In compound fertilizer production, several quality variables need to be monitored and controlled simultaneously. It is very diifficult to measure these variables on-line by existing instruments and sensors. So, soft-s...In compound fertilizer production, several quality variables need to be monitored and controlled simultaneously. It is very diifficult to measure these variables on-line by existing instruments and sensors. So, soft-sensor technique becomes an indispensable method to implement real-time quality control. In this article, a new model of multi-inputs multi-outputs （MIMO） soft-sensor, which is constructed based on hybrid modeling technique, is proposed for these interactional variables. Data-driven modeling method and simplified first principle modelingmethod are combined in this model. Data-driven modeling method based on limited memory partial least squares（LM-PLS） al.gorithm is used to build soft-senor models for some secondary variables.then, the simplified first principle model is used to compute three primary variables on line. The proposed model has been used in practicalprocess; the results indicate that the proposed model is precise and efficient, and it is possible to realize on line quality control for compound fertilizer process.展开更多
The implementation of pasture contracting policies in the Tibetan Plateau has been of widespread concern in the scientific community and related government departments. Studying the effects of the implementation of pa...The implementation of pasture contracting policies in the Tibetan Plateau has been of widespread concern in the scientific community and related government departments. Studying the effects of the implementation of pasture contracting policies will help us understand herders' attitudes toward those policies and to amend existing policies effectively.This paper analyzes 135 herder families' grazing management behavior using participatory rural appraisal(PRA), quantitative analysis and a Logistic regression model in three townships of Nagqu County in remote areas of the Tibetan Plateau, China. The results show that the herders have become settled and are no longer nomadic, so the settlement project has basically been completed and the policy of contracting for grazing rights is being gradually implemented in Nagqu County. Since the grazing rights and pastures were under contract, group-based management has been widely accepted in this area, which helps the herders deal with constraints, such as limited pasture area, a small grazing radius, controlled family animal husbandry and an uneven distribution of water. The herders that have more family members available for labor, higher proportion of family members with good health, and higher income from animal husbandry tend to choose household-based management.Herders tend to choose group-based management when higher quality winter pastures are available.展开更多
基金Supported by the National Natural Science Foundation of China （No.60421002） and the New Century 151 Talent Project of Zhejiang Province.
文摘In compound fertilizer production, several quality variables need to be monitored and controlled simultaneously. It is very diifficult to measure these variables on-line by existing instruments and sensors. So, soft-sensor technique becomes an indispensable method to implement real-time quality control. In this article, a new model of multi-inputs multi-outputs （MIMO） soft-sensor, which is constructed based on hybrid modeling technique, is proposed for these interactional variables. Data-driven modeling method and simplified first principle modelingmethod are combined in this model. Data-driven modeling method based on limited memory partial least squares（LM-PLS） al.gorithm is used to build soft-senor models for some secondary variables.then, the simplified first principle model is used to compute three primary variables on line. The proposed model has been used in practicalprocess; the results indicate that the proposed model is precise and efficient, and it is possible to realize on line quality control for compound fertilizer process.
基金supported by the National Natural Science Foundation of China (No. 41071066)the National Basic Research Program of China (No. 2010CB951704)the Dissertation Fellowship of the Peking University-Lincoln Institute Center for Urban Development and Land Policy
文摘The implementation of pasture contracting policies in the Tibetan Plateau has been of widespread concern in the scientific community and related government departments. Studying the effects of the implementation of pasture contracting policies will help us understand herders' attitudes toward those policies and to amend existing policies effectively.This paper analyzes 135 herder families' grazing management behavior using participatory rural appraisal(PRA), quantitative analysis and a Logistic regression model in three townships of Nagqu County in remote areas of the Tibetan Plateau, China. The results show that the herders have become settled and are no longer nomadic, so the settlement project has basically been completed and the policy of contracting for grazing rights is being gradually implemented in Nagqu County. Since the grazing rights and pastures were under contract, group-based management has been widely accepted in this area, which helps the herders deal with constraints, such as limited pasture area, a small grazing radius, controlled family animal husbandry and an uneven distribution of water. The herders that have more family members available for labor, higher proportion of family members with good health, and higher income from animal husbandry tend to choose household-based management.Herders tend to choose group-based management when higher quality winter pastures are available.
