The proliferation of heterogeneous networks,such as the Internet of Things(IoT),unmanned aerial vehicle(UAV)networks,and edge networks,has increased the complexity of network operation and administration,driving the e...The proliferation of heterogeneous networks,such as the Internet of Things(IoT),unmanned aerial vehicle(UAV)networks,and edge networks,has increased the complexity of network operation and administration,driving the emergence of digital twin networks(DTNs)that create digital-physical network mappings.While DTNs enable performance analysis through emulation testbeds,current research focuses on network-level systems,neglecting equipment-level emulation of critical components like core switches and routers.To address this issue,we propose v Fabric(short for virtual switch),a digital twin emulator for high-capacity core switching equipment.This solution implements virtual switching and network processor(NP)chip models through specialized processes,deployable on single or distributed servers via socket communication.The v Fabric emulator can realize the accurate emulation for the core switching equipment with 720 ports and 100 Gbit/s per port on the largest scale.To our knowledge,this represents the first digital twin emulation framework specifically designed for large-capacity core switching equipment in communication networks.展开更多
In this paper,the transmission performances are studied in cognitive radio networks with primary user emulator and relay existence.In the proposed network,the users include primary users,secondary users and primary us...In this paper,the transmission performances are studied in cognitive radio networks with primary user emulator and relay existence.In the proposed network,the users include primary users,secondary users and primary user emulators.The decreasing access priority of the users are primary users,primary user emulators and secondary users.Different user access to the network results in different transmission effects.We impose interference power constraints on the secondary users to protect the primary users from being interfered.We also adopt the transmission mechanism that transits among more than one secondary transmitters,secondary receivers and relays.The transition models of the transmission states are proposed to describe the transmission mechanism.To investigate the transmission performances,the theory of effective capacity is adopted.The transmission performances in terms of effective capacity are expressed and demonstrated under different transmission policies.The overall effective capacity,as the overall data traffic in the cognitive radio network,is calculated.Besides,the overall effective capacity is demonstrated under different transmission strategies.The results show the greedy transmission strategy outperforms the rest of the transmission 8 policies in the overall effective capacity.For a larger number of the users,the effective capacity converges to a certain value.展开更多
The mathematical physics model of mine methane and coal dust explosion propagation was established in the research,by using continuous phase,combustion,par- ticulate equations of mathematical physics.Based upon the da...The mathematical physics model of mine methane and coal dust explosion propagation was established in the research,by using continuous phase,combustion,par- ticulate equations of mathematical physics.Based upon the data from mine methane drainage roadway explosion,and mine methane and coal dust explosion propagation ex- perimental studies,the numerical emulator system of mine methane and coal dust explo- sion software was developed by using prevalent flow simulation platform,which can be used to simulate the explosion accidents process effectively.In addition,the system can also be used to determine whether coal dust involved in the explosion,and to simulate accurately the transition from deflagration to detonation in methane explosion,propagation velocity of explosion shock,attenuation pattern,and affected area of explosion.展开更多
As commercial memristors are still unavailable in the market, mathematic models and emulators which can imitate the features of the mernristor are meaningful for further research. In this paper, based on the analyses ...As commercial memristors are still unavailable in the market, mathematic models and emulators which can imitate the features of the mernristor are meaningful for further research. In this paper, based on the analyses of characteristics of the q-φ curve, an exponential flux-controlled model, which has the quality that its memductance （memristance） will keep monotonically increasing or decreasing unless the voltage＇s polarity reverses （if not approach the boundaries）, is constructed. A new approach to designing the floating emulator of the memristor is also proposed. This floating structure can flexibly meet various demands for the current through the memristor （especially the demand for a larger current）. The simulations and experiments are presented to confirm the effectiveness of this model and its floating emulator.展开更多
