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Learning from Neighbors and Differentiating Export Quality

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China & World Economy 2024年第4期32卷 1-32页

作者： Qiming Liu Bin Qiu Huw Edwards Bo Gao school of Economics and management Southeast UniversityChina Business school Loughborough UniversityUK

This paper explores how learning from neighboring firms affects new exporters' product quality. It builds a Bayesian learning model to study how new exporters revise their prior beliefs about foreign customers' preferences for product quality from neighboring pioneering exporters. The model shows that a new exporter improves its product quality when it receives a positive quality-preference signal from its neighbors. The learning process of a firm depends on the number of neighbors, the level and heterogeneity of their export quality, and its own prior knowledge of the market. Highly disaggregated firm–product–country level transaction data provide robust evidence for this. The results also suggest that the impact of neighboring signals on a new exporter's quality can be channeled through the importation of high-quality intermediate inputs and more fixed investment. Learning effects are heterogeneous across firms and learning can influence other aspects of export performance.

关键词： Bayesian learning export quality information spillovers uncertainty

A comprehensive framework for predicting public opinion by tracking multi-informational dynamics

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Frontiers of Computer Science 2024年第4期18卷 197-199页

作者： Mingtao SUN Yan WEI Shan JIANG Guozhu JIA school of Economics and management Beihang UniversityBeijing 100191China school of Software Beihang UniversityBeijing 100191China school of Economics Wuhan University of TechnologyWuhan 430070China

1 Introduction In the digital landscape,trivial rumors can spark significant online reactions[1].Accurate prediction of public opinion is important for crisis management,misinformation mitigation,and fostering public ***,existing methods often fail to thoroughly investigate multiple informational factors and their timely interactions[2-4],thereby limiting their efficacy in analysing public opinion.

关键词： thereby thoroughly limiting

Digital technology,the industrial internet,and cost stickiness

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China Journal of Accounting Research 2024年第1期17卷 45-73页

作者： Lili Hui Huobao Xie Xiaofang Chen school of management Wuhan University of TechnologyWuhanChina Research Institute of Digital Governance and management Decision Innovation Wuhan University of TechnologyWuhanChina school of Economics and management Wuhan UniversityWuhanChina

The deep integration of digital technology with the real economy has reconstructed production *** explore the impact of digital technology on the resource allocation behavior and efficiency of manufacturing *** a sample of Chinese A-share listed manufacturing firms over the 2010–2021 period,we find that digital technology alleviates cost stickiness,especially in enterprises with a high level of Industrial Internet platform *** effect occurs by optimizing the labor force structure and improving the economic benefits of labor capital *** analysis shows that this effect is pronounced in enterprises with high levels of labor intensity and business *** findings shed new light on the consequences and mechanism of enterprise cost optimization that is driven by technologydriven reforms.

关键词： Digital Technology Cost Stickiness The Industrial Internet Labor Production Factor Empowerment

Robust reinforcement learning with UUB guarantee for safe motion control of autonomous robots

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Science China(Technological Sciences) 2024年第1期67卷 172-182页

作者： ZHANG RuiXian HAN YiNing SU Man LIN ZeFeng LI HaoWei ZHANG LiXian school of Astronautics Harbin Institute of TechnologyHarbin 150001China school of management Harbin Institute of TechnologyHarbin 150001China Beijing Institute of Tracking and Telecommunication Technology Beijing 100094China

This paper addresses the issue of safety in reinforcement learning(RL)with disturbances and its application in the safety-constrained motion control of autonomous *** tackle this problem,a robust Lyapunov value function(rLVF)is *** rLVF is obtained by introducing a data-based LVF under the worst-case disturbance of the observed *** the rLVF,a uniformly ultimate boundedness criterion is *** criterion is desired to ensure that the cost function,which serves as a safety criterion,ultimately converges to a range via the policy to be ***,to mitigate the drastic variation of the rLVF caused by differences in states,a smoothing regularization of the rLVF is *** train policies with safety guarantees under the worst disturbances of the observed states,an off-policy robust RL algorithm is *** proposed algorithm is applied to motion control tasks of an autonomous vehicle and a cartpole,which involve external disturbances and variations of the model parameters,*** experimental results demonstrate the effectiveness of the theoretical findings and the advantages of the proposed algorithm in terms of robustness and safety.

