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Optimal Liquidation Strategy of Multi-assets Based on Minimum Loss Probability

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Journal of Systems Science and Systems Engineering 2020年第5期29卷 555-571页

作者： Qixuan luo Can jia Shaobo Zhao Handong Li School of Systems Science Beijing Normal UniversityBeijing 100875China School of Government Beijing Normal UniversityBeijing 100875China

Based on the minimum loss probability criterion,this paper discusses the optimal strategy in multi-asset ***,we give the framework of the multi-asset liquidation problem and obtain the boundary conditions of the optimal liquidation strategy under the assumption of linear price impact functions and transform the multi-asset liquidation problem into the portfolio liquidation *** this basis,the asymptotic solution and numerical solution of the optimal liquidation strategy are ***,we simulate the trajectories of the optimal liquidation strategy and analyze the effects of parameters changes.

关键词： Minimum loss probability multi-asset liquidation permanent impact temporary impact optimal liquidation strategy

Estimation and testing of linkages between forest structure and rainfall interception characteristics of a Robinia pseudoacacia plantation on China’s Loess Plateau

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Journal of Forestry Research 2022年第2期33卷 529-542页

作者： Changkun Ma Yi luo Mingan Shao Xiaoxu jia State Key Laboratory of Eco-Hydraulics in Northwest Arid Region Xian University of TechnologyXianChina Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100190China

Understanding the interaction between canopy structure and the parameters of interception loss is essential in predicting the variations in partitioning rainfall and water resources as affected by changes in canopy structure and in implementing water-based management in semiarid forest *** this study,seasonal variations in rainfall interception loss and canopy storage capacity as driven by canopy structure were predicted and the linkages were tested using seasonal filed *** study was conducted in nine 50 m×50 m Robinia pseudoacacia plots in the semiarid region of China’s Loess *** rain-fall,throughfall and stemflow were measured in seasons with and without leaves in 2015 and *** show that measured average interception loss for the nine plots were 17.9% and 9.4% of gross rainfall during periods with leaves (the growing season) and without leaves, respectively. Average canopy storage capacity estimated using an indirect method was 1.3 mm in the growing season and 0.2 mm in the leafless season. Correlations of relative interception loss and canopy storage capacity to canopy variables were highest for leaf/wood area index (LAI/WAI) and canopy cover, fol-lowed by bark area, basal area, tree height and stand density. Combined canopy cover, leaf/wood area index and bark area multiple regression models of interception loss and canopy storage capacity were established for the growing season and in the leafless season in 2015. It explained 97% and 96% of the variations in relative interception loss during seasons with and without leaves, respectively. It also explained 98% and 99% of the variations in canopy storage capacity during seasons with and without leaves, respectively. The empiri-cal regression models were validated using field data col-lected in 2016. The models satisfactorily predicted relative interception loss and canopy storage capacity during seasons with and without leaves. This study provides greater under-standing a

关键词： Rainfall interception loss Canopy storage Canopy structure Regression models China’s Loess Plateau

Psychoactive Substance Use and the Impact on the AIDS Epidemic Among the MSM Population:a Meta-Analysis—Worldwide,2014-2023

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China CDC weekly 2024年第42期6卷 1086-1092,I0001-I0006页

作者： Donghang luo Jie Xu wei luo National Center for AIDS/STD Control&Prevention Chinese Center for Diseases Control and PreventionBeijingChina

What is already known about this topic?There is a correlation between psychoactive substance use and heightened human immunodeficiency virus(HIV)susceptibility in men who have sex with men(MSM)populations,although the precise impact on transmission risk remains *** is added by this report?In MSM populations,rush poppers and amphetamines are widely used,with rates of 10.91%and 9.97%.In China,rush poppers usage is notably higher at 47.26%.For other regions and coutries,amphetamines(12.86%),rush poppers(3.62%),and GHB(3.34%)are most ***,17%of MSM use psychoactive substances,with higher HIV risk from amphetamines[Odds ratio(OR)3.06]compared to rush poppers(OR 1.51)and general substances(OR 1.76).What are the implications for public health practice?This study supports the idea that targeting specific regions and types of psychoactive substances for reduction among MSM populations can help decrease HIV transmission as well as promote prevention strategies.

