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AN IMAGE MAGNIFICATION ALGORITHM USING THE GVF CONSTRAINT MODEL

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Journal of Electronics(China) 2008年第4期25卷 568-571页

作者： Li Xiaoguang lam kin-man Shen Lansun Signal and Information Processing Laboratory Beijing University of Technology Beijing 100022 China Centre for Multimedia Signal Processing Department of Electronic and Information Engineering The Hong Kong Polytechnic University Hong Kong China

An image magnification method with a Gradient Vector Flow(GVF)constraint-basedanisotropic diffusion model is proposed in this letter.A Low-Resolution(LR)image is first magnifiedusing bilinear interpolation,and then an iterative image restoration method,with the use of an ani-sotropic diffusion model and a Gaussian moving-average constraint,is applied to the magnified *** estimated GVF of a High-Resolution(HR)image can be used to remove the jagged effect and topreserve the textural structure in the ***,the use of the Gaussian moving-average LRmodel can provide a data fidelity constraint,which renders a magnified image closer to the ideal *** results show that the proposed method can improve the quality of magnifiedimages in terms of both objective and subjective criteria.

关键词： Image magnification Super resolution Anisotropic diffusion Gradient-Vector Flow (GVF)

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基于感兴趣区的图像编码与渐进传输

电子学报 2004年第3期32卷 411-415页

作者：卓力沈兰荪 lam kin-man 北京工业大学信号与信息处理研究室北京100022 Department of Electronic & Information Engineering HongKong Polytechnic University

本文采用一种任意形状的整型或非整型小波变换 ,结合高效的SPIHT(SetPartitioningInHierarchicalTrees)图像编码算法 ,分别实现了任意形状感兴趣区的无损压缩和非感兴趣的有损压缩算法 .另外本文还提出了两种感兴趣区优先编码策略 ,可... 详细信息

本文采用一种任意形状的整型或非整型小波变换 ,结合高效的SPIHT(SetPartitioningInHierarchicalTrees)图像编码算法 ,分别实现了任意形状感兴趣区的无损压缩和非感兴趣的有损压缩算法 .另外本文还提出了两种感兴趣区优先编码策略 ,可以保证在极低的码率下感兴趣区的重建质量远远好于非感兴趣区的重建质量 ,满足用户快速、个性化的浏览需求 .这些方法得到的压缩码流都具有嵌入的特点。

关键词：适形小波编码提升小波 SPHT算法感兴趣区渐进传输图像编码图像传输

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一种基于分形码和模型约束的图像放大算法

电子学报 2006年第3期34卷 433-436页

作者：张晓玲沈兰荪 lam kin-man 北京工业大学信号与信息处理研究室北京100022 香港理工大学电子与资讯工程系

图像放大技术在众多研究领域中有着重要的应用.本文提出一种基于分形码和模型约束的图像放大算法,分形码能够包含图像的空间信息和图像本身的自相似信息,模型约束能够有效的限制放大引入的误差.我们首先对图像采用多种值域块分割方案计... 详细信息

图像放大技术在众多研究领域中有着重要的应用.本文提出一种基于分形码和模型约束的图像放大算法,分形码能够包含图像的空间信息和图像本身的自相似信息,模型约束能够有效的限制放大引入的误差.我们首先对图像采用多种值域块分割方案计算得到多组分形码,并由此得到多个放大图像,然后对放大图像进行平均,从而降低编码误差,最后采用约束模型对放大图像进行修正.实验结果表明,利用本文的方法可以大大提高放大图像的PSNR.

关键词：图像放大分形编码模型约束

一种基于自样本学习的人脸图像超分辨率复原算法

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高技术通讯 2009年第4期19卷 377-381页

作者：李晓光沈兰荪 lam kin man 王素玉北京工业大学信号与信息处理研究室北京100124 香港理工大学电子及资讯工程学系

针对人脸图像超分辨率复原问题,提出了一种新的基于自样本学习的超分辨率复原算法。该算法从输入图像本身提取训练样本库,并采用矢量量化的方法对训练样本进行分类。再利用并行设计的多类预测器对每类样本进行学习训练,指导高频信息的... 详细信息

针对人脸图像超分辨率复原问题,提出了一种新的基于自样本学习的超分辨率复原算法。该算法从输入图像本身提取训练样本库,并采用矢量量化的方法对训练样本进行分类。再利用并行设计的多类预测器对每类样本进行学习训练,指导高频信息的估计重建。对来自输入图像本身的自样本训练集合和来自特定训练图像库的特定训练样本集合进行了对比研究。实验结果表明提出算法在图像重建质量和实现速度上都有很好的表现。

