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Optimizing CNN Architectures for Face Liveness Detection:Performance,Efficiency,and Generalization across Datasets 被引量:1
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作者 Smita Khairnar Shilpa Gite +2 位作者 Biswajeet Pradhan Sudeep D.Thepade Abdullah Alamri 《Computer Modeling in Engineering & Sciences》 2025年第6期3677-3707,共31页
Face liveness detection is essential for securing biometric authentication systems against spoofing attacks,including printed photos,replay videos,and 3D masks.This study systematically evaluates pre-trained CNN model... Face liveness detection is essential for securing biometric authentication systems against spoofing attacks,including printed photos,replay videos,and 3D masks.This study systematically evaluates pre-trained CNN models—DenseNet201,VGG16,InceptionV3,ResNet50,VGG19,MobileNetV2,Xception,and InceptionResNetV2—leveraging transfer learning and fine-tuning to enhance liveness detection performance.The models were trained and tested on NUAA and Replay-Attack datasets,with cross-dataset generalization validated on SiW-MV2 to assess real-world adaptability.Performance was evaluated using accuracy,precision,recall,FAR,FRR,HTER,and specialized spoof detection metrics(APCER,NPCER,ACER).Fine-tuning significantly improved detection accuracy,with DenseNet201 achieving the highest performance(98.5%on NUAA,97.71%on Replay-Attack),while MobileNetV2 proved the most efficient model for real-time applications(latency:15 ms,memory usage:45 MB,energy consumption:30 mJ).A statistical significance analysis(paired t-tests,confidence intervals)validated these improvements.Cross-dataset experiments identified DenseNet201 and MobileNetV2 as the most generalizable architectures,with DenseNet201 achieving 86.4%accuracy on Replay-Attack when trained on NUAA,demonstrating robust feature extraction and adaptability.In contrast,ResNet50 showed lower generalization capabilities,struggling with dataset variability and complex spoofing attacks.These findings suggest that MobileNetV2 is well-suited for low-power applications,while DenseNet201 is ideal for high-security environments requiring superior accuracy.This research provides a framework for improving real-time face liveness detection,enhancing biometric security,and guiding future advancements in AI-driven anti-spoofing techniques. 展开更多
关键词 Face liveness detection cross-dataset generalization real-time face authentication transfer learning DenseNet201 VGG16 InceptionV3 deep learning
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Stress-Induced Endogenous Cannabinoid Signaling Contributes to Fear Generalization
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作者 Yanan Yue Xia Zhang Yuan Dong 《Neuroscience Bulletin》 2025年第6期1123-1126,共4页
The phenomenon of fear memory generalization can be defined as the expansion of an individual's originally specific fear responses to a similar yet genuinely harmless stimulus or situation subsequent to the occurr... The phenomenon of fear memory generalization can be defined as the expansion of an individual's originally specific fear responses to a similar yet genuinely harmless stimulus or situation subsequent to the occurrence of a traumatic event[1].Fear generalization within the normal range represents an adaptive evolutionary mechanism to facilitate prompt reactions to potential threats and to enhance the likelihood of survival. 展开更多
关键词 STRESS adaptive mechanism originally specific fear responses fear memory generalization endogenous cannabinoid signaling fear generalization adaptive evolutionary mechanism enhance likelihood survival
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DDIRNet:robust radar emitter recognition via single domain generalization
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作者 WU Honglin LI Xueqiong +2 位作者 HUANG Junjie JIN Ruochun TANG Yuhua 《Journal of Systems Engineering and Electronics》 2025年第2期397-404,共8页
Automatically recognizing radar emitters from com-plex electromagnetic environments is important but non-trivial.Moreover,the changing electromagnetic environment results in inconsistent signal distribution in the rea... Automatically recognizing radar emitters from com-plex electromagnetic environments is important but non-trivial.Moreover,the changing electromagnetic environment results in inconsistent signal distribution in the real world,which makes the existing approaches perform poorly for recognition tasks in different scenes.In this paper,we propose a domain generaliza-tion framework is proposed to improve the adaptability of radar emitter signal recognition in changing environments.Specifically,we propose an end-to-end denoising based domain-invariant radar emitter recognition network(DDIRNet)consisting of a denoising model and a domain invariant representation learning model(IRLM),which mutually benefit from each other.For the signal denoising model,a loss function is proposed to match the feature of the radar signals and guarantee the effectiveness of the model.For the domain invariant representation learning model,contrastive learning is introduced to learn the cross-domain feature by aligning the source and unseen domain distri-bution.Moreover,we design a data augmentation method that improves the diversity of signal data for training.Extensive experiments on classification have shown that DDIRNet achieves up to 6.4%improvement compared with the state-of-the-art radar emitter recognition methods.The proposed method pro-vides a promising direction to solve the radar emitter signal recognition problem. 展开更多
关键词 radar emitter recognition domain generalization DENOISING contrastive learning data augmentation.
