Current Issue : July - September Volume : 2014 Issue Number : 3 Articles : 4 Articles
The QoS offered by the IEEE 802.11e reference scheduler is satisfactory in the case of Constant Bit Rate traffic streams, but\nnot yet in the case of Variable Bit Rate traffic streams, whose variations stress its scheduling behavior. Despite the numerous\nproposed alternative schedulers with QoS, multimedia applications are looking for refined methods suitable to ensure service\ndifferentiation and dynamic update of protocol parameters. In this paper a scheduling algorithm, Unused Time Shifting Scheduler\n(UTSS), is deeply analyzed. It is designed to cooperate with a HCCA centralized real-time scheduler through the integration of\na bandwidth reclaiming scheme, suitable to recover nonexhausted transmission time and assign that to the next polled stations.\nUTSS dynamically computes with an O(1) complexity transmission time providing an instantaneous resource overprovisioning.\nThe theoretical analysis and the simulation results highlight that this injection of resources does not affect the admission control\nnor the centralized scheduler but is suitable to improve the performance of the centralized scheduler in terms of mean access delay,\ntransmission queues length, bursts of traffic management, and packets drop rate. These positive effects are more relevant for highly\nvariable bit rate traffic....
Despite the rising commodification of heritage sites and practices, children engagement in their own cultures remains incredibly\nlow, greatly endangering the future preservation of nations� unique nonrenewable resource. Considering children�s very early\nengagement with cultural attitudes and identities, it is increasingly critical to develop a deeply rooted culture of responsibility and\nconservation from the earliest years, ensuring that children naturally feel invested in their surroundings. Unfortunately, heritage\neducation remains largely undervalued, with most efforts relying on in-person experiences in formal cultural institutions. This\npaper thus aims to explore how heritage education can be redefined, using some of the most innovative virtual imaging and\nartificial reality technologies to at once expand access and engagement with one�s own history.Though there have been introductory\napplications of this edutainment multimedia technology, it will require a multidisciplinary team to create heritage programming\nwhich is as entertaining as it is intellectually challenging for young children.With the rich resources of 3D imaging and interactive\nprogramming already at our disposal, we are well-equipped to do so, given a coordinated effort....
In the process of the H.264 video coding, special attention should be paid to the subjective quality of the image. This paper applies\nthe structural similarity (SSIM) based subjective evaluation to the rate control in the H.264 coding and proposes to combine the\nSSIM and the mean absolute difference (MAD) to perform the macroblock layer bit allocation instead of the MAD. Experimental\nresults show that the proposed method is correlating better with the human visual system and thus achieves better subjective image\nquality....
Images may be corrupted by salt and pepper impulse noise due to noisy sensors or channel transmission errors. A denoising\nmethod by detecting noise candidates and enforcing image sparsity with a patch-based sparse representation is proposed. First,\nnoise candidates are detected and an initial guide image is obtained via an adaptive median filtering; second, a patch-based sparse\nrepresentation is learnt from this guide image; third, a weighted l1-l1 regularization method is proposed to penalize the noise\ncandidates heavier than the rest of pixels. An alternating direction minimization algorithm is derived to solve the regularization\nmodel. Experiments are conducted for 30%~90% impulse noise levels, and the simulation results demonstrate that the proposed\nmethod outperforms total variation andWavelet in terms of preserving edges and structural similarity to the noise-free images....
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