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Innovative Machine Learning Approaches for Drinking Water Quality Classification:Addressing Data Imbalances with Custom SMOTE Sampling Strategy
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作者 Borislava Toleva Ivan Ivanov Kalina Kitova 《Journal of Environmental & Earth Sciences》 2025年第3期262-273,共12页
This study demonstrates the complexity and importance of water quality as a measure of the health and sustainability of ecosystems that directly influence biodiversity,human health,and the world economy.The predictabi... This study demonstrates the complexity and importance of water quality as a measure of the health and sustainability of ecosystems that directly influence biodiversity,human health,and the world economy.The predictability of water quality thus plays a crucial role in managing our ecosystems to make informed decisions and,hence,proper environmental management.This study addresses these challenges by proposing an effective machine learning methodology applied to the“Water Quality”public dataset.The methodology has modeled the dataset suitable for providing prediction classification analysis with high values of the evaluating parameters such as accuracy,sensitivity,and specificity.The proposed methodology is based on two novel approaches:(a)the SMOTE method to deal with unbalanced data and(b)the skillfully involved classical machine learning models.This paper uses Random Forests,Decision Trees,XGBoost,and Support Vector Machines because they can handle large datasets,train models for handling skewed datasets,and provide high accuracy in water quality classification.A key contribution of this work is the use of custom sampling strategies within the SMOTE approach,which significantly enhanced performance metrics and improved class imbalance handling.The results demonstrate significant improvements in predictive performance,achieving the highest reported metrics:accuracy(98.92%vs.96.06%),sensitivity(98.3%vs.71.26%),and F1 score(98.37%vs.79.74%)using the XGBoost model.These improvements underscore the effectiveness of our custom SMOTE sampling strategies in addressing class imbalance.The findings contribute to environmental management by enabling ecology specialists to develop more accurate strategies for monitoring,assessing,and managing drinking water quality,ensuring better ecosystem and public health outcomes. 展开更多
关键词 Data Modeling Class imbalance SMOTE Machine Learning Classification Model Estimation Water Quality Dataset
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Increase in global per capita cropland imbalance across countries from 1985 to 2022:A threat to achieving Sustainable Development Goals
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作者 Tingting Zhao Xiao Zhang +3 位作者 Wendi Liu Jinqing Wang Zhehua Li Liangyun Liu 《Geography and Sustainability》 2025年第2期253-264,共12页
Sustainable Development Goal 2(SDG 2,zero hunger)highlights that global hunger and food insecurity have worsened since 2015,driven in part by growing imbalance.Addressing the challenge of achieving SDG 2 in the face o... Sustainable Development Goal 2(SDG 2,zero hunger)highlights that global hunger and food insecurity have worsened since 2015,driven in part by growing imbalance.Addressing the challenge of achieving SDG 2 in the face of rapid global population growth requires sustained attention to global and national cropland changes.Accurately quantifying the correlation between population and cropland area(i.e.,SDG 2.4.1 per capita cropland)and analyzing the trends of global cropland imbalance are essential for a comprehensive understanding of SDG 2.In this study,we utilized a new global 30 m land-cover dynamic dataset(GLC_FCS30D)to analyze cropland dynamics,quantify per capita cropland and its changes across various countries and levels of development.Our results indicate that the global cropland area expanded by 0.944 million km^(2)from 1985 to 2022,with an average expansion rate of 2.42×10^(4)km^(2)/yr.However,the