The current research of state of charge(SoC) online estimation of lithium-ion battery(LiB) in electric vehicles(EVs)mainly focuses on adopting or improving of battery models and estimation filters. However, little att...The current research of state of charge(SoC) online estimation of lithium-ion battery(LiB) in electric vehicles(EVs)mainly focuses on adopting or improving of battery models and estimation filters. However, little attention has been paid to the accuracy of various open circuit voltage(OCV) models for correcting the SoC with aid of the ampere-hour counting method. This paper presents a comprehensive comparison study on eighteen OCV models which cover the majority of models used in literature. The low-current OCV tests are conducted on the typical commercial LiFePO/graphite(LFP) and LiNiMnCoO/graphite(NMC) cells to obtain the experimental OCV-SoC curves at different ambient temperature and aging stages. With selected OCV and SoC points from experimental OCV-SoC curves, the parameters of each OCV model are determined by curve fitting toolbox of MATLAB 2013. Then the fitting OCV-SoC curves based on diversified OCV models are also obtained. The indicator of root-mean-square error(RMSE) between the experimental data and fitted data is selected to evaluate the adaptabilities of these OCV models for their main features, advantages,and limitations. The sensitivities of OCV models to ambient temperatures, aging stages, numbers of data points,and SoC regions are studied for both NMC and LFP cells. Furthermore, the influences of these models on SoC estimation are discussed. Through a comprehensive comparison and analysis on OCV models, some recommendations in selecting OCV models for both NMC and LFP cells are given.展开更多
An underground iron mine in China has been used as a case-study to research the subsidence due to ore extraction and backfilling during open stoping operations. A 3-D discontinuum numerical model was built incorporati...An underground iron mine in China has been used as a case-study to research the subsidence due to ore extraction and backfilling during open stoping operations. A 3-D discontinuum numerical model was built incorporating geologic complexities including faults and interfaces between different lithologies,and the stoping and backfilling sequence adopted from the mine plans. The stoping was carried out in two vertically stacked horizontal layers, with a total of 16 stopes. Large displacements of up to 50 cm were observed along the roof of the stopes, and a maximum surface subsidence of 22.5 cm was observed.Backfilling was found to eliminate subsequent displacements and subsidence. The extraction of the upper orebody was found to influence displacements in the lower orebody. Finally, a subsidence profile was constructed to show the subsidence at all locations along the length of the surface and region of influence on the surface.展开更多
Aiming at the characteristics of modularity and reconfigurable in open architecture computer numerical control (CNC) system, the open architecture CNC system, Harbin Institute of Tech- nology computer numerical cont...Aiming at the characteristics of modularity and reconfigurable in open architecture computer numerical control (CNC) system, the open architecture CNC system, Harbin Institute of Tech- nology computer numerical control (HITCNC), is researched and manufactured based on the interface standards. The system's external interfaces are coincident with the corresponding international standards, and the internal interfaces follow the open modular architecture controller (OMAC) agreement. In the research and manufacturing process, object-oriented technology is used to ensure the openness of the HITCNC, and static programming is applied in the CNC system according to the idea of modularization disassembly. The HITCNC also actualizes real-time and unreal-time modules adopting real-time dynamical linked library (RTDLL) and component object model (COM). Finite state ma- chine (FSM) is adopted to do dynamically modeling of HITCNC. The complete separation between the software and the hardware is achieved in the HITCNC by applying the SoftSERCANS technique. The application of the above key techniques decreases the programming workload greatly, and uses software programs replacing hardware functions, which offers plenty technique ensures for the openness of HITCNC. Finally, based on the HITCNC, a three-dimensional milling system is established. On the system, series experiments are done to validate the expandability and interchangeability of HITCNC. The results of the experiments show that the established open architecture CNC system HITCNC is correct and feasible, and has good openness.展开更多
This paper discribes the importance and necessity of the study on the data structures for displaying the mining field using the interactive technology in open pit design and planning,based upon the grid block model. T...This paper discribes the importance and necessity of the study on the data structures for displaying the mining field using the interactive technology in open pit design and planning,based upon the grid block model. The commonly used data structures--rectangular array structure and quadtree structure ,are analyzed. Two compressed data structures--compressed circular link array structure and compressed doubly-linked circular array structure,are proposed,which are much more suitable for displaying the regularly gridded block model. When the two compressed data structures are adopted,the storage space can be tremendously saved and the algorithms are simple,while the requirements of the accuracy and the manipulating speed will be both satisfied for the interactive open pit short range plan formulation.展开更多
