Dyliane Mouri Silva de Souza and Orleans Silva Martins
This study identified how investor sentiment on Twitter is associated with Brazilian stock market return and trading volume.
Abstract
Purpose
This study identified how investor sentiment on Twitter is associated with Brazilian stock market return and trading volume.
Design/methodology/approach
The study analyzes 314,864 tweets between January 1, 2017, to December 31, 2018, collected with the Tweepy library. The companies’ financial data were obtained from Refinitiv Eikon. Using the netnographic method, a Twitter Investor Sentiment Index (ISI) was constructed based on terms associated with the stocks. This Twitter sentiment was attributed through machine learning using the Google Cloud Natural Language API. The associations between Twitter sentiment and market performance were performed using quantile regressions and vector auto-regression (VAR) models, because the variables of interest are heterogeneous and non-normal, even as relationships can be dynamic.
Findings
In the contemporary period, the ISI is positively correlated with stock market returns, but negatively correlated with trading volume. The autoregressive analysis did not confirm the expectation of a dynamic relationship between sentiment and market variables. The quantile analysis showed that the ISI explains the stock market return, however, only at times of lower returns. It is possible to state that this effect is due to the informational content of the tweets (sentiment), and not to the volume of tweets.
Originality/value
The study presents unprecedented evidence for the Brazilian market that investor sentiment can be identified on Twitter, and that this sentiment can be useful for the formation of an investment strategy, especially in times of lower returns. These findings are original and relevant to market agents, such as investors, managers and regulators, as they can be used to obtain abnormal returns.
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Qin Lian, Linian Zhou, Xiao Li, Wei Mao and Dichen Li
The purpose of this paper is to present a new method for the fabrication of a large-scaled muscle scaffold containing an artificial hollow tube network, which may solve the…
Abstract
Purpose
The purpose of this paper is to present a new method for the fabrication of a large-scaled muscle scaffold containing an artificial hollow tube network, which may solve the problems of nutrient supply, oxygen exchange and metabolic waste removal.
Design/methodology/approach
In this paper, a ferric chloride structural strength-enhanced sodium alginate hollow tube was used to build the hollow tube network. Gelatin infill was then added to make a large alginate/gelation gel soft tissue scaffold. A pilot experiment was performed and an osmotic test platform was built to study the perfusion and osmotic ability of the 3D printed hollow tube. The essential fabrication parameters (printing velocity and gap) for building the vascular (i.e., hollow tube) network-contained scaffold were investigated. Moreover, cells in culture were spread within the gelation scaffold, and the circulation characteristics of the hollow tube network were studied.
Findings
The printed large-scaled scaffold that contained a ferric chloride structural strength-enhanced sodium alginate hollow tube had good perfusion ability. The osmotic distance of the hollow tube reached 3.7 mm in 8 h in this experiment.
Research limitations/implications
The osmotic distance was confirmed by perfusing a phenol solution; although it is more reliable to test for cell viability, this will be investigated in our later research.
Practical implications
This research may provide new insights in the area of tissue engineering for large-scaled vascularized scaffold fabrication.
Originality/value
This paper presents a new method for fabricating large-scaled scaffolds, and the perfusion ability and osmotic distance of a ferric chloride structural strength-enhanced sodium alginate hollow tube are shown.
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Yong-Hua Li, Yang Cao, Yong-Xin Wu, Xiao-Ning Bai and Jia-Wei Mao
This paper aims to establish the relationship between crosswind speed and pantograph-catenary lateral deviation, as well as quantify the influence of crosswind speed and rod size…
Abstract
Purpose
This paper aims to establish the relationship between crosswind speed and pantograph-catenary lateral deviation, as well as quantify the influence of crosswind speed and rod size uncertainty on pantograph-catenary contact reliability.
Design/methodology/approach
The closed vector method is used to establish the pantograph-catenary kinematics formula. A new prediction model is proposed by using the bird swarm algorithm to optimize the grey model. The lateral deviation of the pantograph and catenary is predicted via the new model. Then the relationship between the effective length of the rod and operating mileage is inferred by combining the effective length theory with the Gamma process, as well as the pantograph-catenary contact reliability model is established according to reliability theory.
