Superconducting films with the same hole density but different geometric symmetry have been designed and fabricated. The R(H) curves show obvious periodic oscillations with several dips at fractional matching fields. ...Superconducting films with the same hole density but different geometric symmetry have been designed and fabricated. The R(H) curves show obvious periodic oscillations with several dips at fractional matching fields. It is found that the period of the oscillations in the low field is not necessary equal to that derived from the hole density, but consistent with that from the corresponding wire networks when the large disk-like film regions are regarded as nodes. The experimental results of R(H), T_(c)(H) and j_(c)(H) at fractional matching fields within the first oscillation also support the rationality of considering films with large-diametered hole arrays as wire networks. Our results demonstrate that the connectivity of superconducting films with large-diametered hole arrays plays a more important role in the oscillations of R(H) curves.展开更多
The previous research on administration of the transmission capacity in the wired/ wireless ATM networks only focuses on wired part or wireless part. There are very few people do the work extending to the links associ...The previous research on administration of the transmission capacity in the wired/ wireless ATM networks only focuses on wired part or wireless part. There are very few people do the work extending to the links associating with handoff in the whole network. This paper develops the algorithms of transmission capacity administration on the link connecting the base station and base station controller (including the air interface of the base station) and the VPs among the base station controllers in the wired/ wireless ATM networks, which adapt to the traffic state of each service in every cellular cell to allocate (provision) transmission capacity and to reserve handoff guard capacity on these links, respectively. By simulating and analyzing the performance of the algorithm, it is found that it does well for the multimedia communication in which the transmission capacity requirement of each service may be widely different, so that the network bandwidth resource can be used efficiently.展开更多
Double-sided weld pool shapes were determined by multiple welding parameters and wire feed parameters during pulsed GTAW with wire filler. Aiming at such a system with multiple inputs and outputs, an effective modelin...Double-sided weld pool shapes were determined by multiple welding parameters and wire feed parameters during pulsed GTAW with wire filler. Aiming at such a system with multiple inputs and outputs, an effective modeling method, consisting of the impulse signal design, model structure and parameter identification and verification, was developed based on MATLAB software. Then, dynamic neural network models, TDNNM (Topside dynamic neural network model) and BHDNNM (Backside width and topside height dynamic neural network model), were established to predict double-sided shape parameters of the weld pool. The characteristic relationship of the welding process was simulated and analyzed with the models.展开更多
In this paper, an artificial neural network method that can predict the chemical composition of deposited weld metal by CO 2 Shielded Flux Cored Wire Surfacing was studied. It is found that artificial neural networ...In this paper, an artificial neural network method that can predict the chemical composition of deposited weld metal by CO 2 Shielded Flux Cored Wire Surfacing was studied. It is found that artificial neural network is a good approach on studying welding metallurgy processes that cannot be described by conventional mathematical methods. In the same time we explored a new way to study the no equilibrium welding metallurgy processes.展开更多
According to the characteristics of remote welding, including multiple parameters, real-time, and reliability of long wire transmitting, a distributing computer control scheme is adopted. A serial communication networ...According to the characteristics of remote welding, including multiple parameters, real-time, and reliability of long wire transmitting, a distributing computer control scheme is adopted. A serial communication network between the master and the slavery computers is constructed. A synchro-control network among slavery computers is designed. Uniform message format and communication protocols are made. Considering intensive high-frequency noises at the welding zone, a quadruple check mode, including data sum check, parameter type check, welding parameters check and Exclusive OR （ XOR ） check, is adopted to assure the reliability of communication among multiple computers. Based on disturbing circuit, common circuit and sensitive circuit, the measures are brought forward to ensure the stabilization of communication network of remote arc welding by analyzing the wiring principle of anti-high-frequency interference of system bus, signal wires and shielding twisted-pair（STP） wires. The results provide the theoretical and practical references for the manufacture of remote welding robot and the quality of remote welding.展开更多
The weld pool shape control by intelligent strategy was studied. In order to improve the ability of self-learning and self-adaptation of the ordinary fuzzy control, a self-learning fuzzy neural network controller (FNN...The weld pool shape control by intelligent strategy was studied. In order to improve the ability of self-learning and self-adaptation of the ordinary fuzzy control, a self-learning fuzzy neural network controller (FNNC) for backside width of weld pool in pulsed gas tungsten arc welding (GTAW) with wire filler was designed. In FNNC, the fuzzy system was expressed by an equivalence neural network, the membership functions and inference rulers were decided through the learning of the neural network. Then, the FNNC control arithmetic was analyzed, simulating experiment was done, and the validating experiments on varied heat sink workpiece and varied gap workpiece were implemented. The maximum error between the real value and the given one was 0.39mm, the mean error was 0.014mm, and the root-mean-square was 0.14mm. The real backside width was maintained around the given value. The results show that the self-learning fuzzy neural network control strategy can achieve a perfect control effect under different set values and conditions, and is suitable for the welding process with the varied structure and coefficients of control model.展开更多
