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A satellite observation data considered train positioning optimization method with RTK
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作者 YUCHI Zhen-xin LI Wei +3 位作者 GAO Shi-juan CHEN Chun-yang HUANG Su-su JIANG Ji-xiong 《Journal of Central South University》 2025年第4期1548-1568,共21页
In this paper,a novel train positioning method considering satellite raw observation data was proposed,which aims to promote train positioning performance from an innovative perspective of the train satellite-based po... In this paper,a novel train positioning method considering satellite raw observation data was proposed,which aims to promote train positioning performance from an innovative perspective of the train satellite-based positioning error sources.The method focused on overcoming the abnormal observations in satellite observation data caused by railway environment rather than the positioning results.Specifically,the relative positioning experimental platform was built and the zero-baseline method was firstly employed to evaluate the carrier phase data quality,and then,GNSS combined observation models were adopted to construct the detection values,which were applied to judge abnormal-data through the dual-frequency observations.Further,ambiguity fixing optimization was investigated based on observation data selection in partly-blocked environments.The results show that the proposed method can effectively detect and address abnormal observations and improve positioning stability.Cycle slips and gross errors can be detected and identified based on dual-frequency global navigation satellite system data.After adopting the data selection strategy,the ambiguity fixing percentage was improved by 29.2%,and the standard deviation in the East,North,and Up components was enhanced by 12.7%,7.4%,and 12.5%,respectively.The proposed method can provide references for train positioning performance optimization in railway environments from the perspective of positioning error sources. 展开更多
关键词 train operation control system train positioning satellite positioning abnormal-data detection real-time kinematic positioning
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Positive mindset,bright future
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作者 李玉莲 《疯狂英语(新读写)》 2025年第8期71-72,80,共3页
In life,we are bound to encounter various difficulties and setbacks.However,it is of great significance to maintain a positive attitude when were facing these challenges.For me,this lesson was deeply impressed upon me... In life,we are bound to encounter various difficulties and setbacks.However,it is of great significance to maintain a positive attitude when were facing these challenges.For me,this lesson was deeply impressed upon me during a particularly tough period. 展开更多
关键词 bright future maintaining positivity DIFFICULTIES challenging period setbacks positive mindset
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UAV clusters information geometry fusion positioning method with LEO satellite system
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作者 Jiaqi LIU Yi ZHANG +3 位作者 Xingxing ZHU Chengkai Tang Zesheng DAN Yangyang LIU 《Chinese Journal of Aeronautics》 2025年第5期411-427,共17页
The existing Low-Earth-Orbit(LEO)positioning performance cannot meet the requirements of Unmanned Aerial Vehicle(UAV)clusters for high-precision real-time positioning in the Global Navigation Satellite System(GNSS)den... The existing Low-Earth-Orbit(LEO)positioning performance cannot meet the requirements of Unmanned Aerial Vehicle(UAV)clusters for high-precision real-time positioning in the Global Navigation Satellite System(GNSS)denial conditions.Therefore,this paper proposes a UAV Clusters Information Geometry Fusion Positioning(UC-IGFP)method using pseudoranges from the LEO satellites.A novel graph model for linking and computing between the UAV clusters and LEO satellites was established.By utilizing probability to describe the positional states of UAVs and sensor errors,the distributed multivariate Probability Fusion Cooperative Positioning(PF-CP)algorithm is proposed to achieve high-precision cooperative positioning and integration of the cluster.Criteria to select the centroid of the cluster were set.A new Kalman filter algorithm that is suitable for UAV clusters was designed based on the global benchmark and Riemann information geometry theory,which overcomes the discontinuity problem caused by the change of cluster centroids.Finally,the UC-IGFP method achieves the LEO continuous highprecision positioning of UAV clusters.The proposed method effectively addresses the positioning challenges caused by the strong direction of signal beams from LEO satellites and the insufficient constraint quantity of information sources at the edge nodes of the cluster.It significantly improves the accuracy and reliability of LEO-UAV cluster positioning.The results of comprehensive simulation experiments show that the proposed method has a 30.5%improvement in performance over the mainstream positioning methods,with a positioning error of 14.267 m. 展开更多
