Nguyễn Dũng - Academia.edu (original) (raw)

Papers by Nguyễn Dũng

Taiwanese Journal of Mathematics, 2013

Taiwanese Journal of Mathematics, 2014

Communications in Physics, 2012

The 2012 International Conference on Advanced Technologies for Communications, 2012

ABSTRACT Deployment of wireless sensor networks always faces the issue of energy limitation. With... more ABSTRACT Deployment of wireless sensor networks always faces the issue of energy limitation. Without appropriate control policy, data messages might be routed over already-exhausted routes, quickly disrupting network connectivity. If a node transmits data at an excessively high power level, it not only depletes its own energy budget wastefully, but also interferes in other parallel transmissions. In this study, we introduce a cooperative power control strategy in which nodes of routes jointly tune their transmit power regularly over time and upon route setup. Tuning is made under hints of surrounding nodes. Routes are selected based on link metrics that is a function of signal strength, remaining energy, and path loss. To keep balancing power consumption among nodes, energy-aware established routes are considered re-routing periodically. Transmit power of each node is set at a level is just high enough under the hint of its adjacent downstream node. Simulation outputs do demonstrate the soundness of our proposals with respect to connectivity and throughput.

Annales Polonici Mathematici, 2005

... A bounded open set Ω in Cn is said to be hyperconvex if there is a negative plurisubharmonic ... more ... A bounded open set Ω in Cn is said to be hyperconvex if there is a negative plurisubharmonic exhaustion function for Ω. It is a well known result of Kerzman and Rosay (see [KR]) that every bounded pseudoconvex open set with C1 smooth boundary in Cn is hyper-convex. ...

Algebra Colloquium, 2007

We study two classes of Artinian modules called co-Buchsbaum modules and generalized co-Cohen–Mac... more We study two classes of Artinian modules called co-Buchsbaum modules and generalized co-Cohen–Macaulay modules. Some basic properties and characterizations of these modules in terms of 𝔮-weak co-sequences, co-standard sequences, multiplicity, local homology ...

Vietnam Journal of Mathematics, 2014

Contemporary Mathematics, 2006

Communications in Physics, 2013

Applied Physics Letters, 2014

ABSTRACT Schottky junctions (SJ) are considered devices for sensing applications due to their uni... more ABSTRACT Schottky junctions (SJ) are considered devices for sensing applications due to their unique properties. Herein, we report on the design, facile fabrication, and outstanding NO2 gas sensing properties of monolayer graphene (GP)/SnO2 nanowire (NW) SJ devices. The devices were prepared by directly growing single crystal SnO2 NWs on interdigitated Pt electrodes via thermal evaporation, followed by transferring a GP layer grown by chemical vapor deposition on top of the NW chip. The SJ-based sensor showed a reversible response to NO2 gas at concentrations of ppb levels with detection limits of about 0.024 ppb at a low operating temperature of 150 °C and bias voltage (1 V) with a response/recovery time of less than 50 s. The outstanding gas-sensing characteristics of the device were attributed to tuning the Schottky barrier height and barrier width at the tiny area of contact between GP and SnO2 NW through the adsorption/desorption of gas molecules.

Radiation Physics and Chemistry, 1995

rhe acrylamide was grattrd by radiatlon onto starth which is a kind polymeric biomaterial.The ure... more rhe acrylamide was grattrd by radiatlon onto starth which is a kind polymeric biomaterial.The urease was immobilized on the grattrd stnrc h.Somr experiments to observe the quantitative relationshlps between the percent gratt and th(l nc-tivily of immobilized enzyme were determined.The enzyme ac-tivlty was maintained by morc2 thdn sclvrn batch enzyme reactions.

