期刊文献+
共找到49篇文章
< 1 2 3 >
每页显示 20 50 100
浅议电视新闻“角标”的作用
1
作者 高旭 《当代电视》 北大核心 2010年第7期57-57,共1页
"角标",如果从字面意义上浅显地理解,即为"出现在角落处的标志"。对于电视新闻来讲,我们所说的"角标",是指在新闻节目中,荧屏某一角出现的,与新闻内容有着某种关联、传递某种内在信息的图文标志。
关键词 电视新闻 “角标” 新闻节目 新闻内容
原文传递
Semantic role labeling based on conditional random fields 被引量:9
2
作者 于江德 樊孝忠 +1 位作者 庞文博 余正涛 《Journal of Southeast University(English Edition)》 EI CAS 2007年第3期361-364,共4页
Due to the fact that semantic role labeling (SRL) is very necessary for deep natural language processing, a method based on conditional random fields (CRFs) is proposed for the SRL task. This method takes shallow ... Due to the fact that semantic role labeling (SRL) is very necessary for deep natural language processing, a method based on conditional random fields (CRFs) is proposed for the SRL task. This method takes shallow syntactic parsing as the foundation, phrases or named entities as the labeled units, and the CRFs model is trained to label the predicates' semantic roles in a sentence. The key of the method is parameter estimation and feature selection for the CRFs model. The L-BFGS algorithm was employed for parameter estimation, and three category features: features based on sentence constituents, features based on predicate, and predicate-constituent features as a set of features for the model were selected. Evaluation on the datasets of CoNLL-2005 SRL shared task shows that the method can obtain better performance than the maximum entropy model, and can achieve 80. 43 % precision and 63. 55 % recall for semantic role labeling. 展开更多
关键词 semantic role labeling conditional random fields parameter estimation feature selection
下载PDF
Effect of Aerodynamically Stabilized Seeker Dynamics on System Analysis 被引量:3
3
作者 夏群力 祁载康 《Journal of Beijing Institute of Technology》 EI CAS 1999年第4期437-442,共6页
Aim To study the effect of aerodynamically stabilized seeker dynamics on guided bomb system analysis. Methods A thorough analysis of aerodynamically stabilized seeker dynamics was made to show that because of the mu... Aim To study the effect of aerodynamically stabilized seeker dynamics on guided bomb system analysis. Methods A thorough analysis of aerodynamically stabilized seeker dynamics was made to show that because of the much smaller time constant, its dynamic model can be greatly simplified. Results and Conclusion In guided bomb guidance/control digital simulation, with the use of the simplified seeker model, simulation time can be reduced without the loss of simulation accuracy. 展开更多
关键词 guided bomb aerodynamically stabilized seeker local air dislocation angle
下载PDF
STUDY OF NON-CONTACT MEASUREMENT OF FREE-FORM SURFACES
4
作者 徐玉春 张国雄 +2 位作者 解则晓 冯国馨 王春海 《Transactions of Tianjin University》 EI CAS 2001年第4期226-228,共3页
A non contact three dimensional measurement method is presented in this paper.This system consists of a laser triangulation probe,a probe head and a coordinate measuring machine (CMM).The measurement principle of th... A non contact three dimensional measurement method is presented in this paper.This system consists of a laser triangulation probe,a probe head and a coordinate measuring machine (CMM).The measurement principle of the system is discussed,and a system calibration method employing a reference ball is proposed.The geometric model involving four frames is established to calculate the data points based on the reading of the laser probe and position information from the CMM.A measuring experiment for gesso free form surface using this system is carried out. 展开更多
关键词 free form surface coordinate measuring machine PH10 probe head laser triangulation probe CALIBRATION
下载PDF
Effects of Remaining Leaf Combining with IBA on Rooting,Physiological and Biochemical Indicators of Leaves from Bougainvillea spectabilis Cuttings 被引量:1
5
作者 赖瑞云 钟赞华 +3 位作者 张雪芹 林丽仙 苏明华 谢志南 《Agricultural Science & Technology》 CAS 2010年第7期120-123,共4页
[Objective] The research aimed to discuss the effects on rooting,physiological and biochemical indicators of Bougainvillea spectabilis cuttings by remaining leaf combining with soaking cuttings in IBA.[Method] Effects... [Objective] The research aimed to discuss the effects on rooting,physiological and biochemical indicators of Bougainvillea spectabilis cuttings by remaining leaf combining with soaking cuttings in IBA.[Method] Effects of remaining leaf combining with IBA on rooting,physiological and biochemical indicators of B.spectabilis cuttings were studied under the regulation and control of intelligent seed propagation system,and then set four treatments:remaining leaf combining with soaking in clean water,remaining leaf combining with soaking in IBA,defoliation combining soaking in clean water,and defoliation combining with soaking in IBA.[Result] The soluble sugar content was high,but indoleacetic acid oxidase activity was lower in the initial stage of adventitious root differentiation in treatment of remaining leaf.While the rooting number,root length,the root mass growth and survival rate of cutting were obviously higher than that in treatment of defoliation.Compared to the treatment soaking in clean water,the treatment soaking in 500×10^-6 IBA increased the soluble sugar content in leaves of cuttings and enhanced rooting of cuttings.[Conclusion] The survival rate and rooting of cuttings improved obviously in the treatment of remaining leaf combining with soaking in 500×10^-6 IBA before cutting under the regulation and control of intelligent seed propagation system. 展开更多
