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Fault Diagnosis for Manifold Absolute Pressure Sensor(MAP) of Diesel Engine Based on Elman Neural Network Observer 被引量:17
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作者 WANG Yingmin ZHANG Fujun +1 位作者 CUI Tao ZHOU Jinlong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第2期386-395,共10页
Intake system of diesel engine is a strong nonlinear system, and it is difficult to establish accurate model of intake system; and bias fault and precision degradation fault of MAP of diesel engine can't be diagnosed... Intake system of diesel engine is a strong nonlinear system, and it is difficult to establish accurate model of intake system; and bias fault and precision degradation fault of MAP of diesel engine can't be diagnosed easily using model-based methods. Thus, a fault diagnosis method based on Elman neural network observer is proposed. By comparing simulation results of intake pressure based on BP network and Elman neural network, lower sampling error magnitude is gained using Elman neural network, and the error is less volatile. Forecast accuracy is between 0.015?0.017 5 and sample error is controlled within 0?0.07. Considering the output stability and complexity of solving comprehensively, Elman neural network with a single hidden layer and with 44 nodes is presented as intake system observer. By comparing the relations of confidence intervals of the residual value between the measured and predicted values, error variance and failures in various fault types. Then four typical MAP faults of diesel engine can be diagnosed: complete failure fault, bias fault, precision degradation fault and drift fault. The simulation results show: intake pressure is observable and selection of diagnostic strategy parameter reasonably can increase the accuracy of diagnosis;the proposed fault diagnosis method only depends on data and structural parameters of observer, not depends on the nonlinear model of air intake system. A fault diagnosis method is proposed not depending system model to observe intake pressure, and bias fault and precision degradation fault of MAP of diesel engine can be diagnosed based on residuals. 展开更多
关键词 neural network diesel engine intake system fault diagnosis threshold value
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Parameterless Pruning Algorithms for Similarity-Weight Network and Its Application in Extracting the Backbone of Global Value Chain 被引量:1
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作者 Lizhi Xing Yu Han 《Journal of Data and Information Science》 CSCD 2022年第1期57-75,共19页
Purpose:With the availability and utilization of Inter-Country Input-Output(ICIO)tables,it is possible to construct quantitative indices to assess its impact on the Global Value Chain(GVC).For the sake of visualizatio... Purpose:With the availability and utilization of Inter-Country Input-Output(ICIO)tables,it is possible to construct quantitative indices to assess its impact on the Global Value Chain(GVC).For the sake of visualization,ICIO networks with tremendous low-weight edges are too dense to show the substantial structure.These redundant edges,inevitably make the network data full of noise and eventually exert negative effects on Social Network Analysis(SNA).In this case,we need a method to filter such edges and obtain a sparser network with only the meaningful connections.Design/methodology/approach:In this paper,we propose two parameterless pruning algorithms from the global and local perspectives respectively,then the performance of them is examined using the ICIO table from different databases.Findings:The Searching Paths(SP)method extracts the strongest association paths from the global perspective,while Filtering Edges(FE)method captures the key links according to the local weight ratio.The results show that the FE method can basically include the SP method and become the best solution for the ICIO networks.Research limitations:There are still two limitations in this research.One is that the computational complexity may increase rapidly while processing the large-scale networks,so the proposed method should be further improved.The other is that much more empirical networks should be introduced to testify the scientificity and practicability of our methodology.Practical implications:The network pruning methods we proposed will promote the analysis of the ICIO network,in terms of community detection,link prediction,and spatial econometrics,etc.Also,they can be applied to many other complex networks with similar characteristics.Originality/value:This paper improves the existing research from two aspects,namely,considering the heterogeneity of weights and avoiding the interference of parameters.Therefore,it provides a new idea for the research of network backbone extraction. 展开更多
关键词 Inter-Country Input-Output Table Global Production System Global Value Chain Network Backbone Extraction
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Study on Coordinated Development of Regions Based on the Construction of Enterprise Value Network
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作者 Yulong Hao Wei Cui 《Chinese Business Review》 2005年第4期36-40,共5页
Under the background of constructing harmonious economic society, how to realize the coordinated development of regions in the course of region integration is a key problem. According to the relevant theory of enterpr... Under the background of constructing harmonious economic society, how to realize the coordinated development of regions in the course of region integration is a key problem. According to the relevant theory of enterprise gene reconfiguration and enterprise value network construction, we analyzed the problems in the merging course between the value network construction and region economic growth. Finally, we put forward the basic path of coordinated development of regions. 展开更多
关键词 enterprises value network region development regional coordination
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SERVICE VALUE NETWORKS: VALUE, PERFORMANCE AND STRATEGY FOR THE SERVICES INDUSTRY 被引量:3
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作者 John HAMILTON 《Systems Science and Systems Engineering》 CSCD 2004年第4期469-489,共21页
