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XRL-SHAP-Cache:an explainable reinforcement learning approach for intelligent edge service caching in content delivery networks

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Science China(Information Sciences) 2024年第7期67卷 46-71页

作者： Xiaolong XU Fan WU Muhammad BILAL xiaoyu XIA Wanchun DOU Lina yao Weiyi ZHONG School of Software Nanjing University of Information Science and Technology School of Computing and Communications Lancaster University School of Computing Technologies Royal Melbourne Institute of Technology State Key Laboratory for Novel Software Technology Nanjing University School of Computer Science and Engineering University of New South Wales Data 61 Commonwealth Scientific and Industrial Research Organization School of Computer Science Qufu Normal University

Content delivery networks(CDNs) play a pivotal role in the modern internet infrastructure by enabling efficient content delivery across diverse geographical regions. As an essential component of CDNs, the edge caching scheme directly influences the user experience by determining the caching and eviction of content on edge servers. With the emergence of 5G technology, traditional caching schemes have faced challenges in adapting to increasingly complex and dynamic network environments. Consequently, deep reinforcement learning(DRL) offers a promising solution for intelligent zero-touch network governance. However, the blackbox nature of DRL models poses challenges in understanding and making trusting decisions. In this paper,we propose an explainable reinforcement learning(XRL)-based intelligent edge service caching approach,namely XRL-SHAP-Cache, which combines DRL with an explainable artificial intelligence(XAI) technique for cache management in CDNs. Instead of focusing solely on achieving performance gains, this study introduces a novel paradigm for providing interpretable caching strategies, thereby establishing a foundation for future transparent and trustworthy edge caching solutions. Specifically, a multi-level cache scheduling framework for CDNs was formulated theoretically, with the D3QN-based caching scheme serving as the targeted interpretable model. Subsequently, by integrating Deep-SHAP into our framework, the contribution of each state input feature to the agent's Q-value output was calculated, thereby providing valuable insights into the decision-making process. The proposed XRL-SHAP-Cache approach was evaluated through extensive experiments to demonstrate the behavior of the scheduling agent in the face of different environmental inputs.The results demonstrate its strong explainability under various real-life scenarios while maintaining superior performance compared to traditional caching schemes in terms of cache hit ratio, quality of service(QoS),and space utilization.

关键词： deep reinforcement learning (DRL) explainable artificial intelligence (XAI) multi-level cache content delivery network (CDN) D3QN algorithm Deep-SHAP

The Effect of Moisture in Different Altitude Layers on the Eastward Propagation of MJO

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Journal of Meteorological Research 2024年第3期38卷 437-452页

作者： xiaoyu ZHU Zhong ZHONG Yimin ZHU Yunying LI Yijia HU yao HA College of Meteorology and Oceanography National University of Defense Technology Key Laboratory for Virtual Geographic Environment School of Geography Science Nanjing Normal University Jiangsu Collaborative Innovation Center for Climate Change School of Atmospheric Sciences Nanjing University

In this study, driven by ERA5 reanalysis data, the Weather Research and Forecasting(WRF) version 4.0 was used to investigate the eastward propagation of the Madden–Julian oscillation(MJO) in the tropical atmosphere during December–February(DJF) of 2007/2008. The experiment with 11 cumulus parameterization schemes respectively shows that the Grell 3D scheme is one of several worse ones in describing MJO activities. In addition, still by use of the Grell 3D scheme, four nudging assimilation experiments for water vapor in all model vertical layers(Ndg＿all),lower layers(Ndg＿low), middle layers(Ndg＿mid), and upper layers(Ndg＿upp) were conducted. It is found that when the water vapor in the model approaches to the observed value, the model performance for MJO activities is improved greatly. Among the four nudging simulations, Ndg＿all certainly performs best. Although Ndg＿mid is important for the MJO-filtered profiles related to moisture, Ndg＿low and Ndg＿upp exhibit superiority to Ndg＿mid in simulating MJO eastward propagation. Ndg＿low has advantages when MJO features are represented by zonal wind at850 hPa and precipitation because the lower-level MJO-filtered moisture is conducive to the existence of lower-level condensational heating to the east of the MJO convective center. Ndg＿upp performs better when describing the MJO eastward propagation features by outgoing longwave radiation(OLR) since it can capture the moisture and cloud top temperature of deep convection associated with MJO, as well as front Walker cell. These results suggest that the lower-level moisture is more important in regulating the MJO eastward propagation, and the observed maximum MJO-filtered moisture in the middle troposphere might be a phenomenon accompanying the MJO deep convection,but not a factor controlling its eastward propagation.

