Le Vu - Academia.edu (original) (raw)

Papers by Le Vu

Research paper thumbnail of Classification of solvable real Lie groups whose nontrivial coadjoint orbits are of codimension 1

We give a complete classification of the class of simply connected real Lie groups whose nontrivi... more We give a complete classification of the class of simply connected real Lie groups whose nontrivial coadjoint orbits are of codimension 1. Such a Lie group belongs to a well-known class, called the class of MD-groups. By definition, an MD-group is a solvable real Lie group such that its nontrivial coadjoint orbits have the same dimension. The Lie algebra of an MD-group is called an MD-algebra. Some interest properties of MD-algebras will be investigated as well.

Research paper thumbnail of Classification of a Class of Solvable Real Lie Algebras by using Techniques in Matrix Theory

We give a complete classification of the class of Lie algebras of simply connected real Lie group... more We give a complete classification of the class of Lie algebras of simply connected real Lie groups whose nontrivial coadjoint orbits are of codimension 1. Such a Lie group belongs to a well-known class, called the class of MD-groups. The Lie algebra of an MD-group is called an MD-algebra. Some interest properties of MD-algebras will be investigated as well. The techniques used in this paper is elementary techniques in matrix theory and available to apply to more general cases.

Research paper thumbnail of Diagnostic Value of Electrocardiography in Acute Pulmonary Embolism

DIAGNOSTIC VALUE OF ELECTROCARDIOGRAPHY IN ACUTE PULMONARY EMBOLISM Le Thuong Vu** Y Hoc TP. Ho C... more DIAGNOSTIC VALUE OF ELECTROCARDIOGRAPHY IN ACUTE PULMONARY EMBOLISM Le Thuong Vu** Y Hoc TP. Ho Chi Minh * Vol. 15 Supplement of No 1 2011: 342 348 Background: Pulmonary embolism is a high incidence disease in western countries but it is considered a rare disease in Vietnam. One of reason could be the late and/or under diagnosis of this difficulty-in-diagnosis condition. Being a basic test to approach patients suspected of pulmonary embolism, ECG may help to improve the diagnosis of pulmonary embolism. Objective: To determine if the use of ECG abnormalities or their combinations could help to improve the diagnosis of pulmonary embolism. Method: In 197 patients suspected of pulmonary embolism in Cardiovascular and Pulmonary Medicine Department, Cho Ray hospital from 8/2007 to 10/2010, 68 patients found PE by multidetector CT angiography. Sensitivity, specificity, likelyhood ratio was calculated for ECG abnormalities in patients without pre-existence cardio-pulmonary disease and all p...

Research paper thumbnail of Classification of 5-dimensional MD-algebras which have commutive derived ideal

The paper presents a subclass of the class of MD-algebras, i.e., solvable real Lie algebras such ... more The paper presents a subclass of the class of MD-algebras, i.e., solvable real Lie algebras such that their orbits in the co-adjoint representation (say by K-orbits) of corresponding connected and simply connected Lie groups are orbit of zero or maximal dimension. The main result of the paper is the classification up to an isomorphism of all 5-dimensional MD-algebras which have commutative derived ideal.

Research paper thumbnail of Development and Validation of an Analytical Method for Quantitative Determination of Benzene, Toluene, Ethylbenzene, Xylenes in Ambient Air

The study describes the qualitative and quantitative analysis of benzene, toluene, ethylbenzene, ... more The study describes the qualitative and quantitative analysis of benzene, toluene, ethylbenzene, xylene (BTEX) in the ambient air based on chemical desorption with a less toxic solvent followed by gas-chromatography combined mass-spectroscopy (GC-MS). The analytical procedure was modified OSHA’s method in the sampling procedure, the toxic extraction solvent-carbon disulfide (CS2) was changed by the less toxic solvent (acetone), subsequent analysis by GC-MS. The parameters and conditions of the method have been optimized. BTEX quantitative concentration ranging from 2.5 ppb to 450 ppb with detection limits were 1.4 ppb (benzene), 1.1 ppb (toluene), 1.0 ppb (ethylbenzene), 0.7 ppb (xylene (m,p)) and 1.2 ppb (xylene(o)). At a concentration of 100 ppb, the relative standard deviations (RSDs) for BTEX ranged from 3.2% (benzene) to 7.5% (xylene (o)). The new method has also been applied to analyze the real ambient air samples in Ho Chi Minh City. All results indicated that this method can...