Services may be investigated from many perspectives. They encapsulate over 65% of global business, yet many gaps in the services knowledge base exist – particularly from areas including information technology, oper... Services may be investigated from many perspectives. They encapsulate over 65% of global business, yet many gaps in the services knowledge base exist – particularly from areas including information technology, operational, customer targeting, and services provision. This research investigates an emerging and truly disruptive business scenario – the service value network, from a marketing, an operations and services approach. The service value network is defined as the flexible, dynamic, delivery of a service, or product, by a business’s coordinated value chains (supply chains and demand chains working in harmony), such that a value-adding, specific, service solution is effectively, and efficiently, delivered to the individual customer. The ‘physical and virtual service value network customer – business encounter model’ is developed. Impediments to the development of a service value networks are investigated. Eight key areas related to website customer encounters are offered as investigation areas. The customer ‘touch-points’ across the virtual service encounter offers a raft of new research possibilities and possible new pathways to competitive advantage. Approaches to measure service network encounter effectors are explained. Current and future areas of business research are described. This paper frames the research agenda for service value networks. 展开更多
关键词 Service value networks services web services VALUE network virtual service encounter balanced scorecard customer performance
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Dynamic value iteration networks for the planning of rapidly changing UAV swarms 被引量:3
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作者 Wei LI Bowei YANG +1 位作者 Guanghua SONG Xiaohong JIANG 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2021年第5期687-696,共10页
In an unmanned aerial vehicle ad-hoc network(UANET),sparse and rapidly mobile unmanned aerial vehicles(UAVs)/nodes can dynamically change the UANET topology.This may lead to UANET service performance issues.In this st... In an unmanned aerial vehicle ad-hoc network(UANET),sparse and rapidly mobile unmanned aerial vehicles(UAVs)/nodes can dynamically change the UANET topology.This may lead to UANET service performance issues.In this study,for planning rapidly changing UAV swarms,we propose a dynamic value iteration network(DVIN)model trained using the episodic Q-learning method with the connection information of UANETs to generate a state value spread function,which enables UAVs/nodes to adapt to novel physical locations.We then evaluate the performance of the DVIN model and compare it with the non-dominated sorting genetic algorithm II and the exhaustive method.Simulation results demonstrate that the proposed model significantly reduces the decisionmaking time for UAV/node path planning with a high average success rate. 展开更多
关键词 Dynamic value iteration networks Episodic Q-learning Unmanned aerial vehicle(UAV)ad-hoc network Non-dominated sorting genetic algorithm II(NSGA-II) Path planning
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SERVICE VALUE NETWORKS:INTO PRACTICE
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作者 John HAMILTON 《Journal of Systems Science and Systems Engineering》 SCIE EI CSCD 2007年第4期414-423,共10页
Modeling a business to match its customer perceived (and customer desired) outcomes, remains an on-going task. This paper considers shows how a service value networks (SVNs) approach may be engaged to model, and d... Modeling a business to match its customer perceived (and customer desired) outcomes, remains an on-going task. This paper considers shows how a service value networks (SVNs) approach may be engaged to model, and deliver, understanding of the front-end business and its direct engagement with its immediate (or front-end) customers. These front-end customers may be either: (1) its off-line, in-store customers - engaging directly with the business sales staff (or representative), or-(2) its on-line, virtual customers - engaging with the business via internet or remote access. In this situation, both the business, and the customer draw upon their respective viewpoints, and both sides influence the interaction. External to these business and customer influences are additional factors that capture the immediate and broader global effects - termed environmental effects. These three business-customer engagement areas of influence are captured by a SVN SEM approach. Without a business-customer encounter of some kind the likelihood of a services business, and a prospecting customer, successfully engaging in an exchange process is reduced. This exchange may be a physical, and/or services exchange, and/or an information and/or ideas exchange. To the business, this encounter is, in effect, a trade, and as a result, the business targets acquiring an economic exchange that will ultimately deliver a net positive economic outcome. To the customer, external and internal information feeds, servicing, perceived value, and satisfaction, are key encounter drivers. SVNs offers a new way to understand the business-customer encounter, and to then utilize this acquired knowledge to either: (1) build a strategic management model, or (2) reengineer its business networks, and to then create a re-positioned, more customer-aligned business operation - one that is capable of delivering win - win, competitive business-customer solutions. 展开更多
关键词 Service value networks ALIGNMENT structural equation modeling
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Value of Optical Bypass in Packet Ring Networks
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作者 Xu Zhu, Qingji Zeng, Fengqing Liu, Xudong Yang, Shilin Xiao R&D Center for Broadband Optical Networking, Shanghai Jiaotong University, Shanghai 200030, P.R.China 《光学学报》 EI CAS CSCD 北大核心 2003年第S1期755-756,共2页
This paper firstly examines the value of optical bypass scheme in packet ring networks. An Integer Linear Program (ILP) formulation is presented and analytical results under different traffic patterns are given.
