82 research outputs found

    Economic impact of climate change on agriculture: a case of Vietnam

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    Food security, agricultural exports, and livelihoods have improved by rapid agricultural expansion in the previous 30 years. In the coming decades, warming trends and human pressures are expected to exacerbate the impact of climate change on agriculture. A time series of data from 1990 to 2020 examines the economic effects of climate change on Vietnamese farm production. After using the Augmented Dickey-Fuller and Philips-Perron unit root tests, the ARDL bounds testing technique estimates short and long-run cointegration. They found long-run cointegration between the variables. A positive influence of CO2 emissions is identified, although negative impacts of average temperature and rainfall are found. But only in the short term can energy consumption benefit agriculture. Non-climatic factors like crop production and fertiliser consumption have beneficial short- and long-term impacts on agriculture production and yield. Juselius Jhansen As well as proving long-term cointegration between variables. The report advises the Vietnamese government to create and implement many adaptation programmes to preserve the agriculture industry from climate change.Nguyen Van Huong (Faculty of Economics, Hung Yen University of Technology and Education (UTEHY)), Bui Thi Minh Nguyet (Vietnam National University of Forestry), Hoang Van Hung (Faculty of Economics, Hung Yen University of Technology and Education (UTEHY)), Hoang Minh Duc (Faculty of Economics, Hung Yen University of Technology and Education (UTEHY)), Nguyen Van Chuong (University of Financial and Business Administration (UFBA)), Do Minh Tri (Nguyen Van Linh Political School), Phung Van Hien (National Academy of Public Administration (NAPA))Includes bibliographical references

    Study of Multiple Photoneutron Reactions on 197Au Induced by 2.5 GeV Bremsstrahlung

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    We identified eight radionuclides 196^{196}Au, 195^{195}Au, 194^{194}Au, 193^{193}Au, 192^{192}Au, 191^{191}Au, 190^{190}Au, 189^{189}Au formed via the multiple photoneutron reactions 197^{197}Au(γ,kn)197k(\gamma ,kn)^{197 - k}Au with 2.5 GeV\break bremsstrahlung. The yields of radionuclides that decay by emitting γ\gamma -ray were measured using high purity germanium (HPGe) detector coupled to a PC-based multichannel analyzer. In order to improve the accuracy of the experimental results the necessary corrections were made. The obtained results are compared with reference data and the variations of the 197^{197}Au(γ\gamma ,kn)197k^{197 - k}Au reaction yields according to incident bremsstrahlung energy and neutron multiplicity are also discussed

    Fed-LSAE: Thwarting Poisoning Attacks against Federated Cyber Threat Detection System via Autoencoder-based Latent Space Inspection

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    The significant rise of security concerns in conventional centralized learning has promoted federated learning (FL) adoption in building intelligent applications without privacy breaches. In cybersecurity, the sensitive data along with the contextual information and high-quality labeling in each enterprise organization play an essential role in constructing high-performance machine learning (ML) models for detecting cyber threats. Nonetheless, the risks coming from poisoning internal adversaries against FL systems have raised discussions about designing robust anti-poisoning frameworks. Whereas defensive mechanisms in the past were based on outlier detection, recent approaches tend to be more concerned with latent space representation. In this paper, we investigate a novel robust aggregation method for FL, namely Fed-LSAE, which takes advantage of latent space representation via the penultimate layer and Autoencoder to exclude malicious clients from the training process. The experimental results on the CIC-ToN-IoT and N-BaIoT datasets confirm the feasibility of our defensive mechanism against cutting-edge poisoning attacks for developing a robust FL-based threat detector in the context of IoT. More specifically, the FL evaluation witnesses an upward trend of approximately 98% across all metrics when integrating with our Fed-LSAE defense

    Measurement of Thermal Neutron Capture Cross Section and Resonance Integral for the 45^{45}Sc(n,γ)46(n,\gamma)^{46}Sc Reaction with Pulsed Neutrons

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    Thermal neutron capture cross section and resonance integral for the 45^{45}Sc(n,γ)46\gamma )^{46}Sc reaction were measured by the activation method using the 197^{197}Au(n,γ)198\gamma )^{198}Au reaction as a single comparator. The high-purity scandium and gold samples with and without Cd cover with the thickness of 0.5 mm were irradiated in a pulsed neutron field of the 100 MeV electron linac of the Pohang Accelerator Laboratory (PAL). The induced activities in the activated foils were measured with a well calibrated HPGe detector. In order to improve the accuracy of the experimental results the effect of the non-ideal epithermal spectrum was taken in to account by determining the neutron spectrum shape factor (α)\alpha ), and the corrections for the thermal (Gth)_{th}) and the resonance (Gepi)_{epi}) neutron self-shielding effects, the γ\gamma -ray attenuation (Fg)_{g}) and the γ\gamma -ray coincidence summing effect were made. The thermal neutron cross-section for the 45^{45}Sc(n,γ)46\gamma )^{46}Sc reaction has been determined to be σo\sigma _{o} = 27.6 ±\pm 0.8 barn. By assuming the cadmium cut-off energy of 0.55 eV, the resonance integral for the 45^{45}Sc(n,γ)46\gamma )^{46}Sc reaction has been determined to be Io_{o} = 12.7 ±\pm 0.7 bar. The present results are compared with the reference data and discussed

