期刊文献+
共找到10篇文章
< 1 >
每页显示 20 50 100
广义等效均匀剂量生物优化法在食管癌调强计划的应用
1
作者 葛佳林 何瑞龙 +1 位作者 廖润超 许士奇 《承德医学院学报》 2024年第1期5-9,共5页
目的探讨食管癌调强计划中广义等效均匀剂量生物优化法的应用。方法选取承德医学院附属医院8例食管癌患者。每位患者使用三种方式进行运算,分别是对心脏和肺采用单目标物理优化法(PlanA),多目标物理优化法(PlanB)以及广义等效均匀剂量... 目的探讨食管癌调强计划中广义等效均匀剂量生物优化法的应用。方法选取承德医学院附属医院8例食管癌患者。每位患者使用三种方式进行运算,分别是对心脏和肺采用单目标物理优化法(PlanA),多目标物理优化法(PlanB)以及广义等效均匀剂量生物优化法(PlanC)。脊髓及其外放的约束条件保持不变,对比3组计划的优劣。结果在靶区和脊髓以及脊髓外扩剂量没有发生明显变化时,用广义等效均匀剂量生物优化法设计的计划在肺和心脏的大部分均值都下降,Plan A与Plan C对比显示,肺的V5、V10、V20、V30及Dmean均有差异且具有统计学意义(P<0.05),心脏的V5、V10、V20及Dmean均有差异且具有统计学意义(P<0.05)。Plan B与PlanC对比显示,肺的V5、V10、V20、V30、V40及Dmean均有差异且具有统计学意义(P<0.05),心脏的V5、V20及Dmean均有差异且具有统计学意义(P<0.05)。在剂量体积直方图(DVH)的显示中,在计划靶区(PTV)曲线没有明显变化且脊髓及脊髓外扩也没有明显变化的情况下,肺和心脏的曲线均有不同程度的左移。并且肺的正常组织并发症概率(NTCP)下降且具有统计学意义(P<0.05)。结论采用广义等效均匀剂量生物优化法可以降低肺和心脏的照射剂量。广义等效剂量生物优化法要更优于多目标优化法和单目标优化法,可以更好的保护危及器官。 展开更多
关键词 广义等效均匀剂量生物优化法 食管癌 单目标优化 多目标优化
下载PDF
广义等效均匀剂量优化法在左侧乳腺癌调强放疗中的剂量学研究 被引量:4
2
作者 何赟 郭亚 +3 位作者 王亚利 许琨 苏王辉 李宇星 《现代肿瘤医学》 CAS 北大核心 2021年第21期3825-3829,共5页
目的:探讨左侧乳腺癌根治术后调强放疗中广义等效均匀剂量的生物优化法的剂量学优势。方法:选取我院2020年01月到2020年12月30例接受调强放射治疗的左侧乳腺癌患者,每例患者计划靶区均采用剂量-体积的物理优化法;并行危及器官左肺和心... 目的:探讨左侧乳腺癌根治术后调强放疗中广义等效均匀剂量的生物优化法的剂量学优势。方法:选取我院2020年01月到2020年12月30例接受调强放射治疗的左侧乳腺癌患者,每例患者计划靶区均采用剂量-体积的物理优化法;并行危及器官左肺和心脏采用单约束物理优化法(Plan1)、多约束物理优化法(Plan2)以及广义等效均匀剂量的生物优化法(Plan3),右肺、脊髓及其外放的约束条件保持不变,分别评价三组计划的优劣;串行危及器官脊髓及其外放仅采用单约束物理优化法(Plan3)以及广义等效均匀剂量的生物优化法(Plan4),左右肺、心脏的约束条件保持不变,分别评价两组计划的优劣。结果:采用不同优化方法的三组计划Plan1、Plan2和Plan3;以及采用不同优化方法的两组计划Plan3和Plan4靶区的适形度指数CI和均匀性指数HI差异均无统计学意义(P>0.05)。并行危及器官左肺和心脏的剂量Plan3最优,其次是Plan2,最差是Plan1;串行危及器官脊髓及其外放的剂量Plan4优于Plan3且差异均有统计学意义(P<0.05)。结论:广义等效均匀剂量的生物优化法可有效降低危及器官受量且不影响靶区的适形度指数CI以及均匀性指数HI,值得临床中推广使用。 展开更多
关键词 单约束物理优化 多约束物理优化 广义等效均匀剂量 生物优化法 剂量
下载PDF
广义等效均匀剂量在鼻咽癌患者放射治疗计划听力保护中的剂量学研究
3
作者 陈娟 张明 +5 位作者 包超恩 翟福山 樊佳艺 张波 陈伟 刘胤良 《中国医学装备》 2023年第3期21-25,共5页
目的:探讨广义等效均匀剂量(gEUD)的生物优化法在鼻咽癌(NPC)调强放射治疗(IMRT)保护听力的计划设计中剂量学优势。方法:选取医院收治并实施动态IMRT的12例NPC患者,每例患者计划靶区均采用剂量-体积物理优化法。根据调强计划优化条件将... 目的:探讨广义等效均匀剂量(gEUD)的生物优化法在鼻咽癌(NPC)调强放射治疗(IMRT)保护听力的计划设计中剂量学优势。方法:选取医院收治并实施动态IMRT的12例NPC患者,每例患者计划靶区均采用剂量-体积物理优化法。根据调强计划优化条件将危及器官(OAR)耳蜗、内耳分为未限制计划(Plan-A组)、单物理优化法计划(Plan-B组)以及叠加gEUD的生物优化法计划(Plan-B+X组)3组计划方案,分别评价3组计划的双侧耳蜗、内耳接受的最小剂量(D_(min))、平均剂量(D_(mean))、55 Gy剂量的体积百分比(V_(55))和最大剂量(D_(max))。结果:3组计划的双侧耳蜗、内耳的受量均值Plan-B+X组和Plan-B组均低于Plan-A;Plan-B+X组左侧耳蜗的D_(min)、D_(mean)、D_(max)和V_(55)均低于Plan-A组,差异均有统计学意义(t=1.545,t=1.909,t=1.045,t=1.909;P<0.05),右侧耳蜗Plan-B+X组D_(min)、D_(mean)和D_(max)均低于Plan-A组,差异均有统计学意义(t=1.273,t=1.727;t=1.818;P<0.05)。Plan-B+X组左侧、右侧内耳的D_(mean)、V_(55)和D_(max)均低于Plan-A组,差异均有统计学意义(t_(左侧)=1.727,t=1.636,t=1.636;t_(右侧)=1.364,t=1.455,t=1.364;P<0.05)。结论:基于广义等效均匀剂量的生物优化法可有效降低双侧耳蜗、内耳受量,从而改善放射治疗患者不良反应,对于指导NPC患者的放射治疗计划设计具有重要临床意义。 展开更多
关键词 生物优化法 广义等效均匀剂量(gEUD) 动态调强放射治疗(IMRT) 鼻咽癌(NPC)
下载PDF
Two-dimensional cross entropy multi-threshold image segmentation based on improved BBO algorithm 被引量:2
4
作者 LI Wei HU Xiao-hui WANG Hong-chuang 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2018年第1期42-49,共8页
In order to improve the global search ability of biogeography-based optimization(BBO)algorithm in multi-threshold image segmentation,a multi-threshold image segmentation based on improved BBO algorithm is proposed.Whe... In order to improve the global search ability of biogeography-based optimization(BBO)algorithm in multi-threshold image segmentation,a multi-threshold image segmentation based on improved BBO algorithm is proposed.When using BBO algorithm to optimize threshold,firstly,the elitist selection operator is used to retain the optimal set of solutions.Secondly,a migration strategy based on fusion of good solution and pending solution is introduced to reduce premature convergence and invalid migration of traditional migration operations.Thirdly,to reduce the blindness of traditional mutation operations,a mutation operation through binary computation is created.Then,it is applied to the multi-threshold image segmentation of two-dimensional cross entropy.Finally,this method is used to segment the typical image and compared with two-dimensional multi-threshold segmentation based on particle swarm optimization algorithm and the two-dimensional multi-threshold image segmentation based on standard BBO algorithm.The experimental results show that the method has good convergence stability,it can effectively shorten the time of iteration,and the optimization performance is better than the standard BBO algorithm. 展开更多
