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A dimension reduction assisted credit scoring method for big data with categorical features
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作者 Tatjana Miljkovic Pei Wang 《Financial Innovation》 2025年第1期725-754,共30页
In the past decade,financial institutions have invested significant efforts in the development of accurate analytical credit scoring models.The evidence suggests that even small improvements in the accuracy of existin... In the past decade,financial institutions have invested significant efforts in the development of accurate analytical credit scoring models.The evidence suggests that even small improvements in the accuracy of existing credit-scoring models may optimize profits while effectively managing risk exposure.Despite continuing efforts,the majority of existing credit scoring models still include some judgment-based assumptions that are sometimes supported by the significant findings of previous studies but are not validated using the institution’s internal data.We argue that current studies related to the development of credit scoring models have largely ignored recent developments in statistical methods for sufficient dimension reduction.To contribute to the field of financial innovation,this study proposes a Dimension Reduction Assisted Credit Scoring(DRA-CS)method via distance covariance-based sufficient dimension reduction(DCOV-SDR)in Majorization-Minimization(MM)algorithm.First,in the presence of a large number of variables,the DRA-CS method results in greater dimension reduction and better prediction accuracy than the other methods used for dimension reduction.Second,when the DRA-CS method is employed with logistic regression,it outperforms existing methods based on different variable selection techniques.This study argues that the DRA-CS method should be used by financial institutions as a financial innovation tool to analyze high-dimensional customer datasets and improve the accuracy of existing credit scoring methods. 展开更多
关键词 Credit scoring Dimension reduction Logistic regression Majorization-minimization algorithm
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基于贝叶斯优化神经网络的Cu-SiC镀层镀速预测
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作者 魏波 刘翠芳 吕焦盛 《电镀与精饰》 北大核心 2026年第1期123-130,共8页
Cu-SiC镀层镀速受多种因素影响,包括电流密度、镀液成分、温度、搅拌速度等,这些因素与镀速之间存在着复杂的非线性关系。传统的神经网络模型只能处理线性关系,对于复杂的电镀数据特征之间的非线性关系以及时空特性难以有效捕捉,影响了... Cu-SiC镀层镀速受多种因素影响,包括电流密度、镀液成分、温度、搅拌速度等,这些因素与镀速之间存在着复杂的非线性关系。传统的神经网络模型只能处理线性关系,对于复杂的电镀数据特征之间的非线性关系以及时空特性难以有效捕捉,影响了模型超参数的优化速度及预测精度。为此,提出基于贝叶斯优化神经网络的Cu-SiC镀层镀速预测方法。该方法系统性地采集电镀过程中的电流值、镀液温度、镀液pH值、SiC粒子浓度、镀液搅拌速率数据,并采用Z-score标准化方法对每种电镀数据进行归一化处理,以促进模型在不同特征间的有效比较。设计贝叶斯优化神经网络的BO-CNN-LSTM模型,将各种电镀数据的归一化处理结果作为模型输入,同时捕捉电镀数据的空间特征和时间依赖性,利用贝叶斯算法优化层自动搜索模型最优超参数组合。利用最优超参数组合实施模型训练,最终实现Cu-SiC镀层镀速的高效精准预测。实验结果表明,经过贝叶斯算法优化超参数后,该预测方法的决定系数R2显著提升,更接近1。预测结果与实际镀速之间的偏差较小,曲线走势与实际镀速高度一致。此外,该方法的CPU使用率也相对较低。 展开更多
关键词 电镀数据 Z-score标准化 贝叶斯优化算法 BO-CNN-LSTM模型 Cu-SiC镀层 镀速预测
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Improved Hybrid Collaborative Fitering Algorithm Based on Spark Platform 被引量:1
