Lateral Stability Control of Four-Wheel Independent Drive Electric Vehicles Based on Model Predictive Control

Four-wheel independent drive electric vehicle was used as the research object to discuss the lateral stability control algorithm, thus improving vehicle stability under limit conditions. After establishing hierarchical integrated control structure, we designed the yaw moment decision controller based on model predictive control (MPC) theory. Meanwhile, the wheel torque was assigned by minimizing the sum of consumption rates of adhesion coefficients of four tires according to the tire friction ellipse theory. The integrated simulation platform of Carsim and Simulink was established for simulation verification of yaw/rollover stability control algorithm. Then, we finished road experiment verification of real vehicle by integrated control algorithm. The result showed that this control method can achieve the expectation of effective vehicle tracking, significantly improving the lateral stability of vehicle

CFD Simulations to Study Parameters Affecting Gas Explosion Venting in Compressor Compartments

In this work, a series of vented explosions in a typical compressor compartment are simulated using FLACS code to analyze the explosion venting characteristics. The effects of relevant parameters on the pressure peaks (i.e., overpressure and negative pressure) are also numerically investigated, including vent area ratio of the compressor compartment, vent activation pressure, mass per unit area of vent panels, and volume blockage ratio of obstacles. In addition, the orthogonal experiment design and improved grey relational analysis are implemented to evaluate the impact degree of these relevant parameters. The results show that the pressure peaks decrease with the increase of vent area ratio. There is an approximately linearly increasing relationship between the pressure peaks and the vent activation pressure. The pressure peaks increase with the mass per unit area of vent panels. The pressure peaks increase with the volume blockage ratio of obstacles. Based on the grey relational grade values, the effects of these relevant parameters on the overpressure peak are ranked as follows: volume blockage ratio of obstacles > vent activation pressure > vent area ratio > mass per unit area of vent panels. These achievements provide effective guidance for the venting safety design of gas compressor compartments

VTimeLLM: Empower LLM to Grasp Video Moments

Large language models (LLMs) have shown remarkable text understanding capabilities, which have been extended as Video LLMs to handle video data for comprehending visual details. However, existing Video LLMs can only provide a coarse description of the entire video, failing to capture the precise start and end time boundary of specific events. In this paper, we solve this issue via proposing VTimeLLM, a novel Video LLM designed for fine-grained video moment understanding and reasoning with respect to time boundary. Specifically, our VTimeLLM adopts a boundary-aware three-stage training strategy, which respectively utilizes image-text pairs for feature alignment, multiple-event videos to increase temporal-boundary awareness, and high-quality video-instruction tuning to further improve temporal understanding ability as well as align with human intents. Extensive experiments demonstrate that in fine-grained time-related comprehension tasks for videos such as Temporal Video Grounding and Dense Video Captioning, VTimeLLM significantly outperforms existing Video LLMs. Besides, benefits from the fine-grained temporal understanding of the videos further enable VTimeLLM to beat existing Video LLMs in video dialogue benchmark, showing its superior cross-modal understanding and reasoning abilities

Forming alumina (Al2O3) by micro-FAST

The Alumina (Al2O3), also known as Aluminium oxide, has a good thermal conductivity, but it is an electrical insulator. The Alumina is being used widely in the industry. Several research the sintering of Alumina using the conventional hot pressing process or spark plasma sintering (SPS). However, these methods are and have their own limits and disadvantages, such as long process chains and low efficiency with the processes and, rarely developed for the forming of miniature and micro-scale components. In this study conducted in the report. A new process has been used adapted from the electric-current activated sintering techniques (FAST) and it is been combined with micro-forming technology and called the (Micro-FAST). The Alumina powders were loaded directly into the die, followed by electric-sintering under certain pressure. In this paper Ø4.00 mm×4.00 mm and Ø2.00 mm×2.00 mm cylinder solid samples were produced. This experiment was conducted by use of a Gleeble 3800 thermal-mechanical simulator. Several properties of the solid samples, such as relative density, ESM and EDS, were examined, and these showed good results have been obtained

Poly[[diaqua­bis[μ-(2,4-dichloro­phen­oxy)acetato]calcium(II)] monohydrate]

In the title coordination polymer, {[Ca(C8H5Cl2O3)2(H2O)2]·H2O}n, the CaII atom is eight-coordinated by six O atoms from four different (2,4-dichloro­phen­oxy)acetate ligands and two water mol­ecules, and displays a distorted square-anti­prismatic coordination geometry. The compound forms an infinite zigzag chain through connection of the metal centers by (2,4-dichlorphen­oxy)acetate ligands and hydrogen bonding of coordinated and inter­stitial water mol­ecules. These chains are further hydrogen bonded with neighboring chains, forming a supra­molecular network

Fabrication of micro components with MSZ material using electrical-field activated powder sintering technology

The electrical Field Activated Sintering Technology (FAST) process uses low voltage and high current, pressure-assisted sintering and synthesis technique, which has been used recently in materials processing. This method can be used to densify materials and create compounds, and it is similar to hot pressing, but the mechanism of the heating and powder densification are different. In this paper an innovative methodology has been adapted from the FAST process that can decrease the volume of the components into micro scale and called (MicroFAST). This process is a rapid powder consolidation technology and shows the possibility to produce solid parts from powder material. Using MagnesiaStabilized Zirconia (MSZ) powder material, several processing parameters have been investigated, such as pressure, heating rate, heating temperature and holding time, which helped to gain optimum results. In this paper Ø4.00mm × 4.00 mm and Ø2.00mm × 2.00 mm cylinder solid samples were shaped. The SEM and EDS have been conducted and the relative density has been examined and the results showed a very good fabricated sample with 99.83% relative density

Characterization of long-chain acyl-CoA synthetases which stimulate secretion of fatty acids in green algae Chlamydomonas reinhardtii

Additional file 1. Complete list of primers used in this study