关键词 LEO positioning Information fusion UAVclusters Cooperative positioning Distributed
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A Study on the Cumulative Effects of AI-Powered Campus Positive Initiatives on Cultivating Positive Emotions and Psychological Capital among College Students
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作者 Minghua Shao Xinghui Ma 《Journal of Contemporary Educational Research》 2025年第10期376-383,共8页
Higher education is transitioning from mass expansion to high-quality development.In this process,mental health issues among college students have become increasingly prominent,encompassing not only academic stress-in... Higher education is transitioning from mass expansion to high-quality development.In this process,mental health issues among college students have become increasingly prominent,encompassing not only academic stress-induced anxiety but also complex challenges such as interpersonal adaptation difficulties and career planning confusion.Traditional“problem-oriented”intervention models have shown limitations in responsiveness and adaptability,often only passively addressing existing psychological crises rather than preventing them in advance.This study aims to explore an AI-powered“positive psychology”proactive intervention model through developing an intelligent system.The system automatically collects,filters,and personalizes recommendations for positive activities on campus.Using a randomized controlled trial design,we conducted an 8-week intervention study involving 126 college students at a university.The study found that AI-based“campus positive activity”recommendations effectively boost students’positive emotions and promote psychological capital development through cumulative micro-interventions.This provides universities with empirical evidence and innovative methods to implement low-cost,efficient,and scalable mental health promotion programs through smart technology. 展开更多
关键词 Artificial intelligence positive event push notifications positive emotions Psychological capital College students Cumulative effect
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The advances in the diagnosis and treatment of CK19-positive hepatocellular carcinoma
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作者 Jian-Yong Zhuo Hui-Gang Li +2 位作者 Pei-Ru Zhang Di Lu Xiao Xu 《Hepatobiliary & Pancreatic Diseases International》 2025年第5期473-475,共3页
Hepatocellular carcinoma(HCC)is a highly heterogenous dis-ease in histology,genetic aberrations,and protein expression.Over the past decade,the development of new omics techniques has fa-cilitated significant advances... Hepatocellular carcinoma(HCC)is a highly heterogenous dis-ease in histology,genetic aberrations,and protein expression.Over the past decade,the development of new omics techniques has fa-cilitated significant advances in the field of molecular typing stud-ies of HCC.In the era of precision medicine,it is of great signif-icance to improve the efficacy of HCC treatment based on tumor molecular subtyping.Cytokeratin(CK)19-positive HCC has gained increasing atten-tion.Although CK19 is a marker of biliary epithelial cells,10%−30%of HCCs are observed to be CK19 positive[1].Differing from com-bined hepatocellular and cholangiocarcinoma,CK19-positive HCC displays typical HCC morphological features,exhibiting strong co-express of both hepatocyte and cholangiocyte markers within the same tumor cells.Consequently,CK19-positive HCC is also referred to as dual-phenotype HCC,with displaying cholangiolar differenti-ation. 展开更多
关键词 precision medicineit hepatocellular carcinoma diagnosis ck positive biliary epitheli hepatocellular carcinoma hcc omics techniques tumor molecular subtypingcytokeratin ck positive
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Modeling and performance analysis of GNSS-based train positioning system with colored petri nets
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作者 Shuting Chen Daohua Wu +1 位作者 Jiang Liu Siqi Wang 《High-Speed Railway》 2025年第3期175-184,共10页
Global Navigation Satellite System(GNSS)-based continuous and accurate train positioning is one of the key technologies for advanced train operations such as train virtual coupling.However,GNSS-based train positioning... Global Navigation Satellite System(GNSS)-based continuous and accurate train positioning is one of the key technologies for advanced train operations such as train virtual coupling.However,GNSS-based train positioning faces significant challenges in real-world scenarios due to environmental complexities and signal interferences.Considering this issue,this paper presents an approach for modeling and performance analysis of GNSS-based train positioning systems using Colored Petri Nets(CPNs).By systematically modeling the GNSS signal reception