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The use of real-time applications over the Internet is a challenging problem that the QoS epoch attempted to solve by proposing the DiffServ architecture. Today, the only existing service provided by the Internet is still best-effort. As a result, multimedia applications often perform on top of a transport layer that provides a variable sending rate. In an obvious manner, this variable sending rate is an issue for these applications with strong delay constraint. In a real-time context wherearXiv:1207.2863v1 fatcat:26gfj6oimzefddqxcod6tifm54
more »... ansmission can not be used to ensure reliability, video quality suffers from any packet losses. In this position paper, we discuss this problem and motivate why we want to bring out a certain class of erasure coding scheme inside multimedia congestion control protocols such as TFRC.
This paper introduces a redundancy adaptation algorithm for an on-the-fly erasure network coding scheme called Tetrys in the context of real-time video transmission. The algorithm exploits the relationship between the redundancy ratio used by Tetrys and the gain or loss in encoding bit rate from changing a video quality parameter called the Quantization Parameter (QP). Our evaluations show that with equal or less bandwidth occupation, the video protected by Tetrys with redundancy adaptationarXiv:1304.5068v1 fatcat:ht23oie2tzbhtbthy6vqzdlvkq
more »... rithm obtains a PSNR gain up to or more 4 dB compared to the video without Tetrys protection. We demonstrate that the Tetrys redundancy adaptation algorithm performs well with the variations of both loss pattern and delay induced by the networks. We also show that Tetrys with the redundancy adaptation algorithm outperforms FEC with and without redundancy adaptation.
Most of multipath multimedia streaming proposals use Forward Error Correction (FEC) approach to protect from packet losses. However, FEC does not sustain well burst of losses even when packets from a given FEC block are spread over multiple paths. In this article, we propose an online multipath convolutional coding for real-time multipath streaming based on an on-the-fly coding scheme called Tetrys. We evaluate the benefits brought out by this coding scheme inside an existing FEC multipath loaddoi:10.1109/pv.2012.6229754 dblp:conf/pv/ThaiLL12 fatcat:ywozrqqik5ex5ahh3ovaeh5c4e
more »... splitting proposal known as Encoded Multipath Streaming (EMS). We demonstrate that Tetrys consistently outperforms FEC in both uniform and burst losses with EMS scheme. We also propose a modification of the standard EMS algorithm that greatly improves the performance in terms of packet recovery. Finally, we analyze different spreading policies of the Tetrys redundancy traffic between available paths and observe that the longer propagation delay path should be preferably used to carry repair packets.
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LOÀI VE SẦU MỚI THUỘC GIỐNG CHREMISTICA STAL, 1870 (HEMIPTERA: CICADIDAE) Ở VIỆT NAM Phạm Hồng Thái 1 , Jérôme Constant 2 1 Viện Sinh thái và Tài nguyên sinh vật, Viện Hàn lâm KH & CN Việt Nam 2 Viện Khoa ... Từ khóa: Phân bộ ve sầu và rầy, ve sầu, Chremistica, hình thái học, loài mới. ...doi:10.15625/0866-7160/v35n1.2935 fatcat:xa3rnxosind2djusjx6iocxi2q
Most optimal routing problems focus on minimizing travel time or distance traveled. Oftentimes, a more useful objective is to maximize the probability of on-time arrival, which requires statistical distributions of travel times, rather than just mean values. We propose a method to estimate travel time distributions on large-scale road networks, using probe vehicle data collected from GPS. We present a framework that works with large input of data, and scales linearly with the size of thearXiv:1302.6617v1 fatcat:rfcy73j7pbgxdgxcmsovj7v7vu
more »... . Leveraging the planar topology of the graph, the method computes efficiently the time correlations between neighboring streets. First, raw probe vehicle traces are compressed into pairs of travel times and number of stops for each traversed road segment using a 'stop-and-go' algorithm developed for this work. The compressed data is then used as input for training a path travel time model, which couples a Markov model along with a Gaussian Markov random field. Finally, scalable inference algorithms are developed for obtaining path travel time distributions from the composite MM-GMRF model. We illustrate the accuracy and scalability of our model on a 505,000 road link network spanning the San Francisco Bay Area.
Proceedings of the 2011 American Control Conference
In this article, a method for assimilating data into the shallow water equations when some of the model parameters are unknown is presented. The one dimensional Saint-Venant equations are used as a model of water flow in open channels. Using these equations, a nonlinear statespace model is obtained. Lagrangian measurements of the flow velocity field are used as observations or measurements. These measurements may be obtained from a group of drifters equipped with GPS receivers and communicationdoi:10.1109/acc.2011.5991496 fatcat:dlm5xuaotjcq5fclqjbtdaibwa
more »... capabilities which move with the flow and report their position at every time step. Using the derived state-space model, the extended Kalman filter is used to estimate the state and the unknown model parameters given the latest measurements. The performance of the method is evaluated using data collected from an experiment performed at the USDA-ARS Hydraulic Engineering Research Unit (HERU) in Stillwater, Oklahoma in November 2009. M. Rafiee is a Ph.D. candidate in the
The clavatus group of Pyrops Spinola, 1839 is reviewed and redefined. The new combination Pyrops atroalbus (Distant, 1918) comb. nov. is proposed, as atroalbus is reinstated as a full species from status of subspecies of Pyrops watanabei (Matsumura, 1913). Pyrops nigripennis (Chou & Wang, 1985) and Pyrops clavatus mizunumai (Sato & Nagai, 1994) are proposed as junior synonyms of P. clavatus (Westwood, 1839). The Philippine species P. polillensis (Baker, 1925) is removed from the group and notdoi:10.5852/ejt.2017.305 fatcat:4uj3bfx5bzcwdiqpu2rbtc4day
more »... tributed to any of the currently defined species groups. Hence, the clavatus group is restricted to continental Southeast Asia and Taiwan and contains three species: P. atroalbus comb. nov., P. clavatus and P. watanabei. A key to the species of the group and illustrations of the male genitalia are provided. The intraspecific colour variation in the group is discussed and illustrated. The genus Pyrops is removed from the subfamily Fulgorinae and not attributed to any of the currently defined subfamilies of Fulgoridae.
