Sentiment Diffusion of Social Inequality in Microblogs: A Case Study of “Migrant Worker” in Sina Weibo

Migrant workers constitute the main city workforce in China. However, they are the victims of social inequality. Sina Weibo is one of the most important channels for people to share information and public opinions. In order to study into the sentiment diffusion of social inequality over Sina Weibo, we collected a huge number of root microblogs and reposts based on the search query “Migrant Worker”. With applying the sentiment tendency analysis tool provided by Baidu AI, we were able to capture the sentiment flipping process. We found that most microblog users tended to follow the previous users’ sentiment polarity. But the intensity of the sentiment polarity would always get weaken

The Evolution of User Roles in Online Health Communities – A Social Support Perspective

Online Health Communities (OHCs) have become a major source of social support for people with health problems. Using a case study of an OHC among breast cancer survivors, we revealed the types of social support embedded in each post using text mining techniques. Then we aggregated users’ activities in different types of social support and identified different roles that users play in an OHC via unsupervised machine learning techniques. By analyzing how users’ roles change over time, we constructed a transition graph to illustrate the evolution of users’ roles in an OHC. In addition, we discovered that a user’s behavior in receiving social support is correlated with the transition of her role. It was revealed that the types social support received by a user may facilitate or delay her role transitioning. Our research has implications for OHC operators to track users’ behaviors in order to manage and sustain an OHC

Social Media Sentiment and COVID-19 Transmission: Results from a Time-varying SIR Model

COVID-19 has caused 2.48 million deaths worldwide. Efforts have been made to understand its transmission pattern and how to prevent its spreading. This is the first time the human race has experienced a pandemic with the prevalence of social media. Social media plays a critical role in disseminating COVID-19 related information. In this work-in-progress, we study the effect of social media on the transmission of COVID-19. Building upon the past literature on the role of social media in disaster management, we formulate a time-varying SIR model, namely SIRSM, to incorporate the interaction of the susceptible compartment and sentiment polarities in social media. Using Twitter data, we find that SIRSM can capture the spread of COVID-19 in the United States. In addition, our results indicate that negative sentiment on Twitter is associated with a lower transmission rate of the corresponding susceptible compartment

The Effect of the Swimmer’s Trunk Oscillation on Dolphin Kick Performance Using a Computational Method with Multi-Body Motion: A Case Study

The effect of a specific Chinese swimmer’s trunk oscillation on dolphin kick was investigated in order to optimize competitive swimming movement. Using a numerical simulation method based on multi-body motion, different swimmer’s trunk oscillation during a dolphin kick was analyzed. The simulation was conducted using 3D incompressible Navier–Stokes equations and renormalization group k-ε turbulence model, combined with the Volume of Fluid method to capture the water surface. The simulation’s results were evaluated by comparing them with experimental data and with previous studies. The net streamwise forces, mean swimming velocity, and joint moments were also investigated. There was a positive correlation between the mean swimming velocity and the amplitudes of the swimmer’s trunk oscillation, where the Pearson correlation coefficient was 0.986 and the selected model was statistically significant (p < 0.05). In addition, as the mean swimming velocity increased from 1.42 m/s in Variant 1 to 2 m/s in Variant 5, the maximum positive moments of joints increased by about 24.7% for the ankles, 27.4% for the knees, −3.9% for the hips, and 5.8% for the upper waist, whereas the maximum negative moments of joints increased by about 64.5% for the ankles, 28.1% for the knees, 23.1% for the hips, and 10.1% for the upper waist. The relationship between the trunk oscillation and the vortices was also investigated. Therefore, it is recommended that swimmers should try to increase the amplitudes of trunk oscillation to increase their swimming velocity. In order to achieve this goal, swimmers should increase strength training for the ankles, knees, and upper waist during the upkick. Moreover, extra strength training is warranted for the ankles, knees, hips, and upper waist during the downkick

Investigating the Multihoming of Initial Exchange Offerings

Initial exchange offering (IEO), an emerging crowdfunding approach for blockchain ventures, exploded in popularity during the late initial coin offering (ICO) bubble. Most researchers in this field focused on the factors of ICO success, while empirical research on how IEO works is limited. To address this research gap, we investigate the factors that affect the success of IEO projects with regard to multihoming. Our results show that the higher the exchange credibility where the IEO project is launched, the more likely it is to be multihomed. Furthermore, the post-IEO return of the associated token is a significant factor signaling the time interval of its listing on the following exchanges. Our paper extends previous research on crowdfunding for blockchain startups and paves the way for IEO projects to achieve long-term success

Hydrodynamic Characteristics of Different Undulatory Underwater Swimming Positions Based on Multi-Body Motion Numerical Simulation Method

The study of hydrodynamic characteristics of swimming is the main way to optimize the swimming movement. The relationship between position, water depth, and swimming performance of undulatory underwater swimming are one of the main concerns of scholars. Therefore, the aim of this study is to analyze the swimming performance of three different undulatory underwater swimming positions under various swimming depths using a numerical simulation method based on multi-body motion. The simulation was conducted using 3D incompressible Navier–Stokes equations using the RNG k-ε turbulence closure equations, and in combination with the VOF method thus that we could include the water surface in our calculations. Different swimming depths based on the distance from the shoulder joint center to the initial water surface were considered. The velocity of the shoulder joint center was captured with a swimming motion monitoring system (KiSwim) and compared with the calculated results. The study found that there was a significant difference in the hydrodynamic characteristics of the three undulatory underwater swimming positions (i.e., the dorsal, lateral, and frontal positions) when swimming near the water surface, and the difference decreased as the swimming depth increased. There was a negative correlation (R(dorsal) = −0.928, R(frontal) = −0.937, R(lateral) = −0.930) between the swimming velocities of the three undulatory underwater swimming positions and the water depth (water depth = 0.2–0.7 m) and that the lateral position had the greatest average velocity. Therefore, it is recommended that swimmers travel at least 0.5 m below the water surface in any undulatory underwater swimming position in order to avoid excessive drag forces. As the swimmer approaches the water surface, the lateral position is worth considering, which has better velocity and hydrodynamic advantage than the other two undulatory underwater swimming positions

Printed quadrifilar helix antenna with enhanced bandwidth

A circular polarised printed quadrifilar helix antenna with enhanced bandwidth is proposed in this study. The helix antenna offers a very compact size and comprises of four arms with varying width, four open stubs, a feeding network and a metal ground plane. The different widths of the helix arms are employed to improve the impedance bandwidth while their varying pitches generate a cardioid radiation pattern. The antenna exhibits a voltage standing wave ratio ≤ 2 in the frequency range of 1.43-1.63 GHz offering impedance bandwidth of 12%. Good radiation characteristics with high gain, a wide 3 dB axial ratio beamwidth of 180° along with small size makes this antenna an excellent candidate for satellite communications and navigation systems