Finding the best tour for travelling salesman problem using artificial ecosystem optimization

This paper presents a new method based on the artificial ecosystem optimization (AEO) algorithm for finding the shortest tour of the travelling salesman problem (TSP). Wherein, AEO is a newly developed algorithm based on the idea of the energy flow of living organisms in the ecosystem consisting of production, consumption and decomposition mechanisms. In order to improve the efficiency of the AEO for the TSP problem, the 2-opt movement technique is equipped to enhance the quality of the solutions created by the AEO. The effectiveness of AEO for the TSP problem has been verified on four TSP instances consisting of the 14, 30, 48 and 52 cities. Based on the calculated results and the compared results with the previous methods, the proposed AEO method is one of the effective approaches for solving the TSP problem

A hybrid model for aspect-based sentiment analysis on customer feedback: research on the mobile commerce sector in Vietnam

Feedback and comments on mobile commerce applications are extremely useful and valuable information sources that reflect the quality of products or services to determine whether data is positive or negative and help businesses monitor brand and product sentiment in customers’ feedback and understand customers’ needs. However, the increasing number of comments makes it increasingly difficult to understand customers using manual methods. To solve this problem, this study builds a hybrid research model based on aspect mining and comment classification for aspect-based sentiment analysis (ABSA) to deeply comprehend the customer and their experiences. Based on previous classification results, we first construct a dictionary of positive and negative words in the e-commerce field. Then, the POS tagging technique is applied for word classification in Vietnamese to extract aspects of model commerce related to positive or negative words. The model is implemented with machine and deep learning methods on a corpus comprising more than 1,000,000 customer opinions collected from Vietnam's four largest mobile commerce applications. Experimental results show that the Bi-LSTM method has the highest accuracy with 92.01%; it is selected for the proposed model to analyze the viewpoint of words on real data. The findings are that the proposed hybrid model can be applied to monitor online customer experience in real time, enable administrators to make timely and accurate decisions, and improve the quality of products and services to take a competitive advantage

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

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

Dual-layer remote phosphor structure: a novel technique to enhance the color quality scale and luminous flux of WLEDs

The effects of red light-emitting phosphor CaMgSi2O6:Eu2+,Mn2+ on the optical properties of single-layer remote phosphor structure (SRPS) and dual-layer remote phosphor structure (DRPS) are the focus of this study. The differences in color quality and luminous flux (LF) of white light-emitting diodes (WLEDs) between these two structures are also revealed and demonstrated based on the Mie theory. SRPS consists of one mixed phosphor layer betweenCaMgSi2O6:Eu2+,Mn2+ andYAG:Ce3+particles, while DRPS includes two separated layers: red phosphor layer and yellow phosphor layer. In this work, 5% SiO2 is added into the phosphor layers to increase scattering abilities. Discrepancies in structures greatly affect the optical characteristics of WLEDs. The results showed that the color rendering index (CRI) increased with the concentration in both structures with nearly equal values. Meanwhile, color quality scale (CQS) of DPRS is 74 at ACCTs ranging from 5600K to 8500K, higher than CQS of SRPS which is only 71 at 8500K. In addition, the luminous flux of DRPS is significantly higher than SRPS at 2% -14% of CaMgSi2O6:Eu2+,Mn2+. In summary, DRPS is better for color quality and lumen outputin comparison to SRPS and adding the right amount of red phosphor can enhance CQS and LF

Quantifying antimicrobial access and usage for paediatric diarrhoeal disease in an urban community setting in Asia.

OBJECTIVES: Antimicrobial-resistant infections are a major global health issue. Ease of antimicrobial access in developing countries is proposed to be a key driver of the antimicrobial resistance (AMR) epidemic despite a lack of community antimicrobial usage data. METHODS: Using a mixed-methods approach (geospatial mapping, simulated clients, healthcare utilization, longitudinal cohort) we assessed antimicrobial access in the community and quantified antimicrobial usage for childhood diarrhoea in an urban Vietnamese setting. RESULTS: The study area had a pharmacy density of 15.7 pharmacies/km2 (a pharmacy for every 1316 people). Using a simulated client method at pharmacies within the area, we found that 8% (3/37) and 22% (8/37) of outlets sold antimicrobials for paediatric watery and mucoid diarrhoea, respectively. However, despite ease of pharmacy access, the majority of caregivers would choose to take their child to a healthcare facility, with 81% (319/396) and 88% (347/396) of responders selecting a specialized hospital as one of their top three preferences when seeking treatment for watery and mucoid diarrhoea, respectively. We calculated that at least 19% (2688/14427) of diarrhoea episodes in those aged 1 to <5 years would receive an antimicrobial annually; however, antimicrobial usage was almost 10 times greater in hospitals than in the community. CONCLUSIONS: Our data question the impact of community antimicrobial usage on AMR and highlight the need for better education and guidelines for all professionals with the authority to prescribe antimicrobials

