李振华  Zhenhua Li
Special Researcher, Assistant Professor & Ph.D. Advisor, School of Software, Tsinghua University
Research Areas: Cloud Computing/Storage/Download, Mobile Internet, and Big Data
Address: East Main Building - Area 11 (School of Software), Room 212, Tsinghua University, Beijing, China
Email:  lizhenhua1983@gmail.com lizhenhua1983@tsinghua.edu.cn

| News | Career | Research Summary | Awards |


(A photo with the Springer editor: Dr. Xiaolan Yao)

My book published by Springer -- Content Distribution for Mobile Internet: A Cloud-based Approach [Pre+ToC+Ch1]

Best Student Paper Award in MMSys'17 -- A Measurement Study of Oculus 360 Degree Video Streaming [ppt][source code]

Spotlight Paper in IEEE Transactions on Cloud Computing, 2015 -- CHARM: A Cost-efficient Multi-cloud Data Hosting Scheme ... [video]

Cover Article in JTST'17 -- Towards A Full-Stack DevOps Environment (PaaS) for Cloud-Hosted Applications [system]

Cover Article in《中国计算机学会通讯》2014年8月刊  -- 云存储价格战背后的科研缺失

My paper in NDSS'17 -- FBS-Radar: Uncovering Fake Base Stations at Scale in the Wild [ppt][presentation][system with 100M users][news report]

Our paper in VLDB'17 -- Resisting Tag Spam by Leveraging Implicit User Behaviors [ppt]

Our paper in ICDCS'17 -- DeltaCFS: Boosting Delta Sync for Cloud Storage Services by Learning from NFS [ppt]

Two papers in INFOCOM'17 -- NFC-enabled AFC Attack [ppt] and CoCloud (Cross-Cloud File Collaboration) [ppt]

My paper in NSDI'16 -- Exploring Cross-Application Cellular Traffic Optimization with Baidu TrafficGuard [ppt][system with 10M users]

Our paper in WWW'16 -- GoCAD: GPU-assisted Online Content Adaptive Display Power Saving for Mobile Devices in Internet Streaming

Two papers in INFOCOM'16 -- LightSync [ppt] and TailCutter [ppt]

Our paper in IMC'16 -- An Empirical Analysis of a Large-scale Mobile Cloud Storage Service [ppt][dataset]

My paper in IMC'15 -- Offline Downloading in China: A Comparative Study [ppt][news report]

My paper in IMC'14 -- Towards Network-level Efficiency for Cloud Storage Services [ppt][dataset][dataset collector]

2017.01 - now       Special Researcher @ School of Software, Tsinghua University, Beijing, China
2015.11 - now       Assistant Professor @ School of Software, Tsinghua University, Beijing, China
2013.7 - 2015.10   PostDoc @ School of Software, Tsinghua University, Advisor: Prof. Yunhao Liu (ACM/IEEE Fellow)
2009.6 - 2013.6   Ph.D. @ School of EECS, Peking University, Beijing, China, Advisor: Prof. Yafei Dai
2011.9 - 2012.9   Joint-Ph.D. @ University of Minnesota, Twin Cities, Advisor: Prof. Zhi-Li Zhang (IEEE Fellow)
2011.9 - 2012.9   Christianity study @ Stadium Village Church, Minneapolis, Tutor: Robert & Joanne Kraftson
2010.6 - 2010.8   Research Intern @ Tencent Research (Shanghai), Advisor: Yan Huang and Gang Liu
2008.6 - 2009.4   Software Engineer @ Marvell Technologies (Shanghai) Co. Ltd
2007.5 - 2007.10 Research Assistant @ Hong Kong Polytechnic University, Advisor: Prof. Jiannong Cao (IEEE Fellow)
2001.9 - 2008.6   Bachelor & Master @ Dept. of Computer, Nanjing University, Advisor: Prof. Guihai Chen

Research Summary:
My research areas include Cloud Computing (like OpenStack and Aliyun), Cloud Storage (like Dropbox, Google Drive, and 360 CloudDisk), Cloud Download (like QQXuanfeng and Xunlei), and Mobile Internet (like Baidu PhoneGuard). The Google Scholar Citations of my publications have reached 674.

