Search results for: permanent split-capacitor motor
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1488

Search results for: permanent split-capacitor motor

948 The Therapeutic Potential, Functions, and Use of Ibogaine

Authors: João Pedro Zanella, Michel J. O. Fagundes

Abstract:

Introduction: Drug use has been practised by humans universally for millennia, not excluding any population from these habits, however, the rampant drug use is a global concern due to the harm that affects the health of the world population. In this sense, it is observed the reduction of lasting and effective public policies for the resolution, increasing the demand for treatment services. With this comes ibogaine, an alkaloid derived from the root of an African bush (Tabernanthe Iboga), found mostly in Gabon and used widely by the native Bwiti population in rituals, and also other social groups, which demonstrates efficacy against chemical dependence, psychic and emotional disorders, opioid withdrawal was first confirmed by a study in rats done by Michailo Dzoljic and associates in 1988 and again in 1994. Methods: A brief description of the plant, its neurohumoral potential and the effects caused by ingested doses, in a simplified and objective way, will be discussed in the course of this abstract. Results: Ibogaine is not registered or passed by Anvisa, regarding safety and efficacy, and cannot be sold in Brazil. Its illegal trade reaches R$ 5 thousand for a session with the proceeds of the root, and its effect can last up to 72 hours, attributing Iboga's psychoactive effects to the alkaloid called ibogaine. The shrub where Ibogaine is located has pink and yellow flowers, and its fruit produced does not have psychoactive substances, but its root bark contains 6 to 7% indolic alkaloids. Besides extraction from the iboga plant, ibogaine hydrochloride can be semisynthesized from voacangine, another plant alkaloid that acts as a precursor. Its potential has the ability to perform multiple interactions with the neurotransmitter system, which are closely associated with addiction, including nicotinic, opioid and serotoninergic systems. Studies carried out by Edwards found that the doses administered of Iboga should be determined by a health professional when its purpose is to treat individuals for dependence on other drugs. Its use in small doses may cause an increase in sensibility, impaired vision and motor alterations; in moderate quantities, hallucinations, motor and neurological alterations and impaired vision; in high quantities it may cause hallucinations with personal events at a deeper level lasting up to 24 hours or more, followed by motor and visual alterations. Conclusion: The product extracted from the Iboga plant is of great importance in controlling addiction, reducing the need for the use of narcotics by patients, thus gaining a space of extreme importance in the treatment of users of psychoactive substances. It is remarkable the progress of the latest’s research about the usefulness of Ibogaine, and its benefits for certain treatments, even with the restriction of its sale in Brazil. Besides this, Ibogaine has an additional benefit of helping the patient to gain self-control over their destructive behaviours.

Keywords: alkaloids, dependence, Gabon, ibogaine

Procedia PDF Downloads 66
947 The Effects of Circadian Rhythms Change in High Latitudes

Authors: Ekaterina Zvorykina

Abstract:

Nowadays, Arctic and Antarctic regions are distinguished to be one of the most important strategic resources for global development. Nonetheless, living conditions in Arctic regions still demand certain improvements. As soon as the region is rarely populated, one of the main points of interest is health accommodation of the people, who migrate to Arctic region for permanent and shift work. At Arctic and Antarctic latitudes, personnel face polar day and polar night conditions during the time of the year. It means that they are deprived of natural sunlight in winter season and have continuous daylight in summer. Firstly, the change in light intensity during 24-hours period due to migration affects circadian rhythms. Moreover, the controlled artificial light in winter is also an issue. The results of the recent studies on night shift medical professionals, who were exposed to permanent artificial light, have already demonstrated higher risks in cancer, depression, Alzheimer disease. Moreover, people exposed to frequent time zones change are also subjected to higher risks of heart attack and cancer. Thus, our main goals are to understand how high latitude work and living conditions can affect human health and how it can be prevented. In our study, we analyze molecular and cellular factors, which play important role in circadian rhythm change and distinguish main risk groups in people, migrating to high latitudes. The main well-studied index of circadian timing is melatonin or its metabolite 6-sulfatoxymelatonin. In low light intensity melatonin synthesis is disturbed and as a result human organism requires more time for sleep, which is still disregarded when it comes to working time organization. Lack of melatonin also causes shortage in serotonin production, which leads to higher depression risk. Melatonin is also known to inhibit oncogenes and increase apoptosis level in cells, the main factors for tumor growth, as well as circadian clock genes (for example Per2). Thus, people who work in high latitudes can be distinguished as a risk group for cancer diseases and demand more attention. Clock/Clock genes, known to be one of the main circadian clock regulators, decrease sensitivity of hypothalamus to estrogen and decrease glucose sensibility, which leads to premature aging and oestrous cycle disruption. Permanent light exposure also leads to accumulation superoxide dismutase and oxidative stress, which is one of the main factors for early dementia and Alzheimer disease. We propose a new screening system adjusted for people, migrating from middle to high latitudes and accommodation therapy. Screening is focused on melatonin and estrogen levels, sleep deprivation and neural disorders, depression level, cancer risks and heart and vascular disorders. Accommodation therapy includes different types artificial light exposure, additional melatonin and neuroprotectors. Preventive procedures can lead to increase of migration intensity to high latitudes and, as a result, the prosperity of Arctic region.

Keywords: circadian rhythm, high latitudes, melatonin, neuroprotectors

Procedia PDF Downloads 134
946 Integrated Life Skill Training and Executive Function Strategies in Children with Autism Spectrum Disorder in Qatar: A Study Protocol for a Randomized Controlled Trial

Authors: Bara M Yousef, Naresh B Raj, Nadiah W Arfah, Brightlin N Dhas

Abstract:

Background: Executive function (EF) impairment is common in children with autism spectrum disorder (ASD). EF strategies are considered effective in improving the therapeutic outcomes of children with ASD. Aims: This study primarily aims to explore whether integrating EF strategies combined with regular occupational therapy intervention is more effective in improving daily life skills (DLS) and sensory integration/processing (SI/SP) skills than regular occupational therapy alone in children with ASD and secondarily aims to assess treatment outcomes on improving visual motor integration (VMI) skills. Procedures: A total of 92 children with ASD will be recruited and, following baseline assessments, randomly assigned to the treatment group (45-min once weekly individual occupational therapy plus EF strategies) and control group (45-min once weekly individual therapy sessions alone). Results and Outcomes: All children will be evaluated systematically by assessing SI/SP, DLS, and VMI, skills at baseline, 7 weeks, and 14 weeks of treatment. Data will be analyzed using ANCOVA and T-test. Conclusions and Implications: This single-blind, randomized controlled trial will provide empirical evidence for the effectiveness of EF strategies when combined with regular occupational therapy programs. Based on trial results, EF strategies could be recommended in multidisciplinary programs for children with ASD. Trial Registration: The trial has been registered in the clinicaltrail.gov for a registry, protocol ID: MRC-01-22-509 ClinicalTrials.gov Identifier: NCT05829577, registered 25th April 2023

Keywords: autism spectrum disorder, executive function strategies, daily life skills, sensory integration/processing, visual motor integration, occupational therapy, effectiveness