关键词 in et as of Value of Optical Bypass in Packet Ring networks ILP node SONET this link
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Metcalfe's Law and Network Quality: An Extension of Zhang et al. 被引量:9
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作者 Leo Van Hove 《Journal of Computer Science & Technology》 SCIE EI CSCD 2016年第1期117-123,共7页
Zhang et al. exploited data on Facebook and Tencent to validate Metcalfe's law, which states that the aggregate value of a communications network is proportional to the square of the number of users. This note points... Zhang et al. exploited data on Facebook and Tencent to validate Metcalfe's law, which states that the aggregate value of a communications network is proportional to the square of the number of users. This note points out that the value of a social network may be driven not only by its size, but also by increases in the variety and quality of the services offered. I therefore extend Zhang et al.'s approach by explicitly controlling for changes in network quality over time. For the case of Tencent, I also filter out revenues and costs that are unrelated to Tencent's core (social network) services. I find that these two extensions only strengthen Zhang et al.'s conclusions: Metcalfe's law now outperforms the other laws even more clearlv. 展开更多
关键词 Metcalfe's law network value FACEBOOK TENCENT quality cost of revenue
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Economic Benefits and Environmental Costs of China's Exports: A Comparison with the USA Based on Network Analysis 被引量:4
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作者 Ya Liu Yuhuan Zhao +3 位作者 Hao Li Song Wang Yongfeng Zhang Ye Cao 《China & World Economy》 SCIE 2018年第4期106-132,共27页
This' paper decomposes economic benefits (value-added) and environmental costs (CO2) of exports according to their sources, and maps the global value network (GVN) and the global emissions network (GEN) for C... This' paper decomposes economic benefits (value-added) and environmental costs (CO2) of exports according to their sources, and maps the global value network (GVN) and the global emissions network (GEN) for China's exports during 1995-2009 from national, sectoral and national sectoral perspectives. A comparison is conducted between China and the USA. National GVN and GEN show that shares of value-added and CO2 emissions from China in its GVN and GEN both decreased first then increased after 2006, while shares from the USA in its GVN and GEN generally decreased. Seetoral GVN and GEN show that among China's exports, "electrical and optical equipment" and "electricity, gas and water supply" were, respectively, the sectors that obtained the most value-added and emitted the most CO2. National-sectoral G VN and GEN for China exhibited reciprocal and disassortative patterns, and in-strengths and out-strengths of GVN and GEN for China 's exports were mainly captured by several domestic country-sector pairs. 展开更多
关键词 economic benefits environmental costs EXPORTS global emissions network global value network network analysis
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Influences of the Three Gorges Project on seismic activities in the reservoir area 被引量:11
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作者 Yun-Sheng Yao Qiu-Liang Wang +5 位作者 Wu-Lin Liao Li-Fen Zhang Jun-Hua Chen Jing-Gang Li Li Yuan Yan-Nan Zhao 《Science Bulletin》 SCIE EI CAS CSCD 2017年第15期1089-1098,共10页
Reservoir-induced earthquakes related with the construction of the Three Gorges Project have attracted great concerns of the public. Since the first water impoundment on May 25, 2003, a number of earthquakes have occu... Reservoir-induced earthquakes related with the construction of the Three Gorges Project have attracted great concerns of the public. Since the first water impoundment on May 25, 2003, a number of earthquakes have occurred during the water storage stages, in which the largest was the Badong M5.1 earthquake on December 16, 2013. In this paper, the relationships between seismic activities, b value, seismic parameters, and reservoir water level fluctuations are studied. In addition, based on the digital seismic waveform data obtained since 2000, the focal depth changes and focal mechanism characteristics before and after the water impoundment are studied as well. These provide us important information to understand the earthquake mechanisms. The results show that these earthquakes are typical reservoir-induced earthquakes, which are closely related to water infiltration, pore pressure, and water level fluctuations.The majority of the micro and small earthquakes are caused by karst collapse, mine collapse, bank reformation, superficial unloading, and so on. The larger earthquakes are related to the fault structures to some extent. Due to the persistent effects of water impoundment on the seismic and geological environments around the reservoir and water infiltration into the rocks, the influences on the crustal deformation field, gravity field, seepage field, and fault medium-softening action may vary gradually from a higher strength to a weaker one. Therefore, it is possible that small earthquakes and few medium earthquakes(M≤5.5) will occur in the reservoir area in the future. 展开更多
关键词 Three Gorges Project Earthquake monitoring network Reservoir-induced earthquake Seismic activity b value Focal mechanism
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Multiple Linear Regression Application on the Inter-Network Settlement of Internet
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作者 YANG Qing-feng ZHANG Qi-xiang Lǖ Ting-jie 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2006年第2期103-107,共5页
This paper develops an analytical framework to explain the lnternet interconnection settlement issues. The paper shows that multiple linear regression can be used in assessing the network value of lnternet Backbone Pr... This paper develops an analytical framework to explain the lnternet interconnection settlement issues. The paper shows that multiple linear regression can be used in assessing the network value of lnternet Backbone Providers ( IBPs). By using the exchange rate of each network, we can define a rate of network value, which reflects the contribution of each network to interconnection and the interconnected network resource usage by each of the network. 展开更多
关键词 multiple linear regression network value INTERNET SETTLEMENT
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