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ASSESSMENT OF LOCAL INFLUENCE IN A GROWTH CURVE MODEL WITH RAO'S SIMPLE COVARIANCE STRUCTURE 被引量:2
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作者 白鹏 《Acta Mathematica Scientia》 SCIE CSCD 1999年第S1期555-563,共9页
The present paper deals with the problem of assessing the local influence in a growth curve model with Rao's simple covariance structure. Based on the likelihood displacement,the curvature measure is employed to e... The present paper deals with the problem of assessing the local influence in a growth curve model with Rao's simple covariance structure. Based on the likelihood displacement,the curvature measure is employed to evaluate the effects of some minor perturbations on the statistical inference, thus leading to the large curvature direction, which is the most critical diagnostic statistic in the context of the local influence analysis. As an application, the common covariance-weighted perturbation scheme is thoroughly considered. 展开更多
关键词 Growth curve model Rao's simple covariance structure w-model Likelihood displacement CURVATURE
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ADMISSIBILITY OF LINEAR ESTIMATORS IN A GROWTH CURVE MODEL SUBJECT TO AN INCOMPLETE ELLIPSOIDAL RESTRICTION 被引量:2
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作者 张尚立 桂文豪 《Acta Mathematica Scientia》 SCIE CSCD 2008年第1期194-200,共7页
This article considers the admissibility of the linear estimators for the regression coefficients in the growth curve model subject to an incomplete ellipsoidal restriction. The necessary and sufficient conditions for... This article considers the admissibility of the linear estimators for the regression coefficients in the growth curve model subject to an incomplete ellipsoidal restriction. The necessary and sufficient conditions for linear estimators to be admissible in classes of the homogeneous and non-homogeneous linear estimators, respectively, are obtained under the quadratic loss function. They are generalizations of some existing results in literature. 展开更多
关键词 Growth curve model ADMISSIBILITY linear estimator
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BAYESIAN LOCAL INFLUENCE ASSESSMENTS IN A GROWTH CURVE MODEL WITH GENERAL COVARIANCE STRUCTURE 被引量:1
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作者 白鹏 费宇 《Acta Mathematica Scientia》 SCIE CSCD 2000年第4期563-570,共8页
The objective of this paper is to present a Bayesian approach based on Kullback- Leibler divergence for assessing local influence in a growth curve model with general co- variance structure. Under certain prior distri... The objective of this paper is to present a Bayesian approach based on Kullback- Leibler divergence for assessing local influence in a growth curve model with general co- variance structure. Under certain prior distribution assumption, the Kullback-Leibler di- vergence is used to measure the influence of some minor perturbation on the posterior distribution of unknown parameter. This leads to the diagnostic statistic for detecting which response is locally influential. As an application, the common covariance-weighted perturbation scheme is thoroughly considered. 展开更多
关键词 Growth curve model prior and posterior distribution Kullback-Leibler di- vergence Bayesianω-model CURVATURE
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ADMISSIBILITY IN THE GENERAL GROWTH CURVE MODEL WITH RESPECT TO RESTRICTED PARAMETER SETS UNDER MATRIX LOSS FUNCTION 被引量:1
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作者 张尚立 覃红 《Acta Mathematica Scientia》 SCIE CSCD 2010年第1期27-38,共12页
In this paper, we study the issue of admissibility in the growth curve model with respect to restricted parameter sets under matrix loss function. We obtain some neces- sary and sufficient conditions that the linear e... In this paper, we study the issue of admissibility in the growth curve model with respect to restricted parameter sets under matrix loss function. We obtain some neces- sary and sufficient conditions that the linear estimators of KBL are admissible in the class of homogeneous linear estimators and in the class of non-homogeneous linear estimators under the growth curve model with respect to restricted parameter sets, respectively. 展开更多
关键词 growth curve model linear estimation ADMISSIBILITY incomplete ellipsoidalrestriction
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Innovative Development Path of the Pension Model Under the Background of the Aging Society: Taking Chongqing as an Example
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作者 Aihong Wang 《Proceedings of Business and Economic Studies》 2023年第1期1-7,共7页
