Search results for: omega media
509 Quantifying Mobility of Urban Inhabitant Based on Social Media Data
Authors: Yuyun, Fritz Akhmad Nuzir, Bart Julien Dewancker
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Check-in locations on social media provide information about an individual’s location. The millions of units of data generated from these sites provide knowledge for human activity. In this research, we used a geolocation service and users’ texts posted on Twitter social media to analyze human mobility. Our research will answer the questions; what are the movement patterns of a citizen? And, how far do people travel in the city? We explore the people trajectory of 201,118 check-ins and 22,318 users over a period of one month in Makassar city, Indonesia. To accommodate individual mobility, the authors only analyze the users with check-in activity greater than 30 times. We used sampling method with a systematic sampling approach to assign the research sample. The study found that the individual movement shows a high degree of regularity and intensity in certain places. The other finding found that the average distance an urban inhabitant can travel per day is as far as 9.6 km.
Keywords: Mobility, check-in, distance, Twitter.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 788508 Adaptive Image Transmission with P-V Diversity in Multihop Wireless Mesh Networks
Authors: Wei Wang, Dongming Peng, Honggang Wang, Hamid Sharif
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Multirate multimedia delivery applications in multihop Wireless Mesh Network (WMN) are data redundant and delay-sensitive, which brings a lot of challenges for designing efficient transmission systems. In this paper, we propose a new cross layer resource allocation scheme to minimize the receiver side distortion within the delay bound requirements, by exploring application layer Position and Value (P-V) diversity as well as the multihop Effective Capacity (EC). We specifically consider image transmission optimization here. First of all, the maximum supportable source traffic rate is identified by exploring the multihop Effective Capacity (EC) model. Furthermore, the optimal source coding rate is selected according to the P-V diversity of multirate media streaming, which significantly increases the decoded media quality. Simulation results show the proposed approach improved media quality significantly compared with traditional approaches under the same QoS requirements.Keywords: Multirate Multimedia Streaming, Effective CapacityMultihop Wireless Mesh Network
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1461507 The Computer Multimedia Instruction Package for Welding and Brazing
Authors: C. Mongkol
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The objective of this project is to produce computer assisted instruction(CAI) for welding and brazing in order to determine the efficiency of the instruction package and the study accomplishment of learner by studying through computer assisted instruction for welding and brazing it was examined through the target group surveyed from the 30 students studying in the two year of 5-year-academic program, department of production technology education, faculty of industrial education and technology, king mongkut-s university of technology thonburi. The result of the research indicated that the media evaluated by experts and subject matter quality evaluation of computer assisted instruction for welding and brazing was in line for the good criterion. The mean of score evaluated before the study, during the study and after the study was 34.58, 83.33 and 83.43, respectively. The efficiency of the lesson was 83.33/83.43 which was higher than the expected value, 80/80. The study accomplishment of the learner, who utilizes computer assisted instruction for welding and brazing as a media, was higher and equal to the significance statistical level of 95%. The value was 1.669 which was equal to 35.36>1.669. It could be summarized that computer assisted instruction for welding and brazing was the efficient media to use for studying and teaching.Keywords: Computer Assisted Instruction, Achievement, Efficiency of the lesson, Evaluation
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1302506 A Numerical Simulation of the Indoor Air Flow
Authors: Karel Frana, Jianshun S. Zhang, Milos Muller
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The indoor airflow with a mixed natural/forced convection was numerically calculated using the laminar and turbulent approach. The Boussinesq approximation was considered for a simplification of the mathematical model and calculations. The results obtained, such as mean velocity fields, were successfully compared with experimental PIV flow visualizations. The effect of the distance between the cooled wall and the heat exchanger on the temperature and velocity distributions was calculated. In a room with a simple shape, the computational code OpenFOAM demonstrated an ability to numerically predict flow patterns. Furthermore, numerical techniques, boundary type conditions and the computational grid quality were examined. Calculations using the turbulence model k-omega had a significant effect on the results influencing temperature and velocity distributions.Keywords: natural and forced convections, numerical simulations, indoor airflows.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3196505 Wastewater Treatment in Moving-Bed Biofilm Reactor operated by Flow Reversal Intermittent Aeration System
Authors: B. K. Kim, D. Chang, D. J. Son, D. W. Kim, J. K. Choi, H. J. Yeon, C. Y. Yoon, Y. Fan, S. Y. Lim, K. H. Hong
