| 1. |
- von Seidlein, Lorenz, et al.
(author)
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The impact of targeted malaria elimination with mass drug administrations on falciparum malaria in Southeast Asia: A cluster randomised trial
- 2019
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In: PLoS Medicine. - : PUBLIC LIBRARY SCIENCE. - 1549-1277 .- 1549-1676. ; 16:2
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Journal article (peer-reviewed)abstract
- Background The emergence and spread of multidrug-resistant Plasmodium falciparum in the Greater Mekong Subregion (GMS) threatens global malaria elimination efforts. Mass drug administration (MDA), the presumptive antimalarial treatment of an entire population to clear the subclinical parasite reservoir, is a strategy to accelerate malaria elimination. We report a cluster randomised trial to assess the effectiveness of dihydroartemisinin-piperaquine (DP) MDA in reducing falciparum malaria incidence and prevalence in 16 remote village populations in Myanmar, Vietnam, Cambodia, and the Lao Peoples Democratic Republic, where artemisinin resistance is prevalent. Methods and findings After establishing vector control and community-based case management and following intensive community engagement, we used restricted randomisation within village pairs to select 8 villages to receive early DP MDA and 8 villages as controls for 12 months, after which the control villages received deferred DP MDA. The MDA comprised 3 monthly rounds of 3 daily doses of DP and, except in Cambodia, a single low dose of primaquine. We conducted exhaustive cross-sectional surveys of the entire population of each village at quarterly intervals using ultrasensitive quantitative PCR to detect Plasmodium infections. The study was conducted between May 2013 and July 2017. The investigators randomised 16 villages that had a total of 8,445 residents at the start of the study. Of these 8,445 residents, 4,135 (49%) residents living in 8 villages, plus an additional 288 newcomers to the villages, were randomised to receive early MDA; 3,790 out of the 4,423 (86%) participated in at least 1 MDA round, and 2,520 out of the 4,423 (57%) participated in all 3 rounds. The primary outcome, P. falciparum prevalence by month 3 (M3), fell by 92% (from 5.1% [171/3,340] to 0.4% [12/2,828]) in early MDA villages and by 29% (from 7.2% [246/3,405] to 5.1% [155/3,057]) in control villages. Over the following 9 months, the P. falciparum prevalence increased to 3.3% (96/2,881) in early MDA villages and to 6.1% (128/2,101) in control villages (adjusted incidence rate ratio 0.41 [95% CI 0.20 to 0.84]; p = 0.015). Individual protection was proportional to the number of completed MDA rounds. Of 221 participants with subclinical P. falciparum infections who participated in MDA and could be followed up, 207 (94%) cleared their infections, including 9 of 10 with artemisinin-and piperaquine- resistant infections. The DP MDAs were well tolerated; 6 severe adverse events were detected during the follow-up period, but none was attributable to the intervention. Conclusions Added to community-based basic malaria control measures, 3 monthly rounds of DP MDA reduced the incidence and prevalence of falciparum malaria over a 1-year period in areas affected by artemisinin resistance. P. falciparum infections returned during the follow-up period as the remaining infections spread and malaria was reintroduced from surrounding areas. Limitations of this study include a relatively small sample of villages, heterogeneity between villages, and mobility of villagers that may have limited the impact of the intervention. These results suggest that, if used as part of a comprehensive, well-organised, and well-resourced elimination programme, DP MDA can be a useful additional tool to accelerate malaria elimination.
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| 2. |
- Phu, Vu Dinh, et al.