关键词： prevention precise Impact

GPS: graph contrastive learning via multi-scale augmented views from adversarial pooling

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Science China(Information Sciences) 2025年第1期 145-158页

作者： wei JU Yiyang GU Zhengyang MAO Ziyue QIAO Yifang QIN Xiao luo Hui XIONG Ming ZHANG School of Computer Science National Key Laboratory for Multimedia Information ProcessingPeking University Artificial Intelligence Thrust The Hong Kong University of Science and Technology Department of Computer Science University of California

Self-supervised graph representation learning has recently shown considerable promise in a range of fields, including bioinformatics and social networks. A large number of graph contrastive learning approaches have shown promising performance for representation learning on graphs, which train models by maximizing agreement between original graphs and their augmented views(i.e., positive views). Unfortunately, these methods usually involve pre-defined augmentation strategies based on the knowledge of human experts. Moreover, these strategies may fail to generate challenging positive views to provide sufficient supervision signals. In this paper, we present a novel approach named graph pooling contrast(GPS) to address these *** by the fact that graph pooling can adaptively coarsen the graph with the removal of redundancy, we rethink graph pooling and leverage it to automatically generate multi-scale positive views with varying emphasis on providing challenging positives and preserving semantics, i.e., strongly-augmented view and weakly-augmented view. Then, we incorporate both views into a joint contrastive learning framework with similarity learning and consistency learning, where our pooling module is adversarially trained with respect to the encoder for adversarial robustness. Experiments on twelve datasets on both graph classification and transfer learning tasks verify the superiority of the proposed method over its counterparts.

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基于双目视觉和改进YOLOv8n的火灾检测及测距方法

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陕西科技大学学报 2025年第1期43卷 152-160页

作者：刘振董绍江罗家元孙世政潘学娇重庆交通大学机电与车辆工程学院重庆400074

针对火灾检测出现的漏检误检、模型参数量大及定位困难的问题,基于双目视觉和改进YOLOv8n提出了一种轻量化火灾检测及测距方法.通过双目相机拍摄图片,使用改进的检测算法YOLOv8n-AEM和现有的测距算法SGBM进行检测和测距.首先,在主干网... 详细信息

针对火灾检测出现的漏检误检、模型参数量大及定位困难的问题,基于双目视觉和改进YOLOv8n提出了一种轻量化火灾检测及测距方法.通过双目相机拍摄图片,使用改进的检测算法YOLOv8n-AEM和现有的测距算法SGBM进行检测和测距.首先,在主干网络中引入可变核卷积AKConv和EMA注意力机制,通过构建不规则卷积核有效提取火灾的特征;然后,在颈部网络中构建C2f-SCConv模块,通过特征重组降低模型参数,提高检测速度;其次,基于最小点距离改进损失函数,解决火源与光源重叠导致的漏检与误检问题;最后,增加小目标检测头,提高对小火苗的检测能力.实验结果表明,改进后的检测算法P、R、mAP分别为83.6%、76.4%、83.6%,分别提高了2.5%、3.6%、4.8%;参数量和模型大小分别为2.54 M和5.1 MB,分别降低了15.3%和15%;测距精度误差不超过2.5%,证明改进的方法能准确完成火灾的检测及测距.

关键词：火灾检测双目视觉测距 YOLOv8n 轻量化

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Effect of Ti Additions on Mechanical and Thermodynamic Properties of W-Ti Alloys:A First-principles Study

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期 246-257页

作者：张建 NIE wei HUANG Jin ZHU Ke LIU Ruxia 张睿智 luo Guoqiang SHEN Qiang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Institute for Carbon Neutrality University of Science and Technology Beijing

The mechanical and thermodynamic properties of W-Ti alloys (including W15Ti1,W14Ti2,W12Ti4and W8Ti8alloys) were investigated by the first-principles approach based on density functional *** results indicate that W-Ti alloys except W8Ti8are thermodynamically *** modulus and hardness of W-Ti alloys are smaller than those of pure tungsten and gradually decrease with increasing Ti ***,their B/G ratios and Poisson's ratios exceed those of pure tungsten,suggesting that the introduction of Ti decreases the mechanical strength while enhancing the ductility of W-Ti *** thermal expansion coefficients for W-Ti alloys all surpass those of pure tungsten,indicating that the introduction of titanium exacerbates the thermal expansion behavior of W-Ti ***,elevated pressure has the capacity to suppress the thermal expansion tendencies in titanium-doped tungsten *** study offers theoretical insights for the design of nuclear materials by exploring the mechanical and thermodynamic properties of W-Ti alloys.

