Le Nhat Hoang Tran, Laurent Gerbaud, Nicolas Retière and Hieu Nguyen Huu
Static converters generate current harmonics in power grids. For numerous studies, analytical frequency modeling is preferred to carry out their harmonic modeling in the context…
Abstract
Purpose
Static converters generate current harmonics in power grids. For numerous studies, analytical frequency modeling is preferred to carry out their harmonic modeling in the context of sizing by optimization. However, a design by optimization has to consider other constraints, e.g. modeling constraints and operating constraints. In this way, this paper aims to focus on applying an analytical frequency modeling on the sizing by optimization of an aircraft electrical power channel.
Design/methodology/approach
The paper aims to size a multiphysical system by optimization. In this way, the sizing of an aircraft electrical power channel by optimization has been carried out. The models of all the channel components are analytical. Specifically, the frequency model of the power electronics is based on Tran et al. (2016) and is made of equalities and inequalities. Due to this modeling choice, the optimization satisfies hundreds of constraints, such as modeling constraints and static converter operating constraints. Furthermore, transient constraints are only verified after optimization.
Findings
The difficulty is the modeling of the system by taking into account nonlinear implicit equations having several solutions. A solution is the addition of inequality constraints to the model to guide the implicit solving. Furthermore, this greatly helps the optimization algorithm to find the good operating mode of the static converter, at steady state. This aspect is indispensable to validate the sizing model.
Research limitations/implications
The number of the configurations per operating period of the static converters is defined a priori and limited.
Originality/value
The analytical model for the sizing is formulated as a constrained optimization problem. Its solving and the sizing by optimization are carried out by the same optimization algorithm.
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Le Nhat Hoang Tran, Laurent Gerbaud, Nicolas Retiere and H. Nguyen Huu
Static converters generate current harmonics in grids. Numerous studies on analytical frequency models of converters are often required to carry out their harmonic modeling in the…
Abstract
Purpose
Static converters generate current harmonics in grids. Numerous studies on analytical frequency models of converters are often required to carry out their harmonic modeling in the context of sizing by optimization. Some formulations are proposed to solve such models. Each formulation has its own advantages and drawbacks. The paper mainly focuses on two formulations: the first to be solved by Sequential Quadratic Programming (SQP) and the second to be solved by Newton-Raphson (NR). In this way, the paper presents the performances of each formulation and compares the results of both formulations for the modeling of a single-phase diode rectifier.
Design/methodology/approach
The paper aims to compare SQP formulation and NR formulation, and to propose the ways to improve their convergence. In the modeling, by using an explicit formulation of the state variables combined to a numerical method, equations are defined to reduce, as far as possible, the number of unknowns.
Findings
The difficulty is to find the good operating mode of the static converter. So, outside the equations and the constraints, the paper proposes to use the eigenvalues of the state space matrixes to initialize the duration of every configuration and to consider the operating symmetries of the static converter that allow to reduce the research area and also the variables calculated.
Research limitations/implications
The number of the conducting phase per half period is a priori, as the operating mode.
Originality/value
The modeling is based on the use of linear components, ideal switches and the static converter operates in steady-state. The main difficulties are to formulate the equations representing the non-controlled switching of semiconductors, and to solve them.
Trung Thanh Le, Thanh Hieu Nguyen, Son Tung Ha, Quang Khai Nguyen, Nhat Minh Tran and Cong Doanh Duong
This article aims to draw a conceptual model that integrates the view from the entrepreneurial event model with entrepreneurial education and prior self-employment experience. The…
Abstract
Purpose
This article aims to draw a conceptual model that integrates the view from the entrepreneurial event model with entrepreneurial education and prior self-employment experience. The model tests the role of entrepreneurial education on the formation of intentions to become an entrepreneur and examines whether prior self-employed experiences moderate the route from entrepreneurial education, entrepreneurial perceived feasibility (PF) and perceived desirability (PD) into the entrepreneurial intention (EI).
Design/methodology/approach
The authors operated on a sample of 389 master's students by applying Cronbach's alpha, exploratory factor analysis, confirmatory factor analysis and structural equation modelling to illustrate the links between constructs.
Findings
The study found that entrepreneurial education is positively correlated with PF, PD, and intention to enter entrepreneurial activities. PD is determined as a partial mediator in the entrepreneurial education–intention link and full mediator in PF and EI. Moreover, the study revealed that prior self-employed experiences serve as a positive moderator in the path from entrepreneurial education and PD to EI.
Practical implications
The study offers several recommendations based on research findings so as to nurture and promote entrepreneurial activities among master's students.
Originality/value
The current research provides novel insights about the relationship between entrepreneurial education and intentions to become an entrepreneur over and about the central antecedents in the entrepreneurial event model and moderation effects of prior self-employed experiences.
