Search results for: large language models
6555 Multimodal Direct Neural Network Positron Emission Tomography Reconstruction
Authors: William Whiteley, Jens Gregor
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In recent developments of direct neural network based positron emission tomography (PET) reconstruction, two prominent architectures have emerged for converting measurement data into images: 1) networks that contain fully-connected layers; and 2) networks that primarily use a convolutional encoder-decoder architecture. In this paper, we present a multi-modal direct PET reconstruction method called MDPET, which is a hybrid approach that combines the advantages of both types of networks. MDPET processes raw data in the form of sinograms and histo-images in concert with attenuation maps to produce high quality multi-slice PET images (e.g., 8x440x440). MDPET is trained on a large whole-body patient data set and evaluated both quantitatively and qualitatively against target images reconstructed with the standard PET reconstruction benchmark of iterative ordered subsets expectation maximization. The results show that MDPET outperforms the best previously published direct neural network methods in measures of bias, signal-to-noise ratio, mean absolute error, and structural similarity.Keywords: deep learning, image reconstruction, machine learning, neural network, positron emission tomography
Procedia PDF Downloads 956554 Aeroelastic Analysis of Engine Nacelle Strake Considering Geometric Nonlinear Behavior
Authors: N. Manoj
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The aeroelastic behavior of engine nacelle strake when subjected to unsteady aerodynamic flows is investigated in this paper. Geometric nonlinear characteristics and modal parameters of nacelle strake are studied when it is under dynamic loading condition. Here, an N-S based Finite Volume solver is coupled with Finite Element (FE) based nonlinear structural solver to investigate the nonlinear characteristics of nacelle strake over a range of dynamic pressures at various phases of flight like takeoff, climb, and cruise conditions. The combination of high fidelity models for both aerodynamics and structural dynamics is used to predict the nonlinearities of strake (chine). The methodology adopted for present aeroelastic analysis is partitioned-based time domain coupled CFD and CSD solvers and it is validated by the consideration of experimental and numerical comparison of aeroelastic data for a cropped delta wing model which has a proven record. The present strake geometry is derived from theoretical formulation. The amplitude and frequency obtained from the coupled solver at various dynamic pressures is discussed, which gives a better understanding of its impact on aerodynamic design-sizing of strake.Keywords: aeroelasticity, finite volume, geometric nonlinearity, limit cycle oscillations, strake
Procedia PDF Downloads 2776553 Comparison of Johnson-Cook and Barlat Material Model for 316L Stainless Steel
Authors: Yiğit Gürler, İbrahim Şimşek, Müge Savaştaer, Ayberk Karakuş, Alper Taşdemirci
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316L steel is frequently used in the industry due to its easy formability and accessibility in sheet metal forming processes. Numerical and experimental studies are frequently encountered in the literature to examine the mechanical behavior of 316L stainless steel during the forming process. 316L stainless steel is the most common material used in the production of plate heat exchangers and plate heat exchangers are produced by plastic deformation of the stainless steel. The motivation in this study is to determine the appropriate material model during the simulation of the sheet metal forming process. For this reason, two different material models were examined and Ls-Dyna material cards were created using material test data. These are MAT133_BARLAT_YLD2000 and MAT093_SIMPLIFIED_JOHNSON_COOK. In order to compare results of the tensile test & hydraulic bulge test performed both numerically and experimentally. The obtained results were evaluated comparatively and the most suitable material model was selected for the forming simulation. In future studies, this material model will be used in the numerical modeling of the sheet metal forming process.Keywords: 316L, mechanical characterization, metal forming, Ls-Dyna
Procedia PDF Downloads 3056552 An Analysis of the Results of Trial Blasting of Site Development Project in the Volcanic Island
Authors: Dong Wook Lee, Seung Hyun Kim
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Trial blasting is conducted to identify the characteristics of the blasting of the applicable ground before production blasting and to investigate various problems posed by blasting. The methods and pattern of production blasting are determined based on an analysis of the results of trial blasting. The bedrock in Jeju Island, South Korea is formed through the volcanic activities unlike the inland areas, composed of porous basalt. Trial blasting showed that the blast vibration frequency of sedimentary and metamorphic rocks in the inland areas is in a high frequency band of about 80 Hz while the blast vibration frequency of Jeju Island is in a low frequency band of 10~25 Hz. The frequency band is analyzed to be low due to the large cycle of blasting pattern as blast vibration passes through the layered structured ground layer where the rock formation and clickers irregularly repeat. In addition, the blast vibration equation derived from trial blasting was R: 0.885, S.E: 0.216 when applying the square root scaled distance (SRSD) relatively suitable for long distance, estimated at the confidence level of 95%.Keywords: attenuation index, basaltic ground, blast vibration constant, blast vibration equation, clinker layer
