Ngoc Anh Vu, Jae‐Woo Lee, Sangho Kim and Daniel Neufeld
Rotor performance analysis and design are complex due to the wide variation in flow characteristics. Design tools that can rapidly and accurately compute aerofoil data are needed…
Abstract
Purpose
Rotor performance analysis and design are complex due to the wide variation in flow characteristics. Design tools that can rapidly and accurately compute aerofoil data are needed for rotorcraft design and analysis purposes. The purpose of this paper is to describe a process which has been developed that effectively automates the generation of two‐dimensional (2D) aerofoil characteristics tables.
Design/methodology/approach
The process associates a number of commercial software packages and in‐house codes that employ diverse methodologies, including the Navier‐Stokes equation‐solving method, the high‐order panel method and Euler equations solved with the fully coupled viscous‐inviscid interaction (VII) method. The paper describes the development of a general automated generation method that extends from aerofoil shape generation to aerofoil characteristic analysis. The generated data are stored in C81 aerofoil characteristics tables for use in comprehensive rotorcraft analysis codes and rotor blade design. In addition, the methodology could be easily applied for fixed‐wing analysis and design, especially for transonic aircraft.
Findings
The method is demonstrated to achieve aerofoil characteristics quickly and accurately in automated process. Calculations for the SC1095 aerofoil section are presented and compared with existing experimental C81 data and previous studies.
Practical implications
The development of C81 tables is of interest to industry as they seek to update their airfoil tables as new designs. Automated processes to achieve this are helpful and applicable.
Originality/value
The paper presents an effective automated process to generate aerofoil characteristics tables quickly, and accurately.
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Ngoc Anh Vu, Than Lin, Abdulaziz Azamatov, Tun Lwin and Jae‐Woo Lee
The purpose of this paper is to develop an integrated rotorcraft design and virtual manufacturing framework. The framework consists of two major sub‐frameworks which are e‐design…
Abstract
Purpose
The purpose of this paper is to develop an integrated rotorcraft design and virtual manufacturing framework. The framework consists of two major sub‐frameworks which are e‐design and virtual manufacturing frameworks. This paper aims to describe the process of generating a specific framework for helicopter design and manufacturing in general, and a method for main rotor blade design.
Design/methodology/approach
The e‐design process integrates a pre‐conceptual, conceptual and preliminary design phases and includes many high accuracy physics‐based analysis tools and in‐house codes. The development of analysis programs and integration of flow data are discussed under the e‐design process. The virtual manufacturing process discusses physical three‐dimensional (3D) prototypes using rapid prototyping, virtual process simulation model development using Delmia Quest, virtual machine tool simulation and process‐based cost model. Vehicle geometry is modelled parametrically in computer‐aided 3D interactive application (CATIA) V5 to enable integration between the e‐design and virtual manufacturing processes, and then saved in Enovia SmartTeam which is commercial software for product data management (PDM). Data saved in Enovia SmartTeam are used as a database for the virtual manufacturing process.
Findings
The integration framework was constructed by using Model Center software. A multi‐disciplinary design optimization loop for rotor blade considering manufacturing factors is discussed to demonstrate the robustness and efficiency of the framework.
Practical implications
The manufacturing (practical factors) could be considered at an early stage of the rotor blades design.
Originality/value
The gap between theoretical (engineering design: aerodynamic, structural, dynamic, design, etc.) and practical aspects (manufacturing) is bridged through integrated product/process development framework. The modern concurrent engineering approach is addressed for helicopter rotor blade design throughout the case study.
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Ngoc Anh Vu, Young‐Jae Lee, Jae‐Woo Lee, Sangho Kim and In Jae Chung
The purpose of this paper is to study the conceptual design and optimisation of a compound gyroplane. A study of a compound gyroplane configuration and its characteristics was…
Abstract
Purpose
The purpose of this paper is to study the conceptual design and optimisation of a compound gyroplane. A study of a compound gyroplane configuration and its characteristics was performed to develop a sizing program.