Two books: (1) Content Distribution for Mobile Internet: A Cloud-based Approach [Flyer][Pre+ToC+Ch1];   (2) Peer-to-Peer Network: Structure, Application and Design《对等网络:结构、应用与设计》, Google Scholar Citations: 105, Sampling chapters: [Pre][Ch1][Ch2][Ch5][Ch9][Ref]).

50+ papers on recognized conferences (NSDI, NDSS, IMC*3, Middleware, ACM-MM, VLDB, WWW, INFOCOM*4, ICDCS, IPDPS, MMSys, ICPP*4, PAM), workshops (HotStorage, NOSSDAV*2, IWQoS*2), and SCI journals (TPDS*2, TCC, TMC, TOMM*2, COMNET, JPDC, JNCA, JCST, JTST*2).

FBS-Radar: Uncovering Fake Base Stations at Scale in the Wild


✎ Yet another key component of Baidu PhoneGuard, FBS-Radar precisely identifies malicious fake base stations (FBSes) and accurately geolocates FBSes based on crowdsourced data of nearly 100 million users. It protects users from millions of spam and fraud SMS messages per day, and has helped the Ministry of Public Security of China arrest hundreds of FBS operators. Also, we have made a public website that shows the current locations of detected FBSes in real time.

Paper in ISOC NDSS'17.

Cross-App Cellular Traffic Optimization with Baidu TrafficGuard


✎ As a key component of Baidu PhoneGuard, Baidu TrafficGuard is a third-party mobile traffic proxy widely deployed for Android 4.0+ devices in China. It effectively reduces cellular traffic using a network-layer VPN that connects a client-side proxy to a centralized traffic processing cloud. Most importantly, it works transparently across heterogeneous applications, so is not constrained to any specific app.

Paper in USENIX NSDI'16.

Offline Downloading in China: A Comparative Study


✎ Examining two typical implementations of "offline downloading" in China: the  cloud-based approach and the smart AP (access point, also known as home router) based approach. Driven by the measurement findings, we design and implement an intelligent middleware called ODR (Offline Downloading Redirector) to help users achieve the best expected performance.

Paper in ACM IMC'15.

Towards Network-level Efficiency for Cloud Storage Services

✎ Addressing a simple yet critical question: Is the current data sync traffic of cloud storage services efficiently used?        Based on real-world traces and comprehensive experiments, we discover that a considerable portion of the data sync traffic is in a sense wasteful, and can be effectively avoided or significantly reduced via carefully designed data sync mechanisms.

Papers in ACM IMC'14 and CCCF'14 (Cover Article).

Efficient Batched Synchronization for Cloud Storage Services

Acting as a middleware between the user's file storage system and a cloud storage application (e.g. Dropbox), our proposed UDS (i.e. update-batched delayed sync) mechanism properly batches updates from clients to minimize the "traffic overuse problem", while preserving the rapid file synchronization that users expect from cloud storage services.

Paper in ACM/IFIP/USENIX Middleware'13.

Cloud Bandwidth Scheduler


Efficiently scheduling cloud bandwidth into end host peers to maximize the bandwidth multiplier effect with a fine-grained model and fast-convergent iterative algorithm ("FIFA"). This work is simulated on the Xuanfeng system trace and is implemented on the CoolFish VoD streaming prototype.

Paper in IEEE/ACM IWQoS'12.

Cloud Transcoder

✎ Bridging the format and resolution gap between Internet videos and mobile devices by utilizing an intermediate cloud platform. The user only sends his video request to Cloud Transcoder which does everything else: download, transcode, cache, transfer back, and so forth.

Paper in SIGMM NOSSDAV'12.

 ★ Cloud Download  (or says Offline Download)

Achieving high-quality content distribution (especially for unpopular videos) by using cloud utilities to guarantee the data health and enhance the data transfer rate. Please try the large-scale  Xuanfeng Cloud Download system!