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StM:a benchmark for evaluating generalization in reinforcement learning
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作者 YUAN Kaizhao ZHANG Rui +5 位作者 PAN Yansong YI Qi PENG Shaohui GUO Jiaming HE Wenkai HU Xing 《High Technology Letters》 2025年第2期118-130,共13页
The challenge of enhancing the generalization capacity of reinforcement learning(RL)agents remains a formidable obstacle.Existing RL methods,despite achieving superhuman performance on certain benchmarks,often struggl... The challenge of enhancing the generalization capacity of reinforcement learning(RL)agents remains a formidable obstacle.Existing RL methods,despite achieving superhuman performance on certain benchmarks,often struggle with this aspect.A potential reason is that the benchmarks used for training and evaluation may not adequately offer a diverse set of transferable tasks.Although recent studies have developed bench-marking environments to address this shortcoming,they typically fall short in providing tasks that both ensure a solid foundation for generalization and exhibit significant variability.To overcome these limitations,this work introduces the concept that‘objects are composed of more fundamental components’in environment design,as implemented in the proposed environment called summon the magic(StM).This environment generates tasks where objects are derived from extensible and shareable basic components,facilitating strategy reuse and enhancing generalization.Furthermore,two new metrics,adaptation sensitivity range(ASR)and parameter correlation coefficient(PCC),are proposed to better capture and evaluate the generalization process of RL agents.Experimental results show that increasing the number of basic components of the object reduces the proximal policy optimization(PPO)agent’s training-testing gap by 60.9%(in episode reward),significantly alleviating overfitting.Additionally,linear variations in other environmental factors,such as the training monster set proportion and the total number of basic components,uniformly decrease the gap by at least 32.1%.These results highlight StM’s effectiveness in benchmarking and probing the generalization capabilities of RL algorithms. 展开更多
关键词 reinforcement learning(RL) generalization BENCHMARK environment
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Semi-supervised cardiac magnetic resonance image segmentation based on domain generalization
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作者 SHAO Hong HOU Jinyang CUI Wencheng 《High Technology Letters》 2025年第1期41-52,共12页
In the realm of medical image segmentation,particularly in cardiac magnetic resonance imaging(MRI),achieving robust performance with limited annotated data is a significant challenge.Performance often degrades when fa... In the realm of medical image segmentation,particularly in cardiac magnetic resonance imaging(MRI),achieving robust performance with limited annotated data is a significant challenge.Performance often degrades when faced with testing scenarios from unknown domains.To address this problem,this paper proposes a novel semi-supervised approach for cardiac magnetic resonance image segmentation,aiming to enhance predictive capabilities and domain generalization(DG).This paper establishes an MT-like model utilizing pseudo-labeling and consistency regularization from semi-supervised learning,and integrates uncertainty estimation to improve the accuracy of pseudo-labels.Additionally,to tackle the challenge of domain generalization,a data manipulation strategy is introduced,extracting spatial and content-related information from images across different domains,enriching the dataset with a multi-domain perspective.This papers method is meticulously evaluated on the publicly available cardiac magnetic resonance imaging dataset M&Ms,validating its effectiveness.Comparative analyses against various methods highlight the out-standing performance of this papers approach,demonstrating its capability to segment cardiac magnetic resonance images in previously unseen domains even with limited annotated data. 展开更多
关键词 SEMI-SUPERVISED domain generalization(DG) cardiac magnetic resonance image segmentation
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GENERALIZATION ANALYSIS FOR CVaR-BASED MINIMAX REGRET OPTIMIZATION
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作者 TAO Yan-fang DENG Hao 《数学杂志》 2025年第2期111-121,共11页
This paper analyzes the generalization of minimax regret optimization(MRO)under distribution shift.A new learning framework is proposed by injecting the measure of con-ditional value at risk(CVaR)into MRO,and its gene... This paper analyzes the generalization of minimax regret optimization(MRO)under distribution shift.A new learning framework is proposed by injecting the measure of con-ditional value at risk(CVaR)into MRO,and its generalization error bound is established through the lens of uniform convergence analysis.The CVaR-based MRO can achieve the polynomial decay rate on the excess risk,which extends the generalization analysis associated with the expected risk to the risk-averse case. 展开更多