关键词 two-dimensional cross entropy biogeography-based optimization(BBO)algorithm multi-threshold image segmentation
下载PDF
Fuzzy-second order sliding mode control optimized by genetic algorithm applied in direct torque control of dual star induction motor 被引量:1
5
作者 Ghoulemallah BOUKHALFA Sebti BELKACEM +1 位作者 Abdesselem CHIKHI Moufid BOUHENTALA 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第12期3974-3985,共12页
The direct torque control of the dual star induction motor(DTC-DSIM) using conventional PI controllers is characterized by unsatisfactory performance, such as high ripples of torque and flux, and sensitivity to parame... The direct torque control of the dual star induction motor(DTC-DSIM) using conventional PI controllers is characterized by unsatisfactory performance, such as high ripples of torque and flux, and sensitivity to parametric variations. Among the most evoked control strategies adopted in this field to overcome these drawbacks presented in classical drive, it is worth mentioning the use of the second order sliding mode control(SOSMC) based on the super twisting algorithm(STA) combined with the fuzzy logic control(FSOSMC). In order to realize the optimal control performance, the FSOSMC parameters are adjusted using an optimization algorithm based on the genetic algorithm(GA). The performances of the envisaged control scheme, called G-FSOSMC, are investigated against G-SOSMC, G-PI and BBO-FSOSMC algorithms. The proposed controller scheme is efficient in reducing the torque and flux ripples, and successfully suppresses chattering. The effects of parametric uncertainties do not affect system performance. 展开更多
关键词 double star induction machine direct torque control fuzzy second order sliding mode control genetic algorithm biogeography based optimization algorithm
下载PDF
Biodiesel Production by Enzymatic Catalysis Process Using Two Analytical Ways: Gas Chromatography and Total Glycerol Determination
6
作者 Ignacio Contreras Andrade Jonathan Parra Santiago +2 位作者 Jose Ricardo Sodre Joseph Sebastian Pathiyamattom Carlos Alberto Guerrero-Fajardo 《Journal of Chemistry and Chemical Engineering》 2014年第7期717-726,共10页
Currently, biodiesel is presented as one of the best alternatives for gradually replacing the use of fossil fuels, but it has some factors that make it economically impractical if it does not have a government support... Currently, biodiesel is presented as one of the best alternatives for gradually replacing the use of fossil fuels, but it has some factors that make it economically impractical if it does not have a government support. For this reason, research efforts focused on this area have been responsible for optimizing the process of biodiesel production by different catalytic routes to achieve greater efficiency at a lower cost. In this case, the biggest problem has been the high cost generated by an investigation, which in many occasions is the main factor to decide if an investigation could be carried out. Trying to reduce these costs, in the current study, we are using a technique of glycerol quantification by volumetric methods and comparing obtained results with the chromatographic method, which is conventionally used and comparatively much more expensive. Biodiesel employee was obtained by an enzymatic catalysis process varying one of three process variables:oil:alcohol molar ratio, temperature and proportion of catalyst. The numerical differences obtained between the two quantification methods generated relative errors lower than 10%, resulting in some occasions lower than 1%. By gas chromatography analysis the best yield was obtained at the same conditions of the volumetric method, a temperature of 45 ℃, an oil:alcohol ratio 1:4 and 8 wt.