MSPlayer: Multi-Source and multi-Path LeverAged YoutubER

Online video streaming through mobile devices has become extremely popular nowadays. YouTube, for example, reported that the percentage of its traffic streaming to mobile devices has soared from 6% to more than 40% over the past two years. Moreover, people are constantly seeking to stream high quality video for better experience while often suffering from limited bandwidth. Thanks to the rapid deployment of content delivery networks (CDNs), popular videos are now replicated at different sites, and users can stream videos from close-by locations with low latencies. As mobile devices nowadays are equipped with multiple wireless interfaces (e.g., WiFi and 3G/4G), aggregating bandwidth for high definition video streaming has become possible. We propose a client-based video streaming solution, MSPlayer, that takes advantage of multiple video sources as well as multiple network paths through different interfaces. MSPlayer reduces start-up latency and provides high quality video streaming and robust data transport in mobile scenarios. We experimentally demonstrate our solution on a testbed and through the YouTube video service.Comment: accepted to ACM CoNEXT'1

Malakoplakia of Ipsilateral Kidney, Ureter and Bladder

AbstractMalakoplakia is a rare chronic inflammatory disease of the urinary tract, usually caused by Escherichia coli infection. We report a 75-year-old woman who presented with hydronephrosis and pyuria associated with E. coli infection. Abdominal computed tomography revealed several renal stones and severe hydronephrosis of the right kidney. Biopsies of the urinary bladder and ureter revealed erosion and acute inflammation. According to a culture sensitivity test, antimicrobial treatment was prescribed with cephradine 500 mg every 6 hours and amoxicillin-clavulanic acid 100 mg twice daily for 1 month. Because of the advanced hydronephrosis with impaired renal function, a right nephroureterectomy was performed. Malakoplakia of the right kidney, ureter and urinary bladder was confirmed by pathology with Michaelis-Gutmann bodies present in the surgical specimen. The patient tolerated the operation well. She regained a good health status and was regularly followed-up in the urologic department

An image retrieval system based on the feature of color differences among the edges of objects

This paper focuses on color differences among the edges of objects in an image. The variations of colors among the objects in the image can depict the directions and simple geometric shapes of most objects in the image regardless of the influence from the shift variant of objects and scale variant in the image. Based on the feature of color differences among the edges of objects, this paper constructs an image retrieval system. Experimental results show that this system can effectively and quickly deliver the desired database images to the usersFacultad de Informátic

Physiology and Pathophysiology of CLC-1: Mechanisms of a Chloride Channel Disease, Myotonia

The CLC-1 chloride channel, a member of the CLC-channel/transporter family, plays important roles for the physiological functions of skeletal muscles. The opening of this chloride channel is voltage dependent and is also regulated by protons and chloride ions. Mutations of the gene encoding CLC-1 result in a genetic disease, myotonia congenita, which can be inherited as an autosmal dominant (Thomsen type) or an autosomal recessive (Becker type) pattern. These mutations are scattered throughout the entire protein sequence, and no clear relationship exists between the inheritance pattern of the mutation and the location of the mutation in the channel protein. The inheritance pattern of some but not all myotonia mutants can be explained by a working hypothesis that these mutations may exert a “dominant negative” effect on the gating function of the channel. However, other mutations may be due to different pathophysiological mechanisms, such as the defect of protein trafficking to membranes. Thus, the underlying mechanisms of myotonia are likely to be quite diverse, and elucidating the pathophysiology of myotonia mutations will require the understanding of multiple molecular/cellular mechanisms of CLC-1 channels in skeletal muscles, including molecular operation, protein synthesis, and membrane trafficking mechanisms

An image retrieval system based on the feature of color differences among the edges of objects

This paper focuses on color differences among the edges of objects in an image. The variations of colors among the objects in the image can depict the directions and simple geometric shapes of most objects in the image regardless of the influence from the shift variant of objects and scale variant in the image. Based on the feature of color differences among the edges of objects, this paper constructs an image retrieval system. Experimental results show that this system can effectively and quickly deliver the desired database images to the usersFacultad de Informátic

Robust Mobile Data Transport: Modeling, Measurements, and Implementation

Advances in wireless technologies and the pervasive influence of multi-homed devices have significantly changed the way people use the Internet. These changes of user behavior and the evolution of multi-homing technologies have brought a huge impact to today\u27s network study and provided new opportunities to improve mobile data transport. In this thesis, we investigate challenges related to human mobility, with emphases on network performance at both system level and user level. More specifically, we seek to answer the following two questions: 1) How to model user mobility in the networks and use the model for network provisioning? 2) Is it possible to utilize network diversity to provide robust data transport in wireless environments? We first study user mobility in a large scale wireless network. We propose a mixed queueing model of mobility and show that this model can accurately predict both system-level and user-level performance metrics. Furthermore, we demonstrate how this model can be used for network dimensioning. Secondly, with the increasing demand of multi-homed devices that interact with heterogeneous networks such as WiFi and cellular 3G/4G, we explore how to leverage this path diversity to assist data transport. We investigate the technique of multi-path TCP (MPTCP) and evaluate how MPTCP performs in the wild through extensive measurements in various wireless environments using WiFi and cellular 3G/4G simultaneously. We study the download latencies of MPTCP when using different congestion controllers and number of paths under various traffic loads and over different cellular carriers. We further study the impact of short flows on MPTCP by modeling MPTCP\u27s delay startup mechanism of additional flows. As flow sizes increase, we observe that traffic in cellular networks exhibits large and varying packet round trip times, called bufferbloat. We analyze the phenomenon of bufferbloat, and illustrate how bufferbloat can result in numerous MPTCP performance issues. We provide an effective solution to mitigate the performance degradation. Finally, as popular content is replicated at multiple locations, we develop mechanisms that take advantage of this source diversity along with path diversity to provide robust mobile data transport. We demonstrate this in the context of online video streaming, because of its popularity and significant contribution to Internet traffic. We therefore propose MSPlayer, a client-based solution for online video streaming that adjusts network traffic distribution over each path to network dynamics. MSPlayer bypasses the deployment limitations of MPTCP while maintaining the benefits of path diversity, and exploits different content sources simultaneously. MSPlayer can significantly reduce video start-up latency and quickly refill playout buffer for high quality video streaming. We evaluate MSPlayer\u27s performance through YouTube