关键词：超分辨率复原人脸图像放大示例学习自样本多类预测器

一种基于GVF各向异性扩散模型的图像放大算法

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电子学报 2008年第9期36卷 1755-1758页

作者：李晓光沈兰荪 lam kin-man 王素玉北京工业大学信号与信息处理研究室北京100124 Department of Electronic and Information Engineering The Hong Kong Polytechnic UniversityHong Kong

提出了一种基于梯度向量流各向异性扩散模型的图像放大方法.首先低分辨率图像插值放大作为高分辨率图像的初始估计,然后利用基于GVF的平均曲率扩散模型和高斯移动平均低分辨率模型约束进行迭代复原.GVF是一种有旋场,作为外力场用来描述... 详细信息

提出了一种基于梯度向量流各向异性扩散模型的图像放大方法.首先低分辨率图像插值放大作为高分辨率图像的初始估计,然后利用基于GVF的平均曲率扩散模型和高斯移动平均低分辨率模型约束进行迭代复原.GVF是一种有旋场,作为外力场用来描述图像的边缘特征,能够将初始图像中斜向边缘锯齿效应表示为流线型.采用GVF外力场约束平均曲率扩散过程,能够有效去除边缘锯齿现象并保持纹理结构.高斯移动平均模型提供了图像数据保真度约束,使结果更接近理想图像.实验结果表明,本文算法能够有效提高放大图像的主观视觉质量和客观PSNR.

关键词：图像放大梯度向量流各向异性扩散超分辨率复原

Emerging roles and therapeutic potentials of sphingolipids in pathophysiology:emphasis on fatty acyl heterogeneity

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Journal of Genetics and Genomics 2024年第3期51卷 268-278页

作者： Jinming Mu Sin man lam Guanghou Shui State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100101China Lipidall Technologies Company Limited ChangzhouJiangsu 213000China

Sphingolipids not only exert structural roles in cellular membranes,but also act as signaling molecules in various physiological and pathological processes.A myriad of studies have shown that abnormal levels of sphingolipids and their metabolic enzymes are associated with a variety of human ***,blood sphingolipids can also be used as biomarkers for disease *** review summarizes the biosynthesis,metabolism,and pathological roles of sphingolipids,with emphasis on the biosynthesis of ceramide,the precursor for the biosynthesis of complex sphingolipids with different fatty acyl *** possibility of using sphingolipids for disease prediction,diagnosis,and treatment is also *** endogenous ceramides and complex sphingolipids along with their specific fatty acyl chain to promote future drug development will also be discussed.

关键词： Sphingolipids Ceramide Therapeutic targets Microdomain Biomarker

Regulation of PM_(2.5)on mitochondrial damage in H9c2 cells through miR-421/SIRT3 pathway and protective effect of miR-421 inhibitor and resveratrol

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Journal of Environmental Sciences 2024年第4期138卷 288-300页

作者： Shanshan Chen Wenqi Chen Zhiping Li Jianwei Yue Ken kin lam Yung Ruijin Li Institute of Environmental Science Shanxi UniversityTaiyuan 030006China Institute of Judicial Identification Techniques for Environmental Damage Shanxi University and Shanxi Unisdom Testing Technology Co.Ltd.Taiyuan 030006China Department of Biology Hong Kong Baptist UniversityHong KongChina Shanxi Yellow River Laboratory Taiyuan 030006China

Fine particulate matter(PM_(2.5))exposure is associated with cardiovascular disease(CVD)morbidity and *** are sensitive targets of PM_(2.5),and mitochondrial dysfunction is closely related to the occurrence of *** epigenetic mechanism of PM_(2.5)-triggered mitochondrial injury of cardiomyocytes is *** study focused on the mi R-421/SIRT3 signaling pathway to investigate the regulatory mechanism in cardiac mitochondrial dynamics imbalance in rat H9c2 cells induced by PM_(2.5).Results illustrated that PM_(2.5)impaired mitochondrial function and caused dynamics homeostasis ***,PM_(2.5)up-regulated mi R-421 and down-regulated SIRT3 gene expression,along with decreasing p-FOXO3a(SIRT3 downstream target gene)and p-Parkin expression and triggering abnormal expression of fusion gene OPA1 and fission gene ***,mi R-421 inhibitor(mi R-421i)and resveratrol significantly elevated the SIRT3 levels in H9c2 cells after PM_(2.5)exposure and mediated the expression of SOD2,OPA1 and Drp1,restoring the mitochondrial morphology and *** suggests that mi R-421/SIRT3 pathway plays an epigenetic regulatory role in mitochondrial damage induced by PM_(2.5)and that mi R-421i and resveratrol exert protective effects against PM_(2.5)-incurred cardiotoxicity.

