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Online identification and extraction method of regional large-scale adjustable load-aggregation characteristics
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作者 Siwei Li Liang Yue +1 位作者 Xiangyu Kong Chengshan Wang 《Global Energy Interconnection》 EI CSCD 2024年第3期313-323,共11页
This article introduces the concept of load aggregation,which involves a comprehensive analysis of loads to acquire their external characteristics for the purpose of modeling and analyzing power systems.The online ide... This article introduces the concept of load aggregation,which involves a comprehensive analysis of loads to acquire their external characteristics for the purpose of modeling and analyzing power systems.The online identification method is a computer-involved approach for data collection,processing,and system identification,commonly used for adaptive control and prediction.This paper proposes a method for dynamically aggregating large-scale adjustable loads to support high proportions of new energy integration,aiming to study the aggregation characteristics of regional large-scale adjustable loads using online identification techniques and feature extraction methods.The experiment selected 300 central air conditioners as the research subject and analyzed their regulation characteristics,economic efficiency,and comfort.The experimental results show that as the adjustment time of the air conditioner increases from 5 minutes to 35 minutes,the stable adjustment quantity during the adjustment period decreases from 28.46 to 3.57,indicating that air conditioning loads can be controlled over a long period and have better adjustment effects in the short term.Overall,the experimental results of this paper demonstrate that analyzing the aggregation characteristics of regional large-scale adjustable loads using online identification techniques and feature extraction algorithms is effective. 展开更多
关键词 Load aggregation regional large-scale Online recognition Feature extraction method
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CFSA-Net:Efficient Large-Scale Point Cloud Semantic Segmentation Based on Cross-Fusion Self-Attention
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作者 Jun Shu Shuai Wang +1 位作者 Shiqi Yu Jie Zhang 《Computers, Materials & Continua》 SCIE EI 2023年第12期2677-2697,共21页
Traditional models for semantic segmentation in point clouds primarily focus on smaller scales.However,in real-world applications,point clouds often exhibit larger scales,leading to heavy computational and memory requ... Traditional models for semantic segmentation in point clouds primarily focus on smaller scales.However,in real-world applications,point clouds often exhibit larger scales,leading to heavy computational and memory requirements.The key to handling large-scale point clouds lies in leveraging random sampling,which offers higher computational efficiency and lower memory consumption compared to other sampling methods.Nevertheless,the use of random sampling can potentially result in the loss of crucial points during the encoding stage.To address these issues,this paper proposes cross-fusion self-attention network(CFSA-Net),a lightweight and efficient network architecture specifically designed for directly processing large-scale point clouds.At the core of this network is the incorporation of random sampling alongside a local feature extraction module based on cross-fusion self-attention(CFSA).This module effectively integrates long-range contextual dependencies between points by employing hierarchical position encoding(HPC).Furthermore,it enhances the interaction between each point’s coordinates and feature information through cross-fusion self-attention pooling,enabling the acquisition of more comprehensive geometric information.Finally,a residual optimization(RO)structure is introduced to extend the receptive field of individual points by stacking hierarchical position encoding and cross-fusion self-attention pooling,thereby reducing the impact of information loss caused by random sampling.Experimental results on the Stanford Large-Scale 3D Indoor Spaces(S3DIS),Semantic3D,and SemanticKITTI datasets demonstrate the superiority of this algorithm over advanced approaches such as RandLA-Net and KPConv.These findings underscore the excellent performance of CFSA-Net in large-scale 3D semantic segmentation. 展开更多
关键词 Semantic segmentation large-scale point cloud random sampling cross-fusion self-attention
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Image segmentation by level set evolution with region consistency constraint 被引量:5
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作者 ZHONG Li ZHOU Yuan-feng +2 位作者 ZHANG Xiao-feng GUO Qiang ZHANG Cai-ming 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2017年第4期422-442,共21页
