期刊文献+
共找到17篇文章
< 1 >
每页显示 20 50 100
地理学:计量运动的失败与分形研究的崛起 被引量:14
1
作者 陈彦光 《信阳师范学院学报(自然科学版)》 CAS 1999年第3期310-314,共5页
论述地理学计量运动盛衰的前因后果和地理分形研究发展的来龙去脉,说明只有借助分形几何学,地理学的计量化才能成功。文章指出,未来地理学的主流将是分形地理学。
关键词 地理学 计量运动 分形理论
下载PDF
Fast global motion estimation and moving object extraction algorithm in image sequences 被引量:2
2
作者 张涛 费树岷 +1 位作者 李晓东 路红 《Journal of Southeast University(English Edition)》 EI CAS 2008年第2期192-196,共5页
A novel and effective approach to global motion estimation and moving object extraction is proposed. First, the translational motion model is used because of the fact that complex motion can be decomposed as a sum of ... A novel and effective approach to global motion estimation and moving object extraction is proposed. First, the translational motion model is used because of the fact that complex motion can be decomposed as a sum of translational components. Then in this application, the edge gray horizontal and vertical projections are used as the block matching feature for the motion vectors estimation. The proposed algorithm reduces the motion estimation computations by calculating the onedimensional vectors rather than the two-dimensional ones. Once the global motion is robustly estimated, relatively stationary background can be almost completely eliminated through the inter-frame difference method. To achieve an accurate object extraction result, the higher-order statistics (HOS) algorithm is used to discriminate backgrounds and moving objects. Experimental results validate that the proposed method is an effective way for global motion estimation and object extraction. 展开更多
关键词 global motion estimation edge projection higherorder statistics moving object extraction
下载PDF
基于STM32的“智能可穿戴设备”课程实验教学平台设计 被引量:1
3
作者 陆翔 白培瑞 +2 位作者 王鹏 杨业旺 孙农亮 《教育教学论坛》 2020年第38期382-384,共3页
针对生物医学工程专业"智能可穿戴设备技术"课程,设计了一款能够二次开发的人体生理参数实验教学平台。该文分析了平台架构,对光电容积法测血氧脉搏原理和加速度传感器计步原理进行介绍,并对开发平台步态及心率准确性进行测试... 针对生物医学工程专业"智能可穿戴设备技术"课程,设计了一款能够二次开发的人体生理参数实验教学平台。该文分析了平台架构,对光电容积法测血氧脉搏原理和加速度传感器计步原理进行介绍,并对开发平台步态及心率准确性进行测试,准确率均达到95%以上,实现了预期功能。 展开更多
关键词 生理参数监测 可穿戴 嵌入式 运动计量 光电容积法
下载PDF
A framework for quantifying properties of 3-dimensional movement-based signals 被引量:2
4
作者 Shaun TD NEW Richard A PETERS 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第3期327-336,共10页
Understanding how signal properties are optimized for the reliable transmission of information requires accurate de- scription of the signal in time and space. For movement-based signals where movement is restricted t... Understanding how signal properties are optimized for the reliable transmission of information requires accurate de- scription of the signal in time and space. For movement-based signals where movement is restricted to a single plane, measure- ments from a single viewpoint can be used to consider a range of viewing positions based on simple geometric calculations. However, considerations of signal properties from a range of viewing positions for movements extending into three-dimensions (3D) are more problematic. We present here a new framework that overcomes this limitation, and enables us to quantify the extent to which movement-based signals are view-specific. To illustrate its application, a Jacky lizard tail flick signal was filmed with synchronized cameras and the position of the tail tip digitized for both recordings. Camera aligmnent enabled tl^e construction of a 3D display action pattern profile. We analyzed the profile directly and used it to create a detailed 3D animation. In the virtual environment, we were able to film the same signal from multiple viewing positions and using a computational motion analysis algorithm (gradient detector model) to measure local image velocity in order to predict view dependent differences in signal properties. This approach will enable consideration of a range of questions concerning movement-based signal design and evolu- tion that were previously out of reach [Current Zoology 56 (3): 327-336, 2010]. 展开更多
关键词 Signal evolution Sensory Ecology Movement-based signal 3D Display Action Pattern
下载PDF
Probability modeling for robustness of multivariate LQG designing based on ship lateral motion
5
作者 ZHAO Xi-ren PENG Xiu-yan YIN Zhong-feng 《Journal of Marine Science and Application》 2005年第4期18-22,共5页
The robustness of LQG designing for latitudinal movement of ship is mainly discussed, when its hydrodynamic parameters fluctuate around criterion value at random on the proportional distributing. When a given ship sta... The robustness of LQG designing for latitudinal movement of ship is mainly discussed, when its hydrodynamic parameters fluctuate around criterion value at random on the proportional distributing. When a given ship state at the speed of 18 kn and the course of 45° under Rank 5 state of sea, and the hydrodynamic parameters of the ship fluctuate at random on the proportional distributing with a range of ± 10% , ± 20% , ± 30% , the robustness of muhivariate LQG designing for ship is analyzed with applying the probability modeling of relative controlling effect, The result of simulating shows that when the hydrodynamic parameters of ship fluctuates the relative controlling effect of the LQG designing submit to normal distribution and the mean value of relative controlling effect has no remarkable changes comparing to that without perturbation of hydrodynamic parameter, 展开更多
