检索结果-南通市图书馆

Analysis of an Ar plasma jet in a dielectric barrier discharge conjugated with a microsecond pulse

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2019年第9期21卷 73-81页

作者： Duc Ba nguyen quang Hung TRINH Won Gyu LEE Young Sun MOK Department of Chemical and Biological Engineering Jeju National University Jeju 63243 Republic of Korea Center for Advanced Chemistry Institute of Research and Development Duy Tan University 03 Quang Trung Da Nang Vietnam Division of Chemical Engineering and Bioengineering Kangwon National University Chuncheon Kangwon 24341 Republic of Korea

In this work, an Ar plasma jet generated by an AC-microsecond-pulse-driven dielectric barrier discharge reactor, which had two ring-shaped electrodes isolated from the ambient atmosphere by transformer oil, was investigated. By special design of the oil insulation, a chemically active Ar plasma jet along with a safe and stable plasma process as well as low emission of CO and NOxwere successfully achieved. The results indicated that applied voltage and frequency were basic factors influencing the jet temperature, discharge power, and jet length, which increased significantly with the two operating parameters. Meanwhile, gas velocity affected the jet temperature in a reverse direction. In comparison with a He plasma jet, the Ar plasma jet had relatively low jet temperature under the same level of the input parameters, being preferable for bio-applications. The Ar plasma jet has been tested to interact with human skin within 5 min without the perception of burnt skin and electrical shock.

关键词： Ar plasma jet atmospheric pressure plasma jet OES of Ar gas emission of Ar plasma jet transformer oil

Emotion Recognition with Capsule Neural Network

在线全文

学校读者我要写书评

暂无评论

Computer Systems Science & Engineering 2022年第6期41卷 1083-1098页

作者： Loan Trinh Van quang H.nguyen Thuy Dao Thi Le School of Information and Communication Technology Hanoi University of Science and TechnologyHanoi10000Vietnam Faculty of Information Technology University of Transport and CommunicationsHanoi10000Vietnam

For human-machine communication to be as effective as human-tohuman communication, research on speech emotion recognition is *** the models and the classifiers used to recognize emotions, neural networks appear to be promising due to the network’s ability to learn and the diversity in configuration. Following the convolutional neural network, a capsuleneural network (CapsNet) with inputs and outputs that are not scalar quantitiesbut vectors allows the network to determine the part-whole relationships thatare specific 6 for an object. This paper performs speech emotion recognition basedon CapsNet. The corpora for speech emotion recognition have been augmented byadding white noise and changing voices. The feature parameters of the recognition system input are mel spectrum images along with the characteristics of thesound source, vocal tract and prosody. For the German emotional corpus EMODB, the average accuracy score for 4 emotions, neutral, boredom, anger and happiness, is 99.69%. For Vietnamese emotional corpus BKEmo, this score is94.23% for 4 emotions, neutral, sadness, anger and happiness. The accuracy scoreis highest when combining all the above feature parameters, and this scoreincreases significantly when combining mel spectrum images with the featuresdirectly related to the fundamental frequency.

关键词： Emotion recognition CapsNet data augmentation mel spectrum image fundamental frequency

Adaptive data fusion framework for modeling of non-uniform aerodynamic data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2023年第7期36卷 316-336页

作者： Vinh PHAM Maxim TYAN tuan Anh nguyen Chi-Ho LEE L.V.Thang nguyen Jae-Woo LEE Department of Aerospace Information Engineering Konkuk UniversitySeoul 05029Republic of Korea Konkuk Aerospace Design-Airworthiness Institute Konkuk UniversitySeoul 05029Republic of Korea

Multi-fidelity Data Fusion(MDF)frameworks have emerged as a prominent approach to producing economical but accurate surrogate models for aerodynamic data modeling by integrating data with different fidelity ***,most existing MDF frameworks assume a uniform data structure between sampling data sources;thus,producing an accurate solution at the required level,for cases of non-uniform data structures is *** address this challenge,an Adaptive Multi-fidelity Data Fusion(AMDF)framework is proposed to produce a composite surrogate model which can efficiently model multi-fidelity data featuring non-uniform ***,the design space of the input data with non-uniform data structures is decomposed into subdomains containing simplified ***,different MDF frameworks and a rule-based selection process are adopted to construct multiple local models for the subdomain *** the other hand,the Enhanced Local Fidelity Modeling(ELFM)method is proposed to combine the generated local models into a unique and continuous global ***,the resulting model inherits the features of local models and approximates a complete database for the whole design *** validation of the proposed framework is performed to demonstrate its approximation capabilities in(A)four multi-dimensional analytical problems and(B)a practical engineering case study of constructing an F16C fighter aircraft’s aerodynamic *** comparisons of the generated models using the proposed AMDF framework and conventional MDF approaches using a single global modeling algorithm are performed to reveal the adaptability of the proposed approach for fusing multi-fidelity data featuring non-uniform ***,the results indicated that the proposed framework outperforms the state-of-the-art MDF approach in the cases of non-uniform data.