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作者 YOU Zhen HU Hongwen +2 位作者 WANG Yutao XUE Jinyun YI Xinwu 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2023年第5期451-460,共10页
An improved Hybrid Collaborative Filtering algorithm(H-CF)is proposed,addressing the issues of data sparsity,low recommendation accuracy,and poor scalability present in traditional collaborative filtering algorithms.T... An improved Hybrid Collaborative Filtering algorithm(H-CF)is proposed,addressing the issues of data sparsity,low recommendation accuracy,and poor scalability present in traditional collaborative filtering algorithms.The core of H-CF is a linear weighted hybrid algorithm based on the Latent Factor Model(LFM)and the Improved Item Clustering and Similarity Calculation Collaborative Filtering Algorithm(ITCSCF).To begin with,the items are clustered based on their attribute dimension,which accelerates the computation of the nearest neighbor set.Subsequently,H-CF enhances the formula for scoring similarity by penalizing popular items and optimizing unpopular items.This improvement enhances the rationality of scoring similarity and reduces the impact of data sparseness.Furthermore,a weighting function is employed to combine the various improved algorithms.The balance factor of the weighting function is dynamically adjusted to attain the optimal recommendation list.To address the real-time and scalability concerns,the algorithm leverages the Spark big data distributed cluster computing framework.Experiments were conducted using the public dataset Movie Lens,where the improved algorithm’s performance was compared against the algorithm before enhancement and the algorithm running on a single machine.The experimental results demonstrate that the improved algorithm outperforms in terms of data sparsity,recommendation personalization,accuracy,recall,and efficiency. 展开更多
关键词 recommendation algorithm collaborative filtering latent factor model score weighting item clustering SPARK similarity calculation
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TEC and Instrumental Bias Estimation of GAGAN Station Using Kalman Filter and SCORE Algorithm 被引量:1
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作者 Dhiraj Sunehra 《Positioning》 2016年第1期41-50,共10页
The standalone Global Positioning System (GPS) does not meet the higher accuracy requirements needed for approach and landing phase of an aircraft. To meet the Category-I Precision Approach (CAT-I PA) requirements of ... The standalone Global Positioning System (GPS) does not meet the higher accuracy requirements needed for approach and landing phase of an aircraft. To meet the Category-I Precision Approach (CAT-I PA) requirements of civil aviation, satellite based augmentation system (SBAS) has been planned by various countries including USA, Europe, Japan and India. The Indian SBAS is named as GPS Aided Geo Augmented Navigation (GAGAN). The GAGAN network consists of several dual frequency GPS receivers located at various airports around the Indian subcontinent. The ionospheric delay, which is a function of the