Trong Nghia-Nguyen, Sanjay Kumar Shukla, Dang Dinh Chung Nguyen, Le Gia Lam, Phuoc H-Dang and Phu-Cuong Nguyen
This paper aims to present a new discrete method to predict average excess pore pressure and degree of consolidation for soft ground using prefabricated vertical drains under…
Abstract
Purpose
This paper aims to present a new discrete method to predict average excess pore pressure and degree of consolidation for soft ground using prefabricated vertical drains under time-dependent surcharge and/or vacuum loading and multi-soil layers.
Design/methodology/approach
The drain is discretized into a number of mesh points at which the average excess pore pressure is estimated. The conventional Laplace technique is used to solve the analytical equations. The proposed method is validated with previous findings reported in the literature. Moreover, field measurements are used to verify the accuracy of the proposed method with a case history of ground improvement by prefabricated vertical drains using the vacuum consolidation technique.
Findings
In comparison to past studies, this new discrete method is simpler to be implemented in a spreadsheet calculation to achieve a rational solution with less computational time for similar consolidation problems. Moreover, the current approach also incorporates a solution for multi-soil layers, which can hardly be derived by analytical solutions.
Originality/value
According to authors’ knowledge, this is the first-time discrete method by Laplace transform technique is applied for the vertical drain.
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Nghia Nguyen, Thuy-Hien Nguyen, Yen-Nhi Nguyen, Dung Doan, Minh Nguyen and Van-Ho Nguyen
The purpose of this paper is to expand and analyze deeply customer emotions, concretize the levels of positive or negative emotions with the aim of using machine learning methods…
Abstract
Purpose
The purpose of this paper is to expand and analyze deeply customer emotions, concretize the levels of positive or negative emotions with the aim of using machine learning methods, and build a model to identify customer emotions.
Design/methodology/approach
The study proposed a customer emotion detection model and data mining method based on the collected dataset, including 80,593 online reviews on agoda.com and booking.com from 2009 to 2022.
Findings
By discerning specific emotions expressed in customers' comments, emotion detection, which refers to the process of identifying users' emotional states, assumes a crucial role in evaluating the brand value of a product. The research capitalizes on the vast and diverse data sources available on hotel booking websites, which, despite their richness, remain largely unexplored and unanalyzed. The outcomes of the model, pertaining to the detection and classification of customer emotions based on ratings and reviews into four distinct emotional states, offer a means to address the challenge of determining customer satisfaction regarding their actual service experiences. These findings hold substantial value for businesses operating in this domain, as the findings facilitate the evaluation and formulation of improvement strategies within their business models. The experimental study reveals that the proposed model attains an exact match ratio, precision, and recall rates of up to 81%, 90% and 90%, respectively.
Research limitations/implications
The study has yet to mine real-time data. Prediction results may be influenced because the amount of data collected from the web is insufficient and preprocessing is not completely suppressed. Furthermore, the model in the study was not tested using all algorithms and multi-label classifiers. Future research should build databases to mine data in real-time and collect more data and enhance the current model.
Practical implications
The study's results suggest that the emotion detection models can be applied to the real world to quickly analyze customer feedback. The proposed models enable the identification of customers' emotions, the discovery of customer demand, the enhancement of service, and the general customer experience. The established models can be used by many service sectors to learn more about customer satisfaction with the offered goods and services from customer reviews.
Social implications
The research paper helps businesses in the hospitality area analyze customer emotions in each specific aspect to ensure customer satisfaction. In addition, managers can come up with appropriate strategies to bring better products and services to society and people. Subsequently, fostering the growth of the hotel tourism sector within the nation, thereby facilitating sustainable economic development on a national scale.
Originality/value
This study developed a customer emotions detection model for detecting and classifying customer ratings and reviews as 4 specific emotions: happy, angry, depressed and hopeful based on online booking hotel websites agoda.com and booking.com that contains 80,593 reviews in Vietnamese. The research results help businesses check and evaluate the quality of their services, thereby offering appropriate improvement strategies to increase customers' satisfaction and demand more effectively.
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Trong Nghia-Nguyen, Le Thanh Cuong, Samir Khatir, Le Minh Hoang, Salisa Chaiyaput and Magd Abdel Wahab
Concrete gravity dams are important structures for flood control and hydraulic power generation, but they can be vulnerable to seismic activity due to ground movements that…
Abstract
Purpose
Concrete gravity dams are important structures for flood control and hydraulic power generation, but they can be vulnerable to seismic activity due to ground movements that trigger crack propagation.
