检索结果-南通市图书馆

Investigation into the Independent Metering Control Performance of a Twin Spools Valve with switching technology-controlled Pilot Stage

引用

Chinese Journal of Mechanical Engineering 2021年第5期34卷 226-242页

作者： Qi Zhong Huiming Bao Yanbiao Li Haocen Hong Bin Zhang Huayong Yang State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China Key Laboratory of Special Purpose Equipment and Advanced Processing technology Ministry of Education&Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310023China

In hydraulic area,independent metering control(IMC)technology is an effective approach to improve system efficiency and control *** addition,digital hydraulic technology(DHT)has been verified as a reasonable method to optimize system dynamic *** these two technologies into one component can combine their advantages ***,few works focused on *** this paper,a twin spools valve with switching technologycontrolled pilot stage(TSVSP)is presented,which applied DHT into its pilot stage while appending IMC into its main *** on this prototype valve,a series of numerical and experiment analysis of its IMC performance with both simulated load and excavator boom cylinder are carried *** showed fast and robust performance of pressure and flow compound control with acceptable fluctuation phenomenon caused by switching *** time of flow response in excavator cylinder can be controlled within 200 ms,meanwhile,the recovery time of rod chamber pressure under suddenly changed condition is optimized within 250 *** system based on TSVSP can improve both dynamic performance and robust characteristics of the target actuator so it is practical in valve-cylinder system and can be applied in mobile machineries.

关键词： High speed on/off valve(HSV) Digital hydraulic technology(DHT) switching pilot control Twin spools valve Independent metering control(IMC)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Development and Tests of ZW-126/D2000-40 Vacuum Circuit Breakers with Controlled switching technology

引用

CSEE Journal of Power and Energy Systems 2022年第1期8卷 249-257页

作者： Yu Tian Jiayuan Xu Yuan Deng Yongxing Wang Enyuan Dong Jiyan Zou Dalian University of technology Dalian 116024China State Grid Pinggao Group Pingdingshan 467001China

A ZW-126/D2000-40 type single-break vacuum circuit breaker(VCB)with controlled switching technology is designed and produced in this *** results of type tests based on IEC and GB standards are presented.A 126 kV singlebreak vacuum interrupter(VI)with 3/4 coil axial magnetic field(AMF)contacts is used in the VCB,which can interrupt short currents of 40 *** external insulation of the VI is provided by SF_(6) at 0.1 *** order to match the 126 kV single-break VI and controlled switching device,a long-stroke electro-magnetic force actuator(EMFA)with 16 kN closing holding force and 3.5 m/s average opening speed is ***,a position tracking controlled switching device based on closed-loop control using the technology of a fuzzy control algorithm and pulse width modulation is applied to the controlled switching *** device is applied to control the coil current of EMFA and the electromagnetic force,so as to control the EMFA to follow the ideal position *** type tests of 126 kV VCB are all passed according to the IEC62271-100 and GB1984-2014,including dielectric tests,basic short-circuit tests,shortline fault tests,out-of-phase tests,*** strong capacitive current breaking capacity and mechanical strength of the VCB are proved by the capacitive current switching test of class C2,electrical endurance test of class E2 and mechanical endurance test of class *** electromagnetic compatibility(EMC)tests are passed according to the *** controlled switching test of capacitive current was successful according to IEC62271-302 and GB/T30846-2014,and the controlled switching accuracy is less than±0.5 *** test results show that the VCB has excellent performance,which has broad application prospects in special occasions at a 126 kV voltage level,such as a switching capacitor and no-load transformer,etc.

关键词： Controlled switching electro-magnetic force actuator(EMFA) single-break type test vacuum circuit breaker(VCB)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Dynamic performance and control accuracy of a novel proportional valve with a switching technology-controlled pilot stage

引用

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2022年第4期23卷 272-285页

作者： Qi ZHONG En-guang XU Ti-wei JIA Hua-yong YANG Bin ZHANG Yan-biao LI College of Mechanical Engineering Zhejiang University of TechnologyHangzhou310023China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou310027China Key Laboratory of Special Purpose Equipment and Advanced Processing technology Ministry of Education and Zhejiang ProvinceZhejiang University of TechnologyHangzhou310023China

Two-stage directional valves usually employ proportional pilot control technology,which has the disadvantages of dead zones,leakage,and the large moving mass of the pilot *** is difficult,therefore,to achieve fast-response performance of the main *** order to overcome this problem,a switching pilot technology that employs two independent high-speed on/off valves(HSVs)is proposed to replace the traditional pilot proportional *** to the rapid switching characteristics of HSVs,the dead zone of the pilot stage is avoided,and the dynamic response performance of the main valve is *** experiments indicate that the switching frequency of the pilot HSVs and supply pressure of the pilot stage have a very large effect on the dynamic performance and control accuracy of the main *** the switching frequency of the pilot HSVs is helpful for improving main-valve control *** larger supply pressure of the pilot stage can achieve a faster dynamic performance of the main valve while causing larger static *** results show that the switching pilot technology can clearly improve the static and dynamic performances of the main *** the increase of pilot supply pressure,the step rise time is reduced from 21.4 ms to 16.8 ms,and the dynamic performance of the main valve is improved by 21.5%.With the increase of pilot switching frequency,the steady-state error decreases from 24μm to 20μm,and the control accuracy of the main valve is improved by 16.7%.

