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Asymptotic Solution to Scattering Problem on a Set of Small Particles and Application to Creating the Materials with a Peculiar Refractive Index
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作者 Mykhaylo I. Andriychuk 《Journal of Applied Mathematics and Physics》 2020年第3期375-391,共17页
The asymptotic solution to the scattering problem on a set of small particles, supplemented into homogeneous material, is used for modeling the materials with the desired refractive index. The consideration concerns t... The asymptotic solution to the scattering problem on a set of small particles, supplemented into homogeneous material, is used for modeling the materials with the desired refractive index. The consideration concerns the case of acoustic scalar scattering and the solution to initial scattering problem is built using an asymptotic approach. The closed form solution is reduced for the scattering problem. This is significant advantage of approach because there is no need to solve the respective system of boundary integral equations. High accuracy of solving the scattering problem is achieved by choosing the optimal parameters of the domain with small particles. The approach allows obtaining an explicit formula for the refractive index of the resulting inhomogeneous material. The numerical calculations show the possibility to get the specific values of refractive index including its negative values. 展开更多
关键词 SET of Small Particles SCATTERING problem ASYMPTOTIC Solution PECULIAR Refractive index Computational Modeling
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多代理强化学习驱动遗传算法求解软时间窗电动车路径规划问题
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作者 韩玉艳 安俊宇 +3 位作者 杨晓宇 王玉亭 李寰 田鑫茹 《聊城大学学报(自然科学版)》 2026年第1期32-43,I0001-I0010,共22页
针对考虑电动车能耗、订单时间窗和车辆负载等约束条件的路径优化问题,首先,构建了以路径成本最小化为核心优化目标的混合整数规划模型;然后,根据问题特性,提出多代理强化学习驱动的遗传算法(Multi-Agent Reinforcement Learning-Driven... 针对考虑电动车能耗、订单时间窗和车辆负载等约束条件的路径优化问题,首先,构建了以路径成本最小化为核心优化目标的混合整数规划模型;然后,根据问题特性,提出多代理强化学习驱动的遗传算法(Multi-Agent Reinforcement Learning-Driven Genetic Algorithm,MRLGA)。在MRLGA算法中,运用多代理智能体动态调整遗传算法的变异交叉概率以及选择交叉操作,以提升算法的搜索效率;通过引入香农多样性指数衡量种群多样性,避免算法早熟收敛,有效维护种群的多样性;采用2-opt搜索算法增强局部搜索能力,同时引入离散莱维飞行策略提高全局搜索能力,实现对车辆路径的高效规划。最后,通过120个测试算例展开实验,结果表明所提MRLGA算法在满足复杂约束条件下,能有效降低路径成本,验证了算法的有效性和可行性。 展开更多
关键词 车辆路径问题 遗传算法 香农多样性指数 强化学习
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地形抛物方程的折射率反演问题
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作者 李晓燕 《兰州文理学院学报(自然科学版)》 2026年第1期15-22,共8页
针对非均匀介质中地形抛物方程折射率的复数域反演问题,提出了一种基于最优控制理论的梯度下降算法.通过建立包含正则化约束的目标泛函优化模型,设计了一种高效的迭代求解方案.数值实验表明,在典型非均匀介质条件下,该算法能够精确地重... 针对非均匀介质中地形抛物方程折射率的复数域反演问题,提出了一种基于最优控制理论的梯度下降算法.通过建立包含正则化约束的目标泛函优化模型,设计了一种高效的迭代求解方案.数值实验表明,在典型非均匀介质条件下,该算法能够精确地重构复数域折射率的空间分布,并在存在测量噪声的情况下表现出良好的鲁棒性. 展开更多
关键词 反折射率问题 最优控制 梯度下降法 数值实验
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基于Hash算法的DNA序列k-mer index问题的数学建模 被引量:3
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作者 郭方舟 华阳 +1 位作者 董修伟 蔡志丹 《长春理工大学学报(自然科学版)》 2015年第5期116-119,共4页
针对查找DNA序列的相似序列问题,给出了建立索引和查找索引的数学模型,基于Hash算法,建立了依赖于k值大小的顺序索引模型和散列索引模型,特别对较大k值选用了DJBHash函数,有效的避免了Hash冲突问题。最后在硬件平台CPU为2.6GHz、内存为8... 针对查找DNA序列的相似序列问题,给出了建立索引和查找索引的数学模型,基于Hash算法,建立了依赖于k值大小的顺序索引模型和散列索引模型,特别对较大k值选用了DJBHash函数,有效的避免了Hash冲突问题。最后在硬件平台CPU为2.6GHz、内存为8G、操作系统为64位Windows 7的条件下,对100万条长度为100的DNA序列进行了测试,给出了不同k值下建立和查询索引的用时和占用内存情况,有效的解决了DNA序列的k-mer index问题。 展开更多
关键词 HASH算法 索引问题 数学模型 复杂度分析
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软件实验DNA k-mer index四字链表字典树检索算法
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作者 王辉 于立君 +2 位作者 张旭 高菁 魏智红 《实验室科学》 2018年第1期81-84,共4页
针对软件实验中常涉及到的DNA碱基序列k-mer 问题,提出一种基于四字链表字典树的快速检索算法。根据不同的k值建立深度为k的四字字典树,最大程度地避免字符串中重复公共前缀而造成的空间浪费,压缩内存消耗,降低空间复杂度;以叶子节点作... 针对软件实验中常涉及到的DNA碱基序列k-mer 问题,提出一种基于四字链表字典树的快速检索算法。根据不同的k值建立深度为k的四字字典树,最大程度地避免字符串中重复公共前缀而造成的空间浪费,压缩内存消耗,降低空间复杂度;以叶子节点作为k-mer 结束标志建立索引查询链表,并输出k-mer 的所有序列号与位置号,最终完成DNA序列k-mer 问题的建立索引与快速查找任务。实验表明,该算法具有很高的查找效率,且可以减少查询时间,能够高效解决DNA序列的k-mer index问题。 展开更多
