Nguyen Tuan - Academia.edu (original) (raw)

Papers by Nguyen Tuan

Journal of Computer Science and Cybernetics, 2014

Journal of Computer Science and Cybernetics, 2012

Journal of Computer Science and Cybernetics. Open Journal Systems. Journal Help. User Username, P... more Journal of Computer Science and Cybernetics. Open Journal Systems. Journal Help. User Username, Password, Remember me. Language English. ...

Based on the well-known necessary and su-cient condition for the linear-fractional function to be... more Based on the well-known necessary and su-cient condition for the linear-fractional function to be the generator of a cyclic group of n-terms, this paper describes the general form of all linear-fractional functions which are Carleman shifts on the unit circle. Our main result deals with the solvability in a closed form for a class of singular integral equations with Carleman

Page 1. ACTA MATHEMATICA VIETNAMICA Volume 21, Number 2, 1996, pp. 201–211 201 ON A CLASS OF SING... more Page 1. ACTA MATHEMATICA VIETNAMICA Volume 21, Number 2, 1996, pp. 201–211 201 ON A CLASS OF SINGULAR INTEGRAL EQUATIONS WITH ROTATIONS NGUYEN MINH TUAN Abstract. The paper deals with the singular integral equation ...

Mathematische Nachrichten, 2010

International Education Studies, 2011

... Journal of Vocational and Technical Education, 15(1), 28-41 Harvey, L. (2001).Defining and me... more ... Journal of Vocational and Technical Education, 15(1), 28-41 Harvey, L. (2001).Defining and measuring employability. Quality in Higher Education, 7(2), 97-109, http://dx.doi.org/10.1080/13538320120059990 Holmes, L. (2001). ...

Integral Equations and Operator Theory, 2009

In this paper we present the operational properties of two integral transforms of Fourier type, p... more In this paper we present the operational properties of two integral transforms of Fourier type, provide the formulation of convolutions, and obtain eight new convolutions for those transforms. Moreover, we consider applications such as the construction of normed ring structures on $L_{1}({\mathbb{R}})$ , further applications to linear partial differential equations and an integral equation with a mixed Toeplitz-Hankel kernel.

Environmental Science & Policy, 2006

The accumulation and inadequate management of obsolete pesticides and other hazardous chemicals c... more The accumulation and inadequate management of obsolete pesticides and other hazardous chemicals constitutes a threat for health and environment, locally, regionally and globally. Estimates indicate that more than 500,000 tonnes of obsolete pesticides are accumulated globally, especially in developing countries. FAO has been addressing this issue and disposed of approximately 3000 tonnes of obsolete pesticides in Africa and the Near East since the beginning of the 1990s. These pesticide wastes have mainly been shipped to Europe for high-temperature combustion in dedicated incinerators, a treatment option usually not available in developing countries.High temperature cement kilns are however commonly available in most countries and have shown to constitute an affordable, environmentally sound and sustainable treatment option for many hazardous chemicals if adequate procedures are implemented. Cement kilns have been used for disposal of obsolete pesticides in developing countries earlier but no study has been able to verify the destruction efficiency in an unambiguous way. Lessons learned from earlier experiences were used to carry out a test burn with two obsolete insecticides in a cement kiln in Vietnam. The destruction efficiency was measured to be better than 99.9999969% for Fenobucarb and better than 99.9999832% for Fipronil and demonstrated that the hazardous chemicals had been destroyed in an irreversible and environmental sound manner without new formation of dioxins, furans, hexachlorobenzene or PCBs, a requirement of the Stockholm Convention on POPs.

Applied Mathematics and Optimization, 2008

First and second-order approximations are used to establish both necessary and sufficient optimal... more First and second-order approximations are used to establish both necessary and sufficient optimality conditions for local weak efficiency and local firm efficiency in nonsmooth set-constrained vector problems. Even continuity and relaxed convexity assumptions are not imposed. Compactness conditions are also relaxed. Examples are provided to show advantages of the presented results over recent existing ones.

Communications in Physics, 2014

Vietnam Journal of Mechanics, 2012

Communications in Physics, 2012

In this work, we study theoretically the long-range magnetic interaction between two parallel fer... more In this work, we study theoretically the long-range magnetic interaction between two parallel ferromagnetic plates, which arises from the magnetic Casimir effect. The behavior of the interaction is discussed for two configurations when the magnetization is perpendicular or parallel to the plates. The dependence of the Casimir force and Casimir energy on different interplate distances D has been investigated. Results of numerical calculations for a Cobalt system have been also presented.

Human Genetics, 1991

The incidence of allotypes of the genes of the fourth component (C4) and factor B of the compleme... more The incidence of allotypes of the genes of the fourth component (C4) and factor B of the complement system was compared in 252 persons under 45 years of fage (“young” group) with 482 people between 61 and 90 years of age (“old” group). One hundred people older than 90 years of age (nonagenarians) were also investigated. A striking difference was found between the “young” and “old” groups in the incidence (16.1% and 5.4%, respectively) of a silent gene of the C4B allele (C4B✸Q0). This difference was even more marked among “young” and “old” men (17.6% vs 3.4%). The incidence of the C4B✸Q0 allele in women dropped to the level of the men only in the nonagenarian group. The most probable explanation for this finding is that people carrying the C4B✸QO allele die from as yet unidentified disease(s) in their middle-age. Therefore, male (and to a lesser extent female) carriers of this allele may have a considerably shorter life expectancy than individuals without a silent gene in the C4B locus.

