Droplet drift wastes pesticide,pollutes the environment,and has become one of the focus issues of agricultural crop protection.Electrostatic spray technology reduces drift to a certain degree.In order to investigate t...Droplet drift wastes pesticide,pollutes the environment,and has become one of the focus issues of agricultural crop protection.Electrostatic spray technology reduces drift to a certain degree.In order to investigate the droplet drift pattern of a conical electrostatic nozzle,the droplet drift mass center distance was defined as an experimental index and used to conduct experimental wind tunnel studies on droplet drift.A mathematical model of the droplet drift mass center distance versus electrostatic voltage and wind speed was created via the regression method.The test results showed that the electrostatic voltage had an insignificant effect on droplet drift,the wind speed and its interaction with the electrostatic voltage had significant effects on droplet drift.When the wind speed was less than 3 m/s and stable,the crop adsorbability of a droplet had a dominant effect on the droplet drift;the droplet drift decreased with the increase of electrostatic voltage.When the wind speed exceeded 3 m/s and was stable,the reduced droplet particle size had a dominant effect on droplet drift,where droplet drift increased as the electrostatic voltage increased.When the wind speed was 0 m/s and the electrostatic voltage was 12 kV,the minimum droplet drift mass center distance was 35.5 mm,which was 56 mm less than that of conventional nozzle droplet drift.Therefore,a conical electrostatic nozzle is inapplicable for operation in an environment where wind speeds exceed 3 m/s.This study provides a reference for optimizing operational parameters of conical electrostatic nozzles and improving the anti-drift capability of droplets.展开更多
In recent years,multi-rotor unmanned aerial vehicle(UAV)crop protection operations have experienced tremendous growth.Compared with manual operations,they have advantages such as high operational efficiency,small pest...In recent years,multi-rotor unmanned aerial vehicle(UAV)crop protection operations have experienced tremendous growth.Compared with manual operations,they have advantages such as high operational efficiency,small pesticide dosage,and low pesticide hazards for humans.However,the tiny droplets produced during UAV spraying for crop protection are affected by the rotor air flow and will drift in all directions in an uncontrollable manner,severely affecting the pesticide deposition pattern and resulting in pesticide waste.To improve pesticide use efficiency during multi-rotor UAV spraying,an electrostatic spray system was designed based on electrostatic spray technology and a six-rotor UAV.The proper operation parameters for the UAV electrostatic spray were determined by test,which were spray altitude of 50 cm above the crop,spray pressure of 0.3 MPa and charging voltage of 9 kV.Field test was performed based on these parameters.The results showed that compared with non-electrostatic spray,the electrostatic spray improved by 13.6%in the average deposition density above the sampling device and 32.6%in the middle.The research can provide a reference for designing multi-rotor UAV electrostatic spray devices.展开更多
Market demand is becoming increasingly time-sensitive in competitive environments.Hence,supply disruptions will have a more serious impact on the profits of supply chains.This study applies a Stackelberg competition b...Market demand is becoming increasingly time-sensitive in competitive environments.Hence,supply disruptions will have a more serious impact on the profits of supply chains.This study applies a Stackelberg competition between a single supplier and a single manufacturer in a time-sensitive supply chain in a cloud manufacturing environment.We aim to address the supplier’s production capacity recovery issues and the manufacturer’s incentive decision issues after supply disruption.We find that the supplier is in a weak position when the information is symmetrical.The manufacturer can encourage the supplier to shorten the recovery time by raising the unit wholesale price.When the supplier’s unit production cost remains unchanged but the unit wholesale price increases,the profit of the supplier first increases and then decreases.In addition,under the centralized decision-making setting,the optimal recovery time of the supplier is shorter and the optimal unit market price of the product is lower than that under decentralized decision-making.We further find that resource sharing can shorten the optimal recovery time,but it does not necessarily play an incentivizing role.展开更多