Findings
The results obtained show the impacts of uncertainty design parameters of pantograph rods on pantograph-catenary contact reliability index, and the results at crosswind speed of 0 ms−1 and 5 ms−1 are 5.0630 and 4.1442, respectively. The reliability decreases with the increasing crosswind speed, and can be greater than the reliability calculated for rod size degradation due to long-term use.
Originality/value
Most preceding works on pantograph-catenary contact reliability were based on principles of dynamics, without considering the pantograph-catenary relative motion. This research reveals the law of pantograph-catenary relative motion for uncertainty design parameters and crosswind, and quantifies the reliability from the angle of kinematics.
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Abstract
The concept of national fitness has promoted the construction and development of public sports. And how to effectively implement the layout of urban public sports planning has become a hot topic. Based on this, in the study, the layout and integration of the public sports cities in modern cities for the national fitness were mainly discussed. First of all, the research background of the planning and layout of public sports in modern cities under the concept of national fitness was expounded, and the development of urban public sports theory was briefly outlined. Then, the planning and layout of public fitness in modern cities were analyzed. Finally, through the planning and construction projects of public sports in modern cities, the design of public fitness corridor, community road and Sports Park was carried out. It is proved that the scientific and rational planning of sports cities can promote the development of the city.
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Wei Zhang and Jianqin Mao
This paper proposes a robust modeling method of a giant magnetostrictive actuator which has a rate‐dependent nonlinear property.
Abstract
Purpose
This paper proposes a robust modeling method of a giant magnetostrictive actuator which has a rate‐dependent nonlinear property.
Design/methodology/approach
It is known in statistics that the Least Wilcoxon learning method developed using Wilcoxon norm is robust against outliers. Thus, it is used in the paper to determine the consequence parameters of the fuzzy rules to reduce the sensitiveness to the outliers in the input‐output data. The proposed method partitions the input space adaptively according to the distribution of samples and the partition is irrelative to the dimension of the input data set.
Findings
The proposed modeling method can effectively construct a unique dynamic model that describes the rate‐dependent hysteresis in a given frequency range with respect to different single‐frequency and multi‐frequency input signals no matter whether there exist outliers in the training set or not. Simulation results demonstrate that the proposed method is effective and insensitive against the outliers.
Originality/value
The main contributions of this paper are: first, an intelligent modeling method is proposed to deal with the rate‐dependent hysteresis presented in the giant magnetostrictive actuator and the modeling precision can fulfill the requirement of engineering, such as the online modeling issue in the active vibration control; and second, the proposed method can handle the outliers in the input‐output data effectively.
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Abstract
Purpose
This paper aims to investigate the impact of environmental risk on corporate governance through market reaction to bank loan announcements.
Design/methodology/approach
Using the establishment of environment court in China as a quasi-natural experiment, this paper adopt the difference-in-differences approach based on listed firms during 2003–2013 to explore the impact of environment court on corporate governance.
Findings
This paper find that the environment court would weaken the cumulative abnormal return of loan announcements. Then, this paper confirm that the potential reason is that environment court worsens the interest conflict between majority and minority shareholders. Further, cross-sectional analysis suggests that bank’s supervision, market competition and analyst coverage can alleviate the impact of environment court on corporate governance.
Practical implications
Environment courts intensify firms’ internal interest disputes, thus causing the decrease of corporate governance, which can be observed through the effect of bank loan announcements.
Social implications
This paper provide reference for environmental policy formulation and implementation, firms’ decision-makings and improving the banking regulatory system.
Originality/value
This paper makes a contribution to the studies about the impact of environment court on firms’ decision-making and investors’ reaction, the impact of external factors on corporate governance and bank loan announcements effect.