doi:10.1109/pv.2013.6691457 dblp:conf/pv/ThaiCKFLL13 fatcat:uac6iv2afnaupksjaxdyierts4
We present an approach to inform decisions about nonresponse follow-up sampling. The basic idea is (i) to create completed samples by imputing nonrespondents' data under various assumptions about the nonresponse mechanisms, (ii) take hypothetical samples of varying sizes from the completed samples, and (iii) compute and compare measures of accuracy and cost for different proposed sample sizes. As part of the methodology, we present a new approach for generating imputations for multivariatedoi:10.1515/jos-2017-0028 fatcat:z674hjlxvzfq5g5b3xmfiyttfq
more »... nuous data with nonignorable unit nonresponse. We fit mixtures of multivariate normal distributions to the respondents' data, and adjust the probabilities of the mixture components to generate nonrespondents' distributions with desired features. We illustrate the approaches using data from the 2007 U.S. Census of Manufactures.
Materials and Methods Participants for this study were drawn from a cohort of Thai military recruits. ... and HLA B*46 is commonly HLA B*46:01. 24 The latter is part of a common Thai haplotype consisting of A*02:07-Cw*01-B*46:01-DRB1*09-DQB1*03:03. ...doi:10.1089/aid.2015.0120 pmid:26383907 pmcid:PMC4692108 fatcat:amwbzuaubffhzbnh5lpdkvtvou
Tran Thai et al. / Signal Processing: Image Communication 29 (2014) 449-461 In this paper, the encoded symbols are considered as the information and repair packets which are specified by n. ...doi:10.1016/j.image.2014.02.003 fatcat:4pa3fz5m2vap7aw3dvu47yasi4
Cyclodipeptide synthases form cyclodipeptides from two aminoacyl transfer RNAs. They use a ping-pong mechanism that begins with transfer of the aminoacyl moiety of the first aminoacyl tRNA onto a conserved serine, yielding an aminoacyl enzyme. Combining X-ray crystallography, site-directed mutagenesis and affinity labelling of the cyclodipeptide synthase AlbC, we demonstrate that the covalent intermediate reacts with the aminoacyl moiety of the second aminoacyl tRNA, forming a dipeptidyldoi:10.1038/ncomms6141 pmid:25284085 fatcat:gu4wqyywkzgq5lh45tl4kw7enq
more »... and identify the aminoacyl-binding sites of the aminoacyl tRNAs.
2013 American Control Conference
This article investigates the problem of estimating the state of discretized hyperbolic scalar partial differential equations. It uses a Godunov scheme to discretize the socalled Lighthill-Whitham-Richards equation with a triangular flux function, and proves that the resulting nonlinear dynamical system can be decomposed in a piecewise affine manner. Using this explicit representation, the system is written as a switching dynamical system (hybrid system), with an exponential number of modes.doi:10.1109/acc.2013.6580198 fatcat:4hkve7p7oveyhgjvuh3p6aokye
more »... estimation problem is posed using Kalman filtering in each of the linear mode, and the approach becomes computationally tractable by tracking the mode evolution as the estimation is performed at each time step. Numerical results are presented using the Mobile Millennium data set, and compared to results obtained using ensemble Kalman filtering, which is used for estimation in traffic monitoring.
We present an experimental investigation of the formation of shear bands in a granular sample submitted to a biaxial test. Our principal result is the direct observation of the bifurcation at the origin of the localization process in the material. At the bifurcation, the shear band is spatially extended: we observe a breaking of symmetry without any sudden localization of the deformation in a narrow band. Our work thus allows to clearly distinguish different phenomena: bifurcation which is adoi:10.1051/epjconf/201714010001 fatcat:yguwk7lonfgmvmf2s7azdovxry
more »... ctual event which occurs before the peak, localization which is a process that covers a range of deformation of several percents during which the peak occurs and finally stationary shear bands which are well-defined permanent structures that can be observed at the end of the localization process, after the peak.
A new convex optimization framework is developed for the route flow estimation problem from the fusion of vehicle count and cellular network data. The issue of highly underdetermined link flow based methods in transportation networks is investigated, then solved using the proposed concept of cellpaths for cellular network data. With this data-driven approach, our proposed approach is versatile: it is compatible with other data sources, and it is model agnostic and thus compatible with userdoi:10.1016/j.trpro.2015.06.012 fatcat:jwaefqiiordntpnbsjm4ccqvxm
more »... ibrium, systemoptimum, Stackelberg concepts, and other models. Using a dimensionality reduction scheme, we design a projected gradient algorithm suitable for the proposed route flow estimation problem. The algorithm solves a block isotonic regression problem in the projection step in linear time. The accuracy, computational efficiency, and versatility of the proposed approach are validated on the I-210 corridor near Los Angeles, where we achieve 90% route flow accuracy with 1033 traffic sensors and 1000 cellular towers covering a large network of highways and arterials with more than 20,000 links. In contrast to long-term land use planning applications, we demonstrate the first system to our knowledge that can produce route-level flow estimates suitable for short time horizon prediction and control applications in traffic management. Our system is open source and available for validation and extension.
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