Since 2016,community group buying has grown significantly in China,largely driven by its efficient logistics,supply chains,low prices,and convenience.This model has been further popularized during the COVID-19 pandemi...Since 2016,community group buying has grown significantly in China,largely driven by its efficient logistics,supply chains,low prices,and convenience.This model has been further popularized during the COVID-19 pandemic due to its effectiveness in meeting daily needs while minimizing human-to-human contact.A key component of this business model is the“group leaders”-influential individuals within a community responsible for managing group buying activities,which include order collection,supplier liaison,and goods distribution.Their primary task is to form and sustain a reliable community group buying consortium,a task that demands excellent organizational and interpersonal skills.This paper examines this phenomenon using the lens of the differential mode of association,a theoretical model explaining interpersonal relationships in traditional Chinese society.The research indicates that group leaders,through regular interaction with consumers,are able to alter their social network position,increase their influence,understand consumer needs,provide satisfying services,and enhance trust,thereby transforming consumers into loyal group buying participants.This transformation not only brings stability to group buying activities but also reinforces the community influence of group leaders,thus fostering the growth of community group buying.展开更多
Quantitative description of vapor-liquid equilibrium is very useful for designing separation processes. In this study, we combined the Peng-Robinson equation and the Huron-Vidal-Orbey-Sandler mixing rule into a modifi...Quantitative description of vapor-liquid equilibrium is very useful for designing separation processes. In this study, we combined the Peng-Robinson equation and the Huron-Vidal-Orbey-Sandler mixing rule into a modified UNIFAC model for the improvement of predicting vapor-liquid equilibria. The predictions of vapor-liquid equilibria for 62 systems including alcohol- alkane, alcohol-benzene, and amine-water systems demonstrate that the revised parameters remarkably improve the prediction accuracy for many systems. Especially for amine-water system, the mean deviation of components decreases from 0.094 to 0.021, and the mean deviation of pressure from 22.45% to 4.41%.展开更多
Nowadays, because of its wide bandwidth and high communication capability, the optical fiber is more and more used for high data rate transmission of information in railway environments. Conventionally, only one servi...Nowadays, because of its wide bandwidth and high communication capability, the optical fiber is more and more used for high data rate transmission of information in railway environments. Conventionally, only one service is sent over the fiber at a time. However, many different services can be simultaneously conveyed in railway stations such as passenger information service, cellular phone, Wi-Fi... The objective of the work proposed in this paper is to demonstrate the potential benefits of transmitting radio signals over fiber in a railway environment. The main idea is to exploit the full capacity of the fiber by transmitting multiple services using the same fiber. Since, different services are operating in different frequency bands; we propose a new multiplexing technique called Mode Group Diversity Multiplexing （MGDM） to ensure the transmission of multiple services using the same fiber, without additional infrastructure. There are numerous advantages of the proposed technique, e.g., faster and reliable data exchange, high resolution video surveillance capability, high data rate information exchange in railway stations. We present, in this paper, the physical characteristics of optical fibers, performance of MGDM multiplexing technique, and the influence of the laser excitation conditions at the entrance of the fiber on the performances of the system.展开更多
Although the channel-decoupling assumption is often used in design of three-dimensional guidance laws, it loses its rationality for aircrafts with strong kinematics coupling because body rotation arises. To overcome t...Although the channel-decoupling assumption is often used in design of three-dimensional guidance laws, it loses its rationality for aircrafts with strong kinematics coupling because body rotation arises. To overcome this trouble, a novel guiding method was proposed based on Lie-group. After a model of 3D guidance is formulated using vectors, the precision guidance with ending angular constraints can be transformed into a problem involving the relation between directional angles and rotational angular velocities of certain vectors. When the guidance model is imposed a SO(3)-based description, a novel 3D sliding mode guidance law with ending angular constraints can be developed via Lie-group control method and variable structure control theory. Finally, the feasibility and performance of the guidance law were shown by simulating the examples.展开更多
Interactive teaching mode refers to a dynamic process of teaching in which teachers and students and teaching materials will affect each other. It offers language learners a chance to communicate and exchange informat...Interactive teaching mode refers to a dynamic process of teaching in which teachers and students and teaching materials will affect each other. It offers language learners a chance to communicate and exchange information frequently. Group cooperative leaning has long been considered to be one of the most important forms of the interactive teaching mode. English writing,one of the essential English language skills, is an integral part of college English teaching. The high or low level of English writing is a comprehensive reflection of various abilities. This paper aims to explore the application of the interactive teaching model in college English writing class in order to improve students' motivation and ability of English writing, thus can provide an effective way of learning to the current college English writing class.展开更多
