期刊文献+
共找到842篇文章
< 1 2 43 >
每页显示 20 50 100
MOVING OBJECT TRACKING IN DYNAMIC IMAGE SEQUENCE BASED ON ESTIMATION OF MOTION VECTORS OF FEATURE POINTS 被引量:2
1
作者 黎宁 周建江 张星星 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2009年第4期295-300,共6页
An improved estimation of motion vectors of feature points is proposed for tracking moving objects of dynamic image sequence. Feature points are firstly extracted by the improved minimum intensity change (MIC) algor... An improved estimation of motion vectors of feature points is proposed for tracking moving objects of dynamic image sequence. Feature points are firstly extracted by the improved minimum intensity change (MIC) algorithm. The matching points of these feature points are then determined by adaptive rood pattern searching. Based on the random sample consensus (RANSAC) method, the background motion is finally compensated by the parameters of an affine transform of the background motion. With reasonable morphological filtering, the moving objects are completely extracted from the background, and then tracked accurately. Experimental results show that the improved method is successful on the motion background compensation and offers great promise in tracking moving objects of the dynamic image sequence. 展开更多
关键词 motion compensation motion estimation feature extraction moving object tracking dynamic image sequence
下载PDF
Dynamic subduction process of local plate revealed by Ibaraki earthquake sequence of 1982 in Japan 被引量:2
2
作者 DIAO Gui-ling 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2001年第2期141-147,共7页
The kinematics and dynamics of plate tectonics are frontal subjects in geosciences and the strong earthquake occurred along the plate boundary result directly from plate movement. By analyzing Ibaraki earthquake seque... The kinematics and dynamics of plate tectonics are frontal subjects in geosciences and the strong earthquake occurred along the plate boundary result directly from plate movement. By analyzing Ibaraki earthquake sequence, it has been found that the focal fault plane shows a special image of grading expansion along the direction of strike and adjustment along the dip direction respectively. With the consideration of strike, dip and slip directions of focal mechanism, we have confirmed that Ibaraki earthquake belongs to a thrust fault earthquake occurred under the Japan Trench. The cause of the earthquake sequence is discussed in the paper. The study on the temporal-spatial distribution of the earthquake sequence with a time-scale between the year-scale spatial geodetic data and the second-scale moment tensor of the strong earthquake has indicated the dynamic process of Pacific Plate subduction under the Eurasia Plate. According to the average slip distance of earthquake and the velocity of plate movement, it is predicted that a strong earthquake might occur in recent years. 展开更多
关键词 earthquake sequence plate tectonics subduction zone dynamic process
下载PDF
High-Sensitivity Acquisition of Ultrahigh Dynamic Direct Sequence Spread Spectrum Signals in Space Communications 被引量:2
3
作者 徐颖 袁洪 《China Communications》 SCIE CSCD 2013年第10期26-36,共11页
According to the requirements of the high-sensitivity acquisition of Direct Sequence Spread Spectrum(DSSS) signals under ultrahigh dynamic environments in space communications, a three-dimensional joint search of the ... According to the requirements of the high-sensitivity acquisition of Direct Sequence Spread Spectrum(DSSS) signals under ultrahigh dynamic environments in space communications, a three-dimensional joint search of the phase of Pseudo-Noise-code(PN-code),Doppler frequency and its rate-of-change is presented to achieve high sensitivity in sensing high-frequency dynamics. By eliminating the correlation peak loss caused by ultrahigh Doppler frequency and its rate-of-change offset,the proposed method improves the acquisition sensitivity by increasing the non-coherent accumulation time. The validity of the algorithm is proved by theoretical analysis and simulation results. It is shown that signals with a carrier- to-noise ratio as low as 39 dBHz can be captured with high performance when the Doppler frequency is up to ±1 MHz and its rate-of-change is up to ±200 kHz/s. 展开更多