Research paper thumbnail of Asset sales and subsequent acquisitions

International Review of Financial Analysis, 2018

Abstract In this paper, we find that the decisions to retain asset sale proceeds are positively r... more Abstract In this paper, we find that the decisions to retain asset sale proceeds are positively related to the likelihood of subsequent acquisitions. We demonstrate that retention decisions destroy the wealth of shareholders. First, we document negative market reactions towards a retention decision, and the effect is more pronounced when the decision is followed by an unexpected acquisition. Second, we show that subsequent acquisitions reduce the wealth of shareholders, especially when the acquisitions are unexpected by the market. Third, retention sellers' long-run performance declines when they pursue an acquisition following the sale of their assets. Altogether, we provide novel evidence suggesting that retention sellers tend to reallocate proceeds to specific acquisitions that are detrimental to shareholders' wealth.

Research paper thumbnail of MPSLIB: A C++ class for sequential simulation of multiple-point statistical models

Research paper thumbnail of Fabrication and vibration characterization of curcumin extracted from turmeric (Curcuma longa) rhizomes of the northern Vietnam

Research paper thumbnail of Door assembly for a vehicle HVAC system and method for making same

Research paper thumbnail of On the structure of the C * -algebra of the foliation formed by the K- orbits of maximal dimension of the real diamond group

Journal of Operator Theory, 1990

Research paper thumbnail of 20447 鋼製下地在来工法天井の力学的性状に及ぼす吊りボルト長の影響(天井の力学的特性(2),構造I)

学術講演梗概集 B 1 構造i 荷重 信頼性 応用力学 構造解析 基礎構造 シェル 立体構造 膜構造, Jul 20, 2009

Research paper thumbnail of 291 解の多様性を考慮したGA系解法の特性とアーケード構造形態の創生(建築構造)

日本建築学会研究報告 九州支部 1 構造系, Mar 1, 2007

Research paper thumbnail of Les différentes formes de la littérature populaire des Khmers du Nam Bô

Tap Chi Dân Toc Hoc Hanoi, 1978

Les mythes, les contes et legendes, les fables, les contes pour rire, les proverbes et dictons, l... more Les mythes, les contes et legendes, les fables, les contes pour rire, les proverbes et dictons, les chants. (N. Tung, Cedrasemi).

Research paper thumbnail of Classification of Real Solvable Lie Algebras Whose Simply Connected Lie Groups Have Only Zero or Maximal Dimensional Coadjoint Orbits

DESCRIPTION In this paper we study a special subclass of real solvable Lie algebras having small ... more DESCRIPTION In this paper we study a special subclass of real solvable Lie algebras having small dimensional or small codimensional derived ideal. It is well-known that the derived ideal of any Heisenberg Lie algebra is 1-dimensional and the derived ideal of the 4-dimensional real Diamond algebra is 1-codimensional. Moreover, all the coadjoint orbits of any Heisenberg Lie group as well as 4-dimensional real Diamond group are orbits of dimension zero or maximal dimension. In general, a (finite dimensional) real solvable Lie group is called an MDMDMD-group if its coadjoint orbits are zero-dimensional or maximal dimensional. The Lie algebra of an MDMDMD-group is called an MDMDMD-algebra and the class of all MDMDMD-algebras is called MDMDMD-class. Simulating the mentioned above characteristic of Heisenberg Lie algebras and 4-dimensional real Diamond algebra, we give a complete classification of MDMDMD-algebras having 1-dimensional or 1-codimensional derived ideals.