(author)
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Burden of Hospital Acquired Infections and Antimicrobial Use in Vietnamese Adult Intensive Care Units
- 2016
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In: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 11:1
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Journal article (peer-reviewed)abstract
- Background Vietnam is a lower middle-income country with no national surveillance system for hospital-acquired infections (HAIs). We assessed the prevalence of hospital-acquired infections and antimicrobial use in adult intensive care units (ICUs) across Vietnam. Methods Monthly repeated point prevalence surveys were systematically conducted to assess HAI prevalence and antimicrobial use in 15 adult ICUs across Vietnam. Adults admitted to participating ICUs before 08: 00 a.m. on the survey day were included. Results Among 3287 patients enrolled, the HAI prevalence was 29.5% (965/3266 patients, 21 missing). Pneumonia accounted for 79.4% (804/1012) of HAIs Most HAIs (84.5% [855/1012]) were acquired in the survey hospital with 42.5% (363/855) acquired prior to ICU admission and 57.5% (492/855) developed during ICU admission. In multivariate analysis, the strongest risk factors for HAI acquired in ICU were: intubation (OR 2.76), urinary catheter (OR 2.12), no involvement of a family member in patient care (OR 1.94), and surgery after admission (OR 1.66). 726 bacterial isolates were cultured from 622/1012 HAIs, most frequently Acinetobacter baumannii (177/726 [24.4%]), Pseudomonas aeruginosa (100/726 [13.8%]), and Klebsiella pneumoniae (84/726 [11.6%]), with carbapenem resistance rates of 89.2%, 55.7%, and 14.9% respectively. Antimicrobials were prescribed for 84.8% (2787/ 3287) patients, with 73.7% of patients receiving two or more. The most common antimicrobial groups were third generation cephalosporins, fluoroquinolones, and carbapenems (20.1%, 19.4%, and 14.1% of total antimicrobials, respectively). Conclusion A high prevalence of HAIs was observed, mainly caused by Gram-negative bacteria with high carbapenem resistance rates. This in combination with a high rate of antimicrobial use illustrates the urgent need to improve rational antimicrobial use and infection control efforts.
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| 3. |
- Son, Dang Ngoc, et al.
(author)
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A novel design and fabrication of self-heated In2O3 nanowire gas sensor on for ethanol detection
- 2022
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In: Sensors and Actuators A-Physical. - : Elsevier. - 0924-4247 .- 1873-3069. ; 345
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Journal article (peer-reviewed)abstract
- Many attempts have been made on the design and fabrication of low-power consumption gas sensor for application on the Internet of Things and portable devices. The performance of gas sensors includes sensitivity, selectivity, and power consumption, which are strongly dependent on the configuration of the device such as the gap size between two electrodes, the sensing material, and operation principle. Here, self-heated In2O3 nanowire-based gas sensors were designed and fabricated by on-chip growth technique via thermal evaporation to work at room temperature. The effect of electrode gap (10-40 mu m) on the power consumption and gas sensing performance of the In2O3 nanowire sensors was studied. With the large gap of 40 mu m, the sensor exhibited excellent sensing characteristics of low power consumption (1.06 mW) with ability to detect ethanol gas down to 20 ppm effectively. We also examined the role of nanowire conductivity in the performance of the self-heated sensor in the detection of reducing gas. The sensor demonstrated rapid response and recovery times of less than a minute, exceptional stability, and remarkable recovery.
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| 4. |
- Cuc, Nguyen Thi Thu, et al.
(author)
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Hot water treatment prevents Aphelenchoides besseyi damage to Polianthes tuberosa crops in the Mekong Delta of Vietnam
- 2010
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In: Crop Protection. - 0261-2194. ; 29:6, s. 599-602
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Journal article (peer-reviewed)abstract
- Polianthes tuberosa is a commercially valuable flower crop in the Mekong Delta of Vietnam that is propagated by the harvesting and planting of bulbs. The cultivation of P. tuberosa is infected by an endemic Aphelenchoides besseyi nematode that damages a high proportion of plants and persists within the bulbs. Here we report on the comparison of hot water and pesticide treatments as control methods to protect P. tuberosa from A. besseyi damage, and conclude that a hot water treatment consisting of soaking bulbs in water for 30 minutes at 57 °C is the most efficacious method to produce healthy flowers in a cost-effective manner.
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| 5. |
- Nguyen-Tien, Thang, et al.
