Policy Gradient Adaptive Dynamic Programming for Model-Free Multi-Objective Optimal Control

Dear Editor,In this letter,the multi-objective optimal control problem of nonlinear discrete-time systems is investigated.A data-driven policy gradient algorithm is proposed in which the action-state value function is used to evaluate the policy.In the policy improvement process,the policy gradient based method is employed.

分子钙钛矿含能材料DAP-4对固体推进剂能量性能的影响

利用NASA–CEA2软件,在标准条件下,分别计算了含DAP–4((C_(6)H_(14)N_(2))[NH_(4)(ClO_(4))_(3)])的HTPB(端羟基聚丁二烯)推进剂、GAP(聚叠氮缩水甘油醚)推进剂、CMDB(复合改性双基)推进剂和NEPE(硝酸酯增塑聚醚)推进剂的能量性能;重点研究了以DAP–4分别替代RDX(黑索今)、HMX(奥克托今)、CL–20(六硝基六氮杂异伍兹烷)、TKX–50(5,5'–联四唑–1,1'–二氧二羟胺)后推进剂能量的变化趋势;对比了4种含DAP–4推进剂的能量性能。结果表明,当推进剂配方中添加DAP–4后,其标准比冲(I_(sp))和特征速度(C^(*))呈线性趋势增加。特别是当配方中只含DAP–4高能填料时,HTPB、GAP、CMDB、NEPE推进剂的I_(sp)分别达到了2617.5、2688.4、2679.4、2708.7N·s/kg,C^(*)分别达到了1604.1、1634.7、1639.1、1654.7m/s,高于目前已知固体推进剂的比冲和特征速度。同时给出了推进剂燃烧温度和燃烧产物平均分子量的数据,通过分析这2个参数的变化,部分解释了添加DAP–4后推进剂I_(sp)和C^(*)的变化机制,为DAP–4在固体推进剂中的应用提供参考。

SRv6 Policy业务可靠性方案探讨

介绍了SRv6 Policy、SBFD技术及5G承载网络SRv6 Policy业务可靠性方案。针对SBFD误触发问题,提出了在被动端生成BSID、部署引流策略及设置不同检测周期等3种完善措施,这些措施不仅提高了业务的可靠性,还显著提升了网络服务能力.

微流控技术制备微米级DAP-4基含能复合微球及性能研究

为提高分子钙钛矿含能材料(DAP-4)的装药工艺安全性,采用同轴型液滴微流控技术,改变黏结剂聚叠氮缩水甘油醚(GAP)和硝化纤维素(NC)的复合比例(占DAP-4质量的2%)实现了DAP-4基含能复合微球的球形化造粒。通过扫描电镜、X射线衍射仪、差热扫描量热仪、热失重分析仪、高速摄影、撞击感度测试仪和摩擦感度测试仪等系统测试和分析了样品的宏微观形貌、晶体结构、热性能、燃烧性能、机械感度等。结果表明:黏结剂GAP与NC的比例为4∶1时,DAP-4基复合微球(GN41)的球形化效果最好;对DAP-4进行球形化造粒后不会改变其晶体结构,热分解峰温略有提前;DAP-4基复合微球的燃烧时间比原料有轻微延长,总体依然表现出非常平稳的持续燃烧,保留了其优异的燃烧性能;GN41微球在降低机械感度的同时显著改善了流动性,提高了装药工艺安全性。

