Search results for: motor functions
2806 Autobiographical Memory Functions and Perceived Control in Depressive Symptoms among Young Adults
Authors: Meenu S. Babu, K. Jayasankara Reddy
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Depression is a serious mental health concern that leads to significant distress and dysfunction in an individual. Due to the high physical, psychological, social, and economic burden it causes, it is important to study various bio-psycho-social factors that influence the onset, course, duration, intensity of depressive symptoms. The study aims to explore relationship between autobiographical memory (AM) functions, perceived control over stressful events and depressive symptoms. AM functions and perceived control were both found to be protective factors for individuals against depression and were both modifiable to predict better behavioral and affective outcomes. An extensive review of literatur, with a systematic search on Google Scholar, JSTOR, Science Direct and Springer Journals database, was conducted for the purpose of this review paper. These were used for all the aforementioned databases. The time frame used for the search was 2010-2021. An additional search was conducted with no time bar to map the development of the theoretical concepts. The relevant studies with quantitative, qualitative, experimental, and quasi- experimental research designs were included for the review. Studies including a sample with a DSM- 5 or ICD-10 diagnosis of depressive disorders were excluded from the study to focus on the behavioral patterns in a non-clinical population. The synthesis of the findings that were obtained from the review indicates there is a significant relationship between cognitive variables of AM functions and perceived control and depressive symptoms. AM functions were found to be have significant effects on once sense of self, interpersonal relationships, decision making, self- continuity and were related to better emotion regulation and lower depressive symptoms. Not all the components of AM function were equally significant in their relationships with various depressive symptoms. While self and directive functions were more related to emotion regulation, anhedonia, motivation and hence mood and affect, the social function was related to perceived social support and social engagement. Perceived control was found to be another protective cognitive factor that provides individuals a sense of agency and control over one’s life outcomes which was found to be low in individuals with depression. This was also associated to the locus of control, competency beliefs, contingency beliefs and subjective well being in individuals and acted as protective factors against depressive symptoms. AM and perceived control over stressful events serve adaptive functions, hence it is imperative to study these variables more extensively. They can be imperative in planning and implementing therapeutic interventions to foster these cognitive protective factors to mitigate or alleviate depressive symptoms. Exploring AM as a determining factor in depressive symptoms along with perceived control over stress creates a bridge between biological and cognitive factors underlying depression and increases the scope of developing a more eclectic and effective treatment plan for individuals. As culture plays a crucial role in AM functions as well as certain aspects of control such as locus of control, it is necessary to study these variables keeping in mind the cultural context to tailor culture/community specific interventions for depression.Keywords: autobiographical memories, autobiographical memory functions, perceived control, depressive symptoms, depression, young adults
Procedia PDF Downloads 1042805 Analysis of the Probable Maximum Flood in Hydrologic Design Using Different Functions of Rainfall-Runoff Transformation
Authors: Evangelos Baltas, Elissavet Feloni, Dimitrios Karpouzos
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A crucial issue in hydrologic design is the sizing of structures and flood-control works in areas with limited data. This research work highlights the significant variation in probable maximum flood (PMF) for a design hyetograph, using different theoretical functions of rainfall-runoff transformation. The analysis focuses on seven subbasins with different characteristics in the municipality of Florina, northern Greece. This area is a semi-agricultural one which hosts important activities, such as the operation of one of the greatest fields of lignite for power generation in Greece. Results illustrate the notable variation in estimations among the methodologies used for the examined subbasins.Keywords: rainfall, runoff, hydrologic design, PMF
Procedia PDF Downloads 2552804 User Selections on Social Network Applications
Authors: C. C. Liang
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MSN used to be the most popular application for communicating among social networks, but Facebook chat is now the most popular. Facebook and MSN have similar characteristics, including usefulness, ease-of-use, and a similar function, which is the exchanging of information with friends. Facebook outperforms MSN in both of these areas. However, the adoption of Facebook and abandonment of MSN have occurred for other reasons. Functions can be improved, but users’ willingness to use does not just depend on functionality. Flow status has been established to be crucial to users’ adoption of cyber applications and to affects users’ adoption of software applications. If users experience flow in using software application, they will enjoy using it frequently, and even change their preferred application from an old to this new one. However, no investigation has examined choice behavior related to switching from Facebook to MSN based on a consideration of flow experiences and functions. This investigation discusses the flow experiences and functions of social-networking applications. Flow experience is found to affect perceived ease of use and perceived usefulness; perceived ease of use influences information ex-change with friends, and perceived usefulness; information exchange influences perceived usefulness, but information exchange has no effect on flow experience.Keywords: consumer behavior, social media, technology acceptance model, flow experience
Procedia PDF Downloads 3552803 Amplifying Sine Unit-Convolutional Neural Network: An Efficient Deep Architecture for Image Classification and Feature Visualizations
Authors: Jamshaid Ul Rahman, Faiza Makhdoom, Dianchen Lu