% of catalyst, but a yield of 95.5% and 97.1%, respectively. Due to the high precision of gas chromatography, this method is used to carry out a surface response analysis obtaining as ideal operating conditions a temperature of 43.5 ℃, 8.9 wt.%. of catalyst and an oil:alcohol ratio 1:4. 展开更多
关键词 Biodiesel production glycerol determination gas chromatography enzymatic catalysis.
下载PDF
One-step process for production of biodiesel from Jatropha curcas L. seeds: Optimization using Response Surface Methodology (RSM) 被引量:1
7
作者 Asnida Yanti Ani Mohd Fauzi Abdullah Mohd Azlan Mohd Ishak Khudzir Ismail 《Journal of Chemistry and Chemical Engineering》 2009年第12期15-22,共8页
Jatropha curcas L. (JCL) seeds were extracted and transesterified in-situ using supercritical methanol extraction in the absence of catalyst at different temperatures (200-280℃) and pressures (8-12 MPa), and at... Jatropha curcas L. (JCL) seeds were extracted and transesterified in-situ using supercritical methanol extraction in the absence of catalyst at different temperatures (200-280℃) and pressures (8-12 MPa), and at a fixed reaction time of 30 min with seeds-to-methanol ratio of 1:40 w/v. Design of experiment approach using five-level-two-factors design of Response Surface Methodology (RSM) was used to observe the effect of two independent variables i.e. temperature and pressure and the percent of biodiesel yield which required 13 runs. For optimization of the variables, Central Composite Rotatable Design (CCRD) was used for regression analysis and analysis of variance (ANOVA). The optimize conditions suggested by RSM were at T = 280℃ and P = 12.04 MPa. The predicted and experimental biodicsel yields were found to be 56.8% and 59.9%, respectively, with relatively small deviation errors of 1.59%. 展开更多
关键词 Jatropha curcas L. supercritical methanol In situ transesterification BIODIESEL Response Surface Methodology (RSM)
下载PDF
A Biologic Behavior Simulation: Living Migration Algorithm (LMA)
8
作者 李豆豆 邵世煌 齐金鹏 《Journal of Donghua University(English Edition)》 EI CAS 2008年第2期130-134,共5页
Biologic behaviors are the principal source for proposing new intelligent algorithms. Based on the mechanism of the bio-subsistence and the bio-migration, this paper proposes a novel algorithm—Living Migration Algori... Biologic behaviors are the principal source for proposing new intelligent algorithms. Based on the mechanism of the bio-subsistence and the bio-migration, this paper proposes a novel algorithm—Living Migration Algorithm (LMA). The original contributions of LMA are three essential attributes of each individual: the minimal life-needs which are the necessaries for survival, the migrating which is a basal action for searching new living space, and the judging which is an important ability of deciding whether to migrate or not. When living space of all individuals can satisfy the minimal life-needs at some generation, they are considered as the optimal living places where objective functions will obtain the optima. LMA may be employed in large-scale computation and engineering field. The paper mostly operates LMA to deal with four non-linear and heterogeneous optimizations, and experiments prove LMA has better performances than Free Search algorithm. 展开更多
关键词 bio-migration free search particle swarm optimization ant colony search
下载PDF
Optimization for Determination of Esters in Biodiesel Oil by Spectrophotometric Method
9