关键词 k-mer问题 四字字典树 索引链表
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ON HILBERT BOUNDARY VALUE PROBLEMS WITH RADICAL 被引量:4
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作者 路见可 《Acta Mathematica Scientia》 SCIE CSCD 2005年第4期755-760,共6页
The Hilbert boundary value problem Re{λ(t) p√ψ+(t)} = c(t), t∈L of normal type with Holder continuous coefficients is discussed, where L is the unit circle |t| = 1,p ≥2 is any definite integer,ψ^+(t)... The Hilbert boundary value problem Re{λ(t) p√ψ+(t)} = c(t), t∈L of normal type with Holder continuous coefficients is discussed, where L is the unit circle |t| = 1,p ≥2 is any definite integer,ψ^+(t) is the boundary value of the unknown function ψ(z) holomorphic in |z| 〈 1 with single-valued continuous p√ψ+(t) on L. 展开更多
关键词 Hilbert boundary value problem index class h0 Plemelj formula normalized canonical function
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MULTIPLE POSITIVE SOLUTIONS FOR SUPERLINEAR SECOND ORDER SINGULAR BOUNDARY VALUE PROBLEMS WITH DERIVATIVE DEPENDENCE 被引量:2
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作者 闫宝强 《Acta Mathematica Scientia》 SCIE CSCD 2008年第4期851-864,共14页
The existence of at least two positive solutions is presented for the singular second-order boundary value problem{1/p(t)( p(t)x′(t))′+Φ(t)f(t,x(t),p(t)x′(t))=0,0〈t〈1, limt→0 p(t)x′(t)=... The existence of at least two positive solutions is presented for the singular second-order boundary value problem{1/p(t)( p(t)x′(t))′+Φ(t)f(t,x(t),p(t)x′(t))=0,0〈t〈1, limt→0 p(t)x′(t)=0,x(1)=0by using the fixed point index, where f may be singular at x = 0 and px ′= 0. 展开更多
关键词 Boundary value problems SINGULARITY fixed point index
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Existence of Multiple Positive Solutions for Singular Impulsive Boundary Value Problems in Banach Space 被引量:3
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作者 徐西安 《Northeastern Mathematical Journal》 CSCD 2004年第3期317-330,共14页
In this paper, we first obtain some new results about the existence of multiple positive solutions for singular impulsive boundary value problems, and then to illustrate our main results we studied the existence of mu... In this paper, we first obtain some new results about the existence of multiple positive solutions for singular impulsive boundary value problems, and then to illustrate our main results we studied the existence of multiple positive solutions for an infinite system of scalar equations. 展开更多
关键词 Singular problem fixed point index multiple positive solution
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The Relationship of Psychological Symptoms among Mothers of Children in Different Body Mass Index Categories
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作者 Gulsen Meral Aysegul Uslu Asli Bostanci 《Open Journal of Pediatrics》 2016年第2期149-157,共9页
We tried to emphasize the importance of psychological status analysis of the mothers of children, who have abnormal Body Mass Index (BMI), when treating these children. Materials and methods: Our study enrolled mother... We tried to emphasize the importance of psychological status analysis of the mothers of children, who have abnormal Body Mass Index (BMI), when treating these children. Materials and methods: Our study enrolled mothers of 150 children in normal, high and low BMI categories who were admitted to Kagithane State Hospital. The inclusion criteria required that these children had no chronic disease, developmental defect, and diagnosed psychological or physical disease impairing the reliability of the interview. Symptom Check List (SCL-90-R) and Beck Depression Scale (BDS) were used on all mothers of these children. In this study, BDS values of high BMI children’s mothers were significantly higher than those of normal BMI children’s mothers and BDS values of mothers of low BMI children were found to be higher than those of mothers of normal BMI children. The SCL-90-R results between mothers of high and normal BMI, high and low BMI, normal and low BMI children were statistically significant. We observed the effect of the psychological state of the family on childhood eating habits and the higher incidence of childhood feeding problems in families with psychopathology. Currently family therapy is indicated according to guidelines in solving eating disorders in children. This approach may also be useful for children with abnormal BMI. 展开更多