(author)
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Knowledge and practice on prevention of mosquito-borne diseases in livestock-keeping and non-livestock-keeping communities in Hanoi city, Vietnam : A mixed-method study
- 2021
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:2
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Journal article (peer-reviewed)abstract
- Mosquito-borne diseases (MBDs) are causing high morbidity and mortality for humans. Urban livestock keeping is still common in cities around the world. The animals may serve as reservoirs for zoonotic MBDs, which increase the risks for humans. Here we assess the knowledge and practices related to MBDs in households with livestock and without livestock and explore the perceptions of the health care sector about MBDs and livestock keeping in Hanoi city of Vietnam in a cross-sectional study. A quantitative survey was conducted including 513 households with and without livestock-keeping in six districts and complemented with qualitative surveys with four health staff from Hanoi Center of Disease Control and three district health centers. The quantitative survey indicated that the participants possessed basic knowledge on MBDs with an average score of 18.3 out of 35, of which non-livestock-keeping households had a better knowledge than households keeping livestock (p<0.05). Both household categories had low score, 3.5 out of 11, regarding preventive practices against MBDs. The negative binomial model showed that occupation and location of living were factors associated to the knowledge on MBDs. Farmers were likely to have better preventive practices as compared to office workers (p<0.05). Those who had better knowledge also had more adequate preventive practices against MBDs (p<0.001). The qualitative survey revealed that livestock keeping was determined as increasing risks of MBDs due to the increase of mosquito population. It is recommended that community campaigns to raise the awareness and change behavior on MBDs should be organized based on collaboration between the health sector and the veterinary sector for households with and without livestock living in central urban and peri-urban areas. Further studies are needed to confirm the association between urban livestock keeping and potential increasing risks of MBDs such as dengue and Japanese encephalitis.
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| 6. |
- Son, Hoang Nghia, et al.
(author)
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Effects of simulated microgravity on the morphology of mouse embryonic fibroblasts (MEFs)
- 2020
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In: Romanian Biotechnological Letters. - Bucharest : University of Bucharest. - 1224-5984 .- 2248-3942. ; 25:6, s. 2156-2160
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Journal article (peer-reviewed)abstract
- This study aimed to assess the effects of simulated microgravity on mouse embryonic fibroblast (MEF) morphology. The results showed that the area of MEFs under simulated microgravity was 7843.39 +/- 551.31 mu m(2) which was lower than the control group (9832.72 +/- 453.86 mu m(2)) (p < 0.001). The nuclear area of MEFs under simulated microgravity (290.76 +/- 4.58 mu m(2)) and the control group (296.8 +/- 4.58 mu m(2)) did not statistically differ. In addition, the nuclear shape value of the MEFs under simulated microgravity and the control group did not statistically differ (0.86 +/- 0.006 vs. 0.87 +/- 0.003, respectively). The nuclear intensity of MEFs under simulated microgravity (19361 +/- 852) was higher than the control group (16997 +/- 285) (P <0.05). Moreover, the flow cytometry analysis indicated the reduced GO/G1 phase cell ratio and the increased S phase and G2/M phase cell ratio in MEFs under simulated microgravity. Simulated microgravity also induced a decrease in diameter of actin filament bundles of the MEFs under simulated microgravity (1.61 +/- 0.33 mu m) compared to the control group (1.79 +/- 0.32 mu m) (P <0.01). These results revealed that simulated microgravity is capable of inducing the morphological changes of mouse embryonic fibroblasts.
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| 7. |
- Jakobsen, Frida, et al.
(author)
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Urban livestock-keeping and dengue in urban and peri-urban Hanoi, Vietnam.