global per capita cropland area decreased from 0.347 ha in 1985 to 0.217 ha in 2022,mainly due to a higher population increase of nearly 65%in the same period.In the context of globalization,cropland expansion and per capita cropland exhibited spatial imbalances globally,particularly in developing countries.Developing countries saw an increase in total cropland area by 7.09%but a significant decrease in per capita cropland area by 37.38%.From a temporal perspective,the global imbalance has been steadily increasing with the Gini index rising from 0.895 in 1985 to 0.909 in 2022.Consequently,this study reveals an increasing imbalance of global per capita cropland across various countries,which threatens the attainment of the targets of SDG 2. 展开更多
关键词 Sustainable Development Goals GLC_FCS30D Cropland changes Population imbalance
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Distribution and imbalance of basic research funding in environmental chemistry in China
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作者 Weiyi Wang Qian Liu +1 位作者 Guibin Jiang Qiankun Zhuang 《Journal of Environmental Sciences》 2025年第9期267-277,共11页
This study investigates the distribution and imbalances of research funding in the field of Environmental Chemistry,utilizing application and funding data fromthe National Natural Science Foundation of China(NSFC)over... This study investigates the distribution and imbalances of research funding in the field of Environmental Chemistry,utilizing application and funding data fromthe National Natural Science Foundation of China(NSFC)over the past decade.The findings reveal significant regional disparities,with Eastern regions receiving over 70%of the national funding,while the Northeast accounts for only 4%to 6.5%.Additionally,the analysis shows notable differences in funding allocation among various research institutions,with a substantial portion of funds concentrated in a few leading institutions,leading to inequities across different types and levels of organizations.The impact of applicant gender on funding disparities is relatively minor;although female applicants have a slightly lower funding rate,the concentration of funds is marginally higher among females.Furthermore,the study highlights that key projects and talent-oriented initiatives,due to their significant funding concentration,exacerbate the existing imbalances.Overall,this research provides valuable insights for optimizing funding policies and advocates for a more equitable distribution of resources in Environmental Chemistry research,addressing the identified disparities. 展开更多
关键词 Scientific fund National natural science foundation of China Environmental chemistry POLICY Regional imbalance
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Handling class imbalance of radio frequency interference in deep learning-based fast radio burst search pipelines using a deep convolutional generative adversarial network
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作者 Wenlong Du Yanling Liu Maozheng Chen 《Astronomical Techniques and Instruments》 2025年第1期10-15,共6页
This paper addresses the performance degradation issue in a fast radio burst search pipeline based on deep learning.This issue is caused by the class imbalance of the radio frequency interference samples in the traini... This paper addresses the performance degradation issue in a fast radio burst search pipeline based on deep learning.This issue is caused by the class imbalance of the radio frequency interference samples in the training dataset,and one solution is applied to improve the distribution of the training data by augmenting minority class samples using a deep convolutional generative adversarial network.Experi.mental results demonstrate that retraining the deep learning model with the newly generated dataset leads to a new fast radio burst classifier,which effectively reduces false positives caused by periodic wide-band impulsive radio frequency interference,thereby enhancing the performance of the search pipeline. 展开更多
