Zhijia (Jeffrey) Zhao
Ph.D. candidate
Computer Science Department
College of William & Mary

Currently, I am visiting Computer Science Dept. at NC State University under the supervision of Dr. Xipeng Shen.

In the job market for academic / research lab positions.

Contacts


Office: Room 3226, EB II, NCSU
Mailing Address:
3210-K Walnut Creek Parkway
Raleigh, NC 27606

Email: zzhao [at] cs.wm.edu

Research Interests


Programming Systems and Compiler Support for Parallel Computing, Big Data, and Mobile Computing

Research Projects


OptSpec: Parallelizing Finite State Machine-based Computations via Principled Speculation

Finite State Machines (FSMs) play critical roles on applications in many domains. However, the efficiency of these applications are often restricted by the data dependences among state transitions. We solve this problem by speculative parallelization through a principled approach. [PACT12 Poster, ASPLOS14]

HPar: a Parallel and Practical HTML5 Parser

HTML file has been parsed in a sequential way for a long time, even in modern web browsers. We made a first try to make it being parsed in parallel by breaking the various data dependences and handling its special complexities, like auto-error correction and embedded scripts. [TACO13 / HiPEAC14]

PCA: A Program Representation for Predicting Call Sequences

We design and implement a new program representation, called Program Calling Automata (PCA), to predict a sequence of functions/methods that will be invoked during program execution. This has some immediate benefits, such as methods prefetching and advanced JIT optimizations. [OOPSLA14]

SatScore: Uncovering and Avoiding a Principled Pitfall in Responsiveness Measurements of App Launches

Existing work mainly use response delay reduction as the metric for responsiveness. However, we found this metric may not faithfully reflect users' actual experience. A new metric, called SatScore, was proposed to serve as a better alternative. [Ubicomp14]

Publications


OOPSLA14
Call Sequence Prediction through Probabilistic Calling Automata
Zhijia Zhao, Bo Wu, Mingzhou Zhou, Yufei Ding, Jianhua Sun, Xipeng Shen, and Youfeng Wu
ACM SIGPLAN conference on Systems, Programming, Languages and Applications, Portland, USA, 2014 to appear
Ubicomp14
SatScore: Uncovering and Avoiding a Principled Pitfall in Responsiveness Measurements of App Launches
Zhijia Zhao, Mingzhou Zhou and Xipeng Shen
ACM International Joint Conference on Pervasive and Ubiquitous Computing, Seattle, USA, 2014 [PDF] [slides]
ASPLOS14
Challenging the "Embarrassingly Sequential": Parallelizing Finite State Machine-Based Computations through Principled Speculation
Zhijia Zhao, Bo Wu and Xipeng Shen
19th International Conference on Architecture Support for Programming Languages and Operating Systems, Salt Lake City, USA, 2014 [PDF] [slides]
ASPLOS14
Finding the Limit: Examining the Potential and Complexity of Compilation Scheduling for JIT-Based Runtime Systems
Yufei Ding, Mingzhou Zhou, Zhijia Zhao, Sarah Eisenstat and Xipeng Shen
19th International Conference on Architecture Support for Programming Languages and Operating Systems, Salt Lake City, USA, 2014 [PDF]
TACO13
HPar: A Practical Parallel Parser for HTML -- Taming HTML Complexities for Parallel Parsing
Zhijia Zhao, Michael Bebenita, Dave Herman, Jianhua Sun and Xipeng Shen
ACM Transactions on Architecture and Code Optimization. Vol. 10, No. 4, Article 44, Dec. 2013. [PDF] [slides]
PPoPP13
Complexity Analysis and Algorithm Design for Reorganizing Data to Minimize Non-Coalesced Memory Accesses on GPU
Bo Wu, Zhijia Zhao, Eddy Z. Zhang, Yunlian Jiang, and Xipeng Shen
18th ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming. Shenzhen, China, 2013 [PDF]
PACT12 poster
Speculative Parallelization Needs Rigor: Probabilistic Analysis for Optimal Speculation of Finite State Machine Applications
Zhijia Zhao, Bo Wu and Xipeng Shen
21st International Conference on Parallel Architecture and Compilation Techniques. Minneapolis, USA, 2012 (2-page poster paper) [PDF]
OOSPLA12
Exploiting Inter-Sequence Correlations for Program Behavior Prediction
Bo Wu, Zhijia Zhao, Xipeng Shen, Yunlian Jiang, Yaoqing Gao, Raul Silvera
The ACM SIGPLAN conference on Systems, Programming, Languages and Applications. Tucson, USA, 2012 [PDF]
PACT11 SRC
Probabilistic Models towards Optimal Speculation of DFA Applications
Zhijia Zhao and Bo Wu
2nd place out of 29 submissions in PACT 2011 Student Research Competition. Galveston Island, USA

Personal


After work, I mostly enjoy the time with my family - my wife Lifen and our son Evan who is learning to talk (1.5 years-old). My hobbies are cooking and basketball. I also have a strong desire to visit many beautiful places.