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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

Scale and scope economies in small household rice farming in Vietnam

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Journal of Integrative Agriculture 2021年第12期20卷 3339-3351页

作者： Viet-Ngu HOANG Trung Thanh NGUYEN Clevo WILSON thong quoc HO Uttam KHANAL School of Economics and Finance Queensland University of TechnologyBrisbaneQLD 4000Australia Institute for Environmental Economics and World Trade Leibniz University HannoverHannover 30167Germany University of Economics Ho Chi Minh City Ho Chi Minh City 72516Vietnam Agriculture Victoria Department of JobsPrecincts and RegionsHorshamVIC 3400Australia

The Vietnamese agricultural sector has experienced a dramatic structural change based on increased specialization in rice ***,small-scale rice-farmers have continued to grow multiple crops,especially in less developed *** the literature advocates crop diversification for reasons of both economic and ecological sustainability,there lacks empirical evidence as to whether crop diversification brings efficiency and productivity gains to small *** present study is the first applications of the input-oriented stochastic distance function approach in estimating scale and scope economies using data of multi-crop farming households in *** find strong evidence of product-specific economies of *** economies are also present for rice,vegetable,and other annual crop *** suggests that crop diversification enhances efficiency and ***,there still exists significant technical inefficiency in crop production,indicating opportunities to expand farm output at the existing level of inputs and *** specifically,our empirical results indicate that it is desirable to expand vegetable and other annual crop production in mountainous areas while rice cultivation can be further expanded in delta and coastal regions.

关键词： input distance function stochastic frontier economies of scope economies of scale product-specific

Drought and conflicts at the local level: Establishing a water sharing mechanism for the summer-autumn rice production in Central Vietnam

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International Soil and Water Conservation Research 2019年第4期7卷 362-375页

作者： Chuong Van Huynh Catharien Terwisscha van Scheltinga Ty Huu Pham Non quoc Duong Phuong Thi Tran Linh Hoang Khanh Nguyen Tung gia Pham Ngoc Bich Nguyen Jos Timmerman Hue University Viet Nam Climate Change and Adaptive Land and Water Management Group Wageningen Environmental ResearchNetherlands University of Agriculture and Forestry Hue UniversityViet Nam

In recent years,water for agricultural production gradually became a significant challenge in the context of climate change in *** solutions are required,which consider the use of resources for both human needs and ecology,and that account for the equitable distribution and the livelihood of the farmers now and in the *** particular,the farmers in the province of Quang Nam faring water shortage in the cultivation of paddy in the summer-autumn *** arise regarding the sharing of the water between the farmers,the drinking water company and the hydropower *** the context of climate change,the water shortage is expected to increase in the *** article presents the results of participatory action research (PAR) approach to develop a local level mechanism for water sharing,in which stakeholders actively *** sharing mechanism was developed,envisioning a sustainable solution for inclusive water *** mechanism was successfully implemented in two cases,one at commune level (Tho stream) and one at the district level (Mo stream).The participatory approach proved to be successful in setting up a broadly acceptable mechanism that will need to be further incorporated in the institutional set-up.

关键词： Adaptation Agriculture Climate change Governance Rice production Water sharing

Modeling Abstraction Hierarchy levels of the Cyber Attacks Using Random Process

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Open Journal of Statistics 2017年第3期7卷 500-520页

作者： Gilles Durrieu Emmanuel Frenod Thierry Morineau thong quoc Nguyen Université de Bretagne Sud Laboratoire de Mathématiques de Bretagne Atlantique UMR CNRS 6205 Campus de Tohannic Vannes France Université de Bretagne Sud Centre de Recherches en Psychologie Cognition Communication-CRPCC EA 1285 Campus de Tohannic Vannes France

Aspects of human behavior in cyber security allow more natural security to the user. This research focuses the appearance of anticipating cyber threats and their abstraction hierarchy levels on the mental picture levels of human. The study concerns the modeling of the behaviors of mental states of an individual under cyber attacks. The mental state of agents being not observable, we propose a non-stationary hidden Markov chain approach to model the agent mental behaviors. A renewal process based on a nonparametric estimation is also considered to investigate the spending time in a given mental state. In these approaches, the effects of the complexity of the cyber attacks are taken into account in the models.

关键词： Cyber Attacks Abstraction Hierarchy Hidden Markov Chain Nonparametric Estimation Renewal Process

BACTERIAL ENDOCARDITIS:NATURAL HISTORY AND VALVULAR INVOLVEMENT

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中国介入心脏病学杂志 1998年第4期6卷 193-193页

作者： Nguyen quoc Thai Do Doan Loi Nguyen Lan Viet Nguyen Ngoc Tuoc Pham gia Khai Vietnam Heart Institute Hanoi Medical School

A total of 92 patients with baetenal endocarditis (BE) were treatedduring 1/1995-5/1998.48 patients were intravenous drug addicts (ID)(52.2%).The averase age of ID patients was 30.48+/-6.06 *** had been using drugs for more than 6 months (79.3%).Thevegetations were located mainly in the left heart (90.9%).All the casesof BE in ID patients occured in native *** were foundbetween non-ID (NID) and ID with regard to heart failure in ID (62.5%versus 16%) and to cerebral vascular accidents (25% versus 13%).Positive blood cultures were significantly more frequent in ID (95.5%)versus NID (44.4%).Streptoccocal D infections were predominant in ID(56.8%) and Streptococcal alpha infections in NID patients (44.4%),thedifference being statistically *** hospital mortality rate wassimilar in both groups,18.7% and 18.2% in ID and NID *** were no surgical interventions in the ID ***:In an area with high prevalence of rheumatic valvular diseasethe incidence of bacterial endocarditis in ID and NID showed difference *** there were no surgery in the ID group,the short termmortality was *** is a need to investigate the clinical benefit ofvalvular replacement end the survival of the ID and NID patients,in an areawhere resources are limited.

关键词： endocarditis rheumatic versus intravenous prevalence replacement statistically predominant frequent benefit