关键词 Minimax regret optimization(MRO) conditional value at risk(CVaR) distri-bution shift generalization error
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Universal Scaling Laws in Quantum-Probabilistic Machine Learning by Tensor Network: Toward Interpreting Representation and Generalization Powers
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作者 Sheng-Chen Bai Shi-Ju Ran 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第12期35-45,共11页
The interpretation of representations and generalization powers has been a long-standing challenge in the fields of machine learning(ML)and artificial intelligence.This study contributes to understanding the emergence... The interpretation of representations and generalization powers has been a long-standing challenge in the fields of machine learning(ML)and artificial intelligence.This study contributes to understanding the emergence of universal scaling laws in quantum-probabilistic ML.We consider the generative tensor network(GTN)in the form of a matrix-product state as an example and show that with an untrained GTN(such as a random TN state),the negative logarithmic likelihood(NLL)L generally increases linearly with the number of features M,that is,L≃kM+const.This is a consequence of the so-called“catastrophe of orthogonality,”which states that quantum many-body states tend to become exponentially orthogonal to each other as M increases.This study reveals that,while gaining information through training,the linear-scaling law is suppressed by a negative quadratic correction,leading to L≃βM−αM^(2)+const.The scaling coefficients exhibit logarithmic relationships with the number of training samples and quantum channelsχ.The emergence of a quadratic correction term in the NLL for the testing(training)set can be regarded as evidence of the generalization(representation)power of the GTN.Over-parameterization can be identified by the deviation in the values ofαbetween the training and testing sets while increasingχ.We further investigate how orthogonality in the quantum-feature map relates to the satisfaction of quantum-probabilistic interpretation and the representation and generalization powers of the GTN.Unveiling universal scaling laws in quantum-probabilistic ML would be a valuable step toward establishing a white-box ML scheme interpreted within the quantum-probabilistic framework. 展开更多
关键词 QUANTUM generalization SCALING
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The Role and Place of Artificial Neural Network Architectures Structural Redundancy in the Input Data Prototypes and Generalization Development
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作者 Conrad Onésime Oboulhas Tsahat Ngoulou-A-Ndzeli Béranger Destin Ossibi 《Journal of Computer and Communications》 2024年第7期1-11,共11页
Neural Networks (NN) are the functional unit of Deep Learning and are known to mimic the behavior of the human brain to solve complex data-driven problems. Whenever we train our own neural networks, we need to take ca... Neural Networks (NN) are the functional unit of Deep Learning and are known to mimic the behavior of the human brain to solve complex data-driven problems. Whenever we train our own neural networks, we need to take care of something called the generalization of the neural network. The performance of Artificial Neural Networks (ANN) mostly depends upon its generalization capability. In this paper, we propose an innovative approach to enhance the generalization capability of artificial neural networks (ANN) using structural redundancy. A novel perspective on handling input data prototypes and their impact on the development of generalization, which could improve to ANN architectures accuracy and reliability is described. 展开更多
关键词 Multilayer Neural Network Multidimensional Nonlinear Interpolation generalization by Similarity Artificial Intelligence Prototype Development
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Mathematical Definitions of Operators for Cartographic Generalization 被引量:2
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作者 王晓妮 张洁 《Geo-Spatial Information Science》 2003年第1期70-73,共4页