Procedia PDF Downloads 92
945 Control Strategy for a Solar Vehicle Race

Authors: Francois Defay, Martim Calao, Jean Francois Dassieu, Laurent Salvetat

Abstract:

Electrical vehicles are a solution for reducing the pollution using green energy. The shell Eco-Marathon provides rules in order to minimize the battery use for the race. The use of solar panel combined with efficient motor control and race strategy allow driving a 60kg vehicle with one pilot using only the solar energy in the best case. This paper presents a complete modelization of a solar vehicle used for the shell eco-marathon. This project called Helios is cooperation between non-graduated students, academic institutes, and industrials. The prototype is an ultra-energy-efficient vehicle based on one-meter square solar panel and an own-made brushless controller to optimize the electrical part. The vehicle is equipped with sensors and embedded system to provide all the data in real time in order to evaluate the best strategy for the course. A complete modelization with Matlab/Simulink is used to test the optimal strategy to increase the global endurance. Experimental results are presented to validate the different parts of the model: mechanical, aerodynamics, electrical, solar panel. The major finding of this study is to provide solutions to identify the model parameters (Rolling Resistance Coefficient, drag coefficient, motor torque coefficient, etc.) by means of experimental results combined with identification techniques. One time the coefficients are validated, the strategy to optimize the consumption and the average speed can be tested first in simulation before to be implanted for the race. The paper describes all the simulation and experimental parts and provides results in order to optimize the global efficiency of the vehicle. This works have been started four years ago and evolved many students for the experimental and theoretical parts and allow to increase the knowledge on electrical self-efficient vehicle.

Keywords: electrical vehicle, endurance, optimization, shell eco-marathon

Procedia PDF Downloads 242
944 Vascular Crossed Aphasia in Dextrals: A Study on Bengali-Speaking Population in Eastern India

Authors: Durjoy Lahiri, Vishal Madhukar Sawale, Ashwani Bhat, Souvik Dubey, Gautam Das, Biman Kanti Roy, Suparna Chatterjee, Goutam Gangopadhyay

Abstract:

Crossed aphasia has been an area of considerable interest for cognitive researchers as it offers a fascinating insight into cerebral lateralization for language function. We conducted an observational study in the stroke unit of a tertiary care neurology teaching hospital in eastern India on subjects with crossed aphasia over a period of four years. During the study period, we detected twelve cases of crossed aphasia in strongly right-handed patients, caused by ischemic stroke. The age, gender, vernacular language and educational status of the patients were noted. Aphasia type and severity were assessed using Bengali version of Western Aphasia Battery (validated). Computed tomography, magnetic resonance imaging and angiography were used to evaluate the location and extent of the ischemic lesion in brain. Our series of 12 cases of crossed aphasia included 7 male and 5 female with mean age being 58.6 years. Eight patients were found to have Broca’s aphasia, 3 had trans-cortical motor aphasia and 1 patient suffered from global aphasia. Nine patients were having very severe aphasia and 3 suffered from mild aphasia. Mirror-image type of crossed aphasia was found in 3 patients, whereas 9 had anomalous variety. In our study crossed aphasia was found to be more frequent in males. Anomalous pattern was more common than mirror-image. Majority of the patients had motor-type aphasia and no patient was found to have pure comprehension deficit. We hypothesize that in Bengali-speaking right-handed population, lexical-semantic system of the language network remains loyal to the left hemisphere even if the phonological output system is anomalously located in the right hemisphere.

Keywords: aphasia, crossed, lateralization, language function, vascular

Procedia PDF Downloads 169
943 Stroke Rehabilitation via Electroencephalogram Sensors and an Articulated Robot

Authors: Winncy Du, Jeremy Nguyen, Harpinder Dhillon, Reinardus Justin Halim, Clayton Haske, Trent Hughes, Marissa Ortiz, Rozy Saini

Abstract:

Stroke often causes death or cerebro-vascular (CV) brain damage. Most patients with CV brain damage lost their motor control on their limbs. This paper focuses on developing a reliable, safe, and non-invasive EEG-based robot-assistant stroke rehabilitation system to help stroke survivors to rapidly restore their motor control functions for their limbs. An electroencephalogram (EEG) recording device (EPOC Headset) and was used to detect a patient’s brain activities. The EEG signals were then processed, classified, and interpreted to the motion intentions, and then converted to a series of robot motion commands. A six-axis articulated robot (AdeptSix 300) was employed to provide the intended motions based on these commends. To ensure the EEG device, the computer, and the robot can communicate to each other, an Arduino microcontroller is used to physically execute the programming codes to a series output pins’ status (HIGH or LOW). Then these “hardware” commends were sent to a 24 V relay to trigger the robot’s motion. A lookup table for various motion intensions and the associated EEG signal patterns were created (through training) and installed in the microcontroller. Thus, the motion intention can be direct determined by comparing the EEG patterns obtaibed from the patient with the look-up table’s EEG patterns; and the corresponding motion commends are sent to the robot to provide the intended motion without going through feature extraction and interpretation each time (a time-consuming process). For safety sake, an extender was designed and attached to the robot’s end effector to ensure the patient is beyond the robot’s workspace. The gripper is also designed to hold the patient’s limb. The test results of this rehabilitation system show that it can accurately interpret the patient’s motion intension and move the patient’s arm to the intended position.

Keywords: brain waves, EEG sensor, motion control, robot-assistant stroke rehabilitation

Procedia PDF Downloads 368
942 Performance Validation of Model Predictive Control for Electrical Power Converters of a Grid Integrated Oscillating Water Column

Authors: G. Rajapakse, S. Jayasinghe, A. Fleming

Abstract:

This paper aims to experimentally validate the control strategy used for electrical power converters in grid integrated oscillating water column (OWC) wave energy converter (WEC). The particular OWC’s unidirectional air turbine-generator output power results in discrete large power pulses. Therefore, the system requires power conditioning prior to integrating to the grid. This is achieved by using a back to back power converter with an energy storage system. A Li-Ion battery energy storage is connected to the dc-link of the back-to-back converter using a bidirectional dc-dc converter. This arrangement decouples the system dynamics and mitigates the mismatch between supply and demand powers. All three electrical power converters used in the arrangement are controlled using finite control set-model predictive control (FCS-MPC) strategy. The rectifier controller is to regulate the speed of the turbine at a set rotational speed to uphold the air turbine at a desirable speed range under varying wave conditions. The inverter controller is to maintain the output power to the grid adhering to grid codes. The dc-dc bidirectional converter controller is to set the dc-link voltage at its reference value. The software modeling of the OWC system and FCS-MPC is carried out in the MATLAB/Simulink software using actual data and parameters obtained from a prototype unidirectional air-turbine OWC developed at Australian Maritime College (AMC). The hardware development and experimental validations are being carried out at AMC Electronic laboratory. The designed FCS-MPC for the power converters are separately coded in Code Composer Studio V8 and downloaded into separate Texas Instrument’s TIVA C Series EK-TM4C123GXL Launchpad Evaluation Boards with TM4C123GH6PMI microcontrollers (real-time control processors). Each microcontroller is used to drive 2kW 3-phase STEVAL-IHM028V2 evaluation board with an intelligent power module (STGIPS20C60). The power module consists of a 3-phase inverter bridge with 600V insulated gate bipolar transistors. Delta standard (ASDA-B2 series) servo drive/motor coupled to a 2kW permanent magnet synchronous generator is served as the turbine-generator. This lab-scale setup is used to obtain experimental results. The validation of the FCS-MPC is done by comparing these experimental results to the results obtained by MATLAB/Simulink software results in similar scenarios. The results show that under the proposed control scheme, the regulated variables follow their references accurately. This research confirms that FCS-MPC fits well into the power converter control of the OWC-WEC system with a Li-Ion battery energy storage.