As the main component of computer integrated manufacturing system (CIMS), flexible manufacturing system (FMS) should be an open system with reusability and extenchaility. Moreover, as FMS is a complex asynchronous con...As the main component of computer integrated manufacturing system (CIMS), flexible manufacturing system (FMS) should be an open system with reusability and extenchaility. Moreover, as FMS is a complex asynchronous concurrent system, its model also should have the abilities to express the concurrency in the system and to analyze the behavior of the system. It is difficult to use any one method to model such a complex system as FMS. A modeling method using Object-oriented modeling language-unified modeling language (UML) and object-Oriented Petri nets (OPNs) is proposed. Class diagram in UML is used to represent the static relations among the objects in FMS. OPNs are used to model the dynamic behavior of the objects and conduct performance analysis. OPNs also can be used to identify the attributes and operations of the objects. The model can describe the system integrally and can be used to design FMS control software naturally.展开更多
The purpose of this study is to improve environmental sustainability by identifying the most sustainable/least fragile of the three major wildlife conservation access models—open, government, and private—under varyi...The purpose of this study is to improve environmental sustainability by identifying the most sustainable/least fragile of the three major wildlife conservation access models—open, government, and private—under varying environmental and socioeconomic conditions. The private access model is the most sustainable of the three major conservation models because it provides the best information and incentives to balance the needs of humans and wildlife, maintain general wildlife habitat, and adapt quickly to changing environmental and/or socioeconomic conditions. Government-controlled access, however, can be employed as a model of last resort if the private access model shows signs of failing to protect specific species from local extirpation or extinction, which it is most likely to do for migratory species, species with close commercial substitutes, and species with no direct commercial value. Government regulators may also be needed to enforce property rights arrangements like catch shares and to monitor resources that remain open access in case socioeconomic or environmental conditions change sufficiently to trigger the tragedy of the commons. Most treatments of wildlife regulation default to various iterations of the government access model and fail even to consider the costs and benefits of private and open access models. The analysis here instead shows the conditions in which each conservation access model is most appropriate: open when a resource is in high supply and low demand, private most of the time, and government when the others fail to slow resource depopulation/depletion.展开更多
BACKGROUND Since the first living donor liver transplantation(LDLT)was performed by Raia and colleagues in December 1988,LDLT has become the gold standard treatment in countries where cadaveric organ donation is not s...BACKGROUND Since the first living donor liver transplantation(LDLT)was performed by Raia and colleagues in December 1988,LDLT has become the gold standard treatment in countries where cadaveric organ donation is not sufficient.Adequate hepatic venous outflow reconstruction in LDLT is essential to prevent graft congestion and its complications including graft loss.However,this can be complex and technically demanding especially in the presence of complex variations and congenital anomalies in the graft hepatic veins.CASE SUMMARY Herein,we aimed to present two cases who underwent successful right lobe LDLT using a right lobe liver graft with rudimentary or congenital absence of the right hepatic vein and describe the utility of a common large opening drainage model in such complex cases.CONCLUSION Thanks to this venous reconstruction model,none of the patients developed postoperative complications related to venous drainage.Our experience with venous drainage reconstruction models shows that congenital variations in the hepatic venous structure of living liver donors are not absolute contraindications for LDLT.展开更多
将机器人采集到的温度、湿度和位置等数据信息传送至云平台服务器,便于云端数据分析、机器人数据共享以及人机信息交互等。本文应用第4代移动通信技术(the 4th generation mobile communication technology,4G)无线传输技术,设计的机器...将机器人采集到的温度、湿度和位置等数据信息传送至云平台服务器,便于云端数据分析、机器人数据共享以及人机信息交互等。本文应用第4代移动通信技术(the 4th generation mobile communication technology,4G)无线传输技术,设计的机器人与云平台无线数据传输系统主要包括硬件和软件实现2个部分,硬件方面机器人通过32位微控制器(STMicroelectronics32,STM32)嵌入式系统与4G模块组合,将传感器采集到的数据信息,通过Internet网络传输到云平台服务器中,软件部分运用C语言编程通过网络透传模式(transmission control protocol/user datagram protocol, TCP/UDP)实现无线通信过程,最终实验验证了机器人与云平台服务器之间的双向无线数据传输功能。展开更多
Flooding is a common natural disaster that causes enormous economic, social, and human losses. Of various flood routing methods, the dynamic wave model is one of the best approaches for the prediction of the character...Flooding is a common natural disaster that causes enormous economic, social, and human losses. Of various flood routing methods, the dynamic wave model is one of the best approaches for the prediction of the characteristics of floods during their propagations in natural rivers because all of the terms of the momentum equation are considered in the model. However, no significant research has been conducted on how the model sensitivity affects the accuracy of the downstream hydrograph. In this study, a comprehensive analysis of the input parameters 9f the dynamic wave model was performed through field applications in natural rivers and routing experiments in artificial channels using the graphical multi-parametric sensitivity analysis (GMPSA). The results indicate that the effects of input parameter errors on the output results are more significant in special situations, such as lower values of Manning's roughness coefficient and/or a steeper bed slope on the characteristics of a design hydrograph, larger values of the skewness factor and/or time to peak on the channel characteristics, larger values of Manning's roughness coefficient and/or the bed slope on the space step, and lower values of Manning's roughness coefficient and/or a steeper bed slope on the time step and weighting factor.展开更多