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Nhat Minh Tran, Que Giang Ngo and Quyet Thang Tran
The purpose of this study is to investigate the impact of the gender diversity of top management teams (TMTs) on the financial performance (FP) of small and medium enterprises…
Abstract
Purpose
The purpose of this study is to investigate the impact of the gender diversity of top management teams (TMTs) on the financial performance (FP) of small and medium enterprises (SMEs) in Vietnam. This paper also examines the moderating effect of family control on this relationship.
Design/methodology/approach
Using a sample of SMEs in Vietnam, this paper uses descriptive statistics and balance panel regression with random effect to analyse 5,160 firm-year observations of family- and non-family-owned SMEs between 2011 and 2015.
Findings
The findings demonstrate that gender diversity in TMTs shows a negative relationship with the FP of family-controlled SMEs and no significant impact on FP of non-family SMEs. This study also illustrates a positive curvilinear relationship between the female manager rate in TMTs and firms’ FP in family SMEs.
Research limitations/implications
This research study is limited to data from Vietnamese SMEs. Future studies could investigate these relationships with larger firms and in a broader geographical context.
Originality/value
This study provides a better understanding of the impact of TMT gender diversity on FP in Vietnamese SMEs while considering the moderating effect of family control. The findings support some theories relating to managerial gender diversity and the effect of family control on this diversity in family SMEs.
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Thong Le Pham, Nghiem Tan Le, Nhi Nhat Phuong Ho and Thanh Cong Le
This study aims to analyse the consumption inequality between farm and non-farm households in rural Vietnam, using the data from the 2016 Vietnam household living standards survey.
Abstract
Purpose
This study aims to analyse the consumption inequality between farm and non-farm households in rural Vietnam, using the data from the 2016 Vietnam household living standards survey.
Design/methodology/approach
The present paper applies the “recentered influence functions (RIF)” in “Oaxaca-Blinder (OB)” type decomposition as proposed by Firpo et al. (2018) to allow for the flexible distribution of the outcome variables and the non-randomness of non-farm employment that violates the classical linearity assumption.
Findings
Non-farm households have significantly higher per capita consumption expenditure than farm households for the entire distribution. The gap in expenditure is large at low percentiles and narrowing with higher percentiles. At 10th percentile, the gap is estimated at 27.1%, but it is decreasing to 11.1% at 90th percentile. Most of the gaps are explained by the differences in the observed characteristics between farm and non-farm households such as ethnicity, education, income, internal transmittances and household composition. Non-farm households are endowed with more productive factors that result in higher per capita consumption expenditure.
Originality/value
Gaps in ethnicity and education are found to be key predictors of the inequality in consumption expenditures between farm and non-farm households, then, government policies that are aimed at increasing access to non-farm employment and education for ethnic minorities and for rural poor households are pathways to improve rural household welfare and hence reduce inequality.
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Linh Hoang Nguyen and Hoa Phuong Nguyen
Vietnam is an emerging economy in the South East Asia region. Its Generation Z is gradually taking the lead in the country. But rather than breaking away from the previous…
Abstract
Vietnam is an emerging economy in the South East Asia region. Its Generation Z is gradually taking the lead in the country. But rather than breaking away from the previous generations, this generation also shows a strong preference towards local values and solid commitment to social issues. Thus, traditional culture elements are increasingly integrated in every aspect of Generation Z’s life, such as advertising and fashion. Instead of hanging out at coffee places, they go for bubble tea. They still appreciate the traditional values but integrate them within a modern context. Brands chase after these young people by adapting their values into their products and services. In the work place, the Vietnamese Generation Z is less confident. They are partially lost in career development with poor career counselling in the education system. They desire new experience and new learning opportunities. Generation Z, who were born beginning in 1995, emerges in Vietnam as a fresh and promising force.
Nhat Tan Nguyen, Lai Wan Hooi and Mohan V. Avvari
This paper aims to look into the role of transformational leadership and transactional leadership as predictors of employee creativity and organisational innovation. Employee…
Abstract
Purpose
This paper aims to look into the role of transformational leadership and transactional leadership as predictors of employee creativity and organisational innovation. Employee creativity is examined as a potential mediator in the leadership styles–organisational innovation relationships.
Design/methodology/approach
A cross-sectional, quantitative design was adopted and structural equation modelling (SEM) techniques were used to analyse data collected from 369 employees working in 39 public coffee enterprises in Vietnam.
Findings
Transformational leadership and transactional leadership were significant predictors of employee creativity and organisational innovation. Specifically, transformational leadership was instrumental to employee creativity and organisational innovation while transactional leadership was detrimental to these two variables. Additionally, employee creativity partially mediated the relationships between the two leadership styles and organisational innovation.
