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Flying-Capacitor Modular Multilevel Converters with Coupled Inductors for Medium-Voltage Motor Drive System (중전압 전동기 구동시스템을 위한 결합 인덕터를 갖는 플라잉 커패시터 MMC)

  • Le, Duc Dung;Lee, Dong-Choon
    • Proceedings of the KIPE Conference
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    • 2018.11a
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    • pp.173-174
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    • 2018
  • This paper proposes the coupled inductor instead of four non-coupled inductors in each leg of the flying-capacitor modular multilevel converter (MMC) to reduce the dimension, weight and cost of the magnetic core. The simulation results have verified the effectiveness of the proposed coupled inductor.

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ON THE UNIQUENESS OF MEROMORPHIC FUNCTION AND ITS SHIFT SHARING VALUES WITH TRUNCATED MULTIPLICITIES

  • Nguyen, Hai Nam;Noulorvang, Vangty;Pham, Duc Thoan
    • Bulletin of the Korean Mathematical Society
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    • v.56 no.3
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    • pp.789-799
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    • 2019
  • In this paper, we deal with unicity of a nonconstant zero-order meromorphic function f(z) and its shift f(qz) when they share four distinct values IM or share three distinct values with multiplicities truncated to level 4 in the extended complex plane, where $q{\in}\mathbb{C}{\setminus}\{0\}$. We also give an uniqueness result for f(z) sharing sets with its shift.

Between Two Deaths: Representation of the 1968 Huế Massacre 1968 in "Song for the Dead" of Trịnh Công Sơn

  • Anh, Lo Duc
    • SUVANNABHUMI
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    • v.12 no.1
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    • pp.143-156
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    • 2020
  • The 1968 Huế Massacre is a horrifying event rarely mentioned today in Vietnamese history and mass media. It is forgotten perhaps because it is simply indescribable. This study reads a song by Vietnamese musician Trịnh Công Sơn, where he attempted to chronicle the catastrophic images of the massacre. We use the notion of symbolic death in psychoanalysis to interpretation of the song, and shed a new light on how it captured this historical event which eludes understanding.

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FINITENESS AND VANISHING RESULTS ON HYPERSURFACES WITH FINITE INDEX IN ℝn+1: A REVISION

  • Van Duc, Nguyen
    • Bulletin of the Korean Mathematical Society
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    • v.59 no.3
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    • pp.709-723
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    • 2022
  • In this note, we revise some vanishing and finiteness results on hypersurfaces with finite index in ℝn+1. When the hypersurface is stable minimal, we show that there is no nontrivial L2p harmonic 1-form for some p. The our range of p is better than those in [7]. With the same range of p, we also give finiteness results on minimal hypersurfaces with finite index.

CIRCULAR SPECTRUM AND ASYMPTOTIC PERIODIC SOLUTIONS TO A CLASS OF NON-DENSELY DEFINED EVOLUTION EQUATIONS

  • Le Anh Minh;Nguyen Ngoc Vien
    • Communications of the Korean Mathematical Society
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    • v.38 no.4
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    • pp.1153-1162
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    • 2023
  • In this paper, for the bounded solution of the non-densely defined non-autonomous evolution equation, we present the condition for asymptotic periodicity by using the circular spectral theory of functions on the half line and the extrapolation theory of non-densely defined evolution equation.

Prediction of concrete strength in presence of furnace slag and fly ash using Hybrid ANN-GA (Artificial Neural Network-Genetic Algorithm)

  • Shariati, Mahdi;Mafipour, Mohammad Saeed;Mehrabi, Peyman;Ahmadi, Masoud;Wakil, Karzan;Trung, Nguyen Thoi;Toghroli, Ali
    • Smart Structures and Systems
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    • v.25 no.2
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    • pp.183-195
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    • 2020
  • Mineral admixtures have been widely used to produce concrete. Pozzolans have been utilized as partially replacement for Portland cement or blended cement in concrete based on the materials' properties and the concrete's desired effects. Several environmental problems associated with producing cement have led to partial replacement of cement with other pozzolans. Furnace slag and fly ash are two of the pozzolans which can be appropriately used as partial replacements for cement in concrete. However, replacing cement with these materials results in significant changes in the mechanical properties of concrete, more specifically, compressive strength. This paper aims to intelligently predict the compressive strength of concretes incorporating furnace slag and fly ash as partial replacements for cement. For this purpose, a database containing 1030 data sets with nine inputs (concrete mix design and age of concrete) and one output (the compressive strength) was collected. Instead of absolute values of inputs, their proportions were used. A hybrid artificial neural network-genetic algorithm (ANN-GA) was employed as a novel approach to conducting the study. The performance of the ANN-GA model is evaluated by another artificial neural network (ANN), which was developed and tuned via a conventional backpropagation (BP) algorithm. Results showed that not only an ANN-GA model can be developed and appropriately used for the compressive strength prediction of concrete but also it can lead to superior results in comparison with an ANN-BP model.