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Intermittent aeration process can be easily applied on the existing activated sludge system and is highly reliable against the loading changes. It can be operated in a relatively simple way as well. Since the moving-bed biofilm reactor method processes pollutants by attaching and securing the microorganisms on the media, the process efficiency can be higher compared to the suspended growth biological treatment process, and can reduce the return of sludge. In this study, the existing intermittent aeration process with alternating flow being applied on the oxidation ditch is applied on the continuous flow stirred tank reactor with advantages from both processes, and we would like to develop the process to significantly reduce the return of sludge in the clarifier and to secure the reliable quality of treated water by adding the moving media. Corresponding process has the appropriate form as an infrastructure based on u- environment in future u- City and is expected to accelerate the implementation of u-Eco city in conjunction with city based services. The system being conducted in a laboratory scale has been operated in HRT 8hours except for the final clarifier and showed the removal efficiency of 97.7 %, 73.1 % and 9.4 % in organic matters, TN and TP, respectively with operating range of 4hour cycle on system SRT 10days. After adding the media, the removal efficiency of phosphorus showed a similar level compared to that before the addition, but the removal efficiency of nitrogen was improved by 7~10 %. In addition, the solids which were maintained in MLSS 1200~1400 at 25 % of media packing were attached all onto the media, which produced no sludge entering the clarifier. Therefore, the return of sludge is not needed any longer.Keywords: Municipal wastewater treatment, Biological nutrient removal, Alternating flow intermittent aeration system, Reversal flow intermittent aeration system, Moving-bed biofilm reactor, CFSTR, u-City, u-Eco city
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2311504 Customer Relationship Management on Social Media Affecting Brand Loyalty of Siam Commercial Bank in Bangkok
Authors: Charawee Butbumrung
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The purpose of this research was to study customer relationship management on social media affecting brand loyalty of Siam Commercial Bank in Bangkok. The statistics used in data analysis were frequency, mean, standard deviation, and Pearson’s correlation coefficient based on social science statistic program. The result of the study found that the majority of the respondents were female, 37–47 years old of age, bachelor degree of education and monthly income between 10,001 and 15,000 Baht. In addition, customer relationship management in the overall and by each aspect of formulating, maintaining, and extending the customer relationship had a high score. Furthermore, the result of hypothesis testing showed that the difference of the customer’s age, education, occupation, average monthly income had the difference in brand loyalty with the statistical significance level of 0.05 and customer relationship management had related with brand loyalty in the same direction with the low level of statistical significance 0.05.Keywords: Brand loyalty, customer relationship, management, Siam Commercial Bank, social media.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1122503 Interfacial Layer Effect on Novel p-Ni1-xO:Li/n-Si Heterojunction Solar Cells
Authors: Feng-Hao Hsu, Na-Fu Wang, Yu-Zen Tsai, Yu-Song Cheng, Cheng-Fu Yang, Mau-Phon Houng
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This study fabricates p-type Ni1−xO:Li/n-Si heterojunction solar cells (P+/n HJSCs) by using radio frequency (RF) magnetron sputtering and investigates the effect of substrate temperature on photovoltaic cell properties. Grazing incidence x-ray diffraction, four point probe, and ultraviolet-visible-near infrared discover the optoelectrical properties of p-Ni1-xO thin films. The results show that p-Ni1-xO thin films deposited at 300 oC has the highest grain size (22.4 nm), average visible transmittance (~42%), and electrical resistivity (2.7 Ωcm). However, the conversion efficiency of cell is shown only 2.33% which is lower than the cell (3.39%) fabricated at room temperature. This result can be mainly attributed to interfacial layer thickness (SiOx) reduces from 2.35 nm to 1.70 nm, as verified by high-resolution transmission electron microscopy.
Keywords: Heterojunction, nickel oxide, solar cells, sputtering.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1839502 Effect of Genotype, Explant Type and Growth Regulators on The Accumulation of Flavonoides of (Silybum marianum L.) in In vitro Culture
Authors: A. Pourjabar, S.A. Mohammadi, R. Ghahramanzadeh, Gh. Salimi
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The extract of milk thistle contains a mix of flavonolignans termed silymarine.. In order to analysis influence of growth regulators, genotype, explant and subculture on the accumulation of flavonolignans, a study was carried out by using two genotype (Budakalszi and Noor abad moghan cultivars), cotyledon and hypocotyle explants, solid media of MS supplemented by different combinations of two growth regulators; Kinetin (0.1, 1 mg/l) and 2,4-D (1, 2 mg/l). Seeds of the plant were germinated in MS media whitout growth regulators in growth chamber at 26°C and darkness condition. In order to callus induction, the culture media was supplemented whit different concentrations of 2,4-D and kinetin. Calli obtained from explants were sub-cultured four times into the fresh media of the first experiment. flavonoides was extracted from calli in four subcultures. The flavonoid components were determined by high- performance liquid choromatography (HPLC) and separated into Taxifolin, Silydianin+Silychristin, Silybin A+B and Isosilybin A+B. Results showed that with increasing callus age, increased accumulation of silybin A+B, but reduced Isosilybin A+B content. Highest accumulation of Taxifolin was observed at first calli. Calli produced from cotyledon explant of Budakalszi cultivar were superior for Silybin A+B, where calli from hypocotyl explant produced higher amount of Taxifolin and Silydianin+Silychristin. The best cultivar for Silymarin production in this study was Budakalszi cultivar. High amount of SBN A+B and TXF were obtained from hypocotil explant.
