EDUCATION

EXPERIENCE

SKILLS

Coding Languages and Debugging
C, Javascript, Golang, Java, Python, C#, C++, Haskell, Asm-x86

Algorithm and Data Structure

Cloud Computing
OpenStack, AWS

Distributed and Parallel Computing Systems
MapReduce, Apache Spark, CUDA

Web Development
HTML, CSS, Bootstrap, Nginx, ExpressJS, Django, ASP.NET

Database
MySQL, Apache HBase, MongoDB

PROJECTS

CloudFS is a FUSE-based filesystem on Linux to store files in hybrid mode: small files and metadata are stored on local SSD, while big files are stored on Amazon S3 to utilize both the speed of SSD and high capacity of cloud storage. The variations in data locations and access patterns are transparent to user by hidding behind POSIX filesystem functions.

It has full support for deduplication by rabin-fingerprint-anchored chunking, coarse-grained (chunks) local caching, instant snapshotting (and COW), online backup and recovery.

Modules and
data accesses

We design H2Cloud, a cloud storage system consisting of H2Layer and OpenStack Swift to maintain the users' filesystem on the single object storage cloud. By the means, system complexity is greatly reduced compared to dual-cloud solutions like Dropbox; while filesystem operation is expedited by a large scale compared to consistent hashing solutions like Amazon S3.

Dual-cloud Solutions
like Dropbox

Consistent Hashing Solutions
like Amazon S3

Comparison on Performance of
MOVE and DELETE

Filesystem Structure in H2Cloud

The Sound of Tsinghua is an interaction platform based on Wechat to offer ticket booking and information service to all the stuff at Tsinghua University.

Since release in Dec.2014, it has got more than 21,000 subscribers (up to Oct.2015). Also, it has distributed tickets for dozens of activities, including popular ones with more than 2,000 participants and 3,000 subscribers requiring tickets concurrently.

UI for
Administration console

Subscriber increase
statistics diagram

Wechat
UI

Activity
info UI

Readers per broadcast
statistics diagram

Based on UNIX v6 kernel, the GUI module implements a graphic card driver, a complete GUI framework (including kernel model and syscalls) and a set of executable GUI programs. The architecture is originally designed by Leiyu.

Architecture

Core datastructure
Visible Tree

GUI
Start Screen

GUI
Explorer

Multi-process
support

CoDrawboard is a highly fault tolerant distributed realtime collaborative drawboard, which allows all the users connecting to the same arbitrarily big backend cluster to share the same canvas.

Thanks to PAXOS, the system functions well as long as quorum (more than half) backends are alive. With live-switch and offline mode, the users may not even feel the failure no matter how many servers on the backend crush.

Refer to README for more info.

Connecting
to cluster

UI -
the drawboard

Backend
failure tolerence

Television Audience Analytics Web Service performs realtime analytics on ~1 billion pieces of system logging in the TV sets in Tianjin Province, China. Backed by Apache Spark and Hadoop Distributed Filesystem, the system is capable of handling customized analytics requests about television audience in seconds.

DEMO
Active days distribution

DEMO
Total watchtime analytics

DEMO
Tuning times distribution

Js2Jv consists of an interpreter implemented in Java & ANTLR to translate Javascript into Java and a runtime to execute it in JVM. Advanced features of Javascript such as closure, asynchronous model and hashmap-based object are supported.

Overall
working procedure

Js types
implementation

Asynchronous model
implementation

Original vs
generated TAC

Rousey is a wristband-like device which takes advantage of infrared camera and recognizes gestures to provide an invisible mouse as an input to PC/Tablet/Ultrabook to combine accuracy with portability. It is highly commented by engineers from Intel, winning Excellent Works in Intel Mobile Computing Innovation Contest.

Design

Academic
poster

DEMO

Image capture & processing

The network is an ad-hoc cluster consisting of self-made nodes to collect data from distributed sensors for analysis. To ensure both quality and quantity, a protocol based on ZigBee is designed for distributed data analysis and reliable data transfer.

Platform:
TelosB

Distributed data
analysis process

Visualized
data

Smartdental is a product developed by School of Software, Tsinghua University and School of Stomatology, Peking University. Annotation module is an addition supporting manuscript annotations on pathological pictures. The module is checked in to the original version and under review for release.

Smartdental:
original version

Working
process

UI:
Editing annotation

UI:
SYNC to client

The system works on a paper database to recommend contents to potential readers. By using hybrid algorithm (combining collaborative filtering and Tf-Idf) and dynamic estimation, the recommendation accuracy is estimated to be more than 71% (AP@5). A technical report describing the algorithm in detail is provided.

Algorithm
sketch

Technical
report

The tool stitches several related photos to one panorama. By matching SURF vector of images, calculating transforming matrices, searching optimum stitch using minimal-cut algorithm and weakening color discrepancies, photos can be stitched together naturally.

Optimized Algorithm
for keypoint matching

Stitch
searching

Color
correction

DEMO
result

EDUCATION

EXPERIENCE

SKILLS

PROJECTS

AWARDS