To build a rapid and accurate method for greenhouse vegetable landinformation extraction using an index model derived from TM digital data of Qingzhou City, ShandongProvince, based on a systematic analysis of the spec...To build a rapid and accurate method for greenhouse vegetable landinformation extraction using an index model derived from TM digital data of Qingzhou City, ShandongProvince, based on a systematic analysis of the spectral characteristics of different land use typesin the study area, a subset of the image was first made to eliminate the mountainous region notassociated with vegetable distribution, and then water body pixels were masked. With this the V_Iindex model for greenhouse vegetable land extraction was developed. The index model indicatedgreenhouse vegetable land for Qingzhou in April 2002 was concentrated in the southeast and aroundrural residential areas. Field data used for an accuracy evaluation showed that greenhouse hectaresdetermined with remote sensing were 95.9% accurate, and accuracy for the spatial distribution ofgreenhouse vegetable land cross checked with a random sample was 96.3%. Therefore, this approachprovided an effective method for greenhouse vegetable land information extraction and has potentialsignificance for management of greenhouse vegetable production in the study area, as well as NorthChina.展开更多
In order to provide a scientific basis for rice yield estimation and improve the accuracy of yield estimation in Zhejiang Province, regionalization indices for rice yield estimation by remote sensing (RS) in the provi...In order to provide a scientific basis for rice yield estimation and improve the accuracy of yield estimation in Zhejiang Province, regionalization indices for rice yield estimation by remote sensing (RS) in the province were determined by considering the special features of yield estimation by RS, and based on analysis of the natural conditions of Zhejiang Province. The indices determined included rice cropping system, agroclimate, landform, surface feature structure and rice yield level, where rice planting system was considered as the main one. Then regionalization for rice yield estimation by RS was completed by spatial neighboring analysis with the Geographical information System (GIS) technology combined with using of tree algorithm. The province was divided into two regions, i. e., the single-cropping rice region which was subdivided into 3 regions including those in mountains of northwest Zhejiang, water network area of north Zhejiang and mountains of south Zhejiang, and double-cropping rice region which was subdivided into 5 regions including those on plain of north Zhejiang, coastal plains and hills of southeast Zhejiang, Jin-Qu Basin of middle Zhejiang, hills of east Zhejiang, and hills and mountains of northwest Zhejiang. This regionalization took the county borders as the region boundaries, kept the regions connective and made the administrative regions integrity and, then, could meet the requirements of rice yield estimation by RS, showing that the results were quite satisfying.展开更多
In current researches on spectrum leasing, Common model and Property-right model are two main approaches to dynamic spectrum sharing. However, Common model does not consider the obligation of Primary System (PS) and i...In current researches on spectrum leasing, Common model and Property-right model are two main approaches to dynamic spectrum sharing. However, Common model does not consider the obligation of Primary System (PS) and is unfair to Secondary System (SS), while the cooperation based on Property-rights model has problems on its feasibility. This paper proposes a novel system model, in which a Cost-Prediction scheme for Spectrum Leasing (CPSL scheme) is designed to forecast the cost that PS would pay for leasing spectrum. Cost Function is introduced as a criterion to evaluate the potential cost of spectrum leasing for PS. The simulation results show that compared with Common model based scheme, CPSL scheme substantially improves the QoS of the delay-sensitive traffic in SS at the cost of a small degradation of PS performance.展开更多
A stochastic dissipative dynamical system driven by non-Gaussian noise is investigated. A general approximate Fokker-Planck equation of the system is derived through a path-integral approach. Based on the definition o...A stochastic dissipative dynamical system driven by non-Gaussian noise is investigated. A general approximate Fokker-Planck equation of the system is derived through a path-integral approach. Based on the definition of Shannon's information entropy, the exact time dependence of entropy flux and entropy production of the system is calculated both in the absence and in the presence of non-equilibrium constraint. The present calculation can be used to interpret the interplay of the dissipative constant and non-Gaussian noise on the entropy flux and entropy production.展开更多
