The purpose of this article is to consider the classical risk model that is perturbed by a Brownian motion process. The article derives explicit formulas for the joint and…
Abstract
Purpose
The purpose of this article is to consider the classical risk model that is perturbed by a Brownian motion process. The article derives explicit formulas for the joint and marginal probability density functions of the surplus prior to ruin and the deficit at ruin.
Design/methodology/approach
This article first extends the dual argument to probabilistically explain the symmetry between the two random variables related to the so‐called modified ladder height. Then the paper uses renewal arguments to derive the joint distribution of the surplus prior to ruin and the deficit at ruin.
Findings
The study derived an explicit formula for the undiscounted joint density in the perturbed risk model that is directly parallel to formula (3.2) for the classical risk model. The formula clearly shows that in a perturbed risk process, when ruin is caused by a claim, the p.d.f. of the surplus prior to ruin is continuous. In addition, shows that when the claim sizes follow a phase‐type distribution, all the relevant quantities can be conveniently computed.
Originality/value
The dual argument used in this article is novel. The formula first clearly shows that in the perturbed risk model, the p.d.f. of the surplus prior to ruin is continuous. When claim sizes are phase‐type, the formulas can be conveniently computed.
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Keywords
The paper aims to develop a realistic, yet flexible model of insurer net worth.
Abstract
Purpose
The paper aims to develop a realistic, yet flexible model of insurer net worth.
Design/methodology/approach
Inspired by and as an improvement to Powers, the paper develops a multi‐dimensional diffusion model to describe the operations of an insurance company. The paper then explores whether or not this multi‐dimensional model can be approximated conservatively by a homogeneous one‐dimensional diffusion.
Findings
The multi‐dimensional model that is proposed can be approximated conservatively by a homogeneous one‐dimensional diffusion, which is clearly much easier to solve analytically or numerically than a multi‐dimensional system. Also, the Laplace transform of the desired first‐passage time (to ruin) distribution can be stated analytically.
Practical implications
The analysis provides a theoretical model of the relationship between the insurer's ruin‐time distribution and many aspects of the insurer's operations, including loss‐payout patterns, premium‐earning patterns, and investment strategy.
Originality/value
The paper reveals that a multi‐dimensional model can be approximated by a homogeneous one‐dimensional diffusion to achieve a realistic and flexible model that can be used practically.
Details
Keywords
Jiandong Zheng and Xiaoguang Ren
CaCO3 solution was chosen as the research environment in boiling pool heat transfer system using an automatic data collection system and scaling experiments. In this experiment…
Abstract
Purpose
CaCO3 solution was chosen as the research environment in boiling pool heat transfer system using an automatic data collection system and scaling experiments. In this experiment, different concentrations of solution were made and ultrasonic excitation was applied under differing conditions of salt concentration and heat flux, such that the ultrasonics could reduce scale accumulation on the metal surface. The effectiveness of ultrasonics in inhabiting CaCO3 scale formation was evaluated. The paper aims to discuss these issues.
Design/methodology/approach
Different concentration solution was made. Under the condition of different concentration and heat flux, the ultrasonic was introduced, so that it can reduce the scale accumulation on the metal surface. Ultrasonic function in inhabiting CaCO3 scale can be evaluated.
Findings
The results showed that the ultrasonic not only enhanced the heat transfer rate under boiling conditions but also prevented the accumulation of the scale on the metal surface.
Originality/value
The ultrasonic can enhance the heat transfer on the heater surface both in distilled water and scaled solution. In the earlier period, the heat transfer coefficient increases with the heat flux increases.
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Keywords
Jiandong Lu, Xiaolei Wang, Liguo Fei, Guo Chen and Yuqiang Feng
During the coronavirus disease 2019 (COVID-19) pandemic, ubiquitous social media has become a primary channel for information dissemination, social interactions and recreational…
Abstract
Purpose
During the coronavirus disease 2019 (COVID-19) pandemic, ubiquitous social media has become a primary channel for information dissemination, social interactions and recreational activities. However, it remains unclear how social media usage influences nonpharmaceutical preventive behavior of individuals in response to the pandemic. This paper aims to explore the impacts of social media on COVID-19 preventive behaviors based on the theoretical lens of empowerment.
Design/methodology/approach
In this paper, survey data has been collected from 739 social media users in China to conduct structural equation modeling (SEM) analysis.
Findings
The results indicate that social media empowers individuals in terms of knowledge seeking, knowledge sharing, socializing and entertainment to promote preventive behaviors at the individual level by increasing each person's perception of collective efficacy and social cohesion. Meanwhile, social cohesion negatively impacts the relationship between collective efficacy and individual preventive behavior.
Originality/value
This study provides insights regarding the role of social media in crisis response and examines the role of collective beliefs in the influencing mechanism of social media. The results presented herein can be used to guide government agencies seeking to control the COVID-19 pandemic.
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Keywords
Junwu Zhu, Jiandong Wang and Bin Li
The purpose of this paper is to integrate distributed ontologies on the web system and clarify the structure of the integrated one.
Abstract
Purpose
The purpose of this paper is to integrate distributed ontologies on the web system and clarify the structure of the integrated one.
Design/methodology/approach
A formal method based on concept lattices is introduced as a mechanism to form more general semantic level. By checking the extension and the intension of concept, this method extracts the concept pairs satisfying inclusion relations from descartes' set of concepts in distributed ontologies first, and then constructs a concept lattice according to these concept pairs. An algorithm to reduce redundant relations is also proposed to clarify the structure of integrated ontology.
