检索结果-南通市图书馆

Distributed optimal consensus control for multiagent systems based on event-triggered and prioritized experience replay strategies

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2025年第1期68卷 306-321页

作者： Cuijuan ZHANG Lianghao JI Shasha YANG xing guo Huaqing LI Chongqing Key Laboratory of Image Cognition Chongqing University of Posts and Telecommunications Key Laboratory of Intelligent Perception and Computing of Anhui Province Anqing Normal University College of Electronic and Information Engineering Southwest University

This study uses event-triggered(ET) and reinforcement learning methods to investigate the optimal consensus control problem for cooperative-competitive multiagent systems. It proposes a novel distributed ET control strategy, which relies on a prioritized experience replay(PER) policy. This strategy not only conserves communication resources but also ensures acceptable system performance. To implement the proposed method, actor-critic(AC) dual-structured neural networks(NNs) are used to approximate the value function and control policy. In the AC NNs, the weight estimates for the NNs are updated at the moment of event triggering, resulting in a nonperiodic weight adjustment pattern. This approach decreases the computational cost in comparison with the traditional ET mechanism. The PER-based ET mechanism makes full use of valid historical data and effectively establishes a balance between system performance and communication resource ***, it does not require the following two conditions in most existing studies:(1) requirement of the system dynamics model to be known, and(2) persistent excitation. In addition, Zeno behavior is excluded from this study. Finally, a simulation is conducted to confirm the validity of the suggested approach.

关键词： multiagent systems event-triggered mechanism prioritized experience replay dual-structured neural networks optimal consensus control

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

三峡建库前后长江中游河道输沙率变化分析

长江科学院院报 2022年第8期39卷 10-16页

作者：姚仕明邢国栋陈栋长江科学院水利部长江中下游河湖治理与防洪重点实验室武汉430010

三峡建库后,水库下游河道含沙水流长期处于严重次饱和状态,输沙由相对平衡状态转变为不平衡状态,输沙强度较自然条件下发生显著变化。根据三峡水库蓄水运用前后(1992—2017年)长江中游主要水文站断面、床沙与水文资料,从输沙率变化、床... 详细信息

三峡建库后,水库下游河道含沙水流长期处于严重次饱和状态,输沙由相对平衡状态转变为不平衡状态,输沙强度较自然条件下发生显著变化。根据三峡水库蓄水运用前后(1992—2017年)长江中游主要水文站断面、床沙与水文资料,从输沙率变化、床沙粒径变化、平滩流量等角度研究长江中游河道复式断面输沙强度问题,得出以下结论:三峡水库蓄水运用后,进入下游河道的泥沙大幅度较少,长江中游沿程水文站同流量级输沙率明显减少;床沙粒径沿程出现不同程度的粗化,其中荆江河段粗化最为明显,螺山至武汉河段略有粗化;螺山站和汉口站在自然条件下平滩流量附近输沙强度出现峰值,对应的水流挟沙能力为极大值。

关键词：水库下游复式河槽输沙率平滩流量输沙能力

维普期刊数据库博看期刊

Comparison of seven screening methods in the diagnosis of bladder cancer

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2006年第21期119卷 1763-1771页

作者： SUN Yi HE Da-lin MA Qiang WAN xing-yang ZHU guo-dong LI Lei LUO Yong HE Hui YANG Lin Institute of Urology First Affiliated Hospital of Medical School Xi＇an Jiaotong University Xi＇an 710061 China

Background We compared the validity （evaluated by sensitivity and specificity）, reliability （evaluated by reproducibility） and yield （evaluated by predictive value, examining complexity and cost） of individual and combined tests for bladder tumour antigen stat （BTAstat）, nuclear matrix protein 22 （NMP22）, hyaluronic acid （HA）, survivin, CD44v6, vascular endothelial growth factor （VEGF）, and voided urine cytology （VUC） in detecting bladder cancer. And at the same time we evaluated the clinical value of these seven detecting methods in the diagnosis of bladder cancer. Methods The six markers and VUC were detected in the urine of cancer group （151 patients with bladder cancer） and two control groups （50 patients with benign urological diseases and 50 healthy controls）. The sensitivity, specificity, predictive value, reproducibility, examining complexity and checking cost of each marker and combined markers were calculated. Results There was a significant difference between bladder cancer group and the two control groups. The sensitivity, specificity and positive predictive value were as follows： VUC （36.4%, 100.0%, 100%）, BTAstat （76.8%, 87.0%, 89.9%）, NMP22 （77.5%, 81.0%, 86.0%）, HA （82.8%, 83.0%, 88.0%）, survivin （70.2%, 85.0%, 87.6%）, CD44v6 （50.3%, 79.0%, 78.4%）, and VEGF （68.2%, 93.0%, 93.6%）. The highest sensitivities were 91.4% for NMP22＋BTAstat and HA＋NMP22, whereas the combined marker with the lowest sensitivity （62.3%） was VUC＋CD44v6. The highest specificity was 93.0% for the combined use of VUC＋VEGF and HA＋CD44v6 had the lowest specificity （73.0%）. The most convenient examining method was the detection for BTAstat, the lowest cost was the detection for HA, and the best reproducibility were the detection for BTAstat and VUC. Conclusions All the markers have obvious clinical value in diagnosis of bladder cancer. The use of BTAstat＋HA or NMP22＋BTAstat are better examining methods in terms of validity, reliability, and yield.