Power system inherently consists of capacitance and inductance in its components. Equipment with saturable inductance and circuit capacitance provides circumstances of generating ferroresonance, resulting in overvolta...Power system inherently consists of capacitance and inductance in its components. Equipment with saturable inductance and circuit capacitance provides circumstances of generating ferroresonance, resulting in overvoltage and overcurrent in the connected system. The effects of ferroresonance result in insulation failure and hence damage to the equipment is unavoidable. Though many devices are proposed for mitigating such circumstances, a promising technology of using memristors may provide better performance than others in the future. A memristor emulator using the N-channel JFET J310 is used in this work. Unlike other electronic components that replicate memristor properties, the chosen memristor emulator is a passive device since it does not need any external power supply. Simulation and experimental results verify the design of a memristor emulator and the characteristics of an ideal memristor. Experimental results prove that the memristor emulator can suppress the fundamental ferroresonance induced in a prototype single phase transformer. The results of the harmonic analysis also validate the memristor performance against the conventional technique.展开更多
This paper presents the modeling, simulation and practical implementation of an inverter-based diesel generator emulator. The main purpose of this emulator is for the study of frequency variations in diesel-based auto...This paper presents the modeling, simulation and practical implementation of an inverter-based diesel generator emulator. The main purpose of this emulator is for the study of frequency variations in diesel-based autonomous power systems in a laboratory environment where the operation of a real diesel generator is not possible. The emulator basically consists in a voltage source inverter with a second order output filter which voltage references are given by the model of the diesel generator. The control of the emulator is based on the digital signal processor TMS320F2812, where the mathematical models of the diesel generator and the control of the inverter are computed in real-time. Parameters for the model were obtained from commercially available components. Experimental results for different values of speed droop showed that the emulator achieves a satisfactory performance in the transient and stationary response. For the stationary response, the measured frequency deviates from theoretical values with a mean absolute error of: 0.06 Hz for 0% droop, 0.037 Hz for 3% droop, and 0.087 Hz for 5% droop. For the transient response, the measured frequency nadir deviates from simulations in: 0.05 Hz for 0% droop, 0.02 Hz for 3% droop, and 0.1 Hz for 5% droop.展开更多
This paper investigates the subjective assessment of QoE of web and video services over a mobile network. To achieve this, the authors used the network emulator (NetEm) traffic control functionality to simulate the dy...This paper investigates the subjective assessment of QoE of web and video services over a mobile network. To achieve this, the authors used the network emulator (NetEm) traffic control functionality to simulate the dynamic behaviour of a mobile network. Experiments were conducted in a laboratory setting and test conditions were varied to ascertain the QoE, with a focus on QoE metrics such as delay and packet loss ratio. From the experiments conducted, it was observed that there was a negative correlation between delay and average mean opinion score (MOS), and between packet loss ratio and average MOS. The results obtained can be adopted by network operators to provide better services which would lead to improved subscriber base and profitability for the operators and better QoE for the end users.展开更多
This work aims at developing an automatic system for the control of the APS （air plasma spraying） plasma process in which some instability phenomena are present. APS is a versatile technique to produce coatings of p...This work aims at developing an automatic system for the control of the APS （air plasma spraying） plasma process in which some instability phenomena are present. APS is a versatile technique to produce coatings of powder material at high deposition rates. Using this technique, powder particles are injected into a plasma jet, where they are melted and accelerated towards a substrate. The coating microstructures and properties depend strongly on the characteristics of the plasma jet, which can be controlled by the adjustment of the process parameters. However, the imeractions among the spray variables, render optimization and control of this process are quite complex. Understanding relationships between coating properties and process parameters is mandatory to optimize the process technique and the product quality. We are interested in this work to build an on-line control model for the APS process based on the elements of artificial intelligence and to build an emulator that replicates the dynamic behavior of the process as closely as possible.展开更多
In this paper a fuel cell emulator model suitable for each fuel cell type and power level is proposed. A power interface to the electronic load and a digital section are provided. The fuel cell steady-state, dynamic a...In this paper a fuel cell emulator model suitable for each fuel cell type and power level is proposed. A power interface to the electronic load and a digital section are provided. The fuel cell steady-state, dynamic and thermal behaviour is modeled by the digital controller. The emulator architecture is deeply analyzed and remarks on hardware implementation algorithms are provided for further applications. The system is tested on a 10 W Proton Exchange Membrane （PEM） fuel cell and the high accuracy of the proposed emulator is shown by the comparison between experimental and simulation results.展开更多