关键词 FAMILY CHILDREN Body Mass index Feeding problems DEPRESSION
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Positive Solutions for Fractional Differential Equations with Multi-Point Boundary Value Problems 被引量:1
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作者 Lina Zhou Weihua Jiang 《Journal of Applied Mathematics and Physics》 2014年第5期108-114,共7页
In this paper, a fractional multi-point boundary value problem is considered. By using the fixed point index theory and Krein-Rutman theorem, some results on existence are obtained.
关键词 Caputo FRACTIONAL DERIVATIVE FRACTIONAL INTEGRAL BOUNDARY VALUE problem Fixed Point index Theory
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TWO POSITIVE SOLUTIONS TO THREE-POINT SINGULAR BOUNDARY VALUE PROBLEMS 被引量:3
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作者 李宇华 梁占平 《Acta Mathematica Scientia》 SCIE CSCD 2011年第1期29-38,共10页
In this article, we consider the existence of two positive solutions to nonlinear second order three-point singular boundary value problem: -u′′(t) = λf(t, u(t)) for all t ∈ (0, 1) subjecting to u(0) = ... In this article, we consider the existence of two positive solutions to nonlinear second order three-point singular boundary value problem: -u′′(t) = λf(t, u(t)) for all t ∈ (0, 1) subjecting to u(0) = 0 and αu(η) = u(1), where η ∈ (0, 1), α ∈ [0, 1), and λ is a positive parameter. The nonlinear term f(t, u) is nonnegative, and may be singular at t = 0, t = 1, and u = 0. By the fixed point index theory and approximation method, we establish that there exists λ* ∈ (0, +∞], such that the above problem has at least two positive solutions for any λ ∈ (0, λ*) under certain conditions on the nonlinear term f. 展开更多
关键词 Three-point singular boundary value problem positive solutions fixed point index
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Non-Homogeneous Riemann Boundary Value Problem with Radicals 被引量:7
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作者 Lu Jian-ke School of Mathematics and Statistics,Wuhan University,Wuhan 430072, Hubei,China 《Wuhan University Journal of Natural Sciences》 EI CAS 2002年第4期379-382,共4页
The solution of the non-homogeneous Riemann boundary value problem with radicals (1. 2) together with its condition of solvability is obtained for arbitrary positive integersp andq, which generalizes the results for t... The solution of the non-homogeneous Riemann boundary value problem with radicals (1. 2) together with its condition of solvability is obtained for arbitrary positive integersp andq, which generalizes the results for the casep=q=2. 展开更多
关键词 Riemann boundary value problem branch points of radicals index order at infinity sectionally holomorphic functions
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A Generalized Riemann Boundary Value Problem 被引量:11
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作者 LIU Hua LU Jian 《Wuhan University Journal of Natural Sciences》 CAS 2000年第2期147-149,共3页
The generalized Riemann boundary value problem for analytic functions is considered, where the unknown function may have branch points of the second order. Under certain assumptions, its general solution as well as th... The generalized Riemann boundary value problem for analytic functions is considered, where the unknown function may have branch points of the second order. Under certain assumptions, its general solution as well as the condition of solvability is obtained when the solution is required to be of finite order at infinity. 展开更多
