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Probabilistic Automata-Based Method for Enhancing Performance of Deep Reinforcement Learning Systems

IEEE/CAA Journal of Automatica Sinica 2024年第11期11卷 2327-2339页

作者： Min Yang guanjun liu Ziyuan Zhou Jiacun Wang the Department of Computer Science Tongji University IEEE the Computer Science and Software Engineering Department Monmouth University West Long Branch

Deep reinforcement learning(DRL) has demonstrated significant potential in industrial manufacturing domains such as workshop scheduling and energy system ***, due to the model's inherent uncertainty, rigorous validation is requisite for its application in real-world tasks. Specific tests may reveal inadequacies in the performance of pre-trained DRL models, while the “black-box” nature of DRL poses a challenge for testing model behavior. We propose a novel performance improvement framework based on probabilistic automata,which aims to proactively identify and correct critical vulnerabilities of DRL systems, so that the performance of DRL models in real tasks can be improved with minimal model ***, a probabilistic automaton is constructed from the historical trajectory of the DRL system by abstracting the state to generate probabilistic decision-making units(PDMUs), and a reverse breadth-first search(BFS) method is used to identify the key PDMU-action pairs that have the greatest impact on adverse outcomes. This process relies only on the state-action sequence and final result of each trajectory. Then, under the key PDMU, we search for the new action that has the greatest impact on favorable results. Finally, the key PDMU, undesirable action and new action are encapsulated as monitors to guide the DRL system to obtain more favorable results through real-time monitoring and correction mechanisms. Evaluations in two standard reinforcement learning environments and three actual job scheduling scenarios confirmed the effectiveness of the method, providing certain guarantees for the deployment of DRL models in real-world applications.

关键词： Deep reinforcement learning (DRL) performance improvement framework probabilistic automata real-time monitoring the key probabilistic decision-making units (PDMU)-action pair

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Q355/SKH9高速钢激光重频焊接接头冲击韧性分析

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制造技术与机床 2024年第4期 33-37页

作者：孙爽许桂珍刘贯军河南科技学院机电学院河南新乡450000 漯河技师学院机械工程系河南漯河462001 郑州电力职业技术学院机械工程学院河南郑州450064 河南理工大学材料科学与工程学院河南焦作454000

文章采用激光焊接技术制造Q355/SKH9高速钢焊接接头,并开展V型缺口冲击韧性实验。研究结果表明:当试验温度下降后,接头受到了更小冲击吸收能量作用,焊接接头形成了明显梯度冲击韧性;在BM中存在大量回火板条型马氏体组织,HAZ热处理时内... 详细信息

文章采用激光焊接技术制造Q355/SKH9高速钢焊接接头,并开展V型缺口冲击韧性实验。研究结果表明:当试验温度下降后,接头受到了更小冲击吸收能量作用,焊接接头形成了明显梯度冲击韧性;在BM中存在大量回火板条型马氏体组织,HAZ热处理时内部形成了不同焊接热循环过程;在BM和HAZ断口部位形成了许多撕裂棱,表现为准解理断裂;断HAZ具备优异韧性,达到了比BM更优的韧性;经过回火处理后,板条马氏体与粒状贝氏体获得了更强冲击韧性;BM保持相对稳定的显微硬度与剪切强度,HAZ形成了大梯度变化的显微硬度与剪切强度;经过焊接热循环处理与之后回火过程,HAZ基体与晶界部位形成了更多碳化物,增大HAZ强度与硬度。

关键词：高速钢焊接接头冲击韧性显微组织力学性能

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公共卫生风险治理视角下医院传染病防控政策分析

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中华医院管理杂志 2024年第5期40卷 380-386页

作者：易晖刘冠军柳佳鑫闵锐华中科技大学同济医学院附属协和医院总务处武汉430022 华中科技大学同济医学院公共卫生学院武汉430030

目的对我国医院传染病防控政策文本进行量化分析,为优化医院传染病防控政策制定,提升传染病公共卫生风险治理能力提供参考。方法以"医院""传染病""公共卫生""风险管理"等为关键词,在国务院、国家卫生健康委员会官方网站检索2017年10月至... 详细信息