关键词 Fast radio burst Deep convolutional generative adversarial network Class imbalance Radio frequency interference Deep learning
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Initial serum electrolyte imbalances and mortality in patients with traumatic brain injury:a retrospective study
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作者 Ahammed Mekkodathil Ayman El-Menyar +5 位作者 Talat Chughtai Ahmed Abdel-Aziz Bahey Ahmed Labib Shehatta Ali Ayyad Abdulnasser Alyafai Hassan Al-Thani 《World Journal of Emergency Medicine》 2025年第4期331-339,共9页
BACKGROUND:Electrolyte imbalance is common following traumatic brain injury(TBI)and can significantly impact patient outcomes.We aimed to explore the occurrence,patterns,and consequences of electrolyte imbalance in ad... BACKGROUND:Electrolyte imbalance is common following traumatic brain injury(TBI)and can significantly impact patient outcomes.We aimed to explore the occurrence,patterns,and consequences of electrolyte imbalance in adult patients with TBI.METHODS:A retrospective study was conducted from 2016 to 2021 at a level 1 trauma center among hospitalized TBI patients.On admission,the levels of serum electrolytes,including sodium,potassium,calcium,magnesium,and phosphate,were analyzed.Demographics,injury characteristics,and interventions were assessed.The primary outcome was the in-hospital mortality.Multivariate logistic regression analysis was performed to identify independent predictors of mortality in TBI patients.RESULTS:A total of 922 TBI patients were included in the analysis,of whom 902(98%)had electrolyte imbalance.The mean age of patients with electrolyte imbalance was 32.0±15.0 years.Most patients were males(94%).The most common electrolyte abnormalities were hypocalcemia,hypophosphatemia,and hypokalemia.The overall in-hospital mortality rate was 22%in the entire cohort.In multivariate logistic analysis,the predictors of mortality included age(odds ratio[OR]=1.029,95%confidence intervals[CI]:1.013-1.046,P<0.001),low GCS(OR=0.883,95%CI:0.816-0.956,P=0.002),high Injury Severity Score(ISS)scale(OR=1.051,95%CI:1.026-1.078,P<0.001),hypernatremia(OR=2.175,95%CI:1.196-3.955,P=0.011),hyperkalemia(OR=4.862,95%CI:1.222-19.347;P=0.025),low serum bicarbonate levels(OR=0.926,95%CI:0.868-0.988,P=0.020),high serum lactate levels(OR=1.128,95%CI:1.022-1.244,P=0.017),high glucose levels(OR=1.072,95%CI:1.014-1.133,P=0.015),a longer activated partial thromboplastin time(OR=1.054,95%CI:1.024-1.084,P<0.001)and higer international normalized ratio(INR)(OR=3.825,95%CI:1.592-9.188,P=0.003).CONCLUSION:Electrolyte imbalance is common in TBI patients,with the significant prevalence of hypocalcemia,hypophosphatemia,and hypokalemia.However,hypernatremia and hyperkalemia were associated with the risk of mortality,emphasizing the need for further research to comprehend electrolyte dynamics in TBI patients. 展开更多
关键词 Electrolyte imbalance Traumatic brain injury MORTALITY
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IDS-INT:Intrusion detection system using transformer-based transfer learning for imbalanced network traffic 被引量:11
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作者 Farhan Ullah Shamsher Ullah +1 位作者 Gautam Srivastava Jerry Chun-Wei Lin 《Digital Communications and Networks》 SCIE CSCD 2024年第1期190-204,共15页
A network intrusion detection system is critical for cyber security against llegitimate attacks.In terms of feature perspectives,network traffic may include a variety of elements such as attack reference,attack type,a... A network intrusion detection system is critical for cyber security against llegitimate attacks.In terms of feature perspectives,network traffic may include a variety of elements such as attack reference,attack type,a subcategory of attack,host information,malicious scripts,etc.In terms of network perspectives,network traffic may contain an imbalanced number of harmful attacks when compared to normal traffic.It is challenging to identify a specific attack due to complex features and data imbalance issues.To