305 research outputs found
Intrinsic limits governing MBE growth of Ga-assisted GaAs nanowires on Si(111)
Diffusion-enhanced and desorption-limited growth regimes of Ga-assisted GaAs
nanowires were identified. In the latter regime, the number of vertical NWs
with a narrow length distribution was increased by raising the growth
temperature. The maximum axial growth rate; which can be quantified by the
supplied rate of As atoms, is achieved when a dynamical equilibrium state is
maintained in Ga droplets i.e. the number of impinging As atoms on the droplet
surface is equivalent to that of direct deposited Ga atoms combining with the
diffusing ones. The contribution of Ga diffusion to the wire growth was
evidenced by the diameter-dependent NW axial growth rate
Evaluation of plant growth regulators on root formation of semihardwood and hardwood cuttings of Sarcandra glabra (Thunb.) Nakai
The aim of this study is to evaluate the effects of three types of plant growth regulators (α- naphthyl acetic acid, indole-3-acetic acid and β-indol butyric acid) on the root formation of the semihardwood and hardwood cuttings of Sarcandra glabra (Thunb.) Nakai. The effects of plant growth regulators on root formation were evaluated based on living percentage, rooting percentage, secondary rooting percentage, and the number and the length of roots. The results showed that the best root growth regulator was β-IBA. The overall effective concentrations of growth regulators were 1.0 and 1.5%. The living percentage of the semihardwood cuttings was lower than that of the hardwood cuttings. However, the root growth parameters of the semihardwood cuttings were better than those of the hardwood cuttings.
CARE Rapid Gender Analysis for COVID-19
Vietnam reported its first known case of COVID-19 on 23 January 2020. As of 19 May, the country had 324 confirmed cases, with 263 recoveries and no deaths.
In Vietnam, COVID-19 presents a range of contextual challenges including high numbers of migrant workers, high numbers of employees in the garment industry, many people working in the informal sector, and linguistically and culturally diverse ethnic minorities. The impacts of COVID-19 on vulnerable groups, such as migrant workers, informal workers, garment factory workers, and ethnic minorities are further marginalising these groups, exacerbating poverty and inequality and increasing their exposure to other social, economic and protection risks.
Women in Vietnam have historically been underrepresented in public decision-making processes, a trend that is reflected in high-level decision-making structures on COVID-19. This means that even as women are disproportionately affected by the crisis, they have less say in how their country should respond to it
CARE Rapid Gender Analysis for COVID-19 VIETNAM
Vietnam reported its first known case of COVID-19 on 23 January 2020. As of 19 May, the country had 324 confirmed cases, with 263 recoveries and no deaths. In Vietnam, COVID-19 presents a range of contextual challenges including high numbers of migrant workers, high numbers of employees in the garment industry, many people working in the informal sector, and linguistically and culturally diverse ethnic minorities. The impacts of COVID-19 on vulnerable groups, such as migrant workers, informal workers, garment factory workers, and ethnic minorities are further marginalising these groups, exacerbating poverty and inequality and increasing their exposure to other social, economic and protection risks
Updated molecular phylogenetic data for Opisthorchis spp. (Trematoda: Opisthorchioidea) from ducks in Vietnam
Background: An opisthorchiid liver fluke was recently reported from ducks (Anas platyrhynchos) in Binh Dinh Province of Central Vietnam, and referred to as "Opisthorchis viverrini-like". This species uses common cyprinoid fishes as second intermediate hosts as does Opisthorchis viverrini, with which it is sympatric in this province. In this study, we refer to the liver fluke from ducks as "Opisthorchis sp. BD2013", and provide new sequence data from the mitochondrial (mt) genome and the nuclear ribosomal transcription unit. A phylogenetic analysis was conducted to clarify the basal taxonomic position of this species from ducks within the genus Opisthorchis (Digenea: Opisthorchiidae).
Methods: Adults and eggs of liver flukes were collected from ducks, metacercariae from fishes (Puntius brevis, Rasbora aurotaenia, Esomus metallicus) and cercariae from snails (Bithynia funiculata) in different localities in Binh Dinh Province. From four developmental life stage samples (adults, eggs, metacercariae and cercariae), the complete cytochrome b (cob), nicotinamide dehydrogenase subunit 1 (nad1) and cytochrome c oxidase subunit 1 (cox1) genes, and near-complete 18S and partial 28S ribosomal DNA (rDNA) sequences were obtained by PCR-coupled sequencing. The alignments of nucleotide sequences of concatenated cob + nad1 + cox1, and of concatenated 18S + 28S were separately subjected to phylogenetic analyses. Homologous sequences from other trematode species were included in each alignment.
