期刊文献+
共找到30,251篇文章
< 1 2 250 >
每页显示 20 50 100
Dynamic Response Analysis of Towed Cable During Deployment/Retrieval 被引量:5
1
作者 王飞 黄国樑 邓德衡 《Journal of Shanghai Jiaotong university(Science)》 EI 2008年第2期245-251,共7页
A numerical approach was developed to analyze the transient behavior of towed cable during ac- tively controlled deployment/retrieval (DR).The cable motion is described by the lumped parameter method, its correspondin... A numerical approach was developed to analyze the transient behavior of towed cable during ac- tively controlled deployment/retrieval (DR).The cable motion is described by the lumped parameter method, its corresponding boundary conditions are presented.In view of its varying length during DR,two auxiliary arguments are introduced to describe its continuous varying length and discrete number of nodes(equations), the length is determined by the pay out(or reel-in) rate,which is then used to determine the node number by a logic relation.For the discrete mathematical model of towed cable,an algorithm was developed to deal with the discrete governing equations.The simulation results indicate that the cable experiences more com- plex motions due to its varying length,and tension fluctuates seriously in the startup and ending stage of deployment/retrieval.The effect of towing ship's motion in waves on cable during deployment/retrieval is also considered via numerical simulation. 展开更多
关键词 towed cable boundary conditions deployment/retrieval numerical simulation
在线阅读 下载PDF
Target Deployment and Retrieval Using JIAOLONG Manned Submersible in the Depth of 6600 m in Mariana Trench 被引量:3
2
作者 GAO Xiang DING Kang +4 位作者 REN Yu-gang FU Wen-tao DING Zhong-jun ZHAO Sheng-ya LIU Bao-hua 《China Ocean Engineering》 SCIE EI CSCD 2017年第5期618-623,共6页
China's 7000 m manned submersible JIAOLONG carried out an exploration cruise at the Mariana Trench from June to July 2016. The submersible completed nine manned dives on the north and south area of the Mariana Trench... China's 7000 m manned submersible JIAOLONG carried out an exploration cruise at the Mariana Trench from June to July 2016. The submersible completed nine manned dives on the north and south area of the Mariana Trench from the depth of 5500 to 6700 m, to investigate the geological, biological and chemical characteristics in the hadal area. During the cruise, JIAOLONG deployed a gas-tight serial sampler to collect the water near the sea bottom regularly. Five days later, the sub located the sampler in another dive and retrieved it successfully from the same location, which is the first time that scientists and engineers finished the high accuracy in-situ deployment and retrieval using a manned submersible with Ultra-Short Base Line (USBL) positioning system at the depth more than 6600 m. In this task, we used not only the USBL system of the manned submersible but also a compound strategy, including five position marks, the sea floor terrain, the depth contour, and the heading of the sub. This paper introduces the compound strategy of the target deployment and retrieval with the practical diving experience of JIAOLONG, and provides a promising technique for other underwater vehicles such as manned submersible or Remote Operated Vehicle (ROV) under similar conditions. 展开更多
关键词 target deployment and retrieval manned submersible USBL Mariana Trench
在线阅读 下载PDF
Challenges in the Large-Scale Deployment of CCUS 被引量:2
3
作者 Zhenhua Rui Lianbo Zeng Birol Dindoruk 《Engineering》 2025年第1期17-20,共4页
1.Introduction Climate change mitigation pathways aimed at limiting global anthropogenic carbon dioxide(CO_(2))emissions while striving to constrain the global temperature increase to below 2℃—as outlined by the Int... 1.Introduction Climate change mitigation pathways aimed at limiting global anthropogenic carbon dioxide(CO_(2))emissions while striving to constrain the global temperature increase to below 2℃—as outlined by the Intergovernmental Panel on Climate Change(IPCC)—consistently predict the widespread implementation of CO_(2)geological storage on a global scale. 展开更多
关键词 Large-Scale deployment CCUS CHALLENGES Climate Change Mitigation
在线阅读 下载PDF
Endovascular retrieval of a prematurely deployed covered stent 被引量:1
4
作者 Jefferson T Miley Gustavo J Rodriguez Ramachandra P Tummala 《World Journal of Radiology》 CAS 2015年第6期139-142,共4页
