Ho Chi Minh City, Vietnam
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Xu Y.,Hunan University | Li K.,Hunan University | He L.,University of Warwick | Truong T.K.,Hunan University | Truong T.K.,Industry University of Hochiminh City
Journal of Parallel and Distributed Computing | Year: 2013

A new meta-heuristic method, called Chemical Reaction Optimization (CRO), has been proposed very recently. The method encodes solutions as molecules and mimics the interactions of molecules in chemical reactions to search the optimal solutions. The CRO method has demonstrated its capability in solving NP-hard optimization problems. In this paper, the CRO scheme is used to formulate the scheduling of Directed Acyclic Graph (DAG) jobs in heterogeneous computing systems, and a Double Molecular Structure-based Chemical Reaction Optimization (DMSCRO) method is developed. There are two molecular structures in DMSCRO: one is used to encode the execution order of the tasks in a DAG job, and the other to encode the task-to-computing-node mapping. The DMSCRO method also designs four elementary chemical reaction operations and the fitness function suitable for the scenario of DAG scheduling. In this paper, we have also conducted the simulation experiments to verify the effectiveness and efficiency of DMSCRO over a large set of randomly generated graphs and the graphs for real-world problems. © 2013 Elsevier Inc. All rights reserved.


Duong T.,Hunan University | Duong T.,Industry University of Hochiminh City | Jiangang Y.,Hunan University | Truong V.,University of Technical Education Hochiminh City
International Journal of Electrical Power and Energy Systems | Year: 2013

In the deregulated power industry, private power producers are increasing rapidly to meet the increase demand. The purpose of the transmission network is to pool power plants and load centers in order to supply the load at a required reliability, maximum efficiency and at lower cost. As power transfer increases, the power system becomes increasingly more difficult to operate and insecure with unscheduled power flows and higher losses. FACTS devices such as Thyristor Controlled Series Compensator (TCSC) can be very effective to power system security. Proper location of TCSC plays key role in optimal power flow solution and enhancement of system performance without violating the security of the system. This paper applied min cut algorithm to select proper location of TCSC for secured optimal power flow under normal and contingencies operating condition. Proposed method requires a two-step approach. First, the optimal location of the TCSC in the network must be ascertained by min cut algorithm and then, the optimal power flow (OPF) with TCSC under normal and contingencies operating condition is solved. The proposed method was tested and validated for locating TCSC in Six bus, IEEE 14-, IEEE-30 and IEEE-118 bus test systems. Results show that the proposed method is good to select proper location of TCSC for secured OPF.


Nguyen V.-S.,Hunan University | Nguyen V.-S.,Industry University of Hochiminh City | Dong L.-P.,Hunan University | Wang S.-C.,Hunan University | Wang Q.,Hunan University
European Journal of Organic Chemistry | Year: 2015

The first total syntheses of sophoflavescenol (1), flavenochromane C (2), and citrusinol (3) were achieved. These three naturally occurring prenylated or prenyl-cyclized flavonoids have important biological activities such as cytotoxicity against some cancer cell lines, or are lead compounds for the treatment of erectile dysfunction. Starting from 2,4,6-trihydroxyacetophenone and substituted benzaldehydes, the synthesis involved methoxymethyl protection, aldol condensation, cyclization, oxidation with dimethyldioxirane, O-prenylation, microwave-assisted Claisen rearrangement, deprotection, cyclization of the prenyl group, and dehydrogenation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. The overall yields of 1, 2, and 3 were 23, 17, and 16%, respectively. All compounds were characterized by 1H and 13C NMR spectroscopy and MS. The key step of the synthetic route was a regioselective microwave-assisted Claisen rearrangement to form an 8-prenylated flavonoid from a 5-O-prenylflavonoid. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Nguyen V.-S.,Hunan University | Nguyen V.-S.,Industry University of Hochiminh City | Shi L.,Hunan University | Luan F.-Q.,Hunan University | Wang Q.-A.,Hunan University
Acta Biochimica Polonica | Year: 2015

Kaempferide (3,5,7-trihydroxy-4'-methoxyflavone, 1), a naturally occurring flavonoid with potent anticancer activity in a number of human tumour cell lines, was first semisynthesized from naringin. Based on Mannich reaction of kaempferide with various secondary amines and formaldehyde, nine novel kaempferide Mannich base derivatives 2-10 were synthesized. The aminomethylation occurred preferentially in the position at C-6 and C-8 of the A-ring of kaempferide. All the synthetic compounds were tested for antiproliferative activity against three human cancer cell lines (Hela, HCC1954, SK-OV-3) by the standard MTT method. The results showed that compounds 1, 2 and 5-10 were more potent against Hela cells with IC50 values of 12.47-28.24 μM than the positive control cis-platin (IC50 41.25 μM), compounds 5, 6, 8 and 10 were more potent against HCC1954 cells with IC50 values of 8.82-14.97 μM than the positive control cis-platin (IC50 29.68 μM), and compounds 2, 3, 5, 6 and 10 were more potent against SK-OV-3 cells with IC50 values of 7.67-18.50 μM than the positive control cis-platin (IC50 21.27 μM).


Nguyen V.-S.,Hunan University | Nguyen V.-S.,Industry University of Hochiminh City | Shi L.,Hunan University | Li Y.,Hunan University | Wang Q.-A.,Hunan University
Letters in Organic Chemistry | Year: 2014

The novel total synthesis of icaritin (1), naturally occurring with important bioactive 8-prenylflavonoid, was performed via a reaction sequence of 8 steps including Baker-Venkataraman reaction, chemoselective benzyl or methoxymethyl protection, dimethyldioxirane (DMDO) oxidation, O-prenylation, Claisen rearrangement and deprotection, starting from 2,4,6-trihydroxyacetophenone and 4-hydroxybenzoic acid in overall yields of 23%. The key step was Claisen rearrangement under microwave irradiation. MS, 1H and 13C NMR techniques have been used to confirm the structures of all synthetic compounds. © 2014 Bentham Science Publishers.


Solving cooperative problems for multi-agent systems, in which the agent's artificial behaviors are similar to naturally biological behaviors of agents in practice, is a major challenge. The problems become more complex if the controlled agents are multi-input and multi-output (MIMO) nonlinear systems lacking knowledge of internal system dynamics and affected by external disturbances. In this paper, firstly, based on adaptive dynamic programming, three neural networks (NNs) (actor/disturber/critic) of control schemes for two-player games are integrated into the structure with only one NN, known as integrated NN (INN), with the aim of reducing computational complexity and waste of resources. Secondly, an INN weight update law and an online control algorithm, which updates parameters in one iterative step, are designed to find H∞ optimal cooperative control solutions. With the aid of Lyapunov theory, we prove that the INN weight approximation errors and the cooperative tracking errors are uniformly ultimately bounded (UUB), and the system parameters converge to the approximately optimal values. Finally, two simulation studies, one of which is compared to three-NN structures in existing literature, are carried out to show the effectiveness of the proposed INN structure. © 2016 Elsevier B.V.

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