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Responses of estuarine salinity and transport processes to sea level rise in the Zhujiang(Pearl River) Estuary 被引量:6
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作者 CHEN Yuxiang ZUO Juncheng +2 位作者 ZOU Huazhi ZHANG Min ZHANG Kairong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第5期38-48,共11页
Understanding the changes of hydrodynamics in estuaries with respect to magnitude of sea level rise is important to understand the changes of transport process. Based on prediction of sea level rise over the 21st cent... Understanding the changes of hydrodynamics in estuaries with respect to magnitude of sea level rise is important to understand the changes of transport process. Based on prediction of sea level rise over the 21st century, the Zhujiang(Pearl River) Estuary was chosen as a prototype to study the responses of the estuary to potential sea level rise. The numerical model results show that the average salt content, saltwater intrusion distance, and stratification will increase as the sea level rises. The changes of these parameters have obvious seasonal variations. The salt content in the Lingdingyang shows more increase in April and October(the transition periods). The saltwater intrusion distance has larger increase during the low-flow periods than during the highflow periods in the Lingdingyang. The result is just the opposite in Modaomen. The stratification and its increase are larger during the low-flow periods than during the high-flow periods in Lingdingyang. The response results of transport processes to sea level rise demonstrate that:(1) The time of vertical transport has pronounced increase.The increased tidal range and currents would reinforce the vertical mixing, but the increased stratification would weaken the vertical exchange. The impact of stratification changes overwhelms the impact of tidal changes. It would be more difficult for the surface water to reach the bottom.(2) The lengthways estuarine circulation would be strengthened. Both the offshore surface residual current and inshore bottom residual current will be enhanced.The whole meridional resident flow along the transect of the Lingdingyang would be weakened. These phenomena are caused by the decrease of water surface slope(WWS) and the change of static pressure with the increase of water depth under sea level rise. 展开更多
关键词 sea level rise salinity stratification transport process Zhujiang Estuary
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Computerized simulation of TRPO extraction process treating Chinese high level waste 被引量:1
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作者 陈靖 王建晨 宋崇立 《Nuclear Science and Techniques》 SCIE CAS CSCD 1996年第3期129-133,共5页
ComputerizedsimulationofTRPOextractionprocesstreatingChinesehighlevelwasteChenJing(陈靖);WangJian-Chen;(王建晨)an... ComputerizedsimulationofTRPOextractionprocesstreatingChinesehighlevelwasteChenJing(陈靖);WangJian-Chen;(王建晨)andSongChong-Li(宋崇立... 展开更多
关键词 核废料 TRPO萃取 计算机模拟
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Emotion processing in Parkinson's disease: a blood oxygenation level-dependent functional magnetic resonance imaging study 被引量:6
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作者 Mohammed Benzagmout Sa?d Boujraf +8 位作者 Badreeddine Alami Hassane Ali Amadou Halima El Hamdaoui Amine Bennani Mounir Jaafari Ismail Rammouz Mustapha Maaroufi Rabia Magoul Driss Boussaoud 《Neural Regeneration Research》 SCIE CAS CSCD 2019年第4期666-672,共7页