关键词： Madden–Julian oscillation (MJO) nudging technique Weather Research and Forecasting (WRF) model vertical moisture structure

A Catalog of 13CO Clumps from the MWISP in l=10°–20°

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Research in Astronomy and Astrophysics 2024年第5期24卷 218-234页

作者： xiaoyu Luo Sheng Zheng Zhibo Jiang Zhiwei Chen yao Huang Shuguang Zeng Xiangyun Zeng Rui Zhang Chen Long Guangrong Zhou Jinbo Hu Center for Astronomy and Space Sciences China Three Gorges UniversityYichang 443000China College of Electrical Engineering and New Energy China Three Gorges UniversityYichang 443000China College of Science China Three Gorges UniversityYichang 443000China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China

In this study, we present a catalog of molecular clumps extracted from 13CO(J=1-0) emission data of the Milky Way Imaging Scroll Painting(MWISP) project. The data covers the inner Milky Way within the longitude range10°≤l≤20° and the latitude strip of |b|≤ 5°. 25. The workflow for the extraction of clumps, namely Facet-SS-3DClump, consists of two parts: the identification of clump candidates and their verification. First, Facet-SS-3DClump employs FacetClumps to identify clump candidates. Subsequently, high-confidence clumps are obtained by cross-matching with the clumps detected by other algorithms, such as dendrogram. Second, these high-confidence clumps are used as prior knowledge to train a semi-supervised deep clustering approach, SS-3D-Clump, which is applied to verify clump candidates detected by FacetClumps, providing confidence levels for the molecular clumps. Finally, the catalog comprising 18,757 molecular clumps was obtained using Facet-SS-3D-Clump, and the catalog is 90% complete above 37 K km s^(-1). We observe a significant deviation of the mean Galactic latitude for clumps within |b|≤ 2° from the midplane, with b=-0°.110. We found that 82.3% of the dust clumps correspond to 13CO clumps by matching with Herschel infrared dust clumps. In the future, Facet-SS-3D-Clump will be applied to detect 13CO clumps in the entire MWISP data.

关键词： ISM molecules methods data analysis-stars formation

Superior effectiveness and acceptability of saliva samples for the detection of SARS-CoV-2 in China

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Biosafety and Health 2024年第2期6卷 88-91页

作者： Hui yao Ying Shen Zhichao Liang xiaoyu Xue Chenxi Zhao Xiang Xu Yuxin Cai Yonghong Liu Wei Zhang Yang Pan Xiaoli Wang Bejing Office of Global Health Beijing Center for Disease Prevention and ControlBejing 100013China Institute for Infectious Disease and Endemic Disease Control Beijing Center for Disease Prevention and ControlBejing 100013China National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases Bejing Ditan HospitalCapital Medical UniversityBejing 100015China Center for Drug Evaluation National Medical Products AdministrationBejing 100176China School of Public Health Capital Medical UniversityBeijing 100069China

In response to problems of poor sampling quality,low sensitivity,and high demand for medical personnel regarding the current severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)oropharyngeal(OP)swab sampling used in China,we aimed to evaluate the diagnostic performance and acceptability of saliva-based nucleic acid amplification tests(NAATs)in China.The results showed that,using nasopharyngeal(NP)swab results as the gold standard,the overall sensitivities for saliva specimens and OP swabs were 93.3%and 85.0%,the specificities were 92.6%and 93.8%,respectively.The results of an acceptability survey showed that the scores for saliva,OP,and NP samples were 9.46±1.69,8.11±2.42,and 4.58±3.82 out of 10,respectively,with significant differences among the three groups(P

关键词： SARS-CoV-2 Saliva sample Sensitivity Acceptability

Toward Establishing a Low-cost UAV Coordinated Carbon Observation Network(LUCCN):First Integrated Campaign in China