目的对我国医院传染病防控政策文本进行量化分析,为优化医院传染病防控政策制定,提升传染病公共卫生风险治理能力提供参考。方法以"医院""传染病""公共卫生""风险管理"等为关键词,在国务院、国家卫生健康委员会官方网站检索2017年10月至2023年12月印发的医院传染病防控相关政策文件。基于传染病公共卫生风险治理角度,从政策工具(供给型、需求型、环境型)、政策客体(内部客体包括医院、医务工作者,外部客体包括基层医疗卫生机构、疾病预防控制机构和卫生健康行政部门)和风险管理生命周期(风险识别、风险评估、风险控制、风险管理效果评价)3个维度,运用内容分析法对政策文本进行量化分析。结果共纳入98份医院传染病防控相关政策,总计获得539条编码,其中供给型、需求型和环境型政策工具分别有134、179和226条,针对医院、医务工作者、基层医疗卫生机构、疾病预防控制机构和卫生健康行政部门的分别有239、25、24、26和225条,在风险识别、风险评估、风险控制和风险管理效果评价阶段分别有117、34、326和62条。三维交叉分析发现,风险识别阶段多通过环境型政策工具强化医院(29/117)和卫生健康行政部门的责任(23/117);风险评估阶段采用的主要是针对卫生健康行政部门的需求型政策工具(6/34);风险控制阶段利用3类政策工具对各政策客体均提出了要求;风险管理效果评价阶段主要是以环境型政策工具规范卫生健康行政部门的主体责任(33/62),在基层医疗卫生机构、医务工作者和疾病预防控制机构中均无体现。结论我国的医院传染病防控政策中,各类政策工具及风险管理各阶段的政策设计运用均存在差异,政策客体的责任分工尚需优化。政策制定者应合理运用政策工具,从公共卫生治理的角度强化对传染病风险的全生命周期管理和政策覆盖,明确各类政策客体的责任分工,提高医院的传染病公共卫生风险治理能力。

关键词：卫生政策医院公共卫生风险治理传染病防控文本量化分析

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基于耗散稀释理论的声子晶体软支撑石墨烯纳机电谐振器设计与实现

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中国科学：技术科学 2024年第5期54卷 898-910页

作者：刘瑛郑贤德徐博巫佳琦王曾晖吕克洪邱静刘冠军国防科技大学智能科学学院长沙410073 国防科技大学装备综合保障技术重点实验室长沙410073 电子科技大学基础与前沿研究院成都610054

室温品质因数低下是石墨烯纳机电谐振器走向工程应用面临的关键瓶颈,欧姆损耗难以完全解释石墨烯室温低品质因数以及品质因数应力调控现象.耗散稀释理论揭示了传统高应力硅基谐振器品质因数调控的内在能量及耗散机制,有望适用于石墨烯... 详细信息

室温品质因数低下是石墨烯纳机电谐振器走向工程应用面临的关键瓶颈,欧姆损耗难以完全解释石墨烯室温低品质因数以及品质因数应力调控现象.耗散稀释理论揭示了传统高应力硅基谐振器品质因数调控的内在能量及耗散机制,有望适用于石墨烯类二维材料体系.本文基于Zener滞弹性理论,对比分析高应力石墨烯薄板-薄膜模型下的能量分布与耗散特性,揭示边界处弯曲势能在总弯曲势能中的主导作用,指出薄板模型更适宜分析谐振器能量耗散特性.基于耗散稀释理论,结合石墨烯弯曲刚度特性,构建石墨烯纳机电谐振器耗散稀释理论模型,提出声子晶体软支撑耗散稀释机制.采用三角晶格晶胞构建声子晶体,并以此构建声子晶体软支撑石墨烯纳机电谐振器,仿真验证局域态的存在且其品质因数放大因子高于非局域态近5倍,证明了声子晶体软支撑设计提高品质因数的有效性.通过分析局域态的振幅与曲率分布,解释了声子晶体软支撑局域振动能量、抑制耗散的机制.仿真分析品质因数放大因子与软支撑声子晶体层数关系,研究发现仅需2~3层声子晶体即可实现较优局域效果,对谐振器设计具有重要指导意义.针对设计方案,提出了大规模悬空石墨烯背浮法制备工艺与石墨烯声子晶体软支撑结构FIB刻蚀工艺,成功实现了声子晶体软支撑石墨烯纳机电谐振器的制备.扫频测试结果表明,声子晶体软支撑石墨烯谐振器品质因数为圆形鼓膜石墨烯谐振器的2.5倍,验证了声子晶体软支撑结构抑制耗散提高品质因数的有效性.本文所建立石墨烯耗散稀释理论模型与声子晶体软支撑耗散稀释机制为石墨烯纳机电谐振器耗散特性研究提供了新思路,所研制声子晶体软支撑石墨烯纳机电谐振器为石墨烯纳机电谐振器谐振特性分析、耗散机制研究提供了新平台和新方法.