Image segmentation is a key and fundamental problem in image processing,computer graphics,and computer vision.Level set based method for image segmentation is used widely for its topology flexibility and proper mathem... Image segmentation is a key and fundamental problem in image processing,computer graphics,and computer vision.Level set based method for image segmentation is used widely for its topology flexibility and proper mathematical formulation.However,poor performance of existing level set models on noisy images and weak boundary limit its application in image segmentation.In this paper,we present a region consistency constraint term to measure the regional consistency on both sides of the boundary,this term defines the boundary of the image within a range,and hence increases the stability of the level set model.The term can make existing level set models significantly improve the efficiency of the algorithms on segmenting images with noise and weak boundary.Furthermore,this constraint term can make edge-based level set model overcome the defect of sensitivity to the initial contour.The experimental results show that our algorithm is efficient for image segmentation and outperform the existing state-of-art methods regarding images with noise and weak boundary. 展开更多
关键词 level set evolution image segmentation uniformity testing multiple level contours region consistency constraint
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A fast and efficient mesh segmentation method based on improved region growing 被引量:3
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作者 YANG Fei ZHOU Fan +2 位作者 WANG Ruo-mei LIU Li LUO Xiao-nan 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2014年第4期468-480,共13页
Mesh segmentation is one of the important issues in digital geometry processing. Region growing method has been proven to be a efficient method for 3D mesh segmentation. However, in mesh segmentation, feature line ext... Mesh segmentation is one of the important issues in digital geometry processing. Region growing method has been proven to be a efficient method for 3D mesh segmentation. However, in mesh segmentation, feature line extraction algorithm is computationally costly, and the over-segmentation problem still exists during region merging processing. In order to tackle these problems, a fast and efficient mesh segmentation method based on improved region growing is proposed in this paper. Firstly, the dihedral angle of each non-boundary edge is defined and computed simply, then the sharp edges are detected and feature lines are extracted. After region growing process is finished, an improved region merging method will be performed in two steps by considering some geometric criteria. The experiment results show the feature line extraction algorithm can obtain the same geometric information fast with less computational costs and the improved region merging method can solve over-segmentation well. 展开更多
关键词 mesh segmentation feature line region growing dihedral angle.
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Artificial Intelligence-Based Semantic Segmentation of Ocular Regions for Biometrics and Healthcare Applications 被引量:4
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作者 Rizwan Ali Naqvi Dildar Hussain Woong-Kee Loh 《Computers, Materials & Continua》 SCIE EI 2021年第1期715-732,共18页
Multiple ocular region segmentation plays an important role in different applications such as biometrics,liveness detection,healthcare,and gaze estimation.Typically,segmentation techniques focus on a single region of ... Multiple ocular region segmentation plays an important role in different applications such as biometrics,liveness detection,healthcare,and gaze estimation.Typically,segmentation techniques focus on a single region of the eye at a time.Despite the number of obvious advantages,very limited research has focused on multiple regions of the eye.Similarly,accurate segmentation of multiple eye regions is necessary in challenging scenarios involving blur,ghost effects low resolution,off-angles,and unusual glints.Currently,the available segmentation methods cannot address these constraints.In this paper,to address the accurate segmentation of multiple eye regions in unconstrainted scenarios,a lightweight outer residual encoder-decoder network suitable for various sensor images is proposed.The proposed method can determine the true boundaries of the eye regions from inferior-quality images using the high-frequency information flow from the outer residual encoder-decoder deep convolutional neural network(called ORED-Net).Moreover,the proposed ORED-Net model does not improve the performance based on the complexity,number of parameters or network depth.The proposed network is considerably lighter than previous state-of-theart models.Comprehensive experiments were performed,and optimal performance was achieved using SBVPI and UBIRIS.v2 datasets containing images of the eye region.The simulation results obtained using the proposed OREDNet,with the mean intersection over union score(mIoU)of 89.25 and 85.12 on the challenging SBVPI and UBIRIS.v2 datasets,respectively. 展开更多
