Pham Quang Thang - Academia.edu (original) (raw)
Papers by Pham Quang Thang
Advances in Intelligent Systems and Computing, 2018
The efficient classification ability of support vector machine (SVM) has been shown in many pract... more The efficient classification ability of support vector machine (SVM) has been shown in many practical applications, but currently it is significantly slower in testing phase than other classification approaches due to large number of support vectors included in the solution. Among different approaches, simplification of support vector machine (SimpSVM) accelerates the test phase by replacing original SVM with a simplified SVM that uses significantly fewer support vectors. Nevertheless, the final aim of the simplification is to try keeping the simplified solution as similar as possible to the original one. To ameliorate this similarity, in this paper, we present a modification of solution optimization in SimpSVM. The proposed approach is based on stochastic optimization. Experiments on benchmark and sign language datasets show improved results by our modification.
The efficient classification ability of support vector machines (SVMs) has been shown in many pra... more The efficient classification ability of support vector machines (SVMs) has been shown in many practical applications, but currently they are considerably slower in testing phase than other approaches with similar classification performance due to a large number of support vectors included in the solution. Among different approaches, simplification of support vector machine (SimpSVM) speeds-up the testing phase by replacing original SVM with a simplified one that consists of a smaller number of support vectors. However, the ultimate goal of the simplification is to keep the simplified solution as similar to the original solution as possible. To improve this similarity, in this paper, we propose two improved SimpSVMs that are based on stochastic gradient descent. Experiments on some datasets show improved results by our algorithms.
Adenosma bracteosum (Bonati) has been used in traditional and folk medicine in Vietnam as a treat... more Adenosma bracteosum (Bonati) has been used in traditional and folk medicine in Vietnam as a treatment for liver disease but there were few information about its characteristics of antibictie. The aim of the present study was to evaluate antioxidant activity and anti-hyperglycemic potential of extracts from A. bracteosum. Chloroform, ethanolic and aqueous A. bracteosum extracts were tested for their antioxidant activity and inhibition of xanthine oxidase. The results on the ferric reducing/antioxidant power assay (FRAP) and the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay showed that ethanolic and aqueous extracts possessed strong in vitro antioxidant capacity. Ethanolic extract had the highest phenol concentration. In vivo antioxidant activities of ethanolic and aqueous extracts on damaged mouse livers indicated that both extracts were effective against acute CCl 4 -induced hepatic. Results on glucose-induced hyperglycemic mice treated with different doses of ...
Natural Product Communications, 2012
A study of the chemical constituents of a methanolic extract of the roots of Livistona halongensi... more A study of the chemical constituents of a methanolic extract of the roots of Livistona halongensis (Arecaceae) led to the isolation of two new flavanes, 2S,3S-3,5,7,3'-tetrahydroxy-5'-methoxyflavane (1) and 3,7,3'-trihydroxy-5'-methoxyflavane 5- O-β-glucopyranoside (2), together with trans-3,5,3',5'-tetrahydroxy-4-methoxystilbene, saccharose and β-sitosterol-3- O-β-glucopyranoside. The structures of these compounds were elucidated on the basis of spectroscopic data.
Ni-Cr-Mo cast superalloys have entered the dental restoration applications in the recent years. S... more Ni-Cr-Mo cast superalloys have entered the dental restoration applications in the recent years. Some of the published literatures have shown that with the addition of titanium to Ni-Cr-Mo alloys, there are improvements in casting properties and microstructure and then affect on mechanical properties. Together with low casting temperature, titanium has symbiosis influence on both surface roughness and colour of alloys. This paper contains a report on a study carried out on the evaluation of mechanical, metallurgical, casting and surface properties of several Ni-Cr-Mo-Ti alloys. The results show that some of the alloys are superior to conventional Ni74Cr14MoTi3AlCu alloys used in dental restoration applications.
Vietnam Journal of Chemistry, Aug 15, 2012
This work presents an analysis on the supersonic flutter characteristics of Sigmoid FGM (S-FGM) t... more This work presents an analysis on the supersonic flutter characteristics of Sigmoid FGM (S-FGM) thin circular cylindrical shells with metal-ceramic-metal layers surrounded on elastic foundations under aerodynamic loads. Based on the Ilyushin nonlinear supersonic aerodynamic theory with the classical shell theory, the governing equations of S-FGM shells lying in the moving supersonic airflow are derived. By applying Galerkin method with an approximate two-terms Fourier expansion solution leads to a set of nonlinear auto-oscillation equations for determining the nonlinear flutter response and critical velocity. Numerical results are obtained by fourth-order Runge-Kutta method. The influences of volume fraction index, material and geometrical properties, imperfections, initial conditions and the elastic foundations on the nonlinear supersonic flutter characteristics of S-FGM circular cylindrical shells are investigated.
