Keming Li, Mohammad Riaz Uddin and J. David Diltz
Prior research has documented the role of information uncertainty in the cross-sectional variation in stock returns. Miller (1977) hypothesizes that if information uncertainty is…
Abstract
Purpose
Prior research has documented the role of information uncertainty in the cross-sectional variation in stock returns. Miller (1977) hypothesizes that if information uncertainty is caused by differences of opinion, prices will reflect only the positive beliefs due to short-sale constraints. These anomalous stock price behaviors may result from mispricing. In contrast, Merton (1974) asserts that default risk is a function of the uncertainty in the asset value process. Information uncertainty may be subsumed by credit or default risk. The paper aims to discuss these issues.
Design/methodology/approach
The authors employ various sorting techniques and Fama-MacBeth Regressions to test the hypotheses.
Findings
The authors provide empirical evidence consistent with Merton’s (1974) default risk hypothesis and inconsistent with Miller’s (1977) mispricing hypothesis.
Research limitations/implications
Risk aversion and not misplacing is the primary factor driving information-related anomalies in equities markets.
Practical implications
It would be quite difficult to find arbitrage opportunities in equities markets because there appears to be little, if any, mis-pricing due to information uncertainties.
Originality/value
This study provides important information about the primary underlying information-related source of certain empirical anomalies in the cross-section of stock returns.
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China's tobacco industry.
Ziyu Liao, Bai Chen, Tianzuo Chang, Qian Zheng, Keming Liu and Junnan Lv
Supernumerary robotic limbs (SRLs) are a new type of wearable robot, which improve the user’s operating and perceive the user’s environment by extra robotic limbs. There are some…
Abstract
Purpose
Supernumerary robotic limbs (SRLs) are a new type of wearable robot, which improve the user’s operating and perceive the user’s environment by extra robotic limbs. There are some literature reviews about the SRLs’ key technology and development trend, but the design of SRLs has not been fully discussed and summarized. This paper aims to focus on the design of SRLs and provides a comprehensive review of the ontological structure design of SRLs.
Design/methodology/approach
In this paper, the related literature of SRLs is summarized and analyzed by VOSviewer. The structural features of different types of SRLs are extracted, and then discuss the design approach and characteristics of SRLs which are different from typical wearable robots.
Findings
The design concept of SRLs is different from the conventional wearable robots. SRLs have various reconfiguration and installed positions, and it will influence the safety and cooperativeness performance of SRLs.
Originality/value
This paper focuses on discussing the structural design of SRLs by literature review, and this review will help researchers understand the structural features of SRLs and key points of the ontological design of SRLs, which can be used as a reference for designing SRLs.
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Yanbin Liu, Keming Yao and Yuping Lu
The purpose of this paper is to present the flight control law based on the fuzzy logic control methods for Mars airplane, and the research emphasis is placed on the attitude hold…
Abstract
Purpose
The purpose of this paper is to present the flight control law based on the fuzzy logic control methods for Mars airplane, and the research emphasis is placed on the attitude hold and the command track using the fuzzy control.
Design/methodology/approach
The aircraft model is established with the combination of atmospheric environment, aerodynamic force and propulsive action. Then, the dynamic characteristics are analyzed in response to the different flight points for Mars airplane. Afterward, the flight control law is designed by applying the fuzzy logic theory to realize the attitude hold and the command track for Mars airplane.
Findings
The simulation results demonstrate that the proposed control law based on the fuzzy logic control methods is effective to guarantee system stability and relieve coupling dynamics. In addition, this control system can provide strong robustness and good tracking performance for Mars airplane.
Practical implications
The current work offers a new approach for the control law design of Mars airplane. The presented fuzzy control system can be applied to the other unconventional airplanes which will fly under unknown and uncertain environment to implement the complicated tasks such as deep space exploration.
Originality/value
This paper provides the new methods for Mars airplane to design the fuzzy control system which consists of three implementation steps: the fuzzy quantization control step, the fuzzy decoupling control step and the fuzzy attitude control step. Through the progressive design, this presented control system of Mars airplane has strongly nonlinear and robust control ability due to the application of the fuzzy expert concepts.
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Vani Aggarwal and Nidhi Karwasra
The purpose of this study is to provide a comprehensive analysis on the economic relationship between trade openness and economic growth and to identify current developments…
Abstract
Purpose
The purpose of this study is to provide a comprehensive analysis on the economic relationship between trade openness and economic growth and to identify current developments, potential research area and future directions. The emphasis is on the identification of annual growth of publications, country-wise distribution, publication pattern, intellectual structure and cluster analysis of scientific production in this field.
Design/methodology/approach
This study used evaluative techniques, text mining approach and performance analysis to identify possible patterns and correlation and to measure the impact of authors/citations/scientific production. Further, this study used the bibliometric mapping to represent the structural features of scientific production. This study emphasized on identification of the research hotspots based on occurrence of indexed keywords, productive researchers and journals during 2000–2022. Further, cluster analysis is performed using VOS viewer to analyze the current dynamics and future direction of the association between trade openness and economic growth (Eck and Waltman, 2011). Also, co-citation analysis is used in this study to identify the relations among authors or journals or documents using citation data, whereas the bibliographic coupling/mapping is intended to analyze the citing documents. Similarly, co-word analysis is used to study the article keywords that are mainly used to assess the conceptual structure of a concerning subject.