In order to explore the technical methods to improve the ecological carrying capacity of regional land under the premise of limited land use area,an open ecological footprint model is established based on the traditio...In order to explore the technical methods to improve the ecological carrying capacity of regional land under the premise of limited land use area,an open ecological footprint model is established based on the traditional ecological footprint model.Using the two models,this paper evaluates the ecological carrying capacity of Henan Province in 2017.The results indicate that the ecological productive footprint of cultivated land in Henan Province is much larger than the ecological carrying capacity,but the ecological consumption footprint is lower than the ecological carrying capacity.The open ecological footprint model can clearly distinguish the internal and the external ecological consumption footprint after corrected by the consumption adjustment coefficient and the land-use structure adjustment coefficient.Based on the open ecological footprint model,the ecological carrying capacity evaluation results of Henan Province are more realistic.The comprehensive ecological carrying capacity in Henan Province has a surplus,but there are significant differences among different land use types.The cultivated land has the largest ecological carrying capacity surplus,while the fossil energy land has a larger ecological carrying capacity deficit.In the process of achieving sustainable development,Henan Province should focus on reducing energy consumption and improving the ecological carrying capacity of fossil energy land.The paper concludes that the open ecological footprint model can simulate the ecological carrying capacity under different land use structures and different consumption structures.According to the simulation results,the technical methods to improve the ecological carrying capacity under the premise of limited land use scale can be proposed.The research can provide reference for land use structure adjustment,land use planning and land protection in Henan Province.It can also provide scientific basis for ecological protection and high-quality development of the Yellow River basin.展开更多
The objective of this research is to show a new methodology for modeling phenomena present in complex economic systems. The case study we analyzed is the adoption of open organization model among firms operating in a ...The objective of this research is to show a new methodology for modeling phenomena present in complex economic systems. The case study we analyzed is the adoption of open organization model among firms operating in a particular industry. A firm with an open system model creates and captures value taking advantage not only from the internal resource but also from external. The organization could approach to open model acquisition using different focus: external focus namely looking out of its boundary, acting and reacting to competitor innovation, costumers' changing, demand growth, or internal focus remaining inside its boundary improving its best capabilities ignoring what happened outside (Vagnani, Moran, & Simoni, 2010). The actors involved are firms, customers and suppliers linked together through a business to business model. The methodology is based on an Object-Oriented Analysis Field Model that allows to intuitively describe systems characterized by a large number of objects that interact, as in this case of a system composed by different organizational entities. The system simulation allows to analyze how the actors influence the acquisition and diffusion of the open organization model. This approach permits the generation of different classes of objects to represent all actors involved in the evolution of the system and to define the dynamics that determine their interaction. The solution of the model can be approximated using the Mean-Field analysis technique (Kurtz, 1978), following the results proposed in Bobbio, Gribaudo, and Yelek (2008). A qualitative result is illustrated in order to show the applicability of the proposed methodology and to emphasize its relevant features: flexible modeling approach, capacity of solving complex systems and output management facilities. The presented model is comprehensive and its scope is wide; it could be used to study the behavior of enterprises changing model in many different scenarios and situations. In future works quantitative results will be given, and different situations will be analyzed.展开更多
