On the regularization of solution of an inverse ultraparabolic equation associated with perturbed final data

In this paper, we study the inverse problem for a class of abstract ultraparabolic equations which is well-known to be ill-posed. We employ some elementary results of semi-group theory to present the formula of solution, then show the instability cause. Since the solution exhibits unstable dependence on the given data functions, we propose a new regularization method to stabilize the solution. then obtain the error estimate. A numerical example shows that the method is efficient and feasible. This work slightly extends to the earlier results in Zouyed et al. \cite{key-9} (2014).Comment: 19 pages, 4 figures, 1 tabl

IT applications in education and Self-directed learning capacity

For differentiated teaching methods in Vietnam, educators only focus on intellectual ability which is provided in academic report cards. Overlooking psychological and cognitive factors leads to poor performance of differentiated teaching in high school in Vietnam. This application of technology in teaching helps teachers to prepare lessons quickly through available lecture templates, and at the same time take advantage of many resources such as videos, images, electronic documents, etc. help attract learners and improve teaching effectiveness

The Transition in Goods Export Structure in the Northeast Region of Vietnam

The period 2005-2015 is an important stage in the preparation process of bringing Vietnam to basically become an industrialized country by 2020. The economic development of the Northeast with an open and export-oriented economy requires an important role of export activities in the region's socio-economic development. Although it is affected by the global economic crisis, the export value of the region has increased significantly, the structure of exports over the years has positively changed. In more detailed, the rate of raw goods slightly reduced. However, the restructuring of the region's exports has not made a breakthrough and failed to create a suitable structure of export products and made full use of the region’s advantages and potentials. The slow change of exports structure will lead to resource depletion, ecological imbalance, and poor economic efficiency. Keywords: Structure restructuring, Import and export, Northeast of Vietnam, PRODY, export commodities

Health impact of exposure to arsenic-contaminated drinking water in Vietnam

The public health situation of the population of Hanam Province in Vietnam is of great concern, as it is exposed daily to arsenic-contaminated drinking water. Optimising arsenic (As) removal efficiency of current sand filters at household level or switching to cleaner or As-free water sources is crucial to prevent or reduce community health risks

Seismic study of shallow circular tunnel in Red River sand (Vietnam)

Attention should be paid to tunnels' seismic behaviour since many of them have been damaged by earthquakes. The paper presented a seismic study of a shallow circular tunnel by physical modelling on shaking table test. A small scale tunnel model of the Hanoi pilot metro line's underground segment was placed in the middle of a rigid soil container and buried in Red River sand (Vietnam). The table was vibrated along the soil container's long wall, with a simulated seismic wave created from the 1788 Tolmezzo (Italia) accelerogram. Five testing campaigns were executed, and the model's acceleration data were studied. The uni-directional vibration created by the shaking table caused the three-directional vibration of the physical model. The Fast Fourier Transform (FFT) frequency spectrum analyses were performed. The vibration characteristics of the model (i.e., frequency graph's structure, maximal acceleration, dominant frequency, strong-motion duration) in three orthogonal directions under the artificial earthquake action were compared. The obtained results proved the complicated seismic impacts on a shallow tunnel

Further Discussion On Applying Case Study Method In Investment Law Course – A Case Of Education Investment In Vietnam

Purpose: The aim of this study is to focus on clarifying using case study method to improve taching law course. Currently, many universities around the world are applying a new teaching method. It can help students absorb knowledge more efficiently and faster. That is the case study. Using a Case Study allows a deeper understanding of cases as a unit, through comparing the similarities and differences of individual cases. Design/methodology/approach: The study uses qualitative analysis, synthesis and inductive methods, together with studies and references from CPTPP, FTA Agreement, as well as Regulations on assurance of business investment activities. Findings: The application of this method to teaching helps learners to approach very applicable situations. The situations or problems close to the theory will also help them to systematize all the knowledge they have learned to apply to solve the assigned problem. Not only use the knowledge learned, but also learn related knowledge outside the program to solve the problem. Case Study is an extremely interesting and interesting learning method, helping us to associate reality and apply it to solve problems and help us remember longer. If you really understand what a case study is, then apply it to your life and work. The results show the regulations on guaranteeing ownership rights as well as ensuring investors' business investment activities have been clearly stipulated in the 2020 Labor Law of Vietnam. These regulations have concretized the constitutional principle of investors' freedom to invest and do business in industries that are not prohibited by la

Application of the cut-off projection to solve a backward heat conduction problem in a two-slab composite system

The main goal of this paper is applying the cut-off projection for solving one-dimensional backward heat conduction problem in a two-slab system with a perfect contact. In a constructive manner, we commence by demonstrating the Fourier-based solution that contains the drastic growth due to the high-frequency nature of the Fourier series. Such instability leads to the need of studying the projection method where the cut-off approach is derived consistently. In the theoretical framework, the first two objectives are to construct the regularized problem and prove its stability for each noise level. Our second interest is estimating the error in -norm. Another supplementary objective is computing the eigen-elements. All in all, this paper can be considered as a preliminary attempt to solve the heating/cooling of a two-slab composite system backward in time. Several numerical tests are provided to corroborate the qualitative analysis.Peer reviewe

Growth of single crystals of methylammonium lead mixedhalide perovskites

We report the growth and characterization of different bulk single crystals of organo lead mixed halide perovskites CH3NH3PbI3−xBrx by two different crystal growth approaches: (i)anti-solvent diffusion, and (ii) inverse temperature crystallization. In order to control the size and the shape of crystals, we have investigated different experimental growth parameters such as temperature and precursor concentration. The morphology of obtained crystals was observed by optical microscope, whereas their intrinsic crystalline properties were characterized by single crystal as well as powder X-ray diffraction. The results illustrated that the growth and crystalline structure of mixed halide perovskites CH3NH3PbI3−xBrx could be easily tuned

Evaluation Of Agronomic Traits And Adaptation Of Some Promising Salt Tolerant Rice Lines/Varieties Growing In The Coastal Areas In Thanh Hoa Province, Vietnam

Rice (Oryza sativa L.) is the main food in Vietnam and plays an important role in economic activity in this country. However, rice yield and growing areas are adversely influenced by the threats of the devastation caused by the rise of sea level. This study aimed to evaluate the salt effects in field experiments of 19 promising salt tolerance rice lines/varieties carrying QTL/Saltol, which were selected from the BC2F5 breeding combination between FL479 and Bac Thom 7 (BC7). The field experiments were conducted in two consecutive seasons at three saline-affected rice growing areas, including Nga Son, Hoang Hoa and Quang Xuong districts, Thanh Hoa province. The results showed that among those promising rice lines, the HL15 line had the best yield components in all experimented sites, and good agronomic traits with short plant height and shorter growth duration than the BC7 variety (115-117 days) in the spring season and 102-103 days in the summer season, respectively. All tested had the same level of pest resistance/infection as the control variety BT7 under production conditions using pesticides including HL1, HL13 and HL15, which were mildly infected with the bacterial leaf blight, while HL15 variety showed high resistance to pests and diseases. Moreover, the HL2, HL15 and HL19 lines had scored 3, equivalent to FL478 (tolerant), and the survival rate was over 85% compared with the control variety. Overall, our findings showed that the promising purebred variety HL15 had a range of good agronomic characteristics, resistance to major pests and diseases, high yield potential and salinity tolerance of 6‰. The HL15 variety was renamed as SHPT15 and continued to conduct procedures to recognize it as a new rice variety