RSC Adv., 2014
This paper reports on the biosynthesis of copper nanoparticles (NPs) using extract of the Euphorb... more This paper reports on the biosynthesis of copper nanoparticles (NPs) using extract of the Euphorbia esula L leaves as reductant and stabilizer without any surfactant. The catalytic efficiency of the prepared Cu NPs for the reduction of 4-nitrophenol and ligand-free Ullmann-coupling reaction is discussed. The Cu NPs were characterized with UV-vis, XRD and TEM methods. This method has the advantages of high yields, simple methodology, and elimination of ligand and easy work up. 65
Polyhedron, 2015
The potentially tetradentate benzamidine/thiosemicarbazone ligand, Et 2 N-(C=S)-NH-C(Ph)=N-(o-C 4... more The potentially tetradentate benzamidine/thiosemicarbazone ligand, Et 2 N-(C=S)-NH-C(Ph)=N-(o-C 4 H 6)-C(Me)=N-NH-(C=S)-NH-Me (H 2 L) readily reacts with Ni(CH 3 COO) 2 , [PdCl 2 (CH 3 CN) 2 ], [PtCl 2 (PPh 3) 2 ] and (NBu 4)[ReOCl 4 ] under formation of complexes of the compositions [M(L)] (M= Ni (1), Pd (2), Pt (3)) and [ReO(L)(OMe)] (4). In all complexes, H 2 L is doubly deprotonated and bonded to the central meal ion via its N 2 S 2 donor set. Complexes 1, 2 and 3 have distorted square-planar coordination spheres, while the rhenium compound 4 is an octahedral trans oxido/methoxido complex. The H 2 L proligand shows a medium cytotoxicity with an IC 50 value of 21.1 M. While the rhenium complex 4 exhibits a stronger antiproliferative effect (IC 50 = 5.52 M), the nickel, palladium and platinum complexes are almost inactive.
Western Pacific Surveillance and Response Journal, 2015
IFAC Proceedings Volumes, 2005
The leather industry uses a by wastes of meat industry, and, as such, significantly reduces the e... more The leather industry uses a by wastes of meat industry, and, as such, significantly reduces the environmental impact. It is therefore evident that term "waste" is relative. It can be argued that if the "waste" generated in one industry sector can successful be utilised as a raw material in another industry sector for the manufacture of goods, we need to rethink our philosophy on the use of resources. This paper describes a proposed comprehensive computer control and monitoring system for a recycling technological process of both liquid and solid wastes from the tanning industry. The chromium tannery wastes are potential dangerous for the environment. As an experimental laboratory model were built in the Department of Automatic Control Faculty of Technology Tomas Bata University in Zlín an apparatus fully equipped with sensors and actuators. Monitoring and control system was tested on the real equipment.
PLOS ONE, 2015
Introduction Given the overlapping modes of transmission of HIV, hepatitis B virus (HBV), and hep... more Introduction Given the overlapping modes of transmission of HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV), understanding the burden and relationship of these infections is critical for an effective response. Representative data on these infections among males who inject drugs (MWID), the key high-risk population for HIV in Vietnam, are currently lacking. Methods Data and stored specimens from Vietnam's 2009-2010 Integrated Biologic and Behavioral Survey, a cross-sectional study among high-risk populations, were used for this analysis. Plasma samples were tested for HIV, HBV, and HCV using commercial assays. A questionnaire was administered to provide demographic, behavior, and service-uptake information. Provincial-level analyses were conducted to profile MWID enrollees and to provide estimates on the prevalence of HIV, HBV, and HCV infection. Results Among 3010 MWID sampled across 10 provinces, the median (range) HIV prevalence was 28.1% (1.0%-55.5%). Median prevalence for current HBV infection (HBsAg+) was 14.1%
![Research paper thumbnail of Four-Channel Sub-Band Coding with Combination of [8 8 4 2] for Digital Audio Signal Processing](https://attachments.academia-assets.com/95188055/thumbnails/1.jpg)
](Science Journal of Circuits, Systems and Signal Processing, 2013
This paper presents the research result for the four-channel sub-band coding (SBC) with a combina... more This paper presents the research result for the four-channel sub-band coding (SBC) with a combination of share [8 8 4 2]. The research method is based on the Wavelet multi-resolution analysis using ATRAC3 algorithm using filters designed by a novel technique of filter bank called "transit-window". The advantages of the method are as: reduction of ripple of output amplitude response and information lossless at the interface region between two filters. Especially, under wavelet analysis with the change in the base-2 exponential partition factor from SBC [4 4 2] is to SBC [8 8 4 2] and it may be used to record/read audio and digitally broadcast on internet. The result is obtained by using the Matlab/Simulink modeling for the method.
