RESEARCH ON NEARSHORE WAVE CONDITIONS AT NHAT LE COASTAL AREA (QUANG BINH PROVINCE) BY USING MIKE21-SW

Research on marine dynamics, including coastal wave motions, is a concern of countries in the world in general and Vietnam in particular. Coastal wave dynamics has a direct impact on human activities including coastal construction, shipping, irrigation, aquatic resources exploitation, etc. The coastal area of Nhat Le, Quang Binh is one of the areas strongly influenced by the coastal wave regime which increases the risk of coastal erosion, estuarine sedimentation, destroys the economic life, affects marine fishing and directly affects the tourist beach area. This article aims to introduce some research results based on the application of MIKE21-SW model of the Danish Hydraulic Institute (DHI) to simulate coastal wave regime in Nhat Le coastal zone, Quang Binh province. The model results are verified by real-time wave data in long-term from the WaMoS® II Radar System at Quang Binh station. The results show that there are many similarities in wave height and direction between the computational model and the actual observation data from the radar system. This result will be an important basis for research and application for coastal protection, reduction in river mouth sedimentation, clearing and flood drainage in the study area

Innovative Firm Performance Management Using a Recommendation System Based on Fuzzy Association Rules: The Case of Vietnam’s Apparel Small and Medium Enterprises

Purpose: This study aims to apply a classification algorithm based-on fuzzy association rules (FARs) to improve the effectiveness of firms' performance prediction problem. Particularly, this study investigates potential FARs exists between inputs and outputs of firms' performance management process. These extracted FARs could be used to help firm’s managers make better dicision to improve firm’s performance.   Theoretical framework: Private enterprise development has been identified as key to Vietnam's economy that was commonly depended on state enterprise. For that, understanding and improving firms' performance and productivity is one of the most important tasks, from both macro and micro perspectives. There have been many studies on Vietnam's firm performance, but mostly relying on econometric methods that limit the understanding with structural equations. This study, instead, attempts to utilize new achievements of Artificial Intelligence (AI) for this task. Among AI techniques, fuzzy association rule is able to address the relationship between input factors and firm performance indicators. For each company, the finding FARs can be used to predict its performance and then change the business plan or react to improve weekness of organization.   Design/Methodology/Approach: The proposal model is applied on data of small and medium-sized enterprises (SMEs) of the apparel industry in Vietnam in the period 2010-2015. The sample consist of a total of 23637 observation of  Vietnam firms in apparel and textile industry and contains 16 main criterias for those firms.   Finding: A recommendation system (RS) is constructed from disclosed FARs and is a key factor in a novel innovative firms' performance management process. The percentage of classified instances using the mining FARs is not quite high (about 82%), but it is not always the case. Vietnam’s apparel dataset includes rare classes of ROA, therefore applying only frequent FARs is not enough. This issue can be fixed by using both frequent and infrequent FARs.       Research, practical & social implications: The proposed model has a great opportunity to use not only in the small and medium-sized enterprises (SMEs) of the apparel industry but other industrial sectors. FARs support the well-understand of firm performance to firm’s manager and help them better to react. Besides, FARs could be used to create RSs that makes alerts about risk automatically.   Originality/Value: The fact, our current study is the first to inspect the ability of FARs on SMEs of the apparel industry in Vietnam. This study provides theoritical potential knowledge and empirical evidence in the application of FARs technology in innovative firm’s management

The global response: How cities and provinces around the globe tackled Covid-19 outbreaks in 2021