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Activation functions play a decisive role in determining the capacity of Deep Neural Networks (DNNs) as they enable neural networks to capture inherent nonlinearities present in data fed to them. The prior research on activation functions primarily focused on the utility of monotonic or non-oscillatory functions, until Growing Cosine Unit (GCU) broke the taboo for a number of applications. In this paper, a Convolutional Neural Network (CNN) model named as ASU-CNN is proposed which utilizes recently designed activation function ASU across its layers. The effect of this non-monotonic and oscillatory function is inspected through feature map visualizations from different convolutional layers. The optimization of proposed network is offered by Adam with a fine-tuned adjustment of learning rate. The network achieved promising results on both training and testing data for the classification of CIFAR-10. The experimental results affirm the computational feasibility and efficacy of the proposed model for performing tasks related to the field of computer vision.Keywords: amplifying sine unit, activation function, convolutional neural networks, oscillatory activation, image classification, CIFAR-10
Procedia PDF Downloads 1112802 The Desire to Know: Arnold’s Contribution to a Psychological Conceptualization of Academic Motivation
Authors: F. Ruiz-Fuster
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Arnold’s redefinition of human motives can sustain a psychology of education which emphasizes the beauty of knowledge and the exercise of intellectual functions. Thus, education instead of focusing on skills and learning by doing would be centered on ‘the widest reaches of the human spirit’. One way to attain it is by developing children’s inherent interest. Arnold takes into account the fact that the desire to know is the inherent interest which leads students to explore and learn. She also emphasizes the need of exercising human functions as thinking, judging and reasoning. According to Arnold, the influence of psychological theories of motivation in education has derived in considering that all learning and school tasks should derive from children’s needs and impulses. The desire to know and the curiosity have not been considered as basic and active as any instinctive drive or basic need, so there has been an attempt to justify and understand how biological drives guide student’s learning. However, understanding motives and motivation not as a drive, an instinct or an impulse guided by our basic needs, but as a want that leads to action can help to understand, from a psychological perspective, how teachers can motivate students to learn, strengthening their desire and interest to reason and discover the whole new world of knowledge.Keywords: academic motivation, interests, desire to know, educational psychology, intellectual functions
Procedia PDF Downloads 1522801 Meta Model for Optimum Design Objective Function of Steel Frames Subjected to Seismic Loads
Authors: Salah R. Al Zaidee, Ali S. Mahdi
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Except for simple problems of statically determinate structures, optimum design problems in structural engineering have implicit objective functions where structural analysis and design are essential within each searching loop. With these implicit functions, the structural engineer is usually enforced to write his/her own computer code for analysis, design, and searching for optimum design among many feasible candidates and cannot take advantage of available software for structural analysis, design, and searching for the optimum solution. The meta-model is a regression model used to transform an implicit objective function into objective one and leads in turn to decouple the structural analysis and design processes from the optimum searching process. With the meta-model, well-known software for structural analysis and design can be used in sequence with optimum searching software. In this paper, the meta-model has been used to develop an explicit objective function for plane steel frames subjected to dead, live, and seismic forces. Frame topology is assumed as predefined based on architectural and functional requirements. Columns and beams sections and different connections details are the main design variables in this study. Columns and beams are grouped to reduce the number of design variables and to make the problem similar to that adopted in engineering practice. Data for the implicit objective function have been generated based on analysis and assessment for many design proposals with CSI SAP software. These data have been used later in SPSS software to develop a pure quadratic nonlinear regression model for the explicit objective function. Good correlations with a coefficient, R2, in the range from 0.88 to 0.99 have been noted between the original implicit functions and the corresponding explicit functions generated with meta-model.Keywords: meta-modal, objective function, steel frames, seismic analysis, design
Procedia PDF Downloads 2432800 Religious Tattoos Symbols amongst Underground Communities in Surabaya and Sidoarjo, Indonesia: Their Functions and Significances
Authors: Constantius Tri Handoko
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Tattoos on the body of Christian youths seemed interesting as the majority of Christian look at tattoo and tattooing activity are prohibited. This research besides to understand the motivation behind why Christian youth in Surabaya and Sidoarjo, Indonesia being tattooed also focus on the regard to what functions and meanings of the tattoos are. By using visual discourse analysis, the tattoos had relation to the informants’ social lives dimension, such as the Christian symbol tattoos expressed their spiritual life journey, a faith symbol to God, as personal symbols (identity), art expression, as well as fashion. On the other hands, tattoos also became a hatred symbol to Jesus and the Christian faith, since the tattoo wearers who were a former Christians felt disappointed to God as they thought God never help them to survive in their lives.Keywords: tattoo, representation, identity, belief, Christian
Procedia PDF Downloads 2632799 Neuroprotective Effect of Vildagliptin against Cerebral Ischemia in Rats
Authors: Salma A. El-Marasy, Rehab F. Abdel-Rahman, Reham M. Abd-Elsalam