This paper puts forword 11 cartographic generalization operator models and introduces their mathematical definitions,and thus a precise mathematical form and quantitative description has been given to these formerly l... This paper puts forword 11 cartographic generalization operator models and introduces their mathematical definitions,and thus a precise mathematical form and quantitative description has been given to these formerly limited qualitative concepts.The meaning of mathematical definition of operators for cartographic generalization and the application prospect in computer_aided cartography (CAC) is stated.ract The Jurassic strata in Jingyan of Sichuan containing the Mamenchinsaurus fauna are dealt with and divided in this paper. The Mamenchisaurus fossils contained there are compared in morphological features and stratigraphically with other types of the genus on by one. The comprehensive analysis show that the Mamenchisaurus fauna of Jingyan appeared in the early Late Jurassic and is primitive in morphology. The results of the morphological identification and stratigraphical study agree with each other. Their evolutionary processes in different apoches of the Late Jurassic also made clear. Key words Jingyan, Sichuan, Mamenchisaurus Fauna, stratigraphy, evolution 展开更多
关键词 operators for cartographic generalization mathematical definition SELECTION SIMPLIFICATION STRESS
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The Mini-SiTian Array:White Paper 被引量:1
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作者 Henggeng Han Yang Huang +11 位作者 Beichuan Wang Yongkang Sun Cunshi Wang Zhirui Li Junjie Jin Ningchen Sun Kai Xiao Min He Hongrui Gu Zexi Niu Hong Wu Jifeng Liu 《Research in Astronomy and Astrophysics》 2025年第4期94-99,共6页
This paper outlines the scientific goals and observational strategies of the Mini-SiTian Array.Mounted at Xinglong Observatory,the Mini-SiTian Array consists of three 30 cm telescopes and has been in operation since 2... This paper outlines the scientific goals and observational strategies of the Mini-SiTian Array.Mounted at Xinglong Observatory,the Mini-SiTian Array consists of three 30 cm telescopes and has been in operation since 2022.The large field of view,combined with the capability for multi-band photometric observations,enables the Mini-SiTian Array to perform rapid follow-up observations to identify optical counterparts of gravitational waves,capture the early light curves of tidal disruption events and supernovae,and monitor stellar flares,Be star outbursts,and cataclysmic variable stars,although its limiting magnitude is not very deep.By collaborating with the Xinglong2.16 m telescope and leveraging a real-time image processing pipeline,simultaneous photometric and spectroscopic observations could be performed to reveal their underlying physical mechanisms.The observational and research experience provides critical guidance for the implementation of the full-scale SiTian project in the future. 展开更多
关键词 telescopes stars:variables:general stars:flare (stars:)supernovae:general
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Analgesic effect and safety of dexmedetomidine-assisted intravenous-inhalation combined general anesthesia in laparoscopic minimally invasive inguinal hernia surgery 被引量:1
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作者 Qian-Xing Lou Ke-Ping Xu 《World Journal of Gastrointestinal Surgery》 2025年第3期161-170,共10页
BACKGROUND Currently,very few studies have examined the analgesic effectiveness and safety of dexmedetomidine-assisted intravenous-inhalation combined general anesthesia in laparoscopic minimally invasive surgery for ... BACKGROUND Currently,very few studies have examined the analgesic effectiveness and safety of dexmedetomidine-assisted intravenous-inhalation combined general anesthesia in laparoscopic minimally invasive surgery for inguinal hernia.AIM To investigate the analgesic effect and safety of dexmedetomidine-assisted intravenous-inhalation combined general anesthesia in laparoscopic minimally invasive surgery for inguinal hernia.METHODS In this retrospective study,94 patients scheduled for laparoscopic minimally invasive surgery for inguinal hernia,admitted to Yiwu Central Hospital between May 2022 and May 2023,were divided into a control group(inhalation combined general anesthesia)and a treatment group(dexmedetomidine-assisted intrave-nous-inhalation combined general anesthesia).Perioperative indicators,analgesic effect,preoperative and postoperative 24-hours blood pressure(BP)and heart rate(HR),stress indicators,immune function levels,and adverse reactions were com-pared between the two groups.RESULTS Baseline data,including age,hernia location,place of residence,weight,monthly income,education level,and underlying diseases,were not significantly different between the two groups,indicating comparability(P>0.05).No significant difference was found in operation time and anesthesia time between the two groups(P>0.05).However,the treatment group exhibited a shorter postoperative urinary catheter removal time and hospital stay than the control group(P<0.05).Preoperatively,no significant differences were found in the visual analog scale(VAS)scores between the two groups(P>0.05).However,at 12,18,and 24 hours postoper-atively,the treatment group had significantly lower VAS scores than the control group(P<0.05).Although no significant differences in preoperative