- 2019
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In: PLoS Neglected Tropical Diseases. - : Public Library of Science (PLoS). - 1935-2727 .- 1935-2735. ; 13:11
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Journal article (peer-reviewed)abstract
- Urban livestock provides an important source of food and income, but it may increase the risks for disease transmission. Vectors, such as mosquitoes, might increase and thereby cause an enhanced transmission of infectious diseases, such as dengue fever; considered the most important mosquito-borne viral disease globally. This cross-sectional study evaluated the awareness of dengue fever and investigated how the presence of dengue vectors is affected by the keeping of livestock in urban households in the city of Hanoi, Vietnam. From February to March 2018, during the season of lowest occurrence of dengue in Hanoi, 140 households were interviewed, of which 69 kept livestock. A general trend was observed; respondents living in the Dan Phuong district, a peri-urban district, had better knowledge and practice regarding dengue as compared to the urban Ha Dong district. In total, 3899 mosquitoes were collected and identified, of which 52 (1.33%) were Aedes species. A significant difference between the two districts was observed, with more households in Ha Dong having Aedes spp. mosquitoes (p = 0.02) and a higher incidence of dengue fever (p = 0.001). There was no significant association between livestock-rearing and the presence of Aedes spp. mosquitoes (p = 0.955), or between livestock-rearing and the incidence of dengue fever (p = 0.08). In conclusion, this study could not find any indication that households keeping livestock were at higher risk of dengue virus infections in Hanoi during the season of lowest occurrence of dengue, but clearly indicated the need of more information provided to urban inhabitants, particularly on personal protection.
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| 8. |
- Nguyen-Tien, Thang, et al.
(author)
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The Distribution and Composition of Vector Abundance in Hanoi City, Vietnam : Association with Livestock Keeping and Flavivirus Detection
- 2021
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In: Viruses. - : MDPI. - 1999-4915. ; 13:11
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Journal article (peer-reviewed)abstract
- Background: Dengue virus and Japanese encephalitis virus are two common flaviviruses that are spread widely by Aedes and Culex mosquitoes. Livestock keeping is vital for cities; however, it can pose the risk of increasing the mosquito population. Our study explored how livestock keeping in and around a large city is associated with the presence of mosquitoes and the risk of them spreading flaviviruses.Methods: An entomological study was conducted in 6 districts with 233 households with livestock, and 280 households without livestock, in Hanoi city. BG-Sentinel traps and CDC light traps were used to collect mosquitoes close to animal farms and human habitats. Adult mosquitoes were counted, identified to species level, and grouped into 385 pools, which were screened for flaviviruses using a pan-flavivirus qPCR protocol and sequencing.Results: A total of 12,861 adult mosquitoes were collected at the 513 households, with 5 different genera collected, of which the Culex genus was the most abundant. Our study found that there was a positive association between livestock keeping and the size of the mosquito population-most predominantly between pig rearing and Culex species (p < 0.001). One pool of Cx. tritaeniorhynchus, collected in a peri-urban district, was found to be positive for Japanese encephalitis virus.Conclusions: The risk of flavivirus transmission in urban areas of Hanoi city due to the spread of Culex and Aedes mosquitoes could be facilitated by livestock keeping.
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| 9. |
- Pham-Thanh, Long, et al.
(author)
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Zoonotic Flavivirus Exposure in Peri-Urban and Suburban Pig-Keeping in Hanoi, Vietnam, and the Knowledge and Preventive Practices of Pig Farmers
- 2022
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In: Tropical Medicine and Infectious Disease. - : MDPI. - 2414-6366. ; 7:5
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Journal article (peer-reviewed)abstract
- Mosquito-borne diseases (MBDs), including those caused by flaviviruses, remain human health problems for developing and urbanizing economies. This cross-sectional study examined risks of flavivirus exposure through a survey regarding knowledge and practices of pig farmers, and serological analysis of pigs in peri-urban and suburban Hanoi city. A total of 636 pig sera from 179 pig farms in 4 districts, namely, Chuong My, Dan Phuong, Ha Dong, and Bac Tu Liem, were analyzed by a competitive ELISA designed for flavivirus antibody detection. The results indicated a low level of awareness about MBDs among pig farmers, and a high seroprevalence in pigs at 88.5% (95%CI = 85.8-90.9%). Moreover, common practices of pig owners to prevent mosquitoes at home and farm did not show a significant reduction in flavivirus exposure in pigs. At animal level, significant associations between seropositive pigs and the farms with more than 60 pigs, and the district location were found. Farm-level multivariable analysis did not identify significant risk factors for flavivirus exposure. The study suggests that improving awareness of pig owners about MBDs in Hanoi city may be warranted to reduce the risk for MBD flavivirus infections in both humans and pigs.
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| 10. |
- Quang-Thuy, Ha, et al.
