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Trace Projection Transformation： a new method for measurement of debris flow surface velocity fields

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Frontiers of Earth Science 2016年第4期10卷 761-771页

作者： Yan YAN Peng CUI Xiaojun GUO Yonggang GE Key Laboratory of mountain Surface Process and Hazards/Institute of mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China University of Chinese Academy of Sciences Beijing 100049 China center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences Beijing 100101 China

Spatiotemporal variation of velocity is impor- tant for debris flow dynamics. This paper presents a new method, the trace projection transformation, for accurate, non-contact measurement of a debris-flow surface velocity field based on a combination of dense optical flow and perspective projection transformation. The algorithm for interpreting and processing is implemented in C ＋＋ and realized in Visual Studio 2012. The method allows quantitative analysis of flow motion through videos from various angles （camera positioned at the opposite direction of fluid motion）. It yields the spatiotemporal distribution of surface velocity field at pixel level and thus provides a quantitative description of the surface processes. The trace projection transformation is superior to conventional measurement methods in that it obtains the full surface velocity field by computing the optical flow of all pixels. The result achieves a 90% accuracy of when comparing with the observed values. As a case study, the method is applied to the quantitative analysis of surface velocity field of a specific debris flow.

关键词： debris flow surface velocity field spatiotem-poral variation dense optical flow perspective projectiontransformation

Cognition:Accurate and Consistent Linear Log Parsing Using Template Correction

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Journal of Computer Science & Technology 2023年第5期38卷 1036-1050页

作者：田冉刁祖龙姜海洋谢高岗 University of Chinese Academy of Sciences Beijing 100049China Institute of Computing Technology Chinese Academy of SciencesBeijing 100190China Purple mountain Laboratories Nanjing 211111China Computer Network Information center Chinese Academy of SciencesBeijing 100083China

Logs contain runtime information for both systems and users.As many of them use natural language,a typical log-based analysis needs to parse logs into the structured format first.Existing parsing approaches often take two steps.The first step is to find similar words(tokens)or sentences.Second,parsers extract log templates by replacing different tokens with variable placeholders.However,we observe that most parsers concentrate on precisely grouping similar tokens or logs.But they do not have a well-designed template extraction process,which leads to inconsistent accuracy on particular datasets.The root cause is the ambiguous definition of variable placeholders and similar templates.The consequences include abuse of variable placeholders,incorrectly divided templates,and an excessive number of templates over time.In this paper,we propose our online log parsing approach Cognition.It redefines variable placeholders via a strict lower bound to avoid ambiguity first.Then,it applies our template correction technique to merge and absorb similar templates.It eliminates the interference of commonly used parameters and thus isolates template quantity.Evaluation through 16 public datasets shows that Cognition has better accuracy and consistency than the state-of-the-art approaches.It also saves up to 52.1%of time cost on average than the others.

关键词： log analysis log parsing template correction

Experimental and Modeling Study of Forest Fire Effect on Soil Thermal Conductivity

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Pedosphere 2016年第4期26卷 462-473页

作者： Kathleen M.SMITS Elizabeth KIRBY William J.MASSMAN Larry Scott BAGGETT center for the Experimental Study of Subsurface Environmental Processes Department of Civil and Environmental EngineeringColorado School of Mines USDA Forest Service Rocky Mountain Research Station

An understanding of soil thermal conductivity after a wildfire or controlled burn is important to land management and post-fire recovery efforts. Although soil thermal conductivity has been well studied for non-fire heated soils, comprehensive data that evaluate the long-term effect of extreme heating from a fire on the soil thermal conductivity are limited. The purpose of this study was to evaluate the long-term impact of fire on the effective thermal conductivity of soils by directly comparing fire-heated and no-fire control soils through a series of laboratory studies. The thermal conductivity was measured for ten soil samples from two sites within the Manitou Experimental Forest, Colorado, USA, for a range of water contents from saturation to the residual degree of saturation. The thermal conductivity measured was compared with independent estimates made using three empirical models from literature, including the Campbell et al.(1994), Cté and Konrad(2005), and Massman et al.(2008) models. Results demonstrate that for the test soils studied, the thermal conductivity of the fire-heated soils was slightly lower than that of the control soils for all observed water contents.Modeling results show that the Campbell et al.(1994) model gave the best agreement over the full range of water contents when proper fitting parameters were employed. Further studies are needed to evaluate the significance of including the influence of fire burn on the thermal properties of soils in modeling studies.

