The Impact of Monetary Policy on Stock Returns in Vietnamese Stock Market

Understanding the impact of monetary policy on stock returns is crucial to making investment decisions in the stock market. In this paper, I analyzed the impact of monetary policy and the movement of stock returns, using the Vector Auto-Regression approach (VAR) and focusing on the relationships between stock returns, inflation rate, exchange rate and interest rate in Vietnam. The result shows that the stock returns could be well forecasted by using the past information of monetary policy. The analysis of impulse and response of stock returns illustrate that the monetary policy has a small contribution into the innovations of the stock returns and the shocks from monetary policy to stock returns mostly affect stronger in the second month when the own shock of stock returns reduces

Approximation of mild solutions of the linear and nonlinear elliptic equations

In this paper, we investigate the Cauchy problem for both linear and semi-linear elliptic equations. In general, the equations have the form $$\frac{\partial^{2}}{\partial t^{2}}u\left(t\right)=\mathcal{A}u\left(t\right)+f\left(t,u\left(t\right)\right),\quad t\in\left[0,T\right],$$ where $\mathcal{A}$ is a positive-definite, self-adjoint operator with compact inverse. As we know, these problems are well-known to be ill-posed. On account of the orthonormal eigenbasis and the corresponding eigenvalues related to the operator, the method of separation of variables is used to show the solution in series representation. Thereby, we propose a modified method and show error estimations in many accepted cases. For illustration, two numerical examples, a modified Helmholtz equation and an elliptic sine-Gordon equation, are constructed to demonstrate the feasibility and efficiency of the proposed method.Comment: 29 pages, 16 figures, July 201

Research on the dynamics of a heavy mechanized bridge in the deployment phase of the lifting frame

This article presents a dynamic model of the TMM-3M heavy mechanized bridge during the frame lifting stage, which is driven by a hydraulic system, constituting the initial phase of the bridge erection process. The model is constructed as a multi-body dynamic system, taking into account the elastic deformation of the rear outriggers, front tires, and front suspension system. The research model integrates a mechanical system controlled by hydraulic cylinders, with pressure being considered as a variable reacting to external loads during the system's operation. Lagrangian equations of the second kind are utilized to establish a system of differential equations describing the oscillations of the system and form the basis for investigating the dynamics of the frame lifting process. The system of differential equations is solved numerically using MATLAB simulation software based on the Runge-Kutta algorithm. The study has revealed laws regarding the displacement and velocity of components within the system, evaluating the stability of the TMM-3M heavy mechanized bridge during operation. This research paves the way for a comprehensive understanding of the working process of the TMM-3M heavy mechanized bridge, aiming for practical improvements to minimize deployment or retrieval time, reduce the number of deployment team members, enhance the automation of the operation process to reduce the workload for operator

Study on terrain response of the military mobile repair vehicle towing power generator trailer before and after improvement

Mobile repair vehicles play an indispensable role on the battlefield and are increasingly being improved to enhance their effectiveness. When moving to repair locations on the battlefield, they often tow trailers, which include power generator sets. In some cases, these generator sets are replaced by trailers to transport ammunition or carry wounded soldiers. The article proposes improvements to the suspension system on the generator trailers and discusses the impact of vehicle speed and random road roughness on the movement of the mobile repair vehicle-trailer combination before and after the improvements. A dynamic model of the multi-body system is constructed, with the towing vehicle being a three-axle truck. The random roughness profile of the road surface is determined from simulation results based on ISO 8068 standards. The equations of motion are established using Lagrange's method and solved through simulation using Matlab software. The results of the article indicate the oscillation of the mobile repair vehicle-trailer combination when traveling at speeds of 36 km/h and 54 km/h on road surfaces with random roughness levels of class D and class E. After the improvement of the suspension system on the generator trailers, smoother trailer motion is observed. The study has shown that the vertical oscillation amplitude of the trailer decreased by up to 18 %, while the oscillation speed decreased by as much as 40 %. The findings provide a basis for further improving the suspension system on generator trailers to minimize oscillations, which is crucial for replacing generator trailers with specialized trailers for transporting ammunition or wounded soldiers on the battlefield. This is a significant issue in the field of national security and defens

Critical-Path Aware Scheduling for Latency Efficient Broadcast in Duty-Cycled Wireless Sensor Networks

Minimum latency scheduling has arisen as one of the most crucial problems for broadcasting in duty-cycled Wireless Sensor Networks (WSNs). Typical solutions for the broadcast scheduling iteratively search for nodes able to transmit a message simultaneously. Other nodes are prevented from transmissions to ensure that there is no collision in a network. Such collision-preventions result in extra delays for a broadcast and may increase overall latency if the delays occur along critical paths of the network. To facilitate the broadcast latency minimization, we propose a novel approach, critical-path aware scheduling (CAS), which schedules transmissions with a preference of nodes in critical paths of a duty-cycled WSN. This paper presents two schemes employing CAS which produce collision-free and collision-tolerant broadcast schedules, respectively. The collision-free CAS scheme guarantees an approximation ratio of in terms of latency, where denotes the maximum node degree in a network. By allowing collision at noncritical nodes, the collision-tolerant CAS scheme reduces up to 10.2 percent broadcast latency compared with the collision-free ones while requiring additional transmissions for the noncritical nodes experiencing collisions. Simulation results show that broadcast latencies of the two proposed schemes are significantly shorter than those of the existing methods

On the high resolution regional weather forecast model (HRM) and forecasting tropical cyclone motion over the south china sea

Chan (1995) [2] has found that, only 70% in 60 cases of the tropical cyclone (TC) movement test (TMT-90) developed from steering flows. The 30% remain of cases have to be explained by nonbarotropic processes. We are of the opinion that all weak, slow-moving and unexpected changing TCs over the South China Sea are in this 30% set. The nonlinear interaction between barotropic and nonbarotropic processes has affected on motion and structure of such TCs. In this paper, we use the high resolution weather forecast model (HRM), which is able to simulate meso-scale phenomena in limited regions, to predict motion of TCs in the South China Sea in 2002-2004, including two typical weak, slow-moving and unexpected changing TCs Mekhala and Nepartak. We have chosen two forecast domains with different areas and resolutions. The results show that with the smaller domain, appropriate buffer and higher resolution HRM can predict better motion of TCs operating in the South China Sea

Studying the influence of engine speed on the entire process of span-lowering of the heavy mechanized bridge

The paper presents a dynamic model of the TMM-3M heavy mechanized bridge during the span lowering stage. The model is constructed as a multi-body mechanical system, taking into account the elastic deformation of the cable, rear outriggers, front tires, and front suspension system. It is a mechanical model driven by a cable mechanism. Lagrangian equations of the second kind have been applied to establish a system of differential equations describing the oscillations of the mechanical system and serve as the basis for investigating the dynamics of the span-lowering process. The system of differential equations is solved using numerical methods based on MATLAB simulation software. The study has revealed laws of the displacement, velocity, and acceleration of components within the mechanical system, especially those related to the bridge span depending on the choice of the drive speed of the engine during lowering by operator. The research results show that the lowering time increases from 52 seconds to 104 seconds when the engine speed decreases from 1800 rpm to 900 rpm. The tension force on the cable is surveyed to confirm the safety conditions during the span-lowering process. The study also provides recommendations for selecting appropriate engine speeds to minimize span-lowering time while ensuring the safety conditions of the TMM-3M bridge during the span-lowering process. This research is an important part of a comprehensive study on the working process of the heavy mechanized bridge TMM-3M to make practical improvements, aiming to reduce deployment time, decrease the number of deployment crew members, and increase the automation capability of the equipmen