关键词 direct sequence spread spectrum signals space communications ACQUISITION high sensitivity ultrahigh dynamic
下载PDF
Geometric and Dynamical Characteristics of Sequences in Yitong Graben
4
作者 Xie Xinong Sun Yongchuan(Deparment of Mineral Resources, China University of Geosciences, Wuhan430074)Ding Zhengyan Lin Yanzong(Jinn Oilfield Administrative Bureau, Fuyu 131200) 《Journal of Earth Science》 SCIE CAS CSCD 1994年第1期65-70,共6页
Yitong graben belongs to the north segment of the Tanlu fault belt .It was infilled with Eogene, Neogene and Quaternary clastic deposits, each Of them represents a distinct tectonic sequence.Six types of systems ass... Yitong graben belongs to the north segment of the Tanlu fault belt .It was infilled with Eogene, Neogene and Quaternary clastic deposits, each Of them represents a distinct tectonic sequence.Six types of systems association characteristics of distinct depositional systems and spatial disposition are identified in different evolutionary period of the graben.Sequence Stratigraphic framework of the graben is mainly controlled by structural framework,tectonic movement, sources supply, expanding and contracting cycle of lake, position of depositional center. The key factors are structural framework and tectonic movemeat.Through systematic analysis Of regional tectonic settings, it is recognized that Eogene tectonic sequence of Yitong graben was formed under tenso-shear regime. It includes four sequences indicating four tectonic events attributed to tectonic movement of marginal faults.Neogene tectonic sequence was formed under compresso-shear regime, which includes coarse clastic deposits with a thicknessof 0-500m.Pattern of in the Yitong graben indicates the asymmetrical subsisence of marginal faults along two sides and the complicated structural framework. 展开更多
关键词 sequence stratigraphy sequence stratigraphic framework geometry of sequence dynamics Of sequence Yitong graben.
下载PDF
DFF-EDR:An Indoor Fingerprint Location Technology Using Dynamic Fusion Features of Channel State Information and Improved Edit Distance on Real Sequence
5
作者 Ke Han Yunfei Xu +1 位作者 Zhongliang Deng Jiawei Fu 《China Communications》 SCIE CSCD 2021年第4期40-63,共24页
Positioning technology based on wireless network signals in indoor environments has developed rapidly in recent years as the demand for locationbased services continues to increase.Channel state information(CSI)can be... Positioning technology based on wireless network signals in indoor environments has developed rapidly in recent years as the demand for locationbased services continues to increase.Channel state information(CSI)can be used as location feature information in fingerprint-based positioning systems because it can reflect the characteristics of the signal on multiple subcarriers.However,the random noise contained in the raw CSI information increases the likelihood of confusion when matching fingerprint data.In this paper,the Dynamic Fusion Feature(DFF)is proposed as a new fingerprint formation method to remove the noise and improve the feature resolution of the system,which combines the pre-processed amplitude and phase data.Then,the improved edit distance on real sequence(IEDR)is used as a similarity metric for fingerprint matching.Based on the above studies,we propose a new indoor fingerprint positioning method,named DFF-EDR,for improving positioning performance.During the experimental stage,data were collected and analyzed in two typical indoor environments.The results show that the proposed localization method in this paper effectively improves the feature resolution of the system in terms of both fingerprint features and similarity measures,has good anti-noise capability,and effectively reduces the localization errors. 展开更多
关键词 channel state information indoor positioning edit distance on real sequence dynamic parameters feature resolution
下载PDF
探讨磁共振fl3D_cor_dynamic序列在鼻咽癌动态增强扫描中的意义 被引量:1
6
作者 卓水清 江冬平 +2 位作者 崔宝仪 伍振宇 余静萍 《医学信息(医学与计算机应用)》 2014年第25期222-222,共1页
