Search results for: fluent speakers

Authors: Pingping Lin, Xudong Luo

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Natural language often conveys emotions of speakers. Therefore, sentiment analysis on what people say is prevalent in the field of natural language process and has great application value in many practical problems. Thus, to help people understand its application value, in this paper, we survey various applications of sentiment analysis, including the ones in online business and offline business as well as other types of its applications. In particular, we give some application examples in intelligent customer service systems in China. Besides, we compare the applications of sentiment analysis on Twitter, Weibo, Taobao and Facebook, and discuss some challenges. Finally, we point out the challenges faced in the applications of sentiment analysis and the work that is worth being studied in the future.

Keywords: application, natural language processing, online comments, sentiment analysis

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Authors: Hariti Rafika, Fekih Malika, Saighi Mohamed

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Heat transfer by natural convection in storage tanks for LNG is extremely related to heat gains through the walls with thermal insulation is not perfectly efficient. In this paper, we present the study of natural convection in the unsteady regime for natural gas in aware phase using the fluent software. The gas is just on the surface of the liquid phase. The CFD numerical method used to solve the system of equations is based on the finite volume method. This numerical simulation allowed us to determine the temperature profiles, the stream function, the velocity vectors and the variation of the heat flux density in the vapor phase in the LNG storage tank volume. The results obtained for a general configuration, by numerical simulation were compared to those found in the literature.

Keywords: numerical simulation, natural convection, heat gains, storage tank, liquefied natural gas

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Authors: E. Krasnova, E. Bulgakova, V. Shchemelinin

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The paper deals with acoustic-spectrographic voice identification method in terms of its performance in non-native language speech. Performance evaluation is conducted by comparing the result of the analysis of recordings containing native language speech with recordings that contain foreign language speech. Our research is based on Tajik and Russian speech of Tajik native speakers due to the character of the criminal situation with drug trafficking. We propose a pilot experiment that represents a primary attempt enter the field.

Keywords: speaker identification, acoustic-spectrographic method, non-native speech, performance evaluation

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Authors: Ibrahim Garba

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This research involved the use of word distributions and morphological knowledge by speakers of Arabic learning English connected different allomorphs in order to realize how the morphology and syntax of English gives meaning through using interactive crossword puzzles (ICP). Fifteen chapters covered with a class of nine learners over an academic year of an intensive English program were reviewed using the ICP. Learners were questioned about how the use of this gaming element enhanced and motivated their learning of English. The findings were positive indicating a successful implementation of ICP both at creational and user levels. This indicated a positive role technology had when learning and teaching English through adopting an interactive gaming element for learning English.

Keywords: distribution, gaming, interactive-crossword-puzzle, morphology

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Authors: Wenjing Ding, Weiwei Shan, Zijuan, Wang, Chao He

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Liquid spray heat exchanger is the critical equipment of temperature regulating system by gaseous nitrogen which realizes the environment temperature in the range of -180 ℃~+180 ℃. Liquid nitrogen is atomized into smaller liquid drops through liquid nitrogen sprayer and then contacts with gaseous nitrogen to be cooled. By adjusting the pressure of liquid nitrogen and gaseous nitrogen, the flowrate of liquid nitrogen is changed to realize the required outlet temperature of heat exchanger. The temperature accuracy of shrouds is ±1 ℃. Liquid nitrogen spray heat exchanger is simulated by CATIA, and the numerical simulation is performed by FLUENT. The comparison between the tests and numerical simulation is conducted. Moreover, the results help to improve the design of liquid nitrogen spray heat exchanger.

Keywords: liquid nitrogen spray, temperature regulating system, heat exchanger, numerical simulation

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Authors: Hamad Alhajeri, Abdulrahman Almutairi, A. H. Alenezi, M. H. Alhajeri, Ayedh Alajmi

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The flow around three porous cylinders in inline arrangement is investigated in this paper computationally using the commercial code FLUENT. The arrangement generally operates with the dirty gases passing through the porous cylinders, the particulate material being deposited on the outside of the cylinders. However, in a combined cycle power plant, filtration is required to allow the hot exhaust gases to be fed to a turbine without causing any physical damage to the turbine blades. Three cylinder elements are placed in a two-dimensional rectangle duct with fixed face velocity and varying the velocity ratio between the approach and face velocity. Particle trajectories are obtained for a number of particle diameters and different inlet (approach) velocity to face filtration velocity ratios to investigate the behavior of particles around the cylinder.