关键词： Pilot-operated proportional valve switching pilot stage High-speed on/off valve(HSV) Dynamic performance Control accuracy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A rapid switching technology of IP data packet based on Multi-Protocol

引用

International Journal of technology Management 2014年第8期 142-146页

作者： GUO-FANG ZHANG Hainan college of software technology Qionghai 571400 People's Republic of China

The rapid development of network raise the role of WAN. As a large-scale backbone network, the failure of network components can lead to huge loss of data and revenue. How to improve the data switching speed and Quality of Service of network data is more and more important problem which Internet Server Provides cared. Multi-Protocol Lable switching （MPLS） is a new WAN technology which is currently being standardized by IETF. This paper analysise the architecture of MPLS and describe the mechanism of label switching protocol. In addition, this study analyses the encapsulation of data packet at the Label switching Routers which is on the boundary of MPLS network. A Label switching Path （LSP） is built by Label Distribute Protocol in core network. A conclution of ＂one time routed, more times switching＂ routed was reached.

关键词： QoS MPLS label switching protocol backbone network

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Review on Security Defense technology Research in Edge Computing Environment

引用

Chinese Journal of Electronics 2024年第1期33卷 1-18页

作者： Ke SHANG Weizhen HE Shuai ZHANG National Digital switching System Engineering and Technological R&D Center

Edge computing, which achieves quick data processing by sinking data computing and storage to the network edge, has grown rapidly along with the Internet of things. The new network architecture of edge computing brings new security challenges. Based on this, this paper investigates the edge computing security literature published in recent years and summarizes and analyzes research work on edge computing security from different attack surfaces. We start with the definition and architecture of edge computing. From the attack surface between device and edge server, as well as on edge servers, the research describes the security threats and defense methods of edge computing. In addition, the cause of the attack and the pros and cons of defense methods is introduced. The challenges and future research directions of edge computing are given.

关键词： Cloud computing Systems architecture Computer architecture Network architecture Data processing Security Servers

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

An attribute-based access control scheme using blockchain technology for IoT data protection

High-Confidence Computing

引用

High-Confidence Computing 2024年第3期4卷 41-50页

作者： Zenghui Yang Xiubo Chen Yunfeng He Luxi Liu Yinmei Che Xiao Wang Ke Xiao Gang Xu Information Security Center State Key Laboratory of Networking and Switching TechnologyBeijing University of Posts and TelecommunicationsBeijing 100876China Information Center of China North Industries Group Corporation Beijing 100089China School of Information Science and technology North China University of TechnologyBeijing 100144China

With the wide application of the Internet of Things(IoT),storing large amounts of IoT data and protecting data privacy has become a meaningful *** general,the access control mechanism is used to prevent illegal users from accessing private ***,traditional data access control schemes face some non-ignorable problems,such as only supporting coarse-grained access control,the risk of centralization,and high trust *** this paper,an attribute-based data access control scheme using blockchain technology is *** address these problems,attribute-based encryption(ABE)has become a promising solution for encrypted data access ***,we utilize blockchain technology to construct a decentralized access control scheme,which can grant data access with transparency and ***,our scheme also guarantees the privacy of policies and attributes on the blockchain ***,we optimize an ABE scheme,which makes the size of system parameters smaller and improves the efficiency of *** optimizations enable our proposed scheme supports large attribute universe requirements in IoT ***,to prohibit attribute impersonation and attribute replay attacks,we design a challenge-response mechanism to verify the ownership of ***,we evaluate the security and performance of the *** comparisons with other related schemes show the advantages of our proposed *** to existing schemes,our scheme has more comprehensive advantages,such as supporting a large universe,full security,expressive policy,and policy hiding.

关键词： Attribute-based encryption Access control Blockchain IoT data protection

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Lightweight Edge-Side Fault Diagnosis Approach Based on Spiking Neural Network

引用

Computers, Materials & Continua 2024年第6期79卷 4883-4904页

作者： Jingting Mei Yang Yang Zhipeng Gao Lanlan Rui Yijing Lin State Key Laboratory of Networking and switching technology Beijing University of Posts and TelecommunicationsBeijing100876China

Network fault diagnosis methods play a vital role in maintaining network service quality and enhancing user experience as an integral component of intelligent network *** the unique characteristics of edge networks,such as limited resources,complex network faults,and the need for high real-time performance,enhancing and optimizing existing network fault diagnosis methods is ***,this paper proposes the lightweight edge-side fault diagnosis approach based on a spiking neural network(LSNN).Firstly,we use the Izhikevich neurons model to replace the Leaky Integrate and Fire(LIF)neurons model in the LSNN *** neurons inherit the simplicity of LIF neurons but also possess richer behavioral characteristics and flexibility to handle diverse data *** by Fast Spiking Interneurons(FSIs)with a high-frequency firing pattern,we use the parameters of ***,inspired by the connection mode based on spiking dynamics in the basal ganglia(BG)area of the brain,we propose the pruning approach based on the FSIs of the BG in LSNN to improve computational efficiency and reduce the demand for computing resources and energy ***,we propose a multiple iterative Dynamic Spike Timing Dependent Plasticity(DSTDP)algorithm to enhance the accuracy of the LSNN *** on two server fault datasets demonstrate significant precision,recall,and F1 improvements across three diagnosis ***,lightweight indicators such as Params and FLOPs significantly reduced,showcasing the LSNN’s advanced performance and model *** conclude,experiment results on a pair of datasets indicate that the LSNN model surpasses traditional models and achieves cutting-edge outcomes in network fault diagnosis tasks.