and processing process,the performance of the positioning system under various environment scenarios is evaluated.The system model integrates three types of interference signals(i.e.,Amplitude Modulation(AM)signals,Frequency Modulation(FM)signals,and pulse signals)while incorporating environmental factors such as terrain obstructions and tunnel shielding.Additionally,the Extended Kalman Filter(EKF)algorithm is employed to process GNSS observation data,providing accurate train position estimations.The simulation results demonstrate that signal interferences and complex environmental conditions significantly affect the GNSS-based positioning accuracy.This study offers a comprehensive framework for evaluating the performance of GNSS-based train positioning systems in different scenarios,highlighting critical factors that influence positioning accuracy and stability. 展开更多
关键词 GNSS-based train positioning positioning performance Environment scenario GNSS signal interference Colored petri Nets
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A Base Station Deployment Algorithm for Wireless Positioning Considering Dynamic Obstacles
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作者 Aiguo Li Yunfei Jia 《Computers, Materials & Continua》 2025年第3期4573-4591,共19页
In the context of security systems,adequate signal coverage is paramount for the communication between security personnel and the accurate positioning of personnel.Most studies focus on optimizing base station deploym... In the context of security systems,adequate signal coverage is paramount for the communication between security personnel and the accurate positioning of personnel.Most studies focus on optimizing base station deployment under the assumption of static obstacles,aiming to maximize the perception coverage of wireless RF(Radio Frequency)signals and reduce positioning blind spots.However,in practical security systems,obstacles are subject to change,necessitating the consideration of base station deployment in dynamic environments.Nevertheless,research in this area still needs to be conducted.This paper proposes a Dynamic Indoor Environment Beacon Deployment Algorithm(DIE-BDA)to address this problem.This algorithm considers the dynamic alterations in obstacle locations within the designated area.It determines the requisite number of base stations,the requisite time,and the area’s practical and overall signal coverage rates.The experimental results demonstrate that the algorithm can calculate the deployment strategy in 0.12 s following a change in obstacle positions.Experimental results show that the algorithm in this paper requires 0.12 s to compute the deployment strategy after the positions of obstacles change.With 13 base stations,it achieves an effective coverage rate of 93.5%and an overall coverage rate of 97.75%.The algorithm can rapidly compute a revised deployment strategy in response to changes in obstacle positions within security systems,thereby ensuring the efficacy of signal coverage. 展开更多
关键词 Wireless positioning base station deployment dynamic obstacles dynamic obstacle wireless positioning
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A Biomimetic Stress Field Modulation Strategy Inspired by Scorpion Compound Slit Sensilla Enabled High-Accuracy and Low-Power Positioning Sensor for Identifying the Load Incident Angles
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作者 Junqiu Zhang Yu Chen +11 位作者 Haoran Li Jiqi Gao Xiangbo Gu Jiachao Wu Xiaojing Qin Kejun Wang Bin Zhu Daobing Chen Tao Sun Jianhua Fan Zhiwu Han Luquan Ren 《Journal of Bionic Engineering》 2025年第2期727-738,共12页
Numerous arthropods evolve and optimize sensory systems, enabling them to effectively adapt complex and competitive habitats. Typically, scorpions can precisely perceive the prey location with the lowest metabolic rat... Numerous arthropods evolve and optimize sensory systems, enabling them to effectively adapt complex and competitive habitats. Typically, scorpions can precisely perceive the prey location with the lowest metabolic rate among invertebrates. This biological phenomenon contrasts sharply with engineered systems, which generally associates high accuracy with substantial energy consumption. Inspired by the Scorpion Compound Slit Sensilla (SCSS) with a stress field modulation strategy, a bionic positioning sensor with superior precision and minimal power consumption is developed for the first time, which utilizes the particular Minimum Positioning Units (MPUs) to efficiently locate vibration signals. The single MPU of the SCSS can recognize the direction of collinear loads by regulating the stress field distribution and further, the coupling action of three MPUs can realize all-angle vibration monitoring in plane. Experiments demonstrate that the bionic positioning sensor achieves 1.43 degrees of angle-error-free accuracy without additional energy supply. As a proof of concept, two bionic positioning sensors and machine learning algorithm are integrated to provide centimeter (cm)-accuracy target localization, ideally suited for the man-machine interaction. The novel design offers a new mechanism for the design of traditional positioning devices, improving precision and efficiency in both the meta-universe and real-world Internet-connected systems. 展开更多