关键词： Aerodynamic modeling Data fusion Diverse data structure Multi-fidelity data Multi-fidelity surrogate modeling

Emotional Vietnamese Speech Synthesis Using Style-Transfer Learning

在线全文

学校读者我要写书评

暂无评论

Computer Systems Science & Engineering 2023年第2期44卷 1263-1278页

作者： Thanh X.Le An T.Le quang H.nguyen School of Information and Communication Technology Hanoi University of Science and TechnologyHanoi10000Vietnam

In recent years,speech synthesis systems have allowed for the produc-tion of very high-quality ***,research in this domain is now turning to the problem of integrating emotions into ***,the method of con-structing a speech synthesizer for each emotion has some ***,this method often requires an emotional-speech data set with many *** data sets are very time-intensive and labor-intensive to ***,training each of these models requires computers with large computational capabilities and a lot of effort and time for model *** addition,each model for each emotion failed to take advantage of data sets of other *** this paper,we propose a new method to synthesize emotional speech in which the latent expressions of emotions are learned from a small data set of professional actors through a Flow-tron *** addition,we provide a new method to build a speech corpus that is scalable and whose quality is easy to ***,to produce a high-quality speech synthesis model,we used this data set to train the Tacotron 2 *** used it as a pre-trained model to train the Flowtron *** applied this method to synthesize Vietnamese speech with sadness and *** opi-nion score(MOS)assessment results show that MOS is 3.61 for sadness and 3.95 for *** conclusion,the proposed method proves to be more effec-tive for a high degree of automation and fast emotional sentence generation,using a small emotional-speech data set.

关键词： Emotional speech synthesis ﬂowtron speech synthesis style transfer vietnamese speech

Integrating Machine Learning and Evidential Reasoning for User Profiling and Recommendation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science and Systems Engineering 2023年第4期32卷 393-412页

作者： Toan nguyen Mau quang-Hung Le Duc-Vinh Vo Duy Doan Van-Nam Huynh University of Information Technology Ho Chi Minh CityVietnam Vietnam National University Ho Chi Minh CityVietnam Department of Information Technology Quy Nhon UniversityQuy NhonVietnam Ho Chi Minh City University of Banking Ho Chi Minh CityVietnam School of Knowledge Science Japan Advanced Institute of Science and TechnologyIshikawaJapan

User profiles representing users’preferences and interests play an important role in many applications of personalized *** the rapid growth of social platforms,there is a critical need for efficient solutions to learn user profiles from the information they shared on social platforms so as to improve the quality of recommendation *** problem of user profile learning is significantly challenging due to difficulty in handling data from multiple sources,in different formats and often associated with *** this paper,we introduce an integrated approach that combines advanced Machine Learning techniques with evidential reasoning based on Dempster-Shafer theory of evidence for user profiling and *** developed methods for user profile learning and multi-criteria collaborative filtering are demonstrated with experimental results and analysis that show the effectiveness and practicality of the integrated approach.A proposal for extending multi-criteria recommendation systems by incorporating user profiles learned from different sources of data into the recommendation process so as to provide better recommendation capabilities is also highlighted.

关键词： Machine learning Dempster-Shafer theory of evidence user profiles personalized recommendation preferences

Electrochemical Immunosensor for Detection of Atrazine Based on Polyaniline/Graphene

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2016年第6期32卷 539-544页

作者： nguyen Van Chu nguyen Hai Binh Cao Thi Thanh nguyen Van Tu nguyen Le Huy nguyen tuan Dzung Phan Ngoc Minh Vu Thi Thu Tran Dai Lam Institute of Materials Science Vietnam Academy of Science and Technology18 Hoang Quoc VietCau Giay.HanoiViet Nam School of Chemical Engineering.Hanoi University of Science and Technology 1 Dai Co VietHanoiViet Ham Institute for Tropical Technology.Vietnam Academy of Science and Technology 18 Hoang Quoc VietHanoiViet Nam Center for High Technology Development Vietnam Academy of Science and Technology18 Hoang Quoc VietHanoiViet Nam University of Science and Technology of Hanoi.18 Hoang Quoc Viet HanoiViet Ham Graduate University of Science and Technology.Vietnam Academy of Science and Technology 18 Hoang Quoc Viet.HanoiViet Nam

In this study, a novel layer-by-layer polyaniline/graphene （PANi/Gr） structure for electrochemical detec- tion of atrazine was developed. Gr film was synthesized by thermal chemical vapor deposition （CVD） method and transferred onto the PANi-predeposited microelectrode. The properties of PANi/Gr film were thoroughly investigated by high-resolution transmission electron microscopy and Raman techniques. The most attractive feature of this system is a suitable microenvironment, which could provide an amplifi- cation of the conductive signal, thus may contribute to enhancing electron transfer and subsequently improve the sensitivity in electrochemical measurements. With low detection limit （- 43 × 10 -12 g/L）, ac-ceptable stability and good reproducibility, the proposed electrochemical immunosensor could be advantageously extended for multiplexed detection of other agents of environmental pollution.