Procedia PDF Downloads 2696551 Production of Plum (Prunus Cerasifera) Concentrate as Edible Color and Evaluation of Color Change Kinetics
Authors: Azade Ghorbani-HasanSaraei, Seyed-Ahmad Shahidi, Sakineh Alizadeh, Adeleh Maghsoudlou
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Improvement of color, as a quality attribute of Plum Concentrate, has been made possible by the increase in knowledge of kinetic of color change. Three different heating/evaporation processes were employed for the production of pPlum juice concentrate. The Plum juice was concentrated to a final 55 °Bx from an initial °Bx of 15 by microwave heating, rotary vacuum evaporator and evaporating at atmospheric pressure. The final Plum juice concentration of 55 °Bx was achieved in 17, 24 and 57 min by using the microwave, rotary vacuum and atmospheric heating processes, respectively. The colour change during concentration processes was investigated. Total colour differences, Hunter L, a and b parameters were used to estimate the extent of colour loss. All Hunter colour parameters decreased with time. The zero-order, first-order and a combined kinetics model were applied to the changes in colour parameters. Results indicated that variation in TCD followed both first-order and combined kinetics models, and parameters L, a and b followed only combined model. This model implied that the colour formation and pigment destruction occurred during concentration processes of plum juice.Keywords: colour, kinetics, concentration, plum juice
Procedia PDF Downloads 5056550 Development of Swing Valve for Gasoline Turbocharger Using Hybrid Metal Injection Molding
Authors: B. S. So, Y. H. Yoon, J. O. Jung, K. S. Bae
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Metal Injection Molding (MIM) is a technology that combines powder metallurgy and injection molding. Particularly, it is widely applied to the manufacture of precision mobile parts and automobile turbocharger parts because compact precision parts with complicated three-dimensional shapes that are difficult to machining are formed into a large number of finished products. The swing valve is a valve that adjusts the boost pressure of the turbocharger. Since the head portion is exposed to the harsh temperature condition of about 900 degrees in the gasoline GDI engine, it is necessary to use Inconel material with excellent heat resistance and abrasion resistance, resulting in high manufacturing cost. In this study, we developed a swing valve using a metal powder injection molding based hybrid material (Inconel 713C material with heat resistance is applied to the head part, and HK30 material with low price is applied to the rest of the body part). For this purpose, the process conditions of the metal injection molding were optimized to minimize the internal defects, and the effectiveness was confirmed by the fracture strength and fatigue test.Keywords: hybrid metal injection molding, swing valve, turbocharger, double injection
Procedia PDF Downloads 1996549 Parental Negative Emotional States, Parenting Style and Child Emotional and Behavioural Problems: Australia-Indonesia Cross-Cultural Study
Authors: Yulina E. Riany, Divna Haslam, Matthew Sanders
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This cross-cultural study aims to compare the level of parental depression and stress, parenting style use, and child emotional and behavioural problems between parents in Australia as an example of a Western country and parents in Indonesia as an example of Asian culture. A series of hierarchical regressions were undertaken to determine two models examining the factors that predict child problems residing in Australia (Model 1) and in Indonesia (Model 2). The online survey was completed by 179 parents in Australia and 448 parents in Indonesia. Results indicated that Australian parents reported higher levels of depression, authoritative parenting and higher levels of child misbehaviours compared to Indonesian parents. In comparison, Indonesian parents reported higher authoritarian parenting. Analyses performed to examine Model 1 and 2 revealed that parental negative emotional states and parenting style predicted child emotional and behavioural problems in both countries.Keywords: cross-cutural study, parental stress, parenting, child misbehaviour
Procedia PDF Downloads 1046548 Using the Nonlocal Theory of Free Vibrations Nanobeam
Authors: Ali Oveysi Sarabi
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The dimensions of nanostructures are in the range of inter-atomic spacing of the structures which makes them impossible to be modeled as a continuum. Nanoscale size-effects on vibration analysis of nanobeams embedded in an elastic medium is investigated using different types of beam theory. To this end, Eringen’s nonlocal elasticity is incorporated to various beam theories namely as Euler-Bernoulli beam theory (EBT), Timoshenko beam theory (TBT), Reddy beam theory (RBT), and Levinson beam theory (LBT). The surrounding elastic medium is simulated with both Winkler and Pasternak foundation models and the difference between them is studies. Explicit formulas are presented to obtain the natural frequencies of nanobeam corresponding to each nonlocal beam theory. Selected numerical results are given for different values of the non-local parameter, Winkler modulus parameter, Pasternak modulus parameter and aspect ratio of the beam that imply the effects of them, separately. It is observed that the values of natural frequency are strongly dependent on the stiffness of elastic medium and the value of the non-local parameter and these dependencies varies with the value of aspect ratio and mode number.Keywords: nanobeams, free vibration, nonlocal elasticity, winkler foundation model, Pasternak foundation model, beam theories