Parkinson's disease is a neurodegenerative disorder caused by loss of dopamine neurons in the substantia nigra pars compacta. Tremor, rigidity, and bradykinesia are the major symptoms of the disease. These motor i... Parkinson's disease is a neurodegenerative disorder caused by loss of dopamine neurons in the substantia nigra pars compacta. Tremor, rigidity, and bradykinesia are the major symptoms of the disease. These motor impairments are often accompanied by affective and emotional dysfunctions which have been largely studied over the last decade. The aim of this study was to investigate emotional processing organization in the brain of patients with Parkinson's disease and to explore whether there are differences between recognition of different types of emotions in Parkinson's disease. We examined 18 patients with Parkinson's disease(8 men, 10 women) with no history of neurological or psychiatric comorbidities. All these patients underwent identical brain blood oxygenation level-dependent functional magnetic resonance imaging for emotion evaluation. Blood oxygenation level-dependent functional magnetic resonance imaging results revealed that the occipito-temporal cortices, insula, orbitofrontal cortex, basal ganglia, and parietal cortex which are involved in emotion processing, were activated during the functional control. Additionally, positive emotions activate larger volumes of the same anatomical entities than neutral and negative emotions. Results also revealed that Parkinson's disease associated with emotional disorders are increasingly recognized as disabling as classic motor symptoms. These findings help clinical physicians to recognize the emotional dysfunction of patients with Parkinson's disease. 展开更多
关键词 Parkinson’s disease EMOTION processing BLOOD OXYGENATION level-dependent functional magnetic resonance imaging brain activation DOPAMINE neural REGENERATION
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Analysis of sea level changes in the Caspian Sea related to Cosmo-geophysical processes based on satellite and terrestrial data
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作者 Vladimir Kaftan Boris Komitov Sergey Lebedev 《Geodesy and Geodynamics》 2018年第6期449-455,共7页
Analysis results of the average annual sea levels in the Caspian Sea obtained from ground and satellite observations, corresponding to solar activity characteristics, magnetic field data, and length of day are present... Analysis results of the average annual sea levels in the Caspian Sea obtained from ground and satellite observations, corresponding to solar activity characteristics, magnetic field data, and length of day are presented. Spectra of the indicated processes were investigated and their approximation models were also built. Previously assumed statistical relationships between space-geophysical processes and Caspian Sea level(CSL) changes were confirmed. A close connection was revealed between the low-frequency models of the solar and geomagnetic activity parameters and the CSL changes. Predictions extending into the next decades showed a high probability of an increase in the CSL and a decrease of the compared space-geophysical parameters. 展开更多
关键词 CSL Analysis of sea level changes in the Caspian Sea related to Cosmo-geophysical processes based on satellite and terrestrial data LOD SSN
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Algorithm of Dynamic Operation Process of Hydraulic Automatically Operated Canals with Constant-Downstream Level Gates