hemodynamic indicators were found between the two groups(P>0.05),both groups experienced some extent of changes in postoperative HR,diastolic BP(DBP),and systolic BP(SBP).Nevertheless,the treatment group showed smaller changes in HR,DBP,and SBP than the control group(P<0.05).Preoperative immune function indicators showed no significant differences between the two groups(P>0.05).However,postoperatively,the treatment group demonstrated higher levels of CD3+,CD4+,and CD4+/CD8+and lower levels of CD8+than the control group(P<0.05).The rates of adverse reactions were 6.38%and 23.40%in the treatment and control groups,respectively,revealing a significant difference(χ2=5.371,P=0.020).CONCLUSION Dexmedetomidine-assisted intravenous-inhalation combined general anesthesia can promote early recovery of patients undergoing laparoscopic minimally invasive surgery for inguinal hernia.It ensures stable blood flow,improves postoperative analgesic effects,reduces postoperative pain intensity,alleviates stress response,improves immune function,facilitates anesthesia recovery,and enhances safety. 展开更多
关键词 DEXMEDETOMIDINE Intravenous-inhalation combined general anesthesia Inguinal hernia Laparoscopic minimally invasive surgery Analgesia SAFETY
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Associations of polycyclic aromatic hydrocarbons exposure with serum uric acid and hyperuricemia in US adults:The role of systemic inflammation 被引量:1
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作者 Yang Liu Xuejie Ding +7 位作者 Linling Yu Da Shi Ruyi Liang Wei Liu Xuezan Huang Xiuyu Cao Min Zhou Weihong Chen 《Journal of Environmental Sciences》 2025年第4期412-421,共10页
The associations of polycyclic aromatic hydrocarbon(PAH)exposure with serum uric acid(SUA)or hyperuricemia have been rarely assessed.We aimed to investigate the relationships between urinary PAH metabolites and SUA or... The associations of polycyclic aromatic hydrocarbon(PAH)exposure with serum uric acid(SUA)or hyperuricemia have been rarely assessed.We aimed to investigate the relationships between urinary PAH metabolites and SUA or hyperuricemia among US adults and to explore the mediating role of systemic inflammation in the associations.A total of 10,307 US adults were conducted to assess the associations of seven urinary hydroxy–PAH with SUA and hyperuricemia and evaluate the role of C-reactive protein(CRP),a biomarker of systemic inflammation,in such associations.Results showed that each 1-unit increase in ln-transformed 2-hydroxynaphthalene(2-OHNa),1-hydroxyphenanthrene(1-OHPh),2&3-hydroxyphenanthrene(2&3-OHPh)and total hydroxyphenanthrene(OHPh)was associated with a 1.68(95%confidence interval(CI):0.19 to 3.17),2.46(0.78 to 4.13),3.34(1.59 to 5.09),and 2.99(1.23 to 4.75)μmol/L increase in SUA,and a 8%(odds ratio(OR):1.08,1.02 to 1.15),9%(OR:1.09,1.02 to 1.18),13%(OR:1.13,1.05 to 1.22),and 12%(OR:1.12,95%CI:1.03,1.21)increase in hyperuricemia,respectively.Co-exposure of seven PAHs was positively associated with SUA and hyperuricemia,with 2&3-OHPh showing the highest weight(components weights:0.83 and 0.78,respectively).The CRP mediated 11.47%and 10.44%of the associations ofΣOHPh and 2&3-OHPh with SUA and mediated 8.60%and 8.62%in associations ofΣOHPh and 2&3-OHPh with hyperuricemia,respectively.In conclusion,internal levels of PAH metabolites were associated with elevated SUA levels and the increased risk of hyperuricemia among US adults,and CRP played a mediating role in the associations. 展开更多
关键词 Polycyclic aromatic hydrocarbon Serum uric acid HYPERURICEMIA C-reactive protein General population
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Results of endoscopic retrograde cholangiopancreatography procedures at surgical clinics:A multicenter observational study in Türkiye 被引量:1
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作者 Sezgin Yilmaz Esat Taylan Ugurlu +26 位作者 Alpen Yahya Gumusoglu Mahmut Said Degerli Kemal Dolay Emre Balli Yasin Kara Ali Kocataş EkremÇakar Bünyamin Gürbulak Sercan Yüksel Soykan Arikan Hasan Bektaş Yusuf Emre Aytin Doğan Albayrak Ali Fuat Kaan Gok Cemalettin Ertekin Alpaslan FedayiÇalta Serhat Oğuz MustafaÖrmeci Ali HaldunÖzcan BarışSevinç Ömer Karahan İhsan Tümkaya Osman Kones Mehlika Bilgi Kirmaci Mustafa Yavuz Emrah Akın Merve Yeşilsancak 《World Journal of Gastrointestinal Surgery》 2025年第5期249-256,共8页
BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP)is an invasive endoscopic procedure used mainly to treat hepato-pancreato-biliary(HPB)diseases.The need for ERCP has increased with the rising number of H... BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP)is an invasive endoscopic procedure used mainly to treat hepato-pancreato-biliary(HPB)diseases.The need for ERCP has increased with the rising number of HPB diseases over the past decade.Thus,due to increased demand,ERCP is performed at more centers.Currently,it is performed by general surgeons,gastroenterology and invasive radiology specialists in the United States and Europe as recommended by the British Society of Gastroenterology(BSG).AIM To present the results of ERCP procedures from fourteen surgical centers in Türkiye.METHODS Fourteen surgical centers performing ERCP were included in the present study.The age,gender,ERCP indication,success status,post-ERCP complications,ERCP reports and the files of 66993 patients who underwent ERCP were collected from the participating centers.The results are discussed according to the targets declared by the BSG,which are volume load per annum,proportion of successful cannulation(>85%),bile duct clearance rate(>75%),stenting rate for strictures(>80%)and complications(<6%).RESULTS A total of 66993 ERCP procedures were performed in the centers included in the study up to August 2024.29250(43.6%)of the procedures were performed urgently,especially for suppurative cholangitis,biliary tract injuries,etc.The remaining 37743(56.4%)cases were performed electively.50.2%of the patients were female and 49.8%were male.The average ages were 56.5 years for women and 55.9 years for men.General anesthesia was used in 84.1%of the patients while sedation was used in 15.9%.The indications were bile duct stone(78.7%),pancreatic tumor(3.9%),papillary tumor(3.3%),cholangiocarcinoma(2.6%),Oddi sphincter dysfunction(2.4%),bile leakage after cholecystectomy(2%),bile leakage after hydatid cyst surgery(1.9%),biliary stricture(1.7%),and other diseases(3.1%).Hyperamylasemia and post-ERCP pancreatitis were the most common complications as observed in 8.1%of the patients.They were usually self-limited and responded to supportive measures.The frequency of the other complications was also consistent with the literature.CONCLUSION There is a huge shortage of ERCP endoscopists worldwide due to insufficient ERCP training and centers especially in developing and underdeveloped countries.As patients requiring ERCP usually present to surgical practitioners,the incorporation of surgeons into this training program is an effective and reliable solution.The BSG recommends the incorporation of surgeons and radiologists in addition to gastroenterology specialists.This study is the first to present the results of ERCP procedures from fourteen surgical centers throughout Türkiye.The results suggest that the surgical centers included were able to achieve the targets set by the BSG.This study demonstrated that the surgical ERCP units in the present work have reached satisfactory results and provided a reliable and successful ERCP service.There are currently no issues regarding the validity and appropriateness of the surgeons performing ERCP.Therefore,ERCP training should be encouraged in surgeons and more surgical ERCP centers should be provided. 展开更多
关键词 Endoscopic retrograde cholangiopancreatography General surgeon Education Endoscopic retrograde cho-langiopancreatography training Surgical centers Endoscopic retrograde cholangiopancreatography endoscopist
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Using Entropy Penalty Term for Improving the Generalization Ability of Multilayer Feedfoward Networks *
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作者 鲁子奕 杨绿溪 何振亚 《Journal of Southeast University(English Edition)》 EI CAS 1998年第1期29-34,共6页
Generalization ability is a major problem encountered when using neural networks to find the structures in noisy data sets. Controlling the network complexity is a common method to solve this problem. In this paper, h... Generalization ability is a major problem encountered when using neural networks to find the structures in noisy data sets. Controlling the network complexity is a common method to solve this problem. In this paper, however, a novel additive penalty term which represents the features extracted by hidden units is introduced to eliminate the overtraining of multilayer feedfoward networks. Computer simulations demonstrate that by using this unsupervised fashion penalty term, the generalization ability is greatly improved. 展开更多
关键词 generalization OVERTRAINING ENTROPY
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Accurate quantification of the algebraic,multiplicative algebraic,and simultaneous iterative reconstruction techniques in ionosphere rebuilding based on the TIEGCM assessment
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作者 Ao Qi HaiBing Ruan 《Earth and Planetary Physics》 EI CAS 2025年第1期117-126,共10页