Procedia PDF Downloads 5226547 Modernity and Domestic Space in the Feminist Utopias of Herland and Sultana’s Dream
Authors: Nudrat Kamal
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Scholarship exploring the development of the literary tradition of feminist utopias, especially in the sociopolitical context of Europe and North America, has been important and meaningful, but it is, in large part, still restricted to Euro-American texts. This paper will explore Charlotte Perkins Gilman’s feminist utopia Herland (1915) with another feminist utopia written just a decade before, but in a widely different sociopolitical context: Bengali feminist writer Rokeya Sakhawat Hossain’s English short story Sultana’s Dream (1905). The paper will argue that both texts, despite being written in such different cultural and historical contexts, utilize and subvert the public versus private/domestic sphere dichotomy and the restricted gender roles associated with each sphere in order to conceive of specific formulations of feminist modernities that reflect the sociopolitical contexts and feminist movements both writers were writing within. By bringing Gilman’s Herland into conversation with Hossain’s Sultana’s Dream, the paper hopes to illuminate the new meanings that might emerge if the scholarship on Western feminist utopias was to open itself up to the feminist utopias written elsewhere.Keywords: comparative literature, feminist utopias, modernity, South Asian literature, utopias
Procedia PDF Downloads 2176546 Application of Data Mining Techniques for Tourism Knowledge Discovery
Authors: Teklu Urgessa, Wookjae Maeng, Joong Seek Lee
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Application of five implementations of three data mining classification techniques was experimented for extracting important insights from tourism data. The aim was to find out the best performing algorithm among the compared ones for tourism knowledge discovery. Knowledge discovery process from data was used as a process model. 10-fold cross validation method is used for testing purpose. Various data preprocessing activities were performed to get the final dataset for model building. Classification models of the selected algorithms were built with different scenarios on the preprocessed dataset. The outperformed algorithm tourism dataset was Random Forest (76%) before applying information gain based attribute selection and J48 (C4.5) (75%) after selection of top relevant attributes to the class (target) attribute. In terms of time for model building, attribute selection improves the efficiency of all algorithms. Artificial Neural Network (multilayer perceptron) showed the highest improvement (90%). The rules extracted from the decision tree model are presented, which showed intricate, non-trivial knowledge/insight that would otherwise not be discovered by simple statistical analysis with mediocre accuracy of the machine using classification algorithms.Keywords: classification algorithms, data mining, knowledge discovery, tourism
Procedia PDF Downloads 2796545 Cultural Adjustment Problems in Academic and Social Life Experienced by Indonesian Postgraduate Students Studying in London
Authors: Erizal Lugman
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An increasing number of students from Indonesia study in universities in the UK. Because of the substantial cultural differences between the Western and Indonesian cultures, this study investigates the issues in academic and social life experienced by Indonesian postgraduate students, with a sample of 11 Indonesian postgraduate students (8 male, 3 female) studying in London during the cultural adjustment stage. This research made use of a semi-structured interview and was analyzed qualitatively using thematic content analysis to reveal key areas of concern in the academic setting, social life, and language-related issues. The findings confirm that the most challenging aspects experienced by the participants are the use of academic English in academic situations and the students’ lack of critical thinking. Nine out of 11 students agreed that they had problems with writing essays during the cultural adjustment stage. Because of the collectivist culture in Indonesia, making friends with locals was the most concerning issue in the participants’ sociocultural adjustment, followed by difficulty in finding places to pray, looking for Halal food and using the Western toilet system The findings suggest recommendations that the students must be more aware of the cultural differences between Indonesian and Western cultures, including in the academic setting and social life. Also, the lecturers should pay more attention to their speech in the British accent which is sometimes difficult to understand.Keywords: academic adjustment, cultural adjustment, indonesian culture, intercultural communication
Procedia PDF Downloads 1256544 The Quality of Life of Transtibial Amputees: The Prosthetists Role
Authors: Riyona Chetty, Raisuyah Bhagwan, Nalini Govender