We study the magnetic effect of the checkerboard superconducting wire network. Based on the de Gennes- Alexader theory, we obtain difference equations for superconducting order parameter in the wire network. Through s...We study the magnetic effect of the checkerboard superconducting wire network. Based on the de Gennes- Alexader theory, we obtain difference equations for superconducting order parameter in the wire network. Through solving these difference equations, we obtain the eigenvalues, linked to the coherence length, as a function of magnetic field. The diagram of eigenvalues shows a fractal structure, being so-called Hofstadter＇s butterfly. We also calculate and discuss the dependence of the transition temperature of the checkerboard superconducting wire network on the applied magnetic field, which is related to up-edge of the Hofstadter＇s butterfly spectrum.展开更多
For wired local area networks(LANs),their effectiveness and invulnerability are very critical.It is extraordinarily significant to evaluate the network performance effectively in the design of a reasonable network top...For wired local area networks(LANs),their effectiveness and invulnerability are very critical.It is extraordinarily significant to evaluate the network performance effectively in the design of a reasonable network topology and the performance improvement of the networks.However,there are many factors affecting the performance of the networks,and the relation among them is also complicated.How to evaluate the performance of the wired LANs more accurately has been a heavy challenge in the network research.In order to solve the problem,this paper presents a performance evaluation method that evaluates the effectiveness and invulnerability of the wired LANs.Compared to traditional statistical methods,it has the distinct advantage of being able to handle several dependent variables simultaneously and tolerates the measurement errors among these independent variables and dependent variables.Finally,the rationality and validity of this method are verified by the extensive experimental simulation.展开更多
The specific features of the CAN bus is analyzed and the functional performances in the Controller Area Network (CAN) bus system of Wire Harness Assembly Machine (WHAM) is discussed. A reasonable definition of applica...The specific features of the CAN bus is analyzed and the functional performances in the Controller Area Network (CAN) bus system of Wire Harness Assembly Machine (WHAM) is discussed. A reasonable definition of application layer which is not defined in the CAN specification is given for the control system of WHAM. So application layer planning of CAN bus for dynamic priority is presented. With the mechanism of dynamic priority,it becomes easily to find out the error nodes in the CAN bus system of WHAM and realize multi-mode operation.展开更多
软件定义网络(Software Defined Network,SDN)在有线通信系统中具有显著的技术优势,其架构涵盖控制平面、数据平面和应用平面。各平面通过标准化接口交互;在数据中心、城域网等场景中,SDN需满足带宽、延迟等性能要求。采用流量工程路径...软件定义网络(Software Defined Network,SDN)在有线通信系统中具有显著的技术优势,其架构涵盖控制平面、数据平面和应用平面。各平面通过标准化接口交互;在数据中心、城域网等场景中,SDN需满足带宽、延迟等性能要求。采用流量工程路径优化、资源分配优化等策略,结合加权最短路径(Shortest Path First,SPF)算法、参数调整等手段,可提升SDN在有线通信系统中的性能,实现网络高效管理与资源优化配置。展开更多
基金support from the National Natural Science Foundation of China (Grant Nos. 11974412 and 11774400)the National Key R&D Program of China (Grant Nos. 2017YFA0302903 and 2018YFA0305703)。
文摘Superconducting films with the same hole density but different geometric symmetry have been designed and fabricated. The R(H) curves show obvious periodic oscillations with several dips at fractional matching fields. It is found that the period of the oscillations in the low field is not necessary equal to that derived from the hole density, but consistent with that from the corresponding wire networks when the large disk-like film regions are regarded as nodes. The experimental results of R(H), T_(c)(H) and j_(c)(H) at fractional matching fields within the first oscillation also support the rationality of considering films with large-diametered hole arrays as wire networks. Our results demonstrate that the connectivity of superconducting films with large-diametered hole arrays plays a more important role in the oscillations of R(H) curves.
文摘The previous research on administration of the transmission capacity in the wired/ wireless ATM networks only focuses on wired part or wireless part. There are very few people do the work extending to the links associating with handoff in the whole network. This paper develops the algorithms of transmission capacity administration on the link connecting the base station and base station controller (including the air interface of the base station) and the VPs among the base station controllers in the wired/ wireless ATM networks, which adapt to the traffic state of each service in every cellular cell to allocate (provision) transmission capacity and to reserve handoff guard capacity on these links, respectively. By simulating and analyzing the performance of the algorithm, it is found that it does well for the multimedia communication in which the transmission capacity requirement of each service may be widely different, so that the network bandwidth resource can be used efficiently.
文摘Double-sided weld pool shapes were determined by multiple welding parameters and wire feed parameters during pulsed GTAW with wire filler. Aiming at such a system with multiple inputs and outputs, an effective modeling method, consisting of the impulse signal design, model structure and parameter identification and verification, was developed based on MATLAB software. Then, dynamic neural network models, TDNNM (Topside dynamic neural network model) and BHDNNM (Backside width and topside height dynamic neural network model), were established to predict double-sided shape parameters of the weld pool. The characteristic relationship of the welding process was simulated and analyzed with the models.