(author)
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A Bisimulation-based Method of Concept Learning for Knowledge Bases in Description Logics
- 2012
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In: SoICT 2012 - 3rd International Symposium on Information and Communication Technology. - New York, New York, USA : ACM Press. ; , s. 241-249
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Conference paper (peer-reviewed)abstract
- We develop the first bisimulation-based method of concept learning, called BBCL, for knowledge bases in description logics (DLs). Our method is formulated for a large class of useful DLs, with well-known DLs like ALC, SHIQ, SHOIQ, SROIQ. As bisimulation is the notion for characterizing indis-cernibility of objects in DLs, our method is natural and very promising.
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| 11. |
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| 12. |
- Vu, Thanh, et al.
(author)
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NIHRIO at SemEval-2018 task 3 : a simple and accurate neural network model for irony detection in Twitter
- 2018
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In: Proceedings of the 12th international workshop on semantic evaluation. - New Orleans : Association for Computational Linguistics. - 9781948087209 ; , s. 525-530
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Conference paper (peer-reviewed)abstract
- This paper describes our NIHRIO system for SemEval-2018 Task 3 "Irony detection in English tweets". We propose to use a simple neural network architecture of Multilayer Perceptron with various types of input features including: lexical, syntactic, semantic and polarity features. Our system achieves very high performance in both subtasks of binary and multi-class irony detection in tweets. In particular, we rank at fifth in terms of the accuracy metric and the F1 metric. Our code is available at: https://github.com/NIHRIO/IronyDetectionInTwitter
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| 13. |
- Vu, Xuan-Son, 1988-, et al.
(author)
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MC-OCR Challenge : Mobile-Captured Image Document Recognition for Vietnamese Receipts
- 2021
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In: Proceedings - 2021 RIVF International Conference on Computing and Communication Technologies, RIVF 2021. - : IEEE. - 9781665404358 ; , s. 88-93
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Conference paper (peer-reviewed)abstract
- The paper describes the organisation of the "Mobile Captured Receipt Recognition Challenge"(MC-OCR) task at the RIVF conference 2021 1 on recognizing the fine-grained information in Vietnamese receipts captured using mobile devices. The task is organized as a multi-tasking model on a dataset containing 2, 436 Vietnamese receipts. The participants were challenged to build a model that is capable of (1) predicting receipt's quality based on readable information, and (2) recognizing textual information of four required information (i.e., "SELLER", "SELLER ADDRESS", "TIMESTAMP", and "TOTAL COST") in the receipts. MC-OCR challenge happened in one month and top winners of each task will present their solutions at RIVF 2021. Participants were competing on CodaLab.Org from 05th December 2020 to 23rd January 2021. All participants with valid submitted results were encouraged to submit their papers. Within one month, the challenge has attracted 105 participants and recorded about 1, 285 submission entries.
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| 14. |
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| 15. |
- Vu, Xuan-Son, 1988-, et al.
(author)
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Multimodal Review Generation with Privacy and Fairness Awareness
- 2020
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In: Proceedings of the 28th International Conference on Computational Linguistics (COLING), 2020. - Stroudsburg, PA, USA : International Committee on Computational LinguisticsInternational Committee on Computational Linguistics. ; , s. 414-425
-
Conference paper (peer-reviewed)abstract
- Users express their opinions towards entities (e.g., restaurants) via online reviews which can be in diverse forms such as text, ratings, and images. Modeling reviews are advantageous for user behavior understanding which, in turn, supports various user-oriented tasks such as recommendation, sentiment analysis, and review generation. In this paper, we propose MG-PriFair, a multimodal neural-based framework, which generates personalized reviews with privacy and fairness awareness. Motivated by the fact that reviews might contain personal information and sentiment bias, we propose a novel differentially private (dp)-embedding model for training privacy guaranteed embeddings and an evaluation approach for sentiment fairness in the food-review domain. Experiments on our novel review dataset show that MG-PriFair is capable of generating plausibly long reviews while controlling the amount of exploited user data and using the least sentiment biased word embeddings. To the best of our knowledge, we are the first to bring user privacy and sentiment fairness into the review generation task. The dataset and source codes are available at https://github.com/ReML-AI/MG-PriFair.