This study monitors the open/closed states of the windows in 16 residential apartments in representative cities of the hot summer and cold winter zone of China,along with outdoor air temperature,outdoor relative humid...This study monitors the open/closed states of the windows in 16 residential apartments in representative cities of the hot summer and cold winter zone of China,along with outdoor air temperature,outdoor relative humidity and outdoor PM2.5 concentration in 2017,to investigate the window opening/closing behavior.Three window opening models are developed.All the models are validated by modeling a typical residential apartment to compare the predicted indoor CO_(2)concentration with monitored data.It is found that the window opening probability is negatively correlated to both outdoor PM2.5 concentration and outdoor relative humidity,and the probability of window opening reaches the peak value when the outdoor air temperature is 23.7℃.In terms of season,the shortest window opening duration occurs in winter due to the cold outdoor air temperature and high outdoor PM2.5 concentration.Finally,by comparing the correlation between the measured date and simulation results of indoor CO_(2)concentration,this study provides an appropriate window opening model for reference.展开更多
Two experimental tests of three-storied reinforced concrete structural walls having large openings were performed.Based on an original macro model,a multiple modified macro-model was proposed to develop a simple metho...Two experimental tests of three-storied reinforced concrete structural walls having large openings were performed.Based on an original macro model,a multiple modified macro-model was proposed to develop a simple method to design a reinforced concrete structural wall with large openings and various opening locations.The interaction between reinforcement ties and concrete struts formed along the perimeter of openings was neglected in the original model.However,the strut-and-tie node was proposed to take account of such interaction in the proposed model.The predicted behavior of two specimens using such a proposed model was compared with the experimental results.It is shown that the behavior of structural walls with large openings could be modeled well using the proposed model.Moreover,the study indicates that the proposed model is applicable even in cases of multi-story structural walls having large openings and various opening locations.展开更多
If we approximate light quarks as massless and apply the Schwinger confinement mechanism to light quarks,we will reach the conclusion that a light quark and its antiquark will be confined as a boson in the Abelian U(1...If we approximate light quarks as massless and apply the Schwinger confinement mechanism to light quarks,we will reach the conclusion that a light quark and its antiquark will be confined as a boson in the Abelian U(1)QED gauge interaction in(1+1)D,as in an open string.From the work of Coleman,Jackiw,and Susskind,we can infer further that the Schwinger confinement mechanism persists even for massive quarks in(1+1)D.Could such a QED-confined one-dimensional open string in(1+1)D be the idealization of a flux tube in the physical world in(3+1)D,similar to the case of QCD-confined open string?If so,the QED-confined bosons may show up as neutral QED mesons in the mass region of many tens of MeV[Phys.Rev.C 81,064903(2010)&J.High Energy Phys.2020(8),165(2020)].Is it ever possible that a quark and an antiquark be produced and interact in QED alone to form a confined QED meson?Is there any experimental evidence for the existence of a QED meson(or QED mesons)?The observations of the anomalous soft photons,the X17 particle,and the E38 particle suggest that they may bear the experimental evidence for the existence of such QED mesons.Further confirmation and investigations on the X17 and E38 particles will shed definitive light on the question of quark confinement in QED in(3+1)D.Implications of quark confinement in the QED interaction are discussed.展开更多
Geographical simulation is a popular method in geographical and environmental research.Many models developed to address geographic and environmental issues are distributed worldwide.However,due to the lack of portals,...Geographical simulation is a popular method in geographical and environmental research.Many models developed to address geographic and environmental issues are distributed worldwide.However,due to the lack of portals,these models are still difficult to invoke for geographical simulations in open web environments.This study designs and develops a framework to assemble service-oriented models from volunteers distributed worldwide for geographical simulations on the web.The framework consists of three layers(task layer,data exchange layer,and model execution layer)that establish a network of serviceoriented locally shared models and simulation tasks for user configurations.With the help of such a framework,users can configure simulation tasks and invoke suitable models shared worldwide for geographical simulations.This article provides an application of the distributed simulation of gross primary production(GPP)by the Biome-BioGeochemical Cycles(BGC)model in China.This application shows that the framework can be beneficial for model assembly from volunteers’computers and distributed simulation tasks that are run for geographical and environmental issues,which can be applied to Digital Earth initiatives.展开更多
