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Image segmentation by level set evolution with region consistency constraint

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Applied Mathematics(A Journal of Chinese Universities) 2017年第4期32卷 422-442页

作者： ZHONG Li ZHOU Yuan-feng zhang Xiao-feng GUO Qiang zhang cai-ming School of Computer Science and Technology Shandong University School of Information and Electrical Engineering Ludong University School of Computer Science and Technology Shandong University of Finance and Economics

Image segmentation is a key and fundamental problem in image processing,computer graphics,and computer *** set based method for image segmentation is used widely for its topology flexibility and proper mathematical ***,poor performance of existing level set models on noisy images and weak boundary limit its application in image *** 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 *** term can make existing level set models significantly improve the efficiency of the algorithms on segmenting images with noise and weak ***,this constraint term can make edge-based level set model overcome the defect of sensitivity to the initial *** 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.

关键词： level set evolution image segmentation uniformity testing multiple level contours region consistency constraint

Discussion on relationship between minimal energy and curve shapes

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Applied Mathematics(A Journal of Chinese Universities) 2014年第4期29卷 379-390页

作者： LI Xue-mei zhang Yong-xia MA Long ZHOU Yuan-feng zhang cai-ming School of Computer Science and Technology Shandong University Shandong Province Key Lab of Digital Media Technology Shandong University of Finance and Economics

Energy minimization has been widely used for constructing curve and surface in the fields such as computer-aided geometric design, computer graphics. However, our testing examples show that energy minimization does not optimize the shape of the curve sometimes. This paper studies the relationship between minimizing strain energy and curve shapes, the study is carried out by constructing a cubic Hermite curve with satisfactory shape. The cubic Hermite curve interpolates the positions and tangent vectors of two given endpoints. Computer simulation technique has become one of the methods of scientific discovery, the study process is carried out by numerical computation and computer simulation technique. Our result shows that：（1） cubic Hermite curves cannot be constructed by solely minimizing the strain energy; （2） by adoption of a local minimum value of the strain energy, the shapes of cubic Hermite curves could be determined for about 60 percent of all cases, some of which have unsatisfactory shapes, however. Based on strain energy model and analysis, a new model is presented for constructing cubic Hermite curves with satisfactory shapes, which is a modification of strain energy model. The new model uses an explicit formula to compute the magnitudes of the two tangent vectors, and has the properties：（1） it is easy to compute; （2） it makes the cubic Hermite curves have satisfactory shapes while holding the good property of minimizing strain energy for some cases in curve construction. The comparison of the new model with the minimum strain energy model is included.

关键词： computer simulation cubic Hermite curve minimum strain energy curve shape.

Evaluation of Harvest Aid Chemicals for the Cotton-Winter Wheat Double Cropping System

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Journal of Integrative Agriculture 2013年第2期12卷 273-282页

作者： DU ming-wei REN Xiao-ming TIAN Xiao-li DUAN Liu-sheng zhang ming-cai TAN Wei-ming LI Zhao-hu State Key Laboratory of Plant Physiology and Biochemistry/Engineering Research Center of Plant Growth Regulator Ministry of Education/College of Agronomy and Biotechnology China Agricultural University

Timing of harvest is critical for mechanical picking in cotton production, especially in those regions with double cropping system. Appropriate and safe harvest aids will improve timing and facilitate harvest of cotton in the double cropping system. Three defoliants （dimethipin, thidiazuron, and thidiazuron-diuron） and one boll opener （ethephon） were included in this research. They were evaluated for their effects on defoliation, boll opening, seedcotton yield, seed quality, and fiber quality of field grown cotton when used alone or as a mixture in 2009 and 2010. Defoliation and/or boll opening were increased by all three defoliants and ethephon, especially by mixtures of a defoliant and ethephon. First harvest of seedcotton was significantly increased with defoliant-ethephon mixtures. No significant adverse effects were observed on boll weight, lint percentage, seed quality, and fiber properties. It was estimated that tank mixes of ethephon and one of the three defoliants can improve the adjusted gross revenue. Boll opening can be used as an alternative indicator for the adjusted gross revenue, because, it was linearly and positively correlated with the relative adjusted gross revenue and convenient in measurements. Wheat seedling growth was not affected by thidiazuron, whereas its seedling emergence, root dry weight, relative water content, and electrolyte leakage were adversely affected by dimethipin and thidiazuron- diuron when concentration was above 340 and 100 g （a.i.） ha-1, respectively. 90% defoliation and 80% boll opening were observed with the high rate of thidiazuron-ethephon mixture, but no adverse effects on winter wheat. The results suggested that tank mixes of ethephon with thidiazuron can be used effectively and safely in the cotton-winter wheat double cropping system to improve yield without adverse effects on seed quality and fiber quality.

