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ESTIMATE ON THE BLOCH CONSTANT FOR CERTAIN HARMONIC MAPPINGS UNDER A DIFFERENTIAL OPERATOR
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作者 陈洁玲 刘名生 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期295-310,共16页
In this paper,we first obtain the precise values of the univalent radius and the Bloch constant for harmonic mappings of the formL(f)=zfz-zfz,where f represents normalized harmonic mappings with bounded dilation.Then,... In this paper,we first obtain the precise values of the univalent radius and the Bloch constant for harmonic mappings of the formL(f)=zfz-zfz,where f represents normalized harmonic mappings with bounded dilation.Then,using these results,we present better estimations for the Bloch constants of certain harmonic mappings L(f),where f is a K-quasiregular harmonic or open harmonic.Finally,we establish three versions of BlochLandau type theorem for biharmonic mappings of the form L(f).These results are sharp in some given cases and improve the related results of earlier authors. 展开更多
关键词 Bloch-Landau type theorem Bloch constant linear complex operator harmonic mapping biharmonic mapping UNIVALENT
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LINEAR DILATATION OF QUASIREGULAR MAPPINGS IN SPACE 被引量:2
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作者 陈克应 《Acta Mathematica Scientia》 SCIE CSCD 2001年第2期213-220,共8页
This paper presents an explicit upper bound for the linear dilatation of K- quasiregular (K-qr) mappings, which improves S. Rickman's [6, P.37] corresponding re- sult for K-qr mappings and generalizes P. Seittenra... This paper presents an explicit upper bound for the linear dilatation of K- quasiregular (K-qr) mappings, which improves S. Rickman's [6, P.37] corresponding re- sult for K-qr mappings and generalizes P. Seittenranta's [7, Theorem 1.5] result for K- quasiconformal (K-qc) maps. 展开更多
关键词 K-qr mapping K-qc map linear dilatation local index MODULUS normal domain
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Combinations of Right Half-Plane Mappings and Vertical Strip Mappings Convex in the Vertical Direction
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作者 Yulin Cai Zirun She +1 位作者 Fanji Zeng Lu Huang 《Open Journal of Statistics》 2023年第6期941-954,共14页
In this paper, we explore the linear combinations of right half-plane mappings and vertical strip mappings. We demonstrate that the combinations of these harmonic mappings are convex in the vertical direction provided... In this paper, we explore the linear combinations of right half-plane mappings and vertical strip mappings. We demonstrate that the combinations of these harmonic mappings are convex in the vertical direction provided they are locally univalent and sense-preserving. Furthermore, we extend this analysis to a more general case by setting specific conditions. Additionally, we take some common parameters such as  as the dilatation of these harmonic mappings, and prove the sufficient conditions that their combinations are locally univalent and convex in the vertical direction. Several examples are constructed by the Mathematica software to demonstrate our main results. 展开更多
关键词 Harmonic mapping linear Combination Cohn’s Rules Directional Convexi-ty
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Dissipative Properties of ω-Order Preserving Partial Contraction Mapping in Semigroup of Linear Operator
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作者 Akinola Yussuff Akinyele Kamilu Rauf +1 位作者 Aasa Moses Adebowale Omosowon Jude Babatunde 《Advances in Pure Mathematics》 2019年第6期544-550,共7页
This paper consists of dissipative properties and results of dissipation on infinitesimal generator of a C0-semigroup of ω-order preserving partial contraction mapping (ω-OCPn) in semigroup of linear operator. The p... This paper consists of dissipative properties and results of dissipation on infinitesimal generator of a C0-semigroup of ω-order preserving partial contraction mapping (ω-OCPn) in semigroup of linear operator. The purpose of this paper is to establish some dissipative properties on ω-OCPn which have been obtained in the various theorems (research results) and were proved. 展开更多
关键词 SEMIGROUP linear OPERATOR DISSIPATIVE OPERATOR CONTRACTION mapping and RESOLVENT
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Non-Linear Effects in Optical Systems by Lie Algebra and Symplectic Mapping
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作者 Víctor M. Castañ o 《Journal of Modern Physics》 CAS 2022年第11期1314-1323,共10页
