Vietnam Academy of Science and Technology: Journals Online
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A HEDGE ALGEBRAS BASED REASONING METHOD FOR FUZZY RULE BASED CLASSIFIER
Get PDFThe fuzzy rule based classifier (FRBC) design methods have intensively been being studied during last years. The ones designed by utilizing hedge algebras as a formalism to generate the optimal linguistic values along with their (triangular and trapezoidal) fuzzy sets based semantics for the FRBCs have been proposed. Those design methods generate the fuzzy sets based semantics because the classification reasoning method still bases on the fuzzy set theory. One question which has been arisen is whether there is a pure hedge algebras classification reasoning method so that the fuzzy sets based semantic of the linguistic values in the fuzzy rule bases can be replaced with the hedge algebras based semantic. This paper answers that question by presenting a fuzzy rule based classifier design method based on hedge algebras with a pure hedge algebras classification reasoning method. The experimental results over 17 real world datasets are compared to the existing methods based on hedge algebras and fuzzy sets theory showing that the proposed method is effective and produces good results
STRUCTURAL ELUCIDATION OF GLYCOSIDES FROM THE SEEDS OF Entada phaseoloides GROWING IN THUA THIEN HUE
Get PDFEntada phaseoloides (L.) Merr. belongs to Fabaceae family and widely distributes throughout Vietnam, Thailand, Malaysia, Indonesia, Philippines, China, New Guinea, and Australia. In Vietnamese traditional medicine, the seeds of Entada phaseoloides were used for the treatment of stomachache, haemorrhoids, and hernia diseases. In this article, we report the isolation and structural elucidation of four glycosides from the water extract of seeds of E. phaseoloides including phaseoloideside C (1), phaseoloideside E (2), acanthoside D (3), and 1-(3,4,5-trimethoxyphenyl)prop-7-en-9-ol-O-(6ʹʹ-O-α-L-arabinopyranosyl)-β-D-glucopyranoside (4). To the best of our knowledge, compounds 3-4 were isolated from E. phaseoloides for the first time
NUMERICAL STUDY ON THE ABNORMAL SURGE DUE TO ATMOSPHERIC PRESSURE VARIATION ON THE CENTRAL COAST OF VIETNAM
No full textIn this study, the abnormal surge due to atmospheric pressure variation assumed to travel to the Central coast of Vietnam was simulated in some scenarios of maximum atmospheric variation (Pmax), the size (L) and the speed of the movement (Cp) of the atmospheric disturbance. The numerical model is based on two-dimensional long wave model considering the effect of atmospheric pressure variation on the sea level. The results showed that the surge height at the coastal area incresed as the size and maximum atmospheric variation of disturbance pressure increased. In which, when the traveling speed of atmospheric disturbance increased, the surge height increased, reaching to the maximum value of 0.72 m at Cp = 45 km/h, then decreasing. Meanwhile, the wave period decreased gradually to Cp = 30 km/h and was then almost unchanged. The coastal area around the latitude of 13oN was noted to have a higher surge level than both sides that may be due to the high steep of coastal topography. The results of the study are significant in investigation into the reason of abnormal surge in the area as well as serving the planning and disaster preparedness
Impact of sea level rise on current and wave in Van Uc coastal area
Get PDFThis paper presents the results of analysis, comparison of some characteristics of current, wave at Van Uc estuary area when being affected by sea level rise due to climate change based on Delft3D model. Scenario groups are established: The current scenario and the scenarios simulating effect of sea level rise 0.5 m and 1.0 m. The results of calculation and simulation show that the velocity values change locally when sea level rises: Rise in the northern and southern areas (0.2–5 cm/s); decrease in the navigation channel (0.6–30 cm/s). Sea level rise causes the increase of wave height in the coastal area (13.5–43.8% in the dry season and 20–40% in the rainy season) and fewer changes in the outer area
BƯỚC ĐẦU ỨNG DỤNG MÔ HÌNH HỒI QUY PHI TUYẾN ĐÁNH GIÁ KHẢ NĂNG TỰ LÀM SẠCH SINH HỌC VỰC NƯỚC VŨNG RÔ (PHÚ YÊN)
No full textThe self-purification of waters is a complex process, including physical, biological and chemical processes. Based on experimental data in May 2014 and December 2014 in Vung Ro bay (Phu Yen), this paper assesses biological self-purification capicity through the biodegradation of organic matter and nutrient assimilation. The capacity of biodegradation of organic matter is represented by nonlinear regression models of the relationship between BOD and decay time: model of Streeter - Phelps, Young and Clark (1965); Mason et al., (2006). The capacity of nutrient assimilation is represented by the nonlinear regression models of the relationship between photosynthesis and irradiance: Model of Webb et al., (1974); Platt et al., (1980); Eilers and Peeters (1988). Using the least squares method on the nonlinear regression model, the parameters characterizing the self purification process in Vung Ro waters were identified. The study results indicated that the rate of organic biodegradation in Vung Ro waters was 0.1073 ± 0.0781 days-1 (with RMSE = 0.0663 ± 0.0386); the half-time of decay was about 6 days. The maximum intensity of photosynthesis in Vung Ro waters was 57.6881 ± 25.2211 mgC (mgChal)-1h-1 (with RMSE = 3.5900 ± 2.2170); maximum nutrient assimilation of phytoplankton was 9.1719 ± 3.5962 mgN/m3/h and 1.2693 ± 0.4977 mgP/m3/h.Tự làm sạch thủy vực là quá trình phức tạp, bao gồm 3 quá trình chủ yếu: Vật lý, sinh học và hóa học. Trên cơ sở nguồn dữ liệu thí nghiệm vào tháng 5/2014 và 12/2014 tại vịnh Vũng Rô (Phú Yên), bài báo đánh giá khả năng tự làm sạch sinh học thông qua khả năng phân rã chất hữu cơ và đồng hóa muối dinh dưỡng. Khả năng