The 2010 International Conference on Advanced Technologies for Communications, 2010
In this paper, we used second order interpolation method via three successding data points in nar... more In this paper, we used second order interpolation method via three successding data points in narrow area, combined with loop transformation method and used samples to build an algorithm for processing of measurement data to reduce non-linear errors and transformation errors of non-electric measuring devices. Simulation and experimental results shown the ability to reduce errors of measurement devices.
Frontiers in immunology, 2011
One important pathogenic feature of human immunodeficiency virus (HIV)-1 infection is chronic imm... more One important pathogenic feature of human immunodeficiency virus (HIV)-1 infection is chronic immune activation and impaired survival of T and B cells. A decline of resting memory B cells was reported to occur in both children and adults infected with HIV-1; these cells are responsible for maintaining an adequate serological response to antigens previously encountered in life through natural infection or vaccination. Further understanding of the mechanisms leading to impaired B cell differentiation and germinal center reaction might be essential to design new HIV vaccines and therapies that could improve humoral immune responses in HIV-1 infected individuals. In the present article we summarize the literature and present our view on critical mechanisms of B cell development impaired during HIV-1 infection. We also discuss the impact of microbial translocation, a driving force for persistent inflammation during HIV-1 infection, on survival of terminally differentiated B cells and how...
2007 9th International Conference on e-Health Networking, Application and Services, 2007
Abstract-This paper presents a framework and techniques for we address the issues involved in und... more Abstract-This paper presents a framework and techniques for we address the issues involved in understanding, modeling and recognition and automated rating of complex agitation behavior recognizing complex agitation behaviors in sections III and IV. for patients with dementia ...
Aerospace Science and Technology, 2015
dynamic response and vibration of shear deformable piezoelectric functionally graded truncated co... more dynamic response and vibration of shear deformable piezoelectric functionally graded truncated conical panel in thermal environments,
Advances in Intelligent Systems and Computing, 2018
The efficient classification ability of support vector machine (SVM) has been shown in many pract... more The efficient classification ability of support vector machine (SVM) has been shown in many practical applications, but currently it is significantly slower in testing phase than other classification approaches due to large number of support vectors included in the solution. Among different approaches, simplification of support vector machine (SimpSVM) accelerates the test phase by replacing original SVM with a simplified SVM that uses significantly fewer support vectors. Nevertheless, the final aim of the simplification is to try keeping the simplified solution as similar as possible to the original one. To ameliorate this similarity, in this paper, we present a modification of solution optimization in SimpSVM. The proposed approach is based on stochastic optimization. Experiments on benchmark and sign language datasets show improved results by our modification.
The efficient classification ability of support vector machines (SVMs) has been shown in many pra... more The efficient classification ability of support vector machines (SVMs) has been shown in many practical applications, but currently they are considerably slower in testing phase than other approaches with similar classification performance due to a large number of support vectors included in the solution. Among different approaches, simplification of support vector machine (SimpSVM) speeds-up the testing phase by replacing original SVM with a simplified one that consists of a smaller number of support vectors. However, the ultimate goal of the simplification is to keep the simplified solution as similar to the original solution as possible. To improve this similarity, in this paper, we propose two improved SimpSVMs that are based on stochastic gradient descent. Experiments on some datasets show improved results by our algorithms.
Adenosma bracteosum (Bonati) has been used in traditional and folk medicine in Vietnam as a treat... more Adenosma bracteosum (Bonati) has been used in traditional and folk medicine in Vietnam as a treatment for liver disease but there were few information about its characteristics of antibictie. The aim of the present study was to evaluate antioxidant activity and anti-hyperglycemic potential of extracts from A. bracteosum. Chloroform, ethanolic and aqueous A. bracteosum extracts were tested for their antioxidant activity and inhibition of xanthine oxidase. The results on the ferric reducing/antioxidant power assay (FRAP) and the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay showed that ethanolic and aqueous extracts possessed strong in vitro antioxidant capacity. Ethanolic extract had the highest phenol concentration. In vivo antioxidant activities of ethanolic and aqueous extracts on damaged mouse livers indicated that both extracts were effective against acute CCl 4 -induced hepatic. Results on glucose-induced hyperglycemic mice treated with different doses of ...