Configuration management(CM)is an effective method for data modeling and change management in product development,but the study of how it can be adapted for complex product maintenance,repair and overhaul(MRO)has thus...Configuration management(CM)is an effective method for data modeling and change management in product development,but the study of how it can be adapted for complex product maintenance,repair and overhaul(MRO)has thus far been superficial.Research propositions are put forward on the basis of a literature review and verified by a case of a high-speed train MRO company.The findings show that CM can be used in MRO data management with adjustments in its functions.First,MRO-CM planning considers both multistage service and single-stage service to keep data consistent and continuous.Second,MRO data integration with the design/production phase should be considered during configuration identification.Third,baselines and change rules are developed for change control.Finally,status accounting and auditing can be repeatedly used in MRO data management.A systematic MRO-CM framework is generated to assist MRO practitioners in understanding the relationships among different MRO-CM functions.This paper contributes to expanding the theory of CM in MRO for complex products and provides an effective method for managing MRO data from systematic engineering insights.展开更多
This paper intends to understand the form of implementations of Enterprise Information Systems （EISs）. EISs are usually provided as packaged software products. Due to the diversities of implementations, EISs are oft...This paper intends to understand the form of implementations of Enterprise Information Systems （EISs）. EISs are usually provided as packaged software products. Due to the diversities of implementations, EISs are often characterized by their system architectures. A conceptual framework is proposed to delineate the diversity and dynamics of EIS implementations. This framework is constituted of three components, EIS strategy, variety, and process-level performance （SVP）. In particular, the variety of implementations is defined by two constructs, application scope and application depth. A Partial Least Squares structural equation modeling approach is applied to test the hypotheses according to the survey data from 223 project reports of EIS implementations in China. The results show that the EIS strategy and variety can both affect the performance of the implemented EISs. Specifically, application depth has an important mediating effect on the relationship between EIS strategy and performance. EIS strategy and application depth are breakthrough points to improve the performance of the implemented EISs. These findings suggest that the variety plays a central and effective role in the analysis of EIS implementations. This SVP framework highlights the interconnections among its components and captures the form of EIS implementations.展开更多
基金the National Key Technology R&D Program:Study and demonstration of technology and equipment for the entire cycle of large-scale production of high-quality rice(2014BAD06B01).
文摘Droplet drift wastes pesticide,pollutes the environment,and has become one of the focus issues of agricultural crop protection.Electrostatic spray technology reduces drift to a certain degree.In order to investigate the droplet drift pattern of a conical electrostatic nozzle,the droplet drift mass center distance was defined as an experimental index and used to conduct experimental wind tunnel studies on droplet drift.A mathematical model of the droplet drift mass center distance versus electrostatic voltage and wind speed was created via the regression method.The test results showed that the electrostatic voltage had an insignificant effect on droplet drift,the wind speed and its interaction with the electrostatic voltage had significant effects on droplet drift.When the wind speed was less than 3 m/s and stable,the crop adsorbability of a droplet had a dominant effect on the droplet drift;the droplet drift decreased with the increase of electrostatic voltage.When the wind speed exceeded 3 m/s and was stable,the reduced droplet particle size had a dominant effect on droplet drift,where droplet drift increased as the electrostatic voltage increased.When the wind speed was 0 m/s and the electrostatic voltage was 12 kV,the minimum droplet drift mass center distance was 35.5 mm,which was 56 mm less than that of conventional nozzle droplet drift.Therefore,a conical electrostatic nozzle is inapplicable for operation in an environment where wind speeds exceed 3 m/s.This study provides a reference for optimizing operational parameters of conical electrostatic nozzles and improving the anti-drift capability of droplets.
基金The authors acknowledge that the research was financially supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2014BAD06B01)Laboratory of Agricultural Mechanization Engineering Project(Provincial Key Laboratory).