关键词：土壤有效森林火灾热导率实验室模拟经验模型水含量恢复工作

Environmental drivers of soil microbial activity and diversity along an elevational gradient

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Journal of mountain Science 2022年第5期19卷 1336-1347页

作者： PENG Si-li GE Zhi-wei LIU Gang-cai MAO Ling-feng Co-Innovation center for Sustainable Forestry in Southern China College of Biology and the EnvironmentNanjing Forestry UniversityNanjing 210037China Key Laboratory of mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of ScienceChengdu 610041China

Microbial functional and structural patterns and drivers along elevational gradients have recently received increasing attention.In this study,we examined soil bacterial and fungal community diversity,compositions,and microbial activities(i.e.,soil basal respiration and extracellular enzyme activities)across an elevational gradient from 1148 m to 2080 m(consists of six elevations)in the Yuanmou dry-hot valley located in Southwest China.Environmental factors,including soil temperature,moisture content,pH,soil organic carbon(SOC),total nitrogen(TN),the C/N ratio,total phosphorus(TP),and aboveground plant biomass were also determined.The results showed that soil bacterial alpha diversity(Shannon index)was unaffected by elevation,whereas fungal alpha diversity firstly increased significantly from 1148 m to 1539 m but did not increase further at higher elevations.Bacterial Shannon index was significantly correlated with SOC,whereas fungal Shannon index was remarkably associated with soil temperature.Microbial activity,beta diversities and community composition varied with elevation,but none of them showed a consistent trend.Monte Carlo test revealed that soil moisture followed by temperature,and pH,were the primary drivers of bacterial community composition.Soil fungal community composition significantly depended on soil moisture.Overall,our study suggested bacterial diversity and composition were determined by climatic(moisture and temperature)and edaphic properties(SOC and pH),while fungal diversity and composition were structured mainly by climatic factors.These findings may contribute to a better understanding of microbial responses along elevational gradients in this semi-arid region.

关键词： Bacteria Fungi Composition and diversity Basal respiration Enzyme activity

Coupled Model of Two-phase Debris Flow,Sediment Transport and Morphological Evolution

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Acta Geologica Sinica(English Edition) 2016年第6期90卷 2206-2215页

作者： HE Siming OUYANG Chaojun LIU Wei WANG Dongpo Key laboratory of mountain Hazards and Surface Process Chinese Academy of Science Institute of mountain Hazards and Environment (IMHE) Chinese Academy of Sciences center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology

The volume fraction of the solid and liquid phase of debris flows, which evolves simultaneously across terrains, largely determines the dynamic property of debris flows. The entrainment process significantly influences the amplitude of the volume fraction. In this paper, we present a depth-averaged two-phase debris-flow model describing the simultaneous evolution of the phase velocity and depth, the solid and fluid volume fractions and the bed morphological evolution. The model employs the Mohr–Coulomb plasticity for the solid stress, and the fluid stress is modeled as a Newtonian viscous stress. The interfacial momentum transfer includes viscous drag and buoyancy. A new extended entrainment rate formula that satisfies the boundary momentum jump condition （Iverson and Ouyang, 2015） is presented. In this formula, the basal traction stress is a function of the solid volume fraction and can take advantage of both the Coulomb and velocity-dependent friction models. A finite volume method using Roe’s Riemann approximation is suggested to solve the equations. Three computational cases are conducted and compared with experiments or previous results. The results show that the current computational model and framework are robust and suitable for capturing the characteristics of debris flows.

关键词： debris flows two-phase model sediment transport entrainment rate finite volume method

Discussion on a new paradigm of endogenous security towards 6G networks

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Frontiers of Information Technology & Electronic Engineering 2022年第10期23卷 1421-1450页

作者： Xinsheng JI Jiangxing WU Liang JIN Kaizhi HUANG Yajun CHEN Xiaoli SUN Wei YOU Shumin HUO Jing YANG Department of Computer Science and Technology Tsinghua UniversityBeijing 100084China National Digital Switching System Engineering&Technological R&D center Zhengzhou 450002China Purple mountain Laboratories:Networking Communications and SecurityNanjing 211111China

The sixth-generation mobile communication(6G)networks will face more complex endogenous security problems,and it is urgent to propose new universal security theories and establish new practice norms to deal with theªunknown unknownºsecurity threats in cyberspace.This paper first expounds the new paradigm of cyberspace endogenous security and introduces the vision of 6G cyberspace security.Then,it analyzes the security problems faced by the 6G core network,wireless access network,and emerging associated technologies in detail,as well as the corresponding security technology development status and the integrated development of endogenous security and traditional security.Furthermore,this paper describes the relevant security theories and technical concepts under the guidance of the new paradigm of endogenous security.