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作者 ZHANG Li-wei FENG Xiao-bo WANG Chang-de 《Wuhan University Journal of Natural Sciences》 EI CAS 2005年第6期1074-1080,共7页
On the basis of analysis the governing process of downstream water level gates AVIO and AVIS, a mathematical model for simulation of dynamic operation process of hydraulically automated irrigation canals instalIed wit... On the basis of analysis the governing process of downstream water level gates AVIO and AVIS, a mathematical model for simulation of dynamic operation process of hydraulically automated irrigation canals instalIed with AVIO and AVIS gates is presented, the main point of this rnathematical model is firstly applying a set of unsteady flow equations (St. Venant equations here) and treating the condition of gate movement as its dynamic boundary, and then deeoupling this interaction of gate movement with the change of canal flow. In this process, it is necessary to give the gateg open-loop transfer function whose input is water level deviation and output is gate discharge. The result of this simulation for a practical reach has shown it has satisfactory accuracy. 展开更多
关键词 algorithm hydraulically automatic gate AVIO gate AVIS gate downstream level control system unsteady flow dynamic process
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一种基于FCM和LevelSet的MRI医学图像分割方法 被引量:26
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作者 陈志彬 邱天爽 SU Ruan 《电子学报》 EI CAS CSCD 北大核心 2008年第9期1733-1736,共4页
对基于区域的几何活动轮廓模型中的区域项进行了改进.改进后的算法不仅解决了原算法存在的稳定性问题,同时也有效地提高了分割速度.算法还被成功地扩展到能够分割多种脑组织,且分割质量显著提高.多种子初始化方式的采用,进一步降低了算... 对基于区域的几何活动轮廓模型中的区域项进行了改进.改进后的算法不仅解决了原算法存在的稳定性问题,同时也有效地提高了分割速度.算法还被成功地扩展到能够分割多种脑组织,且分割质量显著提高.多种子初始化方式的采用,进一步降低了算法对初始条件的敏感性,同时也减少了人工干预.对模拟和真实脑MRI图像的分割实验证明了改进的可行性和有效性,噪声条件下分割的比较分析也表明改进后的算法具有良好的韧性. 展开更多
关键词 图像处理 模糊聚类 水平集 脑MPd 分割
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基于变分Level Set方法的图像分割 被引量:3
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作者 王文杰 封建湖 《计算机工程与应用》 CSCD 北大核心 2006年第18期68-70,共3页
文章主要利用levelset函数隐式地追踪图像的边界来实现图像分割。在该文中首先给出了一个变分问题以及相应的Euler-Lagrange方程,并且提出了一种求解该方程的数值算法,使得计算速度有了很大的提高。数值算例表明,该水平集算法具有数值... 文章主要利用levelset函数隐式地追踪图像的边界来实现图像分割。在该文中首先给出了一个变分问题以及相应的Euler-Lagrange方程,并且提出了一种求解该方程的数值算法,使得计算速度有了很大的提高。数值算例表明,该水平集算法具有数值稳定性,不会出现振荡现象,可以很好地处理拓扑结构的变化。 展开更多
关键词 图像处理 level SET方法 level set函数 图像分割
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基于Level Set法铸造充型过程气-液两相流数值模拟 被引量:10
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作者 郝静 陈立亮 姜俊侠 《特种铸造及有色合金》 CAS CSCD 北大核心 2008年第10期751-753,共3页
针对目前铸造充型流动模拟最为常见VOF方法的不足,建立了基于Level Set方法的气-液两相流数学模型及求解方法。应用所建立的模型,模拟了气泡的运动过程,并通过水模拟试验进行了验证,模拟结果表明,Level Set方法可以有效地模拟铸造充型... 针对目前铸造充型流动模拟最为常见VOF方法的不足,建立了基于Level Set方法的气-液两相流数学模型及求解方法。应用所建立的模型,模拟了气泡的运动过程,并通过水模拟试验进行了验证,模拟结果表明,Level Set方法可以有效地模拟铸造充型过程中的气-液两相流动,是铸造模拟技术发展的新方向。 展开更多
关键词 铸造 充型 数值模拟 level SET 两相流
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基于Level Set方法的西夏字轮廓提取 被引量:2
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作者 柳长青 《中文信息学报》 CSCD 北大核心 2009年第4期71-76,共6页
随着国内外对西夏研究的不断深入,收藏于世界各地的大批西夏古籍文献通过影印方式陆续出版。如何将这些西夏古籍文献进行数字化、文本化则有着极其重要的意义。首先利用平滑和细化算法对西夏影印文献进行了预处理,然后利用Level set方... 随着国内外对西夏研究的不断深入,收藏于世界各地的大批西夏古籍文献通过影印方式陆续出版。如何将这些西夏古籍文献进行数字化、文本化则有着极其重要的意义。首先利用平滑和细化算法对西夏影印文献进行了预处理,然后利用Level set方法对影印文献中的西夏字进行了轮廓提取。Level Set演化函数在空间方向上采用了四阶紧致差分逼近式离散,计算过程中加入了窄带算法及全局优化方法。实验表明,算法在不增加计算时间的基础上可以得到较精确的西夏字轮廓。 展开更多
关键词 人工智能 模式识别 西夏文信息处理 level SET方法 西夏字 轮廓提取 紧致差分
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Level Set方法在图像处理中的应用 被引量:1
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作者 杨思燕 《电子科技》 2015年第7期153-156,共4页
