Research on the System Safety Management in Urban Railway

Nowadays, rail transport has become one of the most widely utilised forms of transport thanks to its high safety level, large capacity, and cost-effectiveness. With the railway network's continuous development, including urban rail transit, one of the major areas of increasing attention and demand is ensuring safety or risk management in operation long-term remains for the whole life cycle by scientific tools, management of railway operation (Martani 2017), specifically in developed and developing countries like Vietnam. The situation in Vietnam demonstrates that the national mainline railway network has been built and operated entirely in a single narrow gauge (1000mm) since the previous century, with very few updates of manual operating technology. This significantly highlights that up to now, the conventional technique for managing the safety operation in general, and collision in particular, of the current Vietnamese railway system, including its subsystems, is only accident statistics which is not a scientific-based tool as the others like risk identify and analyse methods, risk mitigation…, that are already available in many countries. Accident management of Vietnam Railways is limited and responsible for accident statistics analysis to avoid and minimise the harm caused by phenomena that occur only after an accident. Statistical analysis of train accident case studies in Vietnam railway demonstrates that, because hazards and failures that could result in serious system occurrences (accidents and incidents) have not been identified, recorded, and evaluated to conduct safety-driven risk analysis using a well-suited assessment methodology, risk prevention and control cannot be achieved. Not only is it hard to forecast and avoid events, but it may also raise the chance and amount of danger, as well as the severity of the later effects. As a result, Vietnam's railway system has a high number of accidents and failure rates. For example, Vietnam Rail-ways' mainline network accounted for approximately 200 railway accidents in 2018, a 3% increase over the previous year, including 163 collisions between trains and road vehicles/persons, resulting in more than 100 fatalities and more than 150 casualties; 16 accidents, including almost derailments, the signal passed at danger… without fatality or casual-ty, but significant damage to rolling stock and track infrastructure (VR 2021). Focusing and developing a new standardised framework for safety management and availability of railway operation in Vietnam is required in view of the rapid development of rail urban transport in the country in recent years (VmoT 2016; VmoT 2018). UMRT Line HN2A in southwest Hanoi is the country's first elevated light rail transit line, which was completed and officially put into revenue service in November 2021. This greatly highlights that up to the current date, the UMRT Line HN2A is the first and only railway line in Vietnam with operational safety assessment launched for the first time and long-term remains for the whole life cycle. The fact that the UMRT Hanoi has a large capacity, more complicated rolling stock and infrastructure equipment, as well as a modern communica-tion-based train control (CBTC) signalling system and automatic train driving without the need for operator intervention (Lindqvist 2006), are all advantages. Developing a compatible and integrated safety management system (SMS) for adaption to the safety operating requirements of this UMRT is an important major point of concern, and this should be proven. In actuality, the system acceptance and safety certification phase for Metro Line HN2A prolonged up to 2.5 years owing to the identification of difficulties with noncompliance to safety requirements resulting from inadequate SMS documents and risk assessment. These faults and hazards have developed during the manufacturing and execution of the project; it is impossible to go back in time to correct them, and it is also impossible to ignore the project without assuming responsibility for its management. At the time of completion, the HN2A metro line will have required an expenditure of up to $868 million, thus it is vital to create measures to prevent system failure and assure passenger safety. This dissertation has reviewed the methods to solve the aforementioned challenges and presented a solution blueprint to attain the European standard level of system safety in three-phase as in the following: • Phase 1: applicable for lines that are currently in operation, such as Metro Line HN2A. Focused on operational and maintenance procedures, as well as a training plan for railway personnel, in order to enhance human performance. Complete and update the risk assessment framework for Metro Line HN2A. The dissertation's findings are described in these applications. • Phase 2: applicable for lines that are currently in construction and manufacturing, such as Metro Line HN3, Line HN2, HCMC Line 1 and Line 2. Continue refining and enhancing engineering management methods introduced during Phase 1. On the basis of the risk assessment by manufacturers (Line HN3, HCMC Line 2 with European manufacturers) and the risk assessment framework described in Chapter 4, a risk management plan for each line will be developed. Building Accident database for risk assessment research and development. • Phase 3: applicable for lines that are currently in planning. Enhance safety requirements and life-cycle management. Building a proactive Safety Culture step by step for the railway industry. This material is implemented gradually throughout all three phases, beginning with the creation of the concept and concluding with an improvement in the attitude of railway personnel on the HN2A line. In addition to this overview, Chapters 4 through Chapter 9 of the dissertation include particular solutions for Risk assessment, Vehicle and Infrastructure Maintenance methods, Inci-dent Management procedures, and Safety Culture installation. This document focuses on constructing a system safety concept for railway personnel, providing stringent and scientific management practises to assure proper engineering conditions, to manage effectively the metro line system, and ensuring passenger safety in Hanoi's metro operatio