Emulating massively parallel computer architectures represents a very important tool for the parallel programmers. It allows them to implement and validate their algorithms. Due to the high cost of the massively paral...Emulating massively parallel computer architectures represents a very important tool for the parallel programmers. It allows them to implement and validate their algorithms. Due to the high cost of the massively parallel real machines, they remain unavailable and not popular in the parallel computing community. The goal of this paper is to present an elaborated emulator of a 2-D massively parallel re-configurable mesh computer of size n x n processing elements (PE). Basing on the object modeling method, we develop a hard kernel of a parallel virtual machine in which we translate all the physical properties of its different components. A parallel programming language and its compiler are also devel-oped to edit, compile and run programs. The developed emulator is a multi platform system. It can be installed in any sequential computer whatever may be its operating system and its processing unit technology (CPU). The size n x n of this virtual re-configurable mesh is not limited;it depends just on the performance of the sequential machine supporting the emulator.展开更多
In this paper, multimodel and neural emulators are proposed for uncoupled multivariable nonlinear plants with unknown dynamics. The contributions of this paper are to extend the emulators to multivariable non square s...In this paper, multimodel and neural emulators are proposed for uncoupled multivariable nonlinear plants with unknown dynamics. The contributions of this paper are to extend the emulators to multivariable non square systems and to propose a systematic method to compute the multimodel synthesis parameters. The effectiveness of the proposed emulators is shown through two simulation examples. The obtained results are very satisfactory, they illustrate the performance of both emulators and show the advantages of the multimodel emulator relatively to the neural one.展开更多
A SCSI target emulator is used in a storage area network （SAN） environment to simulate the behavior of a SCSI target for processing and responding to I/O requests issued by initiators. The SCSI target emulator works...A SCSI target emulator is used in a storage area network （SAN） environment to simulate the behavior of a SCSI target for processing and responding to I/O requests issued by initiators. The SCSI target emulator works with general storage devices with multiple transport protocols. The target emulator utilizes a protocol conversion module that translates the SCSI protocols to a variety of storage devices and implements the multi-RAID-level configuration and storage visualization functions. Moreover, the target emulator implements RAM caching, multi-queuing, and request merging to effectively improve the I/O response speed of the general storage devices. The throughput and average response times of the target emulator for block sizes of 4 KB to 128 KB are 150% faster for reads and 67% faster for writes than the existing emulator. With a block size of 16 KB, the I/O latency of the target emulator is only about 20% that of the existing emulator.展开更多
We propose and demonstrate a novel variable PDL emulator based on a LiNbO3 modulator. The proposed emulator could vary the PDL values simply by adjusting the bias voltage of modulator. The results show that the propos...We propose and demonstrate a novel variable PDL emulator based on a LiNbO3 modulator. The proposed emulator could vary the PDL values simply by adjusting the bias voltage of modulator. The results show that the proposed PDL emulator could generate a wide range of PDL values (0 ~ 35 dB). The generated PDL value could be maintained within ±0.02 dB for >70 minutes. The wavelength dependency was about 0.03 dB in the range of 1520 nm~ 1590 nm.展开更多
In this paper, we propose a fast and simple system emulator, called a system performance emulator(SPE), to evaluate long read operations.The SPE estimates how much system-wide performance is enhanced by using a faster...In this paper, we propose a fast and simple system emulator, called a system performance emulator(SPE), to evaluate long read operations.The SPE estimates how much system-wide performance is enhanced by using a faster solid state disk(SSD).By suspending a CPU for a certain time during direct memory access(DMA) transfer and subtracting this suspended time from the total DMA time, the SPE estimates the improvement in system performance expected from an enhanced SSD prior to its manufacture.We also examine the relation between storage performance and system performance using the SPE.展开更多
The intend of this paper is to give a description of the realization of a low-cost wind turbine emulator （WTE） with open source technology from graze required for the condition monitoring to diagnose rotor and stato...The intend of this paper is to give a description of the realization of a low-cost wind turbine emulator （WTE） with open source technology from graze required for the condition monitoring to diagnose rotor and stator faults in a wind turbine generator （WTG）. The WTE comprises of a 2.5 kW DC motor coupled with a 1 kW squirrel-cage induction machine. This paper provides a detailed overview of the hardware and software used along with the WTE control strategies such as MPPT and pitch control. The emulator reproduces dynamic characteristics both under step variations and arbitrary variation in the wind speed of a typical wind turbine （WT） of a wind energy conversion system （WECS）. The usefulness of the setup has been benchmarked with previously verified WT test rigs made at the University of Manchester and Durham University in UK. Considering the fact that the rotor blades and electric subassemblies direct drive WTs are most susceptible to damage in practice, generator winding faults and rotor unbalance have been introduced and investigated using the terminal voltage and generated current. This wind turbine emulator （WTE） can be reconfigured or analyzed for condition monitoring without the need for real WTs.展开更多
