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Profiling of Urban Noise Using Artificial Intelligence

Computer Systems Science & Engineering 2023年第5期45卷 1309-1321页

作者： Le Quang Thao Duong Duc Cuong tran thi tuong anh tran Duc Luong Ph.D.Faculty of Physics VNU University of ScienceHanoi100000Vietnam University of Science Vietnam National UniversityHanoi100000Vietnam The International School of Penang(Uplands) PenangMalaysia Alpha School Hanoi100000Vietnam

Noise pollution tends to receive less awareness compared to other types of pollution,however,it greatly impacts the quality of life for humans such as causing sleep disruption,stress or hearing *** urban sound through the identification of noise sources in cities could help to benefit livability by reducing exposure to noise pollution through methods such as noise control,planning of the soundscape environment,or selection of safe living *** this paper,we proposed a self-attention long short-term memory(LSTM)method that can improve sound classification compared to previous *** attention mechanism will be designed solely to capture the key section of an audio data *** is practical as we only need to process important parts of the data and can ignore the rest,making it applicable when gathering information with long-term *** dataset used is the Urbansound8k dataset which specifically pertains to urban environments and data augmentation was applied to overcome imbalanced data and dataset *** audio sources in the dataset were normalized to mono *** the dataset above,an experiment was conducted to confirm the suitability of the proposed model when applied to the mel-spectrogram and MFCC(Mel-Frequency Cepstral Coefficients)datasets transformed from the original *** the classification accuracy depends on the machine learning models as well as the input data,therefore we have evaluated different class models and extraction methods to find the best *** combining data augmentation techniques and various extraction methods,our classification model has achieved state-of-the-art performance,each class accuracy is up to 98%.

关键词： Urban noise noise classification mel-spectrogram MFCC LSTM self-attention

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transient response of doubly-curved bio-inspired composite shells resting on viscoelastic foundation subject to blast load using improved first-order shear theory and isogeometric approach

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Defence Technology（防务技术） 2024年第8期38卷 171-193页

作者： Thuy tran thi Thu Tu Nguyen anh Hue Nguyen thi Hong Nguyen thi School of Mechanical and Automotive Engineering Hanoi University of IndustryHanoiViet Nam Faculty of Technical Fundamental University of Transport TechnologyHanoiViet Nam Faculty of Mechanical Engineering Thuyloi University175 Tay SonDong DaHanoiViet Nam

Investigating natural-inspired applications is a perennially appealing subject for scientists. The current increase in the speed of natural-origin structure growth may be linked to their superior mechanical properties and environmental resilience. Biological composite structures with helicoidal schemes and designs have remarkable capacities to absorb impact energy and withstand damage. However, there is a dearth of extensive study on the influence of fiber redirection and reorientation inside the matrix of a helicoid structure on its mechanical performance and reactivity. The present study aimed to explore the static and transient responses of a bio-inspired helicoid laminated composite(B-iHLC) shell under the influence of an explosive load using an isomorphic method. The structural integrity of the shell is maintained by a viscoelastic basis known as the Pasternak foundation, which encompasses two coefficients of stiffness and one coefficient of damping. The equilibrium equations governing shell dynamics are obtained by using Hamilton's principle and including the modified first-order shear theory,therefore obviating the need to employ a shear correction factor. The paper's model and approach are validated by doing numerical comparisons with respected publications. The findings of this study may be used in the construction of military and civilian infrastructure in situations when the structure is subjected to severe stresses that might potentially result in catastrophic collapse. The findings of this paper serve as the foundation for several other issues, including geometric optimization and the dynamic response of similar mechanical structures.

关键词： Blast load Modified first-order shear theory Biological composite structures

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Generating highly active oxide-phosphide heterostructure through interfacial engineering to break the energy scaling relation toward urea-assisted natural seawater electrolysis

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Journal of Energy Chemistry 2024年第10期97卷 687-699,I0014页

作者： Ngoc Quang tran Nam Hoang Vu Jianmin Yu Khanh Vy Pham Nguyen Thuy Tien Nguyen tran Thuy-Kieu Truong Lishan Peng thi anh Le Yoshiyuki Kawazoe Center for Innovative Materials and Architectures Ho Chi Minh City 700000Vietnam Vietnam National University Ho Chi Minh City 700000Vietnam Faculty of Materials Science and Technology University of ScienceHo Chi Minh City 700000Vietnam Department of Mechanical Engineering Hanbat National University(HBNU)Daejeon 34158Republic of Korea Key Laboratory of Rare Earths Ganjiang Innovation AcademyChinese Academy of SciencesGanzhou 341119JiangxiChina School of Chemical Engineering-Hanoi University of Science and Technology Hanoi 10000Vietnam New Industry Creation Hatchery Center Tohoku UniversitySendai 980-8579Japan