Findings
Economic growth is a function of trade openness, and it is important to analyze the relationship between trade openness and economic growth. Trade openness tends to become more liberalized over time, to contribute more to economic growth. Empirical evidence suggested that there exists a strong association between trade openness and economic growth. Further, keyword timeline analysis illustrated that the linkage between trade openness and economic growth is current area of interest among researchers. As per bibliometric analysis, China, Pakistan and Malaysia are the three most prolific countries in the terms of published articles on this theme. However, the most influential publications based on h-index and citation on trade openness–economic growth relationship is produced by Turkey. Based on cluster analysis, this study suggests that researchers are currently working on trade openness–economic growth relationship with other variables such as FDI, financial development, labor force, environment degradation and carbon emission, while in future, researchers could work on variables such as technology and sustainable development.
Research limitations/implications
There are some limitations of this study. The first limitation is the authors have used Scopus database, leaving the possibility for future research to use Web of Science, Google Scholar or other similar sources. The second limitation is that the authors have used search terms “trade openness “and “economic growth,” although research could be performed using synonyms or even relevant terms in other languages.
Practical implications
Cluster analysis suggested that researchers are currently working on trade openness–economic growth relationship with other variables such as FDI, financial development, labor force, environment degradation and carbon emission, while in future, researchers could work on variables such as technology and sustainable development. Therefore, this study identified the potential research area in this research domain.
Originality/value
To confirm the originality of this study, to the best of the authors’ knowledge, this is the first study to combine bibliometric analysis and cluster analysis on trade openness–economic growth relationship. This study makes a comparison with phenomena/processes/events in contemporary economic and social reality in the field of trade openness and economic growth relationship.
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Xinchao Zhang, Huanxia Zhang, Danni Pan, Wen Wu, Hui Ma, Jianda Cao and Jia Xu
This paper aims to determine whether application of graphene layers to cuprammonium filaments affords the latter with excellent mechanical properties and improves their electrical…
Abstract
Purpose
This paper aims to determine whether application of graphene layers to cuprammonium filaments affords the latter with excellent mechanical properties and improves their electrical properties. At the same time, a circuit model was established to explore the conductive mechanism of the filament. The actual model is used to verify the correctness of the model.
Design/methodology/approach
The cuprammonium filaments were desizing, the graphene oxide layer-by-layer sizing and reduction integration process by a continuous sizing machine. The electrical properties of mono- and multifilaments in the static condition, as well as the dynamic–mechanical properties of multifilaments, were analysed, and the related conductive mechanism of the filaments was deduced.
Findings
Cuprammonium filaments coated with graphene layers showed good electrical conductivity, and their volume resistance decreased to 4.35 O·cm with increasing number of graphene coats. The X-ray diffraction and thermogravimetric analysis results showed that the graphene layer treatment changed the crystallinity of the copperammonia filaments and improved the thermal stability of the filaments. In the dynamic case, filament resistance was calculated using the equivalent resistance model, and the fitting difference observed was small. This result confirmed the high fit of this circuit model.
Originality/value
Up to the knowledge from literature review, there are no reports on theoretical research on the relation between the electro-mechanical property and structure of conductive filaments.
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The purpose of this paper is to investigate the associations between obesogenic severity, the public health situation, environmental impacts, and health care expenditures in…
Abstract
Purpose
The purpose of this paper is to investigate the associations between obesogenic severity, the public health situation, environmental impacts, and health care expenditures in populations worldwide.
Design/methodology/approach
This ecological study is based on official data available for approximately 140 countries worldwide. This study defines four main variables: obesogenic severity, environmental impact, public health implications (PHI), and health expenditures, all measured through specific indicators. Data were obtained mainly from the WHO, World Bank, and IDF. The indicators were reduced to the main variables through factorial reduction and multiple regression analyses were used to test the main hypotheses.
Findings
Obesogenic severity strongly and positively affects environmental impacts (β=0.6578; p<0.001), PHI-1 (cardiovascular risk factor) (β=0.3137; p<0.001) and PHI-2 (blood glucose and diabetes diagnoses) (β=0.3170; p<0.001). Additionally, environmental impacts strongly and positively affect PHI-1 (β=0.4978; p<0.001) but not PHI-2. Thus, results suggest that environmental impact, PHI-1, and PHI-2 strongly affect health expenditures (β=0.3154; p<0.001, β=0.5745; p<0.001, and β=−0.4843; p<0.001, respectively), with PHI-2 negatively affecting the health expenditures.
Practical implications
This study presents evidence that can aid in decision making regarding public and private efforts to better align budgets and resources as well as predict the needs and expenditures of public health care systems.
Originality/value
This investigation finds that the main variables addressed are strongly associated at the worldwide level. Thus, these analytical procedures can be used to predict public health and health care cost scenarios at the global level.