Energy access,climate change and public health issues are some major drivers for the need for renewable sources.However,most renewable sources,excluding large hydro,have zero or negligible rotational inertia,which is ...Energy access,climate change and public health issues are some major drivers for the need for renewable sources.However,most renewable sources,excluding large hydro,have zero or negligible rotational inertia,which is critical to stabilizing the power system after contingency.Therefore,this paper proposes a droop-based inertia emulator to reduce the rate of change of frequency and frequency deviations.The robustness of the controller is analysed by applying various uncertainties and disturbances of power system components that were carried out using DIgSILENT PowerFactory simulations.The obtained results are compared with existing literature and the desired performance shows an improvement in the rate of change of frequency of 34.78%for an IEEE 6-bus system,24.32%for a 12-bus system and 18%for a 39-bus system.展开更多
The edge computing paradigm is an important supplement to the traditional cloud computing paradigm in current IoT application scenarios.However,edge computing is highly related to a specific application scenario,in wh...The edge computing paradigm is an important supplement to the traditional cloud computing paradigm in current IoT application scenarios.However,edge computing is highly related to a specific application scenario,in which the mobility of edge devices and the geographical distribution of edge infrastructure are strongly correlated.However,it is expensive to deploy the solution in the real world and most current edge computing emulators lack realistic scenario support and mobility support.Therefore,it is challenging to evaluate whether an edge infrastructure deployment solution can satisfy the QoS(Quality-of-Service)requirement of an edge application in a cost-effective manner.In this paper,we propose and implement an edge emulator,MetaCity,which is able to effectively enforce edge computing policies and construct realistic application scenarios.MetaCity can leverage geographical data to establish an emulation environment according to the realistic infrastructure deployment strategy and emulate the mobility process of edge devices based on the actual urban road network.MetaCity can also provide an extensible network QoS monitoring module that supports the concurrent execution of various QoS monitoring in an emulated environment.In addition,MetaCity provides a user-friendly web-based graphical user interface instead of text-based configuration files.For evaluation,three smart transportation-based experiments are conducted to validate the functionality,scalability,and emulation accuracy of MetaCity.展开更多
Multi-organ-on-a-chip(MOOC)technology represents a pivotal direction in the organ-on-a-chip field,seeking to emulate the complex interactions of multiple human organs in vitro through microfluidic systems.This technol...Multi-organ-on-a-chip(MOOC)technology represents a pivotal direction in the organ-on-a-chip field,seeking to emulate the complex interactions of multiple human organs in vitro through microfluidic systems.This technology overcomes the limitations of traditional single-organ models,providing a novel platform for investigating complex disease mechanisms and evaluating drug efficacy and toxicity.Although it demonstrates broad application prospects,its development still faces critical bottlenecks,including inadequate physiological coupling between organs,short functional maintenance durations,and limited real-time monitoring capabilities.Contemporary research is advancing along three key directions,including functional coupling,sensor integration,and full-process automation systems,to propel the technology toward enhanced levels of physiological relevance and predictive accuracy.展开更多
To study the uncertainty quantification of resonant states in open quantum systems,we developed a Bayesian framework by integrating a reduced basis method(RBM)emulator with the Gamow coupled-channel(GCC)approach.The R...To study the uncertainty quantification of resonant states in open quantum systems,we developed a Bayesian framework by integrating a reduced basis method(RBM)emulator with the Gamow coupled-channel(GCC)approach.The RBM,constructed via eigenvector continuation and trained on both bound and resonant configurations,enables the fast and accurate emulation of resonance properties across the parameter space.To identify the physical resonant states from the emulator’s output,we introduce an overlap-based selection technique that effectively isolates true solutions from background artifacts.By applying this framework to unbound nucleus ^(6)Be,we quantified the model uncertainty in the predicted complex energies.The results demonstrate relative errors of 17.48%in the real part and 8.24%in the imaginary part,while achieving a speedup of four orders of magnitude compared with the full GCC calculations.To further investigate the asymptotic behavior of the resonant-state wavefunctions within the RBM framework,we employed a Lippmann–Schwinger(L–S)-based correction scheme.This approach not only improves the consistency between eigenvalues and wavefunctions but also enables a seamless extension from real-space training data to the complex energy plane.By bridging the gap between bound-state and continuum regimes,the L–S correction significantly enhances the emulator’s capability to accurately capture continuum structures in open quantum systems.展开更多