Urea-assisted natural seawater electrolysis is an emerging technology that is effective for grid-scale carbon-neutral hydrogen mass production yet *** scaling relations is an effective strategy to break through the bottleneck of natural seawater ***,by DFT calculation,we demonstrated that the interface boundaries between Ni_(2)P and MoO_(2) play an essential role in the selfrelaxation of the Ni-O interfacial bond,effectively modulating a coordination number of intermediates to control independently their adsorption-free energy,thus circumventing the adsorption-energy scaling *** this conceptual model,a well-defined 3D F-doped Ni_(2)P-MoO_(2) heterostructure microrod array was rationally designed via an interfacial engineering strategy toward urea-assisted natural seawater *** a result,the F-Ni_(2)P-MoO_(2) exhibits eminently active and durable bifunctional catalysts for both HER and OER in acid,alkaline,and alkaline sea water-based *** in-situ analysis,we found that a thin amorphous layer of NiOOH,which is evolved from the Ni_(2)P during anodic reaction,is real catalytic active sites for the OER and UOR ***,such electrode-assembled urea-assisted natural seawater electrolyzer requires low voltages of 1.29 and 1.75 V to drive 10 and600 mA cm^(-2)and demonstrates superior durability by operating continuously for 100 h at 100 mA cm^(-2),beyond commercial Pt/C||RuO_(2) and most previous reports.

关键词： Interfacial engineering Break scaling relationships Doping Natural seawater splitting Urea electrolysis

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EP Aquarii:A New Picture of the Circumstellar Envelope

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Research in Astronomy and Astrophysics 2024年第3期24卷 83-105页

作者： Pham T.Nhung Do T.Hoai Pierre Darriulat Pham Tuan-anh Pham N.Diep Nguyen B.Ngoc tran T.Thai Department of Astrophysics Vietnam National Space CenterVietnam Academy of Science and Technology18Hoang Quoc VietNghia DoCau GiayHa Noivietnam

New analyses of earlier ALMA observations of oxygen-rich AGB star EP Aquarii are presented,which complete a previously published analysis and offer a different interpretation of the morpho-kinematics of the circumstellar *** birth of the equatorial density enhancement(EDE)is shown to occur very close to the star where evidence for rotation has been *** to the star and where outflows have been observed:their interaction with the gas of the nascent EDE is seen to play an important role in the development of the wind and the evolution of its radial velocity from 8 to 10 km s^(-1) on the polar symmetry axis to~2 km s^(-1) at the *** implies complex morpho-kinematics:making reliable interpretations with reasonable confidence is *** particular,it questions an earlier interpretation implying the presence of a white dwarf companion orbiting the star at an angular distance of -0″4 from its *** proposes instead an interpretation in terms of a standard mass ejection associated with a shock wave leaving a void of emission in its *** Doppler velocity wings are seen to consist of two components,the upper velocity end of the global wind,reaching above±12 km s^(-1),and an effective line broadening,confined within 200 mas from the center of the star,reaching above±20 km s^(-1) and interpreted as caused by the pattern of shock waves resulting from the interaction between stellar pulsation and convective cell partition.

关键词： stars AGB and post-AGB-(stars) circumstellar matter-radio lines stars

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A Study on Optimizing the Double-Spine Type Flow Path Design for the Overhead transportation System Using Tabu Search Algorithm

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Intelligent Automation & Soft Computing 2024年第2期39卷 255-279页

作者： Nguyen Huu Loc Khuu Thuy Duy Truong Quoc Dien Le tran Thanh Cong Vu Hoa Binh tran tuong Quan Vo Department of Mechatronics Faculty of Mechanical EngineeringHo Chi Minh City University of Technology(HCMUT)Ho Chi Minh CityVietnam Bach Khoa Research Center for Manufacturing Engineering Ho Chi Minh City University of Technology(HCMUT)Ho Chi Minh CityVietnam VietnamNational University Ho ChiMinh City Ho ChiMinh CityVietnam

Optimizing Flow Path Design(FPD)is a popular research area in transportation system design,but its application to Overhead transportation Systems(OTSs)has been *** study focuses on optimizing a double-spine flow path design for OTSs with 10 stations by minimizing the total travel distance for both loaded and empty *** employ transportation methods,specifically the North-West Corner and Stepping-Stone methods,to determine empty vehicle travel ***,the Tabu Search(TS)algorithm is applied to branch the 10 stations into two main layout *** results obtained from our proposed method demonstrate a reduction in the objective function value compared to the initial feasible ***,we explore howchanges in the parameters of the TS algorithm affect the optimal *** validate the feasibility of our approach by comparing it with relevant literature and conducting additional tests on layouts with 20 and 30 stations.