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Background: During rehabilitation, the prosthetist establishes prosthetic and/or orthotic realistic goals and programmes as well as clinical outcome measures. They are well-positioned to improve the amputee’s physical and psychosocial well-being. Objective: This study aims to explore the ways in which the prosthetist may be able to improve the holistic well-being of the amputee. Methods: Data was collected using a focus group discussion with 16 prosthetists at a medical facility in KwaZulu-Natal, South Africa. Results: The findings indicate that amputees are encouraged to consider physical activities to improve their health. However, a major challenge experienced by the prosthetists was their lack of adequate psychosocial expertise, which affected their ability to offer emotional support. Additional factors such as language barriers, rotational systems, and unrealistic expectations further obstructed optimal service delivery. Conclusion: The prosthetists are adequately skilled in manufacturing the ideal prosthesis and encouraging physical exercise to promote the amputee’s physical health. However, their lack of psychosocial training limits them in providing emotional support during rehabilitation. It is recommended that prosthetists are provided with professional training to provide emotional support as part of holistic healthcare. Clinical relevance: The intention of this study was to provide pertinent recommendations for prosthetists, enabling them to provide holistic quality care to their patients.Keywords: psychological, social, well-being, amputee, prosthetist
Procedia PDF Downloads 296543 Quantum Decision Making with Small Sample for Network Monitoring and Control
Authors: Tatsuya Otoshi, Masayuki Murata
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With the development and diversification of applications on the Internet, applications that require high responsiveness, such as video streaming, are becoming mainstream. Application responsiveness is not only a matter of communication delay but also a matter of time required to grasp changes in network conditions. The tradeoff between accuracy and measurement time is a challenge in network control. We people make countless decisions all the time, and our decisions seem to resolve tradeoffs between time and accuracy. When making decisions, people are known to make appropriate choices based on relatively small samples. Although there have been various studies on models of human decision-making, a model that integrates various cognitive biases, called ”quantum decision-making,” has recently attracted much attention. However, the modeling of small samples has not been examined much so far. In this paper, we extend the model of quantum decision-making to model decision-making with a small sample. In the proposed model, the state is updated by value-based probability amplitude amplification. By analytically obtaining a lower bound on the number of samples required for decision-making, we show that decision-making with a small number of samples is feasible.Keywords: quantum decision making, small sample, MPEG-DASH, Grover's algorithm
Procedia PDF Downloads 626542 Procyclicality of Leverage: An Empirical Analysis from Turkish Banks
Authors: Emin Avcı, Çiydem Çatak
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The recent economic crisis have shown that procyclicality, which could threaten the stability and growth of the economy, is a major problem of financial and real sector. The term procyclicality refers here the cyclical behavior of banks that lead them to follow the same patterns as the real economy. In this study, leverage which demonstrate how a bank manage its debt, is chosen as bank specific variable to see the effect of changes in it over the economic cycle. The procyclical behavior of Turkish banking sector (commercial, participation, development-investment banks) is tried to explain with analyzing the relationship between leverage and asset growth. On the basis of theoretical explanations, eight different leverage ratios are utilized in eight different panel data models to demonstrate the procyclicality effect of Turkish banks leverage using monthly data covering the 2005-2014 period. It is tested whether there is an increasing (decreasing) trend in the leverage ratio of Turkish banks when there is an enlargement (contraction) in their balance sheet. The major finding of the study indicates that asset growth has a significant effect on all eight leverage ratios. In other words, the leverage of Turkish banks follow a cyclical pattern, which is in line with those of earlier literature.Keywords: banking, economic cycles, leverage, procyclicality
Procedia PDF Downloads 2506541 Optimizing the Efficiency of Measuring Instruments in Ouagadougou-Burkina Faso
Authors: Moses Emetere, Marvel Akinyemi, S. E. Sanni
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At the moment, AERONET or AMMA database shows a large volume of data loss. With only about 47% data set available to the scientist, it is evident that accurate nowcast or forecast cannot be guaranteed. The calibration constants of most radiosonde or weather stations are not compatible with the atmospheric conditions of the West African climate. A dispersion model was developed to incorporate salient mathematical representations like a Unified number. The Unified number was derived to describe the turbulence of the aerosols transport in the frictional layer of the lower atmosphere. Fourteen years data set from Multi-angle Imaging SpectroRadiometer (MISR) was tested using the dispersion model. A yearly estimation of the atmospheric constants over Ouagadougou using the model was obtained with about 87.5% accuracy. It further revealed that the average atmospheric constant for Ouagadougou-Niger is a_1 = 0.626, a_2 = 0.7999 and the tuning constants is n_1 = 0.09835 and n_2 = 0.266. Also, the yearly atmospheric constants affirmed the lower atmosphere of Ouagadougou is very dynamic. Hence, it is recommended that radiosonde and weather station manufacturers should constantly review the atmospheric constant over a geographical location to enable about eighty percent data retrieval.Keywords: aerosols retention, aerosols loading, statistics, analytical technique
Procedia PDF Downloads 2956540 Desired Flow of Radioactive Materials from Logistics Service Quality Perspective
