Small and medium-sized enterprises(SMEs)constitute the primary drivers of production within the nation’s existing enterprise landscape.They represent the most dynamic segment of the national economy and play a pivota...Small and medium-sized enterprises(SMEs)constitute the primary drivers of production within the nation’s existing enterprise landscape.They represent the most dynamic segment of the national economy and play a pivotal role in supporting economic growth,fostering employment,and enhancing people’s livelihoods.However,despite their significant and extensive organizational structures,only a fraction of these companies have established internal control systems,and even fewer possess robust ones.Building upon this premise and considering the prevailing circumstances of SMEs,this paper undertakes an empirical analysis of monetary fund management within this sector.It delves into the operational intricacies,exploring how monetary funds should be effectively implemented to ensure their safety and integrity.Furthermore,it proposes viable strategies to enhance the circulation efficiency of monetary funds,thereby maximizing benefits for enterprises.Addressing these challenges is crucial for SME managers striving to achieve sustainable profit growth and navigate the complexities of financial management.展开更多
Based on the pioneering work of Konishi et al. [Phys. Rev. E （1999） 60 4000], a new feedback control scheme is presented to suppress traffic jams based on the coupled map car-following model under the open boundary ...Based on the pioneering work of Konishi et al. [Phys. Rev. E （1999） 60 4000], a new feedback control scheme is presented to suppress traffic jams based on the coupled map car-following model under the open boundary condition. The effect of the safe headway on the traffic system is considered. According to the control theory, the condition under which traffic jams can be suppressed is analyzed. The results are compared with the previous results concerning congestion control. The simulations show that the suppression performance of our scheme on traffic jams is better than those of the previous schemes, although all the schemes can suppress traffic jams. The simulation results are consistent with theoretical analyses.展开更多
In order to prevent smearing the discontinuity, a modified term is added to the third order Upwind Compact Difference scheme to lower the dissipation error. Moreover, the dispersion error is controled to hold back the...In order to prevent smearing the discontinuity, a modified term is added to the third order Upwind Compact Difference scheme to lower the dissipation error. Moreover, the dispersion error is controled to hold back the non physical oscillation by means of the group velocity control. The scheme is used to simulate the interactions of shock density stratified interface and the disturbed interface developing to vortex rollers. Numerical results are satisfactory.展开更多
Cyclohexanol is a commonly used organic compound.Currently,the most promising industrial process for synthesizing cyclohexanol,by cyclohexene hydration,suffers from a low conversion rate and difficult separation.In th...Cyclohexanol is a commonly used organic compound.Currently,the most promising industrial process for synthesizing cyclohexanol,by cyclohexene hydration,suffers from a low conversion rate and difficult separation.In this paper,a three-column process for catalytic distillation applicable in the hydration of cyclohexene to cyclohexanol was established to solve these.Simulation with Aspen Plus shows that the process has good advantages,the conversion of cyclohexene reached 99.3%,and the product purity was>99.2%.The stable operation of the distillation system requires a good control scheme.The design of the control scheme is very important.However,at present,the reactive distillation process for cyclohexene hydration is under investigation experimentally and by steady-state simulation.Therefore,three different plant-wide control schemes were established(CS1,CS2,CS3) and the position of temperature sensitive stage was selected by using sensitivity analysis method and singular value decomposition method.The Tyreus-Luyben empirical tuning method was used to tune the controller parameters.Finally,Aspen Dynamics simulation software was used to evaluate the performance of the three control schemes.By introducing ΔF±20% and χ_(ENE)±5%,comparison the changes in product purity and yield of the three different control schemes.By comparison,we can see that the control scheme CS3 has the best performance.展开更多
In IBVS (image based visual servoing), the error signal in image space should be transformed into the control signal in the input space quickly. To avoid the iterative adjustment and complicated inverse solution of im...In IBVS (image based visual servoing), the error signal in image space should be transformed into the control signal in the input space quickly. To avoid the iterative adjustment and complicated inverse solution of image Jacobian, CMAC (cerebellar model articulation controller) neural network is inserted into visual servo control loop to implement the nonlinear mapping. Two control schemes are used. Simulation results on two schemes are provided, which show a better tracking precision and stability can be achieved using scheme 2.展开更多