The effects of different Planetary Boundary Layer(PBL) structures on pollutant dispersion processes within two idealized street canyon configurations and a realistic urban area were numerically examined by a Computa...The effects of different Planetary Boundary Layer(PBL) structures on pollutant dispersion processes within two idealized street canyon configurations and a realistic urban area were numerically examined by a Computational Fluid Dynamics(CFD) model. The boundary conditions of different PBL structures/conditions were provided by simulations of the Weather Researching and Forecasting model. The simulated results of the idealized 2D and 3D street canyon experiments showed that the increment of PBL instability favored the downward transport of momentum from the upper flow above the roof to the pedestrian level within the street canyon. As a result, the flow and turbulent fields within the street canyon under the more unstable PBL condition are stronger. Therefore, more pollutants within the street canyon would be removed by the stronger advection and turbulent diffusion processes under the unstable PBL condition. On the contrary, more pollutants would be concentrated in the street canyon under the stable PBL condition. In addition, the simulations of the realistic building cluster experiments showed that the density of buildings was a crucial factor determining the dynamic effects of the PBL structure on the flow patterns. The momentum field within a denser building configuration was mostly transported from the upper flow, and was more sensitive to the PBL structures than that of the sparser building configuration. Finally, it was recommended to use the Mellor-Yamada-Nakanishi-Niino(MYNN) PBL scheme, which can explicitly output the needed turbulent variables, to provide the boundary conditions to the CFD simulation.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51507012)Beijing Municipal Natural Science Foundation of China(Grant No.3182035)
文摘The current research of state of charge(SoC) online estimation of lithium-ion battery(LiB) in electric vehicles(EVs)mainly focuses on adopting or improving of battery models and estimation filters. However, little attention has been paid to the accuracy of various open circuit voltage(OCV) models for correcting the SoC with aid of the ampere-hour counting method. This paper presents a comprehensive comparison study on eighteen OCV models which cover the majority of models used in literature. The low-current OCV tests are conducted on the typical commercial LiFePO/graphite(LFP) and LiNiMnCoO/graphite(NMC) cells to obtain the experimental OCV-SoC curves at different ambient temperature and aging stages. With selected OCV and SoC points from experimental OCV-SoC curves, the parameters of each OCV model are determined by curve fitting toolbox of MATLAB 2013. Then the fitting OCV-SoC curves based on diversified OCV models are also obtained. The indicator of root-mean-square error(RMSE) between the experimental data and fitted data is selected to evaluate the adaptabilities of these OCV models for their main features, advantages,and limitations. The sensitivities of OCV models to ambient temperatures, aging stages, numbers of data points,and SoC regions are studied for both NMC and LFP cells. Furthermore, the influences of these models on SoC estimation are discussed. Through a comprehensive comparison and analysis on OCV models, some recommendations in selecting OCV models for both NMC and LFP cells are given.
基金the support from the National Natural Science Foundation of China (No. 51404024)partially funded by the NIOSH of the Centers for Disease Control and Prevention, USA through Contract No.200-201139886 given to the second author
文摘An underground iron mine in China has been used as a case-study to research the subsidence due to ore extraction and backfilling during open stoping operations. A 3-D discontinuum numerical model was built incorporating geologic complexities including faults and interfaces between different lithologies,and the stoping and backfilling sequence adopted from the mine plans. The stoping was carried out in two vertically stacked horizontal layers, with a total of 16 stopes. Large displacements of up to 50 cm were observed along the roof of the stopes, and a maximum surface subsidence of 22.5 cm was observed.Backfilling was found to eliminate subsequent displacements and subsidence. The extraction of the upper orebody was found to influence displacements in the lower orebody. Finally, a subsidence profile was constructed to show the subsidence at all locations along the length of the surface and region of influence on the surface.
基金This project is supported by Provincial Science & Technology Projoct of Heilongjiang, China (No. GB05A501).
文摘Aiming at the characteristics of modularity and reconfigurable in open architecture computer numerical control (CNC) system, the open architecture CNC system, Harbin Institute of Tech- nology computer numerical control (HITCNC), is researched and manufactured based on the interface standards. The system's external interfaces are coincident with the corresponding international standards, and the internal interfaces follow the open modular architecture controller (OMAC) agreement. In the research and manufacturing process, object-oriented technology is used to ensure the openness of the HITCNC, and static programming is applied in the CNC system according to the idea of modularization disassembly. The HITCNC also actualizes real-time and unreal-time modules adopting real-time dynamical linked library (RTDLL) and component object model (COM). Finite state ma- chine (FSM) is adopted to do dynamically modeling of HITCNC. The complete separation between the software and the hardware is achieved in the HITCNC by applying the SoftSERCANS technique. The application of the above key techniques decreases the programming workload greatly, and uses software programs replacing hardware functions, which offers plenty technique ensures for the openness of HITCNC. Finally, based on the HITCNC, a three-dimensional milling system is established. On the system, series experiments are done to validate the expandability and interchangeability of HITCNC. The results of the experiments show that the established open architecture CNC system HITCNC is correct and feasible, and has good openness.