total electron content (TEC), is one of the main sources of error affecting GPS/SBAS accuracy. A dual frequency GPS receiver can be used to estimate the TEC. However, line-of-sight TEC derived from dual frequency GPS data is corrupted by the instrumental biases of the GPS receiver and satellites. The estimation of receiver instrumental bias is particularly important for obtaining accurate estimates of ionospheric delay. In this paper, two prominent techniques based on Kalman filter and Self-Calibration Of pseudo Range Error (SCORE) algorithm are used for estimation of instrumental biases. The estimated instrumental bias and TEC results for the GPS Aided Geo Augmented Navigation (GAGAN) station at Hyderabad (78.47°E, 17.45°N), India are presented. 展开更多
关键词 GPS Aided Geo Augmented Navigation Total Electron Content Instrumental Biases Kalman Filter Score algorithm
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Quality of experience based scheduling algorithm in LTE network with various traffics
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作者 吴志坤 费泽松 +2 位作者 王飞 巩世琪 李娜 《Journal of Beijing Institute of Technology》 EI CAS 2016年第4期547-552,共6页
Quality of experience ( QoE ) based scheduling algorithm of long term evalution ( LTE ) network with various traffics is studied. Utility functions are adopted to estimate mean opinion score (MOS) for different ... Quality of experience ( QoE ) based scheduling algorithm of long term evalution ( LTE ) network with various traffics is studied. Utility functions are adopted to estimate mean opinion score (MOS) for different traffics and a new MOS metric called normalized MOS is defined. A scheduling algorithm based on normalized MOS and greedy algorithm is proposed, aiming at maximizing the entirety MOS level of the whole users in the cell. We compare the performance of the proposed algorithm with other typical scheduling algorithms and the simulation results show that the algorithm pro- posed outperform other ones in term of QoE and fairness. 展开更多
关键词 quality of experience QoE long term evolution LTE multi-application schedu-ling mean opinion score (MOS) greedy algorithm
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Floyd-Warshall Algorithm Based on Picture Fuzzy Information
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作者 Shaista Habib Aqsa Majeed +1 位作者 Muhammad Akram Mohammed M.Ali Al-Shamiri 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第9期2873-2894,共22页
The Floyd-Warshall algorithm is frequently used to determine the shortest path between any pair of nodes.It works well for crisp weights,but the problem arises when weights are vague and uncertain.Let us take an examp... The Floyd-Warshall algorithm is frequently used to determine the shortest path between any pair of nodes.It works well for crisp weights,but the problem arises when weights are vague and uncertain.Let us take an example of computer networks,where the chosen path might no longer be appropriate due to rapid changes in network conditions.The optimal path from among all possible courses is chosen in computer networks