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The burden of stroke is intensely increasing worldwide. Brain injury following transient or permanent focal cerebral ischemia develops ischemic stroke as a consequence of a complex series of pathophysiological events. The aim of this study is to evaluate the possible neuroprotective effect of a dipeptidyl peptidase-4 inhibitor, vildagliptin, independent on its insulinotropic properties in non-diabetic rats subjected to cerebral ischemia. Anaesthetized Wistar rats were subjected to either left middle cerebral artery occlusion (MCAO) or sham operation followed by reperfusion after 30 min of MCAO. The other three groups were orally administered vildagliptin at 3 dose levels (2.5, 5, 10 mg/kg) for 3 successive weeks before subjected to left focal cerebral ischemia/reperfusion and till the end of the study. Neurological deficit scores and motor activity were assessed 24h following reperfusion. 48h following reperfusion, rats were euthanized and their left brain hemispheres were harvested and used in the biochemical, histopathological, and immunohistochemical investigations. Vildagliptin pretreatment improved neurological score deficit, locomotor activity and motor coordination in MCAO rats. Moreover, vildagliptin reduced malondialdehyde (MDA), elevated reduced glutathione (GSH), phosphotylinosital 3 kinase (PI3K), phosphorylated of protein kinase B (p-AKT), and mechanistic target of rapamycin (mTOR) brain contents in addition to reducing protein expression of caspase-3. Also, vildagliptin showed a dose-dependent attenuation in neuronal cell loss and histopathological alterations in MCAO rats. This study proves that vildagliptin exerted the neuroprotective effect in a dose-dependent manner as shown in amelioration of neuronal cell loss and histopathological damage in MCAO rats, which may be mediated by attenuating neuronal and motor deficits, it’s anti-oxidant property, activation of PI3K/AKT/mTOR pathway and its anti-apoptotic effect.Keywords: caspase-3, cerebral ischemia, dipeptidyl peptidase-4 inhibitor, oxidative stress, PI3K/AKT/mTOR pathway, rats, vildagliptin
Procedia PDF Downloads 1552798 MATLAB Supported Learning and Students' Conceptual Understanding of Functions of Two Variables: Experiences from Wolkite University
Authors: Eyasu Gemech, Kassa Michael, Mulugeta Atnafu
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A non-equivalent group's quasi-experiment research was conducted at Wolkite University to investigate MATLAB supported learning and students' conceptual understanding in learning Applied Mathematics II using four different comparative instructional approaches: MATLAB supported traditional lecture method, MATLAB supported collaborative method, only collaborative method, and only traditional lecture method. Four intact classes of mechanical engineering groups 1 and 2, garment engineering and textile engineering students were randomly selected out of eight departments. The first three departments were considered as treatment groups and the fourth one 'Textile engineering' was assigned as a comparison group. The departments had 30, 29, 35 and 32 students respectively. The results of the study show that there is a significant mean difference in students' conceptual understanding between groups of students learning through MATLAB supported collaborative method and the other learning approaches. Students who were learned through MATLAB technology-supported learning in combination with collaborative method were found to understand concepts of functions of two variables better than students learning through the other methods of learning. These, hence, are informative of the potential approaches universities would follow for a better students’ understanding of concepts.Keywords: MATLAB supported collaborative method, MATLAB supported learning, collaborative method, conceptual understanding, functions of two variables
Procedia PDF Downloads 2782797 The Contribution of the PCR-Enzymatic Digestion in the Positive Diagnosis of Proximal Spinal Muscular Atrophy in the Moroccan Population
Authors: H. Merhni, A. Sbiti, I. Ratbi, A. Sefiani
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The proximal spinal muscular atrophy (SMA) is a group of neuromuscular disorders characterized by progressive muscle weakness due to the degeneration and loss of anterior motor neurons of the spinal cord. Depending on the age of onset of symptoms and their evolution, four types of SMA, varying in severity, result in a mutations of the SMN gene (survival of Motor neuron). We have analyzed the DNA of 295 patients referred to our genetic counseling; since January 1996 until October 2014; for suspected SMA. The homozygous deletion of exon 7 of the SMN gene was found in 133 patients; of which, 40.6% were born to consanguineous parents. In countries like Morocco, where the frequency of heterozygotes for SMA is high, genetic testing should be offered as first-line and, after careful clinical assessment, especially in newborns and infants with congenital hypotonia unexplained and prognosis compromise. The molecular diagnosis of SMA allows a quick and certainly diagnosis, provide adequate genetic counseling for families at risk and suggest, for couples who want prenatal diagnosis. The analysis of the SMN gene is a perfect example of genetic testing with an excellent cost/benefit ratio that can be of great interest in public health, especially in low-income countries. We emphasize in this work for the benefit of the generalization of molecular diagnosis of SMA by the technique of PCR-enzymatic digestion in other centers in Morocco.Keywords: Exon7, PCR-digestion, SMA, SMN gene
Procedia PDF Downloads 2422796 Somatosensory-Evoked Blink Reflex in Peripheral Facial Palsy
Authors: Sarah Sayed El- Tawab, Emmanuel Kamal Azix Saba
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Objectives: Somatosensory blink reflex (SBR) is an eye blink response obtained from electrical stimulation of peripheral nerves or skin area of the body. It has been studied in various neurological diseases as well as among healthy subjects in different population. We designed this study to detect SBR positivity in patients with facial palsy and patients with post facial syndrome, to relate the facial palsy severity and the presence of SBR, and to associate between trigeminal BR changes and SBR positivity in peripheral facial palsy patients. Methods: 50 patients with peripheral facial palsy and post-facial syndrome 31 age and gender matched healthy volunteers were enrolled to this study. Facial motor conduction studies, trigeminal BR, and SBR were studied in all. Results: SBR was elicited in 67.7% of normal subjects, in 68% of PFS group, and in 32% of PFP group. On the non-paralytic side SBR was found in 28% by paralyzed side stimulation and in 24% by healthy side stimulation among PFP patients. For PFS group SBR was found on the non- paralytic side in 48%. Bilateral SBR elicitability was higher than its unilateral elicitability. Conclusion: Increased brainstem interneurons excitability is not essential to generate SBR. The hypothetical sensory-motor gating mechanism is responsible for SBR generation.Keywords: somatosensory evoked blink reflex, post facial syndrome, blink reflex, enchanced gain
