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Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： R.A.JAFARI-TALOOKOLAEI H.GHANDVAR E.JUMAEV S.KHATIR T.CUONG-le School of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and Science Center for Engineering Application and Technology Solutions Ho Chi Minh City Open University

This paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP) materials. The strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. The curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. Subsequently, the natural frequencies and transient response of the system are determined. The accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANSYS, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

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A Hybrid Deep learning Approach for PM2.5 Concentration Prediction in Smart Environmental Monitoring

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Intelligent Automation & Soft Computing 2023年第6期36卷 3029-3041页

作者： minh Thanh Vo Anh HVo Huong Bui Tuong le Faculty of Information Technology HUTECH UniversityHo Chi Minh CityVietnam Natural Language Processing and Knowledge Discovery Laboratory Faculty of Information TechnologyTon Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Computing Fundamentals FPT UniversityHo Chi Minh CityVietnam Laboratory for Artificial Intelligence Institute for Computational Science and Artificial IntelligenceVan Lang UniversityHo Chi Minh CityVietnam Faculty of Information Technology Van Lang UniversityHo Chi Minh CityVietnam

Nowadays,air pollution is a big environmental problem in develop-ing *** this problem,particulate matter 2.5(PM2.5)in the air is an air *** its concentration in the air is high in developing countries like Vietnam,it will harm everyone’s *** prediction of PM2.5 concentrations can help to make the correct decision in protecting the health of the *** study develops a hybrid deep learning approach named PM25-CBL model for PM2.5 concentration prediction in Ho Chi minh City,***,this study analyzes the effects of variables on PM2.5 concentrations in Air Quality HCMC *** variables that affect the results will be selected for PM2.5 concentration ***,an efficient PM25-CBL model that integrates a convolutional neural network(CNN)andBidirectionalLongShort-TermMemory(Bi-LSTM)*** model consists of three following modules:CNN,Bi-LSTM,and Fully connected ***,this study conducts the experiment to compare the performance of our approach and several state-of-the-art deep learning models for time series prediction such as LSTM,Bi-LSTM,the combination of CNN and LSTM(CNN-LSTM),and *** empirical results confirm that PM25-CBL model outperforms other methods for Air Quality HCMC dataset in terms of several metrics including Mean Squared Error(MSE),Root Mean Squared Error(RMSE),Mean Absolute Error(MAE),and Mean Absolute Percentage Error(MAPE).

关键词： Time series prediction PM2.5 concentration prediction CNN Bi-LSTM network

Mutual regulation of microglia and astrocytes after Gas6 inhibits spinal cord injury

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Neural Regeneration Research 2025年第2期20卷 557-573页

作者： Jiewen Chen Xiaolin Zeng le Wang Wenwu Zhang Gang Li Xing Cheng Peiqiang Su Yong Wan Xiang Li Department of Spine Surgery The First Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Guangdong Province Key Laboratory of Orthopedics and Traumatology GuangzhouGuangdong ProvinceChina

Invasive inflammation and excessive scar formation are the main reasons for the difficulty in repairing nervous tissue after spinal cord *** and astrocytes play key roles in the spinal cord injury micro-environment and share a close ***,the mechanisms involved remain *** this study,we found that after spinal cord injury,resting microglia(M0)were polarized into pro-inflammatory phenotypes(MG1 and MG3),while resting astrocytes were polarized into reactive and scar-forming *** expression of growth arrest-specific 6(Gas6)and its receptor Axl were significantly down-regulated in microglia and astrocytes after spinal cord *** vitro experiments showed that Gas6 had negative effects on the polarization of reactive astrocytes and pro-inflammatory microglia,and even inhibited the cross-regulation between *** further demonstrated that Gas6 can inhibit the polarization of reactive astrocytes by suppressing the activation of the Yes-associated protein signaling ***,in turn,inhibited the polarization of pro-inflammatory microglia by suppressing the activation of the nuclear factor-κB/p65 and Janus kinase/signal transducer and activator of transcription signaling *** vivo experiments showed that Gas6 inhibited the polarization of pro-inflammatory microglia and reactive astrocytes in the injured spinal cord,thereby promoting tissue repair and motor function ***,Gas6 may play a role in the treatment of spinal cord *** can inhibit the inflammatory pathway of microglia and polarization of astrocytes,attenuate the interaction between microglia and astrocytes in the inflammatory microenvironment,and thereby alleviate local inflammation and reduce scar formation in the spinal cord.