Design/methodology/approach
To better understand the factors that affect the stability of concrete gravity dams against concrete fracture during earthquakes, a concrete plastic damage model has been utilized with two new expressions to simulate compressive and tensile damage variables.
Findings
The findings showed that the crack patterns were strongly influenced by the concrete’s strength. The simulation results led to the proposal of appropriate concrete properties aimed at minimizing damage. These findings, together with the proposed model, offer significant insights that can enhance the safety and stability of concrete gravity dam structures.
Originality/value
This study offers a comprehensive analysis of concrete behavior under varying grades and introduces simple and robust expressions for evaluating concrete parameters in plastic damage models. The versatility of these expressions enables accurate simulation of stress-strain curves for different grades, resulting in excellent agreement between model results and experimental findings. The simulation of the Koyna Dam case study demonstrates a similarity in crack patterns with previous simulations and field observations.
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Sy Tien Do, Viet Thanh Nguyen and Nghia Hoai Nguyen
This study aims to examine the mutual influence of causes of variation orders (VOs), claims/disputes (CDs) on project performance (PP) and stakeholder performance (SP).
Abstract
Purpose
This study aims to examine the mutual influence of causes of variation orders (VOs), claims/disputes (CDs) on project performance (PP) and stakeholder performance (SP).
Design/methodology/approach
Firstly, this study identifies the VOs, the CDs, criteria for measuring the PP and criteria for measuring the SP. Then, a survey questionnaire is created to collect data from stakeholders in construction projects. Using the factor analysis method, this study discovers the constructs of the VOs, CDs, PP and SP. The relationships among the constructs are then uncovered using a structural equation model.
Findings
The research findings confirm that the VOs and CDs have a direct effect on the PP, as well as the PP’s effect on SP, whereas the VOs and CDs have no effect on the SP. It is strongly recommended that critical factors such as poor management, construction method change, design/scope problems, uncontrollable objective problems, impediment problems, lack of commitment among parties and lack of experience and competence of parties should be given special attention to improve the SP.
Originality/value
The results of the study fill the gap in knowledge by examining the mutual influence of the VOs, the CDs, the PP and the SP. Discovering the mutual influence will assist managers in improving the PP and the SP.
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Nghia Nguyen Trong and Cong Thanh Nguyen
Debt, dividend and investment policy constitutes a company's important financial decisions to determine firm performance. The research emphasizes on the problem of overinvestment…
Abstract
Purpose
Debt, dividend and investment policy constitutes a company's important financial decisions to determine firm performance. The research emphasizes on the problem of overinvestment, a phenomenon that worsens firm operation. Furthermore, it clarifies the moderation role of debt and dividend policy in mitigating the negative effect of overinvestment on firm performance in the case of Vietnamese listed companies.
Design/methodology/approach
The research uses all financial statement of non-financial Vietnamese listed companies on Ho Chi Minh and Hanoi Stock Exchange in the period of 2008–2018. The data are collected from Thomson Reuters Eikon. The final data set is comprised of 669 listed companies. The study measures overinvestment though investment demand function and HP filter. Moreover, the research employs the dynamic model, so it has to apply the SGMM method to deal with the problem of endogeneity caused by the lagged dependent variable.
Findings
The research finds that overinvestment is negatively associated with firm performance. Debt or dividend policy separately can moderate the negative effect of overinvestment on firm performance. However, when these two policies are combined, they lessen the positive interaction impact of each policy due to the substitution between debt and dividend policy.
Research limitations/implications
The research may have two limitations. Firstly, the research measures overinvestment indirectly through investment demand function and HP filter. These two measures only help identify the sign that companies may have the problem of overinvestment because we cannot determine whether they overinvest or not in reality. Secondly, when using interaction variables, the problem of multicollinearity may be higher, and this may adjust the signs and significance level of variables in the models.
Practical implications
Practically, the research proposes three policy recommendations. Firstly, a company can exploit debt or dividend policy to limit excessive free cash flow in order to constrain the problem of overinvestment. Secondly, a company should enhance its corporate governance to resolve agency problems. Thirdly, the government should make the financial sector more transparent and effective to improve monitoring functions of various parties in the capital market.
Social implications
Overinvestment sometimes can cause social issues. Overinvestment means that companies make ineffective investment. If they continue this situation over a long time, companies may have financial distress or even go bankruptcy. As a result, it will slow down economic growth and increase unemployment in the economy.
Originality/value
The research is supposed to make two great contributions to the existing empirical studies in two aspects. Firstly, it is the first attempt to take into consideration the interaction between overinvestment and financial policies. Secondly, it helps enhance the fundamental stance of the agency theory, which supports the interdependence of debt, dividend and investment policy.