目的探讨磁共振fl3D_cor_dynamic序列在鼻咽癌动态增强扫描中的应用价值。方法对80例鼻咽癌患者采用fl3D_cor_dynamic序列行MRI动态扫描,分析扫描参数的设置,并利用西门子公司所提供的图像分析后处理软件包,对动态增强MRI 图像进行后处... 目的探讨磁共振fl3D_cor_dynamic序列在鼻咽癌动态增强扫描中的应用价值。方法对80例鼻咽癌患者采用fl3D_cor_dynamic序列行MRI动态扫描,分析扫描参数的设置,并利用西门子公司所提供的图像分析后处理软件包,对动态增强MRI 图像进行后处理、观察及测量各种动态参数。结果用fl3D_cor_dynamic序列进行鼻咽癌动态扫描比传统动态扫描方法更有优势。结论用fl3D_cor_dynamic序列鼻咽癌MRI动态扫描技术对鼻咽癌的诊断、鉴别诊断有一定的应用价值。 展开更多
关键词 脉冲序列 鼻咽癌 动态扫描 磁共振成像
下载PDF
Dynamical Process and Genesis of Late Triassic Sediment Filling in Ordos Basin 被引量:6
7
作者 Jiao Yangquan Lu Zongsheng Zhuang Xinguo Yang ShigongFaculty of Earth Resources, China University of Geosciences, Wuhan 430074 《Journal of Earth Science》 SCIE CAS CSCD 1997年第1期45-48,共4页
Coupling relationship exists in development time of the Qinling orogen and the neighboring Ordos basin, implying that they are connected genetically, that is, the formation and evolution of the Ordos basin are respons... Coupling relationship exists in development time of the Qinling orogen and the neighboring Ordos basin, implying that they are connected genetically, that is, the formation and evolution of the Ordos basin are response to orogeny. The present Ordos basin is a residual part of the Late Triassic large Ordos basin. The primary large Ordos basin was featured by four types of boundaries, i.e. (1) southern thrusting boundary; (2) southwestern strikeslip thrusting boundary; (3) northwestern rifting boundary; and (4) northeastern and northern passive gentle slope type boundary. This basin was composed of sequences A and B. These sequences consist of three parts, i.e. lower alluvial systems tract, middle expanding lacustrine systems tract and the upper contracting lacustrine systems tract. A systems tract is actually a parasequence set. Based on division of sequences stratigraphic units and reconstruction of depositional systems tracts, the present paper proposes that: (1) two episodes occurred during Late Triassic Qinling collision orogeny; (2) collision is stronger in western Qinling than in eastern Qinling. 展开更多
关键词 tectonic sequence dynamics Ordos basin Qinling orogen.
下载PDF
Comparative Analysis of Sequence Characteristics among Different Superimposed Stages of the Chelif Basin,Algeria 被引量:4
8
作者 ZHANG Yuanfu JIANG Zaixing WANG Yue BAO Dandan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2009年第6期1041-1051,共11页
Superimposed basins were investigated with respect to tectonic evolution, sediment deposition and petroleum characteristics within a single superposition stage generally. The comparative study was seldom seen. Sequenc... Superimposed basins were investigated with respect to tectonic evolution, sediment deposition and petroleum characteristics within a single superposition stage generally. The comparative study was seldom seen. Sequence characteristics were compared for two different superimposed stages - an expanding rifting stage and a depression-foreland transition stage - in the Chelif Basin during the Miocene in this paper. A model and mechanism for sequence evolution of superimposed basins in different dynamic situations are discussed with respect to sequence similarities and differences. The compared characters include sequence thickness, sequence boundaries and system tracts, as well as sediment deposition within sequences and sequence development patterns. Finally, some typical features of sequence development concomitant with changes of superimposed stages in the Chelif Basin are discussed. 展开更多
关键词 superimposed basin sequence characteristics sediment deposition structural dynamics petroleum accumulation
下载PDF
THE EFFECT OF BLENDING SEQUENCE ON PHASE MORPHOLOGY OF NYLON 6/ABS/SMA BLENDS 被引量:3
9
作者 Qin, Shu-Hao Yu, Jie +2 位作者 Zheng, Qiang He, Min Zhu, Hong 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2008年第1期73-80,共8页
The preparation process-dependent phase morphology of blends composed of nylon 6 and acrylonitrile-butadiene- styrene(ABS)over a composition range of 30-70 wt% using a styrene-maleic anhydride(SMA)copolymer as the com... The preparation process-dependent phase morphology of blends composed of nylon 6 and acrylonitrile-butadiene- styrene(ABS)over a composition range of 30-70 wt% using a styrene-maleic anhydride(SMA)copolymer as the compatibilizing agent with a constant content(5phr)was investigated.The results of the scanning electron microscope (SEM)observation revealed that compared with the binary blends of nylon 6 and ABS,the existence of SMA caused a composition shift of phase inversion to a higher weight fraction of ny... 展开更多