关键词： astrocytes Axl cell polarization Gas6 Hippo signal inflammatory micro-environment intercellular interaction microglia single-cell sequencing spinal cord injury

Student-Teacher Relationship in the Secondary Schools: A Factorial Study

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Psychology Research 2020年第8期10卷 300-307页

作者： Giap Binh Nga le minh Nguyet Phan Trong ngo Hanoi National University of Education HanoiVietnam

This article contributes to the widening of the international literature concerning the teacher-student relationship under different perspectives:cross-cultural,statistical,and *** work strengthens the psychometric basis of the Student-Teacher Relationship Scale by confirming the three-dimensional structure of the original ***,on the basis of the factor analysis,the instrument proves to apply also to the Vietnamese *** Student-Teacher Relationship Scale,given its validity,can be a serviceable tool for studying such a construct,both as a monitoring scale of a given relationship and as a way to help teachers achieve a better level of awareness of their educational skills.

关键词： student teacher relationships factor analysis Closeness Conflict Dependency

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

Effects of asphalt types and aging on healing performance of asphalt mixtures using induction heating method

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Journal of Traffic and Transportation Engineering(English Edition) 2020年第2期7卷 227-236页

作者： Hai Viet Vo Dae-Wook Park Jung-Woo Seo Tri Ho minh le Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityVietnam Department of Civil Engineering Kunsan National UniversityKimsan 54150South Korea

This paper investigates the effects of types and aging of asphalt binder on healing performance of asphalt mixture modified with steel wool fibers(SWF)using induction heating *** binders PG58-22,PG64-22 and PG76-22,widely used in Korea,were applied in this *** rolling thin film oven(RTFO)and pressure ageing vessel(PAV)tests were conducted to simulate the aging process of asphalt *** healing performance of mixtures was evaluated by the crack-heal process,which included semi-circular bending and induction heating *** cooking oil waste was used as a rejuvenator in order to refresh the aged binder and its healing performance was also *** results indicated that the performance grade(PG)of asphalt binder slightly affected the healing performance of mixtures due to the difference of binder *** addition,the healing level of asphalt mixture was reduced significantly by aged asphalt ***,it was found that using cooking oil waste as a rejuvenator for the aged asphalt mixture can improve its healing performance.

关键词： Asphalt mixture Induction heating Steel wool fibers Healing Aging Cooking oil waste

Myo-inositol versus metformin effects on clinical features, endocrine and metabolic profiles in infertile women with polycystic ovary syndrome: A randomized controlled trial

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Asian pacific Journal of Reproduction 2023年第6期12卷 256-265页

作者： Nguyen Sa Viet le minh Tam le Thanh ngoc Cao Center for OBGYN Hue Central Hospital16 Le Loi StreetHueVietnam Center for Reproductive Endocrinology and Infertility Hue University of Medicine and PharmacyHue University06 Ngo Quyen StreetHueVietnam

Objective:To compare the effectiveness of inositol and metformin on the clinical characteristics,and endocrine and metabolic profiles of infertile polycystic ovarian syndrome(PCOS)women from ***:From June 2018 to August 2022,a randomized trial was undertaken at the Hue Center for Endocrinology and Reproduction on infertile women aged 18 to 40 years with polycystic ovarian *** clinical,endocrine,and metabolic features of these individuals were assessed before and after 3 months of treatment with 2 g of inositol or 1700 mg of metformin per *** pregnancy rates,adverse effects,and tolerance of inositol were ***:The study included 171 infertile PCOS women who were eligible to participate and took part in the baseline assessment,of whom 132 women participated in data analysis after 3 *** metformin treatment,42.1%of women with oligomenorrhea experienced regular *** significantly lowered body mass index(BMI),waist circumference and testosterone levels,but had no effect on other clinical characteristics,endocrine profiles,or metabolic profiles.29.2%Of women reported experiencing side effects.21%Of them attained pregnancy,which resulted in 17.1%of live *** the inositol group,the rate of regular cycle increased by 18.2%and the total testosterone concentration significantly *** overweight/obese women with PCOS,inositol significantly decreased weight,BMI,waist and hip circumferences(Plerated inositol and continued treatment.18.9%Of them became pregnant,leading to 17%of live ***:Metformin and inositol can improve weight and waist circumference in overweight/obese infertile women with *** is associated with a higher rate of regular menstruation,whereas inositol is associated with a lower rate of adverse *** spontaneous conception,clinical pregnancy,and live birth rates between two groups are comparable.