Évaluation des risques d'inondations dans le bassin du fleuve Huong, province de Thua Thien Hue, centre du Vietnam

Les inondations sont un phénomène de plus en plus fréquent dans le monde. Ces catastrophes ont entre autres un impact sur l'environnement et les activités socio-économiques des communautés touchées. Il est donc indispensable pour les autorités de dresser le portrait des risques d'inondation auxquels sont soumises les populations afin de mettre en place des stratégies efficaces de prévention et de lutte. L'un des principaux enjeux actuels au Vietnam pour que ces stratégies soient efficaces est la production de cartes précises des risques d'inondation. En effet, pour le moment, les cartes disponibles ne permettent pas de fournir les informations suffisantes ou exactes nécessaires aux décideurs, notamment en ce qui concerne l'ampleur des impacts environnementaux reliés aux inondations et à leurs conséquences socio-économiques. La présente étude vise à développer une méthode d'évaluation des risques d'inondation s'appuyant sur l'intégration des notions d'aléa d'inondation et de vulnérabilité. L'analyse des risques d'inondation est réalisée grâce à la participation des communautés affectées par ces catastrophes avec l'appui des systèmes d'information géographique (SIG) et de la télédétection. L'utilisation de ces outils permet de compenser dans une très large mesure les données manquantes et de préciser des données considérées pour le moment comme inexactes ou insuffisantes à l'analyse. Les impacts des inondations sur l'environnement et la sphère socio-économique comprennent la vulnérabilité de la communauté à l'inondation et les dommages potentiels à cause de l'occupation du sol. L'étude est réalisée dans le bassin du fleuve Huang, lequel occupe la moitié de la province de Thua-Thien-Hue, dans le centre du Vietnam. Les résultats de l'évaluation des risques d'inondation identifient les problèmes d’inondation dans une perspective intégratrice incluant les conditions socio-économiques et environnementales qui peuvent servir de support aux décisions des autorités locales et régionales.\ud ______________________________________________________________________________ \ud MOTS-CLÉS DE L’AUTEUR : inondation, risque, vulnérabilité, environnement, impact, Thua-Thien-Hue, Vietnam, bassin versant, développement durable, gestion, socio-économique, SIG, télédétection, cartographie

Globalization and infectious diseases: Evidence on the reproduction rate of the COVID-19 pandemic

The file attached to this record is the author's final peer reviewed version.In this paper we investigated the impact of globalization on infectious diseases and found that export values contributed greatly to the reproduction rate of the COVID-19 outbreak. We collected the number of new cases and deaths from the Worldometer and trade data from the International Trade Center. Our sample covered more than 100 countries. In addition, we applied the epidemiology model, namely the SIR model, to relate globalization to the infection rate. Our results indicated that high export values contributed to high infection rate, especially among high income countries. Finally the impacts were not identical across sectors: they ranged from positive in some sectors to insignificant and even negative in others

COVID-19, lockdown and labor uncertainty

In this paper, we investigate the impact of containment and closure poli- cies amid the COVID-19 pandemic on the labor market. We show that these effects depend on the presence of labor uncertainty. In the absence of labor uncertainty, the containment and closure policy resulted in people applying fewer self-protection measures, facing lower income and saving more. We predict that workers will lose their job as a consequence of this policy if and only if the containment elasticity of labor demand is sufficiently large. By contrast, when labor uncertainty is introduced, our model predicts more self-protection, more job loss and fewer savings as a result of a lockdown. In addition, income loss occurs if and only if the elasticity of labor demand is large enough. We test our predictions by employing new survey data collected on representative samples across 6 countries: China, Japan, South Korea, Italy, the UK, and the U.S. The survey collected information from households about their work and living situations and their income and socio-demographic characteristics. We find that young, low-income workers and urban dwellers are more vulnerable to containment and closure policies as they are more likely to lose their jobs and income. More importantly, our data provides supporting evidence to all of the predictions of our model

