85 research outputs found
Vietnamese response to the Sino-Russian cooperation and rivalry since the end of the Cold War
A thesis presented on the Vietnamese response to the changes in the Sino-Russian relations since the end of the Cold War, beginning with an overview of the Sino-Russian relations during and after the Cold War, with an emphasis on the changes in the Sino-Russian relations, covering the overview of Vietnam’s relations with both Russia and China during the Cold War and the impact of the Sino-Russian relations on Viet Nam. Especially Vietnam’s reactions to the changes in the Sino-Russian relations since the end of the Cold War from the perspective of small and middle power’s foreign policy as well as policy recommendations for Viet Nam in order to balance its relations with both Russia and China to exploit the potentials and deepen its relations with these two countries for the objectives of security, development and influence of Viet Nam
ASSESSING THE ADAPTIVE CAPACITY OF HOUSEHOLDS TO CLIMATE CHANGE: A CASE STUDY IN QUANG DIEN DISTRICT, THUA THIEN HUE PROVINCE
Abstract: This study aims to identify the adaptation capacity undertaken by households in response to natural disasters and climate changes (CC). A total of 100 households in two communes including Quang Phuoc and Quang Cong, Quang Dien district were interviewed. The findings indicate that in the last few years, these communes have been badly affected by various types of natural hazards, including typhoons, floods, droughts and, and extremely cold weather. The study demonstrates that the adaptive capacity index in Quang Cong is significantly lower than that in Quang Phuoc (0.50 and 0.52). Also, the current adaptation actions of local households in response to natural disasters and CC have focused on short-term actions only. On the basis of the findings, the study proposes key recommendations to local households in Quang Dien district to effectively mitigate and adapt to natural disasters and CC. The recommendations encompass three groups, namely (i) raising awareness and understanding about CC; (ii) improving the infrastructure system; and (iii) diversifying livelihood strategies to increase income.Keywords: climate change, natural disasters, adaptive capacity, inde
Achieving Better Regret against Strategic Adversaries
We study online learning problems in which the learner has extra knowledge
about the adversary's behaviour, i.e., in game-theoretic settings where
opponents typically follow some no-external regret learning algorithms. Under
this assumption, we propose two new online learning algorithms, Accurate Follow
the Regularized Leader (AFTRL) and Prod-Best Response (Prod-BR), that
intensively exploit this extra knowledge while maintaining the no-regret
property in the worst-case scenario of having inaccurate extra information.
Specifically, AFTRL achieves external regret or \emph{forward
regret} against no-external regret adversary in comparison with
\emph{dynamic regret} of Prod-BR. To the best of our knowledge, our algorithm
is the first to consider forward regret that achieves regret against
strategic adversaries. When playing zero-sum games with Accurate Multiplicative
Weights Update (AMWU), a special case of AFTRL, we achieve \emph{last round
convergence} to the Nash Equilibrium. We also provide numerical experiments to
further support our theoretical results. In particular, we demonstrate that our
methods achieve significantly better regret bounds and rate of last round
convergence, compared to the state of the art (e.g., Multiplicative Weights
Update (MWU) and its optimistic counterpart, OMWU)
Greenhouse gas emissions from piggery and biogas digesters in the Red River Delta of Vietnam
High demand for pork consumption in Vietnam has led to a shift of pig production systems from smallholder to industrial-scale farms, particularly in the Red River Delta. This production intensification also produces massive manure and urine quantities, leading to water, air, and soil pollution. The use of biogas plants has been seen as efficient to achieve in the same time a decrease in pollution, and a provision of biogas resources and bio-organic fertilizers. However, increasing pig head density has been causing great pressure on biogas digesters, as their size is not big enough for treatments anymore. Inappropriate utilization and management of biogas digesters can not only cause losses from pig wastes, but also contributes to increase greenhouse gas (GHG) emissions such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). This case study aims to identify the role and contributions of biogas digesters to better manage the sources of GHG emissions from pig wastes for different types of pig farms. Four provinces of the Red River Delta were selected to test the pig waste management efficiency of biogas digesters and measure GHG emissions from these systems. The findings show that CO2, CH4 and N2O emission rates from pig manure are at least twice as much what is allowed under the Vietnam national technical regulation on ambient air quality. However, the GHGs emission rate does not significantly differ between smallholder and industrial-scale farms in the four surveyed provinces. Sampling position (between inside piggeries and outside the outlet of biogas digesters) did not affect significantly GHG emissions rate. These results confirm that the pig waste management of biogas digesters for both smallholder and industrial-scale pig farms is not efficient and that efforts need to be invested to mitigate GHG emissions in pig production.