HIV-Associated TB in An Giang Province, Vietnam, 2001–2004: Epidemiology and TB Treatment Outcomes

BACKGROUND: Mortality is high in HIV-infected TB patients, but few studies from Southeast Asia have documented the benefits of interventions, such as co-trimoxazole (CTX), in reducing mortality during TB treatment. To help guide policy in Vietnam, we studied the epidemiology of HIV-associated TB in one province and examined factors associated with outcomes, including the impact of CTX use. METHODOLOGY/PRINCIPAL FINDINGS: We retrospectively abstracted data for all HIV-infected persons diagnosed with TB from 2001-2004 in An Giang, a province in southern Vietnam in which TB patients receive HIV counseling and testing. We used standard WHO definitions to classify TB treatment outcomes. We conducted multivariate analysis to identify risk factors for the composite outcome of death, default, or treatment failure during TB treatment. From 2001-2004, 637 HIV-infected TB patients were diagnosed in An Giang. Of these, 501 (79%) were male, 321 (50%) were aged 25-34 years, and the most common self-reported HIV risk factor was sex with a commercial sex worker in 221 (35%). TB was classified as smear-positive in 531 (83%). During TB treatment, 167 (26%) patients died, 9 (1%) defaulted, and 6 (1%) failed treatment. Of 454 patients who took CTX, 116 (26%) had an unsuccessful outcome compared with 33 (70%) of 47 patients who did not take CTX (relative risk, 0.4; 95% confidence interval [CI], 0.3-0.5). Adjusting for male sex, rural residence, TB smear status and disease location, and the occurrence of adverse events during TB treatment in multivariate analysis, the benefit of CTX persisted (adjusted odds ratio for unsuccessful outcome 0.1; CI, 0.1-0.3). CONCLUSIONS/SIGNIFICANCE: In An Giang, Vietnam, HIV-associated TB was associated with poor TB treatment outcomes. Outcomes were significantly better in those taking CTX. This finding suggests that Vietnam should consider applying WHO recommendations to prescribe CTX to all HIV-infected TB patients

Urinary catecholamine excretion, cardiovascular variability, and outcomes in tetanus

Severe tetanus is characterized by muscle spasm and cardiovascular system disturbance. The pathophysiology of muscle spasm is relatively well understood and involves inhibition of central inhibitory synapses by tetanus toxin. That of cardiovascular disturbance is less clear, but is believed to relate to disinhibition of the autonomic nervous system. The clinical syndrome of autonomic nervous system dysfunction (ANSD) seen in severe tetanus is characterized principally by changes in heart rate and blood pressure which have been linked to increased circulating catecholamines. Previous studies have described varying relationships between catecholamines and signs of ANSD in tetanus, but are limited by confounders and assays used. In this study, we aimed to perform detailed characterization of the relationship between catecholamines (adrenaline and noradrenaline), cardiovascular parameters (heart rate and blood pressure) and clinical outcomes (ANSD, mechanical ventilation required, and length of intensive care unit stay) in adults with tetanus, as well as examine whether intrathecal antitoxin administration affected subsequent catecholamine excretion. Noradrenaline and adrenaline were measured by ELISA from 24-h urine collections taken on day 5 of hospitalization in 272 patients enrolled in a 2 × 2 factorial-blinded randomized controlled trial in a Vietnamese hospital. Catecholamine results measured from 263 patients were available for analysis. After adjustment for potential confounders (i.e., age, sex, intervention treatment, and medications), there were indications of non-linear relationships between urinary catecholamines and heart rate. Adrenaline and noradrenaline were associated with subsequent development of ANSD, and length of ICU stay

La structuration sémantique des contenus des documents audiovisuels selon les points de vue de la production