关键词： motion control reinforcement learning robustness stability

Characteristics of a pre-combustion plasma jet igniter

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Chinese Journal of Aeronautics 2024年第7期37卷 178-189页

作者： Jinlu YU Baowen ZHANG Yang YU Bingbing ZHAO Lei ZHANG Aviation Engineering school Air Force Engineering UniversityXi’an 710038China Equipment management and Unmanned Aerial Vehicle Engineering school Air Force Engineering UniversityXi’an 710038China

Plasma ignition technology has delivered good performance in the aerospace industry. In this study, a pre-combustion plasma jet igniter was designed, and its characteristics were examined from three aspects: the morphology, temperature, and discharge characteristics and process of ignition. Images of the OH distribution were obtained by using an OH Planar Laser-Induced Fluorescence(OH-PLIF) experimental system. Results have shown that the proposed plasma jet had a higher OH concentration, longer length, and larger area than those of a traditional igniter. The stability of discharge of the igniter was improved as the equivalence ratio φ was increased, and reducing gas flow reduced the pulsation of the plasma jet. When the input current was increased from 15A to 35 A, the highest average temperature increased from 5127 K to 7987 K. An increase in the equivalence ratio reduced the region of arc ionization, but expanded the regions of the core combustion reaction and the outer flame. Herein, this study has obtained a deep understanding of the jet and ignition law and developed a new idea for the application of plasma in the ignition field.A pre-combustion plasma jet igniter can significantly improve the efficiency of ignition and shorten the ignition process compared with a traditional igniter.

关键词： Pre-combustion plasma igniter Plasma Jet temperature field Ignition process Arc Flame

Coordination for a Closed-loop Supply Chain with Recycling Platform Considering Dynamic Setting

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Journal of Systems Science and Systems Engineering 2024年第4期33卷 425-451页

作者： Zehua Xiang Ting Ji Lingfeng Dong school of management Zhejiang UniversityHangzhou310058China school of Business Hangzhou City UniversityHangzhou310015China Alibaba Business College Hangzhou Normal UniversityHangzhou311121China

This paper presents a dynamic closed-loop supply chain(CLSC)model,incorporating a manufacturer,a retailer,and an internet recycling platform(IRP),utilizing differential game theory while considering the forgetting effect of *** model encompasses factors such as the quality level of used products and Big Data marketing(BDM),comparing optimal equilibriums under decentralized and cooperative decision *** effectively coordinate the dynamic CLSC at each time point,we propose a revenue-sharing and cost-sharing(RSCS)combined *** addition to ensuring reasonable sharing of revenues and costs,this contract allows the manufacturer to flexibly adjust wholesale prices for final products and transfer prices for used products in order to distribute profits appropriately and achieve Pareto optimality within the CLSC ***,our results indicate that there exists a threshold for Big Data marketing efficiency;high-efficiency BDM not only facilitates increased recycling on Internet platforms but also reduces unit recycling costs for ***,when implementing the combined contract,Big Data marketing efficiency does not impact the transfer price paid by manufacturers to Internet recycling platforms.

关键词： Big Data marketing differential game closed-loop supply chain coordination internet recycling platform

Coupled funnel control for supersonic tailless aerial vehicle on penetrating counter air

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Chinese Journal of Aeronautics 2024年第7期37卷 458-481页

作者： Yingyang WANG Peng ZHANG Jilian GUO Jianbo HU Equipment management and Unmanned Aerial Vehicle Engineering school Air Force Engineering UniversityXi’an 710051China Aviation Engineering school Air Force Engineering UniversityXi’an 710038China

