfard, Dr Heydar Sadeghi, Mr Sajjad Mohammadi,
Volume 14, Issue 12 (10-2016)
Abstract
Support foot position is one of the important factors which can affect instep kick quality and ankle joint injury. The aims of this study were to examine the support foot parameters in maximal instep kicking with the preferred and the non-preferred leg and research on risk factors for ankle joint injury in amateur futsal players. In this semi experimental study, twelve young and novice futsal players performed maximal speed place kicks with the preferred and the non-preferred leg. Average of the subjects individual characteristic have contained, age : 21/2±1/5 years, weight : 67/6±5/5 Kg and height :176±4/2 cm. Athletes were kicking the ball towards the goal from 10 meters. amount of support foot pressure were calculated at 300 Hz. To calculate injury of ankle joint, Forces, impulses, position of the fixed leg and maximum pressure of the lateral and medial portions of the foots were determined. Results indicated a significant difference in amount of subtalar joint range of motion. Higher range of motion in dominant leg were caused by a greater flexibility and coordination in this side of the body. In addition there were no significant different in impact of anterior, middle and posterior portion of fixed legs between two support foot. In contrast the maximum pressure in lateral side of non-preferred leg, was significantly more than other foot. In addition, the maximum force in non-preferred leg occurred prior then other foot. These problems can exacerbate ankle injury risk. Because the subjects were novice and they do not have appropriate neuromuscular coordination, can’t show a good movement pattern in non preferred leg. Hence, the absence of neuromuscular coordination can lead to energy loss and high pressure coming into the body, especially the feet and it can exacerbate injuries. In a nutshell, amateur subjects indicated higher quality of biomechanical parameters in support foot of the preferred leg. Also likelihood of ankle sprain in dominant foot was less than other. Also generalization of these results to semi-professional and professional players, need further research.
M Termeh, A Ghanbarzadeh, M.h Honarvar, K Heidari Shirazi,
Volume 18, Issue 19 (7-2020)
Abstract
In a walking cycle design, maximizing the upright balance should be considered in addition to the kinematic constraints, energy consumption rate must be considered. The purpose of this study is to find the optimal step length obtained for each person according to the physical features. In this research, in order to minimize energy consumption rate by considering maximum balance two cost function were defined. the fall cost function was designed based on the concept of MOS and balance index. To investigate the upright balance and to reconstruct the movement pattern, Data from normal walking gait of healthy subjects was taken and seven links model was defined. In this study, the optimal step length was obtained for the person with height, weight and gait cycle characteristics. it is shown that for a person of 92kg mass and 1.87 meters height, the best step length in walking would be 0.54 meters. In this study, the kinematic and kinetic characteristics of human motion were identified by the analysis of gait patterns on a treadmill. Through the calculation of the balance index, individuals are helped to find the optimal step length for which the maximum balance is achieved. The results of the study can provide the optimal step length to correct the gait pattern.
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Volume 20, Issue 23 (9-2022)
Abstract
Background and Aim: Given the widespread trade in some sports, a misjudging decision can not only have huge financial consequences for competitors, but also affect the event itself. The overall purpose of this study was to determine the role of information technology and perceived organizational support on the performance of the referees of the 2018 FIFA World Cup in Russia: to investigate the mediating role of job satisfaction and self-efficacy. Methods: This is a descriptive research, correlation model, based on structural equation modeling, and its type. The statistical population of the study consisted of all referees and assistant referees present at the 2018 FIFA World Cup in Russia, of which 111 referees were 35 middle referees, 63 assistant referees and 13 video assistant referees. Results: The results showed that information technology, perceived organizational support and self-interest have a significant positive effect on the performance of the referees of the 2018 FIFA World Cup in Russia. Job satisfaction does not have a significant effect on the performance of the referees of the 2018 FIFA World Cup in Russia. Conclusion: Information technology is an effective and facilitating factor in arbitrators' decisions, so it is suggested to provide technological infrastructure in order to improve the instant decisions of arbitrators on a larger scale.
Mr Reza Asadi, Dr Mohammad Reza Kordi, Dr Fatemeh Shabkhiz,
Volume 21, Issue 25 (9-2023)
Abstract
Neurodegenerative processes play an important role in the progression of MS. Appropriate exercise training and living in an enriched environment (EE) can improve or prevent the progression of the disease through the secretion of some neurodevelopmental factors in the hippocampus, including irisin and the neutrophic factor derived from the mouse. The aim of the present study was to investigate the effect of 4 weeks of aerobic and resistance training and EE on irisin protein and hippocampus BDNF levels in female C57BL6 mice with experimental autoimmune encephalomyelitis (EAE). 50 female mice (age 8 weeks, average weight 18 ± 2 grams) were randomly divided into five equal groups (10 mice in each group): 1- healthy control, 2- control + EAE, 3- resistance activity + EAE, 4- Aerobic activity + EAE and 5- EE + EAE. The first and second weeks of adaptation to the environment and then induction of EAE were performed. The training groups trained 5 days a week for half an hour a day for 4 weeks, and the EE group was transferred to its equipped cage. 48 hours after the last training session, the mice were anesthetized and then dissected and tissue removed. The ELISA method was used to measure the amounts of proteins, and the analysis of variance and Tukey's t-test were used to determine the differences between the research variables. All analyzes were performed at a significance level of 0.05 and with SPSS22 software. Hippocampal BDNF expression was increased in all three training groups compared to the EAE control group. This increase in the EE and resistance training group was significant compared to both the EAE control group and the swimming training group. Also, hippocampal irisin expression increased in all three training groups compared to the EAE control group, and this increase was significant in the EE and resistance training groups. Also, the expression of irisin in the EE group increased more than the two aerobic swimming and resistance training groups, and this increase was proportional to It was meaningful to the swimming aerobic training group. It seems that EE and resistance training can increase the secretion of nerve growth factors such as irisin and BDNF and thus help to improve MS disease.
Azam Davoodabadi, Saeed Naqeibi, Ali Barzegari, Mohammad Hassaan Dashty Khavidaki,
Volume 22, Issue 27 (8-2024)
Abstract
The aim of this study was the effect of a course of aerobic exercises on depression and oxidative stress factor changes in the hippocampus and prefrontal cortex of rats with Alzheimer's disease. For this purpose, 40 8-week-old male Wistar rats with an average weight of 237±33 grams were randomly divided into four groups of 10: control, exercise, Alzheimer's, and exercise+Alzheimer's. The training protocol consisted of 12 weeks of running on a treadmill at a speed of 12 meters per minute and for 30 minutes in each session. At the end of the training period, the tests of feeding sensation suppression and tail suspension were performed to estimate depression as well as hippocampal and prefrontal malondialdehyde levels using the Bradford method. Also, in order to induce Alzheimer's, an amount of three mg/kg of streptozocin in a volume of five microliters of sterile distilled water was injected into the ventricle of the brain. The results showed that exercise training caused a significant decrease in depression in eating delay tests and immobility duration in Alzheimer's rats. Also, exercise caused a significant decrease in malondialdehyde levels in the hippocampus of Alzheimer's rats, while a significant difference was observed in the prefrontal area. It didn't happen. It seems that sports activity creates immunity against Alzheimer's and is probably effective in preventing depression in Alzheimer's patients.