关键词 LEAF IBA Bougainvillea spectabilis cutting ROOTING Physiological and biochemical indicators
下载PDF
Coordinate unification method of high-precision composite measurement in two dimensions 被引量:1
6
作者 文信 付鲁华 +2 位作者 赵炎 张恒 王仲 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2016年第3期205-213,共9页
Multi-sensor coordinate unification in dimensional metrology is used in order to get holistic, more accurate and reliable information about a workpiece based on several or multiple measurement values from ... Multi-sensor coordinate unification in dimensional metrology is used in order to get holistic, more accurate and reliable information about a workpiece based on several or multiple measurement values from one or more sensors. Because of the problem that standard ball is deficient as a standard artifact in the coordinate unification of high-precision composite measurement in two dimensions (2D) , a new method is proposed in this paper which uses angle gauge blocks as standard artifacts to achieve coordinate unification between the image sensor and the tactile probe. By comparing the standard ball with the angle gauge block as a standard artifact, theoretical analysis and experimental results are given to prove that it is more precise and more convenient to use angle gauge blocks as standard artifacts to achieve coordinate unification of high-precision composite measurement in two dimensions. 展开更多
关键词 high-precision composite measurement image sensor tactile probe coordinate unification angle gauge block
下载PDF
Criteria Conditions for Generalized Diagonally Dominant Matrices 被引量:3
7
作者 TIAN Su-xia 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2007年第1期63-67,共5页
In this paper, some new sufficient conditions for generalized dominant matrices are given, and some results in [1] are generalized and improved.
关键词 generalized diagonal dominant matrices α-diagonal dominant matrix criteria condition
下载PDF
Passive ranging algorithm in terms of polar coordinates 被引量:1
8
作者 浦甲伦 崔乃刚 荣思远 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第3期428-430,共3页
For the missile with passive seeker,the improvement of passive ranger's precision is one of the key issues in development of the defense penetrate strategy. On the offensive warheads,the infrared imaging device wa... For the missile with passive seeker,the improvement of passive ranger's precision is one of the key issues in development of the defense penetrate strategy. On the offensive warheads,the infrared imaging device was used to measure the line-of-sight angle information of the blocker,and then using the algorithm of Kalman Filter under polar coordinates,the distance from the blocker to the warheads was obtained. The simulation result under polar coordinates was compared with that of Cartesian coordinate. The validity of the method was analyzed,and the schemes of improvement were brought out. 展开更多
关键词 KF passive ranging polar coordinate
下载PDF
Experimental Study on the Effectiveness of TLDs under Wave Loading
9
作者 DONGSheng LIHuajun +1 位作者 LUMing TomotsukaTakayama 《Journal of Ocean University of Qingdao》 2002年第1期80-86,共7页
The objective of this study is to experimentally investigate the effectiveness of Tuned Liquid Dampers (TLDs) for suppressing the dynamic response of a platform structure subjected to wave loading and to explore the a... The objective of this study is to experimentally investigate the effectiveness of Tuned Liquid Dampers (TLDs) for suppressing the dynamic response of a platform structure subjected to wave loading and to explore the applicability of TLDs for suppressing the structural vibration of fixed offshore platforms. The experimental model is scaled according to a full size platform by matching its dynamic properties. Rectangular and circular TLDs of various sizes and water depths are examined. The experiments were performed in a 2-D wave flume. The effectiveness of TLDs is evaluated based on their response reduction. By observing the performance and the behavior of TLDs through laboratory experiments, the effects of a number of parameters including container shape, container size, number of dampers, frequency ratio, mass ratio, and incident wave characteristics are investigated. 展开更多
关键词 tuned liquid dampers rectangular container circular container jacket platform VIBRATION
下载PDF
A new measuring method for maximal length, width and thickness dimensions of coarse aggregates
10
作者 段跃华 张肖宁 吴传海 《Journal of Central South University》 SCIE EI CAS 2011年第6期2150-2156,共7页