Various control schemes of automobile pollution are comprehensively evaluated by using the weighting and feyzzy methods, from which several feasible schemes are selected, and then mulit-target decision is made by usin...Various control schemes of automobile pollution are comprehensively evaluated by using the weighting and feyzzy methods, from which several feasible schemes are selected, and then mulit-target decision is made by using the minimum distance and hierarcby analysis methods, for determining the optimal control methods of automobile pollution.展开更多
Two significant issues in Internet-based networked control systems （ INCSs）, transport performance of different protocols and security breach from Internet side, are investigated. First, for improving the performanc...Two significant issues in Internet-based networked control systems （ INCSs）, transport performance of different protocols and security breach from Internet side, are investigated. First, for improving the performance of data transmission, user datagram protocol （UDP） is adopted as the main stand for controllers and plants using INCSs. Second, a dual-channel secure transmission scheme （DCSTS）based on data transmission characteristics of INCSs is proposed, in which a raw UDP channel and a secure TCP （transmission control protocol） connection making use of SSL/TLS （secure sockets layer/transport layer security） are included. Further, a networked control protocol （NCP） at application layer for supporting DCSTS between the controllers and plants in INCSs is designed, and it also aims at providing a universal communication mechanism for interoperability of devices among the networked control laboratories in Beijing Institute of Technology of China, Central South University of China and Tokyo University of Technology of Japan. By means of a networked single-degree-of-free- dom robot arm, an INCS under the new protocol and security environment is created. Compared with systems such as IPSec or SSL/TLS, which may cause more than 91% network throughput deduction, the new DCSTS protocol may yield results ten times better, being just 5.67%.展开更多
In this paper, we propose a well-designed network model with a parameter and study full and partial synchronization of the network model based on the stability analysis. The network model is composed of a star-coupled...In this paper, we propose a well-designed network model with a parameter and study full and partial synchronization of the network model based on the stability analysis. The network model is composed of a star-coupled subnetwork and a globally coupled subnetwork. By analyzing the special coupling configuration, three control schemes are obtained for synchronizing the network model. Further analysis indicates that even if the inner couplings in each subnetwork are very weak, two of the control schemes are still valid. In particular, if the outer coupling weight parameter 0 is larger than （n2 - 2n）/4, or the subnetwork size n is larger than 02, the two subnetworks with weak inner couplings can achieve synchronization. In addition, the synchronizability is independent of the network size in case of 0 〈 0 〈 n/（n ＋ 1 ）. Finally, we carry out some numerical simulations to confirm the validity of the obtained control schemes. It is worth noting that the main idea of this paper also applies to any network consisting of a dense subnetwork and a sparse network.展开更多
The air quantity of variable air volume system for the rooms and the total air quantity of the system changes with the change of room load. Combined with the system composition in the laboratory, the paper determines ...The air quantity of variable air volume system for the rooms and the total air quantity of the system changes with the change of room load. Combined with the system composition in the laboratory, the paper determines the control scheme of the variable air volume system, that is, indoor temperature-control, indoor positive pressure control, air distribution static pressure control, air-supply temperature control and new air volume control. The dotted lines with arrows mean the output signals from the control unit to actuator, and the solid lines with arrows represent the input signals from the actuator to the control unit.展开更多
A new transportation technology known as personal rapid transit （PRT） is being developed by multiple different companies around the world, and one system is under commercial operations in the United Kingdom. Each de...A new transportation technology known as personal rapid transit （PRT） is being developed by multiple different companies around the world, and one system is under commercial operations in the United Kingdom. Each design is different, but they all share a need to operate many automated transit vehicles at very close headways. Safe operation will require a level of control an order of magnitude above any current transit system. As a result, new techniques will be needed for the development and testing of the mechanical and control systems. In this paper an apparatus for developing and testing a PRT vehicle control scheme is demonstrated. This system is composed of independent modules that represent virtual vehicles, a central control system, a man-machine interface and a monitoring device. It can be used to implement and to evaluate the designed vehicle control algorithm. The vehicle control algorithm is designed and simulated in a combined simulation platform that consists of Matlab/Simulink and Labview Simulation Interface Toolkit. Simple operational scenarios are proposed for the testing of the proposed vehicle control apparatus.展开更多