基金supported in part by the National Natural Science Foundation of China(NSFC)under Grant Nos.62171085,62272428,62001087,U20A20156,and 61871097the ZTE Industry-University-Institute Cooperation Funds under Grant No.HC-CN-20220722010。
文摘The proliferation of heterogeneous networks,such as the Internet of Things(IoT),unmanned aerial vehicle(UAV)networks,and edge networks,has increased the complexity of network operation and administration,driving the emergence of digital twin networks(DTNs)that create digital-physical network mappings.While DTNs enable performance analysis through emulation testbeds,current research focuses on network-level systems,neglecting equipment-level emulation of critical components like core switches and routers.To address this issue,we propose v Fabric(short for virtual switch),a digital twin emulator for high-capacity core switching equipment.This solution implements virtual switching and network processor(NP)chip models through specialized processes,deployable on single or distributed servers via socket communication.The v Fabric emulator can realize the accurate emulation for the core switching equipment with 720 ports and 100 Gbit/s per port on the largest scale.To our knowledge,this represents the first digital twin emulation framework specifically designed for large-capacity core switching equipment in communication networks.
基金supported by National Natural Science Foundation of China(No.61379016)
文摘In this paper,the transmission performances are studied in cognitive radio networks with primary user emulator and relay existence.In the proposed network,the users include primary users,secondary users and primary user emulators.The decreasing access priority of the users are primary users,primary user emulators and secondary users.Different user access to the network results in different transmission effects.We impose interference power constraints on the secondary users to protect the primary users from being interfered.We also adopt the transmission mechanism that transits among more than one secondary transmitters,secondary receivers and relays.The transition models of the transmission states are proposed to describe the transmission mechanism.To investigate the transmission performances,the theory of effective capacity is adopted.The transmission performances in terms of effective capacity are expressed and demonstrated under different transmission policies.The overall effective capacity,as the overall data traffic in the cognitive radio network,is calculated.Besides,the overall effective capacity is demonstrated under different transmission strategies.The results show the greedy transmission strategy outperforms the rest of the transmission 8 policies in the overall effective capacity.For a larger number of the users,the effective capacity converges to a certain value.
文摘The mathematical physics model of mine methane and coal dust explosion propagation was established in the research,by using continuous phase,combustion,par- ticulate equations of mathematical physics.Based upon the data from mine methane drainage roadway explosion,and mine methane and coal dust explosion propagation ex- perimental studies,the numerical emulator system of mine methane and coal dust explo- sion software was developed by using prevalent flow simulation platform,which can be used to simulate the explosion accidents process effectively.In addition,the system can also be used to determine whether coal dust involved in the explosion,and to simulate accurately the transition from deflagration to detonation in methane explosion,propagation velocity of explosion shock,attenuation pattern,and affected area of explosion.
基金supported by the National Natural Science Foundation of China(Grant Nos.51377124 and 51221005)the Foundation for the Author of National Excellent Doctoral Dissertation of China(Grant No.201337)+1 种基金the Program for New Century Excellent Talents in University of China(Grant No.NCET-13-0457)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2012JQ7026)
文摘As commercial memristors are still unavailable in the market, mathematic models and emulators which can imitate the features of the mernristor are meaningful for further research. In this paper, based on the analyses of characteristics of the q-φ curve, an exponential flux-controlled model, which has the quality that its memductance （memristance） will keep monotonically increasing or decreasing unless the voltage＇s polarity reverses （if not approach the boundaries）, is constructed. A new approach to designing the floating emulator of the memristor is also proposed. This floating structure can flexibly meet various demands for the current through the memristor （especially the demand for a larger current）. The simulations and experiments are presented to confirm the effectiveness of this model and its floating emulator.