关键词： tumour markers, biological bladder neoplasms urine diagnosis

在线全文

学校读者我要写书评

暂无评论

政府公司——我国PPP项目理想模式之证成

税务与经济 2017年第3期 18-23页

作者：邢栋郭晓珍吉林大学法学院吉林长春130012 厦门理工学院经济管理学院福建厦门361024

近年来,PPP项目在我国发展迅速,已经作为一种重要的公共产品提供方式在全国各地推广。但在其迅速发展的同时,如何为之选择科学有效的载体并依法运行,成为学界探索的热点。源自美国的政府公司,以其灵活的机制、科学的授权、公平的分配、... 详细信息

近年来,PPP项目在我国发展迅速,已经作为一种重要的公共产品提供方式在全国各地推广。但在其迅速发展的同时,如何为之选择科学有效的载体并依法运行,成为学界探索的热点。源自美国的政府公司,以其灵活的机制、科学的授权、公平的分配、适度的监管等特征,应该成为我国PPP项目建设的良好载体的选择之一。因此,在法律保障层面,应在立法、执法、司法等方面为政府公司这一模式进入PPP创造条件。在赋权与控权相结合的权利和权力博弈中,实现项目的健康发展。

关键词： PPP项目政府公司公法人公共产品

Induced neural stem cells regulate microglial activation through Akt-mediated upregulation of CXCR4 and Crry in a mouse model of closed head injury

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第5期20卷 1416-1430页

作者： Mou Gao Qin dong Dan Zou Zhijun Yang Lili guo Ruxiang Xu Department of Neurosurgery Sichuan Academy of Medical Sciences and Sichuan Provincial People’s HospitalSchool of MedicineUniversity of Electronic Science and Technology of ChinaChengduSichuan ProvinceChina Department of Neurosurgery Chinese PLA General HospitalBeijingChina Department of Neurology Fu Xing HospitalCapital Medical UniversityBeijingChina

Microglial activation that occurs rapidly after closed head injury may play important and complex roles in neuroinflammation-associated neuronal damage and *** previously reported that induced neural stem cells can modulate the behavior of activated microglia via CXCL12/CXCR4 signaling,influencing their activation such that they can promote neurological ***,the mechanism of CXCR4 upregulation in induced neural stem cells remains *** this study,we found that nuclear factor-κB activation induced by closed head injury mouse serum in microglia promoted CXCL12 and tumor necrosis factor-αexpression but suppressed insulin-like growth factor-1 ***,recombinant complement receptor 2-conjugated Crry(CR2-Crry)reduced the effects of closed head injury mouse serum-induced nuclear factor-κB activation in microglia and the levels of activated microglia,CXCL12,and tumor necrosis factor-α.Additionally,we observed that,in response to stimulation(including stimulation by CXCL12 secreted by activated microglia),CXCR4 and Crry levels can be upregulated in induced neural stem cells via the interplay among CXCL12/CXCR4,Crry,and Akt signaling to modulate microglial *** agreement with these in vitro experimental results,we found that Akt activation enhanced the immunoregulatory effects of induced neural stem cell grafts on microglial activation,leading to the promotion of neurological recovery via insulin-like growth factor-1 secretion and the neuroprotective effects of induced neural stem cell grafts through CXCR4 and Crry upregulation in the injured cortices of closed head injury ***,these beneficial effects of Akt activation in induced neural stem cells were positively correlated with the therapeutic effects of induced neural stem cells on neuronal injury,cerebral edema,and neurological disorders post–closed head *** conclusion,our findings reveal that Akt activation may enhance the immunoregulatory effects of induced neura

关键词： Akt signaling cerebral edema closed head injury Crry CXCR4 induced neural stem cell microglia neuroinflammation

Graphene Aerogel Composites with Self‑Organized Nanowires‑Packed Honeycomb Structure for Highly Efficient Electromagnetic Wave Absorption

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第2期17卷 533-547页

作者： Xiao You Huiying Ouyang Ruixiang Deng Qiuqi Zhang Zhenzhong xing Xiaowu Chen Qingliang Shan Jinshan Yang Shaoming dong State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050People’s Republic of China Key Laboratory of Inorganic Coating Materials CAS Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050People’s Republic of China Structural Ceramics and Composites Engineering Research Center Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050People’s Republic of China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049People’s Republic of China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210People’s Republic of China School of Materials Science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310018People’s Republic of China University of Chinese Academy of Sciences Beijing 100039People’s Republic of China

