This paper presents an approach to design proportional-integral-derivative controllers for inductionmachines usingmeasurements.Most controlmethods developed for induc-tion machines are generally based on mathematical ...This paper presents an approach to design proportional-integral-derivative controllers for inductionmachines usingmeasurements.Most controlmethods developed for induc-tion machines are generally based on mathematical models.Due to complex dynamics of induction machines,identified models are often unable to perfectly describe their behaviour.Thus,the system performance will be limited by the quality of the identified model.Hence,developing control methods that do not require the availability of system model is advantageous.Here,we propose an approach that uses the frequency response data to directly design controllers.The main idea here is to find controller parameters so that the closed-loop frequency response fits a desired frequency response.Its main advantage is that errors associated with the modelling process are avoided.Moreover,the control design process does not depend on the order and complexity of the plant.A practical application to induction machines illustrates the efficacy of the proposed approach.展开更多
Background:Rice is a major cereal crop and staple food of eastern India,and most farmers depend solely on rice for their livelihood.Rice farming provides both tangible and non-tangible benefits to ecosystems which nee...Background:Rice is a major cereal crop and staple food of eastern India,and most farmers depend solely on rice for their livelihood.Rice farming provides both tangible and non-tangible benefits to ecosystems which need to be maintained and enhanced.These benefits are provided through ecosystem services(ES)that include both marketable and non-marketable.Methods:In this study,the rice farms in eastern India were valued by quantifying the economic value of the services under conventional method of rice cultivation and the gap of ecosystem services value and farm income per unit area were assessed.A stratified random sampling technique was used in this study for selection of agro-climatic zones,districts,blocks,gram panchayat,and study units(households).Soil sampling was also performed for assessing the regulating services(biocontrol of pests,carbon flow,soil erosion,nitrogen fixation),provisioning services(food and by-products),and supporting services(soil fertility,hydrological flow,nutrient cycling,and soil formation).Results:The results indicated that the total economic value of ecosystem services ranged from US$1238 to 1688 ha−1 year−1.The marketed(primary production)and non-marketed ecosystem services values ranged from 66–89 to 11–34%of the total,respectively.Valuation of some of the ecosystem services such as cultural services,biodiversity,and gas regulation,which may play a significant role in total ecosystem services,has not been made due to non-availability of data and appropriate methodology for rice ecosystem.Different values of parameters can explain the variability in ecosystem services among the agro-climatic zones in eastern India.Clustering of locations based on variability of ecosystem services helps in identifying intervention points for sustaining and improving ecosystem services,while permitting sustainable agro-ecological intensification.The highest total economic gap between ES value and farm income was found in the north central plateau zone(US$1063 ha−1 year−1)and the lowest in t展开更多
Encephalitis is an uncommon manifestation of dengue fever.Here we present a 4 years old female child from Northeast Region of India who suffered from dengue encephalitis.To our knowledge,this is probably the first dia...Encephalitis is an uncommon manifestation of dengue fever.Here we present a 4 years old female child from Northeast Region of India who suffered from dengue encephalitis.To our knowledge,this is probably the first diagnosed case of dengue fever from this region.展开更多
基金NPRP grant NPRP09-1153-2-450 from the Qatar National Research Fund(a member of Qatar Foundation).
文摘This paper presents an approach to design proportional-integral-derivative controllers for inductionmachines usingmeasurements.Most controlmethods developed for induc-tion machines are generally based on mathematical models.Due to complex dynamics of induction machines,identified models are often unable to perfectly describe their behaviour.Thus,the system performance will be limited by the quality of the identified model.Hence,developing control methods that do not require the availability of system model is advantageous.Here,we propose an approach that uses the frequency response data to directly design controllers.The main idea here is to find controller parameters so that the closed-loop frequency response fits a desired frequency response.Its main advantage is that errors associated with the modelling process are avoided.Moreover,the control design process does not depend on the order and complexity of the plant.A practical application to induction machines illustrates the efficacy of the proposed approach.
文摘Background:Rice is a major cereal crop and staple food of eastern India,and most farmers depend solely on rice for their livelihood.Rice farming provides both tangible and non-tangible benefits to ecosystems which need to be maintained and enhanced.These benefits are provided through ecosystem services(ES)that include both marketable and non-marketable.Methods:In this study,the rice farms in eastern India were valued by quantifying the economic value of the services under conventional method of rice cultivation and the gap of ecosystem services value and farm income per unit area were assessed.A stratified random sampling technique was used in this study for selection of agro-climatic zones,districts,blocks,gram panchayat,and study units(households).Soil sampling was also performed for assessing the regulating services(biocontrol of pests,carbon flow,soil erosion,nitrogen fixation),provisioning services(food and by-products),and supporting services(soil fertility,hydrological flow,nutrient cycling,and soil formation).Results:The results indicated that the total economic value of ecosystem services ranged from US$1238 to 1688 ha−1 year−1.The marketed(primary production)and non-marketed ecosystem services values ranged from 66–89 to 11–34%of the total,respectively.Valuation of some of the ecosystem services such as cultural services,biodiversity,and gas regulation,which may play a significant role in total ecosystem services,has not been made due to non-availability of data and appropriate methodology for rice ecosystem.Different values of parameters can explain the variability in ecosystem services among the agro-climatic zones in eastern India.Clustering of locations based on variability of ecosystem services helps in identifying intervention points for sustaining and improving ecosystem services,while permitting sustainable agro-ecological intensification.The highest total economic gap between ES value and farm income was found in the north central plateau zone(US$1063 ha−1 year−1)and the lowest in t
文摘Encephalitis is an uncommon manifestation of dengue fever.Here we present a 4 years old female child from Northeast Region of India who suffered from dengue encephalitis.To our knowledge,this is probably the first diagnosed case of dengue fever from this region.