分子钙钛矿含能材料DAP-4的制备及性能表征

采用化学法合成了分子钙钛矿含能材料DAP-4,并采用扫描电镜(SEM)、能量色散光谱(EDS)、X射线衍射仪(XRD)、傅里叶红外光谱(IR)、X射线光电子能谱(XPS)和元素分析对DAP-4性能进行了表征;利用氧弹式量热仪和差示扫描量热仪(DSC)测试了DAP-4的生成焓(ΔH f)及DAP-4的热分解性能,同时测试了其机械感度、爆轰性能和燃烧性能;将DAP-4应用于CMDB推进剂中,测试了其定容和定压燃烧性能。结果表明,DAP-4的生成焓为278.6 kJ/mol,升温速率20℃/min下的热分解峰温高达392.5℃,热分解活化能(E_(K))为247.2 kJ/mol,热爆炸临界温度(T_(b))达到631.6 K,远高于HMX的T_(b)值;DAP-4的撞击感度与TNT相近,摩擦感度与CL-20相近,爆速与RDX接近;DAP-4及其混合炸药的化学储能、作功能力和对金属的加速能力明显高于RDX和HMX,与CL-20持平。定容燃烧实验表明,含DAP-4的CMDB-1推进剂燃烧速率最快,燃烧压力最高,增压速率也最高。定压燃烧实验表明,CMDB-1的燃烧温度最高,达3501℃。

Adaptive Optimal Discrete-Time Output-Feedback Using an Internal Model Principle and Adaptive Dynamic Programming

In order to address the output feedback issue for linear discrete-time systems, this work suggests a brand-new adaptive dynamic programming(ADP) technique based on the internal model principle(IMP). The proposed method, termed as IMP-ADP, does not require complete state feedback-merely the measurement of input and output data. More specifically, based on the IMP, the output control problem can first be converted into a stabilization problem. We then design an observer to reproduce the full state of the system by measuring the inputs and outputs. Moreover, this technique includes both a policy iteration algorithm and a value iteration algorithm to determine the optimal feedback gain without using a dynamic system model. It is important that with this concept one does not need to solve the regulator equation. Finally, this control method was tested on an inverter system of grid-connected LCLs to demonstrate that the proposed method provides the desired performance in terms of both tracking and disturbance rejection.

Research on Policy Diffusion Path and Reproduction of River Chief System

The River Chief System (RCS) has evolved from local innovative practices to a national water governance strategy to address the current challenges in China’s water environmental management. In contrast to existing research that focuses on the strengths, weaknesses, and improvements of RCS, this study uses literature study to reveal the dynamic evolution of RCS through three phases, with RCS spreading from developed coastal areas to central and western inland regions. RCS’s diffusion path involves vertical diffusion between central and local levels and horizontal diffusion among local governments. Moreover, RCS has also achieved conceptual spillover, gradually expanding into other governance domains, such as the Lake Chief System, the Field Chief System, the Forestry Chief System, and the integration of multiple chief roles. However, it is essential to scrutinize the phenomenon of applying similar governance mechanisms to different areas, as it may result in challenges such as overburdening local governments, insufficient public participation, oversimplification of differences in natural resource endowments, and limited applicability. This study also provides suggestions on how to address these challenges. The study contributes theoretical insights and policy implications, providing a foundation for practical policy innovation.

Inactivated H9N2 vaccines developed with early strains do not protect against recent H9N2 viruses:Call for a change in H9N2 control policy

H9N2 virus has been widely distributed in wild birds and poultry around the world since its first emergence in the United States of America in 1966(Gu et al.2017;Carnaccini and Perez 2020).The virus appeared in chickens in China in the early 1990s,and over the last two decades has gradually become the dominant epidemic subtype(Sun and Liu 2015;Bi et al.2020).Although H9N2 virus infection alone cannot cause severe disease or death in poultry,H9N2 virus-infected birds experience a degree of egg production drop and can be easily infected by other pathogens,thus causing economic losses for poultry industry.