address these issues,this paper proposes an Intrusion Detection System using transformer-based transfer learning for Imbalanced Network Traffic(IDS-INT).IDS-INT uses transformer-based transfer learning to learn feature interactions in both network feature representation and imbalanced data.First,detailed information about each type of attack is gathered from network interaction descriptions,which include network nodes,attack type,reference,host information,etc.Second,the transformer-based transfer learning approach is developed to learn detailed feature representation using their semantic anchors.Third,the Synthetic Minority Oversampling Technique(SMOTE)is implemented to balance abnormal traffic and detect minority attacks.Fourth,the Convolution Neural Network(CNN)model is designed to extract deep features from the balanced network traffic.Finally,the hybrid approach of the CNN-Long Short-Term Memory(CNN-LSTM)model is developed to detect different types of attacks from the deep features.Detailed experiments are conducted to test the proposed approach using three standard datasets,i.e.,UNsWNB15,CIC-IDS2017,and NSL-KDD.An explainable AI approach is implemented to interpret the proposed method and develop a trustable model. 展开更多
关键词 Network intrusion detection Transfer learning Features extraction imbalance data Explainable AI CYBERSECURITY
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Exposure to ephedrine attenuates Th1/Th2 imbalance underlying OVA-induced asthma through airway epithelial cell-derived exo-somal lnc-TRPM2-AS 被引量:2
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作者 HU Yan WANG Mengqing +3 位作者 XIE Jing JIAO Luojia DING Yi LUO Yinhe 《Chinese Journal of Natural Medicines》 SCIE CAS CSCD 2024年第6期530-540,共11页
Although various anti-inflammatory medications,such as ephedrine,are employed to manage cough-variant asthma,their underlying mechanisms are yet to be fully understood.Recent studies suggest that exosomes derived from... Although various anti-inflammatory medications,such as ephedrine,are employed to manage cough-variant asthma,their underlying mechanisms are yet to be fully understood.Recent studies suggest that exosomes derived from airway epithelial cells(AECs)contain components like messenger RNAs(mRNAs),micro-RNAs(miRNAs),and long noncoding RNA(lncRNA),which play roles in the occurrence and progression of airway inflammation.This study investigates the influence of AEC-derived exosomes on the efficacy of ephedrine in treating cough-variant asthma.We established a mouse model of asthma and measured airway resist-ance and serum inflammatory cell levels.Real-time polymerase chain reaction(RT-qPCR),Western blotting,and enzyme-linked im-munosorbent assay(ELISA)analyses were used to assess gene and protein expression levels.Exosomes were isolated and character-ized.RNA immunoprecipitation(RIP)and RNA pull-down assays were conducted to examine the interaction between hnRNPA2B1 and lnc-TRPM2-AS1.In the ovalbumin(OVA)-challenged mouse model,ephedrine treatment reduced inflammatory responses,air-way resistance,and Th1/Th2 cell imbalance.Exosomes from OVA-treated AECs showed elevated levels of lnc-TRPM2-AS1,which were diminished following ephedrine treatment.The exosomal lnc-TRPM2-AS1 mediated the Th1/Th2 imbalance in CD4^(+)T cells,with its packaging into exosomes being facilitated by hnRNPA2B1.This study unveils a novel mechanism by which ephedrine ameli-orates OVA-induced CD4^(+)T cell imbalance by suppressing AEC-derived exosomal lnc-TRPM2-AS1.These findings could provide a theoretical framework for using ephedrine in asthma treatment. 展开更多
关键词 ASTHMA EPHEDRINE Exosomal lnc-TRPM2-AS1 Th1/Th2 imbalance HnRNPA2B1 Airway epithelial cells
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Nuciferine alleviates collagen-induced arthritic in rats by inhibiting the proliferation and invasion of human arthritis-derived fibroblast-like synoviocytes and rectifying Th17/Treg imbalance 被引量:1