Several techniques have been reported to address different endovascular device failures. We report the case of a premature deployment of a covered balloon mounted stent during endovascular repair of a posttraumatic ca... Several techniques have been reported to address different endovascular device failures. We report the case of a premature deployment of a covered balloon mounted stent during endovascular repair of a posttraumatic carotid-cavernous fistula(CCF). A 50-year-old male suffered a fall resulting in loss of consciousness and multiple facial fractures. Five weeks later, he developed decreased left visual acuity, proptosis, chemosis, limited eye movements and cranial/orbit bruit. Cerebral angiography demonstrated a direct left CCF and endovascular repair with a 5.0 mm × 19 mm covered stent was planned. Once in the lacerum segment, increased resistance was encountered and the stent was withdrawn resulting in premature deployment. A 3 mm × 9 mm balloon was advanced over an exchange length microwire and through the stent lumen. Once distal to the stent, the balloon was inflated and slowly pulled back in contact with the stent. All devices were successfully withdrawn as a unit. The use of a balloon to retrieve a prematurely deployed balloon mounted stent is a potential rescue option if leaving the stent in situ carries risks. 展开更多
关键词 STENT retrieval COVERED STENT PREMATURE STENT deployment
暂未订购
Evolutionary Particle Swarm Optimization Algorithm Based on Collective Prediction for Deployment of Base Stations
5
作者 Jiaying Shen Donglin Zhu +5 位作者 Yujia Liu Leyi Wang Jialing Hu Zhaolong Ouyang Changjun Zhou Taiyong Li 《Computers, Materials & Continua》 SCIE EI 2025年第1期345-369,共25页
The wireless signals emitted by base stations serve as a vital link connecting people in today’s society and have been occupying an increasingly important role in real life.The development of the Internet of Things(I... The wireless signals emitted by base stations serve as a vital link connecting people in today’s society and have been occupying an increasingly important role in real life.The development of the Internet of Things(IoT)relies on the support of base stations,which provide a solid foundation for achieving a more intelligent way of living.In a specific area,achieving higher signal coverage with fewer base stations has become an urgent problem.Therefore,this article focuses on the effective coverage area of base station signals and proposes a novel Evolutionary Particle Swarm Optimization(EPSO)algorithm based on collective prediction,referred to herein as ECPPSO.Introducing a new strategy called neighbor-based evolution prediction(NEP)addresses the issue of premature convergence often encountered by PSO.ECPPSO also employs a strengthening evolution(SE)strategy to enhance the algorithm’s global search capability and efficiency,ensuring enhanced robustness and a faster convergence speed when solving complex optimization problems.To better adapt to the actual communication needs of base stations,this article conducts simulation experiments by changing the number of base stations.The experimental results demonstrate thatunder the conditionof 50 ormore base stations,ECPPSOconsistently achieves the best coverage rate exceeding 95%,peaking at 99.4400%when the number of base stations reaches 80.These results validate the optimization capability of the ECPPSO algorithm,proving its feasibility and effectiveness.Further ablative experiments and comparisons with other algorithms highlight the advantages of ECPPSO. 展开更多
关键词 Particle swarm optimization effective coverage area global optimization base station deployment
在线阅读 下载PDF
Efficient Method for Trademark Image Retrieval: Leveraging Siamese and Triplet Networks with Examination-Informed Loss Adjustment
6
作者 Thanh Bui-Minh Nguyen Long Giang Luan Thanh Le 《Computers, Materials & Continua》 2025年第7期1203-1226,共24页
Image-based similar trademark retrieval is a time-consuming and labor-intensive task in the trademark examination process.This paper aims to support trademark examiners by training Deep Convolutional Neural Network(DC... Image-based similar trademark retrieval is a time-consuming and labor-intensive task in the trademark examination process.This paper aims to support trademark examiners by training Deep Convolutional Neural Network(DCNN)models for effective Trademark Image Retrieval(TIR).To achieve this goal,we first develop a novel labeling method that automatically generates hundreds of thousands of labeled similar and dissimilar trademark image pairs using accompanying data fields such as citation lists,Vienna classification(VC)codes,and trademark ownership information.This approach eliminates the need for manual labeling and provides a large-scale dataset suitable for training deep learning models.We then train DCNN models based on Siamese and Triplet architectures,evaluating various feature extractors to determine the most effective configuration.Furthermore,we present an Adapted Contrastive Loss Function(ACLF)for the trademark retrieval