关键词： cotton defoliation boll opening double cropping system

Saliency detection based on superpixels clustering and stereo disparity

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Applied Mathematics(A Journal of Chinese Universities) 2016年第1期31卷 68-80页

作者： GAO Shan-shan CHI Jing LI Li ZOU Ji-biao zhang cai-ming School of Computer Science and Technology Shandong University of Finance and Economics Jinan 250014 China School of Computer Science and Technology Shandong University Jinan 250100 China. Shandong Provincial Key Laboratory of Digital Media Technology Jinan 250014 China.

Reliable saliency detection can be used to quickly and effectively locate objects in images. In this paper, a novel algorithm for saliency detection based on superpixels clustering and stereo disparity （SDC） is proposed. Firstly, we use an improved superpixels clustering method to decompose the given image. Then, the disparity of each superpixel is computed by a modified stereo correspondence algorithm. Finally, a new measure which combines stereo disparity with color contrast and spatial coherence is defined to evaluate the saliency of each superpixel. From the experiments we can see that regions with high disparity can get higher saliency value, and the saliency maps have the same resolution with the source images, objects in the map have clear boundaries. Due to the use of superpixel and stereo disparity information, the proposed method is computationally efficient and outperforms some state-of-the-art color- based saliency detection methods.

关键词： Saliency detection superpixels stereo disparity spatial coherence.

Optimizing the application of a novel harvest aid to improve the quality of mechanically harvested cotton in the North China Plain

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Journal of Integrative Agriculture 2021年第11期20卷 2892-2899页

作者： MENG Lu zhang Li-zhen QI Hai-kun DU ming-wei ZUO Yan-li zhang ming-cai TIAN Xiao-li LI Zhao-hu Engineering Research Center of Plant Growth Regulator Ministry of Education/College of Agronomy and BiotechnologyChina Agricultural UniversityBeijing 100193P.R.China College of Resources and Environmental Sciences China Agricultural UniversityBeijing 100193P.R.China Hebei Cottonseed Engineering Technology Research Center Hejian 062450P.R.China

Defoliation is an indispensable step in cotton production with mechanical harvesting,especially in the North China Plain(NCP)where mechanical harvesting is limited by a large proportion of green leaves and unopened bolls at harvest time due to insufficient thermal *** is essential to quantify the optimal use of defoliation products while minimizing yield and quality loss in *** objective of this study was to test the effect of a new defoliant Xinsaili(XSL,a compound of 10% thidiazuron and 40% ethephon)on the spatial distribution of cotton leaves and bolls,yield and quality in the *** were four treatments:XSL 1800 m L ha^(-1),XSL 2700 m L ha^(-1),XSL splitted into two equal applications(1350 m L ha^(-1) for each),and XSL-free(water)*** experiments were conducted in Hebei,China in *** the defoliant treatments did not significantly affect cotton yield and fiber quality compared with the water *** harvest time,the rate of open bolls under XSL 2700 m L ha^(-1) was 13.5% higher than that under XSL-free control,while the other two treatments showed no significant difference,across the two *** percentage of the three XSL treatments showed no difference,but they were on average 42.2% higher than that of XSL-free *** year-round effect of the defoliant XSL was significant,indicating that climate factors would affect its *** was concluded that the optimal dose of XSL in the NCP was 2700 m L ha^(-1),and it was unnecessary to split it into two *** results would promote cotton mechanical harvesting and reduce the labor cost of cotton production in China.

关键词： thidiazuron ethephon defoliation leaf distribution yield components

Isolation and Culture of Rabbit Marrow-derived Mesenchymal Stem Cells

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生物医学工程学杂志 2005年第S1期22卷 163-165页

作者： Ai-ming zhang Lin cai(Department of Orthopedics, Zhongnan Hospital of Wuhan University, Wuhan 430071,China) Department of Orthopedics Zhongnan Hospital of Wuhan University Wuhan 430071 China

1 IntroductionRepair of tissues like bone, cartilage, muscle,etc., is a tough problem in clinical treatment. The recent research show that there are plenty of mesenchymal stem cells (MSCs) in myeloid tissue besides hemopoietic stem cells(HSCs). Just as the pluripotential hemopoietic stem cell can give bone marrow tissue excellent hemopoietic ability and maintain the metabolism of, MSCs can give potential repair ability to bone, cartilage tissue injury[1] . But compared with the HSCs, the content of MSCs in myeloid tissue are not abundant. We separated and purified the MSCs from myeloid tissue through in vitro cell culture,and studied the proliferation and growth characteristics under in vitro culture conditions, providing experimental foundations for further research on repair epiphyseal plate cartilage defect through MSCs tissue engineering.