关键词：石墨烯耗散稀释品质因数声子晶体聚焦离子束

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Net-structure-based conditions to decide compatibility and weak compatibility for a class of inter-organizational workflow nets

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Science China(Information Sciences) 2015年第7期58卷 128-143页

作者： liu guanjun JIANG ChangJun Department of Computer Science Tongji University Key Laboratory of the Ministry of Education for Embedded System and Service Computing Tongji University

Inter-organizational workflow nets(IWF-nets) can well model the interactions among multiple processes by sending/receiving messages. Compatibility and weak compatibility are crucial properties for *** latter guarantees that a system is deadlock-free and livelock-free while the former also guarantees that it has no dead tasks. Our previous work proved that the(weak) compatibility problem is PSPACE-complete for safe IWF-nets. This paper defines a class of IWF-nets in which some simple circuits are allowed. Necessary and sufficient conditions are presented to decide compatibility and weak compatibility for this class, and they are dependent on the net structures only. Algorithms are developed based on these conditions. In addition, we show that the traditional net structures like siphon cannot be easily used to decide the(weak) compatibility of IWF-nets.

关键词： formal method workflow nets compatibility business process model web services composition

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Observable liveness of Petri nets with controllable and observable transitions

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Science China(Information Sciences) 2017年第11期60卷 256-264页

作者： guanjun liu Changjun JIANG Department of Computer Science Tongji University Key Laboratory of Embedded System and Service Computing of Ministry of Education Tongji University E-commerce Transactions and Information Services Collaborative Innovation Center of Shanghai University Knowledge Service Platform Tongji University

Observability and/or controllability are paid much attention to by researchers not only from the control science field[1–3]but also from the computer science field[4–9].Recently,Desel and Kilinc[4]proposed the notion of observable liveness for Petri nets with(un-)observable and(un-)controllable *** purpose of defining observable liveness is to represent that"a user can always enforce the occurrence of any observable transition only by stimulating the net by choosing appropriate enabled controllable transition"[4].An important assumption of

关键词： net cot PN Observable liveness of Petri nets with controllable and observable transitions

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Sensor Optimization Selection Model Based on Testability Constraint

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Chinese Journal of Aeronautics 2012年第2期25卷 262-268页

作者： YANG Shuming QIU Jing liu guanjun Laboratory of Science and Technology on Integrated Logistics Support College of Mechatronics Engineering and AutomationNational University of Defense TechnologyChangsha 410073China

Sensor selection and optimization is one of the important parts in design for testability. To address the problems that the traditional sensor optimization selection model does not take the requirements of prognostics and health management especially fault prognostics for testability into account and does not consider the impacts of sensor actual attributes on fault detectability, a novel sensor optimization selection model is proposed. Firstly, a universal architecture for sensor selection and optimization is provided. Secondly, a new testability index named fault predictable rate is defined to describe fault prognostics requirements for testability. Thirdly, a sensor selection and optimization model for prognostics and health management is constructed, which takes sensor cost as objective function and the defined testability indexes as constraint conditions. Due to NP-hard property of the model, a generic algorithm is designed to obtain the optimal solution. At last, a case study is presented to demonstrate the sensor selection approach for a stable tracking servo platform. The application results and comparison analysis show the proposed model and algorithm are effective and feasible. This approach can be used to select sensors for prognostics and health management of any system.