关键词： Fine particulate matter Rat H9c2 cells Mitochondrial damage MiR-421 SIRT3 Resveratrol

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基于时域局部线性预测的视频镜头变换检测

西安交通大学学报 2006年第10期40卷 1060-1064页

作者：蔡骋王萍林健文谈正西安交通大学电子与信息工程学院西安710049 香港理工大学电子及资讯工程学系多媒体中心

提出了通过时域局部线性预测,在统一框架中准确、高效地检测视频镜头的切变和叠化等镜头变换的新方法.通过理论分析和基于视频数据的线性回归,分别得到叠化预测模式和平稳镜头预测模式.通过同时比较分析两个线性预测模式的误差,在统一... 详细信息

提出了通过时域局部线性预测,在统一框架中准确、高效地检测视频镜头的切变和叠化等镜头变换的新方法.通过理论分析和基于视频数据的线性回归,分别得到叠化预测模式和平稳镜头预测模式.通过同时比较分析两个线性预测模式的误差,在统一框架中检测切变和叠化变换.由于直接在视频流压缩域中进行分析,因此节省了视频解码的时间.采用新方法检测时仅需要对整数进行加、减、比较和移位操作,计算复杂度很低,适合在低功耗、嵌入式设备上运行.采用MPEG-7标准测试视频的实验结果显示:切变检测查全率为95.5%,查准率为93.9%;叠化变换检测查全率为82.2%,查准率为76.0%.检测一段38 min的视频耗时仅3.5 s.

关键词：镜头变换切变检测叠化变换检测线性预测

Comparing 11 early warning scores and three shock indices in early sepsis prediction in the emergency department

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World Journal of Emergency Medicine 2024年第4期15卷 273-282页

作者： Rex Pui kin lam Zonglin Dai Eric Ho Yin Lau Carrie Yuen Ting Ip Ho Ching Chan Lingyun Zhao Tat ChiTsang Matthew Sik Hon Tsui Timothy Hudson Rainer Department of Emergency Medicine School of Clinical MedicineLi Ka Shing Faculty of Medicinethe University of Hong KongHong KongChina School of Public Health Li Ka Shing Faculty of Medicinethe University of Hong KongHong KongChina Accident and Emergency Department Queen Mary HospitalHong KongChina

BACKGROUND:This study aimed to evaluate the discriminatory performance of 11 vital sign-based early warning scores(EWSs)and three shock indices in early sepsis prediction in the emergency department(ED).METHODS:We performed a retrospective study on consecutive adult patients with an infection over 3 months in a public ED in Hong *** primary outcome was sepsis(Sepsis-3 definition)within 48 h of ED *** c-statistics and the DeLong test,we compared 11 EWSs,including the National Early Warning Score 2(NEWS2),Modified Early Warning Score,and Worthing Physiological Scoring System(WPS),etc.,and three shock indices(the shock index[SI],modified shock index[MSI],and diastolic shock index[DSI]),with Systemic Inflammatory Response Syndrome(SIRS)and quick Sequential Organ Failure Assessment(qSOFA)in predicting the primary outcome,intensive care unit admission,and mortality at different time ***:We analyzed 601 patients,of whom 166(27.6%)developed ***2 had the highest point estimate(area under the receiver operating characteristic curve[AUROC]0.75,95%CI 0.70-0.79)and was significantly better than SIRS,qSOFA,other EWSs and shock indices,except WPS,at predicting the primary ***,the pooled sensitivity and specificity of NEWS2≥5 for the prediction of sepsis were 0.45(95%CI 0.37-0.52)and 0.88(95%CI 0.85-0.91),*** discriminatory performance of all EWSs and shock indices declined when used to predict mortality at a more remote time ***:NEWS2 compared favorably with other EWSs and shock indices in early sepsis prediction but its low sensitivity at the usual cut-off point requires further modification for sepsis screening.

关键词： Sepsis Emergency department Clinical prediction rule Early warning score Shock index