Revisiting Customer Complaint Intention: A Case Study of Mobile Service Users in Vietnam

Liem Thanh NGUYEN,Minh Hoang DANG,Thu Duyen TAT,Dinh Gia Trung TRAN 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.9

In the mobile industry, customer complaints play a significant role in retaining customer loyalty to the services provided. Thanks to user complaints, mobile service providers can effectively identify problems and then propose solutions to adapt or improve their services. Hence, it’s critical to understand the relationship between consumer complaints and satisfaction with mobile services. While several studies have shown that customer satisfaction is an intermediary variable that explains customer complaint intention, there have been few studies on the relationship between pre-determinants of their satisfaction, leaving a gap in our understanding of customer complaint intention. To demonstrate an in-depth approach to this matter, authors revisit justice theory and suggest trust and perceived responsibility variables be combined into a research model. A cross-section survey was conducted to collect data from 265 mobile services users of the three biggest mobile service providers in Kien Giang Province, Vietnam. This study employed Structural Equation Modeling (SEM) method to analyze the samples collected. The result showed that customer complaint intention is affected by distributive justice, interactional justice, trust but not procedural justice. Additionally, the moderating role of the perceived responsibility variable to the relationship between customer satisfaction and complaint intention is also proved.

An Adaptive Time-Based Kiln Schedule using Forward Chaining Approach

Liem Yenny Bendatu,YAHYA BERNARDO NUGROHO 대한산업공학회 2018 Industrial Engineeering & Management Systems Vol.17 No.2

Sequential decision problems have been recognized as a strategy which uses search techniques to generate sequence of actions that leads to good states. Current sequential decision problems require a given set of actions while the ac-tions in kiln dry wood process relies on various factors that may diverse from time to time. Predefined kiln schedule has been available to assist kiln operator’s decision making. However, routine decision would be highly affected by either drying problems or customer complaints. Although many works attempt to apply mathematical model and some experiments to predict kiln dry process, relatively little attention has been paid to the problem of discovery sequential pattern from kiln dry wood process data. This study proposes a framework as a decision support for sequential decision problems, specifically, for kiln dry wood process. The framework starts with preprocessing the kiln process data, follows with mapping the preprocessed data into a log, and ends with analyzing as well as verifying the process using quality of predictions performance measures. A case study on real datasets in the field of kiln dry wood process indicate that historical data contain patterns which are able to generate kiln schedule and associated to possible future behavior

A feedforward neural network fuzzy grey predictor-based controller for force control of an electro-hydraulic actuator

Liem, D. T.,Truong, D. Q.,Park, H. G.,Ahn, K. K. Springer Science + Business Media 2016 International Journal of Precision Engineering and Vol.17 No.3

<P>Recently, electro-hydraulic actuators (EHAs) have shown significant advantages over conventionally valve-controlled actuators. EHAs have a wide range of applications where force or position control with high accuracy is exceedingly necessary. Besides the benefits, however, EHA is a highly complex nonlinear system which causes challenges for both modeling and control tasks. This paper aims to develop an effective control approach for force control of a typical EHA system. This control scheme is considered as an advanced combination of a feedforward neural network - based PID (FNNPID) controller and a fuzzy grey predictor (FGP), shortened as feedforward neural network fuzzy grey predictor (FNNFGP). Here, the FNNPID controller is used to drive the system to desired targets. Additionally, a learning mechanism with robust checking conditions is implemented into the FNNPID in order to optimize online its parameters with respect to the control error minimization. Meanwhile, the FGP predictor with self-tuning ability of the predictor step size takes part in, first, estimating the system output in the near future to optimize the controller parameters in advance and, second, creating a compensating control signal accordingly to the system perturbations and, consequently, improving the control performance. Real-time experiments have been carried out to investigate the effectiveness of the proposed control approach.</P>

Hysteresis Modeling of Magneto-Rheological Damper using Self-Tuning Lyapunov-based Fuzzy Approach

