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Real-time algorithm for changes detection in depth of anesthesia signals

EVOLVING SYSTEMS 2013年第1期4卷 3-12页

作者： Sebastiao, Raquel Silva, Margarida M. Rabico, Rui Gama, Joao Mendonca, Teresa Univ Porto LIAAD INESC TEC Rua Ceuta 118 6 P-4050190 Oporto Portugal Univ Porto Fac Ciencias Dept Matemat P-4169007 Oporto Portugal Uppsala Univ Dept Informat Technol Div Syst & Control S-75105 Uppsala Sweden

This paper presents a real-time algorithm for changes detection in depth of anesthesia signals. A Page-Hinkley test (PHT) with a forgetting mechanism (PHT-FM) was developed. The samples are weighted according to their "age'' so that more importance is given to recent samples. This enables the detection of the changes with less time delay than if no forgetting factor was used. The performance of the PHT-FM was evaluated in a two-fold approach. First, the algorithm was run offline in depth of anesthesia (DoA) signals previously collected during general anesthesia, allowing the adjustment of the forgetting mechanism. Second, the PHT-FM was embedded in a real-time software and its performance was validated online in the surgery room. This was performed by asking the clinician to classify in real-time the changes as true positives, false positives or false negatives. The results show that 69 % of the changes were classified as true positives, 26 % as false positives, and 5 % as false negatives. The true positives were also synchronized with changes in the hypnotic or analgesic rates made by the clinician. The contribution of this work has a high impact in the clinical practice since the PHT-FM alerts the clinician for changes in the anesthetic state of the patient, allowing a more prompt action. The results encourage the inclusion of the proposed PHT-FM in a real-time decision support system for routine use in the clinical practice.

关键词： Adaptive systems Data flow analysis change detection algorithms Dynamic behavior

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Spatio-spectral anomalous change detection in hyperspectral imagery

Spatio-spectral anomalous change detection in hyperspectral ...

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IEEE Global Conference on Signal and Information Processing (GlobalSIP)

作者： James Theiler Los Alamos National Laboratory Los Alamos NM USA

ISBN: (纸本)9781479902460

Because each pixel of a hyperspectral image contains so much information, many (successful) algorithms treat those pixels as independent samples, despite the evident spatial structure in the imagery. One way to exploit this structure is to incorporate spatial processing into pixel-wise anomalous change detection algorithms. But if this is done in the most straightforward way, a contaminated cross-covariance is produced. A spatial processing framework is proposed that avoids this contamination and enhances the performance of anomalous change detection algorithms in hyperspectral imagery.

关键词： Hyperspectral imaging change detection algorithms Smoothing methods Detectors Laboratories

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VisualDiff: Document Image Verification and change detection 12th

VisualDiff: Document Image Verification and Change Detection

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International Conference on Document Analysis and Recognition

作者： Rajiv Jain David Doermann Language and Multimedia Processing Laboratory University of Maryland MD USA

ISBN: (纸本)9781479901937

This paper explores the related problems of verification and change detection in document images. The goal is to determine if two document images differ, and if so, to determine precisely what content may have been added, deleted, or otherwise modified. This problem has many potential applications, especially for important legal documents such as contractual agreements. These agreements are often edited, shared and stored as scanned or hardcopy documents, where small, undetected changes between edits could create major differences in the contractual language and thus have severe repercussions. One can view the problem of change detection as tracing the revision history of a set of documents. Thus, in order to validate the performance of this approach, we created the "Enron Revisions" dataset. This dataset contains realistic revisions obtained from attachments in the Enron Corpus, and a series of before and after snapshots of the revisions in images with varying levels of noise from resolution, binarization, and blur. The approach taken in this paper utilizes the SIFT descriptor to align two document images without the benefit of OCR and once aligned, to compare dense descriptors to determine changes that have occurred within the image. As a baseline, this "VisualDiff" is compared to a UNIX diff-like approach on text extracted through OCR and results demonstrate the effectiveness of this approach.

关键词： Optical character recognition software Feature extraction Image segmentation Accuracy Contracts Robustness change detection algorithms

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A novel architecture and algorithm for web page change detection

A novel architecture and algorithm for web page change detec...