关键词 Semantic segmentation ocular regions biometric for healthcare sensors deep learning
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Large-scale Migration of Fluids toward Foreland Basins during Collisional Orogeny: Evidence from Triassic Anhydrock Sequences and Regional Alteration in the Middle-Lower Yangtze Area 被引量:3
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作者 HOUZengqian YANGZhusen LIYinqing ZENGPusheng MENGYifeng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第1期203-220,共18页
The middle-lower Yangtze area underwent a series of complex tectonic evolution, such as Hercynian extensional rifting, Indosinian foreland basining, and Yanshanian transpression-transtension, resulting in a large dist... The middle-lower Yangtze area underwent a series of complex tectonic evolution, such as Hercynian extensional rifting, Indosinian foreland basining, and Yanshanian transpression-transtension, resulting in a large distinctive Cu-Fe-Au metallogenic belt. In the tectonic evolution, large-scale migration and convergence of fluids toward foreland basins induced during the collisional orogeny of the Yangtze and North China continental blocks were of vital importance for the formation of the metallogenic belt. Through geological surveys of the middle-lower Yangtze area, three lines of evidence of large-scale fluid migration are proposed: (1) The extensive dolomitic and silicic alteration penetrating Cambrian-Triassic strata generally occurs in a region sandwiched between the metallogenic belt along the Yangtze River and the Dabie orogenic belt, and in the alteration domain alternately strong and weak alteration zones extend in a NW direction and are controlled by the fault system of the Dabie orogenic belt; it might record the locus of the activities of long-distance migrating fluids. (2) The textures and structures of very thick Middle-Lower Triassic anhydrock sequences in restricted basins along the river reveal the important contribution of the convergence of regional hot brine in restricted basins and the chemical deposition or their formation. (3) Early-Middle Triassic syndepositional iron carbonate sequences and Fe-Cu-Pb-Zn massive sulfide deposits alternate with anhydrock sequences or are separated from the latter, but all of them occur in the same stratigraphic horizon and are intimately associated with each other, being the product of syndeposition of high-salinity hot brine. According to the geological surveys, combined with previous data, the authors propose a conceptual model of fluid migration-convergence and mineralization during the Dabie collisional orogeny. 展开更多
关键词 large-scale migration of fluids collisional orogeny anhydrock sequence regional alteration middle-lower Yangtze River
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Texture feature based automated seeded region growing in abdominal MRI segmentation 被引量:1
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作者 Jie Wu Skip Poehlman +1 位作者 Michael D. Noseworthy Markad V. Kamath 《Journal of Biomedical Science and Engineering》 2009年第1期1-8,共8页
A new texture feature-based seeded region growing algorithm is proposed for automated segmentation of organs in abdominal MR images. 2D Co-occurrence texture feature, Gabor texture feature, and both 2D and 3D Semi- va... A new texture feature-based seeded region growing algorithm is proposed for automated segmentation of organs in abdominal MR images. 2D Co-occurrence texture feature, Gabor texture feature, and both 2D and 3D Semi- variogram texture features are extracted from the image and a seeded region growing algorithm is run on these feature spaces. With a given Region of Interest (ROI), a seed point is automatically se-lected based on three homogeneity criteria. A threshold is then obtained by taking a lower value just before the one causing ‘explosion’. This algorithm is tested on 12 series of 3D ab-dominal MR images. 展开更多
关键词 Image segmentation Seeded region GROWING TEXTURE Analysis
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Observation Mode and Region Segmentation of New Generation Geostationary Meteorological Satellite of China 被引量:1
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作者 Shang Jian Liu Chengbao +2 位作者 Zhao Lei Zhang Zhiqing Yang Lei 《Meteorological and Environmental Research》 CAS 2018年第4期1-4,10,共5页