The use of signals of different frequencies determines the geometrical deviation with respect to the optical axes of a given beam. This angle can be determined by Sympletic Map (SM), a powerful and simple mathematical... The use of signals of different frequencies determines the geometrical deviation with respect to the optical axes of a given beam. This angle can be determined by Sympletic Map (SM), a powerful and simple mathematical tool for the characterization and construction of images in Geometrical Optics. The Sympletic Map constitutes a Lie Group, with an algebra associated: the Lie Algebra. In general, the SM can be expressed as an infinite series, where each term corresponds to different contributions produced by the optical devices that constitute the optical system (lenses, apertures, bandwidth cutoff, etc.). The level of correction to be performed on the image to recover the original object is clear and controllable by SM. This formalism can be extended easily to physical optics to describe diffraction and interference phenomena. 展开更多
关键词 Symplectic mapping Geometrical Optics Non-linear Effects
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Genetic mapping of quantitative trait loci in crops 被引量:7
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作者 Yang Xu Pengcheng Li +1 位作者 Zefeng Yang Chenwu Xu 《The Crop Journal》 SCIE CAS CSCD 2017年第2期175-184,共10页
Dissecting the genetic architecture of complex traits is an ongoing challenge for geneticists.Two complementary approaches for genetic mapping,linkage mapping and association mapping have led to successful dissection ... Dissecting the genetic architecture of complex traits is an ongoing challenge for geneticists.Two complementary approaches for genetic mapping,linkage mapping and association mapping have led to successful dissection of complex traits in many crop species.Both of these methods detect quantitative trait loci(QTL) by identifying marker–trait associations,and the only fundamental difference between them is that between mapping populations,which directly determine mapping resolution and power.Based on this difference,we first summarize in this review the advances and limitations of family-based mapping and natural population-based mapping instead of linkage mapping and association mapping.We then describe statistical methods used for improving detection power and computational speed and outline emerging areas such as large-scale meta-analysis for genetic mapping in crops.In the era of next-generation sequencing,there has arisen an urgent need for proper population design,advanced statistical strategies,and precision phenotyping to fully exploit high-throughput genotyping. 展开更多
关键词 Family-based mapping Natural population-based mapping Mixed linear model MAGIC population Meta-analysis Genotyping by sequencing
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Discontinuous bifurcation and coexistence of attractors in a piecewise linear map with a gap 被引量:5
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作者 屈世显 卢永智 +1 位作者 张林 何大韧 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第12期4418-4423,共6页
Coexistence of attractors with striking characteristics is observed in this work, where a stable period-5 attractor coexists successively with chaotic band-ll, period-6, chaotic band-12 and band-6 attractors. They are... Coexistence of attractors with striking characteristics is observed in this work, where a stable period-5 attractor coexists successively with chaotic band-ll, period-6, chaotic band-12 and band-6 attractors. They are induced by dif- ferent mechanisms due to the interaction between the discontinuity and the non-invertibility. A characteristic boundary collision bifurcation, is observed. The critical conditions are obtained both analytically and numerically. 展开更多
关键词 coexistence of attractors piecewise linear map mapping hole discontinuous bifurcation
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STABILITY RESULTS FOR GENERALIZED CONTRACTIVE MAPPINGS 被引量:1
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作者 黄震宇 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 2000年第1期83-90,共8页
Using a more general contractive definition, this paper continues the study on T stable Ishikawa iteration procedure and generalizes most of the results of Harder and Hicks [1] , Osilike [5] and Rhoades [6-8] . A note... Using a more general contractive definition, this paper continues the study on T stable Ishikawa iteration procedure and generalizes most of the results of Harder and Hicks [1] , Osilike [5] and Rhoades [6-8] . A note on [6][8] is also presented. [WT5,5”HZ] 展开更多
关键词 ISHIKAWA fixed point ITERATION contractive mappingS NORMED linear space T stable.