关键词 Scorpion Compound Slit Sensilla(SCSS) Vibration Source Stress Field Modulation Strategy High-accuracy and low-power positioning Sensor Minimum positioning Unit(MPU)
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Study on the Effect of Spot Size and Non-Linearity on PSD Positioning Accuracy
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作者 WANG Zechuan ZHANG Zhenhua +3 位作者 CHENG Shaowei YANG Haima HUANG Bo LIU Jin 《Wuhan University Journal of Natural Sciences》 2025年第3期213-221,共9页
Position-sensitive detector(PSD)is widely used in precision measurement fields such as flatness detection,auto-collimator systems,and degrees of freedom testing.However,due to factors such as uneven surface resistance... Position-sensitive detector(PSD)is widely used in precision measurement fields such as flatness detection,auto-collimator systems,and degrees of freedom testing.However,due to factors such as uneven surface resistance and differences in electrode structures,the nonlinearity of PSD becomes increasingly severe as the photosensitive surface moves from the center toward the edges of the four electrodes.To address this issue,a PSD nonlinearity correction algorithm is proposed.The algorithm utilizes the particle swarm optimization(PSO)algorithm to determine the optimal weights and thresholds,providing better initial parameters for the back propagation(BP)neural network.The BP neural network then iterates continuously until the error conditions are met,completing the correction process.Furthermore,a PSD nonlinearity correction system was developed,and the influence of different spot sizes on PSD positioning accuracy was simulated based on the current equation under the Gaussian spot model.This validated the robustness of the correction algorithm under varying spot sizes.The results demonstrate that the overall optimized error is reduced by 84.51%,and for spot sizes smaller than 1 mm,the error reduction exceeds 93.89%.This method not only meets the measurement accuracy requirements but also extends the measurement range of PSD. 展开更多
关键词 position-sensitive detector particle swarm algorithm nonlinear optimization spot characteristics positioning accuracy
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Determining the natural vibration period of towering structure using GNSS precise point positioning
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作者 WANG Zhiming WU Jizhong 《Journal of Southeast University(English Edition)》 2025年第2期199-206,共8页
This study explores the use of the Global Navigation Satellite System(GNSS)precise point positioning(PPP)technology to determine the natural vibration periods of towering structures through simulations and field testi... This study explores the use of the Global Navigation Satellite System(GNSS)precise point positioning(PPP)technology to determine the natural vibration periods of towering structures through simulations and field testing.During the simulation phase,a GNSS receiver captured vi-bration waveforms generated by a single-axis motion simulator based on preset signal parameters,analyzing how different satellite system configurations affect the efficiency of extracting vibration parameters.Subsequently,field tests were conducted on a high-rise steel singletube tower.The results indicate that in the simulation environment,no matter the PPP positioning data under single GPS or multisystem combination,the vibration frequency of singleaxis motion simulator can be accurately extracted after frequency do-main analysis,with multisystem setups providing more precise amplitude parameters.In the field test,the natural vibration periods of the main vibration modes of high-rise steel single-tube tower measured by PPP technology closely match the results of the first two modes derived from finite element analysis.The first mode period calculated by the em-pirical formula is approximately 6%higher than those determined through finite element analysis and PPP.This study demonstrates the potential of PPP for structural vibration analysis,offering significant benefits for assessing dynamic responses and monitoring the health of towering structures. 展开更多
关键词 towering structure natural vibration period precise point positioning frequency domain decomposition
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Experimental Study on Shear Mechanical Properties of Light Composite Bridge in Bending Moment Zone
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作者 Han Zhang Shuwen Deng 《Journal of Architectural Research and Development》 2025年第5期8-13,共6页