Short-term traffic flow forecasting is a significant part of intelligent transportation system.In some traffic control scenarios,obtaining future traffic flow in advance is conducive to highway management department t...Short-term traffic flow forecasting is a significant part of intelligent transportation system.In some traffic control scenarios,obtaining future traffic flow in advance is conducive to highway management department to have sufficient time to formulate corresponding traffic flow control measures.In hence,it is meaningful to establish an accurate short-term traffic flow method and provide reference for peak traffic flow warning.This paper proposed a new hybrid model for traffic flow forecasting,which is composed of the variational mode decomposition(VMD)method,the group method of data handling(GMDH)neural network,bi-directional long and short term memory(BILSTM)network and ELMAN network,and is optimized by the imperialist competitive algorithm(ICA)method.To illustrate the performance of the proposed model,there are several comparative experiments between the proposed model and other models.The experiment results show that 1)BILSTM network,GMDH network and ELMAN network have better predictive performance than other single models;2)VMD can significantly improve the predictive performance of the ICA-GMDH-BILSTM-ELMAN model.The effect of VMD method is better than that of EEMD method and FEEMD method.To conclude,the proposed model which is made up of the VMD method,the ICA method,the BILSTM network,the GMDH network and the ELMAN network has excellent predictive ability for traffic flow series.展开更多
The purpose of this paper is to study the issues on keeping the continuous development of Tibetan economy and the relative stability of its ecosystem. Hence, in order to achieve the object, the study analyzes the stat...The purpose of this paper is to study the issues on keeping the continuous development of Tibetan economy and the relative stability of its ecosystem. Hence, in order to achieve the object, the study analyzes the status quo of economic development in Tibet and the problems of resource exploitation. It especially discusses frailty of Tibetan eco-environment, and evaluates the contradictions between the traditional economic developing mode and the safety of plateau＇s ecosystem. It concludes that there is an inevitable clash between the development of Tibetan economy and the safety of plateau＇s eco-system; this problem cannot be avoided by any decision maker, Therefore, the character of Tibetan econvironment and the requirement of its economic development strategy determine that ecological economy developing mode is the only choice for Tibet. This paper suggests that it should be compensated by the national government to assure that Tibetan economy can keep a higher developing speed. In accordance with the feature of plateau eco-economy system and demand of Tibetan economic development, this paper also suggests several methods to apply the ecoeconomy developing strategy of Tibet.展开更多
The controllability problem of heterogeneous interdependent group systems with undirected and directed topology is investigated in this paper. First, the interdependent model of the heterogeneous system is set up acco...The controllability problem of heterogeneous interdependent group systems with undirected and directed topology is investigated in this paper. First, the interdependent model of the heterogeneous system is set up according to the difference of individual characteristics. An extended distributed protocol with the external sliding-mode control is designed, under which it is shown that a heterogeneous interdependent group system is controllable when the corresponding communication topology is controllable. Then, using the network eigenvalue method, the driving individuals are determined for a heterogeneous system with undirected topology. Under directed topology, the maximum match method is utilized to confirm the driving individuals. Some sufficient and necessary conditions are presented to assure that the heterogeneous interdependent group system is structurally controllable. Via theoretical analysis, the controllability of heterogeneous interdependent systems is related to the interdependent manner and the structure of the heterogeneous system. Numerical simulations are provided to demonstrate the effectiveness of the theoretical results.展开更多
文摘Since 2016,community group buying has grown significantly in China,largely driven by its efficient logistics,supply chains,low prices,and convenience.This model has been further popularized during the COVID-19 pandemic due to its effectiveness in meeting daily needs while minimizing human-to-human contact.A key component of this business model is the“group leaders”-influential individuals within a community responsible for managing group buying activities,which include order collection,supplier liaison,and goods distribution.Their primary task is to form and sustain a reliable community group buying consortium,a task that demands excellent organizational and interpersonal skills.This paper examines this phenomenon using the lens of the differential mode of association,a theoretical model explaining interpersonal relationships in traditional Chinese society.The research indicates that group leaders,through regular interaction with consumers,are able to alter their social network position,increase their influence,understand consumer needs,provide satisfying services,and enhance trust,thereby transforming consumers into loyal group buying participants.This transformation not only brings stability to group buying activities but also reinforces the community influence of group leaders,thus fostering the growth of community group buying.
文摘Quantitative description of vapor-liquid equilibrium is very useful for designing separation processes. In this study, we combined the Peng-Robinson equation and the Huron-Vidal-Orbey-Sandler mixing rule into a modified UNIFAC model for the improvement of predicting vapor-liquid equilibria. The predictions of vapor-liquid equilibria for 62 systems including alcohol- alkane, alcohol-benzene, and amine-water systems demonstrate that the revised parameters remarkably improve the prediction accuracy for many systems. Especially for amine-water system, the mean deviation of components decreases from 0.094 to 0.021, and the mean deviation of pressure from 22.45% to 4.41%.
文摘Nowadays, because of its wide bandwidth and high communication capability, the optical fiber is more and more used for high data rate transmission of information in railway environments. Conventionally, only one service is sent over the fiber at a time. However, many different services can be simultaneously conveyed in railway stations such as passenger information service, cellular phone, Wi-Fi... The objective of the work proposed in this paper is to demonstrate the potential benefits of transmitting radio signals over fiber in a railway environment. The main idea is to exploit the full capacity of the fiber by transmitting multiple services using the same fiber. Since, different services are operating in different frequency bands; we propose a new multiplexing technique called Mode Group Diversity Multiplexing （MGDM） to ensure the transmission of multiple services using the same fiber, without additional infrastructure. There are numerous advantages of the proposed technique, e.g., faster and reliable data exchange, high resolution video surveillance capability, high data rate information exchange in railway stations. We present, in this paper, the physical characteristics of optical fibers, performance of MGDM multiplexing technique, and the influence of the laser excitation conditions at the entrance of the fiber on the performances of the system.