task,specifically engineered to mitigate the influence of noisy labels found in automatically created datasets.Experimental results indicate that our proposed model(Efficient-Net_v21_Siamese)performs best at both True Negative Rate(TNR)threshold levels,TNR 0.9 and TNR 0.95,with==respective True Positive Rates(TPRs)of 77.7%and 70.8%and accuracies of 83.9%and 80.4%.Additionally,when testing on the public trademark dataset METU_v2,our model achieves a normalized average rank(NAR)of 0.0169,outperforming the current state-of-the-art(SOTA)model.Based on these findings,we estimate that considering only approximately 10%of the returned trademarks would be sufficient,significantly reducing the review time.Therefore,the paper highlights the potential of utilizing national trademark data to enhance the accuracy and efficiency of trademark retrieval systems,ultimately supporting trademark examiners in their evaluation tasks. 展开更多
关键词 TRADEMARK image retrieval similar search similar retrieval content-based image retrieval similar ranking contrastive learning Siamese TRIPLET citation list
在线阅读 下载PDF
Retrieval of Ozone Profiles Using a Weighted Multiplicative Algebraic Reconstruction Technique from SCIAMACHY Limb Scattering Observations
7
作者 Fang Zhu Fuqi Si +3 位作者 Ke Dou Kai Zhan Haijin Zhou Yuhan Luo 《Journal of Earth Science》 2025年第1期314-326,共13页
This study describes the use of the weighted multiplicative algebraic reconstruction technique(WMART)to obtain vertical ozone profiles from limb observations performed by the scanning imaging absorption spectrometer f... This study describes the use of the weighted multiplicative algebraic reconstruction technique(WMART)to obtain vertical ozone profiles from limb observations performed by the scanning imaging absorption spectrometer for atmospheric chartography(SCIAMACHY).This technique is based on SaskMART(the combination of the multiplicative algebraic reconstruction technique and SaskTRAN radiative transfer model),which was originally developed for optical spectrometer and infrared imaging system(OSIRIS)data.One of the objectives of this study was to obtain consistent ozone profiles from the two satellites.In this study,the WMART algorithm is combined with a radiative transfer model(SCIATRAN),as well as a set of measurement vectors comprising five Hartley pairing vectors(HPVs)and one Chappuis triplet vector(CTV),to retrieve ozone profiles in the altitude range of 10–69 km.Considering that the weighting factors in WMART have a significant effect on the retrievals,we propose a novel approach to calculate the pair/triplet weighting factors using wavelength weighting functions.The results of the application of the proposed ozone retrieval scheme are compared with the SCIAMACHY v3.5 ozone product by University of Bremen and validated against profiles derived from other passive satellite observations or measured by ozonesondes.Between 18 and 55 km,the retrieved ozone profiles typically agree with data from the SCIAMACHY ozone product within 5%for tropics and middle latitudes,whereas a negative deviation exists between 35 and 50 km for northern high latitudes,with a deviation of less than 10%above 50 km.Comparison of the retrieved profiles with microwave limb sounder(MLS)v5.0 indicates that the difference is within±5%between 18 and 55 km,and an agreement within 10%is achieved in other altitudes for tropics and middle latitudes.Comparison of the retrieved profiles with OSIRIS v7.1 indicates that the average deviation is within±5%between 20 and 59 km,and difference of approximately 10%is achieved below 20 km.Compared with ozonesondes data,a general validity of the retrievals is no more than 5%between 15 and 30 km. 展开更多
关键词 retrievalS OZONE profiles WMART SCIAMACHY LIMB
原文传递
Deployment dynamics and experiments of a tendon-actuated flexible manipulator
8
作者 Benteng ZHANG Jialiang SUN Haiyan HU 《Chinese Journal of Aeronautics》 2025年第2期459-477,共19页
The quantity of space debris on Earth orbit has escalated tremendously in recent years, presenting a significant hazard to human space operations. It is urgent to develop effective measures to capture and remove vario... The quantity of space debris on Earth orbit has escalated tremendously in recent years, presenting a significant hazard to human space operations. It is urgent to develop effective measures to capture and remove various space debris. For this purpose, this paper presents a tendon-actuated flexible deployable manipulator. The flexible manipulator consists of several deployable units connected by Cardan joints and actuated by tendons. Compared with the present technologies for capturing space debris such as rigid robotic arm or flying net, this flexible manipulator is deployable, reusable, lightweight and applicable to the capture of large space debris. In order to investigate its deployment dynamics, an accurate dynamic model of the flexible manipulator is established based on the natural coordinate formulation (NCF) and the absolute nodal coordinate formulation (ANCF). Subsequently, numerical simulations are carried out to study the effects of system parameters and the base satellite on its deployment dynamics. Finally, ground experiments for both deployment and bending of the flexible manipulator are conducted to verify its effectiveness and feasibility. 展开更多