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Advances in Atmospheric Sciences 2024年第1期41卷 1-7页

作者： Dongxu YANG Tonghui ZHAO Lu yao Dong GUO Meng FAN xiaoyu REN Mingge LI Kai WU Jing WANG Zhaonan CAI Sisi WANG Jiaxu GUO Liangfu CHEN Yi LIU Carbon Neutrality Research Center(CNRC) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Key Laboratory of Middle Atmospheric Physics and Global Environment Observation(LAGEO) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Remote Sensing Science Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100101China National Remote Sensing Center of China Beijing 100036China The Administrative Center for China’s Agenda 21 Beijing 100862China

In this study,we introduce our newly developed measurement-fed-perception self-adaption Low-cost UAV Coordinated Carbon Observation Network(LUCCN)prototype.The LUCCN primarily consists of two categories of instruments,including ground-based and UAV-based in-situ measurement.We use the GMP343,a low-cost non-dispersive infrared sensor,in both ground-based and UAV-based instruments.The first integrated measurement campaign took place in Shenzhen,China,4 May 2023.During the campaign,we found that LUCCN’s UAV component presented significant data-collecting advantages over its ground-based counterpart owing to the relatively high altitudes of the point emission sources,which was especially obvious at a gas power plant in Shenzhen.The emission flux was calculated by a crosssectional flux(CSF)method,the results of which differed from the Open-Data Inventory for Anthropogenic Carbon dioxide(ODIAC).The CSF result was slightly larger than others because of the low sampling rate of the whole emission cross section.The LUCCN system will be applied in future carbon monitoring campaigns to increase the spatiotemporal coverage of carbon emission information,especially in scenarios involving the detection of smaller-scale,rapidly varying sources and sinks.

关键词： CO_(2) measurement networks power station carbon emission cross-sectional flux method

金纳米粒子-金单晶微米片自由碰撞行为中“热点”限域空间内的表面增强拉曼光谱研究

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化学学报 2024年第3期82卷 281-286页

作者：杨青刘肖宇王晨徐敏敏姚建林苏州大学材料与化学化工学部苏州215123

纳米粒子的自由运动及与其他介质的相互作用研究已成为纳米粒子应用拓展的重要领域,特别是动态行为的实时监测仍然是目前亟待解决的难题.本工作基于表面增强拉曼光谱(SERS)技术及布朗运动下Au纳米粒子与Au单晶微米片碰撞过程中“热点”... 详细信息

纳米粒子的自由运动及与其他介质的相互作用研究已成为纳米粒子应用拓展的重要领域,特别是动态行为的实时监测仍然是目前亟待解决的难题.本工作基于表面增强拉曼光谱(SERS)技术及布朗运动下Au纳米粒子与Au单晶微米片碰撞过程中“热点”的形成,以苯硫酚(TP)为探针分子,实现了碰撞过程中Au纳米粒子自由运动行为的实时监测和动态SERS研究.通过对检测到SERS强度轨迹的“尖峰”及所含“单峰”和“簇峰”的统计分析,深入解析了纳米粒子的微观运动本质及影响因素.结果表明,“尖峰”主要来源于纳米粒子与平面的可逆碰撞所形成的“热点”对SERS的贡献.“单峰”对应Au纳米粒子与平面碰撞后快速离开Au片表面,“簇峰”对应Au纳米粒子与平面碰撞后在Au片表面短暂停留然后离开或可能多个粒子连续碰撞的过程.“尖峰”内多个TP的SERS光谱谱峰的相对强度不同,并表现出振动模式的依赖性,伸缩振动模式出现几率更高,主要来源于动态碰撞过程中“热点”限域空间内分子的取向不同.该研究实现了纳米粒子动态研究,有利于理解纳米粒子的微观运动本质,为研究碰撞过程中“热点”限域空间内动态表界面化学反应奠定基础.

