Exploring S-shape curves and heterogeneity effects of rumor spreading in online collective actions

<abstract> <p>Nowadays online collective actions are pervasive, such as the rumor spreading on the Internet. The observed curves take on the S-shape, and we focus on evolutionary dynamics for S- shape curves of online rumor spreading. For agents, key factors, such as internal aspects, external aspects, and hearing frequency jointly determine whether to spread it. Agent-based modeling is applied to capture micro-level mechanism of this S-shape curve. We have three findings: (a) Standard S-shape curves of spreading can be obtained if each agent has the zero threshold; (b) Under zero-mean thresholds, as heterogeneity (SD) grows from zero, S-shape curves with longer right tails can be obtained. Generally speaking, stronger heterogeneity comes up with a longer duration; and (c) Under positive mean thresholds, the spreading curve is two-staged, with a linear stage (first) and nonlinear stage (second), but not standard S-shape curves either. From homogeneity to heterogeneity, the spreading S-shaped curves have longer right tail as the heterogeneity grows. For the spreading duration, stronger heterogeneity usually brings a shorter duration. The effects of heterogeneity on spreading curves depend on different situations. Under both zero and positive-mean thresholds, heterogeneity leads to S-shape curves. Hence, heterogeneity enhances the spreading with thresholds, but it may postpone the spreading process with homogeneous thresholds.</p> </abstract>

Prognostic Value of the Acute-to-Chronic Glycemic Ratio at Admission in Heart Failure: A Prospective Study

Acute hyperglycemia has been associated with worse prognosis in patients hospitalized for heart failure (HF). Nevertheless, studies evaluating the impact of glycemic control on long-term prognosis have shown conflicting results. Our aim was to assess the relationship between acute-to-chronic (A/C) glycemic ratio and 4-year mortality in a cohort of subjects hospitalized for acute HF. A total of 1062 subjects were consecutively included. We measured glycaemia at admission and estimated average chronic glucose levels and the A/C glycemic ratio were calculated. Subjects were stratified into groups according to the A/C glycemic ratio tertiles. The primary endpoint was 4-year mortality. Subjects with diabetes had higher risk for mortality compared to those without (HR 1.35 [95% CI: 1.10–1.65]; p = 0.004). A U-shape curve association was found between glucose at admission and mortality, with a HR of 1.60 [95% CI: 1.22–2.11]; p = 0.001, and a HR of 1.29 [95% CI: 0.97–1.70]; p = 0.078 for the first and the third tertile, respectively, in subjects with diabetes. Additionally, the A/C glycemic ratio was negatively associated with mortality (HR 0.76 [95% CI: 0.58–0.99]; p = 0.046 and HR 0.68 [95% CI: 0.52–0.89]; p = 0.005 for the second and third tertile, respectively). In multivariable analysis, the A/C glycemic ratio remained an independent predictor. In conclusion, in subjects hospitalized for acute HF, the A/C glycemic ratio is significantly associated with mortality, improving the ability to predict mortality compared with glucose levels at admission or average chronic glucose concentrations, especially in subjects with diabetes.

A Quadratic Regression Model to Quantify Plantation Soil Factors That Affect Tea Quality

Tea components (tea polyphenols, catechins, free amino acids, and caffeine) are the key factors affecting the quality of green tea. This study aimed to relate key biochemical substances in tea to soil nutrient composition and the effectiveness of fertilization. Seventy tea samples and their corresponding plantation soil were randomly collected from Xinyang City, China. The catechins, free amino acids, and caffeine in tea were examined, as well as the soil pH, nitrate (NO3--N), ammonium (NH4+-N), available phosphorus (AP), available potassium (AK), and soil organic matter (SOM). The ordinary kriging was employed to visualize the spatial variation characteristic by ArcGIS. A quadratic regression model was used to analyze the effects of the soil environment on the tea. The results showed that the soil pH of the study area was suitable for cultivating tea plants. The relationship between soil pH and tea polyphenols and catechins presented the U-shape curve, whereas the soil pH and NH4+-N and the free amino acids, the soil pH, and caffeine presented the inverted U-shape curve. Soil management measures could be implemented to control the soil environment for improving the tea quality. The combination of the macro metrological model with individual experimentation could help to analyze the detailed influence mechanisms of environmental factors on plant physiological processes.

The gift that keeps on giving: corporate giving and excessive risk-taking

Corporations have recently started incorporating employees’ prosocial preferences into their incentive schemes, including charitable donations (corporate giving). These donations are mainly discussed in conjunction with the external effects of a firm’s CSR strategy. However, this experiment examines the effect of donations on internal firm operations. Specifically, we investigate whether the presence and structure of corporate giving influences employees’ excessive risk-taking. Such prosocial activities may remediate misaligned incentives often cited as drivers for employees to take excessive risks. Contrary to widespread practice, our experimental evidence suggests that firms could constrain employees' excessive risk-taking by linking existing contributions to project rather than corporate performance, thus providing boundaries around an employee’s involvement in CSR initiatives. We identify project-level giving as an unexplored CSR benefit and infer that personal responsibility effectively changes an employee’s incentive package. Our findings suggest an inverted U-shape curve of effectiveness.