Keywords: Callus culture, Flavonolignans, Silimarine
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1925501 Good Practices in the Development of the Erasmus Mundus Master program in Color in Informatics and Media Technology
Authors: J. Hardeberg, J. Hernandez-Andrès, J. L. Nieves, M. Hauta-Kasari, J. Parkkinen, A. Trémeau
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The main objective of this paper is to identify and disseminate good practice in quality assurance and enhancement as well as in teaching and learning at master level. This paper focuses on the experience of the Erasmus Mundus Master program CIMET (Color in Informatics and Media Technology). Amongst topics covered, we discuss the adjustments necessary to a curriculum designed for excellent international students and their preparation for a global labor market.Keywords: Good practice, internal quality systems, innovationsin curriculum design, challenges of internationalization
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1455500 Numerical Investigation of Improved Aerodynamic Performance of a NACA 0015 Airfoil Using Synthetic Jet
Authors: K. Boualem, T. Yahiaoui, A. Azzi
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Numerical investigations are performed to analyze the flow behavior over NACA0015 and to evaluate the efficiency of synthetic jet as active control device. The second objective of this work is to investigate the influence of momentum coefficient of synthetic jet on the flow behaviour. The unsteady Reynolds-averaged Navier-Stokes equations of the turbulent flow are solved using, k-ω SST provided by ANSYS CFX-CFD code. The model presented in this paper is a comprehensive representation of the information found in the literature. Comparison of obtained numerical flow parameters with the experimental ones shows that the adopted computational procedure reflects nearly the real flow nature. Also, numerical results state that use of synthetic jets devices has positive effects on the flow separation, and thus, aerodynamic performance improvement of NACA0015 airfoil. It can also be observed that the use of synthetic jet increases the lift coefficient about 13.3% and reduces the drag coefficient about 52.7%.
Keywords: Active control, CFD, NACA airfoil, synthetic jet.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1640499 Wet Strength Improvement of Pineapple Leaf Paper for Evaporative Cooling Pad
Authors: T. Khampan, N. Thavarungkul, J. Tiansuwan, S. Kamthai
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This research aimed to modify pineapple leaf paper (PALP) for using as wet media in the evaporation cooling system by improving wet mechanical property (tensile strength) without compromising water absorption property. Polyamideamineepichorohydrin resin (PAE) and carboxymethylcellulose (CMC) were used to strengthen the paper, and the PAE and CMC ratio of 80:20 showed the optimum wet and dry tensile index values, which were higher than those of the commercial cooling pad (CCP). Compared with CCP, PALP itself and all the PAE/CMC modified PALP possessed better water absorption. The PAE/CMC modified PALP had potential to become a new type of wet media.Keywords: wet strength, evaporative cooling, pineapple leaves, polyamideamine-epichorohydrin, carboxymethylcellulose.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2151498 Sterilisation of in vitro Culture Medium of Chrysanthemum by Plant Essential Oils without Autoclaving
Authors: Chockpisit Thepsithar, Aree Thongpukdee, Apichya Daorat
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The alternative technique for sterilization of culture medium to replace autoclaving was carried out. For sterilization of culture medium without autoclaving, some commercial pure essential oils, bergamot oil, betel oil, cinnamon oil, lavender oil and turmeric oil, were tested alone or in combinations with some disinfectants, 10% povidone-iodine and 2% iodine + 2.4% potassium iodide. Each essential oil or combination was added to 25-mL Murashige and Skoog (MS) medium before medium was solidified in a 120-mL container, kept for 2 weeks before evaluating sterile conditions. Treated media, supplemented with essential oils, were compared to control medium, autoclaved at 121 degree Celsius for 15 min. In vitro sterile conditions were found 20 – 100% from these treated media compared to 100% sterile condition from autoclaved medium. Treated media obtained 100% sterile conditions were chosen for culturing chrysanthemum shoots. It was found that 10% povidoneiodine in combination with cinnamon oil (3:1) and 2% iodine + 2.4% potassium iodide in combination with lavender oil (1:3) at the concentration of 36 3L/25 mL medium provided the promising growth of shoot explants.