Natural Product Communications, 2012
A study of the chemical constituents of a methanolic extract of the roots of Livistona halongensi... more A study of the chemical constituents of a methanolic extract of the roots of Livistona halongensis (Arecaceae) led to the isolation of two new flavanes, 2S,3S-3,5,7,3'-tetrahydroxy-5'-methoxyflavane (1) and 3,7,3'-trihydroxy-5'-methoxyflavane 5- O-β-glucopyranoside (2), together with trans-3,5,3',5'-tetrahydroxy-4-methoxystilbene, saccharose and β-sitosterol-3- O-β-glucopyranoside. The structures of these compounds were elucidated on the basis of spectroscopic data.
Ni-Cr-Mo cast superalloys have entered the dental restoration applications in the recent years. S... more Ni-Cr-Mo cast superalloys have entered the dental restoration applications in the recent years. Some of the published literatures have shown that with the addition of titanium to Ni-Cr-Mo alloys, there are improvements in casting properties and microstructure and then affect on mechanical properties. Together with low casting temperature, titanium has symbiosis influence on both surface roughness and colour of alloys. This paper contains a report on a study carried out on the evaluation of mechanical, metallurgical, casting and surface properties of several Ni-Cr-Mo-Ti alloys. The results show that some of the alloys are superior to conventional Ni74Cr14MoTi3AlCu alloys used in dental restoration applications.
Vietnam Journal of Chemistry, Aug 15, 2012
This work presents an analysis on the supersonic flutter characteristics of Sigmoid FGM (S-FGM) t... more This work presents an analysis on the supersonic flutter characteristics of Sigmoid FGM (S-FGM) thin circular cylindrical shells with metal-ceramic-metal layers surrounded on elastic foundations under aerodynamic loads. Based on the Ilyushin nonlinear supersonic aerodynamic theory with the classical shell theory, the governing equations of S-FGM shells lying in the moving supersonic airflow are derived. By applying Galerkin method with an approximate two-terms Fourier expansion solution leads to a set of nonlinear auto-oscillation equations for determining the nonlinear flutter response and critical velocity. Numerical results are obtained by fourth-order Runge-Kutta method. The influences of volume fraction index, material and geometrical properties, imperfections, initial conditions and the elastic foundations on the nonlinear supersonic flutter characteristics of S-FGM circular cylindrical shells are investigated.
RSC Adv., 2014
This paper reports on the biosynthesis of copper nanoparticles (NPs) using extract of the Euphorb... more This paper reports on the biosynthesis of copper nanoparticles (NPs) using extract of the Euphorbia esula L leaves as reductant and stabilizer without any surfactant. The catalytic efficiency of the prepared Cu NPs for the reduction of 4-nitrophenol and ligand-free Ullmann-coupling reaction is discussed. The Cu NPs were characterized with UV-vis, XRD and TEM methods. This method has the advantages of high yields, simple methodology, and elimination of ligand and easy work up. 65
Polyhedron, 2015
The potentially tetradentate benzamidine/thiosemicarbazone ligand, Et 2 N-(C=S)-NH-C(Ph)=N-(o-C 4... more The potentially tetradentate benzamidine/thiosemicarbazone ligand, Et 2 N-(C=S)-NH-C(Ph)=N-(o-C 4 H 6)-C(Me)=N-NH-(C=S)-NH-Me (H 2 L) readily reacts with Ni(CH 3 COO) 2 , [PdCl 2 (CH 3 CN) 2 ], [PtCl 2 (PPh 3) 2 ] and (NBu 4)[ReOCl 4 ] under formation of complexes of the compositions [M(L)] (M= Ni (1), Pd (2), Pt (3)) and [ReO(L)(OMe)] (4). In all complexes, H 2 L is doubly deprotonated and bonded to the central meal ion via its N 2 S 2 donor set. Complexes 1, 2 and 3 have distorted square-planar coordination spheres, while the rhenium compound 4 is an octahedral trans oxido/methoxido complex. The H 2 L proligand shows a medium cytotoxicity with an IC 50 value of 21.1 M. While the rhenium complex 4 exhibits a stronger antiproliferative effect (IC 50 = 5.52 M), the nickel, palladium and platinum complexes are almost inactive.