Keywords: porous cylinders, CFD, fluid flow, filtration

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Authors: Dmitry V. Fomichev, Vladimir V. Solonin

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This paper presents the findings from a numerical simulation of the flow in 37-rod fuel assembly models spaced by a double-wire trapezoidal wrapping as applied to the BREST-OD-300 experimental nuclear reactor. Data on a high static pressure distribution within the models, and equations for determining the fuel bundle flow friction factors have been obtained. Recommendations are provided on using the closing turbulence models available in the ANSYS Fluent. A comparative analysis has been performed against the existing empirical equations for determining the flow friction factors. The calculated and experimental data fit has been shown. An analysis into the experimental data and results of the numerical simulation of the BREST-OD-300 fuel rod assembly hydrodynamic performance are presented.

Keywords: BREST-OD-300, ware-spaces, fuel assembly, computation fluid dynamics

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Authors: Maria Antonietta Marongiu

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Propositional information in discourse is made coherent, intelligible, and persuasive through metadiscourse. The linguistic and rhetorical choices that writers/speakers make to organize and negotiate content matter are intended to help relate a text to its context. Besides, they help the audience to connect to and interpret a text according to the values of a specific discourse community. Based on these assumptions, this work aims to analyse the use of metadiscourse in the spoken performance of teachers in online EFL, ESP, and subject-teacher courses taught in English to non-native learners in higher education. In point of fact, the global spread of Covid 19 has forced universities to transition their in-class courses to online delivery. This has inevitably placed on the instructor a heavier interactional responsibility compared to in-class courses. Accordingly, online delivery needs greater structuring as regards establishing the reader/listener’s resources for text understanding and negotiating. Indeed, in online as well as in in-class courses, lessons are social acts which take place in contexts where interlocutors, as members of a community, affect the ways ideas are presented and understood. Following Hyland’s Interactional Model of Metadiscourse (2005), this study intends to investigate Teacher Talk in online academic courses during the Covid 19 lock-down in Italy. The selected corpus includes the transcripts of online EFL and ESP courses and subject-teachers online courses taught in English. The objective of the investigation is, firstly, to ascertain the presence of metadiscourse in the form of interactive devices (to guide the listener through the text) and interactional features (to involve the listener in the subject). Previous research on metadiscourse in academic discourse, in college students' presentations in EAP (English for Academic Purposes) lessons, as well as in online teaching methodology courses and MOOC (Massive Open Online Courses) has shown that instructors use a vast array of metadiscoursal features intended to express the speakers’ intentions and standing with respect to discourse. Besides, they tend to use directions to orient their listeners and logical connectors referring to the structure of the text. Accordingly, the purpose of the investigation is also to find out whether metadiscourse is used as a rhetorical strategy by instructors to control, evaluate and negotiate the impact of the ongoing talk, and eventually to signal their attitudes towards the content and the audience. Thus, the use of metadiscourse can contribute to the informative and persuasive impact of discourse, and to the effectiveness of online communication, especially in learning contexts.

Keywords: discourse analysis, metadiscourse, online EFL and ESP teaching, rhetoric

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Authors: Qasim Zaheer, Jehanzeb Masud

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The understanding of entrainment and mixing phenomenon in the ejector pump is of pivotal importance for designing and performance estimation. In this paper, the existence of turbulent vortical structures due to Kelvin-Helmholtz instability at the free surface between the motive and the entrained fluids streams are simulated using Embedded LES methodology. The efficacy of Embedded LES for simulation of complex flow field of ejector pump is evaluated using ANSYS Fluent®. The enhanced mixing and entrainment process due to breaking down of larger eddies into smaller ones as a consequence of Vortex Stretching phenomenon is captured in this study. Moreover, the flow field characteristics of ejector pump like pressure velocity fields and mass flow rates are analyzed and validated against the experimental results.