Authors: Tuğçe Yavaş Akış
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In recent years, due to an increased use of radioactive materials, radioactive sources are constantly being transported via air, road and ocean ways for medical, industrial, research etc. purposes throughout the world. The quantity of radioactive materials transported all around the world varies from negligible quantities in shipments of consumer products to very large quantities in shipments of irradiated nuclear fuel. Radioactive materials have been less attractive for social science researchers in literature. In this study, it is aimed to discover desired flow of radioactive materials from logistics service quality (LSQ) perspective. In doing so, case study approach will be employed by using secondary data collected from one of the world’s leading transportation companies’ customer care system reports. Movement of radioactive cargoes containing IR-192 and logistics process will be analyzed with the help of logistics service quality dimensions. Based on the case study that will be conducted, interaction between dimensions, the importance of each dimension in desired flow, and their relevance with desired flow of radioactive materials will be explained. This study will bring out the desired flow of radioactive materials transportation and be a guide for all other companies, employees and researchers.Keywords: logistics service quality, LSQ dimension , radioactive material, transportation
Procedia PDF Downloads 2186539 Evaluating Factors Influencing Information Quality in Large Firms
Authors: B. E. Narkhede, S. K. Mahajan, B. T. Patil, R. D. Raut
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Information quality is a major performance measure for an Enterprise Resource Planning (ERP) system of any firm. This study identifies various critical success factors of information quality. The effect of various critical success factors like project management, reengineering efforts and interdepartmental communications on information quality is analyzed using a multiple regression model. Here quantitative data are collected from respondents from various firms through structured questionnaire for assessment of the information quality, project management, reengineering efforts and interdepartmental communications. The validity and reliability of the data are ensured using techniques like factor analysis, computing of Cronbach’s alpha. This study gives relative importance of each of the critical success factors. The findings suggest that among the various factors influencing information quality careful reengineering efforts are the most influencing factor. This paper gives clear insight to managers and practitioners regarding the relative importance of critical success factors influencing information quality so that they can formulate a strategy at the beginning of ERP system implementation.Keywords: Enterprise Resource Planning (ERP), information systems (IS), multiple regression, information quality
Procedia PDF Downloads 3126538 Experimental and Numerical Analysis of the Effects of Ball-End Milling Process upon Residual Stresses and Cutting Forces
Authors: Belkacem Chebil Sonia, Bensalem Wacef
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The majority of ball end milling models includes only the influence of cutting parameters (cutting speed, feed rate, depth of cut). Furthermore, this influence is studied in most of works on cutting force. Therefore, this study proposes an accurate ball end milling process modeling which includes also the influence of tool workpiece inclination. In addition, a characterization of residual stresses resulting of thermo mechanical loading in the workpiece was also presented. Moreover, the study of the influence of tool workpiece inclination and cutting parameters was made on residual stresses distribution. In order to achieve the predetermination of cutting forces and residual stresses during a milling operation, a thermo mechanical three-dimensional numerical model of ball end milling was developed. Furthermore, an experimental companion of ball end milling tests was realized on a 5-axis machining center to determine the cutting forces and characterize the residual stresses. The simulation results are compared with the experiment to validate the Finite Element Model and subsequently identify the optimum inclination angle and cutting parameters.Keywords: ball end milling, cutting forces, cutting parameters, residual stress, tool-workpiece inclination
Procedia PDF Downloads 2936537 Phytochemical and Biological Study of Chrozophora oblongifolia
Authors: Al-Braa Kashegari, Ali M. El-Halawany, Akram A. Shalabi, Sabrin R. M. Ibrahim, Hossam M. Abdallah
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Chemical investigation of Chrozophora oblongifolia resulted in the isolation of five major compounds that were identified as apeginin-7-O-glucoside (1), quercetin-3-O-glucuronic acid (2), quercetin-3-O-glacturonic acid (3), rutin (4), and 1,3,6-trigalloyl glucose (5). The identity of isolated compounds was assessed by different spectroscopic methods, including one- and two-dimensional NMR. The isolated compounds were tested for their antioxidant activity using different assays viz., DPPH, FRAP, ABTS, ORAC, and metal chelation effects. In addition, the inhibition of target enzymes involved in the metabolic syndrome, such as alpha-glucosidase and pancreatic lipase, were carried out. Moreover, the effect of the compounds on the advanced glycation end-products (AGEs) as one of the major complications of oxidative stress and hyperglycemia in metabolic syndromes were carried out using BSA‐fructose (bovine serum albumin), BSA-methylglyoxal, and arginine methylglyoxal models. The pure isolates showed a protective effect in metabolic syndromes as well as promising antioxidant activity. The results showed potent activity of compound 5 in all measured parameters meanwhile, none of the tested compounds showed activity against pancreatic lipase.Keywords: Chrozophora oblongifolia, antioxidant, pancreatic lipase, metabolic syndromes
