This work presents a benchmarking study between Lagamine, an in-house developed finite element (FE) code, and COMSOL Multiphysics® (Comsol) commercial software in thermal analyses to investigate their capability in modeling complex manufacturing processes. For this purpose, two case studies, including a NAFEMS benchmark for heat transfer with convection and a Directed Energy Deposition (DED) of a bulk sample, were used as test cases. The simulation models using Lagamine and Comsol solvers for each case were described. The underlying algorithms and theories, as well as the soft-ware development, are investigated. The computational results indicate slight differ-ences between Lagamine and Comsol solutions in both case studies. For the NAFEMS test case, the results obtained with Comsol solver appear to be less dependent on the mesh size than those obtained with Lagamine. For the DED test case, within the chosen configurations of Lagamine and Comsol codes, the maximum difference in the highest peak temperatures obtained from the two codes is about 20%. From an engineering point of view, it is suggested to determine parameters of the FE model consistently with the selected FE code to provide the best match with experimental observations.

This article presents how to speculate, design and simulate a mechanical horse based on the point of view of the military man Khong Minh, a talented character in the work "Three Kingdoms" (author La Quan Trung). The behavior of this type of horse closely resembles that of a real horse. That is, it can walk, run, carry goods or people. It is made mainly of wood or steel. The authors speculated that Khong Minh placed a leaf spring in the belly of the mechanical horse. Soldiers just need to rotate so that the leaf spring twists, it will store energy in the form of potential energy. Then, it slowly unfolds, and the potential energy is converted into kinetic energy, transmitting motion to the mechanisms connected to the horse's legs. Finally, the mechanical horse lifted his leg and was able to walk. Despite such speculation, when recreating a mechanical horse, our team of authors used a battery-powered motor instead of leaf springs and gear transmissions as a pre-assembled transmission part in the belly of the mechanical horse. We design additional parts such as the head, tail, belly, legs, etc. to create a complete mechanical horse. The design goal of the author's mechanical horse is to clear people's doubts about the "wooden buffalo mechanical horse" in the literary work "Three Kingdoms". At the same time, this type of mechanical horse is also applied as an amusement ride for people in tourist areas and as a children's toy in the family.

ABSTRACT This paper analyzes the security performance of underlay cognitive energy-harvesting relay radio networks (UCEHRRN) through the Monter-Carlo simulation results. The results clarify the influence of critical operating parameters on the security performance of the system. Furthermore, the security capabilities of UCEHRRN have been compared with those of the live transmission system. Moreover, many results show that the security performance of the system is significantly improved. Analysis of the results also shows that UCEHRRN is especially effective when the direct transmission system cannot achieve security due to objective reasons such as path loss, severe fading, and shadowing.

The electricity obtained from the photovoltaic (PV) system highly depends on various factors such as geographical location, solar radiation, weather conditions and orientation of solar panels. The electricity produced by the solar PV system can be assessed by using simulations. This paper presents a technical feasibility assessment of a 10 kWp rooftop solar PV system for a household in Thu Dau Mot City, Vietnam. The study presents the amount of electricity produced, the performance of the PV system and the system potential to reduce CO2 emissions into the environment. The designing and evaluating of the system performance is done by PV*SOL, PVsyst and PVGIS software. The project provides useful information for the pre-feasibility assessment phase of a residential solar PV project in Vietnam.

It is very common to stabilize the preset value (Wanted value) of analog signals such as temperature, pressure, weight, flow, speed in automatic control. However, these control objects often have some problems such as overshooting, taking a long time to bring the system to a steady value, and large errors. One of the most used systems to overcome these problems is the PID, which is a preset stabilizing system with a quick function that returns the system to the set value in a short time without overshooting. error is close to zero. However, determining the scale parameters Ki, integral Kp, and differential Kd for the system to work optimally is a problem that needs to be studied. This paper presents how to accurately determine differential, integral, and scale coefficients according to 3D virtual reality model. Used a lot in simulation modeling for training and practical applications.

Traditional fossil energy sources are increasingly exhausted, leading to the need for mankind to exploit alternative energy sources; and solar energy can be viewed as infinite. Solar photovoltaic and its applications are increasingly widely studied. However, due to its nonlinearity and unstable nature, high technology is required to achieve good conversion efficiency. One of the techniques to optimize solar cell efficiency is to use the Maximum Power Point Tracking algorithm (MPPT) and P&O is a relatively easy algorithm to implement. This article will present some problems about photovoltaic cells, power converters in solar power systems and using PSIM software to simulate an independent solar system with several harvesting solutions for solar power and compare the efficiency of them.

Electric vehicles (EVs) making a significant contribution to the reduction of fossil fuel consumption and CO2 emissions are expected to thrive in Vietnam in the upcoming years/in the near future. However, such vehicles’ energy demand could become a burden on the transmission networks, causing overloads to the electric grid of the nation. Hence, to solve this problem, a solar PV system can be utilized to fulfill the electricity needs in an EV charging station. This article presents the design, simulation and economic analysis of a grid-connected solar power system for an electric charging station at Thu Dau Mot University (TDMU). The photovoltaic (PV) power system is designed to supply energy to the charging station and office building. The study estimates the generated electricity, the efficiency of the PV power system and the ability to reduce CO2 emissions. This paper can be a recommended input for stakeholders to consider using this energy source for charging vehicles.

With the development of information technology, many applications of robots are increasingly being applied to support research, learning, and teaching. This paper mainly investigates the modeling and simulation of a robotic arm with 3 degrees of freedom (dofs) for different applications. First, Kinematics and dynamics model of the robot based on the standard Denavit Hartenberg (D-H) modeling method, where the forward kinematics of robot is analyzed and computed to obtain by using the inverse kinematics, and then the solution of the robot dynamics is derived. Second, a CAD model of the robot is designed on CATIA software to convert to MapleSim software to simulation and control. Final, numerical simulation is presented to display results. This work provides a potential basis for the realization of the robotic arm in the industrial, education, and research field, which is of great significance for improving manufacturing efficiency and support teaching and research in the robot field.

This article introduces the general issues and benefits of simulation in teaching and scientific research. Thereby, the author illustrates by making 3D drawings, assemblies, videos simulating machine structures for teaching Theoretical mechanics, Construction machine subjects and the author's studies in the mechanical field. The application of simulation in teaching is to create videos by using Solidworks software, simulating the operating principle of machine structures. After that, show the videos to the students, excite them and make the lesson lively. And the simulation application in scientific research is mentioned as the way to use 3D drawings and simulation videos to preview the research results, promptly fix the wrong places. Since then, the research is quick, cost reduction is not worth it. The results of this paper are to point out the unique benefits that contribute positively to simulation in teaching and in scientific research.