In order to establish a new method for measuring the dimensions of coarse aggregates, five different-size flat and elongated (F&E) coarse aggregates were glued into two specimens by epoxy resin, respectively, and ... In order to establish a new method for measuring the dimensions of coarse aggregates, five different-size flat and elongated (F&E) coarse aggregates were glued into two specimens by epoxy resin, respectively, and slice images were obtained by X-ray CT, then the aggregates were extracted by the fuzzy c-means clustering algorithm. Attributions of the particle on different cross-sections were determined by the ‘overlap area method’. And unified three-dimensional Cartesian coordinate system was established based on continuous slice images. The coefficient values of spherical harmonics descriptor representing particles surface profile were gained, then each scanned particle was represented by 60×120 discrete points conformably with spherical harmonics descriptor. The chord length and direction angles were determined by the calculation. With the major axis (L) and orthogonal axis (W and T), the calculated results were compared with those measured by caliper. It is concluded that the new L, W, and T dimension measuring method is able to take the place of the present manual measurement. 展开更多
关键词 coarse aggregate flat and elongated (F&E) aggregate X-ray CT digital image processing fuzzy c-means clustering overlap area method spherical harmonics
下载PDF
Robust Integrated Models for Chinese Predicate-Argument Structure Analysis
11
作者 罗彦彦 浅原正幸 松本裕治 《China Communications》 SCIE CSCD 2012年第3期10-18,共9页
Predicate-Argument (PA) structure anal- ysis is often divided into three subtasks: predicate sense disambiguation, argument identification and argument classification mostly been modeled in To date, they have isol... Predicate-Argument (PA) structure anal- ysis is often divided into three subtasks: predicate sense disambiguation, argument identification and argument classification mostly been modeled in To date, they have isolation. However, this approach neglects logical constraints between them. We therefore exploite integrating predicate sense disambiguation with the latter two subtasks respectively, which verifies that the automatic predicate sense disambiguation could help the se- mantic role labeling task. In addition, a dual de- composition algorithm is used to alleviate the er- ror propagation between argument identification subtask and argument classification subtask by benefitting the argument identification subtask greatly. Experiment results show that our ap- proach leads to a better performance with PA a- nalysis than other pipeline approaches. 展开更多
关键词 semantic role labeling PA structureanalysis dual decomposition joint learning
下载PDF
Seismic Waves in a Layered Half-Space from an Arbitrary Buried Source
12
作者 MENGFanshun WANGZaishan LIJianjun 《Journal of Ocean University of Qingdao》 2003年第2期201-206,共6页
In this paper, a transfer matrix and a three-dimensional dynamic response of a layered half-space to an arbitrary buried source are derived with the aid of a technique which combines the Laplace and two-dimensional Fo... In this paper, a transfer matrix and a three-dimensional dynamic response of a layered half-space to an arbitrary buried source are derived with the aid of a technique which combines the Laplace and two-dimensional Fourier transforms in a rectangular coordinate system. This method is clear in concept, and the corresponding formulas given in the paper are simple and convenient for marine seismic prospecting and other fields' applications. An example is presented and the calculated results are in good agreement with those of the finite element method (FEM). 展开更多
关键词 rectangular coordinates arbitrary buried source layered media transfer matrix seismic wave
下载PDF
Study of LDBPs Shaft Skin Friction for Piles in Cohesiove Soils
13
作者 石名磊 邓学钧 刘松玉 《Journal of Southeast University(English Edition)》 EI CAS 2002年第2期154-158,共5页
The methodology of predicting pile shaft skin ultimate friction has been studied in a systematic way. In the light of that, the analysis of the pile shaft resistance for bored and cast in situ piles in cohesive soil... The methodology of predicting pile shaft skin ultimate friction has been studied in a systematic way. In the light of that, the analysis of the pile shaft resistance for bored and cast in situ piles in cohesive soils was carried out thoroughly in the basis of field performance data of 10 fully instrumented large diameter bored piles (LDBPs) used as the bridge foundation. The undrained strength index μ in term of cohesive soils was brought forward in allusion to the cohesive soils in the consistence plastic state, and can effectively combine the friction angle and the cohesion of cohesive soils in undrained condition. And that the classical ' α method' was modified much in effect to predict the pile shaft skin friction of LDBPs in cohesive soils. Furthermore, the approach of standard penetration test (SPT) N value used to estimate the pile shaft skin ultimate friction was analyzed, and the calculating formulae were established for LDBPs in clay and silt clay respectively. 展开更多
关键词 large diameter bored piles pile shaft skin friction blow count of standard penetration test