Keywords: Kelvin Helmholtz instability, embedded LES, complex flow field, ejector pump

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Authors: Yadab Giri

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Confidence is considered a power of a good speaker, and it also can be taken as a tool for speaking. The paper entitled ‘Developing Speaking Confidence of Students through Communicative Activities’ has been written with the purpose of developing the speaking confidence of the students of the Seventh grade of our context in mind. The research is designed under the interpretive paradigm of action research. During my research, thirteen students from class seven were chosen for the study. It was seen a lot of improvement in their confidence while communicating with other speakers by the end of the eighth week. Though there is a positive result of the invention, some students still did not develop the level of confidence that they could have developed to get a satisfactory response. Therefore, the outcome of my action research is positive because students are eager and interested in speaking daily in the initiation of their English class, and they have improved in their speaking.

Keywords: confidence, speaking skills, action research, reflection with feedback and observation, finally endeavour

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Authors: Han-Taw Chen, Chung-Hou Lai, Tzu-Hsiang Lin, Ge-Jang He

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This study applies the inverse method and three-dimensional CFD commercial software in conjunction with the experimental temperature data to investigate the heat transfer and fluid flow characteristics of the plate-fin heat sink in a closed rectangular enclosure for various values of fin height. The inverse method with the finite difference method and the experimental temperature data is applied to determine the heat transfer coefficient. The k-ε turbulence model is used to obtain the heat transfer and fluid flow characteristics within the fins. To validate the accuracy of the results obtained, the comparison of the average heat transfer coefficient is made. The calculated temperature at selected measurement locations on the plate-fin is also compared with experimental data.

Keywords: inverse method, FLUENT, k-ε model, heat transfer characteristics, plate-fin heat sink

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Authors: Hariti Rafika, Fekih Malika, Saighi Mohamed

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During the period storage of liquefied natural gas, stability is necessarily affected by natural convection along the walls of the tank with thermal insulation is not perfectly efficient. In this paper, we present the numerical simulation of heat transfert by natural convection double diffusion,in unsteady laminar regime in a storage tank. The storage tank contains a liquefied natural gas (LNG) in its gaseous phase. Fluent, a commercial CFD package, based on the numerical finite volume method, is used to simulate the flow. The gas is just on the surface of the liquid phase. This numerical simulation allowed us to determine the temperature profiles, the stream function, the velocity vectors and the variation of the heat flux density in the vapor phase in the LNG storage tank volume. The results obtained for a general configuration, by numerical simulation were compared to those found in the literature.

Keywords: numerical simulation, natural convection, heat gains, storage tank, liquefied natural gas

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Authors: Rose-Juliet Anyanwu

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The principal objective of this paper is to investigate whether some sort of phonological processes, such as elision, aspiration, glottalisation, and hardening can be used to account for the behaviour of the glottal fricative (or approximant, as the case may be) ‘h’ in both French and Yoruba. French and Yoruba speakers generally tend to say, for instance ‘ockey’ and ‘amburger’, instead of ‘hockey’ and ‘hamburger’, respectively. Whereas the Yoruba conversely say, for instance ‘hadd’ for ‘add’, ‘heat’ for ‘eat’ on the one hand and ‘ard’ for ‘hard’, ‘eat’ for ‘heat’ on the other hand, on a similar note, it is not quite clear whether the French, however, if not at least in rare instances, would tend to force themselves to pronounce (in any form whatsoever) the h-sound. Recorded sentences containing h-initial as well as vowel-initial words will be used for the investigation. The present paper is meant to contribute to work on aspiration, compensation, elision, and glottalisation, as well as hardening.