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Stuart Hyde, Don Bredin and Nghia Nguyen
This chapter investigates the correlation dynamics in the equity markets of 13 Asia-Pacific countries, Europe and the US using the asymmetric dynamic conditional correlation GARCH…
Abstract
This chapter investigates the correlation dynamics in the equity markets of 13 Asia-Pacific countries, Europe and the US using the asymmetric dynamic conditional correlation GARCH model (AG-DCC-GARCH) introduced by Cappiello, Engle, and Sheppard (2006). We find significant variation in correlation between markets through time. Stocks exhibit asymmetries in conditional correlations in addition to conditional volatility. Yet asymmetry is less apparent in less integrated markets. The Asian crisis acts as a structural break, with correlations increasing markedly between crisis countries during this period though the bear market in the early 2000s is a more significant event for correlations with developed markets. Our findings also provide further evidence consistent with increasing global market integration. The documented asymmetries and correlation dynamics have important implications for international portfolio diversification and asset allocation.
This article traces the transformation of hát bội, a form of traditional opera in Southern Vietnam, from its primary role as entertainment into a religious activity after the…
Abstract
Purpose
This article traces the transformation of hát bội, a form of traditional opera in Southern Vietnam, from its primary role as entertainment into a religious activity after the Reform (Đổi Mới) were enacted in 1986.
Design/methodology/approach
This research is based on ethnological fieldwork complemented by a review of historical documents and of the available literature on hát bội, cultural policies and on data collected from interviews with artists and spectators at the festival at the shrine to the Lady of the Realm.
Findings
Before 1986, hát bội was performed either as a stand-alone entertainment during the fair portion of community festivals or as part of religious ceremonies. The Reform and the accompanying relaxation of state control over religion and culture promoted the resurgence of popular religious fairs across the nation. New opportunities for hát bội to revive opened, artists left state-sponsored troupes to join private companies that catered to religious festivals. But almost exclusive involvement in religious rites has led to artistic stasis for private hát bội troupes.
Originality/value
This research constitutes novel insights of how the Reform in Vietnam affects the transformation of a traditional performance form.
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Suk-Joong Kim and Michael D. McKenzie
Perhaps the most significant development in the global business arena in the post-war period has been the emergence of the Asia-Pacific rim countries as a significant economic…
Abstract
Perhaps the most significant development in the global business arena in the post-war period has been the emergence of the Asia-Pacific rim countries as a significant economic force.
Adnan Rasul, Saravanan Karuppanan, Veeradasan Perumal, Mark Ovinis and Mohsin Iqbal
The stress concentration factor (SCF) is commonly utilized to assess the fatigue life of a tubular T-joint in offshore structures. Parametric equations derived from experimental…
Abstract
Purpose
The stress concentration factor (SCF) is commonly utilized to assess the fatigue life of a tubular T-joint in offshore structures. Parametric equations derived from experimental testing and finite element analysis (FEA) are utilized to estimate the SCF efficiently. The mathematical equations provide the SCF at the crown and saddle of tubular T-joints for various load scenarios. Offshore structures are subjected to a wide range of stresses from all directions, and the hotspot stress might occur anywhere along the brace. It is critical to incorporate stress distribution since using the single-point SCF equation can lead to inaccurate hotspot stress and fatigue life estimates. As far as we know, there are no equations available to determine the SCF around the axis of the brace.
Design/methodology/approach
A mathematical model based on the training weights and biases of artificial neural networks (ANNs) is presented to predict SCF. 625 FEA simulations were conducted to obtain SCF data to train the ANN.
Findings
Using real data, this ANN was used to create mathematical formulas for determining the SCF. The equations can calculate the SCF with a percentage error of less than 6%.
Practical implications
Engineers in practice can use the equations to compute the hotspot stress precisely and rapidly, thereby minimizing risks linked to fatigue failure of offshore structures and assuring their longevity and reliability. Our research contributes to enhancing the safety and reliability of offshore structures by facilitating more precise assessments of stress distribution.
Originality/value
Precisely determining the SCF for the fatigue life of offshore structures reduces the potential hazards associated with fatigue failure, thereby guaranteeing their longevity and reliability. The present study offers a systematic approach for using FEA and ANN to calculate the stress distribution along the weld toe and the SCF in T-joints since ANNs are better at approximating complex phenomena than standard data fitting techniques. Once a database of parametric equations is available, it can be used to rapidly approximate the SCF, unlike experimentation, which is costly and FEA, which is time consuming.