Procedia PDF Downloads 936536 The Pharmacology and Physiology of Steroid Oral Contraceptives
Authors: Ragy Raafat Gaber Attaalla
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PIP: This review, based on 2 large-scale studies, discusses the pharmacology and physiology of oral steroid contraceptives (OCs). The pharmacological distinction between synthetic and naturally occurring steroids centers on changes in biological activity dependent on compound formulation and an individual's metabolism. OC mechanism of action is explained as the main prevention of ovulation by interference with gonadotropin-releasing hormone. Since some 52 metabolic alterations have been reported in OC users, these phenomena are dealt with in 3 categories: 1) effects on the primary target organs of the female reproductive tract (ovary, myometrium, endometrium, cervix, vagina, breasts, and hypothalamus), 2) general metabolic effects (serum proteins, carbohydrate metabolism, lipid metabolism, water and electrolyte metabolism, body weight, tryptophan metabolism, and vitamins and minerals), and 3) effects on other organ systems (liver, central nervous system, skin, genitourinary, gastrointestinal tract, eye, immune phenomena, and effect on subsequent fertility). The choice of the proper OC formulation and use of OCs by adolescents are discussed. Assessment of OC safety, contraindications, and patient monitoring are provided.Keywords: steroid oral contraceptives, ovulation, female reproductive tract, metabolic effects
Procedia PDF Downloads 846535 Molecular Dynamics Simulation of Free Vibration of Graphene Sheets
Authors: Seyyed Feisal Asbaghian Namin, Reza Pilafkan, Mahmood Kaffash Irzarahimi
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TThis paper considers vibration of single-layered graphene sheets using molecular dynamics (MD) and nonlocal elasticity theory. Based on the MD simulations, Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS), an open source software, is used to obtain fundamental frequencies. On the other hand, governing equations are derived using nonlocal elasticity and first order shear deformation theory (FSDT) and solved using generalized differential quadrature method (GDQ). The small-scale effect is applied in governing equations of motion by nonlocal parameter. The effect of different side lengths, boundary conditions and nonlocal parameter are inspected for aforementioned methods. Results are obtained from MD simulations is compared with those of the nonlocal elasticity theory to calculate appropriate values for the nonlocal parameter. The nonlocal parameter value is suggested for graphene sheets with various boundary conditions. Furthermore, it is shown that the nonlocal elasticity approach using classical plate theory (CLPT) assumptions overestimates the natural frequencies.Keywords: graphene sheets, molecular dynamics simulations, fundamental frequencies, nonlocal elasticity theory, nonlocal parameter
Procedia PDF Downloads 5006534 Improving Forecasting Demand for Maintenance Spare Parts: Case Study
Authors: Abdulaziz Afandi
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Minimizing the inventory cost, optimizing the inventory quantities, and increasing system operational availability are the main motivations to enhance forecasting demand of spare parts in a major power utility company in Medina. This paper reports in an effort made to optimize the orders quantities of spare parts by improving the method of forecasting the demand. The study focuses on equipment that has frequent spare parts purchase orders with uncertain demand. The pattern of the demand considers a lumpy pattern which makes conventional forecasting methods less effective. A comparison was made by benchmarking various methods of forecasting based on experts’ criteria to select the most suitable method for the case study. Three actual data sets were used to make the forecast in this case study. Two neural networks (NN) approaches were utilized and compared, namely long short-term memory (LSTM) and multilayer perceptron (MLP). The results as expected, showed that the NN models gave better results than traditional forecasting method (judgmental method). In addition, the LSTM model had a higher predictive accuracy than the MLP model.Keywords: neural network, LSTM, MLP, forecasting demand, inventory management
Procedia PDF Downloads 1116533 3D Human Body Reconstruction Based on Multiple Viewpoints
Authors: Jiahe Liu, HongyangYu, Feng Qian, Miao Luo
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The aim of this study was to improve the effects of human body 3D reconstruction. The MvP algorithm was adopted to obtain key point information from multiple perspectives. This algorithm allowed the capture of human posture and joint positions from multiple angles, providing more comprehensive and accurate data. The study also incorporated the SMPL-X model, which has been widely used for human body modeling, to achieve more accurate 3D reconstruction results. The use of the MvP algorithm made it possible to observe the reconstructed object from multiple angles, thus reducing the problems of blind spots and missing information. This algorithm was able to effectively capture key point information, including the position and rotation angle of limbs, providing key data for subsequent 3D reconstruction. Compared with traditional single-view methods, the method of multi-view fusion significantly improved the accuracy and stability of reconstruction. By combining the MvP algorithm with the SMPL-X model, we successfully achieved better human body 3D reconstruction effects. The SMPL-X model is highly scalable and can generate highly realistic 3D human body models, thus providing more detail and shape information.Keywords: 3D human reconstruction, multi-view, joint point, SMPL-X