基金Sponsored by the National Natural Science Foundation of China (60374006)
文摘Although the channel-decoupling assumption is often used in design of three-dimensional guidance laws, it loses its rationality for aircrafts with strong kinematics coupling because body rotation arises. To overcome this trouble, a novel guiding method was proposed based on Lie-group. After a model of 3D guidance is formulated using vectors, the precision guidance with ending angular constraints can be transformed into a problem involving the relation between directional angles and rotational angular velocities of certain vectors. When the guidance model is imposed a SO(3)-based description, a novel 3D sliding mode guidance law with ending angular constraints can be developed via Lie-group control method and variable structure control theory. Finally, the feasibility and performance of the guidance law were shown by simulating the examples.
文摘Interactive teaching mode refers to a dynamic process of teaching in which teachers and students and teaching materials will affect each other. It offers language learners a chance to communicate and exchange information frequently. Group cooperative leaning has long been considered to be one of the most important forms of the interactive teaching mode. English writing,one of the essential English language skills, is an integral part of college English teaching. The high or low level of English writing is a comprehensive reflection of various abilities. This paper aims to explore the application of the interactive teaching model in college English writing class in order to improve students' motivation and ability of English writing, thus can provide an effective way of learning to the current college English writing class.
基金Project(61873283)supported by the National Natural Science Foundation of ChinaProject(KQ1707017)supported by the Changsha Science&Technology Project,ChinaProject(2019CX005)supported by the Innovation Driven Project of the Central South University,China。
文摘Short-term traffic flow forecasting is a significant part of intelligent transportation system.In some traffic control scenarios,obtaining future traffic flow in advance is conducive to highway management department to have sufficient time to formulate corresponding traffic flow control measures.In hence,it is meaningful to establish an accurate short-term traffic flow method and provide reference for peak traffic flow warning.This paper proposed a new hybrid model for traffic flow forecasting,which is composed of the variational mode decomposition(VMD)method,the group method of data handling(GMDH)neural network,bi-directional long and short term memory(BILSTM)network and ELMAN network,and is optimized by the imperialist competitive algorithm(ICA)method.To illustrate the performance of the proposed model,there are several comparative experiments between the proposed model and other models.The experiment results show that 1)BILSTM network,GMDH network and ELMAN network have better predictive performance than other single models;2)VMD can significantly improve the predictive performance of the ICA-GMDH-BILSTM-ELMAN model.The effect of VMD method is better than that of EEMD method and FEEMD method.To conclude,the proposed model which is made up of the VMD method,the ICA method,the BILSTM network,the GMDH network and the ELMAN network has excellent predictive ability for traffic flow series.
文摘The purpose of this paper is to study the issues on keeping the continuous development of Tibetan economy and the relative stability of its ecosystem. Hence, in order to achieve the object, the study analyzes the status quo of economic development in Tibet and the problems of resource exploitation. It especially discusses frailty of Tibetan eco-environment, and evaluates the contradictions between the traditional economic developing mode and the safety of plateau＇s ecosystem. It concludes that there is an inevitable clash between the development of Tibetan economy and the safety of plateau＇s eco-system; this problem cannot be avoided by any decision maker, Therefore, the character of Tibetan econvironment and the requirement of its economic development strategy determine that ecological economy developing mode is the only choice for Tibet. This paper suggests that it should be compensated by the national government to assure that Tibetan economy can keep a higher developing speed. In accordance with the feature of plateau eco-economy system and demand of Tibetan economic development, this paper also suggests several methods to apply the ecoeconomy developing strategy of Tibet.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61603137 and 11662002)the Innovation Team Project of Jiangxi Provincial Innovation Drive "5511" Advantaged Science and Technology(Grant No.20165BCB19011)+2 种基金the Natural Science Foundation of Jiangxi Province,China(Grant Nos.20171BAB212016 and 20171BAB202029)the Key Research and Development Project of the Technology Department of Jiangxi Province,China(Grant No.20161BBE53008)the Doctoral Scientific Research Foundation of East China Jiaotong University(Grant No.2003418002)
文摘The controllability problem of heterogeneous interdependent group systems with undirected and directed topology is investigated in this paper. First, the interdependent model of the heterogeneous system is set up according to the difference of individual characteristics. An extended distributed protocol with the external sliding-mode control is designed, under which it is shown that a heterogeneous interdependent group system is controllable when the corresponding communication topology is controllable. Then, using the network eigenvalue method, the driving individuals are determined for a heterogeneous system with undirected topology. Under directed topology, the maximum match method is utilized to confirm the driving individuals. Some sufficient and necessary conditions are presented to assure that the heterogeneous interdependent group system is structurally controllable. Via theoretical analysis, the controllability of heterogeneous interdependent systems is related to the interdependent manner and the structure of the heterogeneous system. Numerical simulations are provided to demonstrate the effectiveness of the theoretical results.