In terms of demands of rice farming in the southern China, the information processing system and the yield measurement system that is installed in combine harvester, are designed and completed. Now the systems have be...In terms of demands of rice farming in the southern China, the information processing system and the yield measurement system that is installed in combine harvester, are designed and completed. Now the systems have been used in demonstration site in the Experiment Base of Shanghai Precision Agriculture. Based on the idea of spatial-oriented, object-oriented, user-oriented, the Farm Geographic Information System for precision farming of rice was developed, which is characterized by intelligence and visualized. The Decision-making Management System is integrated with rice growth model, expert model for rice cultivation. The DGPS, RS, GIS and intelligence sensors and computer technique were adopted in building the artificial intelligence system for measuring grain yield that is installed in combine harvester, so the combine harvester could provide the grain yield distribution map real-timely. The environmental and economic assessment shows that the precision rice farming applied in the demonstration site will benefit the society, economy and ecology greatly.展开更多
New accounting standards set that once any loss of asset impairment is recognized, here mainly refer to long-term assets, it shall not be switched back in the future accounting periods. In the author's opinion, this ...New accounting standards set that once any loss of asset impairment is recognized, here mainly refer to long-term assets, it shall not be switched back in the future accounting periods. In the author's opinion, this provision has some conflicts with the accounting information quality requirements which require reliability, relevance, comparability, and caution. This paper mainly analyzes the contradictions by comparing the provision with the requirements and putting forward relevant solutions. In the end, this paper has drawn the conclusion that the loss of the long-term asset impairment shall be allowed to switch back with certain conditions.展开更多
A large portion of irrigation farmers make use of subjective (intuition) irrigation scheduling methods as supposed to objective or scientific irrigation scheduling methods, which need to be changed. The BEsproeiings...A large portion of irrigation farmers make use of subjective (intuition) irrigation scheduling methods as supposed to objective or scientific irrigation scheduling methods, which need to be changed. The BEsproeiingsWAterbestuursprogram (BEWAB+) irrigation scheduling programme is based on the water balance equation and needs: (1) a crop production function; (2) a relative consumptive water demand curve and (3) an allowable depletion subroutine. The objective of this paper was to describe research aimed at obtaining information on (1) and (2) for pea and also to describe the effect of water application on yield and water use of pea. BEWAB+ uses this information to estimate the daily irrigation water requirements for a particular soil-crop-atmosphere system under irrigation. A field experiment, based on published line-source irrigation methodology, was conducted on a 3 m deep loamy fine sand Bainsvlei or Ustic Quartzipsamment soil near Bloemfontein (26°08′S; 29°01′E) in South Africa. Results showed that there is a linear relationship of the form Ys = 8.07ET - 249 (r2 = 0.91), where Ys is the seed yield of pea (kg/ha) and ET is evapotranspiration for the growing season (mm). The relative consumptive water demand curve is represented by the following third order polynomial function that describes the relationship between time and relative ET for a pea growing season of 120 days: ETrelx = 0.09419646 - 0.01302413x + 0.00059008x2 - 0.00000371x3. ETrelz denotes relative ET and x denotes time in days. A workable balance between practical problem solving and advanced irrigation science has been established with BEWAB+. Pre-plant irrigation schedules can be made for semi-arid areas with the BEWAB+ programme using easily obtainable inputs, like target yield, soil depth and soil particle size distribution information.展开更多
Sustainable agricultural production is of vital importance to food supply security. This study aimed to investigate crop yield response to spatial variability of soil quality at a county scale in the North China Plain...Sustainable agricultural production is of vital importance to food supply security. This study aimed to investigate crop yield response to spatial variability of soil quality at a county scale in the North China Plain (NCP) and subsequently derive key soil quality indicators. Soil samples were geo-referenced and taken in 2008 from both surface (0-20 cm) and subsurface (20-40 cm) layers in 132 fields throughout the Fengqiu County, located in the centre of the NCP, for subsequent soil properties' analyses. Annum crop yields were obtained from the same fields where soil samples were collected. Soil quality was evaluated based on a fuzzy set with 13 soil properties, and its spatial distributions were investigated by integrating geostatistical analysis and geographic information system (GIS) techniques. Soil quality indices were classified into five grades, and their spatial distributions were mapped within the county. The surface soil qualities were about one to two grades higher than the subsurface soil. The quality indices for surface and subsurface soils were positively associated with the annual crop yields, suggesting the importance of both. Soil organic matter, total nitrogen, available P, and available K contributed 50% of the combined weight to the soil quality index and were identified as key indicators of soil quality status in the area in terms of sustainability.展开更多
基金Project supported by the Chinese Ministry of Education (No. [2002] 247).
