An inquiry into the determinants of Vietnamese product export

Export led growth is the model of economic development that Vietnam has been following. While there are a great number of studies on the determinants of aggregate export of Vietnam, there are few that analyze the impacts of different factors on the export of different product groups. This paper aims at filling this gap in research on international trade of Vietnam. The results show that the fast GDP growth of Vietnam, the large population of importing countries, the wide economic gap between Vietnam and the importing countries, the depreciation of domestic currency, the free trade agreements that Vietnam signed and the shared border with the importing countries contribute to the increase of Vietnam’s export of all product groups. In contrast, the GDP of importing countries and population of Vietnam have no clear impacts on the export of any product groups.

Valorisation de fines et granulats issus de bétons recyclés comme matériaux cimentaires

La consommation de béton devient de plus en plus importante en raison d'une urbanisation accrue nécessitant la réhabilitation et la construction de bâtiments et d'infrastructures. Néanmoins, la production de béton qui doit accompagner le développement urbain entraîne des problèmes environnementaux relatifs à la préservation des ressources naturelles qui ne sont pas inépuisables. Malgré des efforts de recyclage, la plupart des matériaux recyclés sont généralement utilisés pour les travaux routiers ou de remblai. En s'inscrivant dans le Projet National Recybéton (PN), ce travail de thèse a pour objectif d'apprécier la valorisation du recyclage des matériaux issus des bétons déconstruits en les intégrant dans de nouveaux bétons. Deux types de matériaux recyclés sont étudiés, les fines qui sont produites en quantités importantes lors de la phase de concassage du béton d'ouvrage démoli, et les granulats (sable et gravillon) qui sont pour la plus grande part issus des granulats naturels initiaux. Le présent travail a donc pour mission de quantifier des propriétés des matériaux cimentaires aux différents états lors de l'utilisation de : * granulats recyclés dans le squelette granulaire, * fines de sable broyé (SBC) et de fines de dépoussiérage (FBC) en tant qu'additions minérales. La première partie est dédiée à l'étude de l'influence de l'état hydrique des granulats recyclés (sable et gravillon) sur l'évolution de la rhéologie du béton dans le temps, et à l'étude de leur incidence sur la résistance à la compression à 28 jours. Les résultats obtenus dans la limite du contexte expérimental nous permettent de suggérer des recommandations sur l'état hydrique initial des recyclés et sur leur taux d'incorporation dans le mélange de béton. La deuxième partie présente l'évaluation de la faisabilité d'utiliser des sables de bétons concassés et des fines de bétons concassés (récupérées industriellement) comme addition minérale dans les matériaux cimentaires. A partir des résultats obtenus, il est possible d'apprécier dans quelle mesure ces fines sont compatibles avec les matrices cimentaires aux états frais, durcissant et durci. La troisième partie propose une piste pour limiter le problème de la Réaction Alcali-Granulat (RAG) dans le béton de granulats recyclés. La stratégie est basée sur deux volets. La première insiste à vérifier l'applicabilité du fascicule de documentation FD P18-464 lors de l'utilisation de granulats recyclés. Le deuxième examine l'intérêt de l'utilisation des additions minérales pour limiter, voire empêcher la RAG.The concrete consumption has been becoming more and more important due to the increase of urbanization requiring the rehabilitation and the construction of buildings and infrastructure. Nevertheless, the concrete production that accompanies the urban development leads to many environmental problems related to the preservation of natural resources which are not inexhaustible. Despite of recycling efforts, most of recycled materials are typically used for road works or embankment. By participating in the French National Project Recybéton, this thesis aims to assess the enhancement of recycling materials issued from deconstructed concretes by incorporating them in new concrete design. Two types of recycled materials will be studied, the powder produced in large quantities during the crushing phase of demolished concrete, and the aggregates (sand and gravel) whose the most part issued from the initial natural aggregates. Therefore, research study aims to quantify the properties of cementitious materials in various states by the use of: • recycled aggregates in the granular skeleton, grinded recycled concrete sand and powder of dust removal as supplementary cementing materials. The first part is dedicated to the study of the influence of moisture states of recycled aggregates (sand and gravel) on the concrete's rheology evolution in time and the study of their impact on 28 days compressive strength. The results obtained within the limit of experimental context will allow suggesting recommendations on the initial moisture state of recycled aggregates and their incorporation's rate in the concrete mix. The second part presents the evaluation of the feasibility of using grinded recycled concrete sand and crushed concrete powder (industrially recovered) as supplementary cementing materials. From the results, it will be possible to assess the extent that these fines are compatible with cement matrix in the fresh state, hardening state and hardened state. The third part proposes a way to limit the problem of Alkali-Aggregate Reaction (AAR) in recycled concrete. The strategy is based on two methods. The first insists to verify the applicability of the FD P18-464 documentation when using recycled aggregates. The second examines the interest in the use of mineral additives to limit or even prevent the AAR

ViSoBERT: A Pre-Trained Language Model for Vietnamese Social Media Text Processing

English and Chinese, known as resource-rich languages, have witnessed the strong development of transformer-based language models for natural language processing tasks. Although Vietnam has approximately 100M people speaking Vietnamese, several pre-trained models, e.g., PhoBERT, ViBERT, and vELECTRA, performed well on general Vietnamese NLP tasks, including POS tagging and named entity recognition. These pre-trained language models are still limited to Vietnamese social media tasks. In this paper, we present the first monolingual pre-trained language model for Vietnamese social media texts, ViSoBERT, which is pre-trained on a large-scale corpus of high-quality and diverse Vietnamese social media texts using XLM-R architecture. Moreover, we explored our pre-trained model on five important natural language downstream tasks on Vietnamese social media texts: emotion recognition, hate speech detection, sentiment analysis, spam reviews detection, and hate speech spans detection. Our experiments demonstrate that ViSoBERT, with far fewer parameters, surpasses the previous state-of-the-art models on multiple Vietnamese social media tasks. Our ViSoBERT model is available only for research purposes.Comment: Accepted at EMNLP'2023 Main Conferenc