关键词 hydrodynamic parameters PERTURBATION LQG designing statislic modeling
下载PDF
Video Image Block-matching Motion Estimation Algorithm Based on Two-step Search
6
作者 金伟其 陈艳 +4 位作者 王岭雪 刘斌 刘崇亮 沈亚中 张桂清 《Journal of Measurement Science and Instrumentation》 CAS 2010年第3期228-232,共5页
Aiming at the shortcoming that certain existing blockingmatching algorithrns, such as full search, three-step search, and dia- mond search algorithms, usually can not keep a good balance between high acoaracy and low ... Aiming at the shortcoming that certain existing blockingmatching algorithrns, such as full search, three-step search, and dia- mond search algorithms, usually can not keep a good balance between high acoaracy and low computational complexity, a block-maching motion estimation algorithm based on two-step search is proposed in this paper. According to the fact that the gray values of adjacent pixels will not vary fast, the algorithm employs an interlaced search pattem in the search window to estimate the motion vector of the objectblock. Simulation and actual experiments demanstrate that the proposed algmithm greatly outperforms the well-known three-step search and dianond search algoritlam, no matter the motion vector is large or small. Comparedc with the full search algorithm, the proposed one achieves similar peffomance but requires much less computation, therefore, the algorithm is well qualified for real-time video image processing. 展开更多
关键词 BLOCK-MATCHING rnation estimation two-step search
下载PDF
A complexity-scalable software-based MPEG-2 video encoder
7
作者 陈国斌 陆新宁 +1 位作者 王兴国 刘济林 《Journal of Zhejiang University Science》 CSCD 2004年第5期572-578,共7页
With the development of general-purpose processors (GPP) and video signal processing algorithms, it is possible to implement a software-based real-time video encoder on GPP, and its low cost and easy upgrade attract d... With the development of general-purpose processors (GPP) and video signal processing algorithms, it is possible to implement a software-based real-time video encoder on GPP, and its low cost and easy upgrade attract developers' interests to transfer video encoding from specialized hardware to more flexible software. In this paper, the encoding structure is set up first to support complexity scalability; then a lot of high performance algorithms are used on the key time-consuming modules in coding process; finally, at programming level, processor characteristics are considered to improve data access efficiency and processing parallelism. Other programming methods such as lookup table are adopted to reduce the computational complexity. Simulation results showed that these ideas could not only improve the global performance of video coding, but also provide great flexibility in complexity regulation. 展开更多
关键词 Video coding Complexity scalability Motion estimation SIMD
下载PDF
现代地理学基本理论及可持续发展研究
8
作者 段杰 李江 《嘉应大学学报》 1997年第6期76-79,共4页
地理学是一门古老的科学,同时也是一门年轻的科学,本文通过对古、近代及现代地理学基本理论思想的研究,提出可持续发展是未来地理学研究的新生面。
关键词 现代地理学 基本理论 可持续发展 发展过程 计量运动 行为革命
下载PDF
Adiabatic correction for the esterification of acetic anhydride by methanol via accurate kinetics
9
作者 Ze Dong Liping Chen +2 位作者 Yingying Ma Haoliang Peng Wanghua Chen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第9期1954-1959,共6页
In the field of adiabatic correction for complex reactions,a simple one-stage kinetic model was used to estimate the real reaction kinetics.However,this assumption simplified the real process,inevitably generated inac... In the field of adiabatic correction for complex reactions,a simple one-stage kinetic model was used to estimate the real reaction kinetics.However,this assumption simplified the real process,inevitably generated inaccurate or even unsafe results.Therefore,it was necessary to find a new correction method for complex reactions.In this work,esterification of acetic anhydride by methanol was chosen as an object reaction of study.The reaction was studied under different conditions by Reaction Calorimeter(RC1).Then,Thermal Safety Software(TSS)was used to establish the kinetic model and estimate the parameters,where,activation energies for three stages were67.09,81.02,73.77 kJ?mol^(-1)respectively,and corresponding frequency factors in logarithmic form were 16.05,19.59,15.72 s^(-1).In addition,two adiabatic tests were performed by Vent Sizing Package2(VSP2).For accurate correction of VSP2 tests,a new correction method based on Enhanced Fisher method was proposed.Combined with kinetics,adiabatic correction of esterification reaction was achieved.Through this research,accurate kinetic parameters for a three-step kinetic model of the esterification reaction were acquired.Furthermore,the correlation coefficients between simulated curves and corrected curves were 0.976 and 0.968,which proved the accuracy of proposed new adiabatic correction method.Based on this new method,conservative corrected results were able to be acquired and be applied in safety assessment. 展开更多