关键词：表面增强拉曼光谱碰撞苯硫酚 “热点” 浓度

Effect of cooling rate on phosphorus segregation behavior and the corresponding precipitation of γ’’ and γ’ phases in IN718 alloy

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Journal of Materials Science & Technology 2019年第7期35卷 1485-1490页

作者： Anwen Zhang Sha Zhang Fang Liu Feng Qi xiaoyu yao Yuanguo Tan Dan Jia Wenru Sun Institute of Metal Research Chinese Academy of SciencesShenyang 110016China College of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Effect of segregation behaviors of P at different cooling rates on the precipitation of γ" and γ' phases and the corresponding strength are investigated. The precipitation of γ" and γ' phases during cooling is sensi-tive to P concentration. With increasing the concentration of Pf the amount of γ" and γ' particles increases after air cooling. With decreasing the cooling rate, the accelerating effect of P on the precipitation of γ" and γ' phases decreased first and then increased, which demonstrates the concentration of P dissolved in the grain interior decreases first and then increases. The different effects of P on γ"and γ' phases with different cooling rates were analyzed by the kinetic characteristic of nonequilibrium grain-boundary seg-regation. The characteristic of nonequilibrium grain-boundary segregation of P in superalloy is further confirmed, and the phenomenon caused by critical cooling rate is captured.

关键词： Phosphorus IN718alloy Segregation behavior γ" and γ' phases

Erratum to:Deriving Temporal and Vertical Distributions of Methane in Xianghe Using Ground-based Fourier Transform Infrared and Gas-analyzer

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Advances in Atmospheric Sciences 2024年第2期41卷 377-377页

作者： Denghui JI Minqiang ZHOU Pucai WANG Yang YANG Ting WANG xiaoyu SUN Christian HERMANS Bo yao Gengchen WANG Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Royal Belgian Institute for Space Aeronomy Brussels 1180Belgium University of Chinese Academy of Sciences Beijing 100049China Meteorological Observation Center China Meteorological AdministrationBeijing 100081China

“Diurnal variation of CH4 at the surface from spring to winter.The time units are in local time(+8 h UTC).The error bar is 1σfor all the observed hourly mean data within that season at that local time.”in the caption of Fig.8 on Page 604 should be“Diurnal variation of CH4 at the surface from spring to winter.The time units are in UTC.The error bar is 1σfor all the observed hourly mean data within that season at that local time.”

关键词： winter season Infrared

Development and validation of an emergency bloodstream infection score for predicting in-hospital mortality in patients with community-acquired bloodstream infections

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World Journal of Emergency Medicine 2023年第4期14卷 280-286页

作者： Xinlei Wang yao Sun xiaoyu Ni Shu Zhang Department of Emergency West China HospitalSichuan UniversityChengdu 610041Chiha

BACKGROUND:Community-acquired bloodstream infections(CABSIs)are common in the emergency departments,and some progress to sepsis and even lead to death.However,limited information is available regarding the prediction of patients with high risk of death.METHODS:The Emergency Bloodstream Infection Score(EBS)for CABSIs was developed to visualize the output of a logistic regression model and was validated by the area under the curve(AUC).The Mortality in Emergency Department Sepsis(MEDS),Pitt Bacteremia Score(PBS),Sequential Organ Failure Assessment(SOFA),quick Sequential Organ Failure Assessment(qSOFA),Charlson Comorbidity Index(CCI),and McCabe–Jackson Comorbid Classification(MJCC)for patients with CABSIs were computed to compare them with EBS in terms of the AUC and decision curve analysis(DCA).The net reclassification improvement(NRI)index and integrated discrimination improvement(IDI)index were compared between the SOFA and EBS.RESULTS:A total of 547 patients with CABSIs were included.The AUC(0.853)of the EBS was larger than those of the MEDS,PBS,SOFA,and qSOFA(all P<0.001).The NRI index of EBS in predicting the in-hospital mortality of CABSIs patients was 0.368(P=0.04),and the IDI index was 0.079(P=0.03).DCA showed that when the threshold probability was<0.1,the net benefit of the EBS model was higher than those of the other models.CONCLUSION:The EBS prognostic models were better than the SOFA,qSOFA,MEDS,and PBS models in predicting the in-hospital mortality of patients with CABSIs.

关键词： Community-acquired bloodstream infection Risk factors In-hospital mortality Emergency department