下载PDF
Self-Similar Solutions of Three-Dimensional Navier-Stokes Equation
14
作者 I.F.Barna 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第10期745-750,共6页
In this article we will present pure three dimensional analytic solutions for the Navier-Stokes and the continuity equations in Cartesian coordinates. The key idea is the three-dimensional generalization of the well-k... In this article we will present pure three dimensional analytic solutions for the Navier-Stokes and the continuity equations in Cartesian coordinates. The key idea is the three-dimensional generalization of the well-known self-similar Ansatz of Barenblatt. A geometrical interpretation of the Ansatz is given also. The results are the Kummer functions or strongly related. Our final formula is compared with other results obtained from group theoretical approaches. 展开更多
关键词 Navier-Stokes equation self-similar solution
下载PDF
Analysis of the Antenna's Setup Errors at the Global Navigation Satellite System Measurements
15
作者 Evangelia Lambrou 《Journal of Civil Engineering and Architecture》 2013年第10期1279-1286,共8页
Today, the GNSS (global navigation satellite system) is used for more complicate and accurate applications such as monitoring or stake out works. The truth lies in the fact that in the most of the times not enough a... Today, the GNSS (global navigation satellite system) is used for more complicate and accurate applications such as monitoring or stake out works. The truth lies in the fact that in the most of the times not enough attention is paid to the antenna's setup. Usually, gross errors are found in the antenna's centering, leveling and in the measurement of its height, which are significant. In this paper, a thoroughly analysis of the above mentioned errors is carried out. The influence of these errors in the calculation of the X, Y, Z Cartesian geocentric coordinates and the ~, 2, h ellipsoid geodetic coordinates of a point P on the earth's surface, is analyzed and is presented in several diagrams. Also a new convenient method for the accurate measurement of the antenna's height is presented and it is strongly proposed. The conclusions outline the magnitude of these errors and prove the significance of the antenna's proper setup at the accurate GNSS applications. 展开更多
关键词 GNSS antenna's height centering and leveling errors GNSS antenna's setup.
下载PDF
English Advertising Language Features and Translation
16
作者 HUI Chun 《Sino-US English Teaching》 2013年第5期383-391,共9页
As a practical style, Advertising English has gradually derived from the English language due to its particular social role. In this respect, this paper will generalise the fundamental knowledge of the advertisement i... As a practical style, Advertising English has gradually derived from the English language due to its particular social role. In this respect, this paper will generalise the fundamental knowledge of the advertisement including its definition, objective, and writing principles. This is followed by an analysis on language features based on vocabulary, grammar, punctuation, and rhetorical devices. However, the main thrust of the thesis is not devoted to a purely linguistic study. Rather, building on the theoretical reflections of equivalent theory and cultural conversion, this paper attempts to find the joint reflecting the similar functions of both English and Chinese. Therefore, This thesis will not confine itself simply to a list of language features but rather go further and crack the "hard nut"--how to tackle translation in advertisements. Little ink, as the case stands, has been spilled over this crux. Taking into consideration the distinctive functions and stylistic features of advertisement, general principles that highlight the qualities of awareness, understanding, conviction, and action will be offered. Based on these general principles, tactics both regular and strategic are tentatively offered. As is often the case, a translator walking on a tightrope plays dual roles: a submissive servant and a defiant master. In this sense, it is proposed that a blend of regular and strategic tactics should be employed in pursuit of an optimum transfer of information. 展开更多
关键词 Advertising English language features TRANSLATION
下载PDF
On the Significance and Use of the Generalized Moist Potential Vorticity Equation
17
作者 FU Shen-Ming SUN Jian-Hua 《Atmospheric and Oceanic Science Letters》 2011年第3期131-135,共5页
In this paper,the continuity and thermodynamic equations including moisture forcings were derived.Using these two equations and the basic momentum equation of local Cartesian coordinates,the budget equation of general... In this paper,the continuity and thermodynamic equations including moisture forcings were derived.Using these two equations and the basic momentum equation of local Cartesian coordinates,the budget equation of generalized moist potential vorticity(GMPV) was derived.The GMPV equation is a good generalization of the Ertel potential vorticity(PV) and moist potential vorticity(MPV) equations.The GMPV equation is conserved under adiabatic,frictionless,barotropic,or saturated atmospheric conditions,and it is closely associated with the horizontal frontogenesis and stability of the real atmosphere.A real case study indicates that term diabatic heating could be a useful diagnostic tool for heavy rainfall events. 展开更多
