An improved pixel-based method is proposed in this paper aiming at density estimation for unidirectional crowds. It is a common situation that the crowd gathered facing towards the same orientation where hazardous eve...
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ISBN:
(纸本)9781629939865
An improved pixel-based method is proposed in this paper aiming at density estimation for unidirectional crowds. It is a common situation that the crowd gathered facing towards the same orientation where hazardous events may be prone to occur due to high density, such as crowds gathered in front of a rostrum, crowds waiting at an entrance, flowing crowds in a passageway, etc. In these situations, the crowd density has a linear relationship with both the proportion of facial region to the foreground and the proportion of inner edges to the foreground edges. Based on above observations, we get a model and solve its parameters by multivariate statistical regression. The experiment shows the proposed method improves the accuracy of the commonly used pixel-based method especially for high-density crowds.
The Galileo E5 and GPS L5 signals are important components of GNSS, however, the Galileo E5 and GPS L5 signals lie within the Aeronautical Radio Navigation Service (ARNS) band, where Distance Measuring Equipment (DME)...
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ISBN:
(纸本)9783642547362
The Galileo E5 and GPS L5 signals are important components of GNSS, however, the Galileo E5 and GPS L5 signals lie within the Aeronautical Radio Navigation Service (ARNS) band, where Distance Measuring Equipment (DME) works in, and strong pulsed interference originating from DME stations can degrade the performance of GNSS receivers. At high altitude, the worse DME interference environment is. Because the similarity between wavelet and DME pulse is higher than that of the GNSS signals, it is easier to detect and remove interference in wavelet packet domain. Although the wavelet packet transformation (WPT) based DME pulse mitigation had been proposed, but the parameters about WPT are not discussed systematically which pay important role in mitigation performance. This paper mainly discusses the parameters selection about WPT including wavelet, composition level, threshold rules and thresholding function. Mitigation Performance are assessed with respect to threshold rules and threholding function by Numerical experiments.
The traditional Bag of Words(BOW) algorithm considers the frequency of visual words only, whereas it ignores their spatial and temporal correlations. Many methods have been designed to remedy this *** this paper, we p...
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The traditional Bag of Words(BOW) algorithm considers the frequency of visual words only, whereas it ignores their spatial and temporal correlations. Many methods have been designed to remedy this *** this paper, we propose a new descriptor to describe the local spatio-temporal distribution information of each point. This new descriptor, combined with HOG3 D, is used to describe human actions. K-means clustering algorithm is introduced to generate codebook of visual words, achieving the integration of two features under the BOW model. Finally, Support Vector Machine(SVM) is used for action recognition. We extensively test our method on the standard Weizmann and KTH action datasets. The results show its validity and good performance.
Motion history image(MHI) and motion energy image(MEI) can recognize simple actions effectively, but they can't represent the velocity information of the actions. Sometimes in the behavior recognition, we must tak...
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Motion history image(MHI) and motion energy image(MEI) can recognize simple actions effectively, but they can't represent the velocity information of the actions. Sometimes in the behavior recognition, we must take the speed into account. For example, touching a person, fierce and friendly touches are two totally different movements. The paper combines the wavelet moment of temporal motion descriptors(MHI and MEI) and the speed feature based on optical flow to represent the action. Wavelet moments are rotation, translation and scale invariance. Foreground is obtained from video sequences by background subtraction. Then we use Lucas-Kanade algorithm to get the regional optical flow information, whose direction amplitude can represent the velocity changes in different direction intervals. Experiments based on video sequences outdoor scenarios carried out to verify the effectiveness of the proposed method.
The directions of arrival(DOA) of interference changes rapidly with time in high-dynamic satellite navigation system, which leads to the mismatch between weights training data and weights applying data during the adap...