关键词 Nylon 6 ABS MORPHOLOGY Blending sequence dynamic mechanical properties
下载PDF
Dynamics of microbial diversity during the composting of agricultural straw 被引量:10
10
作者 CHANG Hui-qing ZHU Xiao-hui +3 位作者 WU Jie GUO Da-yong ZHANG Lian-he FENG Yao 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2021年第5期1121-1136,共16页
The dynamic changes in microbial diversity during the aerobic composting of agricultural crop straw with additives were evaluated using high-throughput sequencing at four phases of composting(mesophilic,thermophilic,c... The dynamic changes in microbial diversity during the aerobic composting of agricultural crop straw with additives were evaluated using high-throughput sequencing at four phases of composting(mesophilic,thermophilic,cooling and maturation phases).In addition,the physicochemical parameters of the composting system were determined in this study.The fermentation time of the thermophilic period was prolonged with the addition of urea or urea combined with a microbial agent.The ratio of C/N and germination index variation indicated that the additives were favorable for composting,because the additives directly changed the physicochemical properties of the compost and had effects on the diversity and abundance of bacteria and fungi.The abundance of operational taxonomic units(OTUs),diversity index(Shannon)and richness index(Chao1)of fungi and bacteria were found to significantly increase when urea+microbial agents were added to straw in the thermophilic phase.The relative abundance of the predominant bacteria and fungi at the phylum and genus levels differed during different composting phases.The abundance of the phyla Firmicutes and Proteobacteria declined in the order of treatments SNW>SN>S(S is straw only compost;SN is straw+5 kg t^(–1) urea compost;and SNW is straw+5 kg t^(–1) urea+1 kg t^(–1) microbial agent compost)in the thermophilic phase.The abundance of the genera Staphylococcus,Bacillus and Thermobifida followed the same order in the mesophilic phase.Ascomycota accounted for more than 92%of the total fungal sequences.With the progression of the composting process,the abundance of Ascomycota decreased gradually.The abundance of Ascomycota followed the order of S>SN>SNW during the thermophilic phase.The abundance of Aspergillus accounted for 4–59%of the total abundance of fungi and increased during the first two sampling periods.Aspergillus abundance followed the order of SNW>SN>S.Additionally,principal component analysis(PCA)revealed that the community compositions in the straw and straw+urea treatments were similar,and that the bacterial communities in treatments S,SN and SNW in the mesophilic phase(at day 1)were different from those observed in three other phases(at days 5,11,and19,respectively),while the fungal communities showed only slight variations in their structure in response to changes in the composting process.Canonical correlation analysis(CCA)and redundancy analysis(RDA)showed that total carbon(TC),NO_(3)^(–)-N(NN),electrical conductivity(EC)and p H were highly correlated with community composition.Therefore,this study highlights that the additives are beneficial to straw composting and result in good quality compost. 展开更多
关键词 crop straws microbial diversity community composition dynamic characteristics high-throughput sequencing
下载PDF
Structure and diversity dynamics of microbial communities at day and night:investigation of meromictic Lake Doroninskoe,Transbaikalia,Russia 被引量:2
11
作者 Evgeniya MATYUGINA Natalia BELKOVA +6 位作者 Svetlana BORZENKO Pavel LUKYANOV Marsel KABILOV Olga BATURINA Alexandra MARTYNOVA-VAN KLEY Armen NALIAN Aleksei PTITSYN 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2018年第6期1978-1992,共15页
