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Comparisons of VAR Model and Models Created by Genetic Programming in Consumer Price Index Prediction in Vietnam

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Open Journal of Statistics 2012年第3期2卷 237-250页

作者： Pham van khanh Military Technical Academy Hanoi Vietnam

In this paper, we present an application of Genetic Programming (GP) to Vietnamese CPI in?ation one-step prediction problem. This is a new approach in building a good forecasting model, and then applying inflation forecasts in Vietnam in current stage. The study introduces the within-sample and the out-of-samples one-step-ahead forecast errors which have positive correlation and approximate to a linear function with positive slope in prediction models by GP. We also build Vector Autoregression (VAR) model to forecast CPI in quaterly data and compare with the models created by GP. The experimental results show that the Genetic Programming can produce the prediction models having better accuracy than Vector Autoregression models. We have no relavant variables (m2, ex) of monthly data in the VAR model, so no prediction results exist to compare with models created by GP and we just forecast CPI basing on models of GP with previous data of CPI.

关键词： Vector Autoregression Genetic Programming CPI Inflation Forecast

Multi-clustering study on the association between human leukocyte antigen-DP-DQ and hepatitis B virus-related hepatocellular carcinoma and cirrhosis in Viet Nam

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World Journal of Gastroenterology 2024年第46期30卷 4880-4903页

作者： Thuy Thu Nguyen Tu Cam Ho Huong Thi Thu Bui van-khanh Tran Tue Trong Nguyen Center for Gene and Protein Research Hanoi Medical UniversityHanoi 116177Viet Nam Institute of Virology TUM School of MedicineTechnical University of MunichMunich 81675Germany Department of Biochemistry Thai Nguyen University of Medicine and PharmacyThai Nguyen 251540Viet Nam Medical Technology Department Hanoi Medical UniversityHanoi 116177Viet Nam Clinical Laboratory Hanoi Medical University HospitalHanoi 116177Viet Nam

BACKGROUND Human leukocyte antigen(HLA)class II molecules are cell surface receptor proteins found on antigen-presenting *** and mutations in the HLA gene can affect the immune system and the progression of hepatitis *** To study the relation between rs2856718 of HLA-DQ,rs3077,and rs9277535 of HLA-DP,hepatitis B virus(HBV)-related cirrhosis,and hepatocellular carcinoma(HCC).METHODS In this case-control study,the genotypes of these single nucleotide polymorphisms(SNPs)were screened in 315 healthy controls,471 chronic hepatitis B patients,250 patients with HBV-related liver cirrhosis,and 251 patients with HCC using TaqMan real-time *** conducted Hardy-Weinberg equilibrium and linkage disequilibrium tests on the genotype distributions of rs2856718,rs3077,and rs9277535 before hierarchical clustering analysis to build the complex interaction between the markers in each patient *** The physical distance separating these SNPs was 29816 kB with the disequilibrium(D’)values ranging from 0.07 to *** close linkage between rs3077 and rs9277535 was attributed to a distance of 21 *** D’value decreased from moderate in the healthy control group(D’=0.50,P<0.05)to weak in the hepatic disease group(D’<0.3,P<0.05).In a combination of the three variants rs2856718,rs3077,and rs9277535,the A allele decreased hepatic disease risk[A-A-A haplotype,risk ratio(RR)=0.44(0.14;1.37),P<0.05].The G allele had the opposite effect[G-A/G-G haplotype,RR=1.12(1.02;1.23),P<0.05].In liver cancer cases,the A-A-A/G haplotype increased the risk of HCC by 1.58(P<0.05).CONCLUSION Rs9277535 affects liver fibrosis progression due to HBV infection,while rs3077 is associated with a risk of HBVrelated *** link between rs2856718,rs3077,and rs9277535 and disease risk was determined using a multiclustering analysis.

关键词： Human leukocyte antigen Multi-clustering study Hepatitis B virus Hepatocellular carcinoma Cirrhosis

Coexistence of the Hypersecretion of Catecholamine,Adrenal Cortical Nodular Hyperplasia,and Nephrotic-Range Proteinuria of Focal Segmental Scleronephrosis:Is It Fat-Induced Hypertension?

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International Journal of Clinical Medicine 2011年第3期2卷 206-211页

作者： khanh vinh quoc Luong Lan Thi hoang Nguyen Si van Nguyen Ninh T.Nguyen Vietnamese American Research Foundation WestminsterUSA Department of Pathology/Garden Grove Medical Center Garden GroveUSA Department of Surgery/UCI Medical Center OrangeUSA

Two patients had a long history of hypertension and one of them also had a nephrotic-range proteinuria secondary to focal segmental scleronephrosis which had been diagnosed by kidney biopsy. They presented with uncontrolled hypertension. Laboratory examination suggested hypersecretion of catecholamines by the left adrenal glands in both patients and primary aldosteronism in one of them. A computed tomography scan revealed small nodules on left adrenal gland in both patients. Patients underwent laparoscopic left adrenalectomy. After surgery, blood pressure was normalized and proteinuria was resolved. Most interestingly, prominent adipocytes infiltrated were detected in the adrenal cortex and were associated with the presence of lymphocytes, which suggested that adipocytes might have a role in the pathogenesis of these diseases in our patients.

