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This paper aims to present a simplified method to analyze the transient characteristics of a fractional-order very high frequency (VHF) resonant boost converter. The transient analytical solutions of state variables obtained by this method could be used as a guide for parameter design and circuit optimization.

The VHF converter is decoupled into a simplified equivalent circuit model and described by the differential equation. The solution of the simplified equivalent circuit model is taken as the main oscillation component of the transient state variable. And the equivalent small parameter method (ESPM) and Kalman filter technology are used to solve the differential equation of the converter to obtain the steady-state ripple component. Then, by superimposing the abovementioned two parts, the approximate transient analytical solution can be acquired. Finally, the influence of the fractional order of the energy storage elements on the transient process of the converter is discussed.

The results from the proposed method agree well with those from simulations, which indicates that the proposed method can effectively analyze the transient characteristic of the fractional-order VHF converter, and the analytical solution derived from the proposed mathematical model shows sufficient accuracy.

This paper proposes for the first time a method to analyze the transient characteristics of a fractional-order VHF resonant boost converter. By combining the main oscillated solution derived from the simplified equivalent circuit model with the steady-state solution based on ESPM, this method can greatly reduce the computation amount to estimate the transient solution. In addition, the discussion on the order of fractional calculus of energy storage components can provide an auxiliary guidance for the selection of circuit parameters and the study of stability.

This study aims to investigate whether auditors compromise their independence for economically important clients in family business settings.

The authors empirically examine the research question based on China for the years 2011 to 2020. The dependent variable is the auditors’ propensity to issue modified audit opinions, which is a proxy for auditor independence. The authors use relative client audit fees as a proxy for client importance. To address endogeneity issues in the selection of family firms, the authors use the two-stage least squares regression model and, subsequently, the propensity score matching and Hausman firm fixed effect modeling.

This study reveals that the propensity to issue modified audit opinions is positively correlated with client importance. Big-N auditors are more likely to issue modified audit opinions for their economically important family firm clients, whereas such evidence is not found for non-Big-N auditors. Results are consistent and robust to endogeneity test and sensitivity analysis.

This study enriches the literature on auditor independence and the effect of family firms’ ownership structure factors on audit reporting behavior for their economically important clients. Findings may prove useful for managers and practitioners interested in family business.

COVID-19 is currently the most serious crisis facing the world, and scholars in the medical and social sciences are working to save lives and mitigate the societal effects of the pandemic. This global public health emergency requires interdisciplinary work to provide comprehensive insight into a rapidly changing situation. However, attempts to integrate the medical and social sciences have met several barriers. This paper aims to identify feasible research opportunities for interdisciplinary studies across tourism and public health regarding COVID-19.

This paper presents a critical review of the literature and generates corresponding conceptual and theoretical frameworks to provide an in-depth discussion.

Tourism-related issues of destination management policies and capital are addressed from an interdisciplinary perspective. The conclusions encourage interdisciplinary research into global health problems, which will promote tourism’s renaissance and sustainable development while enhancing social welfare.

This study focuses on integrating tourism and public health to offer stakeholders recommendations regarding destination management and tourism industry recovery amid COVID-19.

This paper represents a frontier study, critically uncovering a host of innovative interdisciplinary research directions and tourism-focused collaboration opportunities related to COVID-19.

新冠疫情是当今世界面对的最严重的危机, 医学和社会科学领域的学者们在共同努力, 拯救生命, 减轻疫情的社会影响。基于快速变化的形势, 这项全球突发的公共卫生事件亟需跨学科工作来进行全面的调查, 但目前医学和社会科学的融合存在一些阻碍因素。为了应对新冠疫情的爆发, 本文旨在探讨旅游与公共卫生跨学科合作的可行性和研究机会, 并总结潜在的研究主题和未来的研究议程。

本研究对文献进行了批判性的回顾, 并生成了相应的概念和理论框架, 以提供一个全面的, 深入的主题讨论。

研究结果从跨学科的角度讨论了旅游产业中的目的地管理、政策和资本问题。我们的结论鼓励对全球健康问题进行跨学科研究, 这将促进旅游业的复兴和可持续发展, 同时提高社会福利。

目前的研究重点是旅游研究和公共卫生的融合, 为利益攸关方提供关于在危机中目的地管理和旅游业复苏的建议。

本文是一项前沿研究, 批判性地、全面地确定了一系列与新冠疫情相关的旅游领域的跨学科研究方向和合作机会。

关键词：医学, 社会科学, 公共健康, 旅游管理, 跨学科研究, 新冠肺炎

文章类型： 研究型论文

Este trabajo presenta una revisión crítica de la literatura y genera los correspondientes marcos conceptuales y teóricos para proporcionar una discusión en profundidad.