文摘This paper discribes the importance and necessity of the study on the data structures for displaying the mining field using the interactive technology in open pit design and planning,based upon the grid block model. The commonly used data structures--rectangular array structure and quadtree structure ,are analyzed. Two compressed data structures--compressed circular link array structure and compressed doubly-linked circular array structure,are proposed,which are much more suitable for displaying the regularly gridded block model. When the two compressed data structures are adopted,the storage space can be tremendously saved and the algorithms are simple,while the requirements of the accuracy and the manipulating speed will be both satisfied for the interactive open pit short range plan formulation.
基金This project is supported by National Natural Science Foundation of China !(59889505)
文摘As the main component of computer integrated manufacturing system (CIMS), flexible manufacturing system (FMS) should be an open system with reusability and extenchaility. Moreover, as FMS is a complex asynchronous concurrent system, its model also should have the abilities to express the concurrency in the system and to analyze the behavior of the system. It is difficult to use any one method to model such a complex system as FMS. A modeling method using Object-oriented modeling language-unified modeling language (UML) and object-Oriented Petri nets (OPNs) is proposed. Class diagram in UML is used to represent the static relations among the objects in FMS. OPNs are used to model the dynamic behavior of the objects and conduct performance analysis. OPNs also can be used to identify the attributes and operations of the objects. The model can describe the system integrally and can be used to design FMS control software naturally.
文摘The purpose of this study is to improve environmental sustainability by identifying the most sustainable/least fragile of the three major wildlife conservation access models—open, government, and private—under varying environmental and socioeconomic conditions. The private access model is the most sustainable of the three major conservation models because it provides the best information and incentives to balance the needs of humans and wildlife, maintain general wildlife habitat, and adapt quickly to changing environmental and/or socioeconomic conditions. Government-controlled access, however, can be employed as a model of last resort if the private access model shows signs of failing to protect specific species from local extirpation or extinction, which it is most likely to do for migratory species, species with close commercial substitutes, and species with no direct commercial value. Government regulators may also be needed to enforce property rights arrangements like catch shares and to monitor resources that remain open access in case socioeconomic or environmental conditions change sufficiently to trigger the tragedy of the commons. Most treatments of wildlife regulation default to various iterations of the government access model and fail even to consider the costs and benefits of private and open access models. The analysis here instead shows the conditions in which each conservation access model is most appropriate: open when a resource is in high supply and low demand, private most of the time, and government when the others fail to slow resource depopulation/depletion.
文摘BACKGROUND Since the first living donor liver transplantation(LDLT)was performed by Raia and colleagues in December 1988,LDLT has become the gold standard treatment in countries where cadaveric organ donation is not sufficient.Adequate hepatic venous outflow reconstruction in LDLT is essential to prevent graft congestion and its complications including graft loss.However,this can be complex and technically demanding especially in the presence of complex variations and congenital anomalies in the graft hepatic veins.CASE SUMMARY Herein,we aimed to present two cases who underwent successful right lobe LDLT using a right lobe liver graft with rudimentary or congenital absence of the right hepatic vein and describe the utility of a common large opening drainage model in such complex cases.CONCLUSION Thanks to this venous reconstruction model,none of the patients developed postoperative complications related to venous drainage.Our experience with venous drainage reconstruction models shows that congenital variations in the hepatic venous structure of living liver donors are not absolute contraindications for LDLT.
文摘将机器人采集到的温度、湿度和位置等数据信息传送至云平台服务器,便于云端数据分析、机器人数据共享以及人机信息交互等。本文应用第4代移动通信技术(the 4th generation mobile communication technology,4G)无线传输技术,设计的机器人与云平台无线数据传输系统主要包括硬件和软件实现2个部分,硬件方面机器人通过32位微控制器(STMicroelectronics32,STM32)嵌入式系统与4G模块组合,将传感器采集到的数据信息,通过Internet网络传输到云平台服务器中,软件部分运用C语言编程通过网络透传模式(transmission control protocol/user datagram protocol, TCP/UDP)实现无线通信过程,最终实验验证了机器人与云平台服务器之间的双向无线数据传输功能。
文摘Flooding is a common natural disaster that causes enormous economic, social, and human losses. Of various flood routing methods, the dynamic wave model is one of the best approaches for the prediction of the characteristics of floods during their propagations in natural rivers because all of the terms of the momentum equation are considered in the model. However, no significant research has been conducted on how the model sensitivity affects the accuracy of the downstream hydrograph. In this study, a comprehensive analysis of the input parameters 9f the dynamic wave model was performed through field applications in natural rivers and routing experiments in artificial channels using the graphical multi-parametric sensitivity analysis (GMPSA). The results indicate that the effects of input parameter errors on the output results are more significant in special situations, such as lower values of Manning's roughness coefficient and/or a steeper bed slope on the characteristics of a design hydrograph, larger values of the skewness factor and/or time to peak on the channel characteristics, larger values of Manning's roughness coefficient and/or the bed slope on the space step, and lower values of Manning's roughness coefficient and/or a steeper bed slope on the time step and weighting factor.