The algebraic reconstruction technique(ART),multiplicative algebraic reconstruction technique(MART),and simultaneous iterative reconstruction technique(SIRT)are computational methodologies extensively utilized within ... The algebraic reconstruction technique(ART),multiplicative algebraic reconstruction technique(MART),and simultaneous iterative reconstruction technique(SIRT)are computational methodologies extensively utilized within the field of computerized ionospheric tomography(CIT)to facilitate three-dimensional reconstruction of the ionospheric morphology.However,reconstruction accuracy elicits recurrent disputes over its practical application,and people usually attribute this issue to incomplete and uneven coverage of the measurements.The Thermosphere Ionosphere Electrodynamics General Circulation Model(TIEGCM)offers a reasonable physics-based ionospheric background and is widely utilized in ionospheric research.We use the TIEGCM simulations as the targeted ionosphere because the current measurements are far from able to realistically reproduce the ionosphere in detail.Optimized designations of satellite measurements are conducted to investigate the limiting performance of CIT methods in ionospheric reconstruction.Similar to common practice,electron density distributions from outputs of the International Reference Ionosphere(IRI)model are used as the iterative initial value in CIT applications.The outcomes suggest that despite data coverage,iterative initial conditions also play an essential role in ionospheric reconstruction.In particular,in the longitudinal sectors where the iterative initial height of the F2-layer peak electron density(hmF2)differs substantially from the background densities,none of the three CIT methods can reproduce the exact background profile.When hmF2 is close but the ionospheric F2-layer peak density(NmF2)is different between the targeted background and initial conditions,the MART performs better than the ART and SIRT,as evidenced by the correlation coefficients of MART being above 0.97 and those of ART and SIRT being below 0.85.In summary,this investigation reveals the potential uncertainties in traditional CIT reconstruction,particularly when realistic hmF2 or NmF2 values differ substantially from the initial CIT conditions. 展开更多
关键词 computerized ionospheric tomography International Reference Ionosphere model Thermosphere Ionosphere Electrodynamics General Circulation model IONOSPHERE
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Dual encoding feature filtering generalized attention UNET for retinal vessel segmentation
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作者 ISLAM Md Tauhidul WU Da-Wen +6 位作者 TANG Qing-Qing ZHAO Kai-Yang YIN Teng LI Yan-Fei SHANG Wen-Yi LIU Jing-Yu ZHANG Hai-Xian 《四川大学学报(自然科学版)》 北大核心 2025年第1期79-95,共17页
Retinal blood vessel segmentation is crucial for diagnosing ocular and cardiovascular diseases.Although the introduction of U-Net in 2015 by Olaf Ronneberger significantly advanced this field,yet issues like limited t... Retinal blood vessel segmentation is crucial for diagnosing ocular and cardiovascular diseases.Although the introduction of U-Net in 2015 by Olaf Ronneberger significantly advanced this field,yet issues like limited training data,imbalance data distribution,and inadequate feature extraction persist,hindering both the segmentation performance and optimal model generalization.Addressing these critical issues,the DEFFA-Unet is proposed featuring an additional encoder to process domain-invariant pre-processed inputs,thereby improving both richer feature encoding and enhanced model generalization.A feature filtering fusion module is developed to ensure the precise feature filtering and robust hybrid feature fusion.In response to the task-specific need for higher precision where false positives are very costly,traditional skip connections are replaced with the attention-guided feature reconstructing fusion module.Additionally,innovative data augmentation and balancing methods are proposed to counter data scarcity and distribution imbalance,further boosting the robustness and generalization of the model.With a comprehensive suite of evaluation metrics,extensive validations on four benchmark datasets(DRIVE,CHASEDB1,STARE,and HRF)and an SLO dataset(IOSTAR),demonstrate the proposed method’s superiority over both baseline and state-of-the-art models.Particularly the proposed method significantly outperforms the compared methods in cross-validation model generalization. 展开更多
关键词 Vessel segmentation Data balancing Data augmentation Dual encoder Attention Mechanism Model generalization
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Generalization Capabilities of Feedforward Neural Networks for Pattern Recognition
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作者 黄德双 《Journal of Beijing Institute of Technology》 EI CAS 1996年第2期192+184-192,共10页
