425 research outputs found

    Some algorithms related to consistent decision table

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    Rough set theory is useful mathematical tool developed to deal with vagueness and uncertainty. As an important concept of rough set theory, an attribute reduct is a subset of attributes that are jointly sufficient and individually necessary for preserving a particular property of the given information table. Rough set theory is also the most popular for generating decision rules from decision table. In this paper, we propose an algorithm finding object reduct of consistent decsion table. On the other hand, we also show an algorithm to find some attribute reducts and the correctness of our algorithms is proof-theoretically. These our algorithms have polynomial time complexity. Our finding object reduct helps other algorithms of finding attribute reducts become more effectively, especially as working with huge consistent decision table

    Trichinellosis in Vietnam

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    Trichinellosis is a zoonotic parasitic disease with a worldwide distribution. The aim of this work was to describe the epidemiological and clinical data of five outbreaks of trichinellosis, which affected ethnic minorities living in remote mountainous areas of northwestern Vietnam from 1970 to 2012. Trichinellosis was diagnosed in 126 patients, of which 11 (8.7%) were hospitalized and 8 (6.3%) died. All infected people had consumed raw pork from backyard and roaming pigs or wild boar at wedding, funeral, or New Year parties. The short incubation period (average of 9.5 days), the severity of the symptoms, which were characterized by diarrhea, abdominal pain, fever, myalgia, edema, weight loss, itch, and lisping, and the high mortality, suggest that patients had ingested a high number of larvae. The larval burden in pigs examined in one of the outbreaks ranged from 70 to 879 larvae/g. These larvae and those collected from a muscle biopsy taken from a patient from the 2012 outbreak were identified as Trichinella spiralis. Data presented in this work show that the northern regions of Vietnam are endemic areas for Trichinella infections in domestic pigs and humans

    Whether or not the informal economy as an engine for poverty alleviation in Vietnam

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    This paper examines impacts of income from informal employment and informal sector employment on poverty in Vietnam to define whether the informal economy is an accelerator or a decelerator of poverty. Using data from Vietnam Household Living Standard Surveys, we find that although income from informal sources does not account for a large proportion to total income of the poor households in comparison with the non-poorhouseholds, it significantly contributes to poverty reduction. Without earnings from informal sources, 33.4 per cent of the surveyed households in 2010 live under the poverty line and this rate is only 10.34 per cent if informal income is added up. Both probit and quantile analysis affirms that informal earnings significantly mitigate poverty. Interesting findings from quantile regression are that informal earnings have divergent effects across distribution of household income. Particularly, it is a factor reducing poverty in poor households but it negatively affects the economic capacity of the rich households. The policy implication derived from empirical results is that poverty program should be associated with supporting policy for informal employees with low income so that they can improve their living standards

    Whether or not the informal economy as an engine for poverty alleviation in Vietnam

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    This paper examines impacts of income from informal employment and informal sector employment on poverty in Vietnam to define whether the informal economy is an accelerator or a decelerator of poverty. Using data from Vietnam Household Living Standard Surveys, we find that although income from informal sources does not account for a large proportion to total income of the poor households in comparison with the non-poorhouseholds, it significantly contributes to poverty reduction. Without earnings from informal sources, 33.4 per cent of the surveyed households in 2010 live under the poverty line and this rate is only 10.34 per cent if informal income is added up. Both probit and quantile analysis affirms that informal earnings significantly mitigate poverty. Interesting findings from quantile regression are that informal earnings have divergent effects across distribution of household income. Particularly, it is a factor reducing poverty in poor households but it negatively affects the economic capacity of the rich households. The policy implication derived from empirical results is that poverty program should be associated with supporting policy for informal employees with low income so that they can improve their living standards

    Hybrid Magnetic-Semiconductor Oxides Nanomaterial: Green Synthesis and Environmental Catalytic

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    Semiconductor oxide nanoparticles with various properties are used in applications such as photocatalysis, lithium-ion batteries, antimicrobial materials, magnetic and antibacterial materials, sensors, thermally conductive and anti-ferromagnetic films and photocatalysis. Coprecipitation, sol-gel, electrospray synthesis, laser ablation, hydrothermal and green synthesis methods have been developed for the synthesis of semiconductor oxide nanoparticles. The photocatalytic treatment method is environmentally friendly, thorough, and has high efficiency. Hybrid magnetic-Semiconductor oxide nanoparticles materials are aggregated. This results in the combination of the superparameters of the iron oxide nanosystem and the ability to rapidly adsorb pollutants and separate them from environmental water, solid. This is due to characteristic properties such as low superparameter, low toxicity, low electrical conductivity, and large specific surface area. In addition, biosynthesis has attracted attention because it takes advantage of nonhazardous, environmentally friendly biological systems like bacteria, fungi, leaves, vitamins, and yeast to synthesize metal oxide nanopartilces and combined with sonosumbers to increase the dispersion of the system, reduce the size of the catalytic particles, and reduce the reaction time