Keywords: dc-dc bidirectional converter, finite control set-model predictive control, Li-ion battery energy storage, oscillating water column, wave energy converter

Procedia PDF Downloads 100
941 China and the Criminalization of Aggression. The Juxtaposition of Justice and the Maintenance of International Peace and Security

Authors: Elisabetta Baldassini

Abstract:

Responses to atrocities are always unique and context-dependent. They cannot be foretold nor easily prompted. However, the events of the twentieth century had set the scene for the international community to explore new and more robust systems in response to war atrocities, with the ultimate goal being the restoration and maintenance of peace and security. The outlawry of war and the attribution of individual liability for international crimes were two major landmarks that set the roots for the development of international criminal law. From the London Conference (1945) for the establishment of the first international military tribunal in Nuremberg to Rome at the inauguration of the first permanent international criminal court, the development of international criminal law has shaped in itself a fluctuating degree of tensions between justice and maintenance of international peace and security, the cardinal dichotomy of this article. The adoption of judicial measures to achieve peace indeed set justice as an essential feature at the heart of the new international system. Blackhole of this dichotomy is the crime of aggression. Aggression was at first the key component of a wide body of peace projects prosecuted under the charges of crimes against peace. However, the wide array of controversies around aggression mostly related to its definition, determination and the involvement of the Security Council silenced, partly, a degree of efforts and agreements. Notwithstanding the establishment of the International Criminal Court (ICC), jurisdiction over the crime of aggression was suspended until an agreement over the definition and the conditions for the Court’s exercise of jurisdiction was reached. Compromised over the crime was achieved in Kampala in 2010 and the Court’s jurisdiction over the crime of aggression was eventually activated on 17 July 2018. China has steadily supported the advancement of international criminal justice together with the establishment of a permanent international judicial body to prosecute grave crimes and has proactively participated at the various stages of the codification and development of the crime of aggression. However, China has also expressed systematic reservations and setbacks. With the use of primary and secondary sources, including semi-structured interviews, this research aims at analyzing the role that China has played throughout the substantive historical development of the crime of aggression, demonstrating a sharp inclination in the maintenance of international peace and security. Such state behavior seems to reflect national and international political mechanisms that gravitate around a distinct rationale that involves a share of culture and tradition.

Keywords: maintenance of peace and security, cultural expression of justice, crime of aggression, China

Procedia PDF Downloads 209
940 Neuropsychological Deficits in Drug-Resistant Epilepsy

Authors: Timea Harmath-Tánczos

Abstract:

Drug-resistant epilepsy (DRE) is defined as the persistence of seizures despite at least two syndrome-adapted antiseizure drugs (ASD) used at efficacious daily doses. About a third of patients with epilepsy suffer from drug resistance. Cognitive assessment has a crucial role in the diagnosis and clinical management of epilepsy. Previous studies have addressed the clinical targets and indications for measuring neuropsychological functions; best to our knowledge, no studies have examined it in a Hungarian therapy-resistant population. To fill this gap, we investigated the Hungarian diagnostic protocol between 18 and 65 years of age. This study aimed to describe and analyze neuropsychological functions in patients with drug-resistant epilepsy and identify factors associated with neuropsychology deficits. We perform a prospective case-control study comparing neuropsychological performances in 50 adult patients and 50 healthy individuals between March 2023 and July 2023. Neuropsychological functions were examined in both patients and controls using a full set of specific tests (general performance level, motor functions, attention, executive facts., verbal and visual memory, language, and visual-spatial functions). Potential risk factors for neuropsychological deficit were assessed in the patient group using a multivariate analysis. The two groups did not differ in age, sex, dominant hand and level of education. Compared with the control group, patients with drug-resistant epilepsy showed worse performance on motor functions and visuospatial memory, sustained attention, inhibition and verbal memory. Neuropsychological deficits could therefore be systematically detected in patients with drug-resistant epilepsy in order to provide neuropsychological therapy and improve quality of life. The analysis of the classical and complex indices of the special neuropsychological tasks presented in the presentation can help in the investigation of normal and disrupted memory and executive functions in the DRE.

Keywords: drug-resistant epilepsy, Hungarian diagnostic protocol, memory, executive functions, cognitive neuropsychology

Procedia PDF Downloads 57
939 Estimates of (Co)Variance Components and Genetic Parameters for Body Weights and Growth Efficiency Traits in the New Zealand White Rabbits

Authors: M. Sakthivel, A. Devaki, D. Balasubramanyam, P. Kumarasamy, A. Raja, R. Anilkumar, H. Gopi

Abstract:

The genetic parameters of growth traits in the New Zealand White rabbits maintained at Sheep Breeding and Research Station, Sandynallah, The Nilgiris, India were estimated by partitioning the variance and covariance components. The (co)variance components of body weights at weaning (W42), post-weaning (W70) and marketing (W135) age and growth efficiency traits viz., average daily gain (ADG), relative growth rate (RGR) and Kleiber ratio (KR) estimated on a daily basis at different age intervals (1=42 to 70 days; 2=70 to 135 days and 3=42 to 135 days) from weaning to marketing were estimated by restricted maximum likelihood, fitting six animal models with various combinations of direct and maternal effects. Data were collected over a period of 15 years (1998 to 2012). A log-likelihood ratio test was used to select the most appropriate univariate model for each trait, which was subsequently used in bivariate analysis. Heritability estimates for W42, W70 and W135 were 0.42 ± 0.07, 0.40 ± 0.08 and 0.27 ± 0.07, respectively. Heritability estimates of growth efficiency traits were moderate to high (0.18 to 0.42). Of the total phenotypic variation, maternal genetic effect contributed 14 to 32% for early body weight traits (W42 and W70) and ADG1. The contribution of maternal permanent environmental effect varied from 6 to 18% for W42 and for all the growth efficiency traits except for KR2. Maternal permanent environmental effect on most of the growth efficiency traits was a carryover effect of maternal care during weaning. Direct maternal genetic correlations, for the traits in which maternal genetic effect was significant, were moderate to high in magnitude and negative in direction. Maternal effect declined as the age of the animal increased. The estimates of total heritability and maternal across year repeatability for growth traits were moderate and an optimum rate of genetic progress seems possible in the herd by mass selection. The estimates of genetic and phenotypic correlations among body weight traits were moderate to high and positive; among growth efficiency traits were low to high with varying directions; between body weights and growth efficiency traits were very low to high in magnitude and mostly negative in direction. Moderate to high heritability and higher genetic correlation in body weight traits promise good scope for genetic improvement provided measures are taken to keep the inbreeding at the lowest level.