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作者 WANG Hao GENG Xiaolong +7 位作者 AI Fangbin YU Zhilun ZHANG Yan ZHANG Beibei LV Cheng GAO Ruiyang YUE Bei DOU Wei 《Chinese Journal of Natural Medicines》 SCIE CAS CSCD 2024年第4期341-355,共15页
Rheumatoid arthritis(RA)is a chronic autoimmune disorder marked by persistent synovial inflammation and joint degradation,posing challenges in the development of effective treatments.Nuciferine,an alkaloid found in lo... Rheumatoid arthritis(RA)is a chronic autoimmune disorder marked by persistent synovial inflammation and joint degradation,posing challenges in the development of effective treatments.Nuciferine,an alkaloid found in lotus leaf,has shown promising anti-inflammatory and anti-tumor effects,yet its efficacy in RA treatment remains unexplored.This study investigated the antiproliferative effects of nuciferine on the MH7A cell line,a human RA-derived fibroblast-like synoviocyte,revealing its ability to inhibit cell proliferation,promote apoptosis,induce apoptosis,and cause G1/S phase arrest.Additionally,nuciferine significantly reduced the migration and invasion capabilities of MH7A cells.The therapeutic potential of nuciferine was further evaluated in a collagen-induced arthritis(CIA)rat model,where it markedly alleviated joint swelling,synovial hyperplasia,cartilage injury,and inflammatory infiltration.Nuciferine also improved collagen-induced bone erosion,decreased pro-inflammatory cytokines and serum immunoglobulins(IgG,IgG1,IgG2a),and restored the balance between T helper(Th)17 and regulatory T cells in the spleen of CIA rats.These results indicate that nuciferine may offer therapeutic advantages for RA by decreasing the proliferation and invasiveness of FLS cells and correcting the Th17/Treg cell imbalance in CIA rats. 展开更多
关键词 Rheumatoid arthritis Collagen-induced arthritis Fibroblast-like synoviocyte Immune imbalance NUCIFERINE
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Molybdenum and cadmium co-induce necroptosis through Th1/Th2 imbalance-mediated endoplasmic reticulum stress in duck ovaries
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作者 Ting Cui Xueyan Dai +5 位作者 Huiling Guo Dianyun Wang Bingyan Huang Wenjing Pu Xuesheng Chu Caiying Zhang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第8期92-102,共11页
Cadmium(Cd)and excess molybdenum(Mo)pose serious threats to animal health.Our previous study has determined that Cd and/or Mo exposure can cause ovarian damage of ducks,while the specific mechanism is still obscure.To... Cadmium(Cd)and excess molybdenum(Mo)pose serious threats to animal health.Our previous study has determined that Cd and/or Mo exposure can cause ovarian damage of ducks,while the specific mechanism is still obscure.To further investigate the toxic mechanism of Cd and Mo co-exposure in the ovary,forty 8-day-old female ducks were randomly allocated into four groups for 16 weeks,and the doses of Cd and Mo in basic diet per kg were as follows:control group,Mo group(100 mg Mo),Cd group(4 mg Cd),and Mo+Cd group(100 mg Mo+4 mg Cd).Cadmium sulfate 8/3-hydrate(CdSO_(4)·8/3H_(2)O)and hexaammonium molybdate((NH_(4))_(6)Mo_(7)O_(24)·4H_(2)O)were the origins of Cd and Mo,respectively.At the 16th week of the experiment,all ovary tissues were collected for the detection of related indexes.The data indicated that Mo and/or Cd induced trace element disorders and Th1/Th2 balance to divert toward Th1 in the ovary,which activated endoplasmic reticulum(ER)stress and then provoked necroptosis through triggering RIPK1/RIPK3/MLKL signaling pathway,and eventually caused ovarian pathological injuries and necroptosis characteristics.The alterations of above indicators were most apparent in the joint group.Above all,this research illustrates that Mo and/or Cd exposure can initiate necroptosis through Th1/Th2 imbalance-modulated ER stress in duck ovaries,and Mo and Cd combined exposure aggravates ovarian injuries.This research explores the molecular mechanism of necroptosis caused by Mo and/or Cd,which reveals that ER stress attenuation may be a therapeutic target to alleviate necroptosis. 展开更多
