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Quoc C.T.,Danang University of Education
Proceedings of the 2013 13th International Conference on Computational Science and Its Applications, ICCSA 2013 | Year: 2013

The problem of finding maximum flow in network graph is extremely interesting and practically applicable in many fields in our daily life, especially in transportation. Therefore, a lot of researchers have been studying this problem in various methods. In this paper, we offer a different method to solve this problem that is the postflow-pull method with complexity equal to complexity used pre-flow push by A. Goldberg and R.E. Tarjan 1986. In addition, to take more advantage of multi-core architecture of the parallel computing system, we build this algorithm on multiple processors. This is a completely new method not being announced in the world. The results of this paper are basically systematized and proven. The idea of this algorithm is using multi processors to work in parallel by postflow-pull alogrithm. Among these processors, there is one main processor managing data, sending data to the sub processors, receiving data from the sub-processors. The sub-processors simultaneously execute their work and send their data to the main processor until the job is finished, the main processor will show the results of the problem. © 2013 IEEE.


Cuong H.H.,Quangnam University | Vi Dang H.,Danang University of Education | Nhut Pham N.M.,Danang University of Education | Nguyen T.T.,University of Engineering and Technology
Advances in Intelligent Systems and Computing | Year: 2015

In this paper, we study the resource allocation at the infrastructure level, instead of studying how to map the physical resources to virtual resources for better resource utilization in a cloud computing environment. We propose a new algorithm to resource allocation for infrastructure that dynamically allocate the virtual machines among the cloud computing applications based on approach algorithm deadlock detection and can use the threshold method to optimize the decision of resource reallocation. We have implemented and performed our algorithm proposed by using CloudSim simulator. The experiment results show that our algorithm can quickly detect deadlock and then resolve the situation of approximately orders of magnitude in practical cases. © Springer International Publishing Switzerland 2015.


Bau N.Q.,Vietnam National University, Hanoi | Hieu N.V.,Danang University of Education
Progress in Electromagnetics Research Symposium | Year: 2014

The influence of the electromagnetic wave on the quantum acoustomagnetoelectric (QAME) field in a quantum well with a parabolic potential (QWPP) is investigated for an acoustic wave whose wavelength λ = 2π/q is smaller than the mean free path l of the electrons and in the region ql 蠐 1 (where q is the acoustic wave number). The dependence of the QAME field EQAME on the frequency of external acoustic wave ωq, the temperature T, the magnetic field B, the amplitude E0 and frequency Ω of the electromagnetic wave are obtained by using the quantum kinetic equation. Numerical calculation is done, and the result is discussed for a typical AlAs/GaAs/AlAs QWPP. The computational results show that the dependence of the QAME field EQAME on the external acoustic wave frequency ωq, the frequency of electromagnetic wave Ω and the magnetic field B is non-monotonic, the cause of appearance peaks attributes the transition between mini-bands N → N′. The quantum theory of the QAME current in a QW is newly developed.


Nguyen H.H.C.,Quangnam University | Le D.-N.,Haiphong University | Le V.S.,Danang University of Education | Thuy N.T.,Hanoi University of Science and Technology
Frontiers in Artificial Intelligence and Applications | Year: 2015

An allocation of resources to a virtual machine specifies the maximum amount of each individual element of each resource type that will be utilized, as well as the aggregate amount of each resource of each type. In this paper, we present an new approach to improve the deadlock detection algorithm, to schedule the policies of resource supply for allocating multiple resources to competing services running in virtual machines on a heterogeneous distributed platform. We introduce the matrix representation of a deadlock detection problem and some essential features can be mapped into a cloud architecture which can handle multiple requests/grants simultaneously and can detect multiple deadlocks in linear time, hence, significantly improving performance. Our algorithm proposed has a run time complexity of O(min(m,n)), where m is the number of resources and n is the number of processes. The experiments also compare the performance of our algorithm proposed approach with other related works.


PubMed | University of Minnesota, Endangered Primate Rescue Center, Philadelphia Zoological Garden, GreenViet Biodiversity Conservation Center and 4 more.
Type: Journal Article | Journal: Proceedings of the National Academy of Sciences of the United States of America | Year: 2016