Procedia PDF Downloads 6202795 Explaining the Steps of Designing and Calculating the Content Validity Ratio Index of the Screening Checklist of Preschool Students (5 to 7 Years Old) Exposed to Learning Difficulties
Authors: Sajed Yaghoubnezhad, Sedygheh Rezai
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Background and Aim: Since currently in Iran, students with learning disabilities are identified after entering school, and with the approach to the gap between IQ and academic achievement, the purpose of this study is to design and calculate the content validity of the pre-school screening checklist (5-7) exposed to learning difficulties. Methods: This research is a fundamental study, and in terms of data collection method, it is quantitative research with a descriptive approach. In order to design this checklist, after reviewing the research background and theoretical foundations, cognitive abilities (visual processing, auditory processing, phonological awareness, executive functions, spatial visual working memory and fine motor skills) are considered the basic variables of school learning. The basic items and worksheets of the screening checklist of pre-school students 5 to 7 years old with learning difficulties were compiled based on the mentioned abilities and were provided to the specialists in order to calculate the content validity ratio index. Results: Based on the results of the table, the validity of the CVR index of the background information checklist is equal to 0.9, and the CVR index of the performance checklist of preschool children (5 to7 years) is equal to 0.78. In general, the CVR index of this checklist is reported to be 0.84. The results of this study provide good evidence for the validity of the pre-school sieve screening checklist (5-7) exposed to learning difficulties.Keywords: checklist, screening, preschoolers, learning difficulties
Procedia PDF Downloads 1022794 The Relationship between Public Relations and Media Relations: The Case of Hotel Enterprises
Authors: Burcu Oksuz, Volkan Altıintas, Zulfiye Acar Senturk
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Though in the academic literature, it is emphasized that Public Relations (PR) should not be seen only as media relations, in practise, the media relations has a very dominant position at the communication studies carried out by many companies. There are many PR practitioners who have journalism background. However the number of the practitioners who have started to work in the sector after having PR education at the universities has been highly increasing. Therefore, it can be said that previous journalist dominance has diminished at the public relations sector in Turkey. However, by virtue of the fact that some companies and practitioners consider the media coverage the first priority of PR, this much is certain that the dominant position of media relations is ongoing. On the other hand, still many companies measure the success of their PR by how much place their companies have taken. This situation creates major pressure on the PR practitioners to have close relations with the media members and to make them write articles about their companies. Thereupon, PR practitioners have to take the time for the media relations and the media relations comes into prominence more than the other PR functions. The aim of this study is to reveal the PR functions at the companies and to evaluate the position of the media relations in the PR studies. Therefore, it is aimed to find out at what extend the discourse of “Public relations is not media relations” is accepted in practice and actualised. Accordingly, a research about 15 hotel enterprises which are located in the city of İzmir will be carried out. İzmir as one of the most important tourism destinations has many hotels. The PR/corporate communications managers will be interviewed profoundly within the scope of this study and PR functions performed by hotels will be discussed in details in consideration of the datum obtained.Keywords: media relations, public relations, public relations practitioners, Turkey
Procedia PDF Downloads 3842793 Numerical Solutions of Fredholm Integral Equations by B-Spline Wavelet Method
Authors: Ritu Rani
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In this paper, we apply minimalistically upheld linear semi-orthogonal B-spline wavelets, exceptionally developed for the limited interim to rough the obscure function present in the integral equations. Semi-orthogonal wavelets utilizing B-spline uniquely developed for the limited interim and these wavelets can be spoken to in a shut frame. This gives a minimized help. Semi-orthogonal wavelets frame the premise in the space L²(R). Utilizing this premise, an arbitrary function in L²(R) can be communicated as the wavelet arrangement. For the limited interim, the wavelet arrangement cannot be totally introduced by utilizing this premise. This is on the grounds that backings of some premise are truncated at the left or right end purposes of the interim. Subsequently, an uncommon premise must be brought into the wavelet development on the limited interim. These functions are alluded to as the limit scaling functions and limit wavelet functions. B-spline wavelet method has been connected to fathom linear and nonlinear integral equations and their systems. The above method diminishes the integral equations to systems of algebraic equations and afterward these systems can be illuminated by any standard numerical methods. Here, we have connected Newton's method with suitable starting speculation for solving these systems.Keywords: semi-orthogonal, wavelet arrangement, integral equations, wavelet development
Procedia PDF Downloads 1742792 The Comparison of Physical Fitness across Age and Gender in the Lithuanian Primary School Students: Population-Based Cross-Sectional Study
Authors: Arunas Emeljanovas, Brigita Mieziene, Vida Cesnaitiene, Ingunn Fjortoft, Lise Kjonniksen