关键词 MOLYBDENUM Cadmium Th1/Th2 imbalance Endoplasmic reticulum stress NECROPTOSIS OVARY
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Class Imbalanced Problem:Taxonomy,Open Challenges,Applications and State-of-the-Art Solutions
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作者 Khursheed Ahmad Bhat Shabir Ahmad Sofi 《China Communications》 SCIE CSCD 2024年第11期216-242,共27页
The study of machine learning has revealed that it can unleash new applications in a variety of disciplines.Many limitations limit their expressiveness,and researchers are working to overcome them to fully exploit the... The study of machine learning has revealed that it can unleash new applications in a variety of disciplines.Many limitations limit their expressiveness,and researchers are working to overcome them to fully exploit the power of data-driven machine learning(ML)and deep learning(DL)techniques.The data imbalance presents major hurdles for classification and prediction problems in machine learning,restricting data analytics and acquiring relevant insights in practically all real-world research domains.In visual learning,network information security,failure prediction,digital marketing,healthcare,and a variety of other domains,raw data suffers from a biased data distribution of one class over the other.This article aims to present a taxonomy of the approaches for handling imbalanced data problems and their comparative study on the classification metrics and their application areas.We have explored very recent trends of techniques employed for solutions to class imbalance problems in datasets and have also discussed their limitations.This article has also identified open challenges for further research in the direction of class data imbalance. 展开更多
关键词 class imbalance classification deep learning GANs sampling
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A method for establishing a bearing residual life prediction model for process enhancement equipment based on rotor imbalance response analysis
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作者 Feng Wang Haoran Li +3 位作者 Zhenghui Zhang Yan Bai Hong Yin Jing Bian 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期203-215,共13页
A rotating packed bed is a typical chemical process enhancement equipment that can strengthen micromixing and mass transfer.During the operation of the rotating packed bed,the nonreactants and products irregularly adh... A rotating packed bed is a typical chemical process enhancement equipment that can strengthen micromixing and mass transfer.During the operation of the rotating packed bed,the nonreactants and products irregularly adhere to the wire mesh packing in the rotor,thus resulting in an imbalance in the vibration of the rotor,which may cause serious damage to the bearing and material leakage.This study proposes a model prediction for estimating the bearing residual life of a rotating packed bed based on rotor imbalance response analysis.This method is used to determine the influence of the mass on the imbalance in the vibration of the rotor on bearing damage.The major influence on rotor vibration was found to be exerted by the imbalanced mass and its distribution radius,as revealed by the results of orthogonal experiments.Through implementing finite element analysis,the imbalance response curve for the rotating packed bed rotor was obtained,and a correlation among rotor imbalance mass,distribution radius of imbalance mass,and bearing residue life was established via data fitting.The predicted value of the bearing life can be used as the reference basis for an early safety warning of a rotating packed bed to effectively avoid accidents. 展开更多
关键词 Rotating packed bed Mass imbalance Harmonic response analysis Residual life Prediction model
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Multifaceted functions of Drp1 in hypoxia/ischemia- induced mitochondrial quality imbalance: from regulatory mechanism to targeted therapeutic strategy
