期刊文献+
共找到9篇文章
< 1 >
每页显示 20 50 100
Improving the Position Accuracy and Computational Efficiency of UAV Terrain Aided Navigation Using a Two-Stage Hybrid Fuzzy Particle Filtering Method
1
作者 Sofia Yousuf Muhammad Bilal Kadri 《Computers, Materials & Continua》 SCIE EI 2025年第1期1193-1210,共18页
Terrain Aided Navigation(TAN)technology has become increasingly important due to its effectiveness in environments where Global Positioning System(GPS)is unavailable.In recent years,TAN systems have been extensively r... Terrain Aided Navigation(TAN)technology has become increasingly important due to its effectiveness in environments where Global Positioning System(GPS)is unavailable.In recent years,TAN systems have been extensively researched for both aerial and underwater navigation applications.However,many TAN systems that rely on recursive Unmanned Aerial Vehicle(UAV)position estimation methods,such as Extended Kalman Filters(EKF),often face challenges with divergence and instability,particularly in highly non-linear systems.To address these issues,this paper proposes and investigates a hybrid two-stage TAN positioning system for UAVs that utilizes Particle Filter.To enhance the system’s robustness against uncertainties caused by noise and to estimate additional system states,a Fuzzy Particle Filter(FPF)is employed in the first stage.This approach introduces a novel terrain composite feature that enables a fuzzy expert system to analyze terrain non-linearities and dynamically adjust the number of particles in real-time.This design allows the UAV to be efficiently localized in GPS-denied environments while also reducing the computational complexity of the particle filter in real-time applications.In the second stage,an Error State Kalman Filter(ESKF)is implemented to estimate the UAV’s altitude.The ESKF is chosen over the conventional EKF method because it is more suitable for non-linear systems.Simulation results demonstrate that the proposed fuzzy-based terrain composite method achieves high positional accuracy while reducing computational time and memory usage. 展开更多
关键词 Sensor fusion fuzzy logic particle filter composite feature terrain aided navigation
在线阅读 下载PDF
A Multiple Feature Approach for Disorder Normalization in Clinical Notes
2
作者 Lü Chen CHEN Bo +2 位作者 Lü Chaozhen QIU Likun JI Donghong 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2016年第6期482-490,共9页
In this paper we propose a multiple feature approach for the normalization task which can map each disorder mention in the text to a unique unified medical language system(UMLS)concept unique identifier(CUI). We d... In this paper we propose a multiple feature approach for the normalization task which can map each disorder mention in the text to a unique unified medical language system(UMLS)concept unique identifier(CUI). We develop a two-step method to acquire a list of candidate CUIs and their associated preferred names using UMLS API and to choose the closest CUI by calculating the similarity between the input disorder mention and each candidate. The similarity calculation step is formulated as a classification problem and multiple features(string features,ranking features,similarity features,and contextual features) are used to normalize the disorder mentions. The results show that the multiple feature approach improves the accuracy of the normalization task from 32.99% to 67.08% compared with the Meta Map baseline. 展开更多
关键词 natural language processing disorder normalization Levenshtein distance semantic composition multiple features
原文传递
Zircon U-Pb dating,Geochemical Features of the Halunwusu Composite Granites at the Northern Edge of Southern Qilian,Qinghai
3
作者 TAO Gang ZHU Lidong +2 位作者 YANG Wenguang LI Zhiwu XIE Long 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第S1期92-93,共2页
1 Introduction Halunwusu Composite Granites,locates in the northern margin of Belt,between the North Qaidam block and the Central Qilian block,with two phases of magmatic activities.The granites mainly consisits of th... 1 Introduction Halunwusu Composite Granites,locates in the northern margin of Belt,between the North Qaidam block and the Central Qilian block,with two phases of magmatic activities.The granites mainly consisits of the Early 展开更多
关键词 Pb Zircon U-Pb dating Geochemical features of the Halunwusu Composite Granites at the Northern Edge of Southern Qilian Qinghai
在线阅读 下载PDF
Experimental Study of Monitoring and Controlling of Composite Cure Process in Autoclave Featured with Fiber Optic Sensor
4