针对水平集方法在图像处理中的应用问题,文中对水平集原理进行了阐述,并图示了其具体过程。重点研究了水平集方法在图像分割、图像去噪、图像恢复、图像配准、3D动画中的应用。实验结果表明,与传统的图像处理方法相比,水平集方法在处理... 针对水平集方法在图像处理中的应用问题,文中对水平集原理进行了阐述,并图示了其具体过程。重点研究了水平集方法在图像分割、图像去噪、图像恢复、图像配准、3D动画中的应用。实验结果表明,与传统的图像处理方法相比,水平集方法在处理形状较复杂、拓扑变化较为明显的图像均具有良好的优越性。 展开更多
关键词 图像处理 水平集 算法
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全域旅游视角下县域旅游资源等级评价——以安陆市为例
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作者 李玲 张立明 谭本宇 《湖南工业大学学报》 2025年第2期70-77,共8页
针对全域旅游时代旅游资源的重新认定和等级评价问题,对全域旅游时代的旅游资源进行了再认识,应用层次分析法构建了全域旅游视角下县域旅游资源等级评价模型,对安陆市各旅游资源点进行了认定及等级评价。评价结果显示,全市有五级旅游资... 针对全域旅游时代旅游资源的重新认定和等级评价问题,对全域旅游时代的旅游资源进行了再认识,应用层次分析法构建了全域旅游视角下县域旅游资源等级评价模型,对安陆市各旅游资源点进行了认定及等级评价。评价结果显示,全市有五级旅游资源1处、四级旅游资源6处、三级旅游资源12处、二级旅游资源18处、一级旅游资源29处、未评级旅游资源23处,等级结构总体上呈“金字塔形”。针对该等级评价结果,提出了安陆市旅游资源开发的建议。 展开更多
关键词 全域旅游 旅游资源等级评价 层次分析法 安陆市
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基于Level Set方法的曲线演化 被引量:15
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作者 杨猛 汪国平 董士海 《软件学报》 EI CSCD 北大核心 2002年第9期1858-1865,共8页
Level Set方法是一种描述曲线以曲率相关的速度演化的有力工具,最近几年在医学图像处理、自然现象的模拟以及计算机视觉等领域得到了广泛的应用.其中,曲线演化后的平滑算法和轮廓跟踪方法是Level Set方法实际应用中的两个关键算法.给出... Level Set方法是一种描述曲线以曲率相关的速度演化的有力工具,最近几年在医学图像处理、自然现象的模拟以及计算机视觉等领域得到了广泛的应用.其中,曲线演化后的平滑算法和轮廓跟踪方法是Level Set方法实际应用中的两个关键算法.给出了一种平滑Level Set距离函数的简单方法.该方法只采用内插值的方式,消除平面上的全部孤立点以及部分可能产生歧义的点,在允许存在部分冗余点的情况下,利用曲线轮廓跟踪算法,得到平面上所有曲线的轮廓.经过实验验证,该方法简单、高效,适应范围广. 展开更多
关键词 level SET方法 曲线演化 图像处理 计算机视觉
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基于Level Set的海岸线检测 被引量:6
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作者 林政宗 吕科 +2 位作者 杨磊 徐文 翟锐 《电子学报》 EI CAS CSCD 北大核心 2014年第2期391-397,共7页
采用海岸线做为地标进行静止卫星导航是一种重要的遥感图像自动导航方法,此方法在静止卫星遥感图像中选取特定区域,检测其中的海陆分界线,与全球海岸线标准模板库的相应区域进行匹配,依据计算获得的偏移量调整卫星姿态.根据静止卫星图... 采用海岸线做为地标进行静止卫星导航是一种重要的遥感图像自动导航方法,此方法在静止卫星遥感图像中选取特定区域,检测其中的海陆分界线,与全球海岸线标准模板库的相应区域进行匹配,依据计算获得的偏移量调整卫星姿态.根据静止卫星图像自动导航过程的特点,本文提出了一种适用于红外通道的基于水平集算法的海陆分界线检测方法,本方法依据地标模板库进行初始化,采用一种可扩展区域能量泛函推动曲线进行演化,直至收敛.实验结果表明,本方法具有迭代次数少,稳定性好,精度高的特点. 展开更多
关键词 边缘检测 水平集 图像处理
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新一代nm级集成工艺仿真工具——SenTaurus Process 被引量:1
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作者 于英霞 李惠军 +1 位作者 侯志刚 张宪敏 《微纳电子技术》 CAS 2007年第5期231-234,245,共5页
介绍了新思科技(Synopsys Inc.)最新推出的新一代nm级IC制程工艺设计工具——Sen-Taurus Process的基本功能及其仿真领域,详细阐述了SenTaurus Process功能的拓展。对SenTau-rus Process增加的模型库浏览器(PDB)、一维模拟结果输出(Insp... 介绍了新思科技(Synopsys Inc.)最新推出的新一代nm级IC制程工艺设计工具——Sen-Taurus Process的基本功能及其仿真领域,详细阐述了SenTaurus Process功能的拓展。对SenTau-rus Process增加的模型库浏览器(PDB)、一维模拟结果输出(Inspect)及二、三维模拟结果输出(Tecplot SV)工具进行了介绍。重点介绍了SenTaurus Process所嵌入的诸多小尺寸模型。 展开更多
关键词 集成电路 纳米层次 工艺仿真 可制造性设计
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纳米级工艺制程仿真SenTaurus Process的应用
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作者 于英霞 李惠军 +1 位作者 侯志刚 张宪敏 《微纳电子技术》 CAS 2007年第6期295-298,311,共5页
基于Synopsys Inc.最新推出的新一代nm级IC制程工艺设计工具--SenTaurus Process,实现了CMOS架构的nm级NMOS制程的工艺级可制造性设计。仿真结果体现了SenTaurus Process的强大功能和使用SenTaurus Process进行工艺级可制造性设计的必... 基于Synopsys Inc.最新推出的新一代nm级IC制程工艺设计工具--SenTaurus Process,实现了CMOS架构的nm级NMOS制程的工艺级可制造性设计。仿真结果体现了SenTaurus Process的强大功能和使用SenTaurus Process进行工艺级可制造性设计的必要性。 展开更多
关键词 集成电路 纳米层次 工艺仿真 可制造性设计
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Research into Technology of Bao Steel's Pickling Tension Leveler 被引量:5
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作者 Li Tongqing ①, Chen XianlinBeijing University of Science and Technology, Beijing (100083), China, Xu YaohuanBaoshan Iron and Steel Company, Shanghai (201900), China 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 1997年第1期26-32,共7页