Procedia PDF Downloads 506532 The Use of Authentic Videos to Change Learners’ Negative Attitudes and Perceptions toward Grammar Learning
Authors: Khaldi Youcef
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This investigation seeks to inquire into the effectiveness of using authentic videos for grammar teaching purposes. In this investigation, an English animated situation, Hercules, was used as a type of authentic multimedia to teach a particular grammatical structure, namely conditional sentences. This study also aims at investigating the EFL learners’ attitudes toward grammar learning after being exposed to such an authentic video. To reach that purpose, 56 EFL learners were required ultimately to respond to a questionnaire with an aim to reveal their attitudes towards grammar as a language entity and as a subject for being learned. Then, as a second stage of the investigation, the EFL learners were divided into a control group and an experimental group with 28 learners in each. The first group was taught grammar -conditional sentences- using a deductive-inductive approach, while the second group was exposed to an authentic video to learn conditional sentences. There was a post-lesson stage that included a questionnaire to be answered by learners of each group. The aim of this stage is to capture any change in learners' attitudes shown in the pre-lesson questionnaire. The findings of the first stage revealed learners' negative attitudes towards grammar learning. And the third stage results showed the effectiveness of authentic videos in entirely turning learners' attitudes toward grammar learning to be significantly positive. Also, the utility of authentic videos in highly motivating EFL learners can be deduced. The findings of this survey asserted the need for incorporation and integration of authentic videos in EFL classrooms as they resulted in rising effectively learners’ awareness of grammar and looking at it from a communicative perspective.Keywords: multimedia, authentic videos, negative attitudes, grammar learning, EFL learners
Procedia PDF Downloads 856531 A Study on Earthquake Activities and Tectonic Setting in the Northeastern Part of Egypt
Authors: Sayed Abdallah Mohamed Dahy
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Northeastern part of Egypt is considered one of the few regions of the world whereas evidence of historical activities has been documented during the last 48 centuries or more. Instrumental, historical and pre-historical seismicity data indicate that large destructive earthquakes have occurred quite frequently in the investigated area. The main aims in the present study were to redraw attention to the fact that the northeastern part of Egypt is seismically active and this result is associated with earthquake risk in the region. The interaction of the African, Arabian and Eurasian plates and Sinai subplate, is the main factor behind the earthquake activities of northeastern part of Egypt. All earthquakes occur at shallow depth and are concentrated at four seismic zones, these zones including the Gulfs of Suez and Aqaba, around the entrance of the Gulf of Suez and the fourth one is located at the south-west of great Cairo (Dahshour area). The seismicity map of the previous zones shows that the activity is coincide with the major tectonic trends of the Suez rift, Aqaba rift with their connection with the great rift system of the Red Sea and Gulf of Suez-Cairo-Alexandria trend.Keywords: earthquake ectivities, Egypt, northeastern, tectonic setting
Procedia PDF Downloads 3866530 Mirror-Like Effect Based on Correlations among Atoms
Authors: Qurrat-ul-Ain Gulfam, Zbigniew Ficek
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The novel idea to use single atoms as highly reflecting mirrors has recently gained much attention. Usually, to observe the reflective nature of an atom, it is required to couple the atom to an external medium such that a directional spontaneous emission could be realized. We propose an alternative way to achieve the directional emission by considering a system of correlated atoms in free space. It is well known that mutually interacting atoms have a strong tendency to emit the radiation along particular discrete directions. That relieves one from the stingy condition of associating the atomic system to another media and facilitates the experimental implementation to a large degree. Moreover, realistic 3-dimensional collective emission can be taken into account in the dynamics. Two interesting spatial setups have been considered; one where a probe atom is confined in a linear cavity formed by two atomic mirrors and, the other where a probe atom faces a chain of correlated atoms. We observe an evidence of the mirror-like effect in a simple system of a chain of three atoms. The angular distribution of the radiation intensity observed in the far field is greatly affected by the atomic interactions. Hence, suitable directions for enhanced reflectivity can be determined.Keywords: atom-mirror effect, correlated system, dipole-dipole interactions, intensity
Procedia PDF Downloads 5406529 Process of Dimensioning Small Type Annular Combustors
Authors: Saleh B. Mohamed, Mohamed H. Elhsnawi, Mesbah M. Salem
