Electroweak phase transition in the economical 3-3-1 model

We consider the EWPT in the economical 3-3-1 (E331) model. Our analysis shows that the EWPT in the model is a sequence of two first-order phase transitions, $SU(3) \rightarrow SU(2)$ at the TeV scale and $SU(2) \rightarrow U(1)$ at the $100$ GeV scale. The EWPT $SU(3) \rightarrow SU(2)$ is triggered by the new bosons and the exotic quarks; its strength is about $1 - 13$ if the mass ranges of these new particles are $10^2 \,\mathrm{GeV} - 10^3 \,\mathrm{GeV}$. The EWPT $SU(2) \rightarrow U(1)$ is strengthened by only the new bosons; its strength is about $1 - 1.15$ if the mass parts of $H^0_1$, $H^\pm_2$ and $Y^\pm$ are in the ranges $10 \,\mathrm{GeV} - 10^2 \,\mathrm{GeV}$. The contributions of $H^0_1$ and $H^{\pm}_2$ to the strengths of both EWPTs may make them sufficiently strong to provide large deviations from thermal equilibrium and B violation necessary for baryogenesis.Comment: 17 pages, 9 figure

Assessment of haptics-based interaction for assembly tasks in virtual reality

This thesis examines the benefits of haptics-based interaction for performing assembly-related tasks in a virtual environment. A software application that combined freeware and open-source software development kits was developed and demonstrated principles of physics-based modeling in a haptics-enabled immersive virtual environment. A user study was designed to evaluate subjects in performing a series of experiments relevant to the assembly engineering process including weight recognition, part positioning, and assembly simulation. Each experiment featured a structure based on factorial combinations of effects, resulting in a series of designed trials. Methods of assessing user performance were established based on task completion time and accuracy. Using a randomized complete block design, a sample population of forty individuals performed all trials within the experiments in random sequences. Statistical methods were used to analyze the performances of individuals upon the conclusion of the study. When compared to visualsonly methods, the results show that haptics-based interaction is beneficial in improving performance including reduced completion times for weight comparisons, higher placement accuracy when positioning virtual objects, and steadier hand motions along threedimensional trajectories. Furthermore, the results indicate that the accuracy in weight identification is dependent on both the hand controlling the object and sensory modality used. The study was inconclusive in determining the affect of haptics-based interaction on completion times when positioning objects or completing manual assembly tasks

Understanding the Intention to Use the Grab Service in Ho Chi Minh City

The primary objective of this study was to identify the factors that influence Grab’s intention to use its services in Ho Chi Minh City and assess the impact of these factors. The ultimate goal was to provide appropriate recommendations to enhance Grab’s services. The study involved 200 participants from Ho Chi Minh City. To achieve this objective, a quantitative research method was employed, and several analytical techniques were used, including reliability testing using Cronbach’s Alpha coefficient, exploratory factor analysis, correlation analysis, and regression. The analysis results revealed three factors that significantly influence the intention to use Grab services, ranked in descending order of influence: (1) Perceived Usefulness, (2) Price Value, and (3) Alternative Vehicles. These factors play a significant role in shaping customers’ intentions to use Grab’s services. The study acknowledges its limitations and suggests future research directions for similar studies to further explore and refine the understanding of customer behavior in the ride-hailing industry. Keywords: intention, service quality, perceived usefulness, prive value, alternative vehicle