Extreme environmental conditions are key factors in the formation of the structure and diversity of microbial communities. In meromictic ecosystems, extreme conditions and a stable stratification of physical, chemical... Extreme environmental conditions are key factors in the formation of the structure and diversity of microbial communities. In meromictic ecosystems, extreme conditions and a stable stratification of physical, chemical and biological parameters lead to diversity and heterogeneity of microenvironments. Lake Doroninskoe is located in an extreme geographical area and diff ers from other known meromictic reservoirs of the world by a low level of illumination in the chemocline and a rare type of alkaline water in sedimentary rocks formed by evaporative concentration. To understand the key factors that shape the composition and structure of the microbial community, the macro-and micro-variations in space and time are of great importance. We investigated the short-term dynamics of the structure and diversity of microbial communities of the meromictic soda lake, Lake Doroninskoe, at day and night using highthroughput sequencing and bioinformatics. Metagenomic analysis of 16 S rRNA gene amplicons showed that the microbial communities had a high taxonomic diversity both at day and night. Sixteen bacterial and three archaeal phyla were identified. Proteobacteria were dominant and comprised 75% during the day, increasing to 90% at night. Metabolically stable denitrifying bacteria that were able to use a variety of alternative electron acceptors and electron donors were prevalent in Lake Doroninskoe. They belonged to the families Enterobacteriaceae(class Gammaproteobacteria) and Alcaligenaceae(class Betaproteobacteria). Statistically significant differences between day and night microbial communities were found. During the day, the microbial community was the most diverse. We discuss the peculiarities of the underexplored shortterm dynamics of the structure and diversity of the microbial communities of the meromictic soda Lake Doroninskoe, and propose topics for prospective studies. 展开更多
关键词 bacterial DIVERSITY day-night dynamicS MEROMIXIS Lake Doroninskoe high-throughput amplicon sequencing
下载PDF
Protist Interactions and Seasonal Dynamics in the Coast of Yantai, Northern Yellow Sea of China as Revealed by Metabarcoding 被引量:4
12
作者 FU Yingjun ZHENG Pengfei +2 位作者 ZHANG Xiaoli ZHANG Qianqian JI Daode 《Journal of Ocean University of China》 SCIE CAS CSCD 2020年第4期961-974,共14页
Facilitated by the high-throughput sequencing(HTS)technique,the importance of protists to aquatic systems has been widely acknowledged in the last decade.However,information of protistan biotic interactions and season... Facilitated by the high-throughput sequencing(HTS)technique,the importance of protists to aquatic systems has been widely acknowledged in the last decade.However,information of protistan biotic interactions and seasonal dynamics is much less known in the coast ecosystem with intensive anthropic disturbance.In this study,year-round changes of protist community composition and diversity in the coastal water of Yantai,a city along the northern Yellow Sea in China,were investigated using HTS for the V4 region of 18S rDNA.The interactions among protist groups were also analyzed using the co-occurrence network.Data analyses showed that Alveolata,Chlorophyta,and Stramenopiles are the most dominant phytoplanktonic protists in the investigated coastal area.The community composition displayed strong seasonal variation.The abundant families Dino-Group-I-Clade-1 and Ulotrichales_X had higher proportions in spring and summer,while Bathycoccaceae exhibited higher ratios in autumn and winter.Alpha diversities(Shannon and Simpson)were the highest in autumn and the lowest in spring(ANOVA test,P<0.05).Nutrients(SiO42−,PO43−),total organic carbon(TOC),and pH seemed to drive the variation of alpha diversity,while temperature,PO43−and TON were the most significant factors influencing the whole protist community.Co-variance network analyses reveal frequent co-occurrence events among ciliates,chlorophytes and dinoflagellate,suggesting biotic interactions have been induced by predation,parasitism and mixotrophy. 展开更多