This paper studies the generalization capability of feedforward neural networks (FNN).The mechanism of FNNs for classification is investigated from the geometric and probabilistic viewpoints. It is pointed out that th... This paper studies the generalization capability of feedforward neural networks (FNN).The mechanism of FNNs for classification is investigated from the geometric and probabilistic viewpoints. It is pointed out that the outputs of the output layer in the FNNs for classification correspond to the estimates of posteriori probability of the input pattern samples with desired outputs 1 or 0. The theorem for the generalized kernel function in the radial basis function networks (RBFN) is given. For an 2-layer perceptron network (2-LPN). an idea of using extended samples to improve generalization capability is proposed. Finally. the experimental results of radar target classification are given to verify the generaliztion capability of the RBFNs. 展开更多
关键词 feedforward neural networks radial basis function networks multilayer perceptronnetworks generalization capability radar target classification
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What Makes a Good Surgeon?What I Learned Watching Hardy Hendren
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作者 Kevin R.Loughlin 《The Canadian Journal of Urology》 2025年第2期71-72,共2页
Perhaps the greatest compliment that an attending surgeon can bestow on a resident in training,is to comment,“He/she has good hands.”However,what defines good hands?What parameters are used to make that judgment?As ... Perhaps the greatest compliment that an attending surgeon can bestow on a resident in training,is to comment,“He/she has good hands.”However,what defines good hands?What parameters are used to make that judgment?As an academic urologist,I had the opportunity to observe urology and general surgery residents in the operating room over several decades. 展开更多
关键词 UROLOGY urology general surgery residents hands JUDGMENT general surgery RESIDENT operating room surgery
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Adaptable deep learning for holographic microscopy:a case study on tissue type and system variability in label-free histopathology
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作者 Jiseong Barg Chanseok Lee +1 位作者 Chunghyeong Lee Mooseok Jang 《Advanced Photonics Nexus》 2025年第2期39-53,共15页
Holographic microscopy has emerged as a vital tool in biomedicine,enabling visualization of microscopic morphological features of tissues and cells in a label-free manner.Recently,deep learning(DL)-based image reconst... Holographic microscopy has emerged as a vital tool in biomedicine,enabling visualization of microscopic morphological features of tissues and cells in a label-free manner.Recently,deep learning(DL)-based image reconstruction models have demonstrated state-of-the-art performance in holographic image reconstruction.However,their utility in practice is still severely limited,as conventional training schemes could not properly handle out-of-distribution data.Here,we leverage backpropagation operation and reparameterization of the forward propagator to enable an adaptable image reconstruction model for histopathologic inspection.Only given with a training dataset of rectum tissue images captured from a single imaging configuration,our scheme consistently shows high reconstruction performance even with the input hologram of diverse tissue types at different pathological states captured under various imaging configurations.Using the proposed adaptation technique,we show that the diagnostic features of cancerous colorectal tissues,such as dirty necrosis,captured with 5×magnification and a numerical aperture(NA)of 0.1,can be reconstructed with high accuracy,whereas a given training dataset is strictly confined to normal rectum tissues acquired under the imaging configuration of 20×magnification and an NA of 0.4.Our results suggest that the DL-based image reconstruction approaches,with sophisticated adaptation techniques,could offer an extensively generalizable solution for inverse mapping problems in imaging. 展开更多
关键词 holographic microscopy deep learning HISTOPATHOLOGY ADAPTABILITY generalization phase imaging
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2024 US General Election and Changes in its Party Politics
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作者 Xie Tao 《Contemporary World》 2025年第1期44-48,共5页
The US 2024 general election ended with the Republican Party winning the presidential, House and Senate elections at the same time. In the presidential election, the Republican Party not only won more popular votes in... The US 2024 general election ended with the Republican Party winning the presidential, House and Senate elections at the same time. In the presidential election, the Republican Party not only won more popular votes in over 90% counties than in the 2020 general election, but also won seven highly contested swing States with greater edges. This also marks the first time since 2004 that the Republican Party has won a relative majority of popular votes in the presidential election. 展开更多
关键词 House elections US general election presidential election general election Senate elections republican party Republican Party popular votes
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