The aging society has dawned on China,and the pension industry is now considered to be a sunrise industry.In 2020,the number of people over the age of 65 in Chongqing had reached more than 5.47 million.At present,the ... The aging society has dawned on China,and the pension industry is now considered to be a sunrise industry.In 2020,the number of people over the age of 65 in Chongqing had reached more than 5.47 million.At present,the mainstream home-based care,children support,and institutional care cannot fully meet the needs of the elderly for food,housing,medical care,nursing,and entertainment.The value curve model from“Blue Ocean Strategy”is used to look for innovative,differentiated competitive strategies.Through community-sharing pension institutions,it is believed that a new model that provides lower prices and more professional medical care services for the elderly,enriches the spiritual world of the elderly with rich entertainment activities,and connects social services through an elderly studio to meet the needs of the elderly for self-realization can be introduced. 展开更多
关键词 Pension model Value curve model Four-step framework method Community-sharing pension
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An improved model of partition curve based on accumulation normal distribution function 被引量:2
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作者 Sun Wei Chen Jianzhong +1 位作者 Shen Lijuan Li Yonggai 《International Journal of Mining Science and Technology》 SCIE EI 2013年第3期375-380,共6页
Extensive studies based on partition curve of gravity separation have been investigated. All created models are merely used to simulate density distribution at the same size fraction. However, they cannot be used to p... Extensive studies based on partition curve of gravity separation have been investigated. All created models are merely used to simulate density distribution at the same size fraction. However, they cannot be used to predictive distribution of materials depending on compound feature of density and size. According to this situation, an improved model of partition curve based on accumulation normal distribution, which was distinguished from conventional model of accumulation normal distribution for partition curve, was proposed in this paper. It could simulate density distribution at different size fractions by using the density-size compound index and conflating the partition curves at different size fractions as one partition curve. The feasibility of three compound indexes, including mass index, settlement index and transformation index, were investigated. Specific forms of the improved model were also proposed. It is found that transformation index leads to the best fitting results, while the fitting error is only 1.75 according to the fitting partition curve. 展开更多
关键词 Coal preparation Mathematical model Partition curve Accumulation normal distribution model
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Cavitation Bubble Collapse near a Curved Wall by the Multiple-Relaxation-Time Shan-Chen Lattice Boltzmann Model 被引量:1
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作者 薛洪惠 单锋 +2 位作者 郭霞生 屠娟 章东 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第8期83-87,共5页
The cavitation bubble collapse near a cell can cause damage to the cell wall. This effect has received increasing attention in biomedical supersonics. Based on the lattice Boltzmann method, a multiple-relaxation-time ... The cavitation bubble collapse near a cell can cause damage to the cell wall. This effect has received increasing attention in biomedical supersonics. Based on the lattice Boltzmann method, a multiple-relaxation-time Shan–Chen model is built to study the cavitation bubble collapse. Using this model, the cavitation phenomena induced by density perturbation are simulated to obtain the coexistence densities at certain temperature and to demonstrate the Young–Laplace equation. Then, the cavitation bubble collapse near a curved rigid wall and the consequent high-speed jet towards the wall are simulated. Moreover, the influences of initial pressure difference and bubble-wall distance on the cavitation bubble collapse are investigated. 展开更多
关键词 Cavitation Bubble Collapse near a curved Wall by the Multiple-Relaxation-Time Shan-Chen Lattice Boltzmann model
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NUMERICAL INVESTIGATION OF THREE-DIMENSIONAL VISCOUS INCOMPRESSIBLE FLOWS IN DIVERGENT CURVED CHANNELS AND TURBULENT MODEL STUDY
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作者 焦德勇 杨弘炜 +2 位作者 赵志君 苏杰先 冯国泰 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1989年第7期639-646,共8页