Research paper thumbnail of Classification of 5-DIMENSIONAL MD-Algebras Having Commutative Derived Ideals

Advances in Algebra and Combinatorics - Proceedings of the Second International Congress in Algebra and Combinatorics, 2008

In this paper, we study a subclass of the class of MD-algebras, i.e., the class of solvable real ... more In this paper, we study a subclass of the class of MD-algebras, i.e., the class of solvable real Lie algebras such that the K-orbits of its corresponding connected and simply connected Lie groups are either orbits of dimension zero or orbits with maximal dimensions. Our main result is to classify, up to isomorphism, all the 5-dimensional MD-algebras having commutative derived ideals.

Research paper thumbnail of Accuracy of the Fatigue Lifetime of Polysilicon Predicted from its Strength Distribution

MRS Proceedings, 2010

This paper discusses the accuracy of the distribution of the fatigue lifetime of polysilicon thin... more This paper discusses the accuracy of the distribution of the fatigue lifetime of polysilicon thin films predicted from their strength distribution. On the basis of the authors' previous studies, where the fatigue process determining the lifetime was formulated using the well-known fatigue crack extension Paris' law, prediction error ranges for polysilicon specimens with different levels of strength are determined. The errors of the predicted fatigue lifetime in the logarithmic scale, defined as △logN = |log10Nexp-log10Npred| where Nexp and Npred were the experimental and predicted number of cycle, were found to be less than 1 in the range of the cumulative fracture probability F between 0.1 and 0.9. Therefore, based on the measured Paris' law parameters of polysilicon, the fatigue lifetimes of different polysilicon thin film structures can be predicted from their strength distributions with errors of roughly 10% in the logarithmic scale, which was average of percentages ...

Research paper thumbnail of Simulation and Lock-In Phase Analysis in Photoreflectance Modulation Spectroscopy of Gaas And Photoreflectance Investigations of The Heterojunction Structure Alxga1–Xas(N+)/Gaas(P−)/Gaas(P+)

Springer Proceedings in Physics

Abstract. The photoreflectance (PR) is a sensitive optical method for examining the surface and i... more Abstract. The photoreflectance (PR) is a sensitive optical method for examining the surface and interface properties of semiconductors . The important substrates that are available for light emitting technology are GaAs and InP. In this report, we simulate PR Spectra of GaAs in two ...

Research paper thumbnail of Applied particle filter in traffic tracking

2006 International Conference onResearch, Innovation and Vision for the Future

Research paper thumbnail of Effect of segregated impurity phases on lattice thermal conductivity in Y-added CoSb3

Scripta Materialia, 2007

Recently, it has been reported that the family of skutterudite compounds has great practical pote... more Recently, it has been reported that the family of skutterudite compounds has great practical potential for thermoelectric applications in the moderate temperature range [1] and [2]. The skutterudite compounds MX 3 (M = Co, Rh or Ir; X = P, As or Sb) have the CoAs 3 -type cubic structure ...

Research paper thumbnail of Nucleotide sequencing and expression of the fadL gene involved in long-chain fatty acid transport in Escherichia coli

Molecular Microbiology, 1988

The fadL gene of Escherichia coli codes for an outer membrane protein involved in long-chain fatt... more The fadL gene of Escherichia coli codes for an outer membrane protein involved in long-chain fatty acid transport. Its product was purified from outer membrane proteins. We determined the nucleotide sequence of a 2.8-kb chromosomal DNA segment that contains the fadL gene. The fadL gene consists of a 1149-nucleotide coding region and contains a highly hydrophobic polypeptide of 383 amino acids with a calculated molecular weight of 42,380. We have used S1-mapping analysis to identify the transcription initiation site. A region exhibiting extensive dyad symmetry and perfect homology to the catabolite activator protein binding site was detected.