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| 16. |
- Cao, Son Thanh, et al.
(author)
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On the Web Ontology Rule Language OWL 2 RL
- 2011
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In: Proceedings of the 3rd International Conference on Computational Collective Intelligence, Technologies and Applications (ICCCI). - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783642239342 ; , s. 254-264
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Conference paper (peer-reviewed)abstract
- It is known that the OWL 2 RL Web Ontology Language Profile has PTime data complexity and can be translated into Datalog. However, a knowledge base in OWL 2 RL may be unsatisfiable. The reason is that, when translated into Datalog, the result may consist of a Datalog program and a set of constraints in the form of negative clauses. In this paper we first identify a maximal fragment of OWL 2 RL called OWL 2 RL + with the property that every knowledge base expressed in this fragment can be translated into a Datalog program and hence is satisfiable. We then propose some extensions of OWL 2 RL and OWL 2 RL + that still have PTime data complexity.
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| 17. |
- Cao, Son Thanh, et al.
(author)
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WORL : A Web Ontology Rule Language
- 2011
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In: Proceedings of the 3rd International Conference on Knowledge and Systems Engineering (KSE). - : IEEE. - 9781457718489 ; , s. 32-39
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Conference paper (peer-reviewed)abstract
- We develop a Web ontology rule language, called WORL, which combines a variant of OWL 2 RL with eDatalog-with-negation. We disallow the features of OWL 2 RL that play the role of constraints (i.e., the ones that are translated to negative clauses), but allow additional features like negation, the minimal number restriction and unary external checkable predicates to occur in the left hand side of concept inclusion axioms. Some restrictions are adopted to guarantee a translation into eDatalog-with-negation. We also develop the well-founded semantics for WORL and the standard semantics for stratified WORL (SWORL) via translation into eDatalog-with-negation. Both WORL and SWORL have PTime data complexity. In contrast to the existing combined formalisms, in WORL and SWORL negation in concept inclusion axioms is interpreted using nonmonotonic semantics.
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| 18. |
- Cao, Son Thanh, et al.
(author)
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WORL : a nonmonotonic rule language for the semantic web
- 2014
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In: Vietnam Journal of Computer Science. - : Springer Berlin/Heidelberg. - 2196-8888 .- 2196-8896. ; 1:1, s. 57-69
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Journal article (peer-reviewed)abstract
- We develop a new Web ontology rule language, called WORL, which combines a variant of OWL 2 RL with eDatalog ¬ . We allow additional features like negation, the minimal number restriction and unary external checkable predicates to occur at the left-hand side of concept inclusion axioms. Some restrictions are adopted to guarantee a translation into eDatalog ¬ . We also develop the well-founded semantics and the stable model semantics for WORL as well as the standard semantics for stratified WORL (SWORL) via translation into eDatalog ¬ . Both WORL with respect to the well-founded semantics and SWORL with respect to the standard semantics have PTime data complexity. In contrast to the existing combined formalisms, in WORL and SWORL negation in concept inclusion axioms is interpreted using nonmonotonic semantics.
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| 19. |
- Datta, Shuvo Jit, et al.
(author)
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CO2 capture from humid flue gases and humid atmosphere using a microporous coppersilicate
- 2015
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In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 350:6258, s. 302-
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Journal article (peer-reviewed)abstract
- Capturing CO2 from humid flue gases and atmosphere with porous materials remains costly because prior dehydration of the gases is required. A large number of microporous materials with physical adsorption capacity have been developed as CO2-capturing materials. However, most of them suffer from CO2 sorption capacity reduction or structure decomposition that is caused by co-adsorbed H2O when exposed to humid flue gases and atmosphere. We report a highly stable microporous coppersilicate. It has H2O-specific and CO2-specific adsorption sites but does not have H2O/CO2-sharing sites. Therefore, it readily adsorbs both H2O and CO2 from the humid flue gases and atmosphere, but the adsorbing H2O does not interfere with the adsorption of CO2. It is also highly stable after adsorption of H2O and CO2 because it was synthesized hydrothermally.