关键词 coastal zone biotic interaction high-throughput sequencing northern Yellow Sea protist diversity seasonal dynamic
下载PDF
CONTROLLABILITY OF A CLASS OF HYBRID DYNAMIC SYSTEMS (Ⅲ)—MULTIPLE TIME_DELAY CASE 被引量:1
13
作者 谢广明 王龙 叶庆凯 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2003年第9期1063-1074,共12页
The controllability for switched linear systems with time_delay in controls is first investigated. The whole work contains three parts. This is the third part. The definition and determination of controllability of sw... The controllability for switched linear systems with time_delay in controls is first investigated. The whole work contains three parts. This is the third part. The definition and determination of controllability of switched linear systems with multiple time_delay in control functions is mainly investigated. The sufficient and necessary conditions for the one_periodic, multiple_periodic controllability of periodic_type systems and controllability of aperiodic systems are presented,respectively. Finally, the case of distinct delays is discussed, it is shown that the controllability is independent of the size of delays. 展开更多
关键词 hybrid dynamic system switched linear system TIME_DELAY CONTROLLABILITY controllable set switching sequence switching path
下载PDF
CONTROLLABILITY OF A CLASS OF HYBRID DYNAMIC SYSTEMS (Ⅱ)—SINGLE TIME_DELAY CASE 被引量:1
14
作者 谢广明 王龙 叶庆凯 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2003年第9期1051-1062,共12页
The controllability for switched linear systems with time_delay in controls is first investigated. The whole work contains three parts. This is the second part. The definition and determination of controllability of s... The controllability for switched linear systems with time_delay in controls is first investigated. The whole work contains three parts. This is the second part. The definition and determination of controllability of switched linear systems with single time_delay in control functions is mainly investigated. The sufficient and necessary conditions for the one_periodic, multiple_periodic controllability of periodic_type systems and controllability of periodic systems are presented, respectively. 展开更多
关键词 hybrid dynamic system switched linear system TIME_DELAY CONTROLLABILITY controllable set switching sequence switching path
下载PDF
Stratigraphic Sequence and Sedimentary Systems in the Middle-Southern Continental Slope of the East China Sea from Seismic Reflection Data: Exploration Prospects of Gas Hydrate 被引量:1
15
作者 LI Deyong CHEN Hongyan +3 位作者 XU Shujuan XING Junhui CHENG Honggang WANG Jinkai 《Journal of Ocean University of China》 SCIE CAS CSCD 2019年第6期1302-1316,共15页
Many evidences for gas hydrate bearing sediments had been found in the continental slope of the East China Sea,such as bottom simulating reflections(BSRs),undersea gas springs,pyrite associated with methane leakage,mu... Many evidences for gas hydrate bearing sediments had been found in the continental slope of the East China Sea,such as bottom simulating reflections(BSRs),undersea gas springs,pyrite associated with methane leakage,mud diapirs/mud volcanos,bottom-water methane anomalies and so on.In this study,six key stratigraphic interfaces including T_0(seafloor),T_1(LGM,23 kyr B.P.),T_2(2.58 Myr),T_3(5.33 Myr),T_4(11.02 Myr)and T_5(16.12 Myr)were identified,and then five third-order sequences of SQIII1 to SQIII5 were divided.However,T5 in southern continental slope is not found,which shows that the middle-northern Okinawa Trough had begun to rift in the early Miocene,earlier than the southern segment.Four system tracts including lowstand systems tract(LST),transgressive systems tract(TST),highstand systems tract(HST)and falling stage systems tract(FSST)are further divided.The marine erosion interface of 11.02 Myr and regressive unconformity interface of 23 kyr B.P.indicate two large-scale sea level drop events in the research area.Seven typical seismic facies identified in the continental slope are continental shelf-edge deltas,littoral fluvial-delta plains,incised channels or submarine canyons,slope fans,submarine fans or coastal sandbars,littoral-neritic finegrained sediments,mud volcanos and some other geological bodies respectively.The