Keywords: genetic parameters, growth traits, maternal effects, rabbit genetics

Procedia PDF Downloads 436
938 Spatiotemporal Community Detection and Analysis of Associations among Overlapping Communities

Authors: JooYoung Lee, Rasheed Hussain

Abstract:

Understanding the relationships among communities of users is the key to blueprint the evolution of human society. Majority of people are equipped with GPS devices, such as smart phones and smart cars, which can trace their whereabouts. In this paper, we discover communities of device users based on real locations in a given time frame. We, then, study the associations of discovered communities, referred to as temporal communities, and generate temporal and probabilistic association rules. The rules describe how strong communities are associated. By studying the generated rules, we can automatically extract underlying hierarchies of communities and permanent communities such as work places.

Keywords: association rules, community detection, evolution of communities, spatiotemporal

Procedia PDF Downloads 345
937 Reduced Lung Volume: A Possible Cause of Stuttering

Authors: Shantanu Arya, Sachin Sakhuja, Gunjan Mehta, Sanjay Munjal

Abstract:

Stuttering may be defined as a speech disorder affecting the fluency domain of speech and characterized by covert features like word substitution, omittance and circumlocution and overt features like prolongation of sound, syllables and blocks etc. Many etiologies have been postulated to explain stuttering based on various experiments and research. Moreover, Breathlessness has also been reported by many individuals with stuttering for which breathing exercises are generally advised. However, no studies reporting objective evaluation of the pulmonary capacity and further objective assessment of the efficacy of breathing exercises have been conducted. Pulmonary Function Test which evaluates parameters like Forced Vital Capacity, Peak Expiratory Flow Rate, Forced expiratory flow Rate can be used to study the pulmonary behavior of individuals with stuttering. The study aimed: a) To identify speech motor & physiologic behaviours associated with stuttering by administering PFT. b) To recognize possible reasons for an association between speech motor behaviour & stuttering severity. In this regard, PFT tests were administered on individuals who reported signs and symptoms of stuttering and showed abnormal scores on Stuttering Severity Index. Parameters like Forced Vital Capacity, Forced Expiratory Volume, Peak Expiratory Flow Rate (L/min), Forced Expiratory Flow Rate (L/min) were evaluated and correlated with scores of Stuttering Severity Index. Results showed significant decrease in the parameters (lower than normal scores) in individuals with established stuttering. Strong correlation was also found between degree of stuttering and the degree of decrease in the pulmonary volumes. Thus, it is evident that fluent speech requires strong support of lung pressure and requisite volumes. Further research in demonstrating the efficacy of abdominal breathing exercises in this regard is needed.

Keywords: forced expiratory flow rate, forced expiratory volume, forced vital capacity, peak expiratory flow rate, stuttering

Procedia PDF Downloads 252
936 Reproductive Traits for Holstein Cattle

Authors: Ashraf M. Ward, Ruban S. Yu

Abstract:

Data consisting of 2757 records from tow Holstein herds made between 2000 and 2010 were used to examine environmental factors affecting age at first calving (AFC) and calving intervals (CI) and consequently estimate genetic and phenotypic parameters and trends. The overall means and standard errors for AFC and CI were 39.4 ± 7.2 months and 487.5 ± 151.6 days respectively. The respective heritability estimates were 0.091 ± 0.05 and 0.044 ± 0.032, while the repeatability estimate for CI was 0.096 ± 0.001. The genetic trends for CI and AFC were -0.6 d/yr and -0.01 mo/yr respectively and were both significant (P < 0.001), indicating a decrease in mean breeding value over the study period. Phenotypic trends were -0.31 mo/yr and -0.35 d/yr for AFC and CI respectively though non-significant (P > 0.05). The low heritability for CI and AFC indicated that temporary environmental influences were much greater than genetic influences or permanent environmental influences on these traits.

Keywords: Holstein, reproductive, genetic parameters, heritability

Procedia PDF Downloads 701
935 A Study on the Magnetic and Mechanical Properties of Nd-Fe-B Sintered Magnets According to Sintering Temperature

Authors: J. H. Kim, S. Y. Park, K. M. Lim, S. K. Hyun

Abstract:

The effect of sintering temperature on the magnetic and mechanical properties of Nd-Fe-B sintered magnets has been investigated in this study. The sintering temperature changed from 950°C to 1120°C. While remanence and hardness of the magnets increased with increasing sintering temperature, the coercivity first increased, and then decreased. The optimum magnetic and mechanical properties of the magnets were obtained at the sintering temperature of 1050°C. In order to clarify the reason for the variation on magnetic and mechanical properties of the magnets, we systematically analyzed the microstructure.

Keywords: magnetic and mechanical property, microstructure, permanent magnets, sintered Nd-Fe-B magnet

Procedia PDF Downloads 313
934 Effects of Cannabis and Cocaine on Driving Related Tasks of Perception, Cognition, and Action

Authors: Michelle V. Tomczak, Reyhaneh Bakhtiari, Aaron Granley, Anthony Singhal

Abstract:

Objective: Cannabis and cocaine are associated with a range of mental and physical effects that can impair aspects of human behavior. Driving is a complex cognitive behavior that is an essential part of everyday life and can be broken down into many subcomponents, each of which can uniquely impact road safety. With the growing movement of jurisdictions to legalize cannabis, there is an increased focus on impairment and driving. The purpose of this study was to identify driving-related cognitive-performance deficits that are impacted by recreational drug use. Design and Methods: With the assistance of law enforcement agencies, we recruited over 300 participants under the influence of various drugs including cannabis and cocaine. These individuals performed a battery of computer-based tasks scientifically proven to be re-lated to on-road driving performance and designed to test response-speed, memory processes, perceptual-motor skills, and decision making. Data from a control group with healthy non-drug using adults was collected as well. Results: Compared to controls, the drug group showed def-icits in all tasks. The data also showed clear differences between the cannabis and cocaine groups where cannabis users were faster, and performed better on some aspects of the decision-making and perceptual-motor tasks. Memory performance was better in the cocaine group for simple tasks but not more complex tasks. Finally, the participants who consumed both drugs performed most similarly to the cannabis group. Conclusions: Our results show distinct and combined effects of cannabis and cocaine on human performance relating to driving. These dif-ferential effects are likely related to the unique effects of each drug on the human brain and how they distinctly contribute to mental states. Our results have important implications for road safety associated with driver impairment.