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Background: Gender differences in physical fitness were tracked in many studies with lower effect in preschool children and increasing difference among genders across age. In Lithuania, on a population level, secular trends in physical fitness were regularly observed each ten years for the last two decades for 11-18 years old students. However, there is apparently a lack of such epidemiological studies among primary school students. Assessing and monitoring physical fitness from an early age is of particular importance seeking to develop and strengthen physical abilities of youths for future health benefits. The goal of the current study was to indicate age and gender differences in anthropometric measures, musculoskeletal, motor and cardiorespiratory fitness in Lithuanian primary school children. Methods: The study included 3456 1-4th grade students from 6 to 10 years. The data reliably represents the population of primary school children in Lithuania. Among them, 1721 (49.8 percent) were boys. Physical fitness was measured by the 9-item test battery, developed by Fjørtoft and colleagues (2011). Height and weight were measured and body mass index was calculated. Student t test evaluated differences in physical fitness between boys and girls, ANOVA was performed to indicate differences across age. Results: All anthropometric and fitness means that were identified as significantly different were better in boys than in girls and in older than younger students (p < .05). Among anthropometric measures, height was higher in boys aged 7 through 9 years. Weight and BMI differed among boys and girls only at 8 years old. Means of height and weight increased significantly across all ages. Among musculoskeletal fitness tests, means of standing broad jump, throwing a tennis ball and pushing a medicine ball were different between genders within each age group and across all ages. Differences between genders were less likely in motor fitness than in musculoskeletal or cardiorespiratory fitness. Differences in means of shuttle run 10 x 5 test between genders occurred at age 6, 9 and 10 years; running 20 m at age 6 and 9 years, and climbing wall bars at age 9 and 10. Means of Reduced Cooper test representing cardiorespiratory fitness were different between genders within each age group but did not differ among age 6 and 8 as well as 7 and 8 years in boys, and among age 7 and 8 years in girls. Conclusion: In general, the current study confirms gender differences in musculoskeletal, motor and cardiorespiratory fitness found in other studies across the world in primary school and older children. Observed gender differences might be explained by higher physical activity in boys rather than girls. As it is explained by previous literature, older boys and girls had better performances than younger ones, because of the components of fitness change as a function of growth, maturation, development, and interactions among the three processes.Keywords: primary school children, motor fitness, musculoskeletal fitness, cardiovascular fitness
Procedia PDF Downloads 2082791 Some Considerations about the Theory of Spatial-Motor Thinking Applied to a Traditional Fife Band in Brazil
Authors: Murilo G. Mendes
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This text presents part of the results presented in the Ph.D. thesis that has used John Baily's theory and method as well as its ethnographic application in the context of the fife flutes of the Banda Cabaçal dos Irmãos Aniceto in the state of Ceará, northeast of Brazil. John Baily is a British ethnomusicologist dedicated to studying the relationships between music, musical gesture, and embodied cognition. His methodology became a useful tool to highlight historical-social aspects present in the group's instrumental music. Remaining indigenous and illiterate, these musicians played and transmitted their music from generation to generation, for almost two hundred years, without any nomenclature or systematization of the fingering performed on the flute. In other words, his music, free from any theorization, is learned, felt, perceived, and processed directly through hearing and through the relationship between the instrument's motor skills and its sound result. For this reason, Baily's assumptions became fundamental in the analysis processes. As the author's methodology recommends, classes were held with the natives and provided technical musical learning and some important concepts. Then, transcriptions and analyses of musical aspects were made from patterns of movement on the instrument incorporated by repetitions and/or by the intrinsic facility of the instrument. As a result, it was discovered how the group reconciled its indigenous origins with the demand requested by the public power and the interests of the local financial elite from the mid-twentieth century. The article is structured from the cultural context of the group, where local historical and social aspects influence the social and musical practices of the group. Then, will be present the methodological conceptions of John Baily and, finally, their application in the music of the Irmãos Aniceto. The conclusion points to the good results of identifying, through this methodology and analysis, approximations between discourse, historical-social factors, and musical text. Still, questions are raised about its application in other contexts.Keywords: Banda Cabaçal dos Irmãos Aniceto, John Baily, pífano, spatial-motor thinking
Procedia PDF Downloads 1352790 Special Properties of the Zeros of the Analytic Representations of Finite Quantum Systems
Authors: Muna Tabuni
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The paper contains an investigation on the special properties of the zeros of the analytic representations of finite quantum systems. These zeros and their paths completely define the finite quantum system. The present paper studies the construction of the analytic representation from its zeros. The analytic functions of finite quantum systems are introduced. The zeros of the analytic theta functions and their paths have been studied. The analytic function f(z) have exactly d zeros. The analytic function has been constructed from its zeros.Keywords: construction, analytic, representation, zeros
Procedia PDF Downloads 2072789 Burnback Analysis of Star Grain Using Level-Set Technique
Authors: Ali Yasin, Ali Kamran, Muhammad Safdar
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In order to reduce the hefty cost involved in terms of time and project cost, the development and application of advanced numerical tools to address the burn-back analysis problem in solid rocket motor design and development is the need of time. Several advanced numerical schemes have been developed in recent times, but their usage in the design of propellant grain of solid rocket motors is very rare. In this paper, an advanced numerical technique named the Level-Set method has been utilized for the burn-back analysis of star grain to study the effect of geometrical parameters on ballistic performance indicators such as solid loading, neutrality, and sliver percentage. In the level set technique, simple finite difference methods may fail quickly and require more sophisticated non-oscillatory schemes for feasible long-time simulation. For internal ballistic calculations, a simplified equilibrium pressure method is utilized. Preliminary results of the operative conditions, for all the combustion time, of star grain burn-back using level set techniques are compared with published results using CAD technique to test the developed numerical model.Keywords: solid rocket motor, internal ballistic, level-set technique, star grain