Background: Tackling the spread of COVID-19 remains a crucial part of ending the pandemic. Its highly contagious nature and constant evolution coupled with a relative lack of immunity make the virus difficult to control. For this, various strategies have been proposed and adopted including limiting contact, social isolation, vaccination, contact tracing, etc. However, given the heterogeneity in the enforcement of these strategies and constant fluctuations in the strictness levels of these strategies, it becomes challenging to assess the true impact of these strategies in controlling the spread of COVID-19.Methods: In the present study, we evaluated various transmission control measures that were imposed in 10 global urban cities and provinces in 2021 Bangkok, Gauteng, Ho Chi Minh City, Jakarta, London, Manila City, New Delhi, New York City, Singapore, and Tokyo.Findings: Based on our analysis, we herein propose the population-level Swiss cheese model for the failures and pit-falls in various strategies that each of these cities and provinces had. Furthermore, whilst all the evaluated cities and provinces took a different personalized approach to managing the pandemic, what remained common was dynamic enforcement and monitoring of breaches of each barrier of protection. The measures taken to reinforce the barriers were adjusted continuously based on the evolving epidemiological situation.Interpretation: How an individual city or province handled the pandemic profoundly affected and determined how the entire country handled the pandemic since the chain of transmission needs to be broken at the very grassroot level to achieve nationwide control

Дослідження ерозії вапняку на островах кат ба на Північному Сході В'єтнаму з використанням вимiрювача поперечної мікро-ерозії

Erosion rate at the Cat Ba island stations ranged from 0.196 to 0.282 mm/year shows that the average value in comparison with previous study results ranges from ±0.2 to ±0.5 mm with strong eroded level. Relative erosion rate value is the lowest at measuring stations X2 on April 8th, 2015 and the highest is at measuring stations Z7 on November 9th 2015, the average value in comparison with previous study results, ranges from ±0.05 to ±0.2 mm with average eroded level and from ±0.2 to ±0.5 mm with strong eroded level.The results of relative erosion rate on April 8th, 2015 are lower than on November 9th, 2015. Total rainfall values counted from the beginning of the study to the first measuring date (April 8th, 2015) and the second measuring date (November 9th, 2015) are 980.2 mm and 2280 mm, respectively. Therefore, the erosion rate of limestone is strongly affected by changes of total rainfall on the Cat Ba Island.Average relative erosion rates in this study are quite high at some submerged zone stations (about over 0.2 mm/year, on average) and quite low with some stations on land in comparison with some previous studies all over the world. Therefore, it needs more assessment in longer period to study more accurately some other impacts on weathering and erosion processes.В последние годы карстовые ландшафты острова Кат Ба подверглись значительному воздействию вследствие интрузии и глобальных изменений климата. Естественное разрушение карстовых ландшафтов в результате эрозии известняка становится все более распространенной проблемой. Поэтому необходимо углубить исследования методов защиты для эффективного сохранения ландшафтов.В останні роки карстові ландшафти острова Кат Ба зазнали значного впливу внаслiдок iнтрузiї та глобальних змін клімату. Природне руйнування карстових ландшафтів в результатi ерозії вапняку стає все більш росповсюдженою проблемою. Тому необхідно поглибити дослідження методів захисту для ефективного збереження ландшафтів

Advances in theoretical and experimental XAFS studies of thermodynamic properties, anharmonic effects and structural determination of fcc crystals

Thermodynamic properties, anharmonic effects and structural determination of fcc crystals have been studied based on the theoretical and experimental Debye–Waller factors presented in terms of cumulant expansion up to the third order, thermal expansion coefficient, X-ray absorption fine structure (XAFS) spectra and their Fourier transform magnitudes. The advances in these studies are performed by the further development of the anharmonic correlated Einstein model primary only for approximating three first XAFS cumulants into the method using that all the considered theoretical and experimental XAFS parameters have been provided based on only the calculated and measured second cumulants. The obtained cumulants describe the anharmonic effects in XAFS contributing to the accurate structural determination. Numerical results for Cu are found to be in good agreement with the experimental values extracted by using the present advanced method and with those obtained by the other measurements