Keywords: Sterilizing agents, essential oils, disinfectants, MS medium, in vitro culture, chrysanthemum, sterilization of medium without autoclaving
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3986497 Detecting Fake News: A Natural Language Processing, Reinforcement Learning, and Blockchain Approach
Authors: Ashly Joseph, Jithu Paulose
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In an era where misleading information may quickly circulate on digital news channels, it is crucial to have efficient and trustworthy methods to detect and reduce the impact of misinformation. This research proposes an innovative framework that combines Natural Language Processing (NLP), Reinforcement Learning (RL), and Blockchain technologies to precisely detect and minimize the spread of false information in news articles on social media. The framework starts by gathering a variety of news items from different social media sites and performing preprocessing on the data to ensure its quality and uniformity. NLP methods are utilized to extract complete linguistic and semantic characteristics, effectively capturing the subtleties and contextual aspects of the language used. These features are utilized as input for a RL model. This model acquires the most effective tactics for detecting and mitigating the impact of false material by modeling the intricate dynamics of user engagements and incentives on social media platforms. The integration of blockchain technology establishes a decentralized and transparent method for storing and verifying the accuracy of information. The Blockchain component guarantees the unchangeability and safety of verified news records, while encouraging user engagement for detecting and fighting false information through an incentive system based on tokens. The suggested framework seeks to provide a thorough and resilient solution to the problems presented by misinformation in social media articles.
Keywords: Natural Language Processing, Reinforcement Learning, Blockchain, fake news mitigation, misinformation detection.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 40496 An Accurate, Wide Dynamic Range Current Mirror Structure
Authors: Hassan Faraji Baghtash
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In this paper, a low voltage high performance current mirror is presented. Its most important specifications, which are improved in this work, are analyzed and formulated proving that it has such outstanding merits as: Very low input resistance of 26mΩ, very wide current dynamic range of 8 decades from 10pA to 1mA (160dB) together with an extremely low current copy error of less than 0.6ppm, and very low input and output voltages. Furthermore, the proposed current mirror bandwidth is 944MHz utilizing very low power consumption (267μW) and transistors count. HSPICE simulation results are performed using TSMC 0.18μm CMOS technology utilizing 1.8V single power supply, confirming the theoretically proved outstanding performance of the proposed current mirror. Monte Carlo simulation of its most important parameter is also examined showing its sufficiently resistance against technology process variations.
Keywords: Current mirror/source, high accuracy, low voltage, wide dynamic range.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2210495 A Spatial Repetitive Controller Applied to an Aeroelastic Model for Wind Turbines
Authors: Riccardo Fratini, Riccardo Santini, Jacopo Serafini, Massimo Gennaretti, Stefano Panzieri
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This paper presents a nonlinear differential model, for a three-bladed horizontal axis wind turbine (HAWT) suited for control applications. It is based on a 8-dofs, lumped parameters structural dynamics coupled with a quasi-steady sectional aerodynamics. In particular, using the Euler-Lagrange Equation (Energetic Variation approach), the authors derive, and successively validate, such model. For the derivation of the aerodynamic model, the Greenbergs theory, an extension of the theory proposed by Theodorsen to the case of thin airfoils undergoing pulsating flows, is used. Specifically, in this work, the authors restricted that theory under the hypothesis of low perturbation reduced frequency k, which causes the lift deficiency function C(k) to be real and equal to 1. Furthermore, the expressions of the aerodynamic loads are obtained using the quasi-steady strip theory (Hodges and Ormiston), as a function of the chordwise and normal components of relative velocity between flow and airfoil Ut, Up, their derivatives, and section angular velocity ε˙. For the validation of the proposed model, the authors carried out open and closed-loop simulations of a 5 MW HAWT, characterized by radius R =61.5 m and by mean chord c = 3 m, with a nominal angular velocity Ωn = 1.266rad/sec. The first analysis performed is the steady state solution, where a uniform wind Vw = 11.4 m/s is considered and a collective pitch angle θ = 0.88◦ is imposed. During this step, the authors noticed that the proposed model is intrinsically periodic due to the effect of the wind and of the gravitational force. In order to reject this periodic trend in the model dynamics, the authors propose a collective repetitive control algorithm coupled with a PD controller. In particular, when the reference command to be tracked and/or the disturbance to be rejected are periodic signals with a fixed period, the repetitive control strategies can be applied due to their high precision, simple implementation and little performance dependency on system parameters. The functional scheme of a repetitive controller is quite simple and, given a periodic reference command, is composed of a control block Crc(s) usually added to an existing feedback control system. The control block contains and a free time-delay system eτs in a positive feedback loop, and a low-pass filter q(s). It should be noticed that, while the time delay term reduces the stability margin, on the other hand the