Research paper thumbnail of Classification of solvable real Lie groups whose nontrivial coadjoint orbits are of codimension 1

We give a complete classification of the class of simply connected real Lie groups whose nontrivi... more We give a complete classification of the class of simply connected real Lie groups whose nontrivial coadjoint orbits are of codimension 1. Such a Lie group belongs to a well-known class, called the class of MD-groups. By definition, an MD-group is a solvable real Lie group such that its nontrivial coadjoint orbits have the same dimension. The Lie algebra of an MD-group is called an MD-algebra. Some interest properties of MD-algebras will be investigated as well.

Research paper thumbnail of Classification of a Class of Solvable Real Lie Algebras by using Techniques in Matrix Theory

We give a complete classification of the class of Lie algebras of simply connected real Lie group... more We give a complete classification of the class of Lie algebras of simply connected real Lie groups whose nontrivial coadjoint orbits are of codimension 1. Such a Lie group belongs to a well-known class, called the class of MD-groups. The Lie algebra of an MD-group is called an MD-algebra. Some interest properties of MD-algebras will be investigated as well. The techniques used in this paper is elementary techniques in matrix theory and available to apply to more general cases.

Research paper thumbnail of Diagnostic Value of Electrocardiography in Acute Pulmonary Embolism

DIAGNOSTIC VALUE OF ELECTROCARDIOGRAPHY IN ACUTE PULMONARY EMBOLISM Le Thuong Vu** Y Hoc TP. Ho C... more DIAGNOSTIC VALUE OF ELECTROCARDIOGRAPHY IN ACUTE PULMONARY EMBOLISM Le Thuong Vu** Y Hoc TP. Ho Chi Minh * Vol. 15 Supplement of No 1 2011: 342 348 Background: Pulmonary embolism is a high incidence disease in western countries but it is considered a rare disease in Vietnam. One of reason could be the late and/or under diagnosis of this difficulty-in-diagnosis condition. Being a basic test to approach patients suspected of pulmonary embolism, ECG may help to improve the diagnosis of pulmonary embolism. Objective: To determine if the use of ECG abnormalities or their combinations could help to improve the diagnosis of pulmonary embolism. Method: In 197 patients suspected of pulmonary embolism in Cardiovascular and Pulmonary Medicine Department, Cho Ray hospital from 8/2007 to 10/2010, 68 patients found PE by multidetector CT angiography. Sensitivity, specificity, likelyhood ratio was calculated for ECG abnormalities in patients without pre-existence cardio-pulmonary disease and all p...

Research paper thumbnail of Classification of 5-dimensional MD-algebras which have commutive derived ideal

The paper presents a subclass of the class of MD-algebras, i.e., solvable real Lie algebras such ... more The paper presents a subclass of the class of MD-algebras, i.e., solvable real Lie algebras such that their orbits in the co-adjoint representation (say by K-orbits) of corresponding connected and simply connected Lie groups are orbit of zero or maximal dimension. The main result of the paper is the classification up to an isomorphism of all 5-dimensional MD-algebras which have commutative derived ideal.

Research paper thumbnail of Development and Validation of an Analytical Method for Quantitative Determination of Benzene, Toluene, Ethylbenzene, Xylenes in Ambient Air

The study describes the qualitative and quantitative analysis of benzene, toluene, ethylbenzene, ... more The study describes the qualitative and quantitative analysis of benzene, toluene, ethylbenzene, xylene (BTEX) in the ambient air based on chemical desorption with a less toxic solvent followed by gas-chromatography combined mass-spectroscopy (GC-MS). The analytical procedure was modified OSHA’s method in the sampling procedure, the toxic extraction solvent-carbon disulfide (CS2) was changed by the less toxic solvent (acetone), subsequent analysis by GC-MS. The parameters and conditions of the method have been optimized. BTEX quantitative concentration ranging from 2.5 ppb to 450 ppb with detection limits were 1.4 ppb (benzene), 1.1 ppb (toluene), 1.0 ppb (ethylbenzene), 0.7 ppb (xylene (m,p)) and 1.2 ppb (xylene(o)). At a concentration of 100 ppb, the relative standard deviations (RSDs) for BTEX ranged from 3.2% (benzene) to 7.5% (xylene (o)). The new method has also been applied to analyze the real ambient air samples in Ho Chi Minh City. All results indicated that this method can...

