This paper applies the homotopy analysis method to study nonlinear free vibrations. The paper has used the homotopy analysis method to find analytical solutions of a nonlinear two-degree-of-freedom system. Analytical results have found the natural oscillation frequencies, the displacement formula of the system are approximately calculated at the 10th order.

To analyze the drug list (DL) structure used at Military Hospital (MH) 354 according to general criteria and the ABC/VEN classification method. Subjects and methods: A retrospective description of DL of MH 354 from 01/01/2019 to 31/12/2019.

The objects of the thesis: Study and develop the simultaneous analysis method of plant growth stimulants in vegetables using by high-performance liquid chromatography coupled with ion-trapping mass spectrometry. Apply the studied method of analysis and assessment of the current use, residue level and the potential accumulation of plant growth stimulants used in vegetable production in several districts belonged to Hanoi.

The objective of the thesis is to propose collaborative filtering recommender models that apply the proposed measures from the statistical implicative analysis method, tendency of variation in statistical implications, and association rules.

The research aims were to determine strategies in farmers' social capital strengthening to increase trust between farmers and stakeholders, in market structure, and technical-social farmers' empowerment.

The research mainly focused on optimizing the multi responses i.e. tensile strength, impact Strength and elongation while conducting the experiments on Friction Stir Welding process.

This research aims to identify the priority levels of the strategies used by cancer patients’ family members to cope with negative emotions, utilizing Analytic Hierarchy. Next, the proposed model is applied in the cases of Vietnamese cancer patients’ family members.