关键词： Polycystic ovarian syndrome Inositol Metformin Endocrine Metabolic Menstrual cycle Pregnancy

Dealing with the Class Imbalance Problem in the Detection of Fake Job Descriptions

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Computers, Materials & Continua 2021年第7期68卷 521-535页

作者： minh Thanh Vo Anh H.Vo Trang Nguyen Rohit Sharma Tuong le Faculty of Information Technology Ho Chi Minh City University of Technology(HUTECH)Ho Chi Minh CityVietnam Faculty of Information Technology Ton Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Information Technology Ho Chi Minh City Open UniversityHo Chi Minh CityVietnam Department of Electronics&Communication Engineering SRM Institute of Science and TechnologyNCR CampusGhaziabadIndia Informetrics Research Group Ton Duc Thang UniversityHo Chi Minh CityVietnam

In recent years,the detection of fake job descriptions has become increasingly necessary because social networking has changed the way people access burgeoning information in the internet *** fraud in job descriptions can help jobseekers to avoid many of the risks of job ***,the problem of detecting fake job descriptions comes up against the problem of class imbalance when the number of genuine jobs exceeds the number of fake *** causes a reduction in the predictability and performance of traditional machine learning *** therefore present an efficient framework that uses an oversampling technique called FJD-OT(Fake Job Description Detection Using Oversampling Techniques)to improve the predictability of detecting fake job *** the proposed framework,we apply several techniques including the removal of stop words and the use of a tokenizer to preprocess the text data in the first *** then use a bag of words in combination with the term frequency-inverse document frequency(TF-IDF)approach to extract the features from the text data to create the feature dataset in the second ***,our framework applies k-fold cross-validation,a commonly used technique to test the effectiveness of machine learning models,that splits the experimental dataset[the Employment Scam Aegean(ESA)dataset in our study]into training and test sets for *** training set is passed through the third module,an oversampling module in which the SVMSMOTE method is used to balance data before training the classifiers in the last *** experimental results indicate that the proposed approach significantly improves the predictability of fake job description detection on the ESA dataset based on several popular performance metrics.

关键词： Fake job description detection class imbalance problem oversampling techniques

Evaluation of the calibration factors of neutron dose rate meters in a 241Am–Be neutron field

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Nuclear Science and Techniques 2019年第9期30卷 18-23页

作者： Thiem ngoc le Sy minh Tuan Hoang Quynh ngoc Nguyen Hoai-Nam Tran Institute for Nuclear Science and Technology VINATOM 179 Hoang Quoc Viet Hanoi Vietnam Institute of Fundamental and Applied Sciences Duy Tan University Ho Chi Minh City Vietnam

Calibrations were performed for three types of neutron ambient dose equivalent rate meters, i.e., Aloka TPS-451C (Hitachi), KSAR1U.06 (Baltic Scientific Instruments), and Model 12-4 (Ludlum), using a standard field of a 241Am–Be source. The measured total neutron ambient dose equivalent rates, H*(10)' tot, were analyzed to obtain the direct neutron ambient dose equivalent rates, H*(10)' dir, using the ISO 8529-2-recommended generalized- fit method, semiempirical fit method, and reducedfitting method (RFM) fit methods. The calibration factor (CF), defined as the ratio between the conventional true value of the neutron ambient dose equivalent rates in a free field, H*(10)' FF, and H*(10)' dir, was evaluated as one of the important characteristics of the neutron meters in the present work. The fitting results show that the H*(10)' dir values of the meters are in good agreement within the theoretical data within 4%. The averaged CFs of the three neutron meters were evaluated as 0:99 ± 0:01, 1:00 ± 0.03;and 0:99 ± 0:08, respectively. The largest standard uncertainty of these values was determined to be approximately 18.47%(k =1). The standard uncertainty of the CFs obtained using the RFM method was less than 4.23%(k=1), which is the smallest uncertainty among the three methods.

关键词： Neutron meter Calibration factor ^241 Am–Be source