High performance concrete mixture proportioning: multi-objective optimization approach

This paper presents the application of multi-objective optimization approach to high performance concrete mixture proportioning. An integrated mathematical model was developed in order to optimize six criteria, which are the chlorine ion diffusion coefficient, per cubic meter cost, the amount of cement, fly ash, slag, chemical admixture. This model needs to satisfy with ten functional constraints and seven design variables. The Visual Interactive Analysis Method (VIAM) was used to solve the multicriteria task. Eventually, twelve solutions have been found for the different cases in terms of criteria during the process of proportioning high performance concrete mixture. They are all Pareto solutions, which allow experts to choose in the proposed cases

On the Effects of Monetary Policy in Vietnam: Evidence from a Trilemma Analysis

During and after the 2008-2009 global financial crisis, the growth cycle of Vietnam’s economy has shifted from an average annual growth rate of 7%-8% to an average annual growth rate of 5%-6% with a high level of macroeconomic instability and uncertainty from 2009 till 2016. Related studies have speculated that the operations of monetary policies during this period were not effective in recovering the economic growth and stabilizing the overall price level and total output level. This paper provides the first empirical examination of this speculation using the Trilemma framework. Our empirical results show that the State Bank of Vietnam has had adopted a set of policies aiming at maintaining exchange rate stability and interest rate independence while easing the restrictions on capital inflows. The combination of these three monetary policy approaches is found to violate the rule of Trilemma. Consequently, exchange rate and interest rate policies became less effective and failed to stabilize the economy in response to the global economic recession

Dairy Value Chain In Vietnam: Evidences from Bavi Area

Dairy farming, in Vietnam, existed in the early twentieth century thanks to the favorable natural advantage. During many difficult periods, the Vietnam’s dairy industry has developed constantly and contributed significantly to the food needs ensuring. However, Vietnam’s dairy industry still could not satisfy the domestic milk demand. Retail milk prices in Vietnam are very high, whereas the price of milk sold by the dairy farmers is very low. The cause stems from the control of dairy companies in the quantity and quality of milk. Moreover, that control caused an imbalance in the profits and benefits of each actor in the dairy value chain. This study, hence, finds out the distribution of benefits, costs, value-added among the actors, and problems in the practical management in dairy milk value chain with specific focus on Bavi as the case study

An efficient method to reduce the size of consistent decision tables

Finding reductions from decision tables is one of the main objectives in information processing. Many studies focus on attribute reduct that reduces the number of columns in the decision table. The problem of finding all attribute reducts of consistent decision table is exponential in the number of attributes. In this paper, we aim at finding solutions for the problem of decision table reduction in polynomial time. More specifically, we deal with both the object reduct problem and the attribute reduct problem in consistent decision tables. We proved theoretically that our proposed methods for the two problems run in polynomial time. The proposed methods can be combined to significantly reduce the size of a consistent decision table both horizontally and vertically

A Study on Factors Impacting on Profitability: The Case of Vietnam

This study is conducted to investigate factors influencing the profitability of the Vietnamese food processing firms. Data was collected from audited financial statements from listed food processing firms on the Vietnam Stock Exchange. Panel regression model was applied in this study (PLS). The testing methods used in this research were Pearson model; Modified Wald Test, Wooldridge test (for autocorreclation in panel data), Hausman model, especially the relationship between FEM and REM as well as Multicollinearity test based on VIF coeficient. The results shows that DR, SDR and LDR have negative impacts on profitability. In contrast, TDTELT have positive impacts on the profitability. FATA and SIZE impact return on asset (ROA) without statistical significance. SIZE has positive impact on return on equity (ROE) while it impacts negatively on profit margin (PM). Moreover, AGE, GDP growth, and inflation do not have impact on profitability. Keywords: Factors, Return on assets, Food processing firms, Vietnam DOI: 10.7176/RJFA/11-10-07 Publication date:May 31st 202

Unexpected cases in field diagnosis of African swine fever virus in Vietnam: The needs consideration when performing molecular diagnostic tests