关键词： prognostics and health management design for testability fault predictable rate sensor selection and optimization generic algorithm

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Sensor selection of helicopter transmission systems based on physical model and sensitivity analysis

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Chinese Journal of Aeronautics 2014年第3期27卷 643-654页

作者： Lyu Kehong Tan Xiaodong liu guanjun Zhao Chenxu Science and Technology on Integrated Logistics Support Laboratory National University of Defense Technology Department of Electronic Technology Officer’s College of CAPF

In the helicopter transmission systems, it is important to monitor and track the tooth damage evolution using lots of sensors and detection methods. This paper develops a novel approach for sensor selection based on physical model and sensitivity analysis. Firstly, a physical model of tooth damage and mesh stiffness is built. Secondly, some effective condition indicators （Cls） are presented, and the optimal Cls set is selected by comparing their test statistics according to Mann-Kendall test. Afterwards, the selected CIs are used to generate a health indicator （HI） through sen slop estimator. Then, the sensors are selected according to the monotonic relevance and sensitivity to the damage levels. Finally, the proposed method is verified by the simulation and experimental data. The results show that the approach can provide a guide for health monitor- ing of helicopter transmission systems, and it is effective to reduce the test cost and improve the system＇s reliability.

关键词： Condition indicators Health indicator Helicopter transmissionsystems Mann-Kendall test Physical model Sensitivity analysis Sen slop estimator Sensor selection

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流程驱动的导弹装备保障资源配置仿真与优化

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系统工程与电子技术 2024年第9期46卷 3040-3049页

作者：崔巍巍王德芯李连峰王亮刘冠军陈志伟国防科技大学智能科学学院湖南长沙410073 中国运载火箭技术研究院北京100076 西北工业大学无人系统技术研究院陕西西安710129

随着导弹武器装备实战化、体系化发展需求的不断深化,导弹武器装备的保障活动日益复杂,给保障资源的配置带来了挑战。为此,提出基于流程驱动的导弹装备保障资源配置仿真与优化方法。首先,基于导弹装备的保障活动对时效要求高、资源约束... 详细信息

随着导弹武器装备实战化、体系化发展需求的不断深化,导弹武器装备的保障活动日益复杂,给保障资源的配置带来了挑战。为此,提出基于流程驱动的导弹装备保障资源配置仿真与优化方法。首先,基于导弹装备的保障活动对时效要求高、资源约束多等特点,建立流程驱动的导弹保障活动仿真模型与算法。然后,考虑经济规模约束,构建了面向保障效率的导弹装备保障资源优化模型。最后,以典型导弹保障流程为例,对所提模型与方法进行应用分析,验证其有效性与适应性。结果表明,基于流程驱动的保障资源配置仿真与优化方法能够有效规划导弹装备保障活动方案,评估装备保障能力,实现装备保障资源配置方案优化,为导弹装备的合理运用与资源调度提供理论与方法支撑。

关键词：保障资源优化仿真优化导弹装备保障活动仿真

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A novel testability model for health management of heading attitude system

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Chinese Journal of Aeronautics 2013年第1期26卷 201-208页

作者： liu guanjun Yang Shuming Qiu Jing Yang Peng Laboratory of Science and Technology on Integrated Logistics Support College of Mechatronics Engineering and Automation National University of Defense Technology

Prognostics and health management （PHM） is very important to guarantee the reliability and safety of aerospace systems, and sensing and test are the precondition of PHM. Integrating design for testability into early design stage of system early design stage is deemed as a fundamental way to improve PHM performance, and testability model is the base of testability analysis and design. This paper discusses a hierarchical model-based approach to testability modeling and analysis for heading attitude system health management. Quantified directed graph, of which the nodes represent components and tests and the directed edges represent fault propagation paths, is used to describe fault-test dependency, and quantitative testability information is assigned to nodes and directed edges. The fault dependencies between nodes can be obtained by functional fault analysis methodology that captures the physical architecture and material flows such as energy, heat, data, and so on. By incorporating physics of failure models into component, the dynamic process of a failing or degrading component can be projected onto system behavior, i.e., system symptoms. Then, the analysis of extended failure modes, mechanisms and effects is utilized to construct fault evolution-test dependency. Using this integrated model, the designers and system analysts can assess the test suite＇s fault detectability, fault isolability and fault predictability. And heading attitude system application results show that the proposed model can support testability analysis and design for PHM very well.

关键词： Fault evolution Functional fault analysis Physics of failure model Prognostics and health management Quantified directed graph Testability analysis

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