Physica B: Condensed Matter, 2003

Co 75 Fe 5 Si 12 B 8 and Fe 73.5 Nb 3 CuB 9 Si 13.5 ribbons, showing the high magnetoimpedance ef... more Co 75 Fe 5 Si 12 B 8 and Fe 73.5 Nb 3 CuB 9 Si 13.5 ribbons, showing the high magnetoimpedance effect of about 50% under an applied field of 56 Oe, have been obtained by rapid quenching in air. The Co-based ribbons, used as a magnetoimpedance sensor in a simple magnetic field measurement circuit based on a Colpitts high-frequency generator, showed a field sensitivity of 1.2 mV/Oe. r 2002 Published by Elsevier Science B.V.

Kodai Mathematical Journal, 1999

Let V be the complex vector space C 7 , s/ an arrangement in V, i.e. a finite family of hyperplan... more Let V be the complex vector space C 7 , s/ an arrangement in V, i.e. a finite family of hyperplanes in V In , Moishezon associated to any algebraic plane curve <# of degree n a braid monodromy homomorphism θ F s -> B(n), where F s is a free group, B(ή) is the Artm braid group. In this paper, we will determine the braid monodromy for the case when # is an arrangement stf of complex lines in C 2 , using the notion of labyrinth of an arrangement. As a corollary we get the braid monodromy presentation for the fundamental group of the complement to the arrangement.

Glasgow Mathematical Journal, 1992

Relationships between injectivity or generalized injectivity and chain conditions on a module cat... more Relationships between injectivity or generalized injectivity and chain conditions on a module category have been studied by several authors. A well-known theorem of Osofsky [14, 15] asserts that a ring all of whose cyclic right modules are injective is semisimple Artinian. Osofsky's proofs in [14, 15] essentially used homological properties of injective modules, and, later, her arguments were applied by other authors in their studies of rings for which cyclic right modules are quasi-injective, continuous or quasi-continuous (see e.g. [1, 10, 12]). Following [5] (cf. [4]), a module M is called a CS-module if every submodule of M is essential in a direct summand of M. In the recent paper [17], B. L. Osofsky and P. F. Smith have proved a very general theorem on cyclic completely CS-modules from which many known results in this area follow rather easily. In another direction, it was proved in [8] that a finitely generated quasi-injective module with ACC (respectively DCC) on essential submodules is Noetherian (respectively Artinian). This result was also extended to CS-modules in [3, 16], and weak CS-modules in [19].

Fixed Point Theory and Applications, 2013

In this paper, we prove a fixed point theorem on a 2-metric space and show that the main results ... more In this paper, we prove a fixed point theorem on a 2-metric space and show that the main results in Lahiri et al. (Taiwan. J. Math. 15:337-352, 2011) and Singh et al. (J. Adv. Math. Stud. 5:71-76, 2012) may be obtained easily from the axioms of a 2-metric space. Examples are given to validate the results.

Archiv der Mathematik, 1988

ABSTRACT 1. Introduction. Throughout this paper we consider associative rings with identity and u... more ABSTRACT 1. Introduction. Throughout this paper we consider associative rings with identity and unitary modules. A filter Y is a system of subsets of a topological space such that if F u, F~ ~ ~, then there exists a subset F2 ~ o ~ with 0 4= Fz ~ Fun F~. Let R be a ring and M be a right R-module. M is called a linearly topological module if M is a Hausdorff space with continuous addition and continuous mapping M x R ~ M and M contains a basis filter of submodules. A linearly topological module M is called linearly compact if for each filter ~,~ = {Fa} consisting of cosets of closed R-submodules the intersection 0 Fx is not empty. A linearly compact module M is defined to be strictly linearly compact if any factor module of M by an open submodule in Artinian. By [7, Satz 4], a module M is strictly linearly compact if and only if every continuous homomorphism of M in a linearly topological module is open. A ring R is called linearly compact (strictly linearly compact) if R as a right R-module is linearly compact (strictly linearly compact, respectively). If R has a basis filter consisting of two-sided ideals, then we say that R has an ideal basis filter. For basic results concerning linearly compact modules and rings we refer to [7], [8], [11]. Obviously right Artinian rings are strictly linearly compact rings (with the discrete topology). Let X be a set. Then the cardinality of X is denoted by card (X). For topological tings we here introduce a similar notation.

