Time filter

Source Type

Son L.H.,Ha Noi University of Science
Proc. of the IADIS Int. Conf. - Computer Graphics, Visualization, Computer Vision and Image Processing, CGVCVIP 2010, Visual Commun., VC 2010, Web3DW 2010, Part of the MCCSIS 2010 | Year: 2010

The integration between Geographic Information System and Internet gives the opportunity for everyone who wants to use GIS data and functions without installing any proprietary GIS software. Recently, these have been some researches about three dimensional WebGIS systems originated from the idea that GIS should become more familiar and realistic to end-users. However, these researches have limitation in analyzing maps' information and focusing on 3D maps conversion only. In this paper, we will propose the method to construct a three dimensional WebGIS system namely as SGIS-3D based on Digital Elevation Model- DEM and Geographic Modelling Language GeoVRML. Our system also provides some Spatial Analysis operations to exploit information in 3D maps. It is useful for managers, researchers and students who want to explore visual 3D maps for their own specific tasks. © 2010 IADIS. Source

Cuong B.C.,Institute of Mathematics | Son L.H.,Ha Noi University of Science | Chau H.T.M.,University of Economic and Technical Industries
ACM International Conference Proceeding Series | Year: 2010

In this paper, we will propose a two-context fuzzy clustering algorithm (2C-FCM) and its parallel solution so called P2C-FCM for the classification problems. Some initial experiments show the effectiveness of P2C-FCM and 2C-FCM when comparing with traditional Context FCM. The applications of P2C-FCM and 2C-FCM are the basis to generate fuzzy rules for classifying member countries of United Nation Organization (UNO) according to the Human Development Index based on the statistics of UNO in 2005. © 2010 ACM. Source

Minh N.D.,Vietnamese Academy of Agriculture science | Hough R.L.,James Hutton Institute | Thuy L.T.,Vietnam Institute of Agricultural Sciences | Nyberg Y.,Swedish University of Agricultural Sciences | And 4 more authors.
Science of the Total Environment | Year: 2012

This study estimates the dietary exposure to cadmium (Cd), and associated potential health risks, for individuals living and working in a metal recycling community (n = 132) in Vietnam in comparison to an agricultural (reference) community (n = 130). Individual-level exposure to Cd was estimated through analysis of staple foodstuffs combined with information from a food frequency questionnaire. Individual-level exposure estimates were compared with published 'safe' doses to derive a Hazard Quotient (HQ) for each member of the study population. Looking at the populations as a whole, there were no significant differences in the diets of the two villages. However, significantly more rice was consumed by working age adults (18-60. years) in the recycling village compared to the reference village (p < 0.001). Rice was the main staple food with individuals consuming 461 ± 162. g/d, followed by water spinach (103 ± 51. kg/d). Concentrations of Cd in the studied foodstuffs were elevated in the metal recycling village. Values of HQ exceeded unity for 87% of adult participants of the metal recycling community (39% had a HQ > 3), while 20% of adult participants from the reference village had an HQ > 1. We found an elevated health risk from dietary exposure to Cd in the metal recycling village compared to the reference community. WHO standard of 0.4. mg Cd/kg rice may not be protective where people consume large amounts of rice/have relatively low body weight. © 2011 Elsevier B.V. Source

Chau N.T.T.,Ha Noi University of Science | Matsumoto M.,Kyushu University | Miyajima I.,Kyushu University
Journal of the Faculty of Agriculture, Kyushu University | Year: 2014

The use of probiotics has increasingly become popular in shrimp culture not only for disease prevention and nutrition improvement but also because of an increasing demand for environment- friendly aquaculture. However, in Viet Nam, most of probiotics were imported with unknown origin so that they can pose a threat of spreading pathogenic or genetically modified microorganisms, resulting in the broken safe biology. Also, the beneficial effect of using such microbial products in aquaculture is still debatable as their efficacy is yet unclear. The objectives of this paper is to assess the effectiveness on water, sediment quality and shrimp production in ponds treated with a Streptomyces sp. A1 probiotic in Phu Loc district, Thua Thien Hue province (Viet Nam). Results showed that the probiotic could significantly increase pH, salinity, dissolved oxygen and reduce biochemical oxygen demand, chemical oxygen demand, concentrations of NH,-N, NO2-N, NOJ-N, presumptive Vibrio count and total coliforms of shrimp pond water. Simultaneously, the probiotic was likely to maintain pH, moisture, concentrations of total organic carbon, total nitrogen, total phosphorus and total sulfur suitable for shrimp pond sediment, especially reduce total carbon. Moreover, an average of 364.38 kg shrimp/ha was obtained in treated ponds with a feed conversion ratio of 1.10, per day growth of 0.21 g and survival rate of 85.43% compared with 240 kg shrimp/ha, 1.67, 0.13 and 84.97, respectively, in control ponds. This indicates that the addition of the probiotic had a noticeable influence on water and sediment quality of shrimp ponds and shrimp production. The finding of this study will facilitate to apply effectively a novel and safe indigenous probiotic into shrimp aquaculture, thereby improving shrimp aquaculture environment, increasing shrimp production, limiting to use antibiotics and chemicals, ensuring safe products and reaching for the sustainable shrimp aquaculture development of Thua Thien Hue in particular and Viet Nam in general. Source

Chau N.T.T.,Kyushu University | Chau N.T.T.,Ha Noi University of Science | Matsumoto M.,Kyushu University | Miyajima I.,Kyushu University
Journal of the Faculty of Agriculture, Kyushu University | Year: 2014

A strain, Streptomyces sp. A1 isolated from shrimp pond sediments has been identified as an aquaculture probiotic antagonistic to pathogenic Vibrio harveyi V7. In the present study, the different carbon and nitrogen sources and growth factors in a mineral base medium were optimized for enhanced biomass production and antagonistic activity, following response surface methodology (RSM). Accordingly, the minimum and maximum limits of the selected variables were determined and a set of fifty experiments programmed employing central composite design CCD of RSM for the final optimization. The response surface plots of biomass production showed similar pattern with that of antagonistic activity, which indicated a correlation between the biomass and antagonism. The optimum concentrations of the carbon and nitrogen source, and growth factors for both biomass and antagonistic activity were starch (14.62 g/1), casein (0.93 g/1), NaCl (15.6 g/1), DL-α-alanine (0.233 g/1), and vitamin B6 (0.023 g/1). Source

Discover hidden collaborations