based on a variety of parameters.In this paper,we design a new variant of the Floyd-Warshall algorithm that identifies an All-Pair Shortest Path(APSP)in an uncertain situation of a network.In the proposed methodology,multiple criteria and theirmutual associationmay involve the selection of any suitable path between any two node points,and the values of these criteria may change due to an uncertain environment.We use trapezoidal picture fuzzy addition,score,and accuracy functions to find APSP.We compute the time complexity of this algorithm and contrast it with the traditional Floyd-Warshall algorithm and fuzzy Floyd-Warshall algorithm. 展开更多
关键词 Trapezoidal picture fuzzy number score function accuracy function shortest path problem Floyd-Warshall algorithm
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Automatic piano performance interaction system based on greedy algorithm for dexterous manipulator
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作者 Yufei WANG Junfeng YAO +1 位作者 Yalan ZHOU Zefeng WANG 《虚拟现实与智能硬件(中英文)》 EI 2024年第6期473-485,共13页
With continuous advancements in artificial intelligence(AI), automatic piano-playing robots have become subjects of cross-disciplinary interest. However, in most studies, these robots served merely as objects of obser... With continuous advancements in artificial intelligence(AI), automatic piano-playing robots have become subjects of cross-disciplinary interest. However, in most studies, these robots served merely as objects of observation with limited user engagement or interaction. To address this issue, we propose a user-friendly and innovative interaction system based on the principles of greedy algorithms. This system features three modules: score management, performance control, and keyboard interactions. Upon importing a custom score or playing a note via an external device, the system performs on a virtual piano in line with user inputs. This system has been successfully integrated into our dexterous manipulator-based piano-playing device, which significantly enhances user interactions. 展开更多
关键词 Human-robot interaction Piano-playing robot Greedy algorithm Score parsing
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The Comparison between Random Forest and Support Vector Machine Algorithm for Predicting β-Hairpin Motifs in Proteins
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作者 Shaochun Jia Xiuzhen Hu Lixia Sun 《Engineering(科研)》 2013年第10期391-395,共5页
Based on the research of predictingβ-hairpin motifs in proteins, we apply Random Forest and Support Vector Machine algorithm to predictβ-hairpin motifs in ArchDB40 dataset. The motifs with the loop length of 2 to 8 ... Based on the research of predictingβ-hairpin motifs in proteins, we apply Random Forest and Support Vector Machine algorithm to predictβ-hairpin motifs in ArchDB40 dataset. The motifs with the loop length of 2 to 8 amino acid residues are extracted as research object and thefixed-length pattern of 12 amino acids are selected. When using the same characteristic parameters and the same test method, Random Forest algorithm is more effective than Support Vector Machine. In addition, because of Random Forest algorithm doesn’t produce overfitting phenomenon while the dimension of characteristic parameters is higher, we use Random Forest based on higher dimension characteristic parameters to predictβ-hairpin motifs. The better prediction results are obtained;the overall accuracy and Matthew’s correlation coefficient of 5-fold cross-validation achieve 83.3% and 0.59, respectively. 