With vigorous developments in nanotechnology,the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave ***,a hierarchical porous structure and composite heterogeneous interface are constructed successfully to optimize the electromagnetic loss *** macro–micro-synergistic graphene aerogel formed by the ice template‑assisted 3D printing strategy is cut by silicon carbide nanowires(SiC_(nws))grown in situ,while boron nitride(BN)interfacial structure is introduced on graphene *** unique composite structure forces multiple scattering of incident EMWs,ensuring the combined effects of interfacial polarization,conduction networks,and magnetic-dielectric ***,the as-prepared composites present a minimum reflection loss value of−37.8 dB and a wide effective absorption bandwidth(EAB)of 9.2 GHz(from 8.8 to 18.0 GHz)at 2.5 ***,relying on the intrinsic high-temperature resistance of SiC_(nws) and BN,the EAB also remains above 5.0 GHz after annealing in air environment at 600℃ for 10 h.

关键词： Hierarchical porous structure Interface High-temperature resistance Graphene aerogel composites Electromagnetic wave absorption

在线全文

学校读者我要写书评

暂无评论

一α-混合序列的矩不等式及其应用

江西师范大学学报（自然科学版） 2008年第5期32卷 585-588页

作者：黄劲邢国东梧州学院法律与公共管理系广西梧州543002 湖南科技学院数学系永州湖南425100

该文给出了一α-混合随机变量序列部分和的矩不等式,此不等式是用矩的和作为其上界.在它的应用方面,探讨了加权和的收敛性,所得的结果改进了许(2002)所对应的结果.

关键词： α-混合矩不等式加权和

On Bounds of Value-at-Risk and Convex Risk Measure of Portfolio of Weighted Dependent Risks

在线全文

学校读者我要写书评

暂无评论

Chinese Quarterly Journal of Mathematics 2018年第4期33卷 421-433页

作者： xing guo-dong LI Xiao-hu School of Mathematics & Computer Science Shangrao Normal University Shangrao 334001China School of Mathematical Sciences Xiamen University Xiamen 361005China Department of Mathematical Sciences Stevens Institute of Technology HobokenNJ 07030USA

This note analytically derives lower and upper bounds for Value-at-Risk and convex risk measures of a portfolio of weighted risks in the context of positive *** bounds serve as extensions of the corresponding ones due to Bignozzi et al.(2015).Also, DU-spread of value-at-risk and expected shortfall of Bignozzi et al.(2015) are also improved in some particular cases.

关键词： DU-spread Expected shortfall Lower orthant order Upper orthant order Weakly conditional increasing in sequence order

Small extracellular vesicles derived from human induced pluripotent stem cell-differentiated neural progenitor cells mitigate retinal ganglion cell degeneration in a mouse model of optic nerve injury

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第2期20卷 587-597页

作者： Tong Li Hui-Min xing Hai-dong Qian Qiao Gao Sheng-Lan Xu Hua Ma Zai-Long Chi State Key Laboratory of Ophthalmology Optometry and Visual ScienceEye HospitalWenzhou Medical UniversityWenzhouZhejiang ProvinceChina National Clinical Research Center for Ocular Diseases Eye HospitalWenzhou Medical UniversityWenzhouZhejiang ProvinceChina

Several studies have found that transplantation of neural progenitor cells(NPCs)promotes the survival of injured ***,a poor integration rate and high risk of tumorigenicity after cell transplantation limits their clinical *** extracellular vesicles(sEVs)contain bioactive molecules for neuronal protection and *** studies have shown that stem/progenitor cell-derived sEVs can promote neuronal survival and recovery of neurological function in neurodegenerative eye diseases and other eye *** this study,we intravitreally transplanted sEVs derived from human induced pluripotent stem cells(hiPSCs)and hiPSCs-differentiated NPCs(hiPSC-NPC)in a mouse model of optic nerve *** results show that these intravitreally injected sEVs were ingested by retinal cells,especially those localized in the ganglion cell *** with hiPSC-NPC-derived sEVs mitigated optic nerve crush-induced retinal ganglion cell degeneration,and regulated the retinal microenvironment by inhibiting excessive activation of *** analysis further revealed that hiPSC-NPC derived sEVs transported neuroprotective and anti-inflammatory miRNA cargos to target cells,which had protective effects on RGCs after optic nerve *** findings suggest that sEVs derived from hiPSC-NPC are a promising cell-free therapeutic strategy for optic neuropathy.

关键词： exosome miRNA neural progenitor cell neurodegeneration neuroinflammation neuroprotection optic nerve crush optic neuropathy retinal ganglion cell small extracellular vesicles