Keywords: driving, cognitive impairment, recreational drug use, cannabis and cocaine

Procedia PDF Downloads 109
933 Development of Fixture for Pipe to Pipe Friction Stir Welding of Dissimilar Materials

Authors: Aashutosh A. Tadse, Kush Mehta, Hardik Vyas

Abstract:

Friction Stir Welding is a process in which an FSW tool produces friction heat and thus penetrates through the junction and upon rotation carries out the weld by exchange of material within the 2 metals being welded. It involves holding the workpieces stiff enough to bear the force of the tool moving across the junction to carry out a successful weld. The weld that has flat plates as workpieces, has a quite simpler geometry in terms of fixture holding them. In the case of FSW of pipes, the pipes need to be held firm with the chucks and jaws according to the diameter of the pipes being welded; the FSW tool is then revolved around the pipes to carry out the weld. Machine requires a larger area and it becomes more costly because of such a setup. To carry out the weld on the Milling machine, the newly designed fixture must be set-up on the table of milling machine and must facilitate rotation of pipes by the motor being shafted to one end of the fixture, and the other end automatically rotated because of the rotating jaws held tight enough with the pipes. The set-up has tapered cones as the jaws that would go in the pipes thus holding it with the help of its knurled surface providing the required grip. The process has rotation of pipes with the stationary rotating tool penetrating into the junction. The FSW on pipes in this process requires a very low RPM of pipes to carry out a fine weld and the speed shall change with every combination of material and diameter of pipes, so a variable speed setting motor shall serve the purpose. To withstand the force of the tool, an attachment to the shaft is provided which will be diameter specific that will resist flow of material towards the center during the weld. The welded joint thus carried out will be proper to required standards and specifications. Current industrial requirements state the need of space efficient, cost-friendly and more generalized form of fixtures and set-ups of machines to be put up. The proposed design considers every mentioned factor and thus proves to be positive in the same.

Keywords: force of tool, friction stir welding, milling machine, rotation of pipes, tapered cones

Procedia PDF Downloads 98
932 Design of Electromagnetic Field of PMSG for VTOL Series-Hybrid UAV

Authors: Sooyoung Cho, In-Gun Kim, Hyun-Seok Hong, Dong-Woo Kang, Ju Lee

Abstract:

Series hybrid UAV(Unmanned aerial vehicle) that is proposed in this paper performs VTOL(Vertical take-off and landing) using the battery and generator, and it applies the series hybrid system with combination of the small engine and generator when cruising flight. This system can be described as the next-generation system that can dramatically increase the UAV flight times. Also, UAV systems require a large energy at the time of VTOL to be conducted for a short time. Therefore, this paper designs PMSG(Permanent Magnet Synchronous Generator) having a high specific power considering VTOL through the FEA.

Keywords: PMSG, VTOL, UAV, high specific power density

Procedia PDF Downloads 497
931 Building Bridges on Roads With Major Constructions

Authors: Mohamed Zaidour

Abstract:

In this summary, we are going to look in brief at the bridges and their building and construction on most roads and we have followed a simple method to explain each field clearly because the geographical and climatic diversity of an area leads to different methods and types of roads and installation engineering in other areas In mountain areas we need to build retaining walls in areas of rain. It needs to construct ferries to discharge water from roads in areas of temporary or permanent rivers. There is a need to build bridges and construct road installations in the process of collecting the necessary information, such as soil type. This information needs it, engineer, when designing the constructor and in this section, we will identify the types and methods of calculation bridge columns rules phrases the walls are chock.

Keywords: bridges, buildings, concrete, constructions, roads

Procedia PDF Downloads 99
930 Development of a Social Assistive Robot for Elderly Care

Authors: Edwin Foo, Woei Wen, Lui, Meijun Zhao, Shigeru Kuchii, Chin Sai Wong, Chung Sern Goh, Yi Hao He

Abstract:

This presentation presents an elderly care and assistive social robot development work. We named this robot JOS and he is restricted to table top operation. JOS is designed to have a maximum volume of 3600 cm3 with its base restricted to 250 mm and his mission is to provide companion, assist and help the elderly. In order for JOS to accomplish his mission, he will be equipped with perception, reaction and cognition capability. His appearance will be not human like but more towards cute and approachable type. JOS will also be designed to be neutral gender. However, the robot will still have eyes, eyelid and a mouth. For his eyes and eyelids, they will be built entirely with Robotis Dynamixel AX18 motor. To realize this complex task, JOS will be also be equipped with micro-phone array, vision camera and Intel i5 NUC computer and a powered by a 12 V lithium battery that will be self-charging. His face is constructed using 1 motor each for the eyelid, 2 motors for the eyeballs, 3 motors for the neck mechanism and 1 motor for the lips movement. The vision senor will be house on JOS forehead and the microphone array will be somewhere below the mouth. For the vision system, Omron latest OKAO vision sensor is used. It is a compact and versatile sensor that is only 60mm by 40mm in size and operates with only 5V supply. In addition, OKAO vision sensor is capable of identifying the user and recognizing the expression of the user. With these functions, JOS is able to track and identify the user. If he cannot recognize the user, JOS will ask the user if he would want him to remember the user. If yes, JOS will store the user information together with the capture face image into a database. This will allow JOS to recognize the user the next time the user is with JOS. In addition, JOS is also able to interpret the mood of the user through the facial expression of the user. This will allow the robot to understand the user mood and behavior and react according. Machine learning will be later incorporated to learn the behavior of the user so as to understand the mood of the user and requirement better. For the speech system, Microsoft speech and grammar engine is used for the speech recognition. In order to use the speech engine, we need to build up a speech grammar database that captures the commonly used words by the elderly. This database is built from research journals and literature on elderly speech and also interviewing elderly what do they want to robot to assist them with. Using the result from the interview and research from journal, we are able to derive a set of common words the elderly frequently used to request for the help. It is from this set that we build up our grammar database. In situation where there is more than one person near JOS, he is able to identify the person who is talking to him through an in-house developed microphone array structure. In order to make the robot more interacting, we have also included the capability for the robot to express his emotion to the user through the facial expressions by changing the position and movement of the eyelids and mouth. All robot emotions will be in response to the user mood and request. Lastly, we are expecting to complete this phase of project and test it with elderly and also delirium patient by Feb 2015.

Keywords: social robot, vision, elderly care, machine learning

Procedia PDF Downloads 429
929 Wind Generator Control in Isolated Site

Authors: Glaoui Hachemi

Abstract:

Wind has been proven as a cost effective and reliable energy source. Technological advancements over the last years have placed wind energy in a firm position to compete with conventional power generation technologies. Algeria has a vast uninhabited land area where the south (desert) represents the greatest part with considerable wind regime. In this paper, an analysis of wind energy utilization as a viable energy substitute in six selected sites widely distributed all over the south of Algeria is presented. In this presentation, wind speed frequency distributions data obtained from the Algerian Meteorological Office are used to calculate the average wind speed and the available wind power. The annual energy produced by the Fuhrlander FL 30 wind machine is obtained using two methods. The analysis shows that in the southern Algeria, at 10 m height, the available wind power was found to vary between 160 and 280 W/m2, except for Tamanrasset. The highest potential wind power was found at Adrar, with 88 % of the time the wind speed is above 3 m/s. Besides, it is found that the annual wind energy generated by that machine lie between 33 and 61 MWh, except for Tamanrasset, with only 17 MWh. Since the wind turbines are usually installed at a height greater than 10 m, an increased output of wind energy can be expected. However, the wind resource appears to be suitable for power production on the south and it could provide a viable substitute to diesel oil for irrigation pumps and electricity generation. In this paper, a model of the wind turbine (WT) with permanent magnet generator (PMSG) and its associated controllers is presented. The increase of wind power penetration in power systems has meant that conventional power plants are gradually being replaced by wind farms. In fact, today wind farms are required to actively participate in power system operation in the same way as conventional power plants. In fact, power system operators have revised the grid connection requirements for wind turbines and wind farms, and now demand that these installations be able to carry out more or less the same control tasks as conventional power plants. For dynamic power system simulations, the PMSG wind turbine model includes an aerodynamic rotor model, a lumped mass representation of the drive train system and generator model. In this paper, we propose a model with an implementation in MATLAB / Simulink, each of the system components off-grid small wind turbines.