文摘To build a rapid and accurate method for greenhouse vegetable landinformation extraction using an index model derived from TM digital data of Qingzhou City, ShandongProvince, based on a systematic analysis of the spectral characteristics of different land use typesin the study area, a subset of the image was first made to eliminate the mountainous region notassociated with vegetable distribution, and then water body pixels were masked. With this the V_Iindex model for greenhouse vegetable land extraction was developed. The index model indicatedgreenhouse vegetable land for Qingzhou in April 2002 was concentrated in the southeast and aroundrural residential areas. Field data used for an accuracy evaluation showed that greenhouse hectaresdetermined with remote sensing were 95.9% accurate, and accuracy for the spatial distribution ofgreenhouse vegetable land cross checked with a random sample was 96.3%. Therefore, this approachprovided an effective method for greenhouse vegetable land information extraction and has potentialsignificance for management of greenhouse vegetable production in the study area, as well as NorthChina.
基金Project (No. Y97#14-6-2) supported by the Commission of Science, Technology and Industry for NationalDefence, China.
文摘In order to provide a scientific basis for rice yield estimation and improve the accuracy of yield estimation in Zhejiang Province, regionalization indices for rice yield estimation by remote sensing (RS) in the province were determined by considering the special features of yield estimation by RS, and based on analysis of the natural conditions of Zhejiang Province. The indices determined included rice cropping system, agroclimate, landform, surface feature structure and rice yield level, where rice planting system was considered as the main one. Then regionalization for rice yield estimation by RS was completed by spatial neighboring analysis with the Geographical information System (GIS) technology combined with using of tree algorithm. The province was divided into two regions, i. e., the single-cropping rice region which was subdivided into 3 regions including those in mountains of northwest Zhejiang, water network area of north Zhejiang and mountains of south Zhejiang, and double-cropping rice region which was subdivided into 5 regions including those on plain of north Zhejiang, coastal plains and hills of southeast Zhejiang, Jin-Qu Basin of middle Zhejiang, hills of east Zhejiang, and hills and mountains of northwest Zhejiang. This regionalization took the county borders as the region boundaries, kept the regions connective and made the administrative regions integrity and, then, could meet the requirements of rice yield estimation by RS, showing that the results were quite satisfying.
基金supported by the National High Technology Research and Development Program of China ('863' Program, No.2009AA01Z242)National Natural Science Foundation of China (60972080)
文摘In current researches on spectrum leasing, Common model and Property-right model are two main approaches to dynamic spectrum sharing. However, Common model does not consider the obligation of Primary System (PS) and is unfair to Secondary System (SS), while the cooperation based on Property-rights model has problems on its feasibility. This paper proposes a novel system model, in which a Cost-Prediction scheme for Spectrum Leasing (CPSL scheme) is designed to forecast the cost that PS would pay for leasing spectrum. Cost Function is introduced as a criterion to evaluate the potential cost of spectrum leasing for PS. The simulation results show that compared with Common model based scheme, CPSL scheme substantially improves the QoS of the delay-sensitive traffic in SS at the cost of a small degradation of PS performance.
基金National Natural Science Foundation of China under Grant Nos.10472091,10332030,and 10502042
文摘A stochastic dissipative dynamical system driven by non-Gaussian noise is investigated. A general approximate Fokker-Planck equation of the system is derived through a path-integral approach. Based on the definition of Shannon's information entropy, the exact time dependence of entropy flux and entropy production of the system is calculated both in the absence and in the presence of non-equilibrium constraint. The present calculation can be used to interpret the interplay of the dissipative constant and non-Gaussian noise on the entropy flux and entropy production.
基金the Knowledge Innovation Project of the Chinese Academy of Sciences(No.KZCX2-412).