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作者 Shuai Hao He Huang +2 位作者 Rui-Yan Ma Xue Zeng Chen-Yang Duan 《Military Medical Research》 SCIE CAS CSCD 2024年第4期589-615,共27页
Hypoxic-ischemic injury is a common pathological dysfunction in clinical settings.Mitochondria are sensitive organelles that are readily damaged following ischemia and hypoxia.Dynamin-related protein 1(Drp1)regulates ... Hypoxic-ischemic injury is a common pathological dysfunction in clinical settings.Mitochondria are sensitive organelles that are readily damaged following ischemia and hypoxia.Dynamin-related protein 1(Drp1)regulates mitochondrial quality and cellular functions via its oligomeric changes and multiple modifications,which plays a role in mediating the induction of multiple organ damage during hypoxic-ischemic injury.However,there is active controversy and gaps in knowledge regarding the modification,protein interaction,and functions of Drp1,which both hinder and promote development of Drp1 as a novel therapeutic target.Here,we summarize recent findings on the oligomeric changes,modification types,and protein interactions of Drp1 in various hypoxic-ischemic diseases,as well as the Drp1-mediated regulation of mitochondrial quality and cell functions following ischemia and hypoxia.Additionally,potential clinical translation prospects for targeting Drp1 are discussed.This review provides new ideas and targets for proactive interventions on multiple organ damage induced by various hypoxic-ischemic diseases. 展开更多
关键词 Dynamin-related protein 1(Drp1) Hypoxic-ischemic injury Mitochondrial quality imbalance Cell dysfunction Organ damage
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基于联邦学习的代价敏感卷积神经网络分类方法 被引量:1
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作者 王丹 吴腾 +2 位作者 于振华 李冠琛 马志强 《西安科技大学学报》 北大核心 2025年第3期591-606,共16页
为解决传统分布式学习方法在训练分类模型时面临的数据隐私泄露和类不平衡问题,提出了一种基于联邦学习的代价敏感卷积神经网络分类方法(Fed-CoSen)。该方法基于联邦学习框架,通过量化客户端数据的不平衡度,采用加权联邦平均策略进行全... 为解决传统分布式学习方法在训练分类模型时面临的数据隐私泄露和类不平衡问题,提出了一种基于联邦学习的代价敏感卷积神经网络分类方法(Fed-CoSen)。该方法基于联邦学习框架,通过量化客户端数据的不平衡度,采用加权联邦平均策略进行全局模型训练,确保客户端数据的隐私性以及全局模型聚合过程的公平性;结合自适应平衡交叉熵损失函数和代价敏感卷积神经网络,优化客户端局部模型的分类性能。结果表明:在CIFAR-10数据集上模拟的2种联邦学习类不平衡场景、COVID-19数据集上模拟的医疗类不平衡场景中,与对比试验中的最佳方法Fed-Focal相比,Fed-CoSen在精确度上平均提升了1.84%,在召回率上平均提升了1.88%,在F1分数上平均提升了1.87%;充分验证了该方法在保护数据隐私的前提下,处理类不平衡数据分类任务中的有效性和适用性。 展开更多
关键词 联邦学习 类不平衡 加权聚合 深度学习 分类
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融合改进堆叠编码器和多层BiLSTM的入侵检测模型 被引量:3
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作者 陈虹 姜朝议 +2 位作者 金海波 武聪 卢健波 《计算机工程与应用》 北大核心 2025年第3期306-314,共9页
针对基于机器学习入侵检测模型需要大量特征工程,且对不平衡数据处理欠佳,导致检测率低、误报率高等问题。构建了一种SE-MBL的入侵检测模型。采用自适应合成采样(ADASYN)方法对少数类样本进行样本扩展,解决数据不平衡问题,形成相对对称... 针对基于机器学习入侵检测模型需要大量特征工程,且对不平衡数据处理欠佳,导致检测率低、误报率高等问题。构建了一种SE-MBL的入侵检测模型。采用自适应合成采样(ADASYN)方法对少数类样本进行样本扩展,解决数据不平衡问题,形成相对对称的数据集。采用改进的堆叠自编码器进行数据降维,消除特征冗余,并引入Dropout机制来增强信息融合,提升模型的泛化能力。提出一种融合一维CNN和多层BiLSTM的模块,分别提取空间特征和时间特征,以提高模型的分类性能。在NSL-KDD和CICIDS2017数据集上的实验结果表明,该模型可以实现较高的正确率和召回率,优于传统机器学习和深度学习方法。 展开更多
关键词 网络安全 入侵检测 数据不平衡 数据降维 多层BiLSTM
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数字经济是否缓解发展不平衡而促进共同富裕?——基于夜间灯光数据的不平衡测度 被引量:2
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作者 许永洪 苏冰杰 《统计研究》 北大核心 2025年第7期3-16,共14页
致力于从微观数据层面衡量地区发展不平衡,本文首先采用VIIRS夜间灯光数据测算我国31个省份、293个地级市、2841个县的发展不平衡程度。其次,使用北京大学数字普惠金融指数、宏观经济统计数据构造数字经济发展指数,实证考察数字经济及... 致力于从微观数据层面衡量地区发展不平衡,本文首先采用VIIRS夜间灯光数据测算我国31个省份、293个地级市、2841个县的发展不平衡程度。其次,使用北京大学数字普惠金融指数、宏观经济统计数据构造数字经济发展指数,实证考察数字经济及其发展速度对地区发展不平衡的影响及作用机制。研究发现,数字经济有助于缓解地区发展不平衡,且相较于南方地区,数字经济缩小地区发展差距的效应在北方地区更显著,但此影响效果不会因资源禀赋差异而不同。此结论在选择数字经济发展速度作为核心解释变量时仍旧成立。传导机制检验显示,创新和创业水平是数字经济影响地区不平衡的主要传导机制。进一步分析结果表明,数字经济不仅会缓解地区发展不平衡,还有助于缓解地区发展不充分状况,从而为探索共同富裕目标的实现路径提供新的思路。 展开更多
关键词 数字经济 发展不平衡 泰尔指数 夜间灯光数据
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全身骨骼三维建模成像系统检测脊柱矢状位失衡与膝关节参数的相关性 被引量:1
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作者 周峰 符鹏飞 +3 位作者 钱宇帆 许平成 郭炯炯 张磊 《中国组织工程研究》 北大核心 2026年第3期596-603,共8页