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Noise destroys the coexistence of periodic orbits of a piecewise linear map 被引量:1
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作者 王参军 杨科利 屈世显 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第3期205-208,共4页
The effects of Gaussian white noise and Gaussian colored noise on the periodic orbits of period-5(P-5) and period-6(P-6) in their coexisting domain of a piecewise linear map are investigated numerically.The probab... The effects of Gaussian white noise and Gaussian colored noise on the periodic orbits of period-5(P-5) and period-6(P-6) in their coexisting domain of a piecewise linear map are investigated numerically.The probability densities of some orbits are calculated.When the noise intensity is D = 0.0001,only the orbits of P-5 exist,and the coexisting phenomenon is destroyed.On the other hand,the self-correlation time τ of the colored noise also affects the coexisting phenomenon.When τc〈τ〈τc,only the orbits of P-5 appear,and the stability of the orbits of P-5 is enhanced.However,when τ〉τc(τc and τc are critical values),only the orbits of P-6 exist,and the stability of the P-6 orbits is enhanced greatly.When τ〈τc,the orbits of P-5 and P-6 coexist,but the stability of the P-5 orbits is enhanced and that of P-6 is weakened with τ increasing. 展开更多
关键词 piecewise linear map noise periodic orbit
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GIS Based Landslide Susceptibility Mapping with Application of Analytical Hierarchy Process in District Ghizer, Gilgit Baltistan Pakistan 被引量:3
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作者 Irum Rahim Syeda Maria Ali Maria Aslam 《Journal of Geoscience and Environment Protection》 2018年第2期34-49,共16页
District Ghizer is a rugged mountainous territory which experiences several landslides each year. There are 16 major landslide areas and 53 villages that are at high risk to hazards. Keeping in view the severity of na... District Ghizer is a rugged mountainous territory which experiences several landslides each year. There are 16 major landslide areas and 53 villages that are at high risk to hazards. Keeping in view the severity of natural hazards, the present study was designed to generate landslide susceptibility map based on twelve causative factors viz., slope, aspect, elevation, drainage network, Stream Power Index (SPI), Topographic Wetness Index (TWI), lithological units, fault lines, rainfall, road network, land cover and soil texture. Soil texture was determined by particle size analysis and data for other factors were acquired from freely available sources. Analytical Hierarchy Process (AHP) was employed to identify major landslide causative factors in the district Ghizer. Further, a temporal assessment from 1999 till 2015 was generated to assess the impact of land cover change on landslides. It indicated that the barren soil/ exposed rocks and glaciers have reduced while the vegetation and water classes have shown increment. The total area that lies in moderate to very high landslide susceptible zones was 74.38%, while slope is the main landslide causative factor in the district Ghizer. Validation of the susceptibility map showed 88.1% of the landslides in the study area had occurred in the moderate to very high susceptible zones. 展开更多
关键词 LANDSLIDE SUSCEPTIBILITY mapping (LSM) Analytical HIERARCHY Process (AHP) GEOGRAPHIC Information System (GIS) Weighted linear Combination (WLC) Remote Sensing (RS)
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GROUNDWATER QUALITY AND CONTAMINATION INDEX MAPPING IN CHANGCHUN CITY,CHINA 被引量:16
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作者 Hamadoun BOKAR 《Chinese Geographical Science》 SCIE CSCD 2004年第1期63-70,共8页
Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·... Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·Mg2+ or HCO3--Mg2+·Ca2+; SO42--Ca2+ and SO42--Ca2+·Mg2+; Cl--Ca2+; and CO32--Na+. The deteriorations of groundwater quality due to the increase of TDS, NO3-+ NO2-(as Nitrogen) and TH contents have been observed from 1991 to 1998. Scatter analyses showed strong positive correlations between Ca2+, Cl-and NO3-ions and weak negative correlations between the depth of water table and Ca2+, SO42-, Cl-and NO3-ions. A mapping of contaminant index based on Chinese standard of groundwater showed that a large proportion of the groundwater in 1998 was deteriorated by human process. Despite their low values of sodium adsorption ratio (SAR), the most of the sampled wells were not suitable for drinking and agriculture purposes due to higher contents of NO3-, NO2-and Mn2+ ions. 展开更多