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| 20. |
- Du, Yi-Hsien, et al.
(author)
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Noncommutative field theory of the Tkachenko mode : Symmetries and decay rate
- 2024
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In: Physical Review Research. - : American Physical Society. - 2643-1564. ; 6:1
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Journal article (peer-reviewed)abstract
- We construct an effective field theory describing the collective Tkachenko oscillation mode of a vortex lattice in a two-dimensional rotating Bose-Einstein condensate in the long-wavelength regime. The theory has the form of a noncommutative field theory of a Nambu-Goldstone boson, which exhibits a noncommutative version of dipole symmetry. From the effective field theory, we show that, at zero temperature, the decay width Γ of the Tkachenko mode scales with its energy E as Γ∼E3 in the low-energy limit. We also discuss the width of the Tkachenko mode at a small temperature.
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| 21. |
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| 22. |
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| 23. |
- Nguyen, Thanh Son, et al.
(author)
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A case study on the influence of THM coupling on the near field safety of a spent fuel repository in sparsely fractured granite
- 2009
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In: Environmental Geology. - : Springer Science and Business Media LLC. - 0943-0105 .- 1432-0495. ; 57:6, s. 1239-1254
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Journal article (peer-reviewed)abstract
- In order to demonstrate the feasibility of geological disposal of spent CANDU fuel in Canada, a safety assessment was performed for a hypothetical repository in the Canadian Shield. The assessment shows that the maximum long term radionuclide release from such repository would meet international criteria for dose rate; however, uncertainties in the assumed evolution of the repository were identified. Such uncertainties could be resolved by the consideration of coupled Thermal-Hydro-Mechanical-Chemical (THMC) processes. In Task A of the DECOVALEX-THMC project, THM models were developed within the framework of the theory of poroelasticity. Such model development was performed in an iterative manner, using experimental data from laboratory and field tests. The models were used to perform near-field simulations of the evolution of the repository in order to address the above-mentioned uncertainties. This paper presents the definition and rationale of task A and the results of the simulations. From a repository safety point of view, the simulations predict that the maximum temperature would be well below the design target of 100A degrees C; however, the stress on the container can marginally exceed the design value of 15 MPa. However, the most important finding from the simulations is that a rock damage zone could form around the emplacement borehole. Such damage zone can extend a few metres from the walls of the emplacement holes, with permeability values that are orders of magnitude higher than the initial values. The damage zone has the potential to increase the radionuclide transport flux from the geosphere; the effect of such an increase should be taken into account in the safety assessment and mitigated if necessary by the provision of sealing systems.
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| 24. |
- Son, Vi Thanh, et al.
(author)
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Teaching English for young language learners at Grade 5: Teachers' beliefs in two contrasting national approaches compared, and pedagogical implications
- 2019
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In: OpenTESOL-Proceedings of the 7th OpenTESOL intrenational conference 2019 : Innovation and inspiration: Building the future of language education - Innovation and inspiration: Building the future of language education. ; , s. 423-442
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Conference paper (peer-reviewed)abstract
- The aim of the paper was to investigate EFL (English as a foreign language) primary school teachers’ beliefs regarding their teaching methods used in English at grade 5 in the classroom, which was a part of my PhD research (Son, 2018). Interviews (teachers at Grade 5 observed classes; Responses N=2, Sweden and N=3, Vietnam) and questionnaires to English teachers at grade 5 in Swedish and Vietnamese primary schools (additional teachers at Grade 5; Responses N=10, Sweden and N=52, Vietnam) were used. The content of the questionnaire was based on the COLT observation scheme (Spada & Fröhlich, 1995) and adapted to be suitable to the study (Son, 2018) of teaching methods at Grade 5. The teachers’ answers showed the major different degree of focusing on communication and grammar in teaching English classes at primary level between the groups, in spite of some similarities regarding classroom activities (group work), source of material and the languages used in the classroom. The results not only casted light on teachers’ beliefs in two contrasting national approaches in their English teaching methods for young language learners but also led the author to discuss further pedagogical implications
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