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ISBN:
(纸本)9783642547362
The directions of arrival(DOA) of interference changes rapidly with time in high-dynamic satellite navigation system, which leads to the mismatch between weights training data and weights applying data during the adaptive processing. In this case, the conventional adaptive anti-jamming algorithms are invalid since jammers may easily move out of the array pattern nulls and could not be suppressed. In this letter, a novel method of null-widen is deduced based on the Laplace distribution model of the changing interference DOA in high-dynamic environment. By taking the moving interferences as discrete interference sources obey the Laplace distribution, the extension matrix can be obtained and the average covariance matrix can be calculated from matrix product to broaden the width of nulls. The new method does not alter the noise contribution to the covariance matrix and does not require information about interference DOA. The width of nulls is easy to control. In addition, by combining with the power minimization approach, the new null-widen method does not need the DOA of desired satellite signal. The proposed method can provide correctly acquisition.
Compression of stereoscopic and multiview video data becomes more and more important since the bandwidth necessary for storage and transmission linearly increases with the number of camera channels.A new stereo video ...
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Compression of stereoscopic and multiview video data becomes more and more important since the bandwidth necessary for storage and transmission linearly increases with the number of camera channels.A new stereo video coding scheme based on both the joint motion/disparity estimation method of series Delaunay Triangulation mesh and the mesh object depiction of MPEG4 *** the data structure of streams is *** results show that the coder can compress the stereo video very efficiently while maintaining excellent visual perception quality.
First,this paper briefly introduces the concepts and sources of *** this basis,we provide an overview on the theories and methods of multi-dimensional data uncertainty visualization,such as:visual variables and additi...
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First,this paper briefly introduces the concepts and sources of *** this basis,we provide an overview on the theories and methods of multi-dimensional data uncertainty visualization,such as:visual variables and additional visual objects,the application of color in visualization and two commonly used multi-dimensional data representation-parallel coordinates and star ***,with the integration of the color,saturation,parallel coordinates and star glyph,we tentatively propose a visualization method on multi-dimensional data uncertainty.
Prior work about uncertainty visualization has been primarily focused on spatio-temporal or univariate data. Little research has been reported on exploring uncertainty of multidimensional data. Therefore, improved vis...
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Prior work about uncertainty visualization has been primarily focused on spatio-temporal or univariate data. Little research has been reported on exploring uncertainty of multidimensional data. Therefore, improved visualizations applying to parallel coordinate and star glyph will be discussed and utilized to visualize multidimensional uncertainty. Firstly, parallel coordinate will be modified through imposing visual variables and expanding traditional two-dimensional visualization to three-dimensional way. Then the concept of multi-view visualization will be put forward, because of the shortcoming that traditional parallel coordinate can not be mapped with the order of data and the problem of overlapping polylines. Meanwhile, four HCI technologies such as brushing, Linking, Zooming in/out, Hiding are imposed to the improved visualizations to help users to focus on what they find interesting and details of corresponding data with different uncertainty intervals. Eventually, MFC and OPENGL technology will be combined to construct an experimental platform to validate our proposed new ideas.
In the process of disaster situation assessment by using the fuzzy reasoning often requires us to specify fuzzy sets. However, it is unrealistic to provide them beforehand. In this paper, we propose a method to obtain...
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In the process of disaster situation assessment by using the fuzzy reasoning often requires us to specify fuzzy sets. However, it is unrealistic to provide them beforehand. In this paper, we propose a method to obtain the fuzzy sets and the membership functions by using the clustering techniques At first,we present a criteria to find the best number for clustering. Then we can classify each attribute into fuzzy sets and define their membership functions by using the cluster centers we have finded. Finally, we apply this method to a dataset of Civil Aviation Disaster Situation Assessment. The results demonstrated that it is a good way for the fuzzy partition and the membership function definitions.
In recent years,the GPU(graphics processing unit) technology has been highly *** the graphics card that initially limited to rendering,it has developed into a programmable parallel computing platform today and has evo...
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In recent years,the GPU(graphics processing unit) technology has been highly *** the graphics card that initially limited to rendering,it has developed into a programmable parallel computing platform today and has evolved into a high degree of parallelism,multithreaded,multicore processor with tremendous computational horsepower and very high memory *** the power of high intensity of GPU to solve some speed bottlenecks of algorithm will be a research of great *** the classic encrypt algorithm DES as an example,it uses the contrast experiment to show that the result by CUDA parallel computing get a high speed compared with the general program,showing the advantage of the parallel computing.
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