展开更多
关键词 Random FOREST algorithm Support Vector Machine algorithm β-Hairpin MOTIF INCREMENT of Diversity scoring Function Predicted Secondary Structure Information
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Using the Support Vector Machine Algorithm to Predict β-Turn Types in Proteins
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作者 Xiaobo Shi Xiuzhen Hu 《Engineering(科研)》 2013年第10期386-390,共5页
The structure and function of proteins are closely related, and protein structure decides its function, therefore protein structure prediction is quite important.β-turns are important components of protein secondary ... The structure and function of proteins are closely related, and protein structure decides its function, therefore protein structure prediction is quite important.β-turns are important components of protein secondary structure. So development of an accurate prediction method ofβ-turn types is very necessary. In this paper, we used the composite vector with position conservation scoring function, increment of diversity and predictive secondary structure information as the input parameter of support vector machine algorithm for predicting theβ-turn types in the database of 426 protein chains, obtained the overall prediction accuracy of 95.6%, 97.8%, 97.0%, 98.9%, 99.2%, 91.8%, 99.4% and 83.9% with the Matthews Correlation Coefficient values of 0.74, 0.68, 0.20, 0.49, 0.23, 0.47, 0.49 and 0.53 for types I, II, VIII, I’, II’, IV, VI and nonturn respectively, which is better than other prediction. 展开更多
关键词 Support Vector Machine algorithm INCREMENT of Diversity VALUE Position Conservation scoring Function VALUE Secondary Structure Information
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Improvements in the score matrix calculation method using parallel score estimating algorithm
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作者 Geraldo F.D.Zafalon Evandro A.Marucci +3 位作者 Julio C.Momente Jose R.A.Amazonas Liria M.Sato Jose M.Machado 《Journal of Biophysical Chemistry》 2013年第2期47-51,共5页
The increasing amount of sequences stored in genomic databases has become unfeasible to the sequential analysis. Then, the parallel computing brought its power to the Bioinformatics through parallel algorithms to alig... The increasing amount of sequences stored in genomic databases has become unfeasible to the sequential analysis. Then, the parallel computing brought its power to the Bioinformatics through parallel algorithms to align and analyze the sequences, providing improvements mainly in the running time of these algorithms. In many situations, the parallel strategy contributes