low pass filter is added to ensure stability. It is worth noting that, in this work, the authors propose a phase shifting for the controller and the delay system has been modified as e^(−(T−γk)), where T is the period of the signal and γk is a phase shifting of k samples of the same periodic signal. It should be noticed that, the phase shifting technique is particularly useful in non-minimum phase systems, such as flexible structures. In fact, using the phase shifting, the iterative algorithm could reach the convergence also at high frequencies. Notice that, in our case study, the shifting of k samples depends both on the rotor angular velocity Ω and on the rotor azimuth angle Ψ: we refer to this controller as a spatial repetitive controller. The collective repetitive controller has also been coupled with a C(s) = PD(s), in order to dampen oscillations of the blades. The performance of the spatial repetitive controller is compared with an industrial PI controller. In particular, starting from wind speed velocity Vw = 11.4 m/s the controller is asked to maintain the nominal angular velocity Ωn = 1.266rad/s after an instantaneous increase of wind speed (Vw = 15 m/s). Then, a purely periodic external disturbance is introduced in order to stress the capabilities of the repetitive controller. The results of the simulations show that, contrary to a simple PI controller, the spatial repetitive-PD controller has the capability to reject both external disturbances and periodic trend in the model dynamics. Finally, the nominal value of the angular velocity is reached, in accordance with results obtained with commercial software for a turbine of the same type.Keywords: Wind turbines, aeroelasticity, repetitive control, periodic systems.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1281494 Near Perfect Reconstruction Quadrature Mirror Filter
Authors: A. Kumar, G. K. Singh, R. S. Anand
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In this paper, various algorithms for designing quadrature mirror filter are reviewed and a new algorithm is presented for the design of near perfect reconstruction quadrature mirror filter bank. In the proposed algorithm, objective function is formulated using the perfect reconstruction condition or magnitude response condition of prototype filter at frequency (ω = 0.5π) in ideal condition. The cutoff frequency is iteratively changed to adjust the filters coefficients using optimization algorithm. The performances of the proposed algorithm are evaluated in term of computation time, reconstruction error and number of iterations. The design examples illustrate that the proposed algorithm is superior in term of peak reconstruction error, computation time, and number of iterations. The proposed algorithm is simple, easy to implement, and linear in nature.
Keywords: Aliasing cancellations filter bank, Filter banks, quadrature mirror filter (QMF), subband coding.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2514493 Fluid Flow Analysis and Design of a Flow Distributor in a Domestic Gas Boiler Using a Commercial CFD Software
Authors: Lukasz Peronski, Roy Bratley, Derek B. Ingham, Lin Ma, Mohamed Pourkashanian, StephenTaylor
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The aim of the study was to investigate the possible use of commercial Computational Fluid Dynamics (CFD) software in the design process of a domestic gas boiler. Because of the limited computational resources some simplifications had to be made in order to contribute to the design in a reasonable timescale. The porous media model was used in order to simulate the influence of the pressure drop characteristic of particular elements of a heat transfer system on the water-flow distribution in the system. Further, a combination of CFD analyses and spread sheet calculations was used in order to solve the flow distribution problem.Keywords: CFD, domestic gas boilers, flow distribution, heatexchanger, porous media
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2726492 A Structured Mechanism for Identifying Political Influencers on Social Media Platforms: Top 10 Saudi Political Twitter Users
Authors: Ahmad Alsolami, Darren Mundy, Manuel Hernandez-Perez
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Social media networks, such as Twitter, offer the perfect opportunity to either positively or negatively affect political attitudes on large audiences. The existence of influential users who have developed a reputation for their knowledge and experience of specific topics is a major factor contributing to this impact. Therefore, knowledge of the mechanisms to identify influential users on social media is vital for understanding their effect on their audience. The concept of the influential user is related to the concept of opinion leaders' to indicate that ideas first flow from mass media to opinion leaders and then to the rest of the population. Hence, the objective of this research was to provide reliable and accurate structural mechanisms to identify influential users, which could be applied to different platforms, places, and subjects. Twitter was selected as the platform of interest, and Saudi Arabia as the context for the investigation. These were selected because Saudi Arabia has a large number of Twitter users, some of whom are considerably active in setting agendas and disseminating ideas. The study considered the scientific methods that have been used to identify public opinion leaders before, utilizing metrics software on Twitter. The key findings propose multiple novel metrics to compare Twitter influencers, including the number of followers, social authority and the use of political hashtags, and four secondary filtering measures. Thus, using ratio and percentage calculations to classify the most influential users, Twitter accounts were filtered, analyzed and included. The structured approach is used as a mechanism to explore the top ten influencers on Twitter from the political domain in Saudi Arabia.