关键词 Adiabatic correction KINETICS New method Complex reaction ESTERIFICATION Model reaction
下载PDF
Designing Socially Sound Poultry FarmingmMatching Hen Ethology, Farm Management and Landscape Quality
10
作者 D. J. Stobbelaar K. Hendriks 《Journal of Agricultural Science and Technology(A)》 2011年第5期663-671,共9页
In order to receive a licence to produce, poultry farmers have to take into account societal demands, among others: animal welfare, healthy working conditions for the workers and landscape quality. A way to reach a c... In order to receive a licence to produce, poultry farmers have to take into account societal demands, among others: animal welfare, healthy working conditions for the workers and landscape quality. A way to reach a combination of these goals is to create a design for the poultry house and outdoor run. We propose a methodology based on five steps, which enables us to create a design that takes into consideration societal demands and that can be tested on its effects. These five steps are: 1. Giving a theoretical background on the societal demands (hen ethology, farm management and landscape quality) and based on this; 2. Giving a set of design criteria. 3. Describing the cttrrent state of the farm, in order to know its current qualities, 4. Making a design of the farm using the sets of criteria as guiding principle. 5. Reflecting on the design, to show whether the different criteria can be combined and where compromises are needed. A case study on an organic farm in the centre of the Netherlands showed that hen welfare, farm management and landscape quality can be improved together, although some measures do not add to all design criteria. Especially the effect on landscape quality and farm management is variable: the latter is also depending on the personal motivation of the farmer. 展开更多
关键词 Outdoor poultry fanning hen ethology landscape design organic fanning poultry house PLANTING Netherlands.
下载PDF
Research on variable block size motion estimation algorithm for airborne image
11
作者 王科 Huang Dongshan +1 位作者 Ma Li Zhang Yudong 《High Technology Letters》 EI CAS 2014年第3期321-327,共7页
A fast motion estimation algorithm for variable block-size using the "line scan and block merge procedure" is proposed for airborne image compression modules.Full hardware implementation via FPGA is discussed in det... A fast motion estimation algorithm for variable block-size using the "line scan and block merge procedure" is proposed for airborne image compression modules.Full hardware implementation via FPGA is discussed in detail.The proposed pipelined architecture based on the line scan algorithm is capable of calculating the required 41 motion vectors of various size blocks supported by H.264 within a 16 × 16 block in parallel.An adaptive rate distortion cost function is used for various size block decision.The motion vectors of adjacent small blocks are merged to predict the motion vectors of larger blocks for reducing computation.Experimental results show that our proposed method has lower computational complexity than full search algorithm with slight quality decrease and little bit rate increase.Due to the high real-time processing speed it can be easily realized in hardware. 展开更多
关键词 H.264 motion estimation line scan algorithm rate distortion optimization (RDO) FPGA block merge method
下载PDF
Design of the Mobile Phone Charging Device based on Human Motion Energy and Light Energy
12
作者 Liang LV 《International Journal of Technology Management》 2015年第6期131-133,共3页
This paper designs a mechanical swing of placementing mobile phone, which is inspired by the mechanical watch automatic winding process. The use of the kinetic energy generated by human body motion drives the wheel sw... This paper designs a mechanical swing of placementing mobile phone, which is inspired by the mechanical watch automatic winding process. The use of the kinetic energy generated by human body motion drives the wheel swing and the generator, it can carry out mobile phone additional charge through the electronic components rectifier and DC/DC converter regulator, the use of human motion and light energy can extend a fixed charge mobile phone standby time. The human motion power uses electromagnetic coupling technique and collects energy by using foot swing, solar power generation uses DSP chip in TMS320F28927 control a plurality of charging circuit, inverter circuit and solar maximum power point tracking by sampling and multiple output PWM wave. Finally, charging process has the basic constant current process discovered by device testing, the design of human motion and light energy mobile phone charger can satisfy the need of mobile phone rechargeable lithium batteries. 展开更多
关键词 Human body kinetic energy Photovoltaic effect Mobile phone charging Inverter Mechanical balance Solar energy.