El COVID-19 es actualmente la crisis más grave a la que se enfrenta el mundo, y los especialistas en ciencias médicas y sociales están trabajando para salvar vidas y mitigar los efectos sociales de la pandemia. Esta emergencia de salud pública mundial requiere un trabajo interdisciplinario para proporcionar una visión completa de una situación que cambia rápidamente. Sin embargo, los intentos de integrar las ciencias médicas y sociales han encontrado varios obstáculos. El objetivo de este artículo es identificar las oportunidades de investigación viables para los estudios interdisciplinares entre el turismo y la salud pública en relación con la COVID-19.

Las cuestiones relacionadas con el turismo en materia de gestión de destinos, políticas y capital se abordan desde una perspectiva interdisciplinar. Nuestras conclusiones alientan la investigación interdisciplinaria de los problemas de salud global, lo que promoverá el renacimiento del turismo y el desarrollo sostenible, al tiempo que aumentará el bienestar social.

Este estudio se centra en la integración del turismo y la salud pública para ofrecer a las partes interesadas recomendaciones relativas a la gestión de los destinos y la recuperación de la industria turística en medio de COVID-19.

Este trabajo representa un estudio de frontera, que descubre de forma crítica una serie de direcciones innovadoras de investigación interdisciplinaria y oportunidades de colaboración centradas en el turismo en relación con COVID-19.

Palabras clave Ciencias médicas, ciencias sociales, salud pública, gestión del turismo, investigación interdisciplinaria, COVID-19

Investigación

This paper aims to study the influence of cylindrical texture parameters on the lubrication performance of static and dynamic pressure thrust bearings (hereinafter referred to as thrust bearings) and to optimize their lubrication performance using multiobjective optimization.

The influence of texture parameters on the lubrication performance of thrust bearings was studied based on the modified Reynolds equation. The objective functions are predicted through the BP neural network, and the texture parameters were optimized using the improved multiobjective ant lion algorithm (MOALA).

Compared with smooth surface, the introduction of texture can improve the lubrication properties. Under the optimization of the improved algorithm, when the texture diameter, depth, spacing and number are approximately 0.2 mm, 0.5 mm, 5 mm and 34, respectively, the loading capacity is increased by around 27.7% and the temperature is reduced by around 1.55°C.

This paper studies the effect of texture parameters on the lubrication properties of thrust bearings based on the modified Reynolds equation and performs multiobjective optimization through an improved MOALA.

A proliferation of articles surrounding the COVID-19 pandemic is calling for new insights through review. This paper aims to bibliometrically analyze the current progress of research around hospitality and tourism to define the research directions on herd immunity and the prevention of disease under the “new normal.”

This paper analyzed 326 articles regarding COVID-19 published in SSCI hospitality, leisure and tourism journals in 2020 and 2021 by combining manual analysis and bibliometrics to reveal research topics and to gain insight into research structures.

The results of this paper summarized topics related to stakeholders’ mentality and behavior, responses of travel suppliers to the COVID-19 pandemic, economic impact and demand forecasting, social issues of human rights and racism and reflection on tourism and transformation of the industry. More research is called for in the future to focus on a better response to the crisis, including crisis management education and training and the improving the resilience of small- and medium-sized enterprises.

A three-dimensional consideration was proposed to promote the sustainable development of hospitality and tourism.

In the “new normal” phase of herd immunity and disease prevention, to the best of the authors’ knowledge, this is the first paper that provides an up-to-date systematic overview of the evolution of COVID-19 research in tourism and hospitality and encourages more conceptual, practical and futuristic studies.

This paper aims to study the effect of the establishment of bankruptcy courts on bond issuance market. This paper helps to predict that the introduction of bankruptcy courts in China can mitigate price distortions caused by the implicit government guarantees and promote the development of the high-risk bond market.

This paper exploits the staggered introduction of bankruptcy courts across cities to implement a differences-in-differences strategy on bond issuance data. Using bonds issued in China between 2018 and 2020, the impact of bankruptcy courts on the bond issuance market can be analyzed.