Results: Phylogenetic trees were inferred from concatenated (cob + nad1 + cox1) nucleotide sequences and combined 18S + 28S nucleotide sequences of five Opisthorchis sp. BD2013 samples and additional reference taxa. Both trees demonstrated the anticipated clustering of taxa within the superfamily Opisthorchioidea, the paraphyly of the genus Opisthorchis and the sister-species relationship of Opisthorchis sp. BD2013 with O. viverrini.
Conclusions: While it is likely that Opisthorchis sp. BD2013 is distinct from O. viverrini, it is clearly a sister taxon of O. viverrini within the limited number of Opisthorchis species for which appropriate sequence data are available. The new sequences provided here will assist the diagnosis and the taxonomic clarification of the opisthorchiid species
VulCurator: A Vulnerability-Fixing Commit Detector
Open-source software (OSS) vulnerability management process is important
nowadays, as the number of discovered OSS vulnerabilities is increasing over
time. Monitoring vulnerability-fixing commits is a part of the standard process
to prevent vulnerability exploitation. Manually detecting vulnerability-fixing
commits is, however, time consuming due to the possibly large number of commits
to review. Recently, many techniques have been proposed to automatically detect
vulnerability-fixing commits using machine learning. These solutions either:
(1) did not use deep learning, or (2) use deep learning on only limited sources
of information. This paper proposes VulCurator, a tool that leverages deep
learning on richer sources of information, including commit messages, code
changes and issue reports for vulnerability-fixing commit classifica- tion. Our
experimental results show that VulCurator outperforms the state-of-the-art
baselines up to 16.1% in terms of F1-score. VulCurator tool is publicly
available at https://github.com/ntgiang71096/VFDetector and
https://zenodo.org/record/7034132#.Yw3MN-xBzDI, with a demo video at
https://youtu.be/uMlFmWSJYOE.Comment: accepted to ESEC/FSE 2022, Tool Demos Trac
A Solution of Plane Stress Problem Subjected to Horizontal Shear Force by Using Polynomial Airy Stress Function
Many structural analysis problems in civil engineering and mechanical engineering can be treated as plane stress and plane strain problems introduced in the theory of elasticity. One of the popular analytical methods to tackle plane analysis is to determine Airy stress function. In general, the Airy stress function depends on the analyzed domain and the applied loads; however, the number of problems that can be solved by employing this method is limited because of the formidable challenges of guessing trial function. In many cases, the trial Airy stress functions are selected based on the results of a simple beam model or experimental results. This paper introduces a solution of the plane stress subjected to horizontal shear forces by using a polynomial Airy stress function, in which the trail function is predicted from the results of the elementary beam theory of an equivalent model. The numerical investigation on stress distributions was presented, and it showed that although the internal shear force acting on cross-sections have not appeared, shear stress still appeared, and the shear stress diagram had both negative and positive areas
A Solution of Plane Stress Problem Subjected to Horizontal Shear Force by Using Polynomial Airy Stress Function
Many structural analysis problems in civil engineering and mechanical engineering can be treated as plane stress and plane strain problems introduced in the theory of elasticity. One of the popular analytical methods to tackle plane analysis is to determine Airy stress function. In general, the Airy stress function depends on the analyzed domain and the applied loads; however, the number of problems that can be solved by employing this method is limited because of the formidable challenges of guessing trial function. In many cases, the trial Airy stress functions are selected based on the results of a simple beam model or experimental results. This paper introduces a solution of the plane stress subjected to horizontal shear forces by using a polynomial Airy stress function, in which the trail function is predicted from the results of the elementary beam theory of an equivalent model. The numerical investigation on stress distributions was presented, and it showed that although the internal shear force acting on cross-sections have not appeared, shear stress still appeared, and the shear stress diagram had both negative and positive areas
An Extended RFM Model for Customer Behaviour and Demographic Analysis in Retail Industry
Background: Customer segmentation has become one of the most innovative ways which help businesses adopt appropriate marketing campaigns and reach targeted customers. The RFM model and machine learning combination have been widely applied in various areas. Motivations: With the rapid increase of transactional data, the RFM model can accurately segment customers and provide deeper insights into customers’ purchasing behaviour. However, the traditional RFM model is limited to 3 variables, Recency, Frequency and Monetary, without revealing segments based on demographic features. Meanwhile, the contribution of demographic characteristics to marketing strategies is extremely important. Methods/Approach: The article proposed an extended RFMD model (D-Demographic) with a combination of behavioural and demographic variables. Customer segmentation can be performed effectively using the RFMD model, K-Means, and K-Prototype algorithms. Results: The extended model is applied to the retail dataset, and the experimental result shows 5 clusters with different features. The effectiveness of the new model is measured by the Adjusted Rand Index and Adjusted Mutual Information. Furthermore, we use Cohort analysis to analyse customer retention rates and recommend marketing strategies for each segment. Conclusions: According to the evaluation, the proposed RMFD model was deployed with stable results created by two clustering algorithms. Businesses can apply this model to deeply understand customer behaviour with their demographics and launch efficient campaigns
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