关键词 地下水 污染 防治 水质化学 线性回归分析 GIS
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Landslides susceptibility mapping in Guizhou province based on fuzzy theory 被引量:8
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作者 WANG Wei-dong XIE Cui-ming DU Xiang-gang 《Mining Science and Technology》 EI CAS 2009年第3期399-404,共6页
The purpose of this study was to assess the susceptibility of landslides around the area of Guizhou province based on fuzzy theory.In first instance, slope, elevation, lithology, proximity to tectonic lines, proximity... The purpose of this study was to assess the susceptibility of landslides around the area of Guizhou province based on fuzzy theory.In first instance, slope, elevation, lithology, proximity to tectonic lines, proximity to drainage and annual precipitation were taken as independent, causal factors in this study.A landslide hazard evaluation factor system was established by classifying these factors into more subclasses according to some rules.Secondly, a trapezoidal fuzzy number weighting(TFNW) approach was used to assess the importance of six causal factors to landslides in an ArcGIS environment.Thirdly, a landslide susceptibility map was created based on a weighted linear combination model.According to this susceptibility map, the study area was classified into four categories of landslide susceptibility:low, moderate, high and very high.Finally, in order to verify the results obtained, the susceptibility map and the landslide inventory map were combined in the GIS.In addition, the weighting procedure showed that TFNW is an efficient method for weighting causal landslide factors. 展开更多
关键词 滑坡灾害 模糊理论 敏感性 贵州省 绘图 ArcGIS 梯形模糊数 易感性
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Multi-objective Optimal Design of Vibration Absorber with Simple Cell Mapping Algorithm 被引量:1
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作者 Jianqiao Sun Wen Zheng +2 位作者 Furui Xiong Zhichang Qin Qian Ding 《Transactions of Tianjin University》 EI CAS 2017年第5期488-492,共5页
In this paper, we investigate a multi-objective optimal design of a tuned vibration absorber for a two degrees-of-freedom linear system, in which we take white Gaussian noise as the excitation. We use the simple cell ... In this paper, we investigate a multi-objective optimal design of a tuned vibration absorber for a two degrees-of-freedom linear system, in which we take white Gaussian noise as the excitation. We use the simple cell mapping method to obtain solutions to the multi-objective optimization problem. We optimize tuned vibration absorbers in two different configurations. As our objective,we take various features of the response of the power spectrum density function. Our results show that the primary mass vibration with the optimally designed absorber has a lower peak power spectrum value. In addition, the two natural frequencies of the optimized system are further apart than in the non-optimized system, which implies that the absorber has a wider effective region in the frequency domain. 展开更多
关键词 VIBRATION ABSORBER SIMPLE CELL mapping method MULTI-OBJECTIVE optimization
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Mapping QTL for Categorical Traits with Multivariate Regression
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作者 田佺 杨润清 《Journal of Shanghai Jiaotong university(Science)》 EI 2005年第S1期97-102,共6页
Simple linear regression analysis has been used to map QTL for quantitative traits. Many traits of biological interest and/or economical importance in various species show binary phenotypic distributions (e.g., presen... Simple linear regression analysis has been used to map QTL for quantitative traits. Many traits of biological interest and/or economical importance in various species show binary phenotypic distributions (e.g., presence or absence). It has been shown that such a binary trait also can be analyzed with the simple linear regression, subject to virtually no loss in power compared to the generalized linear model analysis. Binary trait is a special case of a multiple categorical trait (e.g., low, medium or high). We propose a mechanism to decompose a multiple categorical trait into an array of correlated binary variables. The categorical trait turned multiple binary traits are analyzed with a multivariate linear regression method. Turning the problem of categorical trait mapping into that of multivariate mapping allows the exploration of pleiotropic effects of QTL for different categories. Efficiency of the method is verified through a series of simulation experiments. 展开更多