关键词 Riemann boundary value problem sectionally holomorphic function order at infinily index
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EXTENSION OF SOLUTIONS TO RIEMANN BOUNDARY VALUE PROBLEMS AND ITS APPLICATION 被引量:2
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作者 路见可 《Acta Mathematica Scientia》 SCIE CSCD 2007年第4期694-702,共9页
In this paper, solutions of Riemann boundary value problems with nodes are extended to the case where they may have singularties of high order at the nodes. Moreover, further extension is discussed when the free term ... In this paper, solutions of Riemann boundary value problems with nodes are extended to the case where they may have singularties of high order at the nodes. Moreover, further extension is discussed when the free term of the problem involved also possesses singularities at the nodes. As an application, certain singular integral equation is discussed. 展开更多
关键词 Riemann boundary value problem class KN index and canonical function in class KN almost bounded almost of order k characteristic singular integral equation
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Existence and Multiplicity of Positive Solutions for a Singular Third-Order Three-Point Boundary Value Problem with a Parameter
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作者 Xingfang Feng Hanying Feng 《Journal of Applied Mathematics and Physics》 2022年第4期1146-1157,共12页
In this paper, we investigate the existence of positive solutions for a singular third-order three-point boundary value problem with a parameter. By using fixed point index theory, some existence, multiplicity and non... In this paper, we investigate the existence of positive solutions for a singular third-order three-point boundary value problem with a parameter. By using fixed point index theory, some existence, multiplicity and nonexistence results for positive solutions are derived in terms of different values of λ. 展开更多
关键词 Three-Point Boundary Value problem Fixed Point index Positive Solution EXISTENCE MULTIPLICITY
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Optimal index shooting policy for layered missile defense system 被引量:2
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作者 LI Longyue FAN Chengli +2 位作者 XING Qinghua XU Hailong ZHAO Huizhen 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第1期118-129,共12页
In order to cope with the increasing threat of the ballistic missile(BM)in a shorter reaction time,the shooting policy of the layered defense system needs to be optimized.The main decisionmaking problem of shooting op... In order to cope with the increasing threat of the ballistic missile(BM)in a shorter reaction time,the shooting policy of the layered defense system needs to be optimized.The main decisionmaking problem of shooting optimization is how to choose the next BM which needs to be shot according to the previous engagements and results,thus maximizing the expected return of BMs killed or minimizing the cost of BMs penetration.Motivated by this,this study aims to determine an optimal shooting policy for a two-layer missile defense(TLMD)system.This paper considers a scenario in which the TLMD system wishes to shoot at a collection of BMs one at a time,and to maximize the return obtained from BMs killed before the system demise.To provide a policy analysis tool,this paper develops a general model for shooting decision-making,the shooting engagements can be described as a discounted reward Markov decision process.The index shooting policy is a strategy that can effectively balance the shooting returns and the risk that the defense mission fails,and the goal is to maximize the return obtained from BMs killed before the system demise.The numerical results show that the index policy is better than a range of competitors,especially the mean returns and the mean killing BM number. 展开更多