A quantitative study of disruptive technology policy texts:An example of China’s artificial intelligence policy

Purpose:The transformative impact of disruptive technologies on the restructuring of the times has attracted widespread global attention.This study aims to analyze the characteristics and shortcomings of China’s artificial intelligence(AI)disruptive technology policy,and to put forward suggestions for optimizing China’s AI disruptive technology policy.Design/methodology/approach:Develop a three-dimensional analytical framework for“policy tools-policy actors-policy themes”and apply policy tools,social network analysis,and LDA topic model to conduct a comprehensive analysis of the utilization of policy tools,cooperative relationships among policy actors,and the trends in policy theme settings within China’s innovative AI technology policy.Findings:We find that the collaborative relationship among the policy actors of AI disruptive technology in China is insufficiently close.Marginal subjects exhibit low participation in the cooperation network and overly rely on central subjects,forming a“center-periphery”network structure.Policy tool usage is predominantly focused on supply and environmental types,with a severe inadequacy in demand-side policy tool utilization.Policy themes are diverse,encompassing topics such as“Intelligent Services”“Talent Cultivation”“Information Security”and“Technological Innovation”,which will remain focal points.Under the themes of“Intelligent Services”and“Intelligent Governance”,policy tool usage is relatively balanced,with close collaboration among policy entities.However,the theme of“AI Theoretical System”lacks a comprehensive understanding of tool usage and necessitates enhanced cooperation with other policy entities.Research limitations:The data sources and experimental scope are subject to certain limitations,potentially introducing biases and imperfections into the research results,necessitating further validation and refinement.Practical implications:The study introduces a three-dimensional analysis framework for disruptive technology policy texts,which is significant for formulating and enhancing disruptive technology policies.Originality/value:This study utilizes text mining and content analysis techniques to quantitatively analyze disruptive technology policy texts.It systematically evaluates China’s AI policies quantitatively,focusing on policy tools,policy actors,policy themes.The study uncovers the characteristics and deficiencies of current AI policies,offering recommendations for formulating and enhancing disruptive technology policies.

Mapping Climate Services for Disaster Risk Management: A Systematic Review and Research Gaps from a Policy Process Perspective

Climate services (CS) are crucial for mitigating and managing the impacts and risks associated with climate-induced disasters. While evidence over the past decade underscores their effectiveness across various domains, particularly agriculture, to maximize their potential, it is crucial to identify emerging priority areas and existing research gaps for future research agendas. As a contribution to this effort, this paper employs the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology to review the state-of-the-art in the field of climate services for disaster risk management. A comprehensive search across five literature databases combined with a snowball search method using ResearchRabbit was conducted and yielded 242 peer-reviewed articles, book sections, and reports over 2013-2023 after the screening process. The analysis revealed flood, drought, and food insecurity as major climate-related disasters addressed in the reviewed literature. Major climate services addressed included early warning systems, (sub)seasonal forecasts and impact-based warnings. Grounded in the policy processes’ theoretical perspective, the main focus identified and discussed three prevailing policy-oriented priority areas: 1) development of climate services, 2) use-adoption-uptake, and 3) evaluation of climate services. In response to the limitations of the prevalent supply-driven and top-down approach to climate services promotion, co-production emerges as a cross-cutting critical aspect of the identified priority areas. Despite the extensive research in the field, more attention is needed, particularly pronounced in the science-policy interface perspective, which in practice bridges scientific knowledge and policy decisions for effective policy processes. This perspective offers a valuable analytical lens as an entry point for further investigation. Hence, future research agendas would generate insightful evidence by scrutinizing this critical aspect given its importance to institutions and climate services capacity, to better understand intricate facets of the development and the integration of climate services into disaster risk management.

The Adjustment of NATO’s Space Policy and Its Implications

Under the US leadership,NATO has been adjusting its space policy and strengthening its space deterrence capabilities to address the so-called“threat”from China and Russia.While the deterrent effect of NATO’s space policy remains to be seen,the various measures taken to implement the policy will have a considerable impact on the global space landscape,accelerating the weaponization of space and making it more difficult to prevent an arms race in space and govern space security.