Purpose–To address the problem that the current train operation mode that train selects one of several offline pre-generated control schemes before the departure and operates following the scheme after the departure,...Purpose–To address the problem that the current train operation mode that train selects one of several offline pre-generated control schemes before the departure and operates following the scheme after the departure,energy-saving performance of the whole metro system cannot be guaranteed.Design/methodology/approach–A cooperative train control framework is formulated to regulate a novel train operation mode.The classic train four-phase control strategy is improved for generating specific energy-efficient control schemes for each train.An improved brute force(BF)algorithm with a two-layer searching idea is designed to solve the optimisation model of energy-efficient train control schemes.Findings–Case studies on the actual metro line in Guangzhou,China verify the effectiveness of the proposed train control methods compared with four-phase control strategy under different kinds of train operation scenarios and calculation parameters.The verification on the computation efficiency as well as accuracy of the proposed algorithm indicates that it meets the requirement of online optimisation.Originality/value–Most existing studies optimised energy-efficient train timetable or train control strategies through an offline process,which has a defect in coping with the disturbance or delays effectively and promptly during real-time train operation.This paper studies an online optimisation of cooperative train control based on the rolling optimisation idea,where energy-efficient train operation can be realised once train running time is determined,thus mitigating the impact of unpredictable operation situations on the energy-saving performance of trains.展开更多
In this study,we investigated on the application of planar lightwave circuit(PLC)technology in energy-saving control of tunnel lighting.The application status of PLC in the field of energy saving followed by the neces...In this study,we investigated on the application of planar lightwave circuit(PLC)technology in energy-saving control of tunnel lighting.The application status of PLC in the field of energy saving followed by the necessity of energy saving in tunnel lighting was analyzed.Finally,the application of PLC in tunnel lighting energy-saving control around the three dimensions of system overall architecture design,control scheme,and program control process was investigated.The results showed that the system meets the requirements of control effect,robustness,and visual effect after trial operation,and is suitable for practical applications.展开更多
文摘Small and medium-sized enterprises(SMEs)constitute the primary drivers of production within the nation’s existing enterprise landscape.They represent the most dynamic segment of the national economy and play a pivotal role in supporting economic growth,fostering employment,and enhancing people’s livelihoods.However,despite their significant and extensive organizational structures,only a fraction of these companies have established internal control systems,and even fewer possess robust ones.Building upon this premise and considering the prevailing circumstances of SMEs,this paper undertakes an empirical analysis of monetary fund management within this sector.It delves into the operational intricacies,exploring how monetary funds should be effectively implemented to ensure their safety and integrity.Furthermore,it proposes viable strategies to enhance the circulation efficiency of monetary funds,thereby maximizing benefits for enterprises.Addressing these challenges is crucial for SME managers striving to achieve sustainable profit growth and navigate the complexities of financial management.
基金supported by the Major Consulting Project of Chinese Academy of Engineering (Grant No. 2012-ZX-22)the Natural Science Foundation of Chongqing Science & Technology Commission of China (Grant No. 2012jjB40002)+2 种基金the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120191110047)the Engineering Center Research Program of Chongqing Science & Technology Commission of China (Grant No. 2011pt-gc30005)the Key Technology R&D Project of Chongqing Science & Technology Commission of China (Grant Nos. 2011AB2052 and 2012gg-yyjsB30001)
文摘Based on the pioneering work of Konishi et al. [Phys. Rev. E （1999） 60 4000], a new feedback control scheme is presented to suppress traffic jams based on the coupled map car-following model under the open boundary condition. The effect of the safe headway on the traffic system is considered. According to the control theory, the condition under which traffic jams can be suppressed is analyzed. The results are compared with the previous results concerning congestion control. The simulations show that the suppression performance of our scheme on traffic jams is better than those of the previous schemes, although all the schemes can suppress traffic jams. The simulation results are consistent with theoretical analyses.
