Towards Hybrid Cloud-assisted Crowdsourced Live Streaming: Measurement and Analysis

Crowdsourced Live Streaming (CLS), most notably Twitch.tv, has seen explosive growth in its popularity in the past few years. In such systems, any user can lively broadcast video content of interest to others, e.g., from a game player to many online viewers. To fulfill the demands from both massive and heterogeneous broadcasters and viewers, expensive server clusters have been deployed to provide video ingesting and transcoding services. Despite the existence of highly popular channels, a significant portion of the channels is indeed unpopular. Yet as our measurement shows, these broadcasters are consuming considerable system resources; in particular, 25% (resp. 30%) of bandwidth (resp. computation) resources are used by the broadcasters who do not have any viewers at all. In this paper, we closely examine the challenge of handling unpopular live-broadcasting channels in CLS systems and present a comprehensive solution for service partitioning on hybrid cloud. The trace-driven evaluation shows that our hybrid cloud-assisted design can smartly assign ingesting and transcoding tasks to the elastic cloud virtual machines, providing flexible system deployment cost-effectively

Chinese compounds : the role of morphosyntactic structure in stress assignment in Shanghai chinese and tone sandhi in mandarin chinese

At the interface of morphosyntax and phonology, some phonological behaviors in Chinese languages are sensitive to word domain (stress assignment/stress resolution and tone sandhi). In this thesis, we focus on how morphosyntactic structures can contribute to some phonological behaviors that remain to be puzzles in the Chinese languages. Additionally, a highly-functional morphosyntax-based framework is shown to be realistic to construct a simplified and consistent model in domain construction of T3 tone sandhi in Chinese Mandarin, which has been considered challenging in the literature. Following “Little x heads” theory (Marantz 1995; Marantz 2001) and syntactic incorporated compounding structures (Harley 2009), we use a syntactic multiple-root incorporated structure for Chinese compounding structures to account for the stress assignment and stress resolution (stress clash avoidance) in Shanghai Chinese with revised Phase Impenetrability for Phonology (rPIP) (Embick 2013). Meanwhile, a tentative Concatenation rule (Pak 2008; Chen 2018) after Linearization of Morphological words is proposed to account for the domain construction in T3 tone sandhi in Mandarin Chinese, which refers to specific morphosyntactic information (morphosyntactic locality characteristics and c-command relations). Different from the literature, we add the syntactic multiple-root incorporated structure of Chinese compounding structures into the algorithm of Concatenation rule. This is proved to be essential to successfully construct a unified framework of T3 tone sandhi in Mandarin Chinese both above and below the classical word domain, showing a noteworthy ability to deal with the exceptional situations in Chen (2009), e.g., syntactic words, phonological words and complex predicates. This project supports that morphosyntax-based analysis under syntactic word formation, e.g., Concatenation rules in Distributed Morphology, is a powerful weapon to reveal the processing logic of some controversial phonological rules vaguely floating between the classical lexical and postlexical rules in the literature, e.g., sandhi behaviours. Under the current framework, differently from multimorphemic structures, the monomorphemic structures seem to be opaque in the application process of specific non-cyclic phonological rules. Such opaque monomorphemic structures can be postulated to be a product or outcome of certain phonological rules’ processing economy and efficiency, instead of a true grammatical identity

Design and Implementation of a FPGA and DSP Based MIMO Radar Imaging System

The work presented in this paper is aimed at the implementation of a real-time multiple-input multiple-output (MIMO) imaging radar used for area surveillance. In this radar, the equivalent virtual array method and time-division technique are applied to make 16 virtual elements synthesized from the MIMO antenna array. The chirp signal generater is based on a combination of direct digital synthesizer (DDS) and phase locked loop (PLL). A signal conditioning circuit is used to deal with the coupling effect within the array. The signal processing platform is based on an efficient field programmable gates array (FPGA) and digital signal processor (DSP) pipeline where a robust beamforming imaging algorithm is running on. The radar system was evaluated through a real field experiment. Imaging capability and real-time performance shown in the results demonstrate the practical feasibility of the implementation