文摘Power system inherently consists of capacitance and inductance in its components. Equipment with saturable inductance and circuit capacitance provides circumstances of generating ferroresonance, resulting in overvoltage and overcurrent in the connected system. The effects of ferroresonance result in insulation failure and hence damage to the equipment is unavoidable. Though many devices are proposed for mitigating such circumstances, a promising technology of using memristors may provide better performance than others in the future. A memristor emulator using the N-channel JFET J310 is used in this work. Unlike other electronic components that replicate memristor properties, the chosen memristor emulator is a passive device since it does not need any external power supply. Simulation and experimental results verify the design of a memristor emulator and the characteristics of an ideal memristor. Experimental results prove that the memristor emulator can suppress the fundamental ferroresonance induced in a prototype single phase transformer. The results of the harmonic analysis also validate the memristor performance against the conventional technique.
文摘This paper presents the modeling, simulation and practical implementation of an inverter-based diesel generator emulator. The main purpose of this emulator is for the study of frequency variations in diesel-based autonomous power systems in a laboratory environment where the operation of a real diesel generator is not possible. The emulator basically consists in a voltage source inverter with a second order output filter which voltage references are given by the model of the diesel generator. The control of the emulator is based on the digital signal processor TMS320F2812, where the mathematical models of the diesel generator and the control of the inverter are computed in real-time. Parameters for the model were obtained from commercially available components. Experimental results for different values of speed droop showed that the emulator achieves a satisfactory performance in the transient and stationary response. For the stationary response, the measured frequency deviates from theoretical values with a mean absolute error of: 0.06 Hz for 0% droop, 0.037 Hz for 3% droop, and 0.087 Hz for 5% droop. For the transient response, the measured frequency nadir deviates from simulations in: 0.05 Hz for 0% droop, 0.02 Hz for 3% droop, and 0.1 Hz for 5% droop.
文摘This paper investigates the subjective assessment of QoE of web and video services over a mobile network. To achieve this, the authors used the network emulator (NetEm) traffic control functionality to simulate the dynamic behaviour of a mobile network. Experiments were conducted in a laboratory setting and test conditions were varied to ascertain the QoE, with a focus on QoE metrics such as delay and packet loss ratio. From the experiments conducted, it was observed that there was a negative correlation between delay and average mean opinion score (MOS), and between packet loss ratio and average MOS. The results obtained can be adopted by network operators to provide better services which would lead to improved subscriber base and profitability for the operators and better QoE for the end users.
文摘This work aims at developing an automatic system for the control of the APS （air plasma spraying） plasma process in which some instability phenomena are present. APS is a versatile technique to produce coatings of powder material at high deposition rates. Using this technique, powder particles are injected into a plasma jet, where they are melted and accelerated towards a substrate. The coating microstructures and properties depend strongly on the characteristics of the plasma jet, which can be controlled by the adjustment of the process parameters. However, the imeractions among the spray variables, render optimization and control of this process are quite complex. Understanding relationships between coating properties and process parameters is mandatory to optimize the process technique and the product quality. We are interested in this work to build an on-line control model for the APS process based on the elements of artificial intelligence and to build an emulator that replicates the dynamic behavior of the process as closely as possible.
文摘In this paper a fuel cell emulator model suitable for each fuel cell type and power level is proposed. A power interface to the electronic load and a digital section are provided. The fuel cell steady-state, dynamic and thermal behaviour is modeled by the digital controller. The emulator architecture is deeply analyzed and remarks on hardware implementation algorithms are provided for further applications. The system is tested on a 10 W Proton Exchange Membrane （PEM） fuel cell and the high accuracy of the proposed emulator is shown by the comparison between experimental and simulation results.
