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视觉注意引导和区域竞争控制的医学图像分割 被引量:6
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作者 罗彤 陈裕泉 《浙江大学学报(工学版)》 EI CAS CSCD 北大核心 2007年第11期1797-1800,共4页
模糊连接度已经成为医学图像分割的实用方法,但其困难在于需要设定多种子点,自动给定的手段不是很有效.为此将种子点等价于视觉特征显著点,提出了在视觉注意模型引导下种子点给定的新方法.通过研究显著点定位与图像特征概率密度估计之... 模糊连接度已经成为医学图像分割的实用方法,但其困难在于需要设定多种子点,自动给定的手段不是很有效.为此将种子点等价于视觉特征显著点,提出了在视觉注意模型引导下种子点给定的新方法.通过研究显著点定位与图像特征概率密度估计之间的关系,引入新的视觉特征估计地图,构造了注意计算模型,采用无阈值方法定位各类物体的视觉显著点并用于引导区域增长方式的图像分割.新的注意计算模型的定量描述能力较以往的模型有很大提高,适用于处理模糊图像.新方法能够完全自动定位种子点,有效分割图像,准确率高.引入多种子点之间的竞争策略加快了图像分割中的区域增长处理过程. 展开更多
关键词 注意计算模型 医学图像分割 模糊连接度 区域竞争增长
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基于模糊连接度的交互式CT图像分割算法 被引量:4
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作者 刘耀辉 鲍苏苏 黄展鹏 《计算机工程与应用》 CSCD 北大核心 2009年第11期216-219,共4页
如何准确地从CT图像中提取出感兴趣的组织,是医学图像分割中的难点。提出了一种基于模糊连接度的交互式CT图像分割算法:先根据用户指定的感兴趣区域的灰度范围预分割图像,然后用户从结果图像中选择目标和背景种子点,计算出各像素点与两... 如何准确地从CT图像中提取出感兴趣的组织,是医学图像分割中的难点。提出了一种基于模糊连接度的交互式CT图像分割算法:先根据用户指定的感兴趣区域的灰度范围预分割图像,然后用户从结果图像中选择目标和背景种子点,计算出各像素点与两类种子点的模糊连接度,最后根据连接度大小将像素点划分到目标或背景区域。分割过程中,用户可以通过增设或删除目标或背景种子点,修正分割的结果。实验表明,该算法能准确有效地分割出感兴趣区域。 展开更多
关键词 模糊连接度 CT图像 区域生长 交互式分割
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ALTERNATING METHOD STUDY ON STRESS ANALYSIS OF SURROUNDING ROCK FOR TWO RANDOM GEOMETRY TUNNELS 被引量:2
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作者 吕爱钟 张路青 《Journal of Coal Science & Engineering(China)》 1997年第2期24-29,共6页
The stress analysis of surrounding rock for two random geometry tunnels is studied in this paper by using Schwarz’s alternating method. The simple and effective alternating algorithm is found, in which the surplus su... The stress analysis of surrounding rock for two random geometry tunnels is studied in this paper by using Schwarz’s alternating method. The simple and effective alternating algorithm is found, in which the surplus surface force is approximated by Fourier series, thus the iteration derivation can be conducted according to the precision required, finally, the stress results with high precision are obtained. 展开更多
关键词 Schwarz's alternating method Fourier series the surplus surface force iteration the doubly connected region
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结合区域生长与模糊连接度的肺气管树分割 被引量:3
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作者 彭双 肖昌炎 《计算机工程与应用》 CSCD 北大核心 2016年第13期201-205,共5页
针对CT图像中因噪声、密度分布不均匀和边界模糊等因素造成肺气管树难以准确分割的问题,提出了一种区域生长与模糊连接度相结合的肺气管树分割流程。通过阈值化及形态学闭操作提取出肺实质以定义感兴趣区域;采用改进迟滞阈值区域生长法... 针对CT图像中因噪声、密度分布不均匀和边界模糊等因素造成肺气管树难以准确分割的问题,提出了一种区域生长与模糊连接度相结合的肺气管树分割流程。通过阈值化及形态学闭操作提取出肺实质以定义感兴趣区域;采用改进迟滞阈值区域生长法预分割出较粗气管并结合局部体积突变指标抑制侧向泄漏;将预分割的结果进行骨架化及修剪来进一步提取出分支点,并以此作为后续分割的新种子点;根据CT图像的灰度均匀性与气管的管状结构特征来构造亲和力函数以计算种子点与其他体素的模糊连接度,并选取合适的阈值对模糊连接度进行阈值分割以提取出完整气管树。实验采用了20例来自EXACT’09竞赛提供的公开数据,分别从分支点、分支数量和分支数比率等方面进行了量化评估。该方法能在较低泄漏情况下成功检测出参考标准中一半以上的分支,平均分支数比率达到59.7%。实验结果表明,该方法可对肺气管树进行较精确的分割。 展开更多
关键词 气管树分割 区域生长 模糊连接度 CT图像
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Brualdi定理的推广及其应用
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作者 陈神灿 《宁夏大学学报(自然科学版)》 CAS 2003年第4期316-320,共5页
引入回路α 对角占优矩阵和矩阵的无向连通性概念,推广了关于不可约矩阵非奇异性的Brualdi定理,得到回路α 对角占优矩阵为H 矩阵的充要条件.作为应用,对经典的Ostrowski和Brualdi关于矩阵特征值的分布区域作了讨论.