    Integrated Cross Sections of the Photo-Neutron Reactions Induced on 197^{197}Au with 60 MeV\text{MeV} Bremsstrahlung

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    Abstract. Seven photo-neutron reactions 197Au(γ,xn)197-xAu (with x=1-7) produced by the bremsstrahlung end-point energy of 60 MeV were identified. In this work, we focus on the measurement of integrated sections. Experiments were carried out based on the activation method in combination with off-line gamma-ray spectrometric technique. The integrated cross sections of the investigated reactions were determined relative to that of the monitoring reaction 197Au(γ,n)196Au. To validate the experimental results, theoretical predictions were also made using the computer code TALYS 1.9. The current integrated cross-sections of the 197Au(γ,xn)197-xAu reactions with 60 MeV bremsstrahlung end point energy are measured for the first time

    Yield Ratios of the Isomeric Pair 179m,g^{179m,g}W Produced in the nat^{nat}W(g,xn)179m,g^{179m,g}W Reactions with 50-65 MeV Bremsstrahlung

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    In this work we present the yield ratios of the 179m,g^{179m,g}W isomeric pair produced in the photonuclear reactions nat^{nat}W(g,xn)179m,g^{179m,g}W  with bremsstrahlung end-point energies of 50-, 55-, 60-, and 65-MeV. The measurements were carried out by the induced activity method in combination with direct gamma-ray spectrometry. The measured activities were corrected for overlapping gamma-ray peaks, self-absorption of low energy gamma-rays and true coincidence summing effects. The present results  are measured for the first time with bremsstrahlung end-point energies beyond the giant dipole resonance region. The obtained results are discussed with respect to the incident bremsstrahlung energies and reaction channel effect

    Validation of Mesocyclops (Copepoda) and community participation as an effective combination for Dengue control in Northern Vietnam

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    The “Programme Meso-Vietnam” was implemented in Vietnam from October 2007 to December 2010 to reduce dengue and dengue hemorrhagic fever incidence and to improve the quality of life in the four project communes. This dengue control project was based on biological control using Mesocyclops, a larvivorous micro-crustacean, as well as on the establishment of a strong community involvement to educate the population on dengue transmission and to reduce Aedes breeding by removal of containers. During three years, a network of collaborators was responsible for introducing Mesocyclops in all the containers defined as key breeding-sites, and regular activities such as community training workshops, school programmes, clean-up campaigns and health promotion through IEC programmess were performed. To make this programme sustainable, local leadership has been strengthened as well. The use of these larvivorous micro-crustaceans as a biological control strategy against dengue over the medium and long term, when combined with community participation and effective health promotion, demonstrated a significant reduction in dengue vector populations and dengue cases.  In Vietnam, this study reconfirms that there is an ecological alternative to systematic use of insecticides to control dengue vector population. (Abstract word count: 186)Le " Programme Meso-Vietnam " a été mis en œuvre au Vietnam entre octobre 2007 et décembre 2010. Ce programme vise à réduire l'incidence de la dengue et de la fièvre hémorragique de la dengue et à améliorer la qualité de vie dans les quatre communes sélectionnées pour le projet. Ce projet de lutte contre la dengue était basé sur un contrôle biologique assuré par des Mésocyclopes, micro-crustacés larvivores, et sur l'établissement d'une forte implication de la communauté pour éduquer la population sur la transmission de la dengue et pour réduire la reproduction des moustiques Aedes par élimination des conteneurs leur servant de site de ponte. Pendant trois ans, un réseau de collaborateurs a été chargé d'introduire des Mésocyclopes dans tous les conteneurs définis comme des sites de reproduction clés, et des activités régulières telles que des ateliers de formation communautaires, des programmes scolaires, des campagnes de nettoyage et des activités de promotion de la santé via les programmes IEC ont été mises en place. En outre, pour assurer la pérennité de ce programme, le leadership local a été renforcé. L'utilisation de ces micro-crustacés larvivores comme stratégie de contrôle biologique de la dengue à moyen et long terme, associée à une participation communautaire et à une promotion efficace de la santé, a permis d'aboutir à une réduction significative des populations vecteurs de la dengue et des cas de dengue. Au Vietnam, cette étude confirme une fois de plus qu'il existe une alternative écologique à l'utilisation systématique d'insecticides pour lutter contre les vecteurs de la dengue.El “Programa Meso-Vietnam” se implementó en Vietnam desde octubre de 2007 hasta diciembre de 2010 para reducir la incidencia del dengue y la fiebre hemorrágica del dengue y para mejorar la calidad de vida en los cuatro municipios del proyecto. Este proyecto de control del dengue se basaba en el control biológico usando Mesocyclops, un microcrustáceo larvívoro, así como en el establecimiento de una fuerte implicación comunitaria para educar a la población sobre la transmisión del dengue y para reducir la cría de Aedes mediante la eliminación de recipientes. Durante tres años, una red de colaboradores fue responsable de la introducción de Mesocyclops en todos los recipientes definidos como sitios clave para la cría, y se realizaron actividades regulares tales como talleres de formación comunitaria, programas escolares, campañas de limpieza y promoción de la salud a través de programas de IEC. Para hacer sostenible este programa, también se reforzó el liderazgo local. El uso de estos microcrustáceos larvívoros como estrategia de control biológico contra el dengue a medio y largo plazo demostró una reducción significativa de las poblaciones de vectores del dengue y los casos de dengue cuando se combinaba con la participación comunitaria y la promoción eficaz de la salud. En Vietnam, este estudio vuelve a confirmar que existe una alternativa ecológica al uso sistemático de insecticidas para controlar la población de vectores del dengue