关键词 CATEGORICAL TRAIT mapping QTL MULTIVARIATE linear regression analysis
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Solution of Nonlinear Advection-Diffusion Equations via Linear Fractional Map Type Nonlinear QCA 被引量:1
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作者 Shinji Hamada Hideo Sekino 《Journal of Quantum Information Science》 2016年第4期263-295,共33页
Linear fractional map type (LFMT) nonlinear QCA (NLQCA), one of the simplest reversible NLQCA is studied analytically as well as numerically. Linear advection equation or Time Dependent Schr&ouml;dinger Equation (... Linear fractional map type (LFMT) nonlinear QCA (NLQCA), one of the simplest reversible NLQCA is studied analytically as well as numerically. Linear advection equation or Time Dependent Schr&ouml;dinger Equation (TDSE) is obtained from the continuum limit of linear QCA. Similarly it is found that some nonlinear advection-diffusion equations including inviscid Burgers equation and porous-medium equation are obtained from LFMT NLQCA. 展开更多
关键词 Nonlinear Quantum Cellular Automaton QCA Quantum Walk linear Fractional map Advection-Diffusion Equation Burgers Equation Porous-Medium Equation SOLITON
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Linear-fitting-based similarity coefficient map for tissue dissimilarity analysis in T2^*-w magnetic resonance imaging
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作者 余绍德 伍世宾 +5 位作者 王浩宇 魏新华 陈鑫 潘万龙 Hu Jiani 谢耀钦 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第12期610-615,共6页
Similarity coefficient mapping(SCM) aims to improve the morphological evaluation of T*2weighted magnetic resonance imaging(T*2-w MRI). However, how to interpret the generated SCM map is still pending. Moreover, ... Similarity coefficient mapping(SCM) aims to improve the morphological evaluation of T*2weighted magnetic resonance imaging(T*2-w MRI). However, how to interpret the generated SCM map is still pending. Moreover, is it probable to extract tissue dissimilarity messages based on the theory behind SCM? The primary purpose of this paper is to address these two questions. First, the theory of SCM was interpreted from the perspective of linear fitting. Then, a term was embedded for tissue dissimilarity information. Finally, our method was validated with sixteen human brain image series from multiecho T*2-w MRI. Generated maps were investigated from signal-to-noise ratio(SNR) and perceived visual quality, and then interpreted from intra- and inter-tissue intensity. Experimental results show that both perceptibility of anatomical structures and tissue contrast are improved. More importantly, tissue similarity or dissimilarity can be quantified and cross-validated from pixel intensity analysis. This method benefits image enhancement, tissue classification, malformation detection and morphological evaluation. 展开更多
关键词 T*2-w magnetic resonance imaging similarity coefficient map linear fitting tissue dissimilarity
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Non-linear Invertible Maps that Preserve Staircase Subalgebras
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作者 ZHAO YAN-XIA XIA YU-LING 《Communications in Mathematical Research》 CSCD 2012年第3期265-274,共10页
Let g be the general linear Lie algebra consisting of all n x n matrices over a field F and with the usual bracket operation {x, y} =xy - yx. An invertible map φ : g →g is said to preserve staircase subalgebras if ... Let g be the general linear Lie algebra consisting of all n x n matrices over a field F and with the usual bracket operation {x, y} =xy - yx. An invertible map φ : g →g is said to preserve staircase subalgebras if it maps every staircase subalgebra to some staircase subalgebra of the same dimension. In this paper, we devote to giving an explicit description on the invertible maps on g that preserve staircase subalgebras. 展开更多