基金Supported by Henan Soft Science Research Plan Project(222400410131)。
文摘In order to explore the technical methods to improve the ecological carrying capacity of regional land under the premise of limited land use area,an open ecological footprint model is established based on the traditional ecological footprint model.Using the two models,this paper evaluates the ecological carrying capacity of Henan Province in 2017.The results indicate that the ecological productive footprint of cultivated land in Henan Province is much larger than the ecological carrying capacity,but the ecological consumption footprint is lower than the ecological carrying capacity.The open ecological footprint model can clearly distinguish the internal and the external ecological consumption footprint after corrected by the consumption adjustment coefficient and the land-use structure adjustment coefficient.Based on the open ecological footprint model,the ecological carrying capacity evaluation results of Henan Province are more realistic.The comprehensive ecological carrying capacity in Henan Province has a surplus,but there are significant differences among different land use types.The cultivated land has the largest ecological carrying capacity surplus,while the fossil energy land has a larger ecological carrying capacity deficit.In the process of achieving sustainable development,Henan Province should focus on reducing energy consumption and improving the ecological carrying capacity of fossil energy land.The paper concludes that the open ecological footprint model can simulate the ecological carrying capacity under different land use structures and different consumption structures.According to the simulation results,the technical methods to improve the ecological carrying capacity under the premise of limited land use scale can be proposed.The research can provide reference for land use structure adjustment,land use planning and land protection in Henan Province.It can also provide scientific basis for ecological protection and high-quality development of the Yellow River basin.
文摘The objective of this research is to show a new methodology for modeling phenomena present in complex economic systems. The case study we analyzed is the adoption of open organization model among firms operating in a particular industry. A firm with an open system model creates and captures value taking advantage not only from the internal resource but also from external. The organization could approach to open model acquisition using different focus: external focus namely looking out of its boundary, acting and reacting to competitor innovation, costumers' changing, demand growth, or internal focus remaining inside its boundary improving its best capabilities ignoring what happened outside (Vagnani, Moran, & Simoni, 2010). The actors involved are firms, customers and suppliers linked together through a business to business model. The methodology is based on an Object-Oriented Analysis Field Model that allows to intuitively describe systems characterized by a large number of objects that interact, as in this case of a system composed by different organizational entities. The system simulation allows to analyze how the actors influence the acquisition and diffusion of the open organization model. This approach permits the generation of different classes of objects to represent all actors involved in the evolution of the system and to define the dynamics that determine their interaction. The solution of the model can be approximated using the Mean-Field analysis technique (Kurtz, 1978), following the results proposed in Bobbio, Gribaudo, and Yelek (2008). A qualitative result is illustrated in order to show the applicability of the proposed methodology and to emphasize its relevant features: flexible modeling approach, capacity of solving complex systems and output management facilities. The presented model is comprehensive and its scope is wide; it could be used to study the behavior of enterprises changing model in many different scenarios and situations. In future works quantitative results will be given, and different situations will be analyzed.
基金Part of the work is supported by National Science Foundation of China(51878408,51508326)the Key laboratory of healthy en-vironment and energy conservation for industrial large space building(2019SA-10-07)This work is supported by the national key project of the Ministry of Science and Technology,China,on“Green Buildings and Building Industrialization”through Grant No.2016YFC0700500.
文摘This study monitors the open/closed states of the windows in 16 residential apartments in representative cities of the hot summer and cold winter zone of China,along with outdoor air temperature,outdoor relative humidity and outdoor PM2.5 concentration in 2017,to investigate the window opening/closing behavior.Three window opening models are developed.All the models are validated by modeling a typical residential apartment to compare the predicted indoor CO_(2)concentration with monitored data.It is found that the window opening probability is negatively correlated to both outdoor PM2.5 concentration and outdoor relative humidity,and the probability of window opening reaches the peak value when the outdoor air temperature is 23.7℃.In terms of season,the shortest window opening duration occurs in winter due to the cold outdoor air temperature and high outdoor PM2.5 concentration.Finally,by comparing the correlation between the measured date and simulation results of indoor CO_(2)concentration,this study provides an appropriate window opening model for reference.