The primate gastrointestinal tract is home to trillions of bacteria, whose composition is associated with numerous metabolic, autoimmune, and infectious human diseases. Although there is increasing evidence that modern and Westernized societies are associated with dramatic loss of natural human gut microbiome diversity, the causes and consequences of such loss are challenging to study. Here we use nonhuman primates (NHPs) as a model system for studying the effects of emigration and lifestyle disruption on the human gut microbiome. Using 16S rRNA gene sequencing in two model NHP species, we show that although different primate species have distinctive signature microbiota in the wild, in captivity they lose their native microbes and become colonized with Prevotella and Bacteroides, the dominant genera in the modern human gut microbiome. We confirm that captive individuals from eight other NHP species in a different zoo show the same pattern of convergence, and that semicaptive primates housed in a sanctuary represent an intermediate microbiome state between wild and captive. Using deep shotgun sequencing, chemical dietary analysis, and chloroplast relative abundance, we show that decreasing dietary fiber and plant content are associated with the captive primate microbiome. Finally, in a meta-analysis including published human data, we show that captivity has a parallel effect on the NHP gut microbiome to that of Westernization in humans. These results demonstrate that captivity and lifestyle disruption cause primates to lose native microbiota and converge along an axis toward the modern human microbiome.


Pham N.M.N.,Vietnam Korea Friendship Information Technology College | Nguyen T.H.,Vietnam Korea Friendship Information Technology College | Le V.S.,Danang University of Education
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

Nowadays, one of the issues in cloud computing is resource optimizing for virtual services to enhance IaaS service performance and meet the requirements of resource exploitation effectively. In this paper, we seek the approach of multi-dimensional resource allocation based on heterogeneous shared hosting platforms for virtual services. We construct the problem as an optimized formulation that uses a linear programming to minimize the number of physical machines. The solution for this formulation is applying the Greedy algorithms to solve and evaluate via emulation-based program. © Springer-Verlag Berlin Heidelberg 2016.


Hong T.T.,Danang University of Education | Dung P.T.,Vietnam Academy of Science and Technology | Quang V.X.,Duy Tan University
Journal of Electronic Materials | Year: 2016

Tellurite glass doped with different concentrations of Eu3+ ions has been prepared by the conventional melting process. Photoluminescence, Raman spectra, phonon side-band spectra, and Judd–Ofelt analysis were carried out. Some spectroscopic parameters were estimated to predict the luminescence efficiency of the materials. The energy transfer between the rare-earth ions was observed, and a model for its cross-relaxation was proposed and quantitatively estimated. The charged intrinsic defects in the form of nonbridging oxygen (NBO) were determined, and the energy transfer between NBO and rare-earth ions observed. The energy-transfer-induced Eu3+ photoluminescence enhancement in tellurite glass is studied. © 2016 The Minerals, Metals & Materials Society


Van Son P.,University of Tsukuba | Van Son P.,Danang University of Education | Fujitsuka A.,University of Tsukuba | Ohshima K.-I.,University of Tsukuba
Journal of Electronic Materials | Year: 2012

In an effort to improve the performance of lead-free solder, Sn-3.5 wt.%Ag (Sn-3.5Ag) solder alloy with 0.03 wt.% carbon black was prepared under high pressure (5.5 GPa) and high temperature (1200°C). We have investigated the microstructure, melting behavior, and mechanical properties of the alloy using x-ray diffraction, differential scanning calorimetry (DSC), Vickers hardness testing, tensile testing, and scanning electron microscopy (SEM). The melting point was found to be unchanged, while the hardness and the tensile strength increased with the addition of carbon black. SEM images showed that the average thickness of the intermetallic compound (IMC) layer decreased with the addition of carbon black, indicating improvement in solder joint reliability. © 2012 TMS.


Pham Q.M.,Danang University of Education
Inverse Problems in Science and Engineering | Year: 2015

In this paper, we investigate an inverse problem in electrical impedance tomography. Based on measured data and the sparsity of conductivity coefficients, we use sparse regularization with a suitable fitting functional that replaces the least square functional as often used. Our main results are the differentiability of the new functional, the well-posedness and convergence rates of the regularization method as well as a discussion on Sobolev gradient. Finally, numerical solutions are analyzed and compared for different measured data-sets. © 2015 Taylor & Francis.


My L.H.T.,Danang University of Education | Huy K.P.,Danang University of Education | Vilavong S.,Danang University of Education
Advances in Intelligent Systems and Computing | Year: 2014

The problem of the displaying characters on a computer is one of the issues to be considered early. Encoding characters, designing fonts, building typing tool to display the characters on the screen is indispensable in the text typing. With the problems relating to text typing and the restrictions of ethnic typing tools so far, the paper proposes a solution using Unicode in encoding the Vietnamese minority languages, applying for the Ede Language from that we can type the ethnic language text in multilingual environment using Unicode fonts and the common Vietnamese typing tool such as Vietkey, Unikey, etc. Based on the results of using Unicode in encoding Ede language, we continue to expand for solving problems of text typing on computers with any ethnic language that has the Latin letters. This paper will also be the basis for our proposal to the competent authorities who unity the using Unicode fonts in the ethnic language text in general and Ede text in particular. © Springer International Publishing Switzerland 2014.

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