基金NKBRSF CG 1990 3 2 80 5 National Natural Science F oundation of China !( No.5 98760 0 2 )
文摘In order to prevent smearing the discontinuity, a modified term is added to the third order Upwind Compact Difference scheme to lower the dissipation error. Moreover, the dispersion error is controled to hold back the non physical oscillation by means of the group velocity control. The scheme is used to simulate the interactions of shock density stratified interface and the disturbed interface developing to vortex rollers. Numerical results are satisfactory.
基金the Natural Science Foundation of Shandong Province China (ZR2017QB006)Focus on Research and Development Plan in Yantai city (2018XSCC038)the Qingchuang Science and Technology Plan Innovation Team of Shandong Province (2019KJC012)。
文摘Cyclohexanol is a commonly used organic compound.Currently,the most promising industrial process for synthesizing cyclohexanol,by cyclohexene hydration,suffers from a low conversion rate and difficult separation.In this paper,a three-column process for catalytic distillation applicable in the hydration of cyclohexene to cyclohexanol was established to solve these.Simulation with Aspen Plus shows that the process has good advantages,the conversion of cyclohexene reached 99.3%,and the product purity was>99.2%.The stable operation of the distillation system requires a good control scheme.The design of the control scheme is very important.However,at present,the reactive distillation process for cyclohexene hydration is under investigation experimentally and by steady-state simulation.Therefore,three different plant-wide control schemes were established(CS1,CS2,CS3) and the position of temperature sensitive stage was selected by using sensitivity analysis method and singular value decomposition method.The Tyreus-Luyben empirical tuning method was used to tune the controller parameters.Finally,Aspen Dynamics simulation software was used to evaluate the performance of the three control schemes.By introducing ΔF±20% and χ_(ENE)±5%,comparison the changes in product purity and yield of the three different control schemes.By comparison,we can see that the control scheme CS3 has the best performance.
基金This project is supported by National Natural Science Foundation of China (No.59990470).
文摘In IBVS (image based visual servoing), the error signal in image space should be transformed into the control signal in the input space quickly. To avoid the iterative adjustment and complicated inverse solution of image Jacobian, CMAC (cerebellar model articulation controller) neural network is inserted into visual servo control loop to implement the nonlinear mapping. Two control schemes are used. Simulation results on two schemes are provided, which show a better tracking precision and stability can be achieved using scheme 2.
文摘Various control schemes of automobile pollution are comprehensively evaluated by using the weighting and feyzzy methods, from which several feasible schemes are selected, and then mulit-target decision is made by using the minimum distance and hierarcby analysis methods, for determining the optimal control methods of automobile pollution.
文摘Two significant issues in Internet-based networked control systems （ INCSs）, transport performance of different protocols and security breach from Internet side, are investigated. First, for improving the performance of data transmission, user datagram protocol （UDP） is adopted as the main stand for controllers and plants using INCSs. Second, a dual-channel secure transmission scheme （DCSTS）based on data transmission characteristics of INCSs is proposed, in which a raw UDP channel and a secure TCP （transmission control protocol） connection making use of SSL/TLS （secure sockets layer/transport layer security） are included. Further, a networked control protocol （NCP） at application layer for supporting DCSTS between the controllers and plants in INCSs is designed, and it also aims at providing a universal communication mechanism for interoperability of devices among the networked control laboratories in Beijing Institute of Technology of China, Central South University of China and Tokyo University of Technology of Japan. By means of a networked single-degree-of-free- dom robot arm, an INCS under the new protocol and security environment is created. Compared with systems such as IPSec or SSL/TLS, which may cause more than 91% network throughput deduction, the new DCSTS protocol may yield results ten times better, being just 5.67%.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11162004,10972011,and 11001069)the Natural Science Foundation of Zhejiang Province,China(Grant Nos.LQ12A01003 and LQ12A01002)the Science Foundation of Guangxi Province,China(Grant No.2013GXNS-FAA019006)
文摘In this paper, we propose a well-designed network model with a parameter and study full and partial synchronization of the network model based on the stability analysis. The network model is composed of a star-coupled subnetwork and a globally coupled subnetwork. By analyzing the special coupling configuration, three control schemes are obtained for synchronizing the network model. Further analysis indicates that even if the inner couplings in each subnetwork are very weak, two of the control schemes are still valid. In particular, if the outer coupling weight parameter 0 is larger than （n2 - 2n）/4, or the subnetwork size n is larger than 02, the two subnetworks with weak inner couplings can achieve synchronization. In addition, the synchronizability is independent of the network size in case of 0 〈 0 〈 n/（n ＋ 1 ）. Finally, we carry out some numerical simulations to confirm the validity of the obtained control schemes. It is worth noting that the main idea of this paper also applies to any network consisting of a dense subnetwork and a sparse network.