In order to make the numerical calculation of viscous flows more convenient for the flows in channel with complicated profile governing equations expressed in the arbitrary curvilinear coordinates were derived by mean... In order to make the numerical calculation of viscous flows more convenient for the flows in channel with complicated profile governing equations expressed in the arbitrary curvilinear coordinates were derived by means of Favre density-weighted averaged method, and a turbulent model with effect of curvature modification was also derived. The numerical calculation of laminar and turbulent flown in divergent curved channels was carried out by means of parabolizeil computation method. The calculating results were used to analyze and investigate the aerodynamic performance of talor cascades in compressors preliminarily. 展开更多
关键词 NUMERICAL INVESTIGATION OF THREE-DIMENSIONAL VISCOUS INCOMPRESSIBLE FLOWS IN DIVERGENT curveD CHANNELS AND TURBULENT model STUDY
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Degree elevation from Bzier curve to C-Bzier curve with corner cutting form
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作者 SHEN Wan-qiang WANG Guo-zhao 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2016年第2期165-176,共12页
The existing results of curve degree elevation mainly focus on the degree of algebraic polynomials. The paper considers the elevation of degree of the trigonometric polynomial, from a Bezier curve on the algebraic pol... The existing results of curve degree elevation mainly focus on the degree of algebraic polynomials. The paper considers the elevation of degree of the trigonometric polynomial, from a Bezier curve on the algebraic polynomial space, to a C-Bezier curve on the algebraic and trigonometric polynomial space. The matrix of degree elevation is obtained by an operator presentation and a derivation pyramid. It possesses not a recursive presentation but a direct expression. The degree elevation process can also be represented as a corner cutting form. 展开更多
关键词 curve modeling Bezier curve C-Bezier curve Degree elevation Corner cutting.
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Nonlinear density wave and energy consumption investigation of traffic flow on a curved road 被引量:1
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作者 金智展 程荣军 葛红霞 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第11期135-143,共9页
A new car-following model is proposed based on the full velocity difference model(FVDM) taking the influence of the friction coefficient and the road curvature into account. Through the control theory, the stability... A new car-following model is proposed based on the full velocity difference model(FVDM) taking the influence of the friction coefficient and the road curvature into account. Through the control theory, the stability conditions are obtained,and by using nonlinear analysis, the time-dependent Ginzburg-Landau(TDGL) equation and the modified Korteweg-de Vries(mKdV) equation are derived. Furthermore, the connection between TDGL and mKdV equations is also given. The numerical simulation is consistent with the theoretical analysis. The evolution of a traffic jam and the corresponding energy consumption are explored. The numerical results show that the control scheme is effective not only to suppress the traffic jam but also to reduce the energy consumption. 展开更多
关键词 car-following model curved road energy consumption time-dependent Ginzburg-Landau(TDGL) equation
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Application Study on 3D Modeling of Axial Compressor Blades Based on CFD and CAD 被引量:3
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作者 WANG Zheng WU Hu +1 位作者 SHI Ya-feng Wang Hong-bo 《International Journal of Plant Engineering and Management》 2009年第1期21-24,共4页
A new method for design of turbomachinery blades is presented. The parameters of a compressor blade are created from the Computational Fluid Dynamics (CFD) software CFX-BladeGen, and are inputted to the Computer Aid... A new method for design of turbomachinery blades is presented. The parameters of a compressor blade are created from the Computational Fluid Dynamics (CFD) software CFX-BladeGen, and are inputted to the Computer Aided Design (CAD) software UG for building a curve surface model to create an entity model in UG. The result shows that the blade model is favorable from the entity effect and reflection analysis and the model process is useful for the CAD model creation of turbomachinery blades. 展开更多
关键词 turbomachinery blade Computational Fluid Dynamics (CFD) Computer Aided Design (CAD) curve surface model entity model
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Stability of rat models of fluid percussion-induced traumatic brain injury: comparison of three different impact forces 被引量:1
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作者 Yun-peng Lin Rong-cai Jiang Jian-ning Zhang 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第7期1088-1094,共7页