文摘In recent years,multi-rotor unmanned aerial vehicle(UAV)crop protection operations have experienced tremendous growth.Compared with manual operations,they have advantages such as high operational efficiency,small pesticide dosage,and low pesticide hazards for humans.However,the tiny droplets produced during UAV spraying for crop protection are affected by the rotor air flow and will drift in all directions in an uncontrollable manner,severely affecting the pesticide deposition pattern and resulting in pesticide waste.To improve pesticide use efficiency during multi-rotor UAV spraying,an electrostatic spray system was designed based on electrostatic spray technology and a six-rotor UAV.The proper operation parameters for the UAV electrostatic spray were determined by test,which were spray altitude of 50 cm above the crop,spray pressure of 0.3 MPa and charging voltage of 9 kV.Field test was performed based on these parameters.The results showed that compared with non-electrostatic spray,the electrostatic spray improved by 13.6%in the average deposition density above the sampling device and 32.6%in the middle.The research can provide a reference for designing multi-rotor UAV electrostatic spray devices.
基金supported by the National Social Science Fund of China under Grant number 17BGL084
文摘Market demand is becoming increasingly time-sensitive in competitive environments.Hence,supply disruptions will have a more serious impact on the profits of supply chains.This study applies a Stackelberg competition between a single supplier and a single manufacturer in a time-sensitive supply chain in a cloud manufacturing environment.We aim to address the supplier’s production capacity recovery issues and the manufacturer’s incentive decision issues after supply disruption.We find that the supplier is in a weak position when the information is symmetrical.The manufacturer can encourage the supplier to shorten the recovery time by raising the unit wholesale price.When the supplier’s unit production cost remains unchanged but the unit wholesale price increases,the profit of the supplier first increases and then decreases.In addition,under the centralized decision-making setting,the optimal recovery time of the supplier is shorter and the optimal unit market price of the product is lower than that under decentralized decision-making.We further find that resource sharing can shorten the optimal recovery time,but it does not necessarily play an incentivizing role.
基金provided by the China Scholarship Council(CSC)under Grant No.201806060035the Open Fund of Key Laboratory of Anhui Higher Education Institutes under Grant No.CS2021-03+1 种基金the Key Project of University Humanities and Social Science Research in Anhui Province under Grant No.SK2020A0173the Research Fund for Young Teachers of Anhui University of Technology under Grant No.QS202014 are acknowledged.
文摘Configuration management(CM)is an effective method for data modeling and change management in product development,but the study of how it can be adapted for complex product maintenance,repair and overhaul(MRO)has thus far been superficial.Research propositions are put forward on the basis of a literature review and verified by a case of a high-speed train MRO company.The findings show that CM can be used in MRO data management with adjustments in its functions.First,MRO-CM planning considers both multistage service and single-stage service to keep data consistent and continuous.Second,MRO data integration with the design/production phase should be considered during configuration identification.Third,baselines and change rules are developed for change control.Finally,status accounting and auditing can be repeatedly used in MRO data management.A systematic MRO-CM framework is generated to assist MRO practitioners in understanding the relationships among different MRO-CM functions.This paper contributes to expanding the theory of CM in MRO for complex products and provides an effective method for managing MRO data from systematic engineering insights.
文摘This paper intends to understand the form of implementations of Enterprise Information Systems （EISs）. EISs are usually provided as packaged software products. Due to the diversities of implementations, EISs are often characterized by their system architectures. A conceptual framework is proposed to delineate the diversity and dynamics of EIS implementations. This framework is constituted of three components, EIS strategy, variety, and process-level performance （SVP）. In particular, the variety of implementations is defined by two constructs, application scope and application depth. A Partial Least Squares structural equation modeling approach is applied to test the hypotheses according to the survey data from 223 project reports of EIS implementations in China. The results show that the EIS strategy and variety can both affect the performance of the implemented EISs. Specifically, application depth has an important mediating effect on the relationship between EIS strategy and performance. EIS strategy and application depth are breakthrough points to improve the performance of the implemented EISs. These findings suggest that the variety plays a central and effective role in the analysis of EIS implementations. This SVP framework highlights the interconnections among its components and captures the form of EIS implementations.