Liem, Dao Thanh,Truong, Dinh Quang,Ahn, Kyoung Kwan Korean Society for Precision Engineering 2015 International Journal of Precision Engineering and Vol.16 No.1

Magneto-rheological (MR) fluid damper is a semi-active control device that has recently received more attention because they offer the adaptability of active control devices without requiring the associated large power sources. But inherent nonlinear nature of the MR fluid damper is one of the challenging aspects for utilizing this device to achieve the high performance. So development of an accurate MR fluid damper model is necessary to take the advantages from its unique characteristics. The focus of this paper is to develop an alternative method for modeling a MR fluid damper by using a so-called self-tuning Lyapunov-based fuzzy model (STLFM). Here, the model is constructed in the form of a center average fuzzy interference system, of which the fuzzy rules are designed based on the Lyapunov stability condition. In addition, in order to optimize the STLFM, the back propagation learning rules are used to adjust the fuzzy weighting net. Firstly, experimental data of a damping system using this damper is used to optimize the model. Next, the optimized model is used to estimate online the damping performance in the real-time conditions. The modeling results prove convincingly that the developed model could represent satisfactorily the behavior of the MR fluid damper.

한국⋅베트남 자동차산업 국제경쟁력 분석: Porter의 다이아몬드 모델을 중심으로

Thanh Liem, Nguyen,현인규 한국유통경영학회 2022 유통경영학회지 Vol.25 No.1

Purpose: The purpose of this paper is to establish a development strategy for the Vietnamese automobile industry using the development process of the Korean automobile industry as a model. To this end, Michael Porter’s Diamond Model is used to compare and analyze the international competitiveness of the automobile industry in Korea and Vietnam to derive meaningful results. Research design, data, and methodology: This study has examined the classical theories related to competition theory of Porter’s Diamond Model, the authors will present the analysis of Korea and Vietnam’s automobile industry with 4 main factors: Factor Conditions, Demand Conditions, Related and Supporting Industries, and Firm Strategy, Structure, and Rivalry. The authors establish research model through literature reviews and data was collected from reliable official sources of two countries and international organizations. The analytical method is normalize the data and assign an index value of 100 to the country with the higher data value, from which the index value of the other country is calculated. The value of each of the four determinants factors is the average of the dependent factors. Results: As a result of the analysis, it was found that the international competitiveness of the Vietnamese automobile industry has competitiveness in terms of demand and support industries, and that international competitiveness, including factor conditions, corporate strategies, structures, and competition, is low. On the other hand, the international competitiveness of the Korean automobile industry was greater than that of Vietnam in the four determinants as expected. Implications: Strategic implications for the development of the Vietnamese automobile industry were presented focusing on the four determinants based on the analysis results. In conclusion, in order to develop the automobile industry, balanced growth in all fields of the country is necessary. In addition, if t he state has a firm will, necessary or insufficient factors can be achieved through cooperation with foreign companies.

Correlation between Tensile and Flexural Behavior of Ultra-high-performance Fiber Reinforced Concrete (UHPFRC)

Duy Liem Nguyen(운위림),Dong Joo Kim(김 동 주),Kyung Taek Koh(고경택),Geum Sung Ryu(류금성) 한국콘크리트학회 2012 한국콘크리트학회 학술대회 논문집 Vol.2012 No.11

Evaluating Load-Carrying Capacity of Short Composite Beam Using Strain-Hardening HPFRC

Duy-Liem Nguyen,Vu-Tu Tran,Ngoc-Thanh Tran,Tri-Thuong Ngo,Manh-Tuan Nguyen 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.4