Video content based indexing is highly related in one hand to the progress of new technologies, and image, audio and multimedia processes. In another hand, it relies on the power and skill of video and multimedia representation standards and domain knowledge organisation. Presently, video content representation is expecting the extension of standards for representing media contents in order to capture the semantics of media in deeper structures and provide formal and rich semantic description. Our work proposes a flexible and high level semantic video content description in the frame of the Production Shot Description Schema (PSDS) from the semiotic approach and the points of view of audiovisual production professionals. We analyse the video content into three semantic layers – sensory, narrative and semiotic – and each level provides its particular ontological description. The semiotic completes the technical and narrative dimensions in explaining the way the dynamic structures of the filmic text manages to produce theses two first semantic interpretations in terms of structural organisation. Semiotic approach facilitates to link the representation of the sensory level with the significance of media structures from one's semiotic points of view and audiovisual professionals classification reasoning. Using both media content automatic detection/recognition process and models, theories, discourses, and terminology of the cinema world, this approach can provide a natural and simple translation between the different semantic levels. We use an object-oriented, multi-points of view, video content description which implies to build the ontological tree of the described domain by selecting significant and essential information and their features. Represented as concepts, they constitute a semantic network where users can browse and retrieve information related with the described contents. Each concept is a node of the concerned domain semantic network. The knowledge associated in the PSDS is then structured by Mpeg-7 and XML Schema formalisms and can be used as the basis to build interactive environments for images edition. Video is an information stream in which data can be marked, annotated, analysed, and edited. Our description metadata format involves information about different steps of the production ((preproduction, production et post-production) in order to facilitate management and handling of video objects as well as representation of their significance. They can be reused in many access frameworks such as content based indexation, retrieval, filtering, analysis and movie apprehension.Dans le contexte des progrès sensibles en termes de technologies de l'information et de normes associées à la vidéo, notre travail propose des outils de description flexible et à forte teneur sémantique des contenus audiovisuels au niveau du plan – le PSDS (Production Shot Description Scheme) – orientés par l'approche sémiotique et selon les points de vue des professionnels de la production. Nous constatons que les contenus audio-visuels ont une triple dimension sémantique – la sémantique technique, la sémantique du monde narratif et la sémiotique – et chaque niveau a sa propre description ontologique. La sémiotique complète la sémantique technique et thématique du contenu de la vidéo en expliquant pour quelles raisons les structures dynamiques du texte filmique peuvent produire ces interprétations sémantiques. Mobilisant tant des techniques d'analyse automatiques des média que des modèles existants, des terminologies, des théories et des discours du monde de cinéma, cette approche peut offrir une traduction naturelle et simple entre les différents niveaux sémantiques. La description orientée-objet à multiples points de vue des contenus implique de mettre en évidence dans l'arbre ontologique les unités significatives du domaine et leurs caractéristiques. Ces unités constituent les informations fondamentales pour l'appréhension du sens du récit. Elles sont représentées par des concepts qui constituent un réseau sémantique où les utilisateurs peuvent naviguer à la recherche d'informations. Chaque concept est un noeud du réseau sémantique du domaine visé. Représentées ensuite selon le formalisme Mpeg-7 et XML Schema, les connaissances intégrées dans les schémas de description du plan de la vidéo peuvent servir de base à la construction d'environnements interactifs d'édition des images. La vidéo y devient un flux informationnel dont les données peuvent être balisées, annotées, analysées et éditées. Les métadonnées analysées dans notre travail, comprenant des informations relevant de trois étapes de la production (pré-production, production et post-production) doivent permettre aux applications de gérer et manipuler les objets de la vidéo, ainsi que les représentations de leur sémantique, afin de les réutiliser dans plusieurs offres d'accès telles que l'indexation du contenu, la recherche, le filtrage, l'analyse et l'appréhension des images du film

Downlink Resource Sharing and Caching Helper Selection Control Maximized Multicast Video Delivery Capacity in Dense D2D 5G Networks

In 5G ultra-dense networks, a large number of mobile users (MUs) request a huge amount of high data rate video traffic causing a peak congestion situation at the macro base station (MBS) and small-cell base stations. This situation certainly reduces the total video capacity delivered to the MUs. In this paper, we exploit the available spectrum and storage resources of the MUs as well as the wireless broadcast nature of device-to-device (D2D) communications to propose a joint downlink resource sharing and caching helper selection (DRS-CHS) control to maximize the multicast video delivery capacity in dense D2D 5G networks. We assume that the MUs are divided into different clusters in which they can communicate with each other by D2D communications. There are two types of MUs in each cluster including the requesting users (RUs) that request the video and the caching helpers (CHs) that have cached the video. In addition, there are some sharing users (SUs) that can share their downlink resources with the CHs and the RUs for D2D multicast communications. A DRS-CHS optimization problem is then formulated and solved for an optimal control process of how to select a CH in each cluster and how to assign an SU to share its downlink resource with the selected CH such that the total video delivery capacity multicasted from the CHs to the RUs in all clusters is maximized. Simulation results demonstrate the benefits of the proposed DRS-CHS control solution compared to other conventional benchmarks