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Building the ARIMA Model for Forecasting the Production of Vietnam’s Coffee Export

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Journal of Applied Mathematics and Physics 2024年第4期12卷 1237-1246页

作者： Duy Quang phung Quoc Thang Trinh Quang Truong Do Ngan Giang nguyen Van Ha nguyen Gia Khiem Ngo thi Minh Ngoc Tran Faculty of Technology and Data Science Foreign Trade University Hanoi Vietnam School of Economics and International Business Foreign Trade University Hanoi Vietnam

Coffee is a significant industry, accounting for 3% of Vietnam’s GDP, with annual export turnover consistently exceeding USD 3 billion. Despite global economic challenges affecting purchasing power at various times, Vietnam’s coffee exports in December 2023 continued to surge, reaching the highest level in the past 9 months at 190,000 tons, a 59.3% increase compared to November 2023, but still a slight 3.5% decrease from the same period last year. The export turnover reached USD 538 million, a 51% increase from November 2023 and a 26.4% increase from the same period last year. Therefore, forecasting the coffee export volume holds significant importance for coffee producers nationwide. this research employs the Box-Jenkins method to construct an ARIMA model for forecasting Vietnam’s coffee export volume based on annual data published by the General Statistics Office. Results indicate that among the models considered, the ARIMA(1, 1, 2) model is the most suitable. The study also provides short-term forecasts for Vietnam’s coffee export volume. However, the current model is limited to forecasting and is not yet optimized, as the assumed linearity in the model is a simplification.

关键词： ARIMA Forecasting Coffee Export Volume Data Science

Freezing Warm Christmas

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Beijing Review 2007年第52期50卷 48-48页

作者： nguyen thi cam phung

A lot of Beijing expats carp at Christmas here because of celebra- tion allegedly without regard for its true spirit. Not me. I’m from Ho Chi Minh City,Viet Nam,where Christmas is more like Mardi Gras than a celebration of Jesus Christ’s birth. Granted,on December 25,people gather in droves at"one particular church"in Saigon,as we still like to *** what happens there is anything but holy. Mayhem,if not murder,ensues.

关键词： than

Transfer Learning for Disease Diagnosis from Myocardial Perfusion SPECT Imaging

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Computers, Materials & Continua 2022年第12期73卷 5925-5941页

作者： phung Nhu Hai nguyen Chi Thanh nguyen Thanh Trung Tran Trung Kien Institute of Information Technology AMSTHanoi11307Vietnam Department of Medical Equipment 108 Military Central HospitalHanoi11610Vietnam

Coronary artery disease(CAD)is one of the most common pathological conditions and the major global cause of *** perfusion imaging(MPI)using single-photon emission computed tomography(SPECT)is a non-invasive method and plays an essential role in diagnosing ***,there is currently a shortage of doctors who can diagnose using SPECT-MPI in developing countries,especially *** on deploying machine learning and deep learning in supporting CAD diagnosis has been noticed for a long ***,these methods require a large dataset and are therefore time-consuming and *** study aims to develop a cost-effective and high-performance CAD classification model to support doctors in these *** this paper,we propose a transfer learning framework for a multi-stage training process with different learning *** process consists of two training stages:a warming up stage in which all layers of a pre-trained model(on ImageNet dataset)are frozen;and a finetuning stage in which a small amount of the top layers are unfrozen and then retrained with a lower learning *** dataset for this study consists of the polar maps from 218 *** popular CNN-based pre-trained models have been investigated,and ResNet152V2-based model has obtained the highest performances with an accuracy of 95.5%,area under the receiver operating characteristic curve(AUC)score 0.932,sensitivity 94.4%,precision 96.4%,and F1-score 95.2%.These performances are competitive or even better than all state-of-the-art approaches in terms of classification accuracy and *** also apply the class activation mapping technique to help explain the model’s predictions and increase the model’s reliability,proving capable of assisting the SPECT image readers in the CAD diagnosis.

关键词： Coronary artery disease deep learning transfer learning SPECTMPI polar maps

Picture-Neutrosophic Trusted Safe Semi-Supervised Fuzzy Clustering for Noisy Data

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Computer Systems Science & Engineering 2023年第8期46卷 1981-1997页

作者： Pham Huy Thong Florentin Smarandache phung The Huan Tran Manh Tuan Tran thi Ngan Vu Duc Thai nguyen Long Giang Le Hoang Son Graduate University of Science and Technology Vietnam Academy of Science and TechnologyHanoi100000Vietnam Institute of Information Technology Vietnam Academy of Science and TechnologyHanoi100000Vietnam VNU Information Technology Institute Vietnam National UniversityHanoi100000Vietnam Department of Mathematics University of New MexicoGallup87301New MexicoUSA University of Information and Communication Technology Thai Nguyen UniversityThai Nguyen250000Vietnam Faculty of Computer Science and Engineering Thuyloi UniversityHanoi100000Vietnam