作者 Mangkorn Kitiphatmontree Kesanee Yindeechat Watchara Youlamyai Arekaradate Retvereeyasakul 《Journal of Chemistry and Chemical Engineering》 2010年第9期1-5,共5页
The simple spectrophotometric method for the determination of esters has been developed. The procedure is based on the quantitative determination of ferric hydroxamate generated from the reaction of esters, hydroxylam... The simple spectrophotometric method for the determination of esters has been developed. The procedure is based on the quantitative determination of ferric hydroxamate generated from the reaction of esters, hydroxylamine hydrochloride in basic solution at 120℃, and ferric chloride. The formed complex was monitored through absorbance at 517 nm. The parameters affecting the absorbance value were explored for optimum analytical performance. The optimum conditions were 1.50 mL of 0.5 M hydroxylamine hydrochloride, 0.40 mL of 6 M sodium hydroxide, 1.00 mL of 3 M hydrochloric acid and 0.50 mL of 5 % ferric chloride. The method exhibits linear response up to 7.50% wt. and a detection limit of 0.23% wt. The linear range and working range were used at the same range 1.25 to 7.50% wt. The proposed method can be applied to biodiesel (B 100) for measuring the esters quantity in the percentage unit of biodiesel oil. 展开更多
关键词 Determination esters BIODIESEL spectrophotometry.
下载PDF
Dolphin swarm algorithm 被引量:9
10
作者 Tian-qi WU Min YAO Jian-hua YANG 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2016年第8期717-729,共13页
By adopting the distributed problem-solving strategy, swarm intelligence algorithms have been successfully applied to many optimization problems that are difficult to deal with using traditional methods. At present, t... By adopting the distributed problem-solving strategy, swarm intelligence algorithms have been successfully applied to many optimization problems that are difficult to deal with using traditional methods. At present, there are many well-implemented algorithms, such as particle swarm optimization, genetic algorithm, artificial bee colony algorithm, and ant colony optimization. These algorithms have already shown favorable performances. However, with the objects becoming increasingly complex, it is becoming gradually more difficult for these algorithms to meet human's demand in terms of accuracy and time. Designing a new algorithm to seek better solutions for optimization problems is becoming increasingly essential. Dolphins have many noteworthy biological characteristics and living habits such as echolocation, information exchanges, cooperation, and division of labor. Combining these biological characteristics and living habits with swarm intelligence and bringing them into optimization problems, we propose a brand new algorithm named the ‘dolphin swarm algorithm' in this paper. We also provide the definitions of the algorithm and specific descriptions of the four pivotal phases in the algorithm, which are the search phase, call phase, reception phase, and predation phase. Ten benchmark functions with different properties are tested using the dolphin swarm algorithm, particle swarm optimization, genetic algorithm, and artificial bee colony algorithm. The convergence rates and benchmark function results of these four algorithms are compared to testify the effect of the dolphin swarm algorithm. The results show that in most cases, the dolphin swarm algorithm performs better. The dolphin swarm algorithm possesses some great features, such as first-slow-then-fast convergence, periodic convergence, local-optimum-free, and no specific demand on benchmark functions. Moreover, the dolphin swarm algorithm is particularly appropriate to optimization problems, with more calls of fitness functions and fewer individuals. 展开更多
关键词 Swarm intelligence Bio-inspired algorithm DOLPHIN OPTIMIZATION
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部