Zeta study of water samples on Ba and Dong Nai river basins

Findings zeta potential in river water samples of Ba and Dong Nai basin in Tay Nguyen area indicated that the properties of colloidal systems in the basin of Ba and Dong Nai river in Tay Nguyen region was relatively stable. The colloidal system was heavily influenced by the pH of the water, not by suspended component. The study also showed the influence of pH value on zeta potential values ​​in river water samples. For the three river water samples, pH values ​​tend to be inversely proportional to the zeta potential. Meanwhile, it is only true for the water samples taken in the middle section and the downstream of Dong Nai river basin, but upstream tended to be directly proportional. In addition, zeta potential in water samples at the regional hydroelectric plant located on 2 river basins, especially water sampled before and after the dams were also studied. The obtained results showed that affects of pH index on the zeta potential values ​​are completely correct and were a good agreement with discovered rules.ReferencesLại Huy Anh và nnk, 2004: Nghiên cứu cấu trúc địa hình, địa mạo, địa động lực lưu vực sông Ba và sông Côn. Báo cáo chuyên đề Viện Địa lý, Hà Nội. Đỗ Đức Dũng, Nguyễn Vũ Huy, 2012: Báo cáo tình hình quản lí lưu vực sông Đồng Nai 2011, Đỗ Tiến Lanh, 2010: Báo cáo đề tài KC08 18/06-10 “Quản lý tổng hợp lưu vực và sử dụng hợp lí tài nguyên nước lưu vực hệ thống sông Đồng Nai”. Lưu trữ tại viện Khoa học Thủy lợi miền Nam. Ngô Đình Tuấn và nnk, 2007: Quản lý tổng hợp tài nguyên nước lưu vực sông Ba, Trường Đại học Thủy lợi, Hà Nội. Nguyễn Viết Phổ, 1999: Tìm hiểu sông Đồng Nai. Hội nghị khoa học, công nghệ và môi trường miền Đông Nam Bộ họp tại Đà Lạt 12/1999, http://dalat.gov.vn Nguyễn Viết Phổ, 2003: Tài nguyên nước Việt Nam, Nhà xuất bản Nông Nghiệp, trang 137-152. Tran Hong Thai, Tran Thi Van, 2011: Assessment of climate change impacts on salinity intrusion in Hong-Thai Binh and Dong Nai river basins, VNU Journal of Science, Earth Sciences 27, 54-61. Zeta Meter 4.0 Instructor, Zeta-Meter Inc., PO Box 3008, Staunton  VA  24402  USA. 2009. Cổng thông tin quan tắc môi trường, Lưu vực sông Đồng Nai, http://www.cem.gov.vn, 01/03/2011.

A waiting time of 7 min is sufficient to reduce bleeding in oculoplastic surgery following the administration of epinephrine together with local anaesthesia

OBJECTIVE: The time taken to reach maximal haemostatic effect following local anaesthesia with epinephrine is generally believed to be <10 min. This is based on clinical experience and indirect measurements of perfusion using methods such as laser Doppler flowmetry and oxygen spectroscopy. However, the only study in which bleeding has been measured quantitatively in an intra-operative setting in humans showed that the full haemostatic effect was not achieved until 30 min after anaesthesia. The aim of this study was to determine the time taken to reach maximum haemostatic effect when using epinephrine for local anaesthesia in oculoplastic surgery.METHODS: Intra-operative bleeding following infiltration anaesthesia with either lidocaine 20 mg/ml (2%) or lidocaine + epinephrine 12.5 μg/ml (1:80 000) was measured after 7, 15 and 30 min in the eyelids of 16 patients undergoing upper eyelid blepharoplasty.RESULTS: Bleeding was decreased by 74.6% (with 95% CI, 6.16-87.6%) 7 min after the injection of lidocaine + epinephrine (p = 0.0048) compared with lidocaine without epinephrine. There was no further decrease in bleeding after 15 or 30 min (p = n.s.).CONCLUSION: The optimal time for skin incision in eyelid surgery is within 7 min of injection of lidocaine with epinephrine. Waiting longer does not lead to a further decrease in bleeding