背景:随着人们生活方式的变化和年龄增长,脊柱矢状位失衡成为一种常见的骨科问题,对膝关节和骨盆的功能产生显著影响。了解脊柱矢状位失衡的影响及其代偿机制,对于改善慢性疼痛的临床管理至关重要。目的:使用全身骨骼三维建模成像系统... 背景:随着人们生活方式的变化和年龄增长,脊柱矢状位失衡成为一种常见的骨科问题,对膝关节和骨盆的功能产生显著影响。了解脊柱矢状位失衡的影响及其代偿机制,对于改善慢性疼痛的临床管理至关重要。目的:使用全身骨骼三维建模成像系统评估脊柱-骨盆-下肢矢状位排列模式,分析脊柱矢状位失衡与膝关节参数的相关性,并探讨其代偿机制。方法:纳入2021-01-01/2023-12-31就诊于苏州大学附属第一医院骨科门诊的71例慢性下腰痛或髌股关节痛患者,采用全身骨骼三维建模成像系统进行放射学测量,确定骨盆倾斜角、骨盆入射角、腰椎前凸角、脊柱矢状轴、整体倾斜角、髋-膝-踝角、屈膝角股骨远端外侧角、胫骨近端内侧角。根据SRS-Schwab脊柱畸形分类按骨盆入射角与腰椎前凸角差值(PI-LL)将患者分为正常组(PI-LL<10°)、代偿组(PI-LL为10°-20°)和失代偿组(PI-LL>20°),检测各组间放射学参数的差异。对比各组患者美国膝关节协会评分和Oswestry功能障碍指数的差异。根据临床症状将患者分为慢性下腰痛组和无慢性下腰痛组、髌股关节痛组和无髌股关节痛组,分析放射学参数差异与临床症状的关系。结果与结论:①PI-LL<20°时,股骨远端外侧角和胫骨近端内侧角趋于稳定;当PI-LL>20°时,其与股骨远端外侧角和胫骨近端内侧角呈线性相关,随着PI-LL增大,股骨远端外侧角值增大、胫骨近端内侧角值减小;②与正常组相比,代偿组骨盆倾斜角明显增大(P<0.01),髋-膝-踝角和屈膝角无明显差异,失代偿组的骨盆倾斜角显著增大(P<0.01),髋-膝-踝角和屈膝角显著减小(P<0.01);与代偿组相比,失代偿组髋-膝-踝角显著减小(P<0.05),而骨盆倾斜角和屈膝角无明显差异;③与无髌股关节痛组相比,髌股关节痛患者腰椎前凸角、股骨远端外侧角、胫骨近端内侧角显著减小(P<0.05),PI-LL显著增大(P<0.05);④慢性下腰痛患者放射学参数与无慢性下腰痛患者均有显著差异(P<0.05);⑤与正常组相比,代偿组和失代偿组的美国膝关节协会评分显著下降、Oswestry功能障碍指数显著升高(P<0.05);与代偿组相比,失代偿组美国膝关节协会评分显著下降、Oswestry功能障碍指数显著升高(P<0.05);⑥PI-LL随着年龄增加而变大,女性PI-LL相比男性较高;⑦提示脊柱与下肢在疾病进展和临床症状中具有重要作用;髌股关节痛和慢性下腰痛与脊柱-骨盆-下肢排列稳定有关;此外,高龄和女性患者的脊柱矢状位失衡较为严重。 展开更多
关键词 全身骨骼三维建模成像系统 膝关节参数 脊柱矢状位失衡 慢性下腰痛 髌股关节痛
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面向类不平衡和重叠的工控数据异常检测的半监督欠采样方法 被引量:1
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作者 顾兆军 扬雪影 +1 位作者 隋翯 张一诺 《计算机应用研究》 北大核心 2025年第1期156-164,共9页
工业控制系统异常检测面临着数据缺乏标签信息、类不平衡和类重叠的耦合问题,导致现有的分类器难以精准检测异常数据。现有的数据级采样方法在打伪标签、数据平衡或检测重叠区域时存在着打伪标签结果不准确、采样效果稳定性差以及重叠... 工业控制系统异常检测面临着数据缺乏标签信息、类不平衡和类重叠的耦合问题,导致现有的分类器难以精准检测异常数据。现有的数据级采样方法在打伪标签、数据平衡或检测重叠区域时存在着打伪标签结果不准确、采样效果稳定性差以及重叠识别率低等问题。为此,提出一种基于半监督学习的欠采样方法(SSLU-LP)。该方法通过异构集成将标签传播机制和单类分类器结合,补充数据伪标签;利用最小生成树策略构建重叠区域检测模型;采用欠采样策略,通过最近邻搜索有选择性地去除部分多数类样本。最后该方法与四种经典分类器结合,在九个工控数据集上与九种混合算法进行比较。实验结果表明,所提方法可以精准地为无标签数据打伪标签,高效且有效检测出不平衡数据集中的重叠数据,改善了分类器的训练效果,提高了分类器的异常检测性能。 展开更多
关键词 工业控制系统 类不平衡 类重叠 半监督学习 异常检测
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中国财政纵向失衡的区域差异、动态演进与空间收敛特征 被引量:1
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作者 王东 苏凯博 《统计与决策》 北大核心 2025年第13期141-146,共6页
在深化财税体制改革与推进区域协调发展战略的进程中,财政纵向失衡作为财政收支结构的核心问题,深刻影响着区域经济均衡与高质量发展。文章运用Dagum基尼系数分解法、马尔可夫链与空间收敛模型深入分析了中国八大综合经济区财政纵向失... 在深化财税体制改革与推进区域协调发展战略的进程中,财政纵向失衡作为财政收支结构的核心问题,深刻影响着区域经济均衡与高质量发展。文章运用Dagum基尼系数分解法、马尔可夫链与空间收敛模型深入分析了中国八大综合经济区财政纵向失衡的区域差异、动态演进与空间收敛特征。研究发现:中国财政纵向失衡水平的空间分布呈现“西部高、东部低”的格局,区域间差异是总体差异的主要来源。各省份的财政纵向失衡水平显示出较强的稳定性,即保持现有状态的可能性较大。在空间溢出效应的影响下,财政纵向失衡中低水平区域可能会受到邻近区域的影响,从而发生状态的跃迁。东北和北部沿海综合经济区存在明显的绝对β收敛特征,但当考虑其他经济影响因素时,仅东北综合经济区表现出条件β收敛,全国及其他地区均表现出发散特征,中国财政纵向失衡差异有进一步扩大的趋势。 展开更多
关键词 财政纵向失衡 区域差异 动态演进 空间收敛
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近今地理学史研究在中国的主要进展 被引量:2
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作者 孙俊 李秋赢 +3 位作者 杨玉玲 肖意婷 和峰燕 何文 《地理科学进展》 北大核心 2025年第3期429-444,共16页
鉴于近今地理学史研究在中国的进展除部分领域外尚无系统总结,论文基于文献梳理,参考科学史研究思潮的演变,讨论了其主要进展及未来值得关注的主要问题。梳理表明:(1)地理学史是中国地理学中一门具有标识度的学术领域,研究成果丰硕、领... 鉴于近今地理学史研究在中国的进展除部分领域外尚无系统总结,论文基于文献梳理,参考科学史研究思潮的演变,讨论了其主要进展及未来值得关注的主要问题。梳理表明:(1)地理学史是中国地理学中一门具有标识度的学术领域,研究成果丰硕、领域覆盖面广、研究群体稳定;(2)领域体系初步建构,形成了学科史、思想史、社会史、编史研究的研究体系,基本与科学史研究领域相对应;(3)地理学史研究思潮多样,基本与当代科学史主要思潮相切合,但对知识社会史、语境论、概念史、阅读史等科学史思潮的借鉴不够,新近地理学思潮下的研究成果较少;(4)研究对象的空间范围、分支领域、主体差异明显,主要体现为聚焦中国地理学史研究,在中国地图学史与近现代历史地理学史,中国近现代著名地理学研究机构、社团、学者方面成果丰硕,与之相应的其他空间范围、分支领域、主体的研究则有所弱化;(5)中国地理学史专门的研究集中在古代阶段,近代阶段逐渐兴起,现当代研究主要是进展回顾、综述文献。未来值得关注的主要问题包括:(1)关注研究的薄弱对象,更为全面地展现中国地理学发展脉络,特别是近百年学科史;(2)强化科学史中知识社会史、语境论、概念史、阅读史等思潮的借鉴,关注现当代地理学思潮下的地理学史研究;(3)留意现当代中国地理学史的社会价值阐释,拓展地理学的社会认知;(4)注重与国外地理学史研究的对话,提升中国学者地理学史研究的国际话语。 展开更多
关键词 地理学史研究 领域体系 多样化思潮 不平衡性 未来研究方向 中国
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健康中国建设中“重医轻卫”对居民健康水平的影响研究——基于政府支出结构视角 被引量:1
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作者 庞瑞芝 郑思源 李倩楠 《贵州财经大学学报》 北大核心 2025年第1期42-50,共9页
深入研究“重医轻卫”对居民健康水平的影响,对优化政府卫生支出结构、提升医疗卫生体系整体效能、推进健康中国战略建设具有重要的现实意义。在研究视角上,与现有文献关注于政府卫生支出总量不同,文章着重从政府支出结构视角,基于2013... 深入研究“重医轻卫”对居民健康水平的影响,对优化政府卫生支出结构、提升医疗卫生体系整体效能、推进健康中国战略建设具有重要的现实意义。在研究视角上,与现有文献关注于政府卫生支出总量不同,文章着重从政府支出结构视角,基于2013—2019年中国省级面板数据,通过双向固定效应模型检验了“重医轻卫”对居民健康水平的影响。结果显示:“重医轻卫”显著降低了居民健康水平,这一结论在使用系统GMM回归缓解内生性以及Tobit广义线性回归模型进行稳健性检验后仍然成立;“重医轻卫”对居民健康水平的影响具有区域异质性,东部和中部地区已经凸显,西部地区暂未显现。 展开更多
关键词 健康中国 公共卫生 政府卫生支出 资源配置失衡 居民健康水平
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