关键词： MSCs bone cell Isolation and Culture of Rabbit Marrow-derived Mesenchymal Stem Cells

Improving maize grain yield by formulating plant growth regulator strategies in North China

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Journal of Integrative Agriculture 2021年第2期20卷 622-632页

作者： GONG Li-sha QU Shu-jie HUANG Guan-min GUO Yu-ling zhang ming-cai LI Zhao-hu ZHOU Yu-yi DUAN Liu-sheng Engineering Research Center of Plant Growth Regulator Ministry of Education/College of Agronomy and BiotechnologyChina Agricultural UniversityBeijing 100193P.R.China Experimental Base Service Center of Agricultural Sciences Jiyang 251400P.R.China

Plant growth regulators(PGRs) are artificially synthesized compounds that have become an important technical guarantee for agricultural production. EDAH(containing 27% ethephon and 3% DA-6) has been proven to inhibit stalk elongation, promote stalk bold and increase mechanical strength and number of vascular bundles. DA-6 could enhance plant photosynthetic capacity and promote cell division and growth. In our study, experiments were performed at summer maize growing season during 2018–2019. The result showed that plant height, ear height and center of gravity height of maize with EDAH+DA-6 treatment were decreased by 10.18, 16.77 and 13.21%, respectively;leaf area and leaf area index also significantly(P<0.001) decreased by 24.11 and 60.15%, respectively;the value of mean tilt angle significantly(P<0.001) increased by 16.72% compared with the control plants, which meant that EDAH+DA-6 could shape more compact plant type. Therefore, lodging rate of maize with EDAH+DA-6 treatment decreased by 6.95% compared with control plants, and the grain yield was increased by 15.51%. In addition, EDAH+DA-6 treatment significantly improved the quality of maize base stalks, such as improving mechanical properties, which increased maize base stalk crushing strength by 22.23%;increased the hemicellulose, cellulose and lignin contents by 6.93, 3.87 and 30.21%, respectively. In conclusion, EDAH+DA-6 treatment could improve summer maize yield by shaping plant morphological characteristics and group photosynthesis.

关键词： plant grown regulators canopy structure lodging resistance photosynthetic

A Research Review of Conic Fitting for the Plane Data Points

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Computer Aided Drafting,Design and Manufacturing 2013年第3期23卷 1-5页

作者： LI Pei-pei zhang cai-ming zhang Xin School of Computer Science and Technology Shandong University Audit Research Institute of China National Audit Office Shandong Key Lab. of Digital Media Technology Shandong University of Finance and Economics

Curve modeling is one of the basic work in computer aided geometric design and computer graphics. For the implicit conic fitting problem in this paper, the research methods that the objective function based on the minimal algebraic distance and geometric distance are summarized. The advantages and disadvantages of every method are analyzed simply, and the applications of the conic fitting are listed.

关键词： conic fitting algebraic distance geometric distance

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保持特征的三维网格模型尺寸调整

计算机学报 2009年第10期32卷 2014-2022页

作者：何军张彩明山东大学计算机科学与技术学院济南250101 山东经济学院计算机科学与技术学院济南250014

提出了一种三维模型尺寸调整的新方法.新方法通过对每条边的缩放来驱动模型尺寸的调整,然后以缩放前后三角形法向的叉乘为目标函数项进行优化,几何意义上,该法向叉乘项表示极小化每个三角形的法向变化;Willmore能量意义上,该项可以近似... 详细信息

提出了一种三维模型尺寸调整的新方法.新方法通过对每条边的缩放来驱动模型尺寸的调整,然后以缩放前后三角形法向的叉乘为目标函数项进行优化,几何意义上,该法向叉乘项表示极小化每个三角形的法向变化;Willmore能量意义上,该项可以近似地极小化缩放带来的能量变化.对需要精确保持某些特征区域的模型,采用带约束的尺寸调整方法,通过引入拉格朗日乘数来求解满足约束条件的优化问题,从而能够精确保持模型的重要特征,目前已有的三维模型尺寸调整方法还不能做到这一点.最后,实例表明文中方法在调整模型尺寸的同时,既能很好地保持模型的敏感特征,也能精确保持某些重要的模型特征.

关键词：三维模型尺寸调整非均匀缩放带约束的尺寸调整法向叉乘