关键词： Overhead transportation systems tabu search double-spine layout transportationmethod empty travel flow path design

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BTEX pollution caused by motorcycles in the megacity of HoChiMinh

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Journal of Environmental Sciences 2013年第2期25卷 348-356页

作者： tran thi Ngoc Lan Pham anh Minh University of Science Vietnam National University227 Nguyen Van CuHoChiMinh 70000Vietnam

Monitoring of benzene, toluene and xylenes （BTEX） was conducted along with traffic counts at 17 roadside sites in urban areas of HoChiMinh. Toluene was the most abundant substance, followed by p,m-xylenes, benzene, o-xylene and ethylbenzene. The maximum observed hour-average benzene concentration was 254 μg/m3 . Motorcycles contributed to 91% of the traffic fleet. High correlations among BTEX species, between BTEX concentrations and the volume of on-road motorcycles, and between inter-species ratios in air and in gasoline indicate the motorcycle-exhaust origin of BTEX species. Daily concentrations of benzene, toluene, ethylbenzene, p,m-xylenes and o-xylene were 56, 121, 21, 64 and 23 μg/m 3 , respectively. p,m-xylenes possess the highest ozone formation potential among the BTEX family.

关键词： air pollution benzene BTEX HoChiMinh motorcycle exhaust

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Fabrication and properties of high efficiency luminescent nanorods EuPO_4·H_2O by soft template method

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Journal of Rare Earths 2011年第12期29卷 1174-1177页

作者： tran Thu Huong tran Kim anh Le thi Vinh W.Strek Hoang thi Khuyen Le Quoc Minh Institute of Materials Science Vietnam Academy of Science and Technology Department of Chemistry Hanoi University of Mining and Geology Institute of Low Temperature and Structure Research University of Engineering and Technology National University Hanoi

Europium orthophosphate monohydrate （EuPO4·H2O） nanorods with typical dimensions of about 10-30 nm in diameter and 300-500 nm in length were prepared by using the soft template method. The effects of using diethylene glycol （DEG） and polyethylene glycol （PEG） polymers as well as the pH values on the size, crystalline structure and morphology of EuPO4·H2O nanorods were investigated. Field emission scanning electron microscopy （FESEM） and X-ray diffraction （XRD） data of the prepared samples were elucidated. The nanorods were highly uniform and their mean length was reduced by using DEG and PEG as soft template agents. For all prepared samples, the rhabdophanetype hexagonal EuPO4·H2O was the dominated phase. The photoluminescence （PL） spectroscopy measurements of EuPO4·H2O nanorods revealed that, under UV excitation, EuPO4·H2O nanorods exhibited strong luminescence with narrow bands corresponding to the intra-4f transitions of ^5D0→^7Fj （j=1, 2, 3, 4） of Eu^3＋ ions. The peaks were found at 594 nm （^5D0→^7F1）, 619 nm （^5D0→^7F2）, 652 nm （^5D0→^7F3）, and 697 nm （^5D0→^7F4）, with the strongest emission at 594 nm.

关键词： soft template method EuPO4·H2O nanorods fluorescence rare earths

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Assessment of different machine learning techniques in predicting the compressive strength of self-compacting concrete

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Frontiers of Structural and Civil Engineering 2022年第7期16卷 928-945页

作者： Van Quan tran Hai-Van thi MAI Thuy-anh NGUYEN Hai-Bang LY Faculty of Civil Engineering University of Transport TechnologyHanoi 100000Vietnam