文摘Emulating massively parallel computer architectures represents a very important tool for the parallel programmers. It allows them to implement and validate their algorithms. Due to the high cost of the massively parallel real machines, they remain unavailable and not popular in the parallel computing community. The goal of this paper is to present an elaborated emulator of a 2-D massively parallel re-configurable mesh computer of size n x n processing elements (PE). Basing on the object modeling method, we develop a hard kernel of a parallel virtual machine in which we translate all the physical properties of its different components. A parallel programming language and its compiler are also devel-oped to edit, compile and run programs. The developed emulator is a multi platform system. It can be installed in any sequential computer whatever may be its operating system and its processing unit technology (CPU). The size n x n of this virtual re-configurable mesh is not limited;it depends just on the performance of the sequential machine supporting the emulator.
文摘In this paper, multimodel and neural emulators are proposed for uncoupled multivariable nonlinear plants with unknown dynamics. The contributions of this paper are to extend the emulators to multivariable non square systems and to propose a systematic method to compute the multimodel synthesis parameters. The effectiveness of the proposed emulators is shown through two simulation examples. The obtained results are very satisfactory, they illustrate the performance of both emulators and show the advantages of the multimodel emulator relatively to the neural one.
基金Supported by the National High-Tech Research and Development (863) Program of China (No. 2001AA111110)
文摘A SCSI target emulator is used in a storage area network （SAN） environment to simulate the behavior of a SCSI target for processing and responding to I/O requests issued by initiators. The SCSI target emulator works with general storage devices with multiple transport protocols. The target emulator utilizes a protocol conversion module that translates the SCSI protocols to a variety of storage devices and implements the multi-RAID-level configuration and storage visualization functions. Moreover, the target emulator implements RAM caching, multi-queuing, and request merging to effectively improve the I/O response speed of the general storage devices. The throughput and average response times of the target emulator for block sizes of 4 KB to 128 KB are 150% faster for reads and 67% faster for writes than the existing emulator. With a block size of 16 KB, the I/O latency of the target emulator is only about 20% that of the existing emulator.
文摘We propose and demonstrate a novel variable PDL emulator based on a LiNbO3 modulator. The proposed emulator could vary the PDL values simply by adjusting the bias voltage of modulator. The results show that the proposed PDL emulator could generate a wide range of PDL values (0 ~ 35 dB). The generated PDL value could be maintained within ±0.02 dB for >70 minutes. The wavelength dependency was about 0.03 dB in the range of 1520 nm~ 1590 nm.
基金Project supported by the Second Brain Korea 21 Project and Samsung Electronics
文摘In this paper, we propose a fast and simple system emulator, called a system performance emulator(SPE), to evaluate long read operations.The SPE estimates how much system-wide performance is enhanced by using a faster solid state disk(SSD).By suspending a CPU for a certain time during direct memory access(DMA) transfer and subtracting this suspended time from the total DMA time, the SPE estimates the improvement in system performance expected from an enhanced SSD prior to its manufacture.We also examine the relation between storage performance and system performance using the SPE.
文摘The intend of this paper is to give a description of the realization of a low-cost wind turbine emulator （WTE） with open source technology from graze required for the condition monitoring to diagnose rotor and stator faults in a wind turbine generator （WTG）. The WTE comprises of a 2.5 kW DC motor coupled with a 1 kW squirrel-cage induction machine. This paper provides a detailed overview of the hardware and software used along with the WTE control strategies such as MPPT and pitch control. The emulator reproduces dynamic characteristics both under step variations and arbitrary variation in the wind speed of a typical wind turbine （WT） of a wind energy conversion system （WECS）. The usefulness of the setup has been benchmarked with previously verified WT test rigs made at the University of Manchester and Durham University in UK. Considering the fact that the rotor blades and electric subassemblies direct drive WTs are most susceptible to damage in practice, generator winding faults and rotor unbalance have been introduced and investigated using the terminal voltage and generated current. This wind turbine emulator （WTE） can be reconfigured or analyzed for condition monitoring without the need for real WTs.