Keywords: aspiration, compensation, glottalisation, hardening

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Authors: Loay Badran

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This article on synonymy came into existence to meet the academic needs of students who specialize in this field. The article has two parts: the first part discusses the forms that authors of textbooks and dictionaries assumed when explaining a word as well as explaining the precision or lack of it thereof in delivering an understandable and clear meaning of using such forms. Meanwhile, the second part of this research article focuses on the application of synonymy and at taking into consideration the point of view of others who dismissed synonymy in its minute details, especially Alaskari in his book “Linguistic Differences” “Al Forouq Alloqhawiyyah”. The author determined that collecting the most commonly-used synonymous notions scattered in Alaskari’s book and compiling them in tables would be of great importance in easing lessons according to the Arabic Alphabet System meanwhile citing all that pertains to the corresponding scattered pages in “Linguistic Differences”.

Keywords: synonymy, semantics, camel, teaching, non-native

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Authors: N. M. M. Ammar, S. M. Mustaqim, N. M. Nadzir

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The most important problem occurs on oil spills in sea water is to reduce the oil spills size. This study deals with the development of high pressurized nozzle using dispersion method for oil leakage in offshore. 3D numerical simulation results were obtained using ANSYS Fluent 13.0 code and correlate with the experimental data for validation. This paper studies the contribution of the process on flow speed and pressure of the flow from two different geometrical designs of nozzles and to generate a spray pattern suitable for dispersant application. Factor of size distribution of droplets generated by the nozzle is calculated using pressures ranging from 2 to 6 bars. Results obtain from both analyses shows a significant spray pattern and flow distribution as well as distance. Results also show a significant contribution on the effect of oil leakage in terms of the diameter of the oil spills break up.

Keywords: arc nozzle, CFD simulation, droplets, oil spills

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Authors: Amitabh Das, Yash Jain, Mohammad Rafiq B. Agrewale, K. C. Vora

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Role of wheel and underbody aerodynamics of vehicle in the formation of drag forces is detrimental to the fuel (energy) consumption during the course of operation at high velocities. This paper deals with the CFD simulation of the flow around the wheels of a bus with different wheel housing geometry and pattern. Based on benchmarking a model of a bus is selected and analysis is performed. The aerodynamic drag coefficient is obtained and turbulence around wheels is observed using ANSYS Fluent CFD simulation for different combinations of wheel-housing at the front wheels, at the rear wheels and both in the front and rear wheels. The drag force is recorded and corresponding influence on energy consumption on an electric bus is evaluated mathematically. A comparison is drawn between energy consumption of bus body without wheel housing and bus body with wheel housing. The result shows a significant reduction in drag coefficient and fuel consumption.

Keywords: wheel-housing, CFD simulation, drag coefficient, energy consumption

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Authors: Si Chen, Caroline Wiltshire, Bin Li

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This study statistically models the surface f0 contour and the underlying pitch target of a well-studied third sandhi tone of Mandarin Chinese. Although the growth curve analysis on the surface f0 contours indicates non-neutralization of this sandhi tone (T3) and the base T2, their underlying pitch targets do show neutralization. These results in Mandarin are also consistent with the perception of native speakers, where they cannot distinguish the third T3 from the base T2, compensating contextual variation. It is possible to use the proposed statistical procedure of testing underlying pitch targets to verify tone sandhi processes in other tonal languages.

Keywords: growth curve analysis, Mandarin Chinese, tone sandhi, underlying pitch target

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Authors: Hsien Hao Teng

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This study uses numerical simulation to analyze the aerodynamic characteristics of the 53-degree Lambda wing with a sweep angle and mainly discusses the numerical simulation results and physical characteristics of the wall y+. Use the commercial software Fluent to execute Mach number 0.15; when the angle of attack attitude is between 0 degrees and 27 degrees, the physical characteristics of the overall aerodynamic force are analyzed, especially when the fluid separation and vortex structure changes are discussed under the condition of high angle of attack, it will affect The instability of pitching moment. In the numerical calculation, the use of wall y+ and turbulence model will affect the prediction of vortex generation and the difference in structure. The analysis results are compared with experimental data to discuss the trend of the aerodynamic characteristics of the Lambda wing.