The compressive strength of self-compacting concrete(SCC)needs to be determined during the construction design *** paper shows that the compressive strength of SCC(CS of SCC)can be successfully predicted from mix design and curing age by a machine learning(ML)technique named the Extreme Gradient Boosting(XGB)algorithm,including non-hybrid and hybrid *** ML techniques,such as Linear regression(LR),K-Nearest Neighbors(KNN),Support Vector Machine(SVM),Decision Trees(DTR),Random Forest(RF),Gradient Boosting(GB),and Artificial Neural Network using two training algorithms LBFGS and SGD(denoted as ANN_LBFGS and ANN_SGD),are also compared with the XGB ***,the hybrid models of eight ML techniques and Particle Swarm Optimization(PSO)are constructed to highlight the reliability and accuracy of SCC compressive strength prediction by the XGB_PSO hybrid *** highest number of SCC samples available in the literature is collected for building the ML *** with previously published works’performance,the proposed XGB method,both hybrid and non-hybrid models,is the most reliable and robust of the examined techniques,and is more accurate than existing ML methods(R2=0.9644,RMSE=4.7801,and MAE=3.4832).Therefore,the XGB model can be used as a practical tool for engineers in predicting the CS of SCC.

关键词： compressive strength self-compacting concrete machine learning techniques particle swarm optimization extreme gradient boosting

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Luminescent and magnetic properties of multifunctional europium(Ⅲ) complex based nanocomposite

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Journal of Rare Earths 2019年第11期37卷 1237-1241页

作者： Hoang thi Khuyen Nguyen Thanh Huong tran Thu Huong Pham thi Lien Do thi anh Thu Nguyen thi anh Huong Wieslaw Strek Le Quoc Minh Institute of Materials Science Vietnam Academy of Science and Technology18 Hoang Quoc VietCau CiayHanoiViet Nam Graduate University of Science and Technology Vietnam Academy of Science and Technology18 Hoang Quoc VietCau GiayHanoiViet Nam Department of Chemistry University of Natural SciencesHanoi National University19 Le Thanh TongHoan KiemHanoiViet Nam Institute of Low Temperature and Structure Research PASOkolna 2Wroclaw 50-422Poland Duy Tan University K7/25 Quang TrungDa DangViet Nam

The luminescent rare earth(RE)complex based multifunctional nanocomposites offer new potential applications of multimodal imaging(magnetic resonance imaging(MRI),fluorescent bioimaging,etc.)that can be associated with therapeutic *** this study,we report some results obtained with novel multifunctional Fe3O4/Si-amine/Eu(NTA)3 nanocomposites that are composed of europium(Ⅲ)complex with 1-(2-naphthoyl)-3,3,3-trifluoroacetone ligands(NTA)(Eu(NTA)3)and superparamagnetic Fe3O4 *** nanocomposites were functionalized with an amine group for biomedicine *** multifunctional Fe3O4/Si-amine/Eu(NTA)3 nanocomposites exhibit both good magnetic behavior of Fe3O4 nanoparticles as a core and strong fluorescent property of europium(Ⅲ)*** characterizations were analyzed by XRD,SEM,EDX and FTIR *** optical properties were studied in detail by UV-VIS spectra and luminescent emission *** magnetic property was estimated by *** effect of concentrations of luminescent Eu(NTA)3 complex on luminescent and magnetic properties is discussed.

关键词： Multifunctional nanocomposite Luminescence Magnetic Europium(Ⅲ)complex Fe3O4 Rare earths

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Fabrication and characterization of YVO_4:Eu^(3+) nanomaterials by the microwave technique

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Journal of Rare Earths 2011年第12期29卷 1137-1141页

作者： tran Thu Huong Vu Duc Tu tran Kim anh Le thi Vinh Le Quoc Minh Institute of Materials Science Vietnamese Academy of Science and Technology University of Engineering and Technology National University Hanoi Departments of Chemistry Hanoi University of Mining and Geology

Fabrication and characterization of YVO4：Eu^3＋ nanophosphors prepared by microwave （MW） irradiation assisted soft template synthesis were reported. The effects of synthesis conditions such as different powers of MW irradiation, pH values and concentration of reac- tion materials on properties of nanophosphor were also investigated to obtain the controllable size, morphology and high luminescence efficiency. Morphology, crystalline structure, and optical properties were characterized by field emission scanning electron microscopy （FE-SEM）, X-ray diffraction （XRD） and fluorescence spectroscopy, respectively. The results showed that YVOa：Eu^3＋ nanophosphors were obtained by using diethyleneglycol （DEG） as soft template, with pH values in the range of 4 to 12, upon microwave irradiation from 300 to 900 W, at temperature of 80 ℃. The high fluorescent YVOa：Eu^3＋ nanocrystals obtained with size from 15 nm down to 8 nm are more effective to develop an ultrahigh sensitive fluorescent label for biomolecule, cell and tissue.

关键词： microwave synthesis method DEG soft template YVO4:Eu^3+ nanophosphor luminescence rare earths

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