Three-axis stabilized Fengyun-4 (FY-4) satellite scries is the new generation of geostationary meteorological satellite in China. The ob-servation flexibility brought by three-axis stabilization makes it possible to... Three-axis stabilized Fengyun-4 (FY-4) satellite scries is the new generation of geostationary meteorological satellite in China. The ob-servation flexibility brought by three-axis stabilization makes it possible to design different observation modes for different targets. Important observation modes of the Advanced Geosynchronous Radiation Imager (AGRI), the core instrument onboard FY-4A, are presented, from the earth obser- vation, navigation and calibration perspective. As the time consumed in full disk and hemisphere observations exceed the time limitation, different region segmentation methods are proposed. Results show the methods are effective, and the full disk as well as hemisphere observations can both be accomplished in the given time. Finally the three-region segmentation method and two-region segmentation method are chosen for full disk and hemisphere observations, respectively, in view of the observation instructions' complexity as well as the time consuming. The research results paved the way for the core instrument's daily operation, and have been used in FY-4A in-orbit test. 展开更多
关键词 FY-4 Observation mode region segmentation Time constraint Full disk Hemisphere observation
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Impacts of a Large-scale Adaptive Blending Scheme for CMA-MESO on Regional Forecasts-A Case Study of Typhoon Haima 被引量:1
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作者 冯家莉 高彦 +5 位作者 夏昕 马玉龙 孙健 李源 陈冬梅 万齐林 《Journal of Tropical Meteorology》 SCIE 2021年第4期330-345,共16页
Large-scale atmospheric information plays an important role in the regional model for the forecasts of weather such as tropical cyclone(TC).However,it is difficult to be fully represented in regional models due to dom... Large-scale atmospheric information plays an important role in the regional model for the forecasts of weather such as tropical cyclone(TC).However,it is difficult to be fully represented in regional models due to domain size and a lack of observation data,particularly at sea used in regional data assimilation.Blending analysis has been developed and implemented in regional models to reintroduce large-scale information from global model to regional analysis.Research of the impact of this large-scale blending scheme for the Global/Regional Assimilation and PrEdiction System(CMA-MESO)regional model on TC forecasting is limited and this study attempts to further progress by examining the adaptivity of the blending scheme using the two-dimensional Discrete Cosine Transform(2D-DCT)filter on the model forecast of Typhoon Haima over Shenzhen,China in 2016 and considering various cut-off wavelengths.Results showed that the error of the 24-hour typhoon track forecast can be reduced to less than 25 km by applying the scale-dependent blending scheme,indicating that the blending analysis is effectively able to minimise the large-scale bias for the initial fields.The improvement of the wind forecast is more evident for u-wind component according to the reduced root mean square errors(RMSEs)by comparing the experiments with and without blending analysis.Furthermore,the higher equitable threat score(ETS)provided implications that the precipitation prediction skills were increased in the 24h forecast by improving the representation of the large-scale feature in the CMA-MESO analysis.Furthermore,significant differences of the track error forecast were found by applying the blending analysis with different cut-off wavelengths from 400 km to 1200 km and the track error can be reduced less than by 10 km with 400 km cut-off wavelength in the first 6h forecast.It highlighted that the blending scheme with dynamic cut-off wavelengths adapted to the development of different TC systems is necessary in order to optimally introduce and ingest the large-scale information from global model to the regional model for improving the TC forecast.In this paper,the methods and data applied in this study will be firstly introduced,before discussion of the results regarding the performance of the blending analysis and its impacts on the wind and precipitation forecast correspondingly,followed by the discussion of the effects of different blending scheme on TC forecasts and the conclusion section. 展开更多
关键词 blending analysis tropical cyclone track forecast tropical cyclone TYPHOON large-scale feature regional model
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Flotation bubble image segmentation based on seed region boundary growing 被引量:4
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作者 Zhang Guoying Zhu Hong Xu Ning 《Mining Science and Technology》 EI CAS 2011年第2期239-242,共4页
在一幅筹款图象分割模糊并且粘附的水泡基于种子区域并且边界成长(SRBG ) 用一个新分割方法被做。位于水泡顶的明亮的象素作为种子区域被提取。种子边界被划分成四条曲线:左顶、正确顶、正确底部、左底部。水泡被沿着相应方向移动这些... 在一幅筹款图象分割模糊并且粘附的水泡基于种子区域并且边界成长(SRBG ) 用一个新分割方法被做。位于水泡顶的明亮的象素作为种子区域被提取。种子边界被划分成四条曲线:左顶、正确顶、正确底部、左底部。水泡被沿着相应方向移动这些曲线到水泡边界从种子边界分割。SRBG 方法能移开吵闹的区域,它避免在分割上和在分割下面问题。每个水泡独立被分割而非分割全部筹款图象。从 SRBG 方法的分割结果是比从分水岭算法的那些更精确的。 展开更多
关键词 图像分割 浮选泡沫 种子 边界 区域生长 分水岭算法 分割方法 泡沫浮选
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MULTI-REGION SEGMENTATION OF SAR IMAGE BY A MULTIPHASE LEVEL SET APPROACH 被引量:2
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作者 Fu Yusheng Cao Zongjie Pi Yiming 《Journal of Electronics(China)》 2008年第4期556-561,共6页