Keywords: windgenerator systems, permanent magnet synchronous generator (PMSG), wind turbine (WT) modeling, MATLAB simulink environment

Procedia PDF Downloads 320
928 Amsan Syndrome in Emergency Department

Authors: Okan Cakir, Okan Tatli

Abstract:

Acute motor and sensory axonal neuropathy (AMSAN) syndrome usually occurs following a postviral infection in two to four weeks and is a polyneuropathy characterized by axonal and sensorial degeneration as a rare variant of Gullian-Barre syndrome. In our case, we wanted to mention that a rare case of AMSAN Syndrome due to prior surgery. A 61-year-old male case admitted to emergency department with complaints of weakness in feet, numbness and incapability to walk. In his history, it was learned that endovascular aneurysm repair (EVAR) had applied for abdominal aort aneurysm two weeks ago before admission, his complaints had been for a couple of days increasingly and bilaterally, and there had been no infection disease history for four weeks. In physical examination, general status was good, vital signs were stable, and there was a mild paresis in dorsal flexion of feet in bilaterally lower extremities. No nuchal rigidity was determined. Other system examinations were normal. Urea:52 mg/dL (normal range: 15-44 mg/dL), creatinine: 1,05 mg/dL (normal range: 0,81-1,4 mg/dL), potassium: 3,68 mmol/L (normal range: 3,5-5,5 mmol/L), glycaemia: 142 mg/dL, calcium: 9,71 mg/dL (normal range: 8,5-10,5 mg/dL), erythrocyte sedimentation rate (ESR): 74 mm/h (normal range: 0-15 mm/h) were determined in biochemical tests. The case was consulted to neurology department and hospitalized. In performing electromyography, it was reported as a bilateral significant axonal degeneration with sensory-motor polyneuropathy. Normal ranges of glycaemia and protein levels were detected in lumbal punction. Viral markers and bucella, toxoplasma, and rubella markers were in normal range. Intravenous immunoglobulin (IVIG) was applied as a treatment, physical treatment programme was planned and the case discharged from neurology department. In our case, we mentioned that it should be considered polyneuropathy as an alternative diagnosis in cases admitting symptoms like weakness and numbness had a history of prior surgery.

Keywords: AMSAN Syndrome, emergency department, prior surgery, weakness

Procedia PDF Downloads 323
927 The People's Tribunal: Empowerment by Survivors for Survivors of Child Abuse

Authors: Alan Collins

Abstract:

This study explains how The People’s Tribunal empowered survivors of child abuse. It examines how People’s tribunals can be effective mean of empowerment; the challenges of empowerment – expectation v. reality; the findings and how they reflect other inquiry findings; and the importance of listening and learning from survivors. UKCSAPT “The People’s Tribunal” was established by survivors of child sex abuse and members of civil society to investigate historic cases of institutional sex abuse. The independent inquiry, led by a panel of four judges, listened to evidence spanning four decades from survivors and experts. A common theme throughout these accounts showed that a series of institutional failures prevented abuse from being reported; and that there are clear links between children being rendered vulnerable by these failures and predatory abuse on an organised scale. It made a series of recommendations including the establishment of a permanent and open forum for victims to share experiences and give evidence, better links between mental health services and police investigations, and training for police and judiciary professionals on the effects of undisclosed sexual abuse. The main findings of the UKCSAPT report were:-There are clear links between children rendered vulnerable by institutional failures and predatory abuse on an organised scale, even if these links often remain obscure. -UK governmental institutions have failed to provide survivors with meaningful opportunities for either healing or justice. -The vital mental health needs of survivors are not being met and this undermines both their psychological recovery and access to justice. -Police and other authorities often lack the training to understand the complex reasons for the inability of survivors to immediately disclose a history of abuse. -Without far-reaching changes in institutional culture and practices, the sexual abuse of children will continue to be a significant scourge in the UK. The report also outlined a series of recommendations for improving reporting and mental health provision, and access to justice for victims were made, including: -A permanent, government-funded popular tribunal should be established to enable survivors to come forward and tell their stories. -Survivors giving evidence should be assigned an advocate to assist their access to justice. -Mental health services should be linked to police investigations to help victims disclose abuse. -Victims who fear reprisals should be provided with a channel though which to give evidence anonymously.

Keywords: empowerment, survivors, sexual, abuse

Procedia PDF Downloads 242
926 Study of Properties of Concretes Made of Local Building Materials and Containing Admixtures, and Their Further Introduction in Construction Operations and Road Building

Authors: Iuri Salukvadze

Abstract:

Development of Georgian Economy largely depends on its effective use of its transit country potential. The value of Georgia as the part of Europe-Asia corridor has increased; this increases the interest of western and eastern countries to Georgia as to the country that laid on the transit axes that implies transit infrastructure creation and development in Georgia. It is important to use compacted concrete with the additive in modern road construction industry. Even in the 21-century, concrete remains as the main vital constructive building material, therefore innovative, economic and environmentally protected technologies are needed. Georgian construction market requires the use of concrete of new generation, adaptation of nanotechnologies to the local realities that will give the ability to create multifunctional, nano-technological high effective materials. It is highly important to research their physical and mechanical states. The study of compacted concrete with the additives is necessary to use in the road construction in the future and to increase hardness of roads in Georgia. The aim of the research is to study the physical-mechanical properties of the compacted concrete with the additives based on the local materials. Any experimental study needs large number of experiments from one side in order to achieve high accuracy and optimal number of the experiments with minimal charges and in the shortest period of time from the other side. To solve this problem in practice, it is possible to use experiments planning static and mathematical methods. For the materials properties research we will use distribution hypothesis, measurements results by normal law according to which divergence of the obtained results is caused by the error of method and inhomogeneity of the object. As the result of the study, we will get resistible compacted concrete with additives for the motor roads that will improve roads infrastructure and give us saving rate while construction of the roads and their exploitation.

Keywords: construction, seismic protection systems, soil, motor roads, concrete

Procedia PDF Downloads 220
925 The Risk of Ground Movements After Digging Two Parallel Vertical Tunnel in Urban

Authors: Djelloul Chafia, Demagh Rafik, Kareche Toufik

Abstract:

Human activities, made without precautions, accelerate the degradation of the soil structure and reduces its resistance. Operations, such as tunnel construction may exercise an influence more or less permanent on the grounds which surrounded them, these structures alter soil it is necessary to predict their impacts by suitable measures. This research is a numerical analysis that deals the risks and effects due to the weakening of the soil after digging two parallel vertical circular tunnels in urban areas, and suggests forecasting techniques based essentially on the organization of underground space. The simulations are performed using the finite-difference code FLAC in a two-dimensional case and with an elasto-plastic behavior of the soil.

