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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]

Abstract: Fish disease and health management is becoming a key barrier and major problem that currently limits expanded production and sustainable development of aquaculture and bring out food-safety issues. There has been a marked growth of interest in developing expert system to aid fish disease/health management. The literature shows that a few have been used to any extent due to the lack of deep user requirement analysis and long-term support and maintenance. This paper presents the effort to apply evolutionary prototyping model in developing an intelligent decision support system for fish disease/health management. The paper describes in detail about the four evolution stages as the system development experienced, every stage including the system design and implementation, feedback and requirement from system evaluation, and system redevelopment until a blown system. At last the evolution process is concluded from three directions. The evolutionary prototyping benefits and challenges experienced during the development and promotion are also discussed from the project management perceptive. [Copyright &y& Elsevier]

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]

Abstract: When a pig shows disease symptoms, it is important to make an accurate diagnosis to support control strategies. Diagnosing diseases in pigs requires considerable expertise. Only a few experts have the ability to do this, and each expert has his own specific domain. To make it more generally accessible and reduce the waiting time, an expert system named Pig-Vet has been developed by China Agricultural University. Based on investigations, this paper analyzes users'' needs and describes the architecture, main components, and their functions. The system has over 300 rules and 202 images and graphics for different types of diseases and symptoms. It can diagnose 54 types of common diseases of pigs. At present the system is in pilot in north of China. The stage achievements in developing the intellectual expert system of pig disease diagnosis are summarized. [Copyright &y& Elsevier]

A new type of roof structure was developed for the shade room in a double-slope greenhouse used for mushroom-vegetable planting. A simulation model was developed to evaluate the thermal performance of the new roof with an insulation thickness of 0.12 m in Beijing, China. The results showed that (1) the indoor air temperature of the shade room with the newly implemented shade roof was 2.7°C-4.9°C higher than that of an ordinary shade room during the winter months; (2) The indoor air temperature of the solar room adjacent to the shade room with the new roof was higher than that of the ordinary solar room and the minimum indoor air temperature of the solar room was increased 1.9°C at winter night; (3) the indoor temperature of the shade room with the new roof design was 2°C-4°C lower than that of the ordinary shade room during the summer months; (4) Under factory production conditions, which were conducted in a controlled environment to promote the annual growth of the edible fungus, the heating energy consumption of the shade room after the implementation of the new roof structure was reduced by 69.3%, the amounted to total energy savings of 61.3% per year. The new roof structure provided a significant improvement in the thermal environment compared to an ordinary shade room, improved the vegetable growth in the winter, and also significantly reduced the energy consumption and production costs. [ABSTRACT FROM AUTHOR]

Low-carbon production is one of the dominating issues in the sustainable development of the food industry with high energy consumption, especially in the table grapes cold chain. The aim of this paper is to propose a profit maximization strategy of table grapes cold chain by integrating the carbon footprint to improve the low-carbon production and sustainability of the cold chain system. The carbon footprint was evaluated by life cycle assessment (LCA) in entire cold chain system of table grapes, and the economic order quantity (EOQ) model was used to develop the profit maximization model with minimal carbon footprint and to maintain the optimal balance between stock and cost. The profit optimization performance, the sensitivity performance and the influencing factors of the decay rate, the carbon emission price, and the distance and carbon emission coefficient in refrigerated transport were analyzed according to the profit maximization model and the inventory data in actual cold chain investigated. The sensitivity performance analysis illustrated that the selling price had the highest sensitivity, and the carbon emission coefficient in storage had the lowest sensitivity. The comprehensive analysis results indicated that there is an optimal combination point between the economy and environment in actual cold chain, which not only reduced the carbon emission, but also had minimal impact on the profit in cold chain. The enterprises should integrate the carbon footprint cost into the profit maximization once the carbon emission tax is levied. The proposed strategy of the profit maximization with carbon footprint constraint is also suitable for improving profit maximization of other low-carbon supply chain applications. [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]

Aquaculture plays a very important role in adjusting Agricultural structure and increasing farmers'' income. But the technological advances in the production and storage of fishery products have exceeded the development of effective market demand over the past one decade. As a result, participants within the fishery industry have frequently found themselves facing increased variable and declining prices negatively affected the fishery industry. So it is desirable to provide decision aids to price forecasting to avoid such market imbalance. An aquatic products price forecasting support system (APPFSS) was developed by China agricultural University. Based on questionnaire and interviews, we analyze the decision problems and user needs. Then the architecture and development of APPFSS were described. At last we discussed on problems we had encountered during development and promotion. [Copyright &y& Elsevier]