Clustering is a crucial method for deciphering data structure and producing new *** to its significance in revealing fundamental connections between the human brain and events,it is essential to utilize clustering for cognitive *** with noisy data caused by inaccurate synthesis from several sources or misleading data production processes is one of the most intriguing clustering *** data can lead to incorrect object recognition and *** research aims to innovate a novel clustering approach,named Picture-Neutrosophic Trusted Safe Semi-Supervised Fuzzy Clustering(PNTS3FCM),to solve the clustering problem with noisy data using neutral and refusal degrees in the definition of Picture Fuzzy Set(PFS)and Neutrosophic Set(NS).Our contribution is to propose a new optimization model with four essential components:clustering,outlier removal,safe semi-supervised fuzzy clustering and partitioning with labeled and unlabeled *** effectiveness and flexibility of the proposed technique are estimated and compared with the state-of-art methods,standard Picture fuzzy clustering(FC-PFS)and Confidence-weighted safe semi-supervised clustering(CS3FCM)on benchmark UCI *** experimental results show that our method is better at least 10/15 datasets than the compared methods in terms of clustering quality and computational time.

关键词： Safe semi-supervised fuzzy clustering picture fuzzy set neutrosophic set data partition with noises fuzzy clustering

软木塞基碳量子点的水热合成及其生物相融荧光成像应用

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新型炭材料 2022年第3期37卷 595-602页

作者： Quang Ngo Khoa Hieu nguyen Ngoc Bao Vo Van Quoc Phuoc Vo thi Ngoc Le Xuan Diem Doc Luong Quang Tri nguyen Minh Son Le Vu Truong Son Le Van Thanh Ha Che thi cam University of Sciences Hue University77 Nguyen HueHueVietnam Faculty of Environmental and Natural Sciences Duy Tan UniversityDa Nang550000Vietnam Institute for Research and Training in Medicine Biology and PharmacyDuy Tan UniversityDa Nang550000Vietnam University of Agriculture and Forestry Hue University102 Phung HungHueVietnam University of Science and Education The University of Da Nang459 Ton Duc ThangLien ChieuDa NangVietnam

以废弃酒瓶软木塞为原料,采用低成本、简单的水热方法合成碳量子点。通过TEM、FTIR、Raman、UV-Vis、PL光谱对碳量子点的结构和光学性能进行分析表征。结果表明,碳量子点的平均直径为6.2±2.7 nm,PL激发谱和碳量子点表面的官能团有关。... 详细信息

以废弃酒瓶软木塞为原料,采用低成本、简单的水热方法合成碳量子点。通过TEM、FTIR、Raman、UV-Vis、PL光谱对碳量子点的结构和光学性能进行分析表征。结果表明,碳量子点的平均直径为6.2±2.7 nm,PL激发谱和碳量子点表面的官能团有关。用硫酸奎宁作为参考,碳量子点的量子效率为1.54%。将获得的碳量子点应用在骨髓间充质干细胞的细胞生物成像上,发现用碳量子点处理后,骨髓间充质干细胞分别在320~380 nm、450~490 nm和450~490 nm范围显示绿色、黄色和红色荧光,表明了碳量子点在荧光成像领域具有潜在的应用价值。

关键词：碳点水热合成荧光荧光图像废酒瓶塞

Optimization, equilibrium, adsorption behavior and role of surface functional groups on graphene oxide-based nanocomposite towards diclofenac drug

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Journal of Environmental Sciences 2020年第7期32卷 137-150页

作者： Thuan Van Tran Duyen thi cam nguyen Hanh TNLe Dai-Viet NVo Sonil Nanda Trinh Duy nguyen nguyen Tat Thanh Hi-Tech Institute Nguyen Tat Thanh UniversityHo Chi Minh City 755414Viet Nam Center of Excellence for Green Energy and Environmental Nanomaterials(CE@GrEEN) Nguyen Tat Thanh UniversityHo Chi Minh City 755414Viet Nam Institute of Hygiene and Public Health Ho Chi Minh City 700000Viet Nam Department of Chemical and Biochemical Engineering University of Western OntarioLondonOntarioCanada