Perception Enhanced Deep Deterministic Policy Gradient for Autonomous Driving in Complex Scenarios

Autonomous driving has witnessed rapid advancement;however,ensuring safe and efficient driving in intricate scenarios remains a critical challenge.In particular,traffic roundabouts bring a set of challenges to autonomous driving due to the unpredictable entry and exit of vehicles,susceptibility to traffic flow bottlenecks,and imperfect data in perceiving environmental information,rendering them a vital issue in the practical application of autonomous driving.To address the traffic challenges,this work focused on complex roundabouts with multi-lane and proposed a Perception EnhancedDeepDeterministic Policy Gradient(PE-DDPG)for AutonomousDriving in the Roundabouts.Specifically,themodel incorporates an enhanced variational autoencoder featuring an integrated spatial attention mechanism alongside the Deep Deterministic Policy Gradient framework,enhancing the vehicle’s capability to comprehend complex roundabout environments and make decisions.Furthermore,the PE-DDPG model combines a dynamic path optimization strategy for roundabout scenarios,effectively mitigating traffic bottlenecks and augmenting throughput efficiency.Extensive experiments were conducted with the collaborative simulation platform of CARLA and SUMO,and the experimental results show that the proposed PE-DDPG outperforms the baseline methods in terms of the convergence capacity of the training process,the smoothness of driving and the traffic efficiency with diverse traffic flow patterns and penetration rates of autonomous vehicles(AVs).Generally,the proposed PE-DDPGmodel could be employed for autonomous driving in complex scenarios with imperfect data.

Tracking direct and indirect impact on technology and policy of transformative research via ego citation network

Purpose:The disseminating of academic knowledge to nonacademic audiences partly relies on the transition of subsequent citing papers.This study aims to investigate direct and indirect impact on technology and policy originating from transformative research based on ego citation network.Design/methodology/approach:Key Nobel Prize-winning publications(NPs)in fields of gene engineering and astrophysics are regarded as a proxy for transformative research.In this contribution,we introduce a network-structural indicator of citing patents to measure technological impact of a target article and use policy citations as a preliminary tool for policy impact.Findings:The results show that the impact on technology and policy of NPs are higher than that of their subsequent citation generations in gene engineering but not in astrophysics.Research limitations:The selection of Nobel Prizes is not balanced and the database used in this study,Dimensions,suffers from incompleteness and inaccuracy of citation links.Practical implications:Our findings provide useful clues to better understand the characteristics of transformative research in technological and policy impact.Originality/value:This study proposes a new framework to explore the direct and indirect impact on technology and policy originating from transformative research.

China’s Proactive Fiscal Policy

In contrast to the traditional Western approach to macro-fiscal management,China’s proactive fiscal policy is founded on a people-centered development philosophy and,with distinctive Chinese characteristics,is a significant policy innovation of macroeconomic management in the Chinese modernization.Although there are notable distinctions between the Western“Keynesian”and the“nonKeynesian”schools of thought,both of these approaches’core policy goals and methodological roots are the same,composing the traditional Western macro-fiscal approach.This approach faces increasing real dilemmas.China’s proactive fiscal policy,however,places greater emphasis on future potential growth rates in addition to equilibrium between supply and demand,achieving a fiscal policy transformation with a new approach.In this paper we argue that with such a new approach,China should reconsider the nature and reasonable level of the fiscal deficit,the function and risk assessment criteria of government debt,the scope and effects of reductions in taxes and fees,its approach and focus of demand management,and the costs and resulting efficiencies of policies in order to develop a new fiscal policy paradigm that is more in line with its stated goals.

Review of China's Energy Policy in 2023

In 2023,China's energy policy primarily focused on deepening systemic and institutional reforms,enhancing energy security capabilities,strengthening energy conservation and carbon reduction,and improving the standard system.It has laid the foundation for China's policy direction,which is predicated on ensuring energy security,centered on economic construction,and aimed at achieving the carbon peak and carbon neutrality goals on schedule.In the current key tasks,China has accelerated the construction of a big unified electricity market,vigorously promoted upgrading industries for low-carbon,high-end,and intelligent development,and established carbon markets and standard systems aligned with international practices,achieving substantial progress.