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Current and future applications of small gas turbine engines annular type combustors have requirements presenting difficult disputes to the combustor designer. Reduced cost and fuel consumption and improved durability and reliability as well as higher temperatures and pressures for such application are forecast. Coupled with these performance requirements, irrespective of the engine size, is the demand to control the pollutant emissions, namely the oxides of nitrogen, carbon monoxide, smoke and unburned hydrocarbons. These technical and environmental challenges have made the design of small size combustion system a very hard task. Thus, the main target of this work is to generalize a calculation method of annular type combustors for small gas turbine engines that enables to understand the fundamental concepts of the coupled processes and to identify the proper procedure that formulates and solves the problems in combustion fields in as much simplified and accurate manner as possible. The combustion chamber in task is designed with central vaporizing unit and to deliver 516.3 KW of power. The geometrical constraints are 142 mm & 140 mm overall length and casing diameter, respectively, while the airflow rate is 0.8 kg/sec and the fuel flow rate is 0.012 kg/sec. The relevant design equations are programmed by using MathCAD language for ease and speed up of the calculation process.Keywords: design of gas turbine, small engine design, annular type combustors, mechanical engineering
Procedia PDF Downloads 3956528 Aspect-Level Sentiment Analysis with Multi-Channel and Graph Convolutional Networks
Authors: Jiajun Wang, Xiaoge Li
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The purpose of the aspect-level sentiment analysis task is to identify the sentiment polarity of aspects in a sentence. Currently, most methods mainly focus on using neural networks and attention mechanisms to model the relationship between aspects and context, but they ignore the dependence of words in different ranges in the sentence, resulting in deviation when assigning relationship weight to other words other than aspect words. To solve these problems, we propose a new aspect-level sentiment analysis model that combines a multi-channel convolutional network and graph convolutional network (GCN). Firstly, the context and the degree of association between words are characterized by Long Short-Term Memory (LSTM) and self-attention mechanism. Besides, a multi-channel convolutional network is used to extract the features of words in different ranges. Finally, a convolutional graph network is used to associate the node information of the dependency tree structure. We conduct experiments on four benchmark datasets. The experimental results are compared with those of other models, which shows that our model is better and more effective.Keywords: aspect-level sentiment analysis, attention, multi-channel convolution network, graph convolution network, dependency tree
Procedia PDF Downloads 1956527 Active Contours for Image Segmentation Based on Complex Domain Approach
Authors: Sajid Hussain
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The complex domain approach for image segmentation based on active contour has been designed, which deforms step by step to partition an image into numerous expedient regions. A novel region-based trigonometric complex pressure force function is proposed, which propagates around the region of interest using image forces. The signed trigonometric force function controls the propagation of the active contour and the active contour stops on the exact edges of the object accurately. The proposed model makes the level set function binary and uses Gaussian smoothing kernel to adjust and escape the re-initialization procedure. The working principle of the proposed model is as follows: The real image data is transformed into complex data by iota (i) times of image data and the average iota (i) times of horizontal and vertical components of the gradient of image data is inserted in the proposed model to catch complex gradient of the image data. A simple finite difference mathematical technique has been used to implement the proposed model. The efficiency and robustness of the proposed model have been verified and compared with other state-of-the-art models.Keywords: image segmentation, active contour, level set, Mumford and Shah model
Procedia PDF Downloads 876526 Development of Low-Cost Vibro-Acoustic, and Fire-Resistant, Insulation Material from Natural and Sustainable Sources
Authors: K. Nasir, S. Ahmad, A. Khan, H. Benkreira
Abstract:
The topic of the research is to develop sustainable fire-resistant materials for vibration and acoustic damping of structure and airborne noises from sustainable recycled materials and biodegradable binders. The paper reports, methods and techniques of enhancing fire resistive, vibration and acoustic properties of building insulation materials made from natural resources like wood and recycled materials like rubber and textile waste. The structures are designed to optimize the number, size and stratification of closed (heat insulating) and open (noise insulating) pores. The samples produced are tested for their heat and noise insulating properties, including vibration damping and their structural properties (airflow resistivity, porosity, tortuosity and elastic modulus). The structural properties are then used in theoretical models to check the acoustic insulation measurements. Initial data indicate that one layer of such material can yield as much as 18 times more damping, increasing the loss factor by 18%.Keywords: fire resistant, vibration damping, acoustic material, vibro-acoustic, thermal insulation, sustainable material, low cost materials, recycled materials, construction material
Procedia PDF Downloads 119