This study conducted shear resistance tests on steel-UHPC composite beams,focusing on structural stiffness changes during the test process,strain analysis of UHPC panels,internal reinforcement bars,steel structures,an... This study conducted shear resistance tests on steel-UHPC composite beams,focusing on structural stiffness changes during the test process,strain analysis of UHPC panels,internal reinforcement bars,steel structures,and shear connectors,as well as the failure processes and modes of UHPC panels and the structure.Through theoretical analysis,the contribution of UHPC panels to the overall vertical shear resistance capability was clarified.A shear load-bearing capacity calculation method was established,thereby considering the combined beam shear bearing capacity calculation formula of the UHPC panel and the steel beam web. 展开更多
关键词 Steel-UHPC composite beam positive moment zone Shear resistance test Bridge design theory and calculation method
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Tracheal intubation in the lateral position in emergency medicine:a narrative review and clinical protocol 被引量:1
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作者 Ping Cui Tingting Wen +4 位作者 Bingduo Wang Shuijing Wu Shiyu Chen Xiangming Fang TILP consortium 《World Journal of Emergency Medicine》 2025年第2期103-112,共10页
BACKGROUND:Tracheal intubation(TI)is a fundamental procedure for securing the airway or assisting ventilation in emergency medicine.Tracheal intubation in the lateral position(TILP)has been utilized in clinical practi... BACKGROUND:Tracheal intubation(TI)is a fundamental procedure for securing the airway or assisting ventilation in emergency medicine.Tracheal intubation in the lateral position(TILP)has been utilized in clinical practice,demonstrating potential advantages in specific scenarios,including emergency settings.However,there is a lack of comprehensive reviews and practical protocols on TILP application.To address this gap,we performed a narrative review,and provided evidence-based recommendations to formulate a practice protocol,to assist clinicians to effectively apply TILP.METHODS:We conducted a narrative review of TILP applications and developed recommendations based on clinical research evidence and clinical experience.Delphi method was used among the TILP consortium to grade the strength of the recommendations and to help reach consensus.The practice protocols were formulated as warranted by advancements in medical knowledge,technology,and practice.RESULTS:This narrative review summarized the current evidence on TILP application,highlighting its safety,efficacy,challenges,and potential complications.In total,24 recommendations and a clinical protocol for TILP application in emergency patients were established.CONCLUSION:TILP is a valuable technique in emergency medicine.We reviewed its application in emergency settings and formulated recommendations along with a clinical practice protocol.Future studies are needed to evaluate the safety and efficacy of TILP,broaden its scope of application,and explore effective training protocols. 展开更多
关键词 Tracheal intubation Lateral position Emergency medicine Critical care
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Clustering optimization strategy for cooperative positioning system aided by UAV 被引量:1
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作者 Hongbo ZHAO Zeqi YIN Shan HU 《Chinese Journal of Aeronautics》 2025年第9期421-435,共15页
For multi-vehicle networks,Cooperative Positioning(CP)technique has become a promising way to enhance vehicle positioning accuracy.Especially,the CP performance could be further improved by introducing Sensor-Rich Veh... For multi-vehicle networks,Cooperative Positioning(CP)technique has become a promising way to enhance vehicle positioning accuracy.Especially,the CP performance could be further improved by introducing Sensor-Rich Vehicles(SRVs)into CP networks,which is called SRV-aided CP.However,the CP system may split into several sub-clusters that cannot be connected with each other in dense urban environments,in which the sub-clusters with few SRVs will suffer from degradation of CP performance.Since Unmanned Aerial Vehicles(UAVs)have been widely used to aid vehicular communications,we intend to utilize UAVs to assist sub-clusters in CP.In this paper,a UAV-aided CP network is constructed to fully utilize information from SRVs.First,the inter-node connection structure among the UAV and vehicles is designed to share available information from SRVs.After that,the clustering optimization strategy is proposed,in which the UAV cooperates with the high-precision sub-cluster to obtain available information from SRVs,and then broadcasts this positioning-related information to other low-precision sub-clusters.Finally,the Locally-Centralized Factor Graph Optimization(LC-FGO)algorithm is designed to fuse positioning information from cooperators.Simulation results indicate that the positioning accuracy of the CP system could be improved by fully utilizing positioning-related information from SRVs. 展开更多