文摘Energy access,climate change and public health issues are some major drivers for the need for renewable sources.However,most renewable sources,excluding large hydro,have zero or negligible rotational inertia,which is critical to stabilizing the power system after contingency.Therefore,this paper proposes a droop-based inertia emulator to reduce the rate of change of frequency and frequency deviations.The robustness of the controller is analysed by applying various uncertainties and disturbances of power system components that were carried out using DIgSILENT PowerFactory simulations.The obtained results are compared with existing literature and the desired performance shows an improvement in the rate of change of frequency of 34.78%for an IEEE 6-bus system,24.32%for a 12-bus system and 18%for a 39-bus system.
基金The work is supported by the National Natural Science Foundation of China under grant No.62102434,No.62002364 and No.U22B2005is partially supported by the Natural Science Foundation of Hunan Province under grant No.2022JJ30667.
文摘The edge computing paradigm is an important supplement to the traditional cloud computing paradigm in current IoT application scenarios.However,edge computing is highly related to a specific application scenario,in which the mobility of edge devices and the geographical distribution of edge infrastructure are strongly correlated.However,it is expensive to deploy the solution in the real world and most current edge computing emulators lack realistic scenario support and mobility support.Therefore,it is challenging to evaluate whether an edge infrastructure deployment solution can satisfy the QoS(Quality-of-Service)requirement of an edge application in a cost-effective manner.In this paper,we propose and implement an edge emulator,MetaCity,which is able to effectively enforce edge computing policies and construct realistic application scenarios.MetaCity can leverage geographical data to establish an emulation environment according to the realistic infrastructure deployment strategy and emulate the mobility process of edge devices based on the actual urban road network.MetaCity can also provide an extensible network QoS monitoring module that supports the concurrent execution of various QoS monitoring in an emulated environment.In addition,MetaCity provides a user-friendly web-based graphical user interface instead of text-based configuration files.For evaluation,three smart transportation-based experiments are conducted to validate the functionality,scalability,and emulation accuracy of MetaCity.
基金supported by the Shenzhen Medical Research Fund(Grant No.A2303049)Guangdong Basic and Applied Basic Research(Grant No.2023A1515010647)+1 种基金National Natural Science Foundation of China(Grant No.22004135)Shenzhen Science and Technology Program(Grant No.RCBS20210706092409020,GXWD20201231165807008,20200824162253002).
文摘Multi-organ-on-a-chip(MOOC)technology represents a pivotal direction in the organ-on-a-chip field,seeking to emulate the complex interactions of multiple human organs in vitro through microfluidic systems.This technology overcomes the limitations of traditional single-organ models,providing a novel platform for investigating complex disease mechanisms and evaluating drug efficacy and toxicity.Although it demonstrates broad application prospects,its development still faces critical bottlenecks,including inadequate physiological coupling between organs,short functional maintenance durations,and limited real-time monitoring capabilities.Contemporary research is advancing along three key directions,including functional coupling,sensor integration,and full-process automation systems,to propel the technology toward enhanced levels of physiological relevance and predictive accuracy.
基金supported by the National Key Research and Development Program(MOST 2023YFA1606404 and MOST 2022YFA1602303)the National Natural Science Foundation of China(Nos.12347106,12147101,and 12447122)the China Postdoctoral Science Foundation(No.2024M760489).
文摘To study the uncertainty quantification of resonant states in open quantum systems,we developed a Bayesian framework by integrating a reduced basis method(RBM)emulator with the Gamow coupled-channel(GCC)approach.The RBM,constructed via eigenvector continuation and trained on both bound and resonant configurations,enables the fast and accurate emulation of resonance properties across the parameter space.To identify the physical resonant states from the emulator’s output,we introduce an overlap-based selection technique that effectively isolates true solutions from background artifacts.By applying this framework to unbound nucleus ^(6)Be,we quantified the model uncertainty in the predicted complex energies.The results demonstrate relative errors of 17.48%in the real part and 8.24%in the imaginary part,while achieving a speedup of four orders of magnitude compared with the full GCC calculations.To further investigate the asymptotic behavior of the resonant-state wavefunctions within the RBM framework,we employed a Lippmann–Schwinger(L–S)-based correction scheme.This approach not only improves the consistency between eigenvalues and wavefunctions but also enables a seamless extension from real-space training data to the complex energy plane.By bridging the gap between bound-state and continuum regimes,the L–S correction significantly enhances the emulator’s capability to accurately capture continuum structures in open quantum systems.