The main goal of this study was to develop the short composite beams using strain-hardening fiber-reinforced concrete (S_HPFRC) and conventional concrete (CC) together. Firstly, the sensitivity of the hybrid fiber system to the enhancement of mechanical properties of plain high performance concrete (P_mortar) was experimentally studied. The ranking of the mechanical properties in terms of sensitive coefficient was observed as follows: direct tensile > splitting tensile > compressive. Next, the responses of short composite beams with various thicknesses of S_HPFRC were investigated under a three-point bending test (3PBT). Six beams with no reinforcement (type A) and six beams with reinforcement were tested (type B) with their identical dimensions of 150 × 150 × 300 mm (depth × width × span length). The compressive strength of S_HPFRC and CC were about 80.65 MPa and 21.12 MPa, respectively. Most of the composite beams were observed to fail in shear mode. And, there was a favorable effect on enhancing the load-carrying capacity of a beam as S_HPFRC was placed at a critical tensile zone. Finally, based on the test data, the analytical equations were proposed for the purpose of predicting shear resistance of the S_HPFRC - CC beam.

베트남 자동차산업의 활성화 전략에 관한 연구: SWOT/AHP 분석기법을 중심으로

Thanh Liem, Nguyen,현인규 한국유통경영학회 2022 유통경영학회지 Vol.25 No.4

Purpose: This study aims to determine the current state of the Vietnamese automobile industry. In particular, it aims to provide valuable information to assist the Vietnamese government in developing its strategy for activating the automobile industry, as well as companies in developing their entry strategy. Research design, data, and methodology: This study uses the combined SWOT/ AHP model. T he A na lytic Hierarchy Process (AHP) is used to quantitatively analyze the SWOT matrix. In order to gather data, documents and reports from the Vietnamese government and international agencies were used to construct a questionnaire. Results: The summary of the research results are as follows. Among the factors contributing to Vietnam’s automobile industry revitalization strategy, “a sta ble macro environment” played a significant role. In addition, among the strong factors, the factors of “adequate manpower at low cost” and “a fa vora ble position to join ASEAN and Asian automobile supply chains,” were found to be very important. Also, among the external environmental opportunity factors, the “deep participation of ATIGA in ASEAN and Asia’s automobile supply chain” and the “potential automobile consumption market” were considered. As a result, the Vietnamese government may consider the above factors when ma king a n a ctiva tion s tra tegy f or t he Vietnamese automobile industry in the future. Implications: The following strategic implications are derived from this study. The SO strategy must be revitalized by creating conditions for imported cars to enter the Vietnamese ma rket, while t he S T stra tegy must be s trengthened by protecting domestic autos. Technology transfer, collaboration with foreign companies, and localization should all be included in the WO strategy. Lastly, the WT strategy requires Vietnamese related agencies to develop binding regulations on imported cars and to quickly improve the rate of localization.

Effect of Temperature and Relative Humidity on Electrical Resistivity of Fiber Reinforced Concretes

NGUYEN, Duy Liem(운위림),KIM, Dong Joo(김동주) 한국콘크리트학회 2014 한국콘크리트학회 학술대회 논문집 Vol.2014 No.10

Hysteresis Modeling of Magneto-Rheological Damper using Self-Tuning Lyapunov-based Fuzzy Approach

Dao Thanh Liem,DINH QUANG TRUONG,안경관 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

Magneto-rheological (MR) fluid damper is a semi-active control device that has recently received more attention because they offerthe adaptability of active control devices without requiring the associated large power sources. But inherent nonlinear nature of theMR fluid damper is one of the challenging aspects for utilizing this device to achieve the high performance. So development of anaccurate MR fluid damper model is necessary to take the advantages from its unique characteristics. The focus of this paper is todevelop an alternative method for modeling a MR fluid damper by using a so-called self-tuning Lyapunov-based fuzzy model(STLFM). Here, the model is constructed in the form of a center average fuzzy interference system, of which the fuzzy rules aredesigned based on the Lyapunov stability condition. In addition, in order to optimize the STLFM, the back propagation learning rulesare used to adjust the fuzzy weighting net. Firstly, experimental data of a damping system using this damper is used to optimize themodel. Next, the optimized model is used to estimate online the damping performance in the real-time conditions. The modeling resultsprove convincingly that the developed model could represent satisfactorily the behavior of the MR fluid damper.