Depth of powers of edge ideals of cycles and trees

Let $I$ be the edge ideal of a cycle of length $n \ge 5$ over a polynomial ring $S = \mathrm{k}[x_1,\ldots,x_n]$. We prove that for $2 \le t < \lceil (n+1)/2 \rceil$, $$\operatorname{depth} (S/I^t) = \lceil \frac{n -t + 1}{3} \rceil.$$ When $G = T_{\mathbf{a}}$ is a starlike tree which is the join of $k$ paths of length $a_1, \ldots, a_k$ at a common root $1$, we give a formula for the depth of powers of $I(T_{\mathbf{a}})$

THE IMPACT OF DATA SECURITY ON THE INTENTION OF VIETNAMESE CONSUMERS TO USE E-WALLETS

E-wallets are used as a form of payment that brings many benefits to users. This article studies the impact of data security on consumer intentions to use e-wallets in the rapidly growing economy of Vietnam. The data consist of 236 observations from a survey of consumers in Vietnam. Covariance-based structural equation modeling (CB-SEM) was employed to test the proposed hypotheses. Research results show that security trust has the greatest impact on the intention to use e-wallets, followed by perceived privacy risk, social influence, and information sensitivity. The study also reveals the role of privacy policies and security concerns in consumer intentions to use e-wallets. Based on the research results, the study provides recommendations for consumers, e-wallet providers, and governmental agencies to increase awareness of and responsibility for information security among the consumers who use e-wallets

Flexible Pavement Life Cycle Cost Analysis by Using Monte-Carlo Method and the Suggestions for Developing Countries

Flexible road pavement plays an essential role in developing an effective, economic, and safe operation road network of any country. In Vietnam, a developing country, the selection of a suitable flexible pavement structure is always a challenge due to fiscal limitations. The traditional determinant method (TDM) by which pavement structures are selected mainly on the basis of initial construction costs and traffic load has been used for many years in the nation. This paper presents the use of Monte Carlo simulation to analyze the entire flexible pavement life cycle cost. Data including initial and maintenance costs and road user costs were collected from several different types of existing flexible pavement in Nghe An province, Vietnam. Random variations of several main inputs were explored in order to develop density distribution functions. These functions then were used as the bases for Monte Carlo simulation. One million simulation runs were implemented and the Net Present Values (NPVs) among pavement types were compared under the light of risk analysis. Research results showed that TDM method provided bias and uncertain results compared to that of Monte Carlo one. In terms of long- term pavement performance, a low-cost pavement structure should not always be considered as a wise selection. Some other suggestions for a developing country as Vietnam were also included

The impact of corruption on the performance of newly established enterprises : empirical evidence from a transition economy

This paper investigates the effects of corruption on the performance of newly established enterprises. Using longitudinal data from enterprise surveys containing virtually all firms over the period from 2011 to 2015 in Vietnam, we find that corruption deteriorates firm financial performance, and subsequently exposes them to a greater failure probability. We further find that, while corruption imposes more harmful effects on the performance and survival of private domestic firms, it exerts no significant impact on state-owned firms. On the other hand, foreign firms are also able to take advantage of corruption to enhance their performance and survivability. In addition, our results suggest that the more mature firms are better at dealing with corruption and can eventually take advantage of it to enhance their performance. The results are robust after various model specifications as well as alternative classifications of newly established firms.Publisher PDFPeer reviewe

BIM-based Competitive Advantages and Competitive Strategies for Construction Consultancy SMEs: A Case Study in Vietnam

Building Information Modelling (BIM) has been proven as an innovative approach to bring values to construction projects as well as stakeholders, including construction consultancy firms. BIM adoption could assist construction consultancy Small and Medium-sized Enterprise (SMEs) in enhancing their competitive capability. Using a case study with a pioneer BIM service providers &nbsp;which is an SME in Vietnam (the Consultant), the paper explores the core competences for delivering BIM services in relation with potential competitive advantages. Four typical BIM market segments have been discovered, which include: i) BIM strategic services, (ii) BIM services, (iii) BIM-enabled services, and (iv) BIM tools development. Exploring six BIM cases, the realized core competences of the Consultant which are reported in the paper include the BIM-related skillful human resources (both in-house and from external), BIM know-hows, reputation, and also the benefits from a BIM network that the Consultant established as an outcome of a granted BIM research project. Focusing on only the first three market segments, the Consultant has taken advantage of their core competences to deliver differentiation and focus strategies to compete and generate competitive advantages. Cost leadership strategies were not very successful in the case study due to that the economies of scale could not be met; however, they can be considered with the provision of BIM-enabled services, when BIM services are delivered together with other consultancy and/or construction services

IDENTIFICATION AND QUANTITATIVE DETERMINATION OF HAZARDOUS NITROPHENOLIC COMPOUNDS IN THE EXHAUST GAS OF DIFFERENT KINDS OF DIESEL ENGINE BASED TRANSPORTATION VEHICLES IN HANOI CITY

Joint Research on Environmental Science and Technology for the Eart