to reducing the computational complexity of the big problems. This work shows some results obtained by an implementation of a parallel score estimating technique for the score matrix calculation stage, which is the first stage of a progressive multiple sequence alignment. The performance and quality of the parallel score estimating are compared with the results of a dynamic programming approach also implemented in parallel. This comparison shows a significant reduction of running time. Moreover, the quality of the final alignment, using the new strategy, is analyzed and compared with the quality of the approach with dynamic programming. 展开更多
关键词 algorithmS scoring Matrix Parallel Programming Alignment Quality
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A Sparse Optimal Scoring Model with Adherent Penalty
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作者 Hou Dandan Liu Yongjin 《数学理论与应用》 2024年第4期100-115,共16页
We consider the task of binary classification in the high-dimensional setting where the number of features of the given data is larger than the number of observations.To accomplish this task,we propose an adherently p... We consider the task of binary classification in the high-dimensional setting where the number of features of the given data is larger than the number of observations.To accomplish this task,we propose an adherently penalized optimal scoring(APOS)model for simultaneously performing discriminant analysis and feature selection.In this paper,an efficient algorithm based on the block coordinate descent(BCD)method and the SSNAL algorithm is developed to solve the APOS approximately.The convergence results of our method are also established.Numerical experiments conducted on simulated and real datasets demonstrate that the proposed model is more efficient than several sparse discriminant analysis methods. 展开更多
关键词 Sparse discriminant analysis Optimal scoring Feature selection BCD method SSNAL algorithm
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基于E5-SHAP算法的可解释英语作文自动评分语言模型
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作者 王兵 单瑞雪 +1 位作者 邢海燕 李盼池 《智能科学与技术学报》 2025年第3期370-380,共11页
针对英语作文自动评分系统因依赖复杂深度学习模型而缺乏可解释性的问题,提出了一种基于E5-SHAP算法的可解释英语作文自动评分模型。该模型基于E5-Base模型编码器提取文本特征,结合均值计算和回归层实现评分输出,并引入自适应加权机制,... 针对英语作文自动评分系统因依赖复杂深度学习模型而缺乏可解释性的问题,提出了一种基于E5-SHAP算法的可解释英语作文自动评分模型。该模型基于E5-Base模型编码器提取文本特征,结合均值计算和回归层实现评分输出,并引入自适应加权机制,从语法、句法、词汇多样性等6个维度综合评估作文质量。模型采用LoRA微调技术优化特定层参数,提高对作文特征的适应性。通过SHAP算法计算各特征对最终评分的影响,从而提供清晰的评分依据和解释路径,提升评分过程的透明性和可信度。实验结果表明,与现有模型相比,该模型在ELLIPSE数据集和自建数据集上的表现均有所提升,二次加权卡帕值(QWK)达0.84,在准确性和可解释性上优于现有模型。 展开更多
关键词 英语作文 自动评分模型 E5-SHAP算法 可解释性
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基于数据驱动-物理模型的制冷空调负荷预测及可调潜力分析
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作者 李彬 罗鑫宇 +3 位作者 祁兵 陈宋宋 石坤 刘颖 《电力信息与通信技术》 2025年第10期43-52,共10页
空调制冷负荷作为电网的关键可调弹性资源,评估其在多样化用电需求下的调节潜力,对于优化负荷管理、推动能效提升及节能减排具有显著作用,然而传统的数据驱动模型预测精度差且过拟合现象严重,同时差异化分析制冷空调负荷的调控潜力存在... 空调制冷负荷作为电网的关键可调弹性资源,评估其在多样化用电需求下的调节潜力,对于优化负荷管理、推动能效提升及节能减排具有显著作用,然而传统的数据驱动模型预测精度差且过拟合现象严重,同时差异化分析制冷空调负荷的调控潜力存在困难。因此,文章通过皮尔森和斯皮尔曼等相关系数法量化不同因素与空调负荷的相关性,筛选关键因素作为构建负荷预测模型的自变量,提出一种引入混沌映射和主动运动策略改进蜣螂算法优化注意力机制的双向长短期记忆神经网络模型,基于数据模型预测的负荷曲线,融合空调物理模型的功率特性聚合,运用专家加权评分法,分析各时段空调负荷的调节潜力,实现精准评估。算例分析表明,所提方法能够精确预测空调负荷结果,评估空调负荷潜力准确性高,为空调负荷参与电网需求响应互动提供可靠的依据。 展开更多
