RaPiD: A toolkit for reliability analysis of non-deterministic systems

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Interpolation guided compositional verification

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STUDY ON TREATMENT OF THE LEACHATE FROM LANDFILL SITE AT NAMSON, SOCSON, HANOI

Joint Research on Environmental Science and Technology for the Eart

Scaling BDD-based timed verification with simulation reduction

Digitization is a technique that has been widely used in real-time model checking. With the assumption of digital clocks, symbolic model checking techniques (like those based on BDDs) can be applied for real-time systems. The problem of model checking real-time systems based on digitization is that the number of tick transitions increases rapidly with the increment of clock upper bounds. In this paper, we propose to improve BDD-based verification for real-time systems using simulation reduction. We show that simulation reduction allows us to verify timed automata with large clock upper bounds and to converge faster to the fixpoint. The presented approach is applied to reachability and LTL verification for real-time systems. Finally, we compare our approach with existing tools such as Rabbit, Uppaal, and CTAV and show that our approach outperforms them and achieves a significant speedup.No Full Tex

INVESTIGATING THE EXPERIENCES OF STUDENTS WITH DISABILITIES WITH E-LEARNING DURING THE COVID-19 PANDEMIC IN VIETNAMESE HIGHER EDUCATION

This study uses a mixed-methods approach to investigate the experiences of Vietnamese university students with disabilities (visual/mobility impairments) with e-learning as a consequence of emergency remote teaching during the COVID-19 pandemic. An analysis of the ideas of 20 surveyed students with disabilities at eight universities in Ho Chi Minh City and six students interviewed afterward shows that students can change their study habits to adapt to e-learning and to enjoy this model of learning. However, the participants revealed that they also want to experience face-to-face learning so that they can interact with their lecturers and peers more effectively and in more diverse ways, as well as assimilate lectures more easily. Furthermore, the research shows that various adjustments should be made by system designers, universities, and lecturers to make e-learning friendlier to disabled students. The recommended adjustments include designing easy-to-use learning tools and platforms, providing lecturers with the necessary tools and facilities to design lessons appropriate for all students, providing psychological and technical support for disabled students, choosing user-friendly learning applications and platforms, providing students with suitable learning resources, and modifying testing and assessment methods

An update and reassessment of vascular plant species richness and distribution in Bach Ma National Park, Central Vietnam

Bach Ma National Park (BMNP) is recognized as an essential biodiversity hotspot in Vietnam because of its diverse topography, high species richness and threatened and endemic species. This study updates the richness and distribution of vascular plant species in the BMNP by intergrading data from literature, field surveys, key-informant interviews and participatory observations. Our results showed that the park has a high diversity of vascular plants with 1,874 species belonging to 192 families, 6 phylums including Psilotophyta, Lycopodiophyta, Equisetophyta, Polypodiophyta, Pinophyta, and Magnoliophyta. It also indicates that 199 out of 1,874 vascular species in the BMNP are listed as endangered, precious and rare plant species of Vietnam. In particular, 55 species are part of the IUCN 2020 list, in which 9 are critically endangered species (CR), 15 are endangered species (EN), and 31 are vulnerable species (VU). According to the rankings of the Red List Vietnam (2007), 6 species of CR (accounting for 13.64% compared with the whole country), 36 species of EN (20%), and 52 species of VU (26%) were found in this area. The results provided that vascular plant species are distributed into 2 types based on high altitude (threshold at 900m), but there are no dominant communities. The findings may be essential information for foresters and biologists to recognize and use it as the newest update for their next scientific research in conservation and resource management.Vườn Quốc gia (VQG) Bạch Mã được xem là một điểm nóng đa dạng sinh học quan trọng ở Việt Nam vì địa hình đa dạng, độ phong phú loài cao, đặc biệt là các loài đặc hữu và nguy cấp. Trong nghiên cứu này, chúng tôi đã cập nhật sự phong phú và phân bố của các loài thực vật bậc cao tại VQG Bạch Mã bằng cách kết hợp dữ liệu từ tổng quan tài liệu, khảo sát thực địa, phỏng vấn người am hiểu và điều tra có sự tham gia. Kết quả cho thấy VQG có hệ thực vật bậc cao phong phú với 1.874 loài, thuộc 192 họ, 6 ngành bao gồm Psilotophyta, Lycopodiophyta, Equisetophyta, Polypodiophyta, Pinophyta, Magnoliophyta. Kết quả chỉ ra rằng 199 trong số 1.874 loài thực vật bậc cao tại VQG này được xếp vào danh sách các loài nguy cấp của Việt Nam. Đặc biệt, có 55 loài thuộc danh mục của IUCN năm 2020, trong đó có 9 loài Cực kỳ nguy cấp (CR), 15 loài Nguy cấp (EN) và 31 loài Sẽ nguy cấp (VU). Trong khi đó, theo xếp hạng của Sách Đỏ Việt Nam (2007), nghiên cứu cho thấy có 6 loài CR (chiếm 13,64% so với cả nước), 36 loài EN (20%) và 52 loài VU (26%). Phát hiện của chúng tôi cũng chỉ ra rằng đặc điểm phân bố của các loài thực vật bậc cao ở VQG Bạch Mã gồm 2 kiểu rừng dựa trên độ cao (mức 900m), nhưng không có quần xã nào chiếm ưu thế. Các kết quả này được kỳ vọng sẽ là nguồn thông tin cần thiết cho các nhà hoạt động lâm nghiệp và sinh vật học sử dụng nó như một bản cập nhật mới nhất cho các nghiên cứu khoa học tiếp theo trong bảo tồn và quản lý tài nguyên