关键词： Electrochemical immunosensor Polyaniline Graphene Atrazine

Mathematical modeling and numerical computation of the effective interfacial conditions for Stokes flow on an arbitrarily rough solid surface

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2021年第5期42卷 721-746页

作者： A.T.TRAN H.LE quang Q.C.HE D.H.nguyen Research and Application Center for Technology in Civil Engineering University of Transport and CommunicationsHanoi 10000Vietnam Laboratoire Modelisation et Simulation Multi-Echelle Unite Mixte de Recherche 8208Centre National de la Recherche ScientifiqueUniversite Gustave EiffelMarne-la-Vallee F-77454France School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China

The present work is concerned with a two-dimensional(2D)Stokes flow through a channel bounded by two parallel solid *** distance between the walls may be arbitrary,and the surface of one of the walls can be arbitrarily *** main objective of this work consists in homogenizing the heterogeneous interface between the rough wall and fluid so as to obtain an equivalent smooth slippery fluid/solid interface characterized by an effective slip *** solve the corresponding problem,two efficient numerical approaches are elaborated on the basis of the method of fundamental solution(MFS)and the boundary element methods(BEMs).They are applied to different cases where the fluid/solid interface is periodically or randomly *** results obtained by the proposed two methods are compared with those given by the finite element method and some relevant ones reported in the *** comparison shows that the two proposed methods are particularly efficient and accurate.

关键词： effective slip length method of fundamental solution(MFS) boundary element method(BEM) Stokeslet micro-channel fluid/solid interface

Fabrication and Characterization of Multi-layer Heat Mirror with Photocatalytic Properties

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2009年第11期26卷 152-155页

作者： Tran Le tuan Tran Huu Chi nguyen Dac Ngoc Son Luu Minh Nam Hoang Dinh Quan nguyen Department of Applied Physics College of Natural Science National University of He Chi Mirth City 227 Nguyen Van Cu District 5 Ward 4 He Chi Minh City Vietnam Department of Chemical Engineering College of Technology National University of He Chi Minh City 168 Ly Thuong Kiet District 10 Ho chi Minh City Vietnam

A novel TiO2（5）/TiO2（buffer）/Ti（4）/Ag（3）/Ti（2）/TiO2（1） multi-layer film coating with corning glass is designed and fabricated by a dc magnetron sputtering method as a renovation of the well-known TiO2/Ti/Ag/Ti/TiO2 system in order to obtain a heat mirror system with photocatalytic properties due to sufficient thickness of the Ti02 layer. The outer TiO2 layer is fabricated in two steps, possibly claimed as two layers TiO2（5） and TiO2（buuer）, among which TiO2（buffer） the 70-nm-thick layer deposited in poor oxygen effectively minimizes the oxidation toward its neighbor Ti（4） layer. The optimal total thickness of the TiO2（5） and TiO（buffer） di-layer is found to be 300nm to yield a highly photo-catalytic property of the film without affecting the optical properties considerably. This multi-layer film can transmit light of above 75-85% in the visible spectrum （380 ≤ λ≤ 760 nm） and reflect radiation of above 90% in the infrared spectrum （ λ≥760 nm）. Such multi-layer coatings are strongly recommended not only as promising transparent heat mirrors but also as photo-catalytic films for architectural window coatings.

关键词： Condensed matter: electrical magnetic and optical Surfaces interfaces and thin films Chemical physics and physical chemistry

Graphical method based on modified maximum force criterion to indicate forming limit curves of 22MnB5 boron steel sheets at elevated temperatures

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2021年第8期28卷 1009-1018页

作者： Thanh Luyen Quoc-tuan Pham Thi-Bich Mac Tien-Long Banh Duc-Toan nguyen Faculty of Mechanical Engineering Hungyen University of Technology and EducationHungyen 160000Vietnam Division of Computational Mathematics and Engineering Institute for Computational ScienceTon Duc Thang UniversityHo Chi Minh City 70000Vietnam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh City 70000Vietnam School of Mechanical Engineering Hanoi University of Science and TechnologyHanoi City 100000Vietnam

A new approach for predicting forming limit curves(FLCs)at elevated temperatures was proposed *** are often used to predict failure and determine the optimal forming parameters of automotive ***,a graphical method based on a modified maximum force criterion was applied to estimate the FLCs of 22MnB5 boron steel sheets at room temperature using various hardening ***,the predicted FLC data at room temperature were compared with corresponding data obtained from Nakazima's tests to obtain the best *** estimate the FLC at elevated temperatures,tensile tests were conducted at various temperatures to determine the ratios of equivalent fracture strains between the corresponding elevated temperatures and room *** at elevated temperatures could be established based on obtained ***,the predicted FLCs at elevated temperatures did not agree well with the corresponding FLC experimental data of Zhou et al.A new method was proposed herein to improve the prediction of FLCs at elevated *** FLC calculated at room tem-perature was utilized to predict the failure of Nakazima's samples via finite element *** on the simulation results at room temperature,the mathematical relationships between the equivalent ductile fracture strain versus stress triaxiality and strain ratio were established and then combined with ratios between elevated and room temperatures to calculate the FLCs at different *** predicted FLCs at elevated temperatures agree well with the corresponding experimental FLC data.

关键词： Forming limit curve Modified maximum force criterion Graphical method Hardening law Finite element method Boron steel sheet Elevated temperature