Design/methodology/approach
The vertical takeoff and landing capabilities of a helicopter are particularly important. The need for efficient hover and the effectiveness of forward flight in the helicopter can cause conflicts within the design process. The designers usually wish to increase the helicopter's maximum forward speed. Recently, the compound aircraft is one of the concepts considered for the purpose of expanding the flight envelope of rotorcraft. The study of the compound gyroplane showed its advance capabilities for this purpose. Understanding its characteristics, a number of calculations are conducted to implement a sizing program for compound gyroplanes based on the conventional helicopter sizing process.
Findings
The results of the sizing program were validated using existing aircraft data such as the Challis Heliplane, Carter Copter, FB‐1 Gyrodyne, and Jet Gyrodyne. The program is appropriate to size a compound gyroplane at the conceptual design phase. An optimisation study was also performed to enhance sizing results. The compromise between the rotor lift sharing factor and the ratio of the wing span (Bw) to rotor diameter (D) was solved by choosing the total gross weight (TOGW) as the objective function, while the design variables are compromising factors. The optimum results showed that the TOGW of all four kinds of compound gyroplanes was considerably reduced.
Originality/value
A conceptual sizing program for unconventional compound aircraft was developed. The study showed that an optimum design process is necessary to enhance the sizing results.
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Effie Lai‐Chong Law and Anh Vu Nguyen‐Ngoc
The rising popularity of social software poses challenges to the design and evaluation of pedagogically sound cross‐cultural online collaborative learning environments (OCLEs). In…
Abstract
Purpose
The rising popularity of social software poses challenges to the design and evaluation of pedagogically sound cross‐cultural online collaborative learning environments (OCLEs). In the literature of computer‐mediated communications, there exist only a limited number of related empirical studies, indicating that it is still an emergent research area. The purpose of this paper is to describe an OCLE – iCamp Space – which addresses the challenges by integrating three pedagogical concepts – cross‐cultural collaboration, self‐directed learning (SDL) and social networking – with the aim to advance participants' competencies and by mixed‐method approaches to evaluating the complex situations.
Design/methodology/approach
A validation field study involving four European countries was conducted. Groups of students co‐created a questionnaire, which was assessed to provide an indicator of task performance. Multi‐source (surveys, blogs, emails, diaries, chats, videoconference and interviews) and multi‐perspective data (facilitators, students and researchers) were studied with social network analysis, content analysis and conversation analysis.
Findings
Motivation of learners as well as facilitators is the critical success factor for an OCLE; voluntary involvement is recommended. Participants should be provided with basic training on the use of selected social software tools. Other critical success factors include task selection that contributes to participants' sense of ownership and moderately structured setting that offers some guidance whilst leaving room for the development of SDL competence.
Originality/value
The paper enhances a limited, albeit increasing, number of empirical studies deploying social software for educational purposes. It thus contributes to a body of applied knowledge that enables a coherent understanding of this specific research topic to be drawn.
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Ngoc Minh Nguyen, Giang Huong Hoang, Ngoc Thi Minh Vu, Linh Duy Bui and Anh Son Ta
This paper aims to examine how differently cognitive and affective country image affects brand loyalty of smartphone brands from two developed countries in Vietnam and how product…
Abstract
Purpose
This paper aims to examine how differently cognitive and affective country image affects brand loyalty of smartphone brands from two developed countries in Vietnam and how product image mediates these effects.
Design/methodology/approach
This research used the cross-sectional design. Data was collected via questionnaires and 517 responses were left after refining. The confirmatory factor analysis and structural equation modeling were applied to analyze the collected data.
Findings
The effects of the cognitive country image on brand loyalty are totally transmitted through product image. The effects of affective country image on brand loyalty are divided into direct and indirect effects transmitted through product image.
Research limitations/implications
Affective country image and product image have complementary effects, whereas cognitive country image and product image have substituting effects on brand loyalty.
Practical implications
International companies from countries with unfavorable country images should concentrate more on improving their product images to improve brand loyalty in foreign markets.