Fluid percussion-induced traumatic brain injury models have been widely used in experimental research for years. In an experiment, the stability of impaction is inevitably affected by factors such as the appearance of... Fluid percussion-induced traumatic brain injury models have been widely used in experimental research for years. In an experiment, the stability of impaction is inevitably affected by factors such as the appearance of liquid spikes. Management of impact pressure is a crucial factor that determines the stability of these models, and direction of impact control is another basic element. To improve experimental stability, we calculated a pressure curve by generating repeated impacts using a fluid percussion device at different pendulum angles. A stereotactic frame was used to control the direction of impact. We produced stable and reproducible models, including mild, moderate, and severe traumatic brain injury, using the MODEL01-B device at pendulum angles of 6°, 11° and 13°, with corresponding impact force values of 1.0 ± 0.11 atm(101.32 ± 11.16 k Pa), 2.6 ± 0.16 atm(263.44 ± 16.21 k Pa), and 3.6 ± 0.16 atm(364.77 ± 16.21 k Pa), respectively. Behavioral tests, hematoxylin-eosin staining, and magnetic resonance imaging revealed that models for different degrees of injury were consistent with the clinical properties of mild, moderate, and severe craniocerebral injuries. Using this method, we established fluid percussion models for different degrees of injury and stabilized pathological features based on precise power and direction control. 展开更多
关键词 nerve regeneration traumatic brain injury fluid percussion impact force pressure curve head fixed impact peak animal models neural regeneration
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Research into Freedom Surface Modeling System of Double Beta Spline in Space
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作者 Liu Xumin Department of Electronic Engineering, Jinzhou Teachers College, Liaoning 121000, P. R. China Xu Weixiang Automation Research Institute, Northern Jiaotong University, Beijing 100044, P. R. China Liu Xumin & Xu Weixiang Research into Freedom Sur 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1997年第3期65-73,共9页
In this paper, we present the double Beta spline curved surface which is controlled by double parameters including the algorithm principles, the treatment of boundary conditions, the alternation of projection, the alg... In this paper, we present the double Beta spline curved surface which is controlled by double parameters including the algorithm principles, the treatment of boundary conditions, the alternation of projection, the algorithms of elimination hiddle line, the process to display and the primiples to produce the shaded curved surface. Based on all the above, a freedom surface modeling system (FSMS) is designed and some examples developed on FSMS are verified and analyzed. 展开更多
关键词 curved surface modeling Double Beta spline curved surface Elimination hiddle line Piece together Shaded curved surface.
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Ideal Drift Response Curve for Robust Optimal Damper Design for Elastic-Plastic MDOF Structures under Multi-Level Earthquakes Dedicated to Professor Karl S.Pister for his 95th birthday
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作者 Hiroki Akehashi Izuru Takewaki 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第12期1181-1207,共27页
A new method of robust damper design is presented for elastic-plastic multi-degree-of-freedom(MDOF)building structures under multi-level ground motions(GMs).This method realizes a design that is effective for various ... A new method of robust damper design is presented for elastic-plastic multi-degree-of-freedom(MDOF)building structures under multi-level ground motions(GMs).This method realizes a design that is effective for various levels of GMs.The robustness of a design is measured by an incremental dynamic analysis(IDA)curve and an ideal drift response curve(IDRC).The IDRC is a plot of the optimized maximum deformation under a constraint on the total damper quantity vs.the design level of the GMs.The total damper quantity corresponds to the total cost of the added dampers.First,a problem of generation of IDRCs is stated.Then,its solution algorithm,which consists of the sensitivity-based algorithm(SBA)and a local search method,is proposed.In the application of the SBA,the passive added dampers are removed sequentially under the specified-level GMs.On the other hand,the proposed local search method can search the optimal solutions for a constant total damper quantity under GMs’increased levels.In this way,combining these two algorithms enables the comprehensive search of the optimal solutions for various conditions of the status of the GMs and the total damper quantity.The influence of selecting the type of added dampers(oil,hysteretic,and so on)and the selection of the input GMs on the IDRCs are investigated.Finally,a robust optimal design problem is formulated,and a simple local search-based algorithm is proposed.A simple index using the IDRC and the IDA curve of the model is used as the objective function.It is demonstrated that the proposed algorithm works well in spite of its simplicity. 展开更多