Keywords: lambda wing, wall function, turbulence model, computational fluid dynamics

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Authors: Lewis Mehl-Madrona, Josephine Conte, Barbara Mainguy

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We explore the historical connection of Andrew Taylor Still with the aboriginal nations placed in Missouri, notably the Shawnee, Pawnee, Kickapoo, Cherokee, and the Pottowattomy. Still was fluent in Shawnee and himself was part Native American (Lumbee). These nations had well-developed forms of hands-on healing as well as practicing lightning bone setting. They were more sophisticated than their European-derived neighbors in treating fractures and discolocations. We trace Still’s writings as evidence for his connectedness with these people and respect for their traditions. We explore the traditional hands-on therapies of these nations and discover that they are quite similar to osteopathy. We propose that Still was a translator of traditional manual medicine of the nations into the mainstream of American society. While, surely, he made his own personal contributions to manual medicine, he did not invent osteopathy de novo but relied on methods that were well-developed across centuries for his inspiration.

Keywords: indigenous healing, indigenous bodywork, American osteopathy, Andrew Taylor Still, Cherokee, Shawnee

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Authors: Yuanxia Zheng, Min Zhong, Cong Xin, Guoxiong Liu, Liqi Zhu

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Trust is a critical foundation of social interaction and development, playing a significant role in the physical and mental well-being of children, as well as their social participation. Previous research has demonstrated that young children do not blindly trust others but make selective trust judgments based on available information. The characteristics of speakers can influence children’s trust judgments. According to Mayer et al.’s model of trust, these characteristics of speakers, including ability, benevolence, and integrity, can influence children’s trust judgments. While previous research has focused primarily on the effects of ability and benevolence, there has been relatively little attention paid to integrity, which refers to individuals’ adherence to promises, fairness, and justice. This study focuses specifically on how keeping/breaking promises affects young children’s trust judgments. The paradigm of selective trust was employed in two experiments. A sample size of 100 children was required for an effect size of w = 0.30，α = 0.05，1-β = 0.85, using G*Power 3.1. This study employed a 2×2 within-subjects design to investigate the effects of moral valence of promises (within-subjects factor: moral vs. immoral promises), and fulfilment of promises (within-subjects factor: kept vs. broken promises) on children’s trust judgments (divided into declarative and promising contexts). In Experiment 1 adapted binary choice paradigms, presenting 118 preschoolers (62 girls, Mean age = 4.99 years, SD = 0.78) with four conflict scenarios involving the keeping or breaking moral/immoral promises, in order to investigate children’s trust judgments. Experiment 2 utilized single choice paradigms, in which 112 preschoolers (57 girls, Mean age = 4.94 years, SD = 0.80) were presented four stories to examine their level of trust. The results of Experiment 1 showed that preschoolers selectively trusted both promisors who kept moral promises and those who broke immoral promises, as well as their assertions and new promises. Additionally, the 5.5-6.5-year-old children are more likely to trust both promisors who keep moral promises and those who break immoral promises more than the 3.5- 4.5-year-old children. Moreover, preschoolers are more likely to make accurate trust judgments towards promisor who kept moral promise compared to those who broke immoral promises. The results of Experiment 2 showed significant differences of preschoolers’ trust degree: kept moral promise > broke immoral promise > broke moral promise ≈ kept immoral promise. This study is the first to investigate the development of trust judgement in moral promise among preschoolers aged 3.5-6.5. The results show that preschoolers can consider both valence and fulfilment of promises when making trust judgments. Furthermore, as preschoolers mature, they become more inclined to trust promisors who keep moral promises and those who break immoral promises. Additionally, the study reveals that preschoolers have the highest level of trust in promisors who kept moral promises, followed by those who broke immoral promises. Promisors who broke moral promises and those who kept immoral promises are trusted the least. These findings contribute valuable insights to our understanding of moral promises and trust judgment.