Originality/value
The findings support previous studies, which have shown that cognitive and affective country images are distinctive dimensions of country image and affect consumer cognition and responses toward products/brands through different mechanisms.
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Ngoc Minh Nguyen, Hoang Huong Giang, Ngoc Thi Minh Vu and Son Anh Ta
This paper examines the moderating effects of online reviews on the relationship between country image, product image, and purchase intention of products from two developed…
Abstract
Purpose
This paper examines the moderating effects of online reviews on the relationship between country image, product image, and purchase intention of products from two developed countries in Vietnam.
Design/methodology/approach
This current research used a cross-sectional design. Data was collected via questionnaires, and 305 responses were left after refining. The collected data were analyzed using exploratory factor analysis, confirmatory factor analysis, structural equation modeling, and multi-group analysis methods.
Findings
Affective country images do not directly affect purchase intention when online review quality and positivity are high. Cognitive country images still directly affect purchase intention when online review positiveness is low. However, online review quantity does not moderate the effects of country images on product images and purchase intention.
Research limitations/implications
Cognitive country image consistently affects purchase intention through the central route independent of online reviews. In contrast, the affective country image will likely affect purchase intention through the peripheral route when online reviews are insufficient for customers.
Practical implications
Firms can mitigate the adverse effects of country image, especially cognitive country image, in foreign markets by improving online review quality and positiveness.
Originality/value
Our study extended existing literature by providing a better understanding of the nature of country image and the roles of country image dimensions in shaping product image and purchase intention in the context of the increasing popularity of online reviews.
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Cong Doanh Duong, Thanh Hieu Nguyen, Thi Viet Nga Ngo, Thi Thu Phuong Pham, Anh Trong Vu and Ngoc Su Dang
This study aims to investigate what drives tourists to continue using ChatGPT for travel purposes. This study focuses on the impact of parasocial interaction on tourists’…
Abstract
Purpose
This study aims to investigate what drives tourists to continue using ChatGPT for travel purposes. This study focuses on the impact of parasocial interaction on tourists’ intention to continue using ChatGPT. It also examines how satisfaction mediates this relationship and the role of technology anxiety as a moderating factor.
Design/methodology/approach
Using a sample of 606 tourists in popular Vietnamese tourist destinations, this study used the SPSS PROCESS macro (Model 4 and Model 14) to estimate the research model.
Findings
The study found that tourists’ satisfaction and parasocial interactions positively influenced their intention to continue using ChatGPT for travel purposes. The tourists’ satisfaction was found to play a partial role in mediating the relationship between parasocial interactions and their intention to continue using ChatGPT. Technology anxiety was found to be a negative moderator of the direct effect of satisfaction and the indirect impact of parasocial interaction on this intention.
Originality/value
This study stands out as a pioneering exploration into the novel intersection of parasocial interaction, satisfaction, and technology anxiety and their influence on tourists’ intention to persist with using ChatGPT for travel-related purposes.
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Hoang-Long Cao, Huynh Anh Duy Nguyen, Trong Hieu Luu, Huong Thi Thu Vu, Diep Pham, Van Thi Ngoc Vu, Hoang Hai Le, Duy Xuan Bach Nguyen, Trong Toai Truong, Hoang-Dung Nguyen and Chi-Ngon Nguyen
COVID-19 hits every country’s health-care system and economy. There is a trend toward using automation technology in response to the COVID-19 crisis not only in developed…
Abstract
Purpose
COVID-19 hits every country’s health-care system and economy. There is a trend toward using automation technology in response to the COVID-19 crisis not only in developed countries but also in those with lower levels of technology development. However, current studies mainly focus on the world level, and only a few ones report deployments at the country level. The purpose of this paper is to investigate the use of automation solutions in Vietnam with locally available materials mainly in the first wave from January to July 2020.
Design/methodology/approach
The authors collected COVID-related automation solutions during the first wave of COVID-19 in Vietnam from January to July 2020 through a search process. The analysis and insights of a panel consisting of various disciplines (i.e. academia, health care, government, entrepreneur and media) aim at providing a clear picture of how and to what extent these solutions have been deployed.