作者 Boming ZHANG, Zhanjun WU , Dianfu WANG and Shanyi DU Center for composite, Harbin Institute of Technology Harbin 150001, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2001年第4期449-452,共4页
With the aid of the latest fiber optic sensing technology parameters in the cure process of ther- mosetting resin-matrix composite, such as temperature, viscosity,void and residual stress, can be monitored entirely an... With the aid of the latest fiber optic sensing technology parameters in the cure process of ther- mosetting resin-matrix composite, such as temperature, viscosity,void and residual stress, can be monitored entirely and efficiently.In this paper, experiment results of viscosity measurement in composite cure process in autoclave using fiber optic sensors are presented. Based on the sensed information, a computer program is utilized to control the cure process. With this technology, the cure process becomes more apparent and controllable, which will greatly improve the cured products and reduce the cost. 展开更多
关键词 Experimental Study of Monitoring and Controlling of Composite Cure Process in Autoclave featured with Fiber Optic Sensor
在线阅读 下载PDF
Composite fixed-length ordered features with index-of-max transformation for high-performing and secure palmprint template protection
5
作者 Zhicheng Cao Weiqiang Zhao +1 位作者 Heng Zhao Liaojun Pang 《Journal of Information and Intelligence》 2025年第1期51-67,共17页
Palmprint recognition has attracted considerable attention due to its advantages over other biometric modalities such as fingerprints,in that it is larger in area,richer in information and able to work at a distance.H... Palmprint recognition has attracted considerable attention due to its advantages over other biometric modalities such as fingerprints,in that it is larger in area,richer in information and able to work at a distance.However,the issue of palmprint privacy and security(especially palmprint template protection)remains under-studied.Among the very few research works,most of them only use orientational features of the palmprint with transformation processing,yielding unsatisfactory recognition and protection performance.Thus,this research work proposes a palmprint feature extraction method for palmprint template protection that is fixed-length and ordered in nature,by fusing point features and orientational features.Firstly,dual orientations are extracted and encoded with more accuracy based on the modified finite Radon transform(MFRAT).Then,SURF feature points are extracted and converted to be fixed-length and ordered features.Finally,composite fixed-length ordered features that fuse up the dual orientations and SURF points are transformed using the irreversible transformation of index-of-max(IoM)to generate the revocable palmprint templates.Experiments show that the matching accuracy of the proposed method of fixed-length and ordered point features are superior to all other feature extraction methods on the PolyU and CASIA datasets.It is also demonstrated that the EERs before and after IoM transformation are better than all other representative template protection methods.A thorough security and privacy analysis including brute-force attack,false accept attack,birthday attack,attack via record multiplicity,irreversibility,unlinkability and revocability is also given,which proves that our proposed method has both high performance and security. 展开更多
关键词 Palmprint recognition Template protection Composite features Fixed-length ordered features SURF MFRAT
原文传递
Interaction behavior recognition from multiple views 被引量:2
6
作者 XIA Li-min GUO Wei-ting WANG Hao 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第1期101-113,共13页
This paper proposed a novel multi-view interactive behavior recognition method based on local self-similarity descriptors and graph shared multi-task learning. First, we proposed the composite interactive feature repr... This paper proposed a novel multi-view interactive behavior recognition method based on local self-similarity descriptors and graph shared multi-task learning. First, we proposed the composite interactive feature representation which encodes both the spatial distribution of local motion of interest points and their contexts. Furthermore, local self-similarity descriptor represented by temporal-pyramid bag of words(BOW) was applied to decreasing the influence of observation angle change on recognition and retaining the temporal information. For the purpose of exploring latent correlation between different interactive behaviors from different views and retaining specific information of each behaviors, graph shared multi-task learning was used to learn the corresponding interactive behavior recognition model. Experiment results showed the effectiveness of the proposed method in comparison with other state-of-the-art methods on the public databases CASIA, i3Dpose dataset and self-built database for interactive behavior recognition. 展开更多