文摘In this paper, an artificial neural network method that can predict the chemical composition of deposited weld metal by CO 2 Shielded Flux Cored Wire Surfacing was studied. It is found that artificial neural network is a good approach on studying welding metallurgy processes that cannot be described by conventional mathematical methods. In the same time we explored a new way to study the no equilibrium welding metallurgy processes.
文摘According to the characteristics of remote welding, including multiple parameters, real-time, and reliability of long wire transmitting, a distributing computer control scheme is adopted. A serial communication network between the master and the slavery computers is constructed. A synchro-control network among slavery computers is designed. Uniform message format and communication protocols are made. Considering intensive high-frequency noises at the welding zone, a quadruple check mode, including data sum check, parameter type check, welding parameters check and Exclusive OR （ XOR ） check, is adopted to assure the reliability of communication among multiple computers. Based on disturbing circuit, common circuit and sensitive circuit, the measures are brought forward to ensure the stabilization of communication network of remote arc welding by analyzing the wiring principle of anti-high-frequency interference of system bus, signal wires and shielding twisted-pair（STP） wires. The results provide the theoretical and practical references for the manufacture of remote welding robot and the quality of remote welding.
文摘The weld pool shape control by intelligent strategy was studied. In order to improve the ability of self-learning and self-adaptation of the ordinary fuzzy control, a self-learning fuzzy neural network controller (FNNC) for backside width of weld pool in pulsed gas tungsten arc welding (GTAW) with wire filler was designed. In FNNC, the fuzzy system was expressed by an equivalence neural network, the membership functions and inference rulers were decided through the learning of the neural network. Then, the FNNC control arithmetic was analyzed, simulating experiment was done, and the validating experiments on varied heat sink workpiece and varied gap workpiece were implemented. The maximum error between the real value and the given one was 0.39mm, the mean error was 0.014mm, and the root-mean-square was 0.14mm. The real backside width was maintained around the given value. The results show that the self-learning fuzzy neural network control strategy can achieve a perfect control effect under different set values and conditions, and is suitable for the welding process with the varied structure and coefficients of control model.
基金Supported by the Teaching and Research Foundation for the Outstanding Young Faculty of Southeast University
文摘We study the magnetic effect of the checkerboard superconducting wire network. Based on the de Gennes- Alexader theory, we obtain difference equations for superconducting order parameter in the wire network. Through solving these difference equations, we obtain the eigenvalues, linked to the coherence length, as a function of magnetic field. The diagram of eigenvalues shows a fractal structure, being so-called Hofstadter＇s butterfly. We also calculate and discuss the dependence of the transition temperature of the checkerboard superconducting wire network on the applied magnetic field, which is related to up-edge of the Hofstadter＇s butterfly spectrum.
基金supported by the National Natural Science Foundations of China(Nos.61572435,61472305,61473222)the Ningbo Natural Science Foundations(Nos.2016A610035,2017A610119)+1 种基金the Complex Electronic System Simulation Laboratory(No.DXZT-JC-ZZ-2015015)the Joint Fund of China State Shipbuilding Corporation(No.6141B03010103)
文摘For wired local area networks(LANs),their effectiveness and invulnerability are very critical.It is extraordinarily significant to evaluate the network performance effectively in the design of a reasonable network topology and the performance improvement of the networks.However,there are many factors affecting the performance of the networks,and the relation among them is also complicated.How to evaluate the performance of the wired LANs more accurately has been a heavy challenge in the network research.In order to solve the problem,this paper presents a performance evaluation method that evaluates the effectiveness and invulnerability of the wired LANs.Compared to traditional statistical methods,it has the distinct advantage of being able to handle several dependent variables simultaneously and tolerates the measurement errors among these independent variables and dependent variables.Finally,the rationality and validity of this method are verified by the extensive experimental simulation.
文摘The specific features of the CAN bus is analyzed and the functional performances in the Controller Area Network (CAN) bus system of Wire Harness Assembly Machine (WHAM) is discussed. A reasonable definition of application layer which is not defined in the CAN specification is given for the control system of WHAM. So application layer planning of CAN bus for dynamic priority is presented. With the mechanism of dynamic priority,it becomes easily to find out the error nodes in the CAN bus system of WHAM and realize multi-mode operation.
文摘软件定义网络(Software Defined Network,SDN)在有线通信系统中具有显著的技术优势,其架构涵盖控制平面、数据平面和应用平面。各平面通过标准化接口交互;在数据中心、城域网等场景中,SDN需满足带宽、延迟等性能要求。采用流量工程路径优化、资源分配优化等策略,结合加权最短路径(Shortest Path First,SPF)算法、参数调整等手段,可提升SDN在有线通信系统中的性能,实现网络高效管理与资源优化配置。