关键词 Optimal damper placement robust damper design multi-level earthquake ideal drift response curve elastic-plastic MDOF model viscous damper hysteretic damper
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一种改进的裂纹扩展率单一曲线模型及模型指数确定 被引量:1
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作者 孙力 黄瀛偲 黄小平 《Journal of Marine Science and Application》 CSCD 2022年第4期104-115,共12页
It is essential to precisely predict the crack growth,especially the near-threshold regime crack growth under different stress ratios,for most engineering structures consume their fatigue lives in this regime under ra... It is essential to precisely predict the crack growth,especially the near-threshold regime crack growth under different stress ratios,for most engineering structures consume their fatigue lives in this regime under random loading.In this paper,an improved unique curve model is proposed based on the unique curve model,and the determination of the shape exponents of this model is provided.The crack growth rate curves of some materials taken from the literature are evaluated using the improved model,and the results indicate that the improved model can accurately predict the crack growth rate in the nearthreshold and Paris regimes.The improved unique curve model can solve the problems about the shape exponents determination and weak ability around the near-threshold regime meet in the unique curve model.In addition,the shape exponents in the improved model at negative stress ratios are discussed,which can directly adopt that in the unique curve model. 展开更多
关键词 Near-threshold regime Crack growth rate Stress ratio Improved unique curve model Shape exponents
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带有不等式约束的生长曲线模型中线性估计的容许性(英文)
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作者 方龙祥 郭大伟 《Northeastern Mathematical Journal》 CSCD 2007年第6期513-522,共10页
For the growth curve model with respect to inequality restriction: Y = XBZ +ε,ε(0, σ2V I), trNB ≥0, this paper gives some necessary and sufficient conditions for the linear estimator of KBL to be admissible in... For the growth curve model with respect to inequality restriction: Y = XBZ +ε,ε(0, σ2V I), trNB ≥0, this paper gives some necessary and sufficient conditions for the linear estimator of KBL to be admissible in the class of homogeneous linear estimators LH and nonhomogeneous linear estimators LI, respectively, under the quadratic loss function tr(d(Y) - KBL)'(d(Y) - KBL). 展开更多
关键词 inequality restriction ADMISSIBILITY growth curve model linear estimator
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A comparative study of adsorption and regeneration with different agricultural wastes as adsorbents for the removal of methylene blue from aqueous solution 被引量:1
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作者 Sana Dardouri Jalila Sghaier 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第9期1282-1287,共6页
Removal of dye from the industrial wastewater is one of the most important subjects in water pollution regulation.Successive adsorption/desorption cycles of a basic dye, methylene blue, on the internal almond shell, s... Removal of dye from the industrial wastewater is one of the most important subjects in water pollution regulation.Successive adsorption/desorption cycles of a basic dye, methylene blue, on the internal almond shell, sheep manure waste and sawdust were investigated using fixed bed column experiments in order to study the adsorption capacity to remove MB and adsorbent regeneration efficiency. The adsorption breakthrough curves were predicted by the Thomas model, Yoon Nelson model, and Wolborska model and modified dose–response model using non-linear regression analysis. The results showed that the modified dose–response model was more suitable for the description of breakthrough curves for three adsorbents only in the first cycle. Although sheep manure waste presents the highest adsorption capacity, it is hard to regenerate and needs more time regeneration. Conversely, the internal almond shell presents lower adsorption capacity, but they are more readily regenerated. 展开更多