Keywords: Twitter, influencers, structured mechanism, Saudi Arabia.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 514491 Application of Turbulence Modeling in Computational Fluid Dynamics for Airfoil Simulations
Authors: Mohammed Bilal
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The precise prediction of aerodynamic behavior is necessary for the design and optimization of airfoils for a variety of applications. Turbulence, a phenomenon of complex and irregular flow, significantly affects the aerodynamic properties of airfoils. Therefore, turbulence modeling is essential for accurately predicting the behavior of airfoils in simulations. This study investigates five commonly employed turbulence models: Spalart-Allmaras (SA) model, k-epsilon model, k-omega model, Reynolds Stress Model (RSM), and Large Eddy Simulation (LES) model. The paper includes a comparison of the models' precision, computational expense, and applicability to various flow conditions. The strengths and weaknesses of each model are highlighted, allowing researchers and engineers to make informed decisions regarding simulations of specific airfoils. Unquestionably, the continuous development of turbulence modeling will contribute to further improvements in airfoil design and optimization, which will be advantageous to numerous industries.
Keywords: Computational fluid dynamics, airfoil, turbulence, aircraft.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 255490 The Yak of Thailand: Folk Icons Transcending Culture, Religion, and Media
Authors: David M. Lucas, Charles W. Jarrett
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In the culture of Thailand, the Yak serve as a mediated icon representing strength, power, and mystical protection not only for the Buddha, but for population of worshipers. Originating from the forests of China, the Yak continues to stand guard at the gates of Buddhist temples. The Yak represents Thai culture in the hearts of Thai people. This paper presents a qualitative study regarding the curious mix of media, culture, and religion that projects the Yak of Thailand as a larger than life message throughout the political, cultural, and religious spheres. The gate guardians, or gods as they are sometimes called, appear throughout the religious temples of Asian cultures. However, the Asian cultures demonstrate differences in artistic renditions (or presentations) of such sentinels. Thailand gate guards (the Yak) stand in front of many Buddhist temples, and these iconic figures display unique features with varied symbolic significance. The temple (or wat), plays a vital role in every community; and, for many people, Thailand’s temples are the country’s most endearing sights. The authors applied folknography as a methodology to illustrate the importance of the Thai Yak in serving as meaningful icons that transcend not only time, but the culture, religion, and mass media. The Yak represents mythical, religious, artistic, cultural, and militaristic significance for the Thai people. Data collection included interviews, focus groups, and natural observations. This paper summarizes the perceptions of the Thai people concerning their gate sentries and the relationship, communication, connection, and the enduring respect that Thai people hold for their guardians of the gates.
Keywords: Communication, Culture, Folknography, Icon, Image, Media, Protection, Religion, Yak.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9730489 Design of Mobile Teaching for Students Collaborative Learning in Distance Higher Education
Authors: Lisbeth Amhag
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The aim of the study is to describe and analyze design of mobile teaching for students collaborative learning in distance higher education with a focus on mobile technologies as online webinars (web-based seminars or conferencing) by using laptops, smart phones, or tablets. These multimedia tools can provide face-toface interactions, recorded flipped classroom videos and parallel chat communications. The data collection consists of interviews with 22 students and observations of online face-to-face webinars, as well two surveys. Theoretically, the study joins the research tradition of Computer Supported Collaborative learning, CSCL, as well as Computer Self-Efficacy, CSE concerned with individuals’ media and information literacy. Important conclusions from the study demonstrated mobile interactions increased student centered learning. As the students were appreciating the working methods, they became more engaged and motivated. The mobile technology using among student also contributes to increased flexibility between space and place, as well as media and information literacy.