关键词 Flexible manipulator Tendon-actuated Dynamic modeling deployment dynamics Ground experiments
原文传递
Dynamic Routing of Theta-Frequency Synchrony in the Amygdalo-Hippocampal-Entorhinal Circuit Coordinates Retrieval of Competing Memories
9
作者 Jiahua Zheng Yiqi Sun +4 位作者 Fuhai Wang Zhongyu Xie Qianyun Wang Jian-Ya Peng Jianguang Ni 《Neuroscience Bulletin》 2025年第4期713-718,共6页
DDeeaarr EEddiittoorr,,The encoding and retrieval of emotional memories demands intricate interplay within the limbic network,where the network state is subject to significant reconfiguration by learning-induced plast... DDeeaarr EEddiittoorr,,The encoding and retrieval of emotional memories demands intricate interplay within the limbic network,where the network state is subject to significant reconfiguration by learning-induced plasticity,behavioral state,and contextual information[1]. 展开更多
关键词 competing memories limbic networkwhere emotional memories theta frequency synchrony encoding retrieval emotional memories dynamic routing amygdalo hippocampal entorhinal circuit memory retrieval
原文传递
EffNet-CNN:A Semantic Model for Image Mining&Content-Based Image Retrieval
10
作者 Rajendran Thanikachalam Anandhavalli Muniasamy +1 位作者 Ashwag Alasmari Rajendran Thavasimuthu 《Computer Modeling in Engineering & Sciences》 2025年第5期1971-2000,共30页
Content-Based Image Retrieval(CBIR)and image mining are becoming more important study fields in computer vision due to their wide range of applications in healthcare,security,and various domains.The image retrieval sy... Content-Based Image Retrieval(CBIR)and image mining are becoming more important study fields in computer vision due to their wide range of applications in healthcare,security,and various domains.The image retrieval system mainly relies on the efficiency and accuracy of the classification models.This research addresses the challenge of enhancing the image retrieval system by developing a novel approach,EfficientNet-Convolutional Neural Network(EffNet-CNN).The key objective of this research is to evaluate the proposed EffNet-CNN model’s performance in image classification,image mining,and CBIR.The novelty of the proposed EffNet-CNN model includes the integration of different techniques and modifications.The model includes the Mahalanobis distance metric for feature matching,which enhances the similarity measurements.The model extends EfficientNet architecture by incorporating additional convolutional layers,batch normalization,dropout,and pooling layers for improved hierarchical feature extraction.A systematic hyperparameter optimization using SGD,performance evaluation with three datasets,and data normalization for improving feature representations.The EffNet-CNN is assessed utilizing precision,accuracy,F-measure,and recall metrics across MS-COCO,CIFAR-10 and 100 datasets.The model achieved accuracy values ranging from 90.60%to 95.90%for the MS-COCO dataset,96.8%to 98.3%for the CIFAR-10 dataset and 92.9%to 98.6%for the CIFAR-100 dataset.A validation of the EffNet-CNN model’s results with other models reveals the proposed model’s superior performance.The results highlight the potential of the EffNet-CNN model proposed for image classification and its usefulness in image mining and CBIR. 展开更多
关键词 Image mining CBIR semantic features EffNet-CNN image retrieval
在线阅读 下载PDF
Asynchronous deployment scheme and multibody modeling of a ring-truss mesh reflector antenna
11
作者 Baiyan He Kangkang Li +3 位作者 Lijun Jia Rui Nie Yesen Fan Guobiao Wang 《Acta Mechanica Sinica》 2025年第5期190-206,共17页