Keywords: promise, trust, moral judgement, preschoolers

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Authors: Rory Patrick O'Kane

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More universities and third level institutions now require at least an IELTS Band 6 for entry into courses of study for non-native speakers of English. This presentation focuses on IELTS Academic Writing Tasks 1 and 2 and in particular on the marking criterion of Coherence and Cohesion. A requirement for candidates aiming at Band 6 and above is that they produce answers which show a clear, overall progression of information and ideas and which use cohesive devices effectively. With this in mind, the presenter will examine what exactly is meant by coherence and cohesion and various strategies which can be used to assist students in improving their scores in this area. A number of classroom teaching ideas will be introduced, and participants will have the opportunity to compare and discuss sample answers written by candidates for this examination with a specific focus on coherence and cohesion. Intended audience: Teachers of IELTS Academic Writing.

Keywords: coherence, cohesion, IELTS, strategies

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Authors: Arfat Bait Jamil

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This study investigates how the compliment response of thanking is performed by Omani and Australian, lecturers and students, in higher educational settings. Semi-structured interviews and observation records were used to collect data. Thanking responses were aggregated from interviews with Omani lecturers and students in Oman, and from Australian lecturers and students in Australia, wherein they were asked to imagine themselves being complimented on five different compliment topics. After the interviews, they used observation record to note down real-life examples of compliment exchanges, along with their opinions. The findings show that thanking is not a simple compliment response. Depending on the context in which the compliment is delivered, thanking does not always suggest positive thoughts or feelings and compliment approval.

Keywords: Australia, compliment responses, Oman, thanking

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Authors: T. Thein, S. Kalyar Myo

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Human uses visual information for understanding the speech contents in noisy conditions or in situations where the audio signal is not available. The primary advantage of visual information is that it is not affected by the acoustic noise and cross talk among speakers. Using visual information from the lip movements can improve the accuracy and robustness of automatic speech recognition. However, a major challenge with most automatic lip reading system is to find a robust and efficient method for extracting the linguistically relevant speech information from a lip image sequence. This is a difficult task due to variation caused by different speakers, illumination, camera setting and the inherent low luminance and chrominance contrast between lip and non-lip region. Several researchers have been developing methods to overcome these problems; the one is lip reading. Moreover, it is well known that visual information about speech through lip reading is very useful for human speech recognition system. Lip reading is the technique of a comprehensive understanding of underlying speech by processing on the movement of lips. Therefore, lip reading system is one of the different supportive technologies for hearing impaired or elderly people, and it is an active research area. The need for lip reading system is ever increasing for every language. This research aims to develop a visual teaching method system for the hearing impaired persons in Myanmar, how to pronounce words precisely by identifying the features of lip movement. The proposed research will work a lip reading system for Myanmar Consonants, one syllable consonants (င (Nga)၊ ည (Nya)၊ မ (Ma)၊ လ (La)၊ ၀ (Wa)၊ သ (Tha)၊ ဟ (Ha)၊ အ (Ah) ) and two syllable consonants ( က(Ka Gyi)၊ ခ (Kha Gway)၊ ဂ (Ga Nge)၊ ဃ (Ga Gyi)၊ စ (Sa Lone)၊ ဆ (Sa Lain)၊ ဇ (Za Gwe) ၊ ဒ (Da Dway)၊ ဏ (Na Gyi)၊ န (Na Nge)၊ ပ (Pa Saug)၊ ဘ (Ba Gone)၊ ရ (Ya Gaug)၊ ဠ (La Gyi) ). In the proposed system, there are three subsystems, the first one is the lip localization system, which localizes the lips in the digital inputs. The next one is the feature extraction system, which extracts features of lip movement suitable for visual speech recognition. And the final one is the classification system. In the proposed research, Two Dimensional Discrete Cosine Transform (2D-DCT) and Linear Discriminant Analysis (LDA) with Active Contour Model (ACM) will be used for lip movement features extraction. Support Vector Machine (SVM) classifier is used for finding class parameter and class number in training set and testing set. Then, experiments will be carried out for the recognition accuracy of Myanmar consonants using the only visual information on lip movements which are useful for visual speech of Myanmar languages. The result will show the effectiveness of the lip movement recognition for Myanmar Consonants. This system will help the hearing impaired persons to use as the language learning application. This system can also be useful for normal hearing persons in noisy environments or conditions where they can find out what was said by other people without hearing voice.