Keywords: sol, weakening, degradation, prevention, tunnel

Procedia PDF Downloads 543
924 Involvement of Nrf2 in Kolaviron-Mediated Attenuation of Behavioural Incompetence and Neurodegeneration in a Murine Model of Parkinson's Disease

Authors: Yusuf E. Mustapha, Inioluwa A Akindoyeni, Oluwatoyin G. Ezekiel, Ifeoluwa O. Awogbindin, Ebenezer O. Farombi

Abstract:

Background: Parkinson's disease (PD) is the most prevalent motor disorder. Available therapies are palliative with no effect on disease progression. Kolaviron (KV), a natural anti-inflammatory and antioxidant agent, has been reported to possess neuroprotective effects in Parkinsonian flies and rats. Objective: The present study investigates the neuroprotective effect of KV, focusing on the DJ1/Nrf2 signaling pathway. Methodology: All-trans retinoic acid (ATRA, 10 mg/kg, i.p.) was used to inhibit Nrf2. Murine model of PD was established with four doses of MPTP (20 mg/kg i.p.) at 2 hours interval. MPTP mice were pre-treated with either KV (200 mg/kg/day p.o), ATRA, or both conditions for seven days before PD induction. Motor behaviour was evaluated, and markers of oxidative stress/damage and its regulators were assessed with immunofluorescence and ELISA techniques. Results: MPTP-treated mice covered less distance with reduced numbers of anticlockwise rotations, heightened freezing, and prolonged immobility when compared to control. However, KV significantly attenuated these deficits. Pretreatment of MPTP mice with KV upregulated Nrf2 expression beyond MPTP level with a remarkable reduction in Keap1 expression and marked elevation of DJ-1 level, whereas co-administration with ATRA abrogated these effects. KV treatment restored MPTP-mediated depletion of endogenous antioxidant, striatal oxidative stress, oxidative damage, and inhibition of acetylcholinesterase activity. However, ATRA treatment potentiated acetylcholinesterase inhibition and attenuated the protective effect of KV on the level of nitric oxide and activities of catalase and superoxide dismutase. Conclusion: Kolaviron protects Parkinsonian mice by stabilizing and activating the Nrf2 signaling pathway. Thus, kolaviron can be explored as a pharmacological lead in PD management.

Keywords: Garcinia kola, Kolaviron, Parkinson Disease, Nrf2, behavioral incompetence, neurodegeneration

Procedia PDF Downloads 80
923 Efficacy of Thrust on Basilar Spheno Synchondrosis in Boxers With Ocular Convergence Deficit. Comparison of Thrust and Therapeutic Exercise: Pilot Experimental Randomized Controlled Trial Study

Authors: Andreas Aceranti, Stefano Costa

Abstract:

The aim of this study was to demonstrate that manipulative treatment combined with therapeutic exercisetherapywas more effective than isolated therapeutic exercise in the short-term treatment of eye convergence disorders in boxers. A randomized controlled trial (RCT) pilot trial was performed at our physiotherapy practices. 30 adult subjects who practice the discipline of boxing were selected after an initial skimming defined by the Convergence Insufficiency Symptom Survey (CISS) test (results greater than or equal to 10) starting from the initial sample of 50 subjects; The 30 recruits were evaluated by an orthoptist using prisms to know the diopters of each eye and were divided into 2 groups (experimental group and control group). The members of the experimental group were subjected to manipulation of the lateral strain of sphenoid from the side contralateral to the eye that had fewer diopters and were subjected to a sequence of 3 ocular motor exercises immediately after manipulation. The control group, on the other hand, received only ocular motor treatment. A secondary outcome was also drawn up that demonstrated how changes in ocular motricity also affected cervical rotation. Analysis of the data showed that the experimental treatment was in the short term superior to the control group to astatistically significant extent both in terms of the prismatic delta of the right eye (0 OT median without manipulation and 10 OT median with manipulation) and that of the left eye (0 OT median without manipulation and 5 OT median with manipulation). Cervical rotation values also showed better values in the experimental group with a median of 4° in the right rotation without manipulation and 6° with thrust; the left rotation presented a median of 2° without manipulation and 7° with thrust. From the results that emerged, the treatment was effective. It would be desirable to increase the sample number and set up a timeline to see if the net improvements obtained in the short term will also be maintained in the medium to long term.

Keywords: boxing, basilar spheno synchondrosis, ocular convergence deficit, osteopathic treatment

Procedia PDF Downloads 73
922 The Origins of Representations: Cognitive and Brain Development

Authors: Athanasios Raftopoulos

Abstract:

In this paper, an attempt is made to explain the evolution or development of human’s representational arsenal from its humble beginnings to its modern abstract symbols. Representations are physical entities that represent something else. To represent a thing (in a general sense of “thing”) means to use in the mind or in an external medium a sign that stands for it. The sign can be used as a proxy of the represented thing when the thing is absent. Representations come in many varieties, from signs that perceptually resemble their representative to abstract symbols that are related to their representata through conventions. Relying the distinction among indices, icons, and symbols, it is explained how symbolic representations gradually emerged from indices and icons. To understand the development or evolution of our representational arsenal, the development of the cognitive capacities that enabled the gradual emergence of representations of increasing complexity and expressive capability should be examined. The examination of these factors should rely on a careful assessment of the available empirical neuroscientific and paleo-anthropological evidence. These pieces of evidence should be synthesized to produce arguments whose conclusions provide clues concerning the developmental process of our representational capabilities. The analysis of the empirical findings in this paper shows that Homo Erectus was able to use both icons and symbols. Icons were used as external representations, while symbols were used in language. The first step in the emergence of representations is that a sensory-motor purely causal schema involved in indices is decoupled from its normal causal sensory-motor functions and serves as a representation of the object that initially called it into play. Sensory-motor schemes are tied to specific contexts of the organism-environment interactions and are activated only within these contexts. For a representation of an object to be possible, this scheme must be de-contextualized so that the same object can be represented in different contexts; a decoupled schema loses its direct ties to reality and becomes mental content. The analysis suggests that symbols emerged due to selection pressures of the social environment. The need to establish and maintain social relationships in ever-enlarging groups that would benefit the group was a sufficient environmental pressure to lead to the appearance of the symbolic capacity. Symbols could serve this need because they can express abstract relationships, such as marriage or monogamy. Icons, by being firmly attached to what can be observed, could not go beyond surface properties to express abstract relations. The cognitive capacities that are required for having iconic and then symbolic representations were present in Homo Erectus, which had a language that started without syntactic rules but was structured so as to mirror the structure of the world. This language became increasingly complex, and grammatical rules started to appear to allow for the construction of more complex expressions required to keep up with the increasing complexity of social niches. This created evolutionary pressures that eventually led to increasing cranial size and restructuring of the brain that allowed more complex representational systems to emerge.