Findings
The experiments demonstrate the effectiveness of the proposed method to reduce redundant relations, and the Nir‐to‐Ncr ratio inclines to 1.05 from 3.13.
Research limitations/implications
Instances of certain concept are not given completely on the web, so it is difficult to check extension of different concepts.
Practical implications
A very useful method of integrating distributed ontologies on the web.
Originality/value
Compared with existing methods, this formal method can be performed by program automatically without any human intervening, and can extract the inclusion relations between concepts from distributed ontologies completely.
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This first chapter is the introduction to the book. The purpose of this book is to address and better understand why China tightly embraces modern sport in contemporary times…
Abstract
This first chapter is the introduction to the book. The purpose of this book is to address and better understand why China tightly embraces modern sport in contemporary times. Some view this as an indicator of glocalisation and a result of Western industrial civilization putting pressure on China to showcase their strengths as a nation. Some important considerations to explore are China's mediated ability to play and compete with the west. Sport is also seen as a channel of observing global political and economic challenges, especially those in the current context of the COVID-19 pandemic and the intense tensions between communities, which certainly inspires further academic development. Given China's recently remarkable achievements in sport, it is high time to show the world more inside stories of sport development across the nation. The contributors of this collection bring foundational Chinese context to each chapter as they examine changing sport cultures at different scales.
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Keywords
Maria Akhtar, Naseer Abbas Khan, Azmat Yar Khan and Asfand Yar Khan
This study explores the impact of metaverse knowledge on freelancer engagement and performance within the gig economy, drawing upon the theoretical framework of social cognitive…
Abstract
Purpose
This study explores the impact of metaverse knowledge on freelancer engagement and performance within the gig economy, drawing upon the theoretical framework of social cognitive theory. The authors investigate the mediating role of freelancer engagement in the relationship between metaverse knowledge and performance, further examining the moderating influence of freelancer experience on these relationships.
Design/methodology/approach
Using a convenient sampling technique, data was collected through questionnaire from 301 freelancers working on various virtual platforms in Pakistan using a five-point Likert scale. Smart PLS 4.0 was used to analyze the data.
Findings
The findings reveal positive direct effect of metaverse knowledge on both freelancer engagement and performance. In addition, freelancer engagement significantly mediates the relationship between metaverse knowledge and performance. Furthermore, the findings affirm that the freelancers experience serves as a moderating factor in the relationship between metaverse knowledge, engagement and performance by indicating positive impact.
Originality/value
This study contributes a novel perspective to the gig economy literature by elucidating the underlying mechanisms through which metaverse knowledge drives freelancer performance via engagement. By examining the unique role of the metaverse in the gig context, the study offers valuable theoretical and practical implications for both scholars and practitioners seeking to understand and enhance freelancer engagement and performance in this evolving digital landscape.
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Keywords
Sabri Burak Arzova and Bertaç Şakir Şahin
The purposes of this study are to contribute to the limited green growth (GG) literature in emerging markets, to analyze GG from a financial economy perspective and to determine…
Abstract
Purpose
The purposes of this study are to contribute to the limited green growth (GG) literature in emerging markets, to analyze GG from a financial economy perspective and to determine the contribution of financial development and innovation to GG in Brazil, Russian Federation, India, China and South Africa and Türkiye (BRICS-T). BRICS-T countries significantly impact the world population, international politics, energy resources and economy. In addition, BRICS-T countries are one of the leading countries in the world with their sustainability efforts. Investigating the GG model in these countries may contribute to structuring emerging economies around the principles of GG and advancing global green transformation efforts.
Design/methodology/approach
The authors applied panel data analysis from 2001 to 2019. GG is economic growth free from environmental depletion in the model. National income, personnel expenditure and foreign direct investments are macroeconomic variables. These variables measure economic development and promote economic and social progress, which is essential for GG. Capital accumulation and innovation are essential tools in GG transformation. Therefore, financial development and patent applications represent the moderating variables. The authors estimate the fixed effect model with Parks-Kmenta robust.
Findings
Empirical results show that national income growth and foreign direct investments positively affect GG. Personnel expenditure negatively affects GG. On the contrary, financial development and patent growth have little moderating role.
Originality/value
This study contributes to the literature on creating a GG model in emerging countries. The study is original in its model and sample.
Details
Keywords
In order to solve the current imbalance of academic resources within the discipline, this article builds a three-dimensional talent evaluation model based on the…
Abstract
Purpose
In order to solve the current imbalance of academic resources within the discipline, this article builds a three-dimensional talent evaluation model based on the topic–author–citation based on the z index and proposes the ZAS index to evaluate scholars on different research topics within the discipline.
Design/methodology/approach
Based on the sample data of the CSSCI journals in the discipline of physical education in the past five years, the keywords were classified into 13 categories of research topics including female sports. The ZAS index of scholars on topic of female sports and so on was calculated, and quantitative indexes such as h index p index and z index were calculated. Comparative analysis of the evaluation effect was performed.
Findings
It is found that compared with the h index and p index, the z index achieves a better balance between the quantity, quality and citation distribution of scholars' results and effectively recognizes that the citation quality is higher and the number of citations of each paper is more balanced. In addition, compared to the z index, this article is based on a ZAS index model with an improved three-dimensional topic–author–citation relationship in research fields such as female sports.
Originality/value
It can identify some outstanding scholars who are engaged in small-scale or emerging topic research such as female sports and are excellent in different research areas. Talents create an objective and fair evaluation environment. At the same time, the ranking ability of ZAS indicators in the evaluation of talents is the strongest, and it is expected to be used in practical evaluations.