下载PDF
Ground Motion and Site Effects on Performance-Based Design
13
作者 Antonio Ferraro Salvatore Grasso Michele Maugeri 《Journal of Civil Engineering and Architecture》 2010年第7期34-41,共8页
The objective of Performance-Based Earthquake Engineering (PBEE) is the analysis of performance objectives with a specified annual probability of exceedance. Increasingly undesirable performance is caused by increas... The objective of Performance-Based Earthquake Engineering (PBEE) is the analysis of performance objectives with a specified annual probability of exceedance. Increasingly undesirable performance is caused by increasing levels of strong ground motion having decreasing annual probabilities of exceedance. The development of this methodology includes three steps: (1) evaluation of the distribution of ground motion at a site; (2) evaluation of the distribution of system response; (3) evaluation of the probability of exceeding decision variables within a given time period, given appropriate damage measures. The work has taken a systematic approach to determine the impact of increasing levels of detail in site characterization on the accuracy of ground motion and site effects predictions. Complementary studies have investigated the use of the following models for evaluating site effects: (1) amplification factors defined on the basis of generalized site categories, (2) one-dimensional ground response analysis, and (3) two-dimensional ground response analysis for surface topography on ground motion. The paper provides a brief synthesis of ground motion and site effects analysis procedures within a Performance-Based Design framework. It focuses about the influence on the evaluation of site effects in some active regions by different shear waves velocity measurements Down Hole (D-H), Cross Hole (C-H), Seismic Dilatometer Marchetti Test (SDMT) and by different variation of shear modulus and damping ratio with strain level and depth from different laboratory dynamic tests for soil characterization: Resonant Column Test (RCT), Cyclic Loading Torsional Shear Test (CLTST). 展开更多
关键词 Site effects Performance Based Design (PBD) ground motion soil non-linearity seismic response analysis
下载PDF
保持健康
14
《中华少年.DK百科.儿童版》 2010年第6期20-21,共2页
你喜欢和小伙伴在公园里玩猫捉老鼠的游戏吗?你们追啊、躲啊、喊啊、笑啊,不一会儿呼吸就变快了,身上也觉得暖烘烘的。运动就是这么有趣,它能让你感到快乐,还能帮你保持健康。
关键词 学前教育 游戏 体育运动 运动计量
原文传递
Unsupervised Spatio-Temporal Segmentation for Extracting Moving Objects in Video Sequences 被引量:1
15
作者 李仁杰 余松煜 王向文 《Journal of Shanghai Jiaotong university(Science)》 EI 2009年第2期154-161,共8页
Extraction of moving objects is an important and fundamental research topic for many video applications. This paper addresses an unsupervised spatio-temporal segmentation scheme to extract moving objects from video se... Extraction of moving objects is an important and fundamental research topic for many video applications. This paper addresses an unsupervised spatio-temporal segmentation scheme to extract moving objects from video sequences.The temporal segmentation localizes moving objects by comparing the motion vector of each block in each frame with the corresponding global motion vector estimated by an outlier rejection(OR) based method.Furthermore,the temporal compensation utilizing the temporal coherence of moving objects is considered in the temporal segmentation to solve the temporarily stopping problem.The detected moving regions usually have discontinuous boundaries and some holes.These regions are then compensated in the spatial domain. In the spatial segmentation,the watershed algorithm considering the global information improves the accuracy of segmentation in the spatial domain.The modified mean filter is presented to suppress some minima.By using a fusion module,moving objects are extracted.Experiments on various sequences have successfully demonstrated the validity of the proposed scheme. 展开更多
关键词 SEGMENTATION SPATIO-TEMPORAL region growing outlier rejection WATERSHED
原文传递
An algorithm for trajectory prediction of flight plan based on relative motion between positions 被引量:7
16
作者 Yi LIN Jian-wei ZHANG Hong LIU 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2018年第7期905-916,共12页