关键词 Brualdi定理 回路α-对角占优矩阵 无向连通性 H-矩阵 特征值 谱包含域
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Evidence of cortical reorganization of language networks after stroke with subacute Broca's aphasia:a blood oxygenation level dependent-functional magnetic resonance imaging study 被引量:8
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作者 Wei-hong Qiu Hui-xiang Wu +7 位作者 Qing-lu Yang Zhuang Kang Zhao-cong Chen Kui Li Guo-rong Qiu Chun-qing Xie Gui-fang Wan Shao-qiong Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2017年第1期109-117,共9页
Aphasia is an acquired language disorder that is a common consequence of stroke.The pathogenesis of the disease is not fully understood,and as a result,current treatment options are not satisfactory.Here,we used blood... Aphasia is an acquired language disorder that is a common consequence of stroke.The pathogenesis of the disease is not fully understood,and as a result,current treatment options are not satisfactory.Here,we used blood oxygenation level-dependent functional magnetic resonance imaging to evaluate the activation of bilateral cortices in patients with Broca's aphasia 1 to 3 months after stroke.Our results showed that language expression was associated with multiple brain regions in which the right hemisphere participated in the generation of language.The activation areas in the left hemisphere of aphasia patients were significantly smaller compared with those in healthy adults.The activation frequency,volumes,and intensity in the regions related to language,such as the left inferior frontal gyrus(Broca's area),the left superior temporal gyrus,and the right inferior frontal gyrus(the mirror region of Broca's area),were lower in patients compared with healthy adults.In contrast,activation in the right superior temporal gyrus,the bilateral superior parietal lobule,and the left inferior temporal gyrus was stronger in patients compared with healthy controls.These results suggest that the right inferior frontal gyrus plays a role in the recovery of language function in the subacute stage of stroke-related aphasia by increasing the engagement of related brain areas. 展开更多
关键词 nerve regeneration functional magnetic resonance imaging cortical functional connectivity language regions neuroplasticity Perisylvian language regions brain activation right hemisphere picture-naming task neural regeneration
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Targeting of AUF1 to vascular endothelial cells as a novel anti-aging therapy
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作者 Jian HE Ya-Feng JIANG +7 位作者 Liu LIANG Du-jin WANG Wen-Xin WEI Pan-Pan JI Yao-Chan HUANG Hui SONG Xiao-Ling LU Yong-Xiang ZHAO 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2017年第8期515-523,共9页
Background Inhibition of aging of vascular endothelial cells (VECs) may delay aging and prolong life. The goal of this study was to prepare anti-CD31 monoclonal antibody conjugated PEG-modified liposomes containing ... Background Inhibition of aging of vascular endothelial cells (VECs) may delay aging and prolong life. The goal of this study was to prepare anti-CD31 monoclonal antibody conjugated PEG-modified liposomes containing the AU-rich region connecting factor 1 (AUF1) gene (CD31-PILs-AUF1) and to explore the effects of targeting CD31-PILs-AUF1 to aging VECs. Methods The mean particle sizes of various PEGylated immunoliposomes (PILs) were measured using a Zetasizer Nano ZS. Gel retardation assay was used to confirm whether PILs had encapsulated the AUF1 plasmid successfully. Fluorescence microscopy and flow cytometry were used to quantify binding of CD31-PILs-AUF1 to target cells. Flow cytometry was also used to analyze the cell cycles of aging bEnd3 cells treated with CD31-PILs-AUF1. We also developed an aging mouse model by treating mice with D-galactose. Enzyme-linked immunosorbent assay (ELISA) was used to evaluate the levels of interleuldn-6 (IL-6) and tumor necrosis factor-or (TNF-ct). The malondialdehyde (MDA) and the superoxide dismutase (SOD) levels were detected by commercial kits. Hematoxylin-eosin (HE) staining was used to determine whether treatment with CD31-PILs-AUF 1 was toxic to the mice. Results CD31-PILs-AUF 1 specifically could targeted bEnd3 VECs and increased the percentage of cells in the S and G2/M phases of aging bEnd3 cells. ELISA showed that content of the IL-6 and TNF-ct decreased in CD31-PILs-AUF1 group. The level of SOD increased, whereas MDA decreased in the CD31-PILs-AUF1 group. Additionally, CD31-PILs-AUF 1 was not toxic to the mice. Conclusion CD31-PILs-AUF 1 targets VECs and may delay their senescence. 展开更多
关键词 Aging AU-rich region connecting factor 1 PEGylated immunoliposomes Vascular endothelial ceils
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一种基于模糊连接度的区域生长毁伤特征提取算法
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作者 曹继平 朱亚红 吴聪伟 《火力与指挥控制》 CSCD 北大核心 2017年第4期75-78,共4页