Research paper thumbnail of Asset sales and subsequent acquisitions

International Review of Financial Analysis, 2018

Abstract In this paper, we find that the decisions to retain asset sale proceeds are positively r... more Abstract In this paper, we find that the decisions to retain asset sale proceeds are positively related to the likelihood of subsequent acquisitions. We demonstrate that retention decisions destroy the wealth of shareholders. First, we document negative market reactions towards a retention decision, and the effect is more pronounced when the decision is followed by an unexpected acquisition. Second, we show that subsequent acquisitions reduce the wealth of shareholders, especially when the acquisitions are unexpected by the market. Third, retention sellers' long-run performance declines when they pursue an acquisition following the sale of their assets. Altogether, we provide novel evidence suggesting that retention sellers tend to reallocate proceeds to specific acquisitions that are detrimental to shareholders' wealth.

Research paper thumbnail of MPSLIB: A C++ class for sequential simulation of multiple-point statistical models

Research paper thumbnail of Fabrication and vibration characterization of curcumin extracted from turmeric (Curcuma longa) rhizomes of the northern Vietnam

Research paper thumbnail of Door assembly for a vehicle HVAC system and method for making same

Research paper thumbnail of On the structure of the C * -algebra of the foliation formed by the K- orbits of maximal dimension of the real diamond group

Journal of Operator Theory, 1990

Research paper thumbnail of 20447 鋼製下地在来工法天井の力学的性状に及ぼす吊りボルト長の影響(天井の力学的特性(2),構造I)

学術講演梗概集 B 1 構造i 荷重 信頼性 応用力学 構造解析 基礎構造 シェル 立体構造 膜構造, Jul 20, 2009

Research paper thumbnail of 291 解の多様性を考慮したGA系解法の特性とアーケード構造形態の創生(建築構造)

日本建築学会研究報告 九州支部 1 構造系, Mar 1, 2007

Research paper thumbnail of Les différentes formes de la littérature populaire des Khmers du Nam Bô

Tap Chi Dân Toc Hoc Hanoi, 1978

Les mythes, les contes et legendes, les fables, les contes pour rire, les proverbes et dictons, l... more Les mythes, les contes et legendes, les fables, les contes pour rire, les proverbes et dictons, les chants. (N. Tung, Cedrasemi).

Research paper thumbnail of Classification of Real Solvable Lie Algebras Whose Simply Connected Lie Groups Have Only Zero or Maximal Dimensional Coadjoint Orbits

DESCRIPTION In this paper we study a special subclass of real solvable Lie algebras having small ... more DESCRIPTION In this paper we study a special subclass of real solvable Lie algebras having small dimensional or small codimensional derived ideal. It is well-known that the derived ideal of any Heisenberg Lie algebra is 1-dimensional and the derived ideal of the 4-dimensional real Diamond algebra is 1-codimensional. Moreover, all the coadjoint orbits of any Heisenberg Lie group as well as 4-dimensional real Diamond group are orbits of dimension zero or maximal dimension. In general, a (finite dimensional) real solvable Lie group is called an MDMDMD-group if its coadjoint orbits are zero-dimensional or maximal dimensional. The Lie algebra of an MDMDMD-group is called an MDMDMD-algebra and the class of all MDMDMD-algebras is called MDMDMD-class. Simulating the mentioned above characteristic of Heisenberg Lie algebras and 4-dimensional real Diamond algebra, we give a complete classification of MDMDMD-algebras having 1-dimensional or 1-codimensional derived ideals.