关键词： Network fault diagnosis edge networks Izhikevich neurons pruning dynamic spike timing dependent plasticity learning

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Distributed adaptive prescribed-time orbit containment control for satellite cluster flight

引用

Chinese Journal of Aeronautics 2024年第8期37卷 342-357页

作者： Tingting ZHANG Shijie ZHANG Huayi LI Xiangtian ZHAO Research Center of Satellite technology Harbin Institute of TechnologyHarbin 150080China State Key Laboratory of Networking and switching technology Beijing University of Posts and TelecommunicationsBeijing 100876China

The distributed prescribed-time orbit containment control for the satellite cluster flight with multiple dynamic leaders is *** directed information communication topology between followers is taken into account in the overall *** the satellite mass is assumed to be constant,a distributed prescribed-time orbit containment controller is,firstly,presented to drive the followers into the dynamic convex hull produced by multiple ***,the parameter uncertainty is considered,and a prescribed-time sliding mode estimator is introduced to estimate the desired velocity of each *** on the estimated state,a novel distributed adaptive prescribed-time orbit containment control scheme is *** Lyapunov stability theory is utilized to prove the prescribed-time stability of the closed-loop ***,several numerical simulations and comparison of different control methods are provided to verify the effectiveness and superiority of the proposed control method.

关键词： Satellite cluster Orbit containment control Prescribed-time control Parameter uncertainty Directed communication graph

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

FL-EASGD:Federated Learning Privacy Security Method Based on Homomorphic Encryption

引用

Computers, Materials & Continua 2024年第5期79卷 2361-2373页

作者： Hao Sun Xiubo Chen Kaiguo Yuan Information Security Center State Key Laboratory ofNetworking and Switching TechnologyBeijing University of Posts and TelecommunicationsBeijing100876China

Federated learning ensures data privacy and security by sharing models among multiple computing nodes instead of plaintext ***,there is still a potential risk of privacy leakage,for example,attackers can obtain the original data through model inference ***,safeguarding the privacy of model parameters becomes *** proposed solution involves incorporating homomorphic encryption algorithms into the federated learning ***,the existing federated learning privacy protection scheme based on homomorphic encryption will greatly reduce the efficiency and robustness when there are performance differences between parties or abnormal *** solve the above problems,this paper proposes a privacy protection scheme named Federated Learning-Elastic Averaging Stochastic Gradient Descent(FL-EASGD)based on a fully homomorphic encryption ***,this paper introduces the homomorphic encryption algorithm into the FL-EASGD scheme to preventmodel plaintext leakage and realize privacy security in the process ofmodel ***,this paper designs a robust model aggregation algorithm by adding time variables and constraint coefficients,which ensures the accuracy of model prediction while solving performance differences such as computation speed and node anomalies such as downtime of each *** addition,the scheme in this paper preserves the independent exploration of the local model by the nodes of each party,making the model more applicable to the local data ***,experimental analysis shows that when there are abnormalities in the participants,the efficiency and accuracy of the whole protocol are not significantly affected.

关键词： Federated learning homomorphic encryption privacy security stochastic gradient descent

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Alarm Log Data Augmentation Algorithm Based on a GAN Model and Apriori

引用

Journal of Computer Science & technology 2024年第4期39卷 951-966页

作者： Yang Yang Yu-Ting Li Yong-Hua Huo Zhi-Peng Gao Lan-Lan Rui State Key Laboratory of Network and switching technology Beijing University of Posts and TelecommunicationsBeijing 100876China The 54th Research Institute of China Electronics technology Group Corporation Shijiazhuang 050081China

The complexity of alarm detection and diagnosis tasks often results in a lack of alarm log *** to the strong rule associations inherent in alarm log data,existing data augmentation algorithms cannot obtain good results for alarm log *** address this problem,this paper introduces a new algorithm for augmenting alarm log data,termed APRGAN,which combines a generative adversarial network(GAN)with the Apriori *** generates alarm log data under the guidance of rules mined by the rule ***,we propose a new dynamic updating mechanism to alleviate the mode collapse problem of the *** addition to updating the real reference dataset used to train the discriminator in the GAN,we dynamically update the parameters and the rule set of the Apriori algorithm according to the data generated in each *** extensive experimentation on two public datasets,it is demonstrated that APRGAN surpasses other data augmentation algorithms in the domain with respect to alarm log data augmentation,as evidenced by its superior performance on metrics such as BLEU,ROUGE,and METEOR.

关键词： data augmentation alarm log data Apriori generative adversarial network(GAN)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：