minimum water depth for hydrate occurrence in the Okinawa Trough is 630 m,and the thickness of gas hydrate stability zone in continental slope is between 0 and 590 m.The calculated bottom boundary of hydrate stability zone is slightly deeper than BSRs on the seismic sections.The re-depositional turbidite sand bodies,such as canyon channels,slope fans and submarine fans developed in Quaternary strata,are the predominant hydrate reservoirs.According to developing process,the dynamic accumulation of hydrate systems can be divided into three evolutionary stages including canyon erosion and hydrate stability zone migration stage,sediments destabilizing and methane leakage stage,and channel filling and hydrate re-occurrence stage. 展开更多
关键词 sequence STRATIGRAPHIC architecture SYSTEMS tract seismic FACIES DEPOSITIONAL system submarine CANYON gas HYDRATE stability zone HYDRATE dynamic accumulation continental slope of the East China Sea
下载PDF
Fast speedometer identification in dynamic scene based on phase correlation 被引量:1
16
作者 王昱棠 付梦印 杨毅 《Journal of Beijing Institute of Technology》 EI CAS 2012年第3期394-399,共6页
Speedometer identification has been researched for many years.The common approaches to that problem are usually based on image subtraction,which does not adapt to image offsets caused by camera vibration.To cope with ... Speedometer identification has been researched for many years.The common approaches to that problem are usually based on image subtraction,which does not adapt to image offsets caused by camera vibration.To cope with the rapidity,robust and accurate requirements of this kind of work in dynamic scene,a fast speedometer identification algorithm is proposed,it utilizes phase correlation method based on regional entire template translation to estimate the offset between images.In order to effectively reduce unnecessary computation and false detection rate,an improved linear Hough transform method with two optimization strategies is presented for pointer line detection.Based on VC++ 6.0 software platform with OpenCV library,the algorithm performance under experiments has shown that it celerity and precision. 展开更多
关键词 speedometer dynamic scene image sequence phase correlation improved linear Hough transform
下载PDF
CONTROLLABILITY OF A CLASS OF HYBRID DYNAMIC SYSTEMS (Ⅰ)—BASIC PROPERTIES AND PRELIMINARY RESULTS
17
作者 谢广明 王龙 叶庆凯 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2003年第9期1041-1050,共10页
The controllability for switched linear system with time_delay in controls was first investigated. The whole work contains three parts. This is the first part, including problem formulation and some preliminaries. Fir... The controllability for switched linear system with time_delay in controls was first investigated. The whole work contains three parts. This is the first part, including problem formulation and some preliminaries. Firstly, the mathematical model of switched linear systems with time_delay in control functions was presented. Secondly, the concept of column space, cyclic invariant subspace and generalized cyclic invariant subspace were introduced. And some basic properties, such as separation lemma, were presented. Finally, a basic lemma was given to reveal the relation between the solution set of a centain integral equations and the generalized cyclic invariant subspace. This lemma will play an important role in the determination of controllability. All these definitions and lemmas are necessary research tools for controllability analysis. 展开更多
关键词 hybrid dynamic system switched linear system TIME_DELAY CONTROLLABILITY generalized cyclic invariant subspace switching sequence switching path
下载PDF
THE GROWTH MODE OF ALTUN FAULT AND IT'S DYNAMICS
18
作者 Cui Junwen, Li Pengwu, Li Li (Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037,China) 《地学前缘》 EI CAS CSCD 2000年第S1期260-260,共1页