Depiction of concrete structures with seismic separation under faraway fault earthquakes

  • Luo, Liang;Nguyen, Hoang;Alabduljabbar, Hisham;Alaskar, Abdulaziz;Alrshoudi, Fahed;Alyousef, Rayed;Nguyen, Viet-Duc;Dang, Hoang-Minh
    • Advances in concrete construction
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    • v.9 no.1
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    • pp.71-82
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    • 2020
  • One of the most suitable methods in structural design is seismic separator. Lead-Rubber Bearing (LRB) is one of the most well-known separation systems which can be used in different types of structures. This system mitigates the earthquake acceleration prior to transferring to the structure efficiently. However, the performance of this system in concrete structures with different heights have not been evaluated thoroughly yet. This paper aims to evaluate the performance of LRB separation system in concrete structures with different heights. For this purpose, three, 16, and 23 story concrete structures are equipped by LRB and exposed to a far-field earthquake. Next, a time history analysis is conducted on each of the structures. Finally, the performance of the concrete structures is compared with each other in the term of their response to the earthquakes and the formation of plastic hinges. The results of the paper show that the rate of change in acceleration response and the ratio of drift along the height of 8 and 23 stories concrete structures are more than those of the 16-stories, and the use of LRB reduces the formation of plastic joints.

Determinants of Accountants' Loyalty Underlying Investment Management: Evidence from FDI Firms in Thanglong Industrial Park

  • NGUYEN, Dang Huy;HA, Son Tung;TRAN, Manh Linh;NGUYEN, Duc Thang;NGUYEN, Thi Xuan Hong;NGUYEN, Dieu Linh;DO, Duc Tai
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.4
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    • pp.287-297
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    • 2020
  • The research aims to investigate the impact levels of determinants on the loyalty of accountants to FDI firms underlying investment management in Thanglong Industrial Park in Hanoi, Vietnam. We conducted a questionnaire consisting of 31 observation variables with a 5-point Likert scale. Independent variables were measured from 1 "without effect" to 5 "strongly". The method of data collection was done through the survey and subjects are accountants in FDI firms doing business in Thanglong Industrial Park in Hanoi. After checking the information on the votes, there are 120 questionnaires with full information for data entry and analysis, This study employs Cronbach's Alpha test, and regression model. The results show that seven determinants including Working environment, The characteristics of working; Training, promotion prospects and development; Income, Personal characteristic, Collective work together and The method of leading had positive relationships with the loyalty of accountants. Based on the findings, some recommendations are given related to such determinants to improve the loyalty of accountants of FDI firms in general and FDI firms in Thanglong Industrial Park in Hanoi in particular. With which, those firms can enhance performance, reduce financial strain, saving on investment in the recruiting process of new staff, increase profitability to ensure investment management.

Factors Affecting Savings Deposit Decision of Individual Customers: Empirical Evidence from Vietnamese Commercial Banks

  • VUONG, Bui Nhat;TUNG, Dao Duy;GIAO, Ha Nam Khanh;DAT, Ngo Tan;QUAN, Tran Nhu
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.7
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    • pp.293-302
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    • 2020
  • Capital mobilization is a traditional business of commercial banks and is one of the core foundations for the development of a bank. Capital mobilization is the main input in the operation of a bank, and this is also the basis for generating output for credit activities as well as other banking activities. This study aims to determine the main factors that affect the decisions of individual customers to put savings deposit in Vietnamese commercial banks. Survey data collected from 403 individual customers were analyzed to provide evidence. The results from the multiple regression analysis by using SPSS software revealed that all scales in this study were reliable, and there were six components impacting the savings deposit decision of individual customers from the strongest to the weakest in the following order: the form of promotion, bank brand, service quality, interest rate policy, and employee knowledge and attitude. Besides, the finding showed customers who have high income tend to have a stronger decision on savings deposits in commercial banks. The main findings of this article provide some empirical implications for marketers in banks and serve as a suggestion to improve these factors in order to retain and attract individual customers' savings deposit decisions.