Research paper thumbnail of Classification of 5-DIMENSIONAL MD-Algebras Having Commutative Derived Ideals

Advances in Algebra and Combinatorics - Proceedings of the Second International Congress in Algebra and Combinatorics, 2008

In this paper, we study a subclass of the class of MD-algebras, i.e., the class of solvable real ... more In this paper, we study a subclass of the class of MD-algebras, i.e., the class of solvable real Lie algebras such that the K-orbits of its corresponding connected and simply connected Lie groups are either orbits of dimension zero or orbits with maximal dimensions. Our main result is to classify, up to isomorphism, all the 5-dimensional MD-algebras having commutative derived ideals.

Research paper thumbnail of Accuracy of the Fatigue Lifetime of Polysilicon Predicted from its Strength Distribution

MRS Proceedings, 2010

This paper discusses the accuracy of the distribution of the fatigue lifetime of polysilicon thin... more This paper discusses the accuracy of the distribution of the fatigue lifetime of polysilicon thin films predicted from their strength distribution. On the basis of the authors' previous studies, where the fatigue process determining the lifetime was formulated using the well-known fatigue crack extension Paris' law, prediction error ranges for polysilicon specimens with different levels of strength are determined. The errors of the predicted fatigue lifetime in the logarithmic scale, defined as △logN = |log10Nexp-log10Npred| where Nexp and Npred were the experimental and predicted number of cycle, were found to be less than 1 in the range of the cumulative fracture probability F between 0.1 and 0.9. Therefore, based on the measured Paris' law parameters of polysilicon, the fatigue lifetimes of different polysilicon thin film structures can be predicted from their strength distributions with errors of roughly 10% in the logarithmic scale, which was average of percentages ...

Research paper thumbnail of Simulation and Lock-In Phase Analysis in Photoreflectance Modulation Spectroscopy of Gaas And Photoreflectance Investigations of The Heterojunction Structure Alxga1–Xas(N+)/Gaas(P−)/Gaas(P+)

Springer Proceedings in Physics

Abstract. The photoreflectance (PR) is a sensitive optical method for examining the surface and i... more Abstract. The photoreflectance (PR) is a sensitive optical method for examining the surface and interface properties of semiconductors . The important substrates that are available for light emitting technology are GaAs and InP. In this report, we simulate PR Spectra of GaAs in two ...

Research paper thumbnail of Applied particle filter in traffic tracking

2006 International Conference onResearch, Innovation and Vision for the Future

Research paper thumbnail of Effect of segregated impurity phases on lattice thermal conductivity in Y-added CoSb3

Scripta Materialia, 2007

Recently, it has been reported that the family of skutterudite compounds has great practical pote... more Recently, it has been reported that the family of skutterudite compounds has great practical potential for thermoelectric applications in the moderate temperature range [1] and [2]. The skutterudite compounds MX 3 (M = Co, Rh or Ir; X = P, As or Sb) have the CoAs 3 -type cubic structure ...

Research paper thumbnail of Nucleotide sequencing and expression of the fadL gene involved in long-chain fatty acid transport in Escherichia coli

Molecular Microbiology, 1988

The fadL gene of Escherichia coli codes for an outer membrane protein involved in long-chain fatt... more The fadL gene of Escherichia coli codes for an outer membrane protein involved in long-chain fatty acid transport. Its product was purified from outer membrane proteins. We determined the nucleotide sequence of a 2.8-kb chromosomal DNA segment that contains the fadL gene. The fadL gene consists of a 1149-nucleotide coding region and contains a highly hydrophobic polypeptide of 383 amino acids with a calculated molecular weight of 42,380. We have used S1-mapping analysis to identify the transcription initiation site. A region exhibiting extensive dyad symmetry and perfect homology to the catabolite activator protein binding site was detected.