Practical implications
Results of this study benefit the management of organisations and policy makers by providing an insight of which leadership style will effectively suit public enterprises to promote employee creativity and foster organisational innovation.
Originality/value
While there is a lack of studies investigating organisational innovation in organisational methods and that the interrelationships between leadership styles, employee creativity and organisational innovation are not fully understood, this study pioneers in examining relationships between leadership styles and organisational innovation that is being mediated by employee creativity. Figuring out that organisational innovation is more likely to be fostered by the positive influence of leadership behaviours and the improvement of employee creativity, in particular, the significant role of employee creativity represents important contributions of the current study.
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Nga Thi Thuy Ho, Hung Trong Hoang, Pi-Shen Seet, Janice Jones and Nhat Tan Pham
The purpose of this study is to examine the determinants of career satisfaction of professional accounting returnees who have studied and/or worked abroad and then returned to…
Abstract
Purpose
The purpose of this study is to examine the determinants of career satisfaction of professional accounting returnees who have studied and/or worked abroad and then returned to work in different types of international workplaces in their home country.
Design/methodology/approach
A survey of professional accounting returnees in Vietnam was undertaken and multiple regression analysis was applied to test the proposed relationships.
Findings
This study finds that career satisfaction is affected by career fit, career sacrifice, types of international workplaces (domestically headquartered firms versus globally headquartered firms) and cross-cultural work readjustment. Further, cross-cultural work readjustment partially mediates the effect of career fit and career sacrifice on career satisfaction.
Practical implications
The research provides the basis for designing career-related employee experiences to support career satisfaction of professional accounting returnees.
Originality/value
This study integrates dimensions of career embeddedness with cross-cultural work readjustment and employee experiences, which are normally studied separately, in different types of international workplaces. It contributes to the limited research on contributors to well-being in the form of career satisfaction among professional returnees in an emerging economy.
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Ho Xuan Thuy, Nguyen Vinh Khuong, Le Huu Tuan Anh and Pham Nhat Quyen
This study aims to investigate the association between corporate governance (CG) and the corporate social responsibility (CSR) information disclosure as well as the moderating…
Abstract
Purpose
This study aims to investigate the association between corporate governance (CG) and the corporate social responsibility (CSR) information disclosure as well as the moderating role of state-ownership between CG and CSR disclosure.
Design/methodology/approach
To examine the relationship between CG and CSR disclosure, this study used the feasible general least squares and generalized method of moments method on a sample of 165 non-financial quoted companies over the 2015–2018 period, which account for about three-fourths of the Vietnamese stock exchange.
Findings
The findings suggest that enterprises with smaller board size consisting mainly of independent directors have a higher CSR disclosure level. Moreover, when the chief executive officer is concurrently the chairman of the board, the level of CSR disclosure falls. Additionally, the moderating role of state ownership enhances CSR disclosure.
Research limitations/implications
The empirical results of this study form a solid foundation for policymakers and other stakeholders’ decisions in investing or establishing policies.
Originality/value
This study provides empirical evidence on the relationship between CG and CSR disclosure in Vietnam – a developing country with no legal requirement on CSR disclosure. Moreover, this study emphasizes the moderating role of state ownership between CG and CSR disclosure, which clarifies the role of state ownership in establishing CG mechanisms.
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The purpose of this paper is to trace the way in which a popular ritual became one of Vietnam’s most important festivals, elevated as a celebration of national heroism and charts…
Abstract
Purpose
The purpose of this paper is to trace the way in which a popular ritual became one of Vietnam’s most important festivals, elevated as a celebration of national heroism and charts its gradual transformation in modern society.
Design/methodology/approach
This research focuses on the combination of a fertility rite and narratives of St Gióng based on nationalism or heroism created a special festival reflecting many traditional cultural characteristics of Vietnam and the Việt people and the transformation of St Gióng from a mythological to a national symbol of heroism in anti-invader history was recorded in texts.
Findings
The paper casts light on the mythologization and historicization of St Gióng in Vietnam’s particular historical context by decoding the Gióng symbol as a core element of the folktales and myths about St Gióng to understand the formation and development of St Gióng in the cultural history of Vietnam.
Research limitations/implications
The paper is not exploring the Gióng symbol within a larger cultural context of nationalism and ethnosymbolic approach in a comparison of national symbolism and heroism.
Practical implications
The paper includes implications for advised scholars to conduct further exploration of the symbol and myth of not only St Gióng in Vietnam but also Kubera in India and Vaisravana in China to connect Kubera, Vaisravana and St Gióng under the connection of literal myth and heroic symbol.
Social implications
The paper shows how processes of historicizing myth and mythologizing history are important features of Vietnamese socio-historical research.
Originality/value
The paper shows how a fertility rite became a historical festival and the figure of St Gióng became a symbol of patriotic heroism.