Analysis of Mechanical Behavior of Different Needle Tip Shapes During Puncture of Carbon Fiber Fabric

In the present study, the fiber-bending around the needle during the piercing process of the carbon fabric is investigated. In this regard, a mathematical model is established to investigate the bending elongation of the carbon fiber around the needle and the interaction between the carbon fiber and the needle tip. Then the mechanical behavior of the carbon fabric when moving down the tip of the steel needle is analyzed. Based on the performed analysis, a shape curve equation that satisfies the puncture needle tip is established. Furthermore, the influence of different needle tip shapes on the mechanical behavior of the carbon fiber is analyzed. The performance of the needle tip is subjected to different loads, including the puncture template, horizontal tension of the fiber to the needle tip, frictional resistance between the fiber and the needle tip, sliding force, and the bending moment. The performed analysis shows that when the shape of the needle tip assumes the form of curve 10, the downward force, horizontal tension, friction resistance, sliding force, and bending moment are minimized. Accordingly, curve 10 is proposed as the optimal shape for the needle tip. The present study is expected to provide theoretical guidance for selecting overall puncture process parameters.

Research on the Critical Technique of Synchronous Rotation Construction With Large Angle for T-shape Curve Rigid Frame Bridge

The superstructure rotation method (SRM) can optimize bridge construction in terms of reducing impacts on traffic, safety, and overall budget. This paper focuses on the key scientific problems of synchronous rotation construction with large angles and takes two T-shaped rigid frame bridges of the Wuyi Expressway over the Chengdu-Kunming Railway as the engineering background. Construction technologies of this project are introduced, including the installation process of spherical hinges, the design of the traction system, and the precision control method. Finite element models of the full-bridge were established to obtain the lateral unbalanced moment of the structure and the test method of the longitudinal unbalanced moment is shown in detail. Furthermore, the key parameters of SRM are analyzed and calculated, including the derivation and modification of the existing static friction coefficient calculation formula of the spherical hinge. Based on the measured data, the accuracy of different friction coefficient prediction formulas is evaluated.

Carbon Productivity and Mitigation: Evidence from Industrial Development and Urbanization in the Central and Western Regions of China

This paper investigates carbon productivity (CP) from the perspectives of industrial development and urbanization to mitigate carbon emissions. We propose a hybrid model that includes a spatial lag model (SLM) and a fixed regional panel model using data from the 17 provinces in the central and western regions of China from 2000 to 2018. The results show that the slowly increasing CP has significant spatial spillover effects, with High–High (H–H) and Low–Low (L–L) spatial distributions in the central and western regions of China. In addition, industrial development and urbanization in the study area play different roles in CP, while economic urbanization and industrial fixed investment negatively affect CP, and population urbanization affects CP along a U-shape curve. Importantly, the results show that the patterns of industrial development and urbanization that influence CP are homogenous and mutually imitated in the 17 studied provinces. Furthermore, disparities in CP between regions are due to industrial workforce allocation (TL), but TL has been inefficient; industrial structure upgrades are slowly improving conditions. Therefore, the findings suggest that, in the short term, policymakers in China should implement industrial development policies that reduce carbon emissions in the western and central regions by focusing on improving industrial workforce allocation.

Modeling view count dynamics for YouTube videos: a multimodal perspective

PurposeYouTube allows its users to upload and view videos on its platform. YouTube provides notification to the subscribers whenever a channel uploads a new video thereby making the channel subscribers the potential viewers of the video. And thus, they are the first to come to know about any new offering. But later on, the view count also increases due to virality, that is, mass sharing of the content by the users on different social media platforms similar to word-of-mouth in the field of marketing. Therefore, the purpose of this paper is to examine different diffusion patterns as they can help to inflate traffic and generate revenue.Design/methodology/approachYouTube's view count grows majorly through virality. The pattern of view count growth has generally been considered unimodal in most of the available research in the field of YouTube. In the present work, the growth process due to views through the subscribers and views due to word-of-mouth (virality) is presented. Considering that the impact of virality in view count growth comes later in the video life cycle; the viewing patterns of both the segments have been mathematically modeled; independently.FindingsDifferent models have been proposed to capture the view count growth pattern and how the impact of virality changes the view count growth curve and thereby results in a multimodal curve structure. The proposed models have been verified on various view count data sets of YouTube videos using SPSS (Statistical Package for the Social Sciences), and their ranks have been determined using a weighted criteria–based approach. The results obtained clearly depict the presence of many modes in the life cycle of view counts.Originality/valueTill now, the literature is evident of the video life cycle following a bell shape curve. This study claims that the initial thrust is by subscribers and then the contribution in the view count by people watching via word-of-mouth comes into picture and brings in another hump in the growth curve.

The Role of Globalization, Economic Growth and Natural Resources on the Ecological Footprint in Thailand: Evidence from Nonlinear Causal Estimations

The environmental issue has become a global problem that needs to be examined frequently, motivating researchers to investigate it. Thus, the present study has investigated the asymmetric impact of globalization, economic growth and natural resources on the ecological footprint in the presence of environmental Kuznets curve (EKC) in Thailand. The study has used annual time series data from 1970 to 2018. The study applied a novel method of nonlinear autoregressive distributive lag (ARDL). In particular, the current study has investigated the effect of positive and negative shocks on the independent variable on the dependent variable. The findings have confirmed that the effect of globalization and natural resources are significant and nonlinear. However, the effect of negative shocks of globalization and natural resources is more dominant on the ecological footprint in Thailand than the positive shocks of both variables. Moreover, the present study has also tested the presence of EKC in Thailand, and the findings confirm the presence of an inverted U-shape curve in the Thailand economy.