关键词 local self-similarity descriptors graph shared multi-task learning composite interactive feature temporal-pyramid bag of words
在线阅读 下载PDF
A hybrid neural network system for prediction and recognition of promoter regions in human genome 被引量:1
7
作者 陈传波 李滔 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2005年第5期401-407,共7页
This paper proposes a high specificity and sensitivity algorithm called PromPredictor for recognizing promoter regions in the human genome. PromPredictor extracts compositional features and CpG islands information fro... This paper proposes a high specificity and sensitivity algorithm called PromPredictor for recognizing promoter regions in the human genome. PromPredictor extracts compositional features and CpG islands information from genomic sequence,feeding these features as input for a hybrid neural network system (HNN) and then applies the HNN for prediction. It combines a novel promoter recognition model, coding theory, feature selection and dimensionality reduction with machine learning algorithm.Evaluation on Human chromosome 22 was ~66% in sensitivity and ~48% in specificity. Comparison with two other systems revealed that our method had superior sensitivity and specificity in predicting promoter regions. PromPredictor is written in MATLAB and requires Matlab to run. PromPredictor is freely available at http://www.whtelecom.com/Prompredictor.htm. 展开更多
关键词 Hybrid neural network Promoter prediction compositional features CpG islands
在线阅读 下载PDF
Magma Chamber Process of Post-collisional Magmatism: Insight from Textural and Elemental Characteristics of Plagioclase from the Tatun Volcanic Group, Northern Taiwan Volcanic Zone 被引量:1
8
作者 ZHANG Xia GUO Kun +4 位作者 ZHANG Yu LAI Zhiqing JIANG Shulong JIANG Wenpeng LI Jingbo 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2022年第5期1587-1599,共13页
The Taiwan mountain belt, one of the youngest orogenies in the world, is caused by the collision of the Luzon arc with the Eurasian margin, which leads to post-collisional extension and magmatism in the Northern Taiwa... The Taiwan mountain belt, one of the youngest orogenies in the world, is caused by the collision of the Luzon arc with the Eurasian margin, which leads to post-collisional extension and magmatism in the Northern Taiwan Volcanic Zone(NTVZ). The magma chamber process in this region has not previously been elucidated in detail. In this paper, the textural and compositional features of plagioclase phenocrysts in basalt from the Tatun Volcanic Group(TTVG) were studied to restrict the dynamics of magma system. Results show that the magma melts in TTVG are mainly sourced from the underlying MORB-like mantle wedge but influenced by incorporation of subduction components, causing the elevated Sr/Y and Ba/Y ratios in magma melts. The subduction components are mainly transported in the form of sediment melt. The plagioclase phenocrysts in the TTVG volcanic rocks are generally coarsely core-sieved with a clear rim. The An contents in the rims of plagioclase are much lower than those of cores, and elevated FeO concentrations are detected in the plagioclase rims. We propose there exists a double-layer magma chamber in this region. The core of the plagioclase was crystalized in the deeper quiescent magma chamber(~21 km), which was subsequently partially dissolved during the ascent of magma melt under H_(2)O-undersaturated condition, forming the typical coarsely sieved texture and synneusis. When this crystal-rich melt migrates into the shallower chamber, water saturation is reached and more sodic plagioclase formed as the rim of phenocryst. Due to the considerably higher fO_(2) in the shallow chamber than in the deeper one, and the distribution of Fe between plagioclase and melt positively correlates with fO_(2), the FeO content in the plagioclase rim elevates in conjunction with increasing fO_(2). 展开更多
关键词 PLAGIOCLASE textural and compositional features dynamics of magma system Tatun Volcanic Group
在线阅读 下载PDF
Semiconductor optical features of silver/silica mesoporous composite 被引量:1
9
《Chinese Science Bulletin》 SCIE CAS 1998年第7期614-615,共2页
关键词 Semiconductor optical features of silver/silica mesoporous composite
在线阅读 下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部