Mesh reflector antennas are the mainstream of large space-borne antennas,and the stretching of the truss achieves their deployment.Currently,the truss is commonly designed to be a single degree of freedom(DOF)deployab... Mesh reflector antennas are the mainstream of large space-borne antennas,and the stretching of the truss achieves their deployment.Currently,the truss is commonly designed to be a single degree of freedom(DOF)deployable mechanism with synchronization constraints.However,each deployable unit’s drive distribution and resistance load are uneven,and the forced synchronization constraints lead to the flexible deformation of rods and difficulties in the deployment scheme design.This paper introduces an asynchronous deployment scheme with a multi-DOF closed-chain deployable truss.The DOF of the truss is calculated,and the kinematic and dynamic models are established,considering the truss’s and cable net’s real-time coupling.An integrated solving algorithm for implicit differential-algebraic equations is proposed to solve the dynamic models.A prototype of a six-unit antenna was fabricated,and the experiment was carried out.The dynamic performances in synchronous and asynchronous deployment schemes are analyzed,and the results show that the cable resistance and truss kinetic energy impact under the asynchronous deployment scheme are minor,and the antenna is more straightforward to deploy.The work provides a new asynchronous deployment scheme and a universal antenna modeling method for dynamic design and performance improvement. 展开更多
关键词 Mesh antenna deployment dynamic Driving scheme Performance evaluation Numerical analysis
原文传递
A Fully Homomorphic Encryption Scheme Suitable for Ciphertext Retrieval
12
作者 Ronglei Hu ChuceHe +3 位作者 Sihui Liu Dong Yao Xiuying Li Xiaoyi Duan 《Computers, Materials & Continua》 2025年第7期937-956,共20页
Ciphertext data retrieval in cloud databases suffers from some critical limitations,such as inadequate security measures,disorganized key management practices,and insufficient retrieval access control capabilities.To ... Ciphertext data retrieval in cloud databases suffers from some critical limitations,such as inadequate security measures,disorganized key management practices,and insufficient retrieval access control capabilities.To address these problems,this paper proposes an enhanced Fully Homomorphic Encryption(FHE)algorithm based on an improved DGHV algorithm,coupled with an optimized ciphertext retrieval scheme.Our specific contributions are outlined as follows:First,we employ an authorization code to verify the user’s retrieval authority and perform hierarchical access control on cloud storage data.Second,a triple-key encryption mechanism,which separates the data encryption key,retrieval authorization key,and retrieval key,is designed.Different keys are provided to different entities to run corresponding system functions.The key separation architecture proves particularly advantageous in multi-verifier coexistence scenarios,environments involving untrusted third-party retrieval services.Finally,the enhanced DGHV-based retrieval mechanism extends conventional functionality by enabling multi-keyword queries with similarity-ranked results,thereby significantly improving both the functionality and usability of the FHE system. 展开更多
关键词 Cloud storage homomorphic encryption ciphertext retrieval identity authentication
在线阅读 下载PDF
Dynamic behavior recognition in aerial deployment of multi-segmented foldable-wing drones using variational autoencoders
13
作者 Yilin DOU Zhou ZHOU Rui WANG 《Chinese Journal of Aeronautics》 2025年第6期143-165,共23页
The aerial deployment method enables Unmanned Aerial Vehicles(UAVs)to be directly positioned at the required altitude for their mission.This method typically employs folding technology to improve loading efficiency,wi... The aerial deployment method enables Unmanned Aerial Vehicles(UAVs)to be directly positioned at the required altitude for their mission.This method typically employs folding technology to improve loading efficiency,with applications such as the gravity-only aerial deployment of high-aspect-ratio solar-powered UAVs,and aerial takeoff of fixed-wing drones in Mars research.However,the significant morphological changes during deployment are accompanied by strong nonlinear dynamic aerodynamic forces,which result in multiple degrees of freedom and an unstable character.This hinders the description and analysis of unknown dynamic behaviors,further leading to difficulties in the design of deployment strategies and flight control.To address this issue,this paper proposes an analysis method for dynamic behaviors during aerial deployment based on the Variational Autoencoder(VAE).Focusing on the gravity-only deployment problem of highaspect-ratio foldable-wing UAVs,the method encodes the multi-degree-of-freedom unstable motion signals into a low-dimensional feature space through a data-driven approach.By clustering in the feature space,this paper identifies and studies several dynamic behaviors during aerial deployment.The research presented in this paper offers a new method and perspective for feature extraction and analysis of complex and difficult-to-describe extreme flight dynamics,guiding the research on aerial deployment drones design and control strategies. 展开更多