Findings
The authors found seven groups of solutions from low to high research and development (R&D) levels deployed across the country with various funding sources. Low R&D solutions were widely spread owing to simplicity and affordability. High R&D solutions were mainly deployed in big cities. Most of the solutions were deployed during the first phases when international supply chains were limited with a significant contribution of the media. Higher R&D solutions have opportunities to be deployed in the reopening phase. However, challenges can be listed as limited interdisciplinary research teams, market demand, the local supporting industry, end-user validation and social-ethical issues.
Originality/value
To the authors’ best knowledge, this is the first study analyzing the use of automation technology in response to COVID-19 in Vietnam and also in a country in Southeast Asia. Lessons learned from these current deployments are useful for future emerging infectious diseases. The reality of Vietnam’s automation solutions in response to COVID-19 might be a reference for other developing countries with similar social-economic circumstances and contributes to the global picture of how different countries adopt technology to combat COVID-19.
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Nguyen Vinh Khuong, Doan Thi Ngoc Anh, Pham Minh Nhu, Tai Vu Tran Trong, Nguyen Thi Kieu Trang and Dang Hoang Kha Thy
This study aims to examine the relationship between key audit matters (KAMs) and the restatement of financial statements, assessing their impact on the financial statement…
Abstract
Purpose
This study aims to examine the relationship between key audit matters (KAMs) and the restatement of financial statements, assessing their impact on the financial statement restatement process.
Design/methodology/approach
This study aims to examine the economic context of Vietnam by analyzing data from 170 listed enterprises on the Vietnam stock exchange from 2010–2021. Feasible generalized least squares and robustness regression are conducted to give results and conclusions.
Findings
The results show that the KAMs disclosure in the financial statements has not really significantly affected the quality of an audit, so the KAMs disclosure does not have too much impact on the restatement of financial statements. However, this study found that the number of disclosed KAMs would partly reflect the shortcoming that exists in companies' financial statements.
Practical implications
The authenticity of financial statements is crucial for companies to meet auditor requirements, particularly KAMs. Restatements can influence business decisions and provide more accurate financial information to stakeholders. Thus, studying the impact of KAMs on restatement is essential for improving the veracity and reliability of financial statements.
Originality/value
This study clarifies the important role of KAMs in financial statements to recommend investors to be more careful in considering KAMs disclosed by auditors in audit reports. In addition, this study helps to add an overview of KAMs in emerging markets like Vietnam, as well as helps stakeholders to improve the legal system on Accounting – Auditing in Vietnam.
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Viet Anh Hoang, Man Dang, Ngoc Vu Nguyen, Ngoc Thang Nguyen and Darren Henry
The purpose of this paper is to investigate the effects of cross-country characteristics on acquirers' target status choice in cross-border mergers and acquisitions across 41…
Abstract
Purpose
The purpose of this paper is to investigate the effects of cross-country characteristics on acquirers' target status choice in cross-border mergers and acquisitions across 41 emerging markets.
Design/methodology/approach
The paper first reviews the existing literature and develops the related hypotheses, in conjunction with the objectives of this paper. We then describe the data employed, variable measurement and examine the effects of cross-country characteristics on the acquirers' target status choice in cross-border mergers and acquisitions while controlling for firm-level and deal-specific characteristics. The paper continues to conduct the robustness check on cross-country determinants of target status choices using the difference independent variables rather than target country-level variables only.
Findings
This research found that the likelihood of a public firm acquired relative to private one is higher if the target firm is located in countries with stronger government quality, weaker economic freedom, better financial market development and lower cultural distance between the host and home countries. The results suggest that bidders actively assess cross-country characteristics as part of their acquisition planning.
Originality/value
Rather than commonly analysed determinants in the previous research such as firm- and deal-specific attributes, value creation and shareholder protection, this paper indicates that institutional environments and economic conditions are closely associated with acquisition risks and benefits and have direct influences on bidder firms' acquisition bidding planning and target choice decision-making.