文摘In terms of demands of rice farming in the southern China, the information processing system and the yield measurement system that is installed in combine harvester, are designed and completed. Now the systems have been used in demonstration site in the Experiment Base of Shanghai Precision Agriculture. Based on the idea of spatial-oriented, object-oriented, user-oriented, the Farm Geographic Information System for precision farming of rice was developed, which is characterized by intelligence and visualized. The Decision-making Management System is integrated with rice growth model, expert model for rice cultivation. The DGPS, RS, GIS and intelligence sensors and computer technique were adopted in building the artificial intelligence system for measuring grain yield that is installed in combine harvester, so the combine harvester could provide the grain yield distribution map real-timely. The environmental and economic assessment shows that the precision rice farming applied in the demonstration site will benefit the society, economy and ecology greatly.
文摘New accounting standards set that once any loss of asset impairment is recognized, here mainly refer to long-term assets, it shall not be switched back in the future accounting periods. In the author's opinion, this provision has some conflicts with the accounting information quality requirements which require reliability, relevance, comparability, and caution. This paper mainly analyzes the contradictions by comparing the provision with the requirements and putting forward relevant solutions. In the end, this paper has drawn the conclusion that the loss of the long-term asset impairment shall be allowed to switch back with certain conditions.
文摘A large portion of irrigation farmers make use of subjective (intuition) irrigation scheduling methods as supposed to objective or scientific irrigation scheduling methods, which need to be changed. The BEsproeiingsWAterbestuursprogram (BEWAB+) irrigation scheduling programme is based on the water balance equation and needs: (1) a crop production function; (2) a relative consumptive water demand curve and (3) an allowable depletion subroutine. The objective of this paper was to describe research aimed at obtaining information on (1) and (2) for pea and also to describe the effect of water application on yield and water use of pea. BEWAB+ uses this information to estimate the daily irrigation water requirements for a particular soil-crop-atmosphere system under irrigation. A field experiment, based on published line-source irrigation methodology, was conducted on a 3 m deep loamy fine sand Bainsvlei or Ustic Quartzipsamment soil near Bloemfontein (26°08′S; 29°01′E) in South Africa. Results showed that there is a linear relationship of the form Ys = 8.07ET - 249 (r2 = 0.91), where Ys is the seed yield of pea (kg/ha) and ET is evapotranspiration for the growing season (mm). The relative consumptive water demand curve is represented by the following third order polynomial function that describes the relationship between time and relative ET for a pea growing season of 120 days: ETrelx = 0.09419646 - 0.01302413x + 0.00059008x2 - 0.00000371x3. ETrelz denotes relative ET and x denotes time in days. A workable balance between practical problem solving and advanced irrigation science has been established with BEWAB+. Pre-plant irrigation schedules can be made for semi-arid areas with the BEWAB+ programme using easily obtainable inputs, like target yield, soil depth and soil particle size distribution information.
基金supported by the National Basic Research Program of China (No. 2011CB100506)the National Natural Science Foundation of China (No. 41271311)+1 种基金the National Key Technology Support Program of China (No. 2012BAD05B0203)the Knowledge Innovation Program of Chinese Academy of Sciences (No. ISSASIP1118)
文摘Sustainable agricultural production is of vital importance to food supply security. This study aimed to investigate crop yield response to spatial variability of soil quality at a county scale in the North China Plain (NCP) and subsequently derive key soil quality indicators. Soil samples were geo-referenced and taken in 2008 from both surface (0-20 cm) and subsurface (20-40 cm) layers in 132 fields throughout the Fengqiu County, located in the centre of the NCP, for subsequent soil properties' analyses. Annum crop yields were obtained from the same fields where soil samples were collected. Soil quality was evaluated based on a fuzzy set with 13 soil properties, and its spatial distributions were investigated by integrating geostatistical analysis and geographic information system (GIS) techniques. Soil quality indices were classified into five grades, and their spatial distributions were mapped within the county. The surface soil qualities were about one to two grades higher than the subsurface soil. The quality indices for surface and subsurface soils were positively associated with the annual crop yields, suggesting the importance of both. Soil organic matter, total nitrogen, available P, and available K contributed 50% of the combined weight to the soil quality index and were identified as key indicators of soil quality status in the area in terms of sustainability.