关键词 Dynamic behavior recognition Aerial deployment technology Variational autoencoder Pattern recognition Multi-rigid-bodydynamics
原文传递
Retrieval analysis in total knee arthroplasty
14
作者 Emerito Carlos Rodriguez-Merchan William J Ribbans 《World Journal of Orthopedics》 2025年第3期28-34,共7页
Retrieval analysis in total knee arthroplasty(TKA)has been little studied in the literature.A narrative review of the literature to understand the current importance of retrieval analysis in TKA has been conducted.On ... Retrieval analysis in total knee arthroplasty(TKA)has been little studied in the literature.A narrative review of the literature to understand the current importance of retrieval analysis in TKA has been conducted.On August 27,2024,a literature search was performed in PubMed using“TKA retrieval analysis”as keywords.A total of 160 articles were found,of which only 19 were analyzed because they were directly related to the subject of this article.Rotating-platform(mobile-bearing)TKA has no surface damage advantage over fixed-bearing TKA.TKAs with central locking mechanisms are more prone to debond from the cement mantle.No major wear of the polyethylene(PE)component in TKA using oxidized zirconium components occurs.Femoral components of cobalt-chromium roughen more than oxidized zirconium femoral components.The use of a polished tibial tray over an unpolished design is advised.At short-run assessment(15 months on average),antioxidant-stabilized highly crosslinked PE components are not clinically different in surface damage,density of crosslinking,or oxidation compared to standard remelted highly crosslinked PE components.A correlation between implant position and PE component surface damage has been reported.It shows the importance of optimizing component position to reduce PE component damage.Contemporary knee tumor megaendoprostheses show notable volumetric metal wear originated at the rotating hinge.Retrieval analysis in TKA renders relevant data on how different prosthetic designs described in the literature perform.Such information can help to improve future prosthetic designs to increase prosthetic survival. 展开更多
关键词 Total knee arthroplasty retrieval analysis RESULTS KNEE ORTHOPEDICS
暂未订购
GBiDC-PEST:A novel lightweight model for real-time multiclass tiny pest detection and mobile platform deployment
15
作者 Weiyue Xu Ruxue Yang +2 位作者 Raghupathy Karthikeyan Yinhao Shi Qiong Su 《Journal of Integrative Agriculture》 2025年第7期2749-2769,共21页
Deep learning-based intelligent recognition algorithms are increasingly recognized for their potential to address the labor-intensive challenge of manual pest detection.However,their deployment on mobile devices has b... Deep learning-based intelligent recognition algorithms are increasingly recognized for their potential to address the labor-intensive challenge of manual pest detection.However,their deployment on mobile devices has been constrained by high computational demands.Here,we developed GBiDC-PEST,a mobile application that incorporates an improved,lightweight detection algorithm based on the You Only Look Once(YOLO)series singlestage architecture,for real-time detection of four tiny pests(wheat mites,sugarcane aphids,wheat aphids,and rice planthoppers).GBiDC-PEST incorporates several innovative modules,including GhostNet for lightweight feature extraction and architecture optimization by reconstructing the backbone,the bi-directional feature pyramid network(BiFPN)for enhanced multiscale feature fusion,depthwise convolution(DWConv)layers to reduce computational load,and the convolutional block attention module(CBAM)to enable precise feature focus.The newly developed GBiDC-PEST was trained and validated using a multitarget agricultural tiny pest dataset(Tpest-3960)that covered various field environments.GBiDC-PEST(2.8 MB)significantly reduced the model size to only 20%of the original model size,offering a smaller size than the YOLO series(v5-v10),higher detection accuracy than YOLOv10n and v10s,and faster detection speed than v8s,v9c,v10m and v10b.In Android deployment experiments,GBiDCPEST demonstrated enhanced performance in detecting pests against complex backgrounds,and the accuracy for wheat mites and rice planthoppers was improved by 4.5-7.5%compared with the original model.The GBiDC-PEST optimization algorithm and its mobile deployment proposed in this study offer a robust technical framework for the rapid,onsite identification and localization of tiny pests.This advancement provides valuable insights for effective pest monitoring,counting,and control in various agricultural settings. 展开更多
