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We estimated the risk posed by hydroxybenzene in farm-raised Crucian carps (Carassius carassius) from a pond on a fish farm in Beijing, China, by analyzing a time-series of observed hydroxybenzene concentrations in fish within a culturing season in year 2006. We used the basic linear regression to model the data and forecast the probability of hydroxybenzene concentration in pond fish exceeding selected health effect criteria (the risk) using Monte Carlo simulation. The risk is highly correlated with the time a fish stays in the pond. The results indicate that the risk-days in pond relationship resembles a sigmoid function with an inflection point around 150 days. The resulting model can be used to demonstrate the benefit of improving water quality in terms of increased fish production. [ABSTRACT FROM AUTHOR]

Variable rate pesticide application holds great potential in precision agriculture where application efficiency depends mainly on plant recognition. The segmentation of the plant from the background is key to plant recognition. The work presented in this paper is a real-time segmentation algorithm that was developed to improve the quality of plant segmentation under natural outdoor light conditions. The plant images were greyed with the colour features H, a*, 13 and Cr respectively, and the plant was segmented from the grey images with a threshold that was computed by an iterative method. Experiments showed that segmentation was generally of good quality if the background was bare soil. The quality of segmentation declines if the images are greyed by H and Cr, and the quality remains stable if they are greyed by a* and 13 when the background is complicated, and, especially with heavy shadows. With respect to segmentation speed, that greyed by Cr was the fastest and that greyed by a* was slowest amongst the four. [ABSTRACT FROM AUTHOR]

E-learning, as an innovative and alternative way of distance learning, provides a strong challenge to traditional learning with its unique advantage. This paper, on the diffusion of e-learning adoption in China, investigates people's perceptions and attitudes toward adopting e-learning, and explores the factors affecting the e-learning adoption behaviour from an innovation adoption perspective. Based on the model of Rogers' innovation adoption theory, every factor of perceived innovative attributes influencing the individual adoption behaviour, namely perceived relative advantage, perceived compatibility, perceived trialability, and perceived observability, will be analysed to test the relationship between the perceived innovative attributes and adoption intention of e-learning. The result shows that the four perceived innovative attributes do have certain influences on people's adoption of e-learning. [ABSTRACT FROM AUTHOR]

Domain concepts acquisition is a key step of knowledge acquisition. In this paper we propose a new method for computing the relationship of domain concepts of China's vegetable supply chain using WordNet and Locally Linear Embedding (LEE) Arithmetic. WordNet is used to construct the high dimension description of the domain concepts and LLE is used to compute the relationship of concepts in low dimension space. The concepts description in the high dimension is in accord with human cognition and the low dimension relationship can reflect the degree of correlation of domain concepts clearly. A computer can deal with domain concepts directly after dimensional transformation. The experiment proves the efficiency of this method. The method can be expanded to deal with other examples of domain concepts acquisition. [ABSTRACT FROM AUTHOR]

The paper analyses the impacts of alteration of agricultural domestic supports on state welfare adopting partiaI equilibrium theory. In order to find out the appropriate levels of agricultural domestic supports in China, a nonlinear programming approach was utilised, based on constraints of the annual financial budget and the Uruguay Round Agreement on Agriculture, to build an optimisation model for levels of China agricultural domestic support was built to aim at the maximum welfare. The result shows that the maximum levels of China "amber box" support are 50 billion dollars from welfare maximisation in the international agricultural product trade. The amber box support is about 174 billion RMB yuan according to the de minimis levels of China with 8.5%. The national annual budgetary expenditure for agriculture was 175.445 billion RMB yuan approximately in 2003, the amber box support of which was only 55.143 billion RMB yuan. [ABSTRACT FROM AUTHOR]