Keywords: Computer self-efficacy, computer supported collaborative learning, distance and open learning, educational design and technologies, media and information literacy, mobile learning.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1903488 Role of Social Capital on Consumer Attitudes, Peer Influence and Behavioral Intentions: A Social Media Perspective
Authors: Qazi Mohammed Ahmed, Osman Sadiq Paracha, Iftikhar Hussain
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The study aims to explore the unaddressed relationship between social capital and consumers’ underlying behavioral intentions. The study postulates that this association is mediated by the role of attitudes and peer influence. The research attains evidence from a usable sample of 673 responses. The majority consists of the young and energetic social media users of Pakistan that utilize virtual communities as a way of life. A variance based structural equation modeling has been applied through SmartPLS 3. The results reveal that social capital exerts a statistically supportive association with both attitudes and peer influence. Contrastingly, this predictor variable shows an insignificant linkage with behavioral intentions but this relationship is fully mediated by consumer attitudes and peer influence. The paper enhances marketing literature with respect to an unexplored society of Pakistan. It also provides a lens for the contemporary advertisers, in terms of supporting their social media campaigns with affiliative and cohesive elements. The study also identifies a series of predictor variables that could further be tested with attitudes, subjective norms and behavioral responses.Keywords: Behavioral intentions, consumer attitudes, peer influence, social capital.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 573487 Nuclear Safety and Security in France in the 1970s: A Turning Point for the Media
Authors: Jandot Aurélia
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In France, in the main media, the concern about nuclear safety and security has not really appeared before the beginning of the 1970s. The gradual changes in its perception are studied here through the arguments given in the main French news magazines, linked with several parameters. As this represents a considerable amount of copies and thus of information, are selected here the main articles as well as the main “mental images” aiming to persuade the readers and which have led the public awareness to evolve. Indeed, in the 1970s, in France, these evolutions were not made in one day. Indeed, over the period, many articles were still in favor of nuclear power plants and promoted the technological advances that were made in this field. They had to be taken into account. But, gradually, grew up arguments and mental images discrediting the perception of nuclear technology. Among these were the environmental impacts of this industry, as the question of pollution progressively appeared. So, between 1970 and 1979, the language has changed, as the perceptible objectives of the communication, allowing to discern the deepest intentions of the editorial staffs of the French news magazines. This is all these changes that are emphasized here, over a period when the safety and security concern linked to the nuclear technology, to there a field for specialists, has become progressively a social issue seemingly open to all.
Keywords: French media discourse, nuclear safety and security, public awareness, persuasion.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1235486 Control of Aspergillus flavus Growth in Tomato Paste by Cinnamomum zeylanicum and Origanum vulgare L. Essential Oils
Authors: F. Kalantari, M. Barzegar, Z. Hamidi-Esfahani
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This study was conducted to evaluate the antifungal activities of Cinnamomum zeylanicum and Origanum vulgare L. essential oil against Aspergillus flavus in culture media and tomato paste. 200 ppm of cinnamon and 500 ppm of oregano completely inhibited A. flavus growth in culture media, while in tomato paste 300 ppm of cinnamon and 200 ppm of oregano had the same effect. Test panel evaluations revealed that samples with 100 and 200 ppm cinnamon were acceptable. The results may suggest the potential use of Cinnamomum zeylanicum essential oil as natural preservative in tomato paste.Keywords: Antimicrobial, Food safety, GC/MS, Natural preservative
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2654485 The Determinants and Outcomes of Pathological Internet use (PIU) among Urban Millennial Teens: A Theoretical Framework
Authors: Pressca Neging, Rosidah Musa, Rabiah Abdul Wahab
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The rapid adoption of Internet has turned the Millennial Teens- life like a lightning speed. Empirical evidence has illustrated that Pathological Internet Use (PIU) among them ensure long-term success to the market players in the children industry. However, it creates concerns among their care takers as it generates mental disorder among some of them. The purpose of this paper is to examine the determinants of PIU and identify its outcomes among urban Millennial Teens. It aims to develop a theoretical framework based on a modified Media System Dependency (MSD) Theory that integrates important systems and components that determine and resulted from PIU.