Traditional methods for plan path prediction have low accuracy and stability. In this paper, we propose a novel approach for plan path prediction based on relative motion between positions(RMBP) by mining historical f... Traditional methods for plan path prediction have low accuracy and stability. In this paper, we propose a novel approach for plan path prediction based on relative motion between positions(RMBP) by mining historical flight trajectories. A probability statistical model is introduced to model the stochastic factors during the whole flight process. The model object is the sequence of velocity vectors in the three-dimensional Earth space. First, we model the moving trend of aircraft including the speed(constant, acceleration, or deceleration), yaw(left, right, or straight), and pitch(climb, descent, or cruise) using a hidden Markov model(HMM) under the restrictions of aircraft performance parameters. Then, several Gaussian mixture models(GMMs) are used to describe the conditional distribution of each moving trend. Once the models are built, machine learning algorithms are applied to obtain the optimal parameters of the model from the historical training data. After completing the learning process, the velocity vector sequence of the flight is predicted by the proposed model under the Bayesian framework, so that we can use kinematic equations, depending on the moving patterns, to calculate the flight position at every radar acquisition cycle. To obtain higher prediction accuracy, a uniform interpolation method is used to correct the predicted position each second. Finally, a plan trajectory is concatenated by the predicted discrete points. Results of simulations with collected data demonstrate that this approach not only fulfils the goals of traditional methods, such as the prediction of fly-over time and altitude of waypoints along the planned route, but also can be used to plan a complete path for an aircraft with high accuracy. Experiments are conducted to demonstrate the superiority of this approach to some existing methods. 展开更多
关键词 Velocity vector Hidden Markov model Gaussian mixture model Machine learning Plan path prediction Relative motion between positions(RMBP)
原文传递
On the atmospheric movement and the imbalance of observed and calculated energy in the surface layer 被引量:5
17
作者 ZUO HongChao XIAO Xia +3 位作者 YANG QiDong DONG LongXiang CHEN JiWei WANG ShuJin 《Science China Earth Sciences》 SCIE EI CAS 2012年第9期1518-1532,共15页
Based on existing researches,here we theoretically summarized the characteristics of the atmospheric movement and turbulent transport of energy and substance in the surface layer as well as the ideal and the actual mo... Based on existing researches,here we theoretically summarized the characteristics of the atmospheric movement and turbulent transport of energy and substance in the surface layer as well as the ideal and the actual models for the turbulent transport.Then,using the data observed with eddy covariance at the semiarid climate and environment monitoring station(SACOL) in Lanzhou University from May to October during four consecutive years(September 2006-August 2010),we conducted a detailed analysis of the turbulent transport in the surface layer,through introducing the relative vertical turbulence intensity to characterize the turbulence strength,RIw=wn(wn+U),and also by adopting the method for controlling data quality at different levels.Our conclusions are:(1) The turbulent transport of energy and substance in the surface layer must obey the law of conservation of energy and the law of conservation of matter,the observed and calculated energy in the surface layer must be balanced,or closed in theory,but the actual observed and calculated energy just approximates the ideal in some degree and is difficult to achieve the energy balance.(2) The energy closure rate depends much on the atmospheric state in the surface layer,and the energy closure rate increases generally with the relative vertical turbulence intensity.(3) By the way of controlling data quality at different levels,it is found that the degree of data quality control can affect the closure rate,but it does not change the fact that the energy closure rate depends on the atmospheric state.(4) The calculation method of surface soil heat flux can affect energy closure rate,but does not change its dependence on the atmospheric state. 展开更多
关键词 surface layer energy balance state relative vertical turbulence intensity turbulence transport data quality control
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部