This paper reveals that bond issuance credit spreads increase and is more sensitive to firm size, profitability and downside risk of issuance entity after the introduction of bankruptcy courts. It also reveals a substantive increase in bond issuance quantity and a decrease in issuer credit ratings following the establishment of bankruptcy courts. In addition, the increase of credit spreads is more prominent for publicly traded bonds, those whose issuers located in provinces with lower judicial confidence, bonds issued by SOEs and bonds with stronger government guarantees. Finally, the role of bankruptcy courts is more pronounced in regions with higher marketization.

This paper relates to previous studies that investigate the impact of laws and institutions on external financing. It helps provide new evidence to this literature on how improvements of efficiency and quality in bankruptcy enforcements relate to the marketization of bond issuance. The results provide further evidence on legal institutions and bond financing.

The purpose of this study is to present a holistic review of journal articles on value cocreation in the tourism and hospitality field. By distinguishing similarities and differences in the contexts of China and other regions, the authors identify targeted research directions.

This study collected 438 English articles and 31 Chinese articles on value cocreation in tourism and hospitality published in the Web of Science, Scopus and China National Knowledge Infrastructure online databases. After analyzing the study location of all articles in the sample, the authors identified 79 English-language articles that adopted China as the context of the study. The first data set included non-China-focused publications and the second data set included China-focused publications. A comparative bibliometric methodology was conducted.

The results indicate similarities and differences between the two data sets in terms of research methods, topics and future research directions. Seven major concepts were identified in the first data set: hospitality value cocreation; the value generation process; key stakeholders; outcome variables; the application of service-dominant logic; peer-to-peer accommodation and destination management. Four research focuses were identified in the second data set: the application of customer-dominant logic; the value generation process; resource integration and the cocreation experience.

This research contributes to the understanding of tourism and hospitality cocreation systems through literature analysis and encourages future research on the nexus of the Chinese and global contexts. This systematic investigation extends the concept of value cocreation by integrating its implementation process and value categories and further evaluates the consequences and benefits of value cocreation, which helps clarify how winners and losers can adjust their strategies accordingly.

The originality of this paper lies in the adopted comparative bibliometric analysis which comprehensively reviewed and compared the characteristics of value cocreation research across two contexts. In addition, the study dialectically assesses Chinese tourism cocreation phenomena and their impacts from a global perspective.

This paper is devoted to prepare micro-cone structure with variable cross-section size by Stereo Lithography Appearance (SLA)-based 3D additive manufacturing technology. It is mainly focused on analyzing the forming mechanism of equipment and factors affecting the forming quality and accuracy, investigating the influence of forming process parameters on the printing quality and optimization of the printing quality. This study is expected to provide a µ-SLA surface preparation technology and process parameters selection with low cost, high precision and short preparation period for microstructure forming.

The µ-SLA process is optimized based on the variable cross-section micro-cone structure printing. Multi-index analysis method was used to analyze the influence of process parameters. The process parameter influencing order is determined and validated with flawless micro array structure.

After the optimization analysis of the top diameter size, the bottom diameter size and the overall height, the influence order of the printing process parameters on the quality of the micro-cone forming is: exposure time (B), print layer thickness (A) and number of vibrations (C). The optimal scheme is A1B3C1, that is, the layer thickness of 5 µm, the exposure time of 3000 ms and the vibration of 64x. At this time, the cone structure with the bottom diameter of 50 µm and the cone angle of 5° could obtain a better surface structure.

This study is expected to provide a µ-SLA surface preparation technology and process parameters selection with low cost, high precision and short preparation period for microstructure forming.

The outbreak of the COVID-19 pandemic plunged global tourism into a huge crisis in 2020. China was confronted with a wave of cancellations by tourism consumers due to COVID-19 and tourist complaints rose dramatically during this period. Although tourism enterprises have quickly introduced measures in response, the effectiveness of targeted policies is expected to be evaluated. Concerned about this phenomenon, this study aims to provide insights into the dim prospects of the tourism industry and to bridge the gap between tourists and enterprises.

The current study adopts a two-step method that combines automatic and manual content analysis to contrastively analyse 647 complaints from the Sina platform and the measures of five online travel agencies (OTAs) taken to deal with COVID-19.

The results reveal that the COVID-19-related information and policies issued by official departments had a promoting effect on tourist complaints. OTAs were the main target of complainers, and three themes of complaints were identified, namely, cancellation barriers, refund barriers and customer relationship management. Although tourism enterprises’ policies covered most dimensions of the three themes, more detailed and mutually beneficial policies need to be formulated in the face of a new round of cancellations.