Keywords: feature extraction, lip reading, lip localization, Active Contour Model (ACM), Linear Discriminant Analysis (LDA), Support Vector Machine (SVM), Two Dimensional Discrete Cosine Transform (2D-DCT)

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Authors: H. Golchoobian, S. Saedodin, M. H. Taheri, A. Sarafraz

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In this paper, natural convection in an attic is numerically investigated. The geometry of the problem is considered to be a triangular enclosure. ANSYS Fluent software is used for modeling and numerical solution. This study is for steady state. Four right-angled triangles with height to base ratios of 2, 1, 0.5 and 0.25 are considered. The behavior of various parameters related to its performance, including temperature distribution and velocity vectors are evaluated, and graphs for the Nusselt number have been drawn. Also, in this study, the effect of geometric shape of enclosure with different height-to-base ratios has been evaluated for three types of boundary conditions of winter, summer day and one another state. It can be concluded that as the bottom side temperature and ratio of base to height of the enclosure increases, the convective effects become more prominent and circulation happened.

Keywords: enclosure, natural convection, numerical solution, Nusselt number, triangular

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Authors: Nguyen Van Que, Nguyen Huy The

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This paper presents combined natural and forced convection of humid air flow. The film condensation of water vapour on a cold floor was investigated using ANSYS Fluent software. User-defined Functions(UDFs) were developed and added to address the issue of film condensation at the surface of the floor. Those UDFs were validated by analytical results on a flat plate. The film condensation model based on mass transfer was used to solve phase change. On the floor, condensation rate was obtained by mass fraction change near the floor. The study investigated effects of inlet velocity, inlet relative humidity and cold floor temperature on the condensation rate. The simulations were done in both 2D and 3D models to show the difference and need for 3D modeling of condensation.

Keywords: heat and mass transfer, convection, condensation, relative humidity, user-defined functions

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Authors: Satish Kumar Dewangan, Santosh Kumar Senapati

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The present work focuses on the investigation of the effect of non-Newtonian behavior on the oil-water stratified flow in a horizontal channel using ANSYS Fluent. Coupled level set and volume of fluid (CLSVOF) has been used to capture the evolving interface assuming unsteady, coaxial flow with constant fluid properties. The diametric variation of oil volume fraction, mixture velocity, total pressure and pressure gradient has been studied. Non-Newtonian behavior of oil has been represented by the power law model in order to investigate the effect of flow behavior index. Stratified flow pattern tends to assume dispersed flow pattern with the change in the behavior of oil to non-Newtonian. The pressure gradient is found to be very much sensitive to the flow behavior index. The findings could be useful in designing the transportation pipe line in petroleum industries.

Keywords: oil-water stratified flow, horizontal channel, CLSVOF, non–Newtonian behaviour.

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Authors: N. G. Thangan, A. B. Deoghare, P. M. Padole

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Computational Fluid Dynamics (CFD) aids in modeling the prototype of a real world processes. CFD approach is useful in predicting the fluid flow, heat transfer mass transfer and other flow related phenomenon. In present study, hydrodynamic characteristics of gas-solid cylindrical fluidized bed is compared with conical fluidized beds. A 2D fluidized bed consists of different configurations of particle size of iron oxide, bed height and superficial velocities of nitrogen. Simulations are performed to capture the complex physics associated with it. The Eulerian multiphase model is prepared in ANSYS FLUENT v.14 which is used to simulate fluidization process. It is analyzed with nitrogen as primary phase and iron oxide as secondary phase. The bed hydrodynamics is assessed prominently to examine effect on fluidization time, pressure drop, minimum fluidization velocity, and gas holdup in the system.