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This paper attempts to critically question present IPE approaches and analyses that aim at assessing China’s role within the international political economy. Thus, unlike common…
Abstract
This paper attempts to critically question present IPE approaches and analyses that aim at assessing China’s role within the international political economy. Thus, unlike common theorizations that see the country as being integrated within US hegemony (Panitch and Gindin) or those accounts that claim that we are already witnessing the “terminal crisis” of US hegemony accompanied by a hegemonic transition toward China (Arrighi), the paper will argue that China was able to gain “relative geopolitical autonomy” as a result of the revolutionary processes it went through and eventually assert itself as a contender state, now just in the process of challenging US hegemony. Dissatisfied with existent theorizations of hegemony, I will be drawing on the critical edition of Gramsci’s Quaderni and attempt to offer a new perspective regarding the conceptualization thereof. Thus applying the elaborated framework of analysis to the current situation, I argue that unlike the US’s ability to counter the challenge of its traditional imperial rivals Germany and Japan as they developed under the grip of US hegemony, the country is facing difficulties in countering China’s ascent. However, while maintaining that China does indeed represent a challenge to US hegemony, particularly in East Asia, I will argue that the idea of a “crisis of US hegemony” is premature as China remains distant from fully realizing hegemonic relations, even at the regional level.
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The coronavirus disease 2019 (COVID-19) pandemic has helped Taiwan gain widespread recognition and commendation. Taiwan's low infection rate is praiseworthy not merely because it…
Abstract
Purpose
The coronavirus disease 2019 (COVID-19) pandemic has helped Taiwan gain widespread recognition and commendation. Taiwan's low infection rate is praiseworthy not merely because it was once considered a high-risk region but because it has weathered the COVID-19 storm without resorting to draconian measures. The purpose of this paper is thus an effort to understand and explain how Taiwan has been able to achieve a fine balance between disease containment and everyday life.
Design/methodology/approach
According to the COVID-19 Government Response Event Dataset, Taiwan’s actions focus mainly on the management of health resource allocation, external border restrictions, quarantine of high-risk cases and the establishment of a centralized crisis task force. On this basis, the authors highlight and discuss the critical factors for Taiwan’s success against COVID-19. Caveats are also detailed to caution some aspects of the lessons to be drawn from it.
Findings
Setting clear goals, effective leadership, active community participation and innovative solutions are four pillars of Taiwan’s success against COVID-19. The island believes that once stringent border controls are strictly executed, virus-free citizens can relax inside. However, those who would like to learn from Taiwan’s experience should be mindful of the likelihood of asymptomatic spread of the disease as well as the unique geographical and social characteristics that contribute to Taiwan’s approach to COVID-19.
Originality/value
The authors’ analysis of Taiwan adds anecdotes to the scholarly discussion on public health emergency management, suggesting that anti-COVID-19 policy would get its intended outcomes only if government leaders and community stakeholders collaborate to set clear goals ahead and implement them with innovative solutions.
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Ching-Fan Chung, Mao-Wei Hung and Yu-Hong Liu
This study employs a new time series representation of persistence in conditional mean and variance to test for the existence of the long memory property in the currency futures…
Abstract
This study employs a new time series representation of persistence in conditional mean and variance to test for the existence of the long memory property in the currency futures market. Empirical results indicate that there exists a fractional exponent in the differencing process for foreign currency futures prices. The series of returns for these currencies displays long-term positive dependence. A hedging strategy for long memory in volatility is also discussed in this article to help the investors hedge for the exchange rate risk by using currency futures.
Jow‐Ran Chang, Mao‐Wei Hung and Feng‐Tse Tsai
This paper aims to provide a new approach to evaluate intellectual property (IP) and uses a cautious view of how volatility impacts the economic value of IPs.
Abstract
Purpose
This paper aims to provide a new approach to evaluate intellectual property (IP) and uses a cautious view of how volatility impacts the economic value of IPs.
Design/methodology/approach
Real option is a useful tool for valuing investments under uncertainty and if it is applied to the valuation of IP with some modifications, it is also widely accepted. However, it is still debatable whether there is a constant rate‐of‐return. This paper incorporates a sensitivity variable to account for the volatility of the expected rate of return. Thus, rate‐of‐return can be a constant or increase with volatility.
Findings
First, it was found in the simple model that Vega may be negative when the option is deep in the money. Second, in the general model, the option can be seen as a sequence of options and under the constant rate‐of‐return shortfall setting, it resembles traditional financial options with positive Vega.
Originality/value
The scenario set‐up allows the authors to explain why uncertainties of future cash flows drive firms to invest now instead of later.