Procedia PDF Downloads 1232788 Field Oriented Control of Electrical Motor for Efficiency Improvement of Aerial Vehicle
Authors: Francois Defay
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Uses of Unmanned aerial vehicle (UAV) are increasing for many applicative cases. Long endurance UAVs are required for inspection or transportation in some deserted places. The global optimization of the efficiency is the aim of the works in ISAE-SUPAERO. From the propulsive part until the motor control, the global optimization can increase significantly the global efficiency. This paper deals with the global improvement of the efficiency of the electrical propulsion for the aerial vehicle. The application case of study is a small airplane of 2kg. A global modelization is presented in order to validate the electrical engine in a complete simulation from aerodynamics to battery. The classical control of the synchronous permanent drive is compared to the field-oriented control which is not yet applied for UAVs. The experimental results presented show an increase of more than 10 percent of the efficiency. A complete modelization and simulation based on Matlab/ Simulink are presented in this paper and compared to the experimental study. Finally this paper presents solutions to increase the endurance of the electrical aerial vehicle and provide models to optimize the global consumption for a specific mission. The next step is to use this model and the control to work with distributed propulsion which is the future for small distance plane.Keywords: electrical propulsion, endurance, field-oriented control, UAV
Procedia PDF Downloads 2372787 An Application of Meta-Modeling Methods for Surrogating Lateral Dynamics Simulation in Layout-Optimization for Electric Drivetrains
Authors: Christian Angerer, Markus Lienkamp
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Electric vehicles offer a high variety of possible drivetrain topologies with up to 4 motors. Multi-motor-designs can have several advantages regarding traction, vehicle dynamics, safety and even efficiency. With a rising number of motors, the whole drivetrain becomes more complex. All permutations of gearings, drivetrain-layouts, motor-types and –sizes lead up in a very large solution space. Single elements of this solution space can be analyzed by simulation methods. In addition to longitudinal vehicle behavior, which most optimization-approaches are restricted to, also lateral dynamics are important for vehicle dynamics, stability and efficiency. In order to compete large solution spaces and to find an optimal result, genetic algorithm based optimization is state-of-the-art. As lateral dynamics simulation is way more CPU-intensive, optimization takes much more time than in case of longitudinal-only simulation. Therefore, this paper shows an approach how to create meta-models from a 14-degree of freedom vehicle model in order to enable a numerically efficient drivetrain-layout optimization process under consideration of lateral dynamics. Different meta-modelling approaches such as neural networks or DoE are implemented and comparatively discussed.Keywords: driving dynamics, drivetrain layout, genetic optimization, meta-modeling, lateral dynamicx
Procedia PDF Downloads 4172786 Monte Carlo Pathwise Sensitivities for Barrier Options with Application to Coco-Bond Calibration
Authors: Thomas Gerstner, Bastian von Harrach, Daniel Roth
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The Monte Carlo pathwise sensitivities approach is well established for smooth payoff functions. In this work, we present a new Monte Carlo algorithm that is able to calculate the pathwise sensitivities for discontinuous payoff functions. Our main tool is the one-step survival idea of Glasserman and Staum. Although this technique yields to new terms per observation, while differentiating, the algorithm is still efficient. As an application, we use the results for a two-dimensional calibration of a Coco-Bond, which we model with different types of discretely monitored barrier options.Keywords: Monte Carlo, discretely monitored barrier options, pathwise sensitivities, Coco-Bond
Procedia PDF Downloads 3582785 Interlanguage Acquisition of a Postposition ‘e’ in Korean: Analysis of the Korean Novice Learners’ Output
Authors: Eunjung Lee
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This study aims to analyze the sentences generated by the beginners who learn ‘e,’ a postposition in Korean and to find out the regularity of learners’ interlanguage upon investigating the usages of ‘e’ that appears by meanings and functions in their interlanguage, and conditions that ‘e’ is used. This study was conducted with mainly two assumptions; first, the learner’s language has the specific type of interlanguage; and second, there is the regularity of interlanguage when students produce ‘e’ under the specific conditions. Learners’ output has various values and can be used as the useful data to understand interlanguage. Therefore, all the sentences containing a postposition ‘e’ by English speaking learners were searched in ‘Learners’ corpus sharing center in The National Institute of Korean Language’ in Korea, and the data were collected upon limiting the levels of learners with Level 1 and 2. 789 sentences that were used with ‘e’ were selected as the final subjects of the analysis. First, to understand the environmental characteristics to be used with a postposition, ‘e’ after summarizing 13 meaning and functions of ‘e’ appeared in three books of Korean dictionary that summarized the Korean grammar, 1) meaning function of ‘e’ that were used in each sentence was classified; 2) the nouns that were combined with ‘e,’ keywords of the sentences, and the characteristics of modifiers, linkers, and predicates appeared in front of ‘e’ were analyzed; 3) the regularity by the novice learners’ meaning and functions were reviewed; and 4) the differences of the regularity by level 1 and 2 learners’ meaning and functions were found. Upon the study results, the novice learners showed 1) they used the nouns related to ‘time(시간), before(전), after(후), next(다음), the next(그다음), then(때), day of the week(요일), and season(계절)’ mainly in front of ‘e’ when they used ‘e’ as the meaning function of time; 2) they used mainly the verbs of ‘go(가다),’ ‘come(오다),’ and ‘go round(다니다)’ as the predicate to match with ‘e’ that was the meaning function of direction and destination; and 3) they used mainly the nouns related to ‘locations or countries’ in front of ‘e,’ a meaning function postposition of ‘place,’ used mainly the verbs ‘be(있다), not be(없다), live(살다), be many(많다)’ after ‘e,’ and ‘i(이) or ka(가)’ was combined mainly in the subject words in case of ‘be(있다), not be(없다)’ or ‘be many(많다),’ and ‘eun(은) or nun(는)’ was combined mainly in the subject words in front of ‘live at’ In addition, 4) they used ‘e’ which indicates ‘cause or reason’ in the form of ‘because( 때문에),’ and 5) used ‘e’ of the subjects as the predicates to match with the predicates such as ‘treat(대하다), like(들다), and catch(걸리다).’ From these results, ‘e’ usage patterns of the Korean novice learners demonstrated very differently by the meaning functions and the learners’ interlanguage regularity could be deducted. However, little difference was found in interlanguage regularity between level 1 and 2. This study has the meaning to try to understand the interlanguage system and regularity in the learners’ acquisition process of postposition ‘e’ and this can be utilized to lessen their errors.Keywords: interlanguage, interlagnage anaylsis, postposition ‘e’, Korean acquisition