关键词 Fixed bed adsorption Breakthrough curves modeling Adsorbents selection Methylene blue REGENERATION
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Crustal structure and accurate hypocenter determination along the Longmenshan fault zone 被引量:9
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作者 赵珠 范军 +2 位作者 郑斯华 长谷川昭 内茂木 《Acta Seismologica Sinica(English Edition)》 CSCD 1997年第6期66-73,共8页
A P and S wave velocity model is obtained for the crust in the region along the Longmenshan fault zone, Sichuan Province, China, by using data from a refraction profiling survey carried out in this region and those fr... A P and S wave velocity model is obtained for the crust in the region along the Longmenshan fault zone, Sichuan Province, China, by using data from a refraction profiling survey carried out in this region and those from local earthquakes. 202 local earthquakes along the fault zone are based on this velocity model, location errors being estimated to be about 1.5 km. The present relocations fairly improved the accuracy of hypocenter locations for earthquakes in this area, which is recognized from small scatter of data in the arrival time distance diagram compared with that for the original locations in the Earthquake Catalogue of Sichuan Seismic Network. The obtained hypocenter distribution shows that shallow earthquakes, confined to the upper crust in the depth range from 3 km to 22 km, are actively occurring along the main fault of the Longmenshan fault zone. The velocity model and the location method are presently used quite effective for precisely locating local earthquakes such as those in Sichuan Province. Installation of these with the real time processing system developed by Tohoku University in the Sichuan Telemetered Seismic Network would help to improve the location accuracy of events beneath the network. 展开更多
关键词 Longmenshan fault zone P wave S wave hypocenter determination velocity model arrive time curve
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A CT Image Segmentation Algorithm Based on Level Set Method 被引量:1
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作者 QU Jing-yi SHI Hao-shan 《Chinese Journal of Biomedical Engineering(English Edition)》 2006年第2期47-52,共6页
Level Set methods are robust and efficient numerical tools for resolving curve evolution in image segmentation. This paper proposes a new image segmentation algorithm based on Mumford-Shah module. The method is used t... Level Set methods are robust and efficient numerical tools for resolving curve evolution in image segmentation. This paper proposes a new image segmentation algorithm based on Mumford-Shah module. The method is used to CT images and the experiment results demonstrate its efficiency and veracity. 展开更多
关键词 MEDICAL IMAGE segmentation Level set Mumford-Shah model curve evolution
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Identification of potential soil water retention using hydric numerical model at arid regions by land-use changes 被引量:1
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作者 Mohamed Abu-hashim Elsayed Mohamed Abd-ElAziz Belal 《International Soil and Water Conservation Research》 SCIE CSCD 2015年第4期305-315,共11页
Assessment of soil water retention in arid region is an input required parameter in precision water management at large scale.Investigations were carried out in Tanta catchment in the middle Nile Delta,Egypt(30145 N,3... Assessment of soil water retention in arid region is an input required parameter in precision water management at large scale.Investigations were carried out in Tanta catchment in the middle Nile Delta,Egypt(30145 N,30155 E),where collecting soil samples covered different hydrological soil groups and land-uses.Based on the natural resource conservation service curve number model(NRCS-CN),CN approach was used to investigate the effect of spatio-temporal variations of different land-uses on soil water retention.Potential soil water retention from 1990 to 2015 was reduced by 118.1 m^(3) per hectare with decreasing cropland area.Urbanization encroachment from 1990 to 2015 was increased by 2.13%by decreasing cropland with 15.3%(5300 ha in 2015).This resulted in losing the potential soil water retention by 625,968.42 m^(3) water for the whole catchment area.Impact of land degradation was pronounced,where 2.65%,29.35%,and 1.11%of the initial crop land-use in 1990 were converted to bare soil,fallow,and urban area,respectively in 2015.Implementation of(S)value of the NRCS-CN model with GIS technique provides useful measure to identify land-use changes of potential water storage capacity at catchment scale. 展开更多
关键词 curve number model Land-use Potential water retention Spatio-temporal variations
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