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IEEE International Advance Computing Conference, IACC

作者： Naveen Kumar Varshney Dilip Kumar Sharma Department of CEA GLA University Mathura India

ISBN: (纸本)9781467345279

Internet is used for exchange of information; subsequently people upload and update web pages and information on constant basis. Due to rapid changes in the content of the web pages it has become very necessary to develop a system which can detect recurrent changes in the minimum browsing time. This paper has devised algorithm for structural changes and defines a text code formula to detect the content changes and also represents Architecture for web page change detection system. Analysis and comparison of various web page change detection algorithms based on various parameters to find out strengths and weaknesses for detecting the changes of web pages is also one of the important features highlighted through this paper.

关键词： Web pages change detection algorithms HTML Crawlers Algorithm design and analysis XML Computer architecture

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Improving change detection using Vertical Surface Normal Histograms and Gaussian Mixture Models in structured environments

Improving change detection using Vertical Surface Normal His...

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International Conference on Advanced Robotics (ICAR)

作者： P. Drews L.J. Manso S.C. da Silva Filho P. Núñez Robotics and Artificial Vision Laboratory (RoboLab) University of Extremadura Intelligent Robotics and Automation Group (NAUTEC) Computational Sciences Center Universidade Federal do Rio Grande Brazil

The interest in change detection techniques for autonomous robots has increased considerably during recent years. This is partly due to the fact that changes in robot's working environments are relevant for most tasks and robotics applications. changes or Novelties are usually detected by comparing the current data acquired by the robot with its previous knowledge (a map or any other model of its surroundings). Gaussian Mixture Models (GMM) have been satisfactorily used for detecting changes in 3D point clouds. However, these methods have drawbacks such as a long computational times and strong dependence on the parameters of the algorithms. In structured environments like offices or homes, it is possible to reduce the number of points to be processed by filtering unlikely-to-change regions of the scene. This paper introduces the concept of Vertical Surface Normal Histogram (VSNH). VSNH provides a method for removing from the point clouds acquired those points associated to the main planes: ceiling, walls and floor. Removing these points decreases the size of the problem and improves the segmentation of the environment into Gaussian Mixture Models. The experimental results demonstrate that the proposed method based on GMM and VSNH achieves change detection in structured indoor environments faster and more accurately than previous approaches.

关键词： Vectors Histograms Robots Three-dimensional displays Measurement change detection algorithms Gaussian mixture model

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An enhanced architecture and algorithm for web page change detection

An enhanced architecture and algorithm for web page change d...

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International Conference on Information Systems and Computer Networks (ISCON)

作者： Naveen Kumar Varshney Dilip Kumar Sharma Department of CEA GLA University Mathura India

ISBN: (纸本)9781467359870

Internet has become very effective way for exchange the information widely. Because of fast changes in the information of the web pages, it has become very necessary to develop a system which can detect changes in the minimum browsing time. The web page change detection system provides the mechanism to detect the changes in the web by using crawler and gives the notification to the user to compare the old and modified pages. In this paper a new algorithm is presented for content changes and structural changes and also presents architecture for web page change detection system. It presents the Text Code for content changes to use the position value of every character in the content and also presents the signature value for structural changes.

关键词： Web pages change detection algorithms Crawlers Service-oriented architecture HTML Computer architecture XML

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Data-efficient quickest change detection in distributed and multi-channel systems

Data-efficient quickest change detection in distributed and ...

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International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： Taposh Banerjee Venugopal V. Veeravalli Dept of Electrical and Computer Engineering Coordinated Science Laboratory University of Illinois Urbana-Champaign USA

ISBN: (纸本)9781479903573

A distributed or multi-channel system consisting of multiple sensors is considered. At each sensor a sequence of observations is taken, and at each time step, a summary of available information is sent to a central decision maker, called the fusion center. At some point of time, the distribution of observations at an unknown subset of the sensor nodes changes. The objective is to detect this change as quickly as possible, subject to constraints on the false alarm rate, the cost of observations taken at the sensors and the cost of communication between the sensors and the fusion center. Minimax formulations are proposed for this problem. An algorithm called DE-Censor-Sum is proposed, and is shown to be asymptotically optimal for the proposed formulations, for each possible post-change scenario, as the false alarm rate goes to zero. It is also shown, via numerical studies, that the DE-Censor-Sum algorithm performs significantly better than the approach of fractional sampling, where the cost constraints are met based on the outcome of a sequence of biased coin tosses, independent of the observation process.