Supersonic Tailless Aerial Vehicles(STAVs)will become an essential force in Penetrating Counter Air(PCA),but STAVs do not have the traditional horizontal and vertical tails,making pitch and yaw control *** attack angle and the sideslip angle need to be limited to ensure that the engine inlet and the aerodynamic rudder at the rear of the vehicle can work properly,which is the so-called security *** addition,the tracking error of the aerodynamic angle needs to be limited to achieve effective attitude control or high-accuracy tracking of trajectories,which is the so-called performance *** this end,an attitude control method that meets the needs of PCA has been devised,based on constraint definition,coupled constraints handling,and control law ***,mathematical descriptions of the security constraints,performance constraints,and control constraints are ***,two treatment methods,coupled command filter and coupled funnel control are proposed for the aerodynamic angle coupled constraint ***,based on Nonlinear Dynamic Inverse(NDI)design,the coupled funnel controller is designed and validated by simulation for two typical mission scenarios,high-altitude penetration and low-altitude surprise *** proposed control method not only satisfies the security and performance constraints of STAV attitude control but also is highly robust.

关键词： Supersonic tailless aircraft Penetrating counter air Funnel control Attitude control Control allocation

Effect of relative humidity on the desulfurization performance of calcium-based desulfurizer

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Journal of Environmental Sciences 2024年第4期138卷 179-188页

作者： Juan Lǖ Yu Fu Haiyan Yu HuanWang Zhe Wang Haiyan Chen school of Environment and Resource Southwest University of Science and TechnologyMianyang 621010China Guangyuan Emergency management bureau Guangyuan 628000China

Low desulfurization efficiency impedes the wide application of dry desulfurization technology,which is a low-cost and simple process,and one significant solution is the development and manufacture of high-performance *** this study,firstly,a steam jet mill was used to digest quicklime;then,we utilized numerical simulation to study the flow field distribution and analyze the driving factors of quicklime digestion;and lastly,the desulfurization performance of the desulfurizer was evaluated under different relative *** results show that the desulfurizer prepared via the steam jet mill had better apparent activity than traditional ***,the entire jet flow field of the steam jet mill is in a supersonic and highly turbulent flow state,with high crushing intensity and good particle acceleration *** contact with the nascent surface maximizes the formation of slaked *** experiments demonstrated that the operating time with 100%desulfurization efficiency and the“break-through”time for the desulfurizer prepared via the steam jet mill is longer than that of traditional desulfurizers,and has significant advantages,especially at low flue gas relative *** with traditional desulfurizers,the desulfurizer prepared via steam jet mill expands the range of acceptable flue gas temperature,and the failure temperature is 1.625 times that of traditional *** work breaks through the technical bottleneck of low dry desulfurization efficiency,which is an important step in pushing forward the application of dry desulfurization.

关键词： Dry desulfurization Relative humidity Desulfurization efficiency High-efficiency desulfurizer Quicklime digestion

Secure state estimation for cyber-physical systems with unknown input sliding mode observer

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Control Theory and Technology 2024年第2期22卷 244-253页

作者： Panpan Zhang Yuwei Ren Yixian Fang Ang Liu school of Information Science and Engineering Shandong Normal UniversityJinan250358ShandongChina school of Information Engineering Shandong Management UniversityJinan250357ShandongChina

In recent years, cyber attacks have posed great challenges to the development of cyber-physical systems. It is of great significance to study secure state estimation methods to ensure the safe and stable operation of the system. This paper proposes a secure state estimation for multi-input and multi-output continuous-time linear cyber-physical systems with sparse actuator and sensor attacks. First, for sparse sensor attacks, we propose an adaptive switching mechanism to mitigate the impact of sparse sensor attacks by filtering out their attack modes. Second, an unknown input sliding mode observer is designed to not only observe the system states, sensor attack signals, and measurement noise present in the system but also counteract the effects of sparse actuator attacks through an unknown input matrix. Finally, for the design of an unknown input sliding mode state observer, the feasibility of the observing system is demonstrated by means of Lyapunov functions. Additionally, simulation experiments are conducted to show the effectiveness of this method.

关键词： Sparse attacks Cyber-physical systems Unknown input sliding mode Secure state estimation Adaptive switching mechanism