关键词 Gittins index shooting policy layered missile defense multi-armed bandits problem Markov decision process
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Solving Intuitionistic Fuzzy Linear Programming Problem 被引量:3
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作者 Arpita Kabiraj Prasun Kumar Nayak Swapan Raha 《International Journal of Intelligence Science》 2019年第1期44-58,共15页
Intuitionistic Fuzzy Set (IFS) can be used as a general tool for modeling problems of decision making under uncertainty where, the degree of rejection is defined simultaneously with the degree of acceptance of a piece... Intuitionistic Fuzzy Set (IFS) can be used as a general tool for modeling problems of decision making under uncertainty where, the degree of rejection is defined simultaneously with the degree of acceptance of a piece of information in such a way that these degrees are not complement to each other. Accordingly, an attempt is made to solve intuitionistic fuzzy linear programming problems using a technique based on an earlier technique proposed by Zimmermann to solve fuzzy linear programming problem. Our proposed technique does not require the existing ranking of intuitionistic fuzzy numbers. This method is also different from the existing weight assignment method or the Angelov’s method. A comparative study is undertaken and interesting results have been presented. 展开更多
关键词 Intuitionistic FUZZY Set Intuitionistic index Intuitionistic FUZZY NUMBER Intuitionistic FUZZY LINEAR PROGRAMMING problem FUZZY LINEAR PROGRAMMING problem
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电机加减速算法轨迹规划技术应用综述
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作者 艾超 庄定洋 +2 位作者 陈立娟 孙家庆 常振鑫 《机电工程》 北大核心 2025年第5期994-1005,共12页
为了解决采用轨迹技术对电机加减速曲线规划时,电机加减速曲线分段较多,各曲线所用参数之间具有一定耦合性,导致该技术在实际应用过程中存在参数优化工作较为复杂和困难的问题,对该技术大量应用实例和相关文献进行了系统性调研分析。首... 为了解决采用轨迹技术对电机加减速曲线规划时,电机加减速曲线分段较多,各曲线所用参数之间具有一定耦合性,导致该技术在实际应用过程中存在参数优化工作较为复杂和困难的问题,对该技术大量应用实例和相关文献进行了系统性调研分析。首先,对当前诸多应用轨迹规划技术的电机加减速算法数学模型及其加减速曲线的综合性进行了分析,对电机加减速算法轨迹规划方法提出了明确的分类;然后,对部分电机加减速算法轨迹规划技术的应用实例在提升控制目标及控制系统整体性能时所选取的优化方向和优化工作进行了深入分析,确定了电机加减速算法轨迹规划技术的性能指标为柔性和实时性,同时也明确了这两者对系统运行平稳性和电机控制性能的影响以及对应的评估标准;最后,对性能指标进行了分析,根据电机加减速算法轨迹规划技术在飞行控制领域和机床加工领域的应用实例,明确了柔性和实时性这两者和电机加减速算法数学模型之间的联系,并列出了电机加减速算法在优化这两者时存在的一系列共性问题。根据以上研究所得电机加减速算法轨迹规划技术的分类标准、性能指标和共性问题,对该技术进行了展望,为多应用场景下的电驱系统高性能控制研究奠定了基础。 展开更多
关键词 梯形加减速算法 指数型加减速算法 S曲线加减速算法 轨迹规划 性能指标 共性问题
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有噪声加权无标度小世界网络的一致性问题
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作者 董宇泽 章忠志 《计算机工程》 北大核心 2025年第6期20-28,共9页
一致性问题是分布式系统和网络控制中的一个基本问题。传统上,关于一致性的研究主要集中于无权网络,忽略了网络中边的权重影响。然而,现实中的网络,如交通网络、社交网络和电力网络,往往具有显著的加权特性,单纯依赖无权网络模型无法充... 一致性问题是分布式系统和网络控制中的一个基本问题。传统上,关于一致性的研究主要集中于无权网络,忽略了网络中边的权重影响。然而,现实中的网络,如交通网络、社交网络和电力网络,往往具有显著的加权特性,单纯依赖无权网络模型无法充分刻画其中的复杂交互行为。为了将权重影响纳入网络分析,重点研究了一类伪分形加权网络簇,探讨了边的权重对网络一致性的影响。利用拉普拉斯矩阵构建基尔霍夫指标与网络一致性的关系,深入分析一致性问题在加权网络中的表现。通过计算在相邻迭代间不同指标的递推关系,推导出相关指标的精确计算公式,包括基尔霍夫指标、加法基尔霍夫指标、乘法基尔霍夫指标和网络一致性等重要量的计算公式。数值分析表明,随着网络规模的增长,加权网络中的一致性逐渐收敛为常数,网络能够更好地抵抗外部噪声的影响。 展开更多
关键词 加权网络 电阻距离 基尔霍夫指标 一致性问题 伪分形网络
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基于奥马哈问题分类系统构建主动脉夹层术后病人康复期随访指标
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作者 郑栋莲 吉双对 +3 位作者 马富珍 马世林 张竹英 郭淑萍 《循证护理》 2025年第6期1045-1051,共7页
目的:构建主动脉夹层(AD)术后病人随访指标,规范病人康复期随访管理内容,及时发现并解决病人疾病康复期的健康相关问题,为制定和完善AD病人随访支持决策提供参考。方法:基于奥马哈问题分类系统,结合文献分析及半结构式访谈提取AD术后病... 目的:构建主动脉夹层(AD)术后病人随访指标,规范病人康复期随访管理内容,及时发现并解决病人疾病康复期的健康相关问题,为制定和完善AD病人随访支持决策提供参考。方法:基于奥马哈问题分类系统,结合文献分析及半结构式访谈提取AD术后病人康复期随访护理需求,初步形成随访指标。于2022年12月—2023年2月选取16名专家进行2轮函询,形成AD术后病人随访指标体系,根据专家意见修订后形成终稿。结果:2轮函询专家的积极系数分别为88.89%、93.75%;专家权威系数为0.900、0.919;肯德尔和谐系数为0.223、0.467(均P<0.001)。最终形成包含4个一级指标、18个二级指标、51个三级指标的AD术后病人康复期随访指标。结论:本研究构建的AD术后病人康复期随访指标的科学性、实用性较强,能为临床护理人员开展随访工作及健康教育支持决策提供参考。 展开更多
关键词 主动脉夹层 康复期 指标体系 问题分类系统 随访 德尔菲技术 护理
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