A set of ENE\|trending fault which locates in the rigid Tarim massif and flexible Qilian massif in the same dynamic system of the uplift of the Qinghai—Tibetan plateau is referred to as the Altun Fault (ALF). ALF dis... A set of ENE\|trending fault which locates in the rigid Tarim massif and flexible Qilian massif in the same dynamic system of the uplift of the Qinghai—Tibetan plateau is referred to as the Altun Fault (ALF). ALF displays a linear geometry or a geometry of overlapping of linear and arcuate segments and a growth and development process of the breakdown segment\|by\|segment, connection segment\|by\|segment and propagation gradually (northeastward migration of the northeast tip, southwestward growth of the southwest tip). The formation of the Altun fault began in the middle or upper Carboniferous. It was characteristic of the sinistral strike\|slip\|thrust before Eocene, of the thrust\|sinistral strike\|slip during Oligocene—Miocene, and of the normal slip, and thrust\|sinistral strike\|slip simultaneously since Miocene. 展开更多
关键词 Altun FAULT sinistral strike\|slip geometry growth MODE o verstep THRUST sequence THRUST propagation transformation FAULT dynamicS MODE l
下载PDF
Polymer translocation through nanopore under external electric field:dissipative particle dynamics study
19
作者 Jinglin MAO Yi YAO +1 位作者 Zhewei ZHOU Guohui HU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2015年第12期1581-1592,共12页
The DNA sequencing technology has achieved a leapfrog development in recent years. As a new generation of the DNA sequencing technology, nanopore sequenc- ing has shown a broad application prospect and attracted vast ... The DNA sequencing technology has achieved a leapfrog development in recent years. As a new generation of the DNA sequencing technology, nanopore sequenc- ing has shown a broad application prospect and attracted vast research interests since it was proposed. In the present study, the dynamics of the electric-driven translocation of a homopolymer through a nanopore is investigated by the dissipative particle dynam- ics (DPD), in which the homopolymer is modeled as a worm-like chain (WLC). The DPD simulations show that the polymer chain undergoes conformation changes during the translocation process. The different structures of the polymer in the translocation process, i.e., single-file, double folded, and partially folded, and the induced current block- ades are analyzed. It is found that the current blockades have different magnitudes due to the polymer molecules traversing the pore with different folding conformations. The nanoscale vortices caused by the concentration polarization layers (CPLs) in the vicinity of the sheet are also studied. The results indicate that the translocation of the polymer has the effect of eliminating the vortices in the polyelectrolyte solution. These findings are expected to provide the theoretical guide for improving the nanopore sequencing tech- nique. 展开更多
关键词 nanopore sequencing technology electric-driven translocation dissipative particle dynamics (DPD)
下载PDF
Dynamic Kinetics of Methanol Synthesis over a Commercial Copper-Based Catalyst
20
作者 陈晓春 李成岳 饶国瑛 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2000年第4期315-320,共6页
Adsorption, surface reaction and process dynamics on the surface of a commercial copper-based catalyst for methanol synthesis from CO/CO2/H2 were systematically studied by means of temperature programmed desorption (T... Adsorption, surface reaction and process dynamics on the surface of a commercial copper-based catalyst for methanol synthesis from CO/CO2/H2 were systematically studied by means of temperature programmed desorption (TPD), temperature programmed surface reaction (TPSR), in-situ Fourier transform-inferred spec-troscopy(FTIR) and stimulus-response techniques. As a part of results, an elementary step sequence was suggested and a group of ordinary differential equations (ODEs) for describing transient conversations relevant to all species on the catalyst surface and in the gas phase in a micro-fixed-bed reactor was derived. The values of the parameters referred to dynamic kinetics were estimated by fitting the solution of the ODEs with the transient response data obtained by the stimulus-response technique with a FTIR analyzer as an on-line detector. 展开更多
关键词 methanol synthesis copper-based catalyst dynamic kinetics elementary step sequence parameter estimation
下载PDF
上一页 1 2 43 下一页 到第
使用帮助 返回顶部