关键词 制冷空调负荷 可调潜力 双向长短期记忆 改进蜣螂算法 专家加权累积打分法
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基于胜任力与CatBoost算法的商照训练评估方法
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作者 孙宏 张兆阳 +1 位作者 兰舰 孟晓娅 《航空工程进展》 2025年第5期183-189,共7页
科学量化飞行训练是优化飞行学员技能训练、提升训练效率的前提。以商照阶段为例,构建基于胜任力评估矩阵的飞行学员技能评估方案,以实现按照胜任力的要求来提高飞行训练效果从而管理、筛选学员。利用Z得分法进行典型阶段胜任力培养需... 科学量化飞行训练是优化飞行学员技能训练、提升训练效率的前提。以商照阶段为例,构建基于胜任力评估矩阵的飞行学员技能评估方案,以实现按照胜任力的要求来提高飞行训练效果从而管理、筛选学员。利用Z得分法进行典型阶段胜任力培养需求分析,设计训练评估工作单;采用典型科目(例如,适航要求或发动机失效)的观测项和评分标准构建测量向量;根据科目观测项—可观察行为(OB)间的映射关系构建胜任力评估矩阵,再利用矩阵范数得到OB展现数量和展现频率的公式,借鉴VENN准则思想并结合CatBoost多分类算法,构建基于OB展现数量和展现频率的胜任力评级模型。结合商照实践考核阶段的学员样本进行实证研究,结果表明:模型准确率达到86.67%,能够很好地将飞行教员评级反映到胜任力评级上。 展开更多
关键词 商照飞行训练 Z得分法 胜任力评估 可观察行为 梯度提升树 CatBoost多分类算法
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基于深度强化学习的综合能源系统优化调度
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作者 梁海峰 闫峰 +1 位作者 尚隽 王楚通 《内蒙古电力技术》 2025年第4期21-29,共9页
为减少智能体达到收敛所需的训练轮数,提高经验样本利用效率,优化综合能源系统(Integrated Energy System,IES)能量调度,引入深度强化学习(Deep Reinforcement Learning,DRL)算法,提出一种基于多环境实例和数据特征分数经验采样机制的... 为减少智能体达到收敛所需的训练轮数,提高经验样本利用效率,优化综合能源系统(Integrated Energy System,IES)能量调度,引入深度强化学习(Deep Reinforcement Learning,DRL)算法,提出一种基于多环境实例和数据特征分数经验采样机制的改进深度确定性策略梯度(Deep Deterministic Policy Gradient,DDPG)算法。首先,借助多环境实例促使智能体和环境进行大量交互,从而获得有效的指导经验;其次,对不同类型数据进行特征量化处理,并依据特征分数进行经验采样,提高样本利用效率;最后,将改进DDPG算法与经典柔性动作-评价(Soft Actor⁃Critic,SAC)算法、双延迟深度确定性策略梯度(Twin Delayed Deep Deterministic Policy Gradient,TD3)算法进行对比实验,实验结果验证了所提算法在提高收敛速度和样本利用效率方面的有效性,并通过算例仿真对模型增量学习后的性能提升进行了验证。 展开更多
关键词 综合能源系统 深度强化学习 改进深度确定性策略梯度算法 多环境实例 特征分数
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CT血管造影与常规CT评估急性缺血性卒中评分的临床对比研究
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作者 于晓丽 刘奎 +1 位作者 杨扬 孟令新 《中国CT和MRI杂志》 2025年第1期13-15,共3页
目的 本研究旨在比较早期CT评分(Aspects)及使用CT血管成像(CTA)原始图像与非增强CT (NCCT)在区分不同时间窗内缺血核心体积≥70mL的梗塞范围方面的表现。方法 分析73例AIS-LVO患者的多模式CT表现。自动软件被用来计算方面区域。衰减变... 目的 本研究旨在比较早期CT评分(Aspects)及使用CT血管成像(CTA)原始图像与非增强CT (NCCT)在区分不同时间窗内缺血核心体积≥70mL的梗塞范围方面的表现。方法 分析73例AIS-LVO患者的多模式CT表现。自动软件被用来计算方面区域。衰减变化定义为所有10个方面区域的相对Hounsfield单位(RHU)值与权重因子的乘积之和。各区域的Rh u值为缺血侧的H U值与对侧的HU值。由于Aspects模板中的每个区域在As pects系统中的权重不成比例,因此相应的权重因子是从多变量线性回归模型中得出的回归系数,该模型用于将区域RH U与缺血核心体积相关联。分别使用CTA和NCCT计算自动纵横比和衰减变化。结果在不同的时间窗内(Rho为0.439~0.637),衰减变化与缺血核心体积相关。以缺血核心≥为70mL,其衰减变化表现与Aspects(曲线下面积0.799~0.891)相近,与DeLong's检验(P=0.079,P=0.373)相近,CTA(AU C=0.842)与NCCT(AUC=0.838)无差异。结论Aspects区域的衰减变化与缺血核心体积相关。在脑梗塞体积的分类中,衰减变化具有与自动化方面相当的高诊断能力。复杂的评分算法不涉及衰减变化的测量。这种测量方法可以作为一种有效、快速、可靠、准确的手段来评估不同时间窗内的脑梗塞范围。通过衰减变化测量梗死体积以确定更适合再灌注治疗的患者的有用性可以在未来的临床试验中得到验证。 展开更多
关键词 CT血管造影 非对比CT 急性缺血性卒中 CT评分算法
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全心运动校正算法对冠状动脉钙化积分CT图像质量及测量可重复性的影响
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作者 张卓璐 安备 +3 位作者 商旭 刘卓 王屹 洪楠 《放射学实践》 北大核心 2025年第12期1543-1547,共5页