关键词： Sensor fusion Delays change detection algorithms Approximation algorithms Sensor systems Random variables

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Long-Term Behavioural change detection through Pervasive Sensing

Long-Term Behavioural Change Detection through Pervasive Sen...

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ACIS International Conference on Software Engineering, Artificial Intelligence, Networking, and Parallel/Distributed Computing (SNPD)

作者： John Kemp Elena Gaura Ramona Rednic James Brusey Coventry University Coventry UK

ISBN: (纸本)9781479903719

The paper proposes an information generation and summarisation algorithm to detect behavioural change in applications such as long-term monitoring of vulnerable people. The algorithm learns the monitored subject's behaviour autonomously post-deployment and provides time-suppressed summaries of the activity types engaged with by the subject over the course of their day to day life. It transmits updates to external observers only when the summary changes by more than a defined threshold. This technique substantially reduces the number of transmission required by a wearable monitoring system, both through summarisation of the raw data into useful information and by preventing transmission of duplicated or predictable data and information. Based on evaluation using simulated activity data, the proposed algorithm results in an average of one transmission per month following an initial convergence period (reaching less than 1 transmission per day after only three days) and detects a change in behaviour after an average of 1.1 days.

关键词： Monitoring Biomedical monitoring Sensors Legged locomotion TV Temperature measurement change detection algorithms

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Hybrid approach for video compression based on scene change detection

Hybrid approach for video compression based on scene change ...

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IEEE International Conference on Signal Processing, Computing and Control (ISPCC)

作者： Ankita P. Chauhan Rohit R. Parmar Shankar K. Parmar Shahida G. Chauhan (GTU): Research Scholar C.E. Dept. Atmiya Institute of tech. and science Rajkot India Asst. Prof. EC Dept. G. H. Patel Engineering College VVNagar India

In order to fulfill the requirement of limited channel bandwidth and of growing video demand like streaming media delivery on internet, and digital library, video compression is necessary. In video compression, temporal redundancy between adjacent frames is removed with block based motion estimation algorithms. Video represents a sequence of frames captured from camera. Scene is a series of consecutive frames captured from narrative point of view. In this paper we present an effective scene change detection method for an uncompressed video. We have divided frames in to blocks and applied a canny edge detector in consecutive frames. Count no of pixels (ones) in each block and compare it with consecutive frames. If scene change happens then number of pixels per block will change, based on that change we can detect scene change in consecutive frame. Here we have presented a hybrid approach, in which we have used scene change detection along with block based motion estimation algorithms (BME) to compress video.

关键词： change detection algorithms Motion estimation PSNR Streaming media Signal processing algorithms Video sequences Histograms

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An efficient geography registration method for InSAR coherent change detection

An efficient geography registration method for InSAR coheren...

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： Wanjun Zhang Hui Zhang Wei Wang Yan Liu Yuanxiang Li Wenxian Yu Department of Electronic Engineering Shanghai Jiao Tong University Shanghai China Beijing Aerospace Automatic Control Institute Beijing China

ISBN: (纸本)9781479911127

In this paper, an efficient geography registration method for INSAR coherent change detection is proposed. In the algorithm, considering Terra-SAR image, firstly we do geography registration on two images by oversampling the geography information in master image, then do coarse and fine registration. In coarse registration, find the range and azimuth shifts by calculating the cross correlation of the intensity sub-images that around ground control points (GCPs). In fine registration, calculate intensity cross correlation of sub-images that around GCPs to find the maximum of correlation map for getting range and azimuth shifts. In coarse and fine registration algorithms, time complexity is determined by the size of sub-image and number of GCPs. The proposed algorithm improves the efficiency while keeping the precision of registration. Experimental results obtained on acquired by Terra-SAR images confirm the effectiveness of the proposed approach.

关键词： Geography Algorithm design and analysis Accuracy Correlation Interpolation Software algorithms change detection algorithms

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