Keywords: fluidized bed, bed hydrodynamics, Eulerian multiphase approach, computational fluid dynamics

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Authors: Mohamed M. Abo Elazm, Ali I. Shehata, Mohamed M. Khairat Dawood

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A computational fluid dynamics (CFD) program FLUENT has been used to predict the fluid flow and heat transfer distribution within concentric heat exchangers. The effect of inlet inclination angle has been investigated with Reynolds number range (3000 – 4000) and Pr=0.71. The heat exchanger is fabricated from copper concentric inner tube with a length of 750 mm. The effects of hot to cold inlet flow rate ratio (MH/MC), Reynolds's number and of inlet inclination angle of 30°, 45°, 60° and 90° are considered. The results showed that the numerical prediction shows a good agreement with experimental measurement. The results present an efficient design of concentric tube heat exchanger to enhance the heat transfer by increasing the swirling effect.

Keywords: heat transfer, swirling effect, CFD, inclination angle, concentric tube heat exchange

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Authors: Geovana Soncin, Larissa Berti

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Some aspects of prosody acquisition remain still unclear, especially regarding atypical speech development processes. This work deals with prosody acquisition and its implications for clinical purposes. Therefore, we analyze speech samples produced by adult speakers, children in typical language development, and children with phonological disorders. Phonological disorder comprises deviating manifestations characterized by inconsistencies in the phonological representation of a linguistic system under acquisition. The clinical assessment is performed mostly based on contrasts whose manifestations occur in the segmental level of a phonological system. Prosodic organization of spoken utterances is not included in the standard assessment. However, assuming that prosody is part of the phonological system, it was hypothesized that children with Phonological Disorders could present inconsistencies that also occur at a prosodic level. Based on this hypothesis, the paper aims to analyze contrastive focus marking in the speech of children with Phonological Disorders in comparison with the speech of children under Typical Language Development and adults. The participants of all groups were native speakers of Brazilian Portuguese. The investigation was designed in such a way as to identify differences and similarities among the groups that could be interpreted as clues of normal or deviant processes of prosody acquisition. Contrastive focus in Brazilian Portuguese is marked by increasing duration, f0, and intensity on the focused element as well as by a particular type of pitch accent (L*+H). Thirty-nine subjects participated, thirteen from each group. Acoustic analysis was performed, considering duration, intensity, and intonation as parameters. Children with PD were recruited in sessions from a service provided by Speech-Language Pathology Therapy; children in TD, paired in age and sex with the first group, were recruited in a regular school; and 20-24 years old adults were recruited from a University class. In a game prepared to elicit focused sentences, all of them produced the sentence “Girls love red dress,” marking focus on different syntactic positions: subject, verb, and object. Results showed that adults, children in typical language development, and children with Phonological Disorders marked contrastive focus differently: typical children used all parameters like adults do; however, in comparison with them, they exaggerated duration and, in the opposite direction, they did not increase f0 in a sufficient magnitude as adults; children with Phonological Disorder presented inconsistencies in duration, not increasing it in some syntactic positions, and also in intonation, not producing the representative pitch accent of contrastive focus. The results suggest prosody is also affected by phonological disorder and give clues of developmental processes of prosody acquisition.

Keywords: Brazilian Portuguese, contrastive focus, phonological disorder, prosody acquisition

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Authors: Han-Taw Chen, Tzu-Hsiang Lin, Chung-Hou Lai

Abstract:

This study applies the inverse method and three-dimensional CFD commercial software in conjunction with the experimental temperature data to investigate the heat transfer and fluid flow characteristics of the plate-fin heat sink in a rectangular closed enclosure. The inverse method with the finite difference method and the experimental temperature data is applied to determine the approximate heat transfer coefficient. Later, based on the obtained results, the zero-equation turbulence model is used to obtain the heat transfer and fluid flow characteristics between two fins. To validate the accuracy of the results obtained, the comparison of the heat transfer coefficient is made. The obtained temperature at selected measurement locations of the fin is also compared with experimental data. The effect of the height of the rectangular enclosure on the obtained results is discussed.

Keywords: inverse method, fluent, heat transfer characteristics, plate-fin heat sink

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