针对传统的区域生长算法在提取军事目标毁伤时,不能较好地处理毁伤区域与背景之间的模糊性,生长结果对种子点的选取敏感等问题,提出了一种基于模糊连接度的区域生长算法。算法以模糊连接度作为生长点与种子点相似度的度量,有效地保持了... 针对传统的区域生长算法在提取军事目标毁伤时,不能较好地处理毁伤区域与背景之间的模糊性,生长结果对种子点的选取敏感等问题,提出了一种基于模糊连接度的区域生长算法。算法以模糊连接度作为生长点与种子点相似度的度量,有效地保持了像素之间的模糊性,按照模糊连接度由强至弱的顺序生长,使得生长的结果对种子点的选取不敏感;采用灰度波动控制和USAN面积相结合的方式作为生长准则,在适应目标区域灰度变化的同时得到了较好的边缘定位效果。实验结果证明了算法的有效性。 展开更多
关键词 模糊连接度 区域生长 特征提取
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Pakistan and the BRICS Plus in the New Era:A Perspective of Neo-Functionalism
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作者 Beenish Sultan Amna Mehmood 《Asian Journal of Middle Eastern and Islamic Studies》 2020年第3期447-463,共17页
China proposed the idea of‘BRICS Plus’in 2017.However,this hint exasperated India owing to its diverse political and strategic preferences.Conspicuously,the reason for India’s disapproval relates to a probable role... China proposed the idea of‘BRICS Plus’in 2017.However,this hint exasperated India owing to its diverse political and strategic preferences.Conspicuously,the reason for India’s disapproval relates to a probable role for Pakistan through the BRICS plus.Particularly,in the backdrop is China’s progress on regional integration through the Belt and Road Initiative(BRI)and the significance extended to the China Pakistan Economic Corridor(CPEC).In fact,inimical impulses for Pakistan were also felt when India attempted to label Pakistan as a country‘promoting state-sponsored terrorism’through a BRICS summit held in Goa in 2016;the move was later vetoed both by China and Russia.Meanwhile,India’s bilateral relations with China also lacked synergy,which sometimes impact their interaction within the BRICS framework.If viewed through the Neo-Functionalism framework and its concept of‘spill-over,’BRICS plus can reinforce incentives of cooperation in various sectors within a larger group of countries.Interest groups will begin to flourish at a regional level and domestically these groups will lobby their governments to further integrate.This will be overall critical for BRICS in order to steadily engage the world order as a multilateral forum.The question is,will India let go of bilateralism and accept the role of regional countries,particularly Pakistan?This article intends to explore the very concept of the transregional organisation of BRICS and the impact of the nature of relations between India and China.It also illustrates how states in the region,specifically Pakistan,have an intrinsic potential to complement the transregional agenda of BRICS and BRICS plus,particularly through its strategic geographic location and CPEC.For the persistent rise of BRICS,members will have to let go of bilateralism and allow the countries on the periphery to play their role. 展开更多
关键词 Pakistan BRICS BILATERALISM regional connectivity neofunctionalism
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Reflections on New Trends in the Oil Market and China-Saudi Arabia Energy Cooperation
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作者 Mo Chen 《Asian Journal of Middle Eastern and Islamic Studies》 2020年第4期505-515,I0002,共12页
President Xi Jinping defined energy cooperation as the‘core of cooperation’between China and Arab states,as he addressed the opening ceremony of China-Arab States Cooperation Forum(CASCF)Ministerial Meeting in 2014.... President Xi Jinping defined energy cooperation as the‘core of cooperation’between China and Arab states,as he addressed the opening ceremony of China-Arab States Cooperation Forum(CASCF)Ministerial Meeting in 2014.1 China and Saudi Arabia,respectively the world’s most important oil importer and exporter,recognise the pivotal status of energy cooperation in bilateral ties.In 2018,Saudi Arabia exported 61.2 million ton of oil(crude oil and oil products)to China,representing the second largest source of supply of China and 11.2%of China’s total oil imports,while China represented the largest oil export market,absorbing 14.4%of Saudi oil export of 2018.The bilateral investment has also started.Saudi Arabia has already constructed and is planning to construct five major petrochemical projects while China and Saudi Arabia have jointly constructed a refinery in Saudi Arabia.New trends are occurring in the global oil market.On the one hand,a tendency of long-term over-supply and low prices has emerged;on the other hand,the competition of oil supply is shifting to Asia.However,these market changes would not weaken China-Saudi energy cooperation.On the contrary,they give more reasons for both sides to strengthen cooperation,so as to address common challenges,especially to promote peace and stability of the Middle East,rationalisation of oil prices,diversification of oil trade denominated currencies,mutual investment in energy field and joint development of renewables.These trends have also indicated the direction for bilateral cooperation to address the challenges.It would be advisable for both countries to open up new prospects in energy cooperation based on the new concept of a community of energy security. 展开更多
关键词 China and Saudi Arabia BILATERALISM regional connectivity NEO-FUNCTIONALISM
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