关键词 Clustering optimization Cooperative positioning Locally-centralized FGO Networking wireless sensors Unmanned aerial vehicles Urban degradation environments
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Posit浮点部件实现
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作者 陈子钰 何军 +4 位作者 尹飞 颜世云 杨剑新 文周旺 马启皓 《计算机应用》 北大核心 2025年第S1期163-169,共7页
首先,介绍Posit浮点格式及相关研究现状;其次,设计并实现一组Posit浮点运算指令,包含7条算术运算指令、3条比较指令和14条格式转换指令;最后,实现一个能全流水执行的Posit浮点部件,并评估它的实现性。该部件支持Posit(32,2)、Posit(32,3... 首先,介绍Posit浮点格式及相关研究现状;其次,设计并实现一组Posit浮点运算指令,包含7条算术运算指令、3条比较指令和14条格式转换指令;最后,实现一个能全流水执行的Posit浮点部件,并评估它的实现性。该部件支持Posit(32,2)、Posit(32,3)和Posit(32,6)这3种格式,包含5级流水的Posit浮点融合乘加(PFMA)子部件和3级流水的Posit浮点格式转换(PFCVT)子部件。相较于支持FP32格式的浮点部件,所提Posit浮点部件在Posit(32,2)格式下的操作数尾数和结果尾数的最大位宽增加了4 bit,并在Posit(32,6)格式下的指数的动态范围提升了近1 072 decades,显著提高了数据表示范围和灵活性;同时,在Posit(32,6)格式下支持的数据动态范围比FP64大了近524 decades。可见,所提部件可用于探索Posit(32,6)在特定领域和应用中替代FP64的可行性,以减少计算系统的存储、访存和通信开销,从而提高计算能效。 展开更多
关键词 posit 浮点算术 融合乘加 浮点转换 指令集
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Advancements and challenges in neuroimaging for the diagnosis of intracranial aneurysms:Addressing false positive diagnoses and emerging techniques
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作者 Nanthida Arora Sombat Muengtaweepongsa 《World Journal of Clinical Cases》 SCIE 2025年第6期48-50,共3页
Despite advancements in neuroimaging,false positive diagnoses of intracranial aneurysms remain a significant concern.This article examines the causes,prevalence,and implications of such false-positive diagnoses.We dis... Despite advancements in neuroimaging,false positive diagnoses of intracranial aneurysms remain a significant concern.This article examines the causes,prevalence,and implications of such false-positive diagnoses.We discuss how conditions like arterial occlusion with vascular stump formation and infundibular widening can mimic aneurysms,particularly in the anterior circulation.The article compares various imaging modalities,including computer tomography angiogram,magnetic resonance imaging/angiography,and digital subtraction angiogram,highlighting their strengths and limitations.We emphasize the im-portance of accurate differentiation to avoid unnecessary surgical interventions.The potential of emerging technologies,such as high-resolution vessel wall ima-ging and deep neural networks for automated detection,is explored as promising avenues for improving diagnostic accuracy.This manuscript underscores the need for continued research and clinical vigilance in the diagnosis of intracranial aneurysms. 展开更多
关键词 Intracranial aneurysms Neuroimaging techniques Computed tomographic angiography Magnetic resonance angiography Digital subtraction angiography False positive diagnoses
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High-precision spot centroid positioning of high-frame-rate short-wave infrared images for satellite laser communication
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作者 FU Peng HE Dao-Gang +1 位作者 LIU Jun WANG Yue-Ming 《红外与毫米波学报》 北大核心 2025年第1期66-77,共12页
The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave... The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave infrared wavelengths as beacon light can reduce atmospheric absorption and signal attenuation.However,there are strong non-uniformity and blind pixels in the short-wave infrared image,which makes the image distorted and leads to the decrease of spot centroid positioning accuracy.Therefore,the high-precision localization of the spot centroid of the short-wave infrared images is of great research significance.A high-precision spot centroid positioning model for short-wave infrared is proposed to correct for non-uniformity and blind pixels in short-wave infrared images and quantify the localization errors caused by the two,further model-based localization error simulations are performed,and a novel spot centroid positioning payload for satellite laser communications has been designed using the latest 640×512 planar array InGaAs shortwave infrared detector.The experimental results show that the non-uniformity of the corrected image is reduced from 7%to 0.6%,the blind pixels rejection rate reaches 100%,the frame rate can be up to 2000 Hz,and the spot centroid localization accuracy is as high as 0.1 pixel point,which realizes high-precision spot centroid localization of high-frame-frequency short-wave infrared images. 展开更多
关键词 satellite laser communication spot centroid positioning short-wave infrared high frame rate NONUNIFORMITY
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On Bowen Entropy for Stable Sets in Positive Entropy Systems
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作者 ZHANG Zhengwei YAN Kesong ZENG Fanping 《数学进展》 北大核心 2025年第1期99-112,共14页
In this paper,we study the Bowen entropy of stable sets in positive entropy G-system of amenable group actions.The lower bound of the Bowen entropy of these sets are estimated.