According to the survey of Bao Steel's pickling tenstion leveler,the technology of the tension leveler is analysed systematically.In order to solve the problem which hinders the production,the given technological ... According to the survey of Bao Steel's pickling tenstion leveler,the technology of the tension leveler is analysed systematically.In order to solve the problem which hinders the production,the given technological parameters of this leveler have been improved and good results achieved. 展开更多
关键词 tension leveler technological parameter PICKLING process
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New Method to Measure the Fill Level of the Ball Mill Ⅱ-Analysis of the Vibration Signals 被引量:1
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作者 HUANG Peng JIA Minping ZHONG Binglin 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第4期553-560,共8页
The exact measurement of the fill level is the key and basic problem for automatic control and optimized operation of the coal pulverizing system. Because the ball mill pulverizing system is non-linearity, long time d... The exact measurement of the fill level is the key and basic problem for automatic control and optimized operation of the coal pulverizing system. Because the ball mill pulverizing system is non-linearity, long time delay and time-varying, the reliable and effective method for measuring the fill level was lacked at present. In order to reduce the influence by various factors on measuring the fill level and improve the measuring accuracy of the fill level, a novel characteristic variable is proposed. A set of wireless transmission device was designed to record vibration signals, and an accelerometer with high accuracy and large measuring range was mounted directly on the mill shell to pick up the vibration signals from the mill shell. A series of data acquisition experiments under various ball load and water content of coal conditions were conducted in an industrial mill to investigate the relationship between the fill level and the angular position of the maximum vibration point of the mill shell through the analysis of the vibration signals. The analytical result of test data clearly show that the angular position of the maximum vibration point on the mill shell decreases as the fill level increases. At the same time, comparing with the traditional characteristic variable, the feature variable of the fill level proposed in this paper is not subject to the effect of the ball load and water content of coal, which provides a new solution and reliable basis for the accurate measurement of the fill level. 展开更多
关键词 ball mill fill level vibration signal signal processing
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Fluvial Processes in the Meandering Reach of the Lower Wei River During the Course of Degradation
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作者 Xia, Junqiang Wang, Guangqian Wu, Baosheng 《四川大学学报(工程科学版)》 EI CAS CSCD 北大核心 2005年第S1期46-51,共6页
This paper presents an analysis of the changes of the longitudinal and lateral profiles in the meander- ing reach of the Lower Wei River over the period from October 1973 to October 1976 during the course of degradati... This paper presents an analysis of the changes of the longitudinal and lateral profiles in the meander- ing reach of the Lower Wei River over the period from October 1973 to October 1976 during the course of degradation.Analysis results indicated that retrogressive erosion and subsequent downstream erosion occurred in the reach due to the lowering in the Tongguan elevation and the inflowing water carrying low sediment con- centrations.At the end of the degradation,the main channel widths of the majority ... 展开更多