Western Pacific Surveillance and Response Journal, 2015
IFAC Proceedings Volumes, 2005
The leather industry uses a by wastes of meat industry, and, as such, significantly reduces the e... more The leather industry uses a by wastes of meat industry, and, as such, significantly reduces the environmental impact. It is therefore evident that term "waste" is relative. It can be argued that if the "waste" generated in one industry sector can successful be utilised as a raw material in another industry sector for the manufacture of goods, we need to rethink our philosophy on the use of resources. This paper describes a proposed comprehensive computer control and monitoring system for a recycling technological process of both liquid and solid wastes from the tanning industry. The chromium tannery wastes are potential dangerous for the environment. As an experimental laboratory model were built in the Department of Automatic Control Faculty of Technology Tomas Bata University in Zlín an apparatus fully equipped with sensors and actuators. Monitoring and control system was tested on the real equipment.
PLOS ONE, 2015
Introduction Given the overlapping modes of transmission of HIV, hepatitis B virus (HBV), and hep... more Introduction Given the overlapping modes of transmission of HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV), understanding the burden and relationship of these infections is critical for an effective response. Representative data on these infections among males who inject drugs (MWID), the key high-risk population for HIV in Vietnam, are currently lacking. Methods Data and stored specimens from Vietnam's 2009-2010 Integrated Biologic and Behavioral Survey, a cross-sectional study among high-risk populations, were used for this analysis. Plasma samples were tested for HIV, HBV, and HCV using commercial assays. A questionnaire was administered to provide demographic, behavior, and service-uptake information. Provincial-level analyses were conducted to profile MWID enrollees and to provide estimates on the prevalence of HIV, HBV, and HCV infection. Results Among 3010 MWID sampled across 10 provinces, the median (range) HIV prevalence was 28.1% (1.0%-55.5%). Median prevalence for current HBV infection (HBsAg+) was 14.1%
Science Journal of Circuits, Systems and Signal Processing, 2013
This paper presents the research result for the four-channel sub-band coding (SBC) with a combina... more This paper presents the research result for the four-channel sub-band coding (SBC) with a combination of share [8 8 4 2]. The research method is based on the Wavelet multi-resolution analysis using ATRAC3 algorithm using filters designed by a novel technique of filter bank called "transit-window". The advantages of the method are as: reduction of ripple of output amplitude response and information lossless at the interface region between two filters. Especially, under wavelet analysis with the change in the base-2 exponential partition factor from SBC [4 4 2] is to SBC [8 8 4 2] and it may be used to record/read audio and digitally broadcast on internet. The result is obtained by using the Matlab/Simulink modeling for the method.
The 2010 International Conference on Advanced Technologies for Communications, 2010
In this paper, we used second order interpolation method via three successding data points in nar... more In this paper, we used second order interpolation method via three successding data points in narrow area, combined with loop transformation method and used samples to build an algorithm for processing of measurement data to reduce non-linear errors and transformation errors of non-electric measuring devices. Simulation and experimental results shown the ability to reduce errors of measurement devices.
Frontiers in immunology, 2011
One important pathogenic feature of human immunodeficiency virus (HIV)-1 infection is chronic imm... more One important pathogenic feature of human immunodeficiency virus (HIV)-1 infection is chronic immune activation and impaired survival of T and B cells. A decline of resting memory B cells was reported to occur in both children and adults infected with HIV-1; these cells are responsible for maintaining an adequate serological response to antigens previously encountered in life through natural infection or vaccination. Further understanding of the mechanisms leading to impaired B cell differentiation and germinal center reaction might be essential to design new HIV vaccines and therapies that could improve humoral immune responses in HIV-1 infected individuals. In the present article we summarize the literature and present our view on critical mechanisms of B cell development impaired during HIV-1 infection. We also discuss the impact of microbial translocation, a driving force for persistent inflammation during HIV-1 infection, on survival of terminally differentiated B cells and how...
2007 9th International Conference on e-Health Networking, Application and Services, 2007
Abstract-This paper presents a framework and techniques for we address the issues involved in und... more Abstract-This paper presents a framework and techniques for we address the issues involved in understanding, modeling and recognition and automated rating of complex agitation behavior recognizing complex agitation behaviors in sections III and IV. for patients with dementia ...
Aerospace Science and Technology, 2015
dynamic response and vibration of shear deformable piezoelectric functionally graded truncated co... more dynamic response and vibration of shear deformable piezoelectric functionally graded truncated conical panel in thermal environments,