phân rã chất hữu cơ được đánh giá thông qua mô hình tương quan phi tuyến giữa BOD và thời gian phân hủy: Mô hình Streeter - Phelps (1925); Mô hình Young và Clark (1965); và Mô hình Mason và nnk., (2006). Trong khi đó, đồng hóa muối dinh dưỡng được đánh giá thông qua khả năng quang hợp cực đại của thực vật phù du - mô hình tương quan phi tuyến giữa năng suất và cường độ ánh sáng: Mô hình Webb và nnk., (1974); Mô hình Platt và nnk., (1980); và Mô hình Eilers và Peeters (1988). Sử dụng phương pháp bình phương tối thiểu trên mô hình hồi quy phi tuyến, các tham số đặc trưng cho quá trình tự làm sạch sinh học tại vực nước Vũng Rô đã được xác định. Theo đó, hằng số tốc độ phân rã sinh học chất hữu cơ tại vực nước Vũng Rô đạt 0,1073 ± 0,0781 ngày-1 (sai số RMSE = 0,0663 ± 0,0386); tương ứng với thời gian bán phân rã khoảng hơn 6 ngày. Cường độ quang hợp cực đại tại vịnh Vũng Rô đạt đạt 57,6881 ± 25,2211 mgC (mgChla)-1h-1 (sai số RMSE = 3,5900 ± 2,2170); tương ứng với khả năng đồng hóa muối dinh dưỡng tối đa của thực vật nổi khoảng 9,1719 ± 3,5962 mgN/m3/h và 1,2693 ± 0,4977 mgP/m3/h
Building database of WEBGIS for the exchange of marine data between Vietnam and ASEAN countries
Get PDFThe system of oceanic database management and exchange is built with the purpose of exchanging the oceanic data between Vietnam and other ASEAN countries. The system can meet the demand of sharing and exchanging oceanic data through internet connection between Vietnam and ASEAN member countries. Besides, the system of oceanic database management and exchange can meet the demands of researches, managements and share of data domestically and internationally. In this paper, we focused on the details of the system of oceanic database management and exchange, such as hardware and software, data storage, data format and data structure, data management and integration, and other issues of interface, security, standards. The WEBGIS oceanic thematic database is properly built and managed for exchanging data domestically and with other ASEAN countries
Study on spatial distribution of coral reefs in Nam Yet island by using GIS and remote sensing techniques
Get PDFResearch and application of GIS and remote sensing techniques combined with field survey in coastal areas of Nam Yet island had been carried out to establish the distribution map of submarine habitats. Depth-invariant index was used to correct water column’s effects on spectral reflectance of each habitat. The results of satellite image classification showed that area with well-developed coral at great depths accounted for 12%, area with well-developed coral at small depths accounted for 9%, area with poorly-developed coral accounted for 13%, dead coral area accounted for 15% and area of sand, grit, pebbles and weathered coral accounted for 51%. The assessment after classification showed that the overall accuracy of the satellite image interpretation process was 94% and the kappa coefficient was 0.93
Antimicrobial and antioxidant activity of bacterial endophytes isolated from leaves of the mangrove plant Rhizophora stylosa
Get PDFMangroves are the most productive ecosystems and contain highly diverse plants and microbial communities. Mangrove endophytes are proved to be a rich source of bioactive secondary metabolites. The biological molecules produced by endophytes play an important role in protection of mangrove plants against herbivores, insects as well as pathogens. The present study aimed to isolate the endophytic bacteria from the mangrove plant Rhizophora stylosa and screen antimicrobial and antioxidant activity of ethyl acetate extracts from the isolated endophytic bacteria. A total of 64 endophytic bacterial strains from R. stylosa leaves were isolated, of which ethyl acetate extracts of 14 isolated endophytic strains showed antimicrobial activity against at least one of reference microorganisms Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 25923, Bacillus subtilis ATCC 27212, Staphylococcus aureus ATCC 12222 and Candida albicans ATCC 7754 with MIC values from 32 to 512 µg/ml. Among them, four strains showed activity against one reference microorganism, five strains showed activity against two reference microorganisms, four strains showed activity against three reference microorganisms, and one strain showed activity against four reference microorganisms. Additionally, the ethyl acetate extracts of 12 isolated endophytic bacteria showed ATBS and DPPH radical scavenging activity with scavenging values from 36.27 ± 2.6% to 71.46 ± 6.6% and from 26.22 ± 3.3% to 57.38 ± 5.8%, respectively. The identification of the five most active endophytic bacteria by 16S rRNA sequences revealed that the endophytes belonged to four genera, including Bacillus, Streptomyces, Pseudovibrio and Pseudomonas. The obtained results suggest that the endophytic bacteria from mangrove plants are a promising reservoir of antimicrobial and antioxidant agents.
The Energy Density of the Universe in the Vector Model for Gravitational Field
No full textWe show that, in the framework of the vector model of gravitational field, the total mass density and the mass of the Universe are quite the same as of experimental observed ones g/cm and kg
Lepton Flavor Violation in Economical 3-3-1 Model with Neutrino Singlets
Get PDFLepton flavor violating (LFV) decays of charged leptons and SM-like Higgs boson are discussed in the framework of the economical 3-3-1 model adding three additional singlets neutrinos (E331). We will show that the appearance of new neutrinos and charged Higgs bosons in this model can result in interesting regions of the parameter space, which satisfy the recent experimental bound of as well as give large . In these regions, the charged Higgs boson mass lies within the range of TeV. Our results show that the LFV decays are important channels to distinguish the E331 and the original economical (E331) models, which predicts suppressed LFV decay rates