    The impact of corporate social responsibility and risk management on financial performance: The case of Vietnamese textile firm

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    The objective of this study is to assess the impact of corporate social responsibility (CSR) and risk management (RM) on financial performance (FP), and evaluate the moderate role of firm size in the relationship between risk management and financial performance. The study was conducted on a re-search sample of 389 Vietnamese textile firms. The results show that corporate social responsibility (CSR) was an optimal measure to minimize risks and improves financial performance. The good CSR policy reduces corporate risk and improves financial performance. Other way, the bad CSR policy increases corporate risk and impacts negatively on financial performance. In addition, the moderate role of firm size in the relationship between risk management and financial performance is statistically significant

    A facile synthesis and properties of bismuth vanadate (BiVO4) photocatalyst by hydrothermal method

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    In this study, BiVO4 photocatalysts were synthesized by hydrothermal method using Bi(NO3)3 5H2O and NH4VO3 as raw materials followed by calcination at different temperatures in the range from 350 °C to 600 °C. The as-synthesized BiVO4 samples were characterized by a number of physicochemical techniques including X-ray diffraction (XRD), Raman analysis, Scanning Electron Microscopy (SEM), and UV-Visible (UV-Vis) light diffuse reflectance spectrophotometry. The effect of temperatures calcination on structure, surface morphology, visible-light photocatalytic activity and light absorption performance of BiVO4 was discussed in details

    The seroprevalence, waning rate, and protective duration of anti-diphtheria toxoid IgG antibody in Nha Trang, Vietnam.

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    BACKGROUND: Diphtheria cases reported in Central Vietnam since 2013 were mainly in children aged 6-15 years, which may reflect an immunity gap. There is little information on population immunity against diphtheria in countries without a school-entry booster dose. We aimed to measure the age-stratified seroprevalence of anti-diphtheria toxoid antibodies, quantify the change in antibody levels in individuals over time, and estimate the length of protective immunity after vaccination in well-vaccinated communities in Vietnam. METHODS: An age-stratified seroprevalence survey among individuals aged 0-55 years was conducted at Nha Trang, Vietnam. The same participants were followed up after two years to quantify the change in antibody levels. IgG was measured using ELISA. The length of protective immunity after vaccination was estimated using a mixed-effect linear regression model with random intercept. RESULTS: Overall seroprevalence was 26% (95%CI:20-32%). Age-stratified seroprevalence was 68% (95%CI:4-11%), 7% (95%CI:4-11%), 12% (95%CI:7-19%), 33% (95%CI:27-40%), and 28% (95%CI:17-43%) among those aged ≤5, 6-15,16-25, 26-35, and 36-55 years, respectively. The antibody levels declined by 47% (95%CI:31-59%) over two years, and the predicted duration of vaccine-derived protective immunity after receiving four doses was 4.3 years (95%CI:3.5-5.3) among participants aged six years or younger. CONCLUSION: Given the low seroprevalence and short period of vaccine protection, a school-entry booster dose (5-7 years) is recommended in Vietnam
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