关键词： 6G security New paradigm of endogenous security Core network Wireless access network

Characteristics of diffuse pollution of nitrogen and phosphorous from a small town in the hilly area of the central Sichuan Basin,China

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Journal of mountain Science 2016年第2期13卷 292-301页

作者： YANG Xiao-lin SHEN Xi ZHU Bo Key Laboratory of mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of Sciences Safety and Emergency Management Research center Henan Polytechnic University

Hydrological and hydro-chemical monitoring of nitrogen(N) and phosphorus(P) in a small urbanized catchment was conducted in the hilly area of the central Sichuan Basin,China,from 2010 through 2011.The diffuse N and P loadings in different forms of total nitrogen(TN) and phosphorus(TP),dissolved nitrogen(DN) and phosphorus(DP),as well as particulate nitrogen(PN) and phosphorus(PP) were calculated based on runoff discharges and chemical analyses.The results revealed that the diffuse pollution concentrations of TN,DN,PN,TP,DP and PP exhibited large variations during rainfall events,with peak concentrations occurring during the initial period.For all of the measured parameters,the event mean concentrations(EMCs) were observed to clearly vary among rainfall events.The EMCs of TN,DN,PN,TP,DP and PP(for all of the observed rainfall events) were 10.04,6.62,3.42,1.30,0.47 and0.83 mg/L,respectively.The losses of diffuse N and P exhibited clear seasonal patterns and mainly occurred during the period from July through September,when the losses totaled 99.3 and 9.6 kg/ha for TN and TP,respectively,accounting for 75% and 74% of the total annual loadings.The mean annual loadings of TN and TP were 124.6 and 12.9 kg/ha,respectively.The results indicate that residential areas in the hilly areaof the central Sichuan Basin are subject to high diffuse N and P loadings,posing a serious risk to the receiving water quality.Ecological buffering belts are recommended to incorporate into the urbanized catchment to reduce diffuse pollution.

关键词：四川盆地磷扩散丘陵区总氮污染特征小城镇降雨过程氮磷负荷

嫦娥五号高钛玄武岩的矿物化学和三维层析成像分析:对月球深部热演化史的指示

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Science Bulletin 2022年第7期67卷 755-761页

作者：蒋云李晔廖世勇殷宗军徐伟彪 Key Laboratory of Planetary Sciences Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China center for Excellence in Comparative Planetology Chinese Academy of SciencesHefei 230026China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Paleontology&Center for Excellence in Life and PaleoenvironmentChinese Academy of SciencesNanjing 210008China

2020年12月,我国首次月球采样返回任务——嫦娥五号,在月球正面的风暴洋北部一举成功返回了1731 g样品.嫦娥五号着陆区位于年轻的月海平原,远离美国Apollo和苏联Luna任务采样点.这些年轻的月海玄武岩对于揭示月球内部的成分和结构以及... 详细信息

2020年12月,我国首次月球采样返回任务——嫦娥五号,在月球正面的风暴洋北部一举成功返回了1731 g样品.嫦娥五号着陆区位于年轻的月海平原,远离美国Apollo和苏联Luna任务采样点.这些年轻的月海玄武岩对于揭示月球内部的成分和结构以及火山活动历史具有十分重要的科学意义.本文利用高分辨率显微CT、扫描电子显微镜、电子探针等技术对编号为CE5C0000YJYX065的嫦娥五号岩屑样品开展了详细的岩石学、矿物学和三维层析成像研究.结果表明,该样品具有细粒至中粒次辉绿结构,少量橄榄石斑晶分布在由辉石、斜长石、钛铁矿和其他副矿物组成的基质中.样品含有极高丰度的钛铁矿(17.8vol.%),并富含磷酸盐矿物(0.5 vol.%).主要组成矿物的化学成分和演化趋势与Apollo和Luna任务返回的高钛玄武岩高度一致.多项证据表明,不同于目前已报道的嫦娥五号中钛和低钛月海玄武岩类型。CE5C0000YJYX065是一种富集稀土元素的高钛月海玄武岩,由此证明嫦娥五号着陆区发生了多次火山活动,其能量来源可能来自放射性元素的衰变.

关键词：月海玄武岩火山活动磷酸盐矿物辉绿结构矿物化学热演化史月球正面风暴洋

Case fatality rate of coronavirus disease 2019(COVID-19) in Iran-a term of caution

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Asian Pacific Journal of Tropical Medicine 2020年第7期13卷 328-330页

作者： Vahid Rahmanian Mohammad Hasan Rabiee Hamid Sharifi Zoonoses Research center Jahrom University of Medical SciencesJahromIran Department of Epidemiology Faculty of Veterinary MedicineUniversity of TehranTehranIran HIV/STI Surveillance Research center WHO Collaborating Center for HIV SurveillanceInstitute for Futures Studies in HealthKerman University of Medical SciencesKermanIran

Coronavirus disease 2019 (COVID-19) has spread to 72 countries by the time of writing this report on 4th March 2020[1].On 20th February 2020,the first two confirmed deaths from COVID-19were reported in Iran.Till 4th March 2020,2 922 confirmed and92 death cases have also been reported till 4th March 2020 in Iran(Figure 1)[1].A key question that remains unanswered or controversial among the public,media,and researchers is the exact COVID-19 case fatality rate (CFR) in Iran.Why does the CFR in Iran appear to be higher compared to the rest of the world until now?Or why the fatality rate is high at the beginning of the epidemic in Iran?

关键词： Figure fatal Iran