In this letter,a multiphase level set approach unifying region and boundary-based infor-mation for multi-region segmentation of Synthetic Aperture Radar(SAR)image is presented.Anenergy functional that is applicable fo... In this letter,a multiphase level set approach unifying region and boundary-based infor-mation for multi-region segmentation of Synthetic Aperture Radar(SAR)image is presented.Anenergy functional that is applicable for SAR image segmentation is defined.It consists of two termsdescribing the local statistic characteristics and the gradient characteristics of SAR image respectively.A multiphase level set model that explicitly describes the different regions in one image is proposed.The purpose of such a multiphase model is not only to simplify the way of denoting multi-region by levelset but also to guarantee the accuracy of segmentation.According to the presented multiphase model,the curve evolution equations with respect to edge curves are deduced.The multi-region segmentationis implemented by the numeric solution of the partial differential equations.The performance of theapproach is verified by both simulation and real SAR images.The experiments show that the proposedalgorithm reduces the speckle effect on segmentation and increases the boundary alignment accuracy,thus correctly divides the multi-region SAR image into different homogenous regions. 展开更多
关键词 合成孔径雷达 图像处理 图像分割 多相水平集法
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An Automatic Segmentation of Kidney in Serial Abdominal CT Scans Using Region Growing Approach 被引量:1
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作者 高岩 王博亮 《Journal of Donghua University(English Edition)》 EI CAS 2010年第2期225-228,共4页
Automatic kidney segmentation from abdominal CT images is a key step in computer-aided diagnosis for kidney CT as well as computer-aided surgery. However,kidney segmentation from CT images is generally performed manua... Automatic kidney segmentation from abdominal CT images is a key step in computer-aided diagnosis for kidney CT as well as computer-aided surgery. However,kidney segmentation from CT images is generally performed manually or semi-automatically because of gray levels similarities of adjacent organs/tissues in abdominal CT images. This paper presents an efficient algorithm for segmenting kidney from serials of abdominal CT images. First,we extracted estimated kidney position(EKP) according to the statistical geometric location of kidney within the abdomen. Second,we analyzed the intensity distribution of EKP for several abdominal CT images and exploit an adaptive threshold searching algorithm to eliminate many other organs/tissues in the EKP. Finally,a novel region growing approach based on labeling is used to obtain the fine kidney regions. Experimental results are comparable to those of manual tracing radiologist and shown to be efficient. 展开更多
关键词 腹的 CT 图象 肾分割 估计的肾位置(EKP ) 适应区域成长
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Census and Segmentation-Based Disparity Estimation Algorithm Using Region Merging
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作者 Viral H. Borisagar Mukesh A. Zaveri 《Journal of Signal and Information Processing》 2015年第3期191-202,共12页
Disparity estimation is an ill-posed problem in computer vision. It is explored comprehensively due to its usefulness in many areas like 3D scene reconstruction, robot navigation, parts inspection, virtual reality and... Disparity estimation is an ill-posed problem in computer vision. It is explored comprehensively due to its usefulness in many areas like 3D scene reconstruction, robot navigation, parts inspection, virtual reality and image-based rendering. In this paper, we propose a hybrid disparity generation algorithm which uses census based and segmentation based approaches. Census transform does not give good results in textureless areas, but is suitable for highly textured regions. While segment based stereo matching techniques gives good result in textureless regions. Coarse disparities obtained from census transform are combined with the region information extracted by mean shift segmentation method, so that a region matching can be applied by using affine transformation. Affine transformation is used to remove noise from each segment. Mean shift segmentation technique creates more than one segment of same object resulting into non-smoothness disparity. Region merging is applied to obtain refined smooth disparity map. Finally, multilateral filtering is applied on the disparity map estimated to preserve the information and to smooth the disparity map. The proposed algorithm generates good results compared to the classic census transform. Our proposed algorithm solves standard problems like occlusions, repetitive patterns, textureless regions, perspective distortion, specular reflection and noise. Experiments are performed on middlebury stereo test bed and the results demonstrate that the proposed algorithm achieves high accuracy, efficiency and robustness. 展开更多