HELLO ASEAN Visa-free policy sparks surge of Chinese tourists to Southeast Asia

As of March 1,Malaysia,Singapore,and Thailand have all implemented visa-free entry policy for Chinese citizens,allowing stays of up to 30 days.The three Southeast Asian countries have been popular destinations for Chinese outbound tourists since the late 1980s and early 1990s.The implementation of the visa-free entry policy is expected to attract more Chinese tourists,especially young people,to travel to Southeast Asia and boost the recovery of the tourism industry in the region.

COMRADES FOREVER--To Lam’s visit demonstrates that China remains Vietnam’s top foreign policy priority

On August 20,2024,General Secretary of the Communist Party of Vietnam(CPV)Central Committee and Vietnamese President To Lam concluded his state visit to China.China was the destination for Lam's first overseas visit after taking office as general secretary of the CPV Central Committee,which clearly demonstrates that the heads of both countries attach importance to developing the bilateral relations and that Vietnam regards China as the strategic choice and top priority for its foreign policy.

Moderating effect of corporate financialization on the impact of climate policy on corporate green innovation:Evidence from China

With intensifying global climate change,humanity is confronted with unparalleled environmental challenges and risks.This study employs the staggered difference-in-difference model to examine the relationship between climate policy and green innovation in the corporate financialization context.Using Chinese-listed company data from 2008 to 2020,our analysis reveals a favorable correlation between China’s carbon emission trading policy(CCTP)and advancements in green innovation.Furthermore,we find that the level of corporate financialization moderates this correlation,diminishing the driving effect of CCTP on green innovation.Additionally,results of heterogeneity analysis show that this moderating consequence is more evident in non-state owned and low-digitization enterprises compared with state-owned and high-digitization ones.Our findings contribute to the existing literature by clarifying the interaction between CCTP,green innovation,and corporate financialization.Our research provides valuable insights for policymakers and stakeholders seeking to strengthen climate policies and encourages green innovation in different types of businesses.

Paired Assistance:Policy Rationale and Economic Performance as Illustrated by Xizang and Xinjiang

This study highlights the changing priorities of China’s paired assistance throughout the past decades,as well as its theoretical implications and economic growth effects for recipient regions.Using panel data from 32 prefecture-level cities from 1990 to 2020,this study uses the multiperiod difference-in-differences approach to examine how paired assistance has contributed to economic growth in Xizang Autonomous Region and Xinjiang Uygur Autonomous Region.The findings indicate that,first,the implementation of the paired assistance policy has boosted economic growth in Xizang and Xinjiang.Second,paired assistance has stimulated economic growth in recipient communities by improving infrastructure.Third,paired assistance has contributed to economic growth in recipient communities by providing improved public services such as education and healthcare.Improvements to public services have a relatively smaller indirect effect in short term than infrastructure development on economic growth.Yet both education and healthcare are crucial to people’s quality of life in recipient communities.This paper has refined and broadened research on the effects of paired assistance,providing preference for future policymaking.

The Impact of the Monetary Policy During the COVID-19 in the Brazilian Banking Sector

The COVID-19 pandemic caused an outbreak on the global productive chains,transforming companies and society in general.Governments adopted anticyclical policies such as basic interest rates reduction as response.Brazil basic interest rate is denominated Selic.The application of these policies requires the protagonist of bank’s financial intermediation.This study aims to verify two events-under the perspective of the efficient markets’theory.The first is the communication of the first death by COVID-19-and the subsequent,Selic rate reduction to 2%p.a.-and its effects on bank’s shares prices.The hypotheses presented are:H1-The announcement of the first death by COVID-19 negatively impacts the banks’shares returns and H2-The announcement of the Selic interest rate-during the COVID-19-positively impacts the return of the banks’shares.We adopt event study methodology in a final sample of nine and 15 banks to Events 1 and 2 respectively.The results confirm H1 as well as the semi-strong informational efficiency market.H2 is not confirmed.Results confirm the non-effectiveness of the anticyclical policy of basic interest rate reduction.This contributes to the discussion about the impacts of COVID-19 and the efficacy of anticyclical policies.