Background: The first confirmed case of African swine fever (ASF) in Vietnam was reported officially in February 2019. To date, ASF virus (ASFV) have been detected in 63/63 provinces in Vietnam. Currently, real-time polymerase chain reaction (PCR) is considered to be a powerful tool for viral detection in field samples, including ASFV. However, some recent reports have suggested that mismatches in primer and probe binding regions may directly affect real-time PCR qualification, leading a false-negative result.Aim: This study aims to further examine a conflicting result obtained from two OIE recommended methods, conventional PCR and real-time PCR, for ASFV detection.Methods: Two ASF suspected pigs from different provinces in the north of Vietnam were selected for this study based on clinical signs and postmortem lesions. The different results obtained by OIE-recommended conventional PCR and real-time PCR were further analyzed by the Sanger sequencing method and virus isolation in combination with hemadsorption (HAD) test using porcine alveolar macrophages cells.Results: The results showed that when the primer sequence matched perfectly with the sequences of field isolates, a mutation in probe binding region was found, indicating that a single mismatch in the probe binding site may cause a false-negative result by real-time PCR in detecting ASFV in clinical samples in Vietnam. An agreement between conventional PCR, using PPA1/PPA2 primers and two golden standard methods, virus isolation in combination with HAD assay, and sequencing method was observed in this study.Conclusion: A single mismatch in the probe binding site caused a failse-negative result by realtime PCR method in field diagnosis of ASFV. The needs consideration when selecting the appropriate molecular diagnostic methods is based on the current databases of ASFV sequences,  particularly for epidemiological surveillance of ASF. Keywords: African swine fever, PCR, Pigs, Real-time PCR, Vietna

Brza serotipizacija virusa afričke kuge svinja zasnovana na analizi kratkih fragmenata EP402R gena koji kodira CD2-like protein

The first confirmed case of African swine fever (ASF) in Vietnam was officially reported in February 2019. To date, the ASF virus (ASFV) has been detected in all 63 cities/provinces in Vietnam. In order to get a better understanding of the potential role of the EP402R gene in a grouping of ASFV serotypes, thirty ASFV sequences of EP402R genes (accession numbers: MN711757-86) from North Central Coast of Vietnam and 68 well-known references of serotype groups from previous studies were further analyzed. Interestingly, we found that a short fragment of 90 nucleotides was very typical for 8 serological groups of ASFVs. A primer set was designed to amplicon the short fragment of 90 nucleotides using the Primer3 program to establish a simplified method for the serotyping of ASFV. Our results indicated that phylogenetic analysis of the short fragment (90 nucleotides) of the EP402R gene is a very specific and useful method for ASFV serotyping when compared to the previous method using a long fragment (816 nucleotides) of this gene and well-known serotype references based on haemadsorption inhibition (HAI) assay.Prvi potvrđen slučaj afričke kuge svinja (ASF) u Vijetnamu bio je zvanično prijavljen u februaru 2019. godine. Do danas, ASF virus (ASFV) je detektovan u 63 provincije Vijetnama. Radi boljeg razumevanja potencijalne uloge EP402R gena u grupisanju ASFV serotipova, analizirano je trideset ASFV sekvenci EP402R gena (pristupni brojevi: MN711757-86) poreklom iz Centralne severne obale Vijetnama i 68 referentnih uzoraka serotip grupa koji su dobro poznati iz prethodnih studija. Interesantan je bio nalaz da je kratak fragment od 90 nukleotida bio tipičan za 8 seroloških grupa ASF virusa. Dizajniran je set prajmera sa ciljem amplifi kacije kratkih fragmenata (90 nukleotida), korišćenjem Primer3 programa, a za uspostavljanje jednostavne metode serotipiziranja ASFV. Rezultati ukazuju da je fi logenetska analiza kratkih fragmenata (90 nukleotida) EP402R gena je veoma specifična i predstavlja korisnu metodu serotipizacije ASFV u poređenju sa prethodno opisanim metodama koje su koristile duge fragmente (816 nukleotida) ovog gena kao i dobro poznate referentne serotipove dobijene metodom inhibicije hemadsorbcije

Dataset of Vietnamese students’ intention in respect of study abroad before and during COVID-19 pandemic

The Covid-19 Pandemic had completely disrupted the worldwide educational system. Many schools chose the online delivery mode for students in case learning losses incurred during social distance decree. However, as to these students who are currently in the study abroad planning stages, reached an intention crossroads, whether standing for certain unchanging decisions in study abroad destinations or changing swiftly due to the unexpected policies in quarantine. This case opened to interpretation, which was based on our e-survey since 3 May to 13 May 2020 with 397 responses covering a range of Vietnamese students. In this dataset, we focused on (i) Students’ Demographics; (ii) The previous intention of students to study abroad before and during the Covid-19 ravaged and (iii) Their intention afterwards