Keywords: mental representations, iconic representations, symbols, human evolution

Procedia PDF Downloads 36
921 Frequency Decomposition Approach for Sub-Band Common Spatial Pattern Methods for Motor Imagery Based Brain-Computer Interface

Authors: Vitor M. Vilas Boas, Cleison D. Silva, Gustavo S. Mafra, Alexandre Trofino Neto

Abstract:

Motor imagery (MI) based brain-computer interfaces (BCI) uses event-related (de)synchronization (ERS/ ERD), typically recorded using electroencephalography (EEG), to translate brain electrical activity into control commands. To mitigate undesirable artifacts and noise measurements on EEG signals, methods based on band-pass filters defined by a specific frequency band (i.e., 8 – 30Hz), such as the Infinity Impulse Response (IIR) filters, are typically used. Spatial techniques, such as Common Spatial Patterns (CSP), are also used to estimate the variations of the filtered signal and extract features that define the imagined motion. The CSP effectiveness depends on the subject's discriminative frequency, and approaches based on the decomposition of the band of interest into sub-bands with smaller frequency ranges (SBCSP) have been suggested to EEG signals classification. However, despite providing good results, the SBCSP approach generally increases the computational cost of the filtering step in IM-based BCI systems. This paper proposes the use of the Fast Fourier Transform (FFT) algorithm in the IM-based BCI filtering stage that implements SBCSP. The goal is to apply the FFT algorithm to reduce the computational cost of the processing step of these systems and to make them more efficient without compromising classification accuracy. The proposal is based on the representation of EEG signals in a matrix of coefficients resulting from the frequency decomposition performed by the FFT, which is then submitted to the SBCSP process. The structure of the SBCSP contemplates dividing the band of interest, initially defined between 0 and 40Hz, into a set of 33 sub-bands spanning specific frequency bands which are processed in parallel each by a CSP filter and an LDA classifier. A Bayesian meta-classifier is then used to represent the LDA outputs of each sub-band as scores and organize them into a single vector, and then used as a training vector of an SVM global classifier. Initially, the public EEG data set IIa of the BCI Competition IV is used to validate the approach. The first contribution of the proposed method is that, in addition to being more compact, because it has a 68% smaller dimension than the original signal, the resulting FFT matrix maintains the signal information relevant to class discrimination. In addition, the results showed an average reduction of 31.6% in the computational cost in relation to the application of filtering methods based on IIR filters, suggesting FFT efficiency when applied in the filtering step. Finally, the frequency decomposition approach improves the overall system classification rate significantly compared to the commonly used filtering, going from 73.7% using IIR to 84.2% using FFT. The accuracy improvement above 10% and the computational cost reduction denote the potential of FFT in EEG signal filtering applied to the context of IM-based BCI implementing SBCSP. Tests with other data sets are currently being performed to reinforce such conclusions.

Keywords: brain-computer interfaces, fast Fourier transform algorithm, motor imagery, sub-band common spatial patterns

Procedia PDF Downloads 109
920 Hip Strategy in Dynamic Postural Control in Recurrent Ankle Sprain

Authors: Radwa Elshorbagy, Alaa Elden Balbaa, Khaled Ayad, Waleed Reda

Abstract:

Introduction: Ankle sprain is a common lower limb injury that is complicated by high recurrence rate. The cause of recurrence is not clear; however, changes in motor control have been postulated. Objective: to determine the contribution of proximal hip strategy to dynamic postural control in patients with recurrent ankle sprain. Methods: Fifteen subjects with recurrent ankle sprain (group A) and fifteen healthy control subjects (group B) participated in this study. Abductor-adductors as well as flexor-extensor hip musculatures control was abolished by fatigue using the Biodex Isokinetic System. Dynamic postural control was measured before and after fatigue by the Biodex Balance System. Results: Repeated measures MANOVA was used to compare between and within group differences, in group A fatiguing of hip muscles (flexors-extensors and abductors-adductors) increased overall stability index (OASI), anteroposterior stability index (APSI) and mediolateral stability index (MLSI) significantly (p=0.00) whereas; in group B fatiguing of hip flexors-extensors increased significantly OASI and APSI only (p= 0.017, 0.010; respectively) while fatiguing of hip abductors-adductors has no significant effect on these variables. Moreover, patients with ankle sprain had significantly lower dynamic balance after hip muscles fatigue compared to the control group. Specifically, after hip flexor-extensor fatigue, the OASI, APSI and MLSI were increased significantly than those of the control values (p= 0.002, 0.011, and 0.003, respectively) whereas fatiguing of hip abductors-adductors increased significantly in OASI and APSI only (p=0.012, 0.026, respectively). Conclusion: To maintain dynamic balance, patients with recurrent ankle sprain seem to rely more on the hip strategy. This means that those patients depend on a top to down instead of down to top strategy clinical relevance: patients with recurrent ankle sprain less efficient in maintaining the dynamic postural control due to the change in motor strategies. Indicating that health care providers and rehabilitation specialists should treat CAI as a global/central and not just as a simple local or peripheral injury.

Keywords: hip strategy, ankle strategy, postural control, dynamic balance

Procedia PDF Downloads 322
919 The Contribution of Hip Strategy in Dynamic Postural Control in Recurrent Ankle Sprain

Authors: Radwa El Shorbagy, Alaa El Din Balbaa, Khaled Ayad, Waleed Reda

Abstract:

Introduction: Ankle sprain is a common lower limb injury that is complicated by high recurrence rate. The cause of recurrence is not clear; however, changes in motor control have been postulated. Objective: to determine the contribution of proximal hip strategy to dynamic postural control in patients with recurrent ankle sprain. Methods: Fifteen subjects with recurrent ankle sprain (group A) and fifteen healthy control subjects (group B) participated in this study. Abductor-adductors as well as flexor-extensor hip musculatures control was abolished by fatigue using the Biodex Isokinetic System. Dynamic postural control was measured before and after fatigue by the Biodex Balance System Results: Repeated measures MANOVA was used to compare between and within group differences, In group A fatiguing of hip muscles (flexors-extensors and abductors-adductors) increased overall stability index (OASI), anteroposterior stability index (APSI) and mediolateral stability index (MLSI) significantly (p= 0.00) whereas; in group B fatiguing of hip flexors-extensors increased significantly OASI and APSI only (p= 0.017, 0.010; respectively) while fatiguing of hip abductors-adductors has no significant effect on these variables. Moreover, patients with ankle sprain had significantly lower dynamic balance after hip muscles fatigue compared to the control group. Specifically, after hip flexor-extensor fatigue, the OASI, APSI and MLSI were increased significantly than those of the control values (p= 0.002, 0.011, and 0.003, respectively) whereas fatiguing of hip abductors-adductors increased significantly in OASI and APSI only (p=0.012, 0.026, respectively). Conclusion: To maintain dynamic balance, patients with recurrent ankle sprain seem to relay more on the hip strategy. This means that those patients depend on a top to down instead of down to top strategy clinical relevance: patients with recurrent ankle sprain less efficient in maintaining the dynamic postural control due to the change in motor strategies. Indicating that health care providers and rehabilitation specialists should treat CAI as a global/central and not just as a simple local or peripheral injury.

Keywords: ankle sprain, fatigue hip muscles, dynamic balance

Procedia PDF Downloads 286