To study patterns and determinants of HIV prevalence and risk-behaviour characteristics in differ... more To study patterns and determinants of HIV prevalence and risk-behaviour characteristics in different population groups in four border provinces of Viet Nam. We surveyed four population groups during April-June 2002. We used stratified random-cluster sampling and collected data concomitantly on HIV status and risk behaviours. The groups included were female sex workers (n = 2023), injecting drug users (n = 1391), unmarried males aged 15-24 years (n = 1885) and different categories of mobile groups (n = 1923). We found marked geographical contrasts in HIV prevalence, particularly among female sex workers (range 0-24%). The HIV prevalence among injecting drug users varied at high levels in all provinces (range 4-36%), whereas lower prevalences were found among both unmarried young men (range 0-1.3%) and mobile groups (range 0-2.5%). All groups reported sex with female sex workers. Less than 40% of the female sex workers had used condoms consistently. The strongest determinants of HIV infection among female sex workers were inconsistent condom use (adjusted odds ratio [OR], 5.3; 95% confidence interval [CI], 2.4-11.8), history of injecting drug use and mobility, and, among injecting drug users, sharing of injection equipment (adjusted OR, 7.3; 95% CI, 2.3-24.0) and sex with non-regular partners (adjusted OR 3.4; 95% CI 1.4-8.5). The finding of marked geographical variation in HIV prevalence underscores the value of understanding local contexts in the prevention of HIV infection. Although lacking support from data from all provinces, there would appear to be a potential for sex work to drive a self-sustaining heterosexual epidemic. That the close links to serious injecting drug use epidemics can have an accelerating effect in increasing the spread of HIV merits further study.

North American Journal of Aquaculture, 2003

Abstract.Because bluegills Lepomis macrochirus are considered important both as a source of fora... more Abstract.Because bluegills Lepomis macrochirus are considered important both as a source of forage for largemouth bass Micropterus salmoides and as a sport fish, there is strong demand for juveniles and subadults for stocking purposes. Although spawning and extensive ...

Aquaculture, 2002

Responses of Nile tilapia to varying concentrations of aflatoxin B1 (AFB) were investigated under... more Responses of Nile tilapia to varying concentrations of aflatoxin B1 (AFB) were investigated under controlled laboratory conditions. Nile tilapia (2.7 g) were fed semipurified diets containing 0, 0.25, 2.5, 10, or 100 mg AFB/kg of diet for 8 weeks. Weight gain and hematocrit of fish fed with 0.25 mg AFB/kg were not significantly different from that of the control; however, diets containing higher levels of AFB had significantly (P<0.05) reduced weight gain and hematocrit. Histologically, livers of fish fed with diets containing 10 mg AFB/kg contained excess lipofuscin and irregularly sized hepatocellular nuclei. Diets containing 100 mg AFB/kg caused weight loss and severe hepatic necrosis; 60% of the fish in this treatment died by the end of the 8-week feeding period. No lesions were observed in the spleen, stomach, pyloric intestine, head kidney, or heart of fish in all treatments. These results indicate that acute and subchronic effects of AFB to Nile tilapia are unlikely if dietary concentrations are 0.25 mg/kg or less.

Wear, 1993

... Wear, 74 (1981) 67-83. 3 Nguyen Anh Tuan, Pham Van Khoi and Ngo Nhat Thai, Some problems conc... more ... Wear, 74 (1981) 67-83. 3 Nguyen Anh Tuan, Pham Van Khoi and Ngo Nhat Thai, Some problems concerning wear of diesel piston-ring, EUROTRIB'89, 5th Int. Tribology Congr., Helsinki, June 12-15, 1989, Finnish Society for Tribology, Vol. 5, 1989. ...

physica status solidi (c), 2007

A systematic study of exchange bias in MnPd/Co bilayers has been carried out in both parallel and... more A systematic study of exchange bias in MnPd/Co bilayers has been carried out in both parallel and perpendicular directions, where the dependences of blocking temperature, exchange bias and unidirectional anisotropy constant on the thicknesses of MnPd and Co layers were investigated. One of the particular interests is that the blocking temperature of parallel exchange bias is higher than that of perpendicular exchange bias which can be interpreted as the difference of the ordering in parallel and perpendicular direction. The other is that a huge unidirectional anisotropy constant, J K = 5.5 erg/cm 2 was observed, which is in reasonable agreement with the theoretical prediction based on the model by Meiklejohn and Bean.

physica status solidi (a), 2009

Exchange bias has been studied for a series of MnPd/Co bilayers sputtered onto Si(100) by an RF s... more Exchange bias has been studied for a series of MnPd/Co bilayers sputtered onto Si(100) by an RF sputter-deposition system. The double-shifted loops with an anomalous training effect have been observed. The manifestation of doubleshifted loops is interpreted as the coexistence of positive exchange bias and negative exchange bias, which is in agreement with the temperature dependence and the observed anomalous training effect.

Physica B: Condensed Matter, 2003

High coercivity was obtained in Co-Cu granular films, RF sputtered on Si(1 0 0) substrates, when ... more High coercivity was obtained in Co-Cu granular films, RF sputtered on Si(1 0 0) substrates, when the Co content is less than about 40 at% and annealed at high temperatures. Perpendicular anisotropy was observed in the Co-rich films, where the Co content is not less than about 40 at% atom. The reasons for the high coercivity and the perpendicular anisotropy in these Co-Cu films are discussed. r 0921-4526/03/$ -see front matter r 2002 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 1 -4 5 2 6 ( 0 2 ) 0 1 7 5 7 -X