关键词 Stereo Vision CENSUS TRANSFORM Mean Shift segmentation AFFINE TRANSFORM region MERGING
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An Image Segmentation Algorithm Based on a Local Region Conditional Random Field Model
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作者 Xiao Jiang Haibin Yu Shuaishuai Lv 《International Journal of Communications, Network and System Sciences》 2020年第9期139-159,共21页
To reduce the computation cost of a combined probabilistic graphical model and a deep neural network in semantic segmentation, the local region condition random field (LRCRF) model is investigated which selectively ap... To reduce the computation cost of a combined probabilistic graphical model and a deep neural network in semantic segmentation, the local region condition random field (LRCRF) model is investigated which selectively applies the condition random field (CRF) to the most active region in the image. The full convolutional network structure is optimized with the ResNet-18 structure and dilated convolution to expand the receptive field. The tracking networks are also improved based on SiameseFC by considering the frame relations in consecutive-frame traffic scene maps. Moreover, the segmentation results of the greyscale input data sets are more stable and effective than using the RGB images for deep neural network feature extraction. The experimental results show that the proposed method takes advantage of the image features directly and achieves good real-time performance and high segmentation accuracy. 展开更多
关键词 Image segmentation Local region Condition Random Field Model Deep Neural Network Consecutive Shooting Traffic Scene
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Watershed-based Image Segmentation with Region Merging and Edge Detection 被引量:1
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作者 Salman N H 《High Technology Letters》 EI CAS 2003年第1期58-63,共6页
The clustering technique is used to examine each pixel in the image which assigned to one of the clusters depending on the minimum distance to obtain primary classified image into different intensity regions. A waters... The clustering technique is used to examine each pixel in the image which assigned to one of the clusters depending on the minimum distance to obtain primary classified image into different intensity regions. A watershed transformation technique is then employes. This includes: gradient of the classified image, dividing the image into markers, checking the Marker Image to see if it has zero points (watershed lines). The watershed lines are then deleted in the Marker Image created by watershed algorithm. A Region Adjacency Graph (RAG) and Region Adjacency Boundary (RAB) are created between two regions from Marker Image. Finally region merging is done according to region average intensity and two edge strengths (T1, T2). The approach of the authors is tested on remote sensing and brain MR medical images. The final segmentation result is one closed boundary per actual region in the image. 展开更多
关键词 医学图像 脑图像 分水岭 图象分割 边缘检测 区域合并
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Two-stage image segmentation based on edge and region information
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作者 冉鑫 戚飞虎 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2007年第4期533-540,共8页
A two-stage method for image segmentation based on edge and region information is proposed. Different deformation schemes are used at two stages for segmenting the object correctly in image plane. At the first stage, ... A two-stage method for image segmentation based on edge and region information is proposed. Different deformation schemes are used at two stages for segmenting the object correctly in image plane. At the first stage, the contour of the model is divided into several segments hierarchically that deform respectively using affine transformation. After the contour is deformed to the approximate boundary of object, a fine match mechanism using statistical information of local region to redefine the external energy of the model is used to make the contour fit the object's boundary exactly. The algorithm is effective, as the hierarchical segmental deformation makes use of the globe and local information of the image, the affine transformation keeps the consistency of the model, and the reformative approaches of computing the internal energy and external energy are proposed to reduce the algorithm complexity. The adaptive method of defining the search area at the second stage makes the model converge quickly. The experimental results indicate that the proposed model is effective and robust to local minima and able to search for concave objects. 展开更多
关键词 现行等高线模型 图象分割 仿射转换 领域信息
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SEED REGION SELECTION AND HOMOGENEITY CRITERION FOR DOORPLATE IMAGE SEGMENTATION IN MOBILE ROBOT NAVIGATION