Papers in ACM-MM'11 and JCST'15.

Cloud Tracker  (or says Open-P2SP content distribution)


✎ Dynamically tracking and integrating various third-party servers, contents and data transfer protocols all over the Internet into a large, open and federated P2SP (peer-to-server/peer) platform, so as to accelerate the content distribution from servers to clients and among peer swarms. It also facilitates load-balancing among the involved servers. Please try the large-scale  Xuanfeng system!

Papers in ACM-MM'11 and TPDS'13.

P2P Media Streaming Optimization


Optimizing several critical performance metrics (e.g., playback continuity, startup latency, media source switching time, and overlay resilience) of P2P video streaming.

Papers in IPDPS'08, ICPP'08, 《软件学报》'08, ICPP'09, JPDC'10, ICPADS'10, ICCCN'11, TPDS'11TOMM'12, etc.


2017 Best Student Paper Award of ACM Multimedia Systems Conference
2017 Cover Article of JTST February Issue(《 清华学报(英文版)》2月刊封面文章)
2017 全国高校云计算应用创新大赛(创意赛)二等奖,指导教师
2016 全国高校云计算应用创新大赛(创意赛)二等奖,指导教师
2015 Spotlight Paper of IEEE Transactions on Cloud Computing (Jul-Sep Issue)
2015  1st Prize of Natural Sciences, Ministry of Education(教育部自然科学奖一等奖)
2015 CAAI PhD Thesis Award(中国人工智能学会优秀博士学位论文奖)
2014 Cover Article of CCCF August Issue(《中国计算机学会通讯》8月刊封面文章)
2009 中国大学出版社图书奖首届优秀学术著作一等奖
2009, 2010, 2011, 2012 1st, 2nd, 3rd & 4th President's PhD Scholarships of Peking University(北京大学第1/2/3/4届博士生校长奖学金¥36000*3.5
2011-2012 Scholarship for Studying Overseas from China Scholarship Council(国家公派留学奖学金$1600*12
2012 Academic Innovation Award of Peking University(北京大学“学术创新奖”)
2012 Ten Academic Elites of EECS, Peking University(北京大学信息学院“学术十杰”)
2009 Outstanding Master's Degree Thesis of Jiangsu Province, 2009(江苏省2009年度优秀硕士学位论文奖)
2008, 2010 Tung OOCL Scholarship(董氏东方奖学金 )¥5000*2
2008 HP Excellent Student Scholarship(惠普奖学金)¥5000
2007 Nanrui Company Scholarship(南瑞继保奖学金 )¥4000
2003, 2004 National Scholarship for Chinese Undergraduates(本科生国家奖学金 )¥8600 + 10600
2002, 2004 People's Scholarship of Nanjing University(南京大学人民奖学金 )¥1500 + 2500
2003 National English Contest of College Students, the second prize(全国大学生英语竞赛二等奖)

桃花庵歌 (明)唐寅

桃花坞里桃花庵,桃花庵下桃花仙。  桃花仙人种桃树,又摘桃花卖酒钱。

酒醒只在花前坐,酒醉还来花下眠。  半醒半醉日复日,花落花开年复年。

但愿老死花酒间,不愿鞠躬车马前。  车尘马足富者趣,酒盏花枝贫者缘。

若将富贵比贫贱,一在平地一在天。  若将贫贱比车马,他得驱驰我得闲。

世人笑我太疯癫,我笑他人看不穿。  不见五陵豪杰墓,无花无酒锄作田。


by 洛兵

晚钟敲响从城市那边  飞来宁静的翅膀
有家的人请回你们的家  没家的人请走进那夕阳

晚钟敲响从夕阳的眼中  流出宁静的凄凉
爱我的人请过来一起唱  恨我的人请躲开那月光

晚钟敲响从新月的梦里  落下宁静的忧伤
生者依旧习惯地擦去泪水  逝者已矣请返回你们的天堂

晚钟敲响从天堂上面  传来星空的回荡
醒来的人请守好你们的梦想  沉睡的人请把一切遗忘