This research attempts to investigate tourism customer complaint behaviours in the case of COVID-19 and to provide tourism enterprises receiving different complaints with practical insights into crisis management. It contributes to simultaneously minimizing business losses and maintaining customer relationships in the service industry, improving the industry’s performance under potential crises in the future.

危机信息、沟通策略和客户投诉行为:以COVID-19为例

2020年, 新冠肺炎大流行的爆发使全球旅游业陷入巨大危机。由于新冠肺炎疫情, 中国面临了旅游消费者的退订浪潮, 期间游客投诉大幅上升。虽然旅游企业迅速采取了应对措施, 但预期将评估有针对性的政策的有效性。考虑到这一现象, 本研究旨在为旅游业的暗淡前景提供见解, 并弥合游客和企业之间的差距。

本研究采用自动内容分析和人工手动编码相结合的两步方法, 对来自新浪平台的647起游客投诉和5家在线旅行社应对COVID-19的措施进行对比分析。

结果显示, 官方部门发布的新冠肺炎相关信息和政策对旅游投诉的数量起到了刺激作用。在线旅行社是投诉者的主要目标, 并确定了游客投诉的三个主题:取消障碍、退款障碍和客户关系管理。虽然旅游企业政策涵盖了这三个主题的大部分层面, 但面对新一轮的取消, 还需要制定更详细和互利的政策。

本研究试图调查COVID-19情况下的旅游客户投诉行为, 为收到不同投诉的旅游企业提供危机管理的实用见解。它有助于在服务行业同时减少业务损失和维护客户关系, 提高行业在未来潜在危机下的绩效。

Información de crisis, estrategias de comunicación y medidas adoptadas ante las reclamaciones de los clientes: el caso de COVID-19

El presente estudio adopta un método en dos fases que combina el análisis de contenido automático y manual para analizar de forma contrastiva 647 reclamaciones de la plataforma Sina y las medidas de cinco agencias de viajes online (OTA) adoptadas para hacer frente a la COVID-19.

El estallido de la pandemia COVID-19 sumió al turismo mundial en una enorme crisis en 2020. China tuvo que hacer frente a una oleada de cancelaciones por parte de los consumidores turísticos debido a la COVID-19, y las quejas de los turistas aumentaron drásticamente durante este periodo. Aunque las empresas turísticas introdujeron rápidamente medidas de respuesta, se espera que se evalúe la eficacia de dichas políticas. Preocupado por este fenómeno, el presente estudio pretende aportar información sobre las sombrías perspectivas de la industria turística y tender un puente entre los turistas y las empresas.

Los resultados revelan que la información y las políticas relacionadas con el COVID-19 emitidas por los departamentos oficiales tuvieron un efecto promotor de las quejas de los turistas. Las OTAs fueron el principal objetivo de los reclamantes, y se identificaron tres temas de reclamaciones: barreras de cancelación, barreras de reembolso y gestión de la relación con el cliente. Aunque las políticas de las empresas turísticas cubrían la mayoría de las dimensiones de los tres temas, es necesario formular políticas más detalladas y mutuamente beneficiosas ante una nueva oleada de cancelaciones.

Esta investigación trata de investigar el comportamiento de las reclamaciones de los clientes turísticos en el caso de COVID-19 y de proporcionar a las empresas turísticas que reciben diferentes reclamaciones una visión práctica de la gestión de crisis. Contribuye a minimizar simultáneamente las pérdidas comerciales y a mantener las relaciones con los clientes en el sector de los servicios, mejorando el rendimiento de la industria ante posibles crisis en el futuro.

This paper aims to provide a framework of the supervised hyperspectral classification, to study the traditional flowchart of hyperspectral image (HIS) analysis and processing. HSI technology has been proposed for many years, and the applications of this technology were promoted by technical advancements.

First, the properties and current situation of hyperspectral technology are summarized. Then, this paper introduces a series of common classification approaches. In addition, a comparison of different classification approaches on real hyperspectral data is conducted. Finally, this survey presents a discussion on the classification results and points out the classification development tendency.

The core of this survey is to review of the state of the art of the classification for hyperspectral images, to study the performance and efficiency of certain implementation measures and to point out the challenges still exist.

The study categorized the supervised classification for hyperspectral images, demonstrated the comparisons among these methods and pointed out the challenges that still exist.