Wearable devices for remote monitoring of hospitalized patients with COVID-19 in Vietnam

Patients with severe COVID-19 disease require monitoring with pulse oximetry as a minimal requirement. In many low- and middle- income countries, this has been challenging due to lack of staff and equipment. Wearable pulse oximeters potentially offer an attractive means to address this need, due to their low cost, battery operability and capacity for remote monitoring. Between July and October 2021, Ho Chi Minh City experienced its first major wave of SARS-CoV-2 infection, leading to an unprecedented demand for monitoring in hospitalized patients. We assess the feasibility of a continuous remote monitoring system for patients with COVID-19 under these circumstances as we implemented 2 different systems using wearable pulse oximeter devices in a stepwise manner across 4 departments

A novel diagnostic model for tuberculous meningitis using Bayesian latent class analysis

Background Diagnosis of tuberculous meningitis (TBM) is hampered by the lack of a gold standard. Current microbiological tests lack sensitivity and clinical diagnostic approaches are subjective. We therefore built a diagnostic model that can be used before microbiological test results are known. Methods We included 659 individuals aged ≥ 16 years with suspected brain infections from a prospective observational study conducted in Vietnam. We fitted a logistic regression diagnostic model for TBM status, with unknown values estimated via a latent class model on three mycobacterial tests: Ziehl–Neelsen smear, Mycobacterial culture, and GeneXpert. We additionally re-evaluated mycobacterial test performance, estimated individual mycobacillary burden, and quantified the reduction in TBM risk after confirmatory tests were negative. We also fitted a simplified model and developed a scoring table for early screening. All models were compared and validated internally. Results Participants with HIV, miliary TB, long symptom duration, and high cerebrospinal fluid (CSF) lymphocyte count were more likely to have TBM. HIV and higher CSF protein were associated with higher mycobacillary burden. In the simplified model, HIV infection, clinical symptoms with long duration, and clinical or radiological evidence of extra-neural TB were associated with TBM At the cutpoints based on Youden’s Index, the sensitivity and specificity in diagnosing TBM for our full and simplified models were 86.0% and 79.0%, and 88.0% and 75.0% respectively. Conclusion Our diagnostic model shows reliable performance and can be developed as a decision assistant for clinicians to detect patients at high risk of TBM. Summary Diagnosis of tuberculous meningitis is hampered by the lack of gold standard. We developed a diagnostic model using latent class analysis, combining confirmatory test results and risk factors. Models were accurate, well-calibrated, and can support both clinical practice and research

Isolation and genetic characterization of waterfowl parvovirus in ducks in Northern Vietnam

Background and Aim: Short beak and dwarfism syndrome (SBDS), a highly contagious disease, has been reported in duck farms in Vietnam since 2019. In this study, we evaluated the virulence and characterized the virus obtained from SBDS cases in North Vietnam. Materials and Methods: Polymerase chain reaction was used to detect waterfowl parvovirus in ducks, and the virus from positive samples was inoculated into 10-day-old duck-embryonated eggs to reproduce the disease in young ducklings to determine the virulence and subjected to phylogenetic analysis of non-structural (NS) and VP1 gene sequences. Results: Goose parvovirus (GPV) was isolated from ducks associated with SDBS in Vietnam. The virus Han-GPV2001 is highly virulent when inoculated into 10-day-old duck embryos and 3-day-old ducklings. The mortality rate of duck embryos was 94.35% within 6 days of virus inoculation. Inoculating 3-day-old ducks with the virus stock with 104.03 EID50 through intramuscular and neck intravenous administration resulted in 80% and 66.67% of clinical signs of SDBS, respectively, were shown. Phylogenetic analysis based on the partial NS and VP1 gene sequences revealed that the viral isolate obtained in this study belonged to novel GPV (NGPV) and was closely related to previous Vietnamese and Chinese strains. Conclusion: A GPV strain, Han-GPV2001, has been successfully isolated and has virulence in duck-embryonated eggs as well as caused clinical signs of SBDS in ducks. Phylogenetic analyses of partial genes encoding NS and capsid proteins indicated that the obtained GPV isolate belongs to the NGPV group