关键词： Pheochromocytoma Aldosteronism Adipocyte Nephrotic Syndrome Focal Segmental Scleronephrosis Adrenal Cortical Hyperplasia

A comparative analysis of weight-based machine learning methods for landslide susceptibility mapping in Ha Giang area

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Big Earth Data 2023年第4期7卷 1005-1034页

作者： Thanh Trinh Binh Thanh Luu Trang Ha Thi Le Duong Huy Nguyen Trong van Tran Thi Hai van Nguyen khanh Quoc Nguyen Lien Thi Nguyen Faculty of Computer Science Phenikaa UniversityYen NghiaHa DongHanoi 12116Vietnam Phenikaa Research and Technology Institute(PRATI) A&A Green Phoenix Group JSCNo.167 Hoang NganTrung HoaCau GiayHanoi 11313Vietnam Northwestern Geological Division General Department of Geology and Minerals of VietnamHanoiVietnam Youth union office Thuyloi University175 Tay SonDong DaHanoiVietnam Center of Remote Sensing and Geohazards Vietnam Institute of Geosciences and Mineral ResourcesHanoiVietnam

Landslide susceptibility maps (LSMs) are very crucial for planningpolicies in hazardous areas. However, the accuracy and reliability ofLSMs depend on available data and the selection of suitable *** study is conducted to produce LSMs by combinations of machinelearning methods and weighting techniques for Ha Giang province,Vietnam, where has limited data. In study area, we gather 11 landslideconditioning factors and establish a landslide inventory *** the weights of classes (or factors) is very important toprepare data for machine learning methods to generate LSMs. Wefrst use frequency ratio (FR) and analytic hierarchy process (AHP)techniques to generate the weights. Then, random forest (RF), supportvector machine (SVM), logistic regression (LR), and AHP methods arecombined with FR and AHP weights to yield accurate and reliableLSMs. Finally, the performance of these methods is evaluated by fivestatistical metrics, ROC and R-index. The empirical results have shownthat RF is the best method in terms of R-index and the five metrics, *** rate (0.9661), FP rate (0.0), ACC (0.9835), MAE (0.0046), and RMSE(0.0350) for this study area. This study opens the perspective of weightbasedmachine learning methods for landslide susceptibility mapping.

关键词： Landslide logistic regression random forest SvM Vietnam

Viral co-infections among children with confirmed measles at hospitals in Hanoi,Vietnam,2014

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Asian Pacific Journal of Tropical Medicine 2017年第2期10卷 164-167页

作者： Hang Le khanh Nguyen Loan Phuong Do van Thanh Thi Trieu Son Vu Nguyen Phuong Vu Mai hoang Hien Thi Pham Thanh Thi Le Huong Thi Thu Tran Cuong Duc Vuong Mai Thi Quynh Le National Institute of Hygiene and Epidemiology No 1-Yesrsin streetHanoiVietnam

Objective:To characterize viral co-infections among representative hospitalized measles cases during the 2014 Hanoi ***:Throat swabs were collected from 54 pediatric patients with confirmed measles,and molecular diagnostics performed for 10 additional viral respiratory pathogens(Influenza A/H1N1pdm09;A/H3N2 and influenza B;Parainfluenza 1,2,3;Respiratory Synctial Virus,RSV;human Metapneumovirus,hM PV;Adenovirus and Picornavirus).Results:Twenty-one cases(38.9%) showed evidence of infection with other respiratory viruses:15 samples contained measles plus one additional virus,and 6 samples contained measles plus 2 additional *** was detected as a predominant cause of co-infections(13 cases;24.1%),followed by RSV(6 cases;11.1%),A/H1N1pdm09(3 cases;5.6%),PIV3(3 cases;3.7%),Rhinovirus(3 cases;3.7%) and hM PV(1 case;1.96%).Conclusions:Viral co-infections identified from pediatric measles cases may have contributed to increased disease severity and high rate of fatal *** treatment of measles cases may require control of multiple viral respiratory pathogens.

关键词： Measles virus Respiratory viruses Co-infection

Structural and luminescent properties of (Eu,Tb) PO_4·H_2O nanorods/nanowires prepared by microwave technique

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Journal of Rare Earths 2011年第12期29卷 1170-1173页

作者： Nguyen Thanh Huong Nguyen Duc van Dinh Manh Tien Do khanh Tung Nguyen Thanh Binh Tran Kim Anh Le Quoc Minh Institute of Materials Science Vietnam Academy of Science and Technology University of Engineering and Technology National University HanoiVietnam

Nanowires/nanorods of europium/terbium orthophosphate monohydrate with Eu^3＋ concentration of 6, 11, and 20 at.% were prepared by microwave synthesis method. The effects of Eu^3＋ doping concentration on structure, morphology and optical properties of nanomaterials were also investigated. The results showed that, for all studied Eu^3＋ doping concentrations, a single-crystalline phase of rhabdophane-type （Eu,Tb）PO4·H2O nanowires/nanorods was obtained by using microwave heating of an aqueous solution of terbium（Ⅲ） nitrate, europium（Ⅲ） nitrate and NH4H2PO4 with pH=2. The length and width of these nanowires/nanorods ranged from 150 to 300 nm and from 10 to 50 nm, respectively. The evidence of energy transfer from Tb^3＋ to Eu^3＋ due to the energy overlap between the donor Tb^3＋ and the acceptor Eu^3＋was observed obviously via a significant enhancement in the luminescent intensity of Eu^3＋. Keywords：