关键词 mobile counting real-time processing pest detection tiny object identification algorithm deployment
在线阅读 下载PDF
A Base Station Deployment Algorithm for Wireless Positioning Considering Dynamic Obstacles
16
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
在线阅读 下载PDF
Optimized Deployment Method for Finite Access Points Based on Virtual Force Fusion Bat Algorithm
17
作者 Jian Li Qing Zhang +2 位作者 Tong Yang Yu’an Chen Yongzhong Zhan 《Computer Modeling in Engineering & Sciences》 2025年第9期3029-3051,共23页
In the deployment of wireless networks in two-dimensional outdoor campus spaces,aiming at the problem of efficient coverage of the monitoring area by limited number of access points(APs),this paper proposes a deployme... In the deployment of wireless networks in two-dimensional outdoor campus spaces,aiming at the problem of efficient coverage of the monitoring area by limited number of access points(APs),this paper proposes a deployment method of multi-objective optimization with virtual force fusion bat algorithm(VFBA)using the classical four-node regular distribution as an entry point.The introduction of Lévy flight strategy for bat position updating helps to maintain the population diversity,reduce the premature maturity problem caused by population convergence,avoid the over aggregation of individuals in the local optimal region,and enhance the superiority in global search;the virtual force algorithm simulates the attraction and repulsion between individuals,which enables individual bats to precisely locate the optimal solution within the search space.At the same time,the fusion effect of virtual force prompts the bat individuals to move faster to the potential optimal solution.To validate the effectiveness of the fusion algorithm,the benchmark test function is selected for simulation testing.Finally,the simulation result verifies that the VFBA achieves superior coverage and effectively reduces node redundancy compared to the other three regular layout methods.The VFBA also shows better coverage results when compared to other optimization algorithms. 展开更多
关键词 Multi-objective optimization deployment virtual force algorithm bat algorithm fusion algorithm
在线阅读 下载PDF
Event-Driven Attention Network:A Cross-Modal Framework for Efficient Image-Text Retrieval in Mass Gathering Events
18
作者 Kamil Yasen Heyan Jin +4 位作者 Sijie Yang Li Zhan Xuyang Zhang Ke Qin Ye Li 《Computers, Materials & Continua》 2025年第5期3277-3301,共25页
Research on mass gathering events is critical for ensuring public security and maintaining social order.However,most of the existing works focus on crowd behavior analysis areas such as anomaly detection and crowd cou... Research on mass gathering events is critical for ensuring public security and maintaining social order.However,most of the existing works focus on crowd behavior analysis areas such as anomaly detection and crowd counting,and there is a relative lack of research on mass gathering behaviors.We believe real-time detection and monitoring of mass gathering behaviors are essential formigrating potential security risks and emergencies.Therefore,it is imperative to develop a method capable of accurately identifying and localizing mass gatherings before disasters occur,enabling prompt and effective responses.To address this problem,we propose an innovative Event-Driven Attention Network(EDAN),which achieves image-text matching in the scenario of mass gathering events with good results for the first time.Traditional image-text retrieval methods based on global alignment are difficult to capture the local details within complex scenes,limiting retrieval accuracy.While local alignment-based methods aremore effective at extracting detailed features,they frequently process raw textual features directly,which often contain ambiguities and redundant information that can diminish retrieval efficiency and degrade model performance.To overcome these challenges,EDAN introduces an Event-Driven AttentionModule that adaptively focuses attention on image regions or textual words relevant to the event type.By calculating the semantic distance between event labels and textual content,this module effectively significantly reduces computational complexity and enhances retrieval efficiency.To validate the effectiveness of EDAN,we construct a dedicated multimodal dataset tailored for the analysis of mass gathering events,providing a reliable foundation for subsequent studies.We conduct comparative experiments with other methods on our dataset,the experimental results demonstrate the effectiveness of EDAN.In the image-to-text retrieval task,EDAN achieved the best performance on the R@5 metric,while in the text-to-image retrieval task,it showed superior results on both R@10 and R@5 metrics.Additionally,EDAN excelled in the overall Rsummetric,achieving the best performance.Finally,ablation studies further verified the effectiveness of event-driven attention module. 展开更多
