http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Machine Fault Diagnosis and Prognosis: The State of The Art
Tung, Tran Van,Yang, Bo-Suk Korean Society for Fluid machinery 2009 International journal of fluid machinery and syste Vol.2 No.1
Machine fault diagnostic and prognostic techniques have been the considerable subjects of condition-based maintenance system in the recent time due to the potential advantages that could be gained from reducing downtime, decreasing maintenance costs, and increasing machine availability. For the past few years, research on machine fault diagnosis and prognosis has been developing rapidly. These publications covered in the wide range of statistical approaches to model-based approaches. With the aim of synthesizing and providing the information of these researches for researcher's community, this paper attempts to summarize and classify the recent published techniques in diagnosis and prognosis of rotating machinery. Furthermore, it also discusses the opportunities as well as the challenges for conducting advance research in the field of machine prognosis.
Fault diagnosis of induction motor based on decision trees and adaptive neuro-fuzzy inference
Tran, Van Tung,Yang, Bo-Suk,Oh, Myung-Suck,Tan, Andy Chit Chiow Elsevier 2009 expert systems with applications Vol.36 No.2
<P><B>Abstract</B></P> <P>This paper presents a fault diagnosis method based on adaptive neuro-fuzzy inference system (ANFIS) in combination with decision trees. Classification and regression tree (CART) which is one of the decision tree methods is used as a feature selection procedure to select pertinent features from data set. The crisp rules obtained from the decision tree are then converted to fuzzy if-then rules that are employed to identify the structure of ANFIS classifier. The hybrid of back-propagation and least squares algorithm are utilized to tune the parameters of the membership functions. In order to evaluate the proposed algorithm, the data sets obtained from vibration signals and current signals of the induction motors are used. The results indicate that the CART–ANFIS model has potential for fault diagnosis of induction motors.</P>
Tung Van TRAN,Tri M. HOANG 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.4
This study examines the effect of international capital flows on corporate capital structures in Vietnam by analyzing panel data from all non-financial listed firms from 2005 to 2014 using pooled ordinary least square (OLS) with a variance estimator. The analysis includes a comparison of the signs and significance of the variable coefficients from the perking order and static trade-off theories to the empirical results to determine the optimum approach to the corporate capital structure given Vietnam’s high-inflation environment. The results indicate that international capital flows have a positive relation to the debt ratio in the long term, and the relationship is more robust for 2005–2009 than for 2010–2014. Corporate capital structures adjusted to changes in the business environment in different sub-periods (2005–2009 and 2010–2014). When the economic environment became more favorable, the pecking order theory’s predictive power increased, and that of trade-off theory lessened. Manufacturing and non-manufacturing firms required different capital structure decisions to fuel their operations and grow under foreign competition. The analysis demonstrates that firms should intensify their use of long-term debt relative to the availability of capital, which is an implication not only for firms in particular but also for industrial innovation overall.
The Roles of Health Consciousness and Service Quality toward Customer Purchase Decision
TRAN, Tung Anh,PHAM, Ngan Thi,PHAM, Kien Van,NGUYEN, Linh Cam Tran Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.8
The study investigates how marketing mix factors are mediated by health consciousness and service quality in creating fresh fruit buying decisions of customers in Vietnam. This study employs samples of customers in Vietnam via the survey questionnaire. The authors have used a total of 256 responses that acquired the valid criteria. The compound of data analysis comprises reliability test, validity test, exploratory factor analysis, group analysis and multiple regression analysis to structure the hypothesized model. Respectively, the structural equation model (SEM) is applied to conduct the multiple multivariate equations. By the assumption of causal-effect relationship between independent variables such as marketing mixed factors, and mediator as health consciousness and service quality, which potentially impact on purchase decision; the SEM method is deployed. The results reveal that consumers have paid no attention to the marketing mix factors, but they care much about service quality and health consciousness. Thus, health consciousness and service quality are effective mediators. These findings are new and contribute to the consumer behavior and retail marketing literature. The findings of this study can provide assistance to managers in the given field to understand more easily the consumer behavior about fresh fruits, then improve their own performance.