Taiwanese Journal of Mathematics, 2013

Taiwanese Journal of Mathematics, 2014

Communications in Physics, 2012

The 2012 International Conference on Advanced Technologies for Communications, 2012

ABSTRACT Deployment of wireless sensor networks always faces the issue of energy limitation. With... more ABSTRACT Deployment of wireless sensor networks always faces the issue of energy limitation. Without appropriate control policy, data messages might be routed over already-exhausted routes, quickly disrupting network connectivity. If a node transmits data at an excessively high power level, it not only depletes its own energy budget wastefully, but also interferes in other parallel transmissions. In this study, we introduce a cooperative power control strategy in which nodes of routes jointly tune their transmit power regularly over time and upon route setup. Tuning is made under hints of surrounding nodes. Routes are selected based on link metrics that is a function of signal strength, remaining energy, and path loss. To keep balancing power consumption among nodes, energy-aware established routes are considered re-routing periodically. Transmit power of each node is set at a level is just high enough under the hint of its adjacent downstream node. Simulation outputs do demonstrate the soundness of our proposals with respect to connectivity and throughput.

Annales Polonici Mathematici, 2005

... A bounded open set Ω in Cn is said to be hyperconvex if there is a negative plurisubharmonic ... more ... A bounded open set Ω in Cn is said to be hyperconvex if there is a negative plurisubharmonic exhaustion function for Ω. It is a well known result of Kerzman and Rosay (see [KR]) that every bounded pseudoconvex open set with C1 smooth boundary in Cn is hyper-convex. ...

Algebra Colloquium, 2007

We study two classes of Artinian modules called co-Buchsbaum modules and generalized co-Cohen–Mac... more We study two classes of Artinian modules called co-Buchsbaum modules and generalized co-Cohen–Macaulay modules. Some basic properties and characterizations of these modules in terms of 𝔮-weak co-sequences, co-standard sequences, multiplicity, local homology ...

Vietnam Journal of Mathematics, 2014

Contemporary Mathematics, 2006

Communications in Physics, 2013

Applied Physics Letters, 2014

ABSTRACT Schottky junctions (SJ) are considered devices for sensing applications due to their uni... more ABSTRACT Schottky junctions (SJ) are considered devices for sensing applications due to their unique properties. Herein, we report on the design, facile fabrication, and outstanding NO2 gas sensing properties of monolayer graphene (GP)/SnO2 nanowire (NW) SJ devices. The devices were prepared by directly growing single crystal SnO2 NWs on interdigitated Pt electrodes via thermal evaporation, followed by transferring a GP layer grown by chemical vapor deposition on top of the NW chip. The SJ-based sensor showed a reversible response to NO2 gas at concentrations of ppb levels with detection limits of about 0.024 ppb at a low operating temperature of 150 °C and bias voltage (1 V) with a response/recovery time of less than 50 s. The outstanding gas-sensing characteristics of the device were attributed to tuning the Schottky barrier height and barrier width at the tiny area of contact between GP and SnO2 NW through the adsorption/desorption of gas molecules.

Radiation Physics and Chemistry, 1995

rhe acrylamide was grattrd by radiatlon onto starth which is a kind polymeric biomaterial.The ure... more rhe acrylamide was grattrd by radiatlon onto starth which is a kind polymeric biomaterial.The urease was immobilized on the grattrd stnrc h.Somr experiments to observe the quantitative relationshlps between the percent gratt and th(l nc-tivily of immobilized enzyme were determined.The enzyme ac-tivlty was maintained by morc2 thdn sclvrn batch enzyme reactions.