关键词 positive entropy stable set Bowen entropy amenable group action
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Normalized Positive Ground State Solutions for Nonhomogeneous Kirchhoff Equations
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作者 ZHANG Xiaocang XU Liping 《应用数学》 北大核心 2025年第3期711-720,共10页
This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of norm... This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of normalized positive solutions for this equation via the Trudinger-Moser inequality and variational methods.Moreover,these solutions are also ground state solutions.Additionally,the article also characterized the asymptotic behavior of solutions.The results of this article expand the research of relevant literature. 展开更多
关键词 Normalized positive ground state solution Nonhomogeneous Kirchhoff equation Variational method Exponential critical growth Trapping potential
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Real pairwise completely positive matrices
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作者 ZHOU Anwa HE Jiayi 《运筹学学报(中英文)》 北大核心 2025年第3期160-178,共19页
In this paper,we introduce the real pairwise completely positive(RPCP)matrices with one of them is necessarily positive semidefinite while the other one is necessarily entrywise nonnegative,which has a real pairwise c... In this paper,we introduce the real pairwise completely positive(RPCP)matrices with one of them is necessarily positive semidefinite while the other one is necessarily entrywise nonnegative,which has a real pairwise completely positive(RPCP)decomposition.We study the properties of RPCP matrices and give some necessary and sufficient conditions for a matrix pair to be RPCP.First,we give an equivalent decomposition for the RPCP matrices,which is different from the RPCP-decomposition and show that the matrix pair(X,X)is RPCP if and only if X is completely positive.Besides,we also prove that the RPCP matrices checking problem is equivalent to the separable completion problem.A semidefinite algorithm is also proposed for detecting whether or not a matrix pair is RPCP.The asymptotic and finite convergence of the algorithm are also discussed.If it is RPCP,we can further give a RPCP-decomposition for it;if it is not,we can obtain a certificate for this. 展开更多
关键词 real pairwise completely positive matrices truncated moment problem semidefinite relaxation
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The predictive value of NLR and SII in anti⁃MDA5 antibody⁃positive dermatomyositis with rapidly progressive interstitial lung disease
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作者 CAI Qingqing YOU Hanxiao +7 位作者 WANG Lei LÜChengyin SHI Yumeng QIU Yulu WU Lingyun WANG Fang ZHANG Miaojia TAN Wenfeng 《南京医科大学学报(自然科学版)》 北大核心 2025年第2期196-207,共12页
Objective:To evaluate the predictive value of the neutrophil⁃to⁃lymphocyte ratio(NLR)and the systemic immune⁃inflammation index(SII)in predicting patients with anti⁃melanoma differentiation⁃associated gene 5⁃positive(... Objective:To evaluate the predictive value of the neutrophil⁃to⁃lymphocyte ratio(NLR)and the systemic immune⁃inflammation index(SII)in predicting patients with anti⁃melanoma differentiation⁃associated gene 5⁃positive(anti⁃MDA5+)dermatomyositis(DM)develop into the rapidly progressive interstitial lung disease(RPILD).Methods:We retrospectively analyzed the clinical and laboratory data of 124 anti⁃MDA5+DM patients from the First Affiliated Hospital of Nanjing Medical University between March 2019 and September 2023.We identified independent risk factors associated with the development and mortality of RPILD with the Cox regression analysis,and determined the optimal cut⁃off values for predicting adverse outcomes with the receiver operating characteristic(ROC)curve analysis.Results:Among the 124 patients,36 patients(29.03%)developed RPILD,and 39 patients(31.45%)died during the follow⁃up period.The results of multivariate Cox regression analysis showed that the elevated NLR was an independent risk factor for RPILD development,while the elevated SII expression was independently associated with the increased mortality of RPILD.Based on the ROC curve analysis,NLR>6.12 was a predictor for RPILD,and SII>875.79 was associated with increased mortality risk of RPILD.Conclusion:Both NLR and SII are accessible,cost⁃effective,and reliable prognostic indicators for the prognosis of patients with anti⁃MDA5^(+)DM,providing a valuable guidance for clinical management and risk stratification of the disease. 展开更多
关键词 anti⁃melanoma differentiation⁃associated gene 5⁃positive dermatomyositis neutrophil⁃to⁃lymphocyte ratio rapidly pro⁃gressive interstitial lung disease systemic immune⁃inflammation index
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