    Evaluation of water loss and solute uptake during osmotic treatment of white radishes (Raphanus sativus L.) in salt-sucrose solution

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    White radish, scientifically known as Raphanus sativus L., is a yearly vegetable. Currently, it was being grown and widely used in the world, including Vietnam. These plants have been used as food or food processing. The osmotic treatment of vegetables involves the removal of water from plants in which the solids from the osmotic solution are transported to the plant material by osmosis. By this procedure, sucrose and saline solution are usually performed. White radishes were dehydrated in different hypertonic solutions by combined sucrose and NaCl at three different concentrations, including 9 runs. Mass transfer behaviour was applied according to three common models such as Fick’s second law, Weibull and Peleg’s equations based on the change of moisture and solid content of white radish during osmotic dehydration. The obtained results showed that the mass transfer was fast at initial stage and became slowly at the later stage. The effective moisture (Dm) and solid diffusivities (Ds) were ranged from 1.0186 to 1.2826x10-8 and from 1.0692 to 2.3322x10-8 (m2/s) respectively. The Peleg’s equation was found to be the best fitting for water loss and solid uptake thanks to the high determination coefficient (>97.64%) and the low average relative error (<3.174%). Raised up solution concentration resulted in higher water loss and mass gain

    Density Functional Based Tight Binding Study on Wurzite Core-Shell Nanowires Heterostructures Zno/Zns

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    We present a Density Functional Based Tight Binding study on the crystallography and electronic structures of various II-VI wurtzite core-shell, core-multi-shell ZnO/ZnS unsaturated nanowires (NW) of circular and hexagonal cross sections and examine the dependence of interface stress and formation energy on nanowire lateral size with diameter range from 20A˚\mathring{A} upto 40A˚\mathring{A}. Young's modulus of the wires along the axial growth direction have been estimated. Also the tensile tests have been applied for various wires to show the diameter dependences of their mechanical properties. The electronic properties of these heterostructure nanowires (e.g., Projected Band Structure, Density of State, charge transfer via Mulliken population analysis) also exhibit diameter-dependent behavior

    Dynamic Analysis of Mindlin Plates Resting on a Viscoelastic Foundation Subjected to Moving Loads During Abrupt Braking using Moving Element Method

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    The paper proposes a new computational approach using the moving element method (MEM) for simulating the dynamic responses of Mindlin plate resting on a viscoelastic foundation subjected to moving loads during abrupt braking. In this approach, the governing equations as well as the plate element mass, damping and stiffness matrices are formulated in a convected coordinate in which the origin is attached to the applied point of the moving load. Thus, the proposed method simply treats the moving loads as ‘stationary’ at the nodes of the plate to avoid updating the locations of moving loads due to the change of the contact points on the plate. The interaction between the moving load and the plate during abrupt braking is accounted for through the vertical force and tangential wheel-pavement friction force. The effects of wheel sliding, load deceleration magnitude, friction coefficient, and plate thickness on the dynamic responses of plate are investigated

    An Analytical Framework Considering the Effects of Online Teaching Quality on Student Satisfaction

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    COVID-19 spreads across the world in late 2019 has affected to several aspects of social life. One of the most important sectors, which face difficulties was education, thus most universities have transferred from traditional education to online education through the internet to make their academic year going. This study aims to review the effects of online teaching quality on student satisfaction, a positive attitude resulting from an evaluation of students’ online teaching experience in higher education. Through applying the SERVQUAL model to measure the effects of online teaching quality on students’ satisfaction, it can be expected to get better the online teaching quality of higher education institutions in Vietnam. Keywords: Online teaching, student satisfaction, higher education, COVID-19, educational institution. DOI: 10.7176/EJBM/13-6-08 Publication date:March 31st 202

    Density Functional Based Tight Binding Study on Wurtzite ZnO Prismatic Nanoparticles

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    We have performed the Density Functional Tight Binding (DFTB) study on the structural properties of Zinc Oxide Nanoparticles (NP), focusing on the effects induced by the surfaces and quantum size effect. Effects of surface relaxation and surface stress which is absent in atomistic model are taken carefully into account. The studying Nanoparticle size range up to 2.3nm. We illustrated the structural properties changes by decreasing NP sizes while the typical length of surface relaxation (about 1nm) remain unchanged and comparable with the particle size. The NP electronic properties, i.e. Density of State (DOS), charge transfer in hetero-bond also showed the deviation from bulk material value
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