关键词 potential vorticity moist potential vorticity
下载PDF
SiamADN:Siamese Attentional Dense Network for UAV Object Tracking 被引量:2
18
作者 WANG Zhi WANG Ershen +2 位作者 HUANG Yufeng YANG Siqi XU Song 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2021年第4期587-596,共10页
Single object tracking based on deep learning has achieved the advanced performance in many applications of computer vision.However,the existing trackers have certain limitations owing to deformation,occlusion,movemen... Single object tracking based on deep learning has achieved the advanced performance in many applications of computer vision.However,the existing trackers have certain limitations owing to deformation,occlusion,movement and some other conditions.We propose a siamese attentional dense network called SiamADN in an end-to-end offline manner,especially aiming at unmanned aerial vehicle(UAV)tracking.First,it applies a dense network to reduce vanishing-gradient,which strengthens the features transfer.Second,the channel attention mechanism is involved into the Densenet structure,in order to focus on the possible key regions.The advance corner detection network is introduced to improve the following tracking process.Extensive experiments are carried out on four mainly tracking benchmarks as OTB-2015,UAV123,LaSOT and VOT.The accuracy rate on UAV123 is 78.9%,and the running speed is 32 frame per second(FPS),which demonstrates its efficiency in the practical real application. 展开更多
关键词 unmanned aerial vehicle(UAV) object tracking dense network corner detection siamese network
下载PDF
A Computer Modeling of the China Central Television Headquarters in Beijing
19
作者 Valentina Forcella 《Journal of Civil Engineering and Architecture》 2013年第11期1353-1368,共16页
This paper deals with the computer modeling of structures starting from a point cloud. The CCTV (China Central Television) tower headquarters is the case for study because the shape of this building is non-stellar, ... This paper deals with the computer modeling of structures starting from a point cloud. The CCTV (China Central Television) tower headquarters is the case for study because the shape of this building is non-stellar, concave and multi-connected. It is composed of sowns and chains. The sown is the representation of a horizontal plane formed by dense points. The chain is a planar path modeled by rare points. The CCTV structure is defined only by the three orthogonal Cartesian coordinates of the points. The proposed computer modeling uses a sequence of procedures and the desired outputted 3D model is consistent. The first procedure is devoted to attributing points to their voxel and to estimating three values needed afterwards. The second procedure is devoted to analyzing clusters vertically and horizontally, to preliminarily distinguishing chains from sowns and to generating relational matching. The third procedure is devoted to building closed paths between all chains and all their projections on sowns. The fourth procedure is devoted to connecting points with triangles. The fifth procedure, still being implemented, is devoted to interpolating triangles with triangular splines. The results show it is possible to achieve the 3D model using the above mentioned procedures. These procedures are written, implemented and tested and they form a library of people's own software. The code is written using Matlab. It is not possible to obtain the required 3D model if the procedures are applied in the wrong order or one step is skipped. To conclude, it is possible to obtain the computer model of the CCTV using the provided sequence of procedures. 展开更多
关键词 CCTV tower cluster analysis Delaunay triangulation B6zier spline.
下载PDF
Influences of attack angle and mach number on aerodynamic characters of typical sections of extra-long blade in a steam turbine
20
作者 杨其国 韩万金 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2007年第4期474-479,共6页
On super-sonic or trans-sonic planar cascade wind tunnel of free jet intermittent type, wind blowing experiments were performed on the typical sections of stator and rotor blades in the last stage of ultra-ultra-criti... On super-sonic or trans-sonic planar cascade wind tunnel of free jet intermittent type, wind blowing experiments were performed on the typical sections of stator and rotor blades in the last stage of ultra-ultra-critical steam turbine with extra-long blade of 1200mm. The influences of attack angle and Mach number on the aerodynamic performances of these sections of the blade profiles were verified, and their operating ranges were also specified. 展开更多
关键词 ultra-ultra-critical steam turbine extra-long blade attack angle and mach number typical section experimental investigation
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部