Data-driven approach to machine condition prognosis using least square regression tree
Van Tung Tran,양보석 대한기계학회 2009 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.23 No.5
Machine fault prognosis techniques have been profoundly considered in the recent time due to their substantial profit for reducing unexpected faults or unscheduled maintenance. With those techniques, the working conditions of components, the trending of fault propagation, and the time-to-failure are precisely forecasted before they reach the failure thresholds. In this work, we propose the least square regression tree (LSRT) approach, which is an extension of the classification and regression tree (CART), in association with one-step-ahead prediction of time-series forecasting techniques to predict the future machine condition. In this technique, the number of available observations is first determined by using Cao’s method and LSRT is employed as a prediction model in the next step. The proposed approach is evaluated by real data of a low methane compressor. Furthermore, a comparative study of the predicted results obtained from CART and LSRT are carried out to prove the accuracy. The predicted results show that LSRT offers the potential for machine condition prognosis.
A dense, pinholes-free pure cubic phase CsPbBr3 nanocrystals film for high-performance photodetector
Thanh-Tung Duong,Phuong-Nam Tran,Tuan-Pham Van,Duy-Hung Nguyen,Van-Dang Tran 대한금속·재료학회 2024 ELECTRONIC MATERIALS LETTERS Vol.20 No.2
This study demonstrates a simple centrifugal coating method to prepare high-quality pure cubic phase CsPbBr 3 nanocrystalfi lm. The resultant perovskite layers possess a uniform and dense 500 nm-thick, with a bandgap of 2.38 eV, a low trap-statedensity of 6.9 × 10 − 15 cm − 3 , and carrier mobility of approximately 19.8 cm 2 V − 1 s − 1 . Furthermore, CsPbBr 3 NCs-basedself-powered photodetectors with high charge carriers’ charge transfer are fabricated. The device shows a low dark currentdensity of 1.93 × 10 − 7 A/cm 2 at room temperature. Such photodetectors show the highest responsivity of 3.0 AW − 1 ,specifi c detectivity of 1.2 × 10 13 Jones, and external quantum effi ciency (EQE) of 920% at zero bias voltage. The proposedmethod shows signifi cant promise for use in the lab fabrication of optoelectronic devices based on thin fi lms of nanocrystalperovskite materials.
Parametric Resonance of Acoustic and Optical Phonons in a Doped Semiconductor Superlattice
Tran Cong Phong,Luong Van Tung,Nguyen Quang Bau 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.4
The parametric resonance of acoustic and optical phonons in a doped superlattice with a nondegenerative electron gas in the presence of a laser field is theoretically predicted by using a set of quantum transport equations for the phonons. Dispersions of the resonant phonon frequency and the threshold amplitude of the field for parametric amplification of the acoustic phonons are obtained. The amplitude is also estimated for realistic semiconductor models
Chemical Components from the Vietnamese Soft Coral Lobophytum sp.
Tung, Nguyen Huu,Minh, Chau Van,Kiem, Phan Van,Huong, Hoang Thanh,Nam, Nguyen Hoai,Cuong, Nguyen Xuan,Quang, Tran Hong,Nhiem, Nguyen Xuan,Hyun, Jae-Hee,Kang, Hee-Kyoung,Kim, Young-Ho 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.4
Chromatographic separation resulted in the identification of one new squalene derivative, named lobophytene (1), three cembranoid diterpenes (2-4), and two sterols (5 and 6) from the Vietnamese marine soft coral Lobophytum sp. Their structures were identified on the basis of extensive spectroscopic data and comparison of those with reported data. Compounds 1 and 2 showed significant cytotoxic activities against lung (A549) and colon (HT-29) cell lines with $IC_{50}$ values of 8.2 and $5.6\;{\mu}M$ for 1; 5.1 and $1.8\;{\mu}M$ for 2, respectively.