关键词 general linear Lie algebra staircase subalgebra non-linear map
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Linear Maps Preserving Idempotency of Products of Matrices on Upper Triangular Matrix Algebras
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作者 QI JING Ji GUO-XING 《Communications in Mathematical Research》 CSCD 2009年第3期253-264,共12页
Let Tn be the algebra of all n × n complex upper triangular matrices. We give the concrete forms of linear injective maps on Tn which preserve the nonzero idempotency of either products of two matrices or triple ... Let Tn be the algebra of all n × n complex upper triangular matrices. We give the concrete forms of linear injective maps on Tn which preserve the nonzero idempotency of either products of two matrices or triple Jordan products of two matrices. 展开更多
关键词 linear map MATRIX IDEMPOTENT product of two matrices triple Jordan product of two matrices
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Non-Traveling Wave Solutions for the (1 + 1)-Dimensional Burgers System by Riccati Equation Mapping Approach
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作者 Ruiyang Xu Songhua Ma 《Applied Mathematics》 2013年第10期123-125,共3页
Starting from the symbolic computation system Maple and Riccati equation mapping approach and a linear variable separation approach, a new family of non-traveling wave solutions of the (1 + 1)-dimensional Burgers syst... Starting from the symbolic computation system Maple and Riccati equation mapping approach and a linear variable separation approach, a new family of non-traveling wave solutions of the (1 + 1)-dimensional Burgers system is derived. 展开更多
关键词 Riccati Equation mapping APPROACH linear Variable Separation APPROACH BURGERS SYSTEM Non-Traveling Wave Solutions
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An Automatic Approach for Satisfying Dose-Volume Constraints in Linear Fluence Map Optimization for IMPT
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作者 Maryam Zaghian Gino Lim +1 位作者 Wei Liu Radhe Mohan 《Journal of Cancer Therapy》 2014年第2期198-207,共10页
Prescriptions for radiation therapy are given in terms of dose-volume constraints (DVCs). Solving the fluence map optimization (FMO) problem while satisfying DVCs often requires a tedious trial-and-error for selecting... Prescriptions for radiation therapy are given in terms of dose-volume constraints (DVCs). Solving the fluence map optimization (FMO) problem while satisfying DVCs often requires a tedious trial-and-error for selecting appropriate dose control parameters on various organs. In this paper, we propose an iterative approach to satisfy DVCs using a multi-objective linear programming (LP) model for solving beamlet intensities. This algorithm, starting from arbitrary initial parameter values, gradually updates the values through an iterative solution process toward optimal solution. This method finds appropriate parameter values through the trade-off between OAR sparing and target coverage to improve the solution. We compared the plan quality and the satisfaction of the DVCs by the proposed algorithm with two nonlinear approaches: a nonlinear FMO model solved by using the L-BFGS algorithm and another approach solved by a commercial treatment planning system (Eclipse 8.9). We retrospectively selected from our institutional database five patients with lung cancer and one patient with prostate cancer for this study. Numerical results show that our approach successfully improved target coverage to meet the DVCs, while trying to keep corresponding OAR DVCs satisfied. The LBFGS algorithm for solving the nonlinear FMO model successfully satisfied the DVCs in three out of five test cases. However, there is no recourse in the nonlinear FMO model for correcting unsatisfied DVCs other than manually changing some parameter values through trial and error to derive a solution that more closely meets the DVC requirements. The LP-based heuristic algorithm outperformed the current treatment planning system in terms of DVC satisfaction. A major strength of the LP-based heuristic approach is that it is not sensitive to the starting condition. 展开更多
关键词 FLUENCE map Optimization (FMO) linear PROGRAMMING (LP) Nonlinear PROGRAMMING (NLP) Dose-Volume Constraint (DVC) Intensity-Modulated Proton Therapy (IMPT)
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