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Characteristics of nonlinear evolution of wavepackets in boundary layers

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Science China(Physics,Mechanics & Astronomy) 2013年第2期56卷 250-256页

作者： YU Min luo JiSheng LI jia Department of Mechanics Tianjin University

The nonlinear evolution of a finite-amplitude disturbance in a 3-D supersonic boundary layer over a cone was investigated recently by Liu et al. using direct numerical simulation （DNS）. It was found that certain small-scale 3-D disturbances amplified rapidly. These disturbances exhibit the characteristics of second modes, and the most amplified components have a well- defined spanwise wavelength, indicating a clear selectivity of the amplification. In the case of a cone, the three-dimensionality of the base flow and the disturbances themselves may be responsible for the rapid amplification. In order to ascertain which of these two effects are essential, in this study we carried out DNS of the nonlinear evolution of a spanwise localized disturbance （wavepacket） in a flat-plate boundary layer. A similar amplification of small-scale disturbances was observed, suggesting that the direct reason for the rapid amplification is the three-dimensionality of the disturbances rather than the three-dimensional nature of the base flow, even though the latter does alter the spanwise distribution of the disturbance. The rapid growth of 3-D waves may be attributed to the secondary instability mechanism. Further simulations were performed for a wavepacket of first modes in a supersonic boundary layer and of Tollmien-Schlichting （T-S） waves in an incompressible boundary layer. The re- suits show that the amplifying components are in the band centered at zero spanwise wavenumber rather than at a finite spanwise wavenumber. It is therefore concluded that the rapid growth of 3-D disturbances in a band centered at a preferred large spanwise wavenumber is the main characteristic of nonlinear evolution of second mode disturbances in supersonic boundary layers.

关键词： boundary layer wavepacket nonlinear evolution second mode spanwise small-scale disturbance

Nucleolar histone deacetylases HDT1,HDT2,and HDT3 regulate plant reproductive development

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Journal of Genetics and Genomics 2022年第1期49卷 30-39页

作者： Yu luo Dong-Qiao Shi Peng-Fei jia Yuan Bao Hong-Ju Li wei-Cai Yang State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China College of Advanced Agricultural Sciences University of Chinese Academy of SciencesBeijing 100049China

Nucleolus is a membrane-less organelle where ribosomes are assembled, and ribosomal RNAs(r RNAs)transcribed and processed. The assembled ribosomes composed of ribosomal proteins and r RNAs synthesize proteins for cell survival. In plants, the loss of nucleolar ribosomal proteins often causes gametophytically or embryonically lethality. The amount of r RNAs are under stringent regulation according to demand and partially switched off by epigenetic modifications. However, the molecular mechanism for the selective activation or silencing is still unclear, and the transcriptional coordination of r RNAs and ribosomal proteins is also unknown. Here, we report the critical role of three Arabidopsis nucleolar proteins HDT1,HDT2, and HDT3 in fertility and transcription of r DNAs and r RNA processing-related genes through histone acetylation. This study highlights the important roles of transcriptional repression of ribosome biogenesisrelated genes for plant reproductive development.

关键词： Histone deacetylase rRNAs Ribosome Reproductive development

Graft cholangiopathy: etiology, diagnosis, and therapeutic strategies

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Hepatobiliary & Pancreatic Diseases International 2014年第1期13卷 10-17页

作者： Ying luo Wen-Bin Ji wei-Dong Duan Sheng Ye jia-Hong Dong Department of Hepatobiliary Surgery Chinese PLA General Hospital

BACKGROUND: Graft cholangiopathy has been recognized as a significant cause of morbidity, graft loss, and even mortality in patients after orthotopic liver transplantation. The aim of this review is to analyze the etiology, pathogenesis, diagnosis and therapeutic strategies of graft cholangiopathy after liver transplantation. DATA SOURCE: A PubMed database search was performed to identify articles relevant to liver transplantation, biliary complications and cholangiopathy. RESULTS: Several risk factors for graft cholangiopathy after liver transplantation have been identified, including ischemia/ reperfusion injury, cytomegalovirus infection, immunological injury and bile salt toxicity. A number of strategies have been attempted to prevent the development of graft cholangiopathy, but their efficacy needs to be evaluated in large clinical studies. Non-surgical approaches may offer good results in patients with extrahepatic lesions. For most patients with complex hilar and intrahepatic biliary abnormalities, however, surgical repair or re-transplantation may be required. CONCLUSIONS: The pathogenesis of graft cholangiopathy after liver transplantation is multifactorial. In the future, more efforts should be devoted to the development of more effective preventative and therapeutic strategies against graft cholangiopathy.

关键词： liver transplantation bile ducts complications ischemia/reperfusion injury therapy