Keywords: Internet, media system dependency theory, millennial, pathological internet use.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2407484 A New Solution for Natural Convection of Darcian Fluid about a Vertical Full Cone Embedded in Porous Media Prescribed Wall Temperature by using a Hybrid Neural Network-Particle Swarm Optimization Method
Authors: M.A.Behrang, M. Ghalambaz, E. Assareh, A.R. Noghrehabadi
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Fluid flow and heat transfer of vertical full cone embedded in porous media is studied in this paper. Nonlinear differential equation arising from similarity solution of inverted cone (subjected to wall temperature boundary conditions) embedded in porous medium is solved using a hybrid neural network- particle swarm optimization method. To aim this purpose, a trial solution of the differential equation is defined as sum of two parts. The first part satisfies the initial/ boundary conditions and does contain an adjustable parameter and the second part which is constructed so as not to affect the initial/boundary conditions and involves adjustable parameters (the weights and biases) for a multi-layer perceptron neural network. Particle swarm optimization (PSO) is applied to find adjustable parameters of trial solution (in first and second part). The obtained solution in comparison with the numerical ones represents a remarkable accuracy.Keywords: Porous Media, Ordinary Differential Equations (ODE), Particle Swarm Optimization (PSO), Neural Network (NN).
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1706483 The Portuguese Press Portrait of “Environmental Refugees“
Authors: Inês Vieira
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The migration-environment nexus has gained increased interest from the social research field over the last years. While straightly connected to human security issues, this theme has pervaded through the media to the public sphere. Therefore, it is important to observe how did the discussions over environmentally induced migrations develop from the scientific basis to the media attention, passing through some political voices, and in which ways might these messages be interpreted within the broader public discourses. To achieve this purpose, the analysis of the press entries between 2004 and 2010 in three of the main Portuguese newspapers shall be presented, specially reflecting upon the events, protagonists, topics, geographical attributions and terms/expressions used to define those who migrate due to environmental degradation or disasters.
Keywords: Climate refugees, environmental refugees, environmentally induced migrations, Portuguese written press
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1555482 Compact Ultra-Wideband Printed Monopole Antenna with Inverted L-Shaped Slots for Data Communication and RF Energy Harvesting
Authors: Mohamed Adel Sennouni, Jamal Zbitou, Benaissa Abboud, Abdelwahed Tribak, Hamid Bennis, Mohamed Latrach
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A compact UWB planar antenna fed with a microstrip-line is proposed. The new design consist of a rectangular patch with symmetric l-shaped slots and fed by 50 Ω microstrip transmission line and a reduced ground-plane which have a periodic slots with an overall size of 47 mm x 20 mm. It is intended to be used in wireless applications that cover the ultra-wideband (UWB) frequency band. A wider impedance bandwidth of around 116.5% (1.875 – 7.115 GHz) with stable radiation pattern is achieved. The proposed antenna has excellent characteristics, low profile and costeffective compared to existing UWB antennas. The UWB antenna is designed and analyzed using CST Microwave Studio in transient mode to verify antenna parameters improvements.
Keywords: UWB Planar Antenna, L-shaped Slots, Wireless Applications, impedance band-width, radiation pattern, CST Microwave Studio.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2754481 Comparison of Physico-Chemical Properties And Fatty Acid Compostion of Elateriospermum Tapos (Buah Perah), Palm Oil And Soybean Oil
Authors: Siti Hamidah, Lee Nian Yian, Azizi Mohd
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Elateriospermum tapos seed (buah perah) is the one of the rich sources of polyunsaturated fatty acids. It contains high percentage of oleic acid which is the important component to develop nervous system and also α-linolenic acid (ALA) which is the precursor of omega-3 fatty acids series to synthesize eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). However, there is less study about this valuable oilseed and exploit its potential. Therefore, this paper is to assess the comparison of physico-chemical properties and fatty composition of perah oil to palm oil and soybean oil. From the comparison, perah oil shows low peroxide value means it has good oxidative stability and also high iodine values shows that it can be used in paint industry. The study shown that perah oil is comparable to palm oil and soybean oil, so it has high potential to be exploited in the oleochemical, pharmaceutical, cosmetics and paint industries.Keywords: α-linolenic acid, palm oil, perah oil, soybean oil
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2438480 Does Leisure Time Use Contribute to a Wage Increase of the Thai People?
Authors: Siriwan Saksiriruthai
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This paper develops models to analyze the relationship between leisure time and wage change. Using Thailand-s Time Use Survey and Labor Force Survey data, the estimation of wage changes in response to leisure time change indicates that media receiving, personal care and social participation and volunteer activities are the ones that significantly raise hourly wages. Thus, the finding suggests the stimulation in time use for media access to enhance knowledge and productivity, personal care for attractiveness and healthiness in order to raise productivity, and social activities to develop connections for possible future opportunities including wage increase. These activities should be promoted for productive leisure time and for welfare improvement.Keywords: Leisure, wage, time use, Thailand.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1577