Procedia PDF Downloads 1292784 Some Basic Problems for the Elastic Material with Voids in the Case of Approximation N=1 of Vekua's Theory
Authors: Bakur Gulua
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In this work, we consider some boundary value problems for the plate. The plate is the elastic material with voids. The state of plate equilibrium is described by the system of differential equations that is derived from three-dimensional equations of equilibrium of an elastic material with voids (Cowin-Nunziato model) by Vekua's reduction method. Its general solution is represented by means of analytic functions of a complex variable and solutions of Helmholtz equations. The problem is solved analytically by the method of the theory of functions of a complex variable.Keywords: the elastic material with voids, boundary value problems, Vekua's reduction method, a complex variable
Procedia PDF Downloads 1272783 Tool for Analysing the Sensitivity and Tolerance of Mechatronic Systems in Matlab GUI
Authors: Bohuslava Juhasova, Martin Juhas, Renata Masarova, Zuzana Sutova
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The article deals with the tool in Matlab GUI form that is designed to analyse a mechatronic system sensitivity and tolerance. In the analysed mechatronic system, a torque is transferred from the drive to the load through a coupling containing flexible elements. Different methods of control system design are used. The classic form of the feedback control is proposed using Naslin method, modulus optimum criterion and inverse dynamics method. The cascade form of the control is proposed based on combination of modulus optimum criterion and symmetric optimum criterion. The sensitivity is analysed on the basis of absolute and relative sensitivity of system function to the change of chosen parameter value of the mechatronic system, as well as the control subsystem. The tolerance is analysed in the form of determining the range of allowed relative changes of selected system parameters in the field of system stability. The tool allows to analyse an influence of torsion stiffness, torsion damping, inertia moments of the motor and the load and controller(s) parameters. The sensitivity and tolerance are monitored in terms of the impact of parameter change on the response in the form of system step response and system frequency-response logarithmic characteristics. The Symbolic Math Toolbox for expression of the final shape of analysed system functions was used. The sensitivity and tolerance are graphically represented as 2D graph of sensitivity or tolerance of the system function and 3D/2D static/interactive graph of step/frequency response.Keywords: mechatronic systems, Matlab GUI, sensitivity, tolerance
Procedia PDF Downloads 4332782 Aging Evaluation of Ammonium Perchlorate/Hydroxyl Terminated Polybutadiene-Based Solid Rocket Engine by Reactive Molecular Dynamics Simulation and Thermal Analysis
Authors: R. F. B. Gonçalves, E. N. Iwama, J. A. F. F. Rocco, K. Iha
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Propellants based on Hydroxyl Terminated Polybutadiene/Ammonium Perchlorate (HTPB/AP) are the most commonly used in most of the rocket engines used by the Brazilian Armed Forces. This work aimed at the possibility of extending its useful life (currently in 10 years) by performing kinetic-chemical analyzes of its energetic material via Differential Scanning Calorimetry (DSC) and also performing computer simulation of aging process using the software Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS). Thermal analysis via DSC was performed in triplicates and in three heating ratios (5 ºC, 10 ºC, and 15 ºC) of rocket motor with 11 years shelf-life, using the Arrhenius equation to obtain its activation energy, using Ozawa and Kissinger kinetic methods, allowing comparison with manufacturing period data (standard motor). In addition, the kinetic parameters of internal pressure of the combustion chamber in 08 rocket engines with 11 years of shelf-life were also acquired, for comparison purposes with the engine start-up data.Keywords: shelf-life, thermal analysis, Ozawa method, Kissinger method, LAMMPS software, thrust
Procedia PDF Downloads 1272781 Identifying Psychosocial, Autonomic, and Pain Sensitivity Risk Factors of Chronic Temporomandibular Disorder by Using Ridge Logistic Regression and Bootstrapping
Authors: Haolin Li, Eric Bair, Jane Monaco, Quefeng Li
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The temporomandibular disorder (TMD) is a series of musculoskeletal disorders ranging from jaw pain to chronic debilitating pain, and the risk factors for the onset and maintenance of TMD are still unclear. Prior researches have shown that the potential risk factors for chronic TMD are related to psychosocial factors, autonomic functions, and pain sensitivity. Using data from the Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) study’s baseline case-control study, we examine whether the risk factors identified by prior researches are still statistically significant after taking all of the risk measures into account in one single model, and we also compare the relative influences of the risk factors in three different perspectives (psychosocial factors, autonomic functions, and pain sensitivity) on the chronic TMD. The statistical analysis is conducted by using ridge logistic regression and bootstrapping, in which the performance of the algorithms has been assessed using extensive simulation studies. The results support most of the findings of prior researches that there are many psychosocial and pain sensitivity measures that have significant associations with chronic TMD. However, it is surprising that most of the risk factors of autonomic functions have not presented significant associations with chronic TMD, as described by a prior research.Keywords: autonomic function, OPPERA study, pain sensitivity, psychosocial measures, temporomandibular disorder