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作者 Yang Guosheng Tan Min 《Journal of Electronics(China)》 2005年第5期505-512,共8页
Focused on the seed region selection and homogeneity criterion in Seeded Region Growing (SRG), an unsupervised seed region selection and a polynomial fitting homogeneity criterion for SRG are proposed in this paper. F... Focused on the seed region selection and homogeneity criterion in Seeded Region Growing (SRG), an unsupervised seed region selection and a polynomial fitting homogeneity criterion for SRG are proposed in this paper. First of all, making use of Peer Group Filtering (PGF) techniques, an unsupervised seed region selection algorithm is presented to construct a seed region. Then based on the constructed seed region a polynomial fitting homogeneity criterion is applied to solve the concrete problem of doorplate segmentation appearing in the robot navigation along a corridor. At last, experiments are performed and the results demonstrate the effectiveness of the proposed algorithm. 展开更多
关键词 图象分割 SRG 区域选择性 同质标准 多项式近似值
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Research on the Marketing of Rural Tourism on the Basis of Market Segmentation 被引量:9
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作者 XIAO Xiao Collge of Tourism and Urban-rural Planning, CDUT, Chengdu 610059, China 《Asian Agricultural Research》 2011年第8期1-4,7,共5页
With the development of modern agriculture and the further improvement in balancing urban and rural development, rural tourism ushered in a new opportunity for development. However, due to lack of market segmentation,... With the development of modern agriculture and the further improvement in balancing urban and rural development, rural tourism ushered in a new opportunity for development. However, due to lack of market segmentation,rural tourism in China is facing many problems.The rural tourists will be classified based on the market segmentation in this article,and then put forward four aspects from the use of different target market strategy, develop network marketing, Implements the region brand strategy and international marketing strategy.The aim is to offer advices and suggestions to the sustainable development of the rural tourism. 展开更多
关键词 RURAL TOURISM MARKET segmentation The region CHARA
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Review of Theory and Methods of Image Segmentation 被引量:6
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作者 Xuejun WU 《Agricultural Biotechnology》 CAS 2018年第4期136-141,共6页
Image segmentation refers to the technique and process of partitioning a digital image into multiple segments based on image characteristics so as to extract the object of interest from it. It is a key step from image... Image segmentation refers to the technique and process of partitioning a digital image into multiple segments based on image characteristics so as to extract the object of interest from it. It is a key step from image processing to image analysis. In the mid-1950s, people began to study image segmentation. For decades, various methods for image segmentation have been proposed. In this paper, traditional image segmentation methods and some new methods appearing in recent years were reviewed. Thresholding segmentation methods, region-based, edge detection-based and segmentation methods based on specific theoretical tools were introduced in detail. 展开更多
关键词 Image segmentation THRESHOLD region edge detection
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Validating the Runoff from the PRECIS Model Using a Large-Scale Routing Model 被引量:3
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作者 曹丽娟 董文杰 +2 位作者 许吟隆 张勇 Michael SPARROW 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2007年第5期855-862,共8页
The streamflow over the Yellow River basin is simulated using the PRECIS (Providing REgional Climates for Impacts Studies) regional climate model driven by 15-year (1979-1993) ECMWF reanalysis data as the initial ... The streamflow over the Yellow River basin is simulated using the PRECIS (Providing REgional Climates for Impacts Studies) regional climate model driven by 15-year (1979-1993) ECMWF reanalysis data as the initial and lateral boundary conditions and an off-line large-scale routing model (LRM). The LRM uses physical catchment and river channel information and allows streamflow to be predicted for large continental rivers with a 1°×1° spatial resolution. The results show that the PRECIS model can reproduce the general southeast to northwest gradient distribution of the precipitation over the Yellow River basin, The PRECIS- LRM model combination has the capability to simulate the seasonal and annual streamflow over the Yellow River basin. The simulated streamflow is generally coincident with the naturalized streamflow both in timing and in magnitude. 展开更多
关键词 regional climate model large-scale routing model model validation RUNOFF the Yellow River
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