关键词 Mass gathering events image-text retrieval attention mechanism
在线阅读 下载PDF
Toward a Large Language Model-Driven Medical Knowledge Retrieval and QA System:Framework Design and Evaluation
19
作者 Yuyang Liu Xiaoying Li +6 位作者 Yan Luo Jinhua Du Ying Zhang Tingyu Lv Hao Yin Xiaoli Tang Hui Liu 《Engineering》 2025年第7期270-282,共13页
Recent advancements in large language models(LLMs)have driven remarkable progress in text process-ing,opening new avenues for medical knowledge discovery.In this study,we present ERQA,a mEdical knowledge Retrieval and... Recent advancements in large language models(LLMs)have driven remarkable progress in text process-ing,opening new avenues for medical knowledge discovery.In this study,we present ERQA,a mEdical knowledge Retrieval and Question-Answering framework powered by an enhanced LLM that integrates a semantic vector database and a curated literature repository.The ERQA framework leverages domain-specific incremental pretraining and conducts supervised fine-tuning on medical literature,enabling retrieval and question-answering(QA)tasks to be completed with high precision.Performance evaluations implemented on the coronavirus disease 2019(COVID-19)and TripClick data-sets demonstrate the robust capabilities of ERQA across multiple tasks.On the COVID-19 dataset,ERQA-13B achieves state-of-the-art retrieval metrics,with normalized discounted cumulative gain at top 10(NDCG@10)0.297,recall values at top 10(Recall@10)0.347,and mean reciprocal rank(MRR)=0.370;it also attains strong abstract summarization performance,with a recall-oriented understudy for gisting evaluation(ROUGE)-1 score of 0.434,and QA performance,with a bilingual evaluation understudy(BLEU)-1 score of 7.851.The comparable performance achieved on the TripClick dataset further under-scores the adaptability of ERQA across diverse medical topics.These findings suggest that ERQA repre-sents a significant step toward efficient biomedical knowledge retrieval and QA. 展开更多
关键词 Large language models Medical knowledge Information retrieval Vector database
在线阅读 下载PDF
Joint Retrieval of PM_(2.5) Concentration and Aerosol Optical Depth over China Using Multi-Task Learning on FY-4A AGRI
20
作者 Bo LI Disong FU +4 位作者 Ling YANG Xuehua FAN Dazhi YANG Hongrong SHI Xiang’ao XIA 《Advances in Atmospheric Sciences》 2025年第1期94-110,共17页
Aerosol optical depth(AOD)and fine particulate matter with a diameter of less than or equal to 2.5μm(PM_(2.5))play crucial roles in air quality,human health,and climate change.However,the complex correlation of AOD–... Aerosol optical depth(AOD)and fine particulate matter with a diameter of less than or equal to 2.5μm(PM_(2.5))play crucial roles in air quality,human health,and climate change.However,the complex correlation of AOD–PM_(2.5)and the limitations of existing algorithms pose a significant challenge in realizing the accurate joint retrieval of these two parameters at the same location.On this point,a multi-task learning(MTL)model,which enables the joint retrieval of PM_(2.5)concentration and AOD,is proposed and applied on the top-of-the-atmosphere reflectance data gathered by the Fengyun-4A Advanced Geosynchronous Radiation Imager(FY-4A AGRI),and compared to that of two single-task learning models—namely,Random Forest(RF)and Deep Neural Network(DNN).Specifically,MTL achieves a coefficient of determination(R^(2))of 0.88 and a root-mean-square error(RMSE)of 0.10 in AOD retrieval.In comparison to RF,the R^(2)increases by 0.04,the RMSE decreases by 0.02,and the percentage of retrieval results falling within the expected error range(Within-EE)rises by 5.55%.The R^(2)and RMSE of PM_(2.5)retrieval by MTL are 0.84 and 13.76μg m~(-3)respectively.Compared with RF,the R^(2)increases by 0.06,the RMSE decreases by 4.55μg m~(-3),and the Within-EE increases by 7.28%.Additionally,compared to DNN,MTL shows an increase of 0.01 in R^(2)and a decrease of 0.02 in RMSE in AOD retrieval,with a corresponding increase of 2.89%in Within-EE.For PM_(2.5)retrieval,MTL exhibits an increase of 0.05 in R^(2),a decrease of 1.76μg m~(-3)in RMSE,and an increase of 6.83%in Within-EE.The evaluation suggests that MTL is able to provide simultaneously improved AOD and PM_(2.5)retrievals,demonstrating a significant advantage in efficiently capturing the spatial distribution of PM_(2.5)concentration and AOD. 展开更多
关键词 AOD PM_(2.5) FY-4A multi-task learning joint retrieval
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部