Procedia PDF Downloads 1882780 Currency Exchange Rate Forecasts Using Quantile Regression
Authors: Yuzhi Cai
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In this paper, we discuss a Bayesian approach to quantile autoregressive (QAR) time series model estimation and forecasting. Together with a combining forecasts technique, we then predict USD to GBP currency exchange rates. Combined forecasts contain all the information captured by the fitted QAR models at different quantile levels and are therefore better than those obtained from individual models. Our results show that an unequally weighted combining method performs better than other forecasting methodology. We found that a median AR model can perform well in point forecasting when the predictive density functions are symmetric. However, in practice, using the median AR model alone may involve the loss of information about the data captured by other QAR models. We recommend that combined forecasts should be used whenever possible.Keywords: combining forecasts, MCMC, predictive density functions, quantile forecasting, quantile modelling
Procedia PDF Downloads 2562779 Matrix Valued Difference Equations with Spectral Singularities
Authors: Serifenur Cebesoy, Yelda Aygar, Elgiz Bairamov
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In this study, we examine some spectral properties of non-selfadjoint matrix-valued difference equations consisting of a polynomial type Jost solution. The aim of this study is to investigate the eigenvalues and spectral singularities of the difference operator L which is expressed by the above-mentioned difference equation. Firstly, thanks to the representation of polynomial type Jost solution of this equation, we obtain asymptotics and some analytical properties. Then, using the uniqueness theorems of analytic functions, we guarantee that the operator L has a finite number of eigenvalues and spectral singularities.Keywords: asymptotics, continuous spectrum, difference equations, eigenvalues, jost functions, spectral singularities
Procedia PDF Downloads 4462778 Concepts of Instrumentation Scheme for Thought Transfer
Authors: Rai Sachindra Prasad
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Thought is physical force. This has been well recognized but hardly translated visually or otherwise in the sense of its transfer from one individual to another. In the present world of chaos and disorder with yawning gaps between right and wrong thinking individuals, if it is possible to transfer the right thoughts to replace the wrong ones it would indeed be a great achievement in the present situation of the world which is torn with violence with dangerous thoughts of individuals. Moreover, such a possibility would completely remove the barrier of language between two persons, which at times proves to be a great obstacle in realizing a desired purpose. If a proper instrumentation scheme containing appropriate transducers and electronics is designed and implemented to realize this thought ransfer phenomenon, this would prove to be extremely useful when properly used. Considering the advancements already made in recording the nerve impulses in the brain, which are electrical events of very short durations that move along the axon, it is conceivable that this may be used to good effect in implementing the scheme. In such a proposition one shoud consider the roles played by pineal body, pituitary gland and ‘association’ areas. Pioneer students of brain have thought that associations or connections between sensory input and motor output were made in these areas. It is currently believed that rather than being regions of simple sensory-motor connections, the association areas process and integrate sensory information relayed to them from the primary sensory areas of the cortex and from the thalamus, after the information has been processed, it may be sent to motor areas to be acted upon. Again, even though the role played by pineal body is not known fully to neurologists its interconnection with pituitary gland is a matter of great significance to the ‘Rishis’ and; Seers’ s described in Vedas and Puranas- the ancient Holy books of Hindus. If the pineal body is activated through meditation it would control the pituitary gland thereby the individual’s thoughts and acts. Thus, if thoughts can be picked up by special transducers, these can be connected to suitable electronics circuitry to amplify the signals. These signals in the form of electromagnetic waves can then be transmitted using modems for long distance transmission and eventually received by or passed on to a subject of interest through another set of electronics circuit and devices.Keywords: modems, pituitary gland, pineal body, thought transfer
Procedia PDF Downloads 3722777 Second Order Optimality Conditions in Nonsmooth Analysis on Riemannian Manifolds
Authors: Seyedehsomayeh Hosseini
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Much attention has been paid over centuries to understanding and solving the problem of minimization of functions. Compared to linear programming and nonlinear unconstrained optimization problems, nonlinear constrained optimization problems are much more difficult. Since the procedure of finding an optimizer is a search based on the local information of the constraints and the objective function, it is very important to develop techniques using geometric properties of the constraints and the objective function. In fact, differential geometry provides a powerful tool to characterize and analyze these geometric properties. Thus, there is clearly a link between the techniques of optimization on manifolds and standard constrained optimization approaches. Furthermore, there are manifolds that are not defined as constrained sets in R^n an important example is the Grassmann manifolds. Hence, to solve optimization problems on these spaces, intrinsic methods are used. In a nondifferentiable problem, the gradient information of the objective function generally cannot be used to determine the direction in which the function is decreasing. Therefore, techniques of nonsmooth analysis are needed to deal with such a problem. As a manifold, in general, does not have a linear structure, the usual techniques, which are often used in nonsmooth analysis on linear spaces, cannot be applied and new techniques need to be developed. This paper presents necessary and sufficient conditions for a strict local minimum of extended real-valued, nonsmooth functions defined on Riemannian manifolds.Keywords: Riemannian manifolds, nonsmooth optimization, lower semicontinuous functions, subdifferential
Procedia PDF Downloads 361