关键词： microwave technique nanowires/nanorods energy transfer fluorescence spectroscopy rare earths

Spatio-Temporal Analysis of Drought in the North-Eastern Coastal Region of Vietnam Using the Standardized Precipitation Index (SPI)

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Atmospheric and Climate Sciences 2023年第2期13卷 175-200页

作者： Nguyen van Tuan Nguyen van Hieu Nguyen Khac Bang Pham hoang Hai Nguyen khanh van Le Vinh Ha Tran Thi Hoa Lê Trọng Hiếu Institute of Water Resources Planning Hanoi Vietnam Institute of Environment and Public Health Vietnam Union of Science and Technology Associations Hanoi Vietnam Thai Binh University Thai Binh Vietnam Faculty of Electronics and Telecommunications Electric Power University Hanoi Vietnam

Spatio-temporal analysis of drought provides valuable information for drought management and damage mitigation. In this study, the Standardized Precipitation Index at the time scale of 6 months (SPI-6) is selected to reflect drought conditions in the North-Eastern coastal region of Vietnam. The drought events and their characteristics from 1981 to 2019 are detected at 9 meteorological stations and 10 Chirps rainfall stations. The spatio-temporal variation of drought in the study region is analyzed on the basis of the number, duration, severity, intensity, and peak of the detected drought events at the 19 stations. The results show that from 1981 to 2019 the drought events mainly occurred with 1-season duration and moderate intensity and peak. The number, duration, severity, and peak of the drought events were the greatest in the period 2001-2010 and were the smallest in the period 2011-2019. Among the 19 stations, the drought duration tends to decrease at 11 stations, increase at 7 stations, and has a slight variant at 1 station;the drought severity tends to decrease at 14 stations, increase at 4 stations, and has not a significant trend at 1 station;the drought intensity tends to decrease at 17 stations, increase at 1 station, and has a slight variant at 1 station;and the drought peak tends to decrease at 18 stations and increase at 1 station.

关键词： Spatio-Temporal Analysis of Drought Standardized Precipitation Index (SPI) Drought Characteristics

A Chance–Constrained Data Envelopment Analysis Approach to Problem Provincial Productivity Growth in Vietnamese Agriculture from 1995 to 2007

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Open Journal of Statistics 2011年第3期1卷 217-235页

作者： Nguyen Khac Minh Pham van khanh 不详

This study employs a chance-constrained data envelopment analysis (CDEA) approach with two models (model A and model B) to decompose provincial productivity growth in Vietnamese agriculture from 1995 to 2007 into technological progress and efficiency change. The differences between the chance - constrained programming model A and model B are assumptions imposed on the covariance matrix. The decomposition allows us to identify the contributions of technical change and the improvement in technical efficiency to productivity growth in Vietnamese production. Sixty-one provinces in Vietnam are classified into Mekong - technology and other -technology categories. We conduct a Mann-Whitney test to verify whether the two samples, the Mekong technology province sample and the other technology sample, are drawn from the same productivity change populations. The result of the Mann-Whitney test indicates that the differences between the Mekong technology category and the other technology category from two models are more significant. Two important questions are whether some provinces in the samples could maintain their relative efficiency rank positions in comparison with the others over the study period and how to further examine the agreements between the two models. The Kruskal - Wallis test statistic shows that technical efficiency from both models for some provinces are higher than those of them in the study period. The Malmquist results show that production frontier has contracted by around 1.3 percent and 0.31 percent from chance-constrained model A and model B, respectively, a year on average over the sample period. To examine the agreements or disagreements in the total factor productivity indexes we compute the correlation between Malmquist indexes, which is positive and not very high. Thus there is a little discrepancy between the two Malmquist indexes, estimated from the chance - constrained models A and B.

关键词： Total Factor Productivity Technical Efficiency Change Technological Progress Chance-Constrained Programming

Forecasting the Convergence State of per Capital Income in Vietnam

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American Journal of Operations Research 2013年第6期3卷 487-496页

作者： Nguyen Khac Minh Pham van khanh Military Technical Academy Hanoi Vietnam National Economics University Hanoi Vietnam

Convergence problem of an economic variable represents an underlying forecast of neoclassical economic growth model. This paper aims to analyze the convergence of provincial per capita GDP stability in Vietnam over the period of 1991-2007. This can be done by two approaches including bias data-based regression method for testing convergence and Markov chain model for describing features of long-term tendency of per capita income in Vietnam growth in provinces. The regression method results in the signs of convergence. To apply Markov process, we divide total pattern into 5 per capita income classes. Result estimated from the Markov chain model shows the poor convergence.

关键词： Convergence Regression Method Markov Proces