关键词 the Lower Wei River fluvial processes batse level of erosion channel widening channel undercut
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A conditioned level-set method with block-division strategy to flame front extraction based on OH-PLIF measurements 被引量:3
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作者 韩乐 蔡国飙 +2 位作者 徐旭 Renou Bruno Boukhalfa Abdelkrim 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第5期639-652,共14页
A novel approach to extract flame fronts, which is called the conditioned level-set method with block division (CLSB), has been developed. Based on a two-phase level-set formulation, the conditioned initialization a... A novel approach to extract flame fronts, which is called the conditioned level-set method with block division (CLSB), has been developed. Based on a two-phase level-set formulation, the conditioned initialization and region-lock optimiza-tion appear to be beneficial to improve the efficiency and accuracy of the flame contour identification. The original block- division strategy enables the approach to be unsupervised by calculating local self-adaptive threshold values autonomously before binarization. The CLSB approach has been applied to deal with a large set of experimental data involving swirl- stabilized premixed combustion in diluted regimes operating at atmospheric pressures. The OH-PLIF measurements have been carried out in this framework. The resulting images are, thus, featured by lower signal-to-noise ratios (SNRs) than the ideal image; relatively complex flame structures lead to significant non-uniformity in the OH signal intensity; and, the mag- nitude of the maximum OH gradient observed along the flame front can also vary depending on flow or local stoichiometry. Compared with other conventional edge detection operators, the CLSB method demonstrates a good ability to deal with the OH-PLIF images at low SNR and with the presence of a multiple scales of both OH intensity and OH gradient. The robustness to noise sensitivity and intensity inhomogeneity has been evaluated throughout a range of experimental images of diluted flames, as well as against a circle test as Ground Truth (GT). 展开更多
关键词 OH-PLIE flame front extraction level-SET optical signal processing
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DIMENSION RESULTS FORORNSTEIN-UHLENBECK TYPE MARKOVPROCESS
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作者 邓爱姣 刘禄勤 《Acta Mathematica Scientia》 SCIE CSCD 1999年第4期417-424,共8页
Let {X-t, t greater than or equal to 0} be an Ornstein-Uhlenbeck type Markov process with Levy process A(t), the authors consider the fractal properties of its ranges, give the upper and lower bounds of the Hausdorff ... Let {X-t, t greater than or equal to 0} be an Ornstein-Uhlenbeck type Markov process with Levy process A(t), the authors consider the fractal properties of its ranges, give the upper and lower bounds of the Hausdorff dimensions of the ranges and the estimate of the dimensions of the level sets for the process. The existence of local times and occupation times of X-t are considered in some special situations. 展开更多
关键词 Levy process Ornstein-Uhlenbeck type Markov process RANGE level set Hausdorff dimension local time occuption time
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