Physica B: Condensed Matter, 2003

Co 75 Fe 5 Si 12 B 8 and Fe 73.5 Nb 3 CuB 9 Si 13.5 ribbons, showing the high magnetoimpedance ef... more Co 75 Fe 5 Si 12 B 8 and Fe 73.5 Nb 3 CuB 9 Si 13.5 ribbons, showing the high magnetoimpedance effect of about 50% under an applied field of 56 Oe, have been obtained by rapid quenching in air. The Co-based ribbons, used as a magnetoimpedance sensor in a simple magnetic field measurement circuit based on a Colpitts high-frequency generator, showed a field sensitivity of 1.2 mV/Oe. r 2002 Published by Elsevier Science B.V.

Kodai Mathematical Journal, 1999

Let V be the complex vector space C 7 , s/ an arrangement in V, i.e. a finite family of hyperplan... more Let V be the complex vector space C 7 , s/ an arrangement in V, i.e. a finite family of hyperplanes in V In , Moishezon associated to any algebraic plane curve <# of degree n a braid monodromy homomorphism θ F s -> B(n), where F s is a free group, B(ή) is the Artm braid group. In this paper, we will determine the braid monodromy for the case when # is an arrangement stf of complex lines in C 2 , using the notion of labyrinth of an arrangement. As a corollary we get the braid monodromy presentation for the fundamental group of the complement to the arrangement.

Glasgow Mathematical Journal, 1992

Relationships between injectivity or generalized injectivity and chain conditions on a module cat... more Relationships between injectivity or generalized injectivity and chain conditions on a module category have been studied by several authors. A well-known theorem of Osofsky [14, 15] asserts that a ring all of whose cyclic right modules are injective is semisimple Artinian. Osofsky's proofs in [14, 15] essentially used homological properties of injective modules, and, later, her arguments were applied by other authors in their studies of rings for which cyclic right modules are quasi-injective, continuous or quasi-continuous (see e.g. [1, 10, 12]). Following [5] (cf. [4]), a module M is called a CS-module if every submodule of M is essential in a direct summand of M. In the recent paper [17], B. L. Osofsky and P. F. Smith have proved a very general theorem on cyclic completely CS-modules from which many known results in this area follow rather easily. In another direction, it was proved in [8] that a finitely generated quasi-injective module with ACC (respectively DCC) on essential submodules is Noetherian (respectively Artinian). This result was also extended to CS-modules in [3, 16], and weak CS-modules in [19].

Fixed Point Theory and Applications, 2013

In this paper, we prove a fixed point theorem on a 2-metric space and show that the main results ... more In this paper, we prove a fixed point theorem on a 2-metric space and show that the main results in Lahiri et al. (Taiwan. J. Math. 15:337-352, 2011) and Singh et al. (J. Adv. Math. Stud. 5:71-76, 2012) may be obtained easily from the axioms of a 2-metric space. Examples are given to validate the results.

Archiv der Mathematik, 1988

ABSTRACT 1. Introduction. Throughout this paper we consider associative rings with identity and u... more ABSTRACT 1. Introduction. Throughout this paper we consider associative rings with identity and unitary modules. A filter Y is a system of subsets of a topological space such that if F u, F~ ~ ~, then there exists a subset F2 ~ o ~ with 0 4= Fz ~ Fun F~. Let R be a ring and M be a right R-module. M is called a linearly topological module if M is a Hausdorff space with continuous addition and continuous mapping M x R ~ M and M contains a basis filter of submodules. A linearly topological module M is called linearly compact if for each filter ~,~ = {Fa} consisting of cosets of closed R-submodules the intersection 0 Fx is not empty. A linearly compact module M is defined to be strictly linearly compact if any factor module of M by an open submodule in Artinian. By [7, Satz 4], a module M is strictly linearly compact if and only if every continuous homomorphism of M in a linearly topological module is open. A ring R is called linearly compact (strictly linearly compact) if R as a right R-module is linearly compact (strictly linearly compact, respectively). If R has a basis filter consisting of two-sided ideals, then we say that R has an ideal basis filter. For basic results concerning linearly compact modules and rings we refer to [7], [8], [11]. Obviously right Artinian rings are strictly linearly compact rings (with the discrete topology). Let X be a set. Then the cardinality of X is denoted by card (X). For topological tings we here introduce a similar notation.