Reducing pig density per piggery is highly recommended. The modification of biogas digester structure to separate solid pig manure and urine should also be considered. Otherwise, the application of other alternative aerobic or anaerobic digestion technologies should also be encouraged and promoted. Biogas digesters in pig production have a significant role to play in Vietnam government’s mitigation strategies, as well as from the perspective of biosafety and animal husbandry policies
Last Round Convergence and No-Instant Regret in Repeated Games with Asymmetric Information
This paper considers repeated games in which one player has more information
about the game than the other players. In particular, we investigate repeated
two-player zero-sum games where only the column player knows the payoff matrix
A of the game. Suppose that while repeatedly playing this game, the row player
chooses her strategy at each round by using a no-regret algorithm to minimize
her (pseudo) regret. We develop a no-instant-regret algorithm for the column
player to exhibit last round convergence to a minimax equilibrium. We show that
our algorithm is efficient against a large set of popular no-regret algorithms
of the row player, including the multiplicative weight update algorithm, the
online mirror descent method/follow-the-regularized-leader, the linear
multiplicative weight update algorithm, and the optimistic multiplicative
weight update
Assessing the adaptive capacity of households to climate change: a case study in Quang Dien District, Thua Thien Hue Province
peer reviewedThis study aims to identify the adaptation capacity undertaken by households in response to natural disasters and climate changes (CC). A total of 100 households in two communes including Quang Phuoc and Quang Cong, Quang Dien district were interviewed. The findings indicate that in the last few years, these communes have been badly affected by various types of natural hazards, including typhoons, floods, droughts and, and extremely cold weather. The study demonstrates that the adaptive capacity index in Quang Cong is significantly lower than that in Quang Phuoc (0.50 and 0.52). Also, the current adaptation actions of local households in response to natural disasters and CC have focused on short-term actions only. On the basis of the findings, the study proposes key recommendations to local households in Quang Dien district to effectively mitigate and adapt to natural disasters and CC. The recommendations encompass three groups, namely (i) raising awareness and understanding about CC; (ii) improving the infrastructure system; and (iii) diversifying livelihood strategies to increase income
Consideration on lateral vibration of automobiles in quasi-planar model with wheel separation and road deformation taken into account
This article considers lateral vibration of an automobile in a so-called quasi-planar model where both the loss of contact and road deformation are taken into account. The automobile with dependent suspension is modeled as a vibration system which has two masses and four degrees of freedom. The deformed road is modeled as an elastic beam which has uniform rectangular cross-section, is simply supported at the two ends and lies on the Kelvin's visco-elastic ground. The loss of contact and the change in dimensions of contact areas are considered. The differential equations of motion of the vehicle-road coupled system which contains a partial differential equation are transformed into a set of all ordinary differential equations by applying the Bubnov-Galerkin’s method. A procedure for numerically solving the transformed differential equations of motion is proposed. Some illustrating results coming from numerical consideration are also presented in the paper
Consideration of the problem about vibration of automobile in one fourth model with taking road deformation and the loss of contact into account
This paper presents an approach to the problem about vibration of automobiles in one-fourth model where both road deformation and the loss of contact are taken into account. Contact characteristics such as the geometry of the contact area, pressure distribution, the relation between the contact force and the dimensions of the contact area, and therefore the change in dimensions of the contact area with respect to time are mentioned. Deformed road is modeled as an elastic beam which is simply supported at the two ends and lies on Kelvin’s visco-elastic ground. The differential equations of motion for both states of contact and losing contact are unified by introducing a so-called contact state parameter. The partial differential equation among the differential equations of motion of the vehicle-road coupled system is transformed into a system of all ordinary differential equations by applying the Bubnov-Galerkin’s method. A procedure for numerically solving the ordinary differential equations of motion of the vibration system under consideration is proposed and some numerical results for illustration are also presented in the paper
Evaluating the impacts of rice-based protection dykes on floodwater dynamics in the vietnamese mekong delta using geographical impact factor (Gif)
This study aims at evaluating the geographical influences of rice-based protection dykes on floodwater regimes along the main rivers, namely the Mekong and the Bassac, in the Vietnamese Mekong Delta (VMD). Specifically, numerous low dykes and high dykes have been constructed particularly in the upper delta’s floodplains to protect the double and triple rice cropping against the annual flooding. For the whole deltaic domain, a 1D-quasi-2D hydrodynamic model setup was used to simulate seventy-two (72) scenarios of dyke construction development in the context of low, medium, and high floods that occurred in the VMD to examine the effects of different flood magnitudes on a certain dyke construction area. Based on the model simulation results, we established an evaluation indicator, the so-called Geographical Impact Factor (GIF), to evaluate the impacts of zone-based dyke compartments on the floodwater regimes along the main rivers for different kinds of floods. Our findings revealed different rates of influences on the floodwater levels along the Mekong and Bassac Rivers under different scenarios of zone-based high-dyke developments. GIF is a useful index for scientists and decision-makers in land use planning, especially in rice intensification, in conjunction with flood management for the VMD and for similar deltas worldwide
DETERMINATION OF ARSENIC (ILL AND V) BY ANODIC STRIPPING VOLTAMMETRY ON GOLD FILM ELECTRODE
Joint Research on Environmental Science and Technology for the Eart
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