基金Project supported by the Grants-in-Aid for Scientific Research of Japan (No. 16206056)the Scientific Research Foundation for Talent Introduction (No. 113201-811132)
文摘Two experimental tests of three-storied reinforced concrete structural walls having large openings were performed.Based on an original macro model,a multiple modified macro-model was proposed to develop a simple method to design a reinforced concrete structural wall with large openings and various opening locations.The interaction between reinforcement ties and concrete struts formed along the perimeter of openings was neglected in the original model.However,the strut-and-tie node was proposed to take account of such interaction in the proposed model.The predicted behavior of two specimens using such a proposed model was compared with the experimental results.It is shown that the behavior of structural walls with large openings could be modeled well using the proposed model.Moreover,the study indicates that the proposed model is applicable even in cases of multi-story structural walls having large openings and various opening locations.
基金supported in part by the Division of Nuclear Physics,U.S.Department of Energy under Contract No.DE-AC05-00OR22725 with UT-Battelle,LLC.
文摘If we approximate light quarks as massless and apply the Schwinger confinement mechanism to light quarks,we will reach the conclusion that a light quark and its antiquark will be confined as a boson in the Abelian U(1)QED gauge interaction in(1+1)D,as in an open string.From the work of Coleman,Jackiw,and Susskind,we can infer further that the Schwinger confinement mechanism persists even for massive quarks in(1+1)D.Could such a QED-confined one-dimensional open string in(1+1)D be the idealization of a flux tube in the physical world in(3+1)D,similar to the case of QCD-confined open string?If so,the QED-confined bosons may show up as neutral QED mesons in the mass region of many tens of MeV[Phys.Rev.C 81,064903(2010)&J.High Energy Phys.2020(8),165(2020)].Is it ever possible that a quark and an antiquark be produced and interact in QED alone to form a confined QED meson?Is there any experimental evidence for the existence of a QED meson(or QED mesons)?The observations of the anomalous soft photons,the X17 particle,and the E38 particle suggest that they may bear the experimental evidence for the existence of such QED mesons.Further confirmation and investigations on the X17 and E38 particles will shed definitive light on the question of quark confinement in QED in(3+1)D.Implications of quark confinement in the QED interaction are discussed.
基金supported by National Natural Science Foundation of China:[Grant Numbers 41871285,41930648,42071361,42071363,and U1811464].
文摘Geographical simulation is a popular method in geographical and environmental research.Many models developed to address geographic and environmental issues are distributed worldwide.However,due to the lack of portals,these models are still difficult to invoke for geographical simulations in open web environments.This study designs and develops a framework to assemble service-oriented models from volunteers distributed worldwide for geographical simulations on the web.The framework consists of three layers(task layer,data exchange layer,and model execution layer)that establish a network of serviceoriented locally shared models and simulation tasks for user configurations.With the help of such a framework,users can configure simulation tasks and invoke suitable models shared worldwide for geographical simulations.This article provides an application of the distributed simulation of gross primary production(GPP)by the Biome-BioGeochemical Cycles(BGC)model in China.This application shows that the framework can be beneficial for model assembly from volunteers’computers and distributed simulation tasks that are run for geographical and environmental issues,which can be applied to Digital Earth initiatives.
基金supported by the China Meteorological Administration Special Public Welfare Research Fund (No. GYHY201106033)the National Natural Science Foundation of China (No. 41175004)
文摘The effects of different Planetary Boundary Layer(PBL) structures on pollutant dispersion processes within two idealized street canyon configurations and a realistic urban area were numerically examined by a Computational Fluid Dynamics(CFD) model. The boundary conditions of different PBL structures/conditions were provided by simulations of the Weather Researching and Forecasting model. The simulated results of the idealized 2D and 3D street canyon experiments showed that the increment of PBL instability favored the downward transport of momentum from the upper flow above the roof to the pedestrian level within the street canyon. As a result, the flow and turbulent fields within the street canyon under the more unstable PBL condition are stronger. Therefore, more pollutants within the street canyon would be removed by the stronger advection and turbulent diffusion processes under the unstable PBL condition. On the contrary, more pollutants would be concentrated in the street canyon under the stable PBL condition. In addition, the simulations of the realistic building cluster experiments showed that the density of buildings was a crucial factor determining the dynamic effects of the PBL structure on the flow patterns. The momentum field within a denser building configuration was mostly transported from the upper flow, and was more sensitive to the PBL structures than that of the sparser building configuration. Finally, it was recommended to use the Mellor-Yamada-Nakanishi-Niino(MYNN) PBL scheme, which can explicitly output the needed turbulent variables, to provide the boundary conditions to the CFD simulation.