The texture of livelihoods: Migration and making a living in Hanoi

10.1080/00220388.2013.858130Journal of Development Studies503368-38

The impact of ICT on service trade

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.While trade in goods has been investigated extensively over decades, studies on trade in services are relatively new. In this paper we investigate the impacts of information and communication technology (ICT) on trade in services . We measured ICT by four dimensions, including the subscriptions to broadband, fixed telephones, mobile phones and Internet. Our sample covered more than 200 countries, from 2005 to 2015. We employed the modified gravity model and found that all four dimensions had significant impacts on the expansion trade in services, but mobile subscriptions is the most consistent dimension. Finally the effects of ICT in exporting and importing countries are similar

Mechanism of Inverse Magnetoresistance in High-TaT_{a} Annealed MnNi/Co/Ag(Cu)/Py Spin Valves

The magnetic transport properties -- magnetoresistive (MR) effects of MnNi/Co/Ag(Cu)/\break Py pinned spin valve structures (SVs) prepared by rf sputtering method and annealed at $T_{a} = 100$°C - 500°C for 30 minutes in high vacuum ($\sim 10^{ - 5}$ torr) are investigated. The received results show a change in the observed MR behaviors from a normal giant magnetoresistance effect to an inverse magnetoresistance effect after annealing at high temperatures, 300°C and 400°C, for these SVs. The origin and mechanism of the IMR behavior are analyzed and discussed. These results will suggest an ability to manufacture SV devices used the IMR effect for enhancing the application capacities for SV-sensor systems

Detection of a Sudan dye at low concentrations by surface-enhanced Raman spectroscopy using silver nanoparticles

Sudan dyes are red colorants banned from use for food due to their toxic properties. However, because of the cheapness, they are sometimes adulterated into food illegally. Currently surface-enhanced Raman spectroscopy (SERS) is emerging as a good method to detect residues (including trace amounts) of Sudan dyes in food. In this report we present the SERS detection of Sudan I (a type of Sudan dyes) to concentrations as low as 1 ppb, using a very simple SERS substrate, which is made from silver nanoparticles chemically deposited on silicon surface

Strategic Risk Determinants Influencing Growth of SMEs: The Case of Vietnam

Risk is inherent in all business functions and in every kind of activities. This is especially true for small and medium sized enterprises (SMEs) that are most exposed to the harmful effects of the risks, due to limited resources and structural features. Therefore, this study is conducted for identifying the relationship and impact strategic risk determinants including Political risks, Technological risks, Social risks on the growth of 30 small and medium forest enterprises (SMFEs) in Dien Bien as the case study. Political risks, Technological risks, Social risks are independent variables and the growth of SMFEs is a dependent variable. Data were collected through the questionnaire survey and using mean, correlation and regression analysis for this paper. The results show that there is a statistically significant negative correlation between strategic risk determinants on SMFEs growth. Keywords: Political risks, Technological risks, Social risks, Growth, SME

Trade Liberalization and Markup: Micro Evidence from China

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.This paper presents evidence from highly disaggregated Chinese firm-product data that, given productivity, input tariff reductions induce an incumbent importer/exporter to increase product markups. We further investigate empirically the mechanisms underlying this trade liberalization effect, and find that input tariff reductions decrease marginal costs, and their effects on markup adjustments are more profound among firms with higher import dependence. Moreover, we exploit unique features of Chinese data by comparing results for two trade regimes: ordinary trade (wherein firms pay import tariffs to import) and processing trade (wherein firms are not subject to import tariffs). While the aforementioned trade liberalization effects and mechanisms only apply to ordinary trade, processing trade samples are used in a placebo test. The paper also shows that more productive firms charge higher markups for products. All these findings are robust to alternative markup measures including one estimate using physical-quantity output data, different production function specifications, a subsample consisting only of pure exporters, and estimations based on our theoretical derivations