469745
An opportunistic video scheduling algorithm over shared wireless downlink
This paper presents a novel video scheduling algorithm for streaming MPEG video over multi-user shared wireless link, in which video sessions are scheduled based on both location-dependent channel condition and instantaneous frame delay. This algorithm also employs a pro-active frame discard mechanism to discard potential problematic frames. The numerical results show that the proposed algorithm is able to significantly improve link throughput and guarantee long-term fairness.
34513226
Incorporating priority scheme in IPv6 over ATM networks
An effective method to support multiple QoS classes in IPv6 over ATM networks is implemented by mapping of the priority field in IPv6 to the ATM cell. Such a scheme might not be necessary for simple congestion control in a network of equal capacity links; however, it might be important for multicasting to destinations reachable through a very diverse capacity network. When network congestion occurs, the cell loss requirements for different services can be satisfied by selectively discarding low priority cells. The results obtained show how the QoS can be affected by this field and how priority can be given for more important traffic in times of network congestion.
46136838
IPv6 traffic with multi-class QoS in VPN
Abstract This paper focuses on the modeling and performance analysis for IPv6 traffic with multi-class QoS in virtual private networks (VPNs). The multi-class QoS is implemented on differentiated service basis using priority scheme of 4 bits defined in the packet header of IPv6. A VPN-enabled IP router is modeled as a tandem queuing system in which each output link consists of two parallel priority output queues. The high-priority queue is used to carry the delay sensitive traffic while the low-priority queue is used to carry the delay insensitive traffic. On the other hand, multiple thresholds are implemented in each queue, respectively, for packet loss priority control. The performance analysis is done using fluid flow techniques. The numerical results obtained from the analysis show that the differentiated service based on the priority schemes defined in IPv6 is able to effectively satisfy the multi-class QoS requirement for supporting multimedia services in VPN. The performance trade-off between the delay sensitive traffic and delay insensitive traffic in terms of traffic throughput, packet loss probability and end-to-end delay in VPN networks is presented.
205935860
An ATM cross-connecting node using optical CDMA
An asynchronous transfer mode (ATM) cross-connecting node is proposed based on direct sequence optical code division multiple access (DS-OCDMA). No buffering is necessary to facilitate switching because code conversion is instead emulating the switching function. The switch is also capable of limited dynamic bandwidth allocation. It is free from timing jitters and switching delay is significantly reduced. The switch provides a new approach to asynchronous cross-connection in the ATM core network, locally or over a wider area. The performance with the new proposed switch is evaluated using prime and modified prime OCDMA codes.
35154579
Incorporating priority scheme in IPv6 over ATM networks
An effective approach to support multiple QoS classes in IPv6 running over ATM networks is implemented by mapping the priority field of IPv6 into the ATM format. Such a scheme might not be necessary for simple congestion control in a network of equal capacity links, however, it might be important for multicasting to destinations reachable through a very diverse capacity network. When network congestion occurs, the cell loss requirements for different services can be satisfied by selectively discarding low priority cells. As the multi-priority scheme used in IPv6 is a ''differentiated service'' mechanism to enhance the QoS by best effort, its performance is certainly affected by the background traffic when these multi-priority traffic are multiplexed at the ATM level. This paper focuses on the performance with multi-priority scheme under different traffic conditions to determine the loss characteristics. The expected results are how QoS is affected and how priority can be given for more important traffic in the case of congested network.
205934323
Effect of delay and delay jitter on voice/video over IP
Internet, especially in the situation when network has bursty background traffic. However, it is usually difficult to evaluate the statistics of delay and delay jitter in such bursty traffic environment due to their transient queuing nature. This paper focuses on the performance behavior of delay and delay jitter at IP packet level and also their effects on the performance of voice and video packet streams when they are multiplexed with bursty background traffic in IP routers. The performance analysis of delay and delay jitter is done using the transient queuing solution technique. The numerical results are presented in terms of probability density functions (pdfs) of delay and delay jitter, which focus on their effects on speech samples and video frames.
140083992
Boosting image classification with LDA-based feature combination for digital photograph management
Image classification is of great importance for digital photograph management. In this paper we propose a general statistical learning method based on boosting algorithm to perform image classification for photograph annotation and management. The proposed method employs both features extracted from image content (i.e., color moment and edge direction histogram) and features from the EXIF metadata recorded by digital cameras. To fully utilize potential feature correlations and improve the classification accuracy, feature combination is needed. We incorporate linear discriminant analysis (LDA) algorithm to implement linear combinations between selected features and generate new combined features. The combined features are used along with the original features in boosting algorithm for improving classification performance. To make the proposed learning algorithm more efficient, we present two heuristics for selective feature combinations, which can significantly reduce training computation without losing performance. The proposed image classification method has several advantages: small model size, computational efficiency and improved classification performance based on LDA feature combination.
52862068
Robust face alignment based on local texture classifiers
We propose a robust face alignment algorithm with a novel discriminative local texture model. Different from the conventional descriptive PCA local texture model in ASM, classifiers using LUT-type Haar-like features are trained from a large data set as local texture model. The strong discriminative power of the classifier greatly improves the accuracy and robustness of local searching on faces with expression variation and ambiguous contours. A Bayesian framework is configured for shape parameter optimization and the algorithm is implemented in a hierarchical structure for efficiency. Extensive experiments are reported to show its accuracy and robustness.
35345915
Ranking Component Retrieval Results by Leveraging User History Information
62394
Support vector machine learning for image retrieval
A novel method of relevance feedback is presented based on support vector machine learning in the content-based image retrieval system. A SVM classifier can be learned from training data of relevance images and irrelevance images marked by users. Using the classifier, the system can retrieve more images relevant to the query in the database efficiently. Experiments were carried out on a large-size database of 9918 images. It shows that the interactive learning and retrieval process can find correct images increasingly. It also shows the generalization ability of SVM under the condition of limited training samples.
12511043
Real-time lossless compression of mosaic video sequences
This paper presents a simple, fast coding technique for lossless compression of mosaic video data. The design of a video codec needs to strike a balance between the compression performance and the codec throughput. Aiming to make the encoding throughput high enough for real-time lossless video compression, we propose a hybrid scheme of inter and intraframe coding. Interframe predictive coding is invoked only when the motion between adjacent frames is modest and a simple motion compensation operation can significantly improve the compression performance. Otherwise, still frame compression is performed to keep the complexity low. Experimental results show that the proposed scheme achieves higher lossless video compression ratio than existing methods such as JPEG-LS and JPEG-2000.