目的:探讨全心运动校正算法对冠状动脉钙化积分CT扫描图像质量及测量可重复性的影响。方法:回顾性分析2024年11-12月在本院行心脏CT平扫发现有冠脉钙化斑块的211例患者的CT图像。对CT扫描原始数据分别采用无校正的标准算法及第二代冠脉... 目的:探讨全心运动校正算法对冠状动脉钙化积分CT扫描图像质量及测量可重复性的影响。方法:回顾性分析2024年11-12月在本院行心脏CT平扫发现有冠脉钙化斑块的211例患者的CT图像。对CT扫描原始数据分别采用无校正的标准算法及第二代冠脉运动校正算法(snapshot freeze 2,SSF2;GE Healthcare)算法进行图像重建。由两位观察者分别应用4分制评分方法(1分不合格,4分优秀)对两种重建图像的质量进行评估,并采用配对Wilcoxon符号秩检验对两组评分进行比较。基于两组图像分别用两款软件计算冠状动脉钙化积分,并采用Bland Altman比较两款软件测量结果的一致性。结果:基于标准图像和校正图像,测量的冠脉钙化积分分别为353±492和323±461,差异有统计学意义(P<0.001);两组的图像质量评分分别为2.1±0.8和3.5±0.5,差异有统计学意义(P<0.001)。与标准图像相比,矫正图像上测得的钙化积分的一致性区间更窄。结论:与标准算法相比,全心运动校正算法可抑制钙化斑块运动伪影,降低钙化积分并提高测量可重复性。 展开更多
关键词 体层摄影术 X线计算机 冠状动脉 钙化积分 运动校正算法
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基于评分机制的类贪心森林优化特征选择算法 被引量:1
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作者 王霞 张珊 +1 位作者 王勇 王卓然 《控制与决策》 北大核心 2025年第2期517-527,共11页
森林优化特征选择算法(FSFOA)具有良好的分类性能和维度缩减能力,但其初始化森林的质量参差不齐,局部播种和全局播种的随机性较大,且适应度评估代价较高导致计算效率较低.针对上述问题,提出一种基于评分机制的类贪心森林优化特征选择算... 森林优化特征选择算法(FSFOA)具有良好的分类性能和维度缩减能力,但其初始化森林的质量参差不齐,局部播种和全局播种的随机性较大,且适应度评估代价较高导致计算效率较低.针对上述问题,提出一种基于评分机制的类贪心森林优化特征选择算法(FSGLFOA-SM).首先,以每维决策变量的分类精度为其得分构建评分机制,提出类贪心初始化策略以生成较优质的初始化森林;其次,提出基于评分比较的类贪心局部播种策略,使评分相对较高的决策变量获得更大的局部播种概率;然后,在全局播种阶段提出类贪心遗传算子播种策略,对候选森林择优重建并进行遗传、类贪心交叉和变异操作,以保留评分较高的特征维度,有利于提高全局播种阶段的分类准确率;最后,为解决昂贵适应度评估带来的计算效率低下问题,建立历史数据库,在适应度评估前先进行库内查找,减少了重复解个体的计算量.实验结果表明,相比9个对比算法,FSGLFOA-SM在16个UCI数据集上的分类精度和维度缩减率更加优越. 展开更多
关键词 特征选择森林优化算法 评分机制 类贪心 初始化 播种策略 计算效率
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重建算法与滤过核对冠状动脉钙化积分人工智能测量的影响研究
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作者 马梓轩 牛延涛 +3 位作者 刘丹丹 张永县 刘云福 袁琳 《CT理论与应用研究(中英文)》 2025年第5期872-877,共6页
目的:分析重建算法与滤过核对人工智能(AI)测量冠状动脉钙化积分的影响,评估AI测量钙化积分的准确度及危险分层的一致性。方法:连续选取2024年1月冠状动脉钙化积分CT图像进行回顾性分析,共纳入30例,男性18例,女性12例。改变重建算法(FB... 目的:分析重建算法与滤过核对人工智能(AI)测量冠状动脉钙化积分的影响,评估AI测量钙化积分的准确度及危险分层的一致性。方法:连续选取2024年1月冠状动脉钙化积分CT图像进行回顾性分析,共纳入30例,男性18例,女性12例。改变重建算法(FBP、迭代iDose4 level 1~5)与滤过核(Cardiac Standard、Cardiac Sharp)重建出12组图像。采用两种方法(AI图像工作站、CT工作站)分别测量12组图像的冠状动脉Agatston积分(AS)、容积积分(VS)以及质量积分(MS)并计算危险分层。对不同重建算法的图像,使用AI测量和CT工作站测量所得AS、VS、MS进行多样本Friedman检验,对两种滤过核的图像,使用AI测量及CT工作站测量所得AS、VS、MS进行配对Wilcox检验。12组图像使用两种测量方法所得AS、VS、MS进行配对Wilcox检验及组内相关系数(ICC)检验。以CT工作站测量所得结果为参考,采用加权Kappa系数,分析危险分层一致性。结果:Cardiac Standard滤过核时,不同重建算法图像AI所得AS与VS存在统计学差异,MS无统计学差异;Cardiac Sharp滤过核时,不同重建算法图像AI所得AS、VS、MS均无统计学差异。不同重建算法图像CT工作站所得AS与VS存在统计学差异。两种滤过核AI所得AS、VS、MS存在统计学差异;两种滤过核CT工作站所得AS、VS均存在统计学差异。滤过核Cardiac Standard下,两种测量方法所得AS、VS、MS均无统计学差异,滤过核Cardiac Sharp下,两种测量方法所得AS、VS均存在统计学差异,一致性均较好;滤过核为Cardiac Stand且使用iDose 1和2的图像组,危险分层一致性最高,Kappa系数为0.967。结论:重建算法与滤过核对AI和CT工作站测量冠状动脉钙化积分影响较大,临床实践中需谨慎选择。 展开更多
关键词 人工智能 重建算法 钙化积分 滤过核
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贫样本约束下的季度用电量最优组合预测
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作者 邓文奇 缪书唯 李振兴 《三峡大学学报(自然科学版)》 北大核心 2025年第4期88-95,共8页
行政区划变更等原因将限制历史季度用电量数量,对其准确预测提出了挑战.为此,本文提出贫样本约束下的季度用电量最优组合预测模型.首先,将季度用电量数据分解为长期、周期、随机3类分量,应用最小二乘法和综合精度分为各类分量选取最佳... 行政区划变更等原因将限制历史季度用电量数量,对其准确预测提出了挑战.为此,本文提出贫样本约束下的季度用电量最优组合预测模型.首先,将季度用电量数据分解为长期、周期、随机3类分量,应用最小二乘法和综合精度分为各类分量选取最佳拟合函数.其次,对各拟合函数加权组合,并应用果蝇优化算法求取最优组合系数,优化综合精度分,得出该模型参数.然后,收集重庆市直辖初期4年共16组季度用电数据验证本文模型,结果表明该模型对第4年季度用电量预测值的平均绝对百分比误差可达8.962%,低于现有4类预测模型.最后,将本文模型应用至吉林和福建,结果表明本文模型的平均绝对百分比误差最小值可至2.472%. 展开更多
关键词 季度用电量预测 贫样本约束 趋势分解 综合精度分 果蝇优化算法
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