文摘The air quantity of variable air volume system for the rooms and the total air quantity of the system changes with the change of room load. Combined with the system composition in the laboratory, the paper determines the control scheme of the variable air volume system, that is, indoor temperature-control, indoor positive pressure control, air distribution static pressure control, air-supply temperature control and new air volume control. The dotted lines with arrows mean the output signals from the control unit to actuator, and the solid lines with arrows represent the input signals from the actuator to the control unit.
文摘A new transportation technology known as personal rapid transit （PRT） is being developed by multiple different companies around the world, and one system is under commercial operations in the United Kingdom. Each design is different, but they all share a need to operate many automated transit vehicles at very close headways. Safe operation will require a level of control an order of magnitude above any current transit system. As a result, new techniques will be needed for the development and testing of the mechanical and control systems. In this paper an apparatus for developing and testing a PRT vehicle control scheme is demonstrated. This system is composed of independent modules that represent virtual vehicles, a central control system, a man-machine interface and a monitoring device. It can be used to implement and to evaluate the designed vehicle control algorithm. The vehicle control algorithm is designed and simulated in a combined simulation platform that consists of Matlab/Simulink and Labview Simulation Interface Toolkit. Simple operational scenarios are proposed for the testing of the proposed vehicle control apparatus.
基金This research was supported by the National Natural Science Foundation of China(Grant No.71971016).On behalf of all co-authors,the corresponding author states that there is no conflict of interest.
文摘Purpose–To address the problem that the current train operation mode that train selects one of several offline pre-generated control schemes before the departure and operates following the scheme after the departure,energy-saving performance of the whole metro system cannot be guaranteed.Design/methodology/approach–A cooperative train control framework is formulated to regulate a novel train operation mode.The classic train four-phase control strategy is improved for generating specific energy-efficient control schemes for each train.An improved brute force(BF)algorithm with a two-layer searching idea is designed to solve the optimisation model of energy-efficient train control schemes.Findings–Case studies on the actual metro line in Guangzhou,China verify the effectiveness of the proposed train control methods compared with four-phase control strategy under different kinds of train operation scenarios and calculation parameters.The verification on the computation efficiency as well as accuracy of the proposed algorithm indicates that it meets the requirement of online optimisation.Originality/value–Most existing studies optimised energy-efficient train timetable or train control strategies through an offline process,which has a defect in coping with the disturbance or delays effectively and promptly during real-time train operation.This paper studies an online optimisation of cooperative train control based on the rolling optimisation idea,where energy-efficient train operation can be realised once train running time is determined,thus mitigating the impact of unpredictable operation situations on the energy-saving performance of trains.
文摘In this study,we investigated on the application of planar lightwave circuit(PLC)technology in energy-saving control of tunnel lighting.The application status of PLC in the field of energy saving followed by the necessity of energy saving in tunnel lighting was analyzed.Finally,the application of PLC in tunnel lighting energy-saving control around the three dimensions of system overall architecture design,control scheme,and program control process was investigated.The results showed that the system meets the requirements of control effect,robustness,and visual effect after trial operation,and is suitable for practical applications.