Aquatic contamination of diclofenac(DCF),an emergent non-steroidal anti-inflammatory drug(NSAIDs),can result in adverse effects to many ecosystems through ***,introducing effective remediation techniques to sequester the pharmaceutical wastes is highly fundamental to prevent their accumulation in the ***,adsorption has been presented as a green and efficient ***,we report the characterization and application of the novel magnetic nanocomposite(GO@CoFe2O4)derived from cobalt-based ferrite(CoFe2O4)and graphene oxide(GO)for DCF *** the optimization procedure,the response surface methodology(RSM)was adopted to investigate the impacts of DCF concentration(1.6-18.4 mg/L),DCF dosage(0.08-0.92 g/L),and solution pH(2.6-9.4)to find the optimum conditions for DCF removal,at 10.5 mg/L,0.74 g/L,and pH 4,*** the adsorption experiments,the kinetic,isotherm,thermodynamic,and intraparticle diffusion models were systematically ***,we have elucidated the role of functional groups on the surface of GO@CoFe2O4 in enhancing the adsorption of DCF *** good removal efficiency(up to 86.1%),high maximum adsorption capacity(32.4 mg/g),GO@CoFe2O4 can be a potential candidate to eliminate DCF drug from water.

关键词： Diclofenac sodium Graphene oxide Magnetic nanocomposite Response surface methodology Pharmaceuticals adsorption

Association between measles antibodies in vaccinated and naturally infected mothers with protective antibodies and the occurrence of measles in their children:A cross-sectional study in the Bavi district of Hanoi

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Asian Pacific Journal of Tropical Medicine 2019年第9期12卷 404-408页

作者： cam Nhat nguyen Quynh Ngoc nguyen Than Huu Dao Le thi Quynh Mai Infectious Disease Prevention und Control Department Center for Disease ControlHonoiVietnom Virology Department National Institute of Hygiene and EpidemiologyHanoiVietnam

Objective:To determine the concentration and rate of decay of maternal IgG antibodies against measles prevalence in infants of vaccinated or naturally infected mothers and study initial measles immunization occurs in nine-month-old ***:In total,401 pregnant women and the same number of their subsequent newborns were recruited in the Bavi district of Hanoi in 2016-2017;they were divided into two groups:Older women(born before 1985,n=201)and younger women(born after 1990,n=200).Samples were collected at five time-points;week 36 of pregnancy,birth(cord),and 3,6,and 9 months after ***-specific IgG antibody levels were ***:In total,77.06% of the 401 pregnant women were seropositive for measles-specific IgG antibodies.A significantly greater proportion of mothers aged 30 and older(88.06%)and their newborn(93.53%)were seropositive compared to the mothers aged 25 and younger(66.00%),and their newborn(72.00%)(Pthis study provides a profile of maternal antibodies against measles in Vietnamese infants and investigates the early susceptibility to measles in both the infants of vaccinated mothers and mothers with naturally acquired *** data suggest that determining the appropriate age for measles vaccination is paramount for the elimination of measles in Vietnam.

关键词： Infant Measles Seropositive National Expanded Program of Immunization Vietnam

Effects of interface trap density on the electrical performance of amorphous InSnZnO thin-film transistor

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Journal of Semiconductors 2015年第2期36卷 82-86页

作者：梁永烨 Kyungsoo Jang S.Velumani cam Phu thi nguyen Junsin Yi National Key Laboratory for Electronic Measurement Technology North University of China College of Information and Communication Engineering Sungkyunkwan University Department of Electrical Engineering (SEES) CINVESTAV-IPN Avenida IPN 6508San Pedro Zacatenco Mexico D.F.

We reported the influence of interface trap density（Nt） on the electrical properties of amorphous InSnZnO based thin-film transistors,which were fabricated at different direct-current（DC） magnetron sputtering *** device with the smallest Nt of 5.68×10^11 cm^-2 and low resistivity of 1.21×10^-3Ω·cm exhibited a turn-on voltage（V（ON）） of-3.60 V,a sub-threshold swing（S.S） of 0.16 V/dec and an on-off ratio（I（ON）/I（OFF）） of^8 x 10^*** increasing Nt,the V（ON）,S.S and I（ON）/I（OFF） were suppressed to-9.40 V,0.24 V/dec and 2.59×10^8,*** V（TH） shift under negative gate bias stress has also been estimated to investigate the electrical stability of the *** result showed that the reduction in Nt contributes to an improvement in the electrical properties and stability.

关键词： a-ITZO TFTs low resistivity interface trap density electrical properties electrical stability

Photodegradation of Cinnamic Acid Solution in the Presence of Various Oxidizing Agents on TiO2 and Fe-TiO2 Catalysts

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材料科学与工程（中英文A版） 2016年第6期6卷 289-300页

作者： Ha cam Anh Luu cam Loc nguyen Tri nguyen phung Anh nguyen thi Nga Tot nguyen thi Thuy Van Hoang Tien Cuong University of Technology Vietnam National University Ho Chi Minh City 268 Ly Thuong